检索结果-南通市图书馆

Underdetermined direction of arrival estimation with nonuniform linear motion sampling based on a small unmanned aerial vehicle platform

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

Defence Technology（防务技术） 2024年第3期33卷 352-363页

作者： Xinwei Wang Xiaopeng Yan tai An Qile Chen Dingkun Huang Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China

Uniform linear array(ULA)radars are widely used in the collision-avoidance radar systems of small unmanned aerial vehicles(UAVs).In practice,a ULA's multi-target direction of arrival(DoA)estimation performance suffers from significant performance degradation owing to the limited number of physical *** improve the underdetermined DoA estimation performance of a ULA radar mounted on a small UAV platform,we propose a nonuniform linear motion sampling underdetermined DoA estimation *** the motion of the UAV platform,the echo signal is sampled at different ***,according to the concept of difference co-array,a virtual ULA with multiple array elements and a large aperture is synthesized to increase the degrees of freedom(DoFs).Through position analysis of the original and motion arrays,we propose a nonuniform linear motion sampling method based on ULA for determining the optimal *** the condition of no increase in the aperture of the physical array,the proposed method obtains a high DoF with fewer sampling runs and greatly improves the underdetermined DoA estimation performance of *** results of numerical simulations conducted herein verify the superior performance of the proposed method.

关键词： Unmanned aerial vehicle(UAV) Uniform linear array(ULA) Direction of arrival(DoA) Difference co-array Nonuniform linear motion sampling method

Automatic modulation recognition of radio fuzes using a DR2D-based adaptive denoising method and textural feature extraction

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4期34卷 328-338页

作者： Yangtian Liu Xiaopeng Yan Qiang Liu tai An Jian Dai Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China China Research and Development Academy of Machinery Equipment Beijing 100089China

The identification of intercepted radio fuze modulation types is a prerequisite for decision-making in interference ***,the electromagnetic environment of modern battlefields is complex,and the signal-to-noise ratio(SNR)of such environments is usually low,which makes it difficult to implement accurate recognition of radio *** solve the above problem,a radio fuze automatic modulation recognition(AMR)method for low-SNR environments is ***,an adaptive denoising algorithm based on data rearrangement and the two-dimensional(2D)fast Fourier transform(FFT)(DR2D)is used to reduce the noise of the intercepted radio fuze intermediate frequency(IF)***,the textural features of the denoised IF signal rearranged data matrix are extracted from the statistical indicator vectors of gray-level cooccurrence matrices(GLCMs),and support vector machines(SVMs)are used for *** DR2D-based adaptive denoising algorithm achieves an average correlation coefficient of more than 0.76 for ten fuze types under SNRs of-10 d B and above,which is higher than that of other typical *** trained SVM classification model achieves an average recognition accuracy of more than 96%on seven modulation types and recognition accuracies of more than 94%on each modulation type under SNRs of-12 d B and above,which represents a good AMR performance of radio fuzes under low SNRs.

关键词： Automatic modulation recognition Adaptive denoising Data rearrangement and the 2D FFT(DR2D) Radio fuze

Colon signet-ring cell carcinoma with chylous ascites caused by immunosuppressants following liver transplantation:A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Surgery 2024年第7期16卷 2343-2350页

作者： Ying Li Yang tai Hao Wu Department of Gastroenterology West China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina

BACKGRoUND Chylous ascites is caused by disruption of the lymphatic system,which is characterized by the accumulation of a turbid fluid containing high levels of triglycerides within the abdominal *** two most common causes are cirrhosis and tuberculosis,and colon signer ring cell carcinoma(SRCC)due to the use of immunosuppressants is extremely rare in cirrhotic patients after liver transplantation,making it prone to misdiagnosis and missed *** SUMMARY A 52-year-old man who underwent liver transplantation and was administered with immunosuppressants for 8 months was admitted with a 3-month history of progressive abdominal ***,based on lymphoscintigraphy and lymphangiography,lymphatic obstruction was considered,and cystellar chyli decompression with band lysis and external membrane stripping of the lymphatic duct was ***,his abdominal distention was persistent without *** paracentesis revealed allogenic cells in the ascites,and immunohistochemistry analysis revealed adenocarcinoma cells with phenotypic features suggestive of a gastrointestinal *** endoscopy was performed,and biopsy showed atypical signet ring cells in the ileocecal *** patient eventually died after a three-month follow-up due to progression of the *** Colon SRCC,caused by immunosuppressants,is an unusual but un-neglected cause of chylous ascites.

关键词： Colonic signer ring cell carcinoma Immunosuppressant Chylous ascites Cirrhosis Liver transplantation Case report

Low-Carbon Dispatching for Virtual Power Plant with Aggregated Distributed Energy Storage Considering Spatiotemporal Distribution of Cleanness Value

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

Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 346-358页

作者： Hongchao Gao tai Jin Guanxiong Wang Qixin Chen Chongqing Kang Jingkai Zhu State Key Laboratory of Power System operation and Control Department of Electrical EngineeringTsinghua UniversityBeijing 100084China Sichuan Energy Internet Research Institute Tsinghua University Chengdu 200016China Power Dispatching and Control Center of Shanghai Municipal Electric Power Company Shanghai 200122China IEEE

The scale of distributed energy resources is increasing,but imperfect business models and value transmission mechanisms lead to low utilization ratio and poor *** address this issue,the concept of cleanness value of distributed energy storage(DES)is proposed,and the spatiotemporal distribution mechanism is discussed from the perspectives of electrical energy and *** on this,an evaluation system for the environmental benefits of DES is constructed to balance the interests between the aggregator and the power system ***,an optimal low-carbon dispatching for a virtual power plant(VPP)with aggregated DES is constructed,where-in energy value and cleanness value are both *** achieve the goal,a green attribute labeling method is used to establish a correlation constraint between the nodal carbon potential of the distribution network(DN)and DES behavior,but as a cost,it brings multiple nonlinear ***,a solution method based on the convex envelope(CE)linear re-construction method is proposed for the multivariate nonlinear programming problem,thereby improving solution efficiency and ***,the simulation verification based on the IEEE 33-bus DN is *** simulation results show that the multidimensional value recognition of DES motivates the willingness of resource users to ***,resolving the impact of DES on the nodal carbon potential can effectively alleviate overcompensation of the cleanness value.

关键词： Distributed energy storage virtual power plant(VPP) spatiotemporal distribution low-carbon dispatching

Luminescence properties and optical sensing behaviors of Sr_(2)GdSbo_(6):Eu^(3+) phosphors

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第8期42卷 1458-1469,I0002页

作者： Youfa tai Ruirui Cui Jun Zhang Chunkai Wang Tingyu Zhao Beiqiao Zhang Chaoyong Deng Key Laboratory of Functional Composite Materials of Guizhou Province College of Big Data and Information EngineeringGuizhou UniversityGuiyang550025China College of Computer and Information Enginering Guizhou University of CommerceGuiyang550014China School of Electronics and Information Engineering Guiyang UniversityGuiyang550005China

Novel orange-red Sr^(2)GdSbo^(6):xEu^(3+)(x=0,0.05,0.1,0.2,0.3,0.4,0.5 and 0.6) phospho rs were successfully prepared by the traditional high-temperature solid-state *** results of Rietveld refinement,energy dispersive spectroscopy(EDS) spectrum and elemental mapping demonstrate that Eu^(3+) successfully replaces the Gd^(3+) sites and distributes uniformly in the particles of *** luminescence properties of Sr_(2)GdSbo_(6):Eu_(3+)phosphors were investigated in *** emission spectra of the strongest emission peak is the ^(5)D_(0)→^(7)F_(1)(593 nm) transition,which can emit orange-red light under393 nm *** the doping concentration of Eu3+ions is x=0.2,the luminescence intensity of the phosphors reaches the *** detailed mechanism of concentration quenching is attributed to dipole-dipole *** thermal stability values of Sr_(2)GdSbo_(6):0.2Eu^(3+) phosphors are 87%,82% and114% under 393,467 and 527 nm excitations,*** causes of the abnormal thermal quenching under 527 nm excitation were *** on the abnormal thermal quenching under527 nm excitation,the optical thermometry properties of Sr_(2)GdSbo_(6):0.2Eu^(3+)phosphors were investigated by fluorescence intensity ratio(FIR) technique,and appreciable relative sensitivity was *** results suggest that Sr_(2)GdSbo_(6):0.2Eu^(3+)phosphors can be potentially applied to w-LEDs and optical thermometers.

关键词： Sr_(2)GdSbo_(6):Eu^(3+) Phosphors Luminescence properties Abnormal thermal quenching Rare earths

A mite parasitoid,Pyemotes zhonghuajia,negatively impacts the fitness traits and immune response of the fall armyworm,Spodoptera frugiperda

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第1期23卷 205-216页

作者： Yanfei Song tai’an Tian Yichai Chen Keshi Zhang Maofa Yang Jianfeng Liu Institute of Entomology Guizhou Provincial Key Laboratory for Agricultural Pest Management of the Mountainous RegionGuizhou University/Scientific Observing and Experiment Station of Crop Pests in GuiyangMinistry of Agriculture and Rural AffairsGuiyang 550025China Administration of Guizhou Fanjingshan National Nature Reserve Jiangkou 554400China Centre for Biodiversity and Biosecurity School of Biological SciencesThe University of AucklandAuckland 1072New Zealand College of Tobacco Science Guizhou UniversityGuiyang 550025China

Parasitoids are key regulators in ecological communities and widely used as agents in biocontrol *** fall armyworm,Spodoptera frugiperda,recently invaded multiple continents and caused substantial economic losses in *** zhonghuajia,a newly identified mite parasitoid,has shown potential for controlling various agricultural insect ***,this study tested the performance of *** in parasitising *** also investigated the sublethal effects of parasitism by *** on host fitness traits,transgenerational impacts,and cellular and humoral *** result showed that the fifth-instar larvae of *** parasitised by 40 *** were all dead(i.e.,a lethal effect),while parasitism by 5 or 10 *** was considered sublethal since many *** survived to adulthood and produced offspring after *** sublethal influences from parasitism by *** resulted in reduced pupal weight,adult emergence rate and fecundity,but increased developmental time and *** at both lethal(40 mites)and sublethal(10 mites)levels impaired the cellular and humoral immunity of *** study presents the first empirical evidence that mite parasitoids can negatively influence host ***,it provides insights into the biocontrol potential of mite parasitoids and their interactions with hosts.

关键词： Pyemotes zhonghuajia Spodoptera frugiperda immunity parasitically-induced influence biocontrol parasitoid

Yolk free egg substitute improves the serum phospholipid profile of mice with metabolic syndrome based on lipidomic analysis

在线全文

学校读者我要写书评

暂无评论

Food Science and Human Wellness 2024年第1期13卷 482-493页

作者： Zhihui Yu Lingyu Fan Fei tai Lixin Zhang Xiaoyu Zhang Yisheng Chen College of Food Science and Engineering Shanxi Agricultural UniversityTaigu 030801China Insitute of Food Nutrition and Safety Shanxi Agricultural UniversityTaiyuan 030031China Shanxi Key Laboratory of Edible Fungi for Loess Plateau Taigu 030801China

In this study,the impacts of egg consumption on mice model of metabolic syndrome(Met S)were comparatively *** were divided into five groups(n=8):normal diet group(ND),high-fat diet group(HFD),HFD with whole egg group(WE),HFD with free-yolk egg substitute group(YFES),and HFD with lovastatin group(Lov).Main biochemical indexes and a non-targeted lipidomic analysis were employed to insight the lipid profile changes in *** was revealed that WE could significantly improve serum biochemical indexes by reducing body weight,low-density lipoprotein cholesterol(LDL-C)and total cholesterol(TC),while increasing high-density lipoprotein *** exhibited remarkably better performance in increasing phosphatidylglycerol and phosphatidic acids,while decreasing phosphatidylinositol than WE.A total of 50 differential lipids biomarkers tightly related to glycerophospholipids metabolism were screened *** C18:2 and C12:1,SM(d18:0/12:0),and SM(d18:1/14:1)were significantly upregulated in YFES compared to *** reduced expression of SREBP-1c and Cpt1a,while did not affect the expression of PPAR-α.Sphingomyelin biomarkers were positively related to the TC(|r|>0.6),while PPAR-αwas negatively correlated with triglyceride and LDL-C *** sum up,YFES attenuated HFD-induced Met S by improving the serum phospholipids,which account for its modulation of glycerophospholipid metabolism.

关键词： Metabolic syndrome Whole egg Yolk free egg substitute Serum Lipidomics

osteology of Turfanodon bogdaensis (Dicynodontia)

在线全文

学校读者我要写书评

暂无评论

古脊椎动物学报（中英文） 2024年第3期62卷 186-200页

作者： SHI Yu-tai LIU Jun Key Laboratory of Vertebrate Evolution and Human origins of Chinese Academy of Sciences Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of SciencesBeijing 100044 College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049

Within the dicynodont genus Turfanodon,there are two recognized species,*** and *** species are known by relatively complete cranial materials,but the mandibles and most postcranial bones have been described only for *** paper reports new dicynodont specimens from Turpan,Xinjiang,referring them to *** can clearly be differentiated from *** by the flatter lateral surface of the snout region,a prominent swelling on the lateral dentary shelf,and the rounded femoral *** diagnosis of Turfanodon is *** combination of a flat circumorbital rim,posterior portion of anterior pterygoid rami with converging ventral ridges,and a possible autapomorphy,a deep notch on scapula forming procoracoid foramen,are *** also differentiated from all dicynodonts other than Myosaurus,Kembawacela and Lystrosaurus by having accessory ridges lateral to the median palatal ridge.

关键词： Turpan,Xinjiang Lopingian,Permian Guodikeng Formation Dicynodontia,Turfanodon osteology,postcranial skeleton

Review on research and development of oxy-coal burner for carbon capture

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第3期67卷 647-672页

作者： GUo JunJun LIU JingZhang ZHANG tai HU Fan LI PengFei LIU ZhaoHui ZHENG ChuGuang State Key Laboratory of Coal Combustion School of Energy and Power EngineeringHuazhong University of Science and Technology Wuhan 430074China CCRC King Abdullah University of Science and Technology(KAUST)Thuwal 23955-6900Kingdom of Saudi Arabia Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China National Key Laboratory of High Efficiency and Low Carbon Utilization of Coal Beijing 100049China Institute of Energy Research Jiangxi Academy of SciencesNanchang 330096China Carbon Neutrality Research Center of Jiangxi Province Nanchang 330096China Faculty of Engineering China University of Geosciences(Wuhan)Wuhan 430074China National Energy Research and Development Center of Clean and Low Carbon Coal-based Power Generation Technologies Wuhan 430074China

In the past two decades, the oxy-fuel combustion of pulverized coal has been extensively developed, leading to the completion of several large industrial pilot oxy-fuel plants worldwide. Various types of oxy-fuel burners have been designed and tested in largescale pilot plants as key components of oxy-fuel combustion. These burners face major challenges in terms of their flame stability because of their decreasing stream momentum ratio and increasing carbon dioxide concentration. However, it offers flexibility in adjusting the oxygen concentration in each burner stream. This study aims to provide a comprehensive review of the state-of-the-art knowledge on oxy-coal burner design and operation in power plants. First, the combustion characteristics under oxy-fuel conditions are briefly introduced. Subsequently, the principal requirements and fundamental parameters of the oxy-coal burners are discussed. The development process of oxy-fuel burners is also presented. Moreover, a compatible design strategy and scaling-up techniques are described for oxy-coal burners developed by the authors over the past ten years. The performances of oxy-coal burners in three large pilot oxy-fuel plants worldwide are summarized and compared. Finally, concluding remarks are provided and potential research needs are suggested.

关键词： carbon capture oxy-fuel combustion oxy-fuel burner pulverized coal compatible design

同方期刊数据库