更多“为了防止塔的共振，塔在操作时激振力的频率fV不得在塔体第一振”相关的问题
2* . 求下列各幂级数的收敛域。(1)
\sum\limits _{n=1}^{\infty }\frac {(-1)^{n}}{\sqrt {n(n+1)}}(x+1)^{n}\ ;(2)
\sum\limits _{n=1}^{\infty }\frac {n^{2}}{3^{n}}x^{2n-1}\ .
对同一被测几何量进行多次重复测量,条件改变时,误差的数值大小按一定的规律变化,这种误差属于随机误差。（2.0分）
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In the atmosphere, carbon dioxide acts rather like a one-way mirror—the glass in the roof of a greenhouse which allows the sun’s rays to enter but prevents the heat from escaping. According to a weather expert’s prediction, the atmosphere will be 3℃ warmer in the year 2050 than it is today, if man continues to burn fuels at the present rate. If this warming up took place, the ice caps in the poles would begin to melt, thus raising sea level several meters and severely flooding coastal cities. Also, the increase in atmospheric temperature would lead to great changes in the climate of the northern hemisphere, possibly resulting in an alteration of the chief food-growing zones. In the past, concern about a man-made warming of the earth has concentrated on the Arctic because the Antarctic is much colder and has a much thicker ice sheet. But the weather experts are now paying more attention to West Antarctic, which may be affected by only a few degrees of warming: in other words, by a warming on the scale that will possibly take place in the next fifty years from the burning of fuels. Satellite pictures show that large areas of Antarctic ice are already disappearing. The evidence available suggests that a warming has taken place. This fits the theory that carbon dioxide warms the earth. However, most of the fuel is burnt in the northern hemisphere, where temperatures seem to be falling. Scientists conclude, therefore, that up to now natural influences on the weather have exceeded those caused by man. The question is: Which natural cause has the most effect on the weather One possibility is the variable behavior of the sun. Astronomers at one research station have studied the hot spots and "cold" spots (that is, the relatively less hot spots) on the sun. As the sun rotates, every 27.5 days, it presents hotter or colder faces to the earth, and different aspects to different parts of the earth. This seems to have a considerable effect on the distribution of the earth’s atmospheric pressure, and consequently on wind circulation. The sun is also variable over a long term: its heat output goes up and down in cycles, the latest trend being downward. Scientists are now finding mutual relations between models or solar-weather interactions and the actual climate over many thousands of years, including the last Ice Age. The problem is that the models are predicting that the world should be entering a new Ice Age and it is not. One way of solving this theoretical difficulty is to assume a delay of thousands of years while the solar effects overcome the inertia of the earth’s climate. If this is right, the warming effect of carbon dioxide might thus be serving as a useful counter-balance to the sun’s diminishing heat.
A．the climate of the world should be becoming coolerB．it will take thousands of years for the inertia of the earth’s climate to take effectC．the man-made warming effect helps to increase the solar effectD．the new Ice Age will be delayed by the greenhouse effect
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最大实体要求适用于
A、需要保证可装配性的场合
B、需要保证较严格配合要求的场合
C、需要保证零件强度和最小壁厚的场合
D、尺寸公差和形位公差要求的精度相差很大的场合。
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疏散压缩气体钢瓶，必须充分暖和，并在水枪掩饰下进行。
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关于IPS产品的安全策略配置，下列说法正确的有（）。
A.可以基于时间段来下发P2P流量控制策略
B.可以基于时间段来下发攻击防护策略
C.可以基于IP地址下发P2P流量控制策略
D.以基于IP地址下发攻击防护策略
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企业电子文件管理是指对企业电子文件的形成、（）及长期保存过程进行高效和系统控制的管理。
A . 接收
B . 维护
C . 利用
D . 处置
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异丙酚（）。|氯胺酮（）。|硫喷妥钠（）。
A.控制局麻药中毒发生惊厥时首选 B.血压升高，心率加快 C.麻醉诱导时，极易出现显著的血压下降 D.属于中效静脉麻醉药，麻醉诱导平稳 E.对肾上腺皮质功能有抑制作用
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1992年，还是洛阳市卫生纸厂厂长的郭新洛心里就萌动着这样一种愿望：摆脱掉目前这个明显带着旧体制烙印、已阻碍了企业形象宣传和发展的企业名称，冠以一个能充分表现产品的特点和现代企业特征的新名称。 名字不过是个代号而已。对于个人来说或许确实如此，而对于产品名称，它的意义就远不止于此了。1992年以前，洛阳市卫生纸厂的产品有五、六个商标，较为杂乱，且不能表现出产品特点等方面的内容，而且“洁美”、“花环”之类的大众化名称又缺乏视听冲击力。在广泛调查市场，比较同类产品的商标标识之后，厂长亲自挂帅，抓起了这项旨在带动企业全局观念根本转变的“商标更新工程”。 他们选择了“纯静”，取纯洁、清静之意，既表明了产品为生活卫生用品的鲜明特征，又具有浪漫的诗意。确定了文字商标后，他们又在报纸上刊登广告，向全社会公开招标“纯静”商标设计图案。此举在当时的洛阳企业界委实引起了不小的震动。此次招标吸引了全国各地的美术设计专业人才的参与，收到投标设计作品上百件。最后，经反复比较研究确认，以“纯静”两字汉语拼音头一字母变形成水滴状的一设计图案为中标设计。 该设计简洁、明快，喻示一滴水珠，将纯洁干净之水洒向人间。 新颖独特的设计，加上新闻媒体的传播配合，使“纯静”品牌较快地占领了本地市场，并为广大消费者所接受。之后，他们投产的女卫生巾、湿面巾均选用了这个商标设计图案。其中，“纯静”牌妇女卫生巾在省同行业评比中屡获第一名，并荣获“1993河南上帝信得过产品奖”。 问： （1）请结合本案例说明商标和品牌的区别。 （2）请简要说明进行品牌设计的原则。若由你为案例中的产品设计品名，你会如何选择？
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托盘化运输是( )运输的起点。
A．联合
B．集装箱
C．集装化
D．散货
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{{*HTML*}}为了保证培训取得预期的效果，必须对培训进行全程（ ）。
A．监控与协调
B．监控与规划
C．监控和评估
D．监控和反馈
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对尿红细胞形态学检查标本的要求，除外
A . A．新鲜晨尿
B . B．加防腐剂
C . C．新鲜餐后尿
D . D．尽快送检
E . E．记录尿量
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压力容器按在生产工艺过程的作用原理分为：反应压力容器、换热压力容器、分离压力容器、储存压力容器，则反应容器的代号（）。
A.R；
B.E；
C.S；
D.C
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