检索结果-南通市图书馆

Reynolds-number scaling analysis on lift generation of a flapping and passive rotating wing with an inhomogeneous mass distribution

引用

Chinese Journal of Aeronautics 2024年第2期37卷 259-269页

作者： Suyang QIN Haotian HANG Yang xiang hong LIU J.C.Wu center for aerodynamics school of aeronautics and astronauticsshanghai jiao tong universityshanghai 200240china

Insects usually fly by passively rotating wings,which has been applied to the design of flapping-wing Micro-Air Vehicles(MAVs)to reduce mechanical *** this paper,a robotic passive rotating-wing model is designed to investigate wing kinematics and lift generation,which are measured by a high-speed camera and a force transducer,*** addition,flow fields are measured using the Particle Image Velocimetry(PIV).Experimental results demonstrate that passive rotating motion has a coordinative relationship with actively stroking *** the stroke amplitude or frequency increases,the rotating amplitude is *** characterize the active stroking motion,a driving Reynolds number Redrivingis defined,which varies from 68 to 366 in this *** the gravity center of the wing towards trailing ed ge induces the increase of additional torque M,which decreases the wing rotating amplitude and promotes the advance of wing *** find that the timing of wing rotation is gradually delayed and the mean lift coefficient C^(-)_(L)monotonously decreases as *** increasing the additional torque M,C^(-)_(L)is slightly improved and approaches to the lift coefficient of a real fruit fly at driving Re approximately equal to *** instantaneous lifts combined with the vortical structures further demonstrate that the lift generation associated with wing rotation is mainly attributed to the growth of the LeadingEdge Vortex(LEV)and the passive wake capture *** wake capture is influenced by LEV,reversal stroke motion and wing additional torque together,which can only maintain the lift at a high level for a considerable *** high-lift generation mechanisms of flapping and passive rotating flight could shed light on the simplified design of MAVs and the improvement of their aerodynamic performance.

关键词： Flapping flight Unsteady lift Passive rotation Vortex flow Leading-edge vortex

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

Bioinspired nanotransducers for neuromodulation

引用

Nano Research 2024年第2期17卷 618-632页

作者： Fan Yang xiang Wu Sa Cai Guosong hong Department of Materials Science and Engineering Stanford UniversityStanfordCA 94305USA Wu Tsai Neurosciences Institute Stanford UniversityStanfordCA 94305USA School of Science Shenzhen Campus of Sun Yat-sen UniversityShenzhen 518107China

The field of neuromodulation has experienced significant advancements in the past decade,owing to breakthroughs in disciplines such as materials science,genetics,bioengineering,photonics,and *** convergence of these fields has resulted in the development of nanotransducers,devices that harness the synergies of these diverse *** nanotransducers,essential for neuromodulation,often draw inspiration from energy conversion processes found in nature for their unique *** this review,we will delve into the latest advancements in wireless neuromodulation facilitated by optical,magnetic,and mechanical *** will examine their working principles,properties,advantages,and limitations in comparison to current methods for deep brain neuromodulation,highlighting the impact of natural systems on their design and ***,we will underscore potential future directions,emphasizing how continued progress in materials science,neuroscience,and bioengineering might expand the horizons of what is achievable with nanotransducer-enabled neuromodulation.

关键词： bioinspired synthesis neuromodulation mechanoluminescence focused ultrasound nanotransducers sono-optogenetics

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

Weak type(1, 1) of the Riesz transform on some direct product manifolds with exponential volume growth

引用

Science China Mathematics 2024年第7期67卷 1599-1622页

作者： hong-Quan Li Jie-xiang Zhu School of Mathematical Sciences Fudan UniversityShanghai200433China Center for Applied Mathematics Tianjin UniversityTianjin300072China

In this paper, we are concerned with the Riesz transform on the direct product manifold H^(n)× M,where H^(n) is the n-dimensional real hyperbolic space, and M is a connected complete non-compact Riemannian manifold satisfying the volume doubling property and generalized Gaussian or sub-Gaussian upper estimates for the heat kernel. We establish its weak type(1, 1) property. In addition, we obtain the weak type(1, 1) of the heat maximal operator in the same setting. Our arguments also work for a large class of direct product manifolds with exponential volume growth. Particularly, we provide a simpler proof of weak type(1, 1) boundedness of some operators considered in the work of Li et al.(2.16).

关键词： Riesz transform heat kernel direct product real hyperbolic space

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

Immunomodulation of Proton-activated G Protein-coupled Receptors in Inflammation

引用

Current Medical Science 2024年第3期44卷 475-484页

作者： Min-shan LI xiang-hong WANG Heng WANG Department of Otolaryngology-Head and Neck Surgery Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China Institute of Allergy and Clinical Immunology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China Hubei Clinical Research Center for Nasal Inflammatory Diseases Wuhan430030China

Proton-activated G protein-coupled receptors(GPCRs),initially discovered by Ludwig in 2.03,are widely distributed in various *** receptors have been found to modulate the immune system in several inflammatory diseases,including inflammatory bowel disease,atopic dermatitis,and ***-activated GPCRs belong to the G protein-coupled receptor family and can detect alternations in extracellular *** detection triggers downstream signaling pathways within the cells,ultimately influencing the function of immune *** this review,we specifically focused on investigating the immune response of proton-activated GPCRs under inflammatory conditions.

关键词： proton-activated G protein-coupled receptors inflammation immunomodulation disease

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

Intelligent responsive self-assembled micro-nanocapsules: Used to delay gel gelation time

引用

Petroleum Science 2024年第4期21卷 2433-2443页

作者： Chuan-hong Kang Ji-xiang Guo Dong-Tao Fei Wyclif Kiyingi Unconventional Petroleum Research Institute China University of Petroleum

In the application of polymer gels to profile control and water shutoff,the gelation time will directly determine whether the gel can "go further" in the formation,but the most of the methods for delaying gel gelation time are complicated or have low *** is an urgent need for an effective method for delaying gel gelation time with intelligent *** by the slow-release effect of drug capsules,this paper uses the self-assembly effect of gas-phase hydrophobic SiO2.n aqueous solution as a capsule to prepare an intelligent responsive self-assembled *** capsule slowly releases the cross-linking agent under the stimulation of external conditions such as temperature and pH value,thus delaying gel gelation *** the pH value is 2.and the concentration of gas-phase hydrophobic SiO2.articles is 10%,the gelation time of the capsule gel system at 30,60,90,and 12.℃ is12.5,13.2.15.2.and 2..1 times longer than that of the gel system without containing capsule,*** with other methods,the yield stress of the gel without containing capsules was 78 Pa,and the yield stress after the addition of capsules was 32. *** intelligent responsive self-assembled micronanocapsules prepared by gas-phase hydrophobic silica nanoparticles can not only delay the gel gelation time,but also increase the gel *** slow release of cross-linking agent from capsule provides an effective method for prolongating the gelation time of polymer gels.

关键词： Profile control and water shutoff Polymer gel Delayed gelation time Intelligent response Self-assembled Micro-nanocapsules

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Insight of enriched basalts into the nature and evolution of mantle lithosphere beneath craton margins

引用

Science China Earth Sciences 2024年第10期67卷 3128-3142页

作者： hong-Kun DAI Jianping ZHENG Qing XIONG Linlin HU xiang ZHOU State Key Laboratory of Geological Processes and Mineral Resources School of Earth SciencesChina University of GeosciencesWuhan 430074China

Refractory lithospheric deep roots are the cornerstone for the prolonged stability of cratons and mantle xenoliths are normally the key targets for study on the evolution of such deep roots. In regions with few mantle xenoliths, the basalts enriched in radiogenic isotopic compositions due to marked lithospheric mantle contribution are crucial to unmask the lithospheric mantle evolution based on a comprehensive study involving petrology, geochemistry and thermodynamic modelling. Here, the Early Cretaceous basalts from the northwest North China Craton with few mantle xenoliths are taken as an example to show the significance of enriched basalts on the study of lithospheric mantle. These basalts are characterized by high silica and alkali contents(SiO_(2.=45.8–59.8 wt.%, K_(2.O+Na_(2.O=4.81–9.88 wt.%), arc-type trace-element patterns and enriched radiogenic isotope compositions(e.g., ε_(Nd)=-2.64–-12.88,^(87)Sr/^(86)Sr=0.7063–0.7093). The TiO_(2. and FeO(total) contents are higher than those of natural and experimental melts from refractory mantle peridotite but comparable to those of partial melts of fertile mantle *** high contents of fluid-loving elements(e.g., Rb and Ba) suggest source metasomatism by aqueous fluids. Combined with thermodynamic modelling and regional tectonic history, these enriched basalts likely record simultaneous decompression melting of asthenosphere and low-extent melting of thin and fertile lithospheric mantle fluxed by aqueous fluids from the subducted Paleo-Asian oceanic slab. The newly unmasked lithospheric mantle under the western NCC contrasts with the coeval thick and refractory one supporting the eastern NCC, and highlights that the craton destruction, especially the loss of its ancient refractory mantle root, should take place in a diachronous manner related to the craton-girded subduction episodes. Our study illustrates the potential of enriched basalts to recover the nature and evolution of mantle lithosphere beneath craton m

关键词： Enriched basalts Lithospheric mantle Northwest North China Craton Tectonic histories Early Cretaceous

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

NbB_(2.Modified Al-Cu Alloys Fabricated by Freeze-Ablation Casting under High Cooling Rate Solidification

引用

Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 921-938页

作者： xiang Kong Yu Wang hong Xu Haotian Fan Yuewu Zheng Beibei Xie School of Materials Science and Engineering North University of ChinaTaiyuan 030051China

At present,improving the properties of aluminum alloys is generally achieved by increasing the cooling rate of the melt and adding micro-nano *** the cooling rate of the melt to improve the refining effect of grain refiner is still a difficult problem in the aluminum alloy casting *** innovative and environmentally friendly casting process,known as freeze ablation,was introduced during the preparation of an Al–NbB_(2. intermediate *** process significantly enhanced the cooling rate of the *** results indicated that the Al–NbB_(2. intermediate alloy produced under high cooling rates had a noticeable refining effect on Al–Cu alloys,with smaller NbB2.particles demonstrating superior refining *** average grain size of the refined Al–Cu alloy decreased from 154 to 69μm,the tensile strength increased by 12.,the fluidity increased by 18.4%,and the hot tearing index decreased from 144 to *** matching degree between NbB_(2. andα-Al was calculated using high-resolution transmission electron microscopy and the edge-to-edge *** was found that the atomic interplanar spacing and the interatomic spacing mismatch between NbB_(2.’s2.>plane and Al were both less than 10%,which further proved that NbB2.could serve as an effective nucleation site forα-Al grains to achieve grain refinement.

关键词： Grain refinement Freeze ablation Particle size control Mechanical properties Process properties

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

A Weakly-Supervised Crowd Density Estimation Method Based on Two-Stage Linear Feature Calibration

引用

IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 965-981页

作者： Yong-Chao Li Rui-Sheng Jia Ying-xiang Hu hong-Mei Sun the College of Computer Science and Engineering Shandong University of Science and TechnologyQingdao 266590 the Faculty of Information Science and Engineering Ocean University of ChinaQingdao 266000China the College of Computer Science and Engineering Shandong University of Science and TechnologyQingdao 266590China the College of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210000China

In a crowd density estimation dataset,the annotation of crowd locations is an extremely laborious task,and they are not taken into the evaluation *** this paper,we aim to reduce the annotation cost of crowd datasets,and propose a crowd density estimation method based on weakly-supervised learning,in the absence of crowd position supervision information,which directly reduces the number of crowds by using the number of pedestrians in the image as the supervised *** this purpose,we design a new training method,which exploits the correlation between global and local image features by incremental learning to train the ***,we design a parent-child network(PC-Net)focusing on the global and local image respectively,and propose a linear feature calibration structure to train the PC-Net simultaneously,and the child network learns feature transfer factors and feature bias weights,and uses the transfer factors and bias weights to linearly feature calibrate the features extracted from the Parent network,to improve the convergence of the network by using local features hidden in the crowd *** addition,we use the pyramid vision transformer as the backbone of the PC-Net to extract crowd features at different levels,and design a global-local feature loss function(L2..We combine it with a crowd counting loss(LC)to enhance the sensitivity of the network to crowd features during the training process,which effectively improves the accuracy of crowd density *** experimental results show that the PC-Net significantly reduces the gap between fullysupervised and weakly-supervised crowd density estimation,and outperforms the comparison methods on five datasets of Shanghai Tech Part A,ShanghaiTech Part B,UCF_CC_50,UCF_QNRF and JHU-CROWD++.

关键词： Crowd density estimation linear feature calibration vision transformer weakly-supervision learning

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

Decoupled water electrolysis:Flexible strategy for pure hydrogen production with small voltage inputs

引用

Journal of Energy Chemistry 2024年第7期94卷 340-356页

作者： Kexin Zhou Jiahui Huang Daili xiang Aijiao Deng Jialei Du hong Liu Institute for Advanced Interdisciplinary Research(iAIR) Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of ShandongUniversity of JinanJinan 250022ShandongChina State Key Laboratory of Crystal Materials Shandong UniversityJinan 250100ShandongChina Zhengzhou Vocational College of Industrial Safety Zhengzhou 451192HenanChina

Hydrogen gas is widely regarded as an ideal green energy carrier and a potential alternative to fossil fuels for coping with the aggravating energy crisis and environmental ***,the vast majority of the world's hydrogen is produced by reforming fossil fuels;however,this hydrogen-making technology is not sustainable or environmentally friendly because ofits high energy consumption and large carbon ***-driven water splitting(2._(2.0-2._(2.+0_(2.)becomes an extensively studied scheme for sustain-able hydrogen *** water electrolysis requires an input voltage higher than 1.2. V and forms a gas mixture of H_(2./O_(2.,which results in high electricity consumption,potential safety hazards,and harmful reactive oxygen *** virtue of the auxiliary redox mediators(RMs)as the robust H^(+)/e^(-)reservoir,decoupled electrolysis splits water at a much lower potential and evolves O_(2.(H_(2.O+RMS_(ox)-O_(2.+H-RMS_(red))and H_(2.(H-RMS_(red)-H_(2.+RMS_(ox))at separate times,rates,and spaces,thus pro-ducing the puretarget hydrogen gas *** electrolysis has accelerated the development ofwater electrolysis technology for H_(2. ***,itis still lack of a comprehensive and in-depth review in this field based on different types of *** review highlights the basic principles and critical progress of this emerging water electrolysis mode over the past *** representative examples are then dis-played in detail according to the differences in the *** rational choice and design of RMs have also been ***,novel applications of decoupled water splitting are briefly discussed,including the manufacture of valuable chemicals,Cl_(2. production,pollutant degradation,and other half-reactions in artificial ***,thekey characteristics and disadvantages of each type of mediator are sum-marized in *** addition,we present an outlook for future directions in decoupled

关键词： Hydrogen production Conventional water splitting Decoupled water splitting Redox mediators Biomimetics

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

Near real-time gravitational wave data analysis of the massive black hole binary with TianQin

引用

Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 175-186页

作者： hong-Yu Chen xiang-Yu Lyu En-Kun Li Yi-Ming Hu MOE Key Laboratory of TianQin Mission TianQin Research Center for Gravitational Physics&School of Physics and AstronomyFrontiers Science Center for TianQinGravitational Wave Research Center of CNSASun Yat-sen University(Zhuhai Campus)Zhuhai 519082China

Space-borne gravitational wave(GW)detectors can detect the merger of massive black *** early warning and localization of GW events before merging can be used to inform electromagnetic telescopes and conduct multimessenger ***,this requires real-time data transmission and analysis *** geocentric orbit of the space-borne GW detector Tian Qin makes it possible to conduct real-time data *** this study,we develop a search and localization pipeline for massive black hole binaries(MBHBs)with Tian Qin under both regular and real-time data transmission *** demonstrate that,with real-time data transmission,MBHBs can be accurately localized on the *** the approaching merger,each analysis can be finished in only 40 *** an MBHB system at a distance of 1 Gpc,if we receive data every hour,then we can pinpoint its location to within less than 1 deg^(2.on the final day before the merger.

关键词： gravitational wave detectors and experiments black holes data analysis algorithms and implementation data management

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：