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81.
Layered lithium transition‐metal oxides, with large capacity and high discharge platform, are promising cathode materials for Li‐ion batteries. However, their high‐rate cycling stability still remains a large challenge. Herein, hierarchical LiNi1/3Co1/3Mn1/3O2 polyhedron assemblies are obtained through in situ chelation of transition metal ions (Ni2+, Co2+, and Mn2+) with amide groups uniformly distributed along the backbone of modified polyacrylonitrile chains to achieve intimate mixing at the atomic level. The assemblies exhibit outstanding electrochemical performances: superior rate capability, high volumetric energy density, and especially ultralong high‐rate cyclability, due to the superiority of unique hierarchical structures. The polyhedrons with exposed active crystal facets provide more channels for Li+ diffusion, and meso/macropores serve as access shortcuts for fast migration of electrolytes, Li+ and electrons. The strategy proposed in this work can be extended to fabricate other mixed transition metal‐based materials for advanced batteries.  相似文献   
82.
Superhydrophobic coatings are widely applicable, e.g., as self-cleaning surfaces or water–oil separation membranes, yet their wider usage is impeded due to costs of fabrication, size, or substrate limitation. Spray-coating is a versatile coating procedures and might offer a good solution for the fabrication of these superhydrophobic coatings, due to the fact that coatings can be fabricated on various materials in a simple, fast, and inexpensive manner. Most procedures rely on hybrid coatings of hydrophobized nanoparticles and a polymeric matrix, which have several drawbacks including the easy loss of nanoparticles and difficult waste handling. Here, the fabrication of the superhydrophobic material, called Fluoropor, for the first time, by spray-coating on various substrates including metals, tissues, concrete, and glass is presented. It is fabricated by spray-coating a mixture of a highly fluorinated monomer blended with porogens followed by photopolymerization. The superhydrophobicity of the material relies on the porous structure on the micro-/nanoscale across the bulk material and does not require any nanoparticles. Excellent self-cleaning ability of these coatings, resistance against thermal and abrasive impact, and their application as oil–water separation membranes are shown. This versatile applicability is highly promising for real-world application as self-cleaning coatings or oil–water separating membranes.  相似文献   
83.
84.
Ti6Al4V alloy has good corrosion resistance due to the formation of the passive oxide films on the surface of Ti6Al4V alloy. However, Ti6Al4V alloy has poor tribocorrosion resistance in the seawater environment. Herein the present work, plasma electrolytic oxidation (PEO) with the electrolyte of glycerol and sodium borate is used to generate PEO coatings on the surface of Ti6Al4V alloy to improve its tribocorrosion properties. The microstructure and tribocorrosion properties of PEO coatings are investigated by using scanning electron microscopy, X-ray diffraction, and tribometer, respectively. The growth kinetics and the tribocorrosion mechanisms of PEO coatings are discussed in detail. It is shown in the results that PEO coatings deposited on the surface of Ti6Al4V alloy are composed of rutile and anatase phases. The surface hardness and thickness of PEO coatings are enhanced with the increase of the voltage and time. The wear rate of Ti6Al4V alloy with PEO coatings is significantly reduced in artificial seawater.  相似文献   
85.
大庆石化总厂规划在“九五”期间将30万t/a乙烯装置扩建到48万t/a,HDPE装置是主要的乙烯使用装置。根据该装置几年来的生产实践及与日本三井油化同类装置生产情况的对比,并经过对主要操作单元的详细计算,对该装置设计能力由14万t/a扩建到24万t/a进行了可行性分析,提出了通过对部分设备进行改造后,产量提高10万t/a是可行的。  相似文献   
86.
To further study the relationship between resistance to apoptosis and drug resistance in harringtonine-resistant HL-60 cells (HR20), cyclosporine A (CsA) 20, 10 micrograms.ml-1 was shown to induce the sensitive HL-60 cells to apoptosis, showing a typical DNA "ladder" band. But the same concentrations of CsA retarded the HR20 cells in G1 phase and could not induce the cells to apoptosis. The cellular daunorubicin accumulation increased when HR20 cells were treated with low concentration of CsA and the reversal of drug resistance by CsA was unrelated to the retardation of cell cycle progression. High phosphorylation of about 50 kDa protein occured when HR20 cells were treated with CsA 10 micrograms.ml-1. The results domonstrate that cyclosporine A retarded the harringtonine-resistant HL-60 cells in G1 phase but induced HL-60 cells to apoptosis, and the retardation was unrelated to drug resistance.  相似文献   
87.
In this paper, a special-purpose qualitative model learning (QML) system using an immune-inspired algorithm is proposed to qualitatively reconstruct biological pathways. We choose a real-world application, the detoxification pathway of Methylglyoxal (MG), as a case study. First a converter is implemented to convert possible pathways to qualitative models. Then a general learning strategy is presented. To improve the scalability of the proposed QML system and make it adapt to future more complicated pathways, a modified clonal selection algorithm (CLONALG) is employed as the search strategy. The performance of this immune-inspired approach is compared with those of exhaustive search and two backtracking algorithms. The experimental results indicate that this immune-inspired approach can significantly improve the search efficiency when dealing with some complicated pathways with large-scale search spaces.  相似文献   
88.
基于静态路由的ISP负载均衡解决方案   总被引:1,自引:0,他引:1  
传统的ISP负载均衡方法主要有2种,一是使用开启BGP协议的高端防火墙;二是使用专业负载均衡设备.本论文建立了1套新型的基于静态路由的ISP负载均衡解决方案.本文首先通过Whois协议获得ISP的AS号码,在公网BGP路由器数据库中根据这个AS号码查询属于不同ISP的全部BGP路由条目;之后将不同ISP(例如中国电信和中国联通)的路由条目导入园区网边界防火墙,使得用户访问实现负载分担和路由备份.本方案适用于大中型企业和大型居民小区园区网,相比传统的负载均衡方法,本方案能够节省大量设备投资.  相似文献   
89.
基于DDS的低通滤波器设计与仿真   总被引:4,自引:0,他引:4  
分析了几种经典滤波器特性,重点研究了DDS系统中低通滤波器的设计方法。根据DDS的结构特点和输出杂散频谱特性,结合滤波器技术指标使用了归一化法完成了一个九阶椭圆函数低通滤波器的设计,使其通带截至频率为120MHz、通带内最大衰减为0.2dB、在135MHz处阻带内最小衰减为66dB。通过Multisim10对其进行仿真后可以得出,使用此种方法设计的低通滤波器过渡带陡峭、幅频特性仿真良好,并且能够很好地满足预期的技术指标。  相似文献   
90.
In this paper, we introduce and study the multi-compartment capacitated arc routing problem—an extension of the classical capacitated arc routing problem, but where the required edges have a demand for different products, and multi-compartment vehicles are available to co-distribute these commodities. We present a local search algorithm that exploits well-known moves (2-opt, re-insert, relocate, exchange and cross). We take advantage of speed up tricks such as marking and neighbour lists, and we combine the procedure with the guided local search meta-heuristic in order to reach high quality solutions. We report on results from extensive computational experiments. Our aim is to reveal in what situations co-distribution by partitioned vehicles saves in routing costs as compared with separate distribution with un-partitioned trucks. We explore sensitivities in key problem characteristics including, the number of commodities, the vehicle capacity, the location of the depot and required edges, the density of required edges, and the demand per commodity for the required edges.  相似文献   
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