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无偿献血人群血液筛查后乙型肝炎病毒传播的残余风险评估

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医学信息 2024年第13期37卷 49-51+55页

作者：余呈丽李瑞娟曲靖市中心血站

目的初步评估曲靖地区无偿献血人群血液筛查后乙型肝炎病毒传播的残余风险度，评价现行筛查模式，对下一步血液筛查工作的改进提供数据基础。方法统计2020年1月1日-2022年12月31日曲靖市中心血站无偿献血者乙型肝炎病毒表面抗原（HBsA... 详细信息

目的初步评估曲靖地区无偿献血人群血液筛查后乙型肝炎病毒传播的残余风险度，评价现行筛查模式，对下一步血液筛查工作的改进提供数据基础。方法统计2020年1月1日-2022年12月31日曲靖市中心血站无偿献血者乙型肝炎病毒表面抗原（HBsAg）以及HBV DNA的筛查数据，采用发病率-窗口期比率数学模型（yield/WP ratio model）分别评估初次献血者及重复献血乙型肝炎病毒传播的残余风险。结果 2020-2022年，曲靖市中心血站共对173 084人次进行乙型肝炎筛查，其中初次献血者79 073人次，重复献血者94 011人次。EliSA检测HBsAg阳性340人次（初次献血者阳性273人次，重复献血者阳性67人次），核酸检测HBV DNA单阳68人次（初次献血者阳性41人次，重复献血者阳性27人次）。初次献血者HBsAg残余风险为10.21/10万人次，重复献血者HBsAg残余风险为3.4/10万人次；初次献血者HBV DNA残余风险为2.04/10万人次，重复献血者HBV DNA残余风险为0.68/10万人次。结论曲靖地区无偿献血人群中重复献血者的乙型肝炎病毒传播残余风险低于初次献血者，增加一次核酸检测能够明显降低乙型肝炎病毒传播的残余风险，对保障血液安全，预防输血感染乙型肝炎病毒具有重要意义。现行筛查模式下，曲靖地区无偿献血人群乙型肝炎病毒传播残余风险较低，处于安全水平。

关键词：无偿献血乙型肝炎病毒 HBsAg HBV DNA 残余风险

WAVE-CURRENT FORCES ON BIPILES IN TANDEM ARRAY

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Journal of Hydrodynamics 1991年第4期3卷 66-75页

作者： yu-cheng, li Feng-long, Wang Dalian Univ of Technology Dalian China

The in-line and lift forces on bipiles in tandem array induced by both irregular waves and currents were investigated experimentally in this paper. The characteristics in both time and frequency domain of inline, lift and resultant forces as well were analyzed. The grouping effect coefficients of in-line and resultant forces on two piles related to KC number and relative spacing parameters are given. A comparison of the magnitude and direction of resultant forces on bipiles in tandem array with the corresponding values for single cylinder is also made.

关键词： Hydrodynamics Fluid Structure Interaction Mathematical Techniques Frequency Domain Analysis Mathematical Techniques Time Domain Analysis Mechanical Variables Measurement Forces Water Waves Analysis

Recent developments in high-performance Nafion membranes for hydrogen fuel cells applications

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Petroleum Science 2022年第3期19卷 1371-1381页

作者： li-yu Zhu yu-cheng li Jing liu Jing He Lu-Ying Wang Jian-Du Lei Beijing Key Laboratory of lignocellulosic Chemistry College of Material Science and TechnologyBeijing Forestry University

As a promising alternative to petroleum fossil energy,polymer electrolyte membrane fuel cell has drawn considerable attention due to its low pollution emission,high energy density,portability,and long operation *** exchange membrane(PEM)like Nafion plays an essential role as the core of fuel cell.A good PEM must have satisfactory performance such as high proton conductivity,excellent mechanical strength,electrochemical stability,and suitable for making membrane electrode assemblies(MEA).However,performance degradation and high permeability remain the main shortcomings of ***,the development of a new PEM with better performance in some special conditions is greatly *** this review,we aim to summarize the latest achievements in improving the Nafion performance that works well under elevated temperature or methanol-fueled *** methods described in this article can be divided into some categories,utilizing hydrophilic inorganic material,metal-organic frameworks,nanocomposites,and ionic *** addition,the mechanism of proton conduction in Nafion membranes is *** composite membranes exhibit some desirable characteristics,but the development is still at an early *** the future,revolutionary approaches are needed to accelerate the application of fuel cells and promote the renewal of energy structure.

关键词： Fossil energy Fuel cell Proton exchange membrane Proton conductivity Inorganic fillers

Integration of urchin-like MnCo_(2)O_(4)@C core–shell nanowire arrays within porous copper current collector for superior performance li-ion battery anodes

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Rare Metals 2024年第2期43卷 599-611页

作者： Xue-Ru Zhang Qiong Wu Yong Zhang Xi-Fei li Ting Xie yu-cheng Wu Instrumental Analysis Center Hefei University of TechnologyHefei230009China Key Laboratory of Advanced Functional Materials and Devices of Anhui Province Hefei230009China School of Materials Science and Engineering Hefei University of TechnologyHefei230009China Institute of Advanced Electrochemical Energy Xi’an University of TechnologyXi’an710048China

Spinel MnCo_(2)O_(4) is a promising energy storage candidate as anode materials in lithium-ion batteries owing to synergistic effects of two intrinsic solid-state redox ***,low conductivity,poor rate capacity and rapid capacity fading have seriously impaired its practical *** overcome the inferiorities,urchin-like MnCo_(2)O_(4)@C core–shell nanowire arrays have been fabricated directly within a porous copper current collector via a facile hydrothermal method followed by a chemical vapor deposition carbonization *** a typical nanowire,the core is composed of interconnected MnCo_(2)O_(4)nanoparticles and the shell shows as a thin amorphous carbon *** integrated MnCo_(2)O_(4)@C/Cu structure could act as working anodes without using additives or polymer *** MnCo_(2)O_(4)@C/Cu possesses slightly longer li-ion insertion/desertion pathway than that of MnCo_(2)O_(4)/Cu,the carbon shell could effectively prevent the pulverization of MnCo_(2)O_(4) and lower down charge transfer resistance and actively participate in li-ion *** rearrangement of carbon atoms during lithiation/delithiation cycling could inhibit the formation of passive solid electrolyte interphase *** a result,the MnCo_(2)O_(4)@C/Cu electrode presents superior rate capacity(600 mAh·g^(−1) at 1 A·g^(−1)) and better stability(797 mAh·g^(−1) after 200 cycles at 100 mA·g^(−1)).The excellent reversible li ion storage capacity,cycling stability and rate capacity endow MnCo_(2)O_(4)@C/Cu great potential as stable and high output integrated anode materials in li-ion batteries.

关键词： MnCo_(2)O_(4)@C Urchin-like nanowire arrays Core-shell Integrated anode materials lithium-ion batteries

The commutant and similarity invariant of analytic Toeplitz operators on Bergman space

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Science China Mathematics 2007年第5期50卷 651-664页

作者： Chun-Ian JIANG yu-cheng li Department of Mathematics Hebei Normal UniversityShijiazhuang 050016China

The famous von Neumann-Wold Theorem tells us that each analytic Toeplitz operator with n + 1-Blaschke factors is unitary to n + 1 copies of the unilateral shift on the Hardy space. It is obvious that the von Neumann-Wold Theorem does not hold in the Bergman space. In this paper, using the basis constructed by Michael and Zhu on the Bergman space we prove that each analytic Toeplitz operator M B(z) is similar to n + 1 copies of the Bergman shift if and only if B(z) is an n + 1-Blaschke product. From the above theorem, we characterize the similarity invariant of some analytic Toeplitz operators by using K 0-group term.

关键词： Bergman space analytic Toeplitz operators invariant subspace commutant similarity invariant K 0-group 32A36 46J40 47A15

Growth of Aligned Carbon Nanotubes on Large Scale by Methane Decomposition with Deactivation Inhibitor

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Journal of Natural Gas Chemistry 2007年第4期16卷 382-388页

作者： Hao yu Zhili li cheng Zhang Feng Peng Hongjuan Wang School of Chemical and Energy Engineering South China University of Technology Guangzhou 510650 Guangdong China

The effects of additives containing iron or nickel during chemical vapor deposition （CVD） on the growth of carbon nanotubes （CNTs） by methane decomposition on Mo/MgO catalyst were investigated. Ferrocene and nickel nitrate were introduced as deactivation inhibitors by in-situ evaporation during CVD. The precisely controlled in-situ introduction of these inhibitors increased the surface renewal of catalyst, and therefore prevented the catalyst from deactivation. Using this method, aligned multi-walled CNTs with parallel mesopores can be produced on a large scale.

关键词： aligned carbon nanotubes chemical vapor deposition deactivation inhibitor methane decomposition Mo/MgO catalyst ferrocene nickel nitrate

Hydrodynamic coefficients of a simplified floating system of gravity cage in waves

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第5期9卷 654-663页

作者： Chang-wen WU Fu-kun GUI yu-cheng li Wei-huan FANG Marine Science School Zhejiang Ocean University Zhoushan 316000 China State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China College of Animal Sciences Zhejiang University Hangzhou 310058 China

Numerical simulation and experimental tests were carried out to examine the hydrodynamic behaviors of a double-column floating system of gravity cage under wave conditions. A floating system of gravity cage can be treated as a small-sized floating structure when compared with the wavelengths. The main problem in calculating the wave loads on the small-sized floating structure is to obtain the reasonable force coefficients, which may differ from a submerged structure. In this paper, the floating system of gravity cage is simplified to a 2D problem, where the floating system is set symmetrically under wave conditions. The motion equations were deduced under wave conditions and a specific method was proposed to resolve the problem of wave forces acting on a small-sized floating system of gravity cage at water surface. Results of the numerical method were compared with those from model tests and the hydrodynamic coefficients Cn and Cr were studied. It is found that Cn ranges from 0.6 to 1.0 while Cr is between 0.4 and 0.6 in this study. The results are useful for research on the hydrodynamic behavior of the deep-water gravity sea cages.

关键词： Gravity cage Floating system Hydrodynamic coefficients Waves

The Effect of Vineyard Cover Crop on Main Monomeric Phenols of Grape Berry and Wine in Vitis viniferal L. cv. Cabernet Sauvignon

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Agricultural Sciences in China 2010年第3期9卷 440-448页

作者： XI Zhu-mei ZHANG Zhen-wen cheng yu-feng li Hua College of Enology Northwest A＆F University/Shaanxi Engineering Research Center for Viti-Viniculture Yangling 712100 P.R.China

This study was conducted to determine the effect of cover crop inter-row in vineyard on main mono-phenol content of grape berry and wine. Three such cover crops, two perennial legumes （white clover and alfalfa） and a perennial gramineous grass （tall fescue） were sown in vineyard. The main phenolic compounds of mature grape berry and wines vinified under the same conditions were extracted with ethyl acetate and diethyl ether and analyzed by high- performance liquid chromatography （HPLC） by comparing to soil tillage. A total of ten phenolic compounds were identified and quantified in the different grape berry and wines, including nonflavonoids （hydroxybenzoic and hydroxycinnamic acids） and flavonoids （flavanols and flavonols）. The concentration of flavonoid compounds （409.43 to 538.63 mg kg^-1 and 56.16 to 81.30 mg L^-1） was higher than nonflavonoids （76.91 to 98.85 mg kg^-1 and 30.65 to 41.22 mg L^-1） for Cabernet Sauvignon grape and wine under different treatments, respectively. In the flavonoid phenolics, Catechin was the most abundant in the different grapes and wines, accounting for 74.94 to 79.70% and 48.60 to 50.62% of total nonanthocyanin phenolics quantified, respectively. Compared to soil tillage, the sward treatments showed a higher content of main mono-phenol and total nonanthocyanin phenolics in grapes and wines. There were significant differences between two cover crop treatments （tall fescue and white clover） and soil tillage for the content of benzoic acid, salicylic acid, caffeic acid, catechin, and total phenolics in the grape berry （P 〈 0.05 or P〈0.01）. The wine from tall fescue cover crop had the highest gallic acid, caffeic acid and catechin. Cover crop system increased the total nonanthocyanin phenolics of grapes and wines in order of the four treatments： tall fescue, white clover, alfalfa, and soil tillage （control）. Cover crop in vineyard increased total phenols of grape berry and wine, and thus improved the quality of wine evidently.

关键词： vineyard cover crops inter-row Cabernet Sauvignon grape berry wine monomeric phenols

Evolution of inner wall wrinkle defects in the sinking zone of a thick-walled steel tube during radial forging

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Advances in Manufacturing 2024年第2期12卷 396-408页

作者： yu-Zhao Yang cheng Xu li-Xia Fan School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094People’s Republic of China

An axial wrinkle defect was observed in the inner wall of the sinking zone of a thick-wall steel tube processed by cold radial *** can evolve into *** present study focuses on the evolution of wrinkles and the effects of process parameters on them using a three-dimensional radial forging process finite element model,radial forging experiments,and surface morphology *** results indicated that the vertical section angle of the hammer die and the size of the tube blank significantly affect the evolution of *** height-to-width ratioλwas introduced to describe the morphology of *** had an approximately linear relationship with the radius reduction in the sinking *** was a linear correlation between the growth slope ofλand the axial to circumferential strain ratio|εr/εθ|,which can predict theλunder few process *** the 30SiMn2MoVA steel,at the junction of the forging and sinking zones,the threshold ofλof the wrinkle that can evolve into a fissure is approximately 1.123.

关键词： Radial forging Inner wall Wrinkle defects Evolution Sinking zone