Molecular orbital study of the bridge bonding in an electron deficient molecule [(CH3)2ALH]2

The electronic distribution in the AlH₂Al bridge of the dimethyl aluminium hybride dimer was computed through ab initio SCF calculation. Comparison with diborane shows an increased role of the ionic Al⁺H ₂ ^2– Al⁺ structures with respect to the usual covalent three-center bonds.     

Synthese und Geruch von (E)- und (Z)-bis-homo-ß-Santalol

Summary The synthesis of the title compounds is described. Guided by theoretical considerations and molecular modeling studies, the influence of the bulky group opposite to the osmophorically important primary hydroxyl function on the odour impression is determined. The organoleptic evaluation proved the predicted sandal like odour of the (Z)-isomer and its also predicted absence with (E)-isomer. A moderate increase of the volume of the bulky group shows no influence on the sandalwood odour of the new analogue.

     

Tethering versus Non‐Coordination of Hydroxy and Methoxy Side Chains in Arene Half Sandwich Dichloro Ruthenium Complexes

We are reporting on the hydroxyalkyl appended arene ruthenium half sandwich complexes [{η⁶‐C₆H₅(CH₂)_nOH}RuCl₂] (n = 2, 3) and the methyl ether of the hydroxypropyl derivative. Most significantly, a structural comparison between the hydroxypropyl complex 1a and its methyl ether 2a reveals, that the latter adopts the conventional dichloro bridged dimeric structure while 1a is a monomer. Coordinative saturation of the ruthenium centre is achieved by intramolecular coordination of the appended hydroxy function, thus rendering the functionalized arene an eight electron donor chelate ligand. The structure is further stabilized by intermolecular OH···Cl hydrogen bridges between a terminal chloride ligand of one and the coordinated hydroxy group of a neighbour molecule, resulting in a sheet structure. These intermolecular interactions appear to be even stronger in the hydroxyethyl analogue. Several phosphine adducts have been prepared from the hydroxy or alkoxy functionalized [(η⁶‐arene)RuCl₂]_n precursors, including water soluble P(CH₂OH)₃ adducts. Electrochemical properties of the phosphine adducts and of the dichloro bridged aryl ether complex 2a are also discussed.     

Encrypted signal-based reversible data hiding with public key cryptosystem

Encrypted image-based reversible data hiding (EIRDH) is a well-known method allowing that (1) the image provider gives the data hider an encrypted image, (2) the data hider embeds the secret message into it to generate the encrypted image with the embedded secret message to the receiver, and (3) finally the receiver can extract the message and recover the original image without encryption. In the literature, the data hider and image provider must be specific parties who know the shared key with the receiver in traditional encrypted image-based reversible data hiding. In this paper, we propose an encrypted signal-based reversible data hiding (ESRDH) with public key cryptosystem, not only for images. The proposed scheme is secure based on Paillier homomorphic encryption. Finally, the experimental results show that the proposed scheme has much payload and high signal quality.     

传统信令在NGN中的应用实现

主要介绍了传统PSTN网向NGN演进，重点讲述了传统信令网与NGN的融合，提出把传统电路交换机演进成媒体网关控制器，并讲述了其中信令模块的实现。     

数字电视增值业务短信系统的设计与实现

设计了一种以遥控器作为短信业务的通信终端,立足于广电现有网络的一种短信支撑平台。主要介绍了该短信系统的网络架构、网络初始化、链路检测、短信发送等业务流程,并对多功能遥控器的设计进行了简单介绍。     

基于隧道传输技术IPv4向IPv6的过渡

IPv4向IPv6的迁移更好的解决了网络容量与网络性能。在分析IPv6数据报文及其结构特点的基础上，提出了基于隧道传输技术IPv4向IPv6过渡的必然性与可行性，重点论述了GRE隧道传输、手动隧道传输及自动隧道传输三种方式，并就其工作原理和实现过程进行了较为详细的分析和概括。同时，对过渡技术做了一定的预测。     

伏拱对赵州桥力学行为的影响

采用数值计算的方法分析了赵州桥上的两对伏拱对桥身拱轴线形状及拱券应力分布的影响，一方面阐明了伏拱的存在使桥体的圆弧形拱轴线与符合力学原理的恒载压力线十分接近，另一方面，说明伏拱的存在明显消除了桥体拱券中的拉应力，加强了桥体的安全性，从而对这座千年古桥的卓越力学性能有了进一步的认识。     

Windows消息机制在VB编程中的应用

介绍了Windows消息机制，重点讨论了消息的组成，VB应用程序中消息的传送过程，分析了如何使用API函数拦截VB应用程序中对象的消息，从而解决了VB应用程序中某些对象对特定消息的不响应问题。应用文中所介绍的方法，作者在教育机器人平台软件中成功地实现了鼠标滚轮消息的拦截，提高了软件操作的灵活性。实践证明，这种消息拦截技术有很强的实用性，可以解决一些VB中用常规方法不能解决的问题，实现关键技术的突破。     

MonitorView：一种电信业务运营支撑系统统一管理体系

针对目前存在的网络运营商内多种业务运营支撑系统并存、难以进行统一管理的问题,研究提出了一种通用的 BOSS 系统应用管理体系 MonitorView。它基于一种面向应用的 Manager-Agent 管理协议,设计实现了一种面向应用管理的通用 Agent 模型和支持异构平台通信的消息中间件 SRB(service request broker),并提出了一种统一的基于元消息的管理消息体系和基于数据库表结构的体系实现,从而实现了面向异构 BOSS 系统管理的一种动态可定制的通用管理应用。