相关试题
【判断题】
Ca2+、Mg2+和HCO3-所形成的硬度叫永久硬度
【判断题】
当水的PH≥8.3时，表明天然水中不存在CO2
【判断题】
天然水中的溶解物质只是一些以离子态存在的物质
【判断题】
水中的硬度大小就是指水中Ca2+、Mg2+含量的多少
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混床反洗后，树脂分为两层，上层为阳树脂，下层为阴树脂
【判断题】
进水的含盐量和树脂的再生程度对混床的出水水质和运行周期都有很大的影响
【判断题】
除盐系统中，水流速过慢，交换效果反而不好，所以运行时，流量不应太小
【判断题】
鼓风式除碳器不仅可以除去水中的CO2，而且可以除去水中的O2
【判断题】
离子交换树脂由交联剂、单体和活性基团物质三部分组成
【判断题】
阴阳床石英砂垫层，粒度从上到下依次增大
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在水的混凝处理过程中，助凝剂本身不起混凝作用，而是充当凝絮的骨架材料
【判断题】
一级除盐系统中，除碳器应设置在阴床之前
【判断题】
在离子交换器运行过程中，进水流速愈大，交换器的工作交换容量愈大，周期制水量也愈大
【判断题】
普通混床中，阴阳离子交换树脂体积比例一般为1：1
【判断题】
混床中树脂失效程度越大，反洗分层越容易
【判断题】
离子交换树脂受铁、铝及其氧化物污染后，颜色变深
【判断题】
在阴离子交换器再生过程中，加热再生液到30～40℃，可以提高再生效果
【判断题】
阴床失效时，最先穿透树脂层的阴离子是Cl-
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混凝剂在水中的混凝处理过程中，其本身也发生电离、水解、形成胶体和凝聚等过程
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在逆流再生固定床中，中间配水装置以上的树脂也起离子交换作用
【判断题】
进行混凝和沉淀处理时，应及时清除泥渣，以使沉淀过程更完全，更快速
【判断题】
在一级除盐设备中，阴床出水不合格是由于阳床失效造成的
【判断题】
大孔型离子交换树脂具有抗氧化性能和抗有机物污染性能好、机械强度大、交换速度快等优点
【判断题】
原水中Ca2+含量高，则H型交换器失效后就能用硫酸再生
【判断题】
树脂在吸着不同离子后，密度不同，沉降速度也不同
【判断题】
长期贮存树脂，最好把树脂转变成盐型，浸泡在水中
【判断题】
采用逆流再生的离子交换器再生后，底层交换剂的含Na+量对出水水质起着决定性的作用
【判断题】
一般来说，树脂的颗粒越小，交换反应越快，但压头损失相应增大
【判断题】
阴离子交换器失效时会出现电导率暂时下降的现象
【判断题】
排污损失水量与冷却塔的蒸发损失水量和浓缩倍率无关
【判断题】
循环水中CO2散失后，重碳酸盐硬度易转变成碳酸钙从水中析出
【判断题】
锅炉炉管的向火侧较背火侧易发生腐蚀、过热和爆管
【判断题】
循环水的浓缩倍率越高，其中Ca(HCO3)2分解的可能越小
【判断题】
在混床运行中，阴、阳离子的交换反应几乎是同时进行的，基本上清除了交换的影响，故出水水质很好
推荐试题
【单选题】
Of the following, is NOT among the three major radio and TV networks in America.
A. A. the National Broadcasting System (NBS)
B. B. the Public Broadcasting Service (PBS)
C. C. the Columbia Broadcasting System (CBS)
D. D. the American Broadcasting System (ABS)
【单选题】
is sold especially to the upper or upper-middle class and it has a reputation for its serious attitude and great bulk.
A. A. The Washington Post
B. B. The New York Times
C. C. Los Angeles Times
D. D. New York Daily News
【单选题】
Of the following universities, has NOT cultivated any American President yet.
A. A. Harvard University
B. B. Massachusetts Institute of Technology
C. C. Princeton University
D. D. Yale University
【单选题】
To get a bachelor’s degree, all undergraduate students are required to do the following except .
A. A. attending lectures and completing assignments
B. B. passing examinations
C. C. working for communities
D. D. earning a certain number of credits
【单选题】
Of the following, is NOT the responsibility of the board of trustees in U. S. institutions.
A. A. choosing the president
B. B. establishing policies for administrators and faculty
C. C. approving budget and other financial project
D. D. decide which student to enroll
【单选题】
Of the following, are NOT among the categories of American higher education.
A. A. universities and colleges
B. B. research institutions
C. C. technical institutions
D. D. community colleges
【单选题】
Higher education in the United States began with the founding of
A. A. Yale University
B. B. Harvard University
C. C. Princeton University
D. D. New York University
【单选题】
Of the following subjects, are NOT offered to elementary school students.
A. A. mathematics and languages
B. B. politics and business education
C. C. science and social studies
D. D. music and physical education
【单选题】
Formal education in the United States consists of , secondary and higher education.
A. A. kindergarten
B. B. public
C. C. elementary
D. D. private
【单选题】
At present, U. S. exports account for of the world’s total.
A. A. 10%
B. B. 15%
C. C. 20%
D. D. 25%
【单选题】
is not one of the three giants in American automobile industry.
A. A. Ford
B. B. General Motors
C. C. Chrysler
D. D. American Motors
【单选题】
The following statements are all true except .
A. A. Agribusinesses reflect the big, corporate nature of many farm enterprises.
B. B. Agribusinesses maintain a balanced trade pattern between agricultural imports and exports.
C. C. Agribusinesses range from one-family corporations to multinational firms.
D. D. Agribusinesses include a variety of farm businesses and structures.
【单选题】
About of American crops are for export.
A. A. half
B. B. one third
C. C. one fourth
D. D. one fifth
【单选题】
President Johnson tried to build a “Great Society” by introducing various programs like the following except .
A. A. Medicare
B. B. Food Stamps
C. C. Education Initiatives
D. D. Unemployment Pension
【单选题】
The following inventions took place during the “second indThe following inventions took place during the “second industrial revolution” except .
A. A. typewriter
B. B. telephone
C. C. electric light
D. D. refrigerator
【单选题】
The first National Bank of the United States was established with the urge of .
A. A. George Washington
B. B. Thomas Jefferson
C. C. Andrew Jackson
D. D. Alexander Hamilton
【单选题】
Chartered companies were NOT granted the by the British King or Queen.
A. A. political authority
B. B. economic rights
C. C. judicial authority
D. D. diplomatic authority
【单选题】
The modern American economy progressed from to , and eventually, to .
A. A. colonial economy, handcraft economy, industrial economy
B. B. farming economy, handcraft economy, industrial economy
C. C. colonial economy, farming economy, industrial economy
D. D. handcraft economy, farming economy, industrial economy
【单选题】
America produces a major portion of the world’s products in the following fields except .
A. A. machinery
B. B. automobiles
C. C. ore
D. D. chemicals
【单选题】
The President is directly voted into office by .
A. A. all citizens of America
B. B. the citizens over 18 years old
C. C. electors elected by the voters
D. D. the senators and representatives
【单选题】
The Supreme Court is composed of justices.
A. A. six
B. B. seven
C. C. eight
D. D. nine
【单选题】
The terms for a Senator and Representative are and years respectively.
A. A. two, four
B. B. two, three
C. C. two, six
D. D. six, two
【单选题】
According to the Constitution, a candidate for President must be .
A. A. at least 35 years old
B. B. at least a 14 years’ resident of the United States
C. C. born in America
D. D. all of the above
【单选题】
The following except are all powers of the President.
A. A. vetoing any bills passed by Congress
B. B. appointing federal judges when vacancies occur
C. C. making laws
D. D. issuing executive orders
【单选题】
All the following except cannot make legislative proposal.
A. A. the Senator
B. B. the Representative
C. C. the Secretary of State
D. D. the President
【单选题】
The following except are guaranteed in the Bill of Rights.
A. A. freedom of religion
B. B. the right to get into people’s house by police
C. C. freedom of speech and of press
D. D. the right to own one’s weapon if one wishes
【单选题】
The Bill of Rights .
A. A. defines the rights of Congress and the rights of the President
B. B. guarantees citizens of the United States specific individual rights and freedoms
C. C. is part of the Declaration of Independence
D. D. has no relationship with the Constitution
【单选题】
The Constitution of the United States .
A. A. gives the most power to Congress
B. B. gives the most power to the President
C. C. tries to give each branch enough power to balance the others
D. D. gives the most power to the Supreme Court
【单选题】
The U. S. Constitution came into effect in .
A. A. 1787
B. B. 1789
C. C. 1791
D. D. 1793
【单选题】
The Vietnam War was a long-time suffering for Americans, and it continued throughout the terms of Presidents .
A. A. Johnson, Nixon and Ford
B. B. Truman, Eisenhower and Kennedy
C. C. Kennedy, Johnson and Nixon
D. D. Eisenhower, Kennedy and Johnson
【单选题】
President applied New Deal to deal with the problems of the Great Depression.
A. A. Wilson
B. B. Truman
C. C. Roosevelt
D. D. Kennedy
【单选题】
The policy of the United States was at the beginning of the two world wars.
A. A. neutrality
B. B. full involvement
C. C. partial involvement
D. D. appeasement
【单选题】
Abraham Lincoln issued to grant freedom to all slaves.
A. A. Declaration of Independence
B. B. Constitution
C. C. Emancipation Proclamation
D. D. Bill of Rights
【单选题】
In May 1775, was held in Philadelphia and began to assume the functions of a national government.
A. A. the First Continental Congress
B. B. the Second Continental Congress
C. C. the Boston Tea Party
D. D. the Congress of Confederation
【单选题】
The first shots of the American dependence were fired in .
A. A. Concord
B. B. Lexington
C. C. Philadelphia
D. D. Boston
【单选题】
“No taxation without representation” was the rallying slogan of .
A. A. the settlers of Virginia
B. B. the people of Pennsylvania
C. C. the colonists in New England
D. D. the people of the 13 colonies
【单选题】
The Seven Years’ War occurred between the .
A. A. French and American Indians
B. B. French and Spaniards
C. C. French and British
D. D. British and American Indians
【单选题】
Pilgrim Fathers are a group of who came to America to avoid persecution in England.
A. A. Protestants
B. B. Puritans
C. C. Catholics
D. D. Christians
【单选题】
The first successful English colony in North America was founded at in .
A. A. Jamestown, Louisiana
B. B. Boston, Massachusetts
C. C. Jamestown, Virginia
D. D. Plymouth, Georgia
【单选题】
The characteristic of dominant American culture is .
A. A. English-speaking, northern European, Roman Catholic and middle-class
B. B. English-speaking, western European, Roman Catholic and upper-class
C. C. English-speaking, northern European, Protestant and upper-class
D. D. English-speaking, western European, Protestant and middle-class
