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Two-Stage Online Debiased Lasso Estimation and Inference for High-Dimensional Quantile regression with Streaming Data

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Journal of Systems Science & Complexity 2024年第3期37卷 1251-1270页

作者： PENG Yanjin wang Lei School of Statistics and Data Science KLMDASRLEBPS and LPMCNankai UniversityTianjin 300071China

In this paper,the authors propose a two-stage online debiased lasso estimation and statistical inference method for high-dimensional quantile regression(Qr)models in the presence of streaming *** the first stage,the authors modify the Qr score function based on kernel smoothing and obtain the online lasso smoothed Qr estimator through iterative *** estimation process only involves the current data batch and specific historical summary statistics,which perfectly accommodates to the special structure of streaming *** the second stage,an online debiasing procedure is carried out to eliminate biases caused by the lasso penalty as well as the accumulative approximation error so that the asymptotic normality of the resulting estimator can be *** authors conduct extensive numerical experiments to evaluate the performance of the proposed *** experiments demonstrate the effectiveness of the proposed method and support the theoretical *** application to the Beijing PM2.5 Dataset is also presented.

关键词： Adaptive tuning asymptotic normality debiased lasso online updating quantile regres-sion

Mn-based cathode materials for rechargeable batteries

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Science China Chemistry 2024年第1期67卷 87-105页

作者： xu Zhang Shiqi Liu Boya wang Guoqing wang Haozhe Du xuanyu wang Haidong Zhang Shu Zhao Lin wang Haijun Yu Institute of Advanced Battery Materials and Devices Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China Key Laboratory of Advanced Functional Materials Ministry of EducationBeijing University of TechnologyBeijing 100124China Create Energy&Benefit Future Co.Ltd. Beijing 100176China

The rapid expansion of renewable energies asks for great progress of energy-storage technologies for sustainable energy supplies,which raises the compelling demand of high-performance rechargeable *** satisfy the huge demand from the coming energy-storage market,the resource and cost-effectiveness of rechargeable batteries become more and more ***(Mn)as a key transition element with advantages including high abundance,low cost,and low toxicity derives various kinds(spinels,layered oxides,polyanions,Prussian blue analogs,etc.)of high-performance Mn-based electrode materials,especially cathodes,for rechargeable batteries ranging from Li-ion batteries,Na-ion batteries,aqueous batteries,to multivalent metal-ion *** is anticipated that Mn-based materials with Mn as the major transition-metal element will constitute a flourishing family of Mn-based rechargeable batteries(Mn rBs)for large-scale and differentiated energy-storage *** the other hand,several critical issues including Jahn-Teller effect,Mn dissolution,and O release greatly hinder the pace of Mn rBs,which require extensive material optimizations and battery/system *** review aims to provide an investigation about Mn-based materials and batteries for the coming energy-storage demands,with compelling issues and challenges that must be overcome.

关键词： manganese cathode materials Mn-based rechargeable batteries energy storage

Effect of Operation Parameters on the Thermal Characteristics in a Planar Solid Oxide Fuel Cell

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Journal of Thermal Science 2024年第5期33卷 1974-1989页

作者： wang Mingyuan wang Ke wang Yongqing CHEN Jiangshuai AN Bo TU Shantung School of Mechanics and Safety Engineering Zhengzhou UniversityZhengzhou 450001China Key Laboratory of Process Heat Transfer and Energy Saving of Henan Province Zhengzhou UniversityZhengzhou 450002China School of Mechanical and Power Engineering Zhengzhou UniversityZhengzhou 450001China Key Laboratory of Pressure Systems and Safety(MOE) East China University of Science&TechnologyShanghai 200237China

Effective operation strategies in the solid oxide fuel cell(SOFC)can adjust the spatial distribution of temperature gradient favoring the long-term *** investigate the effects of different operating conditions on the thermal behavior inside SOFC,a three-dimensional model is developed in this *** model is verified by comparing it with the experimental *** heat generation rate and its variation under different operating conditions are *** combined effects of operating voltage and gas temperature are considered to be the key factor influencing the temperature *** to the original case,the temperature of SOFC decreases by 21.4 K when the fuel velocity reaches 5 m/*** the maximum temperature gradient increases by21.2%.Meanwhile,higher fuel velocities can eliminate about 32%of the area with higher temperature *** when the oxidant velocity reaches 7.5 m/s,the peak temperature gradient effectively decreases by 16.59%.Simultaneous adjustment of the oxidant and fuel velocities can effectively reduce the peak temperature gradient and increase the safety *** effects of operation conditions on the temperature gradient of the cell are clarified in this study,which can be a reference for further research on the reliability of SOFCs.

关键词： SOFC heat generation temperature gradient distribution heat source thermal behavior

Hollow structured Fe@C nanorods for boosting dehydrogenation properties of α-AlH_(3)

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Nano research 2024年第9期17卷 8184-8191页

作者： Yuan Zhao Qingshuang wang Dongming Yin xiaoli wang Shouliang Li Chunli wang Long Liang Shaolei Zhao Limin wang Yong Cheng School of Materials Science and Engineering Changchun University of Science and TechnologyChangchun 130022China State Key Laboratory of rare Earth resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology College of Chemistry and Chemical EngineeringDezhou UniversityDezhou 253023China Henan Nayu New Material Co. Ltd.Xinxiang 453000China

α-AlH_(3)is regarded as one of the most promising hydrogen storage materials due to its high hydrogen storage capacity(10.1 wt.%,148 kg·m^(-3)).However,in practical applications,the associated hydrogen release temperature remains relatively *** effectively address this issue,hollow structured Fe@C nanorods derived from Fe-MOF are introduced as highly efficient catalyst to optimize the dehydrogenation properties ofα-AlH_(3).Comparatively,the initial hydrogen release temperature ofα-AlH_(3)+3 wt.%Fe@C is reduced to 94.2℃,which is significantly lower than that of pureα-AlH_(3)(137.8℃).At 100 and 120℃,it exhibits hydrogen capacities of 5.38 wt.%and 7.47 wt.%,respectively,whereas pureα-AlH_(3)only delivers hydrogen capacities of 0.24 wt.%and 5.94 wt.%under the same *** density functional theory(DFT)calculations further indicate that the existence of Fe@C catalyst can make the length of Al-H bond increase,which is more conducive to the release of *** results show that the synergistic effect of Fe and porous carbon in Fe@C nanorods can improve the hydrogen desorption kinetics ofα-AlH_(3),providing a good prospect for the application ofα-AlH_(3)in hydrogen storage fields.

关键词： Fe@C α-AlH_(3) dehydrogenation catalyst

Editorial of special issue on the 20th anniversary of Wuhan National Laboratory for Optoelectronics(WNLO)

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Chinese Optics Letters 2024年第2期22卷 1-2页

作者： Jian wang WNLO Huazhong University of Science and Technology

On the occasion of the 20th anniversary of the founding of Chinese Optics Letters,Wuhan National Laboratory for Optoelectronics(WNLO)has also gone through 20 *** is one of six national research centers approved by the Ministry of Science and Technology of China in *** predecessor was Wuhan National Laboratory for Optoelectronics(preparatory),one of five national laboratories approved for preparatory construction by the Ministry of Science and Technology of China in November *** was jointly built by the Ministry of Science and Technology of China,Ministry of Education of China,Hubei Provincial Government,and Wuhan Municipal Government.

关键词： jointly anniversary Wuhan

Ce-and La-doped polymetallic layered double hydroxides for enhanced oxygen evolution reaction performance at high current density

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Science China Chemistry 2024年第8期67卷 2586-2598页

作者： rinel r.Kimaka P. Ping wang Miao He Senyao Meng Jiasai Yao Huawei Li Cheng Yang Zhenxing Li State Key Laboratory of Heavy Oil Processing College of New Energy and MaterialsChina University of Petroleum(Beijing)Beijing 102249China

Polymetallic layered double hydroxides are promising cost-effective catalysts for the oxygen evolution reaction(OEr) due to their versatile anionic and cationic tunability. Nevertheless, several challenges persist, notably, issues related to low electrical conductivity, poor catalytic activity, and stability, especially at high current density. Herein, we report the design of Ce-and Ladoped Co Ni Fe-layered double hydroxide(Ce La Co Ni Fe-LDH) nanosheets through a facile and scalable in situ self-assembly strategy that displays enhanced OEr activity. Experimental and theoretical investigations provide insights into the impact of Ceand La-doping by comparing Ce Co Ni Fe-LDH, La Co Ni Fe-LDH, and pristine Co Ni Fe-LDH, all synthesized using the same methodology. These results reveal that doping Ce^(3+)and La^(3+)into Co Ni Fe-LDH substantially improves its electronic structure,resulting in enhanced conductivity, more oxygen vacancies(Vo), electron interaction, and active site formation. Consequently,significantly reduced overpotentials of 175, 314, and 424 m V at 10, 100, and 500 m A cm^(-2), respectively, and a highly stable current density of 120 h in 1 M KOH were achieved. Notably, these performance metrics surpass those of unmodified LDHs and are competitive with many lanthanide-doped transition metal-based LDH electrocatalysts, as well as noble metal catalysts like ruthenium catalysts. This work represents a pioneering effort in doping Ce^(3+)and La^(3+)ions into a functional Co Ni Fe-based electrocatalyst, offering inspiring OEr performance and scalability potential.

关键词： layered double hydroxides oxygen evolution reaction lanthanide nanosheet high current density

Interface matters: how to print single atoms?

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Science China Materials 2024年第3期67卷 1002-1003页

作者： Dingsheng wang Department of Chemistry Tsinghua UniversityBeijing 100084China

recently, single-atom catalysts (SACs) have emerged as highly efficient catalysts for multiple reactions, making them as the new stars in the catalytic field [1–7]. Single metal atoms can be anchored onto various supports (such as defective carbon, oxides, sulfides and carbides [8]), endowing single atoms with diverse electronic and coordination structures.

关键词： sulfide coordination oxides

Diamond: asymmetry leads to continuous hardening

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Science China Materials 2024年第3期67卷 1000-1001页

作者： Zhongchang wang International Iberian Nanotechnology Laboratory(INL) Braga 4715-330Portugal School of Chemistry Beihang UniversityBeijing 100191China

Naturally occurring and synthetic materials are often polycrystalline comprising various species of grain boundaries(GBs),many of which are randomly *** is known that GBs play a pivotal role in affecting a broad range of material properties,and the nature of GBs is dedicated by grain orientation,growth history and processing conditions.

关键词： conditions Diamond continuous

A Study on the Impact of Chemical Structure on the Evolution of Aggregate Structure in Fiber-shaped High Density Polyethylene Vitrimer

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Chinese Journal of Polymer Science 2024年第10期42卷 1557-1565页

作者： Bing wang Yuan-Chu Gao Hai wang Hui Niu State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of Technology

Vitrimers have emerged as a prominent research area in the field of polymer materials. Most of the studies have focused on synthesizing polymers with versatile dynamic crosslinking structures, while the impact of chemical structure on aggregate structure of vitrimers, particularly during polymer processing, remains insufficiently investigated. The present study employed commercial maleic anhydride-grafted-high density polyethylene (M-g-HDPE) as the matrix and hexanediol as the crosslinker to facilely obtain fiber-shaped HDPE vitrimers through a reaction extrusion and post-drawing process. Through chemical structure characterization, morphology observation, thermal and mechanical properties investigation, as well as aggregate structure analysis, this work revealed the influence of dynamic bonds on the formation of aggregate structures during fiber-shaped vitrimers processing. A small amount of dynamic bonds in HDPE restricts the motion of PE chain during melt-extruding and post-drawing, resulting in a lower orientation of the PE chains. However, lamellar growth and fibril formation during post-drawing at high temperature are enhanced to some extent due to the competition between dynamic bond and chain relaxation. The uneven morphology of fibershaped HDPE vitrimers can be attributed to the stronger elastic effect brought by dynamic bonding, which plays a more dominant role in determining the mechanical properties of fiber-shaped vitrimers compared to aggregate *** Vitrimers have emerged as a prominent research area in the field of polymer *** of the studies have focused on synthesizing polymers with versatile dynamic crosslinking structures,while the impact of chemical structure on aggregate structure of vitrimers,particularly during polymer processing,remains insufficiently *** present study employed commercial maleic anhydride-grafted-high density polyethylene (M-g-HDPE) as the matrix and hexanediol as the crosslinker to facile

关键词： Aggregate structures Fiber-shaped High density polyethylene vitrimer Transesterification reaction