检索结果-南通市图书馆

SAR regional all-azimuth observation orbit design for target 3D reconstruction

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2024年第3期35卷 609-618页

作者： wang yanan ZHOU Chaowei LIU Aifang MAO Qin Beijing Institute of Tracking and Communication Technology Beijing 100094China Nanjing Research Institute of Electronics Technology Nanjing 210012China Shanghai Aerospace Electronic Technology Institute Shanghai 201109China

Three-dimensional(3D) synthetic aperture radar(SAR)extends the conventional 2D images into 3D features by several acquisitions in different aspects. Compared with 3D techniques via multiple observations in elevation, e.g. SAR interferometry(InSAR) and SAR tomography(TomoSAR), holographic SAR can retrieve 3D structure by observations in azimuth. This paper focuses on designing a novel type of orbit to achieve SAR regional all-azimuth observation(AAO) for embedded targets detection and holographic 3D reconstruction. The ground tracks of the AAO orbit separate the earth surface into grids. Target in these grids can be accessed with an azimuth angle span of360°, which is similar to the flight path of airborne circular SAR(CSAR). Inspired from the successive coverage orbits of optical sensors, several optimizations are made in the proposed method to ensure favorable grazing angles, the performance of 3D reconstruction, and long-term supervision for SAR sensors. Simulation experiments show the regional AAO can be completed within five hours. In addition, a second AAO of the same area can be duplicated in two days. Finally, an airborne SAR data process result is presented to illustrate the significance of AAO in 3D reconstruction.

关键词： synthetic aperture radar(SAR) orbit design all-azimuth observation(AAO) three-dimensional(3D)reconstruction successive coverage

Impact Force Localization and Reconstruction via ADMM-based Sparse Regularization Method

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2024年第3期37卷 170-188页

作者： yanan wang Lin Chen Junjiang Liu Baijie Qiao Weifeng He Xuefeng Chen National Key Lab of Aerospace Power System and Plasma Technology Xi’an Jiaotong UniversityXi’an 710049China School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China

In practice,simultaneous impact localization and time history reconstruction can hardly be achieved,due to the illposed and under-determined problems induced by the constrained and harsh measuring *** l_(1) regularization can be used to obtain sparse solutions,it tends to underestimate solution amplitudes as a biased *** address this issue,a novel impact force identification method with l_(p) regularization is proposed in this paper,using the alternating direction method of multipliers(ADMM).By decomposing the complex primal problem into sub-problems solvable in parallel via proximal operators,ADMM can address the challenge *** mitigate the sensitivity to regularization parameters,an adaptive regularization parameter is derived based on the K-sparsity ***,an ADMM-based sparse regularization method is developed,which is capable of handling l_(p) regularization with arbitrary p values using adaptively-updated *** effectiveness and performance of the proposed method are validated on an aircraft skin-like composite ***,an investigation into the optimal p value for achieving high-accuracy solutions via l_(p) regularization is *** turns out that l_(0.6)regularization consistently yields sparser and more accurate solutions for impact force identification compared to the classic l_(1) regularization *** impact force identification method proposed in this paper can simultaneously reconstruct impact time history with high accuracy and accurately localize the impact using an under-determined sensor configuration.

关键词： Impact force identification Non-convex sparse regularization Alternating direction method of multipliers Proximal operators

Effect of kerosene injection states on mixing and combustion characteristics in a cavity-based supersonic combustor

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第4期37卷 308-320页

作者： Xu LIU Peibo LI Fei LI Hongbo wang Mingbo SUN Chao wang Yixin YANG Dapeng XIONG yanan wang Science and Technology on Scramjet Laboratory College of Aerospace Science and EngineeringNational University of Defense TechnologyChangsha 410073China

It has been found that the static pressure distribution along the axial direction of liquid kerosene is lower than that of the gaseous kerosene under the same flow condition and overall equivalent ratio from previous *** further investigate this phenomenon,a compressible two-phase parallel simulation method is utilized to analyze the mixing and combustion characteristics of gaseous and liquid kerosene jets in a cavity-based supersonic *** numerical results are consistent with the experiments and demonstrate that gaseous injection leads to a cavity shear layer that dives deeper into the cavity,forming two recirculation zones in the front and rear of the *** contrast,the cavity shear layer is closer to the mainstream during liquid injection,and only a large recirculation zone is formed in the rear of the *** a result of the cavity shear layer and the recirculating flow,the fuel vapor of gaseous injection accumulates in the front of the cavity,while for the liquid injection,the fuel vapor disperses in the cavity,cavity shear layer,and the region above,and the rear of the cavity has a higher fuel vapor concentration than the *** unique fuel distribution causes the combustion area to be concentrated in the cavity during the gaseous injection but dispersed inside and downstream of the cavity during the liquid *** a result,forming a thermal throat under the same conditions is more challenging during liquid injection,and the generated static pressure distribution is lower than that during the gaseous injection.

关键词： Gaseous injection Liquid injection Mixing process Combustion Supersonic flow

Heat management technology for solid-state high voltage and high repetitive pulse generators:Towards better effects and reliability

在线全文

学校读者我要写书评

暂无评论

High Voltage 2024年第1期9卷 2-21页

作者： yanan wang Linyuan Ren Zihao Yang Saikang Shen Zichen Deng Qi Yuan Weidong Ding Zhenjie Ding School of Electrical Engineering Xi'an Jiaotong UniversityXi'anChina School of Electronic and Information Engineering Xi'an Jiaotong UniversityXi'anChina

Solid-state high voltage high repetitive pulse generators have a broad prospect in various *** high power and high-frequency operation of the pulse generator suffer from the massive heat dissipation problem,which limits the improvement of the output parameters and even affects the *** article focuses on heat management technology for high voltage high repetitive pulse ***,the typical circuit topology of the high repetitive pulse generators was *** the perspective of different application requirements,the demands of the heat management design were ***,the heat generation characteristics and difficulties of solid-state high voltage high repetitive pulse generators were ***,the different stateof-art cooling techniques were reviewed,and their applicability and limitations for the high voltage high repetitive generators were ***,a flow chart for heat management design was given.

关键词： pulse state high

Unraveling the regulatory network of flower coloration in soybean:Insights into roles of GmMYBA3 and GmMYBR1

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

The Crop Journal 2024年第2期12卷 443-455页

作者： Ruifang Gao Yueqing Li yanan wang Xiaotong Shan Siqi Yang Ye Zhang Saiyu Ma Chunbao Zhang Jianchun Qin Li wang Xiang Gao College of Plant Science Jilin UniversityChangchun 130062JilinChina Key Laboratory of Molecular Epigenetics of MOE and Institute of Genetics&Cytology Northeast Normal UniversityChangchun 130024JilinChina Soybean Research Institute National Engineering Research Center for SoybeanJilin Academy of Agricultural SciencesChangchun 130033JilinChina

Anthocyanins play crucial roles in pollen protection and pollinator attraction in flowering ***,the mechanisms underlying flower color determination and whether floral anthocyanin regulators participate in other processes remain largely unresolved in soybeans(Glycine max).In this study,we investigated the genetic components and mechanisms governing anthocyanin biosynthesis in soybean *** and genetic studies have characterized two antagonistic regulators,the positive activator GmMYBA3 and the negative repressor GmMYBR1,that modulate the gene expression of anthocyanin biosynthesis in soybean *** findings revealed a regulatory interplay between GmMYBA3 and GmMYBR1 bridged by GmTT8a,highlighting the complexity of anthocyanin regulation in different soybean *** of additional soybean cultivars demonstrated the universality of GmMYBA3 and GmMYBR1 in regulating floral anthocyanin biosynthesis-related genes,with GmF3’5’H identified as a crucial determinant of white flower *** study provides a molecular mechanism underlying soybean flower color determination,paving the way for the molecular modification of soybean flowers to probably enhance their resistance to abiotic stresses and attractiveness to pollinators.

关键词： Anthocyanin Flower color determination MBW complex MYB repressor Pleiotropic regulator

CRISPR/Cas9 system and its applications in nervous system diseases

在线全文

学校读者我要写书评

暂无评论

Genes & Diseases 2024年第2期11卷 675-686页

作者： Haibin Jiang Mengyan Tang Zidi Xu yanan wang Mopu Li Shuyin Zheng Jianghu Zhu Zhenlang Lin Min Zhang The Second School of Medicine Wenzhou Medical UniversityWenzhouZhejiang 325035China The First School of Medicine Wenzhou Medical UniversityWenzhouZhejiang 325035China Department of Pediatrics The Second School of MedicineThe Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical UniversityWenzhouZhejiang 325027China Key Laboratory of Perinatal Medicine of Wenzhou WenzhouZhejiang 325027China Key Laboratory of Structural Malformations in Children of Zhejiang Province WenzhouZhejiang 325000China Zhejiang Provincial Clinical Research Center for Pediatric Disease WenzhouZhejiang 325027China

The clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)system is an acquired immune system of many bacteria and archaea,comprising CRISPR loci,Cas genes,and its associated *** system can recognize exogenous DNA and utilize the Cas9 protein's nuclease activity to break DNA double-strand and to achieve base insertion or deletion by subsequent DNA *** recent years,multiple laboratory and clinical studies have revealed the therapeutic role of the CRISPR/Cas9 system in neurological *** article reviews the CRISPR/Cas9-mediated gene editing technology and its potential for clinical application against neurological diseases.

关键词： CRISPR/Cas9 Gene editing Mutation Neurological diseases Therapeutics

Photocatalytic C(sp^(3))-H gem-Difluoroallylation and Alkylation with Alkenes via a Base-Assisted Formal 1,2-Hydrogen Atom Transfer of Amidyl Radicals

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

Chinese Journal of Chemistry 2024年第18期42卷 2203-2210页

作者： Meifang Tang Bingbing Feng Yanyang Bao Zhongtian Xu Chao Huang Hanliang Zheng Gangguo Zhu yanan wang Zheliang Yuan Key Laboratory of the Ministry of Education for Advanced Catalysis Materials College of Chemistry and Materials SciencesZhejiangNormalUniversity688YingbinRoadJinhuaZhejiang321004China

Compared to well-established 1,5-HAT of N-centered radicals,the synthetic applications of 1,2-HAT process were scarce due to the high barrier and constrained three-membered transition ***,we have developed a novel C(sp')-H gem-difluoroallylation via a base assisted formal 1,2-HAT of amidyl radicals with the reductive quenching cycle of *** transformation enables the efficient formation ofα-aminoalkyl radicals via 1,2-HAT and showcases good functional group *** preliminary mechanistic experiments,along withDensity Functional Theory(DFT)calculations demonstrate thefeasibility of 1,2-HAT of amidyl radicals,especially when assisted by a ***,our method also succeeds in the Giese addition of electron-deficient alkenes as well as styrene.

关键词： 1,2-Hydrogen atom transfer Amidyl radicals gem-Difluoroallylation Alkenes Photocatalysis Defluoroalkylation

Restoring cellular calcium homeostasis to rescue ER stress by 1,2-bis(2-aminophenoxy)ethane-N,N,N’,N’-tetraacetic acid acetoxymethyl ester-loaded lipid-mPLGA hybrid-nanoparticles for acute kidney injury therapy

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

Chinese Chemical Letters 2024年第3期35卷 337-345页

作者： Jingwen Zhang Jiahui Yan yanan wang Hong Liu Xueping Sun Yuchao Gu Liangmin Yu Changcheng Li Jun Wu Zhiyu He Frontiers Science Center for Deep Ocean Multispheres and Earth System and Key Laboratory of Marine Chemistry Theory and TechnologyMinistry of EducationOcean University of ChinaQingdao 266100China College of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China School of Medicine and Pharmacy Ocean University of ChinaQingdao 266003China Sanya Oceanographic Institution Ocean University of ChinaQingdao 572024China Bioscience and Biomedical Engineering Thrust The Hong Kong University of Science and Technology(Guangzhou)NanshaGuangzhou 511400China Division of Life Science The Hong Kong University of Science and TechnologyHong Kong 999077China

Early pathogenesis of ischemia-reperfusion(I/R)-induced acute kidney injury(AKI)is dominated by intracellular calcium overload,which induces oxidative stress,intracellular energy metabolism disorder,inflammatory activation,and a series of pathologic cascaded reactions that are closely intertwined with self-amplifying and interactive feedback loops,ultimately resulting in cell damage and kidney ***,most nanomedicines originate from the perspective of antioxidant stress,which can only quench existing reactive oxide species(ROS)but cannot prevent the continuous production of ROS,resulting in insufficient *** a safe and promising drug,BAPTA-AM is hydrolyzed into BAPTA by intracellular esterase upon entering cells,which can rapidly chelate with overloaded Ca^(2+),restoring intracellular calcium homeostasis,thus inhibiting ROS regeneration at the ***,we designed a KTP-targeting peptide-modified yolk-shell structure of liposome–poly(ethylene glycol)methyl ether-block-poly(L-lactide-co-glycolic)(mPLGA)hybrid nanoparticles(<100 nm),with the characteristics of high encapsulation rate,high colloid stability,facile modification,and prolonged blood circulation *** the BA/mPLGA@Lipo-KTP was targeted to the site of kidney injury,the cholesteryl hemisuccinate(CHEMS)in the phospholipid bilayer,as an acidic cholesterol ester,was protonated in the simulated inflammatory slightly acidic environment(pH 6.5),causing the liposomes to rupture and release the BA/mPLGA nanoparticles,which were then depolymerized by intracellular *** BAPTA-AM was diffused and hydrolyzed to produce BAPTA,which can rapidly cut off the malignant loop of calcium overload/ROS generation at its source,blocking the endoplasmic reticulum(ER)apoptosis pathway(ATF4–CHOP–Bax/Bcl-2,Casp-12–Casp-3)and the inflammatory pathway(TNF-α–NF-κB–IL-6 axes),thus alleviating pathological changes in kidney tissue,thereby inhibiting the expression of renal tubular marker kidney injury mole

关键词： BAPTA-AM Calcium overload Acid-responsive AKI ER stress

Physical information-enhanced graph neural network for predicting phase separation

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第7期33卷 278-283页

作者：张亚强王煦文王雅楠郑文 Institute of Public-Safety and Big Data College of Computer Science and Technology(College of Data Science)Taiyuan University of TechnologyJinzhong 030600China Shanxi Engineering Research Centre for Intelligent Data Assisted Treatment Changzhi Medical CollegeChangzhi 046000China Innovation Academy for Microsatellites of Chinese Academy of Sciences Shanghai 200050China

Although phase separation is a ubiquitous phenomenon, the interactions between multiple components make it difficult to accurately model and predict. In recent years, machine learning has been widely used in physics simulations. Here,we present a physical information-enhanced graph neural network(PIENet) to simulate and predict the evolution of phase separation. The accuracy of our model in predicting particle positions is improved by 40.3% and 51.77% compared with CNN and SVM respectively. Moreover, we design an order parameter based on local density to measure the evolution of phase separation and analyze the systematic changes with different repulsion coefficients and different Schmidt *** results demonstrate that our model can achieve long-term accurate predictions of order parameters without requiring complex handcrafted features. These results prove that graph neural networks can become new tools and methods for predicting the structure and properties of complex physical systems.

关键词： graph neural network phase separation machine learning dissipative particle dynamics