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Microstructure evolution of Al_(0.6)CoCrFeNi high entropy alloy powder prepared by high pressure gas atomization

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Transactions of Nonferrous Metals Society of China 2018年第5期28卷 939-945页

作者： Shang-cheng ZHOU Peng ZHANG Yun-fei XUE Fu-chi WANG Lu WANG Tang-qing CAO Zhen TAN bao-ynan cheng Ben-peng WANG School of Materials Science and Engineering Beijing Institute of Technology Beijing 100081 China National Key Laboratory of Science and Technology on Materials under Shock and Impact Beijing Institute of Technology Beijing 100081 China College of Materials Science and Engineering Beijing University of Technology Beijing 100124 China

The influence of cooling rate on the microstructure of Al0.6CoCrFeNi high entropy alloy（HEA） powders was investigated. The spherical HEA powders（D50≈78.65 μm） were prepared by high pressure gas atomization. The different cooling rates were achieved by adjusting the powder diameter. Based on the solidification model, the relationship between the cooling rate and the powder diameter was developed. The FCC phase gradually disappears as particle size decreases. Further analysis reveals that the phase structure gradually changes from FCC＋BCC dual-phase to a single BCC phase with the increase of the cooling rate. The microstructure evolves from planar crystal to equiaxed grain with the cooling rate increasing from 3.19×10^4 to 1.11×10^6 K/s.

关键词： Al0.6CoCrFeNi high entropy alloy high pressure gas atomization spherical powder microstructure cooling rate

CO2-facilitated upcycling of polyolefin plastics to aromatics at low temperature

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National Science Review 2024年第5期11卷 236-243页

作者： Yi Ding Shuchi Zhang cheng Liu Yu Shao Xiulian Pan Xinhe bao State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences University of Chinese Academy of Sciences Department of Chemical Physics University of Science and Technology of China

Plastics are one of the most produced synthetic materials and largest commodities, used in numerous sectors of human life. To upcycle waste plastics into value-added chemicals is a global challenge. Despite significant progress in pyrolysis and hydrocracking, which mainly leads to the formation of pyrolysis oil,catalytic upcycling to value-added aromatics, including benzene, toluene and xylene（BTX）, in one step, is still limited by high reaction temperatures（>500°C） and a low yield. We report herein CO2-facilitated upcycling of polyolefins and their plastic products to aromatics below 300°C, enabled by a bifunctional Pt/Mn Ox-ZSM-5 catalyst. ZSM-5 catalyzes cracking of polyolefins and aromatization, generating hydrogen at the same time, while Pt/Mn Ox catalyzes the reaction of hydrogen with CO2, consequently driving the reaction towards aromatization. Isotope experiments reveal that 0.2 kg CO2is consumed per 1.0 kg polyethylene and 90% of the consumed CO2is incorporated into the aromatic products. Furthermore, this new process yields 0.63 kg aromatics（BTX accounting for 60%）, comparing favorably with the conventional pyrolysis or hydrocracking processes, which produce only 0.33 kg aromatics. In this way, both plastic waste and the greenhouse gas CO2are turned into carbon resources, providing a new strategy for combined waste plastics upcycling and carbon dioxide utilization.

关键词： polyolefins carbon dioxide aromatics upcycling bifunctional catalysis

Assembly of peptide nanostructures with controllable sizes

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Nano Research 2024年第1期17卷 151-161页

作者： Dan cheng Fan Jia Yun-bao Jiang Vincent P.Conticello Tao Jiang The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation Department of ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361005China Department of Chemistry Emory UniversityAtlanta 30033USA

Controlled peptide assembly offers significant promise to develop synthetic supramolecular nanostructures to display material and biological properties that mimic protein assemblies in *** the progress in forming peptide nanostructures of various morphology,there exists a distinct gap between natural and synthetic assembly systems in terms of size *** nanostructures with a narrow size distribution that can be tuned over a wide range of length-scales is essential for applications that require precise spacing between *** approach provides the opportunity to correlate materials and biological properties of interest with assembly *** this review,we discuss representative endeavors over the past two decades for design of size-controllable peptide nanostructures using tunable building *** mechanisms for size control,e.g.,molecular frustration,template-directed peptide assembly,and multi-component peptide co-assembly,will also be *** also demonstrate the applicable scopes of these strategies and suggest potential future avenues for scientific advances in this field.

关键词： peptide assembly controllable size template multi-component

A new method for evaluating wedges of steel plates and strips

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Journal of Iron and Steel Research International 2024年第7期31卷 1719-1735页

作者： Xiao-bao Ma Xiao-xin Ma Tao Wang Zhong-kai Ren Yu-cheng Ren College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan 030024ShanxiChina Ministry of Education Engineering Research Center of Advanced Metal Composite Forming Technology and Equipment Taiyuan University of TechnologyTaiyuan 030024ShanxiChina National Key Laboratory of Metal Forming Technology and Heavy Equipment Taiyuan University of TechnologyTaiyuan 030024ShanxiChina China National Heavy Machinery Research Institute Co. Ltd.Xi'an 710018ShaanxiChina Faculty of Mechanical Engineering Hebei University of ArchitectureZhangjiakou 075000HebeiChina

To overcome the inaccuracy problem of the traditional wedge evaluation of steel plates and strips caused by the ran-domness of the thicknesses of two local points and improve the reliability of the wedge index,the double-centroid method for the wedge evaluation was proposed,and a model based on the centroid theory was ***,an integral model for the discrete thickness values of the cross-section profiles was *** discussion focused on the distinct characteristics of the two-point method,asymmetric method,and double-centroid method in evaluating the asymmetric distribution of *** three methods were employed to evaluate the wedge values of both the theoretical and measured cross-sections of steel plates and strips,and the accuracies of three wedge evaluation models were analyzed and *** results showed that the double-centroid method objectively reflects the degree and variation characteristics of the wedge values of the cross-sections of steel plates and strips,and this method is feasible,reliable,and outstanding.

关键词： Steel plate and strip Wedge Two-point method Double-centroid method Reliability

Lung ultrasound score evaluation of the effect of pressure-controlled ventilation volume-guaranteed on patients undergoing laparoscopicassisted radical gastrectomy

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World Journal of Gastrointestinal Surgery 2024年第6期16卷 1717-1725页

作者： Jian Tan cheng-Ming bao Xiao-Yuan Chen Department of Critical Care Medicine Lishui District People's HospitalNanjing 211200Jiangsu ProvinceChina Department of Ultrasound Medicine Lishui District People's HospitalNanjing 211200Jiangsu ProvinceChina

BACKGROUND Laparoscopic-assisted radical gastrectomy(LARG)is the standard treatment for early-stage gastric carcinoma(GC).However,the negative impact of this proce-dure on respiratory function requires the optimized intraoperative management of patients in terms of *** To investigate the influence of pressure-controlled ventilation volume-guaranteed(PCV-VG)and volume-controlled ventilation(VCV)on blood gas analysis and pulmonary ventilation in patients undergoing LARG for GC based on the lung ultrasound score(LUS).METHODS The study included 103 patients with GC undergoing LARG from May 2020 to May 2023,with 52 cases undergoing PCV-VG(research group)and 51 cases undergoing VCV(control group).LUS were recorded at the time of entering the operating room(T0),20 minutes after anesthesia with endotracheal intubation(T1),30 minutes after artificial pneumoperitoneum(PP)establishment(T2),and 15 minutes after endotracheal tube removal(T5).For blood gas analysis,arterial partial pressure of oxygen(PaO_(2))and partial pressure of carbon dioxide(PaCO_(2))were *** airway pressure(P_(peak)),plateau pressure(Pplat),mean airway pressure(P_(mean)),and dynamic pulmonary compliance(C_(dyn))were recorded at T1 and T2,1 hour after PP establishment(T3),and at the end of the operation(T4).Postoperative pulmonary complications(PPCs)were ***-and postoperative serum interleukin(IL)-1β,IL-6,and tumor necrosis factor-α(TNF-α)were measured by enzyme-linked immunosorbent *** Compared with those at T0,the whole,anterior,lateral,posterior,upper,lower,left,and right lung LUS of the research group were significantly reduced at T1,T2,and T5;in the control group,the LUS of the whole and partial lung regions(posterior,lower,and right lung)decreased significantly at T2,while at T5,the LUS of the whole and some regions(lateral,lower,and left lung)increased *** comparison with the control group,the whole and regional LUS of the research group were reduc

关键词： Lung ultrasound score Pressure-controlled ventilation volume-guaranteed Laparoscopic-assisted radical gastrectomy Blood gas analysis indexes Pulmonary ventilation

Degradation analysis and doping modification optimization for high-voltage P-type layered cathode in sodium-ion batteries

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Journal of Energy Chemistry 2024年第2期89卷 1-9,I0002页

作者： bao Zhang Yi Zhao Minghuang Li Qi Wang Lei cheng Lei Ming Xing Ou Xiaowei Wang National Engineering Laboratory for High-Efficiency Recovery of Refractory Nonferrous Metals School of Metallurgy and EnvironmentCentral South UniversityChangsha 410083HunanChina Zhejiang Power New Energy Co. LTDZhuji 311800ZhejiangChina

Advancing high-voltage stability of layered sodium-ion oxides represents a pivotal avenue for their progress in energy storage *** this,a comprehensive understanding of the mechanisms underpinning their structural deterioration at elevated voltages remains insufficiently *** this study,we unveil a layer delamination phenomenon of Na_(0.67)Ni_(0.3)Mn_(0.7)O_(2)(NNM)within the 2.0-4.3 V voltage,attributed to considerable volumetric fluctuations along the c-axis and lattice oxygen reactions induced by the simultaneous Ni^(3+)/Ni^(4+)and anion redox *** introducing Mg doping to diminished Ni-O antibonding,the anion oxidation-reduction reactions are effectively mitigated,and the structural integrity of the P2 phase remains firmly intact,safeguarding active sites and precluding the formation of novel *** Na_(0.67)Mg_(0.05)Ni_(0.25)Mn_(0.7)O_(2)(NMNM-5)exhibits a specific capacity of100.7 mA h g^(-1),signifying an 83%improvement compared to the NNM material within the voltage of2.0-4.3 *** investigation underscores the intricate interplay between high-voltage stability and structural degradation mechanisms in layered sodium-ion oxides.

关键词： Soidum ion batteries Layer cathode materials P-type High-voltage performance Degradation analysis

Quantifying the Temporal and Spatial Spread of COVID-19:Empirical Evidence from Shanghai

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Journal of Systems Science and Information 2024年第3期12卷 309-322页

作者： Haowen bao Zishu cheng Yuying SUN Yongmiao HONG Shouyang WANG Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China School of Economics and Management and MOE Social Science Laboratory of Digital Economic Forecasts and Policy SimulationUniversity of Chinese Academy of SciencesBeijing 100190China School of Entrepreneurship and Management ShanghaiTech UniversityShanghai 201210China

The worldwide spread of COVID-19 has caused a grave threat to human life, health, and socio-economic development. It is of great significance to study the transmission mechanism of COVID-19 and evaluate the effect of epidemic prevention policies. This paper employs a spatial dynamic panel data(SDPD) model to analyze the temporal and spatial spread of COVID-19, incorporating the time-varying features of epidemic transmission and the impact of geographic *** studies on the COVID-19 outbreak in Shanghai during early 2022 show that the intra-regional transmission of COVID-19 dominated the cross-regional one. Additionally, strict policies are found to effectively reduce the transmission risk of COVID-19 and curb the spillover effect of the epidemic in Shanghai on other regions. Based on these results, we provide three policy suggestions. Furthermore,this research methodology can be extended to investigate other infectious diseases, thereby providing a scientific framework and theoretical basis for evaluating the spread risk of pandemics and formulating appropriate strategies.

关键词： COVID-19 spatial econometrics epidemic prevention policy dynamic

Bone marrow mesenchymal stem cells in treatment of peripheral nerve injury

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World Journal of Stem Cells 2024年第8期16卷 799-810页

作者： Xiong-Fei Zou bao-Zhong Zhang Wen-Wei Qian Florence Mei cheng Department of Orthopedic Surgery Peking Union Medical College HospitalBeijing 100730China College of Nursing The Ohio State UniversityOhioOH 43210United States

Peripheral nerve injury(PNI)is a common neurological disorder and complete functional recovery is difficult to *** recent years,bone marrow mesenchymal stem cells(BMSCs)have emerged as ideal seed cells for PNI treatment due to their strong differentiation potential and autologous trans-plantation *** review aims to summarize the molecular mechanisms by which BMSCs mediate nerve repair in *** key mechanisms discussed include the differentiation of BMSCs into multiple types of nerve cells to promote repair of nerve *** also create a microenvironment suitable for neuronal survival and regeneration through the secretion of neurotrophic factors,extracellular matrix molecules,and adhesion ***,BMSCs release pro-angiogenic factors to promote the formation of new blood *** modulate cytokine expression and regulate macrophage polarization,leading to ***,BMSCs synthesize and release proteins related to myelin sheath formation and axonal regeneration,thereby promoting neuronal repair and ***,this review explores methods of applying BMSCs in PNI treatment,including direct cell trans-plantation into the injured neural tissue,implantation of BMSCs into nerve conduits providing support,and the application of genetically modified BMSCs,among *** findings confirm the potential of BMSCs in treating ***,with the development of this field,it is crucial to address issues related to BMSC therapy,including establishing standards for extracting,identifying,and cultivating BMSCs,as well as selecting application methods for BMSCs in PNI such as direct transplantation,tissue engineering,and genetic *** these issues will help translate current preclinical research results into clinical practice,providing new and effective treatment strategies for patients with PNI.

关键词： Bone marrow mesenchymal stem cells Peripheral nerve injury Schwann cells Myelin sheath Tissue engineering

Molecule-based vertical transistor via intermolecular charge transport throughπ-πstacking

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Nano Research 2024年第5期17卷 4573-4581页

作者： cheng Liu cheng Fu Lingyu Tang Jianghua Wu Zhangyan Mu Yamei Sun Yanghang Pan Bailin Tian Kai bao Jing Ma Qiyuan He Mengning Ding Key Laboratory of Mesoscopic Chemistry School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China Jiangsu Key Laboratory of Advanced Organic Materials School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China National Laboratory of Solid State Microstructures Jiangsu Key Laboratory of Artificial Functional MaterialsCollege of Engineering and Applied SciencesCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China Department of Materials Science and Engineering City University of Hong KongHong Kong 999077China

Theπ-πstacking is a well-recognized intermolecular interaction that is responsible for the construction of electron hopping channels in numerous conducting frameworks/***,the exact role ofπ-to-πchannels within typical single crystalline organic semiconductors remains unclear as the orientations of these molecules are diverse,and their control usually requires additional side chain groups that misrepresent the intrinsic properties of the original semiconducting ***,the construction of conduction channels with intrinsicπ-πstacking in the molecule-based device is crucial for the utilization of their unique transport characteristics and understanding of the transport *** this end,we present a molecular intercalation strategy that integrates two-dimensional layered materials with functional organic semiconductor molecules for functional molecule-based *** organic semiconductor molecules can be effectively intercalated into the van der Waals gaps of semi-metallic TaS_(2) withπ-πstacking configuration and controlled intercalant *** results show that the vertical charge transport in the stacking direction shows a tunneling-dominated mechanism that strongly depends on the molecular ***,we demonstrated a new type of molecule-based vertical transistor in which TaS_(2) andπ-πstacked organic molecules function as the electrical contact and the active channel,***/off ratios as high as 447 are achieved under electrostatic modulation in ionic liquid,comparable to the current state-of-the-art molecular *** study provides an ideal platform for probing intrinsic charge transport acrossπ-πstacked conjugated molecules and also a feasible approach for the construction of high-performance molecule-based electronic devices.

关键词： π-πstacking electrochemical intercalation organic semiconductor electrical transport tunneling field effect transistor