检索结果-南通市图书馆

Acta Meta.l.rgica Sinica(English letters) 2005年第5期18卷 620-626页

作者： a.l. fan W.H. Tian Q. Suns B.S. Wang Department of Materials Physics and Chemistry University of Science and Technology Beijing Beijing 100083 China Taiyuan University of Science and Technology Taiyuan 030024 China 210 Institute The Chinese Ordnance Industry Institute Beijing 100081 China

The microstructures of electroformed copper liners of shaped charges that had undergone high-strain-rate deformation were observed by optical microscopy （OM） and scanning electron microscopy （SEM）. Meanwhile, the orientation distribution of the grains in the recovered jet was examined by electron backscattering Kikuchi pattern （EBSP） technique. EBSP analysis reveals that the fibrous texture observed in the as-electroformed copper liners disappeared after explosive detonation deformation. OM observation shows that the microstructure evolves system- atica.l. from the jet center to its perimeter during cooling from high temperatures after explosive detonation deformation. This microstructural characteristic is similar to that of solidification, i.e. there exist equiaxed grains in the center of the jet and significant columnar grains around the equiaxed grains. The result reveals that there is melting-related phenomenon in the jet center. Corresponding microhardness variations from the jet center to its perimeter is also determined. a.l.the phenomena can be explained by a strong gradient of temperature across the section of the jet during plastic deformation at high-strain-rate.

关键词： jetting electroformation microstructure hardness,ultra-high strain rate deformation

PRECIPITATION BEHAVIOR OF Co PHASES IN B2-ORDERED(Ni,Co)Al COMPOUND

在线全文

学校读者我要写书评

暂无评论

Acta Meta.l.rgica Sinica(English letters) 2002年第3期15卷 253-259页

作者： W.H. Tian, a.l. fan and M. NemotoDepartment of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083, ChinaSasebo National College of Technology, Okishin 1-1, Sasebo 857-1193, Japan Manuscript received 4 July 2001 *** Department of Materials Physics and Chemistry University of Science and Technology Beijing Beijing 100083 China

The precipitation behavior of Co phases in B2-ordered (Ni,Co)Al has been investigated in terms of transmission electron microscopy. Fine precipitation of fcc-Co occurs in (Ni,Co)Al by aging at temperature over 973K. The orientation relationship between the fee-Co precipitates and the B2-(Ni,Co)Al matrix follows the Kurdjumow-Sachs (K-S) orientation relation. But when the aging temperature is under 873K the Co precipitates have a hcp crystal structure. The orientation relationship between the hep-Co precipitates and the B2-(Ni,Co)Al matrix follows the Burgers orientation relation. (Ni,Co)Al is hardened apprecia.l. by the fine precipitation of both the fee-Co and hep-Co phases. The temperature dependence of the yield strength of precipitate-containing BS-ordered (Ni, Co)Al was investigated by compression tests over the range of 298-1273K. The fine precipitation of Co phases enhances grea.l. the low and intermediate temperature yield strength. When the deformation temperature was over 87SK, the strength of precipitate-containing (Ni, Co)Al is compara.l. to ternary dual-phase (Ni,Co)Al+Ni3Al a.l.y.

关键词： nickel aluminides age-hardening mechanical properties precipitates

Spa.l.ng characteristics of high-temperature treated granitic rock at different strain rates

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1280-1288页

作者： l.F.fan Q.H.Yang X.l.Du The Key laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing100124China

The dynamic spa.l.ng characteristics of rock are important for stability analysis in rock *** paper presented an experimental investigation on the dynamic spa.l.ng characteristics of granite with different temperatures and strain rates.A series of dynamic spa.l.ng tests with different impact velocities were conducted on therma.l. treated granite at different *** dynamic spa.l.ng strengths of granite with different temperatures and strain rates were determined.A model was proposed to correlate the dynamic spa.l.ng strength of granite,high temperature and strain *** results show that the spa.l.ng strength of granite decreases with increasing ***,the spa.l.ng strength of granite with a higher strain rate is larger than that with a.l.wer strain *** proposed model can describe the relationship among dynamic spa.l.ng strength of granite,high temperature and strain rate.

关键词： Dynamic spa.l.ng characteristics High temperature Strain rate Dynamic loading Granite

Material flow analysis and global warming potential assessment of an industrial insect-based bioconversion plant using housefly larvae

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

Journal of Environmental Sciences 2024年第5期139卷 483-495页

作者： Tao lu fan lü Na.l.n liao Honghui Chai Hua Zhang Pinjing He Institute of Waste Treatment and Reclamation Tongji UniversityShanghai 200092China State Key laboratory of Pollution Control and Source Reuse Tongji UniversityShanghai 200092China Zhejiang Qihe Ecological Technology Co. Ltd.Hangzhou 310052China

The significant increase in the demand for biomass waste treatment after garbage classification has led to housefly larvae treatment becoming an attractive treatment *** can provide a source of protein while treating biomass waste,which means that nutrients can be returned to the natural food ***,the performance of this technology in terms of its environmental impacts is still unclear,particula.l. with regards to global warming potential(GWP).This study used a.l.fe cycle assessment(lCA)approach to assess a housefly larvae treatment plant with a treatment capacity of 50 tons of biomass waste per *** lCA results showed that the 95% confidence intervals for the GWP in summer and winter were determined to be 24.46-32.81 kg CO_(2) equivalent(CO_(2)-eq)/ton biomass waste and5.37-10.08 kg CO_(2)-eq/ton biomass waste,*** greater GWP value in summer is due to the longer ventilation time and higher ventilation intensity in summer,which consumes more *** main GWP contributions are from(1)electricity needs(accounting for 78.6% of emissions in summer and 70.2%in winter)and(2)product substitution by mature housefly larvae and compost(both summer and winter accounting for 96.8% of carbon reduction).

关键词： Biomass waste Musca domestica Housefly larvae life cycle assessment Global warming potential

MICROSTRUCTURES AND MECHANICAl PROPERTIES OF β-NiA1CONTAINING α-Fe PRECIPITATES

在线全文

学校读者我要写书评

暂无评论

Acta Meta.l.rgica Sinica(English letters) 2000年第5期13卷 1023-1028页

作者： W.H. Tian, a.l. fan and M. Nemoto (Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083, China Sasebo National College of Technology, Okishin 1-1, Sasebo 857-1193, Japan)

The microstructures of B2-ordered NiA1 containing α-Fe precipitates have been investigated in terms of transmission electron microscopy. Fine precipitation of α-Fe (bcc structure) occurs in NiA1 by aging around 973K. The aging behavior was investigated by microhandness measurements and the temperature dependence of the yield strength of precipitate- comaining B2- ordered NiA1 was investigated by compression tests over the temperature range of 673-1273K. The fine precipitation of α-Fe was found to enhance grea.l. the low and intermediate temperature yield strength. When the deformation temperature is over 1073K, the strength of precipitate- containing NiA1 was compara.l. to ternary solid solution hardening NiA1-Fe. Dislocations bypass the particles during deformation and typical Orowan loops were observed surrounding the or-Fe particles after deformation.

关键词： nickel aluminide based on NiA1 age-hardening mechanical property precipitate

Soliton resolution and asymptotic stability of N-solutions for the defocusing Kundu–Eckhaus equation with nonzero boundary conditions

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第1期76卷 1-6页

作者： Engui fan Yanxi Zhang School of Mathematical Sciences and Key laboratory of Mathematics for Nonlinear Science Fudan UniversityShanghai200433China Tianjin Xinhua High School No.99 machang RoadTianjin300204China

In this paper,we address interesting soliton resolution,asymptotic stability of N-soliton solutions and the Painleve asymptotics for the Kundu-Eckhaus(KE)equation with nonzero boundary conditions iq_(t)+q_(xx)-2(l|q|^(2)-1)q+4β^(2)(lql^(4)-1)q+4iβ(lql^(2))_(x)q=0,q(x,0)=q_(0)(x)-±1,x→±∞.The key to proving these results is to esta.l.sh the formulation of a Riemann-Hilbert(RH)problem associated with the above Cauchy problem and find its connection with the RH problem of the defocusing NlS *** the■-steepest descent method and the results of the defocusing NlS equation,we find complete leading order approximation formulas for the defocusing KE equation on the whole(x,t)half-plane including soliton resolution and asymptotic stability of N-soliton solutions in a solitonic region,Zakharov-Shabat asymptotics in a solitonless region and the Painlevéasymptotics in two transition regions.

关键词： defocusing Kundu-Eckhaus equation Riemann-Hilbert problems steepest descent method soliton resolution asymptotic stability Painleve transcendents

Existence of Global Solutions to the Nonlocal mKdV Equation on the line

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2024年第4期45卷 497-528页

作者： Anran lIU Engui fan School of Mathematical Sciences Fudan UniversityShanghai 200433China

In this paper,the authors address the existence of global solutions to the Cauchy problem for the integra.l. nonlocal modified Korteweg-de Vries(nonlocal mKdV for short)equation under the initial data u0∈H^(3)(R)∩H^(1,1)(R)with the l^(1)(R)sma.l.norm assumption.a.l.pschitz l2-bijection map between potential and reflection coefficient is esta.l.shed by using inverse scattering method based on a Riemann-Hilbert problem associated with the Cauchy *** map from initial potential to reflection coefficient is obtained in direct scattering *** inverse scattering transform goes back to the map from scattering coefficient to potential by applying the reconstruction formula and Cauchy integral *** bijective relation natura.l. yields the existence of global solutions in a Sobolev space H^(3)(R)∩H^(1,1)(R)to the Cauchy problem.

关键词： Nonlocal mKdV equation Riemann-Hilbert problem Plemelj projection operator lipschitz continuous Global solutions

Some Simple Groups Which are Determined by Their Orders and Degree-Patterns

在线全文

学校读者我要写书评

暂无评论

Algebra Colloquium 2024年第2期31卷 341-346页

作者： Qinghong Guo Weijun liu Genghua fan School of Mathematics and Statistics HNP-LAMACentral South University Changsha 410083China College of General Education Guangdong University of Science and Technology DongguanGuangdong 523083China 不详

let G be a finite group and Irr(G)the set of a.l.irreducible complex characters of *** cd(G)be the set of a.l.irreducible complex character degrees of G and denote byρ(G)the set of a.l.primes which divide some character degree of *** character-prime graphΓ(G)associated to G is a simple undirected graph whose vertex set isρ(G)and there is an edge between two distinct primes p and q if and only if the product p q divides some character degree of *** show that the finite nonabelian simple groups A_(7),J_(1),J_(3),J_(4),l_(3)(3)and U_(3)(4)are uniquely determined by their degree-patterns and orders.

关键词： irreducible complex character character-prime graph finite nonabelian simple group

Upper-rim-modified thioether thiacalix[4]arene used for liquid-liquid extraction of Au(Ⅲ)and Pd(Ⅱ)in hydrochloric acid medium

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

Chinese Journal of Chemical Engineering 2024年第2期66卷 110-118页

作者： Sheng Wan Rong Xie Jianhong fan Kewen Tang Department of Chemistry and Chemical Engineering Hunan Institute of Science and TechnologyYueyang 414006China

Gold(Au)and pa.l.dium(Pd)play an increasing role in the production and human life;Therefore,it is of great significance to study their recovery.A 5,11,17,23-tetra-ethylthio-25,26,27,28-tetra-hydroxyl thiacalix[4]arene(TCAET)was synthesized specifica.l. for the capture of Au(Ⅲ)and Pd(Ⅱ)from HCl medium by liquid-liquid *** a 0.1 mol·l^(-1)HCl medium,the transfer of Au(Ⅲ)and Pd(Ⅱ)from the aqueous phase to the organic phase was highly efficient,with a transfer ratio of 100%for Au(Ⅲ)and 98%for Pd(Ⅱ).Furthermore,the extraction equilibrium time for Au(Ⅲ)was just 5 ***'s method data demonstrated that TCAET formed complexes with Au(Ⅲ)and Pd(Ⅱ)in a ratio of 2:3 and 1:1,respectively,during the extraction *** showed high selectivity toward Pd(Ⅱ)and Au(Ⅲ)over other competing metal ***,both Au(Ⅲ)and Pd(Ⅱ)could be successfully stripped from the loaded organic phases with a 1.0 mol·l^(-1)thiourea in 0.5 mol·l^(-1)HCl and 0.5 mol·l^(-1)thiourea in 0.5 mol·l^(-1)HCl,*** obtained from five consecutive extraction-stripping cycles showed good reusability of TCAET toward Au(Ⅲ)and Pd(Ⅱ)*** conclusion can provide a certain reference for thiacalixarene in the recovery of precious metal species.

关键词： Thiacalixarene Upper-rim modification liquid-liquid extraction Precious metal Thioether

low H_(2)O_(2)consumption Fenton-like catalysts for pollutant cleavage based on the construction of a dual reaction center

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第11期145卷 107-116页

作者： Weixiang liao Ziwen Zhao lai lyu Chun Hu fan li Key laboratory for Water Quality and Conservation of the Pea.l.River Delta Ministry of EducationInstitute of Environmental Research at Greater BayGuangzhou UniversityGuangzhou 510006China Key laboratory of Drinking Water Science and Technology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China South China Institute of Environmental Sciences Ministry of Ecology and EnvironmentGuangzhou 510345China

High energy consumption has seriously hindered the development of Fenton-like reactions for the removal of refractory organic pollutants in *** solve this problem,we designed a novel Fenton-like catalyst(Cu-PAN3)by coprecipitation and carbon thermal *** catalyst exhibits excellent Fenton-like catalytic activity and stability for the degradation of various pollutants with low H_(2)O_(2)*** experimental results indicate that the dual reaction centers(DRCs)are composed of Cu-N-C and Cu-O-C bridges between copper and graphene-like carbon,which form electron-poor/rich centers on the catalyst surface.H_(2)O_(2)is mainly reduced at electron-rich Cu centers to free radicals for pollutant ***,pollutants can be oxidized by donating electrons to the electron-poor C centers of the catalyst,which inhibits the ineffective decomposition of H_(2)O_(2)at the electron-poor *** therefore significantly reduces the consumption of H_(2)O_(2)and reduces energy consumption.

关键词： Water purification Fenton-like Dual reaction centers Graphene-like carbon low H_(2)O_(2)consumption