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Partners in Epoxide Copolymerization Catalysis:Approach to High Activity and Selectivity

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Chinese Journal of Polymer Science 2022年第11期40卷 1331-1348页

作者： Xiao-Bing Lu bai-hao Ren State Key Laboratory of Fine Chemicals Dalian University of TechnologyDalian 116024China

The ring-opening alternating copolymerization processes of epoxides with small-molecule monomers,such as carbon dioxide(CO_(2)),carbonyl sulfide(COS)and cyclic anhydrides,are powerful strategies for preparing polymeric materials with degradable carbonate/ester/thiocarbonate main-chain backbone *** catalysts selected for copolymerization processes play crucial roles in determining their reaction rates and productivities,as well as the selectivity,regio-and stereochemistry,compositions,and the molecular weights of their resultant *** processes often generate undesirable byproducts such as polyether or ether linkages dispersed randomly within the copolymer's chain,and/or more thermodynamically stable cyclic *** this account,we outline our efforts of over a dozen years on developing highly active well-defined metal catalysts based on inter-and intra-molecular synergistic strategies to selectively produce completely alternating copolymers from epoxides and various small-molecule *** attention was paid to the enantioselective resolution copolymerization processes of racemic epoxides via regioselective ring-openings,and the asymmetric copolymerization processes of meso-epoxides with CO_(2),COS,or cyclic anhydrides via dissymmetrical ring-openings using multichiral catalytic systems,and affording isotactic copolymers with main-chain *** addition,this account provides a thorough mechanistic understanding of the high reactivities,excellent selectivity,and unprecedented stereochemical controls of these copolymerization systems,mediated by interand intramolecular synergistic catalysis.

关键词： Epoxide Ring-opening copolymerization Synergistic catalysis CO_(2) Stereochemistry control

Experimental and Numerical Studies on the Diffusion of CO2 from Oil to Water

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Journal of Thermal Science 2020年第1期29卷 268-278页

作者： LI Binfei ZHANG Qiliang CAO Aiqing bai hao XU Jianguo School of Petroleum Engineering China University of Petroleum(East China)Qingdao 266580China Beijing Oil&Gas Pipeline Control Center PetroChinaBeijing 100007China School of Mechanical and Electronic Engineering China University of Petroleum(East China)Qingdao 266580China Jilin Oilfield PetroChinaSongyuan 138000China

Injecting CO2 into oil reservoirs can improve the oil recovery,meanwhile achieve CO2 *** diffusion of CO2 in oil-water systems has a substantial impact on this *** interface significantly affects the mass transfer of CO2 between oil and water *** this paper,based on the determination of the CO2 diffusion coefficient in oil or water phases,the diffusion processes of CO2 from oil to water were experimentally investigated under different pressures.A numerical method was proposed to calculate the pressure drop and the diffusion coefficient in the process of CO2 diffusion from oil to *** experimental results indicated that the CO2 diffusion coefficient in oil or water increased rapidly with pressure up to the critical pressure of CO2 and gradually slowed down *** CO2 diffusion from oil to water was much slower than that in oil or *** diffusion coefficient of CO2 from oil to water was one magnitude lower than that in the single liquid phase of oil or water,and the effect of pressure was not *** on the diffusion coefficient of CO2 in a single liquid phase and the proposed numerical method,the pressure drop and the numerical diffusion coefficient in the process of CO2 diffusion from oil to water were *** relative errors between the experimental and numerical results were within 9%.Therefore,the numerical method proposed herein can be used to predict the diffusion process of CO2 from oil to water and the diffusion coefficient associated with this process.

关键词： CO2-oil-water system CO2 diffusion mass transfer pressure decay method numerical method

Energy-absorbing porous materials:Bioinspired architecture and fabrication

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Nano Research 2024年第2期17卷 679-690页

作者： Junheng Zhao Meng Li Jiewei Chen Weiwei Gao hao bai State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310058China Department of Polymer Science and Engineering Zhejiang UniversityHangzhou 310058China

Energy-absorbing materials are widely used in transportations,sports,and the military ***,porous materials,including natural and artificial materials,have attracted tremendous attentions due to their light weight and excellent energy absorption *** review summarizes the recent progresses in the natural and artificial energy-absorbing porous ***,we review the typical natural porous materials including cuttlebone,bighorn sheep horn,pomelo peel,and sunflower stem *** architectures,energy absorption abilities,and mechanisms of these typical natural materials and their bioinspired materials are ***,we provide a review on the fabrication methods of artificial energy-absorbing porous materials,such as conventional foaming and three-dimensional(3D)***,we address the challenges and prospects for the future development of energy-absorbing porous *** importantly,our review provides a direct guidance for the design and fabrication of energy-absorbing porous materials required for various engineering applications.

关键词： energy-absorbing porous materials natural materials natural structures bioinspired materials

New method to implement digital down converter in radar system

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Journal of Systems Engineering and Electronics 2005年第4期16卷 775-780页

作者： Ma Zhigang Wen Biyang Zhou hao bai Liyun Radio Propagation Lab Electronics and informations school Wuhan Univ. Wuhan 430079 P. R. China

Digital down converter （DDC） is the main part of the next generation high frequency （HF） radar. In order to realize the single chip integrations of digital receiver hardware in the next generation HF Radar, a new design for DDC by using FPGA is presented. Some important and practical applications are given in this paper, and the result can prove the validity. Because we can adjust the parameters freely according to our need, the DDC system can be adapted to the next generation HF radar system.

关键词： high frequency radar FPGA DDC decimation.

Simulation method for measurement of the cross-section of the^(14)N(n,a)^(11)B reaction using a gridded ionization chamber

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Nuclear Science and Techniques 2021年第8期32卷 1-11页

作者： Yi-Wei Hu hao-Yu Jiang Zeng-Qi Cui Jie Liu hao-Fan bai Huai-Yong bai Jin-Xiang Chen Guo-Hui Zhang State Key Laboratory of Nuclear Physics and Technology Institute of Heavy lon PhysicsSchool of Physics.PekingUniversityBeijing 100871China Institute of Materials China Academy of EngineeringPhysicsJiangyou 621907China

A simulation method for measurement of the cross-section of the^(14)N(n,a)^(11)B reaction with gas and solid samples using a gridded ionization chamber(GIC)has been *** the simulation,the experimental spectra of both^(14)N(n,a)^(11)B events and background from other reactions can be predicted,and the experimental scheme can be *** to the simulation results,the optimal experimental parameters,including the pressure of the working gas and the compositions of the working gas and the sample,can be *** addition,the simulation results can be used to determine the valid event area and calculate the detection efficiency for valid events.A measurement of the cross-sections of the^(14)N(n,a)^(11)B reaction at E_(n)=4.25,4.50,4.75,5.00,5.25,and 5.50 MeV,based on the 4.5-MV Van de Graff accelerator at Peking University(PKU)using a GIC as the detector for the outgoing a particles,has been *** good agreement of the spectra from the simulation and experiment demonstrated the universality of this simulation method,which can be used to accurately measure neutroninduced light-charged particle emission reactions.

关键词： Gridded ionization chamber Monte Carlo simulation Cathode–anode two-dimensional spectrum ^(14)N(n,a)^(11)B reaction

Effect of electric pulse on the crystal structure of solidified copper ingots

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International Journal of Minerals,Metallurgy and Materials 2013年第6期20卷 556-562页

作者： Li-hua Zhao Li Zhan hao bai Da-qiang Cang State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing Shougang Steel Co. Ltd.Sales Company

To obtain advanced quality pure copper, the microstructure of solidified copper was optimized by imposing electric pulse on liquid copper in this study. Experiments were performed to determine the effect of electric pulse voltage, arrangement mode of electrodes, and energy input on the microstructure of solidified copper. The results show that, when the energy input of electric pulse is bigger than 28.95 kJ per ton copper, the percent of fine grains increases noticeably with the increase of energy input; but when the energy input of electric pulse is smaller than 28.95 kJ per ton copper, the percent of fine grains decreases with the increase of energy input. The influence order of above factors on grain refinement is electric pulse voltage 〉 arrangement mode of electrodes 〉 energy input. According to the above experimental results, the optimum process conditions are chosen as the voltage being 400 V and the energy input greater than 28.95 kJ per ton copper. Meanwhile, the best arrangement mode of electrodes should be that, one electrode is immerged in the middle of liquid copper in the crystallizer, and the other is connected to the inner wall of the crystallizer, which is divided into two electrode poles for the symmetrical electric field distribution.

关键词： copper solidification crystal structure electric pulse

Microstructure and properties of high emissivity coatings

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Journal of University of Science and Technology Beijing 2008年第5期15卷 627-632页

作者： Zhigang Dan Daqiang Cang Huimin Zhou hao bai Yanbin Zong Chinese Research Academy of Environmental Sciences Beijing 100012 China School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China Shangdong Huimin Technology Development Company Jinan 250100 China

A new coating on lining in industrial furnace for energy saving has been developed. Properties and microstructure of the coatings were revealed by emissivity instrument,X-ray diffraction （XRD）,transmission electron microscope （TEM） and scanning electron microscope （SEM）,respectively. The result indicates that the emissivity of coatings is higher than 0.90 and the thickness of coatings is about 200 μm. ZrO2,Cr2O3 and SiC in the coating benefit practical applications of coatings at high temperature with durable high emissivity and the continuous structure between the coatings and the substrate makes the coatings high cohesion and excellent adhesion for both specimens with and without sintering at high temperature. Result from laboratory experiment shows that the heating speed of specimen with coating is higher than that of controlled specimen and the temperature increases 30°C during the heating. The average temperature drop of specimen with coatings has a 13.5% improvement in the cooling speed. The application of coatings on the checker brick in a blast furnace of 1750m^3 indicates that the coating causes the blast temperature to an average increase of 28°C,reduces the fluctuation of blast temperature before the blowing-in and leads to a fuel saving of 10% approximately.

关键词： high emissivity coatings industrial furnace energy saving

Heat distribution model under hydrogen-rich low-carbon conditions in blast furnace

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Journal of Iron and Steel Research International 2024年第3期31卷 584-594页

作者： Gang Wang Jun Xu Kun He Zhong-ping Zou hao bai School of Metallurgy and Ecological Engineering University of Science and Technology BeijingBeijing 100083China CISDI Low-Carbon Blast Furnace Research Office MCC Low-Carbon Technology Research InstituteChongqing 401122China

Low carbon development of blast furnaces is one of the key technological directions in the current development of *** to the differences in the physical and chemical properties of hydrogen and carbon,hydrogen-rich media entering a blast furnace will change the heat distribution,thus affecting the stability of ***,a heat distribution model was proposed to study the temperature distribution in a blast furnace,simultaneously considering gas-solid heat exchange,slag and iron melting,and chemical *** model was used to analyze the temperature distribution of a 2300 m^(3) blast furnace and was verified via comparison with actual production ***,the effects of the injection rate of hydrogen-rich media,H2 concentration,and oxygen enrichment rate of the blast on the temperature distribution were *** indicated that the increase in the injection rate of the hydrogen-rich media decreased the amount of direct reduction and led to an increase in the furnace ***,an increase in the oxygen enrichment rate led to a decrease in the furnace temperature,but could reduce the solid fuel ratio,while the change in H2 concentration had less effect on the temperature *** combination of hydrogen-rich media injection and the increase in the oxygen enrichment rate would help to adjust the temperature distribution to the same level as the conventional blast furnace conditions.

关键词： Heat distribution Blast furnace Low-carbon condition Hydrogen enrichment Calculation model

Promising applications of human-derived saliva biomarker testing in clinical diagnostics

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International Journal of Oral Science 2023年第1期15卷 16-32页

作者： Mengyuan Song hao bai Ping Zhang Xuedong Zhou Binwu Ying Department of Laboratory Medicine West China HospitalSichuan UniversityChengduChina State Key Laboratory of Oral Diseases&Human Saliva Laboratory&National Clinical Research Center for Oral Diseases&West China Hospital of Stomatology Sichuan UniversityChengduChina

Saliva testing is a vital method for clinical applications,for its noninvasive features,richness in substances,and the huge *** to its direct anatomical connection with oral,digestive,and endocrine systems,clinical usage of saliva testing for these diseases is ***,for other diseases that seeming to have no correlations with saliva,such as neurodegenerative diseases and psychological diseases,researchers also reckon saliva *** papers are being produced in this *** summaries of recent literature give newcomers a shortcut to have a grasp of this ***,we focused on recent research about saliva biomarkers that are derived from humans,not from other *** review mostly addresses the proceedings from 2016 to 2022,to shed light on the promising usage of saliva testing in clinical *** recap the recent advances following the category of different types of biomarkers,such as intracellular DNA,RNA,proteins and intercellular exosomes,cell-free DNA,to give a comprehensive impression of saliva biomarker testing.

关键词： clinical testing mostly