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Flexible, thermal processable, self-healing, and fully bio-based starch plastics by constructing dynamic imine network

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Green Energy & Environment 2024年第10期9卷 1610-1618页

作者： Xiaoqian Zhang Haishan Zhang Guowen zhou Zhiping Su xiaohui wang State Key Laboratory of Pulp and Paper Engineering South China University of Technology

The serious environmental threat caused by petroleum-based plastics has spurred more researches in developing substitutes from renewable *** is desirable for fabricating bioplastic due to its abundance and renewable ***,limitations such as brittleness,hydrophilicity,and thermal properties restrict its widespread *** overcome these issues,covalent adaptable network was constructed to fabricate a fully bio-based starch plastic with multiple advantages via Schiff base *** strategy endowed starch plastic with excellent thermal processability,as evidenced by a low glass transition temperature （Tg=20.15℃）.Through introducing Priamine with long carbon chains,the starch plastic demonstrated superior flexibility （elongation at break=45.2%） and waterproof capability （water contact angle=109.2°）.Besides,it possessed a good thermal stability and self-adaptability,as well as solvent resistance and chemical *** work provides a promising method to fabricate fully bio-based plastics as alternative to petroleum-based plastics.

关键词： Bioplastic Covalent adaptable networks Schiff base chemistry Thermal processability Self-healing

Prediction of damage potential in mainshock–aftershock sequences using machine learning algorithms

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Earthquake Engineering and Engineering Vibration 2024年第4期23卷 919-938页

作者： zhou zhou wang Meng Han Miao Yu xiaohui Lu Dagang School of Civil and Transportation Engineering Beijing University of Civil Engineering and ArchitectureBeijing 100044China Multi-Functional Shaking Tables Laboratory Beijing University of Civil Engineering and ArchitectureBeijing 100044China College of Civil Engineering Tongji UniversityShanghai 200092China College of Civil Engineering and Architecture Guilin University of TechnologyGuilin 541004China School of Civil Engineering Harbin Institute of TechnologyHarbin 150090China

Assessing the potential damage caused by earthquakes is crucial for a community’s emergency *** this study,four machine learning(ML)methods—random forest,extremely randomized trees,AdaBoost(AB),and gradient boosting(GB)—were employed to develop prediction models for the damage potential of the mainshock(DIMS)and mainshock–aftershock sequences(DIMA).Building structures were modeled using eight single-degree-of-freedom(SDOF)systems with different hysteretic rules.A set of 662 recorded mainshock–aftershock(MS-AS)ground motions was selected from the PEER *** intensity measures(IMs)were chosen to represent the characteristics of the mainshock and *** results revealed that the selected ML methods can well predict the structural damage potential of the SDOF systems,except for the AB *** GB model exhibited the best performance,making it the recommended choice for predicting DIMS and DIMA among the four ML ***,the impact of input variables in the prediction was investigated using the shapley additive explanations(SHAP)*** high-correlation variables were sensitive to the structural period(T).At T=1.0 s,the mainshock peak ground velocity(PGVM)and aftershock peak ground displacement(PGDA)significantly influenced the prediction of *** T increased to 5.0 s,the primary high-correlation factor of the mainshock IMs changed from PGVM to the mainshock peak ground displacement(PGDM);however,the highcorrelation variable of the aftershock IMs remained *** high-correlation factors for DIMS showed trends similar to those of ***,a table summarizing the first and second high-correlation variables for predicting DIMS and DIMA were provided,offering a valuable reference for parameter selection in seismic damage prediction for mainshock–aftershock sequences.

关键词： machine learning mainshock-aftershock damage potential prediction the high-correlation variables SDOF systems

An interesting synergistic effect of heteronuclear dual-atom catalysts for hydrogen production:Offsetting or promoting

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Nano Research 2024年第6期17卷 5742-5752页

作者： Zhonghao wang Wei Tang Jialin Liu gang zhou School of Science Hubei University of TechnologyWuhan 430068China

To elucidate the synergistic effect of dual-atom catalysts(DACs)at the microscopic level,we propose and construct a prototype heteronuclear system,CuNi/TiO_(2),in which the two elements of a pair have significantly different d electron-donating abilities,as a piece in the *** density functional theory calculations,we investigate charge-dependent configurations of Cu-Ni dimers anchored on TiO_(2)by the mixing of individual constituent *** d electron-donating ability determines deposition sequence and position of transition metal atoms on oxides,establishing dimer pattern and metal-support *** interaction between Cu and Ni,beyond the coordination environment,predominately contributes to the synergistic effect.A complex adsorption-reduction behavior of H species on CuNi/TiO_(2)is *** reaction mechanism and catalytic activity of CuNi/TiO_(2)for hydrogen production are *** room temperature and high H coverages,CuNi/TiO_(2)shows better performance and efficiency than Ni1/TiO_(2).Our findings provide a new understanding of the synergistic effect on structure-activity relationships of supported dimers,which would be beneficial in the future design of various DACs or even atomically dispersed metal catalysts.

关键词： dual-atom catalysts heteronuclear/homonuclear dimers synergistic effect density functional theory hydrogen production

Stereoselective recognition of morphine enantiomers by μ-opioid receptor

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National Science Review 2024年第3期11卷 183-191页

作者： Yibo wang Van A.Ngo xiaohui wang Laboratory of Chemical Biology Changchun Institute of Applied ChemistryChinese Academy of Sciences Advanced Computing for Life Sciences and Engineering Group Science Engagement Section National Center for Computational Sciences Oak Ridge National Lab School of Applied Chemistry and Engineering University of Science and Technology of China Beijing National Laboratory for Molecular Sciences

Stereospecific recognition of chiral molecules plays a crucial role in biological systems. The μ-opioid receptor（MOR） exhibits binding affinity towards（-）-morphine, a well-established gold standard in pain management, while it shows minimal binding affinity for the（+）-morphine enantiomer, resulting in a lack of analgesic activity. Understanding how MOR stereoselectively recognizes morphine enantiomers has remained a puzzle in neuroscience and pharmacology for over half-a-century due to the lack of direct observation techniques. To unravel this mystery, we constructed the binding and unbinding processes of morphine enantiomers with MOR via molecular dynamics simulations to investigate the thermodynamics and kinetics governing MOR's stereoselective recognition of morphine enantiomers. Our findings reveal that the binding of（-）-morphine stabilizes MOR in its activated state, exhibiting a deep energy well and a prolonged residence time. In contrast,（+）-morphine fails to sustain the activation state of ***, the results suggest that specific residues, namely D1142.50and D1473.32, are deprotonated in the active state of MOR bound to（-）-morphine. This work highlights that the selectivity in molecular recognition goes beyond binding affinities, extending into the realm of residence time.

关键词： stereoselective recognition thermodynamics and kinetics residence time morphine enantiomers μ-opioid receptor

Online estimation and characteristic analysis of double nugget diameters during aluminum/steel resistance spot welding process

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Journal of Iron and Steel Research International 2024年第8期31卷 2053-2067页

作者： Kang zhou Wen-xiao Yu Bao-kai Ren gang wang School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China

Online estimation of the double nugget diameters was performed by means of a back propagation neural *** double nugget diameters were obtained using actual welding experiment and numerical simulation,according to different characteristics of aluminum nugget and steel *** input of the neural network was some key characteristic parameters extracted from dynamic power signal,which were peak point,knee point and their variation rate over time,as well as heat energy delivered into the welding *** architecture of the neural network was confirmed by confirming the number of neurons in hidden layer through a series of *** key parameters of the neural network were obtained by means of training 81 arrays of data ***,the neural network was used to test the remaining 20 arrays of verifying data set,and the results showed that both of the mean errors for the two nugget diameters were below 3%.In addition,corresponding analyses showed that the accuracy of two nugget diameters was higher than that of tensile-shear strength.

关键词： Resistance spot welding Aluminum Steel Double nugget Dynamic power signal.Neural network

Bunch-length measurement at a bunch-by-bunch rate based on time–frequency-domain joint analysis techniques and its application

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Nuclear Science and Techniques 2024年第4期35卷 165-175页

作者： Hong-Shuang wang Xing Yang Yong-Bin Leng Yi-Mei zhou Ji-gang wang Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230026China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

This paper presents a new technique for measuring the bunch length of a high-energy electron beam at a bunch-by-bunch rate in storage *** technique uses the time–frequency-domain joint analysis of the bunch signal to obtain bunch-by-bunch and turn-by-turn longitudinal parameters,such as bunch length and synchronous *** bunch signal is obtained using a button electrode with a bandwidth of several *** data acquisition device was a high-speed digital oscilloscope with a sampling rate of more than 10 GS/s,and the single-shot sampling data buffer covered thousands of *** bunch-length and synchronous phase information were extracted via offline calculations using Python *** calibration coefficient of the system was determined using a commercial streak ***,this technique was tested on two different storage rings and successfully captured various longitudinal transient processes during the harmonic cavity debugging process at the Shanghai Synchrotron Radiation Facility(SSRF),and longitudinal instabilities were observed during the single-bunch accumulation process at Hefei Light Source(HLS).For Gaussian-distribution bunches,the uncertainty of the bunch phase obtained using this technique was better than 0.2 ps,and the bunch-length uncertainty was better than 1 *** dynamic range exceeded 10 *** technology is a powerful and versatile beam diagnostic tool that can be conveniently deployed in high-energy electron storage rings.

关键词： Bunch-by-bunch diagnostic Bunch-length measurement Synchronous phase measurement Joint time–frequency-domain analysis Longitudinal instability

Alignment error modeling and control of a double-sided microlens array during precision glass molding

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Microsystems & Nanoengineering 2024年第2期10卷 311-322页

作者： Zihao Zeng Tianfeng zhou Qian Yu Jia zhou gang wang Qiuchen Xie Zifan wang Xiaoqiang Yao Yubing Guo School of Medical Technology Beijing Institute of TechnologyNo.5 Zhongguancun South StreetHaidian DistrictBeijing100081China School of Mechanical Engineering Beijing Institute of TechnologyNo.5 Zhongguancun South StreetHaidian DistrictBeijing100081China

Double-sided microlens arrays(DSMLAs)include combinations of two single-sided MLAs to overcome positioning errors and greatly improve light transmissivity compared to other types of *** glass molding(PGM)is used to fabricate DSMLAs,but controlling alignment errors during this process is *** this paper,a mold assembly was manufactured with a novel combination of materials to improve the alignment accuracy of mold cores during PGM by using the nonlinear thermal expansion characteristics of the various materials to improve the DSMLA alignment *** establishing a mathematical model of the DSMLA alignment error and a thermal expansion model of the mold-sleeve pair,the relationship between the maximum alignment error of the DSMLA and the mold-sleeve gap was *** research provides a method to optimize the mold-sleeve gap and minimize the alignment error of the *** measured DSMLA alignment error was 10.56μm,which is similar to the predicted maximum alignment *** measurements showed that the uniformity of the homogenized beam spot was 97.81%,and the effective homogeneous area accounted for 91.66%of the total *** proposed method provides a novel strategy to improve the performance of DSMLAs.

关键词： sided alignment error

Microstructure,elastic/mechanical and thermal properties of CrTaO_(4):A new thermal barrier material?

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Journal of Advanced Ceramics 2024年第3期13卷 373-387页

作者： Shuang Zhang xiaohui wang Chao Zhang Huimin Xiang Yingwei Li Cheng Fang Mingliang Li Hailong wang Yanchun zhou School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Civil Engineering Wuhan UniversityWuhan 430072China

CrTaO_(4)(or Cr_(0.5)Ta_(0.5)O_(2))has been unexpectedly found to play a decisive role in improving the oxidation resistance of Cr and Ta-containing refractory high-entropy alloys(RHEAs).This rarely encountered complex oxide can effectively prevent the outward diffusion of metal cations from the ***,the oxidation kinetics of CrTaO_(4)-forming RHEAs is comparable to that of the well-known oxidation resistant Cr_(2)O_(3)-and Al_(2)O_(3)-forming Ni-based ***,CrTaO_(4)has been ignored and its mechanical and thermal properties have yet to be *** fill this research gap and explore the untapped potential for its applications,here we report for the first time the microstructure,mechanical and thermal properties of CrTaO_(4)prepared by hot-press sintering of solid-state reaction synthesized *** the HAADF and ABF-STEM techniques,rutile crystal structure was confirmed and short range ordering was directly *** addition,segregation of Ta and Cr was ***,CrTaO_(4)exhibits elastic/mechanical properties similar to those of yttria stabilized zirconia(YSZ)with Young’s modulus,shear modulus,and bulk modulus of 268,107,and 181 GPa,respectively,and Vickers hardness,flexural strength,and fracture toughness of 12.2±0.44 GPa,142±14 MPa,and 1.87±0.074 MPa·m^(1/2).The analogous elastic/mechanical properties of CrTaO_(4)to those of YSZ has spurred inquiries to lucrative leverage it as a new thermal barrier *** measured melting point of CrTaO_(4)is 2103±20 *** anisotropic thermal expansion coefficients areα_(a)=(5.68±0.10)×10^(-6)K^(-1),α_(c)=(7.81±0.11)×10^(-6)K^(-1),with an average thermal expansion coefficient of(6.39±0.11)×10^(-6)K^(-1).The room temperature thermal conductivity of CrTaO_(4)is 1.31 W·m^(-1)·K^(-1)and declines to 0.66 W·m^(-1)·K^(-1)at 1473 K,which are lower than most of the currently well-known thermal barrier *** the perspective of matched thermal expansion coefficient,CrTaO_(4)per

关键词： microstructure synthesis thermal conductivity thermal expansion coefficient melting point CrTaO_(4) mechanical and thermal properties

Performance and mechanism of La-Fe metal-organic framework as a highly efficient adsorbent for fluoride removal from mine water

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Journal of Environmental Sciences 2024年第5期139卷 245-257页

作者： Chaomin Jia Jianbing wang Huijiao wang Sichao Zhu xiaohui Zhang Yuxiang wang School of Chemical&Environmental Engineering China University of Mining&Technology-BeijingBeijing 100083China Beijing Polytechnic Beijing 100176China Chinese Society for Urban Studies Beijing 100835China

Water fluoride pollution has caused non-negligible harm to the environment and humans,and thus it is crucial to find a suitable treatment *** this study,La-Fe@PTA adsorbent was synthesized for the defluoridation of mine *** results showed that the optimum conditions for defluoridation by La-Fe@PTA were p H close to 7.0,the initial F-concentration of 10 mg/L,the dosage of 0.5 g/L and the adsorption time of 240 *** with SO_4^(2-),Cl^(-),NO_(3)^(-),Ca^(2+)and Mg^(2+),CO_(3)^(2-)and HCO_(3)^(-)presented severer inhibition on fluoride uptake by La-Fe@*** adsorption process fits well with the pseudo-second-order kinetic model and Freundlich model,and the maximum adsorption capacity of Langmuir model was 95 mg/***-bed adsorption results indicated that fluoride in practical fluorinated mine water could be effectively removed from 3.6 mg/L to less than 1.5 mg/L within130 bed volume(BV)by using 1.5 g La-Fe@***,the adsorbent still had good adsorption capacity after regeneration,which confirms the great application potential of La-Fe@PTA as a fluoride ion *** mechanism analysis showed that La-Fe@PTA adsorption of fluorine ions is a physicochemical reaction driven by electrostatic attraction and ion exchange.

关键词： Adsorption La-Fe@PTA Fluoride ion Mine water Mechanism