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Structure-guided protein design of fluoroacetate dehalogenase for kinetic resolution of rac-2-bromobutyric acid

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Green Synthesis and Catalysis 2020年第1期1卷 60-65页

作者： Shu Wang Zhanbing Cheng Yanbing Xu Lu Yang Jian-Bo Wang Zhenhua Tian Xudong Qu Shanghai R&D Center Abiochem Co.Ltd.Shanghai 200241China State Key Laboratory of Microbial Metabolism School of Life Sciences and BiotechnologyShanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of Phytochemistry R&D of Hunan Province and Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research(Ministry of Education)College of Chemistry and Chemical EngineeringHunan Normal UniversityChangsha 410081China

r-2-Bromobutyric acid is a very important intermediate for the synthesis of agrochemicals and *** of rac-2-bromobutyric acid(rac-2-BBA)provides a promising process for r-2-bromobutyric acid(r-2-BBA)*** fluoroacetate dehalogenase(FAcd)has been always studied in the defluorination *** found that FAcd rPA1163 showed detectable activity but no enantioselectivity towards *** iterative saturation mutagenesis(ISM)of FAcd rPA1163 resulted in a mutant H155V/W156r/Y219M,which catalyzed the kinetic resolution of rac-2-BBA to produce r-2-BBA with enhanced activity and enantioselectivity(99.3%ee).The high preference for S-2-bromobutyric acid(S-2-BBA)is of synthetic *** docking analysis indicated that the H155V/W156r/Y219M mutation reduced steric hindrance and broadened the halide *** is not only the steric hindrance but also the electrostatic environment that has an effect on the activity and enantioselectivity.

关键词： Fluoroacetate dehalogenase Semi-rational design Enzyme engineering Kinetic resolution 2-bromobutyric acid

Study on Vapor-Liquid Equilibrium and Microscopic Properties of Glycine + H2o, L-Histidineand + H2o and L-Tryptophan + H2o

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SSrN 2023年

作者： Li, Xia Liu, Weiping Yin, Yahui Zhou, Yu Xu, Xianzhen Xiang, Hongfei College of Chemistry and Chemical Engineering Qingdao Application Technology Innovation Center of Photoelectric Biosensing for Clinical Diagnosis and Treatment Shandong Sino-Japanese Center for Collaborative Research of Carbon Nanomaterials Qingdao University Shandong Qingdao266071 China Qingdao Marine Hydrogen Equipment Technology Innovation Center Qingdao Boting Hydrogen Age Ocean Technol R&D Ctr Qingdao Boting Technol Co Ltd Shandong Hydrogen Times Marine Technology Co Ltd Shandong Qingdao266100 China Department of Orthopedics Affiliated Hospital of Qingdao University Shandong Qingdao266003 China

Vapor-liquid equilibrium (VLE) is essential for separation processes such as distillation and absorption in chemical production. In this work, the VLE of glycine, L-histidine and L-tryptophan aqueous solutions was measured at pressures ranging from 5.3 kPa to 101.1 kPa. The NrTL model was used, which has been successfully correlated with VLE data at temperatures between 298.15 K and 373.85 K, and the model parameters were obtained. In addition, the absorption peaks of three amino acid aqueous solutions were analyzed by Fourier transform infrared spectroscopy (FTIr) from a microscopic perspective. The results showed that the higher the solubility of amino acid in water, the stronger the hydrogen bond interaction with water. Furthermore, the total mean interaction energy of water in the systems was studied by coSMOthermX. Based on the calculations, the total mean interaction energy was little affected by concentration. The structure–activity relationship was established between the microscopic interactions and the macroscopic VLE. © 2023, The Authors. All rights reserved.

关键词： Amino acids

development of an Energetic System Model for Long-Tail Electric Boat combining Solar Panels and a Prototype of E-Engine

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Development of an Energetic System Model for Long-Tail Elect...

International conference on Electrical Machines and Systems (ICEMS)

作者： d. Pham Hung V. Tran Tuan S. Kreuawan S. Udomkaew M. Phattanasak Q. Nguyen duc School of Electrical & Electronic Engineer. Hanoi University of Science and Technology Hanoi Vietnam R&D Department Real BPM Co. Ltd. Samutsakorn Thailand Faculty of Technical Education King Mongkut’s University of Technology Bangkok Thailand Department of Electrical Engineering Electric Power University Hanoi Vietnam

ISBN: (数字)9781665493024

ISBN: (纸本)9781665493031

This paper proposes the prototype of e-tail and the energetic system model for all electric long-tail boat equipping with solar panels. It offers many advantages over a traditional internal combustion engine (ICE) propulsion system, thanks to the combination of the electric powertrain and the solar panel. Besides low noise and zero-emission, characteristics of electric engine allow regenerative braking and starting the propeller in the water. The prototype of e-tail is presented. The energetic system model is built to sizing optimally the battery capacity depending on the consumption of the e-tail boat driven by the e-engine. The simulations results are performed on a testcase of Phong Nha cave tourism boat. With 5 solar panels and 4 kWh of battery capacity, the boat can operate independently without external power source at least 1 round-trip 4 days in a week in winter and maximum 2 trips per day every day in summer.

关键词： Water resistors Propellers Simulation Boats Prototypes Quality of service

Exclusively catalytic oxidation of toluene to benzaldehyde in an O/W emulsion stabilized by hexadecylphosphate acid terminated mixed-oxide nanoparticles

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Chinese Journal of Catalysis 2020年第2期41卷 341-349页

作者： Changshun deng Mengxia Xu Zhen dong Lei Li Jinyue Yang Xuefeng Guo Luming Peng Nianhua Xue Yan Zhu Weiping ding Key Laboratory of Mesoscopic Chemistry School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210093JiangsuChina Luoyang R&D Center of Technology Sinopec Engineering(Group)Co.Ltd.Luoyang 471003HenanChina

A series of hexadecylphosphate acid(HdPA) terminated mixed-oxide nanoparticles have been investigated to catalyze the oxidation of toluene exclusive to benzaldehyde under mild conditions in an emulsion of toluene/water with the catalysts as stabilizers. With the HdPA-Fe2 O3/Al2 O3 as the basic catalyst, a series of transition metals, such as Mn, co, Ni, Cu, Cr, Mo, V, and Ti, was respectively doped to the basic catalyst to modify the performance of the catalytic system, in expectation of influencing the mobility of the lattice oxygen species in the oxide catalysts. Under normally working conditions of the catalytic system, the nanoparticles of catalysts located themselves at the interface between the oil and water phases, constituting the Pickering emulsion. Both the doped iron oxide and its surface adsorbed hexadecylphosphate molecules were essential to the catalytic system for excellent performances with high toluene conversions as well as the exclusive selectivity to benzaldehyde. Under optimal conditions, ~83% of toluene conversion and >99% selectivity to benzaldehyde were obtained, using molecular oxygen as oxidant and HdPA-(Fe2 O3-Ni O)/Al2 O3 as the catalyst. This process is green and low cost to produce high quality benzaldehyde from O2 oxidation of toluene.

关键词： Toluene oxidation Benzaldehyde Hexadecylphosphate acid Molecular oxygen Pickering

Achieving Low-Temperature Tensile ductility in a Swaged W-Y2o3 Alloy

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SSrN 2022年

作者： Fan, Feng Jianbao, Wang Youyun, Lian Xiao, Chen Yingmin, Wang Jiupeng, Song Xiang, Liu Southwestern Institute of Physics Chengdu China Key Laboratory of Materials Modification by Laser Ion and Electron Beams Dalian University of Technology Dalian China China National R&D Center for Tungsten Technology Xiamen Tungsten Co. Ltd Xiamen China School of Materials Science and Engineering Xihua University Chengdu China

The low temperature brittleness of tungsten (W)-based materials has been a long standing problem for their practical applications. In this study, bulk W-Y 2 O 3 alloy rods of 12 mm in diameter were prepared by industrial hydrogen sintering and temperature-controlled rotary swaging. The swaged W-Y 2 O 3 alloy contains a low content of gas impurities ( texture in the grain structure. At room temperature, the alloy exhibits pronounced yielding and a certain uniform plastic deformation on tensile loading along the axial direction of the rod, and evident bending ductility as well. The mechanical properties of the swaged W-Y 2 O 3 alloy are superior to the known bulk W-based alloys in the temperature range from room temperature to 200 ℃. The excellent room temperature plastic deformation ability of swaged tungsten alloy is originated from its special texture and bimodal grain structure features, which results in grain boundary separation than blocks effective the cracking on tensile loading along the [110] texture direction. © 2022, The Authors. All rights reserved.

关键词： Temperature

HELPS for Emergency Location Service: Hyper-Enhanced Local Positioning System

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arXiv

arXiv 2024年

作者： Moon, Hichan Park, Hyosoon Seo, Jiwon The Department of Electronic Engineering Hanyang University Seoul Korea Republic of Seoul Korea Republic of Stanford University StanfordCA United States Samsung Electronics Co. Korea Republic of Infoseize Systems Co. Seoul Korea Republic of Yonsei University Korea Republic of The Network Business Division R&D team Samsung Electronics Ltd. Korea Republic of The School of Integrated Technology Yonsei University Incheon Korea Republic of Pohang Korea Republic of Daejeon Korea Republic of

In this study, we propose a novel positioning and searching system for emergency location services, namely the hyper-enhanced local positioning system (HELPS), which is applicable to all mobile phone users, including legacy feature phone users. In the case of an emergency, rescuers are dispatched with portable signal measurement equipment around the estimated location of the emergency caller. Each signal measurement device measures the uplink signal from the mobile phone of the caller. After calculating the rough location of the caller’s mobile phone based on these measurements, rescuers can efficiently search for the caller using the received uplink signal strength. Thus, the positioning accuracy in a conventional sense is not a limitation for rescuers in finding the caller. HELPS is not a traditional positioning system but rather a system with humans in the loop designed to reduce search time in emergencies. HELPS can provide emergency location information even in environments where the GPS or Wi-Fi is not functional. Furthermore, for HELPS operation, no hardware changes or software installations are required on the caller’s mobile phone. copyright © 2024, The Authors. All rights reserved.

关键词： Global positioning system

core-Shell Cu@Al2o3 Fillers for Enhancing Thermal conductivity and retaining Electrical Insulation of Epoxy composites

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SSrN 2022年

作者： Wang, Zelong Zhang, Yanan Yi, Jungang Cai, Ning Guo, Jia Key Laboratory for Green Chemical Process of Ministry of Education School of Chemical Engineering and Pharmacy Wuhan Institute of Technology Wuhan430073 China Hunan Green Automotive Coatings Engineering Technology Center R&D Department Hunan Xiangjiang Kansai Paint Co. Ltd. Changsha410100 China College of Chemistry and Chemical Engineering Huanggang Normal University Huanggang438000 China

Heat accumulation has emerged as a critical issue that affects the performance and reliability of modern electronic devices in their evolving toward miniaturization, high power density and high integration. The application of thermally interface materials (TIMs) as a thermal management strategy is commonly employed to tackle this problem. Herein, we report highly thermally conductive but electrically insulating Cu@Al2O3/epoxy composites. Stemming from the excellent thermal conductivity of Cu, the Cu@Al2O3/epoxy composites exhibit thermal conductivity of 1.32 W/m·K at 10 vol% filler content, which is nearly 7 times higher than that of the epoxy resin. Simultaneously, the Cu@Al2O3/epoxy composites still retain a high electrical resistivity of 2.3×1013 Ω·cm, which is 6 orders of magnitude greater than that of Cu/epoxy composites without Al2O3 barrier layers, because the dense nanoscale insulating Al2O3 shell effectively inhibits the electron transfer. In addition, the Cu@Al2O3/epoxy composites possess lower dielectric constant and dielectric loss, and better mechanical properties than those of unmodified Cu/epoxy composites. The epoxy composites filled with core-shell structured Cu@Al2O3 particles have high thermal conductivity and outstanding electrical insulation, which are potential TIMs for advanced electronic thermal management. © 2022, The Authors. All rights reserved.

关键词： Epoxy composites

SO 3 Li-grafted ion-conducting agents for graphite-based lithium-ion batteries with extended cycle life

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Chinese Chemical Letters 2025年

作者： Shijie Liao dongming Cheng Xinyan Xu Qiyue Li Shengzhe Xu Jianchao Zhang Helei Wei Ying Wei Qi Li Kai Li Zihan Long Yuanyuan Luo Yunhui Huang Mingfeng Tan Bo Lin Henghui Xu School of Materials Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China Global R&D Center Guangxi Liugong Metathings Technology Co. Ltd. Liuzhou 545007China

Graphite, the most widely used anode material in lithium-ion batteries, faces significant limitations due to sluggish lithium-ion diffusion across the conventional organic solid electrolyte interphase (SEI) during cycling. In this work, we propose the incorporation of SO 3 Li-grafted graphene as an ion-conducting agent (ICA) to enhance lithium-ion transport kinetics within graphite anodes. The –SO 3 Li functional groups regulate the Li + solvation structure through anion-solvent dipole interactions, promoting the formation of a lithium fluoride (LiF)-rich SEI that ensures uniform lithium-ion flux and significantly extends battery cycle life. This SO 3 Li-grafted ICA also mitigates mechanical strain within the graphite anode during repeated cycling, improving structural integrity over long-term operation, evidenced by fiber optic sensing technology. As a result, a 3 Ah Gr||LiFePO 4 pouch cell incorporating this functionalized ion-conducting agent achieves excellent cycling performance, retaining 86.4% of its capacity after 1200 cycles at 1 C. These findings demonstrate the effectiveness of functionalized ICAs in addressing the intrinsic limitations of graphite, providing a promising strategy for developing long-life lithium-ion batteries for practical energy storage applications.

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High-Frequency Loss Analysis and related Magnetic Properties of Fe-Based Amorphous Soft Magnetic composites with different Granularity Matches

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SSrN 2022年

作者： Sun, Haibo Zhu, Feng Zhou, Guohua Zong, Changbao Wang, Jinghui School of Materials Science and Energy Engineering Foshan University Foshan528000 China Product R&D Center China Amorphous Technology CO. LTD Foshan528241 China Physical Science and Technology College Yichun University Yichun336000 China Intelligent Manufacturing Institute Foshan Polytechnic Foshan528137 China

The regulation mechanism of comprehensive soft magnetic properties for the Fe-based amorphous powder cores with different granularity match schemes used in high-frequency applications were investigated in detail. Herein, the FeSiBCCr amorphous particles with three different average diameters of 2.20 μm (P1), 12.52 μm (P2), and 27.65 μm (P3) were employed. Based on the establishment of loss separation model, the total core loss ( P cv , at 25-900 kHz, 0.1 T) was divided into hysteresis loss P h , eddy current loss P e , and residual loss P r . The particle size matching, which can directly affect the core’s density under constant parameters, has a significant impact on the magnetic properties of powder cores. With the increase in the density induced by varying granularity match scheme, the real-part of complex permeability μ' increases, while the P cv , P h , P r , and dC-bias property of powder core show reducing trend. This is attributed to the decrease in air gap in the composites, which is closely related to the pinning of domain movement and coercivity. The powder core with the granularity match scheme of 30:60:10 for P1%: P2%: P3% exhibits the excellent comprehensive magnetic properties including a stable μ' of 41.2 up to 3 MHz, high dC-property of 74.3%@100 Oe, and low P cv of 10389.5 kW/m 3 at 900 kHz, 0.1 T. This work offers insights into regulating magnetic properties for the powder core toward high-frequency applications, particularly referring to the granularity matching. © 2022, The Authors. All rights reserved.

关键词： Particle size