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Effect of nitriding Current Density on the Surface Properties and Crystallite Size of Pulsed Plasma-nitrided AISI 316L

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journal of Materials Science and Chemical Engineering 2015年第1期3卷 45-51页

作者： j. C. Díaz-Guillén E. E. Granda-Gutiérrez G. Vargas-Gutiérrez M. R. Díaz-Guillén j. A. Aguilar-Martínez L. álvarez-Contreras Corporación Mexicana de Investigación en Materiales S.A. de C.V.-Cátedras-COnACyT Saltillo México Centro de Investigación y Estudios Avanzados del IPn Saltillo México GMyPQ Instituto de Investigaciones Eléctricas Cuernavaca México Universidad Autónoma de nuevo León FIME-CIIIA Apodaca México Centro de Investigación en Materiales Avanzados S.C. Chihuahua México

In this work, plasma-nitrided AISI 316L stainless steel samples were performed by ion nitriding process under pulsed direct current (DC) discharge at different current densities (1 to 2.5 mA/ cm2). The effect of nitriding current density on the size of crystalline coherently diffracting domains (crystallite size) and strain grade was investigated using X-ray diffraction (XRD) coupled with Williamson-Hall method. Additionally, hardness and wear resistance of the nitriding layer were characterized using a Vickers indenter and pin-on-disk technique respectively. Results showed a decrease in crystallite size from 99 nm for untreated samples to 1.4 nm for samples nitrided at 2.5 mA/cm2 promoted both: an increase in hardness from 226 HV25g to 1245 HV25g, and a considerably decrease in volume loss by wear effect.

关键词： Plasma nitriding Strain Crystallite Size Hardness Wear Stainless

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缆索承重桥的最近发展及展望

世界桥梁 1988年第1期 1-13+26页

作者： n.j.Gimsing ,严国敏

1.引言以缆索支承长跨桥梁的原理,美国已于十九世纪向世人介绍。之后约100年间主要仍在美国发展。纵观这个时期的桥梁结构体系,地锚式悬索桥是很有代表性的。其中特别引人注

关键词：地锚式悬索桥主跨索网主孔斜缆斜拉索桥斜拉桥缆索主缆悬吊体系加劲梁特大跨度双层桥面大贝尔特桥主梁缆索体系吊索

COUPLED VIBRATIOn OF STRUCTURAL THIn-WALLED CORES

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Acta Mechanica Solida Sinica 2000年第1期13卷 81-88页

作者： Shiu Cho nG j.S.Kuang Department of Civil Engineering Hong Kong University of Science and Technology

This paper presents an analysis of the coupled vibration of asymmetric core structures in tall buildings. The governing equation of free vibration and its corresponding eigenvalue problem, which is a set of equations for laterally flexural vibrations in two different directions coupled by a warping-St. Venant torsional vibration, are derived. Based on the Calerkin method, a generalized approximate method is developed for the analysis of coupled vibration and thus proposed for determining the natural frequencies and mode shapes of the structure in triply-coupled vibration. The results of the proposed method for the example structure show good agreement with those of the FEM analysis. The proposed method has been shown to provide a simple and rapid, yet accurate, means for coupled vibration analysis of core structures.

关键词： coupled vibration analysis asymmetric core structure Galerkin method natural frequency mode shape

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Scale of seismic and rock burst hazard in the Silesian companies in Poland

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Mining Science and Technology 2009年第5期19卷 604-608页

作者： PATY■SKA Renata KABIESZ józef Central Mining Institute

Presently the seismic and rock burst hazard appears still to be important in most of hard coal mines in Poland. Recently, there was a significant increase of seismic activity of the Silesian rock massive, when compared with the previous years. In the period 1999-2008 the hard coal mines experienced 34 rock bursts. The causes of rockburst occurrence are presented based on the analysis of the rockbursts occurring in the Polish hard coal mines. The scale of the rockburst hazard has been characterized with respect to the mining and geological conditions of the existing exploitation. Of the factors influencing the state of rockburst hazard, the most essential one is considered the depth interval ranging from 600 m to 900 m. The basic factors that promote the rockburst occurrence are as follows： seismogenic strata, edges and remnants, goal, faults, pillars and excessive paneling.

关键词： rockbursts mining and geological conditions

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Appropriate management of asymptomatic carotid stenosis

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Stroke & Vascular neurology 2016年第2期1卷 64-71页

作者： j David Spence Hongsong Song Guanliang Cheng Robarts Research Institute Western UniversityLondonOntarioCanada Peking University Third Hospital BeijingThe People’s Republic of China Huai’an First People’s Hospital Nanjing Medical UniversityHuai’anThe People’s Republic of China

With modern intensive medical therapy,the annual risk of ipsilateral stroke in patients with asymptomatic carotid stenosis(ACS)is now down to∼0.5%.Despite this,there is a widespread practice of routine intervention in ACS with carotid endarterectomy(CEA)and stenting(CAS).This is being justified on the basis of much higher risks with medical therapy in trials conducted decades ago,compared with lower risks of intervention in recent trials with no medical *** extrapolations are *** recent trials have shown that after subtracting periprocedural risks the outcomes with CEA and CAS are now comparable to medical therapy,the periprocedural risks still far outweigh the risks with medical *** the asymptomatic carotid trial(ACT)1 trial,the 30-day risk of stroke or death was 2.9%with CAS and 1.7%with *** the CREST trial,the 30-day risk of stroke or death among asymptomatic patients was 2.5%for stenting and 1.4%for ***,intensive medical therapy is much safer than either CAS or *** only patients with ACS who should receive intervention are those who can be identified as being at high *** best validated method is transcranial Doppler embolus *** approaches in development for identifying vulnerable plaques include intraplaque haemorrhage on MRI,ulceration and plaque lucency on ultrasound,and plaque inflammation on positron emission tomography/*** medical therapy for ACS includes smoking cessation,a Mediterranean diet,effective blood pressure control,antiplatelet therapy,intensive lipid-lowering therapy and treatment with B vitamins(with methylcobalamin instead of cyanocobalamin),particularly in patients with metabolic B12 deficiency.A new strategy called‘treating arteries instead of risk factors’,based on measurement of carotid plaque volume,is promising but requires validation in randomised trials.

关键词： carotid asymptomatic stenosis

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散货船结构强度

大连船研 1999年第1期 28-39页

作者： j·n·马琦王汉苍英国劳氏船级社

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pH值对土壤吸附磷酸盐的影响的模拟试验

土壤学进展 1986年第6期 23-28页

作者： n.j.Barrow 常月帆

关于施用石灰是否会减少磷素的固定,存在很多争议。有人认为施用石灰增加了对磷酸盐的吸附,但有人指出,施加石灰减少了吸附,或者与吸附无关。可见,pH值与磷酸盐吸附之间的关系十分混乱,这表明某一给定的实验结果受着多种因素的影响,而... 详细信息

关于施用石灰是否会减少磷素的固定,存在很多争议。有人认为施用石灰增加了对磷酸盐的吸附,但有人指出,施加石灰减少了吸附,或者与吸附无关。可见,pH值与磷酸盐吸附之间的关系十分混乱,这表明某一给定的实验结果受着多种因素的影响,而且在不同的实验中,这些因素的作用程度也不同。在Haynes的综述中,提到了两个因素。一是pH值可影响有机磷酸盐的矿化,另一个

关键词：磷酸盐电荷反应磷肥吸附量静电位土壤吸附 pH

Synthesis and Catalyzing Behavior of Olefin Polymerization of cis-Cyclopentene Bridged Titanocenes

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Chinese Chemical Letters 2000年第11期11卷 979-980页

作者： Li j.S. Xiong C.H. Ma Y.Q. Li j. Chen X. Inst. of Elemento-Organic Chemistry Nankai University Tianjin 300071 China Department of Chemistry Tianjin Normal University Tianjin 300070 China

Two cis-cyclopentene bridged titanocenes have been synthesized. Two homogeneous Ziegler catalysts prepared by activation of synthesized compounds with methylalumoxane are active for ethylene polymerization reactions.

关键词： cis Ti Synthesis and Catalyzing Behavior of Olefin Polymerization of cis-Cyclopentene Bridged Titanocenes

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Protective effect of Sida cordata leaf extract against CCl_4 induced acute liver toxicity in rats

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Asian Pacific journal of Tropical Medicine 2013年第4期6卷 280-284页

作者： Sunil Mistry KR Dutt j jena Gayatri College of Pharmacy Gayatri ViharSambalpurOrissa-768200India CMR College of Pharmacy KandlakoyaMedchan RoadHyderabad-501401India Department of Pharmacology VSS Medical CollegeSambalpur University

Objective:To investigate the hepatoprotective potential of Sida cordata（Malvaceae）（***） in experimental rats to validate its traditional ***:Wister albino rats were divided into 6 groups:Croup 1 served as control;CroupⅡserved as hepatotoxic（CCl4 treated） group; CroupⅢ,Ⅳand V served as（100,200 and 400 mg/kg b.w.） *** leaf extract（SCLE） treated groups;CroupⅥserved as positive control（Silymarin） treated *** marker enzymes serum glutamate oxyloacetic transaminase,serum glutamic pyruvic transaminase,pancreatic enzymatic antioxidants superoxide dismutase（SOD）,lipid peroxidation,catalase（CAT）,reduced glutathione（CSH） were measured and compared along with histopathological ***: Obtained results show that the treatment with SCI.E significantly（Pnd dosedependently reduced CCl4 induced elevated serum level of hepatic ***, SCLE significantly（up to Pn in the liver tissue and restored activities of defence antioxidant enzymes CSH,SOD and CAT towards normal levels,which was confirmed by the histopathological ***:The results of this study strongly indicate the protective effect of SCLE against CCl4 induced acute liver toxicity in rats and thereby scientifically support its traditional use.

关键词： Sida cordata Histopathology Hepatoprotective CCl_4