检索结果-南通市图书馆

Numerical Simulation of the Mass Movement Process of the 2018 Sedongpu Glacial Debris Flow by Using the Fluid-Solid Coupling Method

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Earth Science 2024年第2期35卷 583-596页

作者： Xing-Yu Long Yu-Xiang Hu bin-Rui gan Jia-Wen Zhou State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu610065China College of Water Resource and Hydropower Sichuan UniversityChengdu610065China

In the context of global warming and intensified human activities,glacier instability in plateau regions has increased,and glacier debris flows have become active,which poses a significant threat to the lives and property of people and socioeconomic *** mass movement process of glacier debris flows is extremely complex,so this paper uses the 2018 Sedongpu glacier debris flow event on the Qinghai-Tibet Plateau as an example and applies a numerical simulation method to invert the whole process of mass *** view of the interaction between phases in the process of motion,we use the fluid-solid coupling method to describe the mass *** granular-flow model and drift-flux model are employed in FLOW3D software to study the mass movement process of glacier debris flows and explore their dynamic *** results indicate that the glacier debris flow lasted for 700 s,and the movement process was roughly divided into four stages,including initiation,scraping,surging and deposition;the depositional characteristics calculated by the fluid-solid coupling model are consistent with the actual survey results and have good reliability;strong erosion occurs during the mass movement,the clear volume amplification effect,and the first wave climbs 17.8 m across the *** fluid-solid coupling method can better simulate glacier debris flows in plateau regions,which is helpful for the study of the mechanism and dynamic characteristics of such disasters.

关键词： glacial debris flow Qinghai-Tibet Plateau fluid-solid coupling FLOW3D mass movement depositional characteristics disasters engineering geology

A novel HfNbTaTiV high-entropy alloy of superior mechanical properties designed on the principle of maximum lattice distortion

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20期79卷 109-117页

作者： Zibing An Shengcheng Mao Yinong Liu Li Wang Hao Zhou bin gan Ze Zhang Xiaodong Han Beijing Key Lab of Microstructure and Property of Advanced Materials Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing100124China Department of Mechanical Engineering The University of Western AustraliaPerthWA6009Australia Nano and Heterogeneous Structural Materials Center School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing210094China Beijing Key Laboratory of Advanced High Temperature Materials Central Iron and Steel Research InstituteBeijing100081China State Key Laboratory of Silicon Materials Department of Materials Science and EngineeringZhejiang UniversityHangzhou310058China

This paper reports a synergistic design of high-performance BCC high-entropy alloy based on the combined consideration of the principles of intrinsic ductility of elements,maximum atomic size difference for solid solution strengthening and the valence electron concentration criterion for *** single-phase BCC HfNbTaTiV alloy thus designed exhibited a high compressive yield strength of 1350 MPa and a high compressive ductility of>45%at the room *** represents a 50%increase in yield strength relative to a HfNbTaTiZr *** is attributed to the maximized solid solution strengthening effect caused by lattice distortion,which is estimated to be 1094 *** alloy was also able to retain 53%of its yield strength and 77%of its ductility at 700℃.These properties are superior to those of most refractory BCC high-entropy alloys reported in the literature.

关键词： High-entropy alloy Solid solution strengthening Strengthening mechanism Mechanical properties

Extracting Variable-Depth Logical Document Hierarchy from Long Documents:Method,Evaluation,and Application

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2022年第3期37卷 699-718页

作者： Rong-Yu Cao Yi-Xuan Cao gan-bin Zhou Ping Luo Key Laboratory of Intelligent Information Processing of Chinese Academy of Sciences Institute of Computing TechnologyChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China WeChat Search Application Department Tencent Holdings Ltd.Beijing 100080China Peng Cheng Laboratory Shenzhen 518066China

In this paper,we study the problem of extracting variable-depth"logical document hierarchy"from long documents,namely organizing the recognized"physical document objects"into hierarchical *** discovery of logical document hierarchy is the vital step to support many downstream applications(e.g.,passage-based retrieval and high-quality information extraction).However,long documents,containing hundreds or even thousands of pages and a variable-depth hierarchy,challenge the existing *** address these challenges,we develop a framework,namely Hierarchy Extraction from Long Document(HELD),where we"sequentially"insert each physical object at the proper position on the current *** whether each possible position is proper or not can be formulated as a binary classification *** further improve its effectiveness and efficiency,we study the design variants in HELD,including traversal orders of the insertion positions,heading extraction explicitly or implicitly,tolerance to insertion errors in predecessor steps,and so *** for evaluations,we find that previous studies ignore the error that the depth of a node is correct while its path to the root is *** such mistakes may worsen the downstream applications seriously,a new measure is developed for a more careful *** empirical experiments based on thousands of long documents from Chinese financial market,English financial market and English scientific publication show that the HELD model with the"root-to-leaf"traversal order and explicit heading extraction is the best choice to achieve the tradeoff between effectiveness and efficiency with the accuracy of 0.972,6,0.729,1 and 0.957,8 in the Chinese financial,English financial and arXiv datasets,***,we show that the logical document hierarchy can be employed to significantly improve the performance of the downstream passage retrieval *** summary,we conduct a systematic study on this task in terms of methods

关键词： logical document hierarchy long documents passage retrieval

Superb cryogenic strength of equiatomic CrCoNi derived from gradient hierarchical microstructure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2019年第6期35卷 957-961页

作者： bin gan Jeffrey M. Wheeler Zhongnan Bi Lin Liu Jun Zhang Hengzhi Fu School of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 China Laboratory for Nanometallurgy Department of Materials Science ETH Zurich Vladimir-Prelog-Weg 5 Zurich CH-8093 Switzerland Central Iron and Steel Research Institute No. 76 Xueyuannan Road Beijing 100081 China

This work demonstrates the effectiveness of a cryogenic torsional pre-straining for significantly improving the cryogenic strength of an equiatomic CrCoNi alloy. The origin of this phenomenon is elucidated by various microstructural characterization tools, which shows that the sequential torsion and tension tests lead to the observed hierarchical microstructure through the activation of different twinning systems and stacking faults. This gives rise to the significant increase in the yield strength from 600 MPa to 1215 MPa,while the fracture strain changes from 68% to 48%. The current study reveals that the incorporation of nanotwins architecture by shear deformation may constitute a viable strategy to tune the mechanical performance and, in particular, to dramatically increase the strength while keeping a good ductility.

关键词： Medium entropy alloy CrCoNi Torsion Hierarchical microstructure Strengthening

Research Progress of Metal-Based Shielding Materials for Neutron and Gamma Rays

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2021年第12期34卷 1609-1617页

作者： bin gan Shichang Liu Zhen He Fucai Chen Haoxuan Niu Jingchang Cheng Bo Tan Bo Yu Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu610213China State Key Laboratory of Light Alloy Casting Technology for High-End Equipment Shenyang Research Institute of Foundry Co.Ltd.Shenyang110022China

The radiation generated by nuclear reaction is harmful to human body and equipment,thus the radiation shielding materials that employ the shielding ability from neutron and gamma rays are the best candidates according to application situations and radiation *** this paper,the researches of metal-based neutron and gamma rays or multiple purpose shielding materials are systematically summarized,and the respective and principal problems of these materials with respect to shielding effectiveness and other performances,such as corrosion,mechanical properties,manufacture,etc.,are ***,the prospect of shielding materials is outlined,which suggests that the development of highly efficient and multiply functional radiation shielding materials with good environmental compatibility is one of the future development trends.

关键词： Radiation shielding materials Metal-based Boron-containing shielding materials High density alloys

Molecular dynamics simulation and micropillar compression of deformation behavior in iridium single crystals

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2023年第10期42卷 3510-3517页

作者： Jia-Qi Wu Rui Hu Jie-Ren Yang bin gan Gong-Liao Luo Yi Liu Xi-Ming Luo State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an710072China State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metal Sino-platinum Metals Co.Ltd.Kunming Institute of Precious MetalsKunming650106China

The compression behaviors of iridium single crystals with different crystalline orientations were investigated by micropillar compression tests and molecular dynamics(MD) *** results indicated that the deformation process of iridium single crystals with [100]and [110] orientations was presented as the stacking faults expansion and the formation of Lomer-Cottrell *** the occurrence of Lomer-Cottrell locks was considered as the interaction of stacking faults on {111} planes by MD *** evolution of crystal structure in compression indicated that the Lomer-Cottrell locks might contribute to the large plastic deformation of iridium single ***,the deformation features in MD simulations showed that the elastic modulus(E) and yield stress(σ_(s)) of iridium single crystals were significantly influenced by the *** elastic modulus and yield stress gradually decreased with an increased temperature for all ***,the single crystal with a closely spaced lattice structure exhibited superior mechanical properties at a same temperature.

关键词： Iridium single crystal Crystalline orientation Deformation behavior Molecular dynamics Micropillar compression

Ectopic intrauterine device in the bladder causing cystolithiasis:A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2022年第10期10卷 3194-3199页

作者： Hai-Tao Yu Yong Chen Yong-Peng Xie Ting-bin gan Xin Gou Department of Urology The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400010China

BACKGROUND An intrauterine device(IUD)is a commonly used contraceptive among women in *** is widely used because it is safe,effective,simple,economic,and *** the possible complications,an ectopic IUD in the bladder is *** occurs insidiously,has a long course,is associated with a high risk for injury,and is difficult to *** SUMMARY A 44-year-old woman was admitted for repeated episodes of urinary frequency,urgency,and dysuria over three *** tests revealed significantly elevated urine leukocytes and *** culture suggested colonization with Enterococcus *** computed tomography images suggested an abnormally positioned IUD that was protruding into the *** revealed a metallic foreign body with multiple stones on its surface in the left posterior bladder *** foreign body measured approximately 1 *** revealed the arm of a V-type metal IUD embedded in the middle and upper sections of the anterior wall of the cervical *** majority of the IUD was located in the uterine *** was performed,and a holmium laser was utilized to break the stones attached to the portion of the IUD in the *** IUD was then removed through *** Ectopic IUDs in the bladder can be diagnosed with thorough imaging and safely removed through cystoscopy or hysteroscopy.

关键词： Migrated intrauterine device Cystoscopy Hysteroscopy Bladder stones Urinary tract infection Case report

Successful management of tubular colonic duplication using a laparoscopic approach: A case report and review of the literature

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2020年第15期8卷 3291-3298页

作者： gan-bin Li Jia-gang Han Zhen-Jun Wang Zhi-Wei Zhai Yu Tao Department of General Surgery Beijing Chaoyang HospitalCapital Medical UniversityBeijing 100020China

BACKGROUND Alimentary duplication is a rare congenital disease with a reported incidence of 1 per 4500 persons,although the exact incidence has been difficult to *** to previous reports,the most common site of duplication is the ileum,and colonic duplication is *** to different types and locations of the duplication,the manifestations are varied,which makes establishing an accurate diagnosis before surgery a *** SUMMARY A 17-year-old female patient sought evaluation in our department with constipation and chronic abdominal pain for 12 years;she had difficulty defecating and had dry stools since she was a *** abdominal computed tomography revealed two extremely enlarged loops of bowel full of stool-like intestinal contents in the left lower abdomen,which led us to consider the possibility of colonic duplication.A laparoscopic exploration was performed,which revealed a tubular duplicated colon that shared a common opening with the transverse colon.A left hemi-colectomy was performed with a side-to-side *** pathologic results confirmed the *** the 6-mo followup,the patient was doing well without constipation or abdominal *** Colonic duplication is a rare alimentary abnormality in *** to the nonspecific manifestations and low incidence,it is usually difficult to make an accurate diagnosis *** is the mainstay of treatment,even though some patients are asymptomatic.

关键词： Colonic duplication Diagnosis Laparoscopy Case report

Origin of the high propensity for nanoscale deformation twins in CrCoNi medium-entropy alloy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第16期183卷 63-71页

作者： Nan-Jun Liu Zhang-Jie Wang Jun Ding Mark Asta Robert O.Ritchie bin gan Evan Ma Zhi-Wei Shan Center for Advancing Materials Performance from the Nanoscale(CAMP-Nano) State Key Laboratory for Mechanical Behavior of MaterialsXi’an Jiaotong UniversityXi’an 710049China Center for Alloy Innovation and Design(CAID) State Key Laboratory for Mechanical Behavior of MaterialsXi’an Jiaotong UniversityXi’an 710049China Materials Sciences Division Lawrence Berkeley National LaboratoryBerkeleyCA 94720United States Department of Materials Science&Engineering University of CaliforniaBerkeleyCA 94720United States Beijing Key Laboratory of Advanced High Temperature Materials Central Iron and Steel Research InstituteBeijing 100081China

Single-phase face-centered cubic(fcc)high/medium-entropy alloys(H/MEAs)exhibit a much higher tendency to form nanoscale deformation twins than conventional fcc metals with similar low stacking fault energies(SFEs).This extraordinary propensity for nanotwin formation in H/MEAs cannot therefore be ex-plained by their low SFEs ***,using in situ compression tests of CrCoNi in comparison with Ag nanopillars inside a transmission electron microscope,we found that in the CrCoNi MEA,a high density of nanoscale twins continuously formed with an average thickness of 4.6 *** contrast,for similar experiments on Ag with almost identical SFE,following the nucleation of a few twins,they could further thicken to above one hundred nanometers by twin boundary *** dynamics calculations indicated that in the highly-concentrated CrCoNi solid solution,the magnitude of the energy barriers for nucleating a stacking fault as a twin precursor in the pristine lattice and for the thickening of an existing twin both span a wide range and largely overlap with each ***,twin thickening through successive addition of atomic layers is prone to discontinuation,giving way to the nucleation of new twins at other sites where a lower energy barrier is encountered for partial-dislocation mediated fault formation.

关键词： High-entropy alloys CrCoNi Nanotwins Twin nucleation