检索结果-南通市图书馆

The patterns of surface capillary-gravity short-crested waves with uniform current fields in coastal waters

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2006年第5期22卷 433-441页

作者： Hu huang Jia fu Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China

A fully three-dimensional surface gravitycapillary short-crested wave system is studied as two progressive wave-trains of equal amplitude and frequency, which are collinear with uniform currents and doubly-periodic in the horizontal plane, are propagating at an angle to each other. The first- and second-order asymptotic analytical solutions of the short-crested wave system are obtained via a perturbation expansion in a small parameter associated with the wave steepness, therefore depicting a series of typical three-dimensional wave patterns involving currents, shallow and deep water, and surface capillary waves, and comparing them with each other.

关键词： Short-crested waves Uniform currents Patterns Surface capillary-gravity waves Finite depth and deep water

Coherent Control of a Simple Quantum System

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 1997年第6期14卷 417-420页

作者： LIN fu-cheng Shanghai Institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201800

The quantum dynamics of a three-level Vee-system can be controlled by using two single-mode cw *** dc component of the probability for finding a specific state in laser fields can be obtained by matching the intensities,phases and detunings of the lasers to relevant eigenvalues of the quantum *** selectivity of control does not depend strongly on the laser intensities but the absolute amount of the product does *** are generally three paths to reach such a dc component control and,at some points,two of them cross each other causing a near 100%*** stability of the process to the fluctuation of the experiment was analyzed.

关键词： tuning quantum Quantum

Effects of mean shear on the vortex identification and the orientation statistics

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

Theoretical & Applied Mechanics Letters 2023年第4期13卷 280-286页

作者： Tianyi Bai cheng cheng Lin fu Department of Mechanical and Aerospace Engineering The Hong Kong University of Science and TechnologyHong Kong 999077China Department of Mathematics The Hong Kong University of Science and TechnologyHong Kong 999077China HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute Shenzhen 815057China

This work compares the threshold applied to the swirling strength as well as the vortex orientation statistics in the total and fluctuating velocity fields using direct numerical simulations of compressible and incompressible turbulent channel *** is concluded that the difference in the swirling strength for vortex identification is minimal in the logarithmic region such that these two situations share the same *** the vortex orientation,the inclination angle remains ***,as the wall-normal distance increases,a more and more obvious distinction is noticed for its orientation with respect to the spanwise(z)*** is mainly due to their intrinsic differences and attendant contrasting preference for the vortex identification,i.e.,vortices rotating in the−z direction for the total velocity field and in the z direction for the fluctuating *** observations function as a reasonable explanation for various remarks in previous studies.

关键词： Vortex Compressible wall-bounded turbulence Turbulence structure Channel flows

Selective and stable Au-Cu bimetallic catalyst for CO-PROX

在线全文

学校读者我要写书评

暂无评论

Nano Research 2023年第7期16卷 9031-9038页

作者： Feng Hong Guanjian cheng Weihao Hu Shengyang Wang Qike Jiang Junhong fu Botao Qiao Jiahui huang Dalian National Laboratory for Clean Energy Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China College of Energy Soochow Institute for Energy and Materials Innovations(SIEMIS)Soochow UniversitySuzhou 215006China CAS Key Laboratory of Science and Technology on Applied Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China School of Chemistry and Chemical Engineering Yulin UniversityYulin 719000China University of Chinese Academy of Sciences Beijing 100049China

Gold-based catalysts are promising in CO preferential oxidation(CO-PROX)reaction in H_(2)-rich stream on account of their high intrinsic activity for CO elimination even at ambient ***,the decrease of CO conversion at elevated temperature due to the competition of H_(2)oxidation,together with the low stability of gold nanoparticles,has posed a dear ***,we report that Au-Cu bimetallic catalyst prepared by galvanic replacement method shows a wide temperature window for CO total conversion(30-100℃)and very good catalyst stability without deactivation in a 200-h *** characterizations combined with density functional theory(DFT)calculation reveal that the synergistic effect of Au-Cu,the electron transfer from Au to Cu,leads to not only strengthened chemisorption of CO but also weakened dissociation of H_(2),both of which are helpful in inhibiting the competition of H_(2)oxidation thus widening the temperature window for CO total conversion.

关键词： gold catalysis CO preferential oxidation(CO-PROX) electronic interaction galvanic replacement

Geant4 used in medical physics and hadrontherapy technique

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

Nuclear Science and Techniques 2006年第5期17卷 276-279页

作者： TANG Shi-Biao YIN Ze-Jie huang Huan cheng Yan cheng fu-Hui MAO Feng-Hua Department of Modern Physics University of Science and Technology of China Hefei 230026 China

This article mainly presents the application of Geant4 package (Geant4.7.0, 2005), developed by CERN (the Center of European Research of Nucleus), in medical physics and a novel technique, namely, hadrontherapy. The distribution of energy deposition in a water model by different radiation beams was also given. The results show that the distributions for proton beams are completely different from those for other radiation beams. Charged particles like protons exhibit little scattering when they penetrate the matter and give the highest energy deposition near the end of their range just before they reach the resting state. These characteristics permit very precise control of the shape of the energy distribution inside the patient’s body.

关键词：医学物理学强子治疗技术辐射能分布能量沉积欧洲核物理研究中心

Gamma ray absorption of cylindrical fissile material with dual shields

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2005年第5期16卷 266-272页

作者： WU Chen-Yan TIAN Dong-Feng cheng Yi-Ying huang Yong-Yi LU fu-Quan YANG fu-Jia Institute of Mathematics Fudan University Shanghai 200433 Institute of Modern Physics Fudan University Shanghai 200433 Institute of Applied Physics and Computational Mathematics Beijing 100088 Department of Physics University of Rhode Island 02881-0817 USA

This work analyzed the gamma ray attenuation effect from the self-absorption and shield attenuation per-spectively. An exact mathematical equation was given for the geometric factor of the cylindrical fissile material with dual shields. In addition, several approximation approaches suitable for real situation were discussed, especially in the radial and axial directions of the cylinders, since the G-factors have simple forms. Then the space distribution patterns of the G-factor were analyzed based on numerical result and effective ways to solve the geometric informa-tion of the cylindrical fissile material, the radii and the heights, were deduced. This method was checked and verified by numerical calculation. Because of the efficiency of the method, it is ideal for application in real situations, such as nuclear safeguards, which demands speed of detection and accuracy of geometric analysis.

关键词： γ射线裂变反应核反应堆吸收能力

Machine learning and numerical investigation on drag reduction of underwater serial multi-projectiles

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2022年第2期18卷 229-237页

作者： Xi huang cheng cheng Xiao-bing Zhang School of Energy and Power Engineering Nanjing University of Science and TechnologyNanjing210094China

To increase launching frequency and decrease drag force of underwater projectiles,a serial multiprojectiles structure based on the principle of supercavitation is proposed in this *** drag reduction and supercavitation characteristics of the underwater serial multi-projectiles are studied with computational fluid dynamics(CFD)and machine ***,the numerical simulation model for the underwater supercavitating projectile is established and verified by experimental *** the evolution of the supercavitation for the serial multi-projectiles is *** addition,the effects of different cavitation numbers and different distances between projectiles are investigated to demonstrate the supercavitation and drag reduction ***,the artificial neural network(ANN)model is established to predict the evolution of drag coefficient based on the data obtained by CFD,and the results predicted by ANN are in good agreement with the data obtained by *** finding provides a useful guidance for the research of drag reduction characteristics of underwater serial projectiles.

关键词： Drag reduction Serial multi-projectiles Machine learning Artificial neural network(ANN) Numerical simulation

Separation-and-Recovery Technology for Organic Waste Liquid with a High Concentration of Inorganic Particles

在线全文

学校读者我要写书评

暂无评论

Engineering 2018年第3期4卷 406-415页

作者： Hualin Wang Pengbo fu Jianping Li Yuan huang Ying Zhao Lai Jiang Xiangchen Fang Tao Yang Zhaohui huang cheng huang National Engineering Laboratory for Industrial Wastewater Treatment East China University of Science and Technology Shanghai 200237 China Sinopec Luoyang Petrochemical Engineering Corporation Luoyang 471003 China Sinopec Jinling Petrochemical Corpora tion Nanjing 210033 China Sinopec Dalian (fushun) Research Institute of Petroleum and Petrochemicals Fushun 113001 China Sinopec Zhenhai Refining and Chemical Company Ningbo 315207 China

The environmentally friendly and resourceful utilization of organic waste liquid is one of the frontiers of environmental engineering. With the increasing demand for chemicals, the problem of organic waste liq- uid with a high concentration of inorganic pollutants in the processing of petroleum, coal, and natural gas is becoming more serious. In this study, the high-speed self-rotation and flipping of particles in a three- dimensional cyclonic turbulent field was examined using a synchronous high-speed camera technique; the self-rotation speed was found to reach 2000-6000 rad.s 1. Based on these findings, a cyclonic gas- stripping method for the removal of organic matter from the pores of particles was invented. A techno- logical process was developed to recover organic matter from waste liquid by cyclonic gas stripping and classifying inorganic particles by means of airflow acceleration classification. A demonstration device was built in Sinopec＇s first ebullated-bed hydro-treatment unit for residual oil. Compared with the T-STAR fixed-bed gas-stripping technology designed in the United States, the maximum liquid-removal effi- ciency of the catalyst particles in this new process is 44.9% greater at the same temperature, and the time required to realize 95% liquid-removal efficiency is decreased from 1956.5 to 8.4 s. In addition, we achieved the classification and reuse of the catalyst particles contained in waste liquid according to their activity. A proposal to use this new technology was put forward regarding the control of organic waste liquid and the classification recovery of inorganic particles in an ebullated-bed hydro-treatment process for residual oil with a processing capacity of 2×106 t.a^1. It is estimated that the use of this new tech- nology will lead to the recovery of 3100 t.a 1 of diesel fuel and 647 t.a^1 of high-activity catalyst; in addi- tion, it will reduce the consumption of fresh catalyst by 518 t.a^1. The direct economic benefits of this pr

关键词： Organic waste liquid Inorganic particles Cyclonic gas stripping Particle self-rotation Airflow acceleration classification

Systematic analysis and modeling of the FLASH sparing effect as a function of dose and dose rate

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

Nuclear Science and Techniques 2024年第10期35卷 51-58页

作者： Qi-Bin fu Yan Zhang Yu-cheng Wang Tu-Chen huang Hong-Yu Zhu Xiao-Wu Deng Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China Department of Radiation Oncology State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineSun Yat-sen University Cancer CenterGuangzhou 510060China

Ultrahigh-dose-rate radiotherapy(FLASH-RT)is a revolutionary radiotherapy technology that can spare normal tissues without compromising tumor *** qualitative experimental results have been reported,quantitative and systematic analysis of data is ***,the FLASH effect response model to the dose or dose rate is still *** study investigated the relationships between the FLASH effect and experimental parameters,such as dose,dose rate,and other factors by analyzing published in vivo experimental data from animal *** data were modeled based on logistic regression analysis using the sigmoid *** model was evaluated using prediction accuracy,receiver operating characteristic(ROC)curve,and area under the ROC *** showed that the FLASH effect was closely related to the dose,mean dose rate,tissue type,and corresponding biological *** dose rate corresponding to a 50% probability of triggering cognitive protection in the brain was 45 Gy s^(-1).The dose rate corresponding to a 50% probability of triggering intestinal crypt survival and regeneration was 140 Gy s^(-1).For the skin toxicity effect,the dose corresponding to a 50% probability of triggering the FLASH effect was 24 *** study helps to characterize the conditions underlying the FLASH effect and provides important information for optimizing experiments.

关键词： FLASH radiotherapy Sparing effect Systematic analysis Dose rate Dose Biological endpoints