检索结果-南通市图书馆

Applying rotation-invariant star descriptor to deep-sky image registration

Frontiers of Computer Science 2018年第5期12卷 1013-1025页

作者： haiyang zhou Yunzhi YU College of Optical Science and Engineering Zhejiang University Hangzhou 310027 China Department of Computer Science University of Southern California Los Angeles CA 90089-0781 USA

Image registration is a critical process of many deep-sky image processing applications. Image registration methods include image stacking to reduce noise or achieve long exposure effects within a short exposure time, image stitching to extend the field of view, and atmospheric turbu- lence removal. The most widely used method for deep-sky image registration is the triangle- or polygon-based method, which is both memory and computation intensive. Deepsky image registration mainly focuses on translation and rotation caused by the vibration of imaging devices and the Earth＇s rotation, where rotation is the more difficult problem. For this problem, the best method is to find corresponding rotation-invariant features between different images. In this paper, we analyze the defects introduced by applying rotation-invariant feature descriptors to deep-sky image reg- istration and propose a novel descriptor. First, a dominant orientation is estimated from the geometrical relationships between a described star and two neighboring stable stars. An adaptive speeded-up robust features （SURF） descriptor is then constructed. During the construction of SURF, the local patch size adaptively changes based on the described star size. Finally, the proposed descriptor is formed by fusing star properties, geometrical relationships, and the adaptive SURF. Extensive experiments demonstrate that the proposed descriptor successfully addresses the gap resulting from applying the traditional feature-based method to deep-sky image registration and performs well compared to state-of-the-art descriptors.

关键词： image registration feature descriptor deep-skyimage rotation-invariant descriptor

来源：

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

Research on the Error Averaging Effect in A Rolling Guide Pair

引用

Chinese Journal of Mechanical Engineering 2019年第4期32卷 104-115页

作者： Yanbing Ni haiyang zhou Cuiyan Shao Jinhe Li Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education Tianjin University

By studying the e ects of geometric precision on kinematic accuracy, an error mapping model has been established, based on the hypothesis that a motion pair and its installation surface are rigid. However, when using this assumption,there is a significant error induced in high-precision computer numerical control(CNC) machine tools as compared with reality. One of the most important reasons for this error is failing to consider the error averaging e ect of motion pair elements. Therefore, this work examines a high-precision horizontal machining center as its research object, and analyzes the error averaging mechanism of a rolling guide pair under a deformation of the rolling elements. The carriage bearing forces caused by guideway straightness errors are obtained by constructing a geometric error model of a single carriage. The relationship between guideway straightness errors and carriage bearing forces is described by a transfer function in the spatial frequency domain, and its characteristics are analyzed. It quantifies the so-called error averaging e ect of the rolling guide system and, on this basis, a static model for four carriages is established to reflect the error averaging e ect of the rolling guide pair on the position and orientation errors of the motion pair. In addition, it is found that the wavelengths and phase di erences of guideway errors a ect this error averaging mechanism, but the amplitude and preload have little influence thereon. The experiment result shows that the kinematic straightness errors in the x-and y-directions were approximately 1/3 to 1/2 of the guideway straightness errors in the corresponding directions. The results can be used to guide the precision design and assembly of machine tools.

关键词： Rolling guide pair Error averaging mechanism Guideway straightness errors Precision design

来源：

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

A large-grain-size thick-film polycrystalline diamond detector for x-ray detection

引用

Plasma Science and Technology 2020年第12期22卷 97-103页

作者： Ping XU Yi YU haiyang zhou Changjun QIU School of Resources Environment and Safety Engineering University of South ChinaHengyang 421001People's Republic of China School of Physics University of Science and Technology of ChinaHefei 230026People's Republic of China School of Mechanical Engineering University of South ChinaHengyang 421001People's Republic of China

A diamond film with a size of 6×6×0.5 mm^3 is fabricated by electron-assisted chemical vapor deposition. Raman spectrum analysis, x-ray diffraction and scanning electron microscope images confirm the high purity and large grain size, which is larger than 300 μm. Its resistivity is higher than 10^12 W· cm. Interlaced-finger electrodes are imprinted onto the diamond film to develop an x-ray detector. Ohmic contact is confirmed by checking the linearity of its current–voltage curve. The dark current is lower than 0.1 n A under an electric field of 30 k V cm^-1. The time response is 220 ps. The sensitivity is about 125 m A W^-1 under a biasing voltage of 100 V.A good linear radiation dose rate is also confirmed. This diamond detector is used to measure x-ray on a Z-pinch, which has a double-layer 'nested tungsten wire array'. The pronounced peaks in the measured waveform clearly characterize the x-ray bursts, which proves the performance of this diamond detector.

关键词： polycrystalline diamond film x-ray detector electron-assisted chemical vapor deposition

来源：

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

Mechanical Properties and Fire Retardancy of Wood Flour/High-Density Polyethylene Composites Reinforced with Continuous Honeycomb-Like Nano-SiO_(2)Network and Fire Retardant

引用

Journal of Renewable Materials 2020年第5期8卷 485-498页

作者： haiyang zhou Xiaoyu Wang Xiaolong Hao Qingwen Wang Rongxian Ou Key Laboratory for Biobased Materials and Energy of Ministry of Education College of Materials and EnergySouth China Agricultural UniversityGuangzhou510642China Guangdong Laboratory for Lingnan Modern Agricultural Science and Technology Guangzhou510642China College of Arts South China Agricultural UniversityGuangzhou510642China

The mechanical properties of wood flour/high-density polyethylene composites(WPC)were improved by adding a small amount of nano-SiO_(2)to obtain a network-structured WPC with a continuous honeycomb-like nano-SiO_(2)*** wood flour was modified with a fire retardant(a mixture of sodium octabonate and amidine urea phosphate)to improve its fire *** flexural properties,creep resistance,thermal expansion,and fire retardancy of the WPC were compared to a control(WPCCTRL)without nano-SiO_(2)or fire *** flexural strength and modulus of the WPC containing only 0.55 wt.%nano-SiO_(2)were 6.6%and 9.1%higher than the control,respectively,while the creep strain and thermal expansion rate at 90°C were 33.8%and 13.6%lower,*** cone calorimetry tests revealed that the nano-SiO_(2)network physically shielded the WPC,giving it lower heat release and smoke production *** thermal expansion was further decreased by incorporating fire retardants into the WPC,which showed the lowest total heat release and total smoke production and the highest mass *** study demonstrates a facile procedure for producing WPC with desired performances by forming a continuous honeycomb-like network by adding a small amount of nanoparticles.

关键词： Wood plastic composites nano-SiO_(2) mechanical properties creep fire retardancy

来源：

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

Remineralization of initial enamel caries in vitro using a novel peptide based on amelogenin

引用

Frontiers of Materials Science 2015年第3期9卷 293-302页

作者： Danxue LI Xueping LV Huanxin TU Xuedong zhou haiyang YU Linglin ZHANG State Key Laboratory of Oral Diseases West China Hospital of Stomatology Sichuan University Chengdu 610041 China

Dental caries is the most common oral disease with high incidence, widely spread and can seriously affect the health of oral cavity and the whole body. Current caries prevention measures such as fluoride treatment, antimicrobial agents, and traditional Chinese herbal, have limitations to some extent. Here we design and synthesize a novel peptide based on the amelogenin, and assess its ability to promote the remineralization of initial enamel caries lesions. We used enamel blocks to form initial lesions, and then subjected to 12-day pH cycling in the presence of peptide, NaF and HEPES buffer. Enamel treated with peptide or NaF had shallower, narrower lesions, thicker remineralized surfaces and less mineral loss than enamel treated with HEPES. This peptide can promote the remineralization of initial enamel caries and inhibit the progress of caries. It is a promising anti-caries agent with various research prospects and practical application value.

关键词： dental caries peptide remineralization

来源：

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

Genomic analysis of schistosomiasis-associated colorectal cancer reveals a unique mutational landscape and therapeutic implications

引用

Genes & Diseases 2023年第3期10卷 657-659页

作者： Dong Yu Anqi Wang Jing Zhang Xinxing Li Caifeng Jiang haiyang zhou Center for Translational Medicine Naval Medical UniversityShanghai 200433China Department of Colorectal Surgery Changzheng HospitalNaval Medical UniversityShanghai 200003China Department of Pathology Changzheng HospitalNaval Medical UniversityShanghai 200003China Department of General Surgery Shanghai Tongji HospitalTongji UniversityShanghai 200062China Department of Gastroenterology Dushu Lake Hospital Affiliated to Soochow UniversitySuzhouJiangsu 215123China

The schistosomiasis-associated colorectal cancer (SA-CRC) is thought to be caused by the chronic inflammation as a result of schistosomal ova deposition in the submucosal layer of the intestine (Fig. S1). It is reported that SA-CRC differs from sporadic colorectal cancer (S-CRC) in terms of epidemiological features, histological patterns, and clinical outcomes,1 which is also supported by our institutional data (Table S1 and Fig. S2). Here we investigate the genomic alternations and probable molecular determinants of pathogenesis in Chinese SA-CRC.

关键词： colorectal schistosomiasis cancer

来源：

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

Fabrication of a single-crystal diamond neutron detector and its application in 14.1 MeV neutron detection in deuterium-tritium fusion experiments

引用

Plasma Science and Technology 2023年第7期25卷 14-18页

作者：许平余羿周海洋 School of Physics Xihua UniversityChengdu 610039People’s Republic of China Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082People’s Republic of China Department of Plasma Physics and Fusion Engineering University of Science and Technology of ChinaHefei 230026People’s Republic of China

A single-crystal diamond detector is fabricated to diagnose 14.1 MeV deuterium-tritium(D-T)fusion *** size of its diamond film is 4.5 mm×4.5 mm×500μ*** film is sandwiched by a flat,strip-patterned gold *** dark current of this detector is experimentally measured to be lower than 0.1 nA under an electric field of 30 kV cm^(-1).This diamond detector is used to measure D-T fusion neutrons with a flux of about 7.5×10^(5) s^(-1)cm^(-2).The pronounced peak with a central energy of 8.28 MeV characterizing the^(12)C(n,α)~9Be reaction in the neutron energy spectrum is experimentally diagnosed,and the energy resolution is better than 1.69%,which is the best result reported so far using a diamond detector.A clear peak with a central energy of 6.52 MeV characterizing the^(12)C(n,n')3αreaction is also identified with an energy resolution of better than 7.67%.

关键词： neutron diagnostic deuterium-tritium neutron single-crystal diamond neutron detector

来源：

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

A numerical survey of parameters to reach ignition condition for axial compression of a large-sized field reversed configuration

引用

Plasma Science and Technology 2024年第5期26卷 47-55页

作者：李宜霖廖晖周海洋孙玄 Department of Plasma Physics and Fusion Engineering School of Nuclear Science and TechnologyUniversity of Science and Technology of ChinaHefei 230026People’s Republic of China

Field reversed configuration(FRC)is widely considered as an ideal target plasma for magnetoinertial ***,its confinement and stability,both proportional to the radius,will deteriorate inevitably during radial ***,we propose a new fusion approach based on axial compression of a large-sized *** axial compression can be made by plasma jets or plasmoids converging onto the axial ends of the *** parameter space that can reach the ignition condition while preserving the FRC's overall quality is studied using a numerical model based on different FRC confinement *** is found that ignition is possible for a large FRC that can be achieved with the current FRC formation techniques if compression ratio is greater than 50.A more realistic compression is to combine axial with moderate radial compression,which is also presented and calculated in this work.

关键词： field reversed configuration magnetized target fusion axial compression

来源：

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

A RANDOM FUNCTIONAL CENTRAL LIMIT THEOREM FOR PROCESSES OF PRODUCT SUMS OF LINEAR PROCESSES GENERATED BY MARTINGALE DIFFERENCES

引用

Chinese Annals of Mathematics,Series B 2003年第4期24卷 449-456页

作者： WANG YUEBAO YANG YANG zhou haiyang Department of Mathematics, Suzhou University, Suzhou 215006, Jiangsu, China. Department of Mathematics, Suzhou University, Suzhou 215006, Jiangsu, China. Suzhou Univ Dept Math Suzhou 215006 Peoples R China

A random functional central limit theorem is obtained for processes of partial sums andproduct sums of linear processes generated by non-stationary martingale differences. It devel-ops and improves some corresponding results on processes of partial sums of linear processesgenerated by strictly stationary martingale differences, which can be found in [5].

关键词： Ilandom functional central limit theorem Processes of product sums

来源：

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

Cyclotron Resonance of Free Magnetopolaron in Quantum Well Wires

引用

Journal of Materials Science & Technology 1993年第4期9卷 263-267页

作者： haiyang zhou Kadi ZHU Shiwei GU Dept.of Applied Physics,Jiaotong University,Shanghai,200030,China

The cyclotron resonance of magnetopolaron in quantum well wires (QWWs) have been studied with the use of variational solutions to the effective mass equation. The results show that both the abso- lute value of the electron-phonon interaction energy and the cyclotron resonance frequency de- crease with the increase of the sizes of QWWs, and also that the cyclotron resonance frequency in- creases with the external magnetic field.

关键词： cyclotron resonance magnetopolaron quantum well wires

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：