检索结果-南通市图书馆

Formation mechanism of large grains inside annealed microstructure of GH4169 superalloy by cellular automation method

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2019年第7期35卷 1403-1411页

作者： Ming-Song chen Zong-Huai Zou y.c.lin Hong-Bin Li Guan-Qiang Wang School of Mechanical and Electrical Engineering Central South UniversityChangsha410083China State Key Laboratory of High Performance complex Manufacturing Changsha410083China college of metallurgies and energy North China Science and Technologies UniversityTangshan063009China

In authors’ previous work [Mater. charact. 141 (2018) 212-222]. it was found that the heterogeneous deformed microstructures can be replaced by the relatively homogeneous recrystallized grains through an annealing treatment. However, there are still some relatively large recrystallized grains. To find the reasons for the formation of large grains, some new annealing treatment tests were done, and the cellular automation (cA) simulations were carried out in the present work. The experimental results showed that the microstructural evolution during annealing treatment is significantly affected by the content of S phase. So. the effects of δ phase on the nucleation and growth of grains are carefully considered in the cA model to accurately simulate the microstructural evolution behavior. By the cA simulation, it is found that the dislocation density rapidly decreases due to the nucleation of static recrystallization (SRX) and the growth of dynamc recrystallization (DRX) nuclei at the early stage of annealing. The high initial dislocation density provide the high velocity for the growth of DRX nuclei, which is responsible for the formation of coarse grains, However, the growth rate of SRX nuclei is relatively small due to the low dislocation density and pinning effects of δ phase.

关键词： GH4169 superalloy cellular automation model coarse grains Annealing treatment Recrystallization behavior

Detection of Breaking Waves Using X-Band Pulse Radar in the Nearshore Region

在线全文

学校读者我要写书评

暂无评论

china Ocean Engineering 2013年第4期27卷 549-556页

作者： y.c.lin c.c.chang M.c.Lee H.c.chan J.M.Leu Department of Hydraulic and Ocean Engineering National Cheng-Kung University Department of Soil and Water conservation National Chung Hsing University Department of Hospitality Management Taiwan Shoufu University

An X-band pulsed Doppler microwave radar has been used to determine the characteristics of breaking waves. Field experiments were conducted at the Shuang-Si estuary in the north of Taiwan in the winter of 2005. Analyses on maxima radar cross section and Doppler frequency shift are done to characterize wave breaking zones. Based on observations of breaking waves, the wave breaking zones are shown to be located at water depths of 1.8 to 2.2 m in the experimental site. In general, the results indicate that a radar system has the potential to delineate the spatial variation of breaking waves clearly and that this is sufficient to achieve a measurement operation for near-shore air-sea interaction events.

关键词： radar Doppler effect wave breaking coastal zone

Methods and mechanisms for uniformly refining deformed mixed and coarse grains inside a solution-treated Ni-based superalloy by two-stage heat treatment

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第18期77卷 47-57页

作者： Guan-Qiang Wang Ming-Song chen Hong-Bin Li y.c.lin Wei-Dong Zeng yan-yong Ma School of Mechanical and Electrical Engineering Central South UniversityChangsha 410083China Light Alloy Research Institute Central South UniversityChangsha 410083China State Key Laboratory of High Performance complex Manufacturing Changsha 410083China college of Metallurgies and Energy North China University Science and TechnologyTangshan 063009China

The uniform refinement mechanisms and methods of deformed mixed and coarse grains inside a solution-treatment Ni-based superalloy during two-stage annealing treatment have been *** two-stage heat treatment experiments include an aging annealing treatment(AT)and a subsequent recrystallization annealing treatment(RT).The object of AT is to precipitate someδphases and consume part of storage energy to inhibit the grain growth during RT,while the RT is to refine mixed and coarse grains by *** can be found that the recrystallization grains will quickly grow up to a large size when the AT time is too low or the RT temperature is too high,while the deformed coarse grains cannot be eliminated when the AT time is too long or the RT temperature is too *** addition,the mixed microstructure composed of some abnormal coarse recrystallization grains(AcRGs)and a large number of fine grains can be observed in the annealed specimen when the AT time is 3 h and RT temperature is 980℃.The phenomenon attributes to the uneven distribution ofδphase resulted from the heterogeneous deformation energy when the AT time is too *** the regions with a large number ofδphases,the recrystallization nucleation rate is promoted and the growth of grains is limited,which results in fine ***,in the regions with fewδphases,the recrystallization grains around grain boundaries can easily grow up,and the new recrystallization nucleus is difficult to form inside grain,which leads to ***,in order to obtain uniform and fine annealed microstructure,it is a prerequisite to precipitate even-distributedδphase by choosing a suitable AT time,such as 12 ***,a relative high RT temperature is also needed to promote the recrystallization nucleation aroundδ*** optimal annealing parameters range for uniformly refining mixed crystal can be summarized as:900℃×12 h+990℃×(40-60 min)and 900℃×12 h+1000℃×(10-15 min).

关键词： Ni-based superalloy Aging annealing Recrystallization annealing Grain refinement Microstructural evolution Mixed grain microstructure

Hot deformation behavior of a Sr-modified Al-Si-Mg alloy:constitutive model and processing maps

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of china 2018年第4期28卷 592-603页

作者： y.c.lin Shun-cun LUO Xing-you JIANG yi TANG Ming-song cHEN School of Mechanical and Electrical Engineering Central South UniversityChangsha 410083China Light Alloy Research Institute Central South UniversityChangsha 410083China State Key Laboratory of High Performance complex Manufacturing Central South UniversityChangsha 410083China

Isothermal compression experiments were conducted to study the hot deformation behaviors of a Sr-modified Al-Si-Mg alloy in the temperature range of 300-420°c and strain rate range of 0.01-10 s-1.A physically-based model was developed to accurately predict the flow ***,processing maps were established to optimize hot working *** is found that decreasing the strain rate or increasing the deformation temperature reduces the flow *** high activation energy is closely related to the pinning of dislocations from Si-containing ***,the deformed grains and the Si-containing dispersoids in the matrix are elongated perpendicular to the compression direction,and incomplete dynamic recrystallization(DRX)is discovered on the elongated boundaries in domain with peak *** flow instability is mainly attributed to the flow localization,brittle fracture of eutectic Si phase,and formation of adiabatic shear *** optimum hot working window is 380-420°c and 0.03-0.28 s-1.

关键词： Al-Si-Mg alloy constitutive model processing map microstructure

Data-driven Static Equivalence with Physics-informed Koopman Operators

在线全文

学校读者我要写书评

暂无评论

cSEE Journal of Power and Energy Systems 2024年第1期10卷 432-438页

作者： Wei lin changhong Zhao Maosheng Gao c.y.chung Department of Electrical Engineering The Hong Kong Polytechnic UniversityHong Kong SARChina Department of Information Engineering The Chinese University of Hong KongHong Kong SARChina School of Electrical Engineering Chongqing UniversityChongqing 400044China

With deployment of measurement units,fitting static equivalent models of distribution networks(DNs)by linear regression has been recognized as an effective method in power flow analysis of a transmission *** volatility of measurements caused by variable distributed renewable energy sources makes it more difficult to accurately fit such equivalent *** tackle this challenge,this letter proposes a novel data-driven method to improve equivalency accuracy of DNs with distributed energy *** letter provides a new perspective that an equivalent model can be regarded as a mapping from internal conditions and border voltages to border power *** mapping can be established through 1)Koopman operator theory,and 2)physical features of power flow equations at the root node of a *** of the proposed method is demonstrated on the IEEE 33-bus and IEEE 136-bus test systems connected to a 661-bus utility system.

关键词： Data-driven distribution network Koopman operator theory static equivalent model

伴宫颈间质浸润的子宫内膜癌:3 T MR扩散加权成像与动态增强成像的诊断准确性

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

国际医学放射学杂志 2017年第4期 480-481页

作者： G.lin y.T.Huang A.chao y.c.lin L.y.yang R.c.Wu 朱珍 Department of Medical Imaging and Intervention Institute for Radiological Research Chang Gung Memorial Hospital at Linkouand Chang Gung University

摘要目的比较扩散加权（DW）成像和动态增强（DcE）MR成像在检测子宫内膜癌宫颈间质浸润的诊断准确性。方法83例连续的子宫内膜癌女性病人进行术前3 T MRI检查,包括T;W、DW（b=0、1 000 s/mm;）和DcE MRI。以组织病理学检查为金标准,2...

摘要目的比较扩散加权（DW）成像和动态增强（DcE）MR成像在检测子宫内膜癌宫颈间质浸润的诊断准确性。方法83例连续的子宫内膜癌女性病人进行术前3 T MRI检查,包括T;W、DW（b=0、1 000 s/mm;）和DcE MRI。以组织病理学检查为金标准,2位放射科医师独立评估宫颈间质浸润的表现。结果由阅片者1和阅片者2评估宫颈间质浸润的

关键词：

动态增强MRI、扩散加权MRI以及18F-FDGPET/cT对口咽与下咽鳞状细胞癌病人化疗后生存率的预测

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

国际医学放射学杂志 2017年第1期 107-108页

作者： S.H.Ng c.T.Liao c.y.lin S.c.chan y.c.lin T.c.yen 柴超 Department of Medical Imaging and Radiological Sciences Chang Gung Memorial Hospital Chang Gung University

摘要目的前瞻性评估治疗前动态增强MRI、扩散加权MRI与;F-FDG PET/cT对口咽与下咽鳞状细胞癌病人化疗后生存率的预测。方法组织学证实的患有口咽与下咽鳞状

关键词：扩散加权口咽 MRI 动态增强病人化疗鳞状细胞癌生存率 cT

Distinct Electrical and Mechanical Responses of a cu-10Fe composite Prepared by Hot-Pressed Sintering and Post Treatment

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) 2024年第2期37卷 255-265页

作者： X.y.yue S.y.Peng X.Zhang c.N.He y.Z.Tian Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang110819China School of Materials Science and Engineering and Tianjin Key Laboratory of composite and Functional Materials Tianjin UniversityTianjin300350China Research centre for Metallic Wires Northeastern UniversityShenyang110819China

A cu-10wt%Fe composite was prepared through hot-pressed sintering,and the material was subsequently solution *** hot-pressed sintered and solution treated materials were rolled and *** precipitation behavior and performance changes were systematically studied by using scanning electron microscopy and transmission electron *** contrast to the hot-pressed sintered specimen,the solution treatment significantly affects the thermal stability and properties of the cu-10wt%Fe *** cu-10wt%Fe composite was prepared after solid solution,cold rolling and aging at 773 K for 1 h,and it obtained excellent tensile strength of 494 MPa,uniform elongation of 16.3%,electrical conductivity of 51.1%IAcS and softening temperature of 838 *** for the distinct difference in thermal stability and properties between hot-pressed sintered and solution treated specimens were *** findings provide a theoretical basis for designing high-performance cu-based in-situ composites by post treatment.

关键词： cu-Fe composite Hot-pressed sintering Thermal stability Strength Electrical conductivity

基于深度学习的下咽癌MRI全自动分割与影像组学特征提取

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

国际医学放射学杂志 2023年第6期 750-750页

作者： y.c.lin G.lin S.Pandey c.H.yeh J.J.Wang c.y.lin 鄢英男

摘要目的利用卷积神经网络对下咽癌（HPc）进行MRI全自动分割和影像组学特征提取。方法收集222例HPc病人的MR影像，其中178例用于训练，44例用于测

关键词：