微纳米气泡形成羟基自由基的研究进展

从微纳米气泡溶液中是否可以产生·OH、·OH的鉴别方法、·OH的生成机理以及强化·OH的生成等几个方面论述了微纳米气泡溶液中生成·OH的研究进展.电子自旋共振技术和荧光分光光度法作为检测·OH的2种技术,均存在一定的误导性,对于荧光分光光度法,最重要的就是排除H2 O2的干扰.此外,目前要获得含有高浓度·OH的微纳米气...     

二维金属有机框架材料的制备及其应用

二维金属有机框架（MOFs）作为一类新型的二维多孔材料,具有厚度小、比表面积大、孔隙率高、可接触活性位点丰富等优点,在众多领域都具有研究和潜在的应用价值。本文简要综述了近年来二维MOFs的制备方法,包括“自上而下”和“自下而上”两种策略。自上而下法操作简单,有广泛的适用性;自下而上法可以通过控制实验条件在一定程度上实现对材料的可控制备。阐述了二维MOFs在电化学储能、催化、传感、气体分离等领域的应用研究。深层剖析了二维MOFs的特性对储能器件电化学性能以及反应催化活性的影响。此外,二维MOFs的高电导率和电荷转移率还促进了其在电化学传感器方面的发展;基于二维MOFs的分子筛膜也越来越受到研究人员的关注。最后指出了二维MOFs存在易团聚、厚度难以精确控制、制取成本较高、产率偏低等问题,提出了解决方案及其未来的发展方向。     

Analysis of Temperature Effect in Quadruple Gate Nano-scale FinFET

Silicon - Quadruple gate FinFET is a promising candidate among other multi-gate MOS devices due to it’s better scalability and higher short channel effect suppression capability in advanced...     

A panoramic view of Li7P3S11 solid electrolytes synthesis,structural aspects and practical challenges for all-solid-state lithium batteries

The development of an inorganic electrochemical stable solid-state electrolyte is essentially responsible for future state-of-the-art all-solid-state lithium batteries (ASSLBs). Because of their advantages in safety, working temperature, high energy density, and packaging, ASSLBs can develop an ideal energy storage system for modern electric vehicles (EVs). A solid electrolyte (SE) model must have an economical synthesis approach, exhibit electrochemical and chemical stability, high ionic conductivity, and low interfacial resistance. Owing to its highest conductivity of 17 mS·cm^-1, and deformability, the sulfide-based Li₇P₃S₁₁ solid electrolyte is a promising contender for the high-performance bulk type of ASSLBs. Herein, we present a current glimpse of the progress of synthetic procedures, structural aspects, and ionic conductivity improvement strategies. Structural elucidation and mechanistic approaches have been extensively discussed by using various characterization techniques. The chemical stability of Li₇P₃S₁₁ could be enhanced via oxide doping, and hard and soft acid/base (HSAB) concepts are also discussed. The issues to be undertaken for designing the ideal solid electrolytes, interfacial challenges, and high energy density have been discoursed. This review aims to provide a bird's eye view of the recent development of Li₇P₃S₁₁-based solid-state electrolyte applications and explore the strategies for designing new solid electrolytes with a target-oriented approach to enhance the efficiency of high energy density all-solid-state lithium batteries.     

微波诱导催化脱硝研究进展

发展经济高效的烟气脱硝技术是大气污染控制领域的重要研究方向,利用微波诱导催化技术开展烟气脱硝已成为当前热点方向。本文对近年国内外研究人员关于微波诱导催化治理烟气NO_x的研究成果进行了综述,详细介绍了微波还原脱硝和微波氧化脱硝相关成果,重点讨论了以碳酸氢铵和活性炭为还原剂的微波诱导还原催化脱硝技术以及ZSM-5、金属氧化物和钙钛矿型混合氧化物微波催化还原脱硝技术。最后通过对比微波还原脱硝和微波氧化脱硝两种方法,提出研发微波催化氧化脱硝技术、探究其反应机理是开发新型烟气脱硝技术的重要方向。     

流域生态环境需水与缺水的快速评估(Ⅰ)：理论

为识别生态环境缺水严重的区域,合理评价生态环境用水的配置效果,本文提出了一种新的流域生态环境需水与生态环境缺水快速评估方法。将流域的生态环境需水满足程度定义为,流域"实际生态环境用水"与流域在未受或少受人类活动干扰时的"自然状态条件下的生态环境用水"的接近程度。以土地利用资料为基础,运用层次分析法构建流域生态环境需水特征指标来表征流域生态环境用水的相对大小;借鉴水体生物快速评估法的思想,通过流域单元划分、参照单元选择、参照组构建、参照组匹配、观测值与期望值的比较计算等步骤,可以对不同级别流域的生态环境缺水问题进行深入分析,从而快速识别生态环境缺水严重区域、预测其生态环境缺水动态变化,并对生态环境用水配置效果进行评价。     

Multi-Objective Operating Rules for Danjiangkou Reservoir Under Climate Change

The natural variations of climatic system, as well as the potential influence of human activity on global warming, have changed the hydrologic cycle and threatened current water resources management. And the conflicts between different objectives in reservoir operation may become more and more challenging because of the impact of climate change. This study aims at deriving multi-objective operating rules to adapt to climate change and alleviate the conflicts. By combining the reservoir operation function and operating rule curves, an adaptive multi-objective operation model was proposed and developed. The optimal operating rules derived both by dynamic programming and NSGA-II method were compared and discussed. The projection pursuit method was used to select the best operating rules. The results demonstrate that the reservoir operating rules obtained by NSGA-II can increase the power generation and water supply yield and reliability, and the rules focusing on water supply can significantly increase the reservoir annual water supply yield (by 18.7 %). It is shown that the proposed model would be effective in reservoir operation under climate change.     

Kinetics of semicarbazide and nitrofurazone in chicken eggs and egg powders

The accumulation, depletion and partitioning of semicarbazide (SEM) and its parent compound nitrofurazone (NFZ) in eggs were studied using hens fed NFZ at therapeutic and sub-therapeutic levels. Dietary NFZ correlated strongly with NFZ and total SEM in eggs, while 28% of observed SEM was present in the form of parent NFZ. Depletion half-life in eggs was 2.4 days for SEM and 1.1 days for NFZ. NFZ accumulated preferentially in yolk (57-63%) as opposed to albumen, while 71-80% of SEM was found in yolk. In whole egg, 29% of SEM was present as tissue-bound residues compared with 80% in breast muscle. Whilst NFZ and SEM were partly degraded by pasteurization and spray drying, sufficient NFZ remained to suggest it might be detectable in egg powders when SEM is observed at low microg kg(-1) concentrations. NFZ was detectable in whole eggs during ingestion of only 0.1% of the therapeutic NFZ dose, making detection of intact NFZ in eggs a feasible means to prove conclusively the administration of this banned compound.     

The potential of sphingomyelin as a chemopreventive agent in AOM-induced colon cancer model: wild-type and p53+/- mice

A protective effect of sphingolipids on colorectal cancer (CRC) has been reported in certain mouse strains. It is unknown if sphingolipids are protective in a p53 deficiency mouse model of CRC. This study investigated the effect of sphingomyelin (SM) on intestinal sphingomyelinase (SMase) activity, colonic epithelial biology and azoxymethane (AOM)-induced CRC. Groups of wild-type (C57BL/6J) and p53+/- mice were fed 0.1% SM diet for 4 wk, administered a single AOM injection and then killed 6 h later to measure apoptosis and proliferation. Separately, both mouse types were fed 0.05% SM diet, administered three AOM injections and killed 33-38 wk later to measure tumour formation. SM significantly increased SMase activity and reduced proliferation (p < 0.05) in wild-type and p53+/- mice. SM did not regulate baseline apoptosis, apoptotic response to AOM or apoptosis in tumours, nor did it restore defective apoptosis in p53+/- mice. There was a nonsignificant trend to reduced tumour incidence with SM in wild-type (p = 0.15) and p53+/- (p = 0.12) mice. In conclusion, while increasing intestinal SMase activity and suppressing proliferation, SM did not promote any form of apoptosis and failed to achieve significant protection in these mice. Further investigation to understand the variable effect of SM in preventing CRC is warranted.     

Drinking behavior of lactating dairy cows and prediction of their water intake

The water intake of 41 lactating dairy cows managed according to current dairy farm practices was individually and continuously monitored to 1) investigate drinking behavior and 2) determine factors affecting water intake. The cows were housed in a free-stall barn and fed once daily with a corn silage and concentrate-based total mixed ration (48% dry matter content; 20.6 ± 3.3 kg/d of dry matter intake). Cows were milked twice daily, with a yield of 26.5 ± 5.9 kg/d. The daily free water intake (FWI) was 83.6 ± 17.1 L, achieved during 7.3 ± 2.8 drinking bouts. The drinking bout water intake was 12.9 ± 5.0 L. Almost three-fourths of the FWI occurred during working hours (0600 to 1900 h). Consumption peaks corresponded to feeding and milking times. More than one quarter of the daily FWI was met during the 2 h after each milking. About 75% of the present cows visited the watering point at least once during the 2 h after the evening milking. It is probable that drinking behavior evolved with lactation, but further studies are required to identify the relationship between lactation stage and drinking behavior. The most relevant factors affecting the daily FWI of lactating cows were best combined according to the following predictive equation: (R² = 0.45; n = 41 cows, n = 1,837): FWI, L/d = 1.53 × dry matter intake (kg/d) + 1.33 × milk yield (kg/d) + 0.89 × dry matter content (%) + 0.57 × minimum temperature (°C) - 0.30 × rainfall (mm/d) - 25.65. The results obtained using these equations were in agreement with the equations developed by other researchers.