Enhanced Hydrolysis of Cellulose to Reducing Sugars on Kaolinte Clay Activated by Mineral Acid

Catalysis Letters - Kaolinite, a natural, layered phyllosilicate, has been used as the solid catalyst for the hydrolysis of cellulose in our previous work. In the present study, kaolinite was...     

PVP-assisted Sn-Ti microspheres for the efficient B–V oxidation of cyclohexanone

Journal of Porous Materials - New Sn-Ti microspheres were first successfully synthesized by a PVP-assisted sol-gel method in this paper, and their performance in the B–V oxidation of...     

Characterization of Urine Stem Cell-Derived Extracellular Vesicles Reveals B Cell Stimulating Cargo

Elucidation of the biological functions of extracellular vesicles (EVs) and their potential roles in physiological and pathological processes is an expanding field of research. In this study, we characterized USC–derived EVs and studied their capacity to modulate the human immune response in vitro. We found that the USC–derived EVs are a heterogeneous population, ranging in size from that of micro–vesicles (150 nm–1 μm) down to that of exosomes (60–150 nm). Regarding their immunomodulatory functions, we found that upon isolation, the EVs (60–150 nm) induced B cell proliferation and IgM antibody secretion. Analysis of the EV contents unexpectedly revealed the presence of BAFF, APRIL, IL–6, and CD40L, all known to play a central role in B cell stimulation, differentiation, and humoral immunity. In regard to their effect on T cell functions, they resembled the function of mesenchymal stem cell (MSC)–derived EVs previously described, suppressing T cell response to activation. The finding that USC–derived EVs transport a potent bioactive cargo opens the door to a novel therapeutic avenue for boosting B cell responses in immunodeficiency or cancer.     

Operational optimization of a building-level integrated energy system considering additional potential benefits of energy storage

As a key component of an integrated energy system (IES), energy storage can effectively alleviate the problem of the times between energy production and consumption. Exploiting the benefits of energy storage can improve the competitiveness of multi-energy systems. This paper proposes a method for day-ahead operation optimization of a building-level integrated energy system (BIES) considering additional potential benefits of energy storage. Based on the characteristics of peak-shaving and valley-filling of energy storage, and further consideration of the changes in the system’s load and real-time electricity price, a model of additional potential benefits of energy storage is developed. Aiming at the lowest total operating cost, a bi-level optimal operational model for day-ahead operation of BIES is developed. A case analysis of different dispatch strategies verifies that the addition of the proposed battery scheduling strategy improves economic operation. The results demonstrate that the model can exploit energy storage’s potential, further optimize the power output of BIES and reduce the economic cost.     

Si CMOS Ka-band millimeter wave power amplifier

In order to meet the requirement of higher transmission power for the millimeter wave radar or communication system,a Ka band power amplifier is designed based on the 65 nm bulk Si CMOS process.This power amplifier works at 30~32 GHz ,and consists of two-stage CASCODE differential pairs structure amplifiers.Neutralizing capacitances are used to enhance its stability,and the on chip matching network is realized based on transformer coils.After testing,the maximum output power of the power amplifier in the operating frequencies is 16.3 dBm.Its maximum PAE is 16.9 %,-1 dB compression point is 13.2 dBm,and power gain is 23.6 dB.The power amplifier chip presented in this paper has advantages in power gain and chip area utilization,which provides a feasible high power output design example for the silicon-based millimeter wave power amplifier.     

考虑降低碳排放的多源微网经济调度方法

在低碳电力的背景下,含多种新能源的微网系统成为节能减排的重要模式.为保证新能源消纳同时兼顾微网的经济性与环保性,本文将碳交易机制引入微网的运行调度模型中,构建了含风电、光伏发电、燃气轮机的微网优化调度模型.该模型综合考虑了碳交易成本,风电、光伏发电的运行成本和外购能源成本以及电力平衡的相关约束.算例对本文模型与传统无碳交易模型的调度结果进行对比,并分析了不同新能源消纳比例的碳排放量、运行成本等,从不同角度验证了该模型的有效性.     

内建电场调控光生电荷分离效率的研究进展

光催化技术是解决现今环境污染和能源危机的重要手段之一,然而大部分催化剂的光催化效率较低,提高光生电荷的分离是提高光催化效率的一种有效方法。首先对催化剂的光催化原理进行了概述;结合近年来国内外在提高光生电荷分离效率方面取得的最新成果及进展,从内建电场的产生机理入手,综述了半导体p⁃n结、异相结、极化表面和铁电材料极化对光生电荷分离效率及光催化性能的影响;最后对内建电场在未来光催化领域的发展方向进行了展望。     

镍基高温合金GH536在室温下的锯齿流变行为

对镍基高温合金GH536进行了室温拉伸试验(加载速率分别为0.06 mm/min,0.6 mm/min,3.6 mm/min和36 mm/min),研究其在室温拉伸变形过程中的锯齿流变行为.结果表明:合金在低于3.6 mm/min的加载速率下,由于合金中原始退火孪晶界对位错滑移的阻碍作用,在其应力-应变曲线上出现了以B型锯齿为主的A型、B型两种锯齿,且在拉伸变形后合金内原始退火孪晶界出现了不同程度的变形;当加载速率为36 mm/min时,由于位错滑移速度加快,孪晶界与快速移动的位错相遇后发生分解,孪晶界几乎消失,锯齿效应变得不明显;此外,在不同加载速率和应变下,合金应力-应变曲线上锯齿的振幅大小不同,这主要与移动和固定位错的密度相关.     

可替换式偏心支撑钢框架抗震性能

为了研究耗能梁段屈服类型、柱轴压和震后替换耗能梁段对可替换式偏心支撑钢框架抗震性能的影响,采用拟静力循环加载的方法对4个可替换式偏心支撑钢框架进行试验,并从滞回曲线、刚度退化、延性系数和构件应变等方面分析其抗震性能. 结果表明,耗能梁段屈服类型对可替换式偏心支撑钢框架抗震性能影响较大,随着耗能梁段从剪切型过渡到弯曲型,结构的承载能力、延性和耗能能力均呈下降趋势;随着柱轴压的增加,试件的初始刚度和延性系数逐渐降低;震后替换耗能梁段的模型与原模型相比,仅耗能能力有所下降,其余性能变化不大,说明这种结构具有良好的可替换性. 通过对应变分析发现,直至试验结束,耗能梁以外绝大部分区域仍处于弹性阶段,说明耗能梁段作为第一道抗震防线可以保护其他构件.     

排采连续性对煤层气开采的影响

排采连续性对煤层气开发至关重要。但是,在排采过程中关井现象不可避免,重新开井后如何排采、制定合理的排采制度是提高产量的关键。通过对煤层气生产阶段理论进行分析,结合关井前后矿场数据,同时借助数值模拟方法,对关井过程中储层参数变化进行了研究。结果表明,关井明显改变储层物性参数,造成井筒附近煤层含水饱和度增加,井底压力升高,同时引起近井地带自由气重新吸附,降低气体渗流能力。因此,重新开井后快速排水有助于沟通气体渗流通道,提高气体流动能力,增加产气量。