检索结果-南通市图书馆

Multiple-stage spatial-temporal cooperative guidance without time-to-go estimation

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 Aeronautics 2024年第9期37卷 399-416页

作者： Chunyan WANG weilin WANG wei dong Jianan WANG Fang deng School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China National Key Lab of Autonomous Intelligent Unmanned Systems Beiing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

This paper investigates the spatial-temporal cooperative guidance problem for multiple flight vehicles without relying on time-to-go ***,a two-stage cooperative guidance strategy,namely the cooperative guidance and the Proportional Navigation Guidance(PNG)stage strategy,is developed to realize the spatial-temporal constraints in two *** the former stage,two controllers are designed and superimposed to satisfy both impact time consensus and impact angle *** the convergent conditions are satisfied,the flight vehicles will switch to the PNG stage to ensure zero miss *** further extend the results to three dimensions,a planar pursuit guidance stage is additionally imposed at the beginning of *** to the inde-pendence of time-to-go estimation,the proposed guidance strategy possesses great performance in satisfying complex spatial-temporal constraints even under flight speed ***,several numerical simulations are implemented to verify the effectiveness and advantages of the proposed results under different scenarios.

关键词： Cooperative guidance Guided missiles Impact time consensus Impact angle constraint Spatial-temporal cooperative guidance

Quantitatively Evaluating the Erosion and Preservation of Supergene Oxide Zones:Evidence from the yulong Porphyry Cu Deposit,Eastern Tibetan Plateau

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 Earth Science 2024年第1期35卷 280-282页

作者： Xiao-dong deng Jian-wei Li State Key Laboratory of Geological Processes and Mineral Resources and School of Earth ResourcesChina University of GeosciencesWuhan 430074China

*** and erosion of sulfide ore deposits are important for understanding the post-mineralization processes that have significant effects on the preservation of primary orebodies(Velasco et al.,2013;Braxton et al.,2009;Brimhall et al.,1985).Supergene oxide zones are often developed in sulfide ore deposits,and are mainly composed of iron oxides and hydroxides zones in weathering profile(Andrew,1984;Thornber et al.,1981).

关键词： Eastern Tibetan weathering

In situ sulfur-doped mesoporous tungsten oxides for gas sensing toward benzene series

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第7期35卷 502-507页

作者： yu deng Yan Liu Yonghui deng Jinsheng Cheng Yidong Zou wei Luo State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai 201620China Department of Chemistry State Key Laboratory of Molecular Engineering of PolymersShanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsiChEMFudan UniversityShanghai 200433China Department of Polymeric Materials School of Materials Science and EngineeringTongji UniversityShanghai 201804China Henry-Fork School of Food Sciences Shaoguan UniversityShaoguan 512005China State Key Lab of Transducer Technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China

Benzene series as highly toxic gases have inevitably entered human life and produce great threat to human health and ecological environment,and thus it is distinctly meaningful to monitor benzene series with quickly,real-time and efficient ***,novel sulfur-doped mesoporous WO_(3)materials were synthesized via classical in-situ solvent evaporation induced co-assembly strategy combined with doping engineering,which possessed highly crystallized frameworks,high specific surface area(40.9–63.8 m^(2)/g)and uniform pore size(~18 nm).Benefitting from abundant oxygen vacancy and defects via S-doping,the tailored mesoporous S/m WO_(3)exhibited excellent benzene sensing performance,including high sensitivity(50 ppm vs.48),low detection limit(ca.500 ppb),outstanding selectivity and favorable *** addition,the reduction of band gap resulted from S-doping promotes the carrier migration in the sensing materials and the reaction at the gas–solid sensing *** provides brand-new approach to design sensitive materials with multiple reaction sites.

关键词： Mesoporous materials Benzene series Tungsten oxides Sulfur doping Gas sensor

Field-based evidence for the enrichment of intrinsic antibiotic resistome stimulated by plant-derived fertilizer in agricultural soil

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第1期135卷 728-740页

作者： Shihai Liu Ziming Han dong Zhu Xiao Luan Liujie deng Liping dong Min Yang yu Zhang State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China State Environmental Protection Engineering Center for Harmless Treatment and Resource Utilization of Antibiotic Residues Khorgos 835007China University of Chinese Academy of Sciences Beijing 100049China

Animal manures have been demonstrated to enhance antibiotic resistance in agricultural ***,little is known about the effects of plant-derived fertilizer on soil antibiotic ***,metagenomic sequencing was used to investigate the effects of a plantderived fertilizer processed from sugarcane and beet on soil antibiotic resistance genes(ARGs)in a soybean field along crop growth *** profiles in the soils amended by plant-derived fertilizer were compared with those in the soils amended by chicken *** abundance and diversity of total ARGs in the soils amended by plant-derived fertilizer were significantly(P<0.05)elevated at the sprout stage,to a level comparable to that in the manured ***,unlike chicken manure mainly introducing manure-borne ARGs to soil,the plant-derived fertilizer was indicated to mainly enrich multidrug resistance genes in soil by nourishing indigenous *** with abundances in amended soils significantly(P<0.05)higher than in unamended soils at the sprout stage of soybean were considered as enriched *** in the abundance of the enriched ARGs was observed in both the amended soils from the sprout to the *** analysis further identified Proteobacteria and Bacteroidetes as the primary bacterial taxa involved in the temporal variation of the enriched ARGs in the soils amended by plant-derived fertilizer,while in manured soils were Firmicutes and *** revealed by multivariate statistical analyses,variation of the enriched ARGs in the soils amended by plant-derived fertilizer was majorly attributed to the response of co-occurred bacteria to depleting nutrients,which was different from the failed establishment of manure-borne bacteria in the manured *** study provided field-based evidence that plant-derived fertilizer stimulated the intrinsic antibiotic resistome,and proposed attention to the un-perceived risk since some clinically relevant ARGs originate and evolve fr

关键词： Organic fertilizer Intrinsic antibiotic resistance Indigenous bacteria Metagenomic sequencing

GPa-level pressure-induced enhanced corrosion resistance in TiZrTaNbSn biomedical high-entropy alloy

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第3期21卷 265-275页

作者： Xiao-hong Wang yu-lei deng Qiao-yu Li Zhi-xin Xu Teng-fei Ma Xing Yang Duo dong dong-dong Zhu Xiao-hong Yang Key Laboratory of Air-driven Equipment Technology of Zhejiang Province Quzhou UniversityQuzhou 324000ZhejiangChina School of Materials Science and Engineering Taizhou UniversityTaizhou 318000ZhejiangChina

TiZrTaNb-based high-entropy alloys(HEAs)are research frontier of biomedical materials due to their high hardness,good yield strength,excellent wear resistance and corrosion ***,as an essential trace element in the human body that plays a significant role in physiological *** has stable chemical properties and a low elastic *** this study,a new material,TiZrTaNbSn HEAs,was proposed as a potential biomedical *** Ti_(35)Zr_(25)Ta_(15)Nb_(15)Sn_(10)biomedical high-entropy alloys(BHEAs)were successfully prepared through an arc melting furnace and then remelted using a German high-temperature and high-pressure apparatus under GPa-level(4 GPa and 7 GPa).The precipitation behavior of the needle-like HCP-Zr_(5)Sn_(3)phase that precipitates discontinuously at the grain boundary was successfully *** phase constitution,microstructure,and corrosion resistance of the alloy were *** results show that the needle-like HCP-Zr_(5)Sn_(3)phase is eliminated and the(Zr,Sn)-rich nano-precipitated phase is precipitated in the microstructure under high pressure,which leads to the narrowing of grain boundaries and consequently improves the corrosion resistance of the *** addition,the formation mechanisms of(Zr,Sn)-rich nanoprecipitates in BHEAs were *** Zr and Sn dissolve in the matrix due to the effect of high pressure,during the cooling process,they precipitate to form a(Zr,Sn)-rich nano-precipitated phase.

关键词： biomedical HEAs precipitation grain boundary corrosion resistance TiZrTaNbSn

Uplift, climate and biotic changes at the Eocene-Oligocene transition in south-eastern Tibet

在线全文

学校读者我要写书评

暂无评论

National Science Review 2019年第3期6卷 495-504页

作者： Tao Su Robert A.Spicer Shi-Hu Li He Xu Jian Huang Sarah Sherlock Yong-Jiang Huang Shu-Feng Li Li Wang Lin-Bo Jia wei-yu-dong deng Jia Liu Cheng-Long deng Shi-Tao Zhang Paul J.Valdes Zhe-Kun Zhou Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences University of Chinese Academy of Sciences State Key Laboratory of Paleobiology and Stratigraphy Nanjing Institute of Geology and Paleontology Chinese Academy of Sciences School of Environment Earth and Ecosystem Sciences The Open UniversityMK7 6AA UK Guangdong Provincial Key Laboratory of Geodynamics and Geohazards School of Earth Sciences and Engineering Sun Yat-sen University Institute of Geology and Paleontology Linyi University Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of Botany Chinese Academy of Sciences State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Faculty of Land Resource Engineering Kunming University of Science and Technology School of Geographical Sciences and Cabot Institute University of Bristol

The uplift history of south-eastern Tibet is crucial to understanding processes driving the tectonic evolution of the Tibetan Plateau and surrounding areas. Underpinning existing palaeoaltimetric studies has been regional mapping based in large part on biostratigraphy that assumes a Neogene modernization of the highly diverse, but threatened, Asian biota. Here, with new radiometric dating and newly collected plant-fossil archives, we quantify the surface height of part of the south-eastern margin of Tibet in the latest Eocene(～34 Ma) to be ～3 km and rising, possibly attaining its present elevation(3.9 km) in the early Oligocene. We also find that the Eocene–Oligocene transition in south-eastern Tibet witnessed leaf-size diminution and a floral composition change from sub-tropical/warm temperate to cool temperate, likely reflective of both uplift and secular climate change, and that, by the latest Eocene, floral modernization on Tibet had already taken place, implying modernization was deeply rooted in the Palaeogene.

关键词： biodiversity Eocene Oligocene plant fossil Qinghai-Tibetan Plateau uplift

Development of an enhanced online tritium monitoring system using plastic scintillation fiber array

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

NUCLEAR SCIENCE AND TECHNIQUES 2024年第10期35卷 1-11页

作者： Cheng, Wen-yu deng, Ke Zeng, You-Shi Liu, wei Zhang, Qin Chinese Acad Sci Shanghai Inst Appl Phys Shanghai 201800 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China

Tritium, a radioactive nuclide discharged by nuclear power plants, poses challenges for removal. Continuous online monitoring of tritium in water is crucial for real-time radiation data, given its predominant existence in the environment as water. This paper presents the design, simulation, and development of a tritium monitoring device utilizing a plastic scintillation fiber (PSF) array. Experimental validation confirmed the device's detection efficiency and minimum detectable activity. The recorded detection efficiency of the device is 1.6x10-3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$1.6\times 10{-3}$$\end{document}, which exceeds the theoretically simulated value of 4x10-4\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$4\times 10{-4}$$\end{document} by four times. Without shielding, the device can achieve a minimum detectable activity of 3165BqL-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$3165\,\hbox {Bq}\,\hbox {L}{-1}$$\end{document} over a 1600-second measurement duration. According to simulation and experimental results, enhancing detection efficiency is possible by increasing the number and length of PSFs and implementing rigorous shielding measures. Additionally, reducing the diameter of PSFs can also improve detection efficiency. The minimum detectable activity of the device can be further reduced using the aforementioned methods.

关键词： Tritium Plastic scintillating fiber array Detector WATER SOIL

Leaf fossils of Sabalites(Arecaceae)from the Oligocene of northern Vietnam and their paleoclimatic implications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plant Diversity 2022年第4期44卷 406-416页

作者： Ai Song Jia Liu Shui-Qing Liang Truong Van Do Hung Ba Nguyen wei-yu-dong deng Lin-Bo Jia Cedric Del Rio Gaurav Srivastava Zhuo Feng Zhe-Kun Zhou Jian Huang Tao Su Institute of Palaeontology Yunnan Key Laboratory for PalaeobiologyMEC International Joint Laboratory for Palaeobiology and PalaeoenvironmentYunnan Key Laboratory of Earth System ScienceYunnan UniversityKunming650500China CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla666303China Vietnam National Museum of Nature Vietnam Academy of Science and Technology18 Hoang Quoc VietHanoiViet Nam Graduate Academy of Science and Technology Vietnam Academy of Science and Technology18 Hoang Quoc VietHanoiViet Nam CAS Key Laboratory of Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming650204China Birbal Sahni Institute of Palaeosciences Lucknow226007India

Recent paleobotanical investigations in Vietnam provide a good opportunity to improve our understanding of the biodiversity and paleoclimatic conditions in the geological past of Southeast ***(Arecaceae)are a diverse family of typical thermophilous plants with a relatively low tolerance for *** this study,we describe well-preserved fossil palm leaves from the Oligocene dong Ho Formation of Hoanh Bo Basin,northern *** of the fossil leaves,such as a fan-shaped costapalmate lamina,an unarmed petiole,a costa slightly enlarged at the base that then tapers distally into the blade,and well-preserved amphistomatic leaves with cuticles,suggest that they represent a new fossil species,which we herein designate Sabalites colaniae ***,***,*** et *** *** with other paleontological and palaeoclimatic evidence,we conclude that a warm climate prevailed in northern Vietnam and nearby areas during the Oligocene.

关键词： Fossil Leaf Oligocene Paleoclimate Palm Vietnam

Maternal weight and its association with risk of overweight in offspring:a trajectory analysis from a birth cohort in China

在线全文

学校读者我要写书评

暂无评论

World Journal of Pediatrics 2024年第5期20卷 496-505页

作者： Rui deng wei-Qin Li Xing-Xiu Li Liu-Mei wei Jie Hu Jun-Hong Leng Bin dong Institute of Child and Adolescent Health School of Public HealthPeking University Health Science CenterNo.38 Xueyuan RdHaidian DistrictBeijing100191China Tianjin Women and Children’s Health Center No.96 Guizhou RdHeping DistrictTianjin300070China Menzies Health Institute Queensland Griffith UniversityNathanQLD4111Australia

Background Most studies on the association of maternal pregnancy weight with offspring weight trajectory have a short follow-up *** study aimed to explore the associations of maternal prepregnancy body mass index(BMI)and gestational weight gain(GWG)with childhood weight trajectories in a 7-year birth *** A total of 946 mother–child pairs(467 boys and 479 girls)from a longitudinal birth cohort in Tianjin City,China,were included in this study,ranging from pregnancy to offspring at 7 *** outcome variable was defined as overweight or not overweight in offspring at the last round.A group-based trajectory model was applied to identify childhood BMI trajectory *** Five discrete BMI trajectory groups were identified and characterized as constant underweight(25.2%),constant normal weight(42.8%),and high or increasing trajectory[at risk of overweight(16.9%),progressive overweight(11.0%)and progressive obesity(4.1%)].Maternal prepregnancy overweight was associated with 1.72(95%CI 1.14–2.60,P=0.01)to 4.02(95%CI 1.94–8.36,Pweight[relative risk ratio(RRR)2.09,95%CI 1.27–3.46,P=0.004]and progressive obesity(RRR 3.33,95%CI 1.13–9.79,P=0.029).Children in all high or increasing trajectory groups were associated with greater overweight risk at the last round[risk ratios(RRs)ranged from 3.54(95%CI 2.53–4.95,Pweight and excessive gestational weight gain were associated with increasing or high-level childhood body mass index trajectories as well as a greater risk of overweight at 7 years.

关键词： Body-weight trajectory Child Gestational weight gain Overweight Pregnancy