检索结果-南通市图书馆

Acta Mechanica Solida Sinica 2018年第6期31卷 683-697页

作者： Yajun yin Department of Engineering Mechanics School of Aerospace EngineeringTsinghua UniversityBeijing 100084China

This paper studies the particle time derivatives of the characteristic geometric quantities on soft curved surfaces in Lagrangian *** the basis of differential geometry, the calculation formulas for the particle time derivatives of the base vectors,metric tensor, Christoffel symbol,unit normal vector,curvature tensor and scalar curvatures on soft curved surface are *** limitations of particle time derivatives,*** non-covariance,are pointed *** research paves the way for studying particle time derivative of any tensor field on soft curved surface.

关键词： Soft curved surfaces Lagrangian description Characteristic geometric quantities Particle time derivative

Generalized Covariant Derivative with Respect to Time in Flat Space(Ⅰ):Eulerian Description

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 Mechanica Solida Sinica 2016年第4期29卷 345-358页

作者： Yajun yin Department of Engineering Mechanics School of Aerospace EngineeringTsinghua University

This paper reports a new derivative in the Eulerian description in flat space-the generalized covariant derivative with respect to time. The following contents are included:(a) the restricted covariant derivative with respect to time for Eulerian component is defined;(b) the postulate of the covariant form invariability in time field is set up;(c) the generalized covariant derivative with respect to time for generalized Eulerian component is defined;(d) the algebraic structure of the generalized covariant derivative with respect to time is made clear;(e) the covariant differential transformation group in time filed is derived. These progresses reveal the covariant form invariability of Eulerian space and time.

关键词： Eulerian description covariant form invariability generalized Eulerian component generalized covariant derivative with respect to time covariant differential transformation group

Activin A receptor type 1C single nucleotide polymorphisms associated with esophageal squamous cell carcinoma risk in Chinese population

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2025年第1期17卷 39-51页

作者： Si-Yun Lin Hou Huang Jin-Jie Yu Feng Su Tian Jiang Shao-Yuan Zhang Lu Lv Tao Long Hui-Wen Pan Jun-Qing Qi Qiang Zhou Wei-Feng Tang Guo-Wen Ding Li-Ming Wang Li-Jie Tan Jun yin Department of Thoracic Surgery Zhongshan Hospital Affiliated to Fudan UniversityShanghai 200032China Shanghai Key Laboratory of Clinical Geriatric Medicine Huadong Hospital Affiliated to Fudan UniversityShanghai 200040China Department of Cardiothoracic Surgery The Affiliated People's Hospital of Jiangsu UniversityZhenjiang 212002Jiangsu ProvinceChina Department of Thoracic Surgery Sichuan Cancer Hospital&InstituteChengdu 610042Sichuan ProvinceChina Department of Cardiothoracic Surgery Nanjing Drum Tower HospitalThe Affiliated Hospital of Nanjing University Medical SchoolNanjing 210000Jiangsu ProvinceChina Department of Respiratory and Critical Care Medicine Shanghai Xuhui Central HospitalShanghai 200032China

BACKGROUND Transforming growth factor-β(TGF-β)superfamily plays an important role in tumor progression and *** A receptor type 1C(ACVR1C)is a TGF-βtype I receptor that is involved in tumorigenesis through binding to dif-ferent *** To evaluate the correlation between single nucleotide polymorphisms(SNPs)of ACVR1C and susceptibility to esophageal squamous cell carcinoma(ESCC)in Chinese Han *** In this hospital-based cohort study,1043 ESCC patients and 1143 healthy controls were *** SNPs(rs4664229,rs4556933,rs77886248,rs77263459,rs6734630)of ACVR1C were assessed by the ligation detection reaction ***-Weinberg equilibrium test,genetic model analysis,stratified analysis,linkage disequi-librium test,and haplotype analysis were *** Participants carrying ACVR1C rs4556933 GA mutant had significantly decreased risk of ESCC,and those with rs77886248 TA mutant were related with higher risk,especially in older male *** the haplotype analysis,ACVR1C Trs4664229Ars4556933Trs77886248Crs77263459Ars6734630 increased risk of ESCC,while Trs4664229Grs4556933Trs77886248Crs77263459Ars6734630 was associated with lower susceptibility to *** ACVR1C rs4556933 and rs77886248 SNPs were associated with the susceptibility to ESCC,which could provide a potential target for early diagnosis and treatment of ESCC in Chinese Han population.

关键词： Activin A receptor type 1C Single nucleotide polymorphisms Esophageal squamous cell carcinoma Genetic susceptibility Hospital-based cohort study

Generalized covariant differentiation and axiom-based tensor analysis

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

Applied Mathematics and Mechanics(English Edition) 2016年第3期37卷 379-394页

作者： Yajun yin Department of Engineering Mechanics School of Aerospace EngineeringTsinghua University

This paper reports the new progresses in the axiomatization of tensor anal- ysis, including the thought of axiomatization, the concept of generalized components, the axiom of covariant form invariability, the axiomatized definition, the algebraic structure, the transformation group, and the simple calculation of generalized covariant differentia- tions. These progresses strengthen the tendency of the axiomatization of tensor analysis.

关键词： tensor analysis axiom of covariant form invariability generalized compo-nent generalized covariant differentiation covariant differential transformation group

在线全文

学校读者我要写书评

暂无评论

农业拖拉机尾灯多色注塑模具设计

农机化研究 2025年第1期47卷 239-242,247页

作者：尹小定赵会娟江西机电职业技术学院机械工程学院南昌330013 济源职业技术学院机电工程系河南济源454650

以农业拖拉机尾灯为研究对象,分析了尾灯的内部结构和工艺性,并针对双色模具的特殊性,分析了模具成型方案和设计流程,基于AutoCAD和CAE软件完成了尾灯双色塑件模具的设计。开模试验表明:该产品符合设计需求,整个产品结构稳定,透明度好,... 详细信息

以农业拖拉机尾灯为研究对象,分析了尾灯的内部结构和工艺性,并针对双色模具的特殊性,分析了模具成型方案和设计流程,基于AutoCAD和CAE软件完成了尾灯双色塑件模具的设计。开模试验表明:该产品符合设计需求,整个产品结构稳定,透明度好,设计的模具结构合理、工艺流程可靠,能够满足实际的生产应用,工程应用价值较高。

关键词：农业拖拉机尾灯 CAD CAE 双色塑件模具

Review on the study of metallurgical process engineering

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2021年第8期28卷 1253-1263页

作者： Rui-yu yin Central Iron and Steel Research Institute Beijing 100081China

After nearly one hundred years of research, metallurgy(metallurgical science and engineering) has gradually become a system with three levels of knowledge:(1) micro metallurgy at the atomic/molecular scale,(2) process metallurgy at the procedure/device, and(3) macrodynamic metallurgy at the full process/process group. Macro-dynamic metallurgy development must eliminate the concept of an "isolated system" and establish concepts of "flow," "process network," and "operating program" to study the "structure–function–efficiency" in the macrodynamic operation of metallurgical manufacturing processes. It means considering "flow" as the ontology and observing dynamic change by"flow" to solve the green and intelligent potential of metallurgical enterprises. Metallurgical process engineering is integrated metallurgy, toplevel designed metallurgy, macro-dynamic operated metallurgy, and engineering science level metallurgy. Metallurgical process engineering is a cross-level, comprehensive, and integrated study of the macro-dynamic operation of manufacturing processes. Metallurgical process engineering studies the physical nature and constitutive characteristics of the dynamic operation of steel manufacturing process, as well as the analysis-optimization of the set of procedure functions, coordination-optimization of the set of procedures' relations, and reconstruction-optimization of the set of procedures in the manufacturing process. The study establishes rules for the macro operation of the manufacturing process, as well as dynamic and precise objectives of engineering design and production operation.

关键词： metallurgical process engineering cross-level comprehensive integration macro-dynamic operation new branch of metallurgy

NUMERICAL SIMULATION AND FIELD IMPLEMENTATION OF SURFACTANT FLOODING

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2006年第1期18卷 109-117页

作者： yin Dai-yin PU Hui Department of Petroleum Engineering Daqing Petroleum Institute Daqing 163318 China

Based on the features of surfactant flooding, a mathematical model for surfactant flooding is established. The adsorption-retentlon, convection diffusion of surfactant and influence of concentration change upon relative permeability curve are included in the model. The novel description of adsorption quantity of surfaetant and relative permeability curve are presented, which enhance the coincidence between mathematical model and field practice, the relative errors of main development indexes arc within 6%. The model is applied to the numerical research of the surfactant flooding in the untabulated beds of Xingl-3 surfactant flooding pilot site of No. 4 Oil Production Company of Daqing Oilfield, the influences of surfaetant concentration, injection quantity, slug combination mode upon the development effect and economic benefit are quantitatively analyzed, the injection scheme is optimized as follows： surfaetant concentration is 0.5%, slug volume is 0.02 PV, slug combination mode is 2 slugs. After the implementation of scheme in oilfield, the cumulative increase of oil is 2186.0 t, up to nearly 30%.

关键词： Surfactant mathematical model injection scheme numerical simulation recovery efficiency

墨鱼干碱水-纯水组合复水工艺优化及复水前后质构特性

在线全文

学校读者我要写书评

暂无评论

食品工业科技 2025年第1期46卷 181-189页

作者：顾俊浩尹明雨王锡昌上海海洋大学食品学院上海201306

目的:探究墨鱼干复水最优工艺参数及其复水前后的质构变化。方法:通过先用碱水后用纯水的组合复水方式进行处理,以复水率和蛋白损失率为优化指标进行条件优化,随后对墨鱼干复水前后的质构特性以及蛋白质二级结构、组织形态等相关指标进... 详细信息

目的:探究墨鱼干复水最优工艺参数及其复水前后的质构变化。方法:通过先用碱水后用纯水的组合复水方式进行处理,以复水率和蛋白损失率为优化指标进行条件优化,随后对墨鱼干复水前后的质构特性以及蛋白质二级结构、组织形态等相关指标进行分析。结果:碱水处理墨鱼干的最佳条件为:碳酸钠浓度0.50%、时间2.0 h、温度50℃、料液比1:20 g/mL;在此基础上,进行纯水处理的最佳条件为:时间1.0 h、温度50℃、料液比为1:20 g/mL。两步处理后,墨鱼干的复水率为261.10%±7.10%,蛋白损失率为16.80%±0.74%。复水处理使墨鱼干的硬度、胶着性和咀嚼性显著降低,而弹性则显著上升(P<0.05),并使肌原纤维蛋白的结构折叠,且肌纤维的间隙增加。结论:本研究明确墨鱼干最优复水参数并改善其质构特性,为墨鱼干的高质化加工利用提供理论参考。

关键词：墨鱼干复水工艺复水率蛋白损失率质构特性

同方期刊数据库

Influence of natural deposition plane orientation on oedometric consolidation behavior of three typical clays from southeast coast of China

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第11期14卷 767-777页

作者： Qi-yin ZHU yin-fu JIN Zhen-yu yin Pierre-Yves HICHER Department of Civil Engineering Shanghai Jiao Tong University LUNAM University Ecole Centrale de NantesGeM UMR CNRS 6183 Nantes France

The parameters obtained from oedometric consolidation tests are commonly used in the development of constitutive modeling and for engineering practice. This paper focuses on the influence of the natural deposition plane orientation on oedometric consolidation behavior of three natural clays from the southeast coast of China. Oedometer tests were conducted on intact specimens prepared by sampling at a series of angles relative to the natural deposition plane. For each specimen, yield stress,compressibility indexes, secondary compression, and permeability coefficients were determined. The influence of the sampling angle on these properties was investigated, revealing that yield stress, compression index, swelling index, creep index, ratio of secondary compression coefficient to compression index(Cae/Cc) and permeability coefficient were all dependent to some extent on the sampling angle. These findings indicate the role of the anisotropy due to the natural deposition on the oedometric consolidation behavior.

关键词： Clay Compressibility Consolidation Creep Permeability Natural deposition

Analysis Aspects of Ricci Flow on Conical Surfaces

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2022年第5期38卷 807-857页

作者： Hao yin School of Mathematical Sciences University of Science and Technology of ChinaHefei 230026P.R.China

In this paper,we establish a framework for the analysis of linear parabolic equations on conical surfaces and use them to study the conical Ricci *** particular,we prove the long time existence of the conical Ricci flow for general cone angle and show that this solution has the optimal regularity,namely,the time derivatives of the conformal factor are bounded and for each fixed time,the conformal factor has an explicit asymptotic expansion near the cone points.

关键词： Ricci flow conical singularity