检索结果-南通市图书馆

Journal of Iron and Steel Research International 2020年第2期27卷 141-147页

作者： dan-qing jiang Rui Wang Qiong Zhang Zhen-qiang Zhang Ting-sheng Tu jiang Wang Zhong-ming Ren School of Materials Science and Engineering Shanghai UniversityShanghai 200444China State Key Laboratory of Advanced Special Steel Shanghai UniversityShanghai 200444China

The effect of final electromagnetic stirring on the solidification structure,element segregation,and carbides of GCrl5 bearing steel was *** experiment of continuous casting of the steel was carried out by using a continuous casting physical simulation apparatus with the final electromagnetic *** liquid core profile was revealed by the pour-out method during the solidification *** ingots were produced under different electromagnetic stirring parameters for *** results show that,at the final stage of solidification,intense electromagnetic stirring exacerbates the central carbon segregation,resulting in more serious precipitation of the primary *** is also found that the carbides in the segregation area are dominantly M3C type,together with a small amount of M7C3-type and M3C2-type *** this physical simulation model,the optimal stirring parameters to obtain a fine and homogeneous structure are the liquid pool width of 15 mm,current intensity of 150 A,and stirring frequency of 5 Hz.

关键词： GCrl5 bearing steel Solidification structure Continuous casting Final electromagnetic stirring Segregation Carbide

Melting and floating processes of inorganic materials in molten steel:Visualization physical simulation and mathematical modelling

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Foundry 2023年第2期20卷 89-98页

作者： Jin-hu Lai Sheng Yu Yang-jian Xu dan-qing jiang San-san Shuai jiang Wang Zhong-ming Ren State Key Laboratory of Advanced Special Steel School of Materials Science and EngineeringShanghai UniversityShanghai 200444China Shaoxing Institute of Technology Shanghai UniversityShaoxing 312000ZhejiangChina

It has been demonstrated that heat absorption method by using the inorganic material rod to cool the molten steel can significantly reduce the macrosegregation level of the large steel ***,owing to the opacity of the molten steel,the physical mechanism of the heat absorption method is not *** this work,a transparent hydraulic physical model with water and paraffin wax was built to simulate the melting and floating processes of inorganic materials in the molten steel.A mathematical simulation was also carried out to analyze the connection between the actual ingot and the physical *** show that it is feasible to simulate the molten steel and inorganic materials with water and paraffin *** the help of the physical model,the process of the melting of paraffin wax and its floating to the surface of water were clearly observed,during which the temperature of water at some characteristic positions in the mold was *** visualization findings demonstrate that the melting and floating processes of paraffin wax can help to bring the heat from the center of the mold to the top surface more quickly,which reduces the superheat and significantly accelerates the cooling rate of *** experimental results show that for the water with a certain superheat,the use of a larger mass of paraffin wax can accelerate the cooling of the water,but there is a risk of incomplete melting of the paraffin wax.A higher superheat of water will lead to a quicker melting rate for a given mass of paraffin wax,while a lower superheat leads to the incomplete melting of paraffin wax as well.

关键词： water and paraffin wax heat absorption method physical simulation superheat large steel ingot

Influence of mechanical reduction amount on internal quality of continuous casting billets by thermal and numerical simulation

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2023年第6期30卷 1234-1243页

作者： dan-qing jiang Shu-jian Sun Han Wu Yang-jian Xu Fu-hai Zhu Zhen-qiang Zhang jiang Wang Zhong-ming Ren School of Materials Science and Engineering Shanghai UniversityShanghai 200444China State Key Laboratory of Advanced Special Steel Shanghai UniversityShanghai 200444China

With establishment of thermal and numerical simulation models,the influence of reduction amount on solidification structure,segregation and shrinkage porosity of continuous casting(CC)billets was *** thermal–mechanical coupled simulation results indicated that with an increase in reduction amount,the temperature in the central area decreases,and the reduction efficiency firstly increases and then decreases,reaching the maximum value at reduction amount of 6 *** analysis showed that increasing the reduction amount is beneficial for the refinement of central solidification ***,the internal cracks are more likely to appear at higher reduction *** X-ray computerized tomography results revealed that a higher reduction amount can significantly reduce the volume fraction and equivalent diameter of the central shrinkage porosities of CC billets and increase the sphericity of ***,the macrosegregation of carbon along the central line is improved as the reduction amount increases;while the reduction amount exceeds 8 mm,the segregation degree will not change any more.

关键词： Mechanical reduction Solidification structure Porosity Thermal simulation Continuous casting billet

Odorant receptor orthologues from moths display conserved responses to cis-jasmone

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2024年第4期31卷 1107-1120页

作者： Xiao-qing Hou Zhongqiang Jia dan-dan Zhang Guirong Wang Shenzhen Branch Guangdong Laboratory for Lingnan Modern AgricultureSynthetic Biology Laboratory of the Ministry of Agriculture and Rural AffairsAgricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhenGuangdong ProvinceChina State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina Department of Biology Lund UniversityLundSweden

In insects,the odorant receptor(OR)multigene family evolves by the birth-and-death evolutionary model,according to which the OR repertoire of each species has undergone specific gene gains and losses depending on their chemical environment,resulting in taxon-specific OR lineage radiations with different sizes in the phylogenetic *** the general divergence in the gene family across different insect orders,the ORs in moths seem to be genetically conserved across species,clustered into 23 major clades containing multiple orthologous groups with single-copy gene from each *** hypothesized that ORs in these orthologous groups are tuned to ecologically important compounds and functionally ***-Jasmone is one of the compounds that not only primes the plant defense of neighboring receiver plants,but also functions as a behavior regulator to various *** test our hypothesis,using Xenopus oocyte recordings,we functionally assayed the orthologues of BmorOR56,which has been characterized as a specific receptor for *** results showed highly conserved response specificity of the BmorOR56 orthologues,with all receptors within this group exclusively responding to *** is supported by the dN/dS analysis,showing that strong purifying selection is acting on this ***,molecular docking showed that the ligand binding pockets of BmorOR56 orthologues to cis-jasmone are *** together,our results suggest the high conservation of OR for ecologically important compounds across Heterocera.

关键词： cis-jasmone evolutionary conservation functional characterization molec-ular docking moths purifying selection

An adaptive finite-difference method for seismic traveltime modeling based on 3D eikonal equation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第1期21卷 195-205页

作者： Bao-Ping Qiao qing-qing Li Wei-Guang He dan Zhao Qu-Bo Wu CNNC Beijing Research Institute of Uranium Geology Beijing 100029China National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao 266580ShangdongChina SINOPEC Geophysical Research Institute Nanjing211103JiangsuChina

3D eikonal equation is a partial differential equation for the calculation of first-arrival traveltimes and has been widely applied in many scopes such as ray tracing,source localization,reflection migration,seismic monitoring and tomographic *** recent years,many advanced methods have been developed to solve the 3D eikonal equation in heterogeneous ***,there are still challenges for the stable and accurate calculation of first-arrival traveltimes in 3D strongly inhomogeneous *** this paper,we propose an adaptive finite-difference(AFD)method to numerically solve the 3D eikonal *** novel method makes full use of the advantages of different local operators characterizing different seismic wave types to calculate factors and traveltimes,and then the most accurate factor and traveltime are adaptively selected for the convergent updating based on the Fermat *** with global fast sweeping describing seismic waves propagating along eight directions in 3D media,our novel method can achieve the robust calculation of first-arrival traveltimes with high precision at grid points either near source point or far away from source point even in a velocity model with large and sharp *** numerical examples show the good performance of the AFD method,which will be beneficial to many scientific applications.

关键词： 3D eikonal equation Accurate traveltimes Global fast sweeping 3D inhomogeneous media Adaptive finite-difference method

Difluoromethyl phenoxathiinium salt: A new general and versatile difluoromethylating reagent with divergent ·CF_(2)H, CF_(2)H^(+), and :CF_(2) reactivities

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第3期67卷 953-962页

作者： Yuan-qing Gu Hong-Xin Long dan-dan Zhang Mei-Feng Ruan Guo-Kai Liu School of Pharmacy Shenzhen University Medical SchoolShenzhen UniversityShenzhen 518055China

Development of practical and versatile electrophilic difluoromethylating reagent is still a grand challenge so far due to its inherent instability or low ***,we report the design and synthesis of difluoromethyl phenoxathiinium tetrafluoroborate(PT-CF_(2)H^(+)BF_(4)^(-)) as a novel difluoromethylating reagent,which proves to be a bench-stable,general,powerful and versatile reagent with divergent·CF_(2)H,CF_(2)H^(+),and:CF_(2) *** use of this reagent,we demonstrated a vast array of difluoromethyl radical transfer reactions via diverse pathways involving photocatalyst-free visible-light induction,visible-light photoredox catalysis and visible-light mediation single electron transfer of EDA ***,the green and highly effective CF_(2)H^(+) and:CF_(2) transfer reactions were also readily accomplished.

关键词： difluoromethyl phenoxathiinium salt versatile difluoromethylating reagent difluoromethyl radical difluoromthyl cation difluorocarbene

Assembly of peptide nanostructures with controllable sizes

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第1期17卷 151-161页

作者： dan Cheng Fan Jia Yun-Bao jiang Vincent P.Conticello Tao jiang The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation Department of ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361005China Department of Chemistry Emory UniversityAtlanta 30033USA

Controlled peptide assembly offers significant promise to develop synthetic supramolecular nanostructures to display material and biological properties that mimic protein assemblies in *** the progress in forming peptide nanostructures of various morphology,there exists a distinct gap between natural and synthetic assembly systems in terms of size *** nanostructures with a narrow size distribution that can be tuned over a wide range of length-scales is essential for applications that require precise spacing between *** approach provides the opportunity to correlate materials and biological properties of interest with assembly *** this review,we discuss representative endeavors over the past two decades for design of size-controllable peptide nanostructures using tunable building *** mechanisms for size control,e.g.,molecular frustration,template-directed peptide assembly,and multi-component peptide co-assembly,will also be *** also demonstrate the applicable scopes of these strategies and suggest potential future avenues for scientific advances in this field.

关键词： peptide assembly controllable size template multi-component

HTDcr:a job execution framework for high-throughput computing on supercomputers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第1期67卷 69-85页

作者： Jiazhi jiang dan HUANG Hu CHEN Yutong LU Xiangke LIAO School of Computer Science and Engineering Sun Yat-sen University School of Software Engineering South China University of Technology

High-throughput computing(HTC) is a computing paradigm that aims to accomplish jobs by easily breaking them into smaller,independent ***,it requires a large amount of computing power for a long *** existing HTC frameworks are job-oriented without support for coscheduling with hardware architecture and task-level ***,most of the frameworks reach a limited scale,and their usability needs further ***,we present HTDcr,a job execution framework for the HTC on *** study aims to improve the throughput,task dispatching,and usability of the *** detail,the throughput optimizations include a sophisticated designed task management system,a hierarchical scheduler,and the co-optimization of the task-scheduling strategy with the application and hardware *** optimizations for usability include a programable execution workflow,mechanisms for more robust and reliable service qualities,and a fine-grained resource allocation system for the colocation of multiple *** to our evaluations,HTDcr can achieve outstanding scalability and high throughput on large-scale clusters for the HTC *** evaluate HTDcr with several microbenchmarks and real-world applications on Tianhe-2 and Sunway TaihuLight to demonstrate its effects on existing design *** instance,the task scheduling for two real-world applications integrated with the application and hardware characteristics achieves 1.7× and 1.9× speedups over the basic task-scheduling strategy.

关键词： high-throughput computing supercomputer task scheduling middleware password guessing

Visceral adipose tissue predicts severity and prognosis of acute pancreatitis in obese patients

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Hepatobiliary & Pancreatic Diseases International 2024年第5期23卷 458-462页

作者： Yuan Tian qing Huang Yu-Tang Ren Xuan jiang Bo jiang Department of Gastroenterology Beijing Tsinghua Changgung HospitalSchool of Clinical MedicineTsinghua UniversityBeijing 102218China

Acute pancreatitis is a common systemic inflammatory disease, manifested by a spectrum of severity, ranging from mild in the majority of patients to severe acute pancreatitis. Patients with severe acute pancreatitis suffer from severe local and systemic complications and organ failure, leading to a poor prognosis. The early recognition of the severe condition is important to improve prognosis. Obesity has risen in tandem with an increase in the severity of acute pancreatitis in recent years. Studies have revealed that adipose tissue, particularly visceral adipose tissue is associated with the prognosis of acute pancreatitis. This review discussed the role of visceral adipose tissue in obese patients with acute pancreatitis and explored the possible mechanism involved.

关键词： Visceral adipose tissue Obesity Acute pancreatitis

Interfacial reaction between AZ91D magnesium alloy melt and mild steel under high temperature

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第2期21卷 159-167页

作者： Jia-hong Dai Jian-yue Zhang Bin jiang Xiang-jun Xu Zhong-tao jiang Hong-mei Xie qing-shan Yang Guo-qing Zhang College of Materials Science and Engineering Yangtze Normal UniversityChongqing 408100China National Engineering Research Center for Magnesium Alloys College of Materials Science and EngineeringChongqing UniversityChongqing 400044China Chongqing Jiulongyuan High-tech Industry Group Co. Ltd.Chongqing 400080China Loncin Industry Co. Ltd.Chongqing 400080China Department of Materials Science and Engineering The Ohio State UniversityColumbusOH 43210USA Chongqing Key Laboratory of Materials Surface&Interface Science Chongqing University of Arts and SciencesChongqing 402160China School of Metallurgy and Material Engineering Chongqing University of Science and TechnologyChongqing 401331China

The metallurgical quality control of magnesium(Mg)and Mg alloys in melting process is required to ensure a satisfied mechanical and corrosion performance,while the typical used steel crucible introduces impurities and interfacial interaction during melting ***,a systematic study about impurities diffusion and interfacial interaction between molten Mg and steel is *** the present study,the interfacial reaction between molten AZ91D Mg alloy and mild steel during melting process was investigated with the melting temperatures of 700℃,750℃ and 800℃.The results show that Al(Fe,Mn)intermetallic layer is the intermetallic primarily formed at the interfaces of AZ91D melt and mild ***,Al_(8)(Mn,Fe)5is indexed between Al(Fe,Mn)and ***_(3)C appears between the mild steel and Al(Fe,Mn)at 700℃ and 750℃,but absent at 800℃ due to the increased solubility of carbon in Mg *** is found that the growth of the intermetallic layer is controlled by diffusion mechanism,and Al and Mn are the dominant diffusing species in the whole interfacial reaction *** measuring the thickness of different layers,the growth constant was *** increases from 1.89(±0.03)×10^(-12)m^(2)·s^(-1)at 700℃ to 3.05(±0.05)×10^(-12)m^(2)·s^(-1)at 750℃,and 5.18(±0.05)×10^(-12)m^(2)·s^(-1)at 800℃.Meanwhile,the content of Fe is linearly increased in AZ91D with the increase of holding time at 700℃ and 750℃,while it shows a significantly increment after holding for 8 h at 800℃,indicating holding temperature is more crucial to determine the Fe content of AZ91D than holding time.

关键词： AZ91D mild steel interface reaction intermetallic growth kinetics