A New Watermarking Protocol against Conspiracy

A trusted third party introduced in watermarking protocols would decrease the security and affect the implementation of the protocols. In this paper, a new watermarking protocol with an un-trusted third party （UTTP） was proposed. Based on the idea of all-or-nothing disclosure of secret （ANDOS）, all of the buyer, the seller and the third party didn＇t know the exact watermark, which was embedded in a digital content for tracing piracy. The proposed protocol provided mechanisms to trace piracy and protect customer＇s right. In addition, the problem that a seller colluded with UTTP to frame the buyer, namely, the conspiracy problem, could be avoided.     

Fair E-Payment Protocol Based on Simple Partially Blind Signature Scheme

0 Introduction The advent of E-commerce demands for a secure communication of digital information. It has been proven for years that this can be achieved by cryptography. Digital signature schemes are essential for E-commerce as they allow one to authoriz…     

Palaeolake and palaeoenvironment between 42 and 18 kaBP in tengger desert, NW China

Comprehensive field investigations and laboratory analyses show that palaeolakes, including fresh- mesohaline water Megalake Tengger and other semi-con- nected, isolated water bodies, during late Pleistocene covered an area of more than 20000 km², which is more than half of the Tengger Desert in NW China. Stratigraphic correlation and chronological evidence indicate that before ca. 42000 aBP the area was more arid. The palaeolakes started to develop around 40000 uncal. ¹⁴C aBP but until 37000 ¹⁴C aBP their scope was limited. High water levels established from 35000 ¹⁴C aBP lasted until 22000 ¹⁴CaBP. Lake levels regressed between 22000 and 20000 ¹⁴C aBP but transgressed from 20000 to 18600 ¹⁴C aBP. Subsequently, water level declined further and the Megalake Tengger finally desiccated at around 18000 ¹⁴C aBP. Megalake Tengger possessed a fresh-mesohaline water property, implying that the regional precipitation increased significantly. During the period of Megalake Tengger, the climate was warmer-humid than present. The annual rainfall was 250 to 350 mm more than that of today and the temperature was 1.5 to 3.0℃ higher.     

基于主动网络技术的在线拍卖

为了解决系统客户／服务器（C／S）结构网络在线拍卖的不足，提出了一种基于主动网络技术的网络在线拍卖结构。在主动节点上安装过滤器，过滤低竞争价格，提高拍卖服务器的处理性能；在重负载的情况下实现了负载动态平衡。服务器以主动信包的形式向主动节点发布最新竞价，减少网络延迟。仿真实验表明：该结构不仅较好地解决了传统网络结构在线拍卖系统的不足，同时在性能方面也有所提高。     

中美艺术设计教育之比较

美国的教育事业高度发达，教育体制十分灵活，教育体系非常完整。美国有众多的艺术设计院校（系），并且多实行开放性、灵活性教学，积极与国际接轨，开展全方位的交流与合作。而与中国现行的教育方式和教育方法相比，美国的艺术设计教育更加注重顺应社会需求，培养务实人才，强调学生实际动手能力；同时注意对相关学科的研究，收集、整理各类资料信息。面对目前我国艺术设计教育规模的日益扩大，学生人数不断增多，老问题和新现象层出不穷。高等艺术院校应以素质培养为重点，着眼于可持续发展人才的培养，改革传统教学组织形式和僵化、落后的教学管理方式，为提高我国的综合国力，培养新世纪的设计人才而努力。     

无声破碎剂改型复合剂的研究

目前,国内无声破碎剂产品在使用中受温度的限制,造成某些型号的破碎剂因季节的变化而不能使用,给用户带来损失。本课题主要目的是确定一种改型复合剂,以实现无声破碎剂的超期使用。经研究和试验表明:这种改型复合剂扩大了破碎剂的温度适用范围,并具明显的增效作用。     

一种结构新颖的数字PABX会议电路

数字交换系统中实现会议电话比在模拟系统中要困难得多。因为PCM数字语音信号是非线性的,因而不能象在模拟系统那样直接将与会者的语音信号相加,而需要作特殊处理。本文简要介绍数字会议电话的原理及其实现方法,并就会议电路设计中常遇到的问题进行讨论。文章以总线TDM数字PABX为基础,对一个中规模会议电路的设计提出了一种新的话音开关型会议电路,并给出了其硬件框图和软件流程图。     

外语课堂教学与管理

随着社会的发展，教育改革的不断深入，外语教学已成为当今学校教育的重点。从对教师的管理、学生的管理和外语课堂的管理等方面阐述了外语课堂教学中教学管理的创新。     

钢筋混凝土受弯构件的优化设计—一类离散型非线性规划

研究钢筋混凝土受弯构件的优化设计问题，建立了新的数学模型—一类离散型非线性规划，给出了计算步骤与若干算例．提出的算法容易在微机上实现，所有可行解都是整数解，而且所得最优值在一定条件下是总体最优值．     

Co（Ⅱ）对青霉素酰化酶的激活作用

文中报道Ｃｏ（Ⅱ）对巨大芽孢杆菌青霉素酰化酶的激活作用。并用荧光光谱法对其可能的机理进行了研究。结果表明：Ｃｏ（Ⅱ）对青霉素酰化酶具有荧光猝来作用，但并没有引起整个酶分子空间构象的变化，而是与活性部位的某些基团发生了络合作用，有利于底物的诱导契合从而引起酶活力的提高。