检索结果-南通市图书馆

Soil moisture estimation based on BeiDou Bl interference signal analysis

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2016年第12期59卷 2427-2440页

作者： YAN SongHua ZHAO Fen chen nengcheng gong jianya School of Electronic Information Wuhan University State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan University

BeiDou Navigation Satellite System reflectometry(BDS-R) is an emerging area of BD(BeiDou) applications that uses multipath reflected signals in microwave remote *** moisture estimation is one of the potential important applications of *** study aims to investigate the feasibility of soil moisture estimation based on BD B1 band interference signals,which are composed of direct and reflected BD signals and can be readily captured using low-cost commercial BDS *** this paper,a theoretical background for soil estimation from interference signals was introduced,and an analysis of field experimental data was ***,a cosine model for the interference signal power was built,and a non-uniform power spectrum analysis was performed on the received interference signals to determine its main ***,a least squares curve fitting was applied on the interference signal power to extract its *** relationship between the soil moisture and the phase was then *** months of experimental data were collected at BaoXie,Wuhan and analyzed for further *** results show that the phase of the interference signals increases with the increase of soil *** correlation coefficient between the phase and the in-situ soil moisture value is approximately ***,the relationship between the phase and soil moisture is employed to estimate soil *** show that using BDS-R to measure soil moisture is feasible,which demonstrates a great potential of new application of the BD system.

关键词： BDS-R Soil moisture estimation Interference signal Non-uniform power spectrum Least squares curve fitting SNR

A DISTRIBUTED HYPERMAP MODEL FOR INTERNET GIS

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Geo-Spatial Information Science 2000年第4期3卷 9-15页

作者： Yuan Xiangru chen nengcheng gong jianya Department of Computer Science University of Zurich

The rapid development of Internet technology makes it possible to integrate GIS with the Internet,forming Internet *** GIS is based on a distributed client/server architecture and TCP/IP & *** constructing and designing Internet GIS,we face the problem of how to express information units of Internet *** order to solve this problem,this paper presents a distributed hypermap model for Internet *** model provides a solution to organize and manage Internet GIS information *** also illustrates relations between two information units and in an internal information unit both on clients and *** the basis of this model,the paper contributes to the expressions of hypermap relations and hypermap *** usage of this model is shown in the implementation of a prototype system.

关键词： Internet GIS distributed hypermap model hypermedia hypergraph hyperlink

Potassium and calcium channels in different nerve cells act as therapeutic targets in neurological disorders

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第5期20卷 1258-1276页

作者： Qing Qiu Mengting Yang Danfeng gong Haiying Liang Tingting chen Department of Pharmacology School of PharmacyNantong UniversityNantongJiangsu ProvinceChina Jiangsu Province Key Laboratory of Inflammation and Molecular Drug Target NantongJiangsu ProvinceChina Department of Pharmacy Longyan First Affiliated Hospital of Fujian Medical UniversityLongyanFujian ProvinceChina

The central nervous system, information integration center of the body, is mainly composed of neurons and glial cells. The neuron is one of the most basic and important structural and functional units of the central nervous system, with sensory stimulation and excitation conduction functions. Astrocytes and microglia belong to the glial cell family, which is the main source of cytokines and represents the main defense system of the central nervous system. Nerve cells undergo neurotransmission or gliotransmission, which regulates neuronal activity via the ion channels, receptors, or transporters expressed on nerve cell membranes. Ion channels, composed of large transmembrane proteins, play crucial roles in maintaining nerve cell homeostasis. These channels are also important for control of the membrane potential and in the secretion of neurotransmitters. A variety of cellular functions and life activities, including functional regulation of the central nervous system, the generation and conduction of nerve excitation, the occurrence of receptor potential, heart pulsation, smooth muscle peristalsis, skeletal muscle contraction, and hormone secretion, are closely related to ion channels associated with passive transmembrane transport. Two types of ion channels in the central nervous system, potassium channels and calcium channels, are closely related to various neurological disorders, including Alzheimer's disease, Parkinson's disease, and epilepsy. Accordingly, various drugs that can affect these ion channels have been explored deeply to provide new directions for the treatment of these neurological disorders. In this review, we focus on the functions of potassium and calcium ion channels in different nerve cells and their involvement in neurological disorders such as Parkinson's disease, Alzheimer's disease, depression, epilepsy, autism, and rare disorders. We also describe several clinical drugs that target potassium or calcium channels in nerve cells and could be u

关键词： astrocytes calcium channels central nervous system extracellular ion concentration microglia neurological disorders neurons potassium channels

A virtual globe-based vector data model:quaternary quadrangle vector tile model

在线全文

学校读者我要写书评

暂无评论

International Journal of Digital Earth 2016年第3期9卷 230-251页

作者： Mengyun Zhou Jing chen jianya gong State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhanPR China

This study proposes a virtual globe-based vector data model named the quaternary quadrangle vector tile model(QQVTM)in order to better manage,visualize,and analyze massive amounts of global multi-scale vector *** model integrates the quaternary quadrangle mesh(a discrete global grid system)and global image,terrain,and vector data.A QQVTM-based organization method is presented to organize global multi-scale vector data,including linear and polygonal vector *** addition,tilebased reconstruction algorithms are designed to search and stitch the vector fragments scattered in tiles to reconstruct and store the entire vector geometries to support vector query and 3D analysis of global *** organized vector data are in turn visualized and queried using a geometry-based *** experimental results demonstrate that the QQVTM can satisfy the requirements for global vector data organization,visualization,and ***,the QQVTM performs better than unorganized 2D vectors regarding rendering efficiency and better than the latitude–longitude-based approach regarding data redundancy.

关键词： multi-resolution modeling discrete global grid system vector data organization tile-based reconstruction geometry-based rendering

Characteristic changes in astrocyte properties during astrocyte-to-neuron conversion induced by NeuroD1/Ascl1/Dlx2

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

Neural Regeneration Research 2025年第6期20卷 1801-1815页

作者： Qing He Zhen Wang Yuchen Wang Mengjie Zhu Zhile Liang Kanghong Zhang Yuge Xu gong chen GHM Institute of CNS Regeneration Jinan UniversityGuangzhouGuangdong ProvinceChina

Direct in vivo conversion of astrocytes into functional new neurons induced by neural transcription factors has been recognized as a potential new therapeutic intervention for neural injury and degenerative disorders. However, a few recent studies have claimed that neural transcription factors cannot convert astrocytes into neurons, attributing the converted neurons to pre-existing neurons mis-expressing transgenes. In this study, we overexpressed three distinct neural transcription factors––NeuroD1, Ascl1, and Dlx2––in reactive astrocytes in mouse cortices subjected to stab injury, resulting in a series of significant changes in astrocyte properties. Initially, the three neural transcription factors were exclusively expressed in the nuclei of astrocytes. Over time, however, these astrocytes gradually adopted neuronal morphology, and the neural transcription factors was gradually observed in the nuclei of neuron-like cells instead of astrocytes. Furthermore,we noted that transcription factor-infected astrocytes showed a progressive decrease in the expression of astrocytic markers AQP4(astrocyte endfeet signal), CX43(gap junction signal), and S100β. Importantly, none of these changes could be attributed to transgene leakage into preexisting neurons. Therefore, our findings suggest that neural transcription factors such as NeuroD1, Ascl1, and Dlx2 can effectively convert reactive astrocytes into neurons in the adult mammalian brain.

关键词： aquaporin-4 Ascl1 astrocyte cortex Dlx2 gap junction glia-to-neuron conversion neural regeneration NeuroD1 reprogramming

Layout graph model for semantic façade reconstruction using laser point clouds

在线全文

学校读者我要写书评

暂无评论

Geo-Spatial Information Science 2021年第3期24卷 403-421页

作者： Hongchao Fan Yuefeng Wang jianya gong Department of Civil and Environmental Engineering Norwegian University of Science and TechnologyTrondheimNorway State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhanChina

Building façades can feature different patterns depending on the architectural style,function-ality,and size of the buildings;therefore,reconstructing these façades can be *** particular,when semantic façades are reconstructed from point cloud data,uneven point density and noise make it difficult to accurately determine the façade *** inves-tigating façade layouts,Gestalt principles can be applied to cluster visually similar floors and façade elements,allowing for a more intuitive interpretation of façade *** propose a novel model for describing façade structures,namely the layout graph model,which involves a compound graph with two structure *** the proposed model,similar façade elements such as windows are first grouped into clusters.A down-layout graph is then formed using this cluster as a node and by combining intra-and inter-cluster spacings as the ***,a top-layout graph is formed by clustering similar *** extracting relevant parameters from this model,we transform semantic façade reconstruction to an optimization strategy using simulated annealing coupled with Gibbs *** façade point cloud data with different features were selected from three datasets to verify the effectiveness of this *** experimental results show that the proposed method achieves an average accuracy of 86.35%.Owing to its flexibility,the proposed layout graph model can deal with different types of façades and qualities of point cloud data,enabling a more robust and accurate reconstruc-tion of façade models.

关键词： Building façade semantic reconstruction point cloud compound graph model stochastic process

Advances in urban information extraction from high-resolution remote sensing imagery

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

Science China Earth Sciences 2020年第4期63卷 463-475页

作者： jianya gong Chun LIU Xin HUANG School of Remote Sensing and Information Engineering Wuhan UniversityWuhan 430079China State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan 430079China

The study of urban area is one of the hottest research topics in the field of remote sensing. With the accumulation of high-resolution(HR) remote sensing data and emerging of new satellite sensors, HR observation of urban areas has become increasingly possible, which provides us with more elaborate urban information. However, the strong heterogeneity in the spectral and spatial domain of HR imagery brings great challenges to urban remote sensing. In recent years, numerous approaches were proposed to deal with HR image interpretation over complex urban scenes, including a series of features from low level to high level, as well as state-of-the-art methods depicting not only the urban extent, but also the intra-urban variations. In this paper, we aim to summarize the major advances in HR urban remote sensing from the aspects of feature representation and information extraction. Moreover, the future trends are discussed from the perspectives of methodology, urban structure and pattern characterization, big data challenge, and global mapping.

关键词： High-resolution Urban remote sensing Feature extraction Land use/land cover classification Change detection

Deep neural network for remote-sensing image interpretation: status and perspectives

在线全文

学校读者我要写书评

暂无评论

National Science Review 2019年第6期6卷 1082-1086页

作者： Jiayi Li Xin Huang jianya gong School of Remote Sensing and Information Engineering Wuhan University State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan University

Deep neural networks(DNNs) refer to end-to-end mappings(i.e. from data to information) by stacking a large number of filters learned from massive samples. By courtesy of the comprehensive Earth observation platforms and convenient data access, remote-sensing practitioners are dealing with very large and ever-growing data volumes, which call for fast and transferrable machine-learning

关键词： status and perspectives image Deep neural network for remote-sensing image interpretation

Hypoxia-preconditioned bone marrow-derived mesenchymal stem cells protect neurons from cardiac arrest-induced pyroptosis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第4期20卷 1103-1123页

作者： Xiahong Tang Nan Zheng Qingming Lin Yan You Zheng gong Yangping Zhuang Jiali Wu Yu Wang Hanlin Huang Jun Ke Feng chen Shengli Clinical Medical College of Fujian Medical University Fujian Medical UniversityFuzhouFujian ProvinceChina Department of Emergency Fujian Provincial HospitalFuzhouFujian ProvinceChina Fujian Provincial Key Laboratory of Emergency Medicine FuzhouFujian ProvinceChina The Second Department of Intensive Care Unit Fujian Provincial Hospital South BranchFuzhouFujian ProvinceChina

Cardiac arrest can lead to severe neurological impairment as a result of inflammation,mitochondrial dysfunction,and post-cardiopulmonary resuscitation neurological *** preconditioning has been shown to improve migration and survival of bone marrow–derived mesenchymal stem cells and reduce pyroptosis after cardiac arrest,but the specific mechanisms by which hypoxia-preconditioned bone marrow–derived mesenchymal stem cells protect against brain injury after cardiac arrest are *** this end,we established an in vitro co-culture model of bone marrow–derived mesenchymal stem cells and oxygen–glucose deprived primary neurons and found that hypoxic preconditioning enhanced the protective effect of bone marrow stromal stem cells against neuronal pyroptosis,possibly through inhibition of the MAPK and nuclear factor κB ***,we transplanted hypoxia-preconditioned bone marrow–derived mesenchymal stem cells into the lateral ventricle after the return of spontaneous circulation in an 8-minute cardiac arrest rat model induced by *** results showed that hypoxia-preconditioned bone marrow–derived mesenchymal stem cells significantly reduced cardiac arrest–induced neuronal pyroptosis,oxidative stress,and mitochondrial damage,whereas knockdown of the liver isoform of phosphofructokinase in bone marrow–derived mesenchymal stem cells inhibited these *** conclude,hypoxia-preconditioned bone marrow–derived mesenchymal stem cells offer a promising therapeutic approach for neuronal injury following cardiac arrest,and their beneficial effects are potentially associated with increased expression of the liver isoform of phosphofructokinase following hypoxic preconditioning.

关键词： bone marrow–derived mesenchymal stem cells cardiac arrest cardiac resuscitation hypoxic preconditioning liver isoform of phosphofructokinase mitochondria neuroinflammation oxidative stress pyroptosis reactive oxygen species