检索结果-南通市图书馆

GAS-SOLIDS FLOW BEHAVIOR WITH A GAS VELOCITY CLOSE TO ZERO

在线全文

学校读者我要写书评

暂无评论

China Particuology 2006年第3期4卷 167-177页

作者： H. zhang J.-x. Zhu Department of Chemical Engineering University of Western Ontario London Ontario Canada N6A 5B9 Canada

In a 9.3 m high and 0.10 m i.d. gas-solids downflow fluidized bed （downer）, the radial and ax.al distributions of the local solids holdups and particle velocities along the downer column were measured with the superficial gas velocity set to zero. A unique gas-solids flow structure was found in the downer system with zero gas velocity, which is completely different from that under conditions with higher gas velocities, in terms of its radial and ax.al flow structures as well as its micro flow structure. The gas-solids flow pattern under zero gas velocity conditions, together with that under low gas velocity conditions, can be considered as a special regime which differs from that under higher gas velocity conditions. According to the hydrodynamic properties of the two regimes, they can be named the ＂dense annulus＂ regime for the flow pattern under zero or low gas velocity conditions and the ＂dense core＂ regime for that under higher gas velocity conditions.

关键词： downer reactor gas-solids cocurrent downflow fluidized bed hydrodynamics flow development particle velocity solids holdup solids flux flow regime

STUDY ON THE PREDICTIVE METHOD OF BUCKLING DEFORMATIONS OF THIN-PLATE WELDED STRUCTURES

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

Acta Metallurgica Sinica(English Letters) 2000年第1期13卷 178-186页

作者： x. Q. Yang L. x. Huo Y. F. zhang and J. x. Yan (School of Material Science and Engineering, Tianjin University, Tianjin 300072, China)

The buckling formation and influence factors during welding thin - plated structures were investigated based on finite element methods, An engineering treatment method for prdicating the buckling distor- tion was proposed in here. It was used the equivalent applied thermal - load to simulate the welding residual stress,therefore the calculation of complex.welding distoriton can be transformed into 3D elas- tic structural applied- load analyses, which can reduce the quantities of calculating works effectively. The validation of the method was verified by comparison of the numerical simulation and ex.erimental results. The simulation of buckling distorition for side - walled structrues of paseenger train was per- formed and the calculation was in agreement with measuring results in general. It was shown that the main factors for producing the buckling were the intermittent fillet and ping the during welding the stiffened beams and columns to the *** ex.stence of the free edge of panels would reduce the crit- ical buckling stress and enlarge the deflection obviously,but the continuous weld in closed frames didn' t degrade the buckling situation.

关键词： welding buckling distortion equivalent applied thermal-lood,numerical simulation

INFLUENCE OF Ge ON THE ANTIFERROMAGNETIC TRANSITION AND γ→ε MARTENSITIC TRANSFORMATION OF Fe-24Mn ALLOYS

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2002年第6期15卷 517-524页

作者： B. zhang, x. Lu Z.x. Qin, H.B. Chang and x.Y. RuanDepartment of Plastic Deforming, Shanghai Jiaotong University, Shanghai 200030, ChinaDepartment of Materials Science & Engineering, Dalian Railway Institute, Dalian 116028, China Dept. of Plastic Deforming Shanghai Jiaotong Univ. Shanghai 200030 China Dept. of Mat. Sci. and Eng. Dalian Railway Inst. Dalian 116028 China

The aims of the work were to study the effect of Ge (0-6wt. %) on the paramagnetic-antiferromagnetic transition and martensitic transformation of Fe-Mn alloy using the susceptibility, micro structure ex.mination, x.ray diffraction (x.D) and latticeparameter measurement. Ge lowers the Néel temperature, TN, and enhances the magnetic susceptibility x. changing the Pauli paramagnetism above TN to paramagnetismstate obeying the Curie Weiss law, which is essentially similar to that of γ-Fe-Mnalloys containing Al or Si; Ge depresses γ-ε martensitic transformation, whichattribute to Ge increasing the stacking fault energy; Moreover, Ge increases the lattice parameter of γ phase, and low content Ge increases the lattice parameter of γphase more than that of high Ge content. Comparing Ge(4s24p2) with Si(3s23p2) and Al(3s2 3p1), which have the same outer-shell of electron structures, we found that their effects on the martensitic transformation of Fe-Mn alloy are completely different. The result suggests the outer-shell of electron is not the main factor of governing the Ms temperature of Fe-Mn alloy although it is essential in the alloy's antiferromagnetic transition. The relation among the Ms temperature, stacking fault energy and lattice parameter of austenite, has been discussed in brief.

关键词： antiferromagnetic transition martensitic transformation lattice parameter

Delineation of Groundwater and Soil Contamination Using EM Survey at an Industrial Abandoned Site

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Science and Engineering 2011年第5期5卷 545-549页

作者： S.H. zhang x. Wang College of Resource and Environment Engineering Liaoning Technical University Fuxin 123000 China

It is important to evaluate and monitor the environmental impacts by the activity in our hand with appropriate methods, and the geophysical techniques have often been used in the subsurface environmental monitoring and remediation processes. In the study an electromagnetic survey （EM） is performed to delineate deeply the ex.ent of contamination at an industrial abandoned site, to detect the spread of groundwater and soil contamination, to locate possible pathways of leachate plumes. Based on the analysis of the geophysical anomaly of electrical conductivity, the survey area is delineated into three zones： original zone, transitional zone and contaminated zone. It was inferred that the high conductivity zones correspond to the contaminated zones of groundwater and soil. The survey demonstrates that EM method has the ability to measure small changes in subsurface properties involving ground water and is sensitive to the conductive layers. The measurement shows the behavior of groundwater and soil contamination and the position of groundwater pipelines, and it is beneficial to help waste management processes and to determine possible locations of monitoring wells so as to monitor the environment in the survey area in the future.

关键词： Electromagnetic survey pollution ground water monitoring.

Evaluating the Potential Economic Benefits of the New South Wales Node of Australia＇s Integrated Marine Observing System： [NSW-IMOS]

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

Sociology Study 2011年第6期1卷 395-406页

作者： Fan zhang x. H. Wang E. Barber University of New South Wales Australia

The Integrated Marine Observing System [IMOS] is an Australian national program for observing the oceans around Australia. As one of its important nodes, the New South Wales Integrated Marine Observing System （NSW-IMOS] aims to provide more accurate descriptions of the East Australian Current [EAC]. The purpose of this paper is to evaluate the potential economic benefits from NSW-IMOS. Six.related sectors which can potentially be among its main beneficiaries are considered： beach recreation, commercial fishing, recreational fishing, recreational boating, natural hazard predictions, and oil spill mitigation. The 1% constant percentage increase evaluation method is used to estimate the potential economic benefits to these six.beneficiaries. By using this method, our study shows that the total potential economic benefit for these sectors is estimated to be $ 6.07 million per year. We consider that this is indicative but not conclusive in demonstrating some of the potential economic benefits that can be provided from information gathered by NSW-IMOS facilities. We conclude with further evaluative approaches that could be used to provide more accurate estimates of potential economic benefits.

关键词： Ocean observing systems economic evaluation IMOS (Integrated Marine Observing System) Australia New South Wales [NSW]

Synthetic Studies on 1-Amino-1-Cyclopropane-Carbox.lic Acid( Ⅰ )——The Cyclopropanation via Addition-Elimination Reactions

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

Chemical Research in Chinese Universities 1992年第4期8卷 377-381页

作者： zhang, x. A., Campbell, M. M. and Brown, D. W. (School of Chemistry, University of BATH, U. K. )

Various addition-elimination approaches have been ex.lored for diastereoselective construction of 1-amino- 1-cyclopropane-carbox.lic acid (ACPC) derivatives, and the desired product was obtained from a reaction of cyc... 详细信息

关键词： Synthesis 1-Amino-1-Cyclopropane-Carbox.lic acid Addition-elimination reac-tion cyclopropanation

GAS-SOLIDS FLOW BEHAVIOR WITH A GAS VELOCITY CLOSE TO ZERO

在线全文

学校读者我要写书评

暂无评论

Particuology 2006年第Z1期 167-177页

作者： H. zhang and J.-x. Zhu* Department of Chemical Engineering, University of Western Ontario, London, Ontario, Canada N6A 5B9, Canada

In a 9.3 m high and 0.10 m i.d. gas-solids downflow fluidized bed (downer), the radial and ax.al distribu- tions of the local solids holdups and particle velocities along the downer column were measured with the superficial gas velocity set to zero. A unique gas-solids flow structure was found in the downer system with zero gas velocity, which is completely different from that under conditions with higher gas velocities, in terms of its radial and ax.al flow structures as well as its micro flow structure. The gas-solids flow pattern under zero gas velocity conditions, together with that under low gas velocity conditions, can be considered as a special regime which differs from that under higher gas velocity conditions. According to the hydrodynamic properties of the two regimes, they can be named the “dense annulus” regime for the flow pattern under zero or low gas velocity conditions and the “dense core” regime for that under higher gas ve- locity conditions.

关键词： downer reactor gas-solids cocurrent downflow fluidized bed hydrodynamics flow development particle velocity solids holdup solids flux flow regime

MLCROSTRUCTURE AND PROPERTIES OF C-Cu NANOSTRUCTURE THIN FILM

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2002年第2期15卷 198-202页

作者： Y.N. Sun, K.x. zhang, x. Gao, D. Q. Yang, Z.D. Lin and Y. Guo Lauzhou Institute of Physics, P.O. Box.94, Lanzhou 730000, China

Nanostructured C-Cu thin films were deposited by reactive sputtering method and cosputtering method. The relationships between microstructures, properties, and deposition parameters were studied and the results obtained from TEM, AFM, and x.S. indicate that the thin films are nanostructural, and have good in-depth uniformity. The selected area electron diffraction (SAED) found that the nanosize Cu particles have the fcc structure and the others are amorphous carbon or nanocrystallized graphitic carbon. The peak positions of the Cu and C in x.S indicate them to be at the elemental state. In the JR transmission spectrum, diamond two-phonon absorption and graphite Reman peaks were observed, which suggests microcrystal diamond particles and graphite components ex.ist in the C-Cu film. The higher electrical resistivity was obtained.

关键词： C-Cu film nanostructure optical and electrical properties

PRODUCTION OF ULTRA-FINEα-AL_2O_3 PO WDERSFROM AMMONIUM A LUMINUM CARBONATE HY DROx.DE

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1999年第5期12卷 1194-1197页

作者： F. zhang1) , x. D. Sun1) , J. You2) , Z. zhang2) , L. x. Ding3)and Y. M. Wang3)1) School of Materials and Metallurgy , Northeastern University , Shenyang 110006 , China2) Liaoning Analyzing and Testing Research Center , Shenyang

Synthesis of a m m oniu m alu min u m carbonate hydrox.de ( A A C H) w as investigated usinga m m oniu m alu min u m sulfate and a m moniu m hydro carbonate as the starting m aterials . Itw as found that A A C Hcan be synthesized by adding a m m oniu m alu m inu m sulfate solution torapidly stirred a m moniu m hydro - carbonate solution at a tem perature of 30 ℃. A A C Hcantransfor m to α Al2 O3 co m pletely by calcining at 1100 ℃ for 1 hour , and the obtained po w ders , with a particle size of 100 n m , can be sintered to 98 99 % relative density at 1500 ℃for 2 hours .

关键词： a m moniu m alu m inu m carbonate hydrox.de α alu mina ultra - finepow der sintering