Theoretical study of the femtosecond-resolved photoelectron spectrum of the NO molecule

The effect of laser fields on the NO interaction potentials is obtained by the calculation of time-resolved photoelectron spectrum (TRPES) using the time-dependent wave-packet method. The calculation not only shows that the overlap of the pump-probe pulses makes some NO molecular "invisible" states visible, but also that the coupling strength and the positions of relevant curves change on increasing the laser intensity. These changed potentials affect their dynamical behavior and influence the shape and position of each peak in TRPES. That the coupling strength of relevant potentials can be changed by the field-matter interaction is consistent with our ab initio calculations.

Stable Isotope Probing:Linking Functional Activity to Specific Members of Microbial Communities

Linking organisms or groups of organisms to specific functions within natural environments is a fundamental challenge in microbial ecology. Advances in technology for manipulating and analyzing nucleic acids have made it possible to characterize the members of microbial communities without the intervention of laboratory culturing. Results from such studies have shown that the vast majority of soil organisms have never been cultured, highlighting the risks of culture-based approaches in community analysis. The development of culture-independent techniques for following the flow of substrates through microbial communities therefore represents an important advance. These techniques, collectively known as stable isotope probing (SIP), involve introducing a stable isotope-labeled substrate into a microbial community and following the fate of the substrate by extracting diagnostic molecular species such as fatty acids and nucleic acids from the community and determining which specific molecules have incorporated the isotope. The molecules in which the isotope label appears provide identifying information about the organism that incorporated the substrate. Stable isotope probing allows direct observations of substrate assimilation in minimally disturbed communities, and thus represents an exciting new tool for linking microbial identity and function. The use of lipids or nucleic acids as the diagnostic molecule brings different strengths and weaknesses to the experimental approach, and necessitates the use of significantly different instrumentation and analytical techniques. This short review provides an overview of the lipid and nucleic acid approaches, discusses their strengths and weaknesses, gives examples of applications in various settings, and looks at prospects for the future of SIP technology.

支持场景方法的界面设计工具

用户界面是交互式软件系统中重要组成部分。它在应用软件中平均占开发量 和运行时间的40%~50%[Myers 1989]。界面设计工具可以用可视化的方法支持用 户界面的快速设计、减少手动开发工作量来提高系统的开发效率。同时还能够根 据用户定制系统，满足了不同用户的个性化需求。图形用户界面是最广泛应用的 用户界面，针对图形用户界面的设计已有Visual Studio，Qt Designer等成熟的设计 工具。使用软件界面设计工具能够将软件的用户界面部分和应用逻辑部分分离， 使设计人员更专注于软件界面的交互方式和现实效果，而开发人员则更专注软件 的应用逻辑实现。使用设计工具开发还能够根据用户变化改变设计来满足用户多 种多样的需求。 场景的概念最初是由Kahn[Kahn 1962]提出的，之后由Carroll领导的团队提出 了基于场景设计的一般框架[Rosson 2001]。场景设计方法在描述用户使用软件的 交互行为和系统反馈上面有着很强的能力[Go 2004]。然而，以往基于场景的设计 方法都使用文字来描述场景，缺少相应用户界面设计工具的支持。 本文通过研究分析基于场景设计方法，设计并实现了支持场景设计方法的界 面设计工具。该工具将软件界面场景以图形形式展示给设计人员，辅助用户对软 件界面需求进行发掘，帮助设计人员开展界面设计。本文的主要工作有： 1、以基于场景方法为指导确立了以图形化形式对场景进行描述的基本流程。 通过对已有界面设计工具进行分析得出软件界面设计的一般过程，并研究分析了 基于场景设计方法在软件界面设计中的使用及其优势。 2、在概要设计角度介绍了场景树、状态迁移图和界面布局可视化描述方式对 场景方法的支持。并详细介绍了界面设计工具的整体架构，重点阐述了各个模块 间的不同功能及在界面设计过程所起的作用。 3、详细分析了设计工具生成软件界面文档的描述规范。针对基于场景设计的 各个阶段阐述了与之对应的软件界面设计步骤。最后简单介绍了使用生成的文档 来开发与应用逻辑相关代码的过程。 4、以个人信息管理系统作为应用实例介绍整个界面软件的设计过程。并在此 基础上介绍了几个使用设计工具进行设计的实际系统，最后对设计工具未来的应 用和改进进行了展望。

Synthesis and crystal structure of aluminium complex with 3-hydroxyflavone

[Al(C15H9O3)(3)](2) . 2CHCl(3) . 8H(2)O was synthesized, and its crystal structure was determined. It belongs to trigonal system, R3, a=b=1. 655 8(3) nm, c=3. 646 5(20) nm, alpha = beta = 90 degrees, gamma = 120 degrees, V = 8. 656 08(0. 005 86) nm(3). D-c = 1.45 g/cm(3), mu(Mo K alpha) = 3. 20 cm(-1), F (000) = 3 924. The crystal structure was solved by Patterson and Fourier techniques, and refined by a block-diagonal least-squares method. A total of 3 737 independent intensity data were collected, of which 1 033 with I greater than or equal to 3 sigma(I-0) were observed, R = 0. 091 8, Rw=0. 091 8. Al3+ ion was 6-coordinated, bound to six oxygen atoms from three 3-hydroxyflavones to form a distortional coordination octahedron.

基于USB接口的无线温湿度监测系统

针对环境温湿度检测的需求,设计了一种点对多点的星型无线温湿度监控网络。以无线通信模块nRF401为基础,配合AT89C2051和数字温湿度传感器SHT11构建了从机,以P89C51RD2BN单片机和USB接口芯片PDIUSBD12构建了主机。对系统的硬件原理及温湿度采集方法进行了介绍,对无线通信协议及USB固件设计方法进行了较详细分析。经上位机软件测试,系统运行稳定,具有较好实用性,可应用于多种场合的无线温湿度监测。

基于Petri网的Web数据库访问的建模研究

本文针对多用户访问Web数据库的过程进行了分析并提出改进思路,然后利用带抑止弧的扩充Petri网对改进后的访问过程进行建模。

基于C/S模式的多水下机器人仿真平台网络通信研究

文章研究了基于客户端/服务器(C/S)模式的多水下机器人仿真平台中网络通信的关键技术。文章介绍了该仿真平台的结构和功能,分析了仿真平台的信息流向和通信特点,在此基础上,提出了适合该仿真平台应用的网络通信协议和时钟同步方案,并详细讨论了Windows和QNX两种不同操作系统上的应用程序之间进行网络通信的实现方法。

CIMS信息集成环境下轧钢企业财务管理系统的实现

以鞍钢冷轧厂计算机集成制造系统开发为背景 ,介绍了基于Client/Server方式 ,以OR ACLE为后台数据库的财务管理系统的设计与实现。运用软件工程和数据库理论 ,结合ORACLERDBMS的特点 ,并对实现方法做了比较全面地论述。最后 ,探讨了通向财务信息集成的途径