全面推进我国生态工业建设步伐势在必行

从可持续发展的角度,对我国目前的工业运作和发展模式进行了分析,指出了其主要的弊端,进一步论述我国全面推进生态工业建设步伐的必要性和紧迫性,并提出了相应的实施策略。     

基于小波变换的分级图像检索

提出了一种基于小波变换的分级图像检索方法,对图像的色彩分量进行Daubechies小波变换,提取低频及高频信息构建特征向量.将查询图像与数据库中图像的特征向量进行方差、不变矩和向量夹角余弦值的分级筛选,取得了较好的检索效果.     

神经肽、神经递质与肿瘤的关系

对神经肽及神经递质对肿瘤增殖和分化的调控作用、调控机理及肿瘤细胞表面的神经肽受体的研究进展进行了综述。     

前向安全的签密方案

提出了一个基于Schnorr签名体制的、具有前向安全性质的签密方案,弥补已有签密方案大多不具备前向安全性的缺陷,该方案能够实现即使签密者的密钥泄漏,以前产生的签密仍然有效的目标.同时还证明了方案的正确性,并对方案的安全性进行了分析,得出该方案是有效的,且满足不可伪造性和保密性.     

A step towards global key distribution

Large random bit-strings known as 'keys' are used to encode and decode sensitive data, and the secure distribution of these keys is essential to secure communications across the globe. Absolutely secure key exchange between two sites has now been demonstrated over fibre and free-space optical links. Here we describe the secure exchange of keys over a free-space path of 23.4 kilometres between two mountains. This marks a step towards accomplishing key exchange with a near-Earth orbiting satellite and hence a global key-distribution system.     

分步规划实施医药销售管理信息化

文章分析了医药企业对销售行业信息管理的需求,阐述了基于B/S架构和移动平台的医药销售信息系统的规划方案,以及如何克服信息系统实施中潜在的障碍和缺陷,并就医药供应链上销售信息的集成问题提出了展望,该方案对于其它行业采用信息技术辅助销售管理同样也有参考价值.     

一种光伏系统的变步长MPPT算法

具体分析了目前太阳能PV电池面板主流的P＆O算法,提出了一种新型改进型P＆O算法,有效的结合了固定启动电压法的快速响应和变步长P＆O算法的高稳定性和高效率的优势.通过MATLAB SIMULINK建立仿真DC升压电路模块和变步长算法模块,对此种算法进行了深度的分析,并与基础P＆O算法的输入输出波形比较,验证了此设计算法可以更有效地对光伏系统的最大功率输出点进行追踪.     

绥中36-1油田氮气泡沫逐级调驱实验研究

多层砂岩油藏非均质严重,大段多小层笼统注水时注入水沿高渗透层窜流;利用氮气泡沫驱可有效改善注入剖面。在前人双管实验研究的基础上,创新提出应用三管并联驱替注泡沫逐级调驱的实验方法,重点研究了不同渗透率级差、相同渗透率级差不同渗透率级别和气液比对氮气泡沫调驱效果的影响。研究结果表明经过氮气泡沫调驱后,泡沫有效发挥了调整分流作用,使高渗管、中渗管和低渗管的产液量趋于均匀,体现了"分级堵调、逐级启动"的特性,有效改善了非均质储层的开发效果,对该类油藏的高效开发有一定的借鉴意义。     

一种变步长自适应信道估计算法

针对传统的LMS算法收敛速度慢和对时变信道跟踪能力弱的缺点做了改进,提出一种应用于LTE-A ( Long Term Evolution-Advanced)系统的变步长LMS( least mean square)信道估计算法,设计一种误差函数来控制步长因子,仿真结果表明比传统算法能明显降低MSE( Mean Squared Error,均方误差),提高信道估计的精度。     

Horses damp the spring in their step.

The muscular work of galloping in horses is halved by storing and returning elastic strain energy in spring-like muscle-tendon units.These make the legs act like a child's pogo stick that is tuned to stretch and recoil at 2.5 strides per second. This mechanism is optimized by unique musculoskeletal adaptations: the digital flexor muscles have extremely short fibres and significant passive properties, whereas the tendons are very long and span several joints. Length change occurs by a stretching of the spring-like digital flexor tendons rather than through energetically expensive length changes in the muscle. Despite being apparently redundant for such a mechanism, the muscle fibres in the digital flexors are well developed. Here we show that the mechanical arrangement of the elastic leg permits it to vibrate at a higher frequency of 30-40 Hz that could cause fatigue damage to tendon and bone. Furthermore, we show that the digital flexor muscles have minimal ability to contribute to or regulate significantly the 2.5-Hz cycle of movement, but are ideally arranged to damp these high-frequency oscillations in the limb.