Theoretical investigation on cyclic reciprocal derivative chronopotentiometry: Kinetic study of totally irreversible electrode processes

Theoretical expressions and mathematical analysis in cyclic reciprocal derivative chronopotentiometry (CRDCP) are presented for totally irreversible electrode processes corresponding to the application of symmetrical and unsymmetrical programmed currents. For two successive unsymmetrical programmed currents, the effect of the currents ratio b (b = |I₂(t)/I₁(t)|) on the (dt/dE)–E curves is discussed. The electrochemical behavior of totally irreversible electrode processes has been studied corresponding to the application of the unique unsymmetrical programmed Φ^m(I₀) proposed recently. CRDCP characteristic parameters obtained for totally irreversible electrode processes are different from those of reversible electrode processes. Therefore, a comparison of CRDCP between both mechanisms is presented. Based on the mathematical derivation, alternative methods for kinetic measuring are described. It is prospected that CRDCP is convenient and applicable for studying the reversibility of the electrode processes in form of CRDCP characteristic parameters.     

蒸发工段电解液预热工艺改造总结

针对蒸发工段电解液预热效果不理想，从工艺、设备两方面入手，对电解液预热工艺进行了改造，并对经济效益进行了分析。     

季戊四醇合成技术进展与市场分析

介绍了季戊四醇国内外生产现状，市场需求及发展趋势，重点介绍季戊四醇分离技术进展，分析我国国外先进水平存在的差距，并提出一些发展建议。     

溶胶-凝胶法CaO-P2O5-SiO2系生物玻璃的制备及机理探讨

以正硅酸乙酯[Si(OC2H5)4]、四水硝酸钙[Ca(NO3)2*4H2O]等作为前驱体,采用溶胶-凝胶工艺制备CaO-P2O5-SiO2系生物活性玻璃,把制备的样品放在模拟体液中浸泡一段时间后取出,以X-射线衍射、红外光谱等手段对其作物相分析,确定在玻璃的表面有羟基磷灰石相生成,同时对其形成机理做了进一步探讨.     

可持续发展的挑战与过程系统工程的机遇

可持续系统是一种全局性的系统工程,按规模大小可分为4个层次:全球性的系统,地理边界为特征的系统,局部的或分布的业务系统,可持续发展技术。本文从这4个层次上探讨了可持续发展带来的挑战。今后任何工业过程,包括化学工程,不可能再作为一个孤立的对象来对待,必须考虑工业过程、人类社会及生态环境的交互作用。过程系统工程处于独特位置,最适合把各学科的成果汇集到一个系统工程框架中,来应对这种挑战。     

230 kt/a烟气制酸系统的运行及改造情况

介绍230kt／a诺兰达炉铜冶炼烟气制酸装置的运行及技术改造。装置采用稀酸洗净化、ⅣⅠ-Ⅲ Ⅱ“3 1”两转两吸工艺流程，运行中发现板式酸冷却器堵塞、电除雾器腐蚀、气体换热器积酸和漏气等现象，通过更换为阳极保护管壳式酸冷却器、在电除雾器前增设湍冲洗涤器、调整换热管的喷铝成分等措施，收到良好的效果。     

Performance analysis for range expansion in heterogeneous networks

In this paper, the uplink and downlink performance of a two-tier heterogeneous network （HetNet） with range expansion （RE） is analyzed. Different from previous works, base stations （BSs） are modeled as a spatial Poisson point process. This model can not only capture the irregularity of the BS deployment but also lead to closed form expressions. With the analytical results, the impacts of several key parameters on the coverage and throughput performance are investigated. Our results justifies the effectiveness of RE and Pico deployment. Based on our analyses, certain attention should be made on the RE design to balance the uplink and downlink performance. Our analyses are corroborated by simulations and can thus serve as a flexible and quick guidance for system design without complicated and time-consuming system-level platform construction and simulation.     

和利时MACS V控制系统在450t/h循环流化床锅炉中的应用

以浙江嘉化能源化工股份有限公司兴港热电厂背压热电机组节能技改项目（6#锅炉、汽机）为背景,结合循环流化床锅炉的运行特点及控制要求,介绍和利时MACSV系列分散控制系统的应用及实现的功能.     

加工条件对PP/芳纶复合材料横向拉伸性能的影响

对单向聚丙烯／芳纶纤维复合材料的横向拉伸性能进行了研究，讨论了压制时间、成型温度、成型压力，以及芳纶纤维的体积含量等对复合材料体系横向拉伸强度的影响。结果发现，随着压制时间、成型温度的增加，复合材料体系的横向拉伸强度提高；随成型压力的提高，复合材料的横向拉伸强度先升后降。此外，复合材料的横向拉伸强度随着芳烃纤维体积含量的增加而大幅度降低。     

ON THE EXISTENCE OF STATIONARY THRESHOLD AUTOREGRESSIVE MOVING-AVERAGE PROCESSES

Abstract. Conditions for the existence of causal and strictly stationary solutions of the equations defining a self-exciting threshold autoregressive moving-average (SETARMA) model are derived. For threshold autoregressive models we allow the autoregressive coefficients to be random and derive sufficient conditions for geometric ergodicity and the existence of strictly and weakly stationary solutions of the defining equations.