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用分子束研究·F(2p)与CH3F和CH3Cl的化学反应

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化学学报 1988年第1期46卷 82-84页

作者：史济良李方琳蒋锡夔邱元武周士康刘颂豪中国科学院上海有机化学研究所上海中国科学院安徽光学精密机械研究所合肥

近年来,我们在研究含氟烯烃和烷烃的红外激光诱导氧化和氯化反应的基础上,深入研究了红外激光诱导卤代烷烃的脱卤化氢并生成:CF卡宾和:CFCF卡宾的反应以往的研究往往是根据反应产物推论反应机理,认为在反应过程中存在着卡宾中间体,但在... 详细信息

近年来,我们在研究含氟烯烃和烷烃的红外激光诱导氧化和氯化反应的基础上,深入研究了红外激光诱导卤代烷烃的脱卤化氢并生成:CF卡宾和:CFCF卡宾的反应以往的研究往往是根据反应产物推论反应机理,认为在反应过程中存在着卡宾中间体,但在实验中未能直接检测到.Kakimoto曾报道过在流动体系中测到了·F+CHF和·F+CHCl反应中:CHF和:CHCl的激光荧光激发谱,但没有讨论卡宾形成的机理.Hirota在讨论·F+CHF反应时,认为:CHF可能由攫氢过程产生而对于·F+CHCl反应同时生成

关键词：化学反应跃迁 CH3F 荧光激发激发谱激光荧光染料激光攫氢反应分子束粒子束光子计数器偶合反应红外激光

Glucose-conjugated chitosan nanoparticles for targeted drug delivery and their specific interaction with tumor cells

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Frontiers of Materials Science 2014年第4期8卷 363-372页

作者： Jing LI fang-kui MA Qi-Feng DANG xing-Guo LIANG xi-Guang CHEN College of Food Science and Engineering Ocean University of China Qingdao 266003 China Freshwater Fisheries Research Institute of Shandong Province Jinan 250013 China College of Marine Life Science Ocean University of China Qingdao 266003 China

A novel targeted drug delivery system, glucose-conjugated chitosan nanoparticles （GCNPs）, was developed for specific recognition and interaction with glucose transporters （Gluts） over-expressed by tumor cells. GC was synthesized by using succinic acid as a linker between glucosamine and chitosan （CS）, and successful synthesis was confirmed by NMR and elemental analysis. GCNPs were prepared by ionic crosslinking method, and characterized in terms of morphology, size, and zeta potential. The optimally prepared nanoparticles showed spherical shapes with an average particle size of （187.9 ± 3.8） nm and a zeta potential of （-15.43 ± 0.31） mV. The GCNPs showed negligible cytotoxicity to mouse embryo fibroblast and 4T1 cells. Doxorubicin （DOX） could be efficiently entrapped into GCNPs, with a loading capacity and encapsulation efficiency of 20.11% and 64.81%, respectively. DOX-Ioaded nanoparticles exhibited sustained-release behavior in phosphate buffered saline （pH 7.4）. In vitro cellular uptake studies showed that the GCNPs had better endocytosis ability than CSNPs, and the antitumor activity of DOX/GCNPs was 4-5 times effectiveness in 4T1 cell killing than that of DOX/CSNPs. All the results demonstrate that nanoparticles decorated with glucose have specific interactions with cancer cells via the recognition between glucose and Gluts. Therefore, Gluts-targeted GCNPs may be promising delivery agents in cancer therapies.

关键词： drug delivery target nanoparticle glucose transporter (Glut) chitosan(CS)

Phosphorus accumulation and eutrophication in feed-supply freshwater fishponds

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Journal of Environmental Sciences 2006年第4期18卷 816-821页

作者： ZHANG Ming-kui fang Li-ping Institute of Soil and Water Resources and Environmental Science College of Natural Resource and Environmental Sciences Zhejiang UniversityHangzhou 310029 China

The rapid growth and intensification of freshwater fishery can cause imbalances between phosphorus （P） input in feed and its output in produce. This aquaculture can result in enriching exogenous P in fishponds and, consequently, accelerates the process of eutrophication. To assess relations among input, accumulation, release of P and as a consequence degrading water quality in terms of chlorophyll-a （Chl-a） in freshwater fishponds, fourteen fishponds with feed supply, nine fishponds without feed supply, and five nonfish ponds in Shaoxing Plain, southeast China were selected for comparing P accumulation in their waters and surface sediments. Surface sediment samples were collected from each pond to evaluate their total P, water soluble P, Olsen P, algal available P, and P fractions. Water samples were also collected from the ponds to measure concentrations of dissolved P and Chl-a. Total P in the sediments ranged from 0.88 to 1.73 g/kg in the fishponds with feed supply, that in the non-fish ponds ranged from 0.47 to 0.86 g/kg. Organic P, accounted for 23% to 60% of total P in the sediments, was an important P fraction and increased linearly with increasing organic matter. Long-term application of feeds resulted in increased P availability in the bottom sediments and degradation of water quality in the freshwater fishponds. Compared with non-fish ponds, sediments from the feed-supplied fishponds contained considerably higher Olsen P, algal available P, and water soluble P. Higher proportions of the labile P （NH4Cl-P） and potentially labile P （NaOH-IP） were also found in the sediments from the fishponds. High solubility of P in the sediments resulted in elevation of P and chlorophyll-a concentration in the pond water. The dissolved P concentration in the pond water increased in the order of non-fish ponds （12μg/L）〈 fishponds without feed supply （24 μg/L）〈 fishponds with feed supply （66 μg/L）. Linear correlations between concentrations of total P, Olsen-P, algal avail

关键词： eutrophication freshwater fishery phosphorus fraction water quality

New Macrocyclic Diamide from Rauvolfia Yunnanensis Tsiang

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Chemical Research in Chinese Universities 2008年第3期24卷 303-305页

作者： GENG Chang-an LIU xi-kui State Key Laboratory of Phytochemistry and Plant Resourses in West China Kunming Institute of Botany Chinese Academy of Sciences Kunming 650204 P. R. China Graduate School of the Chinese Academy of Sciences Beijing 100039 P. R. China

A new macrocyclic diamide, 22-membered macrocyclic diamide, named cyclodicaprylamide（2）, and five known compounds, bis（2-ethylhexyl） phthalate（1）, ethyl 3,4,5-trimethoxybenzoate（3）, ethyl 3,4,5-trimethoxycinnamate （4）, （＋）-syringaresinol（5）, loliolide（6）, were isolated from the roots of Rauvolfia yunnanensis Tsiang. Their structures were elucidated based on NMR, 2D NMR, and MS spectrum, respectively. They were obtained from it for the first time.

关键词： Rauvolfia yunnanensis Cyclodicaprylamide (+)-Syringaresinol Loliolide

Controllable Nanostructural Transitions in Grafted Nanoparticle-Block Copolymer Composites

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Nano Research 2010年第5期3卷 356-362页

作者： Guang-kui Xu xi-Qiao Feng Shou-Wen Yu Institute of Biomechanics and Medical Engineering Department of Engineering MechanicsTsinghua UniversityBeijing 100084China

We report a theoretical investigation of self-assembled nanostructures of polymer-grafted nanoparticles in a block copolymer and explore underlying physical mechanisms by employing the self-consistent field method. By varying the particle concentration or the chain length and density of the grafted polymer, one can not only create various ordered morphologies (e.g., lamellar or hexagonally packed patterns) but also control the positions of nanoparticles either at the copolymer interfaces or in the center of one-block domains. The nanostructural transitions we here report are mainly attributed to the competition between entropy and enthalpy.

关键词： Block copolymer nanocomposite pattern formation self-assembly self-consistent field theory

Long-wave infrared emission properties of strain-balanced InAs/In_(x)Ga_(1-x)As_(y)Sb_(1-y)type-Ⅱsuperlattice on different substrates

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Rare Metals 2024年第7期43卷 3194-3204页

作者： Chao Shi Xuan fang Hong-Bin Zhao Deng-kui Wang xi Chen Dan fang Dong-Bo Wang xiao-Hua Wang Jin-Hua Li State Key Laboratory of High Power Semiconductor Lasers School of PhysicsChangchun University of Science and TechnologyChangchun 130022China State Key Laboratory of Advanced Materials for Smart Sensing China General Research Institute for Nonferrous MetalsBeijing 100088China Department of Opto-Electronic Information Science School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China

High-performance type-Ⅱsuperlattices ofⅢ-Ⅴsemiconductor materials play an important role in the development and application of infrared optoelectronic *** the quality of epitaxial materials and clarifying the luminescent mechanism are of great significance for practic al applic *** this work,strain-balanced and high-quality In As/In_(x)Ga_(1-x)As_(y)Sb_(1-y)superlattices without lattice mismatch were achieved on InAs and GaSb substrates *** grown on In As substrate could exhibit higher crystal quality and surface flatness based on high-resolution X-ray diffraction(HRXRD)and atomic force microscopy(AFM)measurements'***,the strain distribution phenomenon from geometric phase analysis indicates that fluctuations of alloy compositions in superlattices on GaSb substrate are more *** addition,the optical properties of superlattices grown on different substrates are discussed *** of the difference in fluctuations of element composition and interface roughness of superlattices on different substrates,the superlattices grown on In As substrate would have higher integral intensity and narrower full-width at half maximum of long-wave infrared ***,the thermal quenching of emission intensity indicates that the superlattices grown on the In As substrate have better recombination ability,which is beneficial for increasing the operating temperature of infrared optoelectronic devices based on this type of superlattices.

关键词： Photoluminescence Alloy compositions fluctuations InAs(Sb)/In_(x)Ga_(1-x)As_(y)Sb_(1-y) Type-Ⅱsuperlattice Substrate

Crystal plasticity behavior of single-crystal pure magnesium under plane-strain compression

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Rare Metals 2017年第7期36卷 541-549页

作者： Bai-Li xi Gang fang Department of Mechanical Engineering Tsinghua University Beijing 100084China State Key Laboratory of Tribology Beijing 100084China

A phenomenological crystal plasticity constitu- tive model for magnesium single crystal was presented. Four deformation mechanisms （including basal （a）, pris- matic （a）, pyramidal （c ＋ a） slip and tension twin） and their interactions were considered. Twin-induced lattice reorientation was also incorporated in the model. The proposed model was then applied to the simulation of plane-strain compression deformation for different orien- tations. Related material parameters were calibrated at first according to the classical channel-die tests. The predicted macro-and microscopic responses, along with the experi- mental results, show strong orientation-dependent proper- ties. It is also found in the simulation that basal slip in the twinned region is active even before the saturation of twin activity in a twin-favored case. Furthermore, the effect of an initial deviation angle on the mechanical responses was evaluated, which is proved to be also orientation-depen- dent. Basal slip is found to be easily activated due to a slight deviation, while a slight deviation in the twin-fa- vored case could result in a significant difference in the mechanical behavior after the reorientation. The effort on the study of magnesium single crystal in the present work contributes to further polycrystalline analysis.

关键词： Magnesium Crystal plasticity Slip and twin Orientation deviation

Analysis of level structure and monopole effects in Ca isotopes

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Nuclear Science and Techniques 2024年第10期35卷 161-167页

作者： Jin Li Ai-xi Chen Amir Jalili Han-kui Wang School of Science Zhejiang Sci-Tech UniversityHangzhou 310018China

Understanding the properties of nuclei near the double magic nucleus^(40)Ca is crucial for both nuclear theory and *** this study,Ca isotopes were investigated using an extended pairing-plus-quadrupole model with monopole *** negative-parity states of^(44)Ca were coupled with the intruder orbital g_(9/2)at 4 *** values of E_(4+)/E_(2+)agree well with experimental trend from^(42)Ca to^(50)Ca,considering monopole effects between νf_(7/2)and νp_(3/2)(νf_(5/2)).This monopole effect,determined from data of^(48)Ca and^(50)Ca,supports the proposed new nuclear magic number N=34 by predicting a high-energy 2^(+)state in^(54)Ca.

关键词： Shell model Doubly magic Isotopes Monopole effects Level structure

A revisit of the local scour around bridge piers under an ice-covered flow condition-An experimental study

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Journal of Hydrodynamics 2021年第5期33卷 928-937页

作者： Jun Wang kui Wang Bi-he fang Jueyi Sui School of Civil and Hydraulic Engineering Hefei University of TechnologyHefei 230009China School of Engineering University of Northern British ColumbiaPrince GeorgeBCCanada

In this study,by changing both pier diameters and particle sizes of sand bed in flume experiments,the scour process around cylindrical bridge piers under an ice-covered flow condition has been *** is found that the appearance of an ice cover on the water surface caused a deeper and wider scour hole in comparison with that in an open flow with identical flow rates,implying a larger volume of scour hole under an ice-covered flow *** to the scouring process at a bridge pier under an open flow condition,both the depth and volume of a scour hole increase with the flow velocity and pier *** with results under an open flow condition,for identical flow rates,the maximum depth of a scour hole under an ice-covered flow condition increased by about 20%-30%,and both the scour area and volume of a scour hole increased by about 40%-50%.A flow at Froude number of 0.15 is the demarcation point for assessing an obvious impact of an ice cover on the local scour around a bridge pier in this experimental *** data collected from laboratory experiments,equations have been developed to calculate the maximum scour depth,scour area and scour *** of present study have been compared with those of others.

关键词： Bridge pier ice cover local scour scour area scour depth scour volume