检索结果-南通市图书馆

Structure and Properties of Chemically-reduced Functionalized Graphene Oxide Platelets

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2015年第5期31卷 458-462页

作者： A.Pruna d.Pullini d.Busquets University of Bucharest 405 Atomistilor Str077125 Bucharest-MagureleRomania Institute of Materials Technology University Politecnica of ValenciaCamino de Vera s/n46022 ValenciaSpain Fiat Research Centre

Green reduction of graphene oxide(GO) functionalized with 3-aminopropyltriethoxysilane and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride/N-hydroxysuccinimide was performed by using ascorbic acid and sodium *** obtained materials were characterized by thermo-gravimetric analysis,transmission electron microscopy.X-ray diffraction,UV-Vis,Fourier transform infrared and Raman spectroscopy *** results indicated a strong dependence of the materials properties such as deoxygenation degree,absorption peak shift,crystallite size and functionalization degree on the functionalization approach and reducing agent.

关键词： Covalent functionalization Graphene oxide Reductio

Mechanical and wear behaviour of AZ91d magnesium matrix hybrid composite reinforced with boron carbide and graphite

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2017年第1期5卷 20-25页

作者： I.Aatthisugan A.Razal Rose d.Selwyn Jebadurai department of mechanical engineering srm universitykattankulathurkancheepuram districttamil nadu 603203india

In this experimental study,magnesium(AZ91d)based boron carbide(B4C)and graphite(Gr)particle reinforced hybrid composite materials were manufactured by stir *** tribological and mechanical properties of these composite materials were *** results of the tests revealed that the graphite reinforced hybrid composites exhibited a lower wear loss compared to the unreinforced AZ91d alloy and AZ91d–B4C *** was found that with an increase in the B4C content,the wear resistance increased monotonically with hardness and ultimate tensile strength *** study revealed that the addition of both a hard reinforcement(e.g.,B4C)and soft reinforcement(e.g.,graphite)significantly improves the wear resistance of magnesium *** entire results designate that the hybrid magnesium composites can be considered as an excellent material where high strength,ultimate tensile strength and wear-resistant components are of major importance,primarily in the aerospace and automotive engineering sectors.

关键词： Stir casting Hybrid composite Magnesium AZ91d Mechanical Wear Boron carbide

The Improbable Association between the Herbicide 2,4-d and Polyneuropathy

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

Biomedical and Environmental Sciences 1990年第1期3卷 43-51页

作者： J.L.MATTSSON d.L.EISENBRANdT Health & Environmental Sciences. The dow Chemical Company. Midland. Michigan 48674

Isolated case reports have circumstantially linked the use of the herbicide 2.4-dichlorophen-oxyacetic acid (2,4-d) to polyneuropathy. However, a critical review of the literature reveals numerous reasons for doubting a relationship of 2.4-d to polyneuropathy: (1) too few cases given the wide use of the chemical: (2) no valid toxicologic or epidemiologic evidence; (3) the diversity of antecedent illness; (4) an unlikely time sequence of antecedent illness to exposure (pharmacokinetics); (5) the lack of polyneuropathy in medical patients given repetitive doses of 2.4-d; (6) the lack of polyneuropathy in heavily exposed military personnel involved in operation Ranch Hand; (7) the biological properties of 2.4-d which minimize penetration of 2.4-d into the nervous system under normal exposure conditions; and (8) the lack of polyneuropathy in a variety of experimental animal species given 2,4-d by several routes of exposure and at dose levels and durations of exposure many times greater than human applicator exposure. Thus, the weight of evidence indicates that 2.4-d is an unlikely cause of polyneuropathy. 1990 Academic Press. Inc.

关键词： The Improbable Association between the Herbicide 2 4-d and Polyneuropathy

The Effect of External Magnetic Field on Electron Scale Kelvin–Helmholtz Instability

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第9期24卷 236-247页

作者： d.Tsiklauri Joule Physics Laboratory School of ScienceEngineering and EnvironmentUniversity of SalfordManchesterM54WTUK

We use particle-in-cell,fully electromagnetic,plasma kinetic simulation to study the effect of external magnetic field on electron scale Kelvin–Helmholtz instability(ESKHI).The results are applicable to collisionless plasmas when,e.g.,solar wind interacts with planetary magnetospheres or a magnetic field is generated in AGN *** find that as in the case of magnetohydrodynamic(MHd)KHI,in the kinetic regime,the presence of an external magnetic field reduces the growth rate of the *** the MHd case,there is a known threshold magnetic field for KHI stabilization,while for ESKHI this is to be analytically *** a kinetic analytical expression,we use several numerical simulation runs to establish an empirical dependence of ESKHI growth rate,Γ(B_(0))ω_(pe),on the strength of the applied external magnetic *** find the best fit is hyperbolic,Γ(B_(0))ω_(pe)=Γ_(0)ω_(pe)/(A+BB_(0)),where Γ_(0) is the ESKHI growth rate without an external magnetic field and B_(0)=B_(0)/B_(MHd)is the ratio of external and two-fluid MHd stability threshold magnetic field,derived *** analytical theory to back up this growth rate dependence on the external magnetic field is *** results suggest that in astrophysical settings where a strong magnetic field pre-exists,the generation of an additional magnetic field by the ESKHI is suppressed,which implies that nature provides a“safety valve”—natural protection not to“over-generate”magnetic field by the ESKHI ***,we find that our two-fluid MHd threshold magnetic field is the same(up to a factor √γ_(0))as the dC saturation magnetic field,previously predicted by fully kinetic theory.

关键词： instabilities magnetic fields plasmas Sun:heliosphere ISM:magnetic fields

Elastic modulus and hardness of cortical and trabecular bovine bone measured by nanoindentation

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2006年第B2期16卷 744-748页

作者： HOdGSON P d Centre for Material and Fibre Innovationdeakin University Geelong VIC 3217Australia

The elastic modulus and hardness of several microstructure components of dry bovine vertebrae and tibia have been investigated in the longitude and transverse directions using nanoindentation. The elastic modulus for the osteons and the interstitial lamellae in the longitude direction were found to be (24.7±2.5) GPa and (30.1±2.4) GPa. As it's difficult to distinguish osteons from interstitial lamellae in the transverse direction, the average elastic modulus for cortical bovine bone in the transverse direction was (19.8±1.6) GPa. The elastic modulus for trabecular bone in the longitude and transverse direction were (20±2) GPa and (14.7±1.9) GPa respectively. The hardness also varied among the microstructure components in the range of 0.41-0.89 GPa. Analyses of variance show that the values are significantly different.

关键词：牛骨弹性模量硬度骨皮质骨小梁纳米压痕法测量生物力学

Tsallis agegraphic dark energy model with the sign-changeable interaction

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2020年第1期72卷 96-101页

作者： Y d Xu School of Science Jiangsu Ocean UniversityLianyungang 222005China

In this paper,we study the evolution of a spatially flat universe composed of Tsallis agegraphic dark energy(TAdE)and a pressureless dark matter(dM),by assuming that there is a signchangeable interaction between TAdE and *** density,deceleration parameter and the equation of state parameters(EoS)show satisfactory behaviors in the *** analysis we find that the accelerated expansion of the universe can be achieved at the late time if model parametersδ>2 and-2/3dE model by means of statefinder diagnostic and w–w’analysis.

关键词： Tsallis agegraphic dark energy cosmological evolution statefinder w–w’analysis

Water vapor δd dynamics over China derived from SCIAMACHY satellite measurements

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2014年第4期57卷 813-823页

作者： LIU ZhongFang Kei YOSHIMURA Casey d.KENNEdY WANG XinHui PANG ShuoGuang Tianjin Key Laboratory of Water Resource and Environment Tianjin Normal University Atmosphere and Ocean Research Institute University of Tokyo United States department of Agriculture Agricultural Research ServicePasture Systems and Watershed Management Research UnitEast WarehamMA 02538USA

This study investigates water vapor isotopic patterns and controls over China using high-quality water vapor δd data retrieved from the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography （SCIAMACHY） observations. The results show that water vapor δd values on both annual and seasonal time-scales broadly exhibit a continental effect, with values largely decreasing northwestward from coastal lowlands to high-elevation mountainous regions. However, region-specific analysis reveals spatially distinct patterns of water vapor dd between seasons. In the monsoon domain （e.g., China south of 35~N）, depletion in d in the summer and fall seasons is closely tied to monsoon moisture sources （the Indian and Pacific oceans） and subsequent amount effect, but higher 8d values in winter and spring are a result of isotopically-enriched conti- nental-sourced moisture proceeded by less rainout. In contrast, farther inland in China （non-monsoon domain）, moisture is de- rived overwhelmingly from the dry continental air masses and local evaporation, and 8d values are largely controlled by the temperature effect, exhibiting a seasonality with isotopically enriched summer and depleted winter/spring. The observation that the spatial pattern of water vapor δd is the opposite to that of precipitation δd in the summer season also suggests that partial evaporation of falling raindrops is a key driver of water vapor isotope in the non-monsoon domain. This study highlights the importance of non-Rayleigh factors in governing water vapor isotope, and provides constraints on precipitation isotope inter- pretation and modern isotope hydrological processes over China.

关键词： water vapor δd moisture sources evapotranspiration droplet evaporation China

design and development of a web-based 3d cadastral visualisation prototype

在线全文

学校读者我要写书评

暂无评论

International Journal of digital Earth 2015年第7期8卷 538-557页

作者： davood Shojaei Abbas Rajabifard Mohsen Kalantari Ian d.Bishop Ali Aien department of Infrastructure Engineering Centre for Spatial Data Infrastructures and Land AdministrationThe University of MelbourneMelbourneAustralia

Three-dimensional(3d)developments of land,such as complex high-rises,put enormous pressure on current land administration systems that have ad hoc approaches to 3d property *** approaches are unable to support effective 3d storage,analysis and visualisation of property *** visualisation is one of the essential components in realisation of a truly 3d ***,several 3d visualisation applications and cadastral prototypes have been developed around the ***,they do not effectively represent ownership information in 3d because they have not been developed based on 3d cadastral visualisation *** candidate 3d visualisation solutions were compared with user-derived visualisation criteria,a web-based 3d visualisation prototype was designed and *** functionality,usability and efficiency of the prototype were evaluated by potential users involved in the registration and management of *** there was a high level of enthusiasm for the features of the prototype,the results also suggest further directions for development of 3d cadastral visualisation.

关键词： 3d visualisation 3d cadastre WebGL legal objects physical objects 3d cadastral visualisation

3d biofabrication of vascular networks for tissue regeneration:A report on recent advances

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 Pharmaceutical Analysis 2018年第5期8卷 277-296页

作者： M.d.Sarker Saman Naghieh N.K.Sharma Xiongbiao Chen division of Biomedical Engineering College of Engineering University of Saskatchewan department of Mechanical Engineering College of Engineering University of Saskatchewan

Rapid progress in tissue engineering research in past decades has opened up vast possibilities to tackle the challenges of generating tissues or organs that mimic native structures. The success of tissue engineered constructs largely depends on the incorporation of a stable vascular network that eventually anastomoses with the host vasculature to support the various biological functions of embedded cells. In recent years, significant progress has been achieved with respect to extrusion, laser, micro-molding, and electrospinning-based techniques that allow the fabrication of any geometry in a layer-by-layer fashion. Moreover, decellularized matrix, self-assembled structures, and cell sheets have been explored to replace the biopolymers needed for scaffold fabrication. While the techniques have evolved to create specific tissues or organs with outstanding geometric precision, formation of interconnected, functional, and perfused vascular networks remains a challenge. This article briefly reviews recent progress in 3d fabrication approaches used to fabricate vascular networks with incorporated cells, angiogenic factors, proteins, and/or peptides. The influence of the fabricated network on blood vessel formation, and the various features, merits, and shortcomings of the various fabrication techniques are discussed and summarized.

关键词： 3d bioprinting Tissue engineering Vascularization Extrusion Laser-based printing Co-axial printing