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Spatial resolution and image processing for pinhole camera-based X-ray fluorescence imaging: a simulation study

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Nuclear Science and Techniques 2022年第5期33卷 135-153页

作者： Ze He Ning Huang Peng Wang zi-Han chen Bo Peng Key Laboratory of Radiation Physics and Technology of the Ministry of Education Institute of Nuclear Science and TechnologySichuan UniversityChengdu 610064China

Spatial resolution and image-processing methods for full-field X-ray fluorescence(FF-XRF)imaging using X-ray pinhole cameras were studied using Geant4simulations with different geometries and algorithms for image *** main objectives were:(1)calculating the quantum efficiency curves of specific cameras,(2)studying the relationships between the spatial resolution and the pinhole diameter,magnification,and camera binning value,and(3)comparing image-processing methods for pinhole camera *** results were obtained using a point and plane source as the X-ray fluorescence emitter and an array of 100×100 silicon pixel detectors as the X-ray *** quantum efficiency of a back-illuminated deep depletion(BI-DD)structure was above 30%for the XRF energies in the 0.8–9 keV range,with the maximum of 93.7%at 4 *** best spatial resolution of the pinhole camera was 24.7μm and 31.3 lp/mm when measured using the profile function of the point source,with the diameter of 20μm,magnification of 3.16,and camera bin of 1.A blind deconvolution algorithm with Gaussian filtering performed better than the Wiener filter and Richardson iterative methods on FF-XRF images,with the signal-to-noise ratio of 7.81 dB and improved signalto-noise ratio of 7.24 dB at the diameter of 120μm,magnification of 1.0,and camera bin of 1.

关键词： Full-field X-ray fluorescence(FF-XRF) X-ray pinhole camera Spatial resolution Image processing

Supervised Vessels Classification Based on Feature Selection

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Journal of Computer Science & Technology 2017年第6期32卷 1222-1230页

作者： Bei-Ji Zou Yao chen cheng-Zhang Zhu Zai-Liang chen zi-Qian Zhang School of Information Science and Engineering Central South University Changsha 410083 China ‘Mobile Health' Ministry of Education-China Mobile Joint Laboratory Central South University Changsha 410083 China College of Literature and Journalism Central South University Changsha 410083 China

Arterial-venous classification of retinal blood vessels is important for the automatic detection of cardiovascular diseases such as hypertensive retinopathy and stroke. In this paper, we propose an arterial-venous classification （AVC） method, which focuses on feature extraction and selection from vessel centerline pixels. The vessel centerline is extracted after the preprocessing of vessel segmentation and optic disc （OD） localization. Then, a region of interest （ROI） is extracted around OD, and the most efficient features of each centerline pixel in ROI are selected from the local features, grey-level co-occurrence matrix （GLCM） features, and an adaptive local binary patten （A-LBP） feature by using a max-relevance and min-redundancy （mRMR） scheme. Finally, a feature-weighted K-nearest neighbor （FW-KNN） algorithm is used to classify the arterial-venous vessels. The experimental results on the DRIVE database and INSPIRE-AVR database achieve the high accuracy of 88.65% and 88.51% in ROI, respectively.

关键词： fundus image arterial-venous classification adaptive local binary patten(A-LBP) feature selection feature-weighted K-nearest neighbor(FW-KNN)

Resonances for positron–helium and positron–lithium systems in kappa-distribution plasma

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Chinese Physics B 2018年第12期27卷 244-249页

作者： zi-Shi Jiang Ya-chen Gao Key Laboratory of Electronics Engineering College of Heilongjiang ProvinceHeilongjiang Universityand College of Physical Science and TechnologyHeilongjiang UniversityHarbin 150080China Department of Physics Harbin Institute of TechnologyHarbin 150001China Department of Mathematics University of MalayaKuala LampurMalaysia

S-wave resonances of positron–helium and positron–lithium systems in kappa-distribution plasmas are investigated using Hylleraas-type wave functions in the framework of the stabilization method. A model potential approach is used to represent the interactions between the outer electron, the positron and the core. The resonance parameters(position and width) of positron–helium and positron–lithium systems below the Ps(2s) threshold are reported as a function of screening parameter and spectral index of plasma.

关键词： positron–atom scattering kappa-distribution plasmas model potential approach variational method

MOFs-based functional materials for aqueous micro/nanoplastics elimination

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Chinese Chemical Letters 2023年第9期34卷 5-6页

作者： Chong-chen Wang zi-chen Zhang Xiao-Hong Yi Beijing Key Laboratory of Functional Materials for Building Structure and Environment Remediation School of Environment and Energy EngineeringBeijing University of Civil Engineering and ArchitectureBeijing 100044China

The massive distribution of microplastics(MPs)and even nanoplastics(NPs),which resulted from the wide utilization and mismanagement of plastics,exerted serious risk and threat to ecosystem and human health due to thei... 详细信息

关键词： plastics functional massive

Development of an indirect competitive ELISA for simultaneous detection of enrofloxacin and ciprofloxacin

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2011年第11期12卷 884-891页

作者： hai-tang ZHANG Jin-qing JIANG zi-liang WANG Xin-yao CHANG Xing-you LIU San-hu WANG Kun ZHAO Jin-shan chen College of Animal Science Henan Institute of Science and Technology Xinxiang 453003 China Henan Higher Education Engineering Technology Research Center for Animal Diseases Control and Residues Supervision Xinxiang 453003 China

Modified 1-ethyl-3-(3-dimethylaminopropy) carbodiimide(EDC) method was employed to synthesize the artificial antigen of enrofloxacin(ENR),and New Zealand rabbits were used to produce anti-ENR polyclonal antibody(pAb).Based on the checkerboard titration,an indirect competitive enzyme-linked immunosorbent assay(ELISA) standard curve was *** assay was sensitive and had a linear range from 0.6 to 148.0 μg/kg(R2=0.9567),with the half maximal inhibitory concentration(IC50) and limit of detection(LOD) values of 9.4 μg/kg and 0.2 μg/kg,*** all the competitive analogues,the produced pAb exhibited a high cross-reactivity to ciprofloxacin(CIP)(87%),the main metabolite of ENR in *** optimization,the matrix effects can be ignored using a 10-fold dilution in beef and 20-fold dilution in *** overall recoveries and coefficients of variation(CVs) were in the ranges of 86%-109% and 6.8%-13.1%,*** can be concluded that the established ELISA method is suitable for simultaneous detection of ENR and CIP in animal tissues.

关键词： Enrofloxacin Ciprofloxacin Indirect competitive ELISA Animal tissues

Structural abnormalities of trigeminal root with neurovascular compression revealed by high resolution diffusion tensor imaging

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Asian Pacific Journal of Tropical Medicine 2012年第9期5卷 749-752页

作者： Jing chen zi-Yi Guo Qi-Zhou Liang hai-Yan Liao Wen-Rui Su Cai-Xiang chen Shui-Xi Fu Xiang-Jun Han Radiology Department Municipal Hospital of Haikou

Objective:To detect neurovascular compression-induced structural abnormalities of trigeminal nerves(TGN) by diffusion tensor imaging(DTI).Methods:The affected ipsilateral TGN(iTGN) and unaffected contralateral TGN(cTGN) of 20 trifacial neuralgia(TIM) patients as well as the bilateral TGN of 10 normal controls(nTGN) were examined by DTI and 3D high resolution MR] using a 3.0 T MRI *** fractional anisotropy and apparent diffusion coefficieiil(ADC) were ***:Compared with the cTGN and nTGN,the *** significantly lower fraction of anisotropy(FA),significantly higher *** significantly smaller volume and crosssectional area(P<0.05).Conclusions:The increase in ADC and decrease in FA has a close relationship with morphological changes of TGN,and the DTI could provide valuable diagnostic information on TGN structure forTN patients.

关键词： Trigeminal nerves Diffusion tensor imaging Trifacial neuralgia Apparent diffusion coefficient Fraction of anisotropy

Max-utility subcarrier allocation for heterogeneous services in wireless OFDM system

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The Journal of China Universities of Posts and Telecommunications 2009年第1期16卷 51-57页

作者： chen zi-xiong SUN Kai YUAN Jun WANG Ying Key Laboratory of Universal Wireless Communication Beijing University of Posts and Telecommunications Beijing 100876 China College of Eleclxonic Information Engineering Inner Mongolia University Hohhot 010021 China

In future wireless network, one user will require multiple homogeneous or heterogeneous services simultaneously. Then, the scheduling algorithm is not only responsible for assigning a resource block to different users but also sharing the assigned resource block among multiple services for one user. Most of the traditional scheduling algorithms are designed to serve one service per user, and cannot be applied directly to this scenario because of the fairness criterion. This article focuses on adaptive resource allocation for multiple services per user at the downlink of orthogonal frequency division multiplexing （OFDM） based system. This article addresses this integrative resource scheduling problem based on utility function. First, the optimal algorithm for dynamic subcarrier allocation and share is deduced for homogeneous best-effort service system. Then the algorithm is extended to heterogeneous services system by classifying the delay sensitive service according to the head-of-line packet delay. The design goal is to maximize aggregate utility function to exploit multiuser diversity gain to the greatest extent even as guaranteeing quality of service （QoS） for delay sensitive service.

关键词： heterogeneous service multiuser diversity radio resource scheduling utility function

Data driven composite shape descriptor design for shape retrieval with a VoR-Tree

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Applied Mathematics(A Journal of Chinese Universities) 2018年第1期33卷 88-106页

作者： WANG zi-hao LIN Hong-wei XU chen-kai School of Mathematical Science State Key Lab.of CAD&CG Zhejiang University

We develop a data driven method(probability model) to construct a composite shape descriptor by combining a pair of scale-based shape descriptors. The selection of a pair of scale-based shape descriptors is modeled as the computation of the union of two events, i.e.,retrieving similar shapes by using a single scale-based shape descriptor. The pair of scale-based shape descriptors with the highest probability forms the composite shape descriptor. Given a shape database, the composite shape descriptors for the shapes constitute a planar point set.A VoR-Tree of the planar point set is then used as an indexing structure for efficient query operation. Experiments and comparisons show the effectiveness and efficiency of the proposed composite shape descriptor.

关键词： shape descriptor shape retrieval shape analysis data-driven model

Study on vibration of dragon wash basin and free surface waves inside

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Acta Mechanica Sinica 2019年第1期35卷 15-23,I0001页

作者： zi-Yu Guo Xiao-Peng chen Lai-Bing Jia Bin Xu School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi'an 710129China School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an 710072China

We conducted experimental and numerical studies on the vibrating modes of a dragon wash basin (DWB) and the free surface waves inside the DWB. Both the vibration of the DWB and the sound produced were studied carefully. It was found that the DWB can be excited at different intrinsic modes under different excitation, including striking and rubbing it fast/slowly. However, with gentle rubbing, the DWB will be excited mainly at the first vibrating mode. We showed that the concave side wall of a DWB decreases the intrinsic frequencies (compared with a straight side wall), and the ears of a DWB lead to breaking of the vibrating-axisymmetry and cause the separation of modes I/II and IV/V as well. A theoretical model, in which the water is assumed to be incompressible and inviscid, is applied to the first order vibration and predicts the relation of vibrating frequency versus water depth in the system. The measurement shows that both the radial and azimuthal waves are produced as DWB is working. The frequency of the first component of the surface wave is twice as large as the second one induced by non-linear effects. For both the radial and azimuthal waves, the dispersion relation is presented in the framework of capillary wave theory.

关键词： Dragon wash basin Eigen-mode vibration Surface wave