检索结果-南通市图书馆

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

Sedimentary paleoenvironment and its control on organic matter enrichment in the Mesoproterozoic hydrocarbon source rocks in the Ordos Basin, southern margin of the North China Craton

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第4期21卷 2257-2272页

作者： Zhi-chen Wu Ju-Ye Shi tai-Liang Fan Ming Jiang School of Energy Resources China University of Geosciences (Beijing) Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Enrichment Mechanism Ministry of Education China University of Geosciences (Beijing)

The black shale of the Mesoproterozoic Cuizhuang Formation in the Changcheng System in Yongji city,North China Craton, is a potential source rock. Understanding the organic matter enrichment mechanism is crucial for evaluating source rock resources and understanding oil and gas accumulation *** this study, we evaluated the sedimentary paleoenvironment and organic matter enrichment mechanisms of shale using thin section observations, mineral composition analysis, organic geochemistry, and elemental geochemistry. We found significant differences in the sedimentary paleoenvironment and organic matter enrichment mechanisms between the lower Cuizhuang Formation and the Beidajian Formation shale. The Cuizhuang Formation was deposited in a late-stage, restricted basin environment during the rift phase, and elemental and geochemical indicators showed that the Cuizhuang Formation was in a suboxic-anoxic water environment, that was influenced by a warm and humid paleoclimate and submarine hydrothermal activities, which promoted the accumulation of organic matter. However, the enrichment of organic matter in the Cuizhuang Formation was mainly controlled by redox *** formation of suboxic-anoxic water environments may be closely related to the warm and humid paleoclimate and submarine hydrothermal activities. Warm conditions promote continental weathering and increase marine productivity, thereby consuming oxygen in the bottom water. Moreover, acidic hydrothermal activity also helps to establish an anoxic environment. Our results reveal the effects controlling various coupled mechanisms dominated by redox conditions, which may explain the development of source rocks in the Cuizhuang Formation.

关键词： Cuizhuang formation Paleoproterozoic source rocks Marine productivity Paleoenvironments Submarine hydrothermal activity Organic matter enrichment

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

在线全文

同方期刊数据库

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

Identification of aircraft longitudinal aerodynamic parameters using an online corrective test for wind tunnel virtual flight

在线全文

学校读者我要写书评

暂无评论

CHINESE JOURNAL OF AERONAUTICS 2024年第9期37卷 261-275页

作者： tai, Shang Bu, chen Wang, Yanling Yue, Ting Liu, Hailiang Wang, Lixin Beihang Univ Sch Aeronaut Sci & Engn Beijing 100191 Peoples R China AVIC Aerodynam Res Inst Harbin 150001 Peoples R China

The identification of aerodynamic parameters is accomplished through the test data of the dynamic movement of scaled aircraft models flying dynamically in wind tunnel, which can realize the accurate acquisition of the aerodynamic model of the aircraft in the preliminary stage for aircraft design, and it is of great significance for improving the efficiency of aircraft design. However, the translational motion of the test model in the wind tunnel virtual flight is subject to constraints that result in distinct flight dynamics compared to free flight. These constraints have implications for the accuracy of aerodynamic derivatives obtained through the identification of wind tunnel test data. With this issue in mind, the research studies the differences in longitudinal dynamic characteristics between unconstrained free flight and wind tunnel virtual flight, and innovatively proposes an online correction test based wind tunnel virtual flight test technique. The longitudinal trajectory and velocity changes of the model are solved online by the aerodynamic forces measured during the test, and then the coupled relationship between aircraft translation and rotation is used to correct the model's pitch attitude motion online. For the first time, the problem of solving the data approximation for free flight has been solved, eliminating the difference between the dynamics of wind tunnel virtual flight and free flight, and improving the accuracy of the aerodynamic derivative identification results. The experiment's findings show that accurate aerodynamic derivatives can be identified based on the online correction test data, and the observed behaviour of the identified motion model has similarities to that of the free flight motion model. (c) 2024 Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics. This is an open access article under the CC BY-NC-ND license (http://***/ licenses/by-nc-nd/4.0/).

关键词： Wind tunnels Displacement constraints Online solution Flight control law Aerodynamic parameter identification MODEL SIMULATION STABILITY MANEUVER DESIGN RIG

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

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 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

Epitaxial growth of borophene on graphene surface towards efficient and broadband photodetector

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 3053-3060页

作者： Zenghui Wu chen Shifan Zitong Wu Yi Liu Wei Shao Xinchao Liang Chuang Hou Guoan tai The State Key Laboratory of Mechanics and Control of Mechanical Structures and Laboratory of Intelligent Nano Materials and Devices of Ministry of Education College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China

In-situ integration of multiple materials with well-defined interfaces as heterostructures is of great interest due to their unique properties and potential for new device *** of its polymorphism and diverse bonding geometries,borophene is a promising candidate for two-dimensional heterostructures,but suitable synthesis conditions have limited its potential *** this end,we demonstrate the vertical borophene and graphene heterostructures which form by epitaxial growth of borophene onto multilayer graphene on Cu substrates via chemical vapor deposition,where hydrogen and NaBH_(4) are respectively used as the carrier gas and the boron *** lattice structure of the as-synthesized borophene well coincides with the predictedα′-boron *** borophene-based photodetector shows an excellent broadband photoresponse from the ultraviolet(255 nm)to the infrared(940 nm)wavelengths,with enhanced responsivity compared to pristine borophene or graphene *** work informs emerging efforts to integrate borophene into nanoelectronic applications for both fundamental investigations and technological applications.

关键词： borophene graphene heterostructure photodetector two-dimensional materials

Patient-centered care in diabetes care-concepts,relationships and practice

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

World Journal of Diabetes 2024年第7期15卷 1417-1429页

作者： Tsung-tai chen Wei-Chih Su Mei-I Liu Department of Public Health College of MedicineFu Jen Catholic UniversityNew Taipei 24205Taiwan Department of Gastroenterology Taipei Tzu-Chi HospitalNew Taipei 23142Taiwan Department of Pediatric Endocrinology Mackay Children's HospitalTaipei 10449Taiwan

We still do not have comprehensive knowledge of which framework of patientcentered care(PCC)is appropriate for diabetes care,which elements of PCC are evidence-based,and the mechanism by which PCC elements are associated with outcomes through *** this review,we elaborate on these *** found that for diabetes care,PCC elements such as autonomy support(patient individuality),cooperation and collaboration(system-level approach),communication and education(behavior change techniques),emotional support(biopsychosocial approach),and family/other involvement and support are critically *** of these factors are directly associated with different patient outcomes and indirectly associated with outcomes through patient *** present the practical implications of these PCC elements.

关键词： Diabetes mellitus Patient-centered care Autonomy support Patient activation Patient adherence

Air pressure law of a reservoir constructed in karst sinkholes

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 Mountain Science 2024年第3期21卷 1048-1057页

作者： YU Bo tai Shengping ZHENG Kexun chen Shiwan HAN Xiao WANG Senlin ZUO Shuangying Power China Guiyang Engineering Corporation Limited Guiyang 550081China College of Resources and Environmental Engineering Key Laboratory of Karst Georesources and EnvironmentMinistry of EducationGuizhou UniversityGuiyang 550025China

Karst sinkholes with natural negative landform provide favorable conditions for the pumped storage reservoir construction for less excavation ***,the construction of the reservoir would plug the natural karst channels for water and air,which would cause remarkable air pressure in karst channels when the groundwater level fluctuates.A large laboratory simulation test was carried out to study the air pressure variation of a reservoir built on the karst *** air pressure in the karst channel and inside the model was monitored during the groundwater rising and falling *** showed that the variation of air pressure in the karst channel and the surrounding rock exhibited a high degree of *** air pressure increased rapidly at the initial stage of water level rising,followed by a slight decrease,then the air pressure increased sharply when the water level approached the top of the karst *** initial peak of air pressure and the final peak of air pressure were defined,and both air pressure peaks were linearly increasing with the water level rising *** negative air pressure was also analyzed during the drainage process,which was linearly correlated with the water level falling *** causes of air pressure variation in karst channels of a pumped storage reservoir built on the karst sinkhole were *** initial rapid increase,then slight decrease and final sudden increase of air pressure were controlled by the combined effects of air compression in karst channel and air seepage into the surrounding *** the drainage process,the instant negative air pressure and gradual recovering of air pressure were controlled by the combined effects of negative air pressure induced by water level falling and air supply from surrounding *** work could provide valuable reference for the reservoir construction in karst area.

关键词： Simulation test Karst sinkhole Pumped storage reservoir Air pressure Flow rate