无隔膜电解槽制备铁氰化钾的研究

在无隔膜电解槽中采用钛阳极、铜阴极电解制备铁氰化钾。本文探索了影响此过程电流效率及能耗的各种因素，分析确立了实际应用的电解条件     

PMN-PZT压电陶瓷的凝胶注模研究

对三元系PMN—PZT压电陶瓷的凝胶注模成形工艺进行了研究,重点讨论了分散剂加入量、pH值、球磨时间与注模浆料流变之间的关系,当分散剂用量为0 .95 %～1 .0 5 % ,pH值为10 .5～11 .5 ,球磨时间为8h时,可以制备出固相含量为5 5 % ,粘度小于1Pa·s的PMN -PZT压电陶瓷悬浮体。将凝胶注模与传统模压成形工艺制备的样品进行了比较,通过扫描电镜(SEM )显微形貌分析和电学性能测定。结果表明:凝胶注模工艺制备的样品与模压工艺制备的样品相比较,其显微结构均匀致密、晶粒大小与晶界分布均匀,气孔率更小,电学性能更均匀。     

A schema aware ETL workflow generator

Extract, Transform and Load (ETL) processes organized as workflows play an important role in data warehousing. As ETL workflows are usually complex, various ETL facilities have been developed to address their control-flow process modeling and execution control. To evaluate the quality of ETL facilities, Synthetic ETL workflow test cases, consisting of control-flow and data-flow aspects are needed to check ETL facility functionalities at construction time and to validate the correctness and performance of ETL facilities at run time. Although there are some synthetic workflow and data set test case generation approaches existed in literatures, little work is done to consider both aspects at the same time specifically for ETL workflow generators. To address this issue, this paper proposes a schema aware ETL workflow generator with which users can characterize their ETL workflows by various parameters and get ETL workflow test cases with control-flow of ETL activities, complied schemas and associated recordsets. Our generator consists of three steps. First, with type and ratio of individual activities and their connection characteristic parameter specification, the generator will produce ETL activities and form ETL skeleton which determine how generated activities are cooperated with each other. Second, with schema transformation characteristic parameter specification, e.g. ranges of numbers of attributes, the generator will resolve attribute dependencies and refine input/output schemas with complied attributes and their data types. In the last step, recordsets are generated following cardinality specifications. ETL workflows in specific patterns are produced in the experiment in order to show the ability of our generator. Also experiments to generate thousands of ETL workflow test cases in seconds have been done to verify the usability of the generator.     

浓乳液方法制备微孔结构分离膜

通过浓乳液聚合,制备了一系列由乳胶粒子粘接而成的膜材料,对其中的"类粒子"结构和微通道体系进行了表征.通过对工艺参数的调节,可以得到具有不同尺寸微通道结构的分离膜.     

A Stochastic Optimization Model to Reduce Expected Post-Disaster Response Time Through Pre-Disaster Investment Decisions

This paper seeks to enhance network survivability under a disaster and reduce the expected post-disaster response time for transportation networks through pre-disaster investment decisions. The planning focuses on determining the links of the network to strengthen through investment under two types of uncertainties: the disaster characteristics, and the surviving network under each disaster. A bi-level stochastic optimization model is proposed for this problem, in which link investment decisions are made at the upper level to enhance the network survivability subject to a budget constraint such that the expected post-disaster response time is minimized at the lower level. A two-stage heuristic algorithm is proposed to obtain effective solutions efficiently. The numerical experiments indicate that the proposed heuristic algorithm converges to a fixed point representing a feasible solution, within an acceptable tolerance level, of the bi-level stochastic optimization model which is an effective solution under disasters of moderate severity. Parametric and sensitivity analyses reinforce the need for a holistic approach that integrates multiple relevant considerations to determine the link investment decisions.     

HamleDT: Harmonized multi-language dependency treebank

We present HamleDT—a HArmonized Multi-LanguagE Dependency Treebank. HamleDT is a compilation of existing dependency treebanks (or dependency conversions of other treebanks), transformed so that they all conform to the same annotation style. In the present article, we provide a thorough investigation and discussion of a number of phenomena that are comparable across languages, though their annotation in treebanks often differs. We claim that transformation procedures can be designed to automatically identify most such phenomena and convert them to a unified annotation style. This unification is beneficial both to comparative corpus linguistics and to machine learning of syntactic parsing.     

Dielectrophoresis in aqueous suspension: impact of electrode configuration

Dielectrophoresis (DEP) allows to moving neutral or charged particles in liquids by supplying a non-uniform electric field. When using alternating current and insulated electrodes, this is possible in conducting media such as aqueous solutions. However, relatively high field strength is required that is discussed to induce also an undesired Joule heating effect. In this paper, we demonstrate boundary conditions for avoiding this side effect and suggest a novel design of an interdigitated electrode (IDE) configuration to reduce the power consumption. Numerical simulation using OpenFOAM demonstrated that, when replacing conventional plate IDE by cylindrical micro-IDE in microchannel systems, the dielectrophoretic force field, i.e., the electric field gradient squared, becomes stronger and more homogeneously distributed along the electrodes array. Also the resulting particle DEP velocities were highest for the cylindrical IDE. The simulations were experimentally confirmed by measuring velocity of resin particle located at the subsurface of demineralized water. Surprisingly the fluid flow induced by electrothermal effect turned out to be negligible in microchannels when compared to the DEP effect and becomes dominant only for distances between particle and IDE larger than 6,000 μm. The well-agreed experimental and simulation results allow for predicting particle motion. This can be expected to pave the way for designing DEP microchannel separators with high throughput and low energy consumption.     

Cure kinetics of T700/BMI prepreg used for advanced thermoset composite

A new isothermally based, cure kinetic model for the prepreg was presented using an industrially supplied prepreg rather than pure resin. The matrix resin was bismaleimide (BMI) resins, and the reinforcement was carbon fiber T700–12S. The BMI prepreg was measured from 170 to 220°C by isothermal DSC. The isothermal cure reaction heat increases with the increment of cure temperature. The DSC data were analyzed by the proposed nth‐order reaction model. An increase in reaction rate was observed at higher temperature in both neat and prepreg. After reaching the peak value, the reaction rate dropped off faster in prepreg, resulting in a lower average value of the ultimate heat of reaction. It was suggested the presence of carbon fiber had an effect on the cure kinetics as a heat sink. The carbon fibers imposed restrictions on the molecular mobility of the reactive species and did not change the cure mechanism. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2238–2241, 2005     

真空蒸馏法从铟中脱除Cd、Tl的研究

介绍真空蒸馏法取代传统试剂法从铟中脱除镉和铊。通过实验研究了采用真空蒸馏的方法从铟中脱除铊的最佳工艺条件。实验表明,控制蒸馏温度950℃,恒温时间40m in,即可使残余物中铊的含量为0.0006%,铟的挥发率2.14%。     

Inspection of Remanent Polarization in the Ferroelectric Ceramic PZT 95/5 Through Pyroelectric Effect

Shock-induced depoling of the ferroelectric (FE) ceramic PZT 95/5 is utilized in a number of pulsed power devices. Nondestructive testing of remanent polarization of PZT 95/5 is developed by pyroelectric effect in this paper. Approximately linear relation between the change of polarization during low- to high-temperature rhombohedral FE phase and the remanent polarization was found through pyroelectricity of a single piece of PZT 95/5 ceramics. The change of polarization of a prototype for shock-driven pulsed power during the FE_HT↔FE_LT phase transformation was also investigated through directly measuring the pyroelectric current. Results indicate that pyroelectric effect caused by the reversible FE_HT–FE_LT phase transition could be used as a non-destructive inspection for the remanent polarization of a prototype about shock-driven pulsed power supply.