检索结果-南通市图书馆

Microstructure and mechanical properties of Ti-6Al-4V-5% hydroxyapatite composite fabricated using electron beam powder bed fusion

引用

Journal of Materials Science & Technology 2019年第2期35卷 309-321页

作者： césar A.Terrazas Lawrence E.Murr Diego Bermudez Edel Arrieta david A.Roberson Ryan B.Wicker W.M.keck center for 3D Innovation The University of Texas at El PasoEl PasoTX 79968USA Department of Mechanical Engineering The University of Texas at El PasoTX 79968USA Department of Metallurgical Materials and Biomedical EngineeringThe University of Texas at El PasoTX 79968USA

A novel, Ti-6 Al-4 V(Ti64)/Hydroxyapatite(HA at 5% by weight concentration) metal/ceramic composite has been fabricated using electron beam powder bed fusion(EPBF) additive manufacturing(AM): specifically, the commercial electron beam melting(EBM?) process. In addition to solid Ti64 and Ti64/5% HA samples, four different unit cell(model) open-cellular mesh structures for the Ti64/5% HA composite were fabricated having densities ranging from 0.68 to 1.12 g/cm^3, and corresponding Young's moduli ranging from 2.9 to 8.0 GPa, and compressive strengths ranging from ~3 to 11 MPa. The solid Ti64/5%HA composite exhibited an optimal tensile strength of 123 MPa, and elongation of 5.5% in contrast to a maximum compressive strength of 875 MPa. Both the solid composite and mesh samples deformed primarily by brittle deformation, with the mesh samples exhibiting erratic, brittle crushing. Solid, EPBF-fabricated Ti64 samples had a Vickers microindentation hardness of 4.1 GPa while the Ti64/5%HA solid composite exhibited a Vickers microindentation hardness of 6.8 GPa. The lowest density Ti64/5%HA composite mesh strut sections had a Vickers microindentation hardness of 7.1 GPa. Optical metallography(OM) and scanning electron microscopy(SEM) analysis showed the HA dispersoids to be highly segregated along domain or grain boundaries, but homogeneously distributed along alpha(hcp) platelet boundaries within these domains in the Ti64 matrix for both the solid and mesh composites. The alpha platelet width varied from ~5 μm in the EPBF-fabricated Ti64 to ~1.1 m for the Ti64/5%HA mesh strut. The precursor HA powder diameter averaged 5 μm, in contrast to the dispersed HA particle diameters in the Ti64/5%HA composite which averaged 0.5 m. This work highlights the use of EPBF AM as a novel process for fabrication of a true composite structure, consisting of a Ti64 matrix and interspersed and exposed HA domains, which to the authors' knowledge has not been reported before. The results also illu

关键词： Hydroxyapatite (HA) Metal-matrix ceramic composites Open-cellular (mesh) structures Electron-beam powder bed fusion (EPBF) Additive manufacturing (AM) Mechanical properties Microstructure characterization

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Ultrasonic Approach of Rayleigh Pitch-catch contact Ultrasound Waves on cFRP Laminated composites

引用

Journal of Materials Science & Technology 2008年第3期24卷 407-409页

作者： In-Young Yang kwang-Hee Im Uk Heo david k Hsu Je-Woong Park Hak-Joon kim Sung-Jin Song School of Mechanical Eng. Chosun Univ Department of Automotive Eng. Woosuk Univers-ity center for Nondestructive Evaluation Iowa State University Dept.of Naval Arch.and Ocean Eng. Chosun Univ School of Mechanical Eng. Sungkyunkwan University

cFRP （carbon fiber reinforced plastics） composite materials have wide applicability because of their inherent design flexibility and improved material properties. However, impacted composite structures have 50%-75% less strength than undamaged structures. In this work, a cFRP composite material was nondestructively characterized in order to ensure product quality and structural integrity of cFRP and one-sided pitch-catch technique was developed to measure impacted-damaged area by using an automated-data acquisition system in an immersion tank. A pitch-catch signal was found to be more sensitive than normal incidence backwall echo of longitudinal wave under defect conditions in the composite.

关键词： Impact damages c-scanner carbon fiber reinforced plastics (cFRP) Pitchcatch mode

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Substrate selection and seasonal variation in abundance and size composition of isopod Lirceus fontinalis in Ontario streams, canada

引用

chinese Journal of Oceanology and Limnology 2007年第2期25卷 215-220页

作者： ZHAO Xiaoxia Michael G FOX david c. LASENBY Alexis c. ARMIT Dolly N. kOTHAWALA Watershed Ecosystems Graduate Program Trent University Peterborough Ontario K9J 7B8 Canada Environmental ＆ Resource Studies Program and Department of Biology Trent University Peterborough ON K9J 7B8 Canada Department of Biology Trent University Peterborough ON K9J 7B8 Canada

The abundance and size composition of stream isopods Lirceusfontinalis were investigated from April 2001 to August 2002 in 3 streams in southem Ontario, canada. Effects of current speed was released from the analysis by choosing slow flowing water. The effects of substrate, season and water depth on the abundance, distribution and size composition of the isopods were analyzed. It was found that substrate and season influence isopods the most. The rocky substrate with attached filamentous macro-algae contains an isopod abundance 7.05 times that of bare rock substrate and 14.6 times that of free-sand and mud substrate. There was a large variation with respect to seasonali .ty in both abundance and size composition of the isopods, with the highest abundance occumng in summer and the lowest in winter and spring; individual isopods also tend to be larger in the winter and spring. In all substrates, shallow areas tend to support higher densities of isopods than deeper areas.

关键词： isopods Lirceusfontinalis, size abundance substrate seasonal variation Ontario

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An integrated approach to site-specific management zone delineation

引用

Frontiers of Agricultural Science and Engineering 2018年第4期5卷 432-441页

作者： Yuxin MIAO david J.MULLA Pierre c.ROBERT Precision Agriculture center Department of SoilWater and ClimateUniversity of Minnesota

Dividing fields into a few relatively homogeneous management zones(MZs) is a practical and costeffective approach to precision agriculture. There are three basic approaches to MZ delineation using soil and/or landscape properties, yield information, and both sources of information. The objective of this study is to propose an integrated approach to delineating site-specific MZ using relative elevation, organic matter, slope, electrical conductivity, yield spatial trend map, and yield temporal stability map(ROSE-YSTTS) and evaluate it against two other approaches using only soil and landscape information(ROSE) or clustering multiple year yield maps(cMYYM). The study was carried out on two no-till corn-soybean rotation fields in eastern Illinois, USA. Two years of nitrogen(N) rate experiments were conducted in Field B to evaluate the delineated MZs for site-specific N management. It was found that in general the ROSE approach was least effective in accounting for crop yield variability(8.0%–9.8%), while the cMYYM approach was least effective in accounting for soil and landscape(8.9%–38.1%), and soil nutrient and pH variability(9.4%–14.5%). The integrated ROSE-YSTTS approach was reasonably effective in accounting for the three sources of variability(38.6%–48.9%, 16.1%–17.3% and 13.2%–18.7% for soil and landscape, nutrient and pH, and yield variability, respectively), being either the best or second best approach. It was also found that the ROSE-YSTTS approach was effective in defining zones with high,medium and low economically optimum N rates. It is concluded that the integrated ROSE-YSTTS approach combining soil, landscape and yield spatial-temporal variability information can overcome the weaknesses of approaches using only soil, landscape or yield information,and is more robust for MZ delineation. It also has the potential for site-specific N management for improved economic returns. More studies are needed to further evaluate their appropriateness for precision N

关键词： economically optimum nitrogen rate fuzzy cluster analysis precision nitrogen management site-specific management soil landscape property yield map

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Handheld high-throughput plasmonic biosensor using computational on-chip imaging

引用

Light(Science & Applications) 2014年第1期3卷 388-397页

作者： Arif E cetin Ahmet F coskun Betty c Galarreta Min Huang david Herman Aydogan Ozcan Hatice Altug Department of Electrical and computer Engineering Boston UniversityBostonMA 02215USA Departments of Electrical Engineering and Bioengineering University of CaliforniaLos Angeles(UCLA)Los AngelesCA 90095USA Division of chemistry and chemical Engineering California Institute of TechnologyPasadenaCA 91125USA Pontificia Universidad catolica del Peru Departamento de Ciencias-QuimicaAvenida Universitaria 1801Lima 32Peru Bioengineering Department Ecole Polytechnique Federale de Lausanne(EPFL)Lausanne CH-1015Switzerland california NanoSystems Institute University of California Los AngelesLos Angeles(UCLA)Los AngelesCA90095USA

We demonstrate a handheld on-chip biosensing technology that employs plasmonic microarrays coupled with a lens-free computational imaging system towards multiplexed and high-throughput screening of biomolecular interactions for point-of-care applications and resource-limited *** lightweight and field-portable biosensing device,weighing 60 g and 7.5 cm tall,utilizes a compact optoelectronic sensor array to record the diffraction patterns of plasmonic nanostructures under uniform illumination by a single-light emitting diode tuned to the plasmonic mode of the *** a sensitive plasmonic array design that is combined with lens-free computational imaging,we demonstrate label-free and quantitative detection of biomolecules with a protein layer thickness down to 3 *** large-scale plasmonic microarrays,our on-chip imaging platform enables simultaneous detection of protein mono-and bilayers on the same platform over a wide range of biomolecule *** this handheld device,we also employ an iterative phase retrieval-based image reconstruction method,which offers the ability to digitally image a highly multiplexed array of sensors on the same plasmonic chip,making this approach especially suitable for high-throughput diagnostic applications in field settings.

关键词： computational imaging high-throughput biodetection lens-free imaging on-chip sensing plasmonics point of care diagnostics telemedicine

来源：

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

Nutrition and Oral Medicine 2005

引用

丛书名： Nutrition and Health

2005年

作者： Riva Touger-Decker david A. Sirois connie c. Mobley

来源：畅想之星图书光盘版（南... 评论

在线全文

畅想之星图书光盘版（南通市图书馆镜像）

学校读者我要写书评

暂无评论

Multi-Wavelength Optical Packet Routing Technologies Based on Superstructured Fiber Bragg Gratings

引用

光学学报 2003年第S1期23卷 699-700页

作者： Benn c. Thomsen Peh c. Teh Morten Ibsen david J. Richardson Optoelectronics Research centre University of Southampton Southampton SO17 1BJ UK.Optoelectronics Research Centre University of Southampton Southampton SO17 1BJ UK.Optoelectronics Research Centre University of Southampton Southampton SO17 1BJ UK.Optoelectronics Research Centre University of Southampton Southampton SO17 1BJ UK.

A WDM compatible Edge-to-Edge Self-Routed optical packet switched network that simplifies the optical processing is proposed. The system employs all-optical packet label generation and recognition using coded superstr... 详细信息

关键词： WDM in of as OcL that Multi-Wavelength Optical Packet Routing Technologies Based on Superstructured Fiber Bragg Gratings on

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influence of climate on Soil Organic carbon in chinese Paddy Soils

引用

chinese Geographical Science 2017年第3期27卷 351-361页

作者： WANG Dandan YAN Yechao LI Xinhui SHI Xuezheng ZHANG Zhongqi david c WEINDORF WANG Hongjie XU Shengxiang School of Geography and Remote Sensing Nanjing University of Information Science & Technology Nanjing 210044 China State key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008China Jiangsu Normal University Xuzhou 221116 China Department of Plant and Soil Sciences Texas Tech University Lubbock 79409 USA

Soil organic carbon(SOc) is a major component of the global carbon cycle and has a potentially large impact on the greenhouse effect. Paddy soils are important agricultural soils worldwide, especially in Asia. Thus, a better understanding of the relationship between SOc of paddy soils and climate variables is crucial to a robust understanding of the potential effect of climate change on the global carbon cycle. A soil profile data set(n = 1490) from the Second National Soil Survey of china conducted from 1979 to 1994 was used to explore the relationships of SOc density with mean annual temperature(MAT) and mean annual precipitation(MAP) in six soil regions and eight paddy soil subgroups. Results showed that SOc density of paddy soils was negatively correlated with MAT and positively correlated with MAP(P c density with MAT and MAP were weak and varied among the six soil regions and eight paddy soil subgroups. A preliminary assessment of the response of SOc in chinese paddy soils to climate indicated that climate could lead to a 13% SOc loss from paddy soils. compared to other soil regions, paddy soils in Northern china will potentially more sensitive to climate change over the next several decades. Paddy soils in Middle and Lower Yangtze River Basin could be a potential carbon sink. Reducing the climate impact on paddy soil SOc will mitigate the positive feedback loop between SOc release and global climate change.

关键词： soil organic carbon paddy soils mean annual temperature mean annual precipitation climate change

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

comparative Study of Gut Microbiota in Breast cancer Patients versus controls in Abidjan, côte d’Ivoire

引用

Advances in Microbiology 2024年第9期14卷 405-415页

作者： M’Bengue Gbonon Valérie Gnahore Djeda Franck kouadio kouamé Assohoun Stanislas coulibaly Safiatou Diplo Flore Bernadette Sekongo Mamadou Osseni Akandji Afran Sidje Arlette N’Guessan Jean-david Dosso Mireille Molecular Genetics Platform Institut Pasteur de Cte dIvoire Abidjan Cte dIvoire Laboratory of Biology and Health UFR Biosciences Flix Houphout Boigny University Abidjan Cte dIvoire Department of Environment and Health Institut Pasteur de Cte dIvoire Abidjan Cte dIvoire Bioinformatics & computational Biology Group National Computing Center of Cte dIvoire Flix Houphout Boigny University Bingerville Cte dIvoire National Blood Transfusion center Abidjan Cte dIvoire Oncology Department Treichville University Hospital Abidjan Cte dIvoire

context: The gut microbiota represents a complex ecosystem encompassing all unicellular microorganisms residing in the digestive tract, primarily bacteria, fungi, archaea, and even viruses. The relationship between the host and the microbiota is symbiotic: bacteria benefit from a stable environment, while the host gains numerous capabilities in terms of digestion, metabolism, nutrition, and immunity. However, numerous studies suggest that the gut microbiota plays a crucial role in various non-communicable diseases, including obesity, chronic inflammatory bowel diseases, allergic and immune disorders, behavioral disorders, and even certain cancers. The objective of our study was to characterize the gut microbiota of a group of breast cancer patients by comparing it to that of control subjects in côte d’Ivoire, using a metagenomic approach. Method: A case-control study was conducted from May 2020 to September 2023. A total of 85 women (39 cases and 46 controls) were recruited, and stool samples were collected from both breast cancer patients and healthy women. Among these, ten (10) samples from patients and ten (10) samples from healthy women were randomly selected for the study of the gut microbiota. The gut microbiota was characterized by sequencing the V4 region of 16S rRNA using metagenomic NGS technology, and bioinformatic analysis was performed using the mothur pipeline. Results: In women with breast cancer, we observed a reduction in the relative abundance of the phyla Firmicutes and Bacteroidetes, as well as an increase in the phyla Actinobacteria and Verrucomicrobia. Additionally, their microbiota exhibited lower chao1 and Sobs diversities compared to the control women (p cular variance analysis (AMOVA) revealed a significant difference between the case and control groups (p cant difference in the relative abundance of major phyla within the gut microbiota of cases compared to healthy controls. It wil

关键词： Gut Microbiota 16S Metagenomic Sequencing Breast cancer Dysbiosis

来源：

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

clinical implications of exercise immunology

引用

Journal of Sport and Health Science 2012年第1期1卷 12-17页

作者： david c.Nieman Human Performance Laboratory Appalachian State UniversityNorth Carolina Research CampusKannapolisNC 28081USA

Maintaining leanness and a physically active lifestyle during adulthood reduces systemic inflammation,an underlying factor in multiple chronic *** anti-inflammatory influence of near-daily physical activity in lowering c-reactive protein,total blood leukocytes,interleukin-6,and other inflammatory cytokines may play a key role in lowering risk of cardiovascular disease,certain types of cancer,type 2 diabetes,sarcopenia,and *** exercise training causes favorable perturbations in immunity and a reduction in incidence of upper respiratory tract infection(URTI).During each bout of moderate exercise,an enhanced recirculation of immunoglobulins,neutrophils,and natural killer cells occurs that persists for up to 3-h *** exercise-induced surge in immune cells from the innate immune system is transient but improves overall surveillance against *** moderate exercise continues on a near-daily basis for 12-15 weeks,the number of symptoms days with URTI is decreased 25％-50％ compared to randomized sedentary *** and animal studies support this inverse relationship between URTI risk and increased physical ***(c)2012,Shanghai University of *** and hosting by Elsevier *** rights reserved.

关键词： Inflammation Natural killer cells Neutrophils Physical activity Upper respiratory tract infection

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：