包合作用降低十六烷基三甲基溴化铵在黏土上的吸附

固定十六烷三甲基溴化铵(CTAB)浓度为0.15 mmol/L,改变β-环糊精(β-CD)浓度,测定了β-CD/CTAB混合水溶液30℃时的表面张力,由表面张力升高段与稳定段的拐点,求出水溶液中β-CD-CTAB包合物的包合比为1.53:1.通过红外光谱确认了该包合物的存在.测定不同浓度的该包合物溶液与钠基蒙脱土相互作用8小时后的表面张力,由CTAB溶液表面张力～溶液浓度曲线求得吸附后包合物溶液中CTAB浓度,取为吸附平衡浓度,并计算CTAB在钠基蒙脱土上的吸附量,构建包合物溶液中CTAB的吸附等温线,与采用相同方法求得的CTAB的溶液吸附等温线相比,CTAB的饱和吸附量降低75%.讨论了有关的机理.此结果为阳离子表面活性剂用作驱油剂提供了新思路.图7参7.     

一种随机化的软件模型生成方法

模型转换是模型驱动开发的核心技术. 当要把模型转换用于工业生产时, 其性能成为影响这一技术成败的关键因素之一. 为了测试模型转换程序的性能, 需要能够快速地生成一组具有较大规模的模型数据用于作为测试的输入数据. 本文提出一种随机化的模型生成方法. 该方法能够根据元模型的定义以及用户输入的约束条件随机、正确地生成模型文件. 实验结果也表明, 本方法和其它方法相比具有更好的生成效率, 从而更加适合支持模型转换的性能测试.     

异构多核上多级并行模型支持及性能优化

低功耗及廉价性使得异构多核在超级计算机计算资源中占有重要比例.然而,异构多核具有高带宽及松耦合一致性等特点,获得理想的存储及计算性能需要更多地考虑底层硬件细节.实现了一种针对典型的异构多核Cell BE 处理器的多级并行模型CellMLP,通过C 语言扩展编译指导语句,实现了对数据并行、任务并行以及流水并行编程模型的支持,提高了并行程序生产率.运行支持优化方面,数据并行采用SPE 并行数据传输、双缓冲等优化手段来提高数据传输带宽;任务并行使用一种新式混合任务队列以支持异步任务窃取,降低SPE 线程间竞争,提高了任务并行的可扩展性;流水并行首次使用阻塞信号传输机制实现SPE 线程间的低开销同步操作.实验对Stream,NASBenchmark 及BOTS 等应用进行了测试,结果表明,CellMLP 可对多种典型并行应用进行高效支持.与目前同类编程模型SARC 及CellSs 进行性能对比,其结果表明,CellMLP 实际数据传输带宽以及非规则应用的支持方面具有明显优势.     

Petri网的同步距离计算

同步距离是刻画事件之间同步关系的一个重要的定量分析手段。本文提出了同步距离计算网SDCNet的概念模型并讨论了计算同步距离的几个结论,给出了S_元中初始标识的配置算法以及以此为基础计算同步距离的算法。分析表明该算法与可覆盖性树的生成算法具有相同的复杂性。     

Urban Traffic Information Service Application Grid

Traffic information processing is very complicated because of dynamic, cooperative and distributed features.This paper describes the prototype system version 2.0 of Urban Traffic Information Service Application Grid (UTISAG),which is based on the previous version. In this version, a new architecture and more enhanced services are introduced.The remarkable characteristic of the new system is providing dynamic information services for travelers by grid technology.Therefore, the key research includes integrating large multi-source traffic data, forecasting route status, simulating regional traffic flow parallelly, and implementing optimum dynamic travel scheme based on massive GPS data.     

压缩感知研究

经典的香农采样定理认为,为了不失真地恢复模拟信号,采样频率应该不小于奈奎斯特频率(即模拟信号频谱中的最高频率)的两倍.但是其中除了利用到信号是有限带宽的假设外,没利用任何的其它先验信息.采集到的数据存在很大程度的冗余.Donoho等人提出的压缩感知方法(Compressed sensing或Compressive Sa...     

基于ALUA的多路径存储系统

随着网络存储技术的不断深入发展与广泛应用,存储多路径技术成为信息系统容灾与故障恢复方案中的核心技术之一.在现有存储多路径技术的基础上,提出了一种基于ALUA的多路径存储子系统总体框架,并重点在逻辑卷控制器属主管理、ALUA属性与路径选择策略配置和I/O重定向等模块进行了创新性的设计与实现.经过应用测试,该系统很好地解决了存储系统的路径故障迁移和故障恢复问题,并智能地实现了路径间I/O的负载均衡,极大地提高了性能和可靠性.     

PREPARATION OF ULTRAFINE Al 2 O 3 USING PLASMA JET AND ITS APPLICATION FOR SYNTHESIS OF DIMETHYL CARBONATE

A direct preparation of Al 2 O 3 from aluminum and oxygen under plasma jet conditions has been performed in this work. The XRD characterization of such plasma-prepared alumina shows that a production of δ-Al 2 O 3 has been achieved. The size of the alumina particles ranged from several tens to 200 nm, based on SEM analysis. The effectiveness of plasma-prepared alumina as a catalyst support has been demonstrated by the catalytic synthesis of dimethyl carbonate over Pd/Al 2 O 3 .     

Macrochanneled poly (ɛ-caprolactone)/ hydroxyapatite scaffold by combination of bi-axial machining and lamination

A combination of bi-axial machining and lamination was used to fabricate macrochanneled poly (ɛ-caprolactone) (PCL)/hydroxyapatite (HA) scaffolds. Thermoplastic PCL/HA sheets with a thickness of 1 mm, consisting of a 40 wt% PCL polymer and 60 wt% HA particles, were bi-axially machined. The thermoplastic PCL/HA exhibited an excellent surface finish with negligible tearing of the PCL polymer and pull-out of the HA particles. The bi-axially machined sheets were laminated with a solvent to give permanent bonding between the lamina. This novel process produced three-directionally connected macrochannels in the dense PCL/HA body. The macrochanneled PCL/HA scaffold exhibited excellent ductility and reasonably high strength. In addition, good cellular responses were observed due to the osteoconductive HA particles.     

Robust and reliable H infinity controllers for discrete-time systems with parameter uncertainty and actuator failure

New robust and reliable H infinity control algorithms are suggested for discrete-time uncertain systems with time-varying norm-bounded parameter uncertainty in the state matrix as well as with actuator failure among a pre-specified subset of actuators. State feedback controllers can be obtained by deriving and solving modified parameter-dependent Riccati equations, which can stabilize the plant and guarantee a given H infinity-norm bound on attenuation of augmented disturbances - all admissible uncertainties as well as actuator failure. Two robust and reliable H infinity whether the process of fault accommodation is used or not. Performances of two controllers are evaluated through simulation studies for various failures. controllers are derived according to