检索结果-南通市图书馆

A survey of deep learning-based 3D shape generation

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

Computational Visual Media 2023年第3期9卷 407-442页

作者： qun-Ce Xu Tai-jiang Mu Yong-Liang Yang BNRist Department of Computer Science and TechnologyTsinghua UniversityBeijing 100084China Department of Computer Science University of BathBathUK

Deep learning has been successfully used for tasks in the 2D image *** on 3D computer vision and deep geometry learning has also attracted *** achievements have been made regarding feature extraction and discrimination of 3D *** recent advances in deep generative models such as generative adversarial networks,effective generation of 3D shapes has become an active research *** 2D images with a regular grid structure,3D shapes have various representations,such as voxels,point clouds,meshes,and implicit *** deep learning of 3D shapes,shape representation has to be taken into account as there is no unified representation that can cover all tasks *** such as the representativeness of geometry and topology often largely affect the quality of the generated 3D *** this survey,we comprehensively review works on deep-learning-based 3D shape generation by classifying and discussing them in terms of the underlying shape representation and the architecture of the shape *** advantages and disadvantages of each class are further *** also consider the 3D shape datasets commonly used for shape ***,we present several potential research directions that hopefully can inspire future works on this topic.

关键词： 3D representations geometry learning generative models deep learning

Tribological behavior of AISI302 austenitic stainless steel modified by elevated temperature nitrogen plasma immersion ion implantation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2004年第z1期14卷 301-304页

作者： jiang Shao-qun MA Xin-xin SUN Yue School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

AISI302 stainless steel samples were modified by elevated temperature nitrogen plasma immersion ion implantation at temperature ranging from 330 ℃ to 450 ℃. The tribological behaviors of the implanted layers of the samples were investigated. The samples were characterized by Auger electron spectroscopy (AES), glancing angle X-ray diffraction (GXRD), and nanoindentation. The results show that the implantation temperature plays an important rule on the microstructure and surface properties of the implanted layers. The thickness of the modified layer implanted at 390 ℃ is about 9 μm. It is improved about two orders compared with that of the implanted at room temperature. The surface nanohardness and the wear resistance of elevated temperature implanted layers increase significantly, and the friction coefficient decreases obviously in comparison with the unimplanted one. These data suggests that the improvement results from the formation of new phases such as ε-(Fe, Cr, Ni)2+xN, or noncrystal phase.

关键词： austenite stainless steel elevated temperature plasma immersion ion implantation tribology nanohardness

Numerical simulation of pedestrian flow past a circular obstruction

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 Sinica 2011年第2期27卷 215-221页

作者： Yan-qun jiang Ru-Xun Liu Ya-Li Duan Department of Mathematics Southwest University of Science and Technology 621010 Mianyang China Department of Mathematics University of Science and Technology of China 230026 Hefei China

In this paper, a revisiting Hughes’ dynamic continuum model is used to investigate and predict the essential macroscopic characteristics of pedestrian flow, such as flow, density and average speed, in a two dimensional continuous walking facility scattered with a circular obstruction. It is assumed that pedestrians prefer to walk a path with the lowest instantaneous travel cost from origin to destination, under the consideration of the current traffic conditions and the tendency to avoid a high-density region and an obstruction. An algorithm for the pedestrian flow model is based on a cellcentered finite volume method for a scalar conservation law equation, a fast sweeping method for an Eikonal-type equation and a second-order TVD Runge-Kutta method for the time integration on unstructured meshes. Numerical results demonstrate the effectiveness of the algorithm. It is verified that density distribution of pedestrian flow is influenced by the position of the obstruction and the path-choice behavior of pedestrians.

关键词： Pedestrian flow · Continuum model ·Finite volume method · Unstructured meshes · Obstruction

Effect of precipitates on high-temperature strength and irradiation behavior of vanadium-based alloys

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

Journal of Iron and Steel Research International 2018年第12期25卷 1270-1277页

作者： Shao-ning jiang Li-qun Xu Fa-rong Wan School of Mechanical and Automotive Engineering Qilu University of Technology (Shandong Academy of Science) Jinan 250353ShandongChina School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China

The formation of precipitates and their effect on mechanical properties and irradiation damage in V-4CraTi alloys have been investigated using transmission electron microscope,high-temperature tensile tests and high-voltage electron microscope (HVEM).V-4Cr-4Ti alloys were aged for 20-40 h at 873 K,and extremely fine precipitates were produced during the aging process,which coarsened with aging *** results of high-temperature (773,873 and 973 K)tensile tests showed an increase in strength with increasing aging time (i.e:,increasing size of precipitates)while a decrease in the uniform *** was evidence that presence of precipitates strengthened V-4Cr-4Ti *** situ HVEM observations showed that the precipitates restricted the growth rate of dislocation loops induced during electron irradiation at 773 *** interactions between precipitates and irradiation-induced dislocation loops were *** presence of particles alleviated the increase in irradiation hardening up to an irradiation dose of 3.42 dpa (displacement per atom).The precipitates shrank in size during electron irradiation,which was due to the dissolution of constituent atoms of the precipitates into the alloy matrix.

关键词： Aging Precipitate strengthening Electron irradiation Irradiation defect Dislocation loop

Dynamics of stochastic predator-prey models with distributed delay and stage structure for prey

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Biomathematics 2021年第4期14卷 85-120页

作者： qun Liu Daqing jiang Tasawar Hayat School of Mathematics and Statistics Key Laboratory of Applied Statistics of MOE Northeast Normal University Changchun 130024 Jilin ProvinceP.R.China College of Science China University of Petroleum Qingdao 266580Shandong ProvinceP.R.China Nonlinear Analysis and Applied Mathematics(NAAM)-Research Group King A bdulaziz University JeddahSaudi Arabia

In this paper,we analyze two stochastic predator-prey models with distributed delay and stage structure for *** the nonautonomous periodic case of the model,by using Khasminskii’s theory of periodic solution,we show that the system has at least one positive T-periodic *** the model which is disturbed by both white and telegraph noises,we obtain sufficient criteria for positive recurrence of the solutions to the model by constructing a suitable stochastic Lyapunov function with regime *** positive recurrence implies that both prey and predator populations will be persistent in the long term.

关键词： Stochastic predator-prey model stage structure distributed delay periodic solution positive recurrence

Downregulation of the nucleosome-binding protein 1 （NSBP1） gene can inhibit the in vitro and in vivo proliferation of prostate cancer cells

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2010年第5期12卷 709-717页

作者： Ning jiang Li-qun Zhou Xiao-Yu Zhang Department of Urology Peking University First Hospital Beijing 100034 China The Institute of Urology Peking University Beijing 100034 China National Urological Cancer Center Beijing 100034 China

This studay is to construct a lentiviral vector harbouring an RNA interference （RNAi） sequence that targets the gene encoding the human high-mobility group nucleosomal binding protein 1 （NSBP1）; to study its role in inducing G2/M phase arrest and apoptosis in prostate cancer （PCa） DU145 cells; and to assess the effect of its knockdown on cell proliferation in vitro and in vivo. RNAi was applied to knock down NSBP1 expression in the PCa cell line DU145 by lentiviral plasmids producing an NSBP1 small hairpin RNA. After NSBP1 knockdown in DU145 cells, the growth rate of cells was analyzed by MTT, and G2/M cell cycle arrest and apoptosis were assessed using a FAC- Scalibur flow cytometer. Tumour growth was assessed in nude mice. The mRNA and protein expression levels of NSBP1, cyclin B1 and Bcl-2 were analysed in vitro and in vivo by reverse-transcriptase polymerase chain reaction and Western blotting. Knockdown of NSBP1 resulted in a 22.6% decrease in the growth rate of cells compared with the PscNC lentivirus control cells at 96 h, decreased tumour growth in nude mice, and the induction of Gz/M cell cycle arrest （8.78%） and apoptosis （2.19-fold）. Consistent with the cell cycle arrest and apoptosis, the mRNA and protein expression levels of cyclin B 1 and Bcl-2 were decreased. In conclusion, knockdown of NSBP 1 causes a statistically significant inhibition of the in vitro and in vivo growth of the PCa cell line DU145. Growth suppression is at least partially due to NSBP1 knockdown-induced Gz/M cell cycle arrest and apoptosis. The present data provide the evidence that the NSBP1 knockdown-induced G2/M phase arrest and apoptosis may result from negative regulation of cyclin B 1 and Bcl-2 by NSBP1, with the resulting reduced expression of these proteins.

关键词： apoptosis NSBP 1 proliferation prostate cancer RNA interference

Transformation of phthalic acid diesters in an anaerobic/anoxic/oxic leachate treatment process

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2020年第1期28卷 249-253页

作者： qun Wang Lanhui jiang Chengran Fang Hongzhi Mao Haifeng Zhuang Key Laboratory of Recycling and Eco-treatment of Waste Biomass of Zhejiang Province Zhejiang University of Science and TechnologyHangzhou 310023China

Transformations of di-n-butyl phthalate(DBP) and di(2-ethylhexyl) phthalate(DEHP) have been investigated in anaerobic/anoxic/oxic(A/A/O) leachate treatment processes. Although the DBP removal processes are different when the DBP initial concentration is different, the overall system DBP removal efficiencies are high(N 94%).DEHP is much more difficult to remove than DBP. The removal efficiency of DEHP is approximately 75%–78%.The results of mass balance calculations indicate that approximately 33.7%–50.7% of the DBP is degraded by the activated sludge, 48.9%–64.9% accumulates in the system, and 0.4%–1.4% is contained in the final effluent. Approximately 15.0%–19.0% of the DEHP is degraded by activated microcosms, 75.8%–79.0% accumulates in the system, and 5.2%–6.0% is contained in the final effluent. Biodegradation and adsorption to the activated sludge are the main mechanisms for DBP removal and adsorption to the activated sludge is the main mechanism for DEHP removal. The different removal mechanisms of the two PAEs may be related to their different molecular structures. However, PAEs are not really removed when they adsorb onto the sludge. Therefore, methods for decreasing PAEs adsorption and increasing the biodegradation efficiencies of the leachate treatment processes should be further investigated.

关键词： Phthalic acid diesters Leachate Anaerobic–anoxic–oxic system Biodegradation Adsorption

Determination of hydroxyl radicals in TiO2/Ti photoelectrocatalytic oxidation system using Fe（phen）3^2＋ spectrophotometry

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

Journal of Environmental Sciences 2006年第1期18卷 158-161页

作者： jiang Yan-li LIU Hui-ling WANG qun-hui jiang Zhao-hua Department of Environmental Engineering Harbin Institute of Technology Harbin 150001 China Department of Applied Chemistry Harbin Institute of Technology Harbin 150001 China School of Life Science and Chemistry Harbin University Harbin 150086 China

A new method of determining the cumulate concentration of hydroxyl radicals in the TiO2/Ti photoelectrocatalytic（PEC） oxidation system was established by o-phenanthroline-Fe（Ⅱ）（Fe（phen）3^2＋） spectrophotometry and using anion exchange membrane. Fe （phen）3^2＋ can be oxidized to o-phenanthroline-Fe（Ⅲ）（Fe（phen）3^3＋） by strong oxidization of hydroxyl radicals（·OH）. Then the cumulate concentration of hydroxyl radicals can be calculated through determining the change of the Fe（phen）3^3＋ absorbency at 509 nm. In addition, the research results showed the production rate of hydroxyl radicals was affected obviously by pH of solution, the cumulate concentration of hydroxyl radicals was the largest at nearby the initial pH 6.3 （isoelectric point）, and the change direction of pH after illumination tended to nearby isoelectric point.

关键词： TiO2 / Ti catalyst photoelectrocatalysis o-phenanthroline-Fe hydroxyl radical anion exchange membrane

Mechanisms of action of neuropeptide Y on stem cells and its potential applications in orthopaedic disorders

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 Stem Cells 2020年第9期12卷 986-1000页

作者： Jian-qun Wu Nan jiang Bin Yu Department of Orthopedics and Traumatology Huadu District People’s HospitalGuangzhou 510800Guangdong ProvinceChina Division of Orthopaedics and Traumatology Department of OrthopedicsNanfang HospitalSouthern Medical UniversityGuangzhou 510515Guangdong ProvinceChina Guangdong Provincial Key Laboratory of Bone and Cartilage Regenerative Medicine Nanfang HospitalSouthern Medical UniversityGuangzhou 510515Guangdong ProvinceChina

Musculoskeletal disorders are the leading causes of disability and result in reduced quality of *** neuro-osteogenic network is one of the most promising fields in orthopaedic *** Y(NPY)system has been reported to be involved in the regulations of bone metabolism and homeostasis,which also provide feedback to the central NPY system via NPY ***,potential roles of peripheral NPY in bone metabolism remain *** evidence suggests that NPY can regulate biological actions of bone marrow mesenchymal stem cells,hematopoietic stem cells,endothelial cells,and chondrocytes via a local autocrine or paracrine manner by different NPY *** regulative activities of NPY may be achieved through the plasticity of NPY receptors,and interactions among the targeted cells as *** general,NPY can influence proliferation,apoptosis,differentiation,migration,mobilization,and cytokine secretion of different types of cells,and play crucial roles in the development of bone delayed/non-union,osteoporosis,and *** basic research should clarify detailed mechanisms of action of NPY on stem cells,and clinical investigations are also necessary to comprehensively evaluate potential applications of NPY and its receptor-targeted drugs in management of musculoskeletal disorders.

关键词： Neuropeptide Y Bone marrow mesenchymal stem cells Hematopoietic stem cells Fracture Osteoporosis Osteoarthritis