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Utilizing a metal-forging inspired chain combing strategy to enhance properties and expand applications of Nylon 66 plastic via heat inducing

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Nano Research 2024年第3期17卷 2164-2171页

作者： Junyu Yang Jiangwei Zhang Nan Wang guangyuan zhou Division of Energy Materials Daglian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China Innovation Center of Energy Material and Chemistry College of Chemistry and Chemical EngineeringInner Mongolia UniversityHohhot 010021China

The mechanical properties of engineering plastics can be enhanced through effective surface mechanical treatment(SMT),which can be applied to various types of engineering plastics,eliminating the limitations of conventional polymer processing and could potentially extend their applications and improve their performance and reliability as structural-functional materials.Inspired by metal forging,this work proposes a simple and effective SMT strategy to enhance the mechanical properties of polyamide 66(PA66).Tensile tests have shown that SMTed PA66 samples exhibit significant improvements in both Young’s modulus and ultimate tensile strength(UTS),with a 2104 MPa Young’s modulus,almost double that of the pristine samples,and a 35.56%increase in UTS,reaching 183 MPa.Additionally,the modulus within the localized SMTed surface layer could reach up to 14 GPa,which is approximately 14 times higher than that of the pristine sample.The Vickers hardness within the localized SMTed surface layer can be doubled,reaching 10.72 Hv,and the crystallinity can increase by approximately 20%compared to the untreated region.Furthermore,force field molecular dynamics(FFMD)simulations were conducted to investigate the ternary relationship between the SMT method,PA66’s molecular structure,and its properties.The combination of MD simulations and versatile structural characterizations provides evidence that the SMT method’s mechanism,under heat induction,results in a chain-combing procedure that changes the polymer’s molecular morphology microscopically and enhances its mechanical properties macroscopically.

关键词： Nylon 66 mechanical properties hardness crystallinity structural characterizations molecular dynamics simulation

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On the use of deep learning for phase recovery

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Light(Science & Applications) 2024年第2期13卷 190-235页

作者： Kaiqiang Wang Li Song Chutian Wang Zhenbo Ren guangyuan Zhao Jiazhen Dou Jianglei Di George Barbastathis Renjie zhou Jianlin Zhao Edmund Y.Lam Department of Electrical and Electronic Engineering The University of Hong KongHong Kong SARChina School of Physical Science and Technology Northwestern Polytechnical UniversityXi’anChina Department of Biomedical Engineering The Chinese University of Hong KongHong Kong SARChina School of Information Engineering Guangdong University of TechnologyGuangzhouChina Department of Mechanical Engineering Massachusetts Institute of TechnologyCambridgeMAUSA

Phase recovery(PR)refers to calculating the phase of the light field from its intensity measurements.As exemplified from quantitative phase imaging and coherent diffraction imaging to adaptive optics,PR is essential for reconstructing the refractive index distribution or topography of an object and correcting the aberration of an imaging system.In recent years,deep learning(DL),often implemented through deep neural networks,has provided unprecedented support for computational imaging,leading to more efficient solutions for various PR problems.In this review,we first briefly introduce conventional methods for PR.Then,we review how DL provides support for PR from the following three stages,namely,pre-processing,in-processing,and post-processing.We also review how DL is used in phase image processing.Finally,we summarize the work in DL for PR and provide an outlook on how to better use DL to improve the reliability and efficiency of PR.Furthermore,we present a live-updating resource(https://***/kqwang/phase-recovery)for readers to learn more about PR.

关键词： networks phase optics

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Unraveling SO_(2)-tolerant mechanism over Fe_(2)(SO_(4))_(3)/TiO_(2) catalysts for NO_(x) reduction

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Journal of Environmental Sciences 2022年第1期34卷 340-350页

作者： Chong Feng Lupeng Han Penglu Wang Xiangyu Liu guangyuan zhou Dengsong Zhang State Key Laboratory of Advanced Special Steel School of Materials Science and EngineeringInternational Joint Laboratory of Catalytic ChemistryCollege of SciencesShanghai UniversityShanghai 200444China Dalian Institute of Chemical Physics Chinese Academy of SciencesDalian 116023China

Developing low-temperature SO_(2)-tolerant catalysts for the selective catalytic reduction of NO_(x) is still a challenging task.The sulfation of active metal oxides and deposition of ammonium bisulfate deactivate catalysts,due to the difficult decomposition of the as-formed sulfate species at low temperatures(300℃);however,the SO_(2)-tolerant mechanism of metal sulfate catalysts is still ambiguous.In this study,Fe_(2)(SO_(4))_(3)/TiO_(2) and Ce_(2)(SO_(4))_(3)/TiO_(2) catalysts were prepared using the corresponding metal sulfate salt as the precursor.These catalysts were tested for their low-temperature activity and SO_(2) tolerance activity.Compared to Ce_(2)(SO_(4))_(3)/TiO_(2),Fe_(2)(SO_(4))_(3)/TiO_(2) showed significantly better low-temperature activity and SO_(2) tolerance.It was demonstrated that less surface sulfate species formed on Fe_(2)(SO_(4))_(3)/TiO_(2) and Ce_(2)(SO_(4))_(3)/TiO_(2).However,the presence of NO and O_(2) could assist the decomposition of NH_(4)HSO_(4) over Fe_(2)(SO_(4))_(3)/TiO_(2) at a lower temperature,endowing Fe_(2)(SO_(4))_(3)/TiO_(2) with better low-temperature SO_(2) tolerance than Ce_(2)(SO_(4))_(3)/TiO_(2).This study unraveled the SO_(2)-tolerant mechanism of Fe_(2)(SO_(4))_(3)/TiO_(2)at lower temperatures(<300℃),and a potential strategy is proposed for improving the low-temperature SO_(2)-tolerance of catalysts with Fe_(2)(SO_(4))_(3) as the main active component or functional promoter.

关键词： NO_(x) Selective catalytic reduction Sulfate Catalysts SO_(2)-tolerance

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Supplementation of alanine improves biomass accumulation and lipid production of Chlorella pyrenoidosa by increasing the respiratory and metabolic processes

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Journal of Oceanology and Limnology 2024年第2期42卷 570-579页

作者： Yongfu LI Tianze ZHAO Wei SUN Ruiwen GAO guangyuan MA Jiangsu Province Engineering Research Center for Marine Bioresources Sustainable Utilization Key Laboratory of Marine Hazards ForecastingMinistry of Natural ResourcesHohai UniversityNanjing 210098China College of Oceanography Hohai UniversityNanjing 210098China Jiangsu Innovation Center of Marine Bioresources Jiangsu Coast Development Group Co.Ltd.Nanjing 210019China

The function of exogenous alanine(Ala)in regulating biomass accumulation,lipid production,photosynthesis,and respiration in Chlorella pyrenoidosa was studied.Result shows that the supplementation of Ala increased C.pyrenoidosa biomass and lipid production in an 8-d batch culture.The concentration of 10 mmol/L of Ala was optimum and increased the microalgal cell biomass and lipid content by 39.3%and 21.4%,respectively,compared with that in the control(0-mmol/L Ala).Ala supplementation reduced photosynthetic activity while boosting respiratory activity and pyruvate levels,indicating that C.pyrenoidosa used exogenous Ala for biomass accumulation through the respiratory metabolic process.The accelerated respiratory metabolism due to Ala supplementation elevated the substrate pool and improved the lipogenic gene expression,promoting lipid production at last.This study provided a novel method for increasing biomass accumulation and lipid production and elucidated the role of Ala in regulating lipid production.

关键词： alanine Chlorella pyrenoidosa lipid respiration lipogenic gene

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Ultrathin two-dimensional medium-entropy oxide as a highly efficient and stable electrocatalyst for oxygen evolution reaction

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Nano Research 2024年第4期17卷 2555-2562页

作者： guangyuan Yan Tianlu Wang Biwei Zhao Wenjing Gao Tong Wu Liming Ou School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China

Medium-entropy oxides(MEOs)with broad compositional tunability and entropy-driven structural stability,are receiving booming attention as a promising candidate for oxygen evolution reaction(OER)electrocatalysts.Meanwhile,ultrathin two-dimensional(2D)nanostructure offers extremely large specific surface area and is therefore considered to be an ideal catalyst structure.However,it remains a grant challenge to synthesize ultrathin 2D MEOs due to distinct nucleation and growth kinetics of constituent multimetallic elements in 2D anisotropic systems.In this work,an ultrathin 2D MEO(MnFeCoNi)O was successfully synthesized by a facile and low-temperature ionic layer epitaxy method.Benefiting from multi-metal synergistic effects within ultrathin 2D nanostructure,this 2D MEO(MnFeCoNi)O revealed excellent OER electrocatalytic performance with a quite low overpotential of 117 mV at 10 mA·cm^(-2) and an impressive stability for 120 h continuous operation with only 6.9%decay.Especially,the extremely high mass activity(5584.3 A·g^(-1))was three orders of magnitude higher than benchmark RuO_(2)(3.4 A·g^(-1))at the same overpotential of 117 mV.This work opens up a new avenue for developing highly efficient and stable electrocatalysts by creating 2D nanostructured MEOs.

关键词： medium-entropy oxide two-dimensional nanomaterials ionic layer epitaxy oxygen evolution reaction electrocatalysis

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Deep kernel extreme learning machine classifier based on the improved sparrow search algorithm

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The Journal of China Universities of Posts and Telecommunications 2024年第3期 15-29页

作者： Zhao guangyuan Lei Yu School of Automation Xi'an University of Posts and Telecommunications

In the classification problem, deep kernel extreme learning machine(DKELM) has the characteristics of efficient processing and superior performance, but its parameters optimization is difficult. To improve the classification accuracy of DKELM, a DKELM algorithm optimized by the improved sparrow search algorithm(ISSA), named as ISSA-DKELM, is proposed in this paper. Aiming at the parameter selection problem of DKELM, the DKELM classifier is constructed by using the optimal parameters obtained by ISSA optimization. In order to make up for the shortcomings of the basic sparrow search algorithm(SSA), the chaotic transformation is first applied to initialize the sparrow position. Then, the position of the discoverer sparrow population is dynamically adjusted. A learning operator in the teaching-learning-based algorithm is fused to improve the position update operation of the joiners. Finally, the Gaussian mutation strategy is added in the later iteration of the algorithm to make the sparrow jump out of local optimum. The experimental results show that the proposed DKELM classifier is feasible and effective, and compared with other classification algorithms, the proposed DKELM algorithm aciheves better test accuracy.

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Integrating Zeolite and Layered Double Hydroxide for Highly Selective Catalytic Production ofγ-Valerolactone

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CCS Chemistry 2024年第3期6卷 652-662页

作者： Mingkun Gao Guoju Yang guangyuan He Risheng Bai Jialiang Li Yinghao Liu Qiang Zhang Guangrui Chen Donghai Mei Jihong Yu State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryInternational Center of Future ScienceJilin UniversityChangchun 130012 School of Materials Science and Engineering Tiangong UniversityTianjin 300387

The production ofγ-valerolactone(GVL)from biomass derivatives levulinic acid(LA)based on acidbase metallic catalysts offers a sustainable pathway to the synthesis of valuable chemicals and biofuels.However,the development of efficient metallic catalysts with tunable Lewis acid–base and Brønsted acid sites remains a challenge.Herein,for the first time,we integrated zeolite and layered double hydroxide(LDH),in a core–shell structure,wherein zeolite and CoFe-LDH provided the Brønsted acidic sites and Lewis acid sites,respectively.Meanwhile,oxygen vacancies(OV_(x))acting as Lewis bases were generated on the surface of LDH via Ga doping.An efficient cascade catalytic reaction from LA to GVL was successfully achieved over the designed Beta@LDH-OVx catalyst,affording a superior conversion of LA(>99.9%)and an impressive selectivity to GVL(89.18%).Importantly,the“memory effect”of LDH endowed the catalyst with excellent regeneration of metal active sites.Density functional theory calculations revealed that the introduced OVx facilitated the adsorption of carbonyl oxygen in LA and boosted the production of GVL through the synergistic effect of acid/base sites in the composite catalyst.This work presents a rational design route for the construction of multifunctional catalysts by coupling zeolites and LDHs for highly selective catalytic conversion of biomass.

关键词： zeolite layered double hydroxide oxygen vacancies biomass γ-valerolactone

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Potassium alleviated high nitrogen-induced apple growth inhibition by regulating photosynthetic nitrogen allocation and enhancing nitrogen utilization capacity

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Horticultural Plant Journal 2024年第1期10卷 1-14页

作者： Xinxiang Xu guangyuan Liu Jingquan Liu Mengxue Lyu Fen Wang Yue Xing Hao Meng Min Li Yu Jiang Ge Tian Zhanling Zhu Yuanmao Jiang Shunfeng Ge State Key Laboratory of Crop Biology College of Horticulture Science and EngineeringShandong Agricultural UniversityTai'anShandong 271018China Key Laboratory of Biochemistry and Molecular Biology in Universities of Shandong College of Biological and Agricultural EngineeringWeifang UniversityWeifangShandong 261061China

There is a close relationship between potassium(K)and nitrogen(N).However,the roles of K under high N conditions remain unclear.Using a hydroponics approach,we monitored the morphological,physiological,and molecular changes in M9T337 apple(Malus domestica)rootstocks under different nitrate(10 and 30 mmol·L^(-1)NO_(3)^(-))and K supply(0.5,6,10,and 20 mmol·L_(-1)K^(+))conditions.Results revealed that high nitrate inhibited the root growth of M9T337 rootstocks,downregulated the expressions of K transporter genes(MdPT5,MdHKT1,and MdATK1),and reduced the net NO3-and K+influx at the surface of roots,thereby resulting in an N/K imbalance in rootstocks.Further investigation showed that 10 mmol·L^(-1)K increased the activity of N metabolic enzymes(NR,GS,NiR,and GOGAT),upregulated the expressions of genes related to nitrate uptake and transport(MdNRT1.1,MdNRT1.2,MdNRT1.5,and MdNRT2.4),promoted15N transport from the roots to the shoots,optimized leaf N distribution,and improved photosynthetic N utilization efficiency under high nitrate conditions.These results suggest that the negative effects of high nitrate may be related to the N/K imbalance and that reducing N/K in plants by increasing K supply level can effectively alleviate the inhibition of N assimilation by high nitrate stress.

关键词： Apple rootstock K level High nitrate stress N metabolism ^(15)N

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车轮扁疤对高速列车传动齿轮动态特性影响

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城市轨道交通研究 2024年第7期27卷 34-37,42页

作者：陈光圆柳州铁道职业技术学院运输管理学院柳州545616

[目的]车轮扁疤会引起列车传动齿轮振动加剧,因此有必要研究车轮扁疤对高速列车传动齿轮的振动动态特性影响。[方法]基于多体动力学理论和某高速列车传动齿轮的技术参数,构建弯曲-扭转-轴向耦合斜齿轮和车轮扁疤的高速列车整车动力学模... 详细信息

[目的]车轮扁疤会引起列车传动齿轮振动加剧,因此有必要研究车轮扁疤对高速列车传动齿轮的振动动态特性影响。[方法]基于多体动力学理论和某高速列车传动齿轮的技术参数,构建弯曲-扭转-轴向耦合斜齿轮和车轮扁疤的高速列车整车动力学模型;对不同扁疤长度下,高速列车传动齿轮的动态特性,大、小齿轮接触面间的最大接触应力,以及齿轮传递误差进行了计算与分析。[结果及结论]当车轮扁疤长度为0~30 mm时,高速列车大、小齿轮的振动加速度增长不明显;当车轮扁疤长度为30~60 mm时,高速列车大、小齿轮的振动加速度急剧增加,大、小齿轮间的最大接触应力由630 MPa增加至了1250 MPa,增长了2.08倍;随着车轮扁疤长度的增加,齿轮动态传递误差呈现增加的趋势;当车轮扁疤长度为0时,齿轮动态传递误差最大值为9μm;当车轮扁疤长度为60 mm时,齿轮动态传递误差最大值为72μm,齿轮传递误差增加了8倍。

关键词：高速列车车轮扁疤传动齿轮

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异山梨醇型聚碳酸酯的制备方法及性能调控研究进展

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精细化工 2024年第6期41卷 1161-1169页

作者：杨黠凤龙鑫李建国王庆印王公应周光远中国科学院成都有机化学研究所手性药物及材料国家工程研究中心四川成都610041 中国科学院大学北京100049 中国科学院大连化学物理研究所辽宁大连116023

双酚A型聚碳酸酯(BPA-PC)因双酚A具有不可再生和雌激素效应等问题,导致其在食品包装等领域的应用受到限制。近年来,异山梨醇(IS)作为生物基可再生单体、无毒无害,是目前最有希望代替双酚A合成聚碳酸酯的关键原料,用其合成的异山梨醇型... 详细信息

双酚A型聚碳酸酯(BPA-PC)因双酚A具有不可再生和雌激素效应等问题,导致其在食品包装等领域的应用受到限制。近年来,异山梨醇(IS)作为生物基可再生单体、无毒无害,是目前最有希望代替双酚A合成聚碳酸酯的关键原料,用其合成的异山梨醇型聚碳酸酯(IS-PC)具有无毒及优异的光学性能、耐划伤性、热稳定性、生物降解性和生物相容性等,已在包装、汽车、电子电器、生物医学等领域显示出良好的应用前景。该文对IS-PC的制备方法及性能调控进行了综述,详细介绍了熔融酯交换法制备IS-PC的研究现状,重点对调控IS-PC性能的方法进行了分类归纳,并对IS-PC的研究方向进行了展望。

关键词：异山梨醇异山梨醇型聚碳酸酯熔融酯交换法催化剂性能调控

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