检索结果-南通市图书馆

特种铸造及有色合金 2001年第S1期21卷 160-163页

作者： c.enc. Yangc. c.aoc.

A motorc.c.e c.mponent of damper housing was made by semi-solid forming proc.ss. This was used to investigate the effec. of mic.ostruc.ures of feedstoc. on the formability of semisolid proc.ss. The soundness and mic.ostruc.ures of c.sting parts made by dendritic.and non-dendritic.feedstoc. were investigated. Separating of liquid phase was found in the c.sting produc.d by dendritic.feedstoc., whic. might result in defec.s of porosity, while uniform mic.ostruc.ures were found in the c.sting produc.d by no...

关键词： Al-Si-Mg Alloy Semi-solid Forming Damper Housing

渗氮活塞环表面磁控溅射MoN涂层的摩擦学性能

在线全文

学校读者我要写书评

暂无评论

摩擦学学报 2004年第4期24卷 308-312页

作者：马亚军李生华潘国顺金元生王玉琮 tung S c 清华大学摩擦学国家重点实验室北京100084 通用汽车公司美国底特律480909055

利用磁控溅射方法在渗氮活塞环基体上沉积了厚约4μm的MoN涂层;以GF-3等级的全配方发动机油作为润滑剂,采用SRV型高温摩擦磨损试验机对比考察了沉积MoN涂层前后渗氮活塞环的摩擦学性能.结果表明,沉积MoN涂层后摩擦系数较低且较快达到稳... 详细信息

利用磁控溅射方法在渗氮活塞环基体上沉积了厚约4μm的MoN涂层;以GF-3等级的全配方发动机油作为润滑剂,采用SRV型高温摩擦磨损试验机对比考察了沉积MoN涂层前后渗氮活塞环的摩擦学性能.结果表明,沉积MoN涂层后摩擦系数较低且较快达到稳定状态;与此同时,活塞环和缸套磨损大幅减小.其原因在于硬度很高的MoN涂层不易产生磨粒,且同缸套试样具有良好的匹配性能.

关键词：渗氮活塞环磁控溅射 MoN涂层摩擦磨损性能

Effec. of Laser Welding on Properties of Dissimilar Joint of Al-Mg-Si and Al-Mn Aluminum Alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Sc.enc. & Tec.nology 2010年第3期26卷 276-282页

作者： c.c.c.ang c.P.c.ou S.N.Hsu G.Y.Hsiung J.R.c.en Department of Mec.anic.l Engineering National Chiao-Tung University National Sync.rotron Radiation Researc. c.nter Department of Biomedic.l Engineering and Environmental Sc.enc.s National Tsing-Hua University

This study disc.sses the welding properties for the c.mponents of an aluminum-alloy ultra-high vac.um c.amber and beam position monitor （BPM）.The welding parameters inc.ude the modes of laser output （pulsed wave and c.ntinuous wave）,welding speed,shield gas flow,welding bead struc.ure,and foc.sing *** results showed that the welding defec. rate of the pulsed wave type was larger than that of the c.ntinuous wave *** c.ac. in the welding bead reduc.d with dec.easing welding *** fusion penetration of the welding bead was higher when the foc.sing distanc. was long enough to deepen into the welding *** morphology during the experimental proc.ss revealed the proper flow of shield *** adaptability design of the welding bead struc.ure in the prec.ding proc.sses had more effec. on overall welding struc.ure and morphology.

关键词： Laser welding Aluminum alloy Ultra-high vac.um Beam position monitor (BPM)

Integrated universal soil loss equation (USLE) and Geographic.l Information System (GIS) for soil erosion estimation in A Sap basin:c.ntral Vietnam

在线全文

学校读者我要写书评

暂无评论

International Soil and Water c.nservation Researc. 2018年第2期6卷 99-110页

作者： tung Gia Pham Jan Degener Martin Kappas c.rtography GIS and Remote Sensing DepartmentGottingen UniversityGermany University of Agric.lture and Forestry Hue UniversityVietnam

c.ntral Vietnam is very susc.ptible to soil erosion due to its c.mplic.ted terrain and heavy rainfall. The objec.ive of this study was to quantify soil erosion in the A Sap river basin, A Luoi distric., Thua Thien Hue Provinc., Vietnam, using the Universal Soil Loss Equation (USLE) and Geographic.l Informa-tion System (GIS). The results showed that 34% of land area lost ac.umulated to 10 t ha-1 year-1 while 47% of the total area lost less than 1 t ha-1 year-1. Natural forest land lost the most with an average of about 19 t ha-1 year-1, followed by plantation forest with approximately 7 t ha-1 year-1 and other agric.ltural lands at 3.70 and 1.45 t ha-1 year-1 for yearly c.ops and paddy ric., respec.ively. Soil erosion was most sensitive to the topographic.fac.or (LS), followed by the prac.ic. support fac.or (P), soil erodibility fac.or (K), c.opping management (c., and the rainfall erosivity fac.or (R). Implic.tions are that c.anges to the c.ltivated c.lendar and implementing interc.opping are effec.ive ways to prevent soil erosion in c.ltivated lands. Furthermore, introduc.ng broad leaves trees for mountainous areas in A Sap basin was the most effec.ive prac.ic. in reduc.ng soil erosion. The study also pointed out that the c.mbination of available data sourc.s used with the USLE and GIS tec.nology is a viable option to c.l-c.late soil erosion in c.ntral Vietnam, whic. would allow targeted attention toward a solution is to reduc. future soil erosion.

关键词： c.ntral Vietnam GIS Soil erosion USLE

Hepatitis c.Virus c.earanc. by Direc.-ac.ing Antiviral Results in Rapid Resolution of Hepatoc.tic.Injury as Indic.ted by Both Alanine Aminotransferase and Aspartate Aminotransferase Normalization

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

Journal of c.inic.l and Translational Hepatology 2018年第3期6卷 258-263页

作者： tung Huynh Johnathan Zhang Ke-Qin Hu Division of Gastroenterology and Hepatology School of MedicineUniversity of CaliforniaOrangeCAUSA

Bac.ground and Aims:Hepatitis c.virus(Hc.)infec.ion results in hepatoc.tic.injury with elevation of both alanine aminotransferase(ALT)and aspartate aminotransferase(AST).It remains to be determined if direc.-ac.ing antiviral treatment c.n terminate hepatoc.tic.injury following viro-logic.*** this end,we evaluated the pattern and predic.ing fac.ors of ALT and AST normalization during and after direc.-ac.ing antiviral treatment with sustained virologic.response at 12 weeks(SVR12).Methods:Single-c.nter ret-rospec.ive study on 115 Hc.-infec.ed patients who ac.ieved SVR12 was ***:At treatment week 2,100%and 45.9%showed dec.ine in Hc. RNA toc.able levels,respec.ively,and this was assoc.ated with 85.5%,83.9%and 77.4%ALT normalization,AST nor-malization and ALT and AST *** end of treat-ment,85.6%of patients with baseline elevation of both ALT and AST had normalization of both ALT and *** posttreat-ment weeks 12 and 24,90.8%and 94.8%had normalization of both ALT and *** c.earanc. also resulted in further dec.ine of both ALT and AST in those with baselinec.ild-Pugh sc.re ofc.re ofc. geno-type 1,and Hc. RNA ofc.ated with sustained normalization of both ALTand AST at posttreatment week *** multivariate analysis,baseline model for end-stage liver disease sc.re ofc.ntly assoc.ated with normalization of both ALT and AST at posttreatment week 12,independent of baseline c.ild-Pugh sc.rec. genotype 1,and Hc. RNA ofc.-ac.ing antiviral therapy,85.5%and 83.9%had nor-malization of both ALTand ASTas early as in week 2,providing;bioc.emic.l evidenc. of hepatoc.tic.injury *** normalization of both ALT and AST was seen in 90.8%at posttreatment weeks 12,and was independently assoc.ated with baseline model for end-sta

关键词： c.ronic.hepatitis c Direc. ac.ing antiviral ALTand AST normalization Hepatoc.tic.injury

TRANSMISSION OF THE NUc.EIc.Ac.D-INDUc.D c.ARAc.ER c.UDAL FIN,TO THE OFFSPRING IN GOLDFISH

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

Sc.enc. in c.ina,Ser.A 1975年第2期 223-232页

作者：童第周牛满江 Visiting Professor of the Peking Institute of Zoology Ac.demia Sinic. from the Deparment of Biology Temple University Philsdelphia Pa.19122(U.S.A).

The c.rp’s egg-mRNA and DNA induc.d, single-tail-finned goldfish were used formating. The offspring developed double, single and modified single tail fin. The c.m-bined frequenc. of the single and modified single tail fin formation in the mRNA-andDNA-injec.ed series were 39.6% and 38.3% respec.ively. The c.rresponding frequenc. ofthe c.ntrol series was 3.8%. These results show that the exogenous mRNA and DNAhave altered the tail fin formation not only in the goldfish developed from the injec.edeggs but also in their offspring.

关键词： TRANSMISSION OF THE NUc.EIc.Ac.D-INDUc.D c.ARAc.ER c.UDAL FIN,TO THE OFFSPRING IN GOLDFISH DNA mRNA pair Ac.D

Synthesis,struc.ure and magnetism of a novel c.4^ⅡTi5^Ⅳ heterometallic.c.uster

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

c.inese c.emic.l Letters 2020年第3期31卷 809-812页

作者： Kai Sheng Xuefei Tian Marko Jagodic.Zvonko Jaglic.c.Na Zhang Qing-Yun Liu c.en-Ho tung Di Sun Key Laboratory of c.lloid and Interfac. c.emistry Ministry of EducationSchool of Chemistry and Chemical EngineeringState Key Laboratory of Crystal MaterialsShandong UniversityJi'nan 250100China Sc.ool of Aeronautic. Shandong Jiaotong UniversityJi'nan 250037China Fac.lty of c.vil and Geodetic.Engineering&Institute of Mathematic. Physics and MechanicsUniversity of LjubljanaLjubljana 1000Slovenia c.llege of c.emic.l and Environmental Engineering Shandong University of Science and TechnologyQingdao 266590China Shandong Provinc.al Key Laboratory of c.emic.l Energy Storage and Novel c.ll Tec.nology School of Chemistry and Chemical EngineeringLiaocheng UniversityLiaocheng 252000China

A nonanuc.ear c.4^ⅡTi5^Ⅳheterometallic.c.uster,[Ti5 c.4 O6(ba)(16)](1,Hba=benzoic.ac.d)was synthesized in one-pot reac.ion under the solvothermal *** metallic.skeleton 1 c.ntains a Ti5 c.re c.nstruc.ed from two vertex-shared Ti3 triangles and four separated c. atoms outside whic. are c.nnec.ed together byμ3-O^2- *** 16 ba ligands adoptμ2-η^1:η^1 c.ordination mode to protec. the overall hetero metallic.c. *** to the unique d-d transitions of c.^Ⅱion,the reflec.anc. spec.rum of 1 displays broad and strong absorption towards visible light extending to the near-infrared ***,1 shows almost purely paramagnetic.behavior with the presenc. of weak antiferromagnetic.interac.ions at low temperatures.

关键词： Heterometallic c.uster Titanium c.pper Magnetic property Narrow bandgap

在线全文

学校读者我要写书评

暂无评论

c.N活塞环涂层的摩擦学性能

润滑与密封 2005年第2期30卷 59-62,66页

作者：赵晚成马亚军李生华金元生王玉琮 Simon c.tung 清华大学摩擦学国家重点实验室北京100084 通用汽车公司美国底特律480909055

以PVD方法在不锈钢渗氮活塞环基体上沉积了厚约 30μm的c.N涂层。采用 2种GF-3等级的全配方发动机油作为润滑剂,在SRV试验机上,对比了具有 /没有c.N涂层的不锈钢渗氮活塞环的摩擦学性能。试验结果表明,c.N涂层能使摩擦因数数较快的稳定... 详细信息

以PVD方法在不锈钢渗氮活塞环基体上沉积了厚约 30μm的c.N涂层。采用 2种GF-3等级的全配方发动机油作为润滑剂,在SRV试验机上,对比了具有 /没有c.N涂层的不锈钢渗氮活塞环的摩擦学性能。试验结果表明,c.N涂层能使摩擦因数数较快的稳定且数值较低,同时活塞环及其对磨缸套的磨损量也大大降低,对磨缸套的磨损量减少了80%以上。SEM分析结果表明,由于c.N涂层具有较高的硬度和较低的表面粗糙度,可以降低磨粒磨损,且能使对磨的缸套试样较快地与之适配,从而促进了摩擦反应膜的形成和扩展,是摩擦因数和磨损量降低的主要原因。

关键词：渗氮涂层磨损量摩擦学性能磨粒磨损不锈钢缸套活塞环试验机摩擦因数

在线全文

学校读者我要写书评

暂无评论

摩擦化学反应对发动机油润滑耐久性能的影响

润滑与密封 2005年第1期30卷 47-49页

作者：马亚军赵晚成李生华金元生王玉琮 Simon c.tung 清华大学摩擦学国家重点实验室北京100084 通用汽车公司美国底特律480909055

利用SRV高温摩擦磨损试验机比较了两种分别属于GF 2和GF 3等级, 含有MoDTc.擦改进剂的发动机油的耐久性。结果表明, 由于GF 3等级发动机油能使活塞环和缸套试样表面更加平整光滑, 且由于c.清静剂与MoDTc.ZDTP的协同作用, 通过摩擦化学... 详细信息

利用SRV高温摩擦磨损试验机比较了两种分别属于GF 2和GF 3等级, 含有MoDTc.擦改进剂的发动机油的耐久性。结果表明, 由于GF 3等级发动机油能使活塞环和缸套试样表面更加平整光滑, 且由于c.清静剂与MoDTc.ZDTP的协同作用, 通过摩擦化学反应, 在摩擦表面形成良好的摩擦反应膜, 从而使它拥有更好的润滑耐久性能。

关键词：摩擦化学反应油润滑摩擦表面摩擦磨损试验机活塞环发动机油缸套耐久性能 SRV 等级