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Interlayer environment engineered MXene: Pre-intercalated Zn^(2+)ions as intercalants renders the modulated Li storage

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Journal of Energy Chemistry 2022年第5期31卷 306-313页

作者： Yixuan Wang Miao Liu Zhihe Wang Qinhua Gu Bo Liu Cuimei Zhao junkai zhang Shichong Xu Ming Lu Haibo Li Bingsen zhang Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education The Joint Laboratory of MXene MaterialsJilin Normal UniversityChangchun 130103JilinChina Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016LiaoningChina Key Laboratory of Preparation and Application of Environmental Friendly Materials of the Ministry of Education Jilin Normal UniversityChangchun 130103JilinChina School of Materials Science and Engineering University of Science and Techonology of ChinaShenyang 110016LiaoningChina

The intercalation of foreign species into MXene, as an approach of tuning the interlayer environment, is employed to improve electrochemical ion storage behaviors. Herein, to understand the effect of confined ions by the MXene layers on the performance of electrochemical energy storage, Zn^(2+) ions were employed to intercalate into MXene via an electrochemical technique. Zn^(2+) ions induced a shrink of the adjacent MXene layers. Meaningfully, a higher capacity of lithium ion storage was obtained after Zn^(2+) preintercalation. In order to explore the roles of the intercalated Zn^(2+) ions, the structural evolution, and the electronic migration among Zn, Ti and the surface termination were investigated to trace the origination of the higher Li^(+) storage capacity. The pre-intercalated Zn^(2+) ions lost electrons, meanwhile Ti of MXene obtained electrons. Moreover, a low-F surface functional groups was achieved. Contrary to the first shrink, after 200 cycles, a larger interlayer distance was monitored, this can accelerate the ion transport and offer a larger expansile space for lithium storage. This may offer a guidance to understand the roles of the confined ion by two-dimensional(2D) layered materials.

关键词： Ti_(3)C_(2)T_(x)MXene Zinc ions Interlayer intercalation Lithium storage

轻质Fe-Mn-Al-C系高强钢的组织与性能研究进展及其在海洋工程中的应用展望

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上海金属 2024年第3期46卷 13-22,32页

作者：史津铭庞启航李维娟李激光张俊凯张大征辽宁科技大学材料与冶金学院辽宁鞍山114051

轻质Fe-Mn-Al-C系高强钢的特点是强度高、密度低、耐蚀性好、延展性好等,近年来得到了快速发展和广泛应用。通过以不同元素合金化能使轻质高强钢具有不同的显微组织和力学性能。例如,碳和锰的添加能稳定奥氏体,铝的添加能降低密度,某些... 详细信息

轻质Fe-Mn-Al-C系高强钢的特点是强度高、密度低、耐蚀性好、延展性好等,近年来得到了快速发展和广泛应用。通过以不同元素合金化能使轻质高强钢具有不同的显微组织和力学性能。例如,碳和锰的添加能稳定奥氏体,铝的添加能降低密度,某些微合金元素的添加能提高力学性能且抑制κ-碳化物析出。晶界的微米级κ-碳化物对轻质钢的力学性能有不利影响,但经固溶和时效处理后形成的晶内纳米级κ-碳化物能提高钢的强度。轻质钢不仅可应用于汽车制造等领域,在海洋工程也具有广阔的应用前景。

关键词：轻质钢显微组织力学性能固溶处理时效 κ-碳化物

Functional microfluidics:theory,microfabrication,and applications

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International Journal of Extreme Manufacturing 2024年第3期6卷 140-173页

作者： Mingzhu Xie Ziheng Zhan Yinfeng Li junkai Zhao Ce zhang Zhaolong Wang Zuankai Wang Interdisciplinary Research Center of Low-carbon Technology and Equipment College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082People’s Republic of China Energy Research Institute of Shandong Academy of Sciences Qilu University of Technology(Shandong Academy of Sciences)Jinan 250014People’s Republic of China Qian Xuesen Laboratory of Space Technology China Academy of Space Technology(CAST)Beijing 100094People’s Republic of China Department of Mechanical Engineering Hong Kong Polytechnic UniversityHong Kong Special Administrative Region of China 999077People’s Republic of China

Microfluidic devices are composed of microchannels with a diameter ranging from ten to a few hundred ***,quite a small(10-9–10-18l)amount of liquid can be manipulated by such a precise *** the past three decades,significant progress in materials science,microfabrication,and various applications has boosted the development of promising functional microfluidic *** this review,the recent progress on novel microfluidic devices with various functions and applications is ***,the theory and numerical methods for studying the performance of microfluidic devices are briefly ***,materials and fabrication methods of functional microfluidic devices are ***,the recent significant advances in applications of microfluidic devices are highlighted,including heat sinks,clean water production,chemical reactions,sensors,biomedicine,capillaric circuits,wearable electronic devices,and ***,perspectives on the challenges and future developments of functional microfluidic devices are *** review aims to inspire researchers from various fields engineering,materials,chemistry,mathematics,physics,and more—to collaborate and drive forward the development and applications of functional microfluidic devices,specifically for achieving carbon neutrality.

关键词： capillary theory functional devices functional microfluidics

Deep reinforcement learning using least-squares truncated temporal-difference

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CAAI Transactions on Intelligence Technology 2024年第2期9卷 425-439页

作者： junkai Ren Yixing Lan Xin Xu Yichuan zhang Qiang Fang Yujun Zeng College of Intelligence Science and Technology National University of Defense TechnologyChangshaChina State Key Laboratory of Astronautic Dynamics Xi'an Satellite Control CenterXi'anChina

Policy evaluation(PE)is a critical sub-problem in reinforcement learning,which estimates the value function for a given policy and can be used for policy ***,there still exist some limitations in current PE methods,such as low sample efficiency and local convergence,especially on complex *** this study,a novel PE algorithm called Least-Squares Truncated Temporal-Difference learning(LST2D)is *** LST2D,an adaptive truncation mechanism is designed,which effectively takes advantage of the fast convergence property of Least-Squares Temporal Difference learning and the asymptotic convergence property of Temporal Difference learning(TD).Then,two feature pre-training methods are utilised to improve the approximation ability of ***,an Actor-Critic algorithm based on LST2D and pre-trained feature representations(ACLPF)is proposed,where LST2D is integrated into the critic network to improve learning-prediction *** simulation studies were conducted on four robotic tasks,and the corresponding results illustrate the effectiveness of *** proposed ACLPF algorithm outperformed DQN,ACER and PPO in terms of sample efficiency and stability,which demonstrated that LST2D can be applied to online learning control problems by incorporating it into the actor-critic architecture.

关键词： Deep reinforcement learning policy evaluation temporal difference value function approximation

Revealing the key role of non-solvating diluents for fast-charging and low temperature Li-ion batteries

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Journal of Energy Chemistry 2024年第7期94卷 171-180页

作者： Yuping zhang Siyin Li junkai Shi Jiawei Lai Ziyue Zhuang Jingwen Liu Wenming Yang Liang Ma Yue-Peng Cai Jijian Xu Qifeng Zheng School of Chemistry Guangzhou Key Laboratory of Materials for Energy Conversion and StorageSouth China Normal UniversityGuangzhou 510006GuangdongChina Guangzhou Foreign Language School Guangzhou 511455GuangdongChina Department of Chemistry City University of Hong KongHong Kong 999077China

Fast-charging and low temperature operation are of vital importance for the further development of lithium-ion batteries(LIBs),which is hindered by the utilization of conventional carbonate-based electrolytes due to their slow kinetics,narrow operating temperature and voltage ***,an acetonitrile(AN)-based localized high-concentration electrolyte(LHCE)is proposed to retain liquid state and high ionic conductivity at ultra-low temperatures while possessing high oxidation *** originally reveal the excellent thermal shielding effect of non-solvating diluent to prevent the aggregation of Li^(+) solvates as temperature drops,maintaining the merits of fast Li transport and facile desolvation as at room temperature,which bestows the graphite electrode with remarkable low temperature performance(264 mA h g^(-1) at-20 C).Remarkably,an extremely high capacity retention of 97%is achieved for high-voltage high-energy graphite||NCM batteries after 250 cycles at-20 C,and a high capacity of 110 mA h g^(-1)(71%of its room-temperature capacity)is retained at-30°*** study unveils the key role of the non-solvating diluents and provides instructive guidance in designing electrolytes towards fast-charging and low temperature LIBs.

关键词： Li-ion battery Fast-charging Low temperature Non-solvating diluent Shielding effect

Effects of Ag Doping Content and Dispersion on the Photocatalytic and Antibacterial Properties in ZnO Nanoparticles

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Chemical Research in Chinese Universities 2019年第2期35卷 271-276页

作者： GUAN Renquan ZHAI Hongju SUN Dewu zhang junkai WANG Yan LI Jiaxin Key Laboratory of Preparation and Applications of Environmental Friendly Materials Ministry of EducationJilin Normal UniversityChangchun 130103P.R.China College of Chemistry Jilin Normal UniversitySiping 136000P.R.China Key Laboratory of Functional Materials Physics and Chemistry Ministry of EducationJilin Normal UniversityChangchun 130103P.R.China

ZnO nanoparticles(NPs)with different contents of Ag dopants were obtained by one-step solvothermal *** crystalline structures of the prepared composites were characterized by means of X-ray diffraction(XRD).The morphology and composition of the samples were studied by means of scanning transmission electron microscopy(TEM)5 X-ray photoelectron spectroscopy(XPS)and electron microscopy(SEM).Photoluminescence(PL)spectra have been used to investigate pure ZnO,Ag-ZnO and Ag-ZnO-PVP NPs to determine the effect of composition on PL *** was found that the Ag-ZnO samples showed stronger emissions than pure *** catalytic activity of samples was measured by the degradation rate of R6G,which exhibited that Ag-ZnO nanocomposite demonstrated enhanced photocatalytic activity compared to the pure ZnO *** possible influence factors to the photocatalytic and antibacterial activities of the sample were explored,including Ag contents and *** was presented that the photocatalytic activity of Ag-ZnO-PVP was better than that of Ag-ZnO and it showed the highest photocatalytic activity with 7%of Ag *** Ag-ZnO-PVP can kill the Escherichia coli(***)cells.

关键词： Ag-ZnO nanocomposite Photocatalysis:Antibacterial activity Dispersion

新一代人工智能驱动下地图学研究的机遇与挑战

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地球信息科学学报 2024年第1期26卷 35-45页

作者：张岸朱俊锴中国科学院地理科学与资源研究所资源与环境信息系统国家重点实验室北京100101 中国科学院大学北京100049

随着生成式人工智能(AIGC)为代表的新一代人工智能的快速发展,加速了各个学科转向人工智能驱动的科学研究,地理空间智能(GeoAI)技术在解决传统制图学任务注定会比传统的方法具有更好的性能,地图学也因此迎来了新的机遇与挑战,产生智能... 详细信息

随着生成式人工智能(AIGC)为代表的新一代人工智能的快速发展,加速了各个学科转向人工智能驱动的科学研究,地理空间智能(GeoAI)技术在解决传统制图学任务注定会比传统的方法具有更好的性能,地图学也因此迎来了新的机遇与挑战,产生智能地图制图新领域,形成智能地图制图学。地图学研究有人工智能传统,但是过去受限于人工智能工具的计算能力等原因,并未取得很大的进展。随着进入智能化时代,人与机器都将成为制图与读图的主体。地图内容的产生经历了专家生成内容和用户生成内容的阶段,正在向人工智能生成内容阶段发展。人工智能与地图传输模型的结合衍生出智能地图传输模型,包括制图信息智能获取、智能制图、智能读图、地图信息智能解读4个环节,进而从这4个方面对智能地图的研究进展进行了分析和梳理。研究显示,使用智能化方法解决地图学问题的研究仍然处于起步阶段,人工智能与地图学结合仍存在诸多挑战,包括缺乏训练数据集、模型算法缺乏泛化能力和可解释性等,这些也是未来可以发展的方向。

关键词：生成式人工智能智能地图制图学地理空间智能智能读图智能制图

High-quality industrial n-type silicon wafers with an efficiency of over 23% for Si heterojunction solar cells

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Frontiers in Energy 2017年第1期11卷 78-84页

作者： Fanying MENG Jinning LIU Leilei SHEN Jianhua SHI Anjun HAN Liping zhang Yucheng LIU Jian YU junkai zhang Rui ZHOU Zhengxin LIU Research Center for New Energy Technology Shanghai Institute of Microsystem and Information Technology (SIMIT) Shanghai 200050 China Xi'an Longi Silicon Materials Corp. Xi'an 710100 China

n-type CZ-Si wafers featuring longer minority carrier lifetime and higher tolerance of certain metal contamination can offer one of the best Si-based solar cells. In this study, Si heterojuction （SHJ） solar cells which was fabricated with different wafers in the top, middle and tail positions of the ingot, exhibited a stable high efficiency of〉 22% in spite of the various profiles of the resistivity and lifetime, which demonstrated the high material utilization of n-type ingot. In addition, for effectively converting the sunlight into electrical power, the pyramid size, pyramid density and roughness of surface of the Cz-Si wafer were investigated by scanning electron microscope （SEM） and transmission electron microscope （TEM）. Furthermore, the dependence of SHJ solar cell open- circuit voltage on the surface topography was discussed, which indicated that the uniformity of surface pyramid helps to improve the open-circuit voltage and conversion efficiency. Moreover, the simulation revealed that the highest efficiency of the SHJ solar cell could be achieved by the wafer with a thickness of 100 μm. Fortunately, over 23% of the conversion efficiency of the SHJ solar cell with a wafer thickness of 100 μm was obtained based on the systematic optimization of cell fabrication process in the pilot production line. Evidently, the large availability of both n-type ingot and thinner wafer strongly supported the lower cost fabrication of high efficiency SHJ solar cell.

关键词： n-type Cz-Si thinner wafer surface texture,high efficiency SHJ solar cell

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技能培训、工作转换与就业质量

劳动经济研究 2022年第1期10卷 3-29页

作者：张世伟张君凯吉林大学商学与管理学院吉林大学数量经济研究中心

本文基于2014年和2016年中国劳动力动态调查数据,分析了技能培训的就业质量效应,以及工作转换对技能培训就业质量效应的影响。研究发现,技能培训有助于个体工资水平、社会保险享有概率和工作满意度的显著提升;工作转换会显著降低技能培... 详细信息

本文基于2014年和2016年中国劳动力动态调查数据,分析了技能培训的就业质量效应,以及工作转换对技能培训就业质量效应的影响。研究发现,技能培训有助于个体工资水平、社会保险享有概率和工作满意度的显著提升;工作转换会显著降低技能培训对客观就业质量的提升作用,但会显著增加技能培训对主观就业质量的提升作用。研究还发现,伴随工作转换的职业变化和工作单位正规程度的变化是导致工作转换调节技能培训就业质量效应的主要原因;工作转换对技能培训客观就业质量提升效应的消极影响主要体现在低受教育群体、中年劳动力群体和农民工,而工作转换对技能培训主观就业质量提升效应的积极影响主要体现在高受教育群体、青年劳动力群体和城镇工。因此,各地政府在面向城乡各类劳动者积极开展职业技能提升培训时,应注重培养个体长远的职业发展意识,避免频繁更换工作对人力资本和职业发展的损耗。

关键词：技能培训就业质量工作转换