检索结果-南通市图书馆

维普期刊数据库

Many-body Interatomic Potentials for Computer Simulation of Physical Processes in Metals and Alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 1998年第5期14卷 429-433页

作者： Kuznetsov, V.M. rudenskii, g.e. Kadyrov, R.I. Kaminskii, P. Institute of Strength Physics and Material Science Russian Academy of Sciences Siberian Branch Academicheskii av. 2/1 634048 Tomsk Russian Federation

A model of binding forces in metals and alloys, based on the density functional theory and accounted effects of the many-body interactions, was proposed. The developed method can be easily applied for study of metals and alloys by the molecular dynamics simulation. The potentials of interatomic interactions have been found by the proposed method and applied for calculations of equation of state, elastic moduli and phonon dispersion in metals Ni, Al, and alloys NiAl, Ni//3Al. Results of the calculations are in good ag.e.ment with known experimental data both for pure metals and alloys. (edited author abstract) 16 Refs.

关键词： Nickel

维普期刊数据库

Malarg.e.Site Remediation: A Successful Solution for Uranium Mill Tailings

在线全文

学校读者我要写书评

暂无评论

原子能科学技术 2024年

作者： BARARI e DíAZ J g gIOMIA KeMPF R A National Atomic energy Commission Av.Del Libertador 8250 Ciudad Autónoma de Buenos AiresC1429BNP Argentina

Comisión Nacional de energía Atómica(CNeA) has the responsibility for restoring uranium mining facilities once the operations have finished. CNeA, within its environmental Program and in compliance with its legal responsibilities, decides to implement a restoration project for all sites related to the mining and processing of uranium ores. The Malarg.e.Site is located within the Province of Mendoza in the city of Malarg.e. It is the first site to successfully complete its remediation. The activities consist of relocation of tailings to an engineering repository. The tailings management(encapsulation) and rehabilitation of the area was finished in June 2017. The remediation alternative for the ore tailings was selected after conducting comparative studies and submitted the project to the society for consideration. The objective of the encapsulation of the mineral tails is to isolate them from the environment, also proceeding with the decontamination and rehabilitation of the area(landscaping,post-closure monitoring and 20 years monitoring period). encapsulation consisted of the construction of a containment cell for the mine tailings, to isolate them and prevent pollutants from entering the environment through the transfer routes. To clean the impacted areas, the soil was removed, it was incorporated into the encapsulation, and the filling was carried out with natural soils from the *** prevents radon transfer to the environment, as 222Ra is an alpha emitter with a half-life of four days, which produces its own radioactive progeny. Radon progeny are solids, and when a 222Ra nucleus emits an alpha particle into the air, the resulting 218Po nucleus, momentarily electrically charged, adheres to any dust particle. Remediation prevents the discharge into the air containing radon and also containing dust particles charged with intensely radioactive radon progeny. The tasks mentioned make it possible to decrease radon emanation, reduce radiological risks to the

关键词：

Pressurized environments directly influence friction and wear of dry steel contacts—Investigations in a novel high fluid pressure tribometer

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Friction 2024年第7期12卷 1599-1617页

作者： Paul ReICHLe Jakob BARZ georg UMLAUF günter e.M.TOVAR Institute of Interfacial Process engineering and Plasma Technology(IgVP) University of StuttgartStuttgart 70569Germany Fraunhofer Institute for Interfacial engineering and Biotechnology(IgB) Stuttgart 70569Germany

To reduce the usage of classical lubricants in deep drawing,a new tribological system based on volatile lubricants was ***,a volatile medium is injected under high pressure into the interstice between drawing tool and sheet *** on temperature and pressure,the temporary lubricant may exist in its gaseous or liquid *** this study,a novel high fluid pressure tribometer was desig.e. to investigate the friction and wear of dry steel contacts under comparable conditions like in dry deep ***,a new ball-on-disc tribometer was desig.e. and integrated into a high-pressure *** specifically investigate the effects of different environments(technical air,liquid and gaseous carbon dioxide,nitrogen,argon)at atmospheric and high pressure(0.1 MPa,6 MPa)on tribology,the specimens and all components were operating *** the experiments,the friction was measured *** show that the hig.e.t friction occurs in air and the lowest in carbon dioxide *** to the experiments,the wear of the specimens was assessed along with changes in surface chemistry related to tribochemical ***,the tribology of the dry sliding contacts is correlated to changes of the surface *** differences as well as similarities regarding the different fluid environments are *** the results show,the differences between the media used are most pronounced at elevated ***,this work gives clear indications on the suitability of volatile lubricants in dry friction or rather gas lubrication,especially for dry deep drawing.

关键词： dry friction and dry wear gas lubrication carbon dioxide tribo-layer dry metal forming

Management of early oesophageal cancer:An overview

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of gastrointestinal Surgery 2024年第5期16卷 1255-1258页

作者： gavin g Calpin Matthew g Davey Noel e Donlon Department of Surgery Royal College of Surgeons in IrelandDublin D2Ireland Department of Upper gastrointestinal Surgery Beaumont HospitalDublin D09V2N0Ireland

The incidence of esophageal cancer,namely the adenocarcinoma subtype,continues to increase exponentially on an annual *** indolent nature of the disease renders a significant proportion inoperable at first presentation,however,with the increased utilisation of endoscopy,many early lesions are now being identified which are suitable for endotherapeutic *** article details the options available for dealing with early esophageal cancer by endoscopic mean obviating the need for surgery thereby avoiding the potential morbidity and mortality of such intervention.

关键词： esophageal cancer endotherapy endoscopic submucosal resection endoscopic mucosal resection endoscopy

Collective coherent emission of electrons in strong laser fields and perspective for hard x-ray lasers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Matter and Radiation at extremes 2024年第2期9卷 1-3页

作者： e.g.gelfer A.M.Fedotov O.Klimo S.Weber extreme Light Infrastructure eRIC ELI Beamlines Facility25241 Dolní BřežanyCzech Republic HiLASe Centre Institute of Physics of the Czech Academy of Sciences25241 Dolní BřežanyCzech Republic National Research Nuclear University MePhI Moscow 115409Russia FNSPe Czech Technical University in Prague11519 PragueCzech Republic

Coherent motion of particles in a plasma can imprint itself on *** recent advent of high-power lasers—allowing the nonlinear inverse Compton-scattering regime to be reached—has opened the possibility of looking at collective effects in laser–plasma *** certain conditions,the collective interaction of many electrons with a laser pulse can generate coherent radiation in the hard x-ray *** perspective paper explains the limitations under which such a regime might be attained.

关键词： laser scattering coherent

Investigation of the transformation of organic matter of carbonate deposits of the Semiluksky-Mendymsky horizon under hydrothermal conditions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum 2024年第2期10卷 216-223页

作者： S.M.Petrov A.I.Lakhova e.g.Moiseeva A.g.Safiulina Institute of Petroleum Chemistry and Nanotechnologies Kazan National Research Technological University Institute of geology and Oil and gas Technolog.e. Kazan Federal University

The paper presents the results of studies on the transformation of the organic matter of siliceous-clayey carbonate rocks of the Semiluksko-Mendymsky horizon of the Romashkino oil field in a hydrothermal fluid for an hour（with a water-to-rock ratio of 33） at 340℃ and 380℃ and pressu res of 17 and 20 *** a result of hydrothermal treatment,at 340℃ and 17 MPa,based on nitrogen porosimetry and electron microscopy data,transformations of rock-forming minerals in the rock are *** lead to an increase in the volume and average diameter of mesopores in it and the formation of micropores,as well,which improve its filtration *** the same time,the amount of kerogen in the composition of the organic matter decreases and the yield of the petroleum hydrocarbon extract increases,in which,according to the SARA analysis,the content of asphaltenes increases and the content of resins,aromatic and saturated hydrocarbons *** the composition of aroatic hydrocarbons,the proportion of a lkyltri methyl benzenes and dibenzothiophenes increases,phenanthrene homolog.e. appear,and in the composition of saturated hydrocarbons,the amount of iso-structure alkanes decreases relative to the content of linear *** the temperature and pressure of the hydrothermal fluid to 380℃ and 20 MPa increases the deg.e. of kerogen conversion from 12.4% to 23.6%.At the same time,changes occurring in the component composition of petroleum hydrocarbon extracts remains similar to the experiments carried out at 340℃ and 17 MPa;the content of naphthalenes decreases,the content of dibenzothiophenes increases and C11-C17,C19-C22alkyltrimethylbenzenes *** to IR spectroscopy,with increasing temperature and pressure of the hydrothermal fluid the intensity of the absorption bands of the aromatic ring,aliphatic frag.e.ts,and oxygen-containing groups increases in resins;the structural-group composition of asphaltenes changes little:aromaticity and the content of condensed

关键词： Carbonate deposits Organic matter Hydrothermal fluid Mobile hydrocarbons

Combination treatment of inflammatory bowel disease:Present status and future perspectives

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of gastroenterology 2024年第15期30卷 2068-2080页

作者： John K Triantafillidis Constantinos g Zografos Manousos M Konstadoulakis Apostolos e Papalois Inflammatory Bowel Disease Unit "Metropolitan General"HospitalHolargos 15562AtticaGreece Hellenic Society for gastrointestinal Oncology 354 Iera OdosChaidari 12461AtticaGreece The 2^(nd)Department of Surgery University of AthensSchool of MedicineAretaieion HospitalAthens 11528Greece Unit of Surgical Research and Training The 2^(nd)Department of SurgeryUniversity of AthensSchool of MedicineAretaieion HospitalAthens 11528Greece

The treatment of patients with inflammatory bowel disease(IBD),especially those with severe or refractory disease,represents an important challenge for the clinical *** seems to be no exag.e.ation to say that in these patients,not only the scientific background of the gastroenterologist is tested,but also the abundance of“gifts”that he should possess(insight,intuition,determ-ination,ability to take initiative,etc.)for the successful outcome of the *** daily clinical practice,depending on the severity of the attack,IBD is treated with one or a combination of two or more pharmaceutical *** combin-ations include not only the first-line drugs(e.g.,mesalazine,corticosteroids,antibiotics,etc)but also second-and third-line drugs(immunosuppressants and biologic agents).It is a fact that despite the significant therapeutic advances there is still a significant percentage of patients who do not satisfactorily respond to the treatment ***,a part of these patients are going to *** recent years,several small-size clinical studies,reviews,and case reports have been published combining not only biological agents with other drugs(e.g.,immunosuppressants or corticosteroids)but also the combination of two biologi-cal agents simultaneously,especially in severe *** our opinion,it is at least a strange(and largely unexplained)fact that we often use combinations of drugs in a given patient although studies comparing the simultaneous administration of two or more drugs with monotherapy are very *** mentioned above,there is a timid tendency in the literature to combine two biological agents in severe cases unresponsive to the applied treatment or patients with severe extraintestinal *** appropriate dosage,the duration of the administration,the suitable timing for checking the clinical and laboratory outcome,as well as the treatment side-effects,should be the subject of intense clinical research *** this

关键词： Biologics for immune-mediated conditions Dual-targeted treatment Combination treatment Inflammatory bowel disease Crohn’s

Unimolecular Reactions of e-glycolaldehyde Oxide and Its Reactions with One and Two Water Molecules

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research 2024年第1期2023卷 809-824页

作者： Yan Sun Bo Long Donald g.Truhlar Department of Physics Guizhou UniversityGuiyang 550025China College of Materials Science and engineering Guizhou Minzu UniversityGuiyang 550025China Department of Chemistry Chemical Theory Centerand Supercomputing InstituteUniversity of MinnesotaMinneapolisMN 55455-0431USA

The kinetics of Crieg.e.intermediates are important for atmospheric ***,the quantitative kinetics of Crieg.e.intermediates are still very limited,especially for those with hydroxy ***,we calculate rate constants for the unimolecular reaction of e-glycolaldehyde oxide[e-hydroxyethanal oxide,e-(CH_(2)OH)CHOO],for its reactions with H_(2)O and(H_(2)O)_(2),and for the reaction of the e-(CH_(2)OH)CHOO…H_(2)O complex with H_(2)*** the hig.e.t level of electronic structure,we use W3X-L//CCSD(T)-F12a/cc-pVDZ-F12 for the unimolecular reaction and the reaction with water and W3X-L//DF-CCSD(T)-F12b/jun-cc-pVDZ for the reaction with 2 water *** the dynamics,we use a dual-level strategy that combines conventional transition state theory with the hig.e.t level of electronic structure and multistructural canonical variational transition state theory with small-curvature tunneling with a validated density functional for the electronic structure.

关键词： structure kinetics molecular

Identific tion of quantitative trait loci and associated candidate genes for pregnancy success in Angus–Brahman crossbred heifers

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 Animal Science and Biotechnology 2024年第1期15卷 162-170页

作者： Quinn A.Hoorn gabriel A.Zayas eduardo e.Rodrig.e. Laura M.Jensen Raluca g.Mateescu Peter J.Hansen Department of Animal Sciences Donald Henry Barron Reproductive and Perinatal Biology Research Programand the Genetics InstituteUniversity of FloridaGainesvilleFLUSA School of Applied Systems Biology La Trobe UniversityBundooraVIC 3083Australia

Background In beef cattle, more than 50% of the energy input to produce a unit of beef is consumed by the female that produced the calf. Development of genomic tools to identify females with high genetic merit for reproductive function could increase the profitability and sustainability of beef *** genome-wide association studies(gWAS) were performed using a sing.e.step genomic best linear unbiased prediction approach on pregnancy outcome traits from a population of Angus–Brahman crossbred heifers. Furthermore, a validation gWAS was performed using data from another farm. Heifers were genotyped with the Bovine ggP F250 array that contains 221,077 SNPs. In the discovery population, heifers were bred in winter breeding seasons involving a sing.e.round of timed artificial insemination(AI) followed by natural mating for 3 months. Two phenotypes were analyzed: pregnancy outcome to first-service AI(PAI;n = 1,481) and pregnancy status at the end of the breeding season(PeBS;n = 1,725). The heritability was estimated as 0.149 and 0.122 for PAI and PeBS, respectively. In the PAI model, one quantitative trait locus(QTL), located between 52.3 and 52.5 Mb on BTA7, explained about 3% of the genetic variation, in a region containing a cluster of γ-protocadherin genes and SLC25A2. Other QTLs explaining between 0.5% and 1% of the genetic variation were found on BTA12 and 25. In the PeBS model, a large QTL on BTA7 was synonymous with the QTL for PAI, with minor QTLs located on BTA5, 9, 10, 11, 19, and 20. The validation population for pregnancy status at the end of the breeding season were Angus–Brahman crossbred heifers bred by natural mating. In concordance with the discovery population, the large QTL on BTA7 and QTLs on BTA10 and 12 were *** In summary, QTLs and candidate SNPs identified were associated with pregnancy outcomes in beef heifers, including a large QTL associated with a group of protocadherin genes. Confirmation of these associations

关键词： Beef cattle Fertility gWAS QTL

维普期刊数据库