Mathematical modeling and characteristics analysis for the nutation gear drive based on error parameters

We focused on the mathematical modeling and characteristics analysis for the nutation drive based on error parameters. The crown gear tooth profile equation was introduced according to the national standard double circular arc tooth profile and based on the equal tooth strength principle. The nutation drive meshing coordinate system was set up by introducing the cone vertex error, tilt error, nutation angle error and spiral angle error. The tooth profile equations of the double circular arc external and internal spiral bevel gears were further obtained based on the crown gear tooth profile equation concerning above mentioned error parameters. The influences of the nutation gear reducer tooth contact conditions were analyzed with the gear tilt error and axial misalignment error. Finally, the correctness of the theoretical analysis was verified by the contact spot test.     

《朱克曼》三部曲的叙述学阐释

从叙述学角度分析,菲利普·罗斯80年代的《被缚的朱克曼》三部曲的叙述结构存在着一个独特的循环式的特点。三部曲的各个部分之间从叙述时间、叙述视角和叙述对象上看都存在着一定的联系,从而证明,在叙述的内部机制上,该三部曲是一个有机的整体。     

Exact solution of an external circular crack in a piezoelectric solid subjected to shear loading

A three-dimensional, exact analysis is presented in this paper for the problem of an external circular crack in a transversely isotropic piezoelectric medium subjected to arbitrary antisymmetric shear loading. A recently proposed general solution of three-dimensional piezoelectricity is employed. It is shown that four quasi harmonic functions involved in the general solution can be respresented by just one complex potential. Previous results in potential theory are then used to obtain the exact solution of the problem. For point shear loading, Green’s functions for the elastoelectric field are derived in terms of elementary functions. Project supported by Scientific Research Foundation for Returned Overseas Chinese Scholars, State Education Ministry and partly by National Natural Science Foundation of China (NSFC) (10002016).     

非连续单调算子的不动点定理

在Banach空间E中，利用正规锥的性质及压缩原理，通过上下解方法构造出一组迭代序列。所得序列均为Banach空间E中的柯西序列，再利用E的完备性，从而得到非连续单调算子的最大与最小不动点。改进推广了某些已有的结果．     

Reimagining the Wheel: Using Circular Calendars for Planning in Law School Libraries

This essay proposes using a wheel or circular calendar to identify and document the events and projects of an academic law school year, both in and out of the classroom. The idea of harnessing the natural cyclical process of law school for library planning comes from concept mapping, which can conceptualize an issue by using a variety of mapping strategies to organize and show the relationships between pieces of information and a central concept. Using a wheel graphic to visualize a process can facilitate project management and aid in teaching legal research strategy.     

浅论企业参与循环经济——以合同管理为切入点

转变经济发展模式,大力推进循环经济,是建设资源节约型社会的题中应有之义。企业在循环经济中扮演着不同的角色：一方面,企业一如既往地作为市场经济的基本细胞发挥不可或缺、不可替代的作用,没有企业参与的循环经济是不完整的,也是不可能的;另一方面,企业又同时一如既往地实践着其经济人的天性,面对循环经济建立过程中的各种代价,企业的“利益近视”的特性决定了企业必定想方设法逃避承担各种负担。如何对企业的参与提供一种促动和鼓励的机制,既实现环境保护的公共目标,又推动企业自觉主动地参与循环经济,节省执法和司法成本,是循环经济建设的重大问题。合同以其更为柔软的制度刚性和更为灵活的制度安排,能够为企业与政府之间搭起对话和和谐共进的平台。本文以企业参与循环经济为着眼点,深入到环境合同制度的核心,解剖环境合同在企业参与循环经济中的重要意义、制度现状和存在问题,为完善相关制度提供建议。     

A''da''m-自补有向循环图

A'da'm自补有向循环图是循环图中很独特的一类,有很好应用前景,特别在网络时代的今天,A'da'm自补有向循环图更具它独特的魅力。但是,A'da'm自补有向循环图一般结构很难给出,本文给出了三类自补有向循环图。     

杆摆中的内力分析

对杆摆中的内力、法向内力矩及切向内力的功深入的分析讨论,从而深化对“刚体”及“细杆”概念和刚体的内力的理解,并纠正一些文献中的错误。     

集值映射的连续锥选择及其存在性

引入集值映射的锥选择及连续锥选择概念,给出了集值映射连续锥选择的存在性条件以及锥下半连续集值映射的逼近连续锥选择的存在性条件。     

中国旅游循环经济研究动态分析

通过对4年来中国各期刊上发表的有关旅游循环经济68篇文献进行分析讨论,从旅游循环经济的基本内涵与相关概念、旅游循环经济研究的意义和作用、发展战略及对策措施、运行体系及运行模式构建、在区域旅游发展中的应用、在旅游企业中的应用、科技支撑体系和其他方面对旅游循环经济的研究内容进行了研究,认为中国有关旅游循环经济的研究进展迅速,数量不断增加,成果颇丰;研究方法以描述性为主,建构模式等方法使用较少;旅游循环经济的研究随时间变化而各有侧重;未来有关旅游循环经济的研究分支将更加细化,研究方法将更加准确、多样.最后分析了旅游循环经济的研究趋势.