基于三角剖分的雕刻学习曲面轨迹生成

结合雕刻学习的特点，给出了雕刻学习曲面三角剖分数据结构，说明了雕刻学习曲面轨迹生成应注意的问题，并给出了详细的算法说明，该方法能满足雕刻学习曲面雕刻加工的高效和自然等特点，适应了自由曲面几何特性和雕刻数据采集的特殊性，是一种切实可行的方法。     

夏茶进行时

夏日炎炎，身体对水的需求更为强烈，饮料的销售旺季随之到来。名目繁多的饮料中，茶这种传统的饮料仍然成为很多人的选择，而茶的功能也逐渐为人们所知。在日本，据说“茶道士”多长寿高龄，这与他们经常饮茶有密切的关系。而在我国，已将绿茶茶多酚或儿茶素类化合物开发成一种可以预防人体衰老的辅助药物。随着现代科学对茶研究的深入，茶的保健作用也逐渐被人们所重视，与之相关的是成燎原之势的各种含茶保健饮料的开发。[编者按]     

水库汛限水位动态控制综合信息模糊推理模式法及其应用

洪水实时调度中严格按照设计的汛限水位控制,即所谓的“静态控制法,”这种控制法造成一些水库汛期大量弃水,而旬末蓄不到正常蓄水位的问题。本文以申窝水库为例,建立了水库汛限水位动态控制综合信息模糊推理模式法,通过水库长系列调节计算,证明此方法在减少弃水,发电和供水等方面均有比较显著的效益。     

In situ growth of NiS2 nanosheet array on Ni foil as cathode to improve the performance of lithium/sodium-sulfur batteries

The NiS₂ nanosheet array on Ni foil (NiS₂/NF) was prepared using an in situ growth strategy and sulfidation method and was used as the cathode of lithium sulfur battery. The unique nanostructure of the NiS₂ nanosheet array can provide abundant active sites for the adsorption and chemical action of polysulfides. Compared with the sulfur powder coated pure NF (pure NF-S) for lithium sulfur battery, the sulfur powder coated NiS₂/NF (NiS₂/NF-S) electrode exhibits superior electrochemical performance. Specifically, the NiS₂/NF-S delivered a high reversible capacity of 1007.5 mAh g⁻¹ at a current density of 0.1 C (1 C= 1675 mA g⁻¹) and kept 74.5% of the initial capacity at 1.0 C after 200 cycles, indicating the great promise of NiS₂/NF-S as the cathode of lithium sulfur battery. In addition, the NiS₂/NF-S electrode also showed satisfactory electrochemical performance when used as the cathode for sodium sulfur battery.

     

Soil diagnosis and land suitability assessment for vegetation restoration on coal waste piles in Liupanshui,Guizhou, China

This study analyses physicochemical properties of soils from coal waste piles at the Naluozhai Coal Mine that were dumped 5, 15, 25 and 35 years ago, respectively. The soil at a 20-year old coal waste site where Vetiveria Zizanioides was cultivated was taken as a control. Principal components were analysed to determine their weights, and the weighted summation method was used to calculate soil quality integrated index (SQI). Eight indices were considered to assess land suitability for vegetation restoration, namely pH value, soil layer depth, field moisture capacity, stable infiltration, volume weight, total porosity, organic matter content and vegetation coverage. The results showed that vegetative restoration depends primarily on the organic matter content of the coal waste pile; the control pile recorded the highest SQI and it was satisfactory for vegetation restoration; the 35-year old pile was encouraging for vegetation restoration, second only to the control pile.     

MPEG-2纵览

MPEG是英文Moving Picture Expert Group的简称。MPEG早在1988年便开始着手制定视频信号及其伴音压缩的国际标准。目前已相继出台了两个标准，即MPEG-1、MPEG-2。MPEG-2是MPEG-1的扩展，其功能更丰富、更完善，它支持多种采样格式的逐行／隔行视频信号，支持恒速率刚技变速率两种编码方法，支持对比特流的编辑等功能，并在一定条件下与MPEG-1保持前向／后向兼容。     

Source localization and calibration using TDOA and FDOA measurements in the presence of sensor location uncertainty

Source localization accuracy is very sensitive to sensor location error.This paper performs analysis and develops a solution for locating a moving source using time difference of arrival(TDOA)and frequency difference of arrival(FDOA)measurements with the use of a calibration emitter.Using a Gaussian random signal model,we first derive the Cram′er-Rao lower bound(CRLB)for source location estimate in this scenario.Then we analyze the differential calibration technique which is commonly used in Global Positioning System.It is indicated that the differential calibration cannot attain the CRLB accuracy in most cases.A closed-form solution is then proposed which takes a calibration emitter into account to reduce sensor location error.It is shown analytically that under some mild approximations,our approach is able to reach the CRLB accuracy.Numerical simulations are included to corroborate the theoretical developments.     

G1724型剑杆织机电气控制系统MTBF的检测分析

应用可靠性技术对G1724型剑杆织机的电控系统进行了试验和分析,为提高产品质量提供了科学依据.     

铝（Ⅲ）水解聚合形态及在混凝中的应用

总结了对铝的水解化学研究、Al13的研究与进展等，介绍了无机高分子絮凝剂聚合氯化铝的一些相关基础理论知识、研究现状和热点。     

Ways to sparse representation: An overview

Many algorithms have been proposed to find sparse representations over redundant dictionaries or transforms. This paper gives an overview of these algorithms by classifying them into three categories: greedy pursuit algorithms, l _p norm regularization based algorithms, and iterative shrinkage algorithms. We summarize their pros and cons as well as their connections. Based on recent evidence, we conclude that the algorithms of the three categories share the same root: l _p norm regularized inverse problem. Finally, several topics that deserve further investigation are also discussed. Supported by the Joint Research Fund for Overseas Chinese Young Scholars of the National Natural Science Foundation of China (Grant No. 60528004) and the Key Project of the National Natural Science Foundation of China (Grant No. 60528004)