检索结果-南通市图书馆

Effects of rare earth La on the microstructure and melting property of(Ag-Cu_(28))-30Sn alloys prepared by mechanical alloying

在线全文

cnki会议

学校读者我要写书评

暂无评论

Rare Metals 2011年第1期30卷 49-52页

作者： LI Liangfeng QIU Tai YANG Jian FENG Yongbao state key laboratory cultivation base for nonmetal composites and functional materials Southwest University of Science and Technology Mianyang 621010 China College of materials Science and Engineering Nanjing University of Technology Nanjing 210009 China

To obtain novel intermediate temperature alloy solders with a melting temperature of 400-600°C,nominal（Ag-Cu28）-30Sn alloys without or with a trace addition（0.5 or 1.0 wt.%） of rare earth（RE） element La were prepared by mechanical *** aim of this research is to investigate the effects of the addition of La on the microstructures,alloying process and melting properties of（Ag-Cu28）-30Sn *** results show that the addition of La produces no new phase.A trace amount of La addition can effectively refine the grain size,but the excessive addition of 1.0 wt.% La inhibits the alloying *** influence of La on the melting temperatures of solder alloys is ***,the trace addition of 0.5 wt.% La can distinctly reduce the fusion zone and improve the melting property of（Ag-Cu28）-30Sn alloys.

关键词： solders rare earths mechanical alloying microstructure melting

Isothermal Crystallization Kinetics of Poly（Ethylene Terephthalate） Modified by Calcium Lignosulfonate

在线全文

学校读者我要写书评

暂无评论

Isothermal Crystallization Kinetics of Poly（Ethylene Tereph...

2011 IEEE International Conference on Waste Recycling,Ecology and Environment(ICWREE 2011)

作者： Hanbing MA1 2* Xiuyun LI 1 2 Li YANG 1 2 Detian LIAO 1 Shaoliang XIE 1 1 state key laboratory cultivation base for nonmetal composites and functional materials Mianyang 621010 China 2 National Insulating Material Engineering Research Sub-Center Southwest University of Science and Technology Mianyang 621010 China

In this study, the effect of Lignosulfonate（LS） skeleton presence on the isothermal crystallization speed of the Poly（ethylene terephthalate）（PET） molecular chains were investigated by using differential scanning calorimetry （DSC）. The isothermal crystallization kinetics of PET and modified PET were analyzed by the Avrami equation. The results indicated that the crystallization rate increased with the addition of LS but decreased with overmuch LS. The Arvami exponent decreasing along with the adding of LS suggested that the crystallization changed from two-dimensional disk-shaped growth to three-dimensional spherulite growth. In addition, the introduction of LS made it less sensitive to the crystallization temperature of the blends.

关键词： Poly(Ethylene Terephthalate) Calcium Lignosulfonate Isothermal Crystallization Crystallization kinetics

Growth Process and Mechanism of Silver Dendritein HF/AgNO3/Si System

在线全文

cnki会议

学校读者我要写书评

暂无评论

Growth Process and Mechanism of Silver Dendritein HF/AgNO3/S...

2011 IEEE International Conference on Waste Recycling,Ecology and Environment(ICWREE 2011)

作者： Wenbin YANG 1 2 * Kai ZHANG 3 Jinghui FAN3 Juying WU3 Qiang YAN4 1state key laboratory cultivation base for nonmetal Composite and functional materials Southwest University of Science and Technology Mian yang China 2 School of materials Science and Engineering Southwest Universit y of Science and Technology Mian yang China 3 Institute of System Engineering China Academy of Engineening Physics Mian yang China 4 Southwest Institute of Physics Chengdu China

A kind of straightforward method was developed to fabricate Ag dendrites with hierarchical structures in AgNO3/HF/Si system at room temperature . High quality Ag dendrites were produced on silicon substrate as the form of uniform solid film with a thickness of 3 mm . The X-ray diffraction analysis reveals that face-centre cubic Ag phases are dominant in the dendrites. The non-equilibrium potential and anisot ropic growth at different reaction times result in morphological evolution . As the reaction proceeds , the dendritic structure transforms into thermodynamically stable hexagonal structure . It is believed that the global diffusion-limited aggregation as well as the locally oriented attachment of Ag grains are responsible for the formation of Ag dendrites.

关键词： silverdendrite morphology growth process mechanism

高分辨电子显微学进展及其在材料科学中的应用

在线全文

cnki会议

学校读者我要写书评

暂无评论

实验技术与管理 2010年第3期27卷 25-28页

作者：王乙潜梁文双青岛大学国家重点实验室培育基地

简要介绍了高分辨电子显微学的最新进展。主要表现在两个方面：（1）球差校正的高分辨透射电子显微学;（2）原子分辨率的扫描透射电子显微学（或原子序数衬度成像）。两种成像技术均可达到亚埃的分辨率。介绍了这两种技术的各自特点及... 详细信息

简要介绍了高分辨电子显微学的最新进展。主要表现在两个方面：（1）球差校正的高分辨透射电子显微学;（2）原子分辨率的扫描透射电子显微学（或原子序数衬度成像）。两种成像技术均可达到亚埃的分辨率。介绍了这两种技术的各自特点及其在功能材料的微观结构缺陷表征、铁电薄膜的极性确定等方面的应用。随着亚埃分辨率的电子显微学的发展,它必将对材料科学、物理学、纳米科学、化学及生命科学等产生重大的影响。

关键词：高分辨电子显微学功能材料微观结构缺陷铁电极性

Microphthalmia-associated transcription factor and cell proliferation in the retinal pigment epithelium:the role of alternative splice forms

在线全文

学校读者我要写书评

暂无评论

Microphthalmia-associated transcription factor and cell prol...

2012全国发育生物学大会

作者： Xiaoyin Ma,Huirong Li,Juan Yang,Bin Wen,Yu Chen,Xi Jin,Ling Hou Developmental Cell Biology and Disease Program,School of Ophthalmology and Optometry and Eye Hospital,state key laboratory cultivation base,key laboratory of Vision Science of Ministry of Health and Zhejiang Provincial key laboratory of Ophthalmology,Wenzhou Medical College,Wenzhou,325003,China

The mechanism of proliferation in cells of the retinal pigment epithelium(RPE) remains unclear in development. During eye development,Microphthalmia-associated transcription factor(MITF),a basic-helix-loop-helix-leucine zipper protein,is expressed at RPE precursor cells and acts as a master regulator for RPE *** in Mitf such as microphthalmia-vga9 not only cause developmental defects of neural crest stem cell-derived melanocytes in the skin and deafness,but also result in small eyes and retinal degeneration due to abnormalities in RPE differentiation and dysfunction. To investigate whether MITF transcription regulation plays roles in cell proliferation in the RPE during development,here we focus on two alternative splice forms of MITF,which differ in six residues located upstream of the DNA biding basic domain and show different effects on DNA *** found that two alternative splice forms of MITF differentially expressed in quiescent and proliferated cells in the ***,the upregulation of one of the alternative splice forms of MITF in RPE cells increased the cells to arrest in the G1 phase and inhibited the cell proliferation while another did *** are currently attempting to identify potential mechanisms by which alternative splice forms of MITF may regulate RPE cell proliferation in development. Conclusions:Our results suggest that the alternative splice forms of MITF differentially regulate cell proliferation in the retinal pigment epithelium during development.

关键词：

Construction of a Genetic Linkage Map of a Bacterial Blight Resistance Rice Line derived from Oryza meyeriana L.

在线全文

cnki会议

学校读者我要写书评

暂无评论

Construction of a Genetic Linkage Map of a Bacterial Blight ...

中国植物病理学会2012年学术年会

作者： YAN Cheng-Qi~(**) CHEN Li-Na YANG Yong CHENG Xiao-Yue CHENG Ye CHEN Jian-Ping~(***) (state key laboratory Breeding base for Zhejiang Sustainable Pest and Disease Control key laboratory of Plant Protection and Biotechnology,Ministry of Agriculture,China Zhejiang Provincial key laboratory of Plant Virology,Institute of Virology and Biotechnology,Zhejiang Academy of Agricultural Sciences,Hangzhou 310021,China)

＜正＞Y73,a progeny line of asymmetric somatic hybridization between wild rice species Oryza meyeriana *** cultivated rice Oryza sativa L.,combines high bacterial blight（BB） resistance of the wild rice with good agronomic characters of the cultivated *** this study,a genetic linkage map of Y73 was constructed based on a recombinant inbred line（RIL） population derived from a cross between Y73 and a BB susceptible cultivar *** map consisted of 155 simple sequence repeats（SSR） markers and 56 sequence-tagged site（STS） markers,covering about 1 524.5 cM of the rice genome with an average distance between adjacent markers of 7.23 *** genetic linkage map will facilitate the mapping of quantitative trait loci（QTLs） and the isolation of important genes for BB resistance and other agronomic traits,and then will be a valuable resource for marker-assisted breeding.

关键词： Molecular makers Recombinant inbred lines Genetic linkage map Bacterial Blight Y73

在线全文

cnki会议

学校读者我要写书评

暂无评论

新装修办公室甲醛扩散规律及净化模拟

污染防治技术 2017年第6期30卷 23-28页

作者：卢蒙郝富昌孙丽娟河南理工大学河南省瓦斯地质与瓦斯治理重点实验室——省部共建国家重点实验室培育基地煤炭安全生产河南省协同创新中心河南理工大学安全技术培训学院

为了预防新装修办公室的甲醛污染,文中采用CFD方法对比分析了空调开启和关闭状态下甲醛扩散速率及分布特征,并对空气净化器在不同位置的净化效果进行了模拟。研究结果表明:（1）空调通风下甲醛浓度最终达到一个稳定值8.8×10-2mg/m3,要... 详细信息

为了预防新装修办公室的甲醛污染,文中采用CFD方法对比分析了空调开启和关闭状态下甲醛扩散速率及分布特征,并对空气净化器在不同位置的净化效果进行了模拟。研究结果表明:（1）空调通风下甲醛浓度最终达到一个稳定值8.8×10-2mg/m3,要小于空调关闭状态的甲醛浓度,空调通风有利于甲醛的净化;（2）空调关闭和开启状态下室内甲醛浓度平均增长速率分别为1.65×10-6mg/（m3·s）和5.33×10-4mg/（m3·s）,空调通风明显加快了室内甲醛浓度扩散速率;（3）甲醛分布受空调通风影响较大,甲醛浓度竖直面内自上而下呈阶梯状下降,水平面书柜侧甲醛浓度高于办工桌侧;（4）净化器开启几分钟后可将室内甲醛平均浓度降至安全标准范围,相比较来说,净化器放置在房间中部且介于污染源之间区域对甲醛净化效果最好。

关键词：扩散规律净化效果空调通风甲醛

Structure,Electrical Conducting and Thermal Expansion Properties of Ln_(0.6)Sr_(0.4)Co_(0.8)Fe_(0.2)O_3(Ln=La,Pr,Nd,Sm)Ceramics

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(materials Science) 2008年第3期23卷 386-390页

作者：徐庆 School of materials Science and Engineering Wuhan University of Technology

Ln0.6Sr0.4Co0.2Fe0.2O3 （Ln=La, Pr, Nd, Sm） perovskite-type complex oxides were synthesized using a glycine-nitrate process, and the structure, electrical conducting and thermal expansion properties of the resulting ceramics were examined with regard to the nature of the lanthanide cations. The results indicated that the La, Pr and Nd specimens had a rhombohedral symmetry, while an orthorhombic structure was determined for the Sm specimen. The pseudo-cubic lattice constant decreased with smaller lanthanide cations. It was found that the electrical conducting properties declined with decreasing lanthanide cation size. Fortunately, all the compositions remained rather high electrical conductivities exceeding 650 Ω ^-1m·cm^-1 in the intermediate temperature range （600-800 ℃）. An appreciable thermal expansion increase at high temperatures was detected for all the compositions. Decreasing the size of the lanthanide cations resulted in an increase of thermal expansion. With respect to the high electrical conductivities, the Ln0.6Sr0.4Co0.8Fe0.2O3 oxides are considered to be acceptable as mixed conducting component in composite cathode designs together with doped ceria electrolytes.

关键词： electrical conduction Perovskites thermal expansion

基于物方定位一致性约束的光学航空影像多视铅垂线轨迹匹配

在线全文

学校读者我要写书评

暂无评论

光学精密工程 2018年第7期26卷 1784-1793页

作者：张卡盛业华付素霞袁家明陈辉南京师范大学虚拟地理环境教育部重点实验室江苏南京210023 江苏省地理环境演化国家重点实验室培育建设点江苏南京210023 江苏省地理信息资源开发与利用协同创新中心江苏南京210023

针对传统铅垂线轨迹匹配方法在进行地面基元匹配时存在只能得到一个高程值且匹配结果缺乏准确性验证的缺点,本文提出了一种新的基于物方定位一致性约束的光学航空影像多视铅垂线轨迹匹配方法。该算法对传统铅垂线轨迹匹配方法进行了针... 详细信息

针对传统铅垂线轨迹匹配方法在进行地面基元匹配时存在只能得到一个高程值且匹配结果缺乏准确性验证的缺点,本文提出了一种新的基于物方定位一致性约束的光学航空影像多视铅垂线轨迹匹配方法。该算法对传统铅垂线轨迹匹配方法进行了针对性的改进,首先,改善了物方地面基元的像方多视匹配过程,其次,利用地面基元已有的物方平面坐标作为物方定位一致性约束条件,增加了多视匹配结果的准确性检验过程,从而得到可验证的地面元匹配结果。使用实际航空多视影像对本文算法与传统铅垂线轨迹方法进行了对比实验,实验结果显示本文方法在可靠性、准确性和算法效率等定量指标方面,比传统铅垂线轨迹方法分别高出26%、40%和4倍,证明其能得到更加可靠与有效的地面元匹配结果。

关键词：光学航空影像铅垂线轨迹匹配物方地面元物方定位一致性准确性验证