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Late Quaternary ice-rafted detritus events in the Chukchi Basin, western Arctic Ocean

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Chinese Science Bulletin 2010年第4期55卷 432-440页

作者： WANG RuJian xiao WenShen li WenBao SUN YeChen State Key Laboratory of Marine Geology Tong/i University Shanghai 200092 China Alfred Wegener Institute for Polar and Marine Research Bremerhaven 2 7517 Germany

The late Quaternary ice rafted detritus (IRD) events in the Chukchi Basin, western Arctic Ocean are indications of the provenance of the coarser detritus and ice export events, and also document the evolutionary histories of Beaufort Gyre and the North American Ice Sheet (NAIS). The sediment of core M03 from the Chukchi Basin was selected to study the regional response to the ice export events and the NAIS variability. The stratigraphic framework of M03 was established by a combination of lithological features and downcore color change cycles, AMS14C dating with foraminifera abundance and IRD events. The core was also compared with the adjacent core NWR 5 from the Northwind Ridge area. The core extends back to Marine Isotope Stage (MIS) 7. A sedimentary hiatus of 10―20 ka might occur between 16 to 20 cm core depth. Seven IRD events are distinguished from the studied core and are presented during the early MIS 1, MIS 3, MIS 5 and late MIS 7. These IRD are transported by sea ice and icebergs, which were exported to the Beaufort Sea from the M'Clure Strait Ice Stream, Canadian Arctic Archipelago, and brought to the Chukchi Basin by the Beaufort Gyre.

关键词：盆地沉积物晚第四纪北冰洋粗碎屑事件西部管理信息系统 MIS系统

On UAV Serving Node Deployment for Temporary Coverage in Forest Environment:A Hierarchical Deep Reinforcement Learning Approach

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Chinese Journal of Electronics 2023年第4期32卷 760-772页

作者： WANG li WU Xuewei WANG Yanhui xiao Zhe li liang FEI Aiguo School of Computer Science (National Pilot Software Engineering School) Beijing University of Posts and Telecommunications School of Electronic Engineering Beijing University of Posts and Telecommunications

Unmanned aerial vehicles(UAVs) can be effectively used as serving stations in emergency communications because of their free movements, strong flexibility, and dynamic coverage. In this paper, we propose a coordinated multiple points based UAV deployment framework to improve system average ergodic rate, by using the fuzzy C-means algorithm to cluster the ground users and considering exclusive forest channel models for the two cases, i.e., associated with a broken base station or an available base station. In addition, we derive the upper bound of the average ergodic rate to reduce computational complexity. Since deep reinforcement learning(DRL) can deal with the complex forest environment while the large action and state space of UAVs leads to slow convergence, we use a ratio cut method to divide UAVs into groups and propose a hierarchical clustering DRL(HC-DRL) approach with quick convergence to optimize the UAV deployment. Simulation results show that the proposed framework can effectively reduce the complexity, and outperforms the counterparts in accelerating the convergence speed.

关键词： Deep learning Base stations Simulation Clustering algorithms Forestry Reinforcement learning Autonomous aerial vehicles

Ranging pattern and population composition of Rhinopithecus bieti at xiaochangdu,Tibet:Implications for conservation

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Chinese Science Bulletin 2013年第17期58卷 2212-2219页

作者： XIANG ZuoFu xiao Wen HUO Sheng li Ming College of life Science and Technology Central South University of Forestry & Technology Kunming Institute of Zoology Chinese Academy of Sciences Institute of Eastern-Himalaya Biodiversity Research Dali University Key Laboratory of Animal Ecology and Conservation Biology Institute of ZoologyChinese Academy of Sciences

We studied the ranging pattern of the wild black-and-white snub-nosed monkeys(Rhinopithecus bieti) at xiaochangdu,Tibet from June 2003 to March *** the map grid cell method,the group home range were 16.75 km 2 in summer,10.50 km 2 in winter,and 21.25 km 2 total over two *** daily travel length(DTL) averaged 765 m with a range of 350-3500 *** results showed that DTL in winter was significantly shorter than those of in summer and ***,rainfall,food availability,and human disturbance correlated positively with *** to the maximum observed group size and estimated total home range,population density and biomass of *** were 9.1 individuals/km 2 and 88.6 kg/km 2,*** temporal and spatial variations of food resources and patterns of human disturbance largely determine the ranging behavior of *** at xiaochangdu.

关键词：滇金丝猴人口密度测距西藏保护组成人为干扰粮食供应

A topotactic tailored synthesis of waxberry-like mixed-phase TiO_(2) hollow spheres for dye-sensitized solar cells

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Chinese Chemical Letters 2022年第2期33卷 963-967页

作者： Yang-Hong Wu Kai-Yan Yuan Yan-E He Heng Wu li-Jiao Ma Gang Wang xiao-Dong Qiao Bing-Xin Lei zhen-Fan Sun Zhao-Qing liu School of Chemistry and Chemical Engineering Key Laboratory of Electrochemical Energy Storage and Energy Conversion of Hainan ProvinceKey Laboratory of Electrochemical Energy Storage and Light Energy Conversion Materials of Haikou CityHainan Normal UniversityHaikou 571158China School of Chemistry and Chemical Engineering/Institute of Clean Energy and Materials/Guangzhou Key Laboratory for Clean Energy and Materials/Huangpu Hydrogen Innovation Center Guangzhou UniversityGuangzhou 510006China

The waxberry-like mixed-phase TiO_(2)hollow microstructures (WMTHMs) are controllably prepared via a topotactic synthetic method,involving the synthesis of monodispersed Ca TiO_(2)precursors by a solvothermal method and subsequently transforming them into TiO_(2)through a Na_(2)EDTA-assisted ion-exchange *** ratio of anatase-rutile is adjustable,and the two phases are connected well with each *** are composed of radially aligned nanorods,speeding up the electron *** optimum WMTHMs sample shows a specific surface area of 68.05 m^(2)/g and exhibits an excellent light scattering *** cell based on WMTHMs light scattering layer obtained an optimal efficiency of 9.12%.The improvement of cell efficiency is mainly attributed to the high specific surface area,the efficient light scattering,the appropriate ratio of anatase-rutile,the staggered bandgap structure,and the convenient one-dimensional electron transport channel.

关键词： Titanium dioxide Phase composition Topotactic methodology Hollow sphere Dye-sensitized solar cell

Synthesis and Herbicidal Activity of Novel 5-Substituted Benzenesulfonylureas

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Chemical Research in Chinese Universities 2007年第6期23卷 674-678页

作者： WANG Mei-yi MU xiao-li GUO Wan-cheng li Yong-hong li zheng-ming State Key Laboratory of Elemento-Organic Chemistry Research Institute of Elemento-Organic Chemistry Nankai University Tianfin 300071 P. R. China

Sulfonylurea herbicides have been widely used because of their low application rates, good crop sdeetivities and low mammalian toxicities. However, some sulfonylureas might persist unfavourably in the environment with residual problems. In order to look for ecologically safer and environmentally benign sulfonylureas, and on keeping the pyrimidine ring being monosubstitated, 15 novd C5-monosubstituted benzenesulfonylurea compounds were synthesized. The structures of all the compounds synthesized were confirmed by demental analysis and ^1H NMR. Preliminary herbicidal activities of these new sulfonylurea compounds were determined by ALS screening （ in vitro） and pot bioassay experiments（ in vivo）. The herbicidal results show that some novel sulfonylureas are comparable to commercial Foramsulfuron and Monosulfuron.

关键词： Sulfonylurea 5-Substituted phenyl ring Herbicidal activity

Ni_2P/ZrO_2-SBA-15 Dibenzothiophene Hydrodesulfurization Catalysts: Preparation,Characterization and Evaluation

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Transactions of Tianjin University 2018年第4期24卷 340-350页

作者： Hongqin Ma Qiurong li Yang Shi xiao Sun School of Chemical Engineering and Technology Tianjin University

Ni_2P/ZrO_2-SBA-15 catalysts with different zirconium n-propoxide/SBA-15 mass ratios were synthesized to evaluate their dibenzothiophene hydrodesulfurization catalytic activity. Effect of ZrO_2 introduction was investigated. Supports and catalysts were characterized by BET,XRD,^(29)SiNMR,XPS and FTIR. The results indicated that zirconium was incorporated into SBA-15 in the forms of [(–O–)_2 Si(–O–Zr)_2 ] and/or [(–O–)_3 Si–O–Zr],and that the SBA-15 framework structure was maintained after incorporation of ZrO_2. With zirconium content increasing,ZrO_2 was transformed from amorphous phase to tetragonal phase. Zirconium incorporation into SBA-15 supports could facilitate to form more dispersed Ni_2P active phase. There might be some interaction occurring between the P and Zr species. In addition to Ni_2P,another kind of active phase,ZrP,was formed,which might exhibit a better HDS activity than Ni_2P. It was observed that at a temperature of 280 °C,pressure of 3.0 MPa,WHSV of 6.5 h^(-1) and H_2 to oil ratio of 450,the Ni_2P/Zr-SBA(1.5) catalyst,where 1.5 represents zirconium n-propoxide/SBA-15 mass ratio,showed the highest DBT conversion,which was 86.6%,almost 35% higher than that of the Ni_2P/Zr-SBA(0) catalyst.

关键词： Nickel phosphide Hydrodesulfurization ZrO 2 modifi ed SBA-15

Data fusion and simulation-based planning and control in cyber physical system for digital assembly of aeroplane

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International Journal of Modeling, Simulation, and Scientific Computing 2015年第3期6卷 66-84页

作者： Hui li linxuan Zhang Tianyuan xiao Jietao Dong State CIMS Engineering Research Center at Tsinghua University Main Building Room 604 Beijing 100084P.R.China State CIMS Engineering Research Center at Tsinghua University Main Building Room 601 Beijing 100084P.R.China State CIMS Engineering Research Center at Tsinghua University Main Building Room 619 Beijing 100084P.R.China

This paper introduces a CPS application for intelligent aeroplane *** first,the CPS structure is presented,which acquires the characteristics of general CPS and enables“simulation-based planning and control”to achieve high level intelligent *** the paper puts forward data fusion estimation algorithm under synchronous and asynchronous sampling,*** experiment shows that global optimal distributed fusion estimation under synchronized sampling proves to be closer to the actual value compared with ordinary weighted estimation,and multi-scale distributed fusion estimation algorithm of wavelet under asynchronous sampling does not need time registration,it can also directly link to data,and the error is *** paper presents hybrid control strategy under the circumstance of joint action of the inner and outer loop to address the problems caused by the less controllable feature of the parallel mechanism when undertaking online process simulation and control.A robust adaptive sliding mode controller is designed based on disturbance observer to restrain inner interference and maintain *** the same time,an outer collaborative trajectory planning is also *** the experiment results show the feasibility of above proposed methods.

关键词： Intelligent aeroplane assembly cyber physical system multi-sensor data fusion simulation-based control disturbance observer robust adaptive sliding mode controller

Uncovering the solid-phase conversion mechanism via a new range of organosulfur polymer composite cathodes for lithium-sulfur batteries

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Journal of Energy Chemistry 2023年第9期84卷 459-466页

作者： Xiang li Dezhong liu Ziyi Cao Yaqi liao Zexiao Cheng Jie Chen Kai Yuan Xing lin zhen li Yunhui Huang lixia Yuan State Key Laboratory of Material Processing and Die&Mold Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074HubeiChina

The sulfur cathodes operating via solid phase conversion of sulfur have natural advantages in suppressing polysulfide dissolution and lowering the electrolyte dosage,and thus realizing significant improvements in both cycle life and energy *** realize an ideal solid-phase conversion of sulfur,a deep understanding of the regulation path of reaction mechanism and a corresponding intentional material and/or cathode design are highly ***,via covalently fixing of sulfur onto the triallyl isocyanurate,a series of S-triallyl isocyanurate organosulfur polymer composites(STIs) are *** between the structure and the electrochemical conversion behavior of STIs is systematically *** is found that the structure of STIs varies with the synthetic temperature,and correspondingly the electrochemical redox of sulfur can be controlled from conventional "solid-liquid-solid" conversion to the "solid-solid" *** the STI series,the STI-5 composite realizes an ideal solid-phase conversion and demonstrates great potential for building a li-S battery with high-energy density and long-cyclelife:it realizes stable cycling over 1000 cycles in carbonate electrolyte,with a degradation rate of0.053% per cycle;the corresponding pouch cell shows almost no capacity decay for 125 cycles under the conditions of high sulfur loading(4.5 mg cm^(-2)) and lean electrolyte(8 μL mg_s^(-1)).In addition,the tailoring strategy of STI can also apply to other precursors with allyl functional groups to develop new organosulfur polymers for "solid-solid" sulfur *** vulcanized triallyl phosphate(STP) and triallylamine(STA) both show great lithium storage *** strategy successfully develops a new family of organosulfur polymers as cathodes for li-S batteries via solid-phase conversion of sulfur,and brings insights to the mechanism study in li-S batteries.

关键词： Organosulfur polymer lithium–sulfur batteries Allyl functional groups Reaction mechanism Solid–solid conversion

Nonpharmaceutical interventions contribute to the control of COVID-19 in China based on a pairwise model

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Infectious Disease Modelling 2021年第1期6卷 643-663页

作者： xiao-Feng Luo Shanshan Feng Junyuan Yang xiao-Long Peng xiaochun Cao Juping Zhang Meiping Yao Huaiping Zhu Michael Y.li Hao Wang zhen Jin Department of Mathematics North University of ChinaTaiyuanShanxi030051China Complex System Research Center Shanxi UniversityTaiyuan030006ShanxiChina Shanxi Key Laboratory of Mathematical Techniques and Big Data Analysis on Disease Control and Prevention Shanxi UniversityTaiyuan030006ShanxiChina School of Mathematical Sciences Shanxi UniversityTaiyuan030006ShanxiPR China Department of Mathematics and Statistics York UniversityTorontoONM3J 1P3Canada Department of Mathematics and Statistics Sciences University of AlbertaEdmontonAlbertaT6G 2G1Canada

Nonpharmaceutical interventions(NPIs),particularly contact tracing isolation and household quarantine,play a vital role in effectively bringing the Coronavirus Disease 2019(COVID-19)under control in *** pairwise model,has an inherent advantage in characterizing those two NPIs than the classical well-mixed ***,in this paper,we devised a pairwise epidemic model with NPIs to analyze COVID-19 outbreak in China by using confirmed cases during February 3rde22nd,*** explicitly incorporating contact tracing isolation and family clusters caused by household quarantine,our model provided a good fit to the trajectory of COVID-19 *** calculated the reproduction number R=1.345(95%CI:1.230-1.460)for Hubei province and R=1.217(95%CI:1.207-1.227)for China(except Hubei).We also estimated the peak time of infections,the epidemic duration and the final size,which are basically consistent with real *** indicated by simulation that the traced high-risk contacts from incubated to susceptible decrease under NPIs,regardless of infected *** sensitivity analysis showed that reducing the exposure of the susceptible and increasing the clustering coefficient bolster COVID-19 *** the enforcement of household quarantine,the reproduction number R and the epidemic prevalence declined ***,we obtained the resumption time of work and production in China(except Hubei)on 10th March and in Hubei at the end of April 2020,respectively,which is broadly in line with the actual *** results may provide some potential lessons from China on the control of COVID-19 for other parts of the world.

关键词： COVID-19 Pairwise epidemic model Household quarantine Clustering coefficient High-risk contacts