检索结果-南通市图书馆

Metal-organic frameworks with dinuclear metal centers for synergistically boosting CO2 photoreduction

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年第1期 201-208页

作者： Hui-Feng Wang Wen-Jie Shi Yu-Xin Yang Bao-Xia dong Tong-Bu Lu Di-Chang zhong School of Chemistry and Chemical Engineering Yangzhou University Institute for New Energy Materials and Low Carbon Technologies School of Materials Science and Engineering Tianjin University of Technology

Dinuclear metal synergistic catalysis （DMSC） has been proved powerful in boosting CO2reduction,while this has not been achieved in heterogeneous catalysts with long-range order *** this study,we,by introduction of metal catalytic centers into an indium-based metal-organic framework （MOF）,obtained a series of isostructural In-MOFs,including three MOFs with mononuclear metal catalytic center （M-In）,three MOFs with dinuclear homometallic catalytic centers （MM-In）,and three MOFs with dinuclear heterometallic catalytic centers (MM’-In,M/M’=Co（II）,Ni（II）,Zn（II）).It was found that all these MOFs can serve as catalysts for photochemical CO2reduction to *** with M-In,the catalytic activities of MM-In were obviously enhanced,and that of MM’-In was further significantly *** example,the CO yield of Co Zn-In reaches a record value of 12,700μmol g-1h-1,which is 4.0,8.1,9.4,and 18.6-fold higher than that of Co Co-In,Zn Zn-In,Co-In,and Zn-In,***,the catalytic activities of Co Ni-In and Ni Zn-In also show different fold increase than those of corresponding dinuclear homometallic and mononuclear metallic *** results of control experiments and theoretical calculation reveal that the higher catalytic activities of MM-In over M-In can be ascribed to the DMSC effect,and the higher catalytic activity of MM’-In over MM-In can be ascribed to the strengthened DMSC *** work reveals the relationship between DMSC effect and bimetal centers in CO2reduction,which provides new insights into the DMSC and paves a new way to design highly active catalysts for photochemical CO2reduction.

关键词：

同方期刊数据库

在线全文

学校读者我要写书评

暂无评论

植物激素对棉花蕾铃脱落的调控研究进展

作物学报 2025年第1期51卷 1-29页

作者：谢章书谢学方屠小菊刘爱玉董合忠周仲华湖南农业大学农学院/作物生理与分子生物学教育部重点实验室湖南长沙410128 中国热带农业科学院橡胶研究所海南海口571101 山东省农业科学院经济作物研究所山东济南250000

棉花蕾铃脱落是一个普遍存在的现象,有对逆境环境胁迫的主动适应性脱落,也有因品种遗传特性、环境条件、栽培措施以及生物和非生物胁迫被动的受损脱落。蕾铃脱落直接影响着棉花的产量,国内外现有公开报道多集中于20世纪50、60年代关于... 详细信息

棉花蕾铃脱落是一个普遍存在的现象,有对逆境环境胁迫的主动适应性脱落,也有因品种遗传特性、环境条件、栽培措施以及生物和非生物胁迫被动的受损脱落。蕾铃脱落直接影响着棉花的产量,国内外现有公开报道多集中于20世纪50、60年代关于乙烯和脱落酸对棉花蕾铃脱落影响的初步发现。结合其他植物的研究结果来看,蕾铃脱落似乎与生长素、赤霉素和细胞分裂素等促生长类激素的下降以及乙烯和脱落酸等抑制生长类激素的升高密切相关,激素在植物体内不仅介导新陈代谢过程,还协调着与信号通路相关的调控因子,在脱落过程中起着关键作用。本文从植物激素调控入手,综述了近年来包括脱落区形成和作用的分子调控机制以及各激素在棉花蕾铃脱落以及其他植物(生殖)器官脱落过程中的响应和调控机制等。发现目前以棉花蕾铃脱落为对象的研究非常匮乏,且多集中于少数激素对棉花生殖生长影响的有限研究,缺乏对导致蕾铃脱落的深层次机制的探究和解析。因此,未来研究方向应着重于探究棉花蕾铃脱落的遗传基础、发掘新的抗脱落基因资源和培育抗脱落棉花品种,同时加强在以棉花为模型植物下,蕾铃脱落与植物激素调节的关系研究,为提高棉花产量提供理论依据和技术支持。

关键词：棉花植物激素蕾铃脱落研究现状研究方向

Alpha-Decay Study of Unfavored Transitions in Bismuth Isotopes

同方期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2013年第2期30卷 57-60页

作者： NI dong-dong REN zhong-Zhou Department of Physics Nanjing UniversityNanjing 210093 Center of Theoretical Nuclear Physics National Laboratory of Heavy-Ion AcceleratorLanzhou 730000 Kavli Institute for Theoretical Physics Chinese Academy of SciencesBeijing 100190

The unfavoredαtransitions of bismuth isotopes,including the newly observedα-decay fine structure in 209Bi[Beeman et al.,***.108(2012)062501]are investigated by the generalized density-dependent cluster model(GDDCM).Instead of the Wentzel-Kramers-Brillouin barrier penetration probability,the exact solution of the Schr?dinger equation under outgoing Coulomb wave boundary conditions is *** calculatedα-decay half-lives are found to be in good agreement with the experimental data for both odd-A and odd-odd *** indicates that the GDDCM has good applicability for unfavoredαtransitions in addition to favored *** predictions onα-decay half-lives are also made for reference in future experiments.

关键词： decay transitions Transition

Polarization of M2 Line Emitted Following Electron-Impact Excitation of Beryllium-Like Ions

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2013年第6期30卷 85-89页

作者： SHI Ying-Long dong Chen-zhong MA Xiao-yun WU zhong-Wen XIE Lu-You FRITZSCHE Stephan Key Laboratory of Atomic and Molecular Physics&Functional Materials of Gansu Province College of Physics and Electronic EngineeringNorthwest Normal UniversityLanzhou 730070 College of Physics and Information Science Tianshui Normal UniversityTianshui 741001 Helmholtz-Institut Jena Froelstieg 3Jena D-07743Germany and Theoretisch-Physikalisches InstitutFriedrich-Schiller-Universitat JenaMax-Wien-Platz 1Jena D-07743Germany

Detailed calculations are carried out for the electron-impact excitation cross sections from the ground state to the individual magnetic sublevels of the 1s2s^(2)2p^(3)/2 J=2 excited state of highly-charged beryllium-like ions by using a fully relativistic distorted-wave(RDW)*** contributions of the Breit interaction to the linear polarization of the 1s2s^(2)2p^(3)/2 J=2→1s22s2 J=0 magnetic quadrupole(M2)line are investigated systematically for the beryllium isoelectronic sequence with 42≤Z≤*** is found that the Breit interaction depolarizes significantly the linear polarization of the M2 fluorescence radiation and that these depolarization effects increase as the incident electron energy and/or the atomic number is enlarged.

关键词： method. Polarization Electron

Symmetry Reduction and Exact Solutions of the(3+1)-Dimensional Breaking Soliton Equation

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2008年第10期50卷 832-840页

作者： WANG Ling dong zhong-Zhou Department of Mathematics and Computer Science Chizhou University Chizhou 247000 China Shanghai Key Laboratory of Trustworthy Computing East China Normal University Shanghai 200062 China Key Laboratory of Mathematics Mechanization Chinese Academy of Sciences Beijing 100080 China

By means of the generalized direct method,a relationship is constructed between the new solutions andthe old ones of the (3+1)-dimensional breaking soliton *** on the relationship,a new solution is obtainedby using a given solution of the *** symmetry is also obtained for the (3+1)-dimensional breaking *** using the equivalent vector of the symmetry,we construct a seven-dimensional symmetry algebra and getthe optimal system of group-invariant *** every case of the optimal system,the (3+1)-dimensional breakingsoliton equation is reduced and some solutions to the reduced equations are ***,some new explicitsolutions are found for the (3+1)-dimensional breaking soliton equation.

关键词： generalized direct method breaking soliton equation optimal system explicit solution

Rate Function of Large Deviation for a Class of Nonhomogeneous Markov Chains on Supercritical Percolation Network

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2011年第9期27卷 1813-1830页

作者： zhong Hao XU dong HAN School of Finance and Statistics East China Normal University Shanghai 200241 P. R. China Department of Mathematics Shanghai Jiao Tong University Shanghai 200240 P. R. China

We model an epidemic with a class of nonhomogeneous Markov chains on the supercritical percolation network on Zd. The large deviations law for the Markov chain is given. Explicit expression of the rate function for la... 详细信息

关键词： Nonhomogeneous Markov chain large deviation rate function percolation network

Synergistic Action of fMLP-boanmycin Combination on the Growth of Mouse Colon Carcinoma and Its Action Mechanisms

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

Chinese Journal of Cancer Research 2010年第2期22卷 135-140页

作者： zhong-dong Li Yan Gao Department of Pharmacology General Hospital of PLA Air Force Beijing 100142 China

Objective： The inhibitory action of fMLP-boanmycin （BAM） combination on the growth of mouse colon carcinoma and its action mechanisms were observed in order to provide experimental proof for probing novel regimen of chemotactic modulation in combination with chemotherapy in the treatment of cancer. Methods： Cytotoxicity of BAM-fMLP combination to tumor cells was determined by MTT assay in vitro. Antitumor activity of BAM-fMLP combination was assessed in mice subcutaneously transplanted colon carcinoma 26. The amount of superoxide anion （O2 ·^-）released from fMLP stimulated macrophages was determined by NBT assay. The amount of nitric oxide （NO） was indirectly determined by Griess method. Results： BAM-fMLP combination had no synergistic effect on tumor cells（CDI〉0.85）, but BAM at the doses of 10μg/ml, 30μg/ml and 100μg/ml in combination with fMLP at the concentration 20μg / ml exhibited synergistic effect on tumor cells in the presence of macrophages（CDI〈0.75）, fMLP inhibited the growth of colon carcinoma 26 by 50.0% when it at dose of 1 mg/mouse was administered peritumorally. BAM （1 mg/kg, intraperitoneally, three times） alone and BAM - fMLP combination inhibited the growth of colon carcinoma 26 by 38.6% and 78.4%, respectively （CDI=0.71） on day 12. The amount of O2 ·^- released from fMLP 4.6×10^-7 mol/L （0.2μg/ml） stimulated macrophages which were treated by BAM in vitro increased significantly（P〈0.01）, fMLP 2.3×10^-6 mol/L （1μg/ml） could not stimulate macrophages to release NO, but may stimulate macrophages treated with BAM 10μg/ml and 100μg/ml to release NO significantly（P〈0.01）. Conclusion： The inhibitory action of fMLP-boanmycin combination on the growth of mouse colon carcinoma have synergism, which may associate with the increase of O2 ·^- and NO released by macrophages. Chemotactic modulation in combination with chemotherapy may be a novel regimen in the treatment of cancer.

关键词： Chemotactic peptide fMLP Boanmycin Colon carcinoma

Coupling mechanism of mathematical models for sediment transport based on characteristic theory

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2016年第11期59卷 1696-1706页

作者： DING yun LI ZuiSen zhong DeYu KANG YanPing State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing 210098 China Zhejiang Institute of Hydraulics and Estuary Hangzhou 310008 China State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China Jiangsu Hydraulic Research Institute Nanjing 210017 China

This paper aims to explore the coupling mechanism between flow movement, sediment transport and riverbed evolution in currently widely used mathematical models for sediment transport. Based on characteristic theory, analytic forms of eigenvalues,eigenvectors and characteristic relationships of total-sediment transport model, bed-load transport model and suspenedload transport model were derived, respectively. The singular perturbation technology was implemented to obtain the asymptotic solutions to different families of eigenvalues. The results indicate that, interactions between motion variables were explicitly coupled in the characteristics of total-sediment transport model and bed-load transport model. Further qualitative and quantitative analysis demonstrates that high sediment transport intensity and significant riverbed change will inevitably affect the property of flow movement. In the process of deposition, sediment-laden flow will move faster when sediment transport intensity becomes stronger. In contrast, the wave of flow will propagate at slower speed as erosion intensity becomes *** most existing suspended-load transport models, however, the characteristics are decoupled as the interactions between motion variables cannot be integrally illustrated in eigenvalues, eigenvectors and characteristic relationship.

关键词： coupling mechanism mathematical models sediment transport characteristics eigenvalues

Efficient multi-event monitoring using built-in search engines

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2016年第2期10卷 281-291页

作者： Zhaoman zhong Zongtian LIU yun HU Cunhua LI School of Computer Engineering Huaihai Institute of Technology Lianyungang 222006 China School of Computer Engineering and Science Shanghai University Shanghai 200072 China

Users of the internet often wish to follow certain news events, and the interests of these users often overlap. General search engines （GSEs） cannot be used to achieve this task due to incomplete coverage and lack of freshness. Instead, a broker is used to regularly query the built-in search engines （BSEs） of news and social media sites. Each user defines an event profile consisting of a set of query rules called event rules （ERs）. To ensure that queries match the semantics of BSEs, ERs are transformed into a disjunctive normal form, and separated into conjunctive clauses （atomic event rules, AERs）. It is slow to process all AERs on BSEs, and can violate query submission rate limits. Accordingly, the set of AERs is reduced to eliminate AERs that are duplicates, or logically contained by other AERs. Five types of event are selected for experimental comparison and analysis, including natural disasters, accident disasters, public health events, social security events, and negative events of public servants. Using 12 BSEs, 85 ERs for five types of events are defined by five users. Experimental comparison is conducted on three aspects： event rule reduction ratio, number of collected events, and that of related events. Experimental results in this paper show that event rule reduction effectively enhances the efficiency of crawling.

关键词： information retrieval event retrieval event monitoring BSEs event rule reduction