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Selective linear etching of monolayer black phosphorus using electron beams

Chinese Physics B 2020年第8期29卷 400-406页

作者： Yuhao Pan Bao Lei jingsi Qiao Zhixin Hu Wu Zhou Wei Ji Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials&Micro-Nano Devices Renmin University of ChinaBeijing 100872China School of Physical Sciences and CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of SciencesBeijing 100190China Center for Joint Quantum Studies and Department of Physics Institute of ScienceTianjin UniversityTianjin 300350China

Point and line defects are of vital importance to the physical and chemical properties of certain two-dimensional(2D)*** electron beams have been demonstrated to be capable of creating single-and multi-atom defects in 2D materials,the products are often random and difficult to predict without theoretical *** this study,the thermal motion of atoms and electron incident angle were additionally considered to study the vacancy evolution in a black phosphorus(BP)monolayer by using an improved first-principles molecular dynamics *** P atoms in monolayer BP tend to be struck away one by one under an electron beam within the displacement threshold energy range of 8.55-8.79 eV,which ultimately induces the formation of a zigzag-like chain *** chain vacancy is a thermodynamically metastable state and is difficult to obtain by conventional synthesis methods because the vacancy formation energy of 0.79 eV/edge atom is higher than the typical energy in monolayer ***-like quasi-bonds and a charge density wave are formed along the chain vacancy,exhibiting rich electronic *** work proposes a theoretical protocol for simulating a complete elastic collision process of electron beams with 2D layers and will facilitate the establishment of detailed theoretical guidelines for experiments on 2D material etching using focused high-energy electron beams.

关键词： electronic beam radiation simulation black phosphorus chain vacancy

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陆生植物对淡水中藻类化感抑制和机理评述

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环境保护科学 2024年第2期50卷 73-79页

作者：黄凯文汪小雄高静思谢炜平深圳职业技术大学材料与环境工程学院深圳518000

藻类的水华所带来污染问题,严重影响到人们的生产和生活,如何控制藻类的过度生长引起的污染问题,是广大水处理工作者的一大挑战。采用植物的化感作用控藻,有望为控制有害水华或赤潮爆发提供新的途径,但同时也存在一系列的问题需要迫切... 详细信息

藻类的水华所带来污染问题,严重影响到人们的生产和生活,如何控制藻类的过度生长引起的污染问题,是广大水处理工作者的一大挑战。采用植物的化感作用控藻,有望为控制有害水华或赤潮爆发提供新的途径,但同时也存在一系列的问题需要迫切解决。目前,陆生植物在抑藻方面的应用相对较少,仍能挖掘其他高效化感控藻物种。化感控藻的机理一直是研究的热点,目前在宏观、物理、化学、生物、直至微观方面机理的探索做了很多努力,并取得了很大成功。文章对陆生植物在藻污染控制方面的应用、化感物质的提取鉴定和抑藻机理方面进行了概况,并对其实际应用进行展望。

关键词：陆生植物化感作用藻类水华控制

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海上低温油藏纳米复合型高效凝胶体系的优化及性能评价

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石油化工应用 2024年第4期43卷 43-48,54页

作者：李立冬苏程王硕徐静思王新铭中海油田服务股份有限公司上海分公司上海200335 中海油田服务股份有限公司油田生产事业部天津300459 中国石油大学(华东)石油工程学院山东青岛266580

目前,海上油田受沉积环境、疏松岩石结构和强注强采开发模式等因素影响,油藏储层深部窜流通道发育较多,同时常规凝胶调剖体系在低温油藏改善过程中存在成胶困难、强度低和封堵效果欠佳的问题,无法达到封堵要求。为此,本文针对海上低温... 详细信息

目前,海上油田受沉积环境、疏松岩石结构和强注强采开发模式等因素影响,油藏储层深部窜流通道发育较多,同时常规凝胶调剖体系在低温油藏改善过程中存在成胶困难、强度低和封堵效果欠佳的问题,无法达到封堵要求。为此,本文针对海上低温油藏特性,通过筛选Y型聚合物为凝胶主剂,添加纳米型促交剂和引发剂与水溶性酚醛树脂复合交联来制得低温油藏纳米复合型高效凝胶体系。室内通过正交实验来探究水溶性酚醛树脂、纳米型促交剂以及引发剂浓度对Y-1凝胶体系的影响规律,通过SEM、耐盐实验和岩心封堵率实验等表征手段对纳米复合型高效凝胶体系进行性能评测。实验结果表明,该体系成胶时间可控、成胶强度可调和老化稳定性强,在低温条件下,Y-1凝胶体系呈现颗粒物堆积型微观结构,具有结构强度高和稳定性好的特点,岩心封堵率实验表现出良好的封堵效果。

关键词：低温油藏纳米复合型高效凝胶性能评价海上油田

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On the Complex Oscillation of Second Order Linear Differential Equations with Entire Coefficients of [p, q]-Order

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Journal of Mathematical Research with Applications 2015年第2期35卷 172-180页

作者： Jin TU jingsi WEI Chunfang CHEN College of Mathematics and Information Science Jiangxi Normal University

In this paper, the authors investigate the zeros and growth of solutions of second order linear differential equations with entire coefficients of [p, q]-order and obtain some results which improve and generalize some... 详细信息

关键词： linear differential equations [p,q]-order [p,q] exponent of convergence of zerosequence

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Deriving phosphorus atomic chains from few-layer black phosphorus

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Nano Research 2017年第7期10卷 2519-2526页

作者： Zhangru Xiao jingsi Qiao Wanglin Lu Guojun Ye Xianhui Chen Ze Zhang Wei Ji Jixue Li Chuanhong Jin State Key Laboratory of Silicon Materials School of Materials Science and Engineering Zhejiang University Hangzhou 310027 China Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices Renmin University ot China Beijing 100872 China Key Laboratory of Strongly-coupled Quantum Matter Physics Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics University of Science and Technology of China Hefei 230026 China Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing 210093 China

Phosphorus atomic chains, the narrowest nanostructures of black phosphorus （BP）, are highly relevant to the in-depth development of BP-based one-dimensional （1D） nano-electronics components. In this study, we report a top-down route for the preparation of phosphorus atomic chains via electron beam sculpturing inside a transmission electron microscope （TEM）. The growth and dynamics （i.e., rupture and edge migration） of 1D phosphorus chains are experimentally captured for the first time. Furthermore, the dynamic behavior and associated energetics of the as-formed phosphorus chains are further investigated by density functional theory （DFT） calculations. It is hoped that these 1D BP structures will serve as a novel platform and inspire further exploration of the versatile properties of BP.

关键词： black phosphorus one-dimensionalatomic chain density functional theory

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Semi-synthesis of Ubiquitin-propargylamide for identifying deubiquitinase targeting inhibitors

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Chinese Chemical Letters 2019年第3期30卷 743-746页

作者： Xiaodan Tan jingsi Bai Shan Ding Yujing Ren Danning Hong Ziqing Mei Yi-Ming Li School of Biological and Medical Engineering Hefei University of Technology Tsinghua-Peking Center for Life Sciences Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical BiologyDepartment of Chemistry Tsinghua University Biotechnology Research Institute Chinese Academy of Agricultural Sciences School of Biological Science Beijing Institute of Technology

Ubiquitin-propargylamide(Ub-PA) is one of the most widely used activity-based probe to measure the activity of deubiquitinases(DUBs) and help validate DUBs targeting inhibitors. However, current synthetic route of Ub-PA is cumbersome. In this work, we report a novel semi-synthetic strategy to prepare Ub-PA in large-scale. Biochemical assays prove that semi-synthetic Ub-PA is an effective probe in identifying DUBs targeting inhibitors.

关键词： Deubiquitinase Activity-based probe Ubiquitin-propargylamide Protein semi-synthesis Inhibitor identification

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Hydrological and sediment connectivity under freeze-thaw meltwater compound erosion conditions on a loessal slope

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International Soil and Water Conservation Research 2023年第2期11卷 402-411页

作者： Tian Wang jingsi Li Jingming Hou Yongyong Ma Peng Li Yu Tong Jing Li Zhanbin Li State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China Xi'an University of TechnologyXi'an710048ShaanxiChina Key Laboratory of National Forestry Administration on Ecological Hydrology and Disaster Prevention in Arid Regions Xian University of TechnologyXi'an 710048ShaanxiChina Shaanxi Province Institute of Water Resources and Electric Power Investigation and Design Xi'an710005ShaanxiChina

Freeze-thaw processes can influence hydrology,soil erosion,and morphological development by altering the connectivity between active pathways of water and sediment *** flow experi-ments were conducted involving frozen,shallow thawed,and unfrozen soil slopes under 1,2,and 4 L/min runoff rates at a temperature of approximately 5℃.In this study,hydrological connectivity was analysed via the simplified hydrological curve and relative surface connection *** con-nectivity was analysed via the sediment structure connectivity and sediment functional *** indicated that hydrological connectivity was greatest on frozen slopes(FS),followed by shallow thawed slopes(STS),and unfrozen slopes(UFS)given a constant flow *** connectivity increased with increasing runoff rate for each freeze-thaw *** condition and runoff rate exhibited a positive response to the hydrological *** structure connectivity increased with increasing runoff rate for each slope *** ordering of sediment structure connectivity across freeze-thaw condition was that FS was greater than STS while STS was greater than UFS inde-pendent of flow *** functional connectivity included longitudinal,lateral,and vertical con-nectivity *** longitudinal and vertical connectivity indicated a trend of first increasing and then decreasing under the different runoff rates and freeze-thaw *** a given runoff rate,the ordering of sediment longitudinal and vertical connectivity across freeze-thaw condition was that FS was greater than STS while STS was greater than *** lateral connectivity exhibited a trend of first decreasing and then *** ordering of sediment lateral connectivity across freeze-thaw condition was that UFS was greater than STS while STS was greater than *** could more easily reach longitudinal and vertical *** longitudinal and vertical co

关键词： Freeze-thaw Runoff Erosion Structureand functional connectivity Loessal slope

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Effect of ultrasonic modification on the protective activity of Flammulina velutipes polysaccharide to prevent ethanol-induced injury on GES-1 cells

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Food Science and Human Wellness 2023年第6期12卷 2451-2459页

作者： Jinrong Xiao Xin Chen jingsi Zhang Yifan Wang Lei Zhong Qiping Zhan Qiuhui Hu Liyan Zhao College of Food Science and Technology Nanjing Agricultural UniversityNanjing 210095China College of Food Science and Engineering Nanjing University of Finance and EconomicsNanjing 210023China

Flammulina velutipes(***)polysaccharides were modified by ultrasound at the rated power of 150 W and 900 *** monosaccharide composition,ultraviolet-visible,and Fourier transform infrared spectral characteristics of *** polysaccharides(FVP)and their ultrasonic modification products(U-FVPs)were *** protective effects of FVP and U-FVPs on human gastric mucosal cells GES-1 were confi rmed for the first *** mole ratios of glucose and galactose were decreased and the mole ratio of mannose was increased after ultrasonic *** with the original FVP and the FVP modifi ed by ultrasound of 150 W(U-FVP1),the FVP modifi ed by ultrasound of 900 W(U-FVP2)could better prevent ethanol-induced damage to GES-1 *** increasing ultrasound intensity,the protective effect of FVPs on GES-1 cells was significantly enhanced by more effective prevention of intracellular reactive oxygen species(ROS)production and more promotion of expression of triglyceride factor 2(TFF2),prostaglandin E2(PGE2),epidermal growth factor(EGF),and transforming growth factorβ1(TGF-β1)*** ultrasonic modifi cation might be an effective way to develop novel *** polysaccharides that could effectively resist the gastric injury caused by excessive alcohol consumption.

关键词： Flammulina velutipes polysaccharide Ultrasonic modification GES-1 cell Gastric ulcer Ethanol-induced injury

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Market misvaluation and corporate innovation:“Catering”or“risk aversion”?——Empirical evidence from China capital market

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China Journal of Accounting Research 2022年第3期15卷 57-77页

作者： Danglun Luo Zhanfeng Wu jingsi Zhuo Jianmei He Lingnan College Sun Yat-sen UniversityGuangzhouChina Business and Management UCSI UniversityMalaysia

This paper tests how market misvaluation affects corporate *** the“catering effect”observed in the US,we find that estimated stock overvaluation in China is strongly negatively associated with corporate innovation,conforming to our“risk-aversion”*** China,misvaluation affects innovation via finance and management behavior *** effect is more significant in non-state-owned corporations than in state-owned *** turnover rate and ownership concentration play moderating roles in the *** evidence sheds light on the relationship between market risks and corporate innovation in an emerging market.

关键词： Stock misvaluation Corporate inventiveness Catering mechanism Risk aversion

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超临界CO_(2)流体制备发泡聚氯乙烯塑料的研究进展

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中国氯碱 2024年第8期 15-18页

作者：聂婧思单芙蓉丁国军李丽童晓鹏新疆天业(集团)有限公司新疆石河子

主要阐述了超临界CO_(2)流体制备发泡聚氯乙烯塑料的原理及发泡过程。根据生产工艺的不同,超临界CO_(2)发泡工艺可分为间歇成型、注塑成型和挤出成型等。同时探讨了影响发泡聚氯乙烯材料的泡孔结构因素,展望了超临界CO_(2)流体制备发泡... 详细信息

主要阐述了超临界CO_(2)流体制备发泡聚氯乙烯塑料的原理及发泡过程。根据生产工艺的不同,超临界CO_(2)发泡工艺可分为间歇成型、注塑成型和挤出成型等。同时探讨了影响发泡聚氯乙烯材料的泡孔结构因素,展望了超临界CO_(2)流体制备发泡材料的发展前景。

关键词：超临界CO_(2)流体发泡材料聚氯乙烯发泡工艺

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