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Quantitative reconstruction of salinity and precipitation changes in Central Asia over the past 3200 years using diatom and pollen records of lacustrine sediment in Aibi Lake of SW Junggar Basin

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Journal of Earth Science 2025年

作者： Long Pan Guoqiang Li Xiaoyan Wang Ming Jin Xinrong He Luo Qin Zhong Wang Wenwei Zhao Chunzhu Chen Yuanlu Liu Jin Yang Lele Shu key laboratory of Western China's Environmental Systems (ministry of education)， College of Earth and Environmental Sciences， Lanzhou University College of Earth Sciences， Chengdu University of technology School of Geographic Science， Nantong University key laboratory of Land Surface Process and Climate Change in Cold and Arid Regions， Northwest Institute of Eco-Environment and Resources， Chinese Academy of Sciences

The response of lake environments in arid Central Asia to climate change during the Late Holocene over the centennial to millennial timescales remains contentious. The reason that primarily paleoenvironmental proxies interpreting diverse and the scarcity of accurate quantitative reconstruction records. In this study， we employed diatoms and pollen records from lacustrine sediment in the Aibi Lake of SW Junggar Basin to quantitatively reconstruct salinity and watershed precipitation amounts while exploring the associated forcing mechanism. The results indicate that Aibi Lake salinity varied between 2 g/L and 47 g/L during the Late Holocene period， indicating a generally brackish environment， and corresponding to prevailing Tryblionella granulata diatom in the lake basin. Westerly-dominated annual precipitation varied between 250 mm and 320 mm during the Late Holocene period in the basin， exhibiting a generally semi-arid environment and prevailing desert steppe vegetation. The Aibi Lake has a low salinity of average value of ～15 g/L. It exhibits elevated precipitation (average value of ～280 mm) during the periods of the Roman Warm Period (2900-1990 cal yr BP)， Dark Age Cold Period (1570-1140 cal yr BP)， and Little Ice Age (590-120 cal yr BP). The reconstructed precipitation and salinity exhibit a periodicity of ～200 years， which is consistent with the cycle of phase changes of the North Atlantic Oscillation (NAO) and Total Solar Irradiance (TSI). This correlation suggests that variations in NOA and TSI significantly influence the precipitation and salinity changes in Central Asia over centennial to millennial timescales.

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适用于狭小空间的非接触式传感仿生软体机器人（英文）

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Science China materials 2025年

作者：肖宇航周子淞潘兴海刘艳玲梅浩王浩伦蒲伟 key laboratory of advanced Spatial Mechanism and Intelligent Spacecraft Ministry of EducationSchool of Aeronautics and AstronauticsSichuan University Robotic Satellite laboratory School of Aeronautics and AstronauticsSichuan University

近年来,软体机器人概念的提出使得研究者们开始借鉴动物的运动和感知能力,开发出结合生物视觉、触觉等特性的仿生软体机器人,以实现操控、避障和路径规划.软体机器人小型化是近些年来的重点研究领域,然而,受限于较小的体积使其只能具备...

近年来,软体机器人概念的提出使得研究者们开始借鉴动物的运动和感知能力,开发出结合生物视觉、触觉等特性的仿生软体机器人,以实现操控、避障和路径规划.软体机器人小型化是近些年来的重点研究领域,然而,受限于较小的体积使其只能具备单一的行走运动能力,未真正实现仿生机器人的功能集成化.本研究受到自然界中昆虫运动和电感知能力的启发,开发了一款小型且轻质量的(900 mg)电热驱动(ETA)具备电容式非接触传感的软体机器人.电热驱动的PE/CNT/PI复合薄膜驱动器,具备优良的机械性能和灵活性,能实现最大弯曲角度达320°,展现出至少支撑自身重量5倍的负载能力.传感器部分由直径0.2 mm的银丝构成,通过边缘电场的变化检测物体的靠近,信号变化响应灵敏,能有效识别不同直径的障碍物.与其他报道的工作相比,该软体机器人聚焦于检测外部环境,在狭小空间和光线昏暗的环境中具备障碍物感知能力,它还利用在运动过程中生成传感器信号变化来获取有关自身运动姿势的信息,为未来在复杂环境中的应用提供了新的思路与依据.

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Submicrometer-scale ZnO Composite Aggregate Arrays Photoanodes for Dye-sensitized Solar Cells

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Journal of materials Science & technology 2013年第5期29卷 415-418页

作者： Wei Jia Suihu Dang Hairui Liu Zhuxia Zhang Tianbao Li Xuguang Liu Bingshe Xu key laboratory of Interface Science and Engineering in advanced materials Ministry of Education and Research Center of Advanced Materials Science and TechnologyTaiyuan University of Technology

Submicrometer-scale ZnO composite aggregate arrays of nanorods and nanoparticles were prepared by simple wet-chemical route and studied as dye-sensitized solar cells （DSSCs） photoanodes. The ZnO composite aggregate arrays significantly improved the efficiency of DSSCs due to their relatively high surface area, fast electron transport, and enhanced light-scattering capability. A short current density （Jsc） of 11.7 mA/cm2 and an overall solar-to-electric energy conversion efficiency （η） of 3.17% were achieved for the ZnO composite aggregate DSSCs, which were much higher than those obtained for the monodisperse aggregate DSSCs （Jsc = 6.9 mA/cm2, r/= 1.51 %） and ZnO nanorod array DSSCs （Jsc = 4.2 mA/cm2, η= 0.61%）.

关键词： Field emission Semiconductors Chemical synthesis Microstructure

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Microstructure and performance of WC-Co-Cr coating with ultrafine/nanocrystalline structures

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Rare Metals 2018年第11期37卷 968-975页

作者： Xue-Zheng Wang Hai-Bin Wang Xue-Mei Liu Chao Hou Xiao-Yan Song College of materials Science and Engineering Key Laboratory of Advanced Functional Materials Education Ministry of ChinaBeijing University of Technology

The WC-lOCo-4Cr composite powder was synthesized firstly. Then the composite powder was agglomerated to prepare thermal spraying feedstock. The ultrafine/nanostructured WC-lOCo-4Cr coating was prepared by high velocity oxygen fuel thermal spraying. The phase constitution, elemental distribution and microstructure of the coating were characterized by X-ray diffraction and transmission electron microscopy, respectively. The wear resistance and corrosion resistance of the prepared composite coating were tested. The results show that the main phases of the coating include WC, binding phase with partial amorphous structure, with a little WC and Co(Cr)coexisting. The distributions of Co and Cr elements from the phase boundary to the eutectic area then to Co zone were analyzed quantitatively. The mechanisms for the formation of the microstructure and effects of Cr on the performance of the composite coating are proposed.

关键词： In situ synthesis High velocity oxygen fuel Ultrafine/nanostructure Composite coating Phase constitution

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Abrasion Resistance Enhancement of Ultrafine-structured WC-Co Coating Fabricated by using in situ Synthesized Composite Powder

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Journal of materials Science & technology 2013年第11期29卷 1067-1073页

作者： Haibin Wang Xiaoyan Song Chongbin Wei Yang Gao Guangsheng Guo College of materials Science and Engineering Key Laboratory of Advanced Functional MaterialsEducation Ministry of ChinaBeijing University of Technology

The ultrafine WC-Co composite powder was synthesized by a newly developed rapid route based on in situ reactions. By using the as-synthesized composite powder, the granulation processing was then carried out to prepare the ultrafine-structured thermal spraying feedstock. The influences of the heat-treatment process on density of the feedstock powder, phase constitution and wear resistance of the resultant WC-Co coatings fabricated by high velocity oxy-fuel （HVOF） were investigated. The results showed that increasing the heating temperature and extending the holding time leaded to remarkable increase in the density and flowability of the feedstock powder. As a result, the decarburization of the in-flight particles could be decreased and the wear resistance of coating was significantly enhanced. The present study demonstrated that the developed techniques for the ultrafine powder and its thermal-sprayed coatings had very promising applications in scaling up to produce ultrafine-structured cermet coatings with excellent performance.

关键词： WC-Co composite powder Decarburization Density Ultrafine-structured coating Abrasion resistance

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Surface Passivation of Nanocrystalline Silicon Powder Derived from Cryomilling

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Journal of Wuhan University of technology(materials Science) 2014年第1期29卷 65-69页

作者：王志浩 HUANG Zhifeng 陈斐 SHEN Qiang ZHANG Lianmeng State key lab of advanced technology for materials Synthesis and Processing Wuhan University of Technology key laboratory of advanced technology for Specially Functional materials Ministry of Education Wuhan University of Technology

The surface passivation mechanism of nanocrystalline silicon powder was studied. The liquid nitrogen/argon was used as the medium to prepare the nanocrystalline silicon powder, using a cryomilling technology. The X-ray diffraction, transmission electron microscopy, plasma emission spectroscopy and infrared spectrum were used to analyze the prepared samples, and density functional theory was used to investigate the cryomilling process. For nanocrystalline silicon powder cryomilled with liquid N2, the amorphous outer layer with N element is formed On the surface, and chemisorption caused by the formation of Si-N-Si bond leads to the surface passivation; although physisorpfion also he confirmed, the Si-N bond is steady after exploded in air for 30 days and no new bond is observed. For nanocrystalline silicon powder cryomilled with liquid At, no new chemical bond is Observed, Ar element absorbs on the surface of the prepared powder only through physisorption, and after exploded in air for 30 days, a Si-O bond can be observed obviously.

关键词： surface passivation nanocrystalline silicon powder cryomilling

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Effect of heterogeneous microstructure on magnetization reversal mechanism of hot-deformed Nd-Fe-B magnets

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Journal of Rare Earths 2019年第10期37卷 1088-1095页

作者： Yuqing Li Xiaochang Xu Ming Yue Dan Wu Weiqiang Liu Dongtao Zhang key laboratory of advanced Functional materials Ministry of Education of China College of Materials Science and Engineering Beijing University of Technology

The hot-deformed(HD) Nd-Fe-B magnets show heterogeneous microstructure composed of coarse and fine grain regions. It is significant to fully understand the influence of this complex microstructure on the magnetization reversal process which can give the guidance for the enhancement of the magnetic properties. In this paper, the heterogeneous microstructure of the(HD) Nd-Fe-B magnets were characterized from the morphology, size, macro-texture and micro-structure. In addition, the magnetization reversal process of the HD Nd-Fe-B magnets was systematically analyzed by magnetic measurement, insitu domain evolution observation and micromagnetic simulation. The results indicate that the HD NdFe-B magnets mainly consist of fine grain regions(FGRs) and coarse grain regions(CGRs). The FGRs show plate-like grains with fine grain size and strong c-axis texture, while the CGRs show equiaxial grains with large grain size and weak c-axis texture. In particular, it is worth noting that the texture in homogeneity exists not only between FGRs and CGRs, but also inside both the FGRs and CGRs. The dominant coercivity mechanism of the HD Nd-Fe-B magnets is domain wall pinning. Also, the experimental analysis shows that the reverse domain is formed and expanded in the CGRs at low reverse applied field, while the reverse domain occurs in the FGRs at higher reverse applied field. The micromagnetic simulation results also confirm the above magnetization reversal process. In addition, micromagnetic simulation results also show that the orientation of the grains also affects the pinning strength, besides the grain size.

关键词： Hot-deformed Nd-Fe-B magnet Heterogeneous microstructure Magnetization reversal Coercivity mechanism Rare earths

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Preparation and emission property of scandia pressed cathode

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Journal of Rare Earths 2010年第S1期28卷 460-463页

作者：王金淑张喜珠刘伟崔云涛王亦曼周美玲 The key laboratory of advanced Functional materials of ministry of education School of Materials Science and EngineeringBeijing University of Technology

Scandia pressed cathodes were prepared by powder metallurgy method using mixed powder of scandia doped tungsten and barium-calcium aluminates obtained by different mixing *** element distribution uniformity greatly affected the emission *** powder prepared by ball-milling had small particle size and uniform distribution of different *** kind of powder was favorable for the chemical reaction among Ba,Ca aluminates,scandia and tungsten to take place sufficiently to form active substance which can improve the emission *** emission current density of the cathode prepared with ball-milling powder was about 8 times higher than that prepared by manually mixing method,4 times higher than Os coated M-type *** higher content of the active substance on the cathode surface prepared by ball-milling led to the better emission performance of the cathode.

关键词： scandia tungsten pressed cathode rare earths

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Smart Cellulose‑Based Janus Fabrics with Switchable Liquid Transportation for Personal Moisture and Thermal Management

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Nano-Micro Letters 2025年第1期17卷 333-347页

作者： Jianfeng Xi Yanling Lou Liucheng Meng Chao Deng Youlu Chu Zhaoyang Xu Huining Xiao Weibing Wu Jiangsu Co‑Innovation Center of Efficient Processing and Utilization of Forest Resources International Innovation Center for Forest Chemicals and MaterialsJiangsu Provincial Key Lab of Sustainable Pulp and Paper Technology and Biomass MaterialsNanjing Forestry UniversityNanjing 210037People’s Republic of China College of materials Science and Engineering Nanjing Forestry UniversityNanjing 210037People’s Republic of China Department of Chemical Engineering University of New BrunswickFrederictonNB E3B 5A3Canada Macromolecular Chemistry and Bavarian Polymer Institute University of BayreuthBayreuth 95440Germany

The Janus fabrics designed for personal moisture/thermal regulation have garnered significant attention for their potential to enhance human ***,the development of smart and dynamic fabrics capable of managing personal moisture/thermal comfort in response to changing external environments remains a ***,a smart cellulose-based Janus fabric was designed to dynamically manage personal moisture/*** cotton fabric was grafted with N-isopropylacrylamide to construct a temperature-stimulated transport ***,hydrophobic ethyl cellulose and hydrophilic cellulose nanofiber were sprayed on the bottom and top sides of the fabric to obtain wettability *** fabric exhibits anti-gravity directional liquid transportation from hydrophobic side to hydrophilic side,and can dynamically and continuously control the transportation time in a wide range of 3–66 s as the temperature increases from 10 to 40℃.This smart fabric can quickly dissipate heat at high temperatures,while at low temperatures,it can slow down the heat dissipation rate and prevent the human from becoming too *** addition,the fabric has UV shielding and photodynamic antibacterial properties through depositing graphitic carbon nitride nanosheets on the hydrophilic *** smart fabric offers an innovative approach to maximizing personal comfort in environments with significant temperature variations.

关键词： Directional water transport Cotton fabric Anti-gravity directional liquid transportation Janus wettability

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High responsivity and near-infrared photodetector based on graphene/MoSe_2 heterostructure

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Chinese Optics Letters 2019年第2期17卷 7-11页

作者： Beiyun Liu Congya You Chen Zhao Gaoliang Shen Yawei Liu Yufo Li Hui Yan Yongzhe Zhang key laboratory for advanced Functional materials of the ministry of education College of Materials Science and Engineering Beijing University of Technology

Graphene has attracted great interest in optoelectronics, owing to its high carrier mobility and broadband absorption. However, a graphene photodetector exhibits low photoresponsivity because of its weak light absorption. In this work, we designed a graphene/MoSe_2 heterostructure photodetector, which exhibits photoresponse ranging from visible to near infrared and an ultrahigh photoresponsivity up to 1.3 × 104 A·W^(-1) at 550 nm. The electron–hole pairs are excited in a few-layered MoSe2 and separated by the built-in electric field. A large number of electrons shift to graphene, while the holes remain in the MoSe_2, which creates a photogating effect.

关键词： High responsivity near-infrared MoSe2 heterostructure

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