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Characteristics and Preliminary Causes of Tropical Cyclone Extreme Rainfall Events over Hainan Island 被引量:6
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作者 Xianling JIANG Fumin REN +3 位作者 yunjie li Wenyu QIU Zhuguo MA Qinbo CAI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2018年第5期580-591,共12页
The characteristics of tropical cyclone(TC) extreme rainfall events over Hainan Island from 1969 to 2014 are analyzed from the viewpoint of the TC maximum daily rainfall(TMDR) using daily station precipitation dat... The characteristics of tropical cyclone(TC) extreme rainfall events over Hainan Island from 1969 to 2014 are analyzed from the viewpoint of the TC maximum daily rainfall(TMDR) using daily station precipitation data from the Meteorological Information Center of the China Meteorological Administration, TC best-track data from the Shanghai Typhoon Institute,and NCEP/NCAR reanalysis data. The frequencies of the TMDR reaching 50, 100 and 250 mm show a decreasing trend[-0.7(10 yr)^(-1)], a weak decreasing trend [-0.2(10 yr)^(-1)] and a weak increasing trend [0.1(10 yr)^(-1)], respectively. For seasonal variations, the TMDR of all intensity grades mainly occurs from July to October, with the frequencies of TMDR 50 mm and 100 mm peaking in September and the frequency of TMDR 250 mm [TC extreme rainstorm(TCER) events]peaking in August and September. The western region(Changjiang) of the Island is always the rainfall center, independent of the intensity or frequencies of different intensity grades. The causes of TCERs are also explored and the results show that topography plays a key role in the characteristics of the rainfall events. TCERs are easily induced on the windward slopes of Wuzhi Mountain, with the coordination of TC tracks and TC wind structure. A slower speed of movement, a stronger TC intensity and a farther westward track are all conducive to extreme rainfall events. A weaker northwestern Pacific subtropical high is likely to make the 500-h Pa steering flow weaker and results in slower TC movement, whereas a stronger South China Sea summer monsoon can carry a higher moisture flux. These two environmental factors are both favorable for TCERs. 展开更多
关键词 Hainan Island tropical cyclones extreme rainfall events CHARACTERISTICS CAUSES
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Effect of Limited Enzymatic Hydrolysis on Structure Characterization of Glycinin
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作者 Chunhong DUAN Wan SUN +2 位作者 yunjie li Yunlong WANG Siyi PAN 《Agricultural Biotechnology》 CAS 2012年第3期52-54,共3页
[ Objective] This study aimed to characterize the structure of soybean glycinin affected by limited enzymatic hydrolysis. [ Method ] The glycinin was limitedly hydrolyzed by alkaline protease; then the SDS-polyacrylam... [ Objective] This study aimed to characterize the structure of soybean glycinin affected by limited enzymatic hydrolysis. [ Method ] The glycinin was limitedly hydrolyzed by alkaline protease; then the SDS-polyacrylamide gel electrophoresis (SDS-PAGE), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (fTIR) and other means were performed to characterize the glyeinin structure changing during the hydrolysis process. [ Result] SDS-PAGE analysis showed that the subunit contem of glycinin significantly decreased after hydrolysis, and acidic subunits were more susceptible to hydrolysis than alkaline subunits. The scanning electron microscopy revealed that the structure of glycinin powder changed greatly after hydrolysis. The I^TIR results showed that the propor- tions of all conformations of glycinin changed greatly during hydrolysis process. In addition, the protein hydrophobicity and sulfhydryl content were also significantly influenced by hydrolysis. [ Conclusion] The enzymatic hydrolysis greatly changed the conformations of glyeinin, and the change was dependent on the degree of hy- drolysis. 展开更多
关键词 GLYCININ Alkaline proteinase HYDROLYSIS Structure characterization
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Classification and structural characteristics of amorphous materials based on interpretable deep learning
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作者 崔佳梅 李韵洁 +1 位作者 赵偲 郑文 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第9期356-363,共8页
Defining the structure characteristics of amorphous materials is one of the fundamental problems that need to be solved urgently in complex materials because of their complex structure and long-range disorder.In this ... Defining the structure characteristics of amorphous materials is one of the fundamental problems that need to be solved urgently in complex materials because of their complex structure and long-range disorder.In this study,we develop an interpretable deep learning model capable of accurately classifying amorphous configurations and characterizing their structural properties.The results demonstrate that the multi-dimensional hybrid convolutional neural network can classify the two-dimensional(2D)liquids and amorphous solids of molecular dynamics simulation.The classification process does not make a priori assumptions on the amorphous particle environment,and the accuracy is 92.75%,which is better than other convolutional neural networks.Moreover,our model utilizes the gradient-weighted activation-like mapping method,which generates activation-like heat maps that can precisely identify important structures in the amorphous configuration maps.We obtain an order parameter from the heatmap and conduct finite scale analysis of this parameter.Our findings demonstrate that the order parameter effectively captures the amorphous phase transition process across various systems.These results hold significant scientific implications for the study of amorphous structural characteristics via deep learning. 展开更多
关键词 AMORPHOUS interpretable deep learning image classification finite scale analysis
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玉米蜂花粉多糖的抗氧化效果研究
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作者 李云捷 吴进菊 +1 位作者 于博 吴谋成 《食品与营养科学》 2014年第4期77-83,共7页
通过对小鼠组织及体液的体外试验,研究了不同体系中玉米蜂花粉粗多糖及级分的体外抗氧化活性。结果表明,玉米蜂花粉粗多糖及其级分可抑制小鼠肝组织的脂质过氧化,对Fe2+和H2O2诱导的肝组织过氧化物损伤具有保护作用,能减轻线粒体肿胀的... 通过对小鼠组织及体液的体外试验,研究了不同体系中玉米蜂花粉粗多糖及级分的体外抗氧化活性。结果表明,玉米蜂花粉粗多糖及其级分可抑制小鼠肝组织的脂质过氧化,对Fe2+和H2O2诱导的肝组织过氧化物损伤具有保护作用,能减轻线粒体肿胀的发生。 展开更多
关键词 玉米蜂花粉多糖 小鼠 体外 抗氧化
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软骨细胞外基质在软骨组织工程中的研究进展 被引量:2
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作者 李云洁 赵艳红 杨强 《华西口腔医学杂志》 CAS CSCD 北大核心 2019年第2期220-223,共4页
软骨组织工程是修复软骨缺损的有效方式,需要理想的支架材料促进干细胞发挥再生性能。软骨细胞外基质(CECM)能够有效地模仿软骨细胞生存环境,不仅对软骨细胞和干细胞具有良好的生物相容性,满足支架材料的基本要求,还能够促进软骨细胞分... 软骨组织工程是修复软骨缺损的有效方式,需要理想的支架材料促进干细胞发挥再生性能。软骨细胞外基质(CECM)能够有效地模仿软骨细胞生存环境,不仅对软骨细胞和干细胞具有良好的生物相容性,满足支架材料的基本要求,还能够促进软骨细胞分泌基质和诱导干细胞向软骨细胞分化,是一种极具优势的支架材料。CECM良好的促基质分泌和诱导分化作用与其含有多种软骨相关蛋白有关。在实际应用中,CECM存在力学性能不强和细胞渗透不足等问题,联合其他材料能在一定程度上弥补其不足,因此寻找性能更加优化的复合方式是CECM的应用趋势。本文对CECM材料在软骨组织工程中的研究进展作一综述。 展开更多
关键词 软骨细胞外基质 软骨组织工程 软骨再生 干细胞
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Influence of coronary bifurcation angle on atherosclerosis 被引量:4
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作者 Zhaomiao liu Shengwei Zhao +3 位作者 yunjie li Feng Shen Yipeng Qi Qi Wang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2019年第6期1269-1278,共10页
Hemodynamics plays a crucial role in the development and progression of coronary atherosclerosis,which is prone to occur in branch bifurcation.A n individual aortic-coronary artery model and three changed bifurcation ... Hemodynamics plays a crucial role in the development and progression of coronary atherosclerosis,which is prone to occur in branch bifurcation.A n individual aortic-coronary artery model and three changed bifurcation angle models are constructed by Mimics and Freeform based on computed tomography angiography.The influence of different coronary bifurcation angles between left main(LM),left anterior descending(LAD),and left circumflex(LCX)on the blood flow field and related hemodynamic parameters are studied.It is shown that a wider bifurcation angle between LAD and LCX can cause a wider low-wall shear stress area,leading to atherosclerosis.Similarly,a decreased angle between LM and LAD is predisposed to prevent atherosclerosis.The results help to better understand the hemodynamic causes of atherosclerosis with various bifurcation angles in coronary arteries and to provide guidance for clinical assessment and prevention. 展开更多
关键词 ATHEROSCLEROSIS Coronary artery Bifurcation angle HEMODYNAMICS Wall shear stress
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Direction estimation for two steady targets in monopulse radar
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作者 Zhenxing Lu yunjie li Meiguo Gao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2015年第1期61-68,共8页
Traditional monopulse radar cannot resolve two targets present in one range and Doppler cell by means of the monopulse ratio. A novel algorithm is proposed to estimate the directions of two steady targets with two pul... Traditional monopulse radar cannot resolve two targets present in one range and Doppler cell by means of the monopulse ratio. A novel algorithm is proposed to estimate the directions of two steady targets with two pulses. The algorithm has a closedform expression and its variance is derived at high signal-to-noise ratios(SNRs). Furthermore, the pulse pair selection criterion and the estimation method with multiple pulses are given. Finally, some numerical results are shown to validate the proposed algorithm and the effect of slight target fluctuations is tested. 展开更多
关键词 direction estimation two unresolved targets monopulse radar
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HIRFL cooling water-monitoring system design and construct
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作者 yunjie li Yanyu Wang +2 位作者 Detai Zhou Jia Yin Jianjun Su 《Radiation Detection Technology and Methods》 2018年第2期26-30,共5页
Background HIRFL is a heavy ion accelerator built by the Institute of Modern Physics,Chinese Academy of Sciences,which constitutes a total length of over 900 m by the SFC,SSC,CSRm,CSRe and so on.It bears a lot of rese... Background HIRFL is a heavy ion accelerator built by the Institute of Modern Physics,Chinese Academy of Sciences,which constitutes a total length of over 900 m by the SFC,SSC,CSRm,CSRe and so on.It bears a lot of research task of the country,so to ensure its safe operation is very important.Purpose Cool-water system is a key part in HIRFL,and the parameters of the cool-water system need to be monitored before an accident occurs.Methods This article describes three aspects of the system,from the water leakage detection,pressure monitoring,to the water-level monitoring.A complete monitor system was designed and constructed,including the hardware structure;the data transfer mode,as well as specific control program.C++,FLASH and SCADA are used in the monitoring system.Results Fault alarm was performed timely and accurately by the monitoring system,and many accidents were avoided.Conclusion Water system monitoring is an important part of the accelerator control system.It will also play a major role in the construction of large-scale scientific device named HIAF in the further. 展开更多
关键词 HIRFL SCADA Water leakage detection Water pressure monitoring Water level monitoring
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溶剂热制备CuSe纳米片及其储钠性能研究
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作者 李云杰 马光耀 +2 位作者 宋金梅 杨剑 钱逸泰 《中国科学:化学》 CAS CSCD 北大核心 2021年第6期782-790,共9页
由于资源储量丰富,钠离子电池已经成为下一代储能电池的有力候选方案之一.过渡金属硒化物由于具有易于制备、导电性能较好等优点而引起广泛关注.本文使用溶剂热方法成功地制备出六方相CuSe纳米片,并将其作为钠离子电池负极材料,结合多... 由于资源储量丰富,钠离子电池已经成为下一代储能电池的有力候选方案之一.过渡金属硒化物由于具有易于制备、导电性能较好等优点而引起广泛关注.本文使用溶剂热方法成功地制备出六方相CuSe纳米片,并将其作为钠离子电池负极材料,结合多种测试及表征手段对其储钠性能与电化学反应机理进行了研究.电化学测试表明CuSe具有优异的电化学性能.在5 A g^(-1)电流密度下的可逆容量为183.5 mAh g^(-1),容量保持率为70.7%(相对0.1 A g^(-1)电流密度下的可逆容量而言).在2 A g^(-1)循环800圈后,容量保持率高达97.4%.非原位X射线粉末衍射和选区电子衍射测试结果表明,CuSe在储钠过程中会发生不可逆的转化反应生成Cu_(2-x)Se,后续的循环实际上是Cu_(2-x)Se进行钠离子的转化反应. 展开更多
关键词 CuSe纳米片 溶剂热反应 钠离子电池 负极材料 电化学反应机理
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Stoichiometric Conversion of Maltose for Biomanufacturing by In Vitro Synthetic Enzymatic Biosystems 被引量:2
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作者 Guowei li Xinlei Wei +4 位作者 Ranran Wu Wei Zhou yunjie li Zhiguang Zhu Chun You 《BioDesign Research》 2022年第1期217-227,共11页
Maltose is a natural α-(1,4)-linked disaccharide with wide applications in food industries and microbial fermentation. However,maltose has scarcely been used for in vitro biosynthesis, possibly because its phosphoryl... Maltose is a natural α-(1,4)-linked disaccharide with wide applications in food industries and microbial fermentation. However,maltose has scarcely been used for in vitro biosynthesis, possibly because its phosphorylation by maltose phosphorylase (MP)yields β-glucose 1-phosphate (β-G1P) that cannot be utilized by α-phosphoglucomutase (α-PGM) commonly found in in vitrosynthetic enzymatic biosystems previously constructed by our group. Herein, we designed an in vitro synthetic enzymaticreaction module comprised of MP, β-phosphoglucomutase (β-PGM), and polyphosphate glucokinase (PPGK) for thestoichiometric conversion of each maltose molecule to two glucose 6-phosphate (G6P) molecules. Based on this syntheticmodule, we further constructed two in vitro synthetic biosystems to produce bioelectricity and fructose 1,6-diphosphate (FDP),respectively. The 14-enzyme biobattery achieved a Faraday efficiency of 96.4% and a maximal power density of 0.6mW/cm^(2),whereas the 5-enzyme in vitro FDP-producing biosystem yielded 187.0mM FDP from 50 g/L (139mM) maltose by adopting afed-batch substrate feeding strategy. Our study not only suggests new application scenarios for maltose but also provides novelstrategies for the high-efficient production of bioelectricity and value-added biochemicals. 展开更多
关键词 ENZYMATIC utilized MAXIMAL
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Comparison of Two Drought Indices in Studying Regional Meteorological Drought Events in China
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作者 Yongmei WANG Fumin REN +1 位作者 Yilei ZHAO yunjie li 《Journal of Meteorological Research》 SCIE CSCD 2017年第1期187-195,共9页
The composite-drought index (CI), improved weighted average of precipitation index (IWAP), and the objective identification technique for regional extreme events (OITREE) were employed to detect China's regiona... The composite-drought index (CI), improved weighted average of precipitation index (IWAP), and the objective identification technique for regional extreme events (OITREE) were employed to detect China's regional meteorolo- gical drought events (CRMDEs) during 1961-2010. Compared with existing references, CI and IWAP both showed strong ability in identifying CRMDEs. Generally, the results of CI and IWAP were consistent, especially for extreme and severe CRMDEs. During 1961-2010, although the frequencies of extreme and severe CRMDEs based on C! and IWAP both showed weak decreasing trends, the two mean-integrated indices both showed increasing but not signifi- cant trends. However, the results of IWAP were more reasonable than CI's in two aspects. Firstly, the monthly fre- quency of extreme and severe CRMDEs based on IWAP showed a clear seasonal variation, which coincided with the seasonal variation of the East Asian monsoon over central-eastern China, whereas the frequency based on CI presen- ted a much weaker seasonal variation. Secondly, the two sets of results were sometimes inconsistent with respect to the start and end times of a CRMDE, and CRMDEs based on CI generally showed two unreasonable phenomena: (1) under non-drought conditions, a severe drought stage could suddenly occur in a large area; and (2) during the follow- ing period, drought could alleviate gradually in cases of non-precipitation. Comparative analysis suggested that the IWAP drought index possesses obvious advantages in detecting and monitoring regional drought events. 展开更多
关键词 drought index regional drought China comparative analysis
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Control system design for new electronic cooler of HIRFL-CSRm
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作者 Jianjun Su yunjie li +1 位作者 Jianchuan Zhang Yanyu Wang 《Radiation Detection Technology and Methods》 2018年第2期1-7,共7页
Introduction In this paper,we detail the architecture,design,and testing of an accurate and usable electronic cooler control system for the cooling storage main ring at the Heavy Ion Research Facility,Lanzhou,China(HI... Introduction In this paper,we detail the architecture,design,and testing of an accurate and usable electronic cooler control system for the cooling storage main ring at the Heavy Ion Research Facility,Lanzhou,China(HIRFL-CSRm),and present the results of its use.Purpose A control system must manage devices with a high degree of accuracy to satisfy various physical requirements,and to ensure the accuracy of the data acquisition and control characteristics.Methods and materials The software for the system,based on the C++,was developed following the model-view-controller architecture pattern.On the hardware side,an I-7017R module was adopted for analog-to-digital conversion and an I-7065D module for electronic delay.The communication protocol was analyzed,discussed,and implemented.Results The control system was then tested with the 12C3+carbon beam at HIRFL-CSRm.The fast reaction time and high-precision data processing exhibited during beam tuning verified the stability and maintainability of the proposed control system. 展开更多
关键词 HIRFL-CSR Electronic cooler Control system Data acquisition MFC
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