检索结果-南通市图书馆

Turbulent mechanisms in open channel sediment-laden flows

在线全文

学校读者我要写书评

暂无评论

International journal of Sediment Research 2019年第6期34卷 550-563页

作者： Hai Huang Hongwu zhang Deyu Zhong Yinglong j.zhang State Key Laboratory of Hydroscience and Engineering Tsinghua Univ. State Key Laboratory of Plateau Ecology and Agriculture Qinghai University Virginia Institute of Marine Science College of William & MaryCenter for Coastal Resource Management

The effects of turbulence on water-sediment mixtures is a critical issue in studying sediment-laden *** sediment concentrations and particle inertia play a significant role in the effects of turbulence on mixtures.A two-phase mixture turbulence model was applied to investigate the turbulence mechanisms affecting sediment-laden *** two-phase mixture turbulence model takes into account the complicated mechanisms arising from interphase transfer of turbulent kinetic energy,particle collisions,and *** turbulence in sediment-laden flows is the result of the interaction of four factors,*** production,dissipation,diffusion,and inter-phase transfer of turbulent kinetic energy of *** turbulence production and dissipation are two dominant processes which balance the turbulent kinetic energy of *** turbulence production represents turbulence intensity,while the inter-phase transfer of turbulent kinetic energy denotes the effect of particles on the turbulence of sediment-laden ***,the magnitude of the inter-phase interaction term is much less than that of the turbulence production and dissipation terms,due to an approximate local balance between production and dissipation of the turbulent kinetic energy,even the small order of the inter-phase interaction has a significant impact on the turbulent balance of sediment-laden *** presence of particles plays a duel role in the turbulence dissipation of mixtures:both promotion and *** important parameter used to determine the turbulent viscosity of mixtures,which is constant in clear water,is the function of the sediment concentration and particle inertia in sediment-laden flows.

关键词： Turbulence modulation Two-phase mixture turbulence model Suspended sediment Open channels

Square wave volt-coulometry

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 Science Bulletin 1997年第5期42卷 390-396页

作者： Mo, jY zhang, j Mo, SY Department of Chemistry Zhongshan Univenity Guangzhou China Department of Chemistry Hong Kong University Hong Kong

FOR a long time, people pay particular attention to the way to decrease the charging current and improve the Faraday current in the modern square wave voltammetry (SWV), but the effects of random noise on analytical result are ignored. However, it is impossible to avoid the random noise absolutely in the measuring process. Especially, when the concentration is low, the signal is affected seriously by the random noise and it is difficult to get a lower detection limit. So it is necessary to know how to decrease the random noise in order to get a lower detection limit, while trying to find out how to decrease the charging current. A new sampling technique using the square wave potential scan is proposed to smooth the random noise and decrease the detection limit in SWV. The foundation of this new method comes from one of the laws of mathematical statistics; that is, the positive and negative probable errors in a group of detected data exist equally and then the sum of all the errors is ze-

关键词： square wave voltammetry square wave volt-coulometry simple reverse system catalytic system.

Synthesis of ribonucleoside analogues containing thio-substituted 1,3,4-triazole as heterocyclic base

在线全文

学校读者我要写书评

暂无评论

Chinese journal of Chemistry 1997年第4期15卷 379-384页

作者： Ding, Y zhang, j Chen, YQ ost.queensu.ca

New ribonucleoside analogues containing thio-substituted 1,3,4-triazole as heterocyclic base have been synthesized via condensation of the central intermediate 1 with various acids, esters, amides, and anhydrides in a... 详细信息

关键词： ribonucleoside analogues thio-substituted 1,3,4-triazoles heterocyclic base

NUMERICAL MODELING OF DONGZHUANG RESERVOIR ON jING RIVER

在线全文

学校读者我要写书评

暂无评论

journal of Hydrodynamics 2001年第2期13卷 68-71页

作者： Yang, M. zhang, H.Y. zhang, j.H. zhang, H.W. Dept. 5 Beijing Univ. of Aero. and Astron. Beijing 100084 China

The Dongzhuang Reservoir will be constructed on the jing River, which is laden with the highest sediment concentration in the world. The sediment problem is a key challenge for the reservoir design and management. This paper presents essential data, details of sediment scour and siltation calculated by the numerical modeling based on new fundamental equations. Calculated results prove that the reservoir could preserve long-term storage capacity with the operation was offered by the design department.

关键词： Flow of fluids Mathematical models Sediments Storage (materials)

Microbiome and intestinal pathophysiology in post-acute sequelae of COVID-19

在线全文

学校读者我要写书评

暂无评论

Genes & Diseases 2024年第3期11卷 220-231页

作者： jilei zhang Yongguo zhang Yinglin Xia jun Sun Division of Gastroenterology and Hepatology Department of MedicineUniversity of Ilinois ChicagoIL60612USA Uic Cancer Center Department of Microbiology and ImmunologyUniversity of Ilinois ChicagoChicagoIL60612USA jesse Brown VA Medical Center ChicagoIL60612USA

Long CoVID,also known for post-acute sequelae of CovID-19,describes the people who have the signs and symptoms that continue or develop after the acute coviD-19 *** CovID patients suffer from an inflammation or host responses towards the virus approx-imately 4 weeks after initial infection with the SARS CoV-2 virus and continue for an unchar-acterized *** infected with CovID-19 before could experience long-CcovID conditions,including the patients who were infected with SARS CoV-2 virus confirmed by tests and those who never knew they had an infection *** with long CoviD may experience health problems from different types and combinations of symptoms over time,such as fa-tigue,dyspnea,cognitive impairments,and gastrointestinal(Gl)symptoms(e.g.,nausea,vom-iting,diarrhea,decreased or loss of appetite,abdominal pain,and dysgeusia).The critical role of the microbiome in these Gl symptoms and long CovID were reported in clinical patients and experimental ***,we provide an overall view of the critical role of the Gl tract and microbiome in the development of long COVID,including the clinical Gl symptoms in patients,dysbiosis,viral-microbiome interactions,barrier function,and inflammatory bowel disease patients with long *** highlight the potential mechanisms and possible treatment based on Gl health and ***,we discuss challenges and future direction in the long CoVID clinic and research.

关键词： Gastrointestinal symptoms Gl tract Gut microbiome Inflammatorybowel diseases Intestinal barrier Long CoVID Metabolites Tight junctions

State of the art of friction modelling at interfaces subjected to elastohydrodynamic lubrication(EHL)

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

Friction 2021年第2期9卷 207-227页

作者： Zhuming BI Donald W.MUELLER Chris W.j.zhang Civil and Mechanical Engineering Purdue University Fort WayneIN 46805USA Department of Mechanical Engineering University of SaskatchewanSaskatoon SK S7N 5A9Canada

Elastohydrodynamic lubrication(EHL)is a type of fluid-film lubrication where hydrodynamic behaviors at contact surfaces are affected by both elastic deformation of surfaces and lubricant *** of contact interfaces under EHL is challenging due to high nonlinearity,complexity,and the multi-disciplinary *** paper aims to understand the state of the art of computational modelling of EHL by(1)examining the literature on modeling of contact surfaces under boundary and mixed lubricated conditions,(2)emphasizing the methods on the friction prediction occurring to contact surfaces,and(3)exploring the feasibility of using commercially available software tools(especially,Simulia/Abaqus)to predict the friction and wear at contact surfaces of objects with relative reciprocating motions.

关键词： elastohydrodynamic lubrication(EHL) lubricant rheology finite element analysis(FEA) friction prediction Simulia/Abaqus surface roughness coefficient of friction(CoF)

Low-Cycle Fatigue Properties of Nickel-Based Superalloys Processed by High-Gradient Directional Solidification

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2017年第9期30卷 878-886页

作者： Z.D.Fan D.Wang C.Liu G.zhang j.Shen L.H.Lou j.zhang Superalloys Division Institute of Metal ResearchChineseAcademy of SciencesShenyang 110016China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Xi'an Thermal Power Research Institute Co. Ltd.Xi'an 710054China

The low-cycle fatigue （LCF） properties of DD10 （single-crystal） and DZ53 （columnar-grained） superalloys solidified by liquid-metal cooling （LMC） and high-rate solidification （HRS） processes have been systematically investi- gated. It was found that the LCF life of DZ53 solidified by LMC was obviously better than that solidified by HRS. In contrast, for DD10, LMC showed no remarkable influences on LCF properties at high temperature and only improved LCF properties at intermediate temperature. Microstructure examination showed that the cracks generally initiated at microp- ores in the subsurface at intermediate temperature. However, the cracks occurred on the surface due to oxidation, or persistent slip bands near script-MC at high temperature. Therefore, the benefits of LMC technique can be attributed to both of the reduced casting defects which significantly affect the LCF properties at intermediate temperature and the improved microstructural homogeneity which was strongly correlated to the LCF properties of alloys at high temperature.

关键词： Superalloys Rapid solidification Low-cycle fatigue Microstructure

THE EFFECTS OF NEGATIVE BIAS AND FLUX RATIO ON THE PROPERTIES OF TiN THIN FILMS FORMED BY FILTERED CATHODIC ARC PLASMA TECHNIQUE

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 369-374页

作者： Y.j.zhang P.X.Yan Z.G.Wu W.W.zhang j.Wang Q.j.Xue DeparunentofPhysics LanzhouUniversitryLanzhou730000China DeparunentofPhysics LanzhouUniversitryLanzhou730000China／／StateKeyLaboratoryofSolidLubricationInstituteofChemicalPhysicsTheChineseAcademyofSciencesLanzhou730000China StateKeyLaboratoryofSolidLubrication InstituteofChemicalPhysicsTheChineseAcademyofSciencesLanzhou730000China

The filtered cathodic vacuum-arc (FCVA) technique is a supplementary and alterna tive technique with respect to convendtional physical and chemical vapour deposi tion which can remove macro-particles effectively and make the deposition proces s at ambient temperature. In this work, high quality TiN thin films were deposi ted on silicon substrates at low temperature using the improved filtered cathodi c arc plasma (FCAP) technique. AFM, XRD, TEM were employed to characterize the T iN thin films. The effects of the negative substrate bias on the grain size, pre ferred crystalline orientation, surface roughness of TiN thin films were discuss ed.

关键词： TiN filtered cathodic arc plasma preferred orientation

Metal–Organic Framework‑Based Photodetectors

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第11期16卷 675-703页

作者： jin‑Biao zhang Yi‑Bo Tian Zhi‑Gang Gu jian zhang State Key Laboratory of Structural Chemistry Structure of MatterFujian Institute of ResearchChinese Academy of SciencesFuzhouFujian 350002People’s Republic of China College of Chemistry and Materials Science Fujian Nornal UniversityFuzhou 350007FujianPeople’s Republic of China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108FujianPeople’s Republic of China University of Chinese Academy of Science Beijing 100049People’s Republic of China

The unique and interesting physical and chemical properties of metal–organic framework(MOF)materials have recently attracted extensive attention in a new generation of photoelectric *** this review,we summarized and discussed the research progress on MOF-based *** methods of preparing MOF-based photodetectors and various types of MOF single crystals and thin film as well as MOF composites are introduced in ***,the photodetectors applications for X-ray,ultraviolet and infrared light,biological detectors,and circularly polarized light photodetectors are ***,summaries and challenges are provided for this important research field.

关键词： Metal-organic frameworks Semiconductor Photodetectors