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Rare Metals 2024年第2期43卷 500-510页

作者： Cai-Di Han Yong-Chao Zhang Qian Zhang jin-Ting wu Jian gao Ji-Jun Zou Xiao-Dong Zhu State Key Laboratory Base of Eco-Chemical Engineering College of Chemical Engineering Qingdao University of Science and TechnologyQingdao266042China Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China

Electrocatalytic oxygen reduction(ORR)via the 2e−pathway to form H_(2)O_(2) in acidic medium has attracted extensive ***,the low activity,insufficient selectivity and high cost of catalysts have been the ***,CoSe_(2) with abundant Se deficiency was synthesized by a simple hydrothermal method,and the addition of NaBH4-induced CoSe_(2) phase transition from orthorhombic to cubic phase with more Se *** cubic phase CoSe_(2) with abundant Se deficiency can effectively regulate the surface electronic structure with suitable binding energies of*OOH and*O,which shows high activity,selectivity and long-term stability for acidic ORR to H_(2)O_(2).The onset potential is as low as 0.73 V *** hydrogen electrode(RHE),the H_(2)O_(2) selectivity is 84%(0 V ***),and the average electron transfer number is about ***,the H_(2)O_(2) yield measured using a flow cell is as high as 115.92 mmol·gcat.^(−1)·h^(−1) and the Faradaic efficiency is 70%at 0 V ***,which presents high potential in electrocatalytic acidic ORR to H_(2)O_(2) and organic pollutant degradation using the electron-Fenton process.

关键词： Se defected CoSe_(2) Crystal phase transition Electrocatalysis Acidic oxygen reduction Hydrogen peroxide

Geometric and material nonlinearities of sandwich beams under static loads

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Acta Mechanica Sinica 2020年第1期36卷 97-106页

作者： Guangtao Wei Yang jin Linzhi wu Center for Composite Materials Harbin Institute of TechnologyHarbin150001China Center for Advanced Vessels Materials and Mechanics College of Aerospace and Civil EngineeringHarbin Engineering UniversityHarbin150001China

A new theory developed from extended high-order sandwich panel theory(EHSAPT)is set up to assess the static response of sandwich panels by considering the geometrical and material nonlinearities *** geometrical nonlinearity is considered by adopting the Green-Lagrange-type strain for the face sheets and *** material nonlinearity is included as a piecewise function matched to the experimental stress-strain curve using a polynomial fitting technique.A Ritz technique is applied to solve the governing *** results show that the stress stiffening feature is well captured in the geometric nonlinear *** effect of the geometric nonlinearity in the face sheets on the displacement response is more significant when the stiffness ratio of the face sheets to the core is *** geometric nonlinearity decreases the shear stress and increases the normal stress in the sandwich *** comparison with open literature and finite element simulations,the present nonlinear EHSAPT is shown to be sufficiently precise for estimating the nonlinear static response of sandwich beams by considering the geometric and material nonlinearities simultaneously.

关键词： Extended high-order sandwich panel theory Geometrical nonlinearity Material nonlinearity Ritz method

Flow instability of supercritical hydrocarbon fuel in a multi-channel cooling system

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Chinese Journal of Aeronautics 2024年第2期37卷 283-295页

作者： Yichao jin Kun wu Xuejun FAN Institute of Applied Physics and Computational Mathematics Beijing 100094China Institute of Mechanics Chinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Thermally-induced flow instabilities are a critical issue in multi-channel regenerative cooling *** particular,the interactions between Density-Wave Oscillations(DWO)and Flow Maldistribution(FMD)can result in complex and disastrous instability *** study investigates the instability behaviors of hydrocarbon fluid in a four-channel system with a constant heat flux ratio using both frequency-and time-domain *** the heat flux increases,the in-tube flow sequentially destabilizes in each channel and converges to new equilibrium states,leading to the emergence of FMD *** also causes the system eigenvalue to change repeatedly from negative to positive rather than increasing ***,the system eigenvalues are between those of the two most unstable channels,indicating that the stability behavior of the entire system is dictated by the most unstable *** FMD occurs,flow oscillations are activated in channels with weak stability,and the in-tube flow is observed to evolve into various flow patterns,including stable flow,self-sustained oscillation,oscillation divergence,quasiperiodic oscillation,and oscillation *** novel instability mode of oscillation excursion involves a spontaneous transition of operating *** oscillates from an equilibrium state and then stabilizes at a new operational state after oscillation-induced ***,the newfound stable state may also be only temporary,with the in-tube flow regressing to the initial state,resulting in quasi-periodic oscillation.

关键词： Cooling Supercritical fluids Hydrocarbons Flow instability Flow maldistribution Density-wave oscillations

Reduction potential of the energy penalty for CO_(2) capture in CCS

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Frontiers in Energy 2023年第3期17卷 390-399页

作者： Yawen ZHENG Lin gao Song HE Hongguang jin Laboratory of Integrated Energy System and Renewable Energy Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

CO_(2) capture and storage(CCS)has been acknowledged as an essential part of a portfolio of technologies that are required to achieve cost-effective long-term CO_(2) ***,the development progress of CCS technologies is far behind the targets set by roadmaps,and engineering practices do not lead to commercial *** of the crucial reasons for this delay lies in the unaffordable penalty caused by CO_(2) capture,even though the technology has been commonly recognized as *** the aspects of separation and capture technology innovation,the potential and promising direction for solving this problem were analyzed,and correspondingly,the possible path for deployment of CCS in China was *** the carbon neutral target recently proposed by the Chinese government,the role of CCS and the key milestones for deployment were indicated.

关键词： CO_(2)capture and storage(CCS) CO_(2)separation energy penalty

Direct and rapid detection of serum amino acid and monoamine neurotransmitters to assist the diagnosis of panic disorder

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Science China Chemistry 2025年第1期 377-384页

作者： Shiwen Liu Xuerui Wan Meng Zhao Jiaqi Wang Weilan wu Linlin You Yonggui Yuan Qian Xu Rong gao Key Laboratory of Environmental Medicine Engineering Ministry of Education School of Public Health Southeast University Key Laboratory of Modern Toxicology of Ministry of Education Department of Hygienic Analysis and Detection School of Public HealthNanjing Medical University Department of Psychosomatics and Psychiatry Zhongda Hospital School of Medicine Southeast University

The measurement of amino acid and monoamine neurotransmitters（NTs） in serum plays a central role in the identification and monitoring of clinical panic disorder（PD）. However, the strong polarity and chemical heterogeneity of NTs make direct extraction and rapid detection extremely challenging. Herein, we developed a strategy that integrated solid phase extraction based on magnetic Fe3O4coated with polydopamine（Fe3O4@PDA） and direct analysis of mass spectrometry in real time（DART-MS） for quantification of 10 NTs. We systematically investigated the optimal conditions of this strategy to achieve good accuracy and precision. Compared with existing magnetic solid phase extraction methods for NTs detection in biological samples, this strategy could adsorb more targets while having similar adsorption efficiencies, and the total process time was reduced by an average of 69.42%. We rapidly determined the metabolic abnormality of 6 types of NTs in the serum of PD patients and demonstrated their diagnostic accuracy. In addition, an outstanding feature of PD in which tryptophan was more metabolized by the KYN pathway and the 5-hydroxytryptamine pathway was inhibited could be elucidated by this strategy. Our results highlighted the potential ability of Fe3O4@PDA coupled with DART-MS to assist in the clinical diagnosis of PD.

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Active flutter suppression of nonlinear fin-actuator system via inverse system and immersion and invariance method

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Chinese Journal of Aeronautics 2024年第4期37卷 343-362页

作者： jin LU Zhigang wu Chao YANG Chinese Aeronautical Establishment Beijing 100029China School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China

Structural nonlinearities such as freeplay will affect the stability and even flight safety of the fin-actuator *** is a lack of a practical method for designing Active Flutter Suppression (AFS) control laws for nonlinear fin-actuator systems.A design method for the AFS controller of the nonlinear all-movable fin-electromechanical actuator system is established by combining the inverse system and the Immersion and Invariance (I&I) ***,the composite control law combining the inverse system principle and internal model control is used to offset the nonlinearity and dynamics of the actuator,so that its driving torque can follow the ideal ***,the ideal torque of the actuator is designed employing the I&I *** unfavorable oscillation of the fin is suppressed by making the output torque of the actuator track the ideal *** simulation results reveal that the proposed AFS method can increase the flutter speed of the nonlinear finactuator system with freeplay,and a set of controller parameters is also applicable for wider freeplay within a certain *** power required for the actuator does not exceed the power that can be provided by the commonly used aviation *** method can also resist a certain level of noise and external disturbance.

关键词： Aeroelasticity Active flutter suppression Fin-actuator system Freeplay Inverse system Immersion and invariance

Simultaneous purification of minor components in natural products using twin-column recycling chromatography with a step solvent gradient

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Chinese Journal of Chemical Engineering 2024年第5期69卷 212-219页

作者： Guangxia jin Yuxue wu Feng Wei School of Biological and Chemical Engineering NingboTech UniversityNingbo 315100China

The isolation of minor components from complex natural product matrices presents a significant challenge in the field of purification science due to their low concentrations and the presence of structurally similar *** study introduces an optimized twin-column recycling chromatography method for the efficient and simultaneous purification of these elusive *** introducing water at a small flowing rate between the twin columns,a step solvent gradient is created,by which the leading edge of concentration band would migrate at a slower rate than the trailing edge as it flowing from the upstream to downstream ***,the band broadening is counterbalanced,resulting in an enrichment effect for those minor components in separation ***,two target substances,which showed similar peak position in high performance liquid chromatography(HPLC)and did not exceed 1.8%in crude paclitaxel were selected as target compounds for *** using the twin-column recycling chromatography with a step solvent gradient,a successful purification was achieved in getting the two with the purity almost 100%.We suggest this method is suitable for the separation of most components in natural produces,which shows higher precision and recovery rate compared with the common lab-operated separation ways for natural products(thin-layer chromatography and prep-HPLC).

关键词： Solvent gradient Twin-column recycling chromatography Purification Minor component Natural products

Self-assembly of InAs quantum dots on GaAs（O01） by molecular beam epitaxy

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Frontiers of physics 2015年第1期10卷 7-58页

作者： Ju wu Peng jin Key Laboratory of Semiconductor Materials Science and Beijing Key Laboratory ofLow-dimensional Semiconductor Materials and Devices Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

Currently, the nature of self-assembly of three-dimensional epitaxial islands or quantum dots （QDs） in a lattice-mismatched heteroepitaxial growth system, such as InAs/GaAs（001） and Ge/Si（001） as fabricated by molecular beam epitaxy （MBE）, is still puzzling. The purpose of this article is to discuss how the self-assembly of InAs QDs in MBE InAs/GaAs（001） should be properly understood in atomic scale. First, the conventional kinetic theories that have traditionally been used to interpret QD self-assembly in heteroepitaxial growth with a significant lattice mismatch are reviewed briefly by examining the literature of the past two decades. Second, based on their own experimental data, the authors point out that InAs QD self-assembly can proceed in distinctly different kinetic ways depending on the growth conditions and so cannot be framed within a universal kinetic theory, and, furthermore, that the process may be transient, or the time required for a QD to grow to maturity may be significantly short, which is obviously inconsistent with conventional kinetic the- ories. Third, the authors point out that, in all of these conventional theories, two well-established experimental observations have been overlooked： i） A large number of ＂floating＂ indium atoms are present on the growing surface in MBE InAs/GaAs（001）; ii） an elastically strained InAs film on the GaAs（001） substrate should be mechanically unstable. These two well-established experimental facts may be highly relevant and should be taken into account in interpreting InAs QD formation. Finally, the authors speculate that the formation of an InAs QD is more likely to be a collective event involving a large number of both indium and arsenic atoms simultaneously or, alternatively, a morphological/structural transformation in which a single atomic InAs sheet is transformed into a three-dimensional InAs island, accompanied by the rehybridization from the sp2-bonded to sp3- bonded atomic configuration of both indium an

关键词： molecular beam epitaxy InAs quantum dots

Graph Properties and Stratified Presentations of Partially Ordered Sets

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Algebra Colloquium 2016年第1期23卷 51-63页

作者： jin Guo Tongsuo wu Department of Mathematics Shanghai Jiaotong University Shanghai 200240 China

In this paper, we introduce some new definitions such as the U＊L＊ condition to describe the zero-divisor graph G = F（P） of a poser P, and give a new and quick proof to a main result in [2, 4]. By deleting a typical vertex with least degree, we provide an algorithm for finding a maximum clique of a finite graph G. We study some properties of the zero-divisor graphs of posets concerning diameters and girths. We also provide stratified presentations of posets.

关键词： poset chromatic number clique number deleting method stratified presentation

Acidic Electrocatalytic Semihydrogenation of Alkynols to Alkenols on Copper Phosphide at Industrial-Level Current Density

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Chinese Journal of Chemistry 2023年第24期41卷 3618-3624页

作者： Sanyin Yang Jun Bu Rui Bai jin Lin Siying An Yafei wu Ying Guo Jie gao Jian Zhang School of Chemistry and Chemical Engineering Northwestern Polytechnical UniversityXi'anShaanxi710129 China State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi'anShaanxi710072 China Interdisciplinary Research Center of Biology & Catalysis School of Life SciencesNorthwestern Polytechnical UniversityXi'anShaanxi710072 China

Alkenols are important intermediates for the industrial manufacture of various commodities and fine *** present,alkenols are produced via thermocatalytic semihydrogenation of corresponding alkynols using precious metal Pd-based catalysts in pressurized hydrogen *** this work,we highlight an efficient electrocatalytic strategy for selectively reducing alkynols to alkenols under ambient *** 2-methyl-3-butyn-2-ol as a model alkynol,Cu3P nanoarrays anchored on Cu foam remarkably deliver an industrial-level partial current density of 0.79 A·cm^(-2) and a specific selectivity of 98%for 2-methyl-3-buten-2-ol in acidic *** a 40-runs stability test,Cu3P nanoarrays maintain 90%alkynol conversion and 90%alkenol *** in a large two-electrode flow electrolyser,the single-pass alkynol conversion and alkenol selectivity of Cu3P nanoarrays exceed 90%.Moreover,this selective electrocatalytic hydrogenation approach is broadly feasible for the production of various water-soluble *** analyses,theoretical simulation and electrochemical in-situ infrared investigations together reveal that exothermic alkynol hydrogenation,facile alkenol desorption and formation of active H on Cu3P surfaces account for the excellent electrocatalytic performance.

关键词： Alkynol Alkenol Cu_(3)P nanoarrays Electrocatalysis Semihydrogenation Mass spectrometry IR spectroscopy Heterogeneous catalysis