下列选项中,不属于python语言特点的是
以下叙述正确的是
下列关于python的说法中,错误的是
python程序文件的扩展名是
python语言属于
python这个单词是什么含义?
python语言采用严格的“缩进”来表明程序的格式框架。下列说法不正确的是:
下列选项中,不属于python语言特点的是
在python集成开发环境中,可使用()快捷键运行程序。
python是一种跨平台、开源、免费的高级动态编程语言。
在windows平台上编写的python程序无法在unix平台运行。
python既支持面向对象编程,也支持面向过程编程模式。
输入并运行求平均值的程序。
输入并运行温度转换的程序。
输入并运行求最大公约数和最小公倍数的程序。
输入并运行设计函数,求解圆形、长方形、三角形的面积的程序
表达式16/4-2**5*8/4%5/2的值为
计算表达式 123400//100 的值为
下列表达式的值为true的是
与关系表达式x==0等价的表达式是
python表达式中,可以控制运算优先顺序的是
关于python中的复数,下列说法错误的是
下面哪个不是python合法的标识符
下列哪个语句在python中是非法的?
已知x=2,语句x*=x 1执行后,x的值是
下列表达式中,值不是1的是
python 语句x=’car’; y = 2; print (x y)的输出结果是
python 表达式math.sqrt(4)*math.sqrt(9)的值为
一个变量只能存储一个字符
程序中的变量代表内存中的一个存储单元,它的值不可以随时修改
python中,一个字符型数据与整型数据可以互相赋值。
语句标号用标识符表示,它的定名规则与变量名相同,即由字母、数字和下划线组成,其第一个字符必须为字母或下划线
逻辑运算符中的“&&”和“||”低于关系运算符,“!”高于算术运算符
关系表达式的值是一个逻辑值,它的值为“真”或“假”。逻辑表达式的值也是一个逻辑量,它的值也为“真”或“假”
python中认为名为student和student的变量是不同变量
用户所定义的标识符允许使用关键字
已知x = 3,那么赋值语句x = ‘abcedfg'是无常执行的
python变量使用前必须先声明,并且一旦声明就不能在当前作用域内改变其类型了
在python中可以使用if作为变量名
加法运算符可以用来连接字符串并生生成新的字符串
3 4j不是合法的python表达式
4j是合法python数字类型
一个数字5也是合法的python表达式
python语句print(0xa 0xb)的运行结果是:
为了给整型变量a、b、c赋初值10,下面正确的python语句是:
已知字符'a'的ascii值是65,字符变量c1的值是'a',c2的值是'd',执行语句print("%d,%d"%(c1,ord(c2)-2))后,输出结果是:
语句x=input()执行时,如果从键盘输入12并按回车键,则x的值是:
python 3.x语句 print(1, 2, 3, sep=':') 的输出结果是:
在python中最常用的用来在屏幕上输出计算结果的功能函数是
程序流程图中带有箭头的线段表示的是
下面是流程图的基本元素的是
在python 3.x中,使用内置函数input()接收用户输入时,不论用户输入的什么格式,一律按字符串进行返回
python运算符%不仅可以用来求余数,还可以用来格式化字符串。
为了输出",可以使用如下语句print(""")。
python变量名区分大小写,所以student和student不是同一个变量。
字符串'hello\npython'中"\n"表示换行。
输入一矩形的长和宽,计算并输出矩形的面积。
输入三个整数,求这三个数的和以及平均值,并在屏幕上输出。
输入一个三位整数x(999=>x>=100),将其分解出百位、十位、个位,并求出各位之和以及各位之积
已知三角形的三边 a、b、c,,求其面积s。(提示:假设有一个三角形,边长分别为a、b、c,三角形的面积s可由以下公式求得:s=sqrt(p(p-a)(p-b)(p-c)),而公式里的p是半周长:p=(a b c)/2
从键盘上输入一个大写字母,将该大写字母转换成小写字母并输出。
执行下列python语句将产生的结果是( )。 x=2 y=2.0 if(x==y): print(“equal”) else: print(“no equal”)
下列程序运行结果是 a=3 b=5 if a>b: a,b=b,a print ("从小到大输出:") print(a,b)
if else是
python语言对嵌套if语句的规定是:else总是与
当你输入95时,下列程序运行的结果是 results = int(input('成绩为:')) if 100>=results>=90: print('a') elif 90>results>=75: print('b') elif 0<=results<75: print('c') else: print('输入错误!')
x=2 y=2.0 if(x==y): print("相等") else: print("不相等")
下面语句语确的是
以下代码段,试判断假设输入分数为75时,给出的分数等级为: score = eval(input("请输入你的成绩:")) if score >= 60: grade = "d" elif score >= 70: grade = "c" elif score >= 80: grade = "b" elif score >= 90: grade = "a" print("输入成绩属于级别{}".format(grade))
如下代码可以实现当输入6的时候输出x>5,输入4的时候输出 3
如下两段代码功能一样,程序结构也一样 第一段: if a < 0: print("<0") if a == 0: print("=0") if a > 0: print("a>0") 第二段: if a < 0: print("<0") elif a == 0: print("=0") elif a > 0: print("a>0")
if(a=5) 是允许的。
在if语句中,必须出现else。
以下程序段的功能是:将变量a、b的最大值赋给max。 max = a if max < b: max = b
else 总是与它上面最近的且尚未配对的 if 配对。
求一元二次方程的解
求x到y之间(包含x,y)所有的素数
求最大值
字符串统计
整数排序
执行range(2,10,2)后运行结果是:
选出对下列语句不符合语法要求的表达式: for var in _________ : print(var)
若k为整形, 下述while循环执行的次数为 k=1000 while k>1: print(k) k = k/2
下列for循环执行后,输出结果的最后一行是 for i in range(1,3): for j in range(2,5): print(i*j)
下列程序的结果是 sum=0 for i in range(100): if(i): continue sum=sum i print(sum)
下面程序中语句print(i*j)共执行了_次。 for i in range(5): for j in range(2,5): print(i*j)
下面哪个语句不能完成1到10的累加功能, total初值为0。
for i in range(10): …… 中 ,i的循环终值是
下面代码的输出结果是 for i in range(3): print(5,end=',')
continue语句用于
如果仅仅是用于控制循环次数,那么使用for i in range(20)和for i in range(20, 40)的作用是等价的。
带有else子句的循环如果因为执行了break语句而退出的话,则会执行else子句中的代码。
for n in range(2,8,2): print(n,end=' ') 这段程序输出结果是:2 4 6
强制退出当前所在循环结构的关键字是continue。
语句while (!y):中的!y等价于y!=0。
continue用来跳出最内层for或while循环,退出该循环后程序从循环代码后继续执行; break用来结束当前当次循环。
在python语言里,循环结构必须有else子句。
求s的和。
图形打印。
追查车号。
判断素数
求阶乘和
已知x=[1,2,3],执行语句x.append(5)之后,x的值是什么
list("abcd")的结果是
已知list1 = [1, 2, 3, 4, 5, 4, 3, 2, 1],list1[:-1]的值是
已知x=[8,7,6,5,4,3,2,1],那么x.pop(2)的结果是
能将5加到列表list1的末尾的语句是
假设: ls=[1,2,3,4,5] lt=ls ls[4]=1 print(lt[4]) 输出结果是:
字符串函数strip()的作用是
字符串是一个字符序列,对字符串s,从右侧向左第3个字符使用哪种方式索引
x=(4, 5, 6),执行如下代码会有什么结果? x[1] = 1 print(x)
对于字典d={"abc":1,"qwe":3,"zxc":2} ,len(d)的结果是( )。
以下关于字典的说法错误的是( )。
以下关于列表的描述错误的是( )。
python列表、元组、字符串都属于有序序列。
元组tuple是属于可变对象。
已知x是一个列表,那么x = x[3:] x[:3]可以实现把列表x中的所有元素循环左移3位。
元组是不可变的,不支持列表对象的inset()、remove()等方法,也不支持del命令删除其中的元素,但可以使用del命令删除整个元组对象。
语句a = 1,2,3有语法错误。
已知x是个列表对象,那么执行语句y = x之后,对y所做的任何操作都会同样作用到x上。
使用python列表的方法insert()为列表插入元素时不会改变列表中插入位置之后元素的索引。
tuple(x):可以用于生成元组,输入的参数可以是任何组合数据类型。
字符串对象和元组对象是不可变对象,列表对象为可变对象。
已知st="hello world!",使用print(st[0:-1])语句可以输出字符串变量st中的所有内容。
字符串'hello\npython'中"\n"表示换行。
列表去重
删除指定字符
列表排序
杨辉三角
以下哪个方式可以创建一个空的?
以下哪一句会得到{'1','2','3'}?
对于两个s1和s2,s1 < s2的指
对于s,以下哪个操作是不存在的?
对于正确的表达式a[2],a不可能是以下哪个类型?
元组可以作为字典的“键”。
python字典中的“值”不允许重复。
python支持使用字典的“键”作为下标来访问字典中的值。
在字典里,同一个键可以对应两个或多个值。
如果a是一个列表,则语句a=list(set(a))可以删除a中的重复元素。
表达式 {1, 3, 2} > {1, 2, 3} 的值为true。
python中的元素不允许重复。
a={},type(a)结果是。
set(x):可以用于生成,输入的参数可以是任何组合数据类型,返回结果是一个无重复且有序的。
python中的元素可以是元组。
python字典和支持双向索引。
python字典和属于无序序列。
统计并输出字符串中小写元音字母的个数
能被7、9和11整除的数的个数(用实现)
对于函数定义代码的理解,正确的是
在一个函数中如局部变量和全局变量同名,则
下面程序段的输出为 def f1(a,b,c): print(a b) nums=(1,2,3) f1(nums)
以下哪个函数定义正确:
print(type(lambda:3))的输出结果是
下面程序段的输出为 a=1 def fun(a): a=a 2 print(a) fun(a) print(a)
下面关于函数的说法,正确的是
如果函数定义为def hello(username): ,则对该函数的调用不合法的是
以下关于python内置函数的描述,错误的是
在python中导入其他函数库的关键字是
以下哪个程序段是使用递归函数实现1到100求和
在函数中使用return语句可以返回值,所以函数中的return语句后一定要有值。
定义函数时,即使该函数不需要接收任何参数,也必须保留一对空的圆括号来表示这是一个函数。
定义python函数时必须指定函数返回值类型。
定义函数时,带有默认值的参数必须出现在参数列表的最右端,任何一个带有默认值的参数右边不允许出现没有默认值的参数。
在调用函数时,可以通过关键参数的形式进行传值,从而避免必须记住函数形参顺序的麻烦。
实现一个计算非负整数阶乘的简单函数,并利用该函数求 1! 2! 3! ... n! 的值。
求鞍点
求组合数
求n!使用递归调用实现
n阶楼梯上楼问题
在访问文件时,下列说确的是
以"w"模式打开的文件无法进行读操作。
read函数返回的是列表。
readlines函数返回的是列表。
使用python内置的open函数打开某个文件的时候,如果该文件不存在,则可能产生异常。所以一定要使用try except对其进行处理。
python内置的open函数,打开文件的时候可能会产生异常。
以读模式打开文件时,文件指针指向文件开始处。
以追加模式打开文件时,文件指针指向文件尾。
close函数用于文件关闭。
以写模式打开的文件无法进读操作。
fp=fopen("t.txt","r ") 执行后只能对"t.txt"文件进行读操作。
使用内置函数open()打开文件时,只要文件路径正确就总是可以正确打开的。
对文件进行读写操作之后必须显式关闭文件以确保所有内容都得到保存。
python标准库os中的方法isfile()可以用来测试给定的路径是否为文件。
python标准库os中的方法listdir()返回包含指定路径中所有文件和文件夹名称的列表
下面哪个不是python合法的变量名( )
下面的循环体执行的次数与其它不同的是:( )
使用python语言编写的源程序保存时的文件扩展名是( )。
已知x=2,语句x*=x 1执行后,x的值是( ).
下列哪个语句在python中是非法的?
python 3.x中,语句x=input()执行时,如果从键盘输入12并按回车键,则x的值是:( )
下列程序运行结果是: a=3 b=5 if a>b: a,b=b,a print ("从小到大输出:") print (a,b)
若k为整形, 下述while循环执行的次数为:( ) k=1000 while k>1: print(k) k = k/2
下列程序的结果是:( ) sum=0 for i in range(100): if(i): continue sum=sum i print(sum)
以下关于元组的描述正确的是( )
下列程序运行结果是:( ) a=[1,2,1,2,3,3,3,3] result=0 for i in a: result =i print (result)
已知列表x = list(range(5)),那么执行语句x.remove(3)之后,表达式x.index(4)的值为:( )
以下不能创建一个字典的语句是( )
以下叙述正确的是:( )
为了给整型变量x、y、z赋初值10,下面正确的python语句是:( )
python语言对嵌套if语句的规定是:else总是与()
下列for循环执行后,输出结果的最后一行是: for i in range(1,3): for j in range(2,5): print(i*j)
字符串s=”hello\\’world\n”长度为
python是一种跨平台、开源、免费的高级动态编程语言。
同一python变量可以先后赋予不同类型的值。
在python中可以使用if作为变量名.
3 4j不是合法的python表达式.
已知x = 3,那么赋值语句x = ‘abcedfg'是无常执行的.
程序中的变量代表内存中的一个存储单元,它的值不可以随时修改.
如果仅仅是用于控制循环次数,那么使用for i in range(20)和for i in range(20, 40)的作用是等价的。
for n in range(2,8,2): print(n,end=' ') 这段程序输出结果是:2 4 6
python列表中所有元素必须为相同类型的数据。
python使用缩进来体现代码之间的逻辑关系。
python列表、元组、字符串都可以进行增、删、改操作。
使用x=set()和x={} 都可以创建一个空。
输入三个整数,将这三个数由小到大输出。
将一个列表逆序输出。
求指定年月天数
求两个整数的最大公约数和最小公倍数。
统计元音字母个数
besides key points, the other element a summary should include is:
what are the three ways of in-text citation, mentioned in the lecture?
the key points in the summary don’t have to be reported in the same order of logic as in the original text.
in summary writing, the thesis statement, which is the central idea of the original text, is always given as the first sentence, followed and supported by the key points.
even if you give credit, copying many words or ideas from a source, which makes up the majority of your work, is plagiari.
which of the following can be used as hedging expressions?
a book review is a summary of the main idea of a book.
there are two types of book review: elementary ones and advanced ones.
the publication information and the summary of a book are necessary parts of a book review.
though a critique should point out both the strengths and weaknesses of a book, most critiques put emphasis on the weaknesses of a book by saying what the book should have said but failed to do.
which component is not included in a research proposal?
which tense is not used frequently in research writing?
which component follows the research background component?
when working on the literature paragraph, what should your paragraph start with?
what are the three main purposes of writing a research proposal?
in which section of a lab report may the purpose of the experiment be included?
in which section of a lab report may the data of the experiment be presented and yzed?
which of the following visual aids is the best to present numerical data and standardized values for reference?
which of the following visual aids is the best to present trend over time?
which of the four choices may bring a more concise and stronger effect for the following sentence? a time-frequency ysis method is proposed to _______ the magnetotelluric response function.
what is the main purpose of writing a conference proposal?
when yzing the setting where the audience read your conference proposal, what information should you consider?
what are the two main elements used to yze the conference members (the audience of your conference proposal)?
what are the ways to remove unnecessary words?
what are the common types of conference sessions this unit introduced?
what are the two most important elements of the method section?
which of the following headings are commonly found under the method section?
only words or phrases can act as headings, and sentences or sentence fragments cannot.
headings should be in parallel form, which means that you need to make them consistent within the same level.
the active voice is generally preferred in writing a research paper, but for the method section, the passive voice is widely used.
which one is correct when citing references in the text, following the apa format?
if the only way to cite a source is through a secondary source citation, which of the following citations is the correct formatting?
which of the following ones are the basic elements of the results section?
which of the following items are usually included in the discussion section?
when citing one or two authors in-text, never use et al.; instead, always provide the author(s') names.
which of the following elements are usually covered in an abstract of a research paper?
in an abstract, one should report only the important findings of his or her study.
when stating the conclusion in an abstract, one should present the important results or findings.
the key to abstracting a research paper is to look for the 5 elements in your research paper, and write 1-2 sentences for each.
paralleli usually happens at the word or phrase level, and is rarely used at the clause level.
in a research proposal, what does the research background component provide?
which tense should be used when we describe the action of named researcher carrying out a specific study in the past?
which component provides readers with detailed information about the sources you use in your research proposal?
if you were writing the literature review, and you had a sentence indicating that the statement a scholar makes continues to be true, what tense should you use in the sentence?
in a research proposal, what component does the sentence "to date, little is known about how long college students use cell phones in class and how this might influence their learning" suggest?
when writing a conference proposal, what technique you can use to avoid conflict between you and conference members, particularly when you and your audience might believe in different theories?
in a conference proposal, what information does a conclusion component usually include?
which way is more effective to make this sentence more concise, “astonished, the architect circled around the building in amazement”?
what is the main reason that makes the title of a conference proposal important?
in which setting are the conference members reading your proposal?
which of the following is not a feature of a summary?
which of the following choices is correct, concerning the given argumentative thesis? argumentative thesis: government should ban further construction of nuclear power plants for part 1 the potential threat to the safety of local residents. part 2
which of the following is not a way of in-text citation?
the most important difference between a comprehensive review and an elementary review is _____.
which of the following sentences has hedging expressions in it?
which one of the following headings is not included under the method section?
in which of the following sections is the passive voice widely used?
which element of the method section does the following sentence describe? “the test instrument employed in this study was a revised version of the auditory test for language comprehension (carrow, 1968), which permits the assesent of oral language comprehension of english and spanish without requiring language expression.”
which element of the method section do the following sentences describe? “both groups were tested by the same examiner, a mexican-american fluent in both languages. the children were brought inidually to a test area where they engaged in spontaneous conversation...the test required the child to indicate his response by pointing to the picture which corresponded to the examiner’s utterance.”
in which section of a research paper is the following sentences most likely to appear? “intercorrelations of all of the measures of well-being for the total sample are presented in table 2. correlations with prior measures of positive functioning are all positive and significant, with coefficients ranging from .25 to .73. ”
in which section of a research paper is the following sentences most likely to appear? “our findings suggest that increased levels of depression are associated with those who become addicted to the internet. this suggests that clinical depression is significantly associated with increased levels of personal internet use. it is likely that low self-esteem, poor motivation, fear of rejection, and the need for approval associated with depressives contribute to increased internet use.”
the following is an abstract, consisting of 5 sentences. which key element does sentence ② describe? abstract: ①anxiety about tests and test-like situations was examined in a series of studies of elementary school children in 4 connecticut towns. ②high anxiety (ha) and low anxiety (la) groups were identified by general anxiety and test anxiety scales for which format and validation details are presented. ③data support hypotheses concerning fantasies of bodily injury and cues which interfere with the anxious child's performance. ④ratings by fathers of a portion of the sample discriminated between ha and la children; mothers' ratings did not. ⑤implications for school testing programs are discussed.
the following is an abstract, consisting of 5 sentences. which element does sentence ④ describe? abstract: ①research on exposure to television and movie violence suggests that playing violent video games will increase aggressive behavior. ②a meta-ytic review of the video-game research literature reveals that violent video games increase aggressive behavior in children and young s. ③experimental and nonexperimental studies with males and females in laboratory and field settings support this conclusion. ④analyses also reveal that exposure to violent video games increases physiological arousal and aggression-related thoughts and feelings. ⑤playing violent video games also decreases prosocial behavior.
the following is an abstract, consisting of 5 sentences. which element does sentence ① describe? abstract: ①procrastination is variously described as harmful, innocuous, or even beneficial. ②two longitudinal studies examined procrastination among students. ③procrastinators reported lower stress and less illness than nonprocrastinators early in the semester, but they reported higher stress and more illness late in the term, and overall they were sicker. ④procrastinators also received lower grades on all assignments. ⑤procrastination thus appears to be a self-defeating behavior pattern marked by short-term benefits and long-term costs.
in which section of a lab report is the procedure of the experiment likely to appear?
in which section of a lab report may the data of the experiment be presented and yzed?
what kind of visual aid is it?
which of the following visual aids can be best used to present numerical proportions in a lab report?
which of the following visual aids can be best used to present numerical data and standardized values for reference in a lab report?
what are the two methods of making a value statement?
what are the two ways to organize the literature?
what principles should you consider when choosing a topic for a conference proposal?
what words/phrases are considered wordy below?
choose two acceptable paraphrases from the following for the original text, making sure that they should not be considered plagiari. original: we do not yet understand all the ways in which brain chemicals are related to emotions and thoughts, but the salient point is that our state of mind has an immediate and direct effect on our state of body. source: siegel, b. (1986). love, medicine and miracles (p. 69). new york: harper and row.
what are the hedging expressions in the following sentence? “there is experimental work to show that a week or ten days may not be long enough and a fortnight to three weeks is probably the best theoretical period.”
which of the following are typical components of a research paper?
which of the following are usually included under the method section?
the main elements of the method section include:
the results section typically consists of _____.
to make ooth transitions between two ideas, what transitional strategies can be adopted?
which of the following elements are usually covered in an abstract of a research paper?
which of the following may be the essential components of a lab report?
which of the following visual aids may be relatively more appropriate to present changes over time in a lab report?
simple past tense is usually used in the methods section of a research proposal, and future tense is used in the methods section of a research paper.
i can include the sources i read on the reference page even if i do not use them in my research proposal.
if in the literature review, you have a sentence describing the previous researchers’ actual actions, you should use simple past tense in the sentence.
if a gap statement of a research proposal indicates, “compared to the literature on the use of taiwanese in educational and political settings, little is known about its actual use in mass media setting,” the method the author used to make the statement is unresolved conflict.
the component of a research proposal that describes the steps, materials, and ytic techniques you will use in a research proposal is the literature review component.
researchers tend to be more open to various theories related to the topic of your conference proposal than language teachers.
regarding writing a conference proposal, if you are writing for an audience of language teachers, you might want to use more technical terms to show them your professionali, to discuss more theories, and to use more hedging language.
in a conference proposal, unnecessary repetition means the same message has been delivered more than once.
it is important to explain how you collected and yzed data clearly in your conference proposal so that the conference members know you indeed finished your research.
all the information appearing in a conference proposal does not need to appear in the conference presentation.
in summary writing, the thesis statement (the central idea of the original text) must be given, while the key points are not necessary components of a summary.
the key points in the summary should be reported in the same order of logic as in the original text.
the following citation should be considered plagiari. orginal: because of their unique perspective, americans fear globalization less than anyone else, and as a consequence they think about it less than anyone else. citation: according to lester thurow (1993) americans fear globalization less than people from other countries and as a consequence spend less time thinking about it.
in the sentence “in b. yates' article an american love affair, the author refutes the view that modern societies should eradicate the car because of the many sins it commits”, the reporting verb used here is “eradicate”.
a book review is an article that summarizes the main idea of the book and says if it is a good read or not.
for fictions, we can read them critically by judging the the author’s qualification, the author’s goal, the use of visual aids, etc.
in the critique part of a book review, writers should comment on the weaknesses of the book.
compared with the sentence “the medicine has negative impacts on the treatment of this disease”, the sentence “the medicine might have negative impacts on the treatment of this disease” reduces the certainty of the claim by applying a hedging expression.
when writing the method section, the writer should give enough information for others to replicate the study.
the method section is usually the first section to write for the research paper, because you just finish your study and the method is likely to be clear in your mind.
the best way to describe the steps you followed in your study is usually to follow the chronological order.
when writing the introduction section, the writer should use the passive voice as much as possible, because the action is usually emphasized in this section.
in the results section, you should not repeat the numbers already reported in tables, graphs or diagrams.
when citing the work by over 7 authors, one just list the last name of the first author and add “as cited in” before it.
to cite secondary sources, one should write “et al.”followed by the secondary source in parentheses.
compared with sentence ①, sentence ② makes a better transition between two ideas. ①fearing for the loss of danish lands, christian iv signed the treaty of lubeck, effectively ending the danish phase of the 30 years war. but then something else significant happened. the swedish intervention began. ②fearing for the loss of more danish lands, christian iv signed the treaty of lubeck, effectively ending the danish phase of the 30 years war. shortly after danish forces withdrew, the swedish intervention began.
there are basically two types of abstracts: the elementary ones and the comprehensive ones.
in the abstract of a research paper, just present a couple of important results, and don't try to cram a lot of numbers into this part.
the abstract of a research paper should summarize the highlights of all the sections of the paper.
paralleli usually happens at the word or phrase level, and is rarely used at the clause level.
a lab report explains what you did in an experiment, what you learned and what the results meant.
in most cases, in a lab report, the data from an experiment may be presented in the form of written text with the visual aids like tables and charts.
pie charts may be more visualized to present percentage portions that the other visual aids in a lab report.
nouns may be more frequently used than verbs in a lab report in that a lot of technical terms are included.
in a research proposal, what does the research background component provide?
which tense should be used when we describe the action of named researcher carrying out a specific study in the past?
which component provides readers with detailed information about the sources you use in your research proposal?
if you were writing the literature review, and you had a sentence indicating that the statement a scholar makes continues to be true, what tense should you use in the sentence?
in a research proposal, what component does the sentence "to date, little is known about how long college students use cell phones in class and how this might influence their learning" suggest?
when writing a conference proposal, what technique you can use to avoid conflict between you and conference members, particularly when you and your audience might believe in different theories?
in a conference proposal, what information does a conclusion component usually include?
which way is more effective to make this sentence more concise, “astonished, the architect circled around the building in amazement”?
what is the main reason that makes the title of a conference proposal important?
in which setting are the conference members reading your proposal?
which of the following is not a feature of a summary?
which of the following choices is correct, concerning the given argumentative thesis? argumentative thesis: government should ban further construction of nuclear power plants for part 1 the potential threat to the safety of local residents. part 2
which of the following is not a way of in-text citation?
the most important difference between a comprehensive review and an elementary review is _____.
which of the following sentences has hedging expressions in it?
which one of the following headings is not included under the method section?
in which of the following sections is the passive voice widely used?
which element of the method section does the following sentence describe? “the test instrument employed in this study was a revised version of the auditory test for language comprehension (carrow, 1968), which permits the assesent of oral language comprehension of english and spanish without requiring language expression.”
which element of the method section do the following sentences describe? “both groups were tested by the same examiner, a mexican-american fluent in both languages. the children were brought inidually to a test area where they engaged in spontaneous conversation...the test required the child to indicate his response by pointing to the picture which corresponded to the examiner’s utterance.”
in which section of a research paper is the following sentences most likely to appear? “intercorrelations of all of the measures of well-being for the total sample are presented in table 2. correlations with prior measures of positive functioning are all positive and significant, with coefficients ranging from .25 to .73. ”
in which section of a research paper is the following sentences most likely to appear? “our findings suggest that increased levels of depression are associated with those who become addicted to the internet. this suggests that clinical depression is significantly associated with increased levels of personal internet use. it is likely that low self-esteem, poor motivation, fear of rejection, and the need for approval associated with depressives contribute to increased internet use.”
the following is an abstract, consisting of 5 sentences. which key element does sentence ② describe? abstract: ①anxiety about tests and test-like situations was examined in a series of studies of elementary school children in 4 connecticut towns. ②high anxiety (ha) and low anxiety (la) groups were identified by general anxiety and test anxiety scales for which format and validation details are presented. ③data support hypotheses concerning fantasies of bodily injury and cues which interfere with the anxious child's performance. ④ratings by fathers of a portion of the sample discriminated between ha and la children; mothers' ratings did not. ⑤implications for school testing programs are discussed.
the following is an abstract, consisting of 5 sentences. which element does sentence ④ describe? abstract: ①research on exposure to television and movie violence suggests that playing violent video games will increase aggressive behavior. ②a meta-ytic review of the video-game research literature reveals that violent video games increase aggressive behavior in children and young s. ③experimental and nonexperimental studies with males and females in laboratory and field settings support this conclusion. ④analyses also reveal that exposure to violent video games increases physiological arousal and aggression-related thoughts and feelings. ⑤playing violent video games also decreases prosocial behavior.
the following is an abstract, consisting of 5 sentences. which element does sentence ① describe? abstract: ①procrastination is variously described as harmful, innocuous, or even beneficial. ②two longitudinal studies examined procrastination among students. ③procrastinators reported lower stress and less illness than nonprocrastinators early in the semester, but they reported higher stress and more illness late in the term, and overall they were sicker. ④procrastinators also received lower grades on all assignments. ⑤procrastination thus appears to be a self-defeating behavior pattern marked by short-term benefits and long-term costs.
in which section of a lab report is the procedure of the experiment likely to appear?
in which section of a lab report may the data of the experiment be presented and yzed?
what kind of visual aid is it?
which of the following visual aids can be best used to present numerical proportions in a lab report?
which of the following visual aids can be best used to present numerical data and standardized values for reference in a lab report?
what are the two methods of making a value statement?
what are the two ways to organize the literature?
what principles should you consider when choosing a topic for a conference proposal?
what words/phrases are considered wordy below?
choose two acceptable paraphrases from the following for the original text, making sure that they should not be considered plagiari. original: we do not yet understand all the ways in which brain chemicals are related to emotions and thoughts, but the salient point is that our state of mind has an immediate and direct effect on our state of body. source: siegel, b. (1986). love, medicine and miracles (p. 69). new york: harper and row.
what are the hedging expressions in the following sentence? “there is experimental work to show that a week or ten days may not be long enough and a fortnight to three weeks is probably the best theoretical period.”
which of the following are typical components of a research paper?
which of the following are usually included under the method section?
the main elements of the method section include:
the results section typically consists of _____.
to make ooth transitions between two ideas, what transitional strategies can be adopted?
which of the following elements are usually covered in an abstract of a research paper?
which of the following may be the essential components of a lab report?
which of the following visual aids may be relatively more appropriate to present changes over time in a lab report?
simple past tense is usually used in the methods section of a research proposal, and future tense is used in the methods section of a research paper.
i can include the sources i read on the reference page even if i do not use them in my research proposal.
if in the literature review, you have a sentence describing the previous researchers’ actual actions, you should use simple past tense in the sentence.
if a gap statement of a research proposal indicates, “compared to the literature on the use of taiwanese in educational and political settings, little is known about its actual use in mass media setting,” the method the author used to make the statement is unresolved conflict.
the component of a research proposal that describes the steps, materials, and ytic techniques you will use in a research proposal is the literature review component.
researchers tend to be more open to various theories related to the topic of your conference proposal than language teachers.
regarding writing a conference proposal, if you are writing for an audience of language teachers, you might want to use more technical terms to show them your professionali, to discuss more theories, and to use more hedging language.
in a conference proposal, unnecessary repetition means the same message has been delivered more than once.
it is important to explain how you collected and yzed data clearly in your conference proposal so that the conference members know you indeed finished your research.
all the information appearing in a conference proposal does not need to appear in the conference presentation.
in summary writing, the thesis statement (the central idea of the original text) must be given, while the key points are not necessary components of a summary.
the key points in the summary should be reported in the same order of logic as in the original text.
the following citation should be considered plagiari. orginal: because of their unique perspective, americans fear globalization less than anyone else, and as a consequence they think about it less than anyone else. citation: according to lester thurow (1993) americans fear globalization less than people from other countries and as a consequence spend less time thinking about it.
in the sentence “in b. yates' article an american love affair, the author refutes the view that modern societies should eradicate the car because of the many sins it commits”, the reporting verb used here is “eradicate”.
a book review is an article that summarizes the main idea of the book and says if it is a good read or not.
for fictions, we can read them critically by judging the the author’s qualification, the author’s goal, the use of visual aids, etc.
in the critique part of a book review, writers should comment on the weaknesses of the book.
compared with the sentence “the medicine has negative impacts on the treatment of this disease”, the sentence “the medicine might have negative impacts on the treatment of this disease” reduces the certainty of the claim by applying a hedging expression.
when writing the method section, the writer should give enough information for others to replicate the study.
the method section is usually the first section to write for the research paper, because you just finish your study and the method is likely to be clear in your mind.
the best way to describe the steps you followed in your study is usually to follow the chronological order.
when writing the introduction section, the writer should use the passive voice as much as possible, because the action is usually emphasized in this section.
in the results section, you should not repeat the numbers already reported in tables, graphs or diagrams.
when citing the work by over 7 authors, one just list the last name of the first author and add “as cited in” before it.
to cite secondary sources, one should write “et al.”followed by the secondary source in parentheses.
compared with sentence ①, sentence ② makes a better transition between two ideas. ①fearing for the loss of danish lands, christian iv signed the treaty of lubeck, effectively ending the danish phase of the 30 years war. but then something else significant happened. the swedish intervention began. ②fearing for the loss of more danish lands, christian iv signed the treaty of lubeck, effectively ending the danish phase of the 30 years war. shortly after danish forces withdrew, the swedish intervention began.
there are basically two types of abstracts: the elementary ones and the comprehensive ones.
in the abstract of a research paper, just present a couple of important results, and don't try to cram a lot of numbers into this part.
the abstract of a research paper should summarize the highlights of all the sections of the paper.
paralleli usually happens at the word or phrase level, and is rarely used at the clause level.
a lab report explains what you did in an experiment, what you learned and what the results meant.
in most cases, in a lab report, the data from an experiment may be presented in the form of written text with the visual aids like tables and charts.
pie charts may be more visualized to present percentage portions that the other visual aids in a lab report.
nouns may be more frequently used than verbs in a lab report in that a lot of technical terms are included.
马克思主义化产生的第一个重大理论成果是()。
平新时代特色思想,是对()的继承和发展,是()的最新成果,是和实践经验和集体智慧的结晶,是()的重要组成部分,是全全国为实现()而奋斗的行动指南,必须长期坚持并不断发展。
平新时代特色思想的核心内容包括八个明确和十四个坚持。
“”重要思想指共产要始终代表()。
创新解决的是什么问题?
五大发展理念是?
2018年11月7日,银行委、银保监会郭树清指出:在新增公司类贷款中,大型银行对民营企业的贷款不低于2/3.,中小型银行不低于1/3,争取三年以后,银行业对民营企业的贷款占新增公司类贷款的比例不低于50%。
报告指出必须坚持质量第一,效益优先,以为——主线,推动经济发展质量变革、效率变革和动力变革。
在建设人类命运共同体的进程中,我们秉持( )理念,加强同发展家的团结合作。
我国全面依法治国的总目标是
最有利于我国基层群众行使民利的制度性安排是基层代表大会。
十八大以来,我军在组织形态上发生了重大变化,形成了军委管总、( )、( )的新格局
要以培养担当______的时代新人为着眼点,强化教育引导、实践养成、制度保障,发挥核心价值观对国民教育、精神文明创建、精神文化产品创作生产传播的引领作用。
深入挖掘优秀传统文化蕴含的思想观念、______、道德规范,结合时代要求继承创新,让文化展现出永久魅力和时代风采。
加强思想道德建设。有______,有力量,民族有希望。
______是当代精神的集中体现,凝结着全体共同的价值追求。
繁荣发展文艺。文艺是的文艺,必须坚持以______为中心的创作导向,在深入生活、扎根中进行无愧于时代的文艺创造。
要繁荣文艺创作,坚持思想精深、艺术精湛、制作精良相统一,加强现实题材创作,不断推出讴歌、讴歌祖国、讴歌、讴歌______的精品力作。
倡导讲品位、______、讲责任,低俗、庸俗、媚俗。加强文艺队伍建设,造就一大批德艺双馨名家,培育一大批高水平创作人才。
推动文化事业和文化产业发展。满足过上美好生活的新期待,必须提供丰富的______。
要深化文化体制改革,完善文化管理体制,加快构建把______放在首位、社会效益和经济效益相统一的体制机制。
牢牢掌握意识形态工作领导权。意识形态决定文化______和发展道路。
必须推进马克思主义化时代化______,建设具有强大凝聚力和引领力的意识形态,使全体在理想信念、价值理念、道德观念上紧紧团结在一起。
高度重视传播手段建设和创新,提高新闻舆论传播力、引导力、影响力、______。
落实意识形态工作责任制,加强阵地建设和管理,注意区分政治原则问题、______问题、学术观点问题,旗帜鲜明反对和各种错误观点。
要坚持特色文化发展道路,激发全民族文化创新创造活力,建设______。
发展特色文化,就是以马克思主义为指导,坚守文化立场,立足当代现实,结合当今时代条件,发展面向______、面向______、面向______的,民族的科学的大众的文化,推动______协调发展。
牢牢掌握意识形态工作领导权。意识形态决定文化前进路线和发展道路。
要坚持______、为服务,坚持百花齐放、百家争鸣,坚持创造性转化、创新性发展,不断铸就文化新辉煌。
平总指出,全面深化改革总目标是()
平总在报告中强调,构建()的环境治理体系。
的报告提出,着力建设资源节约型、环境友好型社会,实行最严格的生态环境保护制度。
()是民生之源,是改善民生、实现发展成果由共享最重要最直接的方式。
要管,从严治是的建设的根本方针。其中( )是关键。
大学生应当着眼于整个、整个民族,服从服务于中心工作,志存高远。这体现了大学生的( )
在内要净化政治灵魂,弘扬( )价值观。
制度优势的主要来源是( )
共产是特色的开辟者、领导者、推动者,是最大的国情。
坚持共产的领导,坚决听从的决策部署,坚决维护平总的威信。这是坚持 的基本要求。
提出的建设的根本目标是把建设成为始终走在 、衷心拥护、 、经得起各种风浪考验、朝气蓬勃的马克思主义执政。
思想是()化的第一个重大理论成果。
的基本路线最主要的内容是()。
“”重要思想的本质是()。
十八届五中全会指出,坚持创新发展,必须把创新摆在发展全局的()位置。
制造2025计划中提到到2025年把我国制造业建设成()。
建设现代化经济体系,需要扎实管用的政策举措和行动。下列不属于当前应重点抓的工作是()。
的报告指出,就业是最大的民生,要坚持就业优先战略和积极就业政策,实现()。
的报告指出,人与自然是生命共同体,人类必须尊重自然、()、保护自然。
的报告提出,着力建设资源节约型、环境友好型社会、实行()生态环境保护制度。
( )是具有特色的制度安排,是协商民主的重要渠道和专门协商机构。
我国加强当家作主制度保障,使( )成为全面担负起宪法法律赋予的各项职责的工作机关。
新时代我国法治体系建设的首要任务是( )。
共产的制度优势体现在( )。
统揽的“四个伟大”使命中,伟大斗争是( )。
当今世界国际力量对比发生新的变化,我们发展面临的国际环境更加严峻,这就要求我要加强( )
共产人的初心和使命,就是为() ,为民族()。这个初心和使命是激励共产人不断前进的根本动力。
平新时代特色思想回答了() 这个重大时代课题。
特色最本质的特征是()。
特色制度的最大优势是()。
特色进入新时代,我国社会主要矛盾已经转化为日益增长的____和____之间的矛盾。
()是新时代坚持和发展特色根本立场。
从()到(),是“两个一百年”奋斗目标的历史交汇期。
的提出,从()到(),在基本实现现代化的基础上,把我国建成富强民主文明和谐美丽的现代化强国。
特色事业“五位一体”总体布局是指:全面推进经济建设、政治建设、文化建设、社会建设、()。
我国经济已由()阶段转向()阶段,正处在转变发展方式、优化经济结构、转换增长动力的攻关期,建设现代化经济体系是跨越关口的迫切要求和我国发展的战略目标。
的指出,发挥市场在资源配置中的()作用,更好发挥作用,建立完善的宏观调控体系。
设立()新区,是以平同志为核心的深入推进京津冀协同发展作出的一项重大决策部署。
决定支持海南全岛建设(),支持海南逐步探索、稳步推进特色自由贸易港建设,分步骤、分阶段建立自由贸易港政策和制度体系。
关于特色进入了新时代,下列理解正确的是()。
实现梦,要增强对特色的(),坚定不移沿着正确的道路奋勇前进。
新发展理念包括()。
我国深化供给侧结构性改革的举措“三去一降一补”指的是()。
的十八大以来,我国引导应对气候变化国际合作,成为全球生态文明建设的重要()。
加强社会治理制度建设,完善委领导、负责、社会协同、公众参与、法治保障的社会治理体系,提高社会治理()水平。
当前,我国坚持独立自主和平外交政策,积极推进以下外交理念( )。
对军队的绝对领导体现在以下方面( )。
共产人的精神支柱和政治灵魂是( )。
加强的领导必须坚持“四个意识”,自觉在思想上政治上行动上同保持高度一致。“四个意识”是指( )。
落实意识形态责任制,总的要求是敢抓敢管、敢于亮剑,做到()。
核心价值体系由()构成。
平总指出,实现梦,必须()。
平新时代特色思想,是(),是和必须长期坚持的指导思想。
“四个全面”战略布局是()。
全面依法治国是治理的一场深刻革命,必须坚持厉行法治,推进()。
核心价值观对个人层面的要求有()。 a.自由 b.爱国 c.敬业 d.诚信 e.
电力电子器件一般工作在( )状态。
为什么要做电能变换?
模块化可以提高电力电子装置的( )
1957年,通用电气公司研制出第一个晶闸管,标志着电力电子技术的诞生。
电力电子器件一般工作在( )状态。
1957年通用电气(ge)公司研制出第一只( ),它标志着电力电子技术的诞生
电力电子技术包括( )基本变换
模块化可以提高电力电子装置的( )
电力电子技术研究的对象是电力电子器件的应用、电力电子电路的电能变换原理和电力电子装置的开发与应用。.
电力电子技术是利用( )对电能进行(控制、转换和传输)的技术.
什么是电力电子技术
按照器件能够被控的程度,可以将电力电子器件分为( )
当开关频率较高时,电力电子器件的损耗80%为通态损耗。
电力电子器件是指可直接用于处理电能的主电路中,实现( )的电子器件。
电力电子器件一般工作在( )状态。
按照驱动电路信号的性质,可以将电力电子器件分为( )和( )
二极管具有( )特性。
功率二极管的正向平均电流是指,在指定的管壳温度和散热条件下,允许流过的最大( )的平均值
当二极管工作在正向导通状态时,( )
在高速的开关状态下,过大的结电容会导致二极管的单向导电性变差。
二极管两端施加反向电压时,二极管工作在( )状态。
晶闸管是( )驱动的功率半导体器件
晶闸管具有( )、( )和( )三个端口。
晶闸管的导通条件为( )
mosfet属于( )器件
( )二极管的工作频率一般低于1khz,具有容量大的优点。
一个电力电子器件的功率损耗包括( )。
一个电力电子系统包括( )部分。
按照器件能够被控的程度,可以将电力电子器件分为( )
电力二极管的主要类型包括( )。
晶闸管有三个电极,分别是( ),( )和( )。
当开关频率较高时,电力电子器件的损耗80%为开关损耗。
在高速的开关状态下,过小的结电容会导致二极管的单向导电性变差。
半控型电力电子器件控制极只能控制器件的导通,而不能控制器件的关断。
为减小开关损耗,提高效率,电力电子器件一般工作在( )状态。
二极管两端所加正向电压过高时,会引起( )现象
二极管两端施加反向电压过高时,会引起( )现象
电力场效应管mosfet是理想的( )控制器件。
电力mosfet的通态电阻具有( )温度系数。
属于全控型器件的是( )。
属于电流驱动的器件是( )
电力mosfet导通的条件是( )且( )。
ig是由( )和( )两类器件结合而成的复合器件。
晶闸管的导通条件是什么?
功率二极管包括哪些主要的类型?不同种类的二极管各有什么特点?适用于什么应用场合?
电力电子器件按照开关控制能力分可以分为几类?其特点是什么?代表性功率器件有哪些?
维持晶闸管导通的条件是什么?怎样使晶闸管由导通变为关断?
比较电力mosfet、ig和gto的优缺点
相控整流电路的作用是将( )转变成( )
相控整流电路中,滤波器的作用是( )
晶闸管的导通条件是( )和( )
整流电路的作用是( )
单相半波可控整流电路的移相范围是( )
阻感负载时的单相半波可控整流电路,当负载电感很大时,负载电流波动随之增大。
通过改变( )可以改变单相半波可控整流电路的输出电压。
单相半波可控整流电路的移相范围是( )
在单相桥式整流中,晶闸管的移相范围为( )
单相桥式相控整流电路的输出电压平均值是单相半波可控整流电路输出电压的( )
单相半波可控整流电路中,带大电感、不带续流二极管时,输出电压波形中没有负面积。
计算单相桥式整流电路的输出电压平均值时,只需要计算半个周期内的输出电压平均值即可。
单相半波可控整流电路的自然换相点是指( )
三相半波可控整流电路电阻负载的控制角α移相范围是( )。
三相半波可控整流电路带电阻负载时,输出的电压波形处于连续和断续的临界状态时,α的取值为( )
带电感负载的三相半波可控整流电路,当触发角大于30°时,各相晶闸管的导通较为( )
三相全控桥式整流电路带电阻负载电路,当α= ( )时,输出负载电压波形处于连续和断续的临界状态。
三相全控桥式整流电路带电阻负载,当触发角α=0°时,输出的负载电压平均值为( )
三相全控桥式整流电路带大电感负载时,控制角α的有效移相范围是( )
三相桥式半控整流电路采用( )个晶闸管。
三相半波可控整流电路的自然换相点是( )。
关于共阳极三相半波可控整流电路说确的是( )
以下关于三相全控桥式整流电路(阻性负载)说确的是( )
三相桥式半控整流电路带感性负载时,可能发生失控现象的原因有( )
三相半波可控整流电路的输出电压平均值随触发角的增大而增大。
三相桥式半控整流电路,带大电感性负载,有续流二极管时,当电路出故障时会发生失控现象。
三相桥式全控整流电路只能采用双窄脉冲触发。
桥式半控型整流电路带电感性负载时,都有可能发生失控现象,其j9九游的解决方案都是在负载侧并联续流二极管。
下列整流电路中,能够实现有源逆变的电路是( )
变流器工作在逆变状态时,控制角α必须工作在( ) 。
变压器漏感对相控整流电路的影响包括( )
整流电路工作在有源逆变状态的条件是( )
对于相控整流电路,变压器漏感和负载电感都会对电路的换相过程产生影响
无源逆变电路,是把直流电能逆变成交流电能,送给电网。
所有的整流电路都可以工作在有源逆变状态
带续流二极管的单相半波整流电路中,负载电阻r=5ω,ld很大,输出电流id=10a。由交流220v电网供电。求: (1)流过晶闸管和二极管的电流有效值; (2)晶闸管承受的最大电压值。
单相相控桥式整流电路的负载电阻r=10ω,变压器二次侧电压u2=220v,α=0。分别求当有、无ld时, 1)整流电路的输出电压和电流的平均值ud、id; 2)晶闸管电流有效值、平均值 3)变压器电流有效值
某单相可控整流电路给阻性负载和给蓄电池(反电动势负载)供电,在留过负载的电流平均值相同的情况下,哪一种负载下晶体管的额定电流应选大一些?为什么?
某单相桥式全控整流电路,电源电压u2=220v,负载电阻r=2ω,负载电感极大,触发角α=30°,求: (1)画出ud、id、i2的波形; (2)求整流输出平均电压ud、电流id、变压器二次侧电流有效值i2; (3)确定晶闸管的额定电压、额定电流(考略二倍裕量)。
下列说确的是
关于反激变换器,说确的是
正激变换器的输出和输入电压的比值关系满足( )
buck变换器的电感电流脉动与( )有关
使boost变换器工作在dcm模式的方法有( )
升降压变换器可以灵活的改变输出电压的高低和极性。
推挽型隔离直直变换器包括6种工作模式
推挽型隔离直直变换器是一种隔离型的boost变换器
单项交流调压变压电路带阻性负载时,移相角的调节范围是( )
下列说确的是
构成三项变频电路,需要( )组桥式电路,其中至少有不同输出相的( )组桥中的( )个晶闸管同时导通,才能构成回路、形成电流
半控型交流调压变换器的控制方式包括( )
单项交流调压变压电路带阻感性负载时,( )
以下关于矩阵变频电路,说确的是
三相交流调压电路中,应至少有一相正向晶闸管与另一相晶闸管同时导通。
三相交流调压电路可以采用宽脉冲或者双窄脉冲触发。
相控交交变频电路无法实现功率在电源和负载之间的双向传输
电压型逆变电路的直流电源为( ),交流侧输出电压波形为( )
半控型逆变电路不能采用的换流方式是
单相半桥逆变电路的输出电压幅值为( )
对三相电压型逆变电路的说确的是( )
下列说确的是
电流型逆变器由于电流源电流的单向性,逆变桥的各桥臂需要并联无功反馈二极管。
单相半桥逆变电路的负载电压波形与单相桥式逆变电路的负载波形相同,幅值和谐波成分也相同。
单相桥式逆变电路带滞后负载时,负载电流的之后角度越大,换流时,开关要切断的电流幅值也越大。
多重化逆变电路的基本思想是用阶梯波去逼近正弦波
工作在连续导电模式的升压变换器,其输出电影和输入电压比为
单相桥式全控整流电路中,带纯电阻负载时,α角移相范围为( )
由晶闸管构成的逆变器不能采用的换流方式是( )。
下列能够实现有源逆变的整流变换器是( )
整流电路的功率因数总是( )
电力mosfet具有正温度系数,可以实现并联均流
相同移相角条件下,带反电动势负载的单相桥式全控整流电路比其带电阻性负载时,整流输出的电压更小
由于变压器绕组漏感的存在,三相半波可控整流电路在换相时会出现两条支路同时导通的情况
当晶闸管换相时,如果换相裕量时间小于晶闸管的管段时间,可能导致换相失败。
电压型逆变电路,为了反馈感性负载上的无功能量,必须在电力开关器件上反并联二极管
按照电力电子器件的开关控制能力来分,晶闸管属于 型器件
按照电力电子器件的驱动信号性质来分,晶闸管属于 型器件
按照电力电子器件的内部载流子类型来分,晶闸管属于 型器件
三相桥式全控整流电路中,当负载为电阻负载时,晶闸管的最大移相角是 °
在spwm 逆变电路中,当等腰三角波与正弦控制信号之间的频率调制比为常数,这种调制方式称为 调制
整流电路工作于有源逆变状态的条件是什么?
有源逆变和无源逆变电路的主要区别有哪些?
晶闸管额定电压为300v、额定电流100a,维持电流5ma,使用在如下电路中是否合理?为什么?(分析时不考虑电压电流裕量)
画出单相半波可控整流电路,当=60°时,以下三种情况的输出电压和电流、晶闸管的电压和电流的波形。 1) 电阻性负载 2) 大电感负载、接续流二极管 3) 大电感负载、接续流二极管
工作在连续导电模式的升压变换器,其输出电影和输入电压比为
单相桥式全控整流电路中,带纯电阻负载时,α角移相范围为( )
由晶闸管构成的逆变器不能采用的换流方式是( )。
下列能够实现有源逆变的整流变换器是( )
整流电路的功率因数总是( )
电力mosfet具有正温度系数,可以实现并联均流
相同移相角条件下,带反电动势负载的单相桥式全控整流电路比其带电阻性负载时,整流输出的电压更小
由于变压器绕组漏感的存在,三相半波可控整流电路在换相时会出现两条支路同时导通的情况
当晶闸管换相时,如果换相裕量时间小于晶闸管的管段时间,可能导致换相失败。
电压型逆变电路,为了反馈感性负载上的无功能量,必须在电力开关器件上反并联二极管
按照电力电子器件的开关控制能力来分,晶闸管属于 型器件
按照电力电子器件的驱动信号性质来分,晶闸管属于 型器件
按照电力电子器件的内部载流子类型来分,晶闸管属于 型器件
三相桥式全控整流电路中,当负载为电阻负载时,晶闸管的最大移相角是 °
在spwm 逆变电路中,当等腰三角波与正弦控制信号之间的频率调制比为常数,这种调制方式称为 调制
整流电路工作于有源逆变状态的条件是什么?
有源逆变和无源逆变电路的主要区别有哪些?
晶闸管额定电压为300v、额定电流100a,维持电流5ma,使用在如下电路中是否合理?为什么?(分析时不考虑电压电流裕量)
画出单相半波可控整流电路,当=60°时,以下三种情况的输出电压和电流、晶闸管的电压和电流的波形。 1) 电阻性负载 2) 大电感负载、接续流二极管 3) 大电感负载、接续流二极管
绩效管理的着眼点在于()。
以下说法中,你认为专讲座法内容正确的是( )。
在劳动关系的调整方式中,( )的基本特点是体现劳动关系当事人双方的意志。
原始记录的登记制度能保证绩效管理信息的有效性和可靠性,它要求( )。
消费者市场是指所有为了( )而购买商品或服务的个人和家庭所构成的市场。
课程设置的结构由培训部门自行掌握,无需报决策部门和决策者审批后执行。
培训项目规划的内容不包括( )。
情景模拟测试比较适用于招聘( )。
衡量培训效果最常用的经济指标是( )。
不属于工资总额的范畴。
分享制工资的由来是()。
量化对象具有明显数量关系的量化形式是()
劳动关系利益的协调是两大组织间的行为,在阐述企业劳动关系的调整理论时一般以( )为线索,阐述其行为理论和影响,同时涵盖( )的行为。①工会组织;②雇主组织;③。
是目前了解企业经营外部环境情况的主要方法。
工资
c公司采取的薪酬策略为着重成本控制,那么它可能处于()阶段。
分析考评数据的方法
无论是什么样的企业薪酬结构,都要反映不同岗位之间在薪酬结构中的差距,为此要确定若干岗位等级作为岗位评价的依据。
反映岗位或技能的价值,但忽视了员工之间的个体差异的薪酬形式是( )。(5月真)
简要说明工作岗位调查设计方案的构成。[11月三级真]
企业经营环境的微观分析包括()
管理岗位培训规范的内容不包括( )。
按劳动定额所考察的范围,劳动定额水平可分为( )。
对阶级与阶层的叙述正确的是( )。
企业集团的日常经营事务工作是由( )负责。
生产操作性岗位职责包含的内容有( )。
下面关于硬性分配法的叙述,正确的有()。
人力资源的( )能力是企业竞争优势的根本。
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