检索结果-南通市图书馆

Consolidation and Compression Property of Nanocrystalline NiAl Synthesized by Mechanical Alloying

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 1996年第1期12卷 7-10页

作者： liu, zg Guo, JT Shi, NL Hu, ZQ State Key Lab. for RSA Institute of Metal Research Chinese Academy of Sciences Shenyang 110015 China

The mixture of pure nickel and aluminum powders in the composition of Ni50Al50 was subjected to high energy ball milling. The high energy ball milling to 30 h resulted in the formation of a nanocrystalline NiAl with a grain size of about 10 nm. The as-milled NiAl powder was hot-pressed and the compact with a density of 90% was obtained. It was showed that heating to 900 degrees C and holding for more than 2 h failed to induce the coarsening of the fine nanocrystal in the material, the tendency of grain growth was weak. Compression testing showed that the compression ductility at room temperature reached about 7%. The ductility increased with the experimental temperature while the strength decreased drastically at elevated temperature.

关键词： Nickel alloys

Periodic surface structures fabricated by one excimer laser pulse through a silica phase mask grating

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第21期42卷 1787-1792页

作者： Luo, GP Wu, HM Wang, M Zhu, SN Lu, YQ liu, zg Wei, Y Ming, NB Nanjing Univ Natl Lab Solid State Microstruct Nanjing 210093 Peoples R China

RECENTLY, excimer laser devices, which have higher-energy density output in pulsed ultravio-let (UV) light (193 or 248 nm), have been employed to generate some thin film struc-tures. The principle of this technique, which is also called pulsed laser deposition (PLD)technique, is that the exposed material could be ablated out of the sample by the focusing laserbeam, and redeposit on a substrate to form thin-film structures under certain conditions. Onthe other hand, researchers have obtained high-quality Bragg gratings in photosensitive

关键词： excimer laser pulse phase mask grating periodic surface structures.

Cloning and identification of an angiostatic molecule IP-10/crg-2

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 1999年第3期5卷 241-244页

作者： liu zg Yang JH An HZ Wang HY He FT Han ZY Han Y Wu HP Xiao B Fan DM Fourth Mil Med Univ Dept Gastroenterol Xijing Hosp Xian 710032 Shaanxi Prov Peoples R China Harvard Univ Dept Cellular & Mol Biol Cambridge MA 02138 USA

AIM To obtain human and murine cDNAsencoding IFN--y inducible protein 10 (lP--10) andcytokine responsive gene--2 (Crg-2).METHODS The encoding genes of lP-10 and Crg2 were amplified by RT--PCR from Cultured humanfibroblast cells and Balb/ c mouse liver treatedby IFN-y and TNF-a, respectively, and clonedinto plasmids of PUC19 and PGEM3Zf(+ ).RESULTS The nucleotide sequences ot theamplified DNA were confirmed by endonucleasesdigestion and *** Recombinant lP-10/ crg--2 geneclones with 306 hp and 314 hp inserts wereestablished for further research on biologicalactivities and ligands of hiP-10/mCrg--2.

关键词： IP Nature Figure Cloning and identification of an angiostatic molecule IP-10/crg-2

Eldepryl prevents 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced nigral neuronal apoptosis in mice

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

中华医学杂志(英文版) 2001年第3期114卷 16-19+102-103页

作者：郭明陈生弟刘振国陈红专上海瑞金医院神经科!上海200025 上海第二医科大学药学系!上海200025

目的　探讨MPTP和MPP+对黑质多巴胺能神经元和PC12细胞的凋亡的作用及咪多吡 (Eldepryl)对MPTP的拮抗作用。方法　应用MPTP腹腔注射C57 BL小鼠及口服Eldepryl预处理 ,分别用TUNEL法和FACS法对黑质神经元进行凋亡检测 ;体外实验用同样的... 详细信息

目的　探讨MPTP和MPP+对黑质多巴胺能神经元和PC12细胞的凋亡的作用及咪多吡 (Eldepryl)对MPTP的拮抗作用。方法　应用MPTP腹腔注射C57 BL小鼠及口服Eldepryl预处理 ,分别用TUNEL法和FACS法对黑质神经元进行凋亡检测 ;体外实验用同样的方法对分别加入MPP+、MPTP或PBS的PC12细胞进行凋亡检测。结果　MPTP 30mg/kg连续注射 7天能诱致的黑质神经元凋亡 ,Eldepryl预处理能完全拮抗MPTP诱致黑质神经元凋亡 ;MPP+能使PC12细胞发生凋亡 ,而MPTP则不能导致PC12细胞凋结论　MPTP可能通过细胞凋亡机制导致黑质神经元死亡 ,其凋亡作用是通过MPTP代谢转化为MPP+而实现的 ,Eldepryl能抑制MPTP向MPP+的转化 ,从而有效地拮抗MPTP诱致黑质神经元凋亡

关键词： 1-甲基-4-苯基-1,2,3,6-四氢吡啶 1-甲基-4-苯基吡啶离子咪多吡黑质多巴胺能神经元 PC12细胞细胞凋亡帕金森病

Damping Behaviour and Mechanism of Graphite ParticulateReinforced Metal Matrix Composites

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 Materials Science & Technology 1997年第6期13卷 447-451页

作者： liu, YC Yang, GC Lu, YL Zhu, zg Northwestern Polytech Univ State Key Lab Solidificat Proc Xian 710072 Peoples R China Acad Sinica Inst Solid State Phys Internal Frict & Defects Solids Lab Hefei 230031 Peoples R China

The effect of graphite particulate reinforcement on the resultant damping behaviour of ZA27 metal matrix composites (MMCs) has been investigated in an effort to develop a new functional material. The MMCs were processed by a spray atomization and deposition technique. The damping capacity, as well as the relative dynamic modulus, was measured at frequencies of 1 and 4 Hz in the 30 to 200 degrees C temperature range. There exists a transformation point at 55 degrees C in the internal friction and temperature spectrum of the MMCs. It is shown from microstructural analysis that the damping capacity of ZA27 can be significantly improved by the addition of graphites particulates through spray deposition processing. Finally, the operative damping mechanism is discussed in light of the data obtained from characterization of microstructure and damping capacity.

关键词： Graphite Damping Behaviour and Mechanism of Graphite ParticulateReinforced Metal Matrix Composites

The generalized self-similarity and scaling in variance in fluid motions

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第1期42卷 61-64页

作者： liu, SD Lui, SK Jiang, MS Zheng, zg Department of Geophysics Peking Univemity Beijing China Beijing Institute of Meteorology Beijing China

ATMOSPHERIC and oceanic flows stride across very wide scale. For example, the scale of large vortexes is of the order of 10~6 m, while the scale of small vortexes is of only a few millimeters in the atmosphere. The scales of turbulent flows in the inertial range stride across three orders of magnitude in atmospheric surface layer. The monthly mean surface air temperature data in the Northern Hemisphere from 1851 to 1984 include the four different

关键词： self-similarity scaling scaling invariance.

Positron Annihilation Study of the Quenched-in Vacancies in CuZnAl Alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 1995年第6期11卷 409-414页

作者： WEI, zg YANG, DZ Dalian Univ of Technology Dalian China

The excess vacancies in ternary CuZnAl and Ti-doped CuZnAl alloys quenched from temperatures between 673 K and 1223 K, and the behaviour of the quenched-in vacancies on postquench aging in martensite phase have been studied by Doppler broadening measurements. It has been found that adding Ti to the alloys results in the formation of vacancy-Ti solute atom complexes which lowers the mobility of the vacancies. In the Ti-free alloy, the prominent changes in the lineshape S-parameter during the early stage of martensite aging have evidenced the occurrence of vacancy migration to sinks, clustering or vacancy. related atomic distortion. The role of the vacancies in martensite stabilization has been discussed.

关键词： Intermetallics

Influence of recycled polyethylene terephthalate fibres on plastic shrinkage and mechanical properties of concrete

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2022年第6期16卷 792-802页

作者： NecatÖZAŞIK Özgür EREN Department of Civil Engineering Eastern Mediterranean UniversityMersin 99628Turkey

Polyethylene terephthalate bottles production has drastically increased year after year due to high versatility of polyethylene terephthalate plastics and considerable consumption of *** tandem with that increase,the major concern of society has been the improper disposal of this non-biodegradable material to the *** deal with this concern,recycled polyethylene terephthalate bottles were incorporated in concrete as fibre reinforcements in this *** objective of this research is to evaluate the mechanical properties of recycled polyethylene terephthalate fibre reinforced concrete(RPFRC)in comparison with control concrete without *** terephthalate fibres with three different diameters(0.45,0.65,and 1.0 mm)and two lengths(20 and 30 mm)were added at various proportions(0.5%,1.0%,1.5%and 2.0%)by volume of concrete in order to determine the effect of fibres initially on compressive,flexural and splitting tensile strengths of *** results revealed that none of the fibres have detrimental effects up to 1%volume fraction,however further addition caused slight reductions on mechanical properties in some *** shrinkage resistance and impact resistance tests were also performed according to related *** terephthalate fibres were observed to have marked improvements on those *** a good performance could be attributed primarily to the bridging effect of fibres.

关键词： recycled PET fibre-reinforced concrete mechanical properties plastic shrinkage impact energy

Principal Congruence Subgroups of Hecke Groups H(q^(1/2))

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2006年第2期22卷 383-392页

作者： Nihal YILMAZ zgüR Department of Mathematics Balikesir University

Using the notion of quadratic reciprocity, we discuss the principal congruence subgroups of the Hecke groups H（√q）,q 〉 5 prime number.

关键词： Hecke group Principal congruence subgroup Congruence subgroup