检索结果-南通市图书馆

Effect of thermal shield and gas flow on thermal elastic stresses in 300mm silicon crystal

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2006年第z2期25卷 45-50页

作者： gao yu xiao Qinghua ZHOU Qigang DAI xiaolin TU Hailing General Research Institute for Nonferrous Metals Beijing 100088 China General Research Institute for Nonferrous Metals Beijing 100088 China General Research Institute for Nonferrous Metals Beijing 100088 China General Research Institute for Nonferrous Metals Beijing 100088 China General Research Institute for Nonferrous Metals Beijing 100088 China

The thermal elastic stresses induced in 300 mm Si crystal may be great troubles because it can incur the generation of dislocations and undesirable excessive residual stresses. A special thermal modeling tool, CrysVUn, was used for numerical analysis of thermal elastic stresses and stress distribution of 300 mm Si crystal under the consideration of different thermal shields and gas flow conditions. The adopted governing partial equations for stress calculation are Cauchy′s first and second laws of motion. It is demonstrated that the presence and shape of thermal shield, the gas pressure and velocity can strongly affect von Mises stress distribution in Si crystal. With steep-wall shield, however, the maximal stress and ratio of high stress area are relatively low. With slope-wall shield or without shield, both maximal stress and ratio of high stress area are increased in evidence. Whether thermal shields are used or not, the increase of gas flow velocity could raise the stress level. In contrast, the increase of gas pressure cannot result in so significant effect. The influence of thermal shield and gas flow should be attributed to the modification of heat conduction and heat radiation by them.

关键词： thermal elastic stress simulation 300 mm Si single crystal

A Novel Plasticizer for the Preparation of Thermoplastic Starch

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2006年第1期17卷 133-136页

作者： Jin Hui YANG Jiu gao yu xiao Fei MA School of Science Tianjin University Tianjin 300072

in this paper, ethylenebisformamide was synthesized and used as a novel plasticizer for cornstarch to prepare thermoplastic starch （TPS）. FT-IR expressed that ethylenebisformamide formed stronger and stable hydrogen bond with starch molecules compared to the native cornstarch. X-ray diffraction （XRD） showed that the typical A-style crystallinity in the native starch has been destructed. By scanning electron microscope （SEM） native cornstarch granules were proved to transfer to a homogeneous system. After being stored for one week at RH=33%, the mechanical properties of EPTPS was also studied. The elongation reached to 264% utmost. As a novel plasticizer, ethylenebisformamide would be practical to extend TPS application scopes.

关键词： Thermoplastic starch ethylenebisformamide novel plasticizer.

An efficient and facile procedure for synthesis of octyl polyglucoside

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2007年第10期18卷 1173-1175页

作者： Ying Wu Jiu gao yu xiao Fei Ma Jian She Zhang Department of Chemistry School of Science Tianjin University Tianjin 300072 China

Nonionic surfactant alkyl polyglucoside （APG） was prepared by direct glycosidation of alkyl alcohol with glucose in the presence of sulfate acid-silica gel （H2SO4/SiO2） as solid acidic catalyst. The quantity of catalyst was only of 1 wt%, based on the glucose, and the conversion of glucose was close to 100% at 110 ℃ in 1.5 h. The product was characterized by FT-IR, mass and ^1H NMR spectra. The degree of polymerization （DP） of the glucose in the product was 1.37, and critical micelle concentration （CMC） of product was only 0.0104 wt%.

关键词： Alkyl polyglucoside Sulfate acid-silica gel Solid acidic Catalyst

EnKF Assimilation of Satellite-retrieved Cloud Water Path to Improve Tropical Cyclone Rainfall Forecast

在线全文

学校读者我要写书评

暂无评论

Journal of Tropical Meteorology 2021年第3期27卷 201-217页

作者： gao xiao-yu LIN Yan-luan yuE Jian Ministry of Education Key Laboratory for Earth System Modeling Department of Earth System ScienceTsinghua UniversityBeijing 100084 China Center of Numerical Weather Predication China Meteorological AdministrationBeijing 100081 China

Tropical cyclone(TC) rainfall forecast has remained a challenge. To create initial conditions with high quality for simulation, the present study implemented a data assimilation scheme based on the EnKF method to ingest the satellite-retrieved cloud water path(C_(w)) and tested it in WRF. The scheme uses the vertical integration of forecasted cloud water content to transform control variables to the observation space, and creates the correlations between C_(w) and control variables in the flow-dependent background error covariance based on all the ensemble members, so that the observed cloud information can affect the background temperature and humidity. For two typhoons in 2018(Yagi and Rumiba), assimilating C_(w) significantly increases the simulated rainfalls and TC intensities. In terms of the average equitable threat score of daily moderate to heavy rainfall(5-120 mm), the improvements are over 130%, and the dry biases are cut by about 30%. Such improvements are traced down to the fact that C_(w) assimilation increases the moisture content, especially that further away from the TC center, which provides more precipitable water for the rainfall,strengthens the TC and broadens the TC size via latent heat release and internal wind field adjustment.

关键词： tropical cyclone data assimilation EnKF cloud water path

Upconversion luminescent property and EPR study of NaGdF4：yb3＋/Tm3＋ synthesized by the hydrothermal method

在线全文

学校读者我要写书评

暂无评论

Frontiers of Materials Science 2015年第3期9卷 241-246页

作者： Jing LIU Jing-Ying ZHANG Kai LIU Hong-Jian gao xiao-Long yu Yang CAO Zhong-Xin LIU Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources Hainan University Haikou 570228 China

Water soluble upconversion （UC） luminescence hexagonal-phase NaGdF4： yb3＋/Tm3＋ nanoparticles have been successfully synthesized by the hydrothermal method. XRD, SEM, UC photoluminescence spectra and electron paramagnetic resonance （EPR） spectrum were used to characterize the nanoparticles. The intensity of UC emission region could be controlled through different sodium source and the fluorine source, 6PJ→8S7/2 emission of Gd3＋ is also observed at 310 nm. A broad spectrum with a dominant resonance at g of about 2 was observed by the EPR spectrum of the NaGdF4：Yb3＋/Tm3＋ nanoparticles. The transparent NaGdF4：yb3＋/Tm3＋ solution presented naked eye-visible violet-blue light under the 980 nm LD excitation. The current work paves the way for their potential application in infrared tomography and magnetic resonance imaging （MRI）.

关键词： hydrothermal method sodium source fluorine source electron paramagnetic resonance (EPR) magnetic resonance imaging (MRI)

Expression of Interleukin-6 and Interleukin-6 Receptor in Ovine Oocytes During In vitro Maturation

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2012年第8期11卷 1333-1339页

作者： ZHAO Xi-an CANG Ming gao xiao-yu YANG Mei-ling yuAN Jian-long ZHU Bing WANG Zhi-gang LIU Dong-jun Key Laboratory of Ministry of Education of China for Mammal Reproduction Biology and Biotechnology Inner Mongolia UniversityHohhot 010021P.R.China

To study the effects of interleukin-6 （IL-6） and its receptor （IL-6R） during in vitro maturation of ovine oocytes, the mRNA and protein expression levels of IL-6 and IL-6R, along with their localization, were examined during ovine oocytes maturation in vitro through real-time PCR, Western blotting, and immunohistochemistry. Specific patterns of expression of IL-6 and IL-6R were observed at both mRNA and protein levels at each stage of ovine oocytes maturation. IL-6 and IL-6R were distributed primarily on the surface of the cell membrane, with little expression in the cytoplasm or nucleus. IL-6 and IL-6R were expressed significantly at higher levels in the maturation around 4 h, and then decreased dramatically. However the level slightly elevated at 20-24 h. The role of IL-6 and IL-6R on oocytes maturation was studied through in vitro addition of recombinant human IL-6 in different concentrations. The addition of 10 ng mL-1 IL-6 significantly increased the rates of oocytes maturation （P〈0.05）, but did not affect the rates of development of the subsequence IVF ovine embryos. In summary, IL-6 is likely to play an important role in the early ovine oocytes maturation. The expression patterns of the IL-6 and IL-6R on the ovine oocytes maturation open up the possibility of regulatory role of the cytokine in ovine oocytes maturation.

关键词： IL-6 oocyte in vitro maturation real time PCR Western blotting

Observation of acoustic hybrid topological phases induced by the p-d orbital interactions

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 132-139页

作者： xiao Xiang Feng gao yu-Gui Peng Peng Wu Zong-Lin Li Xue-Feng Zhu School of Physics and Innovation Institute Huazhong University of Science and Technology

In spinless systems,growing attention has recently been attracted to synthetic gauge fields,which redefine the fundamental crystal symmetries by utilizing the projective algebraic ***,synthetic gauge fields have been commonly investigated in single orbital systems,and explorations on hybrid orbitals remain elusive in ***,we report the experimental observation of hybrid topological phases induced by hybrid synthetic gauge flux,which is formed by the interaction between p and d orbitals embedded in acoustic *** breaking the translation symmetries of Lxand/or Ly,we unambiguously demonstrate the first-order M?bius edge states and higher-order corner *** work establishes a platform for seeking exotic topological phases induced by hybrid-orbitals interactions and initializing the framework of hybrid-orbitalsrelated topological *** applications can be anticipated in scenarios such as high-quality sensing and robust wave trapping due to the stepwise energy distribution of the hybrid topological phase.

关键词： topological insulator synthetic gauge field projective symmetry corner states

Activation and involvement of JNK1/2 in hydrogen peroxideinduced neurotoxicity in cultured rat cortical neurons

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2004年第5期25卷 88-94页

作者： Wei WANG, Can gao, xiao-yu HOU, Yong LIU, Yan-yan ZONG, Guang-yi ZHANG2Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, Xuzhou 221002, China Research Center for Biochemistry and Molecular Biology Xuzhou Medical College

AIM: To investigate the role of c-Jun N-terminal protein kinase 1 and 2 (JNK1/2) and the main signal pathway forits activation in hydrogen peroxide (H2O2) induced apoptotic-like cortical cell death. METHODS: Using the modelof oxidative stress induced by H2O2, the expression and diphosphorylation of JNK1/2 was examined by immunoblottinganalysis, and neuronal apoptotic like cell death was determined by 4’,6-diamidino-2-phenylindole (DAPI) ***: The elevation in diphosphorylation level of JNK1/2 (4.40-/5.61-fold vs sham control) was associatedwith the concentration of H2O2 (0-100 mol/L) and the development of apoptotic-like cell death (11.04 %-81.01 %).There was no alteration of JNK1/2 protein expression following H2O2 treatment and recovery at different timepoints. Administration with JNK1/2 antisense oligonucleotides not only significantly decreased JNK1/2 proteinexpression and activation level, but also significantly reduced cortical cell death induced by H2O2 ***, both JNK1/2 diphosphorylation and apoptotic-like cell death were largely prevented by pretreatmentwith (5S,10R)-()-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine hydrogen maleate (MK-801)or omission of Ca2+ in incubation medium with ethylene glycol-bis(2-aminoethylether)-N,N,N’,N’-tetraacetic acid(EGTA). CONCLUSION: JNK1/2 is activated and participates in H2O2-induced apoptotic-like death in cultured ratcortical neurons mainly via N-methyl-D-aspartate (NMDA) receptor-mediated influx of extracellular Ca2+.

关键词： c-Jun N-terminal protein kinase calcium N-methylaspartate receptors hydrogen peroxide signaltransduction apoptosis cerebral cortex

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

植物叶片润湿性与光谱反射偏振度关系研究

光谱学与光谱分析 2018年第3期38卷 923-928页

作者：高晓雨卢珊东北师范大学地理科学学院吉林长春130024 中国科学院地理科学与资源研究所资源与环境信息系统国家重点实验室北京100101 中国科学院大学北京100049

城市绿化植物由于其滞尘能力能够有效改善城市大气环境,滞尘能力的主要影响因素是其表面特性和润湿性。植物叶片表面的润湿性和偏振反射特性都与表面粗糙度相关,因此以粗糙度为结点,探究植物表面润湿性与偏振反射光谱的关系,利用偏振反... 详细信息

城市绿化植物由于其滞尘能力能够有效改善城市大气环境,滞尘能力的主要影响因素是其表面特性和润湿性。植物叶片表面的润湿性和偏振反射特性都与表面粗糙度相关,因此以粗糙度为结点,探究植物表面润湿性与偏振反射光谱的关系,利用偏振反射特性对植物叶片润湿性进行快速无损监测。以长春市常见的八种绿色植物叶片为研究对象,利用Kruss DSA 100液滴形状分析系统测量其表面接触角,利用多角度光谱测量装置测量其在不同探测天顶角上的偏振反射光谱,探讨了润湿性能在400~1 000nm波段对植物叶片不同探测天顶角上偏振度的影响。通过相关分析确定八种植物叶片的特征波段,并在特征波段对偏振度随探测天顶角的变化程度与润湿性的关系之间进行定量分析。结果表明,在特征波段(700±10)nm处,偏振度随着探测天顶角的变化程度θ0与接触角距离100°的偏差值θ具有很强的相关性,可决系数R2为0.82,说明偏振度随探测天顶角的变化程度θ0可以反映植物叶片的润湿性,可以利用偏振反射特性对植物叶片润湿性进行分析,研究成果将对今后城市绿化物种的选择提供可行性建议。

关键词：植物叶片润湿性偏振度探测天顶角