电网电容电流的外加信号测量法

介绍了一种新的电网电容电流外加信号单频测量法,弥补了相位法、幅值法、幅值相位法在电力电网中测量的缺陷与不足。     

对发变组-线路接线方式保护装置配置的分析

分析了发变组-线路接线方式的特点,大机组继电保护的重要性,继电保护配置的方式以及应注意的问题,根据继电保护"反事故措施"要求,大机组继电保护必须实现双重化,加强主保护,简化后备保护和二次回路接线,介绍了简单、实用的配置。     

基于Floyd算法的应急指示路径规划

当今很多建筑楼层中,应急指示灯所指示的方向单一,疏散指标路线固定,缺乏灵活多变的指示功能。为实现在动态环境中指示灯路线的规划,本文建议对指示灯进行改进,使其能够双向选择性指示,利用计算机对应急指示灯进行控制。文章讨论了一种实现方案,即将Floyd算法与MATLAB结合起来进行疏散路径的动态规划与优化,从而得到每一点到出口的最佳安全路径。     

Addition of Adipose-Derived Stem Cells to Mesenchymal Stem Cell Sheets Improves Bone Formation at an Ectopic Site

To determine the effect of adipose-derived stem cells (ADSCs) added to bone marrow-derived mesenchymal stem cell (MSC) sheets on bone formation at an ectopic site. We isolated MSCs and ADSCs from the same rabbits. We then prepared MSC sheets for implantation with or without ADSCs subcutaneously in the backs of severe combined immunodeficiency (SCID) mice. We assessed bone formation at eight weeks after implantation by micro-computed tomography and histological analysis. In osteogenic medium, MSCs grew to form multilayer sheets containing many calcium nodules. MSC sheets without ADSCs formed bone-like tissue; although neo-bone and cartilage-like tissues were sparse and unevenly distributed by eight weeks after implantation. In comparison, MSC sheets with ADSCs promoted better bone regeneration as evidenced by the greater density of bone, increased mineral deposition, obvious formation of blood vessels, large number of interconnected ossified trabeculae and woven bone structures, and greater bone volume/total volume within the composite constructs. Our results indicate that although sheets of only MSCs have the potential to form tissue engineered bone at an ectopic site, the addition of ADSCs can significantly increase the osteogenic potential of MSC sheets. Thus, the combination of MSC sheets with ADSCs may be regarded as a promising therapeutic strategy to stimulate bone regeneration.     

Contrastive Clustering for Unsupervised Recognition of Interference Signals

Interference signals recognition plays an important role in anti-jamming communication. With the development of deep learning, many supervised interference signals recognition algorithms based on deep learning have emerged recently and show better performance than traditional recognition algorithms. However, there is no unsupervised interference signals recognition algorithm at present. In this paper, an unsupervised interference signals recognition method called double phases and double dimensions contrastive clustering (DDCC) is proposed. Specifically, in the first phase, four data augmentation strategies for interference signals are used in data-augmentation-based (DA-based) contrastive learning. In the second phase, the original dataset’s k-nearest neighbor set (KNNset) is designed in double dimensions contrastive learning. In addition, a dynamic entropy parameter strategy is proposed. The simulation experiments of 9 types of interference signals show that random cropping is the best one of the four data augmentation strategies; the feature dimensional contrastive learning in the second phase can improve the clustering purity; the dynamic entropy parameter strategy can improve the stability of DDCC effectively. The unsupervised interference signals recognition results of DDCC and five other deep clustering algorithms show that the clustering performance of DDCC is superior to other algorithms. In particular, the clustering purity of our method is above 92%, SCAN’s is 81%, and the other three methods’ are below 71% when jamming-noise-ratio (JNR) is −5 dB. In addition, our method is close to the supervised learning algorithm.     

基于关联选择的可逆逻辑综合算法

可逆逻辑综合是可逆计算的重要内容,为了解决可逆逻辑综合中可逆电路构造和优化问题,提出一种基于关联选择的可逆逻辑综合算法及相应的优化算法.将可逆函数用真值表表示,按真值表从上往下的顺序综合,并若干相关联变量作为综合的目标位,分别计算相对混乱度和绝对混乱度,以最小混乱度原则选取可逆逻辑门.该算法及其优化算法的时间复杂度为O(n2×2n),空间复杂度为O(n×2n),优于最佳算法的空间复杂度O(2n!).通过C++语言实现对3变量全部函数及部分4变量函数的综合,并与其他可逆逻辑综合算法的结果及benchmark范例比较,结果表明平均门数均具有一定优势.     

网络陶瓷增强金属复合材料的研究现状

综述了目前网络陶瓷增强金属基复合材料的发展及研究现状,重点介绍了网络陶瓷预制体及复合材料的主要制备工艺,并指出了各工艺的特点.评述了网络陶瓷增强金属复合材料的性能特点,指出了目前网络陶瓷增强金属基复合材料存在的问题及解决方法,并展望了对网络陶瓷增强金属基复合材料未来的发展方向.     

In Situ Construction of a LiF-Enriched Interface for Stable All-Solid-State Batteries and its Origin Revealed by Cryo-TEM

The application of solid polymer electrolytes (SPEs) is still inherently limited by the unstable lithium (Li)/electrolyte interface, despite the advantages of security, flexibility, and workability of SPEs. Herein, the Li/electrolyte interface is modified by introducing Li₂S additive to harvest stable all-solid-state lithium metal batteries (LMBs). Cryo-transmission electron microscopy (cryo-TEM) results demonstrate a mosaic interface between poly(ethylene oxide) (PEO) electrolytes and Li metal anodes, in which abundant crystalline grains of Li, Li₂O, LiOH, and Li₂CO₃ are randomly distributed. Besides, cryo-TEM visualization, combined with molecular dynamics simulations, reveals that the introduction of Li₂S accelerates the decomposition of N(CF₃SO₂)₂⁻ and consequently promotes the formation of abundant LiF nanocrystals in the Li/PEO interface. The generated LiF is further verified to inhibit the breakage of C O bonds in the polymer chains and prevents the continuous interface reaction between Li and PEO. Therefore, the all-solid-state LMBs with the LiF-enriched interface exhibit improved cycling capability and stability in a cell configuration with an ultralong lifespan over 1800 h. This work is believed to open up a new avenue for rational design of high-performance all-solid-state LMBs.     

我国钢结构工程技术的新进展：新版《建筑施工手册》第16章内容精选

１０年来，我国钢结构工程取得了重大的技术进步，新版《建筑施工手册》增补了近年发展的新材料，新工艺，尤其重点介绍了高层钢结构，钢塔桅结构，高空球形结构吊装技术，并介绍了近年开始发展的钢管混凝土结构。     

浅谈工程车辆空调的设计与选型

工程机械车辆空调与普通车辆空调相比,其工作环境甚为恶劣,例如热负荷高、振动强、灰尘粉尘多;驾驶室密封性差;部分元件散热环境差等.针对上述恶劣工况,对于工程机械车辆空调系统各零部件都有较高的要求.因而空调系统设计要满足高热负荷的驾驶室降温,同时还需要注意零部件的减震,高度关注电器元件在严重的灰尘及特殊粉尘工作环境中的影响...