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Physical dispersion state and fluorescent property of Eu-complex in the Eu-complex/silicon rubber composites

Journal of Rare Earths 2008年第5期26卷 626-632页

作者：温世鹏胡水张小萍张立群刘力 Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials Beijing University of Chemical Technology Key Laboratory for Nanomaterials Ministry of Education Beijing University of Chemical Technology

The fluorescent complex Eu（TTA）2（Phen）（MA）（HTTA=2-Thenoyltrifluoroacetone, Phen=1,10-phenanthroline, MA=Maleic an- hydrider） was synthesized and characterized with elemental analysis, infrared spectrum （IR）, scanning electron microscope （SEM）, X-ray Diffraction（XRD）, differential scanning calorimetry（DSC）, and fluorescent measurement. To explore the effect of different physical dispersion state of Eu-complex on the fluorescent property of the Eu-complex/silicon rubber composites, various quantifies of Eu（TTA）2（phen）（MA） were mixed with silicon rubber （SIR） and peroxide to form uncured composites. These composites were vulcanized to obtain cured Eu-complex/SiR composites at 250 ℃, which was higher than the melting-point of Eu-complex. The SEM, XRD, DSC, and the fluorescent measurement of these composites showed that both the complex molecules dispersed in the silicon rubber during the melting process and the parent Eu-complex particles had positive effects on fluorescent property, whereas the re-crystallized Eu-complex particles and the aggregating complexes formed during the melting-process had negative effects on fluorescent property. For the uncured composites, their fluorescent intensities almost did not change with the increasing amount of Eu-complex. Furthermore, for the composites with small content of Eu-complex, their fluorescent intensities decreased significantly after curing, and this difference in fluorescent intensity became smaller as the content of Eu-complex increases.

关键词： polymer-matrix composites melting blending physical dispersion state fluorescent property rare earths

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Recent advances in nano scaffolds for bone repair

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Bone Research 2016年第4期4卷 206-216页

作者： Huan Yi Fawad Ur Rehman Chunqiu Zhao Bin Liu Nongyue He State Key Laboratory of Bioelectronics (Chien-Shiung Wu Lab) School of Biological Science and Medical Engineering Southeast UniversityNanjing China Department of Biomedical Engineering School of Basic Medical Sciences Nanjing Medical University Nanjing China Hunan Key Laboratory of Green Chemistry and Application of Biological Nanotechnology Hunan University of Technology Zhuzhou China

Biomedical applications of nanomaterials are exponentially increasing every year due to analogy to various cell receptors, ligands, structural proteins, and genetic materials(that is, DNA). In bone tissue, nanoscale materials can provide scaffold for excellent tissue repair via mechanical stimulation, releasing of various loaded drugs and mediators, 3D scaffold for cell growth and differentiation of bone marrow stem cells to osteocytes. This review will therefore highlight recent advancements on tissue and nanoscale materials interaction.

关键词： bone Recent advances in nano scaffolds for bone repair

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Effect of Spatial and Temporal Scales on Habitat Suitability Modeling:A Case Study of Ommastrephes bartramii in the Northwest Pacific Ocean

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Journal of Ocean University of China 2014年第6期13卷 1043-1053页

作者： GONG Caixia CHEN Xinjun GAO Feng TIAN Siquan College of Marine Sciences Shanghai Ocean University The Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources Ministry of Education International Center for Marine Sciences Shanghai Ocean University

Temporal and spatial scales play important roles in fishery ecology,and an inappropriate spatio-temporal scale may result in large errors in modeling fish *** objective of this study is to evaluate the roles of spatio-temporal scales in habitat suitability modeling,with the western stock of winter-spring cohort of neon flying squid （Ornmastrephes bartramii） in the northwest Pacific Ocean as an *** this study,the fishery-dependent data from the Chinese Mainland Squid Jigging Technical Group and sea surface temperature （SST） from remote sensing during August to October of 2003-2008 were *** evaluated the differences in a habitat suitability index model resulting from aggregating data with 36 different spatial scales with a combination of three latitude scales （0.5°,1 ° and 2°）,four longitude scales （0.5°,1°,2° and 4°）,and three temporal scales （week,fortnight,and month）.The coefficients of variation （CV） of the weekly,biweekly and monthly suitability index （SI） were compared to determine which temporal and spatial scales of SI model are more *** study shows that the optimal temporal and spatial scales with the lowest CV are month,and 0.5° latitude and 0.5° longitude for *** in the northwest Pacific *** suitability index model developed with an optimal scale can be cost-effective in improving forecasting fishing ground and requires no excessive sampling *** suggest that the uncertainty associated with spatial and temporal scales used in data aggregations needs to be considered in habitat suitability modeling.

关键词： spatial and temporal scales data aggregation habitat suitability model sea surface temperature Ommastrephes bartramii northwest Pacific Ocean

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Joint PP and PS AVO inversion based on Zoeppritz equations

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Earthquake Science 2011年第4期24卷 329-334页

作者： Xiucheng Wei Tiansheng Chen SINOPEC Key Laboratory of Seismic Multi-Component Technique Beijing 100083 China Petroleum Exploration and Production Research Institute SINOPEC Beijing 100083 China

Considering Zoeppritz equations, reflections of PP and PS are only the function of ratios of density and velocity. So the inversion results will be the same if the ratios are the same but values of density, velocities of P- wave and S-wave are different without strict constraint. This paper makes efforts to explore nonlinear simultaneous PP and PS inversion with expectation to reduce the ambiguity of AVO analysis by utilizing the redundancy of multi-component AVO measurements. Accurate estimation of ratio parameters depends on independence of input data. There are only two independent AVO attributes for PP reflectivity （i.e. intercept and gradient） and two for PS reflectivity （i.e. pseudo-intercept and pseudo-gradient or extreme amplitude）, respectively. For individual PP and PS inversion, the values of least-squares objective function do not converge around a large neighborhood of chosen true model parameters. Fortunately for joint PP and PS inversion the values of the least-squares objective function show closed contours with single minima. Finally the power function fitting is used to provide a higher precision AVO attributes than traditional polynomial fitting. By using the four independent fitting attributes （two independent attributes for PP and PS respectively）, the inversion of four ratio parameters （velocities and densities） would be estimated with less errors than that in traditional method.

关键词： multi-components AVO simultaneous inversion

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Superior adsorption performance of graphitic carbon nitride nanosheets for both cationic and anionic heavy metals from wastewater

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Chinese Journal of Chemical Engineering 2019年第2期27卷 305-313页

作者： Gang Xiao Yaoqiang Wang Shengnan Xu Peifeng Li Chen Yang Yu Jin Qiufeng Sun Haijia Su State Key Laboratory of Chemical Resource Engineering Beijing Advanced Innovation Center for Soft Matter Science and Engineering (BAIC-SM) Beijing University of Chemical Technology

Water pollution caused by highly toxic Cd(II), Pb(II), and Cr(VI) is a serious problem. In the present work,a green and low-cost adsorbent of g-C_3N_4 nanosheets was developed with superior capacity for both cationic and anionic heavy metals. The adsorbent was easily fabricated through one-step calcination of guanidine hydrochloride with thickness less than 1.6 nm and specific surface area of 111.2 m^2·g^(-1). Kinetic and isotherm studies suggest that the adsorption is an endothermic chemisorption process, occurring on the energetically heterogeneous surface based on a hybrid mechanism of multilayer and monolayer adsorption. The tri-s-triazine units and surface N-containing groups of g-C_3N_4 nanosheets are proposed to be responsible for the adsorption *** study on pH demonstrates that electrostatic interaction plays an important role. The maximum adsorption capacity of Cd(II), Pb(II), and Cr(VI) on g-C_3N_4 nanosheets is 123.205 mg·g^(-1), 136.571 mg·g^(-1),and 684.451 mg·g^(-1), respectively. The better adsorption performance of the adsorbent than that of the recently reported nanomaterials and low-cost adsorbents proves its great application potential in the removal of heavy metal contaminants from wastewater. The present paper developed a promising adsorbent which will certainly find applications in wastewater treatment and also provides guiding significance in designing adsorption processes.

关键词： g-C3N4 nanosheets Nanomaterials Adsorption Heavy metals Wastewater

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Physical Layer Security of Multi-hop Aided Downlink MIMO heterogeneous Cellular Networks

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China Communications 2016年第S2期13卷 120-130页

作者： Xiaohui Qi Kaizhi Huang Zhihao Zhong Xiaolei Kang Zhou Zhong national Digital Switching System Engineering & Technological Research Center

This study investigates physical layer security in downlink multipleinput multiple-output(MIMO) multi-hop heterogeneous cellular networks(MHCNs),in which communication between mobile users and base stations(BSs) is established by a single or multiple hops,to address the problem of insufficient security performance of MIMO heterogeneous cellular ***,two-dimensional homogeneous Poisson point processes(HPPPs) are utilized to model the locations of K-tier BSs in MIMO MHCNs and receivers,including those of legitimate users and ***,based on the channel gain distribution and the statistics property of HPPP,the achievable ergodic rates of the main and eavesdropper channels in direct and ad hoc links are derived,***,the secrecy coverage probability and the achievable ergodic secrecy throughput of downlink MIMO MHCNs are explored,and their expressions are ***,the correctness of the theoretical derivation is verified through Monte Carlo simulations.

关键词： multi-hop heterogeneous cellular networks secrecy coverage probability stochastic geometry secrecy throughput

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Distribution and resource evaluation of natural gas hydrate in South China sea by combing phase equilibrium mechanism and volumetric method

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Petroleum Science 2022年第1期19卷 26-36页

作者： Tong Wang Tao Hu Xiong-Qi Pang Xing-Wen Zhang Xiao-Han Liu Zhi Xu En-Ze Wang Zhuo-Ya Wu State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China College of Geosciences China University of Petroleum(Beijing)Beijing102249China School of Earth&Space Sciences Peking UniversityBeijing100871China Research Institute of Petroleum Exploration and Development PetroChina Company LimitedBeijing100083China

China Geological Survey conducted the second trial production of natural gas hydrate(NGH)in the Shenhu Area in South China Sea(SCS)from 2019 to *** with the first trial production in 2017,the second trial showed significantly increased daily gas production and total gas production,and removed some technical obstacles for large-scale NGH resource developments in the ***,current NGH resource evaluation in the SCS is still at the stage of prospective gas content assessment,which is unable to guide further NGH exploration and *** study utilized the hydrate phase balance to delineate the NGH distribution range and effective thickness and volumetric method to evaluate NGH *** on the latest exploration and production data from the Shenhu Area,Monte Carlo simulation was performed to calculate the NGH resource amount with different *** assuming a 50%cumulative probability,the in-situ NGH resources in the SCS was estimated to be11.7×10^(12)m^(3) and the recoverable NGH resources was 2.8×10^(12)m^(3).These results will provide a more reliable resource basis for China to formulate comprehensive development strategies for oil and gas exploration in the SCS.

关键词： South China Sea Oil and gas resource Natural gas hydrate In-situ resource Recoverable resources

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Tribological and Impact Fatigue Behaviors of Pure Titanium Treated by Plasma Ni Alloying

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Journal of Wuhan University of Technology(Materials Science) 2012年第3期27卷 427-431页

作者：贺志勇 Research Institute of Surface Engineering Taiyuan University of Technology

Ni modified layer is prepared on the surface of pure titanium by plasma surface alloying technique. Surface appearance, micro-structure morphology, composition distribution, phase structure and microhardness of Ni modified layer are analyzed. Tribological performance and fatigue behaviors of Ni modified layer of pure titanium are observed using Pin-on-disc tribometer and repeated impact test. The results indicate that the surface mean Ni concentration of Ni modified layer is nearly 18% which is composed of TiNi, Ti2Ni and Ti phase. The maximum surface microhardness of Ni modified layer is approximately 580 HV which is almost two-fold of the hardness of the substrate. The wear resistance of Ni modified layer is improved obviously. The wear mechanism of Ni modified layer shows slight abrasion wearing, while pure titanium is abrasion and adhesion wearing. Ni modified layer presents better impact fatigue strength.

关键词： TA2 Ni modified layer wear impact test

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Disruption of Bacterial Cells by Photocatalysis of Montmorillonite Supported Titanium Dioxide

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Journal of Wuhan University of Technology(Materials Science) 2009年第4期24卷 557-561页

作者：雷绍民 School of Resources and Environmental Engineering Wuhan University of Technology

The photo-induced antibacterial capacity of montmorillonite supported titanium dioxide （TiO2/Mmt for short） was evaluated by using Escherichia coli and Staphylococcus aureus as modal organims. The bactericidal activity of TiO2/Mmt was examined by cell viability assay under different illumination modes. Atomic force microscopy （AFM） and total organic carbon/Total nitrogen （TOC/TN） analyses were employed to investigate the mechanism of the photocatalytic bactericidal process qualitatively and quantitatively. The kinetic data show that TiO2/Mmt has excellent antibacterial performance, and about 99% of both bacteria cells are inactivated within 75 rain illumination. The AFM images demonstrate that the bacterial cells are irreversibly decomposed and some cell components are dissolved. Therefore, the content and phase of carbon and nitrogen in the solution are changed after photocatalytic reaction.

关键词： montmorillonite titanium dioxide photocatalytic antibacterial cell disruption TOC/TN

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The Controlled-releasing Drug Implant based on the Three Dimensional Printing Technology: Fabrication and Properties of Drug Releasing in vivo

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Journal of Wuhan University of Technology(Materials Science) 2009年第6期24卷 977-981页

作者：伍卫刚郑启新 Department of orthopedics Union HospitalTongji medical collegeHuazhong University of Science and Technology

Three dimensional （3D） printing technology was utilized to fabricate a new type of drug implant with complicated architectures, employing levofloxacin （LVFX） and rifampicine （RFP） as model drugs. The prepared drug implant prototype consists of a doublelayer structure, of which the upper region is a reservoir system containing RFP and the lower region is a matrix one containing LVFX. The release test in vivo revealed that LVFX was released in the early stage; no RFP was detected until 8th day; both of them continuously released more than 6 weeks. Therefore, 3D printing technology provides a precise and feasible method to fabricate a controlled-releasing drug implant with complicated architectures and this drug implant may present a new strategy for the prophylaxis and treatment of bone diseases such as combined bone infections and bone tuberculosis in the near future.

关键词： rapid prototyping three dimension printing technology drug implants bone in- fection bone tuberculosis

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