RIA技术在云计算时代的应用

随着科学技术的日新月异及云计算时代的到来,RIA模式成为最受关注的界面交互技术。本文介绍了云计算的概念、与RIA技术的关系以及界面交互技术的发展历程,重点分析了几种主流的RIA解决方案,对云计算时代RIA技术的应用前景进行了展望。     

数字粮库的展望

以计算机技术、多媒体技术和大规模存储技术为基础,以宽带专用网络为纽带,运用粮情测控技术、全球定位系统、地理信息系统、虚拟现实等技术,对国内所有粮库及其存粮情况进行多分辨率、多尺度、多时空和多种类的数字描述。即利用信息技术手段把有关粮库的所有信息在网络上进行数字化虚拟实现,以便于粮库的监测和管理,同时也是为国家粮食管理部门提供一个粮食政策的决策支持平台。     

用于NoC映射的EDA工具设计

片上网络（NoC）作为解决片上系统（SoC）复杂通信问题的新的范例,受到了工业界和学术界的广泛重视。为了保证实时任务在片上网络上的高效运行,从任务到网络拓扑的映射问题成为NoC研究中的关键问题之一。为了得到各种条件下的不同映射结果和性能曲线,本文设计了一种通用的NoC映射EDA工具。该工具基于Matlab的GUI设计方法,具有界面友好、可重配置性、运行速度快、自动导出并存储仿真结果等特点。     

5.2GHz 0.18μm CMOS射频低噪声放大器的设计

采用TSMC 0.18μm CMOS工艺,设计应用于IEEE 802.11a的无线局域网络的低噪声放大器（LNA）。整个电路采用1.8V单电源供电,输入输出匹配良好。用ADS模拟软件对电路进行分析优化,结果表明：在中心频率5.2GHz处,噪声系数为2.51dB,功率增益为17.373dB。     

VPN技术综述

随着INTERNET访问的增加,传统的INTERNET接入服务已越来越不能满足用户需求,因为传统的INTERNET只提供浏览、电子邮件等单一服务,没有服务质量保证,没有权限和安全机制,界面复杂不易掌握,VPN则能解决这些问题。VPN的组网方式为企业提供了一种低成本的网络基础设施,并增加了企业网络功能,扩大了其专用网的范围。文章介绍了VPN的特点和类型以及几种基于INTERNET组建VPN的技术。     

Investigation of modulation parameters in multiplexing gas chromatography

Combination of information technology and separation sciences opens a new avenue to achieve high sample throughputs and therefore is of great interest to bypass bottlenecks in catalyst screening of parallelized reactors or using multitier well plates in reaction optimization. Multiplexing gas chromatography utilizes pseudo-random injection sequences derived from Hadamard matrices to perform rapid sample injections which gives a convoluted chromatogram containing the information of a single sample or of several samples with similar analyte composition. The conventional chromatogram is obtained by application of the Hadamard transform using the known injection sequence or in case of several samples an averaged transformed chromatogram is obtained which can be used in a Gauss–Jordan deconvolution procedure to obtain all single chromatograms of the individual samples. The performance of such a system depends on the modulation precision and on the parameters, e.g. the sequence length and modulation interval. Here we demonstrate the effects of the sequence length and modulation interval on the deconvoluted chromatogram, peak shapes and peak integration for sequences between 9-bit (511 elements) and 13-bit (8191 elements) and modulation intervals Δt between 5 s and 500 ms using a mixture of five components. It could be demonstrated that even for high-speed modulation at time intervals of 500 ms the chromatographic information is very well preserved and that the separation efficiency can be improved by very narrow sample injections. Furthermore this study shows that the relative peak areas in multiplexed chromatograms do not deviate from conventionally recorded chromatograms.     

高平均功率固体激光功率和光束质量关系研究进展

 固体激光的一个重大发展方向和目标是实现“三高”(高平均功率、高光束质量和高效率)激光同时输出,结合相关研究工作和进展,着重论述了固体激光输出功率和光束质量的关系,给出了功率升高、光束质量非线性下降是当前“三高”固体激光研究的一个基本科学技术问题。围绕这一基本问题,评述了一些重要技术途径和手段,并探讨了实现高平均功率高光束质量固体激光输出的可能有效途径。     

基于单色捕捉技术的透平导叶传热系数测量

采用窄带热敏液晶瞬态单色捕捉技术测量叶片全表面传热系数,以预先加热被测叶片并在主流中快速冷却的方法引入温度阶跃,利用3台3CCD（电荷耦合元件）相机对叶片表面的不同区域进行图像采集记录,将图像坐标转换至叶片空间坐标,通过后处理得到叶片表面传热系数。由实验结果分析可知,叶片前缘区域传热系数最大值位于加速最剧烈处,在吸力面...     

我国粮食生产的技术推进模式及影响机制研究

基于农业生产技术的功能性特征及随机前沿理论,构建可分离柯布-道格拉斯形式生产函数,测算我国粮食生产全要素增长率及其组成成分.实证结果表明,1999-2011年间,小麦、稻谷和玉米作物的全要素增长率普遍较低,其中,前沿技术进步率对全要素增长率具有正的贡献;但技术效率(尤其是M技术效率)在逐年降低,是造成全要素增长率偏低的主要原因.在此基础上,对影响我国粮食生产技术效率变化的因素进行理论分析和实证检验.研究发现,以直接补贴为主的农业财政支出政策对BC和M技术效率提高作用明显,且影响效果最强.粮食生产技术的推广与普及、粮食生产的规模化和专业化对技术效率具有显著正向影响,但市场机制的影响效果并没有显现出来.     

Performance of columns packed with the new shell particles,Kinetex-C18

The performance of the new Kinetex-C₁₈ column was investigated. Packed with a new brand of porous shell particles, this column has an outstanding efficiency. Once corrected for the contribution of the instrument extra column volume, the minimum values of the reduced plate heights for a number of low molecular weight compounds (e.g., anthracene and naphtho[2,3-a]pyrene) were between 1.0 and 1.3, breaking the legendary record set 3 years ago by Halo-C₁₈ packed columns. The liquid-solid mass transfer of proteins (e.g., insulin and lyzozyme) is exceptionally fast on Kinetex-C₁₈ much faster than on the Halo-C₁₈ column. The different contributions of dispersion and mass transfer resistances to the column efficiency were determined and discussed. The possible reasons for this extremely high column efficiency are discussed.