皮皮学，免费搜题
登录
搜题
【单选题】
公文的标题一般由哪些要项组成 ( )A.
版头.发文字号
B.
抄送机关.版头.主题词
C.
份号.密级标志.主题词
D.
发文机关名称.事由.
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【单选题】As shown in the figure, the square-sectional slender column with the side length mm of the cross-section is exerted with an axial pressure F= 4 π 2 kN , and the elastic modulus E= 100GPa. Determine th...
A.
n st =1
B.
n st =2
C.
n st =3
D.
n st =4
【单选题】Knowing that represents the critical stress of the slender column, which of the following statements is correct?
A.
is related to the critical load and the cross-sectional area of the column, and is independent of the material.
B.
is related to the s lenderness ratio of the column, and is independent of the cross-sectional area.
C.
is only related to the material, the shape and size of the cross-section of the column.
D.
The value of should not exceed the limit of proportional of the material.
【单选题】Knowing that represents the critical stress of the pressure column, which of the following statements is correct? (1) The value of of the slender column is related to the material. (2) The value of of...
A.
(1), (2)
B.
(3), (4)
C.
(1), (3)
D.
(2), (4)
【单选题】As the both ends pinned slender column with rectangle cross-section is unstable, which is correct in the following options?
A.
The critical pressure force F cr =π 2 EI y /l 2 , and the deflection curve is on the xy plane
B.
The critical pressure force F cr =π 2 EI y /l 2 , and the deflection curve is on the xz plane
C.
The critical pressure force F cr =π 2 EI z /l 2 , and the deflection curve is on the xy plane
D.
The critical pressure force F cr =π 2 EI z /l 2 , and the deflection curve is on the xz plane
【单选题】The slender column AB is exerted by an axial pressure force(see the figure). Assume the critical force of the column is P 1j , which of the following statements is correct?
A.
The axis of column AB will keep straight only as ,, and only compression deformation will be produced for the column.
B.
The axis of column AB will keep straight as , and there will be no bending deformation for the column.
C.
The column AB will not keep equilibrium as .
D.
Make in order to ensure the column AB is in equilibrium.
【简答题】做硫在氧气中燃烧的实验时，在集气瓶内放了少量水来吸收SO 2 ，实验结束后，集气瓶内仍残留一定量的SO 2 。围绕如何处理这些SO 2 的问题，同学们进行了相关探究。 【提出问题】SO 2 是形成酸雨的主要物质。由此想到，选用氢氧化钠等碱性溶液吸收SO 2 ，效果会怎样？ 【设计与实验】 用两套完全相同的装置做对比实验(SO 2 不溶于植物油也不与其反应)，如下图所示： (1)为确保实验的准确性，...
相关题目：