区域低碳协同发展评价:京津冀、长三角和珠三角城市群的比较分析

京津冀、长三角和珠三角城市群是中国经济高度发达、最具发展潜力的区域,在低碳发展方面起到引领作用.从经济、资源、环境和绩效的角度构建区域低碳协同发展评价指标体系,采用结合逼近理想解的TOPSIS方法、灰色关联理论和距离协同模型,利用2005~2014年三大城市群50个城市数据实证分析了三大城市群的低碳协同发展程度.结果表明,三大城市群低碳协同发展度整体上呈现上升趋势,其低碳协同程度从高到底依次为长三角、珠三角和京津冀城市群.     

Divided-difference equation and three-term recurrence relations of some systems of bivariate q-orthogonal polynomials

Partial divided-difference equations and three-term recurrence relations satisfied by the bivariate Askey–Wilson and the bivariate q-Racah polynomials are computed in this work. By using limiting processes, partial divided (or q)-difference equations and three-term recurrence relations are also provided for each of the following families of orthogonal polynomials: the bivariate continuous dual q-Hahn, the bivariate Al-Salam-Chihara, the bivariate continuous q-Hahn, the bivariate q-Hahn, the bivariate dual q-Hahn, the bivariate q-Krawtchouk, the bivariate q-Meixner, and the bivariate q-Charlier polynomials.     

Three‐dimensional printed magnetophoretic system for the continuous flow separation of avian influenza H5N1 viruses

As a result of the low concentration of avian influenza viruses in samples for routine screening, the separation and concentration of these viruses are vital for their sensitive detection. We present a novel three‐dimensional printed magnetophoretic system for the continuous flow separation of the viruses using aptamer‐modified magnetic nanoparticles, a magnetophoretic chip, a magnetic field, and a fluidic controller. The magnetic field was designed based on finite element magnetic simulation and developed using neodymium magnets with a maximum intensity of 0.65 T and a gradient of 32 T/m for dragging the nanoparticle–virus complexes. The magnetophoretic chip was designed by SOLIDWORKS and fabricated by a three‐dimensional printer with a magnetophoretic channel for the continuous flow separation of the viruses using phosphate‐buffered saline as carrier flow. The fluidic controller was developed using a microcontroller and peristaltic pumps to inject the carrier flow and the viruses. The trajectory of the virus–nanoparticle complexes was simulated using COMSOL for optimization of the carrier flow and the magnetic field, respectively. The results showed that the H5N1 viruses could be captured, separated, and concentrated using the proposed magnetophoretic system with the separation efficiency up to 88% in a continuous flow separation time of 2 min for a sample volume of 200 μL.     

A three‐dimensional cadmium coordination polymer based on 1,4‐bis(1,2,4‐triazol‐1‐yl)but‐2‐ene and benzene‐1,3,5‐tricarboxylic acid

The Cd^II three‐dimensional coordination poly[[[μ₄‐1,4‐bis(1,2,4‐triazol‐1‐yl)but‐2‐ene]bis(μ₃‐5‐carboxybenzene‐1,3‐dicarboxylato)dicadmium(II)] dihydrate], {[Cd₂(C₉H₄O₆)₂(C₈H₁₀N₆)]·2H₂O}_n , (I), has been synthesized by the hydrothermal reaction of Cd(NO₃)₂·4H₂O, benzene‐1,3,5‐tricarboxylic acid (1,3,5‐H₃BTC) and 1,4‐bis(1,2,4‐triazol‐1‐yl)but‐2‐ene (1,4‐btbe). The IR spectrum suggests the presence of protonated carboxylic acid, deprotonated carboxylate and triazolyl groups. The purity of the bulk sample was confirmed by elemental analysis and X‐ray powder diffraction. Single‐crystal X‐ray diffraction analysis reveals that the Cd^II ions adopt a five‐coordinated distorted trigonal–bipyramidal geometry, coordinated by three O atoms from three different 1,3,5‐HBTC²⁻ ligands and two N atoms from two different 1,4‐btbe ligands; the latter are situated on centres of inversion. The Cd^II centres are bridged by 1,3,5‐HBTC²⁻ and 1,4‐btbe ligands into an overall three‐dimensional framework. When the Cd^II centres and the tetradentate 1,4‐btbe ligands are regarded as nodes, the three‐dimensional topology can be simplified as a binodal 4,6‐connected network. Thermogravimetric analysis confirms the presence of lattice water in (I). Photoluminescence studies imply that the emission of (I) may be ascribed to intraligand fluorescence.     

接触问题的非线性互补－接触柔度法

基于势能互补原理，不引入额外松弛变量，对库仑摩擦定律未做预先线性化近似，提出了三维弹性摩擦接触问题的非线性互补－接触柔度法，收敛性和收敛速率得到了严格理论保证。数值实验结果表明方法可靠、有效、低存储量、高精度     

光纤陀螺随机游走系数的分析研究

分析了产生随机游走误差的机理,分别采用有关标准和Allan方差进行了随机游走系数的分析和计算。结果表明:随机游走系数是衡量光纤陀螺噪声水平的重要指标,其值的大小体现了陀螺的极限精度。采用Allan方法表述光纤陀螺的静态指标,物理概念清晰,方法简便。     

惯性系统三轴综合测试转台总体设计若干问题的探讨

本文从框架形式、总体布局、轴承的种类和布置方式等方面，讨论了惯性系统三轴综合测试转台总体设计中的若干问题，从设计、制造和使用等方面阐述了各种总体布局形式的优缺点，并提出了自己的相应看法，最后讨论了目前惯导测试设备研究领域需要研究的关键技术。     

三轴转台轴系相交度误差测量方法的研究

—本文提出了一种新的轴系相交度误差测试方法。该方法不存在测量基准安装偏心问题，更适合于大型转台轴系相交度误差的测量     

在PC机上实现开环光纤陀螺数字解调的方法研究

本介绍了开环光纤陀螺输出信号数字调解在通用PC机上的实现方法,合理地选取了相关参数,为研制采用DSP微处理器的数字式光纤陀螺提供良好的技术基础。     

应变花埋丝技术在齿科修复学上的应用研究

本文通过采用三维应变花埋丝技术，对固定义齿修复的牙周应力分布进行了定量分析研究，绘制了修复前后牙周的应力分布随基牙倾斜角度的变化曲线，测得下颌第二磨牙用作固定桥基牙时近中倾斜的最大角度为７０度，从生物力学的角度证明，固定义齿修复有利于倾斜基牙牙周组织健康、为齿科临床上广泛开展倾斜基牙固定修复提供了依据。