检索结果-南通市图书馆

Developing New Applications Based on Laser Additive Manufacturing of wC Cermets and wC Forming Alloys (Invited Paper)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国激光 2009年第12期36卷 3245-3250页

作者： james w.Sears Additive Manufacturing Laboratory South Dakota School of Mines & TechnologyQuad City Manufacturing LaboratoryWestern Illinois University501 E.St.Joseph St.Rapid City SD 5770

Laser additive manufacturing(LAM) of tungsten carbide metal matrix composites(MMCs) has been evaluated for surface modification of hot die forming tools,cutting edges,glass tooling,extrusion mandrels,and other abrasive wear *** work focuses on transitions from tool steels to MMCs through a single pass laser powder deposition *** related to the application of various metal powders and carbides used include surface hardness,porosity,cracking,and *** issues along with factory results that were obtained during this project are discussed.

关键词：激光添加剂碳化钨工具钢金属基复合材料

Response of phytoplankton communities to environmental changes in the Bohai Sea in late summer (2011−2020)

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2024年第10期43卷 107-120页

作者： Yibo wang Zhiliang Liu Yanping Qi Xiao Chen Yang Chen du Su Xiaobo Yuan james Klippel-Cooper Research Center for Marine Science Hebei Normal University of Science and TechnologyQinhuangdao 066004China Hebei Key Laboratory of Ocean Dynamics Resources and EnvironmentsQinhuangdao 066004China North China Sea Environmental Monitoring Center State Oceanic AdministrationQingdao 266033China College of Science and Engineering Flinders UniversityAdelaide 5042Australia

Understanding the dynamics of phytoplankton communities in coastal zones is crucial for the management and conservation of coastal *** research indicated that the phytoplankton community structure and dominant taxa in the Bohai Sea(BHS)have exhibited significant shifts from the 1990s to the early 2010s in response to environmental changes,especially the change in nutrient *** study comprehensively investigated the variations in net-collected phytoplankton(>76μm)community structure,diversity,and environmental factors in the BHS during the late summers of 2011-2020,aiming to understand the recent trend in phytoplankton community structure and to explore the interactions between the communities and the *** the study period,the nutrient status in the BHS was characterized by a decrease in dissolved inorganic nitrogen(DIN)concentration,an increase in dissolved inorganic phosphorus(DIP)concentration,and a return of the nitrogen-to-phosphorus(N/P)molar ratio(hereinafter referred to as N/P ratio)to the Redfield ratio since *** eutrophication index(EI)in the BHS remained stable and was generally at a low level(w an obvious ***,the eutrophication,the imbalance in nutrient ratio,and the shift in phytoplankton community structure did not continue during the study *** increased abundance of phytoplankton was strongly associated with elevated concentrations of DIN,as well as higher N/P and nitrogen-to-silicon(N/Si)ratios,whereas the greater diversity was strongly linked to higher concentrations of *** and dinoflagellates showed significant differences in their interactions with the environment,and their relative dominance was related to water column depth and stratification intensity;their impacts on the phytoplankton community diversity were also significantly *** variations of certain dominant species,i.e.,Skeletonema costatum,Paralia sulcata,and Tr

关键词： Bohai Sea phytoplankton community diversity Dia/Dino index dominant species environmental change

Is it time to rethink combined liver-kidney transplant in hepatitis C patients with advanced fibrosis?

在线全文

学校读者我要写书评

暂无评论

world Journal of Hepatology 2017年第5期9卷 288-292页

作者： Niraj james Shah Mark w Russo Department of Medicine Division of Dige-stive Diseases the University of Mississippi Medical Center Transplant Center-Carolinas Medical Center 6th Floor Morehead Medical Plaza

AIM To reduce hepatic and extrahepatic complications of chronic hepatitis C in kidney transplant *** we conducted a systematic review of kidney only transplant in patients with hepatitis C and advanced *** The 5 year patient survival of kidney transplant recipients with and without hepatitis C cirrhosis ranged from 31% to 90% and 85% to 92%, respectively. Hepatitis C kidney transplant recipients had lower 10-year survival when compared to hepatitis B patients, 40% and 90% respectively. There were no studies that included patients with virologic cure prior to kidney transplant that reported post-kidney transplant outcomes. There were no studies of direct acting antiviral therapy and effect on patient or graft survival after kidney transplantation. CONCLUSION Data on kidney transplant only in hepatitis C patients that reported inferior outcomes were prior to the development of potent direct acting antiviral. with the development of potent directing acting antiviral therapy for hepatitis C with high cure rates studies are needed to determine if patients with hepatitis C, including those with advanced fibrosis, can undergo kidney transplant alone with acceptable long term outcomes.

关键词： Cirrhosis/cirrhotics Renal transplantation Kidney transplantation Mortality Systematic review Graft outcomes Meta-analysis

Competition for food in 2 populations of a wild-caught fish

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2018年第5期64卷 615-622页

作者： Pierre J.C. CHUARD Grant E. BROwN james w.A. GRANT Research School of Biology The Australian National University Canberra ACT 0200 Australia Departmentof Biology Concordia University 7141 Sherbrooke Street West Montreal Quebec Canada H4B 1R6

Aggressive behavior when competing for resources is expected to increase as the ratio of competitors-to-resource ratio （CRR） units increases. Females are expected to be more aggressive than males when competing for food when body size is more strongly related to reproductive suc- cess in females than in males, whereas aggression is predicted to decrease under high ambient predation risk by natural selection. Under the risk allocation model, however, individuals under high ambient predation risk are expected to be more aggressive, and forage more in the absence of imminent risk than their low risk counterparts. An interaction between adult sex ratio （i.e., adult males/females）, ambient predation risk （high vs. low）, and sex on intrasexual competition for mates in Trinidadian guppies Poecilia reticulata has been shown. The interaction suggested an increase in aggression rates as CRR increased, except for males from the high predation population. To compare the patterns of competition for food versus mates, we replicated this study by using food patches. we allowed 4 male or 4 female guppies from high and low predation populations to com- pete for 5, 3, or 1 food patches. The foraging rate was higher in a high rather than low ambient pre- dation risk population. Surprisingly, CRR, sex, and population of origin had no effect on aggression rates. Despite other environmental differences between the 2 populations, the effect of ambient predation risk may be a likely explanation for differences in foraging rates. These results highlight the importance for individuals to secure food despite the cost of competition and predation.

关键词： aggression competitor-to-resource ratio foraging Poecifia reticulata population differences predation risk sex

Iron oxide nanoparticles promote vascular endothelial cells survival from oxidative stress by enhancement of autophagy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Regenerative Biomaterials 2019年第4期6卷 221-229页

作者： Jimei duan Jiuju du Rongrong Jin wencheng Zhu Li Liu Li Yang Mengye Li Qiyong Gong Bin Song james MAnderson and Hua Ai National Engineering Research Center for Biomaterials Sichuan UniversityChengdu 610065P.R.China Shanghai Institute of Biochemistry and Cell Biology Chinese Academy of SciencesShanghai 200031P.R.China Department of Radiology West China HospitalSichuan UniversityChengdu 610041P.R.China Department of Pathology Case Western Reserve UniversityClevelandOH 44106USA Department of Macromolecular Science Case Western Reserve UniversityClevelandOH 44106USA Department of Biomedical Engineering Case Western Reserve UniversityClevelandOH 44106USA

Dextran-coated superparamagnetic iron oxide nanoparticles(Dex-SPIONs)are excellent magnetic resonance imaging contrast agents for disease diagnosis and *** can be delivered to target tissues mainly though vascular endothelium cells,which are major targets of oxidative *** cardiovascular cells,autophagy serves primarily on a pro-survival approach that protects the cells from oxidative stress even some autophagy inducers have been developed for adjuvant therapy of cardiovascular *** study demonstrated that the nanoparticles could be taken up by human umbilical vein endothelial cells(HUVECs)without causing obvious cytotoxicity but triggering ***,our results revealed that Dex-SPIONs could enhance HUVECs survival and reverse the reduction of nitric oxide secretion under the condition of H2O2 ***,these effects could be diminished by the autophagy *** particular,we discovered that Dex-SPIONs evoked autophagy in HUVECs by reducing the phosphorylation of PRAS40,an upstream regulator of autophagy *** results suggested that Dex-SPIONs functions as an autophagic-related antioxidant in HUVECs which may be utilized as an adjuvant therapy to cardiovascular disease associated with oxidative stress.

关键词： human umbilical vein endothelial cells dextran-coated iron oxide nanoparticles autophagy oxidative stress

Structural basis of interaction between the hepatitis C virus p7 channel and its blocker hexamethylene amiloride

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Protein & Cell 2016年第4期7卷 300-304页

作者： Linlin Zhao Shuqing wang Lingyu du Jyoti Dev Liujuan Zhou Zhijun Liu james J. Chou Bo OuYang National Center for Protein Science State Key Laboratory of Molecular Biology Shanghai Institute of Biochemistry and Cell Biology Chinese Academy of Sciences Shanghai 200031 China Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics (Theranostics) School of Pharmacy Tianjin Medical University Tianjin 300070 China Department of Biological Chemistry and Molecular Pharmacology Harvard Medical School Boston MA 02115 USA Shanghai Science Research Center Chinese Academy of Sciences. Shanahai 201204. China

Dear Editor, Hepatitis C virus （HCV） infection, which causes hepatitis C and can chronically lead to serious and life-threatening dis- eases including liver cirrhosis and hepatocellular carcinoma （Lauer and walker, 2001）, is a rising global health problem. More than 170 million people are infected by HCV worldwide and 3-4 million people are infected each year. No effective vaccines are available to prevent HCV infection. Moreover, HCV is a fast mutating RNA virus with seven distinct genotypes and many subtypes within each genotype. The high degree of genetic diversity can lead to further viral resistance to the current therapies within individual patients （Li et al., 2012）. Hence, there remains a strong desire in the medical community to explore new therapeutic opportunities.

关键词： Structural basis interaction between

Usability Assessment of Steering wheel Control Interfaces in Motorsport

在线全文

学校读者我要写书评

暂无评论

Automotive Innovation 2020年第1期3卷 42-52页

作者： james w.H.Brown Neville A.Stanton Kirsten M.A.Revell University of Southampton SouthamptonUK

In order to assess the usability of steering wheel control interfaces in motorsport,it is necessary to employ a set of appropriate *** method selection process first involves identifying the relevant motorsport-based usability *** unique factors associated with context of use in motorsport are then *** are employed to synthesize a set of key performance indicators(KPIs)that require specific *** first KPI relates to error rates;these should be minimized,particularly under high cognitive load on the *** second KPI involves task times;these should be minimized not just to reduce distraction,but also to improve competitive *** third KPI states that usability should be optimized to minimize visual *** fourth KPI advocates the minimizing of interface task load to reduce the effect on the primary *** final KPI states that interface functionality should be easy to learn and *** KPIs provide clear goals to guide the identification of the most appropriate methods for each aspect of *** categories are devised and sets of appropriate methods selected based on the *** then combine into a toolset with an associated application process with the overall goal of providing a means by which motorsport interfaces may be both analysed and improved.

关键词： Usability Motorsport Steering wheel Analysis Assessment

Tuning and Cold Test of a Four-Vane RFQ with Ramped Inter-Vane Voltage for the Compact Pulsed Hadron Source

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2013年第5期30卷 48-51页

作者： XING Qing-Zi du Lei ZHENG Shu-Xin GUAN Xia-Ling LI Jian CAI Jin-Chi GONG Cun-Kui wANG Xue-wu TANG Chuan-Xiang james Billen james Stovall Lloyd Young Key Laboratory of Particle&Radiation Imaging(Ministry of Education) Tsinghua UniversityBeijing 100084 NUCTECH Co.Ltd. Beijing 100084 3905 Circle Drive Los AlamosNM 87544USA Rutherford Appleton Laboratory Harwell OxfordDidcot OX110QXUK LMY Technology 1469 Plantation CircleLincolntonGA 30817USA

A four-vane radio-frequency quadrupole(RFQ)accelerator is under construction for the Compact Pulsed Hadron Source(CPHS)project at Tsinghua *** 3 m-long RFQ will accelerate a 50 keV proton beam from the ECR source to 3 MeV,and deliver it to the downstream drift tube linac(DTL)with a peak current of 50 mA,pulse length of 0.5 ms and beam duty factor of 2.5%.The inter-vane voltage is designed to increase with the longitudinal position to produce a short *** plates are therefore not *** cavity cross section and vane-tip geometry are tailored as a function of the longitudinal position,while limiting the peak surface electric field to 1.8 *** RFQ is designed,manufactured,and installed at Tsinghua *** also present the tuning and cold test results of the RFQ *** final tuning,the relative error of the quadrupole field is within 2%,and the admixture of the two dipole modes are less than 2%of the quadrupole mode.

关键词： beam Van cavity

Investigation of the preparation methodologies of Pd-Cu single atom alloy catalysts for selective hydrogenation of acetylene

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2015年第4期9卷 442-449页

作者： Xinxiang Cao Arash Mirjalili james wheeler wentao Xie Ben w.-L. Jang Department of Chemistry Texas A&M University-Commerce Commerce TX 75429-3011 USA

Galvanic replacement, co-impregnation and sequential impregnation have been employed to prepare Pd-Cu bimetallic catalysts with less than 1 wt-% Cu and ca. 0.03 wt-% Pd for selective hydrogenation of acetylene in excess ethylene. High angle annular dark field-scanning transmission electron microscopy （HAADF-STEM） and H2 chemisorption results confirmed that Pd-Cu singleatom alloy structures were constructed in all three bimetallic catalysts. Catalytic tests indicated that when the conversion of acetylene was above 99%, the selectivity of ethylene of these three single atom alloy catalysts was still more than 73%. Furthermore, the single atom alloy catalyst prepared by sequential incipient wetness impregnation was found to have the best stability among the three procedures used.

关键词： palladium-copper bimetallic catalyst singleatom alloy acetylene hydrogenation HAADF-STEM H2pulse chemisorption