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| 1 | Cold-chain food contamination as the possible origin of COVID-19 resurgence in Beijing显示文摘COVID-19,caused by SARS-CoV-2[1,2],has been contained in China through stringent non-pharmaceutical interventions.Border control and quarantine have effectively prevented the virus from being spread by infected travellers,but the risk of resurgence caused by other routes of introduction and transmission remains unclear,and current strategies to prevent resurgence could be flawed.Since July,SARS-CoV-2 RNA contaminations in frozen food imported from countries with ongoing epidemics have been reported in nine provinces in China[3,4].However,there is no robust evidence of COVID-19 outbreaks initiated by environmentto-human transmission.Here we add to evidence of such transmission by investigating the recent COVID-19 resurgence in Beijing. | Xinghuo Pang Lili Ren Shuangsheng Wu Wentai Ma Jian Yang Lin Di Jie Li Yan Xiao Lu Kang Shichang Du Jing Du Jing Wang Gang Li Shuguang Zhai Lijuan Chen Wenxiong Zhou Shengjie Lai Lei Gao Yang Pan Quanyi Wang Mingkun Li Jianbin Wang Yanyi Huang Jianwei Wang COVID-19 Field Response Group COVID-19 Laboratory Testing Group | 2020 | National Science Review2020，7，12： | 51 |
| 2 | Changes in cropland topsoil organic carbon with different fertilizations under long-term agro-ecosystem experiments across China's Mainland显示文摘Topsoil soil organic carbon(SOC) data were collected from long-term Chinese agro-ecosystem experiments presented in 76 reports with measurements over 1977 and 2006.The data set comprised 481 observations(135 rice paddies and 346 dry croplands) of SOC under different fertilization schemes at 70 experimental sites(28 rice paddies and 42 dry croplands).The data set covered 16 dominant soil types found in croplands across 23 provinces of China's Mainland.The fertilization schemes were grouped into six categories:N(inorganic nitrogen fertilizer only),NP(compound inorganic nitrogen and phosphorus fertilizers),NPK(compound inorganic nitrogen,phosphorus and potassium fertilizers),O(organic fertilizers only),OF(combined inorganic/organic fertilization) and Others(other unbalanced fertilizations such as P only,K only,P plus K and N plus K).Relative change in SOC content was analyzed,and rice paddies and dry croplands soils were compared.There was an overall temporal increase in topsoil SOC content,and relative annual change(RAC,g kg-1 yr-1) ranged -0.14-0.60(0.13 on average) for dry cropland soils and -0.12-0.70(0.19 on average) for rice paddies.SOC content increase was higher in rice paddies than in dry croplands.SOC increased across experimental sites,but was higher under organic fertilization and combined organic/inorganic fertilizations than chemical fertilizations.SOC increase was higher under balanced chemical fertilizations with compound N,P and K fertilizers than unbalanced fertilizations such as N only,N plus P,and N plus K.The effects of specific rational fertilizations on SOC increase persisted for 15 years in dry croplands and 20 years in rice paddies,although RAC values decreased generally as the experiment duration increased.Therefore,the extension of rational fertilization in China's croplands may offer a technical option to enhance C sequestration potential and to sustain long-term crop productivity. | WANG ChengJi1,PAN GenXing1*,TIAN YouGuo2,LI LianQing1,ZHANG XuHui1 & HAN XiaoJun1 1Institute of Resources,Ecosystem and Environment of Agriculture,Nanjing Agricultural University,Nanjing 210095,China 2Center of Soil and Fertilizer Quality Monitoring and Test,Agricultural Ministry of China,Beijing 100026,China | 2010 | Science China(Life Sciences)2010，53，7： | 24 |
| 3 | Research and Application Prospect of Computer Simulation on Heat Treatment Process显示文摘In this paper, a modified temperature-phase transformation-stress/strain field coupled 3D non-linear mathematical model was used in the computer simulation on heat treatment processes of workpieces including catch jaw, anchor ring, cold roller, large-scale bearing roller, nitriding crank shaft, etc. The simulation on complicated technologies such as pre-cooled quenching, double media quenching, self-tempering, difference temperature heating, nitriding distortion was carried out. The optimum design of heat treatment technology has been realized. The successful application of computer simulation on heat treatment have also been demonstrated. | Pan Jiansheng, Li Yongjun, Cu Jianfeng, Hu Mingjuan Open Research Lab for High Temperature Materials & Testing, SJTU, Shanghai, 200030 | 2000 | Journal of Shanghai Jiaotong university(Science)2000，5，1： | 19 |
| 4 | Dense coding scheme using superpositions of Bell-states and its NMR implementation显示文摘Dense coding using superpositions of Bell-states is proposed. The generalized Grover's algorithm is used to prepare the initial entangled states, and the reverse process of the quantum algorithm is used to determine the entangled state in the decoding measurement. Compared with the previous schemes, the superpositions of two Bell-states are exploited. Our scheme is demonstrated using a nuclear magnetic resonance (NMR)quantum computer. The corresponding manipulations are obtained. Experimental results show a good agreement between theory and experiment. We also generalize the scheme to transmit eight messages by introducing an additional two-state system. | ZHANG Jingfu, XIE Jingyi, DENG Zhiwei & LU Zhiheng Key Laboratory for Quantum Information and Measurements, Department of Physics, Tsinghua University, Beijing 100084, China Center for Quantum Information, Tsinghua University, Beijing 100084, China Department of Materials Science and Engineering, Beijing Normal University, Beijing 100875, China Testing and Analytical Center, Beijing Normal University, Beijing 100875, China Department of Physics, Beijing Normal University, Beijing 100875, China | 2005 | Science China(Physics,Mechanics & Astronomy)2005，48，1： | 18 |
| 5 | Quasi-static Analysis of Thrust-loaded Angular Contact Ball Bearings Part Ⅰ:Theoretical Formulation显示文摘Ball bearings play an important role in various rotating machineries,but the complicated kinematic and tribological features of ball bearings make many aspects of their operating behaviors still inconclusive.Most theoretical analyses of ball bearings up to date are based on either the hypothesis of race control or other empirical models to determine the ball motion of ball bearings,but none of these strategies can reveal and consequently employ the intrinsic coupling mechanism between the spin and the tangential traction of contacting bodies rolling upon one another.To remedy the deficiency of current analytical models for ball bearing analysis,the rolling contact theory is employed to establish an explicit link between motions and interactions within ball bearings.A differential slip model is established to precisely define the slip component due to the significant curvature of the common contact patches between the ball and inner/outer raceways.The creepage and the spin ratio are formulated to accurately define the relative rigid motion between the ball and the inner/outer raceway.Then a quasi-static analytical model is established that can accurately determine the motions of the balls and races of the ball bearing.It can also give a vivid description of the slip and traction distributions within the contact area.The analytical model can be effectively used to analyze the operational conditions and tribological features of solid-lubricated ball bearings.It can also be used optimize the construction of ball bearings for specific applications. | CHEN Wenhua1,2,MA Zikui1,GAO Liang1,LI Xinglin3,and PAN Jun2 1 Institute of Mechanical Design,Zhejiang University,Hangzhou 310027,China 2 Institute of Mechanical Design and Manufacturing,Zhejiang Sci-Tech University,Hangzhou 310018,China 3 State Testing Laboratory of Hangzhou Bearing Test & Research Center,Hangzhou 310022,China | 2012 | Chinese Journal of Mechanical Engineering2012，25，1： | 16 |
| 6 | DISLOCATION DISSOCIATIONS AND FAULTENERGIES IN Ni_3Al ALLOYS DOPED WITH PALLADIUM显示文摘Dislocation structures in polycrystalline Ni 3Al alloy doped with palladium deformed at room temperature have been investigated by transmission electron microscopy. The structure consists mainly of dislocations dissociated into a /2〈011〉 super partials bounding an anti phase boundary (APB). Dislocations dissociated into a /3〈112〉 super Shockley partials bounding a superlattice intrinsic stacking fault (SISF) are also common debris. The majority of the SISFs are truncated loops, i.e. the partials bounding the SISF are of similar Burgers vector. These faulted loops are generated from APB coupled dislocations, according to a mechanism for formation of SISFs proposed by Suzuki et al , and recently modified by Chiba et al . The APB energies for {111} and {010} slip planes are measured to be 144±20 mJ/m 2 and 102±11 mJ/m 2 respectively, and the SISF energy has been estimated to be 12 mJ/m 2 in this alloy. It is concluded that the dislocation structure in Ni 74.5 Pd 2Al 23.5 alloy deformed at room temperature is similar to that in binary Ni 3Al, and the difference in fault energies between these two alloys is small. Thus, it seems unlikely that the enhancement of ductility of Ni 74.5 Pd 2Al 23.5 results from only such a small decrease of the ordering energy of the alloy. SISF bounding dislocations also have no apparent influence on the ductilization of Ni 74.5 Pd 2Al 23.5 alloy. | J. Sun *# , C. S. Lee # and J. K. L. Lai # * Open Lab for High Temperature Materials & Tests, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200030, China # Department of Physics and Materials | 1999 | 中国有色金属学会会刊:英文版1999，9，S1： | 16 |
| 7 | Properties and characterization of Au^(3+)-adsorption by mycelial waste of Streptomyces aureofaciences显示文摘Mycelial waste of Streptomyces aureofaciences procured from the aureomycin fermentation industry is used as biosorbent for Au3+. The properties of Au3+ adsorption by the mycelial waste are studied. The results indicate that the optimum pH value of Au3+ adsorption is 3.5. The biosorption is a rapid and non-temperature-dependent process. The bio-sorptive capacity with 45.6 mg/g and efficiency with 91.2% are achieved under the conditions of pH 3.5 and 30℃ for 45 min, in which the ratio is 50 mg/g dry weight for the concentrations of initial Au3+ and the mycelial waste. The Au3+ ions adsorbed on the mycelial waste can be eluted. The observation in a transmission electron microscope shows that the Au3+ ions can be reduced to Au particles by the mycelial waste and the Au can become gold crystals with differentforms and sizes. X-ray photoelectron spectroscopy analysis further proves that the Au3+ can be reduced to Au0 by the mycelial waste. | LIU Yueying, FU Jinkun, HU Hongbo, TANG Dingliang, Nl Zimian & YU Xinsheng1. Department of Biology, 2. State Key Laboratory for Physical Chemistry of Solid Surface, 3. Center for Analysis & Testing, Xiamen University, Xiamen 361005, China | 2001 | Chinese Science Bulletin2001，46，20： | 15 |
| 8 | RESEARCH OF WAVELET TRANSFORM INSTRUMENT SYSTEM FOR SIGNAL ANALYSIS显示文摘After brief describing the Principle of wavelet transform (WT) of signals, a new signals analysis system based on wavelet transform is introduced. The design and development of the instryment of wavelet transform are described. A number of practical uses of this system demonstrate that wavelet transform system is specially functional in identifying and processing impulse, singular and non-smooth signals, so that it should be evaluated the most advanced signal analyzing system. | Qin Shuren Chen Zhikui Tang Baoping Yang Changqi Xu Mingtao He Hui (Test Center, Chongqing University) | 2000 | Chinese Journal of Mechanical Engineering2000，13，2： | 11 |
| 9 | DC ice-melting model for wet-growth icing conductor and its experimental investigation显示文摘Icicles are often formed under the downside surface of conductor in the wet growth icing of overhead power line. When the ice deposit around overhead power line is molten by Joule heat produced by current, the pattern of heat transfer of ice deposit with icicles is dissimilar to that without icicle, so the ice-melting model for the columnar icing conductor cannot be applied to icicle-shaped icing conductor. According to the heat-transfer characteristic of the icicle-shaped icing conductor, this paper puts forward a DC ice-melting model for the icicle-shaped icing conductor. Because this full model includes three-dimensional heat-transfer and interface movement, which cannot be solved in closed form, a finite element scheme in space-domain and a finite difference scheme in time-domain are employed to discretize the governing equations. Firstly the whole ice-melting process on the icicle-shaped icing conductor is simulated by this model. Then the simulated results are validated by ice-melting experiments in the artificial chamber. The study from the model and the experiments shows that the size and length of icicle as well as the space between the adjacent icicles are factors to affect ice-melting. With the shorter icicle space, the bigger icicle size and the longer icicle-length, the surface of ice layer is enlarged and then more heat is taken away by the convection and radiation, so the ice melting time will get longer. | FAN SongHai1,2, JIANG XingLiang1, SHU LiChun1, SUN CaiXin1 & WANG DaXing1,2 1 State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing 400044, China 2 Sichuan Electric Power Test and Research Institute, Chengdu 610072, China | 2010 | Science China(Technological Sciences)2010，53，12： | 9 |
| 10 | Local Outbreak of COVID-19 in Shunyi District Attributed to an Asymptomatic Carrier with a History of Stay in Indonesia—Beijing Municipality,China,December 23,2020显示文摘Summary What is known about this topic?Patients with coronavirus disease 2019(COVID-19)infection can be categorized by severity:asymptomatic infection,mild illness,moderate illness,severe illness,and critical illness.The rate of transmission to a specific group of contacts(the secondary attack rate)may be 3-25 times lower from people who are asymptomatically infected than from those with symptoms.The incubation period is 2-14 days. | COVID-19 Epidemiology Investigation Team Laboratory Testing Team Wenzeng Zhang | 2021 | China CDC weekly2021，3，10： | 9 |
| 11 | 利用全国大学英语四级考试数据为大学英语教学提供服务评价的探索显示文摘本研究利用2007年12月全国大学英语四级考试(简称“四级考试”)有关数据开展评价,评价内容包括对考生英语能力现状的分类及分项实证分析。以及对学生英语成绩的校际差异及其影响因素的实证分析。结果表明,1)不同类型学校(“211工程”和非“211工程”、“大学英语教学改革示范点项目学校”和非“大学英语教学改革示范点项目学校”)的学生英语成绩存在显著差异;2)从分项能力上看,写作和听力能力相对薄弱;3)英语成绩校际差异显著,学校所在省份和学校类型对校际成绩差异都有一定的解释比例。 | National Educational Examinations Authority and National College English Testing Committee | 2009 | 中国考试2009，，1： | 9 |
| 12 | Experimental studies on perturbed acoustic resonant spectroscopy by a small rock sample in a cylindrical cavity显示文摘A measurement system for acoustic resonant spectroscopy (ARS) is estab-lished,and the effects of resonant cavity geometry,inner perturbation samples and envi-ronmental temperature on the ARS are investigated. The ARSs of the small samples with various sizes and acoustic properties are measured. The results show that at the normal pressure,the resonant frequency decreases gradually with the increase of liquid tem-perature in the cylindrical cavity,while the resonant amplitude increases. At certain pres-sure and temperature,both the resonant frequency and the amplitude decrease greatly when there exist air bubbles inside the cavity fluid. The ARS is apparently affected by the sample porosity and the sample location in the resonant cavity. At the middle of the cavity,the resonant frequencies reach their maximum values for all of the measurement samples. The resonant frequencies of the porous rock samples are smaller than those of the com-pacted samples if other acoustic parameters are the same. As the sample is moved from the top to the middle of the cavity along its axis,the resonant amplitude increases gradu-ally for the compacted rocks while decreases for the unconsolidated rocks. Furthermore,the resonant amplitude increases firstly and then decreases if the porosity of the rock sample is relatively small. In addition,through the comparisons between the experimental and theoretical results,it is found that the effects of the acoustic parameters and sizes of the samples and the size of the cylindrical cavity on the laboratory results agree well with the theoretical ones qualitatively. These results may provide basic reference for the ex-periment study of rock acoustic properties in a low frequency using ARS. | CHEN Dehua1,2,WANG Xiuming2,3,CONG Jiansheng1,XU Delong1,SONG Yanjie1 & MA Shuilong4 1. Department of Geophysics,Daqing Petroleum Institute,Daqing 163318,China 2. Institute of Acoustics,Chinese Academy of Sciences,Beijing 100080,China 3. Division of Petroleum,Australian Commonwealth Scientific and Industrial Research Organization,Bent-ley WA 6102,Australia 4. Daqing Testing and Technology Services Corporation,Daqing 163153,China | 2006 | Science China(Physics,Mechanics & Astronomy)2006，49，6： | 8 |
| 13 | Implementation of a multiple round quantum dense coding using nuclear magnetic resonance显示文摘A multiple round quantum dense coding scheme based on the quantum phase estimation algorithm is proposed and implemented in a three qubit nuclear magnetic resonance (NMR) quantum computer. Using an m + 1 qubit system, Bob can transmit one of 2m+1 messages to Alice, through manipulating only one qubit and exchanging it between Alice and Bob for m rounds. The information capacity is enhanced to m + 1 bits as compared to m bits in a classical scheme. The scheme has been demonstrated in NMR system, and the experimental results show a good agreement between theory and experiment. | ZHANG Jingfu1, XIE Jingyi2, WANG Chuan1, DENG Zhiwei3, LU Zhiheng4, & LONG Guilu1,5 1. Key Laboratory For Quantum Information and Measurements of MOE, Department of Physics, Tsinghua University, Beijing 100084,China 2. Department of Materials Science and Engineering, Beijing Normal University, Beijing 100875, China 3. Testing and Analytical Center, Beijing Normal University, Beijing 100875,China 4. Department of Physics, Beijing Normal University, Beijing 100875, China 5. Key Laboratory For atomic and Molecular Nanosciences, Tsinghua University, Beijing 100084,China | 2005 | Science China(Physics,Mechanics & Astronomy)2005，48，6： | 8 |
| 14 | Transmission electron microscopic observationof Au^(3+) biosorption by Saccharomycescerevisiae waste biomass显示文摘本文报告啤酒酵母废菌体对 Au3 +的吸附还原作用。该菌体在金离子起始浓度 2 0 0μg/ ml,菌体浓度2 mg/ ml,p H3 .0和 3 0℃的条件下 ,吸附 60 min,吸附量达 55.9mg/ g干菌体。 TEM观察结果表明 ,溶液中的Au3 +离子能被啤酒酵母废菌体吸附 ,并还原生成 Au0 颗粒。所生成的 Au0 颗粒能形成不同形状和大小的金晶体。吸附在 α- Fe2 O3 和 Si O2 上的 Au3 +离子也能被啤酒酵母废菌体还原形成纳米大小的金颗粒。 | LIU Yue-ying 1 FU Jin-kun 2 LUO Xue-feng 1 NI Zi-mian 3 CHEN Ping 3 YU Xin-sheng 2 ( 1 Department of Biology, 2 Department of Chemistry, 3 Centre of Analysis & Testing, Xiamen University, Xiamen 361005, P. R. China) | 2000 | 电子显微学报2000，19，5： | 7 |
| 15 | Synthesis of todorokite by refluxing process and its primary characteristics显示文摘Single phase and well-crystallined todorokite were synthesized by heating and re-fluxing process from birnessite as a precursor. The average chemical composition of the synthe-sized todorokites by refluxing for 8 h and for 24 h was Mg0.19MnO2.11(H2O)1.15 and Mg0.17- MnO2.10(H2O)0.88, respectively. The crystallinity of the todorokite increased and no other phase was produced with increasing refluxing period. The synthesized todorokites have the same morphologies and the similar structural characteristics with the natural todorokites and hydro-thermally synthesized samples. The chemical compositions of the synthetic tordorokites by re-fluxing process are close to those of todorokites synthesized by hydrothermal process, except a higher average oxidation state of Mn for the former. | FENG Xionghan1, LIU Fan1, TAN Wenfeng1, LIU Xiangwen2 & HU Hongqing1 1. College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China 2. Testing Center, China University of Geosciences, Wuhan 430074, China | 2004 | Science China Earth Sciences2004，47，8： | 7 |
| 16 | Pathways of birnessite formation in alkali medium显示文摘Birnessite is a common weathering and oxidation product of manganese-bearing rocks. An O2 oxidation procedure of Mn(OH)2 in the alkali medium has been used to synthesize birnessite. Fast and powder X-ray diffraction (XRD), transmission electron microscopy (TEM), electron diffraction (ED), energy dispersed X-ray analysis (EDAX), infrared spectroscopy (IR) techniques and chemical composition analysis, Eh-pH equilibrium diagram approaches were employed to investigate the reaction process and pathways of birnessite formation. Results showed that the process of the birnessite formation could be divided into four stages: (1) forma- tion stage for hausmannite and feitknechtite, (2) stage of transformation of hausmannite and feitknechtite to buserite, (3) buserite crystal growing stage, and (4) stage of conversion of buser- ite into birnessite. Mn(OH)2 was mainly present as amorphous state only for a short initial time of oxidation reaction. In the oxidation process, buserite formed following two pathways by recrys- tallization after dissolution of the intermediates, and the transformations of the minerals de- pended on the Eh determined by the dissolved O2 concentration on their surfaces. The results are fundamental in further exploration on the mechanism of birnessite formation in the alkali medium. A great practical significance would also be expected with respect to the areas of mate- rial sciences. | FENG Xionghan1, TAN Wenfeng1, LIU Fan1, HUANG Qiaoyun1 & LIU Xiangwen2 1. College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China 2. Testing Center, China University of Geosciences, Wuhan 430074, China | 2005 | Science China Earth Sciences2005，48，9： | 7 |
| 17 | MICROSTRUCTURAL EVOLUTION AND MECHANISMS OF SUPERPLASTICITY IN LARGE GRAINED IRON ALUMINIDES显示文摘The superplastic behavior has been found in Fe 3Al and FeAl alloys with grain sizes of 100~600 μm. The large grained Fe 3Al and FeAl alloys exhibit all deformation characteristics of conventional fine grain size superplastic alloys. However, superplastic behavior was found in large grained iron aluminides without the usual prerequisites for the superplasticity of a fine grain size and grain boundary sliding. The metallographic examinations have shown that average grain size of large grained iron aluminides decreased during superplastic deformation. Transmission electron microscopy (TEM) observations have shown that there were a great number of subgrain boundaries which formed a network and among which the proportion of low and high angle boundaries increased with the increase of strain. The observed superplastic phenomenon is explained by continuous recovery and recrystallization. During superplastic deformation, an unstable subgrain network forms and these subboundaries absorb gliding dislocations and transform into low and high angle grain boundaries. A dislocation gliding and climb process accommodated by subboundary sliding, migration and rotation, allows the superplastic flow to proceed. | Dongliang Lin (T.L.Lin) and Yi Liu Open Laboratory of Education Ministry of China for High Temperature Materials Tests, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200030, China | 1999 | 中国有色金属学会会刊:英文版1999，9，S1： | 7 |
| 18 | Quasi-static Analysis of Thrust-loaded Angular Contact Ball Bearings Part Ⅱ:Results and Discussion显示文摘Ball bearings are widely employed mechanical components characterized by high precision and quality,and usually play important roles in various rotary machines and mechanisms.Many advanced applications require a deep understanding of their various kinematic and tribological characteristics that are essential to predict the fatigue endurance,relieve the vibration and minimize the power dissipation of ball bearings in particular applications.An angular contact ball bearing under a specified operating condition is simulated with the quasi-static/creepage analytical model proposed in the preceding article.The results demonstrate that the ball bearing is a statically determinate system.That the balls spin on both inner and outer races means the ball is controlled by neither the inner nor the outer raceway.The friction between the ball and raceway renders the inner and outer contact angles unequal.The larger the coefficient of friction is,the larger the angle deviation.The tangential traction perpendicular to the rolling direction due to the spin induces a gyro-like rotation of the ball with respect to the raceway even if no inertial effects are considered.The tangential elastic compliance of contacting surfaces gives rise to locked areas within the contact patch and transforms the sliding lines from circles into spirals.The differential slip due to the close conformity of the ball and raceway makes the sliding and traction distributions asymmetric,which will influence the location of the spinning center of the ball with respect to the raceway.The quasi-static/creepage model can be used to reveal the operating behaviors of ball bearings running under steady conditions and to optimize the design of ball bearings for specific applications. | CHEN Wenhua1,2,MA Zikui1,GAO Liang1,LI Xinglin3,and PAN Jun2 1 Institute of Mechanical Design,Zhejiang University,Hangzhou 310027,China 2 Institute of Mechanical Design and Manufacturing,Zhejiang Sci-Tech University,Hangzhou 310018,China 3 State Testing Laboratory of Hangzhou Bearing Test & Research Center,Hangzhou 310022,China | 2012 | Chinese Journal of Mechanical Engineering2012，25，1： | 7 |
| 19 | UV-induced Self-initiated Graft Polymerization of Acrylamide onto Poly(ether ether ketone)显示文摘Photo-grafting of hydrophilic monomer was used to enhance the hydrophilicity of poly(ether ether ketone) (PEEK) with the aim of extending its applications to biological fields. PEEK sheets were surface modified by grafting of acrylamide(AAm) with ultraviolet(UV) irradiation in the presence or absence of benzophenone(BP). The effects of BP, irradiation time and monomer concentration on the surface wettability of PEEK were investigated. Characteriza tion of modified PEEK using scanning electron microscopy(SEM), energy-disperse spectrometer(EDS) and water contact angle measurements shows that AAm was successfully grafted on PEEK surface both in presence and absence of BP. With the increase in irradiation time and monomer concentration, contact angles decrease to as low as 30°, demonstrating a significant improvement of surface hydrophilicity. In agreement with the decrease in contact angle, under identical conditions, the nitrogen concentration increases, suggesting the increase in grafting degree of the grafting polymerization. This investigation demonstrates a self-initiation of PEEK due to its BP-like structure in the backbone of the polymer. Though the graft polymerization proceeds more readily in the presence of BP, the self-initiated graft polymerization is clearly observed. | CHEN Rui-chao, SUN Hui, LI Ang and XU Guo-zhi College of Materials Science and Mechanical Engineering, National Center for Quality Supervision and Test of Plastic Products, Beijing Technology and Business University, Beijing 100048, P. R. China | 2012 | Chemical Research in Chinese Universities2012，28，1： | 6 |
| 20 | Synthesis and Crystal Structure of Rare Earth Complex withCiprofloxacin显示文摘The complex of rare earth with ciprofloxacin has been synthesized and characterized bymeans of x-ray single crystal diftraction. The structure features of the complex are decribed. | Pin YANG Jia Bin LI Yan Ni TIAN Kai Bei YU (1 Institute of molecular Science, Shanxi University, Taiyuan 0300062 Analysis and Test Cented, Chinese Academy of Sciences, Chengdu 610041) | 1999 | Chinese Chemical Letters1999，10，10： | 6 |
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