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Numerical Simulation for Refraction-Diffraction of waves in water of Slowly Varying Current and Topography

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China Ocean Engineering 1997年第4期12卷 373-386页

作者： Hong, Gw feng, wB Xia, QY Pan, sh Hohai Univ Res Inst Coastal & Ocean Engn Nanjing 210024 Peoples R China

A new numerical finite difference iteration method for refraction-diffraction of waves ia water of slowly varying current and topography is developed in this paper. And corresponding theoretical model including the dissipation term is briefly described, together with some analysis and comparison of computational results of the model with measurements in a hydraulic scale model (Berkhoff et al., 1982). An example of practical use of the method is given, showing that the present model is useful to engineering practice.

关键词： refraction-diffraction of waves on current wave number conservation wave action conservation Eikonal equation time dependent mild slope equation on current energy dissipation

Thermal-hydraulic and stress analysis of AP1000 reactor containment during LOCA in dry cooling mode

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Nuclear Science and Techniques 2017年第6期28卷 73-85页

作者： sh.sheykhi S.Talebi M.Soroush E.Masoumi Department of Energy Engineering and Physics Amirkabir University of Technology(Tehran Polytechnic) Young Researchers and Elite Club Islamic Azad UniversitySouth Tehran Branch

Some kinds of break in the reactor coolant system may cause the coolant to exit rapidly from the failure site,which leads to the loss of coolant accident(LOCA).In this paper,a stress analysis of an AP1000 reactor containment is performed in an LOCA,with the passive containment cooling system(PCCS) being available and not available for cooling the wall's *** variations in the mechanical properties of the wall's containment,including elastic modulus,strength,and stress,are analyzed using the ABAQUS code.A general two-phase model is applied for modeling thermal-hydraulic behavior inside the *** pressure and temperature from thermal-hydraulic models are considered as boundary conditions of the ABAQUS code to obtain distributions of temperature and stress across steel shell of the containment in the *** results indicate that if the PCCS fails,the peak pressure inside the containment exceeds the design ***,the stress would still be lower than the yield stress value,and no risk would threaten the integrity of the containment.

关键词： Two-phase flow LOCA Containment integrity AP1000 reactor

Electrochemically modified piezoelectric crystal biosensor for detection of Staphylococcus aureus

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Chinese Journal of Chemistry 1996年第3期14卷 222-227页

作者： Si, sh Chen, JH He, fJ Nie, LH Yao, SZ HUNAN UNIV NEW MAT RES INSTCHANGSHA 410082HUNANPEOPLES R CHINA

Electropolymerized o-phenylenediamine firm is used as a functional coating for the immobilization of anti-S. aureus antibody on the surface of a gold-plated piezoelectric crystal, and this piezoelectric immunosensor is applied to detect S. aureus. The frequency shift (Delta f = f-20s - f-380s, Hz) between the frequency at the 20th second (after the addition of sample, f-20s) and that at 380 seconds later (f-380s) was introduced to construct a calibration graph, and shortening of assay time was achieved. The S. aureus concentrations in the range of 10(5)-10(9) cells/mL can be detected by this system.

关键词： piezoelectric biosensor detection of S-aureus electrochemical modification

Characteristic Assessment of Stabilized Polyacrylonitrile Nanowebs for the Production of Activated Carbon Nano-Sorbents

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Chinese Journal of Polymer Science 2014年第4期32卷 449-457页

作者： S.Rafiei B.Noroozi sh.Arbab A.K.Haghi Department of Textile Engineering University of Guilan

Polyacrylonitrile （PAN） nanofibers with average diameter of 300 nm were produced by electro-spinning. The nanofibers were stabilized at different temperatures in the range of 180-270 ℃in several duration times and heating rates. fourier transforms infrared （fTIR） spectroscopy, differential scanning calorimetry （DSC） and X-ray diffraction （XRD） analyzing techniques were employed to measure the extent of stabilization reaction. By all procedures, the ranges of temperature and duration time recommended were about 250-270 ℃ and 1-2 h, respectively. Increasing the activation temperature from 800 ℃ to 1200 ℃ caused porosity and pore volume development up to 60% and 0.532 cm3/g, respectively. Pore width of all samples was calculated to be about 0.7 nm confirming micro-pore structure of the produced PAN based activated carbon nanofibers. Comparing dye adsorption for different adsorbents including chitin and granular activated carbon （GAC） showed the highest efficiency for the produced activated carbon nanofibers （ACNfs）.

关键词： Polyacrylonitrile Electro-spinning Stabilization Activated carbon nanofibers Adsorbent.

Experimental and numerical study on plasma nitriding of AISI P20 mold steel

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International Journal of Minerals,Metallurgy and Materials 2016年第9期23卷 1065-1075页

作者： N.Nayebpashaee H.Vafaeenezhad sh.Kheirandish M.Soltanieh Materials Processing Simulation Laboratory(MPS-LAB) School of Materials and Metallurgical EngineeringIran University of Science and Technology(IUST) School of Materials and Metallurgical Engineering Iran University of Science and Technology(IUST)

In this study, plasma nitriding was used to fabricate a hard protective layer on AISI P20 steel, at three process temperatures（450℃, 500℃, and 550℃） and over a range of time periods（2.5, 5, 7.5, and 10 h）, and at a fixed gas N2：H2 ratio of 75vol%：25vol%. The morphology of samples was studied using optical microscopy and scanning electron microscopy, and the formed phase of each sample was determined by X-ray diffraction. The elemental depth profile was measured by energy dispersive X-ray spectroscopy, wavelength dispersive spectroscopy, and glow dispersive spectroscopy. The hardness profile of the samples was identified, and the microhardness profile from the surface to the sample center was recorded. The results show that ε-nitride is the dominant species after carrying out plasma nitriding in all strategies and that the plasma nitriding process improves the hardness up to more than three times. It is found that as the time and temperature of the process increase, the hardness and hardness depth of the diffusion zone considerably increase. furthermore, artificial neural networks were used to predict the effects of operational parameters on the mechanical properties of plastic mold steel. The plasma temperature, running time of imposition, and target distance to the sample surface were all used as network inputs; Vickers hardness measurements were given as the output of the model. The model accurately reproduced the experimental outcomes under different operational conditions; therefore, it can be used in the effective simulation of the plasma nitriding process in AISI P20 steel.

关键词： tool steel plasma nitriding sputtering neural networks

Estimation of wind speeds inside Super Typhoon Nepartak from AMSR2 low-frequency brightness temperatures

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frontiers of Earth Science 2019年第1期13卷 124-131页

作者： Lei ZHANG Xiaobin YIN Hanqing sh Zhenzhan wANG Qing XU Institute of Meteorology and Oceanography National University of Defense TechnologyNanjing 211101China Beijing Piesat Information Technology Co.Ltd Beijing 100195China National Space Science Center Chinese Academy of SciencesBeijing 100190China College of Oceanography Hohai UniversityNanjing 211101China

Accurate estimations of typhoon-level winds are highly desired over the westem Pacific Ocean.A wind speed retrieval algorithm is used to retrieve the wind speeds within Super Typhoon Nepartak (2016)using 6.9- and 10.7-GHz brightness temperatures from the Japanese Advanced Microwave Scanning Radiometer 2 (AMSR2) sensor on board the Global Change Observation Mission-water 1 (GCOM-wl)*** results show that the retrieved wind speeds clearly represent the intensification process of Super Typhoon Nepartak.A good agreement is found between the retrieved wind speeds and the Soil Moisture Active Passive wind speed *** mean bias is 0.51 m/s,and the root-mean-square difference is 1.93 m/s between *** retrieved maximum wind speeds are 59.6 m/s at 04:45 UTC on July 6 and 71.3 m/s at 16:58 UTC on July *** two results demonstrate good agreement with the results reported by the China Meteorological Administration and the Joint Typhoon warning *** addition,feng-Yun 2G (fY-2G) satellite infrared images,feng-Yun 3C (fY-3C)microwave atmospheric sounder data,and AMSR2 brightness temperature images are also used to describe the development and structure of Super Typhoon Nepartak.

关键词： microwave radiometer sea surface wind retrieval AMSR2 Nepartak SMAP

fabrication and Characterization of Alumina/CNTs Nanocomposite Powders, by CCVD Method and Investigation of the Parameter Involved

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Journal of Chemistry and Chemical Engineering 2011年第3期5卷 283-288页

作者： Ali Asghar Hosseini sh Abhari f Physics Department Faculty of Sciences Mazandaran University Babalsar 47416-9544 Iran

Ceramics in general and particularly alumina （Al2O3） are important materials in various industries, but the main problem with these materials is related to some of their mechanical properties including low resistance against mechanical shock （hardness-toughness）, which makes them to be so brittle, and possession of high degree of porosity which reduces their strength and gives them fragile characteristics. Researchers report indicates that the presence of the second phase with suitable properties can improve some of the mechanical properties of these materials and optimize their characteristic. Carbon nanotubes with unique physical characteristics such as large aspect ratio, high strength and Young＇s modulus and improved thermal properties could be suitable candidates for this purpose. In this study, the growth of multi wall carbon nanotubes （MwCNTs） on the alumina support as the matrix of the composite has been carried out, using catalytic chemical vapor deposition （CCVD） method in which the iron nanoparticles has been selected as catalyst materials. Ethylene gas is used as feed materials for carbon source and argon as the carrier gas. In order to achieve a more comprehensive results, we have investigated the effects of some fabricating parameters like catalyst particle size, its weight percentage related to support material, alumina and to the some synthesizing temperature gases flow rate. fabricated ceramics composites samples structures were analyzed using SEM images as well as Raman scattering spectra and X-ray diffraction pattern.

关键词： Alumina nanocomposite CNTs CCVD SEM Raman XRD.

Outcomes of side-to-side conversion hepaticojejunostomy for biliary anastomotic stricture after right-liver living donor liver transplantation

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Hepatobiliary & Pancreatic Diseases International 2013年第1期12卷 42-46页

作者： Kenneth sh Chok See Ching Chan Tan To Cheung Albert CY Chan william w sharr sheung Tat fan Chung Mau Lo Department of Surgery The University of Hong Kong102 Pokfulam RoadHong KongChina State Key Laboratory for Liver Research The University of Hong Kong102 Pokfulam RoadHong KongChina

BACKGROUND:Conversion hepaticojejunostomy is considered the salvage intervention for biliary anastomotic stricture,a common complication of right-liver living donor liver transplantation with duct-to-duct anastomosis,after failed endoscopic *** aim of this study is to compare the outcomes of side-to-side hepaticojejunostomy with those of endto-side ***:Prospectively collected data of 402 adult patients who had undergone right-liver living donor liver transplantation with duct-to-duct anastomosis were *** of biliary anastomotic stricture was made based on clinical,biochemical,histological and radiological *** treatment was the first-line treatment of biliary anastomotic ***:Interventional radiological or endoscopic treatment failed to correct the biliary anastomotic stricture in 13 patients,so they underwent conversion *** of them received end-to-side hepaticojejunostomy and three received side-to-side *** the end-to-side group,two patients sustained hepatic artery injury requiring repeated microvascular anastomosis,two developed restenosis requiring further percutaneous transhepatic biliary drainage and balloon dilatation,and two required revision *** the side-to-side group,one patient developed re-stenosis requiring further endoscopic retrograde cholangiography and balloon *** re-operation was needed in this ***,outcomes in the two groups were similar in terms of liver function and graft ***:Despite the similar outcomes,side-to-side hepaticojejunostomy may be a better option for bile duct reconstruction after failed interventional radiological or endoscopic treatment because it can decrease the chance of hepatic artery injury and allows future endoscopic treatment if re-stricture ***,more large-scale studies are warranted to validate the results.

关键词： right-liver endoscopic treatment living donor liver transplantation biliary anastomotic stricture duct-to-duct anastomosis hepaticojejunostomy

Cooling process of liquid propellant rocket by means of kerosene-alumina nanofluid

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Propulsion and Power Research 2016年第4期5卷 279-286页

作者： Mostafa Mahmoodi sh.Kandelousi Department of Aerospace Engineering Malek-Ashtar University of TechnologyTehranIran Department of Mechanical Engineering Babol University of TechnologyBabolIran

Heat transfer augmentation of kerosene-alumina nanofluid is studied for the possible use in the regenerative cooling channel of semi cryogenic *** basic partial differential equations are reduced to oidinary differential equations which are solved using differential transformation *** and temperature profiles as well as the skin friction coefficient and Nusselt number are *** influence of pertinent parameters such as nanofluid volume fraction,viscosity parameter and Eckert number on the flow and heat transfer characteristics is *** results indicate that adding alumina into the fuel of liquid rocket engine(kerosene)can be considered as the way of enhancing cooling process of chamber and nozzle *** number is an increasing function of viscosity parameter and nanoparticle volume fraction while it is a decreasing Junction of Eckert number.

关键词： Liquid propellant rocket Kerosene Alumina Nanofluid Heat transfer