检索结果-南通市图书馆

Transient stimulated Raman scattering spectroscopy and imaging

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第4期13卷 654-663页

作者： Qiaozhi yu Zhengjian Yao Jiaqi Zhou Wenhao yu Chenjie Zhuang Yafeng Qi Hanqing Xiong National Biomedical Imaging Center College of Future TechnologyPeking UniversityBeijing 100871China Biomedical Engineering Department College of Future TechnologyPeking UniversityBeijing 100871China

Stimulated Raman scattering(SRS)has been developed as an essential quantitative contrast for chemical imaging in recent ***,while spectral lines near the natural linewidth limit can be routinely achieved by state-of-the-art spontaneous Raman microscopes,spectral broadening is inevitable for current mainstream SRS imaging *** is because those SRS signals are all measured in the frequency *** is a compromise between sensitivity and spectral resolution:as the nonlinear process benefits from pulsed excitations,the fundamental time-energy uncertainty limits the spectral ***,the spectral range and acquisition speed are mutually *** we report transient stimulated Raman scattering(T-SRS),an alternative time-domain strategy that bypasses all these fundamental conjugations.T-SRS is achieved by quantum coherence manipulation:we encode the vibrational oscillations in the stimulated Raman loss(SRL)signal by femtosecond pulse-pair sequence excited vibrational wave packet *** Raman spectrum was then achieved by Fourier transform of the time-domain SRL *** all Raman modes are impulsively and simultaneously excited,T-SRS features the natural-linewidth-limit spectral line shapes,laser-bandwidth-determined spectral range,and improved ***~150-fs laser pulses,we boost the sensitivity of typical Raman modes to the sub-mM *** all-plane-mirror high-speed time-delay scanning,we further demonstrated hyperspectral SRS imaging of live-cell metabolism and high-density multiplexed imaging with the natural-linewidth-limit spectral resolution.T-SRS shall find valuable applications for advanced Raman imaging.

关键词： scattering excited mutually

BL03HB: a Laue microdiffraction beamline for both protein crystallography and materials science at SSRF

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第7期35卷 68-78页

作者： Zhi-Jun Wang Si-Sheng Wang Zheng-Huang Su Li yu yu-Zhu Wang Bo Sun Wen Wen Xing-yu Gao Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai201210China University of Chinese Academy of Science Beijing100049China

A Laue microdiffraction beamline (BL03HB) was constructed at the Shanghai SynchrotronRadiation Facility (SSRF). This beamline featu res two consecutive focusing points in twodifferent sectors within its end station, the first dedicated to protein crystallography and theother tailored to materials science applications. Based on a superbend dipole magnet with amagnetic field of 2.29 T, a two-stage focusing design was implemented with two sets of Kirkpatrick- Baez mirrors to achieve a micro white beam as small as 4.2 um X4.3 pμm at the firstsector and 09 pum X 1.3 pum at the second sector in the standard beamline operation mode at *** X-ray microbeam in the two sectors can be easily switched between monochromatic andwhite beams by moving a four-bounce monochromator in or out of the light path, respectively. Inthe protein crystallography sector, white-beam Laue microdifraction was dermonstrated tosuccessully determine the structure of protein crystals from only a few images of diffraction data .collected by a Pilatus 2 M area detector. In the materials science sector, the white -beam Lauediffraction was collected in a reflection geometry using another Pilatus 2 M area detector, whichcould map the microstructural distribution on the sample surface by scanning the samples. Ingeneral, the BL03HB beamline promotes the application of Laue microdiffraction in both proteincrystallgraphy and materials science. This paper presents a comprehensive overview of theBL03HB beamline, end station, and the first commission results.

关键词： Crystallography White-beam Laue microdiffraction Beamline Synchrotron

Simulating the GRF of Humanoid Robot Vertical Jumping Using a Simplified Model with a Foot Structure for Foot Design

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 Bionic Engineering 2024年第1期21卷 112-125页

作者： Chuanku Yi Xuechao Chen yu Zhang Zhangguo yu Haoxiang Qi Yaliang Liu Qiang Huang School of Mechatronical Engineering Beijing Institute of TechnologyZizhuyaunHaidianBeijing 100081China Beijing Advanced Innovation Center for Intelligent Robots and Systems Beijing Institute of Tec

There are many theories and tools for human or robot motion simulation,but most of them require complex *** LNZN model(a simplified model named by the proposers)simplifies the human model and facilitates simulation of the Ground Reaction Force(GRF)of body landing by spring damping model and ignoring joint rotation movements,which can reduce the amount of computation *** this paper,the LNZN model of human running is selected as the basis and is modified to obtain the LNZN model of a robot,which expands the application of the LNZN *** to the structure of the human foot,a foot structure is then added to the simplified model to reduce the *** also applied driving forces to the new model to simulate the whole high jump motion of the robot to expand the functions of the LNZN *** obtained GRF data were anastomotic to the actual experimental *** addition,the effects of variables,such as the mass,hardness,and damping,of the foot on the GRF at the moment of landing were also ***,based on the guidelines obtained for the design of the robot’s foot structure,we fabricated new robot’s feet and installed them on the actual robot and achieved a better cushioning effect than the original foot in experiments.

关键词： LNZN model-GRF simulation Humanoid foot structure Foot parameters

Growth of Ag/g-C_(3)N_(4) nanocomposites on nickel foam to enhance photocatalytic degradation of formaldehyde under visible light

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 Environmental Sciences 2024年第3期137卷 432-442页

作者： Ze Wang Zhi Huang Jiang yu Xiao Shao Weidong Peng Jie yu Yinying Jiang Department of Environmental Science and Engineering College of Architecture and EnvironmentSichuan UniversityChengdu 610065China Institute of New Energy and Low Carbon Technology Sichuan UniversityChengdu 610065China School of Agriculture and Environment University of Western AustraliaPerth 6907Western AustraliaAustralia Yibin Institute of Industrial Technology Sichuan UniversityYibin 644000China

Formaldehyde is a pollutant that significantly affects the indoor air ***,conventional remediation approaches can be challenging to deal with low-concentration formaldehyde in an indoor *** this study,Photocatalysts of Ag/graphitic carbon nitride(g-C_(3)N_(4))/Ni with 3D reticulated coral structure were prepared by thermal polymerization and liquid phase photo-deposition,using nickel foam(NF)as the *** demonstrated that when the Ag concentration was 3%,and the relative humidity was 60%,the Ni/Ag/g-C_(3)N_(4)showed the maximum degradation rate of formaldehyde at 90.19%under visible light irradiation,and the formaldehyde concentration after degradation was lower than the Hygienic standard stated by the Chinese *** porous structure of Ni/Ag/g-C_(3)N_(4)and the formation of Schottky junctions promoted the Adsorption efficiency and degradation of formaldehyde,while the nickel foam carrier effectively promoted the desorption of degradation ***,the degradation rate was only reduced by3.4%after 16 recycles,the three-dimensional porous structure extended the lifetime of the *** study provides a new strategy for the degradation of indoor formaldehyde at low concentrations.

关键词： Graphitic carbon nitride(g-C_(3)N_(4)) Nickel foam(NF) Ag Formaldehyde Photocatalysis

More tree growth reduction due to consecutive drought and its legacy effect for a semiarid larch plantation in Northwest China

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 Forestry Research 2024年第2期35卷 188-196页

作者： Yanfang Wan Pengtao yu Yanhui Wang Jiamei Li yushi Bai Yipeng yu Bingbing Liu Xiaocha Wei Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration Ecology and Nature Conservation InstituteChinese Academy of ForestryBeijing 100091People’s Republic of China

Extreme climate has increasingly led to negative impacts on forest ecosystems globally,especially in semiarid areas where forest ecosystems are more ***,it is poorly understood how tree growth is affected by different drought *** 2006–2009,the larch plantations in the semiarid areas of Northwest China were negatively affected by four consecutive dry years,which was a very rare phenomenon that may occur frequently under future climate *** this study,we analyzed the effect of these consecutive dry years on tree growth based on the data of the tree rings in the dominant layer of the forest canopy on a larch *** found that the tree-ring width index(RWI)in dry years was lower than that in normal years,and it experienced a rapidly decreasing trend from 2006 to 2009(slope=-0.139 year^(-1),r=-0.94)due to water supply deficits in those dry *** induced legacy effects of tree growth reduction,and consecutive dry years corresponded with greater growth reductions and legacy *** reductions and legacy effects were significantly stronger in the third and fourth consecutive dry years than that of single dry year(p<0.05),which might have been due to the cumulative stress caused by consecutive dry *** results showed that larch trees experienced greater tree growth reduction due to consecutive dry years and their legacy effect,and the trees had lower recovery rates after consecutive dry *** results highlight that consecutive dry years pose a new threat to plantations under climate warming,and thus,the effect of climate extremes on tree growth should be considered in growth models in semiarid areas.

关键词： Tree rings Drought effects Legacy effects Growth-climate relationships Larix principis-rupprechtii

Data-driven modeling on anisotropic mechanical behavior of brain tissue with internal pressure

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

Defence Technology（防务技术） 2024年第3期33卷 55-65页

作者： Zhiyuan Tang yu Wang Khalil I.Elkhodary Zefeng yu Shan Tang Dan Peng State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDalian University of Technology116023DalianPR China The Department of Mechanical Engineering The American University in CairoNew Cairo11835Egypt Department of Neurology The Second Hospital of Dalian Medical UniversityDalian116023PR China

Brain tissue is one of the softest parts of the human body,composed of white matter and grey *** mechanical behavior of the brain tissue plays an essential role in regulating brain morphology and brain ***,traumatic brain injury(TBI)and various brain diseases are also greatly influenced by the brain's mechanical *** white matter or grey matter,brain tissue contains multiscale structures composed of neurons,glial cells,fibers,blood vessels,etc.,each with different mechanical *** such,brain tissue exhibits complex mechanical behavior,usually with strong nonlinearity,heterogeneity,and directional *** a constitutive law for multiscale brain tissue using traditional function-based approaches can be very ***,this paper proposes a data-driven approach to establish the desired mechanical model of brain *** focus on blood vessels with internal pressure embedded in a white or grey matter matrix material to demonstrate our *** matrix is described by an isotropic or anisotropic nonlinear elastic model.A representative unit cell(RUC)with blood vessels is built,which is used to generate the stress-strain data under different internal blood pressure and various proportional displacement loading *** generated stress-strain data is then used to train a mechanical law using artificial neural networks to predict the macroscopic mechanical response of brain tissue under different internal ***,the trained material model is implemented into finite element software to predict the mechanical behavior of a whole brain under intracranial pressure and distributed body *** with a direct numerical simulation that employs a reference material model,our proposed approach greatly reduces the computational cost and improves modeling *** predictions made by our trained model demonstrate sufficient ***,we find that the level of internal blood pressur

关键词： Data driven Constitutive law Anisotropy Brain tissue Internal pressure

Effect of Cr_(2)O_(3) on properties of CaO-SiO_(2)-Fe_(t)O-MgO system and dissolution behavior of lime

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) 2024年第4期31卷 870-881页

作者： Shan-nan Li Jian-li Li yue yu Hang-yu Zhu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina

The productivity of the chrome-containing semi-steel converter smelting process is directly affected by the slag-forming speed during the converter preliminary *** effects of Cr_(2)O_(3) content on the physicochemical properties of the CaO-SiO_(2)-Fe_(t)O-MgO system,such as melting temperature,solidification behavior,mineral composition,and lime dissolution rate,were *** results showed that the slag was an amorphous phase at 1500℃.When Cr_(2)O_(3) was added,Ca(Fe,Mg)Si_(2)O_(6) and spinel were formed in the *** the increase in Cr_(2)O_(3) content,the amount of spinel precipitation increased,and the dendritic FegO_(4) crystal gradually changed into the granular(Fe,Mg)(Fe,Cr)2O_(4) *** the Cr_(2)O_(3) content increased from O to 2.91 wt.%,the melting temperature of the slag rose,and the melting range of the slag expanded slightly,but the lime dissolution rate did not *** the Cr_(2)O_(3) content further increased to 9.09 wt.%,the melting temperature continued to rise,the melting range rapidly expanded,and the lime dissolution rate decreased.

关键词： Cr_(2)O_(3) Vanadium-titanium magnetite Converter Slag Lime dissolution

CONVERGENCE OF MODIFIED TRUNCATED EULER-MARUYAMA METHOD FOR STOCHASTIC DIFFERENTIAL EQUATIONS WITH HOLDER DIFFUSION COEFFICIENTS

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 Computational Mathematics 2024年第4期42卷 1109-1123页

作者： Guangqiang Lan yu Jiang College of Mathematics and Physics Beijing University of Chemical TechnologyBeijing 100029China

Convergence of modified truncated Euler-Maruyama(MTEM)method for stochastic differential equations(SDEs)with(1/2+α)-Holder continuous diffusion coefficients are investigated in this *** prove that the MTEM method for... 详细信息

关键词： Stochastic differential equations Modified truncated Euler-Maruyama method Strong convergence One-sided Lipschitz Holder continuous

Method for Detecting Industrial Defects in Intelligent Manufacturing Using Deep Learning

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第1期78卷 1329-1343页

作者： Bowen yu Chunli Xie College of Mechanical and Electrical Engineering Northeast Forestry UniversityHarbin150040China

With the advent of Industry 4.0,marked by a surge in intelligent manufacturing,advanced sensors embedded in smart factories now enable extensive data collection on equipment *** analysis of such data is pivotal for ensuring production safety,a critical factor in monitoring the health status of manufacturing *** defect detection techniques,typically limited to specific scenarios,often require manual feature extraction,leading to inefficiencies and limited versatility in the overall *** research presents an intelligent defect detection methodology that leverages deep learning techniques to automate feature extraction and defect localization *** proposed approach encompasses a suite of components:the high-level feature learning block(HLFLB),the multi-scale feature learning block(MSFLB),and a dynamic adaptive fusion block(DAFB),working in tandem to extract meticulously and synergistically aggregate defect-related characteristics across various scales and hierarchical *** have conducted validation of the proposed method using datasets derived from gearbox and bearing *** empirical outcomes underscore the superior defect detection capability of our *** demonstrates consistently high performance across diverse datasets and possesses the accuracy required to categorize defects,taking into account their specific locations and the extent of damage,proving the method’s effectiveness and reliability in identifying defects in industrial components.

关键词： Industrial defect detection deep learning intelligent manufacturing