期刊文献+
共找到822篇文章
< 1 2 42 >
每页显示 20 50 100
双相不锈钢S31803与SUS316L焊接工艺研究及性能分析
1
作者 王兴伟 于志江 《现代制造技术与装备》 2024年第6期110-112,共3页
对双相不锈钢S31803与不锈钢SUS316L焊接工艺的优化及焊接接头性能进行分析。对双相不锈钢S31803和不锈钢SUS316L的特性与焊接难点等进行分析,对双相不锈钢S31803与不锈钢SUS316L的异种钢焊接工艺、焊接接头组织和性能进行实验,通过实... 对双相不锈钢S31803与不锈钢SUS316L焊接工艺的优化及焊接接头性能进行分析。对双相不锈钢S31803和不锈钢SUS316L的特性与焊接难点等进行分析,对双相不锈钢S31803与不锈钢SUS316L的异种钢焊接工艺、焊接接头组织和性能进行实验,通过实验验证和性能分析,得出关于双相不锈钢S31803与不锈钢SUS316L异种钢焊接工艺的结论和建议。 展开更多
关键词 双相不锈钢 s31803 sus316L 焊接工艺 焊接接头 力学性能 耐蚀性能
下载PDF
基于SU-8和AU-S的光纤传感制备及测试(英文) 被引量:1
2
作者 袁艳玲 薛晨阳 +1 位作者 张强 熊继军 《传感技术学报》 CAS CSCD 北大核心 2012年第5期589-593,共5页
将SU-8光刻胶涂覆在经过表面处理的锥形光纤表面,其表面的环氧基与MPTMS(3-硫丙基三甲氧基硅烷)发生交联作用。TPTMS表面的-SH基与用种子溶液生长法制备的星形纳米颗粒形成很强的化学键AU-S(其能量为170 kJ/mo1)。此外,我们还用这种光... 将SU-8光刻胶涂覆在经过表面处理的锥形光纤表面,其表面的环氧基与MPTMS(3-硫丙基三甲氧基硅烷)发生交联作用。TPTMS表面的-SH基与用种子溶液生长法制备的星形纳米颗粒形成很强的化学键AU-S(其能量为170 kJ/mo1)。此外,我们还用这种光纤传感对不同浓度的酒精和甲胆紫溶液进行了透射谱测量。最后测试结果表明这种表面修饰了星形纳米颗粒的光纤传感对不同的物质和浓度非常灵敏,这种纳米光学传感有望被用于高灵敏度的检测中。 展开更多
关键词 硅烷偶联剂 su-8光刻胶 星形纳米金颗粒 AU-s 纳米修饰
下载PDF
两参数变形量子代数SU(1,1)_(q,s)的相干态及其性质 被引量:1
3
作者 于肇贤 张德兴 《光子学报》 EI CAS CSCD 1995年第5期396-402,共7页
利用SU(1,1)_(q,s)量子代数的两参数变形振子构造出归一化的SU(1,1)_(q,s)相干态,证明了SU(1,1)_(q,s)量子代数的表示基是正交的,并讨论了它的相干态的归一性和完备性。指出(SU(1,1)_(... 利用SU(1,1)_(q,s)量子代数的两参数变形振子构造出归一化的SU(1,1)_(q,s)相干态,证明了SU(1,1)_(q,s)量子代数的表示基是正交的,并讨论了它的相干态的归一性和完备性。指出(SU(1,1)_(q,s)相干态的相干性受参数q、s的影响。 展开更多
关键词 量子代数 相干态 完备性关系 量子群
下载PDF
S25C与SUS405钢的真空扩散焊接的研究
4
作者 杜则裕 圆城敏男 +2 位作者 菊地靖志 池内建二 堀之内力 《焊接》 北大核心 1991年第2期2-5,共4页
研究了S25C与SUS405钢的真空扩散焊接的异种接头结合性能。对于接头的变形率、抗拉强度及硬度进行了试验。提出了获得优质接头的真空扩散焊接的合理工艺参数。
关键词 s25C钢 sus405钢 真空扩散焊 焊接
下载PDF
黑格斯机制与SU(5)大统一场理论 被引量:1
5
作者 游阳明 魏连甲 张学龙 《沧州师范学院学报》 2004年第2期20-23,共4页
较为详细地叙述了对称性自发破缺的概念,给出哥德斯通定理和Higgs机制,进一步讨论了黑格斯机制在G-W-S及SU(5)中的应用。
关键词 黑格斯机制 su(5)群 大统一场理论 弱电统一理论 对称性自发破缺 规范场 量子色动力学 哥德斯通定理 夸克 G-W-s模型
下载PDF
双参数变形光子相位算符与双参数变形量子群SU(1,1)_(q,s)相干态
6
作者 于舸 于肇贤 张德兴 《光子学报》 EI CAS CSCD 1997年第1期15-20,共6页
本文构造了双参数变形光子相位算符,研究了它与双参数变形量子群SU(1,1)q,s相干态之间的关系,得到了一些新的结果.
关键词 双参数变形 光子 相位算符 相干态
下载PDF
利用量子代数SU(1,1)_(q,s)的 Holstein-Primakoff实现讨论双参数变形Jaynes-Cummings模型
7
作者 于舸 张德兴 于肇贤 《光子学报》 EI CAS CSCD 1996年第8期694-698,共5页
本文利用量子代数 SU(1,1)_(q,s)的 Holstein-Primakoff 实现讨论了双参数变形Jaynes-Cummings 模型,并给出了布居数反转的时间演化表达式.
关键词 双参数变形 量子代数 J-C模型 量子光学
下载PDF
利用双参变形自旋相干态计算量子代数SU(2)_(q,s)的Clebsch-Gordan系数
8
作者 于肇贤 于舸 +1 位作者 张德兴 刘业厚 《光子学报》 EI CAS CSCD 1997年第8期673-678,共6页
利用量子代数SU(2)q,s的双参数变形自旋相干态,通过引入量子代数SU(2)q,s的不可约表示张量积空间的Bargmann表示,导出了这一表示中不可约表示基底、双参数变形自旋相干态以及算符的表达式.最后导出了量子代数SU(2)q,s在双参... 利用量子代数SU(2)q,s的双参数变形自旋相干态,通过引入量子代数SU(2)q,s的不可约表示张量积空间的Bargmann表示,导出了这一表示中不可约表示基底、双参数变形自旋相干态以及算符的表达式.最后导出了量子代数SU(2)q,s在双参数变形自旋相干态下的Clebsch-Gordan系数. 展开更多
关键词 C-G系数 双参数变形 量子代数 自旋相干态
下载PDF
从协同到求异:指向教师专业发展的U-S合作优化研究 被引量:1
9
作者 汪明帅 杨扬 《教师发展研究》 2024年第2期83-90,共8页
U-S合作是教师专业发展的重要举措。审视U-S合作的历程可知,U-S合作致力于多方位促进教师专业发展,协同逐渐成为U-S合作促进教师专业发展的底层逻辑。随着合作的持续推进,这一底层逻辑在促进教师专业发展方面所潜在的矛盾也逐渐暴露出... U-S合作是教师专业发展的重要举措。审视U-S合作的历程可知,U-S合作致力于多方位促进教师专业发展,协同逐渐成为U-S合作促进教师专业发展的底层逻辑。随着合作的持续推进,这一底层逻辑在促进教师专业发展方面所潜在的矛盾也逐渐暴露出来。一方面,大学与中小学的文化差异阻碍了协同的深度发生;另一方面,为了实现大学与中小学的协同,双方不得不做出诸多的妥协,在妥协的语境下,中小学教师往往面临着主体性丧失的风险。与之相对,在求异这一核心理念的引领下,跨界学习旗帜鲜明地提出了“差异即资源”的主张,并通过互动场域的营造和互动系统的建构,为“差异即资源”提供了现实可能,也为优化U-S合作提供了新的思路。 展开更多
关键词 U-s合作 教师专业发展 协同 求异
下载PDF
A Research on Middle School Students'English Reading Obstacles and Strategies
10
作者 杨维玱 《海外英语》 2012年第15期43-46,共4页
English reading,a key procedure of English learning and teaching in middle school,is an essential way of getting information from the globe and communicating with others.Therefore,efficient comprehension on reading ma... English reading,a key procedure of English learning and teaching in middle school,is an essential way of getting information from the globe and communicating with others.Therefore,efficient comprehension on reading materials will directly serve for accepting the information.And it is extremely important for middle school students to acquire certain reading ability.At present,great attention has been paid to the course of reading in the instruction of English by the Chinese Education Department.But middle school students'read ing ability is still much lower than the target they should reach because of a set of existing obstacles that prevent them from being effective English readers.What are these obstacles? How to break them down? This paper will first point out and then analyze the obstacles that af fect middle school students'reading ability from two aspects:linguistic obstacles(obstacles of lexicon,grammar and background knowl edge) and non-linguistic obstacles(obstacles of psychology,interest,skill,and habit).After demonstrating different obstacles,the paper also come up with some corresponding strategies in the hope of helping middle school students to be effective English readers. 展开更多
关键词 English READING MIDDLE school sTUDENTs obstacles s
下载PDF
U-G-S模式下现代大学附属学校建设的路径思考
11
作者 郭长江 《现代基础教育研究》 2024年第3期23-26,共4页
U-G-S(大学-政府-学校)三方联动是上海师范大学近年来建设现代大学附属学校的主要模式,上海师范大学、各区政府与中小学校高效协同合作,发挥各方优势,主动服务上海市政府建设“五个新城”的城市战略,办老百姓家门口的好学校。大学附属... U-G-S(大学-政府-学校)三方联动是上海师范大学近年来建设现代大学附属学校的主要模式,上海师范大学、各区政府与中小学校高效协同合作,发挥各方优势,主动服务上海市政府建设“五个新城”的城市战略,办老百姓家门口的好学校。大学附属学校分为挂牌学校和新建学校两种类型,研究从内在机制、实践路径和建设成效三个方面对两类学校的变革发展进行深度剖析,以期为大学附属学校建设提供宝贵经验。 展开更多
关键词 U-G-s模式 建设路径 大学附属学校
下载PDF
SUS304耦合摩擦实验机测控系统的研究
12
作者 刘健康 高志 宋冬冬 《工业仪表与自动化装置》 2009年第4期11-14,共4页
SUS304耦合摩擦实验机是用来模拟SUS304亚稳奥氏体不锈钢的摩擦学问题。该文分析了SUS304耦合摩擦实验机的组成,亚稳奥氏体在耦合摩擦条件下摩擦力的分析,提出了采用工业计算机和PCL-812PG多功能数据采集卡相结合的测控系统在SUS304耦... SUS304耦合摩擦实验机是用来模拟SUS304亚稳奥氏体不锈钢的摩擦学问题。该文分析了SUS304耦合摩擦实验机的组成,亚稳奥氏体在耦合摩擦条件下摩擦力的分析,提出了采用工业计算机和PCL-812PG多功能数据采集卡相结合的测控系统在SUS304耦合摩擦实验机中的应用。采用VC++6.0作为测控系统软件的开发平台,针对PCL-812PG数据采集卡进行二次开发。试验测量结果表明:采用计算机和PCL-812PG多功能数据采集卡的控制系统,能很好地采集实验中耦合摩擦实验机的摩擦力,且与理论分析基本一致。该控制系统稳定性好,结构配置灵活,易于维护和扩展,具有较强的通用性和实用性。 展开更多
关键词 PCL-812PG数据采集卡 耦合摩擦 sus304亚稳奥式体不锈钢 s型传感器
下载PDF
It's Time to Move for School Bus 被引量:1
13
作者 Amy Hu 《China's Foreign Trade》 2011年第23期42-43,共2页
Links Following recent fatal accident,school bus checks kick off nationwide in China According to Xinhua news, twenty-one people, including 19 preschoolers and two adults, died and 43 others were injured when a nine-s... Links Following recent fatal accident,school bus checks kick off nationwide in China According to Xinhua news, twenty-one people, including 19 preschoolers and two adults, died and 43 others were injured when a nine-seat school bus illegally carrying 64 people collided head-on with a 展开更多
关键词 school It’s Time to Move for school Bus
下载PDF
SUS310S的高温持久性能实验研究 被引量:3
14
作者 杨照明 《一重技术》 2009年第3期42-45,共4页
以SUS310S为研究对象,在高温持久试验机上测定了SUS310S钢在800~1100℃时的高温持久强度,采用时间-温度参数法求出不同温度下的持久强度,以及通过高温短时实验来推测低温长时间下的持久强度。最后用最小二乘法处理后得出曲线,再用外推... 以SUS310S为研究对象,在高温持久试验机上测定了SUS310S钢在800~1100℃时的高温持久强度,采用时间-温度参数法求出不同温度下的持久强度,以及通过高温短时实验来推测低温长时间下的持久强度。最后用最小二乘法处理后得出曲线,再用外推法求出持久强度极限。 展开更多
关键词 奥氏体耐热不锈钢 sus310s 高温持久强度
下载PDF
SU(3)_L×U(1)模型
15
作者 聂传辉 《安徽师大学报》 1993年第2期32-37,共6页
1967到1968年,Weinberg与Salam利用自发破缺的Higgs机制提出了完整的SU(2)×U(1)弱电统一规范理论(W—S模型)。本文重新构造了一个非标准的SU(3)_L×U(1)模型,结果与W—S模型相容。
关键词 W-s模型 规范场 量子色动力学
下载PDF
The U.S. School Bus System:What Can China Learn? 被引量:1
16
作者 FENG BANG AND FEI JINGHUA 《The Journal of Human Rights》 2012年第3期22-25,共4页
The school bus system in the United States took its form in 1939 when Frank W. Cyr, from the New York-based Teachers College of Columbia University, organized a national standards conference for school transportation.... The school bus system in the United States took its form in 1939 when Frank W. Cyr, from the New York-based Teachers College of Columbia University, organized a national standards conference for school transportation. Representatives of education and transportation depart- ments from all 48 states, together with school bus manufacturers, attended the 7-day meeting. They worked out 45 standards and rules concerning school bus safety, specifying in detail school bus length, roof height, aisle width, etc. 展开更多
关键词 school Bus system The U.s BUs
下载PDF
分配器壳体S45SU钢锻件的生产试制
17
作者 顾松霞 富军 《大型铸锻件》 2009年第3期20-21,共2页
船用主机分配器壳体S45SU钢锻件探伤要求非常严格。试制给定的化学成分范围较宽,又有严格的力学性能要求,为此我们制定了内控化学成分。严格按照工艺组织生产,成功试制出了S45SU钢锻件。
关键词 船用主机分配器壳体 s45su 冶炼 锻造 热处理
下载PDF
The Use and Value of Green School Grounds in Developing Countries
18
作者 Arlinda Sheqiri Parna Rastgo 《Journal of Environmental Science and Engineering(A)》 2018年第2期92-99,共8页
There is an extensive attention in developed countries to take full advantages of urban green spaces including green school grounds.Those spaces are assessed and established as environmental learning resources,where t... There is an extensive attention in developed countries to take full advantages of urban green spaces including green school grounds.Those spaces are assessed and established as environmental learning resources,where top-down or bottom-up initiatives encourage or initiate projects with the support of school staffs and students.Green school grounds are also used for gardening(food growing)that besides environmental education,those spaces provide health benefits and knowledge,also skills and behavioral benefits.Those approaches in some developing countries are still vague or inapplicable for several reasons.This paper addresses the use and value of school grounds in developing countries as it lacks the opportunities to make the most of green school grounds.This research elaborated five schools,in the city of Podujevo,Kosovo.The findings reveal that the potentials of green school grounds in most of the cases studied have not been utilized.Opportunities offered by the municipality and environmental NGOs(Non-governmental Organizations)are insufficient.The findings suggest the need to rethink the design and use of green school grounds in developing countries. 展开更多
关键词 school environment school GARDENING children’s gardens experimental learning
下载PDF
Factors Affecting Children’s Cholesterol Levels with a View to Prevent Cardiovascular Disease—The Unique Benefits of Health Screening at the Elementary School
19
作者 Akihiro Kihara Hiromi Kawasaki +2 位作者 Satoko Yamasaki Mika Nishiyama Md. Moshiur Rahman 《Health》 2017年第1期172-188,共17页
Background: The prevention of cardiovascular disease (CVD) can substantially contribute to reducing the mortality rate across countries. The level of interest in cholesterol among experts increases when the subjects a... Background: The prevention of cardiovascular disease (CVD) can substantially contribute to reducing the mortality rate across countries. The level of interest in cholesterol among experts increases when the subjects are elderly and obese individuals. However, specialists do not recommend that children should receive the cholesterol test. The objective of this study was to investigate the distribution of cholesterol levels among the children of public school and their parents’ lifestyles that are associated with cholesterol levels, and to assess the need for and utility of cholesterol testing in school settings. Methods: The study investigated a group of 226 fourth-grade public school children aged between 9 and 10 years and guardians in Akitakatacity of Hiroshima Prefecture, Japan. Multiple regression analyses were performed with the logarithmic value of cholesterol levels as a response variable, awareness about lifestyles and health of children as an explanatory variable, and child’s sex and body mass index (BMI) as moderating variables. Using questionnaires about lifestyles, the step-down procedure was applied in multiple regression analyses to narrow down relevant lifestyle variables. Results: The percentage of children with the high total cholesterol (TC) value was about 15 and with low-density lipoprotein (LDL) cholesterol value was about 10. Children with low high-density lipoprotein (HDL) cholesterol value were 5%. Treatment was not required according to the comprehensive assessment. Cholesterol levels were associated with the situation of the children and their guardians as follows, guardian need to consider the food, and child has the correct knowledge about food like how to eat snacks. Conclusions: Children had poor cholesterol levels. From childhood, along with the parents, there is a need to learn about appropriate level of cholesterol for CVD prevention. 展开更多
关键词 Children’s Lifestyle-Related DIsEAsE CARDIOVAsCULAR DIsEAsE HEALTH Promotion for Family school HEALTH
下载PDF
Student capacity building of dengue prevention and control: A study of an Islamic school, Southern Thailand
20
作者 Charuai Suwanbamrung Niran Tapalak +4 位作者 Charuai Jitchun Chairat Promsuwan Somjit Prosupa Yoottapong Muenraj Anan Dumpan 《Health》 2012年第7期366-376,共11页
Dengue has been a critical problem for an Islamic School, Nakhon Si Thammarat province, Southern Thailand. Objectives: 1) to build student capacity;and 2) to evaluate the results of student capacity building. Method: ... Dengue has been a critical problem for an Islamic School, Nakhon Si Thammarat province, Southern Thailand. Objectives: 1) to build student capacity;and 2) to evaluate the results of student capacity building. Method: Participatory Action Research: PAR was applied in three phases: 1) the school-based preparation phase;2) the process of building student capacity phase, and 3) evaluation of the results of the student capacity building. Independent T-Test statistical method was used to analyze student capacity both before and after the intervention. Larval Indices were determined through ratio analysis. Results: Prior to the intervention, there was no clear strategy for combating dengue. In this study, three groups were formed to build student capacity: a leader group, a non-leader group, and a support group. The leader group (48 student leaders), critical to the study, was set as a dengue club named “Eliminate Ades Aegypti, the culprit of dengue” which focused on eight sets of activities: “Dengue or Death”, “Seniors educating juniors”, “Reward for good answers”, “Dengue monitoring team”, “Youth to expel mosquetoes”, “Mosquito or busy”, “Garbage elimination of Pondok”, and “Essential doctors”. The level of student capacity for the prevention and control of dengue of a sampling of 308 student representatives of the Pondok (Islamic school) showed an increase after intervention ( (SD);56.78 (17.06);65.33(15.36) and different statistic significant (P < 0.001). The Larval indices ratio levels had decreased from the original levels (BI = 244, HI = 45, and CI = 26) after intervention (BI = 137, HI = 39, and CI = 19). Dengue morbidity and mortality rates were not found during the study. Discussion: Although there had been an increase in student capacity, a decrease in the larval indices ratio, and the absence of a dengue epidemiology index, the high risk of a dengue epidemic might still be found in the school because the ratio of larval indices were higher than the standard index. Then, the committed participation of students, school, and communities around the school vicinity is needed in building student capacity of dengue prevention and control. 展开更多
关键词 student’s Capacity Building Process DENGUE PREVENTION and Control IsLAMIC school Pondok
下载PDF
上一页 1 2 42 下一页 到第
使用帮助 返回顶部