第一篇:提高练习3
结构力学练习题
编号:JLTG003
1、求 图 示 结 构 A、B 相 对 竖 向 线 位 移,EI= 常 数,a=2m。
qAB2aaaaa
22、求 图 示 结 构 结 点 D 的 水平位 移。(EI = 常 数,链 杆 的 EA =EI/l。)
l/2PDl/2l/2l/2
3、欲 使 图 示 体 系 C 点 无 竖 向 位 移,试 确 定 杆 AD长 度 的 改 变 量。E A =常 数。
DaAaBaCP
4、已 知 图 示 结 构 EI = 常 数,当 B 点 水平位 移 为 零 时,P1/P2 应 为 多少?
P1P2lBl/2l/2
5、图 示 桁 架 下 弦 各 杆 温 度 均 升 高 t℃,已 知 材 料 线 膨 胀 系 数 为 ,试 求
由 此 引 起 的 结 点 D 的 竖 向 位 移 DV。
AD6×3m=18mB4m
6、图 示 状 态 一 与 状 态 二,试 证 明 功 的 互 等 定 理 对 于 该 情 况 不 成 立。
p11t112t
2(a)第 一 状 态
(b)
第 二 状 态
7、图 示 结 构 由 于 a 杆 制 造 时 短 了 0.5cm, 求 结 点 C 的 竖 向 位 移。已 知 l2m。
Clalllll
8、求 图 示
结 构 截 面 A 的 转 角,EI=常 数。
qqaaqaAaaaa
9、当 E 点 有 P = 1 向 下 作 用 时,B 截 面 有 逆 时 针 转 角 ,当 A 点 有 图 示
荷 载 作 用 时,E 点 有 竖 向 位 移 应 为 多 少?
M=1AaBaaaEa
10、计 算 图 示 结 构 A , B 两 截 面 相 对 角 位 移,E I = 常 数。
qAaaBa2a
11、图 示 静 定 桁 架,BC、FE 制 造 时 均 长 了0.003a, 试 求 F、C 两 点 的 相 对 水
平线 位 移。
aaaFBEDCAaaa
12、求 图 示 桁 架 B 点 水平位 移 BH。
Ba一P P a一a一a一EA=常数a一
qlq数 EI=常A2
13、求 图 示 结 构 A 点 水平位 移 AH。
l/2l/2l/2l/2
14、求 图 示 结 构 A 点 竖 向 位 移 AV。
qAlql/2EI=常数2l/2l/2
15、图 示 结 构,EI = 常 数,试 确 定 沿 AB 移 动 的 荷 载 P 在 何 位 置 时,D 点 的
竖 向 位 移 为 最 大,并 求 出 该 最 大 值。
DA2aC1.5axp4aB
16、图 示 结 构 由 于 温 度 改 变 使 C 两 侧 截
面 发 生 相 对 转 角。求 AB 杆 件 的
长 度 改 变 量Δl。又问当Δl等于多大时,可 使 该 相 对 转 角 为 零。已 知 : 各 杆 截 面 对 称 于 形 心 轴,厚 度 h = l /10 , 材 料 线 膨 胀 系 数 为 α,除 AB 杆 件 温 度 不
变 外,其 余 杆 件 外 侧 升 高 20℃,内 侧 升 高 10℃。
ClAlBl17、图 示 组 合 结 构,受 弯 杆 件 忽 略 轴 向 变 形,a=3 m,EI = 常 数。链 杆 EA = 常
数。求 CV。
10kNmaaCaaa
18、图 示 结 构 在 q 作 用 下 C、D 两 截 面 会 发 生 相 对 转 角,若 在 C、D 两 截
面 处 加 一 对 力 偶 M 使 该 相 对 转 角 为 零,求 力 偶 矩 M = ?。E I = 常 数。
AqBCDa/2aaaaM
第二篇:有理数提高练习
1.有1000个数排一行,其中任意相邻的三个数中,中间的数等于它前后两数的和,若第一个数和第二个数都是1,则第1000个数的和等于()
(A)1000(B)1(C)0(D)-1
2.计算|3.14-|-的结果是.3.已知:x4,(y2)24,求xy的值
4、a,b,c三个数在数轴上的位置如图所示,则下列结论中错误的是()(A)a+b<0(B)a+c<0
(C)a-b>0(D)b-c<0ab0c5、123456+……+2005-2006的结果不可能是:()
A、奇数B、偶数C、负数D、整数
6、下列说法正确的是()
A.绝对值等于自身的数是正数; B.绝对值最小的有理数是1;
C.相反数等于自身的数是0;D.倒数等于自身的数是1。
7、已知|a-2|+|b-3|=0,求ab+ba的值。
8、若a、b为有理数,试计算ababc的值,|a||b||abc|
9、a-b的相反数是(),如果a≤b,那么|a-b|=()
|m1|1,求m的取值范围。
10、如果1m53211、3.34×(-22)+5.84×|-4|-()×12 124312、三个互不相等的有理数,既可以表示为1, a+b, a的形式,也可以表示为b0,,b的形式,试求a2001+b2002的值,并说明理由。a
第三篇:提高练习效率
提高练习效率数学课堂练习过程是每一节数学课很重要的环节,但是由于
没有教学新知识环节设计的魅力,练习模式也比较单一,就造成了教师在课前设计教学时往往重视新授知识环节的设计,却忽视了练习教学这一重要的一环!在听过的课例中,许多教师的课是“凤头鸡尾”,开始上得很精彩,可是到练习教学时不仅形式和内容的安排上有欠缺,而且在练习的组织过程中也是没有精心设计和组织,课堂教学的效益就没有达到尽可能高的理想状态。公开课如此,那么随堂课的练习组织呢?因此,课堂练习也要精心设计,精心组织,尽量做到教学方法多样化、教学形式童趣化、组织方式民主化。比如:整堂课40分钟在练习教学的过程中,除了可以采取常用的指名上台表演、集体评价、争当“森林医生”找症结、小组合作交流等形式外,还可以适时采用老师口头出题,学生练习,马上订正,老师很快就可以知道学生学到手 没有,以促进学生在练习成功中获得数学学习的快乐、轻松明晰知识要点的同时,促进学生思维能力、表达能力、问题意识的培养和提高。
第四篇:英语提高 (完形填空练习)
第一节完形填空
It has been argued by some that gifted children should be grouped in special classes, Thehas been on the belief that in regular classes these children are held back in their intellectual(智力的)growth bysituation that has designed for thechildren.There can be little doubt that and take their place in life sooner.However, to take these create serious problems.I observed a number of children who were taken out of a special class and placed in aclass.In the special class, they showed little ability to use their own judgment, relyingon their teachers’ directions.In the regular class, having no worry about ke(http://)eping up, they began to reflect9on many problems, some of which were not on the school program.Many are concerned that gifted children become lose interest in learning.However this.Some top students do feel bored in class, but why they so goes far beyond the work they have in school.Studies have shown that to be bored is to be anxious.The gifted child whop is bored is an1.A.principleB.theoryC.argumentsD.classification
2.A.designingB.groupingC.learningD.living
3.A.smartB.curiousC.matureD.average
4.A.regularB.specialC.smallD.creative
5.A.childrenB.programsC.graduatesD.designs
6.A.intelligentB.competentC.ordinaryD.independent
7.A.separateB.regularC.newD.boring
8.A.speciallyB.slightlyC.wronglyD.heavily
9.A, directlyB.cleverlyC.voluntarilyD.quickly
10.A.doubtedB.boredC.worriedD.tired
11.A.concernB.conclusionC.reflectionD.interest
12.A.studentsB.adultsC.scholarsD.teachers
13.A.talentedB.worriedC.learnedD.interested
华柏校区:88726999 库充校区:88963718 小榄校区:22269296三乡华丰校区:89989158三乡平东校区:89989151
①
14.A.believeB.thinkC.sayD.feel
15.A.outstandingB.intelligentC.anxiousD.ordinary
二.阅读。
Can dogs and cats live in perfect harmony in the same home? People who are thinking about adopting a dog as a friend for their cats are worried that they will fight.A recent research has found a new recipe of success.According to the study, if the cat is adopted before the dog, and if they are introduced when still young(less than 6 months for cats, a year for dogs), it is highly probable that the two pets will get along swimmingly.Two-thirds of the homes interviewed reported a positive relationship between their cat and dog.However, it wasn’t all sweetness and light.There was a reported coldness between the cat and dog in 25% of the homes, while argression and fighting were observed in 10% of the homes.One reason for this is probably that some of their body signals were just opposite.For example, when a cat turns its head away it signals aggression, while a dog doing the samesignals submission.In homes with cats and dogs living peacefully, researchers observed a surprising behaviour.They are learning how to talk each other’s language.It is a surprise that cats can learn how to talk ‘dog’, and dogs can learn how to talk ‘Cat’.What’s interesting is that both cats and dogs have appeared to develop their intelligence.They can learn how to read each other’s body signals, suggesting that the two may have more in common than we previously suspected.Once familiar with each other’s presence and body language, cats and dogs can play together, greet each other nose to nose, and enjoy sleeping together on the sofa.They can easily share the same water bowl and in some cases groom(梳理)each other.The significance of the research on cats and dogs may go beyond pets ─ to people who don’t get along, including neighbors, colleagues at work, and even world superpowers.If cats and dogs can learn to get along, surely people have a good chance.31.The underlined word swimmingly in Paragraph 1 is closest in meaning to ______.A.earlyB.sweetlyC.quicklyD.smoothly
32.Some cats and dogs may fight when ______.A.they are cold to each other
B.they look away from each other
C.they misunderstood each other’s signals
D.they are introduced at an early age
33.What is found surprising about cats and dogs?
A.They eat and sleep each other.B.They observe each other’s behaviors.C.They learn to speak each other’s language.D.They know something from each other’s voices.34.It is suggested in Paragraph 4 that cats and dogs ______.A.have common interests
B.are less different than was thought
C.have a common body language
D.are less intelligent than was expected
35.What can we human beings learn from cats and dogs?
A.We should learn to live in h(http://)armony.B.We should know more about animals.C.We should live in peace with animals.D.We should learn more body languages.三:读写任务
阅读下面短文,然后按要求写一篇150词左右的英语短文
When Sam first got to his boarding school with his parents, he was very happy.He thought he would be able(http://)to go home every weekend.When he was told he would not, he started crying because the thought of not seeing his parents was driving him crazy.He was given uniforms and all other things that he would need for the term.He started crying when it was time for his parents to leave.He was then taken to the dorm, where he saw other children happy.He tried as much as he could to fit in but could not because his mind was at home.He started feeling homesick(想家)安定wanted to go homes as soon as possible.He got sick soon because he could not eat the school food.He could not concentrate in the classroom.All he could think was being at home with his family.He had no mobile phone or other means to get in touch with his parents.He was angry and felt lonely.He thought his parents hated him and that was why they left him in a boarding school.[写作内容]
1.以约30个词概括上文的主要内容。
2.以约120个词讲述一次你(或你的朋友)想家的经历,内容包括:
⑴时间、地点和起因;
⑵想家给学习和生活带来的影响;
⑶你(或你朋友)是如何应对的。
第五篇:《公倍数和公因数》提高练习
例1:马利家的客厅长5.4米,宽4.8米,他爸爸准备在地上贴上一层正方形瓷砖,问至少需要多少块瓷砖?
分析:用若干块正方形瓷砖正好可以沿客厅的长铺一排,所以,所用正方形瓷砖的边长就是马利家客厅长的因数,也就是说,瓷砖的边长必须是客厅长与宽的公因数。题中问“至少需要多少块瓷砖?”,实际是要求所铺的瓷砖尽可能大,即用长和宽的最大公因数作为边长来铺,所需块数最少。
5.4米=540厘米,4.8米=480厘米 540和480的最大公因数是60
(540÷60)×(480÷60)=72(块)
例2:有一种瓷砖的长是35厘米,宽是20厘米。现在打算用这种瓷砖铺一块正方形地,最少需要多少块这样的瓷砖?
分析:长方形瓷砖所铺大正方形的边长既是瓷砖长的倍数,也是瓷砖宽的倍数,所以只要正方形边长是35和20的公倍数,就可以铺成。题中问“最少需要多少块瓷砖?”,实际也是要求所铺的正方形地最小,因为正方形地的边长必须是瓷砖长35厘米和宽是20厘米的最小公倍数140厘米,(140÷35)×(140÷20)=28(块),所以,至少需要用28块这样的瓷砖。
(1)用长是15厘米,宽是8厘米的长方形瓷砖铺成一个正方形。这个正方形的边长最小是多少厘米?最少要用多少块这样的瓷砖?
(2)一个长方形的长是90厘米,宽是36厘米。若要用尽量少的正方形瓷砖来铺满这个长方形,这个瓷砖的边长至少是多少厘米?需要这样的瓷砖多少块?
(3)把36个男生和24个女生分组活动,如果每组里男生与女生的人数分别相等,每个组里最少有几名男生与女生?
(4)一张长是18厘米、宽是12厘米的长方形纸片裁成同样大小的正方形且不许有剩余,正方形的边长最大是多少厘米?最小是多少厘米?最多能裁成多少块?最少呢?
(5)一盒糖,4块4块的数,多3块;6块6块的数,少一块。已知这盒糖的块数在30~40块之间,你知道这盒糖有多少块?
(6)因工地夜间施工需要,要把施工区内的一条长80米得路边的路灯由间隔5米改为间隔4米。除两端两盏不需要移动,中间还有几盏不需要移动?
(7)用长8厘米,宽6厘米的长方形纸片拼成一个正方形,最少需要几张这样的纸片?
(8)将一张长8厘米、宽6厘米的长方形纸片剪成大小相等的正方形,且没有剩余,最少能剪成多少张?
(9)用45朵红花和30朵白花做花束,如果每个花束里红花与白花的朵数分别相同,每个花束里最少要有几朵花?
(10)一张长24厘米、宽16厘米的长方形纸片裁成同样大小的正方形且不许有剩余,正方形的边长最大是多少厘米?最小是多少厘米?最多能裁成多少块?最少呢?
(11)一批同学排方阵,8个8个地数,少7人;6个6个地数,多1人.这批同学最少有几人?
(12)一根木棒长30厘米,从左端起每隔2厘米用红色做个记号,再从右端起每隔3厘米用绿色做个记号,最后沿重复做记号的地方将木棒锯断,这根木棒共被锯成几段?