检索结果-南通市图书馆

A NEW CONCEPT TOWARD INDUSTRIAlIZATION OF Cu-III-VI_2 ThIN FIlM SOlAR CEllS AND SOME PRElIMINARY ExPERIMENT RESUlTS

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 199-203页

作者： l.x.Shao h.l.hwang SchoolofInformationTechnologyandScience ZhanjiangNormalCollegeZhanjiang524048China DepartmentofElectricalEngineering NationalTsingHuaUniversityTaiwan300China

A new concept of full vacuum manufacturing for Cu-III-IV2 thin-film solar cells has been discussed. Cu-III-IV2 thin-film solar cells manufactured using full in- line reactive sputtering will result in lower cost than that of the conventional method with CdS layer fabricated with chemical bath deposition (CBS) method. Us ing reactive sputtering process with organo- metallic gases, the compositions a nd electronic properties of Cu-III-IV2 thin-film can be fine-tuned and precisely controlled. n-type Cu-III-IV2 film and ZnS suffer layer can also be deposited u sing the in-line sputtering instead of using the CdS layer. The environmental po llution problems arising from using CdS can be eliminated and the ultimate goal of full in-line process development can then be realized. Some preliminary exper imental results on a modal solar cell fabricated by the new technique in the new concept have been presented.

关键词： Cu-III-VI2 thin film solar cells full reactive sputtering

Mechanical properties of gas hydrate-bearing sediments during hydrate dissociation

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2018年第2期34卷 266-274页

作者： x.h.Zhang D.S.luo x.B.lu l.l.liu C.l.liu Institute of Mechanics Chinese Academy of SciencesBeijing 100190China College of Engineering University of Chinese Academy of SciencesBeijing 100049China Key laboratory of Gas hydrate Ministry of Land and ResourcesQingdao 266071China Qingdao Institute of Marine Geology Qingdao 266071China

The changes in the mechanical properties of gas hydrate-bearing sediments(GhBS) induced by gas hydrate(Gh) dissociation are essential to the evaluation of Gh exploration and stratum instabilities. Previous studies present substantial mechanical data and constitutive models for GhBS at a given Gh saturation under the non-dissociated condition. In this paper, GhBS was formed by the gas saturated method, Gh was dissociated by depressurization until the Gh saturation reached different dissociation degrees. The stress–strain curves were measured using triaxial tests at a same pore gas pressure and different confining pressures. The results show that the shear strength decreases progressively by 30%–90% of the initial value with Gh dissociation, and the modulus decreases by 50% –75%. Simplified relationships for the modulus, cohesion, and internal friction angle with Gh dissociated saturation were presented.

关键词： Gas hydrate-bearing sediments Dissociation Mechanical properties Shear strength Triaxial test

Stability analyses of the mass abrasive projectile high-speed penetrating into a concrete target Part III: Terminal ballistic trajectory analyses

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2015年第4期31卷 558-569页

作者： h.Wu x.W.Chen Q.Fang x.Z.Kong l.l.he Institute of Systems Engineering China Academy of Engineering Physics State Key laboratory for Disaster Prevention & Mitigation of Explosion & Impact PLA University of Science and Technology

During the high-speed penetration of projectiles into concrete targets （the impact velocity ranges from 1.0 to 1.5 km/s）, important factors such as the incident oblique and attacking angles, as well as the asymmetric abrasions of the projectile nose induced by the target-projectile interactions, may lead to obvious deviation of the terminal ballistic tra- jectory and reduction of the penetration efficiency. Based on the engineering model for the mass loss and nose-blunting of ogive-nosed projectiles established, by using the Differ- ential Area Force law （DAFl） method and semi-empirical resistance function, a finite differential approach was pro- grammed （PENTRA2D） for predicting the terminal ballistic trajectory of mass abrasive high-speed projectiles penetrating into concrete targets. It accounts for the free-surface effects on the drag force acting on the projectile, which are attributed to the oblique and attacking angles, as well as the asymmetric nose abrasion of the projectile. Its validation on the prediction of curvilinear trajectories of non-normal high-speed pene- trators into concrete targets is verified by comparison with available test data. Relevant parametric influential analyses show that the most influential factor for the stability of ter- minal ballistic trajectories is the attacking angle, followed by the oblique angle, the discrepancy of asymmetric nose abrasion, and the location of mass center of projectile. The terminal ballistic trajectory deviations are aggravated as the above four parameters increase.

关键词： Projectile Penetration Concrete Massabrasion Terminal ballistic trajectory

AN ADAPTIVE EFG-FE COUPlING METhOD FOR ThE NUMERICAl SIMUlATION OF ExTRUSION PROCESSES

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English letters) 2008年第5期21卷 380-388页

作者： l.C. liu x.h. Doug C.x. li National Die ＆ Mold CAD Engineering Research Center Shanghai Jiaotong University Shanghai 200030 China

An adaptive EFG-FE coupling method is proposed and developed for the numerical simulation of lateral extrusion and forward-backward extrusion. Initially, the simulation has been implemented by using a conventional FE model. During the deforming process, mesh quality is checked at every incremental step. Distorted elements are automatically converted to EFG nodes, whereas, the less distorted elements are reserved. A new algorithm to generate EFG nodes and interface elements is presented. This method is capable of dealing with large deformation and has higher computational efficiency than using an EFG method wholly. Numerical results demonstrate that the adaptive EFG-FE coupling method has reasonable accuracy and is effective for local bulk metal forming such as extrusion processes.

关键词： Meshless method Coupling method Numerical simulation Extrusion process

homotopy analysis solutions for the asymmetric laminar flow in a porous channel with expanding or contracting walls

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2011年第2期27卷 208-214页

作者： x.-h. Si l.-C. Zheng x.-x. Zhang Y. Chao Applied Science School University of Science and Technology Beijing 100083 Beijing China Department of Mechanical Engineering University of Science and Technology Beijing100083 Beijing China Research Institute of Chemical Defense of the El.A 102205 Beijing China

In this paper, the asymmetric laminar flow in a porous channel with expanding or contracting walls is investigated. The governing equations are reduced to ordinary ones by using suitable similar transformations. homotopy analysis method （hAM） is employed to obtain the expres- sions for velocity fields. Graphs are sketched for values of parameters and associated dynamic characteristics, especially the expansion ratio, are analyzed in detail.

关键词： homotopy analysis method · Expanding or contracting wall · Asymmetric laminar flow · Porous channel · Expansion ratio

STUDY ON PREPARATION, COMPlEx PERMITTIVITY,PERMEABIlITY AND MICROWAVE PROPERTIES OF BaZnzCo(2-z)Fe16O27/SiO2 MICROCRYSTAllINE GlASS CERAMICS

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English letters) 2003年第6期16卷 421-427页

作者： h.J.Zhang x.l.Jia x.Yao l.Y.Zhang highTemperatureCeramicsInstitute ZhengzhouUniversityZhengzhou450052China FunctionalMaterialsResearchlaboratory TongjiUniversityShanghai200092China

BaZnzCo2-zFe16O27/SiO2 microcrystalline glass ceramics with Z=0.0, 0.5, 0.8 and 1.1 were prepared at temperature 1200℃ for 5h by citrate sol-gel process. The complex dielectric constant and complex permeability of BaZnzCo2-zFe16 O27/SiO2-paraffin wax composites had been measured. Both the complex dielectric constant and dielectric loss exhibit almost no variation with frequency in 0.1-6.0Ghz. The real part of permeability decreases with increasing frequency for all samples, and the imaginary part of permeability exhibits a clear resonance peak at 1.44Ghz for Co2 W/SiO2, 1.32Ghz for Zn0.5Co1.5 W/SiO2, 1.20Ghz for Zn0.8Co1.2W/SiO2, and 1.08Ghz for Zn1.1 Co0.9 W/SiO2. It is also showed that the content of zinc has a close effect on the magnetic properties of BaZnzCo2-zFe16O27/SiO2 microcrystalline glass ceramics, the greater the zinc content, the higher the values of imaginary part of permeability and magnetic loss.

关键词： BaZnz Co2-zFe16O27/SiO2 microcrystalline glass ceramics,sol-gel microwave property

Structure evolution of the Fe_(3)C/Fe interface mediated by cementite decomposition in cold-deformed pearlitic steel wires

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第6期101卷 28-36页

作者： Y.T.Zhou x.h.Shao S.J.Zheng x.l.Ma Shenyang National laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Tianjin Key laboratory of Materials laminating Fabrication and Interface Control Technology School of Materials Science and EngineeringHebei University of TechnologyTianjin 300130China

Cold-drawn pearlitic steel wire is irreplaceably used in industry owing to its outstanding mechanical property which is dominated by the cementite/ferrite(Fe_(3)C/Fe) interfaces in the material. however, the fine structures of the Fe3C/Fe interfaces in the deformed wires are less known to date. In this work, transmission electron microscopic investigation was performed on the atomic structures of the interfaces with the Isaichev orientation relationship(OR) in the wires with progressive deformation strains. In addition to the effect of the dislocation/interface interactions, this work revealed that the deformation-induced partial decomposition of cementite plays an important role in the interface reconstruction during deformation. The interfacial carbon vacancies generated by cementite decomposition and particularly, the amorphization of cementite layers in the sample with ε > 1 could effectively annihilated the interfacial dislocations and consequently relaxed the interfacial stress. The correlations between the interface structure changes and the mechanical properties of the wires were discussed.

关键词： Pearlitic steel Cementite decomposition Interface structure Deformation Transmission electron microscopy

Silk-based nerve guidance conduits with macroscopic holes modulate the vascularization of regenerating rat sciatic nerve

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第6期20卷 1789-1800页

作者： Carina hromada Patrick heimel Markus Kerbl lászlóGál Sylvia Nürnberger Barbara Schaedl James Ferguson Nicole Swiadek xavier Monforte Johannes C.heinzel Antal Nógrádi Andreas h.Teuschl-Woller David hercher Department life Science Engineering University of Applied Sciences Technikum WienViennaAustria Austrian Cluster for Tissue Regeneration ViennaAustria ludwig Boltzmann Institute for Traumatology The Research Center in Cooperation with AUVAViennaAustria University Clinic of Dentistry Medical University of ViennaViennaAustria Department of Plastic Reconstructive and Aesthetic SurgeryLandesklinikum Wiener Neustadt2700 Wiener NeustadtAustria Department of Anatomy Histology and EmbryologyAlbert Szent-Györgyi Medical SchoolUniversity of SzegedSzegedHungary Medical University of Vienna Department of Orthopedics and Trauma SurgeryDevision of Trauma SurgeryViennaAustria Department of hand- PlasticReconstructive and Burn SurgeryBG Unfallklinik TuebingenUniversity of TuebingenTuebingenGermany

Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the use of tubular nerve guidance conduits(tNGCs). however, the use of tNGCs results in poor functional recovery and central necrosis of the regenerating tissue, which limits their application to short nerve lesion defects(typically shorter than 3 cm). Given the importance of vascularization in nerve regeneration, we hypothesized that enabling the growth of blood vessels from the surrounding tissue into the regenerating nerve within the tNGC would help eliminate necrotic processes and lead to improved regeneration. In this study, we reported the application of macroscopic holes into the tubular walls of silk-based tNGCs and compared the various features of these improved silk^(+) tNGCs with the tubes without holes(silk^(–) tNGCs) and autologous nerve transplants in an 8-mm sciatic nerve defect in rats. Using a combination of micro-computed tomography and histological analyses, we were able to prove that the use of silk^(+) tNGCs induced the growth of blood vessels from the adjacent tissue to the intraluminal neovascular formation. A significantly higher number of blood vessels in the silk^(+) group was found compared with autologous nerve transplants and silk^(–), accompanied by improved axon regeneration at the distal coaptation point compared with the silk^(–) tNGCs at 7 weeks postoperatively. In the 15-mm(critical size) sciatic nerve defect model, we again observed a distinct ingrowth of blood vessels through the tubular walls of silk^(+) tNGCs, but without improved functional recovery at 12 weeks postoperatively. Our data proves that macroporous tNGCs increase the vascular supply of regenerating nerves and facilitate improved axonal regeneration in a short-defect model but not in a critical-size defect model. This study suggests that further optimizatio

关键词： axon regeneration blood vessel functional recovery macroporous nerve lesion peripheral nerve repair sciatic nerve silk-based nerve guidance conduit vascularization

RESEARCh OF ThE FEEDING SPEED ADOPTING CORED-WIRE METhOD TO SPhEROIDIZE DUCTIlE IRON MElT

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English letters) 2008年第5期21卷 362-368页

作者： G.W. Chang h.x. Wang x.D. Yue h.l. Zhang School of Materials and Chemical Engineering Liaoning University of Technology Jinzhou 121001 China Mechanical and Electronic Engineering Department West Anhui University Liu＇an 237012 China Baotou Wen xin Industry limited Company Baotou 014000 China Manuscript received 29 August 2007

For settling the question of feeding speed in applying the cored-wire method to spheroidize ductile iron melt, ANSYS software was applied to simulate the heat transfer and mass transfer, and the melt time of the steel strip in the iron melt was determined by linking the heat transfer and mass transfer, and then the feeding speed was calcufated. Conclusions have been drawn that the iron layer was formed on the surface of the cored-wire during the wire-feeding process. The thickness is 0.073 mm when the temperature of the iron melt is 1500℃, the time from formation to remelting of the iron layer is 0.063 s. When the temperature of the iron melt is below 1500℃, the time taken for the steel strip to melt is rapidly shortened. When the temperature of the iron melt is above 1500℃, the variation amplitude of the steel strip melt change with time is gradually diminished. The melt time of the steel strip is rapidly increased with the increase of the steel strip thickness. When the temperature of the iron melt is 1500℃ and the carbon content is 4%, the melt time of a steel strip, which has a thickness of 0.5 mm, is thrice that of a steel strip whose thickness is 0.3 mm. The calculation results of the feeding speed are basically in agreement with the applied feeding speed in the factory.

关键词： Ductile iron Spheroidize Feeding speed Numerical simulation