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Plasma Science and Technology 2017年第3期19卷 93-97页

作者： A F POPOVICH V G RALCHeNkO V k BALLA A k MALLIk A A kHOMICH A P BOLSHAkOV D N SOVYk e e ASHkINAZI V Yu YUROV Institute of Radio engineering and electronics of Russian Academy of Sciences Fryazino 141190 Russia General Physics Institute of Russian Academy of Sciences Moscow 119991 Russia Harbin Institute of Technology Harbin 150001 People's Republic of China National Research Nuclear University MePhI Moscow 115409 Russia Central Glass and Ceramic Research Institute Kolkata 700 032 India

Polycrystalline diamond（PCD） films 100 mm in diameter are grown by 915 MHz microwave plasma chemical vapor deposition（MPCVD） at different process parameters,and their thermal conductivity（TC） is evaluated by a laser flash technique（LFT） in the temperature range of230-380 *** phase purity and quality of the films are assessed by micro-Raman spectroscopy based on the diamond Raman peak width and the amorphous carbon（a-C） presence in the *** and increasing dependencies for TC with temperature are found for high and low quality samples,***,as high as 1950 ± 230 W m-1 k-1 at room temperature,is measured for the most perfect material.A linear correlation between the TC at room temperature and the fraction of the diamond component in the Raman spectrum for the films is established.

关键词： thermal conductivity polycrystalline diamond microwave plasma chemical vapordeposition Raman spectroscopy

Distortion Regions near the Grain Boundary and Their effects on Nanocrystalline Materials

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Journal of Materials Science & Technology 2000年第6期16卷 554-558页

作者： Lung, C.W. Long, k. Tian, e.k. Liang, Z.J. Int. Cent. for Mater. Phys. Chinese Acad. of Sci. Shenyang 110015 China

The distortion regions near grain boundaries in α-Fe-C solid solution were studied by the use of internal friction method. It is found that the total thickness of these regions is quite large though the thickness of real grain boundaries is usually very thin. It is also found that the smaller the grain size is, the thicker the total distortion region is got. A model for the structure of distortion regions near grain boundaries is proposed. Their effects on nanocrystalline materials are discussed.

关键词： Distortion Regions near the Grain Boundary and Their effects on Nanocrystalline Materials

kinetics of Silver Dissolution in Nitric Acid from Ag-Au_(0.04)-Cu_(0.10) and Ag-Cu_(0.23) Scraps

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Journal of Materials Science & Technology 2006年第5期22卷 696-700页

作者： S.k.Sadrnezhaad e.Ahmadi M.Mozammel Center of excellence for Advanced Processes of Production of Materials Department of Materials Science and engineering Sharif University of TechnologyTehranIran

kinetics of dissolution of silver present in precious metal 26～85℃. Dissolution rate of silver was much faster than scraps in HNO3 was studied in temperature range of that of copper at all temperatures. effects of particle size, stirring speed, acid concentration and temperature on the rate of dissolving of silver were evaluated. Dissolution rate decreases with particle size and increases with temperature. Dissolving was accelerated with acid concentrations less than 10 mol/L. Concentrations greater than 10 mol/L resulted in slowing down of the dissolution rate. Shrinking core model with internal diffusion equation t/τ=1-3（1-x）^2/3＋2（1-x） could be used to explain the mechanism of the reaction. Silver extraction resulted in activation energies of 33.95 kJ/mol for Ag-Au0.04-Cu0.10 and 68.87 kJ/mol for Ag-Cu0.23 particles. Inter-diffusion of silver and nitrate ions through the porous region of the insoluble alloying layer was the main resistance to the dissolving process. Results were tangible for applications in recycling of the material from electronic silver-bearing scraps, dental alloys, jewelry, silverware and anodic slime precious metal recovery.

关键词： Silver Copper kinetics, Dissolution Shrinking core model Internal diffusion

effects of overburden characteristics on dynamic failure in underground coal mining

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International Journal of Mining Science and Technology 2017年第1期27卷 121-129页

作者： Lawson Heather e. Tesarik Douglas Larson Mark k Abraham Habte NIOSH Office of Mine Safety and Health ResearchGround Control BranchSpokane WA 99207USA

Dynamic failures, or ‘‘bumps", remain an imperative safety concern in underground coal mining, despite significant advancements in engineering controls. The presence of spatially discrete, stiff roof units are one feature that has been linked to these events. However, an empirical stratigraphic review indicates that no significant difference exists in the relative commonality of discrete units between bumping and non-bumping deposits. Instead an apparent relationship exists between reportable bumping and the overall stiffness of the host rock. However, this initial study is too simplistic to be conclusive; to weight the relative impact of changes in a single variable, such as the thickness or location of sandstone members, it must be examined in isolation—i.e., in a setting where all other variables are held *** modelling provides this setting, and the effects of variability in a stiff discrete member in a hypothetical longwall mining scenario are investigated within the context of three stratigraphic ‘‘types",Compliant, Intermediate and Stiff. A modelling experiment examines changes in rupture potential in stiff roof units for each stratigraphic type as discrete unit thickness and location are manipulated through a range of values. Results suggest that the stiff-to-compliant ratio of the host rock has an impact on the relative stress-inducing effects of discrete stiff members. In other words, it is necessary to consider both the thickness and the distance to the seam, within the context of the host rock, to accurately anticipate areas of elevated rupture-induced hazard; acknowledging the presence of a discrete unit within the overburden in general terms is an insufficient indicator of risk. This finding helps to refine our understanding of the role of individual stiff, strong roof members in bumping phenomena, and suggests that a holistic view of overburden lithology and site-specific numerical modelling may be necessary to improve miner safety.

关键词： Dynamic failure Coal mining Bumps Bounces

On Time-Fractional Cylindrical Nonlinear equation

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Chinese Physics Letters 2016年第11期33卷 62-66页

作者： H.G.Abdelwahed e.k.elShewy A.A.Mahmoud College of Science and Humanitarian Studies Physics DepartmentPrince Sattam Bin Abdul Aziz University Theoretical Physics Research Group Physics DepartmentFaculty of ScienceMansoura University

Properties of cylindrical electron acoustic solitons are studied in vortex plasmas. The modil^ea cylindrical korteweg-de Vries （kdV） equation is acquired and converted into the time fractional cylindrical modified kdV equation by Agrawal＇s analysis. Via the Adomian decomposition method, a cylindrical soliton solution to the equation is obtained. The cylindrical time fractional effect on the wave properties is investigated. Further, the increase of the fractional order of time α and hot to trapped electrons temperature β are minimized in both solitary width and amplitude. These influences on the structures of the soliton may be an alternative to the use of higher order perturbation analysis.

关键词： of is as de et in been form that

Spectroscopic studies of gel-grown lanthanum malonate crystals

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Journal of Rare earths 2012年第3期30卷 245-249页

作者： Varghese Mathew Sabu Jacob Lizymol Xavier k.e.Abraham Department of Physics St.Aloysius'CollegeEdathua-689573India Department of Physics S.B.CollegeChanganacherry-686101India

Lanthanum malonate crystals were grown by single tube ionic diffusion through silica gel. The crystallinity of the grown crystals was analyzed by powder X-ray diffraction studies. Fourier transform infrared spectroscopy （FTIR） and fourier transform （FT） Raman studies confirmed the presence of functional groups in the title compound. The optical band gap energy of the material was extracted from diffuse reflectance spectrum.

关键词： lanthanum malonate crystal growth X-ray diffraction analysis DRS studies FTIR and FT Raman studies rare earths

Nanoscale viscoelastic properties and adhesion of polydimethylsiloxane for tissue engineering

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Acta Mechanica Sinica 2014年第1期30卷 2-6页

作者： J.Chen k.e.Wright M.A.Birch School of Mechanical & Systems engineering Newcastle University Arthritis Research Uk (ARUk) Tissue engineering Centre Institute of Cellular MedicineNewcastle UniversityUK Research Uk (ARUk) Tissue engineering Centre Institute of Cellular MedicineNewcastle UniversityUK St James’ University Hospital University of Leeds UK

It has shown that altering crosslink density of biopolymers will regulate the morphology of Mesenchymal Stem Cells （MSCs） and the subsequent MSCs differentia- tion. These observations have been found in a wide range of biopolymers. However, a recent work published in Nature Materials has revealed that MSCs morphology and differen- tiation was unaffected by crosslink density of polydimethyl- siloxane （PDMS）, which remains elusive. To understand such unusual behaviour, we use nanoindentation tests and modelling to characterize viscoelastic properties and sur- face adhesion of PDMS with different base：crosslink ratio varied from 50：1 （50D） to 10：1 （10D）. It has shown that lower crosslink density leads to lower elastic moduli. De- spite lower nanoindentation elastic moduli, PDMS with lowest crosslink density has higher local surface adhesion which would affect cell-biomaterials interactions. This work suggests that surface adhesion is likely another important physical cue to regulate cell-biomaterials interactions.

关键词： Bioploymer- Nanoindentation- Viscoelasticity Surface adhesion

effect of Nitrogen Doping on the electrical Properties of 3C-SiC Thin Films for High-Temperature Sensors Applications

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Acta Metallurgica Sinica(english Letters) 2014年第1期27卷 168-174页

作者： H.k.e.Latha A.Udayakumar V.Siddeswara Prasad Department of Instrumentation Technology Siddaganga Institute of Technology Materials Science Division Council of Scientific and Industrial Research-National Aerospace Laboratories

3C-SiC is a promising structural material for piezoresistive sensors used in high-temperature applications. For sensor development, the preparation of sensor materials and study of its electrical properties, such as resistivity, barrier height of grain boundaries, and temperature coefficient of resistivity, are important in addition to structural properties and these have to be optimized. In the present work, 3C-SiC thin film with in situ doping of nitrogen is prepared through low- pressure chemical vapor deposition by using methyl trichloro silane, ammonia, and hydrogen as precursors. electrical properties of deposited 3C-SiC thin films with varying nitrogen doping concentration through four probe technique are studied. Atomic force microscopy investigations are carried out to study the grain size on and average root-mean-squared roughness 3C-SiC thin films. A decrease in the degree of crystallinity is observed in nitrogen-doped 3C-SiC thin films. The sheet resistivity of nitrogen-doped 3C-SiC thin film is found to decrease with increase in temperature in the range from 303 to 823 k. The sheet resistivity, average temperature coefficient of resistance, and barrier height of the grain boundaries of film doped with 17 at.% of nitrogen are 0.14 cm, -1.0 x 10-n/k, and 0.01 eV, respectively. Comparing all the nitrogen-doped 3C-SiC thin films, the film doped with 17 at.% of nitrogen exhibits an improved structural and electrical properties and it can be used as sensing material for high-temperature applications.

关键词： Low-pressure chemical vapor deposition (LPCVD) 3C-SiC thin film Resistivity Barrier height of grain boundaries: Temperature coefficient of resistivitv (TCR)

enhanced biocompatibility of ZnS:Mn quantum dots encapsulated with Aloe vera extract for therapeutic applications

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Chinese Physics B 2016年第8期25卷 412-416页

作者： Anilkumar M Bindu k R Sneha Saj A Anila e I Cell Culture Laboratory Department of Botany UC College Optoelectronic and Nanomaterials' Research Laboratory Department of Physics UC College Department of Physics SSV College

Toxicity of nanoparticles remains to be a major issue in their application to the biomedical field. Aloe vera（AV） is one of the most widely exploited medicinal plants that have a multitude of amazing properties in the field of *** extract of Aloe vera can be used as a novel stabilising agent for quantum dots to reduce toxicity. We report the synthesis, structural characterization, antibacterial activity and cytotoxicity studies of ZnS：Mn quantum dots synthesized by the colloidal precipitation method, using methanol extract of Aloe vera（AVMe） as the capping agent. The ZnS：Mn quantum dots capped with AVMe exhibit superior performances in biocompatibility and antibacterial activity compared with ZnS：Mn quantum dots without encapsulation.

关键词： quantum dot transmission electron microscopy biocompatibility

Biomimetic Leukocyte Adhesion: A Review of Microfluidic and Computational Approaches and Applications

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Journal of Bionic engineering 2008年第4期5卷 317-327页

作者： J. Hanzlik e. Cretekos k. A. Lamkin-kennard Department of Mechanical engineering Rochester Institute of Technology Rochester

Leukocyte rolling and adhesion are complex physiological processes that have received a great deal of attention over the past decade. Significant increases in the knowledge base related to how leukocytes adhere in shear flows have occurred as a result of the development of novel experimental and computational techniques. Micro- and nano-fabrication techniques have enabled the development of novel flow devices for studying leukocyte adhesion in simple and complex geometries. Improvements in computer technology have enabled simulations of complex flow processes to be developed. As a result of these advances in knowledge related to leukocyte adhesion, numerous novel devices have been developed that mimic the leukocyte rolling and adhesion process. examples of these devices include cell separation and enrichment devices and targeted ultrasound contrast agents. Future advances related to leukocyte rolling and adhesion processes hold great promise for advancing our knowledge of disease processes as well as development of novel therapeutic devices.

关键词： leukocyte microfluidics hydrodynamics