检索结果-南通市图书馆

A highly active and stable Pd/b-doped carbon catalyst for the hydrogenation of 4-carboxybenzaldehyde

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2019年第4期28卷 154-158页

作者： Kai tie Xiulian Pan tie Yu Pan Li Limin He Xinhe bao State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences University of Chinese Academy of Sciences Department of Chemical Physics University of Science and Technology of China

boron had been introduced into the structure of carbon material(bC), which was used as the support of Pd catalyst for hydrogenation of 4-carboxybenzaldehyde(4-CbA). The physical properties and chemical composition of the support and corresponding catalyst were characterized by N2 adsorption–desorption,Raman spectroscopy, inductively coupled plasma optical emission spectroscopy(ICP-OES), element analysis(EA), high-resolution transmission electron microscopy(HRTEM), CO-pulse chemisorption and X-ray photoelectron spectroscopy(XPS). The results demonstrate that Pd/bC catalyst exhibits a superior activity and good stability due to the more uniform dispersion of Pd nanoparticles, the presence of mesoporous structure and the enhanced interaction between Pd nanoparticles and the support, compared to carbon and N-doped carbon supported Pd catalysts(Pd/C and Pd/NC, respectively).

关键词： Heteroatom-doped carbon Palladium Catalytic hydrogenation

Completeness of the system {z^(λ_n)}in L^2[b,α_0]

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2008年第12期24卷 2101-2110页

作者： Ju Hong NING Guan tie DENG Department of Mathematics Jiangxi Normal University Nanchang 330022 P. R. China School of Mathematical Sciences Beijing Normal University Beijing 100875 P. R. China

Let b be an unbounded domain located outside an angle domain with vertex at the origin, A ={λn}（n = 1,2,...） be a sequence of complex numbers satisfying sup ｜ arg（λn）｜〈 α 〈 π/2 and denote by M（∧） = {z^λ, λ ∈ ∧} the corresponding system of functions z^λ（λ∈∧）. Let α0（z） be a weight function defined on b. We obtain a completeness theorem for the system M（∧） in the Hilbert space L^2 [b, α0].

关键词： completeness unbounded domain Hilbert space

Influence of Nitrogen Flow Ratio on the Microstructure, Composition, and Mechanical Properties of DC Magnetron Sputtered Zr-b-O-N Films

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2012年第11期28卷 981-991页

作者： tie-Gang Wang Yanmei Liu Tengfei Zhang Doo-In Kim KwanKHo Kim

Nanocrystalline Zrb2 film and nanocomposite Zr-b-O-N films were prepared by non-reactive as well as re- active magnetron sputtering techniques, respectively. by means of X-ray diffraction analysis, electron probe microanalysis, X-ray photoelectron spectroscopy, and scanning electron microscopy, the influence of nitrogen flow ratio on the film microstructure and characteristics were investigated systematically, including the depo- sition rate, chemical compositions, phase constituents, grain size, chemical bonding, as well as cross-sectional morphologies. Meanwhile, the hardness and adhesion of above films were also evaluated by micro-indentation method and a scratch tester. With increasing the nitrogen flow ratio, the deposition rate of above films de- creased approximately linearly, whereas the contents of N and O in the films increased gradually and tended to saturation. Moreover, the film microstructure was also altered gradually from a fine columnar microstructure to a featureless glass-structure. As the nitrogen flow ratio was 11.7%, the Zr-b-O-N film possessed an typical nanocomposite structure and presented good mechanical properties. During the process of reactive sputtering of metal borides, the introduction of nitrogen can show a pronounced suppression of columnar grain growth and strong nanocomposite structure forming ability.

关键词： Films DC magnetron sputtering Nanocomposite Microhardness Adhesion

Evolution of secondary phase particles during deformation of Al-5Ti-1b master alloy and their effect on α-Al grain refinement

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2018年第12期34卷 2297-2306页

作者： Hong Yu Ning Wang Renguo Guan Di tie Zheng Li Yanan An Yang Zhang State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi'an 710072China School of Materials Science and Engineering Northeastern University.Shenyang 110819 China

Addition of Al-5Ti-1b alloy to molten aluminum alloys can refine α-Al grains effectively and thereby improve their strength and toughness. TiAl;and Tib;in Al-5Ti-1b alloy are the main secondary-phase particles for refinement, while the understanding on the effect of their sizes on α-Al grain refinement continues to be fragmented. Therefore, Al-5Ti-1b alloys with various sizes and morphologies of the secondary-phase particles were prepared by equal channel angular pressing（ECAP）. Evolution of the secondary-phase particles during ECAP process and their impact on α-Al grain refinement were studied by X-ray diffraction and scanning electron microscope（SEM）. Results show that during the ECAP process, micro-cracks firstly appeared inside TiAl;particles and then gradually expanded, which resulted in continuous refinement of TiAl;particles. In addition, micro-distribution uniformity of Tib;particles was improved due to the impingement of TiAl;particles to Tib;clusters during deformation. Excessively large sizes of TiAl;particles would reduce the number of effective heterogeneous nucleus and thus resulted in poor grain refinement effectiveness. Moreover, excessively small TiAl;particles would reduce inhibitory factors for grain growth Q and weaken grain refinement effectiveness. Therefore, an optimal size range of 18-22 μm for TiAl;particles was suggested.

关键词： Equal channel angular pressing process Secondary phases Refinement mechanism Grain refinement effect

Analysis of Energy Saving Reconstruction of Existing Campus Dormitories in Chongqing——Taking Dormitory Six on Campus b of Chongqing University as An Example

在线全文

学校读者我要写书评

暂无评论

Journal of Harbin Institute of Technology(New Series) 2014年第4期21卷 96-102页

作者： Wen-Jing Dong tie-Jun Zhou Run-Zhao Qi Chongqing University Faculty of Architecture and Urban Planning Key Laboratory of New Technology for Construction of Cities in Mountain Area

At present,a large number of historic buildings on campus are lack of energy-saving measures from the design time,especially the dormitories. And the reconstruction mostly focuses on functional reorganization or furniture replacement. However,energy efficiency design has not been paid enough attention,which leads to the high building energy consumption and the harsh physical environment. based on the analysis of climatic characteristics of Chongqing area,taking Dormitory Six on campus b of Chongqing University as an example,the reconstruction of rooms on the top floor and West end are focused to guarantee the equal benefits of the dormitory environment. Through the simulation analysis of the software, on the basis of energy saving reconstruction of common maintenance structure,this thesis discusses the energy saving reconstruction methods and strategies of the existing campus dormitories,which are more suitable for the existing campus dormitories in Chongqing area.

关键词： campus dormitories in Chongqing energy-saving reconstruction optimization reconstruction design planted roof greening of West walls

Curcumin induces the expression of NF-κb and bcl-2/bax in human renal cell carcinoma cell line ACHN

在线全文

学校读者我要写书评

暂无评论

Journal of Nanjing Medical University 2009年第6期23卷 386-391页

作者： Gang Li tie Chong Ziming Wang Department of Urology the Second Affiliated Hospital of Xi an Jiaotong University Xi an 710004 China

Objective： To explore the in vitro effects of curcumin on the proliferation and apoptosis of the human renal cell carcinoma cell line ACHN, and to investigate its mechanisms of action. Methods： The human renal cell carcinoma cell line ACHN was treated with different concentrations of curcumin for 24 h. The MTT assay was used to evaluate the cytotoxic effects of curcumin and flow cytometry was utilized to observe and detect the apoptosis of ACHN cells induced by curcumin. The expression levels of bcl-2, bax and NF-κbP65 mRNA were evaluated by Reverse Transcription-Polymerase Chain Reaction （RT-PCR）, while the expression of bcl- 2, bax, NF-κbP65 and Iκb proteins was evaluated by Western blot. Results： The concentrations of curcumin used significantly inhibited the proliferation of ACHN human renal cell carcinoma cells in vitro in a dose and time-dependent manner （Ftime=5.55, P 〈 0.05; Fdose=110.05, P 〈 0.05）. Obvious apoptosis of cells treated with different concentrations of curcumin could be observed by FCM. Compared with the control group, the apoptosis rates of curcumin-treated cells were markedly increased （F=96.35, P 〈 0.05）. Lower dose of curcumin significantly induced the apoptosis of ACHN cells. With intervention of different concentrations of curcumin （0, 10, 20 and 40 μmol/L） for 24 h, the expression levels of bcl-2 and NF-κbP65 mRNA in ACHN cells were decreased while the expression level of bax mRNA was increased （P 〈 0.05）, and bcl-2, and NF-κbP65 protein decreased, while bax and Iκb protein increased compared with those in the untreated group. Conclusion： Curcumin inhibited proliferation and increased apoptosis of the human renal cell carcinoma cell line ACHN. These curcumin effects appear to involve up-regulating Iκb, down-regulating NF-κb, and regulating the expression of the apoptosis genes bcl-2/bax.

关键词： curcumin renal cell carcinoma apoptosis NF-κb bcl-2

Microstructure evolution and mechanical properties of Ti-b-N coatings deposited by plasma-enhanced chemical vapor deposition

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2012年第S3期22卷 722-728页

作者： Jung Ho SHIN Kwang Soo CHOI tie-gang WANG Kwang Ho KIM Roman NOWAK National Core Research Center for Hybrid Materials Solution Pusan National University School of Materials Science and Engineering Pusan National University State Key Laboratory of Corrosion and Protection Institute of Metal ResearchChinese Academy of Sciences School of Chemical Technology Aalto University

Ternary Ti-b-N coatings were synthesized on AISI 304 and Si wafer by plasma-enhanced chemical vapor deposition (PECVD) technique using a gaseous mixture of TiCl4,bCl3,H2,N2,and *** virtue of X-ray diffraction analysis,X-ray photoelectron spectroscopy,scanning electron microscope,and high-resolution transmission electron microscope,the influences of b content on the microstructure and properties of Ti b N coatings were investigated *** results indicated that the microstructure and mechanical properties of Ti-b-N coatings largely depend on the transformation from FCC-TiN phase to HCP-Tib2 *** increasing b content and decreasing N content in the coatings,the coating microstructure evolves gradually from FCC-TiN/a-bN to HCP-Tib2 /a-bN via FCC-TiN+HCP-Tib2/*** highest microhardness of about 34 GPa is achieved,which corresponds to the nanocomposite Ti-63%b-N (mole fraction) coating consisting of the HCP-Tib2 nano-crystallites and amorphous bN *** lowest friction-coefficient was observed for the nanocomposite Ti-41%b-N (mole fraction) coating consisting of the FCC-TiN nanocrystallites and amorphous bN

关键词： Ti-b-N coating plasma-enhanced chemical vapor deposition (PECVD) nanocomposite coating hardness friction coefficient

Gene therapy that inhibits NF-κb results in apoptosis of human hepatocarcinoma by recombinant adenovirus

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2006年第33期12卷 5287-5292页

作者： tie-Jun Li Li-Ping Jia Xiao-Ling Gao Ai-Long Huang The 9th Hospital of Chongqing Beibei 400700 Chongqing China Institute for Viral Hepatitis Chongqing Medical University Chongqing 400016 China

AIM： To investigate whether the recombinant adenovirus induces the TNF-α-mediated apoptosis in vivo. METHODS： Human hepatocarcinoma cell line （HepG2） cells were transfected into bALb/c nude mice, and the tumor growth curve was drawn. We analyzed apoptosis in HepG2 cells by TUNEL, HE staining and electron microscopy. RESULTS： AdIκbαM was expressed stably and efficiently in HepG2 and could not be degraded by induction of TNF-α. Tumor growth in mice could be reduced remarkably if treated by AdIκbαM plus TNF-α. There was apoptosis of 〉 70% of cells treated with AdIκbαM plus TNF-α and about 50% of cells treated with AdIκbαM. In contrast, there was few cell apoptosis in HepG2 cells treated with phosphate buffered saline and AdIκbαM. HepG2 cells in mice also exhibited a high level of apoptosis after in vivo injection with AdIκbαM. The tumor growth curve indicated the tumor transfected with AdIκbαM could be restrained. CONCLUSION： AdIκbαM gene therapy greatly enhances apoptosis due to inhibition of an NF-κb-mediated antiapoptosis signaling pathway.

关键词： NF-κb Iκbα Adenovirus

Aerosol pollution in China:Present and future impact on environment

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

Particuology 2009年第6期7卷 426-431页

作者： Xuexi tie Junji Cao National Center for Atmospheric Research Boulder CO USA SKLLQG Institute of Earth Environment Chinese Academy of Sdences No. 10 Fenghui South Road High-Tech Zone Xi'an 710075. China

With its dense population, rapid economic growth and dramatic rate of urbanization, China is experiencing extreme air pollution problems. This is particularly the case in Central-Eastern China （CEC）, where the two major cities of beijing and Tianjin are located, in the Yangtze-River Delta （YRD） with the city of Shanghai, and in the Pearl-River Delta （PRD） with the mega-city of Gnangzhou. Space observations show that the atmospheric aerosol load in these three regions is considerably higher than, for example, in the urbanized regions of Europe and North America. The high aerosol concentrations in these regions have raised many environmental problems, such as impact on human health, visibility, and climate changes. In this paper, several crucial issues regarding aerosol pollution in these highly populated regions （CEC, YRD, and PRD） are discussed, including （1） when the aerosol load starts to rapidly increase in these regions; （2） how the high aerosol concentrations affects the environment; and （3） what the potential consequences are under possible low aerosol load in these regions. Discussion on these crucial issues might lead to some insight for better understanding of the characterizations of aerosol pollution due to the rapid economical development in China.

关键词： Aerosols Environment China Present and future effects