DEA方法在城市社区建设绩效评价中的应用

本在运用主成分分析法对评价指标降维的基础上，应用数据包络分析方法对城市社区建设绩效进行了评价，找出了非有效决策单元及今后改进工作的方向，为有关部门提供管理信息和决策依据。     

Research on Classification of Development Level in China＇s Postal Communication

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化学建材概况及发展前景

本文较系统地论述了化学建材的优越性能,国内现状及在我国的发展前景。     

Constructions for planar point processes using concentric circles

Some point processes are obtained by generalising the well-known construction for a two-dimensional Poisson process which locates an event on each of a sequence of concentric circles in a particular way. The constructions considered here have, in general, a random number of events on each circle. Under certain sufficient conditions, the constructed processes are asymptotically Poisson, far from the origin. The obvious regularity in the structure of these processes can be removed at least superficially, by displacing the events independently off the concentric circles.     

机器人工程专业课程建设的思考与实践

我国自2015年开始机器人工程专业本科教育,目前开设机器人工程专业的高校已达301个,机器人工程专业教育呈现出快速发展的态势。与此同时,机器人工程专业在专业内涵、知识体系和课程体系建设上还存在一些矛盾和模糊之处,本文结合东北大学机器人工程专业建设、课程体系和机器人学课程建设等方面情况进行梳理,给出了机器人工程专业课程体系及机器人学课程建设的相关建议。     

Large deviations for the 2D ising model: A lower bound without cluster expansions

We show that a lower large-deviation bound for the block-spin magnetization in the 2D Ising model can be pushed all the way forward toward its correct Wulff value for all >_c.     

Surface tension,step free energy,and facets in the equilibrium crystal

Some aspects of the microscopic theory of interfaces in classical lattice systems are developed. The problem of the appearance of facets in the (Wulff) equilibrium crystal shape is discussed, together with its relation to the discontinuities of the derivatives of the surface tension (n) (with respect to the components of the surface normaln) and the role of the step free energy ^step(m) (associated with a step orthogonal tom on a rigid interface). Among the results are, in the case of the Ising model at low enough temperatures, the existence of ^step(m) in the thermodynamic limit, the expression of this quantity by means of a convergent cluster expansion, and the fact that 2^step(m) is equal to the value of the jump of the derivative / (when varies) at the point =0 [withn=(m ₁ sin ,m ₂ sin , cos )]. Finally, using this fact, it is shown that the facet shape is determined by the function ^step(m).     

基于射线追踪传播模型实现5G室内分布系统仿真的研究

室内分布系统的建设已经成为解决深度覆盖问题的有效手段。目前,5G网络建设发展迅速,室内分布系统建设呈爆炸式增长,室内分布系统的网络规划和设计需要更加精细化。如何有效评估室内信号覆盖效果,成为当前室内分布系统规划设计的重要任务之一。以某大楼为研究对象,用射线追踪传播模型仿真计算覆盖性能指标,并将结果与现有网络的路测数据进行对比。经过校正相关模型参数实现仿真与实测一致,论证仿真为网络部署提供了参考依据。     

Ramberg-Bcklund反应在功能有机分子合成中的应用

碳碳双键广泛地存在于功能有机分子中,其构筑在合成化学中具有极其重要的意义.Ramberg-B?cklund反应是构筑碳碳双键的重要方法之一,其关键步骤是砜在碱性条件下进行1,3-消除,得到环状砜,然后重排除去SO2形成双键.该方法具有良好的立体选择性,底物在不同的反应条件下得到不同构型的产物,因而可以应用于合成许多功能有机分子,具有很好的应用前景.结合自己的研究工作对Ramberg-B?cklund反应在功能有机分子合成中的应用进行了较为系统的总结,也对Ramberg-B?cklund反应的拓展进行了简要介绍.     

乙酰丙酮分光光度法测定室内空气中甲醛的研究

甲醛是室内空气中主要的污染物之一,对其进行准确、快速的测定尤其重要。对现有测定室内空气中甲醛的乙酰丙酮分光光度法作了改进,缩短了分析时间,显著降低检出限至0.0056μg/mL。