检索结果-南通市图书馆

Science china(Life sciences) 2008年第11期51卷 1039-1044页

作者： DONG XiaoQing1, XU Jun2. WANG WeiCai1, Luo Hao1, LIANG XiaoFei1, Zhang Lei1, Wang HanJie1, Wang PengHua2.& CHANG Jin1 1 Institute of Nanobiotechnology, School of Materials Science and Engineering, Tianjin University, Tianjin 300072. china 2.Department of Diabetic Foot, Tianjin Medical University Metabolic Disease Hospital, Tianjin 300070, china Institute of Nanobiotechnology School of Materials Science and Engineering Tianjin University Tianjin China Department of Diabetic Foot Tianjin Medical University Metabolic Disease Hospital Tianjin China

In this study the w/o/w extraction–evaporation technique was adopted to prepare poly(lactic-co-glycolic acid) (PLGA) microspheres loading recombinant human epidermal growth factor (rhEGF). The micro-spheres were characterized for morphology by transmission electron microscopy (tem) and particle size distribution. The release performances, the proliferation effects and therapeutic effects of rhEGF-loaded PLGA microspheres were all studied. The results showed that these spherical micro-spheres had a narrow size distribution and a high drug encapsulation efficiency (85.6%). RhEGF-loaded microspheres enhanced the growth rate of fibroblasts and wound healing more efficiently than pure rhEGF. The number of the proliferating cell nuclear antigen (PCNA) in the epidermis layer with the mi-crosphere treatment was significantly larger than those of the control groups. Overall locally sustained delivery of rhEGF from biodegradable PLGA microspheres may serve as a novel therapeutic strategy for diabetic ulcer repair.

关键词： rhEGF microspheres the diabetic ulcer recombinant human epidermal growth factor PLGA

Effect of Microstructure and Sulfide on Corrosion of Cu-Ni Alloys in Seawater

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2000年第4期16卷 411-415页

作者： Xiaolong ZHU (General research Institute for Nonferrous Metals, Beijing 100088, china) General research Institute for Nonferrous Metals Beijing 100088 China

The microstructure and the corrosion product films have been investigated on Cu-Ni alloys by tem, SEM, AES and electrochemical technique as well as natural seawater exposure tests. Experimental results showed that the alloys had two kinds of microstructure, i.e. recrystallizatjon and incomplete recrystallization. In synthetic seawater containing 2.10^-6 S^2., the stability of the alloy increased with the increase of deformation and annealing temperature, i.e., the degree of recrystallization. After exposure to natural seawater for different periods of time, the corrosion product films of the recrystallized alloy were rich in Ni and compact, and there were cracks in the outer layer which contained a small amount of S; the films of the alloy of incomplete recrystallization became thick, loose and porous, and obviously of layered structure, and the intergranular corrosion took place in the underlying substrate Besides, a great amount of seawater substance existed in the outer layer and some sulfur was found within the grain boundaries that prefer to corrode. The accelerating effect of sulfides in corrosion of Cu-Ni alloys in seawater is attributed to the coexistence and absorption of sulfides and carbides promoting the preference of corrosion where they absorb, and the formation of dissolvable Cu2. results in keeping the surface of the alloys in the active state.

关键词： Effect of Microstructure and Sulfide on Corrosion of Cu-Ni Alloys in Seawater Cu Ni

Preparation of Li_4Ti_5O_(12. submicrospheres and their application as anode materials of rechargeable lithium-ion batteries

在线全文

学校读者我要写书评

暂无评论

Science china Chemistry 2011年第6期54卷 936-940页

作者： ZHANG Ai, ZHENG ZongMin, CHENG FangYi, TAO ZhanLiang & CHEN Jun key laboratory of Advanced Energy Materials Chemistry, Ministry of Education College of Chemistry, Nankai University, Tianjin 300071,{2. key laboratory of Advanced Energy Materials Chemistry Ministry of Education College of Chemistry Nankai University Tianjin China

We report on the preparation of spinel Li4Ti5O12.submicrospheres and their application as anode materials of rechargeable lithium-ion batteries. The spinel Li4Ti5O12.submicrospheres are synthesized with three steps of the hydrolysis of TiCl4 to form rutile TiO2. the hydrothermal treatment of rutile TiO2.with LiOH to prepare an intermediate phase of LiTi2.4+δ, and the calcinations of LiTi2.4+δ to obtain spinel Li4Ti5O12. The as-prepared products are investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (tem). The diameters of Li4Ti5O12.submicrospheres with novel hierarchical microstructures are about 2.0–300 nm with the assembly of 2.–30 nm nanoparticles. The electrochemical properties of Li4Ti5O12.submicrospheres are measured by galvanostatical discharge/charge test and cyclic voltammetry (CV). The as-prepared Li4Ti5O12.display excellent discharge/charge rate and cycling capability. A high discharge capacity of 174.3 mAh/g is obtained in the first discharge at 1 C rate. Meanwhile, there is only tiny capacity fading with nearly 100% columbic efficiency in the sequential 5–50 cycles. Moreover, lithium-ion diffusion coefficient in Li4Ti5O12.is calculated to be 1.03 × 10-7 cm2.s. The present results indicate that the as-prepared Li4Ti5O12.submicrospheres are promising anode candidates of rechargeable Li-ion batteries for high-power applications.

关键词： Li4Ti5O12 TiO2 TiCl4 anode material lithium-ion battery

溶胶凝胶法制备中孔分布集中的氧化铝催化材料

在线全文

学校读者我要写书评

暂无评论

燃料化学学报 2001年第Z1期29卷 80-82页

作者：姚楠熊国兴盛世善何鸣元杨维慎中国科学院大连化学物理研究所催化基础国家重点实验室辽宁大连116023 中国石油化工总公司石油化工科学研究院北京100083

报道一种新的中孔氧化铝催化材料的制备方法。通过该方法可以以无机盐和SB粉为原料经过沉淀、解胶的过程首先制得稳定的铝溶胶 ,然后经过干燥、焙烧得到中孔氧化铝催化材料。用BET ,tem ,DTA和XRD等方法对该中孔氧化铝催化材料的基本物... 详细信息

报道一种新的中孔氧化铝催化材料的制备方法。通过该方法可以以无机盐和SB粉为原料经过沉淀、解胶的过程首先制得稳定的铝溶胶 ,然后经过干燥、焙烧得到中孔氧化铝催化材料。用BET ,tem ,DTA和XRD等方法对该中孔氧化铝催化材料的基本物理化学性质进行了表征。实验结果表明在不使用模板剂的前提下 ,通过本文报道的方法能够制得比表面积较大、中孔分布集中的氧化铝材料 ,并且其孔径分布主要集中在 4nm左右。

关键词：溶胶凝胶氧化铝中孔材料

Micro-and submicrostructural evidence for high-temperature brittle-ductile transition deformation of hornblende: Case study of high-grade mylonites from Diancangshan, western Yunnan

在线全文

学校读者我要写书评

暂无评论

Science china Earth sciences 2007年第10期50卷 1459-1470页

作者： CAO ShuYun, LIU JunLai? & HU Ling State key laboratory of Geological Processes and Mineral Resources (GPMR),{2. University of Geo{2., Beijing 100083,{2. key laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education,{2. University of Geo- {2., Beijing 100083,{2. State key laboratory of Geological Processes and Mineral Resources (GPMR) China University of Geosciences Beijing 100083 China key laboratory of Lithosphere Tectonics and Lithoprobing Technology of Ministry of Education China University of Geosciences Beijing 100083 China

OM (optical microscope)/tem (transmission electron microscope) micro- and submicrostructural analysis of hornblende rocks sheared at high temperatures from the Diancangshan area, western Yunnan reveals evidence for deformation in the brittle-ductile transition of hornblende at middle crustal level (about 637℃ and 0.653 GPa) and mechanisms of deformation in the transitional regime are further discussed. Sheared hornblende rocks at middle crustal level have typical mylonitic microstructures, shown by coarse porphyroclasts and fine matrix grains. Different mineral phases in the rocks show distinct deformation characteristics. Hornblende and feldspar grains are intensely deformed with ob- vious grainsize reduction, but quartz grains are recrystallized dominantly by grain growth. Hornblende grains show typical brittle-ductile transition nature. Initial crystallographic orientations of porphyro- clasts have strong effects on the behavior of grains during deformation. There are mainly two types of porphyroclasts, type I "hard" porphyroclasts and type II "soft" porphyroclasts, with [001] perpendicular and parallel to external shear stresses respectively. "Hard" porphyroclasts generally occur as compe- tent grains that are rarely deformed or sometimes deformed by fracturing and dislocation tangling. "Soft" porphyroclasts are highly deformed primarily by dislocation tangling (as shown in the cores of the porphyroclasts), but twinning, dislocation glide and climb probably due to hydrolytic weakening also contribute to dynamic recrystallization of the porphyroclasts into fine grains in the matrix. The micro- and submicrostructures of the two types of porphyroclasts and fine-grained matrix provide powerful evidence for the behavior of brittle-ductile transition of hornblende grains. It is concluded that twinning nucleation is one of the most important processes that o{2. during dynamic recrystalliza- tion of hornblende crystals at the brittle-ductile transition. (100) [001] t

关键词： hornblende, brittle-ductile transition, micro-and submicrostructures, twinning nucleation recrystallization, Diancangshan

tem Investigations of Thermal Stability of Nanocrystalline Co_(81)Cr_(19)

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 1994年第2期10卷 139-142页

作者： Jingtang WANG Bingzhe DING Huayu TONG and Qihong SONG (State key Lab of RSA, Institute of Metal research, Academia Sinica, Shenyang, 110015,{2.)(To whom correspondence should be addressed) Acad Sinica Shenyang China

In situ transrnission electron microscopic observations were carried out to study the thermal stability of nanocrystalline Co81 Cr19 (n-Co81 Cr19) alloy prepared by d.c. sputtering, The tem results show that the originally existed nanocrystalline phase hcp-CoCr is thermally stable, no apparent grain growth was observed until annealing to the final stage at.800℃. But the evolution of .microstructure of amorphous oxide Co2.ro4. which is formed duting in situ annealing. is drastically affected by the electron irradiation. In the electron irradiated area. the newly formed amorphous oxide Co2.rO4crystallizes at about 550℃. and grows into fine crystals finally. However, in the electron nonirradiated area, the amorphous oxide Co2.rO4 crystallizes at about 630℃. and grows into large strip shaped crystals during afterward annealing. the space between strip shaped crystals are also fine grained hcp-CoCr alloy. XRD analysis result of the thick film Co81 Cr19 is in good agreement with that of in situ tem for the excellent stability of hcp-CoCr

关键词： Cr Co

Investigation on preparing boron nitride by nitriding pure boron at 12.0-1550℃

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2012年第5期22卷 433-439页

作者： Fang Ye a,b,Litong Zhang a,b,Yongsheng Liu a,b,Siwei Li c,Meng Su a,b,Xiaowei Yin a,b,Laifei Cheng a,b a Science and Technology on Thermostructural Composite Materials laboratory,Northwestern Polytechnical University,Xi’an,Shaanxi 710072.PR china b State {2. laboratory of Solidification Processing,Northwestern Polytechnical University,Xi’an,Shaanxi 710072.PR china c {2. laboratory of High Performance Ceramic Fibers(Ministry of Education),College of Materials,Xiamen University,Xiamen,Fujian 361005,PR china Science and Technology on Thermostructural Composite Materials laboratory Northwestern Polytechnical University Xi'an Shaanxi 710072 PR China State key laboratory of Solidification Processing Northwestern Polytechnical University Xi'an Shaanxi 710072 PR China key laboratory of High Performance Ceramic Fibers (Ministry of Education) College of Materials Xiamen University Xiamen Fujian 361005 PR China

Boron nitride(BN) was prepared by nitriding pure boron(B) deposited on carbon substrates by chemical vapor deposition(CVD).Thermodynamic analysis of preparing BN by nitriding CVD B at 12.0-1550℃ was firstly *** then,the effects of nitridation conditions,including temperature,nitridation atmosphere and CVD B microstructure,on the conversion of B to BN were analyzed by scanning electron microscopy(SEM),energy dispersion spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS) and transmission electron microscopy(tem).Results show that the conversion degree of B to BN firstly increased and then slightly decreased with rising *** nitridation degree was controlled by mutual actions between the nitridation of B and consumption of the effective nitrogen source(NH3).The morphology of products and the reaction mechanism between B and N were influenced by nitridation *** high temperatures(1400-1500℃),BN with highly ordered microstructure was *** using N2.H2.as nitridation atmosphere instead of NH3-H2.N2.no BN was obtained in the studied temperature *** microstructure and component of BN obtained in nitridation process were little affected by the microstructure of CVD B.

关键词： Boron Nitridation Boron nitride Thermodynamics Kinetics

TiO_2.coated SnO_2.hollow spheres as anode materials for lithium ion batteries

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2011年第6期30卷 589-594页

作者： YI Jin LI Xiaoping HU Shejun LI Weishan ZENG Ronghua FU Zhao CHEN Lang School of Chemistry and environment South China Normal University Guangzhou 510006 China key laboratory of Electrochemtcal Technology on Energy Storage and Power Generation of Guangdong Higher Education Institutes Guangzhou 510006 China Engineering research Center of Materials and Technology for Electrochemical Energy Storage Ministry of Education Guangzhou 510006 China

TiO2.coated SnO2.（TCS） hollow spheres, which are new anode materials for lithium ion （Li-ion） batteries, were prepared and characterized with X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （tem）, cyclic voltammetry （CV）, and galvanostatic charge/discharge tests. The results obtained from XRD, SEM, and tem show that TiO2.can be uniforrrdy coated on the surface of SnO2.hollow spheres with the assistance of anionic surfactant. The cyclic voltammograms indicate that both TiO2.and SnO2.exhibit the activity for Li-ion storage. The charge/discharge tests show that the prepared TCS hollow spheres have a higher reversible coulomb efficiency and a better cycling stability than the uncoated SnO2.hollow spheres.

关键词： TiO2.coated SnO2 hollow spheres anode lithium ion batteries

Apoptosis Induced by Duck Virual Swollen Head Haemorrhagic Disease Virus in Duck Embryo Fibroblasts Cell

在线全文

学校读者我要写书评

暂无评论

Apoptosis Induced by Duck Virual Swollen Head Haemorrhagic D...

Effects of reproductive condition and gill microstructure on filtration rate of Cristaria plicata(Bivalvia:Unionidae)

第四届第九次全国学术研讨会暨饲料和动物源食品安全战略论坛

作者： ZHANG Na~1 CHENG An-chun~(1,2. WANG Ming-shu~(1,2. LI Chuan-feng~1 CHEN Xiao-yue~1 (1.Avian Disease research Center,College of Veterinary Medicine,Sichuan Agricultural University,Ya’an 62.014, Sichuan,china 2.{2. {2. of Animal Disease and Human Health of Sichuan,Ya’an 62.014,Sichuan,china)

After the replication of duck viral swollen head haemorrhagic disease virus(DSHDV)in duck embryo fibroblasts(DEFs)was successfully *** apoptosic changes were detected after DSHDV infection at different time by light microscope,transmission electron microscopy(tem),DNA Ladder and Annexin V-FITC/PI stained fluorescence-activated cell sorter(FACS).The results show that DSHDV can induce DEFs to undergo the apoptosis change *** morphological apoptotic features including cell shrinkage and condensation,margination of nuclear chromation were observed under light microscope and the formation of apoptotic bodies by *** ladder was shown by DNA fragment analysis at 2.-144h post *** percentage of apoptotic cells were analyzed quantitatively by using FACS.

关键词： duck viral swollen head haemorrhagic disease virus(DSHDV) duck embryo fibroblasts(DEFs) apoptosis

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Effects of reproductive condition and gill microstructure on...