离子色谱法测定大气总悬浮颗粒物中的F~-,Cl~-,NO_3~-及SO_4~(2-)

 介绍了用离子色谱法测定大气总悬浮颗粒物（TSP）中的F~－,Cl~－,NO~-_3及SO~2-_4。对过氯乙烯采样滤膜用去离子水（DIH_2O）作为提取液进行超声波提取。方法的平均回收率分别为F~-98．7％,Cl~-103％,NO~-_3101％及SO~2-_499．8％,相对标准偏差为F~－0．29％,Cl~－0．32％,NO~-_30．30％及SO~2-_40．25％。     

A novel bioreactor operating under non-isothermal conditions

Activity of the β-galactosidase enzyme, immobilized on a nylon membrane, has been assessed in a bioreactor in which the two half-cells, maintained at different temperatures, are filled with substrate solutions coming from and ending in the same reservoir. The experimental results demonstrate that the presence of temperature gradients across the catalytic membrane increases the efficiency of the bioreactor, making it suitable for practical applications. The solution filling the apparatus during the treatment remains unchanged in all components, different from the substrate and its products, while the biocatalyst works at rates higher than those corresponding to comparable isothermal conditions. The production times in biotechnological processes employing immobilized enzymes are reduced proportionally with respect to the applied transmembrane temperature differences.     

考虑刚度折减的多棱锥型套接钢管杆挠度及附加弯矩研究

多棱锥型钢管杆广泛应用于城市周边输电线路,管与管之间通常采用法兰连接,套接连接应用不大。鉴于目前对于多棱锥型套接钢管杆挠度的计算方法研究相对较少,本文根据梁的挠曲线微分方程理论,结合套接节点刚度折减,推导出在常见荷载(弯矩M、水平力P和均布力q)作用下多棱锥型套接钢管杆挠度和附加弯矩的计算方法。最后,选取典型套接钢管杆进行对比分析,得出了一些重要结论。本文对套接钢管杆挠度计算进行细致的研究,可作为输电线路钢管杆套接连接设计的参考     

浙江省“五水共治”决策前后水环境安全评估预警

水环境安全不仅是生态环境问题,更是直接关系区域经济发展和政治稳定的问题.基于"压力-状态-响应"模型和"五水共治"决策构建评估指标体系,应用层次分析评估方法,对浙江省治水前后水环境安全进行评估与预警.结果显示:自2014年治水工作开展以来,浙江省水环境安全趋于好转,安全指数呈上升趋势,2014年、2015年较2013年分别提高了7.38%和16.85%,水环境安全从预警状态转为较安全状态.按照"五水共治"分阶段规划要求,浙江省2017和2020年水环境安全度值分别达到0.754 5和0.798 9,较2015年分别提高7.63%和13.97%,水环境将维持在较安全状态,接近于安全状态的临界值,水环境的明显改善反映了浙江省"五水共治"工作的成效.结合具体指标分析可知,单位GDP废水排放量大、主要污染物排放负荷高、环境污染治理投资总额占GDP比重低等因素是水环境安全的主要胁迫因子,浙江省应优化水资源配置、加快产业结构调整与转型升级、加大环保投入,以降低水资源的环境风险.     

浙江遂昌好川墓地五件出土绿松石珠的科技分析

目前现代测试技术发展较快,为古代玉器的加工技术、产源研究提供了无损研究手段.利用红外光谱和能量色散X射线荧光光谱技术(EDXRF),对浙江省遂昌县好川墓地中M52号墓出土的五件绿松石珠进行无损测试,期望判断其可能的产地来源.红外谱学特征显示,3468和3514 cm-1处可见红外吸收锐谱带,是由于ν(O H)伸缩振动所...     

同位素稀释等离子体质谱法测定地质样品中痕量硼

建立了同位素稀释等离子体质谱法（ID—ICP—MS）测定地质样品中痕量硼的方法。采用减压排空色谱柱分离样品中的大量基体,以减少基体效应的影响,具有试剂用量少、分离速度快、效果好等特点。对两个标准物质GSD-4和GSD-8的测定结果表明,其与参考值吻合得较好,相对偏差均小于6％。3个不同样品的测定结果表明,该方法具有较好的准确度和精密度。     

CFD modeling of particle charging and collection in electrostatic precipitators

A CFD model was developed to describe the particle laden gas flow through an ESP, particle charging and collection. The corona discharge was modeled using the open source software OpenFOAM to solve the Poison and charge conservation equations, and results were entered using user-defined field functions in the commercial CFD software STAR-CCM+. The gas flow, EHD flow, particle charging and dynamics were modeled using STAR-CCM+. The developed CFD model allows for direct solution of the drift and diffusional flux of gas ions. The influence of the various ESP dimensions, operating parameters and ash properties on the collection efficiency are reported.     

稀薄气体动力学矩方法研究综述

临近空间位于航天器入轨与返回的必经区域, 也是临近空间高超声速飞行器长航时飞行空域, 空间环境的特殊性决定了飞行器在穿越时必须考虑稀薄大气环境对飞行器气动力防隔热通讯及控制的影响.Boltzmann方程作为描述气体分子速度分布函数演化规律的微分-积分形式, 在一定条件下能够描述从自由分子流到连续流全流域流动现象.作为Boltzmann方程的宏观表达形式, 矩方程这一经典流体力学方程形式涵盖了Euler方程N-S方程Burnett方程super-Burnett方程及近年来发展的广义流体力学方程——非线性本构关系模型等.由于成熟的CFD数值计算理论及有限矩方程较高的计算效率, 滑移过渡流矩方法相比粒子仿真与Boltzmann模型方程方法具有十分显著的优势和巨大的工程应用潜力.因此, 对近年来传统及新型矩方法研究所取得的进展进行归纳总结, 并针对关键科学问题开展理论与数值计算方法研究, 具有十分重要的理论与工程应用价值.      

Superconducting Properties and Absence of Time Reversal Symmetry Breaking in the Noncentrosymmetric Superconducting Compounds TaxRe1-x(0.1≤x≤0.25)

Unconventional superconductivity,in particular,in noncentrosymmetric systems,has been a long-sought topic in condensed matter physics.Recently,Re-based superconductors have attracted great attention owing to the potential time-reversal symmetry breaking in their superconducting states.We report the superconducting properties of noncentrosymmetric compounds Ta_xRe_1-x with 0.1 ≤x≤0.25,and find that the superconducting transition temperature reaches a maximum of ~8 K at the optimal level x=0.15.Nevertheless,muon-spin rotation and relaxation measurements reveal no time-reversal symmetry breaking existing in its superconducting state,which is in sharp contrast to both centrosymmetric Re metal and many other noncentrosymmetric Re-based superconductors.