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Rational surface charge engineering of haloalkane dehalogenase for boosting the enzymatic performance in organic solvent solutions

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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

Advancing from scalar to vectorial liquid crystal holography:a paradigm shift

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Light(Science & Applications) 2024年第9期13卷 1696-1697页

作者： yan Li Shin-Tson wu Department of Electronic Engineering Shanghai Jiao Tong UniversityShanghai 200240China College of Optics and Photonics University of Central FloridaOrlandoFL 32816USA

A versatile and tunable vectorial holography is demonstrated based on single-layer single-material liquid crystal *** novel approach advances the process from scalar to vectorial holography,opening new opportunities f... 详细信息

关键词： liquid crystal versatile

Impact of Polymer Matrix on Polymer Mechanochromism from Excited State Intramolecular Proton Transfer

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Chinese Journal of Chemistry 2024年第6期42卷 611-616页

作者： Yu wu Xin Cheng Huan Hu shui Hu Zhimin Ma Zhiyong Ma Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing State Key Laboratory of Organic-Inorganic CompositesCollege of Chemical EngineeringBeijing University of Chemical TechnologyBeijing100029 China Center of Advanced Elastomer Materials College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing100029 China College of Engineering Peking UniversityBeijing100871 China

Mechanochromic polymers based on non-covalent changes have attracted much attention ***,we report the impact of inter/intramolecular hydrogen bonds on polymer mechanochromism from the excited state intramolecular proton transfer (ESIPT) ***-NH2-OH and PhMz=2A are designed and obtained by simple and high-yield synthesis,and are connected into polyurethane and poly(methyl acrylate-co-2-ethylhexyl acrylate),*** the initial state,the PhMz-NH2-OH@PU sample shows blue fluorescence from the excited enol form (E*) excitons,owing to intermolecular hydrogen bonds that interrupt the ESIPT reactions but the PhMz=2A@PMA-2-EA sample expresses cyan fluorescence belonging to the excited keto form (K*) emission,implying that the intramolecular hydrogen bonds ***,under stretching,external force can tune the emission of the PhMz=2A@PMA-2-EA sample from K* to E* *** external force can putatively still promote a bond rotation,ESIPT reactions remain equivalently interrupted in both the relaxed and stressed states in a hydrogen-bond donating *** calculation confirms the force-induced increase in dihedral angle for the transition of ESIPT-on/***,PhMz-NH2-OH@PU and PhMz=2A@PMA-2-EA showed disparate initial ESIPT states and further different responses/sensitivity to *** study reports a novel and efficient strategy for enriching mechanochromic investigation and extending the applications of ESIPT reactions.

关键词： Polymer mechanochromism Excited state intramolecular proton transfer Hydrogen bonding Supramolecular chemistry Elastomers

Unlocking the Potential of Poly(butylene succinate)through Incorporation of Vitrimeric Network Based on Dynamic Imine Bonds

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Chinese Journal of Polymer Science 2024年第10期42卷 1414-1424,I0006页

作者： Shan-Song wu Hui-Juan Lu Yi-Dong Li shui-Dong Zhang Jian-Bing Zeng Chongqing Key Laboratory of Soft-Matter Material Manufacturing School of Chemistry and Chemical EngineeringSouthwest UniversityChongqing400715China School of Mechanical and Automotive Engineering South China University of TechnologyGuangzhou510640China

Poly(butylene succinate)(PBS)exhibits many advantages,such as renewability,biodegradability,and impressive thermal and mechanical properties,but is limited by the low melt viscosity and strength resulted from the linear *** address this,vitrimeric network was introduced to synthesize PBS vitrimers(PBSVs)based on dynamic imine bonds through melt polymerization of hydroxyl-terminated PBS with vanillin derived imine containing compound and hexamethylene diisocyanate using trimethylolpropane as a crosslinking *** with different crosslinking degrees were synthesized through changing the content of the crosslinking *** effect of crosslinking degree on the thermal,theological,mechanical properties,and stress relaxation behavior of the PBSVs was studied in *** results demonstrated that the melt viscosity,melt strength,and heat resistance were enhanced substantially without obvious depression in crystallizability,thermal stability,and mechanical properties through increasing crosslinking *** addition,the PBSVs exhibit thermal reprocessability with mechanical properties recovered by more than 90%even after processing for three ***,PBSV with improved melt properties shows significantly improved foamability compared to commercial *** research contributes to the advancement of polymer technology by successfully developing PBS vitrimers with improved properties,showcasing their potential applications in sustainable and biodegradable materials.

关键词： Poly(butylene succinate) Vitrimer Imine bonds Foamability

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 encountered 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

Precontrol of short-period motion for a Tension Leg Platform

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Journal of Ocean Engineering and Science 2024年第3期9卷 264-277页

作者： Hao wu yan Lin Yongxi wu School of Mechatronic Engineering and Automation Shanghai UniversityShanghai 200444China Department of Naval Architecture Dalian University of TechnologyDalian 116023China State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian 116023China School of Mechanics and Engineering Science Shanghai UniversityShanghai 200444China

The Tension Leg Platform(TLP)is a hybrid,compliant platform designed to sustain springing and ringing responses that are correlated to short-period *** the period of short-period motion is within the wave energy concentration region,TLPs may experience sensitive short-period motion,such as resonance and green water,that usually cause serious damage to *** this study,a precontrol methodology is presented as a solution to prevent TLP-sensitive short-period *** applying the precontrol methodology,the parameters of TLP can be predetermined,allowing TLP motion performance to meet the requirements of short-period motion before sensitive motions actually *** example,the damping coefficient should be less than 4.3,the tendons’stiffness should be larger than 0.91×10^(8),and the dimensionless draft should be less than *** development of a precontrol methodology is based on a solid theoretical ***,a series of simple and high-fidelity numerical models are proposed to simulate the natural period of roll,natural period of heave,and green water ***,a constraint regime is generated based on the numerical models and the sensitive motion range of short-period *** constraint regime is divided into two parts:the control range(corresponding to sensitive shortperiod motion)and the feasible range(the complementary set of control ranges in the whole parameter constraint domain).Finally,TLP parameters are derived from the calculated feasible *** precontrol methodology goes beyond the conventional approach of real-time control by changing the control from a remedial action to a preventive action.

关键词： Precontrol Constraint regime Short-period motion TLP

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