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Simulation of FY-2D infrared brightness temperature and sensitivity analysis to the errors of WRF simulated cloud variables

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Science China Earth Sciences 2018年第7期61卷 957-972页

作者： Xiaokang SHI Yaodong LI jianwen liu Xizi XIANG Le liu Beijing Aviation Meteorological Institute Beijing 100085China Guizhou Sub-bureau of Southwest Air Traffic Management Bureau of Civil Aviation of China Guiyang 550002China Guangxi Meteorological Observatory Nanning 530022China

This study simulated FY-2 D satellite infrared brightness images based on the WRF and RTTOV models. The effects of prediction errors in WRF micro-and macroscale cloud variables on FY-2 D infrared brightness temperature accuracy were analyzed. The principle findings were as follows. In the T+0–48 h simulation time, the root mean square errors of the simulated brightness temperatures were within the range 10–27 K, i.e., better than the range of 20–40 K achieved previously. In the T+0–24 h simulation time, the correlation coefficients between the simulated and measured brightness temperatures for all four channels were >0.5. The simulation performance of water channel IR3 was stable and the best. The four types of cloud microphysical scheme considered all showed that the simulated values of brightness temperature in clouds were too high and that the distributions of cloud systems were incomplete, especially in typhoon areas. The performance of the THOM scheme was considered best, followed in descending order by the WSM6, WDM6, and LIN schemes. Compared with observed values, the maximum deviation appeared in the range 253–273 K for all schemes. On the microscale, the snow water mixing ratio of the THOM scheme was much bigger than that of the other schemes. Improving the production efficiency or increasing the availability of solid water in the cloud microphysical scheme would provide slight benefit for brightness temperature simulations. On the macroscale, the cloud amount obtained by the scheme used in this study was small. Improving the diagnostic scheme for cloud amount, especially high-level cloud, could improve the accuracy of brightness temperature simulations. These results could provide an intuitive reference for forecasters and constitute technical support for the creation of simulated brightness temperature images for the FY-4 satellite.

关键词： FY-2D RTTOV WRF Simulated brightness temperature Cloud amount Cloud microphysics scheme TyphoonMatmo

Highly elastic cobweb-like SiO/CNF composites with reconstructed heterostructure for high-efficient lithium storage

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Chinese Chemical Letters 2021年第9期32卷 2914-2918页

作者： Jie liu Miao Ben Andeng liu jianwen liu Shiquan Wang Jiujun Zhang Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials&Ministry of Educational Key Laboratory for the Synthesis and Application of Organic Functional Molecules&College of Chemistry and Chemical Engineering Hubei UniversityWuhan 430062China Institute for Sustainable Energy College of ScienceShanghai UniversityShanghai 200444China

The silicon-based materials are promising candidates for lithium-ion batteries owing to their high energy ***,achieving long lifespan under realistic conditions remains a challenge because of the volume expansion and low *** this work,the highly elastic cobweb-like composite materials consisted by SiO and nanofibers are designed and fabricated for high-efficient lithium storage by ballmilling&electrostatic spinning *** reconstructed heterostructure and highly elastic nanofibers can simultaneously increase the conductivity and inhibit the"expansion effect"of silicon-based *** constructed electrode of n-SiO/CNF delivers an initial capacity of 1700 m Ah/g,and maintains the capacities over 1000 m Ah/g after 100 cycles at the current density of 500 m A/***,this electrode can give an initial coulombic efficiency over 85%and maintains at 98%in the following charge/discharge ***,it exhibits efficient long-term electrochemical performance,maintaining the capacity at about 1000 m Ah/g at a high current density of 1000 m A/g after 1000 *** work could provide a promising strategy for enhancing the performance of siliconbased composite materials for practical application in lithium-ion batteries.

关键词： Lithium ion batteries Silicon-based materials SiO/CNF composites Highly elastic composites Reconstructed heterostructure

Boosting practical high voltage lithium metal batteries by butyronitrile in ether electrolytes via coordination, hydrolysis of C≡N and relatively mild concentration strategy

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Journal of Energy Chemistry 2022年第4期31卷 290-299页

作者： Jingrong Ning Kaijia Duan Kai Wang jianwen liu Shiquan Wang Jiujun Zhang College of Chemistry and Chemical Engineering&Collaborative Innovation Center for Advanced Organic Chemical Materials Co-constructed by the Province and Ministry&Ministry of Educational Key Laboratory for the Synthesis and Application of Organic Functional Molecules Hubei UniversityWuhanHubei 430062China Institute for Sustainable Energy/College of Science Shanghai UniversityShanghai 200444China

Currently ether solvents have been regarded as the most compatible organic solvents with lithium metal in electrolytes of lithium ***,ether solvents are unstable under high voltage (>4.0 V),and prone to side reactions with nickel-rich high-voltage cathode *** this work,a novel dual-solvent electrolyte in ethylene glycol dimethyl ether (DME) and butyronitrile (BN) mixed solvent was designed and fabricated for Li/Li Ni_(0.5)Mn_(0.3)Co_(0.2)O_(2)-based lithium metal *** charged to high voltage4.3 V,the battery cycled in this optimal electrolyte can maintain the capacity at 133.7 m Ah g^(-1) with a retention of 88.84%after 150 cycles at 0.2 C and-10℃.During long-term cycling,the battery also exhibits excellent cycling performance with capacity maintained at about 112.0 m Ah g^(-1) after 500 cycles at 1C and-10℃.BN has strong oxidation resistance and high conductivity,which can inhibit the decomposition of ether solvents under high voltage and improve the low temperature performance of battery ***,the cyano (–C≡N) group in BN molecular has a strong coordination ability with the high-valent metal ions and can mask the active ions on the cathode,correspondingly reducing the corrosion of cathode material by the ***,cyano group can participate in the hydrolysis to remove trace amounts of water and acidic by-products such as HF in the ***,the boosting effect of butyronitrile for ether solvents can provide a promising strategy for enhancing the performance of high voltage lithium metal batteries for practical industrialization.

关键词： Electrolytes Lithium metal batteries Ether solvents Butyronitrile High voltage

Multi-attribute wearable pressure sensor based on multilayered modulation with high constant sensitivity over a wide range

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Nano Research 2023年第5期16卷 7583-7592页

作者： Ning Li Song Gao Yang Li jianwen liu Wenhao Song Guozhen Shen School of Information Science and Engineering University of JinanJinan 250022China Shandong Provincial Key Laboratory of Network Based Intelligent Computing University of JinanJinan 250022China School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing 100081China School of Aeronautical and Astronautical Engineering Purdue University West LafayetteIN 47907USA

Flexible pressure sensors capable of monitoring diverse physiological signals and body movements have garnered tremendous attention in wearable electronic ***,high constant sensitivity over a wide pressure range combined with breathability,biocompatibility,biodegradability is pivotal for manufacturing of reliable pressure sensors in practical sensing *** this work,inspired by the multilayered structure of skin epidermis,we propose and demonstrate a multi-attribute wearable piezoresistive pressure sensor consisting of multilayered gradient conductive poly(ε-caprolactone)nanofiber membranes *** response to externally applied pressure,a layer-by-layer current path is activated inside the multilayered membranes composites,leading to the most salient sensing performance of high constant sensitivity of 33.955 kPa^(−1) within the pressure range of 0–80 *** proposed pressure sensor also exhibits a fast response–relaxation time,a low detection limit,excellent stability,which can be successfully used to measure human physiological ***,an integrated sensor array system that can locate objects’positions is constructed and applied to simulate sitting posture *** results indicate that the proposed pressure sensor holds great potential in health monitoring and wearable electronic devices.

关键词： wearable pressure sensors multilayer structure high constant sensitivity multi-attribute physiological signals monitoring

Synergistic effect of lithiophilic Zn nanoparticles and N-doping for stable Li metal anodes

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Journal of Energy Chemistry 2022年第2期31卷 439-447页

作者： Lei You Shunlong Ju jianwen liu Guanglin Xia Zaiping Guo Xuebin Yu Department of Materials Science Fudan UniversityShanghai 200433China Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials Ministry-of-Education Key Laboratory for Synthesis and Applications of Organic Functional MoleculesCollege of Chemistry and Chemical EngineeringHubei UniversityWuhan 430062HubeiChina School of Chemical Engineering&Advanced Materials The University of AdelaideAdelaideSA 5005Australia

Li metal is the most ideal anode material for next-generation high energy lithium-ion *** uncontrollable growth of Li dendrites,however,hinders its practical ***,we propose the adoption of Zn nanoparticles uniformly embedded in N-doped carbon polyhedra homogeneously built on carbon cloth(Zn@NC@CC)to prevent the formation of Li *** on theoretical calculation and experimental observation,lithiophilic Zn nanoparticles and N-doping inside of the assynthesized Zn@NC play a synergistic role in enhancing the adsorption capacity with Li,thus resulting in uniform Li deposition and complete suppression of Li ***,the porous N-doped carbon polyhedras uniformly distributed on carbon cloth effectively relieves the volume change of Li upon repeated Li stripping/plating process,which contributes to preserving the structural integrity of the whole electrode and hence enhancing its long-term cycling *** from these synergistic effects,the Li-Zn@NC@CC electrode delivers a prolonged lifespan of over 1200 h at 1 mA cm^(-2) with an areal capacity of 1 mA h cm^(-2) in symmetric cells and high Coulombic efficiencies of 95.4%under an ultrahigh capacity of 12 mA h cm^(-2).Remarkably,Li-Zn@NC@CC//LiFePO_(4) full cells deliver a high reversible capacity of 110.2 mA h g^(-1) at 1 C over 200 cycles.

关键词： Li metal anodes Zn nanoparticles N-doping Synergistic effect

Strengthening absorption ability of Co-N-C as efficient bifunctional oxygen catalyst by modulating the d band center using MoC

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Green Energy & Environment 2023年第2期8卷 459-469页

作者： jianwen liu Ying Guo Xian-Zhu Fu Jing-Li Luo Chunyi Zhi Shenzhen Key Laboratory of Polymer Science and Technology Guangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Materials Science and EngineeringShenzhen University518060China Department of Materials Science and Engineering City University of Hong Kong83 Tat Chee AvenueKowloon TongHong KongChina Department of Chemical and Materials Engineering University of AlbertaEdmontonAlbertaT6G 1H9Canada

Co-N-C is a promising oxygen electrochemical catalyst due to its high stability and good ***,due to the limited adsorption ability improvement for oxygen-containing intermediates,it usually exhibits inadequate catalytic activity with 2-electron pathway and high selectivity of hydrogen ***,the adsorption of Co-N-C to these intermediates is modulated by constructing heterostructures using transition metals and their derivatives based on d-band *** heterostructured nanobelts with MoC core and pomegranate-like carbon shell consisting of Co nanoparticles and N dopant(MoC/Co-N-C)are engineered to successfully modulate the d band center of active Co-N-C sites,resulting in a remarkably enhanced electrocatalysis *** optimally performing MoC/Co-N-C exhibits outstanding bi-catalytic activity and stability for the oxygen electrochemistry,featuring a high wave-half potential of 0.865 V for the oxygen reduction reaction(ORR)and low overpotential of 370 mV for the oxygen evolution reaction(OER)at 10 mA cm^(-2).The zinc air batteries with the MoC/Co-N-C catalyst demonstrate a large power density of 180 mW cm^(-2)and a long cycling lifespan(2000 cycles).The density functional theory calculations with Hubbard correction(DFT+U)reveal the electron transferring from Co to Mo atoms that effectively modulate the d band center of the active Co sites and achieve optimum adsorption ability with"single site double adsorption"mode.

关键词： Bifunctional oxygen catalysts Pomegranate-like shell D band theory Enhanced synergistic effect Rechargeable zinc air battery

Diffraction of plane P waves around an alluvial valley in poroelastic half-space

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Earthquake Science 2010年第1期23卷 35-43页

作者： Zhongxian liu jianwen Liang Department of Civil Engineering Tianjin University Tianjin 300072 China

Diffraction of plane P waves around an alluvial valley of arbitrary shape in poroelastic half-space is investigated by using an indirect boundary integral equation method. Based on the Green＇s fimctions of line source in poroelastic half-space, the scattered waves are constructed using the fictitious wave sources close to the interface of the valley and the density of ficti- tious wave sources are determined by boundary conditions. The precision of the method is verified by the satisfaction extent of boundary conditions, and the comparison between the degenerated solutions and available results in single-phase case. Finally, the nature of diffraction of plane P waves around an alluvial valley in poroelastic half-space is investigated in detail through nu- merical examples.

关键词： diffraction plane P waves alluvial valley poroelastic half-space indirect boundary integration equation method

Application and improvement of an adaptive ensemble Kalman filter for soil moisture data assimilation

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Science China Earth Sciences 2010年第11期53卷 1700-1708页

作者： Shi XiaoKang Wen Jun liu jianwen Tian Hui Wang Xin Li YaoDong Chinese Acad Sci Cold & Arid Reg Environm & Engn Res Inst Lab Climate Environm & Disasters Western China Lanzhou 730000 Peoples R China Beijing Aviat Meteorol Inst Beijing 100085 Peoples R China

Accurate assignment of model and observation errors is crucial for the successful application of land surface data assimilation algorithms. Poorly-specified model and observation errors can significantly degrade assimilation results. In 2008, Reichle et al. developed an operational procedure to adaptively tune model and observation errors. In this paper, we modified and applied Reichle's procedure in the Noah land surface model to assimilate observed surface soil moisture data. Numerical simulations showed that: (1) the best estimate of model and observation errors appears when the empirical factor β equals 1.02; (2) the Reichle procedure can be deployed to adaptively tune errors if their true values change slowly; and (3) convergence of the Reichle procedure was improved using better initial errors achieved by iterative computations.

关键词： Noah numerical simulation data assimilation adaptive ensemble Kalman filter soil moisture

Dual-metal zeolite imidazolate framework for efficient lithium storage boosted by synergistic effects and self-assembly 2D nanosheets

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Chinese Chemical Letters 2022年第6期33卷 3291-3295页

作者： Ming Yue Yajing Fu Canping Zhang Junxiao Fu Shiquan Wang jianwen liu College of Chemistry and Chemical Engineering&Collaborative Innovation Center for Advanced Organic Chemical Materials Co-constructed by the Province and Ministry&Ministry of Educational Key Laboratory for the Synthesis and Application of Organic Functional Molecules Hubei UniversityWuhan 430062China Jiangsu Pylon Battery Co. Ltd.Yangzhou 211400China

Metal-organic framework materials(MOFs),such as zeolitic imidazolate framework(ZIF),have been widely used in energy storage due to their advantages such as high structural stability,large specific surface,more active sites and skeleton ***,a novel two-dimensional(2D)Co Cu-ZIF was synthesized by a facile solvothermal *** as-prepared Co Cu-ZIF nanosheets exhibit an ultrahigh reversible capacity of 2287.4 m Ah/g and remains at 1172.1 m Ah/g after 300 cycles at a current density of 100 m A/g,far better than that of the single Co-ZIF and ***,the specific discharge capacity of Co Cu-ZIF nanosheets can maintain at about 590 m Ah/g after 1000 cycles at the current density of 2 A/*** to the synergistic effect of two metals,function of nitrogen in the molecular and selfassembly 2D nanosheets,our research can provide strong support for the practical application of Co Cu-ZIF materials in lithium ion batteries.

关键词： Lithium ion batteries Metal-organic frameworks Co Cu-ZIF nanosheets Synergistic effect Self-assembly