Hierarchical Magnetic Network Constructed by CoFe Nanoparticles Suspended Within “Tubes on Rods” Matrix Toward Enhanced Microwave Absorption

Hierarchical magnetic-dielectric composites are promising functional materials with prospective applications in microwave absorption(MA)field.Herein,a three-dimension hierarchical“nanotubes on microrods,”core–shell magnetic metal–carbon composite is rationally constructed for the first time via a fast metal–organic frameworksbased ligand exchange strategy followed by a carbonization treatment with melamine.Abundant magnetic CoFe nanoparticles are embedded within one-dimensional graphitized carbon/carbon nanotubes supported on micro-scale Mo2N rod(Mo2N@CoFe@C/CNT),constructing a special multi-dimension hierarchical MA material.Ligand exchange reaction is found to determine the formation of hierarchical magnetic-dielectric composite,which is assembled by dielectric Mo2N as core and spatially dispersed CoFe nanoparticles within C/CNTs as shell.Mo2N@CoFe@C/CNT composites exhibit superior MA performance with maximum reflection loss of−53.5 dB at 2 mm thickness and show a broad effective absorption bandwidth of 5.0 GHz.The Mo2N@CoFe@C/CNT composites hold the following advantages:(1)hierarchical core–shell structure offers plentiful of heterojunction interfaces and triggers interfacial polarization,(2)unique electronic migration/hop paths in the graphitized C/CNTs and Mo2N rod facilitate conductive loss,(3)highly dispersed magnetic CoFe nanoparticles within“tubes on rods”matrix build multi-scale magnetic coupling network and reinforce magnetic response capability,confirmed by the off-axis electron holography.     

Blue Luminescence of ZnO Nanoparticles Based on Non‐Equilibrium Processes: Defect Origins and Emission Controls

High concentrations of defects are introduced into nanoscale ZnO through non‐equilibrium processes and resultant blue emissions are comprehensively analyzed, focusing on defect origins and broad controls. Some ZnO nanoparticles exhibit very strong blue emissions, the intensity of which first increase and then decrease with annealing. These visible emissions exhibit strong and interesting excitation dependences: 1) the optimal excitation energy for blue emissions is near the bandgap energy, but the effective excitation can obviously be lower, even 420 nm (2.95 eV < E_g = 3.26 eV); in contrast, green emissions can be excited only by energies larger than the bandgap energy; and, 2) there are several fixed emitting wavelengths at 415, 440, 455 and 488 nm in the blue wave band, which exhibit considerable stability in different excitation and annealing conditions. Mechanisms for blue emissions from ZnO are proposed with interstitial‐zinc‐related defect levels as initial states. EPR spectra reveal the predominance of interstitial zinc in as‐prepared samples, and the evolutions of coexisting interstitial zinc and oxygen vacancies with annealing. Furthermore, good controllability of visible emissions is achieved, including the co‐emission of blue and green emissions and peak adjustment from blue to yellow.     

Effectiveness and petroleum geological significance of tectonic fractures in the ultra-deep zone of the Kuqa foreland thrust belt:a case study of the Cretaceous Bashijiqike Formation in the Keshen gas field

The buried depth of the gas-producing reservoir in the Kuqa foreland thrust belt of the Tarim Basin exceeds 6000 m.The average matrix porosity of the reservoir ...     

Advances and Challenges in Two?Dimensional Organic–Inorganic Hybrid Perovskites Toward High?Performance Light?Emitting Diodes

Two-dimensional (2D) perovskites are known as one of the most promising luminescent materials due to their structural diversity and outstanding optoelectronic p...     

实时数据库压缩死区的研究

厂级监控信息系统(SIS)要处理大量的数据,原始数据不处理就去存储,要耗费大量的磁盘空间。介绍了实时历史数据库里的例外报告技术,应用这种技术,对电厂里的数据特性进行了分析。通过大量数据的统计分析,找出数据本身的特性,为例外报告技术死区的设置提供依据。统计了山西漳山电厂2008年10～12月共85 248个数据,得出了某个温度信号的特性,并绘制了相应曲线,死区设置可以将曲线作为参考。     

Rapid design space exploration by hybrid fuzzy search approach for optimal architecture determination of multi objective computing systems

Design Space Exploration (DSE) with multi-parametric objective in High Level Synthesis (HLS) involves assessing the various design points in the architecture design space to find the optimum solution for the design according to the system requirements specified. Due to the time to market pressure, the cost of solving the problem of architecture selection by exhaustive analysis is strictly forbidden. The tradeoffs linked to the selection of the appropriate design point during architecture evaluation needs careful assessment for efficient design space exploration. Further DSE requires satisfying multiple conflicting multi objective conditions such as increase in accuracy of evaluation during DSE with simultaneous speedup in the exploration process. This paper presents a novel hybrid design space exploration approach which is a combination of the Priority Factor (PF) method and Fuzzy search technique that is rapid and accurate in architecture evaluation and selection. The proposed approach for DSE when applied on a number of benchmarks yielded superior results compared to the current existing DSE approach for architecture selection. The comparison results of the proposed hybrid approach with the current existing approach for different benchmarks are shown and the speedups obtained are also presented.     

Effects of phospholipid hydroperoxide glutathione peroxidase mRNA expression on meat quality of <Emphasis Type=Italic>M. longissimus dorsi</Emphasis> in pigs

Antioxidant enzymes protect muscle tissues against oxidation from reactive oxygen species and increase the stability of the muscle. Phospholipid hydroperoxide glutathione peroxidase (GPx4) is an important antioxidant enzyme in muscle tissue. So the aim of this study was to identify the effects of mRNA expression level of GPx4 gene on meat quality properties in Longissimus dorsi of three pig breeds. Total 36 pigs (12 pigs for each breed) were used to measure the meat quality properties and to analyze the expression levels of GPx4 gene by quantitative real-time PCR. The results showed that meat quality, GPx4 activity, and GPx4 mRNA levels were affected by pig breeds. There were the lowest expressible moisture, drip loss, and cooking loss in Laiwu Pig among the three breeds, and also there were the highest GPx4 activity and the expression levels of GPx4 gene in Laiwu Pig compared with the other two pig breeds. Analysis of meat samples divergent for water-holding capacity identified highly negative associations between expressions levels of GPx4 gene and expressible moisture, drip loss and cooking loss. These results suggest that the higher mRNA expression level of GPx4 gene up-regulate the water-holding capacity and the activity of GPx4, and the expression of GPx4 gene plays an important role in physiological changes related to the meat quality properties and the mechanisms of the antioxidant ion of meat.     

短程硝化反硝化生物脱氮技术的探讨

短程硝化反硝化技术是将硝化反应控制在亚硝酸盐阶段,不进行亚硝酸盐至硝酸盐的转化,直接进行反硝化反应。文章阐述了短程硝化反硝化的形成机理,理论研究进展,系统介绍了短程硝化反硝化影响因素与控制分析,并探讨了短程硝化反硝化生物脱氮技术需深入研究的要点     

MEUF去除废水中重金属和有机物及其浓缩液的处理

胶团强化超滤(MEUF)是一种表面活性剂和超滤相结合的处理含重金属或有机污染物废水的新技术。详细介绍了MEUF技术的原理、表面活性剂的选择、影响处理效果的主要因素,同时针对MEUF技术目前存在的浓缩液处理和表面活性剂回收的问题作了详细的阐述,综述了近年来MEUF技术应用的最新研究成果,并就此技术存在的问题和发展前景作了相关分析,实践表明该技术具有很好的应用前景。