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Impact of observational MJO forcing on ENSO predictability in the Zebiak-Cane model: PartⅠ.Effect on the maximum prediction error

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Acta Oceanologica Sinica 2015年第5期34卷 39-45页

作者： peng Yuehua SONG Junqiang xiang Jie SUN Chengzhi Dalian Naval Academy Institute of Atmospheric Physics Chinese Academy of Sciences College of Computer National University of Defense Technology College of Meteorology and Oceanography PLA University of Science and Technology

With the observational wind data and the Zebiak-Cane model, the impact of Madden-Iulian Oscillation （MJO） as external forcing on El Nino-Southern Oscillation （ENSO） predictability is studied. The observational data are analyzed with Continuous Wavelet Transform （CWT） and then used to extract MJO signals, which are added into the model to get a new model. After the Conditional Nonlinear Optimal Perturbation （CNOP） method has been used, the initial errors which can evolve into maximum prediction error, model errors and their join errors are gained and then the Nifio 3 indices and spatial structures of three kinds of errors are investigated. The results mainly show that the observational MJO has little impact on the maximum prediction error of ENSO events and the initial error affects much greater than model error caused by MJO forcing. These demonstrate that the initial error might be the main error source that produces uncertainty in ENSO prediction, which could provide a theoretical foundation for the adaptive data assimilation of the ENSO forecast and contribute to the ENSO target observation.

关键词： E1 Nifio-Southern Oscillation (ENSO) Madden-/ulian Oscillation (M/O) maximum prediction error,Conditional Nonlinear Optimal Perturbation (CNOP)

A Stiffness Adjustment Mechanism Based on Negative Work for High-efficient Propulsion of Robotic Fish

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Journal of Bionic Engineering 2018年第2期15卷 270-282页

作者： Dong Xu Haining Zeng xiang peng Ziqing Zhao Jingmeng Liu School of Automation Science and Electrical Engineering Beihang University Beijing 100191 China

The applications of robotic fish require high propulsive efficiency mechanism to prolong the mission time. Though many methods were applied, robotic fish still suffers from low efficiency. To improve the efficiency of robotic fish, this paper proposes a variable stiffness mechanism which is based on the negative work. The live fish adjusts its body stiffness to save energy when the muscles do negative work. Inspired by the live fish, a control mechanism based on negative work is proposed to change the stiffness of the robotic fish for higher efficiency. Changing the stiffness of the robotic fish is to change the joint-stiffness. A fuzzy controller is introduced to mimic the variable stiffness mechanism of the fish and depicts the relationship between the stiffness and the negative work. To evaluate the performance of this controller, a two-joint robotic fish model is established based on its kinematic model and hydrodynamic model. The evaluation results show that the robotic fish reduces the energy consumption and improves the propulsion efficiency when introducing the variable stiffness mechanism. Different environments with the control mechanism impact differently on propulsive efficiency. This mechanism may provide a high efficient propulsion control method for the robotic fish.

关键词： robotic fish propulsion efficiency negative work stiffness adjustment

Comparison and modeling of two biofilm processes applied to decentralized wastewater treatment

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Frontiers of Environmental Science & Engineering 2009年第4期3卷 412-420页

作者： Guanglei QIU Liancheng xiang Yonghui SONG Jianfeng peng Ping ZENG peng YUAN Chinese Research Academy of Environmental Sciences Beijing 100012China College of Water Science Beijing Normal UniversityBeijing 100875China

In order to control water pollution in the rapidly urbanizing South China area,biological contact oxidation(BCO)process and biological aerated filter(BAF)process were applied in a pilot-scale experiment for decentralized wastewater *** investigation to find the optimal parameters of the two biofilm systems was conducted on hydraulic loading,organic loading,and aeration *** results indicated that the water reuse criteria required a maximum hydraulic and organic loading of 30.0 m^(3)/(m^(2)·d)and 4.0 kg COD/(m^(3)·d),respectively,as well as a minimum effluent DO of 4.0 mg/*** utilization of a new media allowed BAF to perform better than *** kinetic description of the COD removal process for BAF and BCO are Se=S0e^(-0.639t)/(1+1.035t),and S_(e)=S_(0)/[(1+0.947t)(1+1.242t)],*** correlativity analysis showed that the two models could predict the effluent water quality based on the hydraulic retention ***,the appropriate hydraulic loading for certain effluent water quality demands could be *** two models could be applied to wastewater treatment practice.

关键词： biological contact oxidation biological aerated filter decentralized wastewater treatment kinetic model

Research and development of hydrocracking catalysts and technologies in China

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Frontiers of Chemical Science and Engineering 2018年第4期12卷 867-877页

作者： Chong peng Yanze Du xiang Feng Yongkang Hu xiangchen Fang Dalian Research Institute of Petroleum and Petrochemicals SINOPECDalian 116000China State Key Laboratory of Heavy Oil Processing China University of PetroleumQingdao 266580China

Hydrocracking of petroleum feedstock represents a compelling route for the production of industrial clean fuels, which has triggered the continuous research and development of core technology related areas such as catalysts, reaction engineering and engineering design. This review particularly focuses on the research and development of catalysts and catalytic processes for hydrocracking of petroleum feedstock in China. Hydroprocessing technologies of China keep pace with the up-todate progress of the world, and some of the technologies have achieved leading role in the world. It is noted that China Petroleum and Chemical Corporation has a full range of hydroprocessing technologies and provides corresponding “tailor-made” catalysts. Through the efforts of several generations, 20 categories of the catalysts including more than 60 brands have been developed, among which more than 40 brands have been successfully applied for more than 130 times. Importantly, the pivotal technical improvements including the deep drawing vacuum gas-oil (VGO) and de-asphalting oil hydrocracking technology to improve material adaptability, the high value-added hydrogenation technology to convert high aromatic diesel conversion to naphtha, the hydrocracking technology using VGO-catalytic diesel blends, the Fushun Research Institute of Petroleum and Petrochemicals’ diesel to gasoline and diesel hydrocracking technologies, and the Sheer hydrocracking technology to reduce energy are reviewed.

关键词： hydrocracking process catalyst China

High-performance single-wall carbon nanotube transparent conductive films

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Journal of Materials Science & Technology 2019年第11期35卷 2447-2462页

作者： Song Jiang peng-xiang Hou Chang Liua Hui-Ming Cheng Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Physical Science and Technology ShanghaiTech UniversityShanghai200031China State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai200050China University of Chinese Academy of Sciences Beijing100049China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China Tsinghua-Berkeley Shenzhen Institute Tsinghua UniversityShenzhen518055China

A single-wall carbon nanotube(SWCNT)has superior optical,electrical,and mechanical properties due to its unique structure and is therefore expected to be able to form flexible high-performance transparent conductive films(TCFs).However,the optoelectronic performance of these films needs to be improved to meet the requirements of many *** electrical resistivity of SWCNTTCFs is mainly determined by the intrinsic resistivity of individual SWCNTs and their junction resistance in *** analyze these key factors and focus on the optimization of SWCNTs and their networks,which include the diameter,length,crystallinity and electrical type of the SWCNTs,and the bundle size and interconnects in networks,as well as chemical doping and microgrid *** conclude that isolated/small-bundle,heavily doped metallic or semiconducting SWCNTs with a large diameter,long length and high crystallinity are necessary to fabricate high-performance SWCNTTCFs.A simple,controllable way to construct macroscopic SWCNT networks with Y-type connections,welded junctions or microgrid design is important in achieving a low ***,some insights into the key challenges in the manufacture and use of SWCNT TCFs and their prospects are presented,hoping to shed light on promoting the practical application of SWCNT TCFs in future flexible and stretchable optoelectronics.

关键词： Single-wall carbon nanotube Transparent conductive film Junction resistance Bundle Doping

A new scheme of climate-vegetation regionalization in the Hengduan Mountains Region

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Science China Earth Sciences 2024年第3期67卷 751-768页

作者： Xueqin ZHANG Xiaoming XU xiang LI peng CUI Du ZHENG Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China China-Pakistan Joint Research Center on Earth Sciences Chinese Academy of Sciences-Higher Education Commission of PakistanIslamabad 45320Pakistan

The Hengduan Mountains Region(HMR) is essential for the future ecological protection, clean energy production,Sichuan-Xizang and Yunnan-Xizang railways, and other major infrastructure projects in China. The distributions of climate and vegetation exhibit significant regional differentiation and vertical zonality due to the rugged longitudinal ranges and gorges and the complex disaster-prone environments in HMR. Therefore, it is urgent to develop the climate-vegetation regionalization in HMR to effectively satisfy the national requirements such as agricultural production and ecological protection, mountain disaster risk prevention, and major project construction. We here develop a new scheme of climate-vegetation regionalization with the latest demarcation outcome of HMR, the ground observation from 122 meteorological stations in HMR and its surrounding areas during 1990–2019, and the high-precision remote sensing data of land cover types. The new scheme first constructs the regionalization index system, fully considering the extraordinarily complicated geomorphic pattern of mountains and valleys, the scarcity of meteorological observations, and the remarkable differentiation of climate and vegetation in HMR. The system consists of three primary regionalization indices(i.e., days with daily average temperature steady above 10°C, aridity index, and main vegetation types, dividing the temperature zones, moisture regions, and vegetation subregions, respectively) and three auxiliary indices of the accumulated temperature above 10°C, and the temperatures in January and July. Then, the HMR is divided into five temperature zones, 20 moisture regions, and 55 vegetation subregions. Compared with previous regionalization schemes, the new scheme optimizes the climate spatial interpolation model of thin plate smoothing spline suitable for the unique terrain in HMR. Moreover, the disputed division index threshold between different climatic zones(regions) is scientifically clarifi

关键词： Climate-vegetation regionalization Thin plate smoothing spline(TPSS) GeoDetector Stepwise downscaling pane division method Hengduan Mountains Region

Defects and interface states related photocatalytic properties in reduced and subsequently nitridized Fe_3O_4/TiO_2

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Journal of Materials Science & Technology 2018年第6期34卷 931-941页

作者： Chang Liu xiang Zhu peng Wang Yisen Zhao Yongqing Ma Anhui Key Laboratory of Information Materials and Devices School of Physics and Materials Science Anhui University

The Fe3O4@TiO2 catalyst was reduced in a mixed H2/N2 atmosphere at temperatures of 400, 600, 800 and 1000 ℃ in order to produce the oxygen vacancies （Ov） and Ti^3＋; Simultaneously, Fe3O4 was reduced to Fe, a strongly magnetic material, beneficial for the magnetic separation after the photo-degradation. The optimal catalyst was obtained at the reducing temperature of 800℃, which possesses the good photocatalytic performance and recycled activities; Moreover, its saturation magnetization Ms is highest, reaching 23.8 emu g 1 which improves the magnetic separability. This optimal catalyst was subsequently treated in the NH3 atmosphere at temperatures of 500, 600 and 700 ℃, aiming to investigate the effects of N-doping in TiO2. The 600 ℃ treated catalyst exhibited the optimal photocatalytic performance. The factors that affect the photocatalytic performance are revealed and discussed in detail, including the ratio of Ov and N dopant in TiO2 as well as the interface states between TiO2 and the magnetic particles.

关键词： Photocatalyst Strong magnetic particles Magnetic separability Oxygen vacancy Nitrogen doping

Studies on the Oxazaborolidine-catalyzed Enantioselective Reduction of 3-Morpholin-4-yl-1-phenyl-1-propanone with Density Functional Theory

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Chinese Journal of Structural Chemistry 2005年第4期24卷 413-418页

作者： FANJian-Fen LUYun-xiang WANGQiu-Xia WULi-Fen SUNYun-peng DepartmentofChemistry SuzhouUniversitySuzhou215006China

Density functional theory (DFT) has been applied to study the enantioselective reduction of 3-morpholin-4-yl-1-phenyl-1-propanone with borane catalyzed by (S)-4-benzyl-5,5- diphenyl-1,3,2-oxazaborolidine at the B3LYP/6-31G* level. All molecular species involved in the four reaction steps have been fully optimized and the structural parameters are provided, and the micro process of reaction was also investigated. The catalyst-alkoxyborane adduct formed in step III exhibits a B-O-B-N tetra-atomic ring. Reaction coordination calculations show that BH3 can react with 3-morpholin-4-yl-1-phenyl-1-propanone spontaneously, resulting in the need of 2 mol BH3 in the reaction.

关键词： B3LYP/6-31G* 3-morpholin-4-yl-1-phenyl-1-propanone enantioselective reduction

Intensified warming suppressed the snowmelt in the Tibetan Plateau

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Advances in Climate Change Research 2024年第3期15卷 452-463页

作者： xiang LI peng CUI Xue-Qin ZHANG Fang ZHANG Key Lab of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China China‒Pakistan Joint Research Center on Earth Sciences Chinese Academy of Sciences and Higher Education CommissionIslamabad 45320Pakistan

Understanding how hydrological factors interrelate is crucial when examining the impact of climate warming on ***,these connections are often overlooked,leading to an unclear relationship between temperature and *** study investigates the complex interplay between temperature and snowmelt in the Tibetan Plateau from 1961 to 2020,focusing on how extreme high-temperature events affect the frequency of extreme *** a structural equation model,we detected three temperature-related factors that predominantly influenced snowmelt and extreme *** annual average temperature was found to have a significant indirect impact on snowmelt,mediated by changes in snowfall,snow depth and snow *** contrast,high-temperature days(daily maximum temperatures exceeding the 90th percentile)and heat waves(at least three consecutive high-temperature days)negatively affected extreme snowmelt directly or *** direct effect of increasing extreme temperature events was associated with an earlier onset of high-temperature periods,which accelerated snowmelt and shortened the duration of extreme snowmelt ***,the reduction in snow cover owing to warming emerged as a main factor suppressing snowmelt and extreme snowmelt *** also revealed spatiotemporal variations in the temperature‒snowmelt relationship that highly depended on changes in snowmelt *** study elucidated why warming suppresses snowmelt and extreme snowmelt events in the Tibetan Plateau,highlighting the mediating roles of snow-related and phenological *** findings will provide scientific support for climate simulation and water management policymaking in alpine regions worldwide.

关键词： Climate change Extreme temperature Snowmelt Structural equation model Tibetan Plateau