检索结果-南通市图书馆

Influence of a multi-step process on the thickness reduction error of sheet metal in a flexible rolling process

International Journal of Minerals,Metallurgy and Materials 2019年第1期26卷 76-85页

作者： Yi li ming-zhe li Kai liu Dieless Forming Technology Center Roll Forging Institute Jilin University College of Materials Science and Engineering Jilin University

Flexible rolling is a forming process based on thickness reduction, and the precision of thickness reduction is the key factor affecting bending deformation. The major purpose of the present work is to solve the problem of bending deformation error caused by insufficient thickness reduction. Under the condition of different rolling reductions with the same sheet thickness and the same thickness reduction with different sheet thicknesses, the thickness reduction error of sheet metal is analyzed. In addition, the bending deformation of sheet metal under the same conditions is discussed and the influence of the multi-step forming process on the thickness reduction error is studied. The results show that, under the condition of the same sheet thickness, the thickness reduction error increases with increasing rolling reduction because of an increase in work hardening. As rolling reduction increases, the longitudinal bending deformation decreases because of the decrease of the maximum thickness difference. Under the condition with the same thickness reduction, the thickness reduction error increases because of the decrease of the rolling force with increasing sheet thickness. As the sheet thickness increases, the longitudinal bending deformation increases because of the increase in the maximum thickness difference. A larger bending deformation is divided into a number of small bending deformations in a multi-step forming process, avoiding a sharp increase in the degree of work hardening; the thickness reduction error is effectively reduced in the multi-step forming process. Numerical simulation results agree with the results of the forming experiments.

关键词： flexible rolling convex surface numerical simulation thickness reduction error multi-step forming process

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Optimal Design of Two Road Networks Based on their Properties

引用

Acta Mathematicae Applicatae Sinica 2007年第2期23卷 337-352页

作者： ming-zhe li Yan Zhang Faculty of Economics Fukuoka University 8-19-1 Nanakuma Jonan-ku Fukuoka 814-0180 Japan

In this paper, we discuss some fundamental properties of two idealized typical networks, namely, grid type and radial-circular type. The discussion is based on SPCP （Shortest Path Counting Problem）, which reflects the traffic density of a road segment. Furthermore, we compare their effectiveness based on the obtained results of the above two road networks, and suggest some proposals on the design of car lanes by considering the direction of a road segment in relation to these road networks.

关键词： SPCP DSPCP grid radial-circular optimal design of road networks

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Improving effect on forming quality and accuracy using a polyurethane board positioning/resetting the discrete steel pad in multi-point forming

引用

International Journal of Minerals,Metallurgy and Materials 2019年第4期26卷 447-459页

作者： Er-hu Qu ming-zhe li Rui li College of Materials Science and Engineering Jilin University Roll Forging Institute Jilin University Changchun Ruiguang Technology Co. Ltd.

To improve the quality of multi-point die forming, a new approach using discrete steel pads was proposed. The formability of three different multi-point die forming processes was analyzed through numerical simulation and experiments. Numerical simulation and experimental results showed that the use of discrete steel pads in the multi-point forming process can substantially improve the stress–strain state on the plate and suppress dimple, straight-edge, and wrinkle defects. This analysis verified that the use of discrete steel pads in a multi-point forming process can effectively improve the quality and accuracy with which sheet metal is formed.

关键词： multi-point forming dimple wrinkle numerical simulation forming accuracy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Microstructure,Texture Evolution,and Mechanical Properties of ECAP-Processed ZAT522 Magnesium Alloy

引用

Acta Metallurgica Sinica(English Letters) 2020年第2期33卷 233-242页

作者： Ying Ma Fu-Yin Han Cheng liu ming-zhe li School of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Shanxi Key Laboratory of Advanced Magnesium-Based Materials Taiyuan University of TechnologyTaiyuan 030024China

In this work,the high-strength Mg-5Zn-2Al-2Sn(ZAT522,in wt%) Mg alloys was obtained at 220℃ and 130℃ by a two-step equal channel angular pressing(ECAP).For each stage,two passes were *** results showed a remarkable grain refinement after the first stage of ECAP(A2 samples),leading to a fine-grained structure with average size of 1.40 μ*** additional stage(A4 samples) caused further grain refinement to 1.18 μm,and an ultra-fine grain structure(700 nm)appeared in the precipitate-rich *** grain refinement mechanism for both samples was discussed in *** this end,the original extrusion fiber texture evolved into a new strong texture characterized by the base planes tilted toward the ECAP shear plane,with a higher Schmid factor value of *** with the as-extruded alloy,the yield strength of the A2 samples increased from 180 to 245 MPa,which was mainly attributed to the combined effects of grain boundary strengthening and precipitation *** the case of A4 samples,the dislocation strengthening resulted in a net increase in yield strength to 335 MPa,while the ductility was significantly reduced.

关键词： Mg–5Zn–2Al–2Sn Mg alloy ECAP Microstructure Texture Tension properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Numerical simulation and experimental verification of a novel double-layered split die for high-pressure apparatus used for synthesizing superhard materials

引用

International Journal of Minerals,Metallurgy and Materials 2019年第3期26卷 377-385页

作者： Zhuo Yi Wen-zhi Fu ming-zhe li Rui li liang Zhao li-yan Wang Roll Forging Institute Jilin University College of Materials Science and Engineering Jilin University Changchun Ruiguang Science & Technology Co. Ltd.

Based on the principles of massive support and lateral support, a novel double-layered split die(DLSD) for high-pressure apparatus was designed to achieve a higher pressure-bearing capacity and larger sample cavity. The stress distributions of the DLSDs with different numbers of divided blocks were investigated by the finite element method and compared with the stress distributions of the conventional belt-type die(BTD). The results show that the cylinders and first-layer supporting rings of the DLSDs have dramatically smaller stresses than those of the BTD. In addition, increasing the number of divided blocks from 4 to 10 gradually increases the stress of the cylinder but has minimal influence on the stress of the supporting rings. The pressure-bearing capacities of the DLSDs with different numbers of divided blocks, especially with fewer blocks, are all remarkably higher than the pressure-bearing capacity of the BTD. The contrast experiments were also carried out to verify the simulated results. It is concluded that the pressure-bearing capacities of the DLSDs with 4 and 8 divided blocks are 1.58 and 1.45 times greater than that of the BTD. This work is rewarding for the commercial synthesis of high-quality, large-sized superhard materials using a double-layered split high-pressure die.

关键词： split die prismatic cylinder pressure-bearing capacity high-pressure apparatus superhard material FEM

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influence of deformation path on the forming effect in a multistep flexible rolling process

引用

International Journal of Minerals,Metallurgy and Materials 2018年第10期25卷 1173-1180页

作者： Ying li Wen-zhi Fu ming-zhe li Xiao-dong liu Shuo Sun Zhuo Yi Roll Forging Institute Jilin University College of materials science and engineering Jilin University

The flexible rolling process(FRP) is a novel three-dimensional(3 D) forming process that combines the multipoint and traditional rolling forming. The principle of FRP is based on thickness thinning, so the deformation path significantly impacts the forming effect. In this study, the multistep forming process with different deformation paths was introduced to improve the forming effect of FRP. For instance, with the convex surface part, three finite element models of multistep FRP(MSFRP) were established. The corresponding numerical simulations and forming experiments performed among different deformation paths showed the surface part with a longer effective forming region was obtained and the forming regions with more steps in MSFRP were smoother. Thus, the sheet-metal utilization rate was greatly improved. Moreover, the MSFRP can improve the longitudinal bending effect dramatically and thereby endowing the forming part with a better forming effect. Therefore, MSFRP is a prospective method for broad applications.

关键词： 3D surface forming multistep flexible rolling numerical simulation deformation path forming effect

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Constraints on ultracompact minihalos using neutrino signals from gravitino dark matter decay

引用

Research in Astronomy and Astrophysics 2014年第10期14卷 1215-1220页

作者： Yun-Long zheng Yu-Peng Yang ming-zhe li Hong-Shi Zong Department of Physics Nanjing University Department of Astronomy Nanjing University College of Physics and Electrical Engineering Anyang Normal University Joint Center for Particle Nuclear Physics and CosmologyNanjing University-Purple Mountain Observatory Interdisciplinary Center for Theoretical Study University of Science and Technology of China

Ultracompact dark matter minihalos （UCMHs） would be formed during the early universe if there were large density perturbations. If dark matter can decay into particles described by the standard model, such as neutrinos, these objects would become potential astrophysical sources of emission which could be detected by in- struments such as IceCube. In this paper, we investigate neutrino signals from nearby UCMHs due to gravitino dark matter decay and compare these signals with the back- ground neutrino flux which is mainly from the atmosphere to obtain constraints on the abundance of UCMHs.

关键词： dark matter -- early universe -- dark matter halos

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Risk factors for adverse outcome in low rectal cancer

引用

World Journal of Gastroenterology 2012年第1期18卷 64-69页

作者： Zhi-Hui Chen Xin-ming Song Shi-Cai Chen ming-zhe li Xin-Xin li Wen-Hua Zhan Yu-Long He Department of Gastrointestinaland Pancreatic Surgery The First Affiliated Hospital Sun Yat-senUniversity Guangzhou 510080 Guangdong Province China Department of SurgeryⅡ Huangpu Division ofThe First Affiliated Hospital Sun Yat-sen University Guangzhou510700 Guangdong Province China

AIM: To demonstrate the oncologic outcomes of low rectal cancer and to clarify the risk factors for survival, focusing particularly on the type of surgery performed. METHODS: Data from patients with low rectal carcinomas who underwent surgery, either sphincter-preserving surgery (SPS) or abdominoperineal resection (APR), at The First Aff iliated Hospital of Sun Yat-sen University in China from August 1994 to December 2005 were retrospectively analyzed. RESULTS: Of 331 patients with low rectal cancer, 159 (48.0%) were treated with SPS. A higher incidence of positive resection margins and a higher 5-year cumulative local recurrence rate (14.7% vs 6.8%, P = 0.041) were observed in patients after APR compared to *** five-year overall survival (OS) was 54.6% after APR and 66.8% after SPS (P = 0.018), and the 5-year disease-free survival (DFS) was 52.9% after APR and 65.5% after SPS (P = 0.013). In multivariate analysis, poor OS and DFS were signif icantly related to positive resection margins, pT3-4, and pTNM Ⅲ-Ⅳ but not to the type of surgery. CONCLUSION: Despite a higher rate of positive resection margins after APR, the type of surgery was not identif ied as an independent risk factor for survival.

关键词： Abdominoperineal resection Prognosis Rectal neoplasms Sphincter-preserving surgery Surgery

来源：

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

Decision making module based on stochastic magnetic tunnel junctions

引用

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 202-209页

作者： Yifan Miao li Zhao Yajun Zhang zhe Yuan Center for Advanced Quantum Studies and Department of Physics Beijing Normal University Institute for Nanoelectric Devices and Quantum Computing Fudan University Interdisciplinary Center for Theoretical Physics and Information Sciences Fudan University

In biological neural systems, noise is ubiquitous but does not affect the correct decisions made in the complex cognitive ***-making in biological neural system is typically achieved by accumulating input information over a period of *** by recent developments in neurosciences, we design a decision-making module based on spintronic devices, utilizing superparamagnetic tunnel junctions as artificial neurons. The feasibility of this decision-making module is verified through circuit simulations. Taking a multi-layer perceptron as an example, the module significantly improves the accuracy of the perceptron in the handwritten digit recognition task. Furthermore, the spintronic decision-making module offers advantages over the conventional pooling methods, such as adaptive decision time, high performance and the absence of analog-to-digital conversion. The decision-making module is flexible to be integrated into artificial neural networks and provides a general yet effective solution to enhance performance against device noise.

关键词： neuromorphic computing spintronics magnetic tunnel junction neural networks

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

The Inner Traffic Area and the Dwelling Area of a Frustum Skyscraper

引用

运筹学学报(中英文) 1997年第1期 14-21页

作者： ming-zhe li MASANORI FUSHIMI(Depertment of Mothematind Engineering and Information PhysicsGraduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo 113,Japen)

We formulate the distribution of the inner traffic area and the dwelling area byconsidering two kinds of the inner traffic in a frustum skyscraper. We theoreticallysolve the proposed formulation with respeCt to rectangular case. We also generally copewith the proposed formulation using an iterative method, giving the discription of theconditions and the sketch of the proof for the convergence. Finally, we numericallyanalyze it by applying this method to some examples for various parameter values toinvestigate their inner traffic properties.

关键词： architecture frustum skyscrapers inner traffic integral equations

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：