Theory of Flexural Shear, Bending and Torsion for a Thin-Walled Beam of Open Section

Aspects of the general Vlasov theory are examined separately as applied to a thin-walled channel section cantilever beam under free-end end loading. In particular, the flexural bending and shear that arise under transverse shear and axial torsional loading are each considered theoretically. These analyses involve the location of the shear centre at which transverse shear forces when applied do not produce torsion. This centre, when taken to be coincident with the centre of twist implies an equivalent reciprocal behaviour. That is, an axial torsion applied concentric with the shear centre will twist but not bend the beam. The respective bending and shear stress conversions are derived for each action applied to three aluminium alloy extruded channel sections mounted as cantilevers with a horizontal principal axis of symmetry. Bending and shear are considered more generally for other thin-walled sections when the transverse loading axes at the shear centre are not parallel to the section = s centroidal axes of principal second moments of area. The fixing at one end of the cantilever modifies the St Venant free angular twist and the free warping displacement. It is shown from the Wagner-Kappus torsion theory how the end constrained warping generates an axial stress distribution that varies with the length and across the cross-section for an axial torsion applied to the shear centre. It should be mentioned here for wider applications and validation of the Vlasov theory that attendant papers are to consider in detail bending and torsional loadings applied to other axes through each of the centroid and the web centre. Therein, both bending and twisting arise from transverse shear and axial torsion applied to each position being displaced from the shear centre. Here, the influence of the axis position upon the net axial and shear stress distributions is to be established. That is, the net axial stress from axial torsional loading is identified with the sum of axial stress due to bending and axial stress arising from constrained warping displacements at the fixing. The net shear stress distribution overlays the distributions from axial torsion and that from flexural shear under transverse loading. Both arise when transverse forces are displaced from the shear centre.

针灸推拿疗法对运动性免疫抑制“Open Window”期影响的研究进展

分析大强度运动对机体免疫系统的影响,探讨针灸推拿疗法治疗免疫抑制的机制,并总结针灸治疗运动性免疫抑制的研究现状,认为目前的研究分散,治疗方法、部位单一,并提出今后应深入、系统化研究作用机制,加强多种中医方法联合干预及多穴位组合研究,加强针灸推拿疗法在运动医学领域的运用,以期促进针灸推拿疗法更好地运用于运动医学临床。

The Application of“Broken Window Theory”to College's Daily Management

The daily management of college on the one hand is to constrain the action of students to achieve the maintenance of school's order and on the other hand is to help students develop good habits and remold certain concepts of laws, morality and discipline to finally achieve the goal of education. This paper employed a famous theory of management, that is, the"broken window theory"in the research and finally concluded that the application of"broken window theory"in the daily management of colleges can immediately and effectively prevent some of students'bad behaviors and habits from being spread.

The Application of "Broken Window Theory" to College's Daily Management

The daily management of college on the one hand is to constrain the action of students to achieve the maintenance of school's order and on the other hand is to help students develop good habits and remold certain concepts of laws,morality and discipline to finally achieve the goal of education.This paper employed a famous theory of management,that is,the"broken win dow theory"in the research and finally concluded that the application of"broken window theory"in the daily management of colleges can immediately and effectively prevent some of students'bad behaviors and habits from being spread.

Effect of Window Opening Percentage on the Air Flow Rate of Wind-Driven Natural Ventilation Rooms

According to the investigations of window opening percentage (WOP) of Shanghai in 2011, the WOP varies significantly from season to season and thus affects the air flow rate of natural ventilation rooms. A three-dimensional computional fluid dynamic(CFD) model was applied to simulating the flow fields in a street canyon under different wind speed and WOP. The numerical simulations show that WOP has a significant influence on the static pressure distribution of the downwind building. Therefore, a correction factor k can be used for calculating the flow rate of wind-driven natural ventilation. The results show that k ranges from 0.43 to 0.49 when WOP is 4.44%; when WOP increases to 9.78%, the correction factor k lies in 0.32 and 0.36.

LabVIEW与Open Windows示波器 开创测试测量新理念——“2004设计、验证及测试论坛”侧记

工欲善其事，必先利其器，对于电子设计工程师和检修技术人员来说，一套好的测量分析工具能起到事半功倍的效果。8月18日，Tektronix(泰克）公司和National Instruments(美国国家仪器简称NI）公司共同在西安举办了“2004设计、验证及测试论坛”，这是此次巡回论坛中国大陆的第五站，200多名电子工程师和高校师生参加了此次论坛，会上来自泰克和NI的工程师，分别就新型Open Windows示波器和LabVIEW7.1功能进行了演讲，并现场结合两种产品的应用作了演示。

INVESTIGATION ON KANE DYNAMIC EQUATIONSBASED ON SCREW THEORY FOR OPEN-CHAIN MANIPULATORS

First,screw theory,product of exponential formulas and Jacobian matrix are introduced.Then definitions are given about active force wrench,inertial force wrench,partial velocity twist,generalized active force,and generalized inertial force according to screw theory.After that Kane dynamic equations based on screw theory for open-chain manipulators have been derived. Later on how to compute the partial velocity twist by geometrical method is illustrated. Finally the correctness of conclusions is verified by example.

OPTIMIZATION OF CUT-OFF GRADE IN OPEN-PIT BASED ON CONTROL THEORY

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Inheritance and Innovation of Xi Jinping’s Theory and Practice of Opening Up

Adherence to China’s fundamental national policy of opening up is the only means of developing socialism that incorporates Chinese characteristics.General Secretary Xi Jinping has proposed the construction of a global community with a shared future,explaining the conceptual significance of engaging with the outside world.He has emphasized the importance of following the path of peaceful development and abiding by a mutually beneficial win-win strategy to unlock the country.He has postulated the Belt and Road Initiative and sought international cooperation,laying a robust material foundation to promote increasingly accessible relations between China and other nations worldwide.He has further illuminated the practical value of opening up.Xi Jinping’s conception of opening up represents the inheritance and innovation of a theory of world history and the conceptual and functional significance of unlocking the nation in the manner of Marx,Engels,and Deng Xiaoping.China’s strategy of opening up in the new era is marked by the idea of harmony but not uniformity.This policy was founded on innovation and development,based on China’s achievements through 40 years of reform.

Evaluation of the maintenance window scheme using fuzzy soft set theory

The maintenance window scheme(MWS) is one of the most important railway transportation organizational plans and plays an important role in ensuring railway operational safety. However, MWS setting is a very complicated process, and most countries currently do so with the help of a computer-aided decision system. In general, a decision system can generate multiple alternatives for MWS within an acceptable time. Therefore, how to choose the best option from the alternatives is a vital decision. This paper presents a novel framework for MWS evaluation based on the Chinese railway system. Specifically, the requirements of each department related to MWS setting are analysed, and we construct an evaluation indicator system for MWS based on the preferences of different departments. Then, we apply the fuzzy soft set theory to MWS evaluation, a method that not only effectively deals with evaluation of uncertain information, but also gives flexibility for experts to input their subjective judgment.Additionally, using the ‘‘AND’’ operation of soft set theory allows combing evaluation information from multiple evaluators to give comprehensive results. Finally, a case study illustrates the proposed framework, showing that the proposed evaluation indicator system and evaluation method are effective and practical.

Solving open vehicle problem with time window by hybrid column generation algorithm

This paper addresses the open vehicle routing problem with time window(OVRPTW), where each vehicle does not need to return to the depot after completing the delivery task.The optimization objective is to minimize the total distance. This problem exists widely in real-life logistics distribution process.We propose a hybrid column generation algorithm(HCGA) for the OVRPTW, embedding both exact algorithm and metaheuristic. In HCGA, a label setting algorithm and an intelligent algorithm are designed to select columns from small and large subproblems, respectively. Moreover, a branch strategy is devised to generate the final feasible solution for the OVRPTW. The computational results show that the proposed algorithm has faster speed and can obtain the approximate optimal solution of the problem with 100 customers in a reasonable time.

Thermal Indices Influence on Occupants’ Window Opening Behaviours: A Case of Ibadan and Ogbomoso, Oyo State, Nigeria

Window opening operations are considered as one of the significant way of regulating indoor climate and maintaining thermal comfort in buildings,even when alternative active devices such as fans and air conditioners are available.This study investigates responses of occupants of the traditional core areas of Ibadan and Ogbomoso to thermal comfort conditions(thermal stress)through window opening behaviours.Climatic data of the two cities were subjected to Evans scale to predict their day and night thermal stress and questionnaires were administered to know how occupants respond to changing thermal conditions through window opening behaviours.Descriptive and inferential statistics were used in analysing the data.The study found the morning periods to be the most comfortable,the afternoon periods offer the most hot discomfort condition and cold discomfort is mostly experienced in the evening periods in both cities.Findings revealed that majority of occupants in both cities prefer to keep their windows opened in the morning and afternoon periods and an increase was observed in the numbers of occupants who prefer to keep their windows closed in the evening periods.This is an indication that building occupants in both cities actively respond to thermal stress using window opening operations.Results obtained from chi square analysis concluded that there is a significant relationship between occupants’window opening behaviour and thermal conditions at different periods of the day in both cities.Recommendations were given on how to improve on window opening systems in the future.

The Change and Constancy of “Equality Issue” in Human Rights Theory Research During the 40 Years of Reform and Opening-up

In 1978, academia broke through the theoretical forbidden zone with the slogan of "equality before the law" and initiated a great discussion on some important legal issues including legal equality. During the past 40 years since the reform and opening-up, the relevant research has changed from the ideological contention deeply influenced by class discourse to the abstract theoretical research where class discourse has been fading away, and then turn to the technical and concrete practical research. This "change" is clearly visible and, to a certain extent, reveals the track of the development of human rights theory. However, there is "constancy" in "change". "Constancy" not only lies in the study of legislative equality throughout the past 40 years, but also embodies the inherent logic of theoretical research in response to social development and changes in the times.

基于滑窗OPTICS算法和DATA-SSI算法的桥梁模态参数智能化识别

针对现有基于数据驱动的随机子空间(data-driven stochastic subspace identification,DATA-SSI)算法存在的不足,无法实现稳定图中真假模态的智能化筛选,提出了一种新的模态参数智能化识别算法。首先通过引入滑窗技术来实现对输入信号的合理划分,以避免虚假模态和模态遗漏现象的出现;其次通过引入OPTICS(ordering points to identify the clustering structure)密度聚类算法实现稳定图中真实模态的智能化筛选,最后将所提算法运用于某实际大型斜拉桥主梁结构的频率和模态振型识别过程中。结果表明,所提改进算法识别的频率值结果与理论值(MIDAS有限元结果)以及实际值(现场动力特性实测结果)间的误差均在5%以内,且识别的模态振型图与理论模态振型图具有很高的相似性。

中国特色社会主义市场经济法治理论的理论根源、演进脉络与经验启示

改革开放以来,中国共产党人坚持以马克思主义理论为指导,立足改革开放和社会主义现代化建设新时期、新时代中国特色社会主义经济发展状况和法治建设实践,领导市场经济法治建设经历了十一届三中全会以后的创立阶段、十三届四中全会以后的发展阶段、十六大以后的完善阶段和十八大以来的新发展阶段,在不同发展阶段的具体实际之下丰富和发展了马克思主义法治理论关于法治对经济基础的保障功能和经济基础对作为上层建筑的法治的推动作用的理论论断,对新时代法治经济建设具有重要的理论价值和实践意义。

基于DHMM-ESUM的露天矿运输系统车铲比优化研究

在露天矿生产中,如何利用现有的资源条件对电铲与卡车进行合理配比,充分发挥设备的效率,是提高矿山企业生产效益的关键。以安家岭露天矿生产系统收集的数据为基础,首先运用排队理论构建以电铲为采掘中心,卡车为运输工具的闭合排队网络模型,将运输系统分为4个排队子系统,分析各项服务时间的概率分布;基于离散隐马尔可夫模型(discrete hidden Markov model,DHMM)与拓展求和(extended summation,ESUM)算法分析系统作业性能,获取电铲设备的运行状态和班次生产能力。然后,应用蒙特卡洛法建立随机动态规划模型,以产量期望值最大化为目标对露天矿的车铲比进行优化。最后,对生产系统进行仿真建模分析,结果验证了基于DHMM-ESUM对车铲比进行优化的有效性和准确性。

数字政府背景下政府开放数据创新应用提升路径研究--基于31个省域应用数据的模糊集定性比较分析

政府开放数据是典型的创新扩散模型,受到国家政治制度和府际关系的深刻影响,解释政府开放数据创新应用的提升路径需要以府际关系和制度压力规制为逻辑起点,构建开放数据创新扩散模型,应用模糊集定性比较分析对我国31个省域政府开放数据应用创新扩散规律进行总结。研究发现上级压力规制、公众压力、府际竞争和府际学习因素组合是最典型的政府开放数据应用创新扩散模型,对开放数据创新应用和数据价值实现有更好的促进作用。除此之外,对于经济较发达且对上级财政依赖较小的地区可以通过政策压力、府际竞争和府际学习提升数据开放创新活动;而在经济欠发达且对上级财政依赖较大的地区,上级压力对开放数据应用扩散作用更突出。

企业前瞻性环保导向驱动开放式绿色创新效能提升路径研究——基于供应商资源编排视角

供应商参与制造企业开放式绿色创新是制造企业实施开放式绿色创新的常见形态。从供应商资源编排视角,探究制造企业前瞻性环保导向驱动开放式绿色创新效能提升路径。基于231个制造商—供应商配对样本数据的实证研究表明:供应商作为资源提供者参与以及供应商作为共同创造者参与,是制造企业在开放式绿色创新中编排供应商参与角色的两种形式,能够在前瞻性环保导向与开放式绿色创新效能之间发挥不完全中介作用;制造商—供应商不对称依赖正向调节供应商作为资源提供者参与的中介作用,但对供应商作为共同创造者参与的中介作用发挥负向调节作用;两种供应商参与角色编排形式的中介效应比重会随着双方不对称依赖程度变化而改变。结论不仅能够丰富开放式绿色创新研究,而且可为中国制造企业贯彻落实创新驱动绿色转型发展方针提供理论参考。

多中心半开放式同时送取货的车辆路径问题研究

研究了带软时间窗约束的多配送中心半开放式同时送取货的车辆路径问题,所有客户点均存在送取两种需求,并采用同一辆车同时提供送取服务.车辆服务完路线上所有客户点后,不一定返回起始配送中心,可就近返回任意配送中心.在此条件下,构建了以车辆运输成本、车辆租赁成本、时间窗惩罚成本等总和最小为目标的优化模型.根据问题特征,设计了自适应精英遗传算法对该问题进行求解,引入自适应机制,根据个体的适应度动态地调节交叉和变异概率,采用精英保留策略将优秀个体进行遗传保留,不仅增强了算法的全局优化能力,还均衡了算法的局部搜索能力.通过案例仿真,验证了模型和算法的可行性和有效性.研究成果丰富了车辆路径问题的相关研究,为物流企业提供了一种决策参考.