检索结果-南通市图书馆

Cavitation research with computational fluid dynamics:From Euler-Euler to Euler-Lagrange approach

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第1期36卷 1-23页

作者： Bin ji Zi-yang Wang Huai-yu cheng Rickard E.Bensow State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan430072China Department of Mechanics and Maritime Sciences Chalmers University of TechnologyGothenburgSweden

Unsteady cavitating flow often contains vapor structures with a wide range of different length scales,from micro-bubbles to large cavities,which issues a big challenge to precisely investigate its evolution mechanism by computational fluid dynamics(CFD)*** present work reviews the development of simulation methods for cavitation,especially the emerging Euler-Lagrange ***,the progress of the numerical investigation of hot and vital issues is discussed,including cavitation inception,cloud cavitation inner structure and its formation mechanism,cavitation erosion,and cavitation *** is indicated that the Euler-Lagrange method can determine cavitation inception point *** cloud cavitation,the Euler-Lagrange method can reveal the source of microbubbles and their distribution law inside the shedding *** method also has advantages and great potential in assessing cloud cavitation-induced erosion and *** the ever-growing demands of cavitation simulation accuracy in basic research and engineering applications,how to improve the Euler-Lagrange method’s stability and applicability is still an open *** further promote the application of this advanced CFD simulation technology in cavitation research,some key issues are to be solved and feasible suggestions are put forward for further work.

关键词： numerical simulation Euler-Euler method Euler-Lagrange method bubble dynamicsgy,Gothenburg,Sweden

Photocatalytic activation of sulfite by N-doped porous biochar/MnFe_(2)O_(4) interface-driven catalyst for efficient degradation of tetracycline

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第3期9卷 481-494页

作者： Long cheng Yuanhui ji jiangsu Province Hi-Tech Key Laboratory for Biomedical Research School of Chemistry and Chemical EngineeringSoutheast UniversityNanjing211189China

A novel photo-catalytic system composed of N-doped biochars(NBCs),MnFe_(2)O_(4) and sulfite activation under ultraviolet(NBCs/MnFe_(2)O_(4)/sulfite/UV)was constructed to realize the efficient eliminate of tetracycline(TC).As the carrier of MnFe_(2)O_(4),NBCs were synthesized from alfalfa,which has large specific surface area,graphite like structure and hierarchical porous *** adsorption isotherm indicated that NBCs/MnFe_(2)O_(4)-2:1 had the best adsorption performance for TC(347.56 mg g^(-1)).Through synergistic adsorption and photocatalysis,the removal rate of TC reached 84%,which was significantly higher than that of MnFe_(2)O_(4).Electrochemical impedance spectroscopy(EIS)and Photoluminescence(PL)characterization results showed that the introduction of NBCs improved the separation efficiency of photogenerated electron and hole pairs and enhanced the photocatalytic ***,the adsorption,degradation mechanism and degradation path of TC by the catalyst were systematically analyzed by coupling HPLC–MS measurement with the theoretical *** the advantages of excellent degradation performance,low cost,easy separation and environmental friendliness of NBCs/MnFe_(2)O_(4),this work was expected to provide a new path for the practical application of biochar.

关键词： Biochar MnFe_(2)O_(4) Sulfite Adsorption Photocatalysis

Research progress toward the influence of mosquito salivary proteins on the transmission of mosquito-borne viruses

在线全文

学校读者我要写书评

暂无评论

Insect Science 2024年第3期31卷 663-673页

作者： Zhao-yang Wang Kai-Xiao Nie ji-Chen Niu Gong cheng Tsinghua University-Peking University Joint Center for Life Sciences School of MedicineTsinghua UniversityBejingChina Institute of Infectious Diseases Shenzhen Bay LaboratoryShenzhenGuangdongChina Department of Pathogen Biology School of Basic MedicineShandong First Medical University&Shandong Academy of Medical SciencesJinanChina

Mosquito-borne viruses(MBVs)are a large class of viruses transmitted mainly through mosquito bites,including dengue virus,Zika virus,Japanese encephalitis virus,West Nile virus,and chikungunya virus,which pose a major threat to the health of people around the *** global warming and extended human activities,the incidence of many MBVs has increased *** saliva contains a variety of bioactive protein *** not only enable blood feeding but also play a crucial role in regulating local infection at the bite site and the remote dissemination of MBVs as well as in remodeling the innate and adaptive immune responses of host ***,we review the physiological functions of mosquito salivary proteins(MSPs)in detail,the influence and the underlying mechanism of MSPs on the transmission of MBVs,and the current progress and issues that urgently need to be addressed in the research and development of MSP-based MBV transmission blocking vaccines.

关键词： immune response mosquito-borne virus mosquito salivary protein saliva vaccine transmission

Effect of nano-graphite on mechanical properties and oxidation resistance of ZrB_(2)-SiC-graphite electrode ceramics

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 Iron and Steel Research International 2024年第6期31卷 1502-1513页

作者： Bo-lin yang Chang-liu Kuang Zheng-long Liu Chao Yu cheng-ji Deng Jun Ding The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina

ZrB_(2)-based ceramic composites were prepared by spark plasma sintering using ZrB_(2) powder prepared by molten salt method as raw material and SiC and nano-graphite as *** effects of nano-graphite addition on the physical properties and oxidation resistance of ZrB_(2)-based ceramic samples were *** results show that the addition of an appropriate amount of nano-graphite can effectively improve the density of ZrB_(2)-based ceramic composites and improve the physical properties of the *** flexural strength of the ceramic sample with 8 vol.%nano-graphite reached 418.54 MPa,which was 53.14% higher than that of ZrB_(2)-SiC ceramic material(273.31 MPa),and its oxidation resistance was also significantly *** demonstrats that the addition of an appropriate amount of nano-graphite can effectively improve the physical properties and oxidation resistance of ZrB_(2)-SiC ceramic *** prolonging its service life in application and promoting the development of ZrB_(2)-based ceramic composites,it is of great significance for clean steel smelting.

关键词： ZrB_(2)-SiC-graphite electrode ceramic ZrB_(2)-based ceramic composite Nano-graphite Physical property Oxidation resistance

Compound Product of Hypermatrices

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 Systems Science & Complexity 2024年第1期37卷 169-183页

作者： cheng Daizhan MENG Min ZHANG Xiao ji Zhengping Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China Department of Control Science and Engineering School of Electronics and Information EngineeringTongji UniversityShanghai 201210China National Center for Mathematics and Interdisciplinary Sciences Chinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100149China.

The semi-tensor product(STP)of matrices is generalized to multidimensional arrays,called the compound product of *** product is first defined for three-dimensional hypermatrices with compatible orders and then extended to general *** different types of hyperdeterminants are introduced and certain properties are *** Lie groups and Lie algebras corresponding to the hypermatrix products are ***,these results are applied to dynamical systems.

关键词： Compound semi-tensor product hyperdeterminants hypereigenvalues and hypereigenvectors hypergeneral linear groups hypermatrices.

Effect of micro-Al_(2)O_(3) powders on oxidation and corrosion behaviors of low-carbon MgO-C refractories

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第6期31卷 1522-1534页

作者： yang Chen Zeng-yi Li Hao-bo Tan Yu-ran Fu Jun Ding cheng-ji Deng Chao Yu School of Materials Science and Engineering Hunan Institute of TechnologyHengyang 421002HunanChina The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina

To solve the problem of poor high-temperature service performance caused by low carbonization of MgO-C refractories,low-carbon MgO–C refractories with excellent thermal shock,oxidation and corrosion resistances were successfully designed by using SiC whiskers as reinforcing phases and introducing micro-Al_(2)O_(3) powders as *** results indicated that the addition of micro-Al_(2)O_(3) powders optimized the internal structure of the material,like the columnar β-Si_(3)N_(4) with a stepped distribution and the mosaic structure formed between granular and flaky Mg_(2)SiO_(4),which synergistically strengthened and toughened the material and gave the material excellent mechanical properties and thermal shock ***,the cold modulus of rupture and cold crushing strength after thermal shock were increased by 4.1 and 20.3 MPa,***,the addition of micro-Al_(2)O_(3) powders promoted the formation of fine particles of Mg_(2)SiO_(4),MgAl_(2)O_(4) and MgO,as well as a dense protective layer of Mg_(2)SiO_(4) in the material under high-temperature ***,spinel and high-temperature solid solution were formed in the corrosion *** oxidation and corrosion resistances were greatly improved by 41%and 15%,respectively.

关键词： Low-carbon MgO-C refractory Oxidation resistance Corrosion resistance Thermal shock resistance Micro-Al_(2)O_(3)powder

A Human t-PA Mutant cDNA Cassette Knocked in the Murine fgfr-4 Locus Targeting for Mammary Gland Expression

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2004年第7期36卷 450-456页

作者： Fu-Yu LIN#, Hong-Xing CHEN#, Xuan cheng, Xiao yang*, ji-Xian DENG*, and Pei-Tang HUANG*Beijing Institute of Biotechnology, No.20 Dongdajie Street, Fengtai District, Beijing 100071, China Beijing Institute of Biotechnology No.20 Dongdajie StreetFengtai District Beijing 100071 China

The expression of foreign gene in transgenic animals produced by pronuclear microinjection is often confounded by the position effects caused by not only the nature of chromosomal integration site but also the number and arrangement of multiple transgene copies. Gene targeting provides a new way to overcome these inhibitions by introducing single-copy transgene into a chosen site. The choice of a good chromosomal site will favor transgene expression in a predictable fashion. In this study, we tested a new site (fgfr-4) for foreign gene integration and expression. A t-PA mutant (t-PAm) expression cassette under bovine αs1-casein regulatory sequences was efficiently knocked-in fgfr-4 site through homologous recombination. The t-PAm was expressed in the milk of all targeted mice. Our experiment indicates that the fgfr-4 may be a candidate site for knocking foreign gene to make transgenic animals.

关键词： gene targeting fgfr-4 transgenic mammary gland bioreactor integration site t-PA mutant

Theoretical insights into thermal transport and structural stability mechanisms of triaxial compressed methane hydrate

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

CHINESE PHYSICS B 2024年第9期33卷 494-504页

作者： Chen, Dong-Sheng Miao, Tian-Ting Chang, cheng Guo, Xu-yang Guan, Meng-yang ji, Zhong-Li China Univ Petr Coll Mech & Transportat Engn Beijing Key Lab Proc Fluid Filtrat & Separat Beijing 102249 Peoples R China China Univ Petr State Key Lab Petr Resources & Prospecting Beijing 102249 Peoples R China

The heat transfer and stability of methane hydrate in reservoirs have a direct impact on the drilling and production efficiency of hydrate resources, especially in complex stress environments caused by formation subsidence. In this study, we investigated the thermal transport and structural stability of methane hydrate under triaxial compression using molecular dynamics simulations. The results suggest that the thermal conductivity of methane hydrate increases with increasing compression strain. Two phonon transport mechanisms were identified as factors enhancing thermal conductivity. At low compressive strains, a low-frequency phonon transport channel was established due to the overlap of phonon vibration peaks between methane and water molecules. At high compressive strains, the filling of larger phonon bandgaps facilitated the opening of more phonon transport channels. Additionally, we found that a strain of -0.04 is a watershed point, where methane hydrate transitions from stable to unstable. Furthermore, a strain of -0.06 marks the threshold at which the diffusion capacities of methane and water molecules are at their peaks. At a higher strain of -0.08, the increased volume compression reduces the available space, limiting the diffusion ability of water and methane molecules within the hydrate. The synergistic effect of the strong diffusion ability and high probability of collision between atoms increases the thermal conductivity of hydrates during the unstable period compared to the stable period. Our findings offer valuable theoretical insights into the thermal conductivity and stability of methane hydrates in reservoir stress environments.

关键词： methane hydrate molecular dynamics thermal transport triaxial compression structural stability 65.40.-b 64.60.-i 91.50.Hc 31.15.xv MOLECULAR-DYNAMICS

Volume-averaged modeling of multiphase solidification with equiaxed crystal sedimentation in a steel ingot

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Foundry 2024年第3期21卷 229-238页

作者： Xiao-lei Zhu Shuang Cao Rui Guan ji yang Zhe Ning Xin-gang Ai Sheng-li Li Xin-cheng Miao The key Laboratory of Material Forming and Structure Property Control Anshan 114051LiaoningChina State Key Laboratory of Metal Material for Marine Equipment and Application Anshan 114009LiaoningChina School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051LiaoningChina

Macrosegregation is a critical factor that limits the mechanical properties of *** impact of equiaxed crystal sedimentation on macrosegregation has been extensively studied,as it plays a significant role in determining the distribution of alloying elements and impurities within a *** improve macrosegregation in steel connecting shafts,a multiphase solidification model that couples melt flow,heat transfer,microstructure evolution,and solute transport was established based on the volume-averaged Eulerian-Eulerian *** this model,the effects of liquid phase,equiaxed crystals,columnar dendrites,and columnar-to-equiaxed transition(CET)during solidification and evolution of microstructure can be considered *** sedimentation of equiaxed crystals contributes to negative macrosegregation,where regions between columnar dendrites and equiaxed crystals undergo significant A-type positive macrosegregation due to the ***,noticeable positive macrosegregation occurs in the area of final solidification in the *** improvement in macrosegregation is beneficial for enhancing the mechanical properties of connecting *** mitigate the thermal convection of molten steel resulting from excessive superheating,reducing the superheating during casting without employing external fields or altering the design of the ingot mold is indeed an effective approach to control macrosegregation.

关键词： ingot casting multiphase solidification model equiaxed crystal sedimentation microstructure macrosegregation