检索结果-南通市图书馆

Perturbation to Lie Symmetry and Generalized Hojman Adiabatic Invariants for Relativistic Hamilton System

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2008年第4期49卷 855-858页

作者： zhang xiao-Ni FANG Jian-Hui LIN Peng PANG Ting College of Physics Science and Technology China University of Petroleum Dongying 257061 China

Based on the concept of higher-order adiabatic invariants of mechanical system with action of a small perturbation, the perturbation to Lie symmetry and generalized Hojman adiabatic invariants for the relativistic Hamilton system are studied. Perturbation to Lie symmetry is discussed under general infinitesimal transformation of groups in which time is variable. The form and the criterion of generalized Hojman adiabatic jnvariants for this system are obtained. Finally, an example is given to illustrate the results.

关键词： relativistic Hamilton system Lie symmetry generalized Hojman adiabatic invariant

Immobilization of laccase by Cu^(2+) chelate affinity interaction on surface modified magnetic silica particles and its use for the removal of pentachlorophenol

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2012年第2期23卷 197-200页

作者： Ying Wang Di zhang Fu Rong He xiao Chun Chen The Key Laboratory of Water and Sediment Sciences Ministry of EducationSchool of EnvironmentBeijing Normal UniversityBeijing 100875China State Key Laboratory of Water Environment Simulation School of EnvironmentBeijing Normal UniversityBeijing 100875China Department of Chemical Engineering Beijing University of Chemical TechnologyBeijing 100029China

Magnetic Cu^（2＋）-chelated silica particles using polyacrylamide as a metal-chelating ligand was developed and used for the immobilization of laccase by *** effect of pH and temperature on the enzymatic property of immobilized laccase and its catalytic capacity for pentachlorophenol（PCP） degradation were evaluated *** with free laccase,the immobilized laccase showed improved acid adaptabihty and thermal *** immobilized laccase prepared in this work exhibited a good catalytic capacity for PCP removal from aqueous solutions.

关键词： Magnetic silica Immobilization Laccase Pentachlorophenol

A systematic review of the effects and mechanisms of preoperative 5α-reductase inhibitors on intraoperative haemorrhage during surgery for benign prostatic hyperplasia

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2011年第6期13卷 812-818页

作者： Huan-Tao Zong xiao-Xia Peng Chen-Chen Yang Yong zhang Department of Urology Beijing Chao Yang Hospital University Beijing 100069 China School of Public Health and Family Medicine Capital Medical University Beijing 100069 China

5α-reductase inhibitors （5α-RIs）, including finasteride and dutasteride, are commonly used medical therapies for benign prostatic hyperplasia （BPH）. Many studies reported that preoperative 5α-RI had impact on intraoperative haemorrhage during surgery for BPH, but it was still in controversial. So, we conducted a systematic review of the effects and mechanisms of 5α-RIs on intraoperative bleeding for BPH. MEDLINE, EMBASE, the Cochrane Controlled Trail Register of Controlled Trials and the reference lists of retrieved studies were searched in the analysis. Sixteen publications involving 15 different randomized controlled trials （RCTs） and a total of 1156 patients were used in the analysis, including 10 RCTs for finasteride and five RCTs for dutasteride. We found that preoperative finasteride treatment decreases microvessel density （MVD） in resected prostate specimens. Total blood loss, blood loss per gram of resected prostate tissue and decreases in haemoglobin were all greatly reduced in the finasteride group as compared to controls. Dutasteride appeared to have no effect on bleeding. This meta-analysis shows that preoperative finasteride treatment could decrease intraoperative haemorrhage during surgery for BPH. Preoperative dutasteride had no effect on intraoperative haemorrhage, but further high-qualitv prospective studies are still needed to confirm this observation.

关键词： 5α-reductase inhibitor benign prostate hyperplasia haemorrhage meta-analysis microvessel density

Cementing Properties of Oil Shale Ash

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

Journal of China University of Mining and Technology 2007年第4期17卷 498-502页

作者： FENG xiang-peng NIU Xue-lian BAI Xue LIU xiao-ming SUN Heng-hu Department of Materials Science and Engineering Tsinghua University Beijing 100084 China School of Resource and Safety Engineering China University of Mining ＆ Technology Beijing 100083 China

The oil crisis has prompted renewed interest in direct burning of oil shale as an alternative energy source. A major problem in this process is the large portion of ash produced. The cementing properties of this ash were investi-gated to determine its applicability as a building material. By means of XRD,IR,NMR and ICP,we have studied the effects of burning temperature on the reactivity of ash. Maximum reactivity was obtained with ash samples produced at 700℃ to 900℃. In this range,the strength of oil-shale-based material,with properties similar to cement,which is composed of oil shale and several other kinds of solid wastes,can achieve the standard of 42.5^# cement. Our study has provided an experimental foundation and theoretical base for a massive utilization of oil shale.

关键词： oil shale thermal activation cementitious activity

Electronic Effect of Carbon Support on Pt Catalyst Supported on Graphite Intercalation Compound

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2010年第3期26卷 465-471页

作者： WEI Ang WANG Qing-jing ZHAO xiao-hui zhang Shu-yong Key Lab of Colloid and Interface Chemistry Ministry of Education School of Chemistry and Chemical Engineering Shandong University Jinan 250100 P. R. China

Graphite intercalation compounds（GIC） were tested as an experimental model for studying the electronic effect of carbon support on the catalytic activity and poisoning tolerance of Pt catalyst for direct methanol fuel cells. The GIC samples with different intercalation degrees were prepared by electrolyzing graphite flake in H2SO4 for varying the periods of time. The GIC-supported Pt catalyst was deposited electrochemically. The catalytic activity and poisoning tolerance of the GIC-supported Pt catalysts were evaluated. It was found that GIC with sulfate anion as intercalate was able to catalyze methanol electrooxidation, which could be related to the positive charges generated on the graphite layer upon intercalation. As intercalation degree increased, the catalytic activity of the GIC-supported Pt catalyst decreased while the poisoning tolerance improved. This suggests that electron donation from support to catalyst had great effect on both catalytic activity and poisoning tolerance of Pt catalyst. And intercalation can be adopted as another important way to make modification on carboneous catalyst support.

关键词： Catalyst support Electronic effect Graphite intercalation compound Catalytic activity Poisoning tolerance

Tripartition of Arbitrary Single-Qubit Information via a Class of Asymmetric Four-Qubit W State

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2009年第10期52卷 606-610页

作者： YIN xiao-Feng LIU Yi-Min SHI Shi-Wei zhang Wen zhang Zhan-Jun School of Physics ＆ Material Science Anhui University Hefei 230039 China Department of Physics Shaoguan University Shaoguan 512005 China Key Laboratory of Optoelectronic Information Acquisition ＆ Manipulation of Ministry of Education School of Physics Material Science Anhui University Hefei 230039 China

A four-party scheme is put forward for a sender to partition arbitrary single-qubit information among three receivers by utilizing a class of asymmetric four-qubit W state as quantum channels. In the scheme the sender＇s quantum information can be recovered by the three receivers if and only if they collaborate together. Specifically, they collaborate to perform first two different 2-qubit collective unitary operations and then a single-qubit unitary operation. The scheme is symmetric and （3, 3）-threshold with regard to the reconstruction, for any receiver can be assigned to conclusively recover the quantum information with the other two＇s assistances.

关键词： four-party scheme tripartition arbitrary single-qubit quantum information asymmetric fourqubit W state

Study on microscope hyperspectral medical imaging method for biomedical quantitative analysis

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2008年第9期53卷 1431-1434页

作者： LI QingLi XUE YongQi xiao GongHai zhang JingFa Key Laboratory of Polor Materials and Devices School of Information Science East China Normal University Shanghai 200241 China Shanghai Institute of Technical Physics Chinese Academy of Sciences Shanghai 200081 China aboratory of Development and Diseases Institute of Health Sciences Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai 200030 China School of Medicine Shanghai Jiao Tong University Shanghai 200025 China

A microscopic pushbroom hyperspectral imaging system was developed based on the microscopic technology and spectral imaging technology according to the principle of spectral imager in remote sensing. The basic principle and key technologies of this system were presented and the system per- formance was also analyzed. Some methods and algorithms were proposed to preprocess and nor- malize the microscopic hyperspectral data and retrieve the transmittance spectrum of samples. As a case study, the microscopic hyperspectral imaging system was used to image the retina sections of different rats and get some significant results. Experiment results show that the system can be used for the quantitative assessment and evaluating the effect of medication in biomedical research.

关键词：显微镜数量分析糖尿病性视网膜病变医学成像技术

Catalytic asymmetric brominative dearomatization reaction of benzofurans

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2018年第8期29卷 1212-1214页

作者： xiao-Wei Liang xiaoling Chen Zhiguo zhang Shu-Li You State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Key Laboratory of Biomass Chemical Engineering of Ministry of Education College of Chemical and Biological Engineering Zhejiang University

A catalytic asymmetric brominative dearomatization reaction of benzofuran derivatives was achieved by using hydroquinidine 1,4-phthalazinediyl diether [（DHQ）_2PHAL] as the catalyst and N-bromoacetamide（NBAc） as the brominating reagent. A series of brominated spiro[benzofuran-2,5＇-oxazoles] bearing two contiguous stereogenic centers were obtained in high yields（up to 99%） with excellent enantioselectivity（up to 97% ee）.

关键词： Asymmetric catalysis Bromination Benzofuran Dearomatization Organocatalysis

β-Cyclodextrin polymer based fluorescence enhancement method for sensitive adenosine triphosphate detection

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2019年第6期30卷 1249-1252页

作者： Chunxia Song Yuxin xiao Kunpeng Li xiaoyu zhang Ying Lu Department of Applied Chemistry School of Science Anhui Agricultural University

Adenosine triphosphate plays a crucial role in regulation of many biological pathways and has been used as an indicator for many *** this pape r,based on the fact that β-cyclodextrin polymer(polyβ-CD)could significantly enhance pyrene fluorescence through supramolecular assembly(host-gest interaction),a sensitive and facile method for adenosine triphosphate detection has been developed.A 3’-pyrene-labelled ATP-binding aptamer was employed as the fluorescence probe,which could be digested by exonuclease I to obtain mononucleotides,with pyrene attached *** pyrene attached on mononucleotides could easily enter the hydrophobic cavity of polyβ-CD,accompanied with prominent fluo rescence *** ATP was introduced,ATP and its aptamer could combine together and the obtained hairpin complex could not be cleaved by exonuclease Ⅰ,The pyrene labelled on the probe could not enter the cavity of polyβ-CD belong to the complex’steric hindrance,accompanied with the weak pyrene’*** we could quantify the concentration of adenosine triphosphate facilely by measuring the fluorescence intensity of the *** detection limit of this method for adenosine triphosphate was 11 μmol/L(S/N=3),The developed method showed sufficient selectivity and could successfully assay adenosine triphosphate in biological *** developed method provides a potential platform for biological micromoles assay.

关键词： β-Cyclodextrin polymer Supramolecular assembly Fluorescence Enhancement Adenosine triphosphate