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chinese Journal of chemical Engineering 2024年第1期65卷 276-285页

作者： Yin wu yan Sun Department of Biochemical Engineering School of Chemical Engineering and Technology and Key Laboratory of Systems Bioengineering and Frontiers Science Center for Synthetic Biology(Ministry of Education)Tianjin UniversityTianjin 300350China

Biocatalysis in organic solvents(OSs)has numerous important applications,but native enzymes in OSs often exhibit limited catalytic ***,we proposed a computation-aided surface charge engineering strategy to improve the catalytic performance of haloalkane dehalogenase DhaA in OSs based on the energetic analysis of substrate binding to the DhaA *** variants with enhanced OS resistance were obtained by replacing negative charged residues on the surface with positive charged residue(Arg).Particularly,a four-substitution variant E16R/E93R/E121R/E257R exhibited the best catalytic performance(five-fold improvement in OS resistance and seven-fold half-life increase in 40%(vol)dimethylsulfoxide).As a result,the overall catalytic performance of the variant could be at least 26 times higher than the wild-type *** spectroscopy and molecular dynamics simulation studies revealed that the residue substitution mainly enhanced OS resistance from four aspects:(a)improved the overall structural stability,(b)increased the hydrophobicity of the local microenvironment around the catalytic triad,(c)enriched the hydrophobic substrate around the enzyme molecule,and(d)lowered the contact frequency between OS molecules and the catalytic *** findings validate that computationaided surface charge engineering is an effective and ingenious rational strategy for tailoring enzyme performance in OSs.

关键词： Surface charge engineering Organic solvent resistance Molecular dynamics simulation Haloalkane dehalogenase

Numerical Investigation on characteristics of Supercritical cO_(2)Heat Transfer in Vertical circular Tubes with circumferentially Half-Side Heating

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Journal of Thermal Science 2024年第5期33卷 1744-1756页

作者： ZHANG yan ZHANG Xinyi yan chenshuai wu Wenhua GAO Erman School of Energy and Power Engineering Northeast Electric Power UniversityJilin 132012China

The design of heat exchangers in the advanced supercritical power conversion system cannot be separated from the study of heat transfer ***-side heating mode is often enc.untered for solar receiver and supercritical ***,the characteristics of supercritical cO_(2)(scO_(2))convection heat transfer in vertical tubes with circumferentially half-side heating was numerically investigated through the SST k-ωturbulent model which matches well with the experimental ***,heat transfer between scO_(2)upflow and downflow was *** to film boiling heat transfer at subcritical pressure,numerical results were processed according to the supercritical pseudo-phase transition hypothesis,with liquid-like phase in the tube core region and vapor-like film in the region near the heated tube *** structure of two layers was demarcated by pseudo-critical temperature T_(pc).Therefore,scO_(2)heat transfer was assessed according to double thermal resistances caused by vapor-like film near the wall and core liquid-like *** findings suggest that wall temperature for upflow is higher than that for downflow,which is attributed to larger thermal resistance in the fluid domain for upflow than that for *** difference guarantees the excellent heat transfer performance for downflow than *** is also further concluded that the formation of vapor-like film near the wall due to pseudo-phase transition plays a key role in dominating wall temperature and inducing heat transfer deterioration in half-side heating *** present contribution is significant to the design of supercritical heat exchanger under half-side heating mode.

关键词： supercritical cO_(2) pseudo-phase transition half-side heating thermal resistance flow direction

Global-local combined features to detect pain intensity from facial expression images with attention mechanism

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Journal of Electronic Science and Technology 2024年第3期22卷 80-93页

作者： Jiang wu Yi Shi Shun yan Hong-Mei yan yangtze Delta Region Institute(Huzhou) University of Electronic Science and Technology of ChinaHuzhou313001China MOE Key Laboratory for Neuroinformation School of Life Science and TechnologyUniversity of Electronic Science and Technology of ChinaChengdu611731China college of Engineering University of California at Santa BarbaraSanta Barbara93106USA

The estimation of pain intensity is critical for medical diagnosis and treatment of *** the development of image monitoring technology and artificial intelligence,automatic pain assessment based on facial expression and behavioral analysis shows a potential value in clinical *** paper reports a framework of convolutional neural network with global and local attention mechanism(GLA-cNN)for the effective detection of pain intensity at four-level thresholds using facial expression ***-cNN includes two modules,namely global attention network(GANet)and local attention network(LANet).LANet is responsible for extracting representative local patch features of faces,while GANet extracts whole facial features to compensate for the ignored correlative features between *** the end,the global correlational and local subtle features are fused for the final estimation of pain *** under the unBc-McMaster Shoulder Pain database demonstrate that GLA-cNN outperforms other state-of-the-art ***,a visualization analysis is conducted to present the feature map of GLA-cNN,intuitively showing that it can extract not only local pain features but also global correlative facial *** study demonstrates that pain assessment based on facial expression is a non-invasive and feasible method,and can be employed as an auxiliary pain assessment tool in clinical practice.

关键词： Attention convolutional neural network Facial expression Pain intensity

Selection Method for New Energy Output Guaranteed Rates considering Optimal Energy Storage configuration

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cSEE Journal of Power and Energy Systems 2024年第2期10卷 539-547页

作者： Xin cheng Tong wu Wei Yao yan yang Guangdong Power Grid corporation Guangzhou 510620China State Key Laboratory of Advanced Electromagnetic Engineering and Technology and School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The output of new energy represented by wind power and photovoltaic power features volatility and randomness. It is a practical approach to use the guaranteed rate with statistical characteristics to analyze the output coefficient of new energy. However, there is a lack of analysis and demonstration on the value of the new energy output guaranteed rate. To solve this problem, a selection method for the new energy output guaranteed rate considering optimal energy storage configuration is proposed. First, the influence of the new energy output guaranteed rate on the new energy output coefficient is analyzed. Secondly, with the goal of minimizing the comprehensive costs, an optimal configuration model of energy storage based on the output guaranteed rate of new energy is constructed, and particle swarm optimization is used for the optimization solution. Then, according to the optimal energy storage configuration results under different guaranteed rates, a reasonable new energy output guaranteed rate is determined by maximizing the comprehensive benefits obtained from energy storage. Finally, an example applied to the power grid in an area of Guangdong in Southern china is provided to illustrate the effectiveness of the proposed method.

关键词： Energystorage optimization guaranteed output guaranteed rate new energy consumption

Resource allocation for D2D-assisted haptic communications

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Digital communications and Networks 2024年第1期10卷 63-74页

作者： yan wu chao Yue yang yang Liang Ao college of Telecommunication Engineering Army Engineering University of PLANanjing210000China

Haptic communications is recognized as a promising enabler of extensive services by enabling real-time haptic control and feedback in remote environments,e.g.,teleoperation and autonomous *** the strict transmission requirements on reliability and latency,Device-to-Device(D2D)communications is introduced to assist haptic *** particular,the teleoperators with poor channel quality are assisted by auxiliaries,and each auxiliary and its corresponding teleoperator constitute a D2D ***,the haptic interaction and the scarcity of radio resources pose severe challenges to the resource allocation,especially facing the sporadic packet ***,the contentionbased access scheme is applied to achieve low-latency transmission,where the resource scheduling latency is omitted and users can directly access available *** this context,we derive the reliability index of D2D pairs under the contention-based access scheme,i.e.,closed-loop packet error ***,the reliability performance is guaranteed by bidirectional power control,which aims to minimize the sum packet error probability of all D2D *** game theory is introduced to solve the problem with low ***,a distributed power control algorithm based on synchronous log-linear learning is proposed to converge to the optimal Nash *** results demonstrate the superiority of the proposed learning algorithm.

关键词： Haptic communications D2D Power control contention-based access Potential game

Mixing effects of high-speed jets in gas-solid riser and downer reactors

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Particuology 2024年第9期92卷 196-209页

作者： Zihan yan Dongdong Wang Lining wu c.unxi Lu college of chemical Engineering and Environment State Key Laboratory of Heavy Oil ProcessingChina University of Petroleum-BeijingBeijing102249China

For the high-temperature and short-contact time gas-solid reaction process,riser and downer are considered appropriate *** realize an intensive and complete mixing of reactants with catalysts,the feed raw is always introduced in the form of high-speed *** this study,in order to investigate the mixing effects of different types of high-speed jets in riser and downer,traceable ozone is injected with the high-speed feed jets to react with catalyst *** detecting the decomposition of ozone,the gas-solid mixing and reaction in riser and downer under the influence of both co-current and c.unter-current injections are *** relative ozone concentration is used to reflect the location reaction extent and its radial nonuniformity index is proposed to compare the results in riser and *** is found that the jet influence zone in downer provides a relatively better environment for the mixing of feed jets with *** the riser,introduction of c.unter-current injections could improve the uniformity of gas-solid mixing in the initial contact region of feed with catalysts.

关键词： Riser Downer Gas-solid two-phase flow Jet

Porous silica nano-flowers stabilized Pt-Pd bimetallic nanoparticles as heterogeneous catalyst for efficiently synthesizing guaiacol from 2-methoxycyclohexanol

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chinese Journal of chemical Engineering 2024年第6期70卷 222-233页

作者： Junbo Feng Junyan wu Dongdong yan Yadong Zhang School of chemical Engineering Zhengzhou UniversityZhengzhou 450001China State Key Laboratory of coking coal Exploitation and comprehensive Utilization Pingdingshan 467000China Jiyuan Research Institute Zhengzhou UniversityJiyuan 459000China School of Materials and chemical Engineering Zhongyuan University of TechnologyZhengzhou 450007China

Porous silica nano-flowers(Kcc-1)immobilized Pt-Pd alloy NPs(Pt-Pd/Kcc-1)with different mass ratios of Pd and Pt were successfully prepared by a facile in situ one-step reduction,using hydrazinium hydroxide as a reducing *** as-synthesized silica nanospheres possess radial fibers with a distance of 15 nm,exhibiting a high specific surface area(443.56 m^(2)·g^(-1)).Meanwhile,the obtained Pt-Pd alloy NPs are uniformly dispersed on the silica surface with a metallic particle size of 4-6 nm,which exist as metallic Pd and Pt on the surface of monodisperse Kcc-1,showing the transfer of electrons from Pd to *** as-synthesized 2.5%Pt-2.5%Pd/Kcc-1 exhibited excellent catalytic activity and stability for the continuous dehydrogenation of 2-methoxycyclohexanol to prepare *** with Pt or Pd single metal supported catalysts,the obtained 2.5%Pt-2.5%Pd/Kcc-1 shows 97.2%conversion rate of 2-methoxycyclohexanol and 76.8%selectivity for guaiacol,which attributed to the significant synergistic effect of bimetallic Pt-Pd alloy ***,turn over frequency value of the obtained 2.5%Pt-2.5%Pd/Kcc-1 NPs achieved 4.36 s^(-1),showing higher catalytic efficiency than other two monometallic *** pathways of dehydro-aromatization of 2-methoxycyclohexanol over the obtained catalyst are ***,the obtained 2.5%Pt-2.5%Pd/Kcc-1 NPs prove their potential in the dehydrogenation of 2-methoxycyclohexanol,while the kinetics and mechanistic study of the dehydrogenation reaction over the catalyst in a continuous fixed-bed reactor may provide valuable information for the development of green,outstanding and powerful synthetic pathway of guaiacol.

关键词： Supported catalyst Nanoparticles Dehydrogenation 2-Methoxycyclohexanol Guaiacol

Multi-blade rubbing characteristics of the shaft-disk-blade-casing system with large rotation

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 111-136页

作者： Zhiyuan wu Linchuan ZHAO Han yan Ge yan Ao cHEN Wenming ZHANG State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Institute of Aerospace Systems Engineering Shanghai 201108China

Blade rubbing faults cause detrimental impact on the operation of aeroengines. Most of the existing studies on blade rubbing in the shaft-disk-blade-casing(SDBc) system have overlooked the elastic deformation of the blade, while some only consider the whirl of the rotor, neglecting its spin. To address these limitations, this paper proposes a dynamic model with large rotation for the SDBc system. The model incorporates the spin and whirl of the rotor, enabling the realistic reproduction of multiblade rubbing faults. To verify the accuracy of the SDBc model with large rotation and demonstrate its capability to effectively consider the rotational effects such as the centrifugal stiffening and gyroscopic effects, the natural characteristics and dynamic responses of the proposed model are compared with those obtained from reported research and experimental results. Furthermore, the effects of the rotating speed, contact stiffness,and blade number on the dynamic characteristics of the SDBc system with multi-blade rubbing are investigated. The results indicate that the phase angle between the rotor deflection and the unbalance excitation force increases with the increasing rotating speed,which significantly influences the rubbing penetration of each blade. The natural frequency of the SDBc system with rubbing constrain can be observed in the acceleration response of the casing and the torsional response of the shaft, and the frequency is related to the contact stiffness. Moreover, the vibration amplitude increases significantly with the product of the blade number under rubbing, and the rotating frequency approaches the natural frequency of the SDBc system. The proposed model can provide valuable insight for the fault diagnosis of rubbing in bladed rotating machinery.

关键词： shaft-disk-blade-casing(SDBc) large rotation spin and whirl multi-blade rubbing rotational effect

Advances of Electrochemical and Electrochemiluminescent Sensors Based on covalent Organic Frameworks

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Nano-Micro Letters 2024年第2期16卷 395-422页

作者： Yue cao Ru wu yan‑yan Gao yang Zhou Jun‑Jie Zhu Key Laboratory for Organic Electronics and Information Displays(KLOEID)and Institute of Advanced Materials(IAM) Nanjing University of Posts and Telecommunications(NJUPT)Nanjing 210023People’s Republic of China State Key Laboratory of Analytical chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023People’s Republic of China

covalent organic frameworks(cOFs),a rapidly developing category of crystalline conjugated organic polymers,possess highly ordered structures,large specific surface areas,stable chemical properties,and tunable pore *** the first report of boroxine/boronate ester-linked cOFs in 2005,cOFs have rapidly gained popularity,showing important application prospects in various fields,such as sensing,catalysis,separation,and energy *** them,cOFs-based electrochemical(Ec)sensors with upgraded analytical performance are arousing extensive *** this review,therefore,we summarize the basic properties and the general synthesis methods of cOFs used in the field of electroanalytical chemistry,with special emphasis on their usages in the fabrication of chemical sensors,ions sensors,immunosensors,and ***,the emerged cOFs in the electrochemiluminescence(EcL)realm are thoroughly covered along with their preliminary ***,final conclusions on state-of-the-art cOFs are provided in terms of Ec and EcL sensors,as well as challenges and prospects for extending and improving the research and applications of cOFs in electroanalytical chemistry.

关键词： covalent organic frameworks Electrochemistry Electrochemiluminescence Sensors

cobalt doping amount determines dominant reactive species in peroxymonosulfate activation via porous carbon catalysts co-doped by cobalt and nitrogen

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Journal of Environmental Sciences 2024年第4期138卷 212-226页

作者： Xiang Li Limeng wu Aiqin Zhang Shaohua wu yan Lin c.unping yang Key Laboratory of Jiangxi Province for Persistent Pollutants control and Resources Recycle Nanchang Hangkong UniversityNanchang 330063China Academy of Environmental and Resource Sciences School of Environmental Science and EngineeringGuangdong University of Petrochemical TechnologyMaoming 525000China college of Environmental Science and Engineering Hunan University and Key Laboratory of Environmental Biology and Pollution Control(Hunan University)Ministry of EducationChangsha 410082China

Switching the reaction routes in peroxymonosulfate(PMS)-based advanced oxidation processes have attracted much attention but remain ***,a series of co-N/c catalysts with different compositions and structures were prepared by using bimetallic zeolitic imidazolate frameworks based on ZIF-8 and ZIF-67(x Zn/co-ZIFs).Results show that co doping amount could mediate the transformation of the activation pathway of PMS over coN/*** co doping amount was less than 10%,the constructed x co-N/c/PMS system(x≤10%)was singlet oxygen-dominated reaction;however further increasing co doping amount would lead to the generation and coexistence of sulfate radicals and high-valent cobalt,besides singlet ***,the nitrogen-coordinated co(co-NX)sites could serve as main catalytically active sites to generate singlet *** excess co doping amount caused the formation of co nanoparticles from which leached co ions were responsible for the generation of sulfate radicals and high-valent *** to undoped N/c,co doping could significantly enhance the catalytic *** 0.5%co-N/c could achieve the optimum degradation(0.488 min^(-1))and mineralization abilities(78.4%)of sulfamethoxazole among the investigated co-N/c catalysts,which was superior to most of previously reported *** addition,the application prospects of the two systems in different environmental scenarios(pH,inorganic anions and natural organic matter)were assessed and showed different degradation *** study provides a strategy to regulate the reactive species in PMS-based advanced oxidation process.

关键词： Peroxymonosulfate Sulfate radical Singlet oxygen cobalt Zeolitic imidazolate framework Advanced oxidation process