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Science china(Technological sciences) 2005年第z1期48卷 146-156页

作者： zhang lei1,2. wei zuoan1,{2., chinese academy of sciences, Beijing 100080, china 2.Graduate School, chinese academy of sciences, Beijing 100060, china chinese Acad Sci Inst Mech Beijing 100080 Peoples R China chinese Acad Sci Grad Sch Beijing 100060 Peoples R China

Three-dimensional discrete element face-to-face contact model with fissure water pressure is established in this paper and the model is used to simulate three-stage process of landslide under fissure water pressure in the opencast mine, according to the actual state of landslide in Panluo iron mine where landslide happened in 1990 and was fathered in 1999. The calculation results show that fissure water pressure on the sliding surface is the main reason causing landslide and the local soft interlayer weakens the stability of slope. If the discrete element method adopts the same assumption as the limit equilibrium method, the results of two methods are in good agreement; while if the assumption is not adopted in the discrete element method, the critical φ numerically calculated is less than the one calculated by use of the limit equilibrium method for the sameC. Thus, from an engineering point of view, the result from the discrete element model simulation is safer and has more widely application since the discrete element model takes into account the effect of rock mass structures.

关键词： face-to-facecontactmodel, fissure water pressure, three-dimensional discrete element method,landslide.

Fast-Charging Sodium-Ion Batteries Enabled by Molecular-Level Designed Nitrogen and Phosphorus Codoped Mesoporous Soft Carbon

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Research 2024年第2期2023卷 329-337页

作者： lei liu Zhuzhu Du Jiaqi Wang Hongfang Du Sheng Wu Mengjun li Yixuan {2. Jinmeng Sun Zhipeng Sun wei Ai Frontiers Science Center for Flexible Electronics(FSCFE)and Shaanxi institute of Flexible Electronics(SIFE) Northwestern Polytechnical University(NPU)127 West Youyi RoadXi'an 710072China Fujian Cross Strait institute of Flexible Electronics(Future Technologies) Fujian Normal UniversityFuzhou 350117China School of Materials and Energy Guangdong University of TechnologyGuangzhou510006 GuangdongChina

Soft carbons have attracted extensive interests as competitive anodes for fast-charging sodium-ion batteries(SIBs);however,the high-rate performance is still restricted by their large ion migration barriers and sluggish reaction ***,we show a molecular design approach toward the fabrication of nitrogen and phosphorus codoped mesoporous soft carbon(NPSC).The key to this strategy lies in the chemical cross-linking reaction between polyphosphoric acid and p-phenylenediamine,associated with pyrolysis induced in-situ self-activation that creates mesoporous structures and rich heteroatoms within the carbon *** to the enlarged interlayer spacing,reduced ion diffusion length,and plentiful active sites,the obtained NPSC delivers a superb rate capacity of 2.5 mAh g-1 at 10 A g-1 and an ultralong cycle life of 4,700 cycles at 5 A g^(-1).Remarkably,the full cell shows 99%capacity retention during 100 continuous cycles,and maximum energy and power densities of 191 Wh kg^(-1)and 9.2.kW kg^(-1),*** believe that such a synthetic protocol could pave a novel venue to develop soft carbons with unique properties for advanced SIBs.

关键词： kinetics carbons linking

Construction of multifunctional lanthanum manganese mixed nanoparticles mediated by ionic liquids for selective aerobic oxidation of cyclohexane

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Rare Metals 2024年第5期43卷 2205-2221页

作者： Hao li Rui-Rui zhang Ke-Xin li Shuang wei Yu-Mei {2. Rui-Xia {2. Beijing Key Laboratory of Ionic liquids Clean Process CAS Key Laboratory of Green Process and EngineeringState Key Laboratory of Multiphase Complex SystemsInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of chinese academy of sciences Beijing 100049China

Selective oxidation of alkanes to produce highvalue chemicals is an essential strategy and means to realize efficient utilization of *** this work,a strategy of lanthanum manganese mixed metal oxides(LMMO)regulated via a facile ionic liquid(IL)-assisted hydrothermal method was proposed to construct the multifunctional catalysts,which exhibited excellent catalytic performance in the selective aerobic oxidation of *** 8.9%cyclohexane conversion with 90%KA oi(cyclohexanol and cyclohexanone)selectivity was achieved over the optimal LMMO catalyst under mild *** effects of anion type,carbon chain length and concentration of ILs on the structure and properties of catalysts were investigated through various characterizations,indicating the structure-directing and template effect of ILs on the multifunctional *** formation of self-assembled spherical nanoparticles followed the"dissolution-nucleation-proliferation"mechanism with the introduction of 1-butyl-3-methylimidazolium hydrogen sulfate,ascribing the synergistic effect between the microenvironment of ILs and the hydrothermal ***,the high reactive oxygen concentration redox capacity,and suitable basic sites of LMMO catalysts mediated by ILs enhance the activation of C-H bonds and molecular oxygen,simultaneously influencing the adsorption and desorption of the substrate.A comprehensive understanding of the high KA oil selectivity and radical reaction mechanism was elucidated based on in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)and radical trapping *** recycling and regeneration experiments further illuminated that the removal of adsorbed cyclohexanone acting on the LMMO catalyst was the key to achieve high KA oil selectivity.

关键词： Ionic liquids Nanoparticle Multifunctional catalyst Cyclohexane oxidation

The global image of the Moon obtained by the Chang'E-1:Data processing and lunar cartography

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Science china Earth sciences 2010年第8期53卷 1091-1102页

作者： li ChunLai1, liu JianJun1, REN Xin1, MOU lingli1, ZOU Yongliao1, zhang HongBo1, Lü Chang1, liu JianZhong1, ZUO wei1, SU Yan1, WEN weiBin1, BIAN wei1, ZHAO BaoChang2. YANG JianFeng2. ZOU XiaoDuan1, WANG Min1, XU Chun1, KONG DeQing1, WANG XiaoQian1, WANG Fang1, GENG liang1, zhang ZhouBin1, ZHENG lei1, ZHU XinYing1, li JunDuo1 & OUYANG ZiYuan11 National Astronomical Observatories, chinese academy of sciences, Beijing 100012. china 2.Xi’an institute of Optics and Precision mechanics, chinese academy of sciences, Xi’an 710119, china 1. National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China2. Xi’an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi’an 710119 China

The global lunar image of the first phase of chinese Lunar Exploration Program is the first image that covered all over the surface of the Moon. It will serve as a critical foundation for succeeding exploration and scientific research. In this paper, the acquisition, characteristics, and data quality of Chang'E-1 CCD image data are described in detail. Also described are the methodology and procedure of data processing. According to rule of planetary cartography, the image data have been processed, geometrically corrected, and then mosaicked and merged in a scale of 1:2.5 million. The results of data processing and charting show that the image data of Chang'E-1 CCD and their geometric precision meet the demand of charting a map in the scale of 1:2.5 million. The relative geometric positioning precision of the global image is better than 2.0 m, and the absolute geometric positioning precision is slightly better than that of the ULCN2.05 and Clementine lunar basemap (V2.0). The plane positioning precision is approximately 100-1500 m. This global image proves to be the best global image of the Moon so far in terms of space coverage, image quality, and positioning precision.

关键词： Chang’E-1 lunar CCD data processing lunar image position lunar global image

Monaural voiced speech segregation based on elaborate harmonic grouping strategies

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Science china(Information sciences) 2011年第12期54卷 2491-2500页

作者： liu WenJu 1 , zhang Xueliang 1 , JIANG {2. 1 , li Peng 2.& XU Bo 2.1 National Laboratory of Pattern Recognition, institute of Automation, chinese academy of sciences, Beijing 100190, china 2.Digital Media Content Technology Research Center, institute of Automation, chinese academy of sciences, Beijing 100190, china 1. National Laboratory of Pattern Recognition Institute of Automation Chinese Academy of Sciences Beijing 100190 China2. Digital Media Content Technology Research Center Institute of Automation Chinese Academy of Sciences Beijing 100190 China

In this paper, an enhanced algorithm based on several elaborate harmonic grouping strategies for monaural voiced speech segregation is proposed. Main achievements of the proposed algorithm lie in three aspects. Firstly, the algorithm classifies the time-frequency (T-F) units into resolved and unresolved ones by carrier-to-envelope energy ratio, which leads to more accurate classification results than by cross-channel correlation. Secondly, resolved T-F units are grouped together according to minimum amplitude principle, which has been verified to exist in human perception, as well as the harmonic principle. Finally, "enhanced" envelope autocorrelation function is employed to detect amplitude modulation rates, which helps a lot in reducing half-frequency error in grouping of unresolved units. Systematic evaluation and comparison show that performance of separation is greatly improved by the proposed algorithm. Specifically, signal-to-noise ratio (SNR) is improved by 0.96 dB compared with that of previous method. Besides, our algorithm is also effective in improving the PESQ score and subjective perception score.

关键词： computational auditory scene analysis voiced speech separation harmonistic principle minimum amplitude principle elaborate harmonic grouping strategies

Primary scientific results of Chang'E-1 lunar mission

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Science china Earth sciences 2010年第11期53卷 1565-1581页

作者： OUYANG ZiYuan1,2. li ChunLai1, ZOU Yongliao1, zhang HongBo1, Lü Chang1, liu JianZhong1, liu JianJun1, ZUO wei1, SU Yan1, WEN weiBin1, BIAN wei1, ZHAO BaoChang3, WANG JianYu4, YANG JianFeng3, CHANG Jin5, WANG HuanYu6, zhang XiaoHui7, WANG ShiJin7, WANG Min1, REN Xin1, MU lingli1, KONG DeQing1, WANG XiaoQian1, WANG Fang1, GENG liang1, zhang ZhouBin1, ZHENG lei1, ZHU XinYing1, ZHENG YongChun1, li JunDuo1, ZOU XiaoDuan1, XU Chun1, SHI ShuoBiao1, GAO YiFei1 & GAO GuanNan1 1 National Astronomical Observatories, chinese academy of sciences, Beijing 100012. china 2.institute of Geochemistry, chinese academy of sciences, Guiyang 550002. china 3 Xi’an institute of Optics and Precision mechanics, chinese academy of sciences, Xi’an 710119, china 4 Shanghai institute of Technical Physics, chinese academy of sciences, Shanghai 2.0083, china 5 Purple Mountain Observatory, chinese academy of sciences, Nanjing 2.0008, china 6 institute of High Energy Physics, chinese academy of sciences, Beijing 100049, china 7 Center for Space Science and Applied Research, chinese academy of sciences, Beijing 100190, china 1. National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China2. Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China3. Xi’an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi’an 710119 China4. Shanghai Institute of Technical Physics Chinese Academy of Sciences Shanghai 200083 China5. Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China6. Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China7. Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190 China

The strategic plan for the development of the unmanned chinese Lunar Exploration Program is characterized by three distinct stages: "orbiting around", "landing on" and "returning from" the Moon. The first chinese lunar probe, Chang'E-1, which was successfully launched on October 2.th, 2.07 at Xichang Satellite Launch Center, and guided to crash on the Moon on March 1st, 2.09, at 52.36°E, 1.50°S, in the north of Mare Fecunditatis, is the first step towards the "orbiting around" stage. The Chang'E-1 mission lasted 495 days, exceeding the expected life-span by about four months. A total of 1.37 TB raw data was received from Chang'E-1. It was then processed into 4 TB scientific data products at various levels. Many scientific results have been obtained by analyzing these data, including especially the "global lunar image from the first chinese lunar explora- tion mission". All scientific goals of Chang'E-1 have been achieved. It provides much useful materials for further advances of lunar sciences and planetary chemistry. Meanwhile, these results will serve as a firm basis for future chinese lunar missions.

关键词： lunar orbiter Chang’E-1 scientific data results

A universal strategy of multi-objective active learning to accelerate the discovery of organic electrode molecules

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Science china Chemistry 2024年第11期67卷 3681-3687页

作者： Jiayi Du Jun Guo wei liu Ziwei li Gang Huang Xinbo zhang State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied Chemistry Chinese Academy of Sciences School of Applied Chemistry and Engineering University of Science and Technology of China School of Materials Science and Engineering Changchun University of Science and Technology

Organic electrode molecules hold significant potential as the next generation of cathode materials for li-ion batteries. In this study, we have introduced a multi-objective active learning framework that leverages Bayesian optimization and non-dominated sorting genetic algorithms-Ⅱ. This framework enables the selection of organic molecules characterized by high theoretical energy density and low gap(LUMO-HOMO)(LUMO, lowest unoccupied molecular orbital; HOMO, highest occupied molecular orbital). Remarkably, after only two cycles of active learning, the determination of coefficient can reach 0.962.for theoretical energy density and 0.92. for the gap with a modest dataset of 300 molecules, showcasing superior predictive capabilities. The 2.3,5,6-tetrafluorocyclohexa-2.5-diene-1,4-dione, selected by non-dominated sorting genetic algorithms-Ⅱ, has been successfully applied to li-ion batteries as cathode materials, demonstrating a high capacity of 2.8 m Ah g-1and a long cycle life of 1,000 cycles. This outcome underscores the high reliability of our framework. Furthermore, we have also validated the universality and transferability of our framework by applying it to two additional databases, the QM9 and OMEAD. When the training dataset of the model includes at least 500 molecules, the determination of coefficient essentially reaches approximately0.900 for four targets: gap, reduction potential, LUMO, and HOMO. Therefore, the universal framework in our work provides innovative insights applicable to other domains to expedite the screening process for target materials.

关键词： organic electrode molecules li-ion batteries active learning multi-objective Bayesian optimization

Laser altimetry data of Chang'E-1 and the global lunar DEM model

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Science china Earth sciences 2010年第11期53卷 1582-1593页

作者： li ChunLai1, REN Xin1, liu JianJun1, ZOU XiaoDuan1, MU lingli1, WANG JianYu2. SHU Rong2. ZOU Yongliao1, zhang HongBo1, Lü Chang1, liu JianZhong1, ZUO wei1, SU Yan1, WEN weiBin1, BIAN wei1, WANG Min1, XU Chun1, KONG DeQing1, WANG XiaoQian1, WANG Fang1, GENG liang1, zhang ZhouBin1, ZHENG lei1, ZHU XinYing1, li JunDuo1 & OUYANG ZiYuan1 1 National Astronomical Observatories, chinese academy of sciences, Beijing 100012. china 2.Shanghai institute of Technical Physics, chinese academy of sciences, Shanghai 2.0083, china 1. National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China2. Shanghai Institute of Technical Physics Chinese Academy of Sciences Shanghai 200083 China

The Laser AltiMeter (LAM), as one of the main payloads of Chang'E-1 probe, is used to measure the topography of the lunar surface. It performed the first measurement at 02.2. on November 2.th, 2.07. Up to December 4th 2.08, the total number of measurements was approximately 9.12.million, covering the whole surface of the Moon. Using the LAM data, we constructed a global lunar Digtal Elevation Model (DEM) with 3 km spatial resolution. The model shows pronounced morphological characteristics, legible and vivid details of the lunar surface. The plane positioning accuracy of the DEM is 445 m (1σ), and the vertical accuracy is 60 m (1σ). From this DEM model, we measured the full range of the altitude difference on the lunar sur-face, which is about 19.807 km. The highest point is 10.62. km high, on a peak between crater Korolev and crater Dirichlet-Jackson at (158.656°W, 5.441°N) and the lowest point is -9.178 km in height, inside crater Antoniadi (172.413°W, 70.368°S) in the South Pole-Aitken Basin. By comparison, the DEM model of Chang'E-1 is better than the USA ULCN2.05 in accuracy and resolution and is probably identical to the DEM of Japan SELENE, but the DEM of Chang'E-1 reveals a new lowest point, clearly lower than that of SELENE.

关键词： Chang’E-1 laser altimetry lunar DEM topographic tops of the Moon

Relationship between environmental evolution and human activities in the northeastern Qinghai-Xizang Plateau throughout the past millennium and its implications for the onset of the Anthropocene

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Science china Earth sciences 2024年第11期67卷 3536-3549页

作者： Yang PU Xueqiong wei Jianbao liu Ke {2. Beibei li Zhudeng wei Mengmeng {2. Tong HE Yanjun WANG Xiaohua SHAO School of Geographical sciences Nanjing University of Information Science and Technology Key Laboratory of Alpine Ecology Institute of Tibetan Plateau Research Chinese Academy of Sciences State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences

In current research on the Anthropocene, assessing the impact of human activities via stratigraphic records of sediments and demarcating the Anthropocene epoch globally are critical scientific issues that urgently need to be addressed. The northeastern Qinghai-Xizang Plateau(QXP), where humans first settled permanently in large numbers in the QXP, has varying sedimentary environments that are extremely sensitive to human activities. In contrast to other regions of the QXP, the northeastern sector boasts a richer array of climatic and environmental reconstruction sequences. This distinctive feature renders it an exemplary locale for investigating the stratigraphic boundary of the Anthropocene. Through in-depth analysis and integration of existing paleoclimate and paleoenvironment sequences in the northeastern QXP, we draw the following conclusions:(1) Throughout the past millennium, the impact of human activities on the environment of the northeastern QXP has become increasingly significant, especially in the past 2.0–300 years, gradually overshadowing climatic factors.(2. Since AD 1950,multiple physicochemical indicators related to human activities in the northeastern QXP have shown exponential growth,forming a distinct peak within the past millennium and clearly depicting the global “Great Acceleration” phenomenon and its development process.(3) Intensified human activities have driven swift environmental shifts and “decoupled” the interplay between climatic variations and the ecological environment, propelling the northeastern QXP into the “Early Anthropocene”from the “Late Holocene”. On the basis of the above findings, we construct a model suitable for identifying the stratigraphic boundary of the Anthropocene in the northeastern QXP and note that since the ecological environment in the northeastern QXP has entered the “Early Anthropocene”, the climate signals of certain physicochemical indicators in sediments are gradually becoming weaker, whereas the signals of

关键词： Anthropocene Qinghai-Xizang Plateau (QXP) Climate change Environmental evolution Human activities

Fabricating bio-inspired high impact resistance carbon nanotube network films for multi-protection under an extreme environment

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Nano Research 2024年第9期17卷 7793-7802页

作者： Mingquan Zhu Kailu Xiao wei zhang Xudong {2. Yunxiang Bai Shijun Wang Peng zhang Feng Gao Congying Wang Wenqiang Xu Huiyong li Xianqian Wu Chao Wang Hui zhang Luqi liu Zhong zhang CAS Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China University of chinese academy of sciences Beijing 100049China Department of Materials Science and Engineering Texas A&M UniversityCollege StationTexas 77840USA institute of mechanics Chinese Academy of SciencesBeijing 100190China School of Astronautics Harbin Institute of TechnologyHarbin150001China CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsUniversity of Science and Technology of ChinaHefei 230027China

The fabrication of light-weight,highly impact-resistant,and energy-absorbent materials is urgently demanded in many facets of the society from body armor to aerospace engineering,especially under an extreme *** nanotubes(CNTs),one of the strongest and toughest materials ever found,also have good conductivity,chemical stability,and thermal stability,etc,making them a competitive candidate as building blocks to help achieve the above *** this work,a kind of CNT network was prepared by using chlorosulfonic acid(CSA)to release the internal stress of super-aligned carbon nanotube films(SA-CNTF)and dendritic polyamide amine(PAMAM)to further introduce multiple hydrogen bonds and interlocking *** fabricated bioinspired carbon nanotube network films(PAMAM@C-CNTF)have a high toughness of 45.97 MJ/m3,showing an increase of 42.%compared to neat *** importantly,the anti-impact performance of the films(e.g.,with a maximum specific energy absorption of 1.40 MJ/kg under 80-100 m/s projectile impact)is superior to that of conventional protective materials from steel and Kevlar fiber,and also exceeds that of any other reported carbon-based *** hierarchical energy dissipation mechanism was further revealed through experiment and *** functions including intelligent heating/anti-icing,ultraviolet protection,as well as electromagnetic interference shielding properties make these network films have great potential in practical multi-protection applications,especially under an extreme environment.

关键词： carbon nanotubes composites mechanical properties multi-function