检索结果-南通市图书馆

Dual-objective two-photon microscope for volumetric imaging of dense scattering biological samples by bidirectional excitation and collection

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonics Research 2024年第6期12卷 1351-1361页

作者： MUYUE ZHAI JING YU yanhui HU HANG YU BEICHEN XIE YI YU DAWEI li AIMIN WANG HEPING CHENG National Biomedical Imaging Center College of Future TechnologyPeking UniversityBeijing 100871China Research Unit of Mitochondria in Brain Diseases Chinese Academy of Medical SciencesPKU-Nanjing Institute of Translational MedicineNanjing 211500China Beijing Transcend Vivoscope Biotech Beijing 100085China College of Engineering Peking UniversityBeijing 100871China Academy for Advanced Interdisciplinary Studies Peking UniversityBeijing 100871China Center for Quantitative Biology Peking UniversityBeijing 100871China School of Electronics Peking UniversityBeijing 100871China State Key Laboratory of Advanced Optical Communication System and Networks Peking UniversityBeijing 100871China

Full view observation throughout entire specimens over a prolonged period is crucial when exploring the physiological functions and system-level ***-photon microscopy(MPM)has been widely employed for such purposes owing to its deep penetration ***,the current MPM struggles with balancing the imaging depth and quality while avoiding photodamage for the exponential increasement of excitation power with the imaging ***,we present a dual-objective two-photon microscope(Duo-2P),characterized by bidirectional two-photon excitation and fluorescence collection,for long-duration volumetric imaging of dense scattering ***-2P effectively doubles the imaging depth,reduces the total excitation energy by an order of magnitude for samples with a thickness five times the scattering length,and enhances the signal-to-noise ratio up to 1.4 *** these advantages,we acquired volumetric images of a 380-μm suprachiasmatic nucleus slice for continuous 4-h recording at a rate of 1.67 s/volume,visualized the calcium activities over 4000 neurons,and uncovered their state-switching *** conclude that Duo-2P provides an elegant and powerful means to overcome the fundamental depth limit while mitigating photodamages for deep tissue volumetric imaging.

关键词： excitation overcome exponential

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

补肾解毒方对核辐射孕鼠的防护作用

西部中医药 2024年第3期37卷 1-4页

作者：石鹏展李延晖王三强张蓉乔祚杨云霜中国人民解放军火箭军特色医学中心北京100088

目的:观察补肾解毒方对核辐射所致孕鼠生殖系统损伤的防护作用。方法:将30只C57BL/6J孕鼠随机分为空白组、辐射组、中药组各10只,中药组灌胃补肾解毒方13.5 g/(kg·d),其他两组灌胃0.2 mL生理盐水,各组均灌胃20天;辐射组、中药组小鼠于... 详细信息

目的:观察补肾解毒方对核辐射所致孕鼠生殖系统损伤的防护作用。方法:将30只C57BL/6J孕鼠随机分为空白组、辐射组、中药组各10只,中药组灌胃补肾解毒方13.5 g/(kg·d),其他两组灌胃0.2 mL生理盐水,各组均灌胃20天;辐射组、中药组小鼠于灌胃第11天接受一次性4 Gy^(60)Co-γ射线全身照射。辐射后当日及辐射第10天观察小鼠一般情况、体质量、胎盘指数以及血清孕酮含量、雌二醇水平。结果:空白组小鼠精神状况良好,毛发光泽,饮食饮水量及粪便表现正常;辐射组及中药组辐射后当日小鼠即出现躁动不安、饮食饮水量下降,粪便干燥等情况;辐射后第10天,辐射组小鼠毛色黯淡无光,精神萎靡,缺乏活力,饮水饮食量减少,粪便干燥;中药组小鼠毛色正常,饮食饮水量基本趋于正常组,大便正常;辐射当天各组小鼠体质量比较差异无统计学意义(P>0.05),辐射后第10天空白组小鼠体质量增加(P<0.01),辐射组与中药组体质量减少(P<0.01),中药组高于辐射组(P<0.05);与空白组比较,辐射组与中药组孕鼠胎盘指数及血清孕酮含量、雌二醇水平均降低(P<0.01),中药组高于辐射组(P<0.05)。结论:补肾解毒方可改善辐射孕鼠一般状态,促进辐射孕鼠体质量、雌孕激素水平及胎盘指数恢复。

关键词：辐射损伤补肾解毒方防护作用小鼠

响应面试验优化福林酚法测定三叶木通果皮多酚含量及其抗氧化活性

在线全文

学校读者我要写书评

暂无评论

农产品加工 2024年第5期 70-74页

作者：李艳辉杨蕊西何靖怡袁亚宏岳田利盛庆林西北大学食品科学与工程学院陕西西安710069

对比80%甲醇、60%乙醇、水3种溶剂提取的三叶木通果皮的体外抗氧化活性。结果表明,80%甲醇提取物具有最强的总抗氧化能力(20.51±0.02) mg/g,清除DPPH自由基能力(28.33±0.12) mg/m L,对Fe^(2+)络合能力(23.11±0.14) mg EDTA-2Na/g,对... 详细信息

对比80%甲醇、60%乙醇、水3种溶剂提取的三叶木通果皮的体外抗氧化活性。结果表明,80%甲醇提取物具有最强的总抗氧化能力(20.51±0.02) mg/g,清除DPPH自由基能力(28.33±0.12) mg/m L,对Fe^(2+)络合能力(23.11±0.14) mg EDTA-2Na/g,对·OH引起的p BR322质粒DNA氧化损伤的保护能力。采用响应面优化福林酚法测定三叶木通果皮80%甲醇粗提粉的多酚含量,将福林酚稀释倍数设为2,将20%碳酸钠用量设为1 m L,将反应温度设定为27℃,将反应时间设定为110 min,所得80%甲醇提取物中多酚含量为(18.91±0.38) mg/g。

关键词：三叶木通八月瓜多酚体外抗氧化能力响应面法

Tuning interaction strength between CeO_(2) and iridium to promote CO oxidation over Ir/TiO_(2)

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第4期42卷 651-659页

作者： Lu Dai Binghua li Yuhan Peng Xianwei Hao Runquan Xuan Hua Huang Yiming Bi liping Xu yanhui Zhang Yun Guo Fangqi Du li Wang Hui Wang Technology Center China Tobacco Zhejiang Industrial Co.Ltd.Hangzhou310024China Research Institute of Industrial Catalysis East China University of Science and TechnologyShanghai200237China

The interaction between support and noble metal plays a crucial role in heterogeneous catalysis ***,how to tune metal support interactions to optimize the activity still needs further ***_(2) was introduced to promote CO oxidation ove r Ir/TiO_(2) by adjusting the interaction strength between iridium(Ir)and CeO_(2).The strong interaction between Ir and CeO_(2) blocks CO adsorption and causes low CO oxidation ***,introducing CeO_(2) on Ir/TiO_(2) produces localized interaction between Ir and CeO_(2),which can tune the surface electronic state of Ir,so a"volcano curve"relationship between CO oxidation activity and electronic state is *** amount of CeO_(2) on Ir/TiO_(2)(Ir/Ce_(0.2)Ti)leads to CO complete oxidization at 22℃,and a new pathway for CO oxidation was *** study demonstrates that the utilization of tuning interaction strength between active metal and support is a potential method to increase the catalytic activity.

关键词： CO oxidation CeO_(2) Localized interaction Interaction strength Supported Ir catalysts Rareearths

Robust H-infinity control of uncertain stochastic time-delay linear repetitive processes

在线全文

学校读者我要写书评

暂无评论

控制理论与应用（英文版） 2010年第4期8卷 491-495页

作者： yanhui li Ji QI Xiaoyu QI Electrical and Information Engineering College Northeast Petroleum University Daqing Heilongiiang 163318 China Institute of Computer and Control Engineering Qiqihar University Qiqihar Heilongjiang 161006 China

Repetitive processes are a distinct class of 2D systems of both theoretic and practical *** robust H-infinity control problem for uncertain stochastic time-delay linear continuous repetitive processes is investigated in this ***,sufficient conditions are proposed in terms of stochastic Lyapunov stability theory,It o differential rule and linear matrix inequality *** corresponding controller design is then cast into a convex optimization *** is focused on constructing an admissible controller,which guarantees that the closed-loop repetitive processes are mean-square asymptotically stable and have a prespecified H-infinity performance γ with respect to all energy-bounded input signals.A numerical example illustrates the effectiveness of the proposed design scheme.

关键词： Stochastic time-delay repetitive processes H-infinity control LMI Parameter uncertainty

Analysis of G-banding in tumor cell lines derived from human neural stem cells

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2006年第2期1卷 115-117页

作者： Junhua Zou yanhui li Department of Medical Genetics Peking University HealthScience Center Beijing100083 China

BACKGROUND： The application of neural stem cell （NSC） is restricted because of its tumorigenesis, and the possible pathogenesis needs investigation. OBJEETIVE： To compare the differences of chromosomal G-banding between human NSCs （hNSCs） derived tumor cell line and hNSCs derived normal cell lines. DESIGN： A randomized controlled observation SETTING ： Building of Anatomy, Peking University Health Science Center MATERIALS ①The hNSC lines and hNSC-derived tumor cell lines were provided by the Research Center of Stem Cells, Peking University; DMEM/F12 （1：1） medium, N2 additive, B27 additive epidermal growth factor （EGF） and basic fibroblast growth factor （bFGF） were produced by GIBCO BRL Company （USA）; fetal bovine serum by HYCLONE Company （USA）. METHODS： The experiments were carried out in the Department of Genetics, Peking University Health Science Center from February 2003 to July 2004. Human fetal striatal NSCs were inoculated hypodermically on the right scapular of nude mice; Normal human fetal striatal NSCs were cultured to 5-8 passages as controls. Karyotyping was performed on the 5^th passage of hNSC-derived tumor cells at 6 weeks after hNSC transplantation into nude mice （T1） and tumor cells at 15 weeks after transplantation （T2）. Metaphase chromosomes were examined with microscope, G-banding cytogenetic analysis and karyotyping were performed according to the Cytoscan Karyotyping FISH and CGH software system （United biotechnology USA Corporation）. MAIN OUTCOME MEASURES： G-banded analytical results of human fetal striatal nerve stem cells derived tumor cell lines （T1 and T2） of metaphase chromosomes were observed. RESULTS： ① Chromosome analysis of hNSC-derived tumor cell lines 1 （T1）： Twenty-five well-spread metaphases were randomly selected for analysis. The karyotypes were 64, XX （8, 32%）; 65, XX （1, 4%）; 67, XX （5, 20%）; 68, XX （11, 44%）. The modal number of chromosomes in this cell lines was 68, which were all hypotriploid. The analysis of 8 G-ba

关键词： stem cell

Effects of Cu,Fe and Co addition on the glass-forming ability and mechanical properties of Zr-Al-Ni bulk metallic glasses

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2012年第12期55卷 2367-2371页

作者： li yanhui ZHANG Wei DONG Chuang AKIHIRO Makino School of Materials Science and Engineering Dalian University of TechnologyDalian 116024China Institute for Materials Research Tohoku UniversitySendai 980-8577Japan

The thermal stability,glass-forming ability(GFA) and mechanical properties of Zr60Al15Ni25xTMx(TM = Cu,Fe and Co,x = 0-10) bulk metallic glasses(BMGs) were systematically *** 5-10 at.% Cu greatly enhances the thermal stability and GFA of the base ***60Al15Ni15Cu10 BMG exhibits the largest supercooled liquid region of 104 K and critical diameter of 18 ***,addition of 5-10 at.% Fe or Co decrease the thermal stability and *** addition,the plasticity of the BMG can be improved by adding of Cu,while the strength is decreased ***60Al15Ni20Cu5 BMG has the largest plastic strain of 5.5% with a yield stress of 1755 MPa and Young's modulus of 83 *** of Co brings an increase of strength but a lower of plasticity,and additional Fe reduces the strength and plasticity simultaneously.

关键词：玻璃形成能力块体非晶合金力学性能 Cu基合金热稳定性大块金属玻璃铁建筑面积

Passivity breakdown on 436 ferritic stainless steel in solutions containing chloride

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2019年第4期35卷 637-643页

作者： Jiaming Wang Shengsheng Qian yanhui li Digby D.Macdonald Yiming Jiang Jin li Department of Materials Science Fudan University Department of Materials Science and Engineering University of California at Berkeley Key Laboratory of Thermo-Fluid Science and Engineering of MOE Xi'an Jiaotong University

Passivity breakdown on 436 ferritic stainless steel(FSS) has been investigated in solutions containing different concentrations of chloride at 25?C and interpreted in terms of the point defect model(PDM). The measured near-normal distributions of passivity breakdown potentials for 436 FSS under experimental conditions are in good agreement with the calculated results according to the PDM. The linear dependence of breakdown potential on the square root of potential scanning rate, which was described by the PDM,provides the estimation of the critical concentration of condensed vacancies at the metal/film interface,which leads to the passivity breakdown. This value is in good agreement with that calculated from the microstructure properties of the alloy substrate and the barrier layer of the passive film. This study demonstrates the validity of the PDM in describing the passivity breakdown on 436 FSS in NaCl solutions.

关键词： 436 ferrite stainless steel Passivity breakdown Point defect model Chloride ions

Evolutionary Game Analysis on E-Commerce Personalization and Privacy Protection

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2018年第1期23卷 17-24页

作者： li yanhui XU Lu liU Bailing School of Information Management Central China Normal University

Personalized products and services in e-commerce bring consumers many new experiences, but also trigger a series of information security issues. Considering the bounded rationality of the game participants, in this paper, we propose an evolutionary game model of privacy protection between firms and consumers based on e-commerce personalization. Evolutionary stable strategies（ESSs） are obtained from the equilibrium points according to the model analysis, and then simulation experiments are launched to validate the decision-making results and the influencing mechanism of various factors. The results show that the model can eventually evolve toward a win-win situation by wisely varying its various factors, such as ratios of initial strategies, cost of privacy protection, commodity prices, and other related factors. Further, we find that reducing the possibility of the privacy breach under the premise of privacy protection can help promote the e-commerce personalization.

关键词： e-commerce personalization privacy protection evolutionary game