Design of a Novel Sort of Luminescent Terbium(III) Hybrid Materials with Potential Molecular Bridge

Summary. A kind of precursor molecule (abbreviated as EPDA–APMS) was synthesized by means of the amidation reaction of 5-ethylpyridine-2,3-dicarboxylic acid (EPDA) with a crosslinking molecule (3-aminopropyl)trimethoxysilane (APMS). Then the hybrid materials were obtained by reaction of this kind of monomer (EPDA–APMS), tetraethoxysilane (TEOS) and Tb(NO₃)₃·6H₂O by an in-situ sol-gel process, resulting in a novel molecular hybrid material (named as Tb–EPDA–APMS) with double chemical bonds (Tb–O coordination bond and Si–O covalent bond). Ultraviolet absorption, phosphorescence, and fluorescence spectra were applied to characterize the photophysical properties of the obtained hybrid material. The strong luminescence of Tb³⁺ substantiates optimum energy match and effective intramolecular energy transfer between the triplet state energy of modified ligand bridge and emissive energy level of Tb³⁺.     

Design and Performance Analysis of Electronic Seal Protection Systems Based on AES

A very promising application of active RFID systems is the electronic seal, an electronic device to guarantee the authenticity and integrity of freight containers. To provide freight containers with a high level of tamper resistance, the security of electronic seals must be ensured. In this paper, we present the design and implementation of an electronic seal protection system. First, we propose the eSeal Protection Protocol (ePP). Next, we implement and evaluate various cryptographic primitives as building blocks for our protocol. Our experimental results show that AES‐CBC‐MAC achieves the best performance among various schemes for message authentication and session key derivation. Finally, we implement a new electronic seal system equipped with ePP, and evaluate its performance using a real‐world platform. Our evaluation shows that ePP guarantees a sufficient performance over an ARM9‐based interrogator.     

Parallel algorithm for efficient calculation of second derivatives of conformational energy function in internal coordinates

A parallel algorithm for efficient calculation of the second derivatives (Hessian) of the conformational energy in internal coordinates is proposed. This parallel algorithm is based on the master/slave model. A master processor distributes the calculations of components of the Hessian to one or more slave processors that, after finishing their calculations, send the results to the master processor that assembles all the components of the Hessian. Our previously developed molecular analysis system for conformational energy optimization, normal mode analysis, and Monte Carlo simulation for internal coordinates is extended to use this parallel algorithm for Hessian calculation on a massively parallel computer. The implementation of our algorithm uses the message passing interface and works effectively on both distributed-memory parallel computers and shared-memory parallel computers. We applied this system to the Newton–Raphson energy optimization of the structures of glutaminyl transfer RNA (Gln-tRNA) with 74 nucleotides and glutaminyl-tRNA synthetase (GlnRS) with 540 residues to analyze the performance of our system. The parallel speedups for the Hessian calculation were 6.8 for Gln-tRNA with 24 processors and 11.2 for GlnRS with 54 processors. The parallel speedups for the Newton–Raphson optimization were 6.3 for Gln-tRNA with 30 processors and 12.0 for GlnRS with 62 processors. © 1998 John Wiley & Sons, Inc. J Comput Chem 19: 1716–1723, 1998     

采用FSM和消息机制的DSP语音抗噪系统

提出一种DSP语音抗噪系统,在程序设计中,引入消息和状态机(FSM)的方法,采用消息驱动机制设计程序,将数据获取和数据处理分离,大大提高了中断响应速度,很好地解决了快速采集数据和数据处理耗时之间的矛盾,程序结构清晰,模块之间的耦合度低,扩展性平滑,实现语音抗噪算法的实时运行。     

安庆长江公路大桥区域稳定性及桥位线选址遥感应用研究

安庆长江公路大桥区域稳定性及预选桥位线方案是大桥建设前期的一项重要基础性工作。本文是利用航、卫片地质解译调查 ,分析研究拟选桥址区及其外围的地质构造特征 ,新、老断层的分布情况及其活动性 ,并进行区域稳定性评价 ;利用5 0至 90年代的航、卫片资料 ,分析评价了拟选桥址区长江岸带变迁及稳定性 ;对预选桥址区工程地质条件及优选桥位线方案进行比较与论证。     

A reexamination of virial coefficients of the Lennard-Jones fluid

The fourth-order virial coefficients have been calculated exactly to five decimal places for pure fluids of the Lennard-Jones potential at many points in the phase diagram. The calculations were performed through direct evaluation of the integrals, or diagrams, which make up the density expansion of the radial distribution function: included were the standard fast Fourier transform method of evaluating the simply connected diagrams and the evaluation of the bridge diagram for the fourth order in density by expansion in Legendre polynomials. The polynomial-order dependence of the bridge diagram calculation and the range dependence of the simply connected diagrams of the fourth order are found to have more significance than was thought from previous studies, especially in the low-temperature range. This result was confirmed by direct evaluation of the diagrams which construct the virial coefficients, as given by Rowlinson, Barker, and coworkers. This calculation confirmed that numerical convergence has not been achieved at the precision levels previously reported in the literature. These differences, though minor at higher temperatures, can be seen to be more significant at the lower temperature ranges. Received: 31 July 2000 / Accepted: 18 September 2000 / Published online: 21 December 2000     

Message—Driven Bean在异步消息传输中的应用

讨论了EJB2．0中Message-Driven Bean的一些新特性和运行机制，通过实例讲述了在构建异步消息传输中Message-Driven Bean的应用，并讨论了它的优势、缺陷，以及与Session Bean的比较。     

七号信令系统的MTP部分在S12-CDMA MSC中的应用

介绍了七号信令系统的消息传递部分（MTP）的功能以及MTP在S12－CDMA（码分多址）MSC（移动交换机）中的应用，包括涉及到的硬件模块和人机命令，阐述了用人机命令创建MTP数据的步骤和信令链路告警的处理方法，此外还指出了其中的命令和参数与公网中S12EC74版交换机的区别。     

基于GSM模块D15的单片机短信息收发系统设计

介绍用MCS-51系列单片机控制GSM数据模块D15收发短信息的原理、硬件电路和AT控制命 令集,并且对短信息收发的PDU格式和用户数据的编译码进行了分析.     

基于身份的具有消息恢复的签名方案研究

数字签名不仅可以提供信息的加密解密,还可以提供信息来源的鉴别、信息的完整性保证等。论文提出了一种基于身份的具有消息恢复的数字签名方案。与其它基于身份的签名方案相比,该方案的优点在于节省通信带宽,只需要很小的通信量,因此,可广泛应用于移动电子商务中。