治理黄河泥沙的新途径——小北干流放淤

介绍了黄河泥沙的主要来源及危害,提出了治理黄河泥沙的新举措——小北干流放淤,分析了小北干流放淤的客观性和必要性,指出了小北干流放淤对黄河治理的长远影响。     

Netperf的工作原理及应用

Netperf是一个用于衡量网络各方面性能的测试工具,可以进行不同模式的网络性能测试.作者分析了netperf的工作原理和程序代码,使用netperf的TCP流性能、TCP请求/应答测试主机间经过SOCKS服务器通信与直接通信的性能差异,测试结果说明使用SOCKS服务器提高网络安全对网络性能影响不大.     

LVDS技术在数字电视码流传输卡中的应用

在数字电视码流传输卡中，为解决数据传输中高速率与低电压之间的矛盾，将数字电视码流以LVDS信号形式输入至机顶盒，在不依赖于特定供电电压的同时，实现了高速数据传输．本文基于DS90c031芯片，实现了TTL到LVDS电平的转换，方案可行，输出码率3～30Mb／s，码流连续、无误码。     

Fried参数r0的季节变化与东亚副热带急流活动

在塔塔尔斯基理论模式框架下,计算得到的Fired参数r0在我国的地理分布存在明显的季节变化.这一变化与东亚副热带急流的活动相吻合.在副热带急流轴下方哈德来环流的下沉区域内,可能找到兼有云量覆盖少和视宁度好的优良(光学/红外)天文台址.     

基于VC++的网络视频会议之远程教学系统

介绍基于VC 纯软件的网络视频会议之远程教学系统，系统利用流媒体及MPEG—4等先进技术，实现了点对点单路及8 1多路音视频实时传输，并详细说明了系统底层编码／解码及传输的实现和程序结构。     

传感数据库研究与应用

首先介绍的是传感数据库的概念、体系结构;然后将传感数据库和传统数据库进行比较,提出传感数据库研究的关键技术;最后,展望了传感数据库在当今各行各业的应用.     

Composite Chaotic Pseudo-Random Sequence Encryption Algorithm for Compressed Video

Stream cryptosystems, which implement encryption by selecting parts of the block data and header information of the compressed video stream, achieve good real-time encryption with high flexibility. Chaotic random number generator-based approaches, for example, logistics maps, are comparatively promising approachs, but are vulnerable to attacks by nonlinear dynamic forecasting. A composite chaotic cryptography scheme was developed to encrypt the compressed video with the logistics map with a Z(2^31-1) field linear congruential algorithm to strengthen the security of the mono-chaotic cryptography. The scheme maintained real-time performance and flexibility of the chaotic sequence cryptography. The scheme also integrated asymmetrical public-key cryptography and encryption and identity authentification of control parameters at the initialization phase. Encryption is performed in a layered scheme based on the importance of the data in a compressed video stream. The composite chaotic cryptography scheme has the advantage that the value and updating frequency of the control parameters can be changed online to satisfy the network requirements and the processor capability, as well as the security requirements. Cryptanalysis shows that the scheme guarantees robust security, provides good real-time performance, and has flexible implementation. Statistical evaluations and tests verify that the scheme is effective.     

撞击流浓缩器浓缩溶液的数学模型

在理论分析的基础上导出了撞击流浓缩器浓缩溶液的数学模型,并通过实验结果验证了模型的正确性;计算结果得到了浓缩器内气、液温度和速度及液滴浓度和累积蒸发量沿轴向位移的变化。     

离心叶轮回转S1流面流动数值计算方法探讨

采用贴体坐标下的有限差分法计算了离心泵叶轮回转S1流面流动,并用试验结果进行了验证,发现了流层厚度对流动数值计算有重要影响.     

A new species of Didogobius (Teleostei: Gobiidae) from the Adriatic Sea

Didogobius schlieweni sp. nov. is described from a single specimen collected among pebbles in shallow water at Unije island, near Cres, in the northern Adriatic Sea. The holotype has vivid dark and pale patterning, and is assigned to Didogobius on the basis of head neuromast patterns and meristic features. Diagnostic values of the latter are D2 I/12, A I/11, P 17, and LL 55–56. A key to species of the Chromogobius and Didogobius complex is provided.