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The Impact of Transformational Leadership on Commitment to Change Among Jordanian Government Accountant Toward IPSAS Implementation
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作者 Mohammad Abu Zraiq Rosnia Masruki 《Journal of Modern Accounting and Auditing》 2024年第3期73-88,共16页
IPSAS was accepted by Jordan’s government in accordance with worldwide trends.The Jordanian Ministry of Finance launched cash-basis IPSAS in 2015 and planned to implement accrual accounting by January 1,2021.However,... IPSAS was accepted by Jordan’s government in accordance with worldwide trends.The Jordanian Ministry of Finance launched cash-basis IPSAS in 2015 and planned to implement accrual accounting by January 1,2021.However,the commitment to change remains uneven,hindering the full shift.Moving from old accounting processes to new ones is tough.Even then,it hasn’t been implemented,creating a gap due to the difficulty in committing to new accounting standards throughout implementation due to obstacles.Thus,knowing government accountants’issues is essential to applying IPSAS in government accounting.This study examines how transformational leadership affects government accountants’commitment to IPSAS adoption in Jordan’s public sector.This study used a quantitative approach to survey Jordanian Ministry of Finance accountants.The 384-person study had a 78%response rate.Additionally,PLS-SEM was used to confirm variable relationships.Transformational leadership positively predicted IPSAS implementation,according to the study. 展开更多
关键词 IPSAS commitment to change transformational leadership government accountant Ministry of Finance Jordan
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The Effect of Executive Management Support and Cost Accountant Competency on CMS Design Effectiveness and Its Consequences: An Empirical Research of Manufacturing Business in Thailand* 被引量:1
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作者 Nattawut Tontiset 《Journal of Modern Accounting and Auditing》 2018年第2期60-69,共10页
The objective of this research is to examine the antecedents and consequences of cost management systems (CMS) design effectiveness of manufacturing businesses in Thailand. The effect of CMS design effectiveness on ... The objective of this research is to examine the antecedents and consequences of cost management systems (CMS) design effectiveness of manufacturing businesses in Thailand. The effect of CMS design effectiveness on cost information quality is investigated. Moreover, the effect of cost information quality on business success is investigated. Furthermore, executive management support and cost accountant competency are assumed to become the antecedents of CMS design effectiveness. Electronics manufacturing businesses in Thailand are samples of the research. A mail survey procedure via the questionnaire was used for data collection from accounting controllers. The results indicate that CMS design effectiveness has a positive significant effect on cost information quality. Moreover, cost information quality also has a positive significant effect on business success. Additionally, both executive management support and cost accountant competency have a positive significant effect on CMS design effectiveness. 展开更多
关键词 cost management system cost information quality business success executive management support cost accountant competency
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水田动力底盘逆向建模与质心验证——基于Geomagic Design X
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作者 何剑飞 曾志浩 +5 位作者 郭梓游 李贵蓉 钟文能 钟顺 王在满 李庆 《农机化研究》 北大核心 2024年第10期248-253,共6页
针对目前农业机械仿真和优化模型精度不高的问题,提出了一种构建精确模型的逆向建模方法。应用光学扫描仪采集点云数据,基于Geomagic Design X处理点云数据并重构零部件模型,在SolidWorks中完成水田动力底盘的装配。以VP6D-CQ型水田动... 针对目前农业机械仿真和优化模型精度不高的问题,提出了一种构建精确模型的逆向建模方法。应用光学扫描仪采集点云数据,基于Geomagic Design X处理点云数据并重构零部件模型,在SolidWorks中完成水田动力底盘的装配。以VP6D-CQ型水田动力底盘为例,将测得的实际质心位置与所建的模型质心位置进行比较,并对提出的逆向建模方法进行了试验验证以及误差分析。结果表明:总质量、x坐标、y坐标、z坐标的误差值分别为4.55%、3.62%、2.23%、4.81%,误差值均在5%内。此方法可构建准确的三维模型,为后续仿真优化数据精确性奠定了基础,与传统的研发相比较,可缩短农业机械研发周期、降低设计成本。 展开更多
关键词 水田 动力底盘 逆向建模 质心验证 Geomagic design X 数字样机
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App Designer辅助教学方法探索与实践——以软件无线电课程为例
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作者 向新 刘宇峰 +2 位作者 梁源 王瑞 何林远 《中国现代教育装备》 2024年第19期148-151,共4页
软件无线电作为通信学科的必修课程,具有承上启下的重要作用。因课程原理抽象、理论公式复杂,学员在学习过程存在理解掌握难、实践应用难等问题。通过对当前软件无线电教学过程中存在的不足与困难进行分析,提出利用MATLAB App Designer... 软件无线电作为通信学科的必修课程,具有承上启下的重要作用。因课程原理抽象、理论公式复杂,学员在学习过程存在理解掌握难、实践应用难等问题。通过对当前软件无线电教学过程中存在的不足与困难进行分析,提出利用MATLAB App Designer辅助课程教学,从教学准备、课堂互动、自主实验、反馈提升四个方面开展课程教学改革。实践表明,该方法对于提升学员的工程思维、系统思维具有显著效果,同时可以增强学员理论联系实际的能力。 展开更多
关键词 软件无线电 MATLAB App designer 教学方法改革 理实结合
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Alloy design for laser powder bed fusion additive manufacturing:a critical review 被引量:3
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作者 Zhuangzhuang Liu Qihang Zhou +4 位作者 Xiaokang Liang Xiebin Wang Guichuan Li Kim Vanmeensel Jianxin Xie 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第2期29-63,共35页
Metal additive manufacturing(AM)has been extensively studied in recent decades.Despite the significant progress achieved in manufacturing complex shapes and structures,challenges such as severe cracking when using exi... Metal additive manufacturing(AM)has been extensively studied in recent decades.Despite the significant progress achieved in manufacturing complex shapes and structures,challenges such as severe cracking when using existing alloys for laser powder bed fusion(L-PBF)AM have persisted.These challenges arise because commercial alloys are primarily designed for conventional casting or forging processes,overlooking the fast cooling rates,steep temperature gradients and multiple thermal cycles of L-PBF.To address this,there is an urgent need to develop novel alloys specifically tailored for L-PBF technologies.This review provides a comprehensive summary of the strategies employed in alloy design for L-PBF.It aims to guide future research on designing novel alloys dedicated to L-PBF instead of adapting existing alloys.The review begins by discussing the features of the L-PBF processes,focusing on rapid solidification and intrinsic heat treatment.Next,the printability of the four main existing alloys(Fe-,Ni-,Al-and Ti-based alloys)is critically assessed,with a comparison of their conventional weldability.It was found that the weldability criteria are not always applicable in estimating printability.Furthermore,the review presents recent advances in alloy development and associated strategies,categorizing them into crack mitigation-oriented,microstructure manipulation-oriented and machine learning-assisted approaches.Lastly,an outlook and suggestions are given to highlight the issues that need to be addressed in future work. 展开更多
关键词 laser powder bed fusion alloy design PRINTABILITY crack mitigation
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Web Layout Design of Large Cavity Structures Based on Topology Optimization 被引量:1
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作者 Xiaoqiao Yang Jialiang Sun Dongping Jin 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2665-2689,共25页
Large cavity structures are widely employed in aerospace engineering, such as thin-walled cylinders, blades andwings. Enhancing performance of aerial vehicles while reducing manufacturing costs and fuel consumptionhas... Large cavity structures are widely employed in aerospace engineering, such as thin-walled cylinders, blades andwings. Enhancing performance of aerial vehicles while reducing manufacturing costs and fuel consumptionhas become a focal point for contemporary researchers. Therefore, this paper aims to investigate the topologyoptimization of large cavity structures as a means to enhance their performance, safety, and efficiency. By usingthe variable density method, lightweight design is achieved without compromising structural strength. Theoptimization model considers both concentrated and distributed loads, and utilizes techniques like sensitivityfiltering and projection to obtain a robust optimized configuration. The mechanical properties are checked bycomparing the stress distribution and displacement of the unoptimized and optimized structures under the sameload. The results confirm that the optimized structures exhibit improved mechanical properties, thus offering keyinsights for engineering lightweight, high-strength large cavity structures. 展开更多
关键词 Topology optimization lightweight design web layout design cavity structure
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Design Principles and Mechanistic Understandings of Non-Noble-Metal Bifunctional Electrocatalysts for Zinc-Air Batteries 被引量:2
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作者 Yunnan Gao Ling Liu +10 位作者 Yi Jiang Dexin Yu Xiaomei Zheng Jiayi Wang Jingwei Liu Dan Luo Yongguang Zhang Zhenjia Shi Xin Wang Ya‑Ping Deng Zhongwei Chen 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第9期13-48,共36页
Zinc-air batteries(ZABs)are promising energy storage systems because of high theoretical energy density,safety,low cost,and abundance of zinc.However,the slow multi-step reaction of oxygen and heavy reliance on noble-... Zinc-air batteries(ZABs)are promising energy storage systems because of high theoretical energy density,safety,low cost,and abundance of zinc.However,the slow multi-step reaction of oxygen and heavy reliance on noble-metal catalysts hinder the practical applications of ZABs.Therefore,feasible and advanced non-noble-metal elec-trocatalysts for air cathodes need to be identified to promote the oxygen catalytic reaction.In this review,we initially introduced the advancement of ZABs in the past two decades and provided an overview of key developments in this field.Then,we discussed the work-ing mechanism and the design of bifunctional electrocatalysts from the perspective of morphology design,crystal structure tuning,interface strategy,and atomic engineering.We also included theoretical studies,machine learning,and advanced characterization technologies to provide a comprehensive understanding of the structure-performance relationship of electrocatalysts and the reaction pathways of the oxygen redox reactions.Finally,we discussed the challenges and prospects related to designing advanced non-noble-metal bifunctional electrocatalysts for ZABs. 展开更多
关键词 Zinc-air batteries Bifunctional electrocatalysts design principles Mechanistic understandings
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Accelerated design of high-performance Mg-Mn-based magnesium alloys based on novel bayesian optimization 被引量:2
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作者 Xiaoxi Mi Lili Dai +4 位作者 Xuerui Jing Jia She Bjørn Holmedal Aitao Tang Fusheng Pan 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第2期750-766,共17页
Magnesium(Mg),being the lightest structural metal,holds immense potential for widespread applications in various fields.The development of high-performance and cost-effective Mg alloys is crucial to further advancing ... Magnesium(Mg),being the lightest structural metal,holds immense potential for widespread applications in various fields.The development of high-performance and cost-effective Mg alloys is crucial to further advancing their commercial utilization.With the rapid advancement of machine learning(ML)technology in recent years,the“data-driven''approach for alloy design has provided new perspectives and opportunities for enhancing the performance of Mg alloys.This paper introduces a novel regression-based Bayesian optimization active learning model(RBOALM)for the development of high-performance Mg-Mn-based wrought alloys.RBOALM employs active learning to automatically explore optimal alloy compositions and process parameters within predefined ranges,facilitating the discovery of superior alloy combinations.This model further integrates pre-established regression models as surrogate functions in Bayesian optimization,significantly enhancing the precision of the design process.Leveraging RBOALM,several new high-performance alloys have been successfully designed and prepared.Notably,after mechanical property testing of the designed alloys,the Mg-2.1Zn-2.0Mn-0.5Sn-0.1Ca alloy demonstrates exceptional mechanical properties,including an ultimate tensile strength of 406 MPa,a yield strength of 287 MPa,and a 23%fracture elongation.Furthermore,the Mg-2.7Mn-0.5Al-0.1Ca alloy exhibits an ultimate tensile strength of 211 MPa,coupled with a remarkable 41%fracture elongation. 展开更多
关键词 Mg-Mn-based alloys HIGH-PERFORMANCE Alloy design Machine learning Bayesian optimization
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A study on accountant regulation and accountant behavior alienation
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作者 GAO Jing-xiao 《Chinese Business Review》 2009年第1期64-66,共3页
This paper describes the relation of accountant regulation and accountant behavior alienation through institutional economics. The creation and development of the accountant regulation are result that restrain account... This paper describes the relation of accountant regulation and accountant behavior alienation through institutional economics. The creation and development of the accountant regulation are result that restrain accountant behavior alienation, accountant behavior alienation is unceasing mutant after the development of accountant regulation. 展开更多
关键词 accountant regulation accountant behavior alienation
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Accounting for natural-climatic conditions in the design of roads in western Siberia
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作者 Vladimir N.Efimenko Sergey V.Efimenko Alexey V.Sukhorukov 《Research in Cold and Arid Regions》 CSCD 2015年第4期307-315,共9页
The paper proposes a methodological scheme that thoroughly accounts for natural-climatic conditions which can impair the stability and longevity of transport facilities (roadways), to ensure the best possible qualit... The paper proposes a methodological scheme that thoroughly accounts for natural-climatic conditions which can impair the stability and longevity of transport facilities (roadways), to ensure the best possible quality of the initial road design. Factors determining the formation of water-heating mode subgrade soils are allocated, and an information database for mathematical modeling of geocomplexes is shown. Values of strength and deformability of clay soils are calculated within the limits of the defined, homogeneous road districts in Western Siberia to provide the required level of reliability of design solutions. 展开更多
关键词 transport facilities road-climatic zoning water-heating mode subgrade soils design geocomplexes
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The Multi-Disciplined Skills Required of Forensic Accountants
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作者 Maria Italia 《Journal of Modern Accounting and Auditing》 2012年第3期365-373,共9页
Forensic accountants today are required to possess a number of characteristics and skills that are derived from a range of disciplines. They must be inquisitive, able to delve into motivations, operations and justific... Forensic accountants today are required to possess a number of characteristics and skills that are derived from a range of disciplines. They must be inquisitive, able to delve into motivations, operations and justifications underlying the behavior of white collar criminals. They must be able to simplify technical accounting information and convey it effectively orally and in writing to a court or tribunal; be able to trace information via information technology tools; have an understanding of the adversarial legal system and the rules of evidence. Universities offering forensic accounting courses in various formats are on the increase. The aim of this paper is to investigate the subject areas that any course specializing in forensic accounting needs to cover. 展开更多
关键词 forensic accounting FRAUD accounting information systems white collar crime
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Inverse design of mechanical metamaterial achieving a prescribedconstitutive curve 被引量:1
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作者 Zongliang Du Tanghuai Bian +4 位作者 Xiaoqiang Ren Yibo Jia Shan Tang Tianchen Cui Xu Guo 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2024年第1期16-22,共7页
Besides exhibiting excellent capabilities such as energy absorption,phase-transforming metamaterials offer a vast design space for achieving nonlinear constitutive relations.This is facilitated by switching between di... Besides exhibiting excellent capabilities such as energy absorption,phase-transforming metamaterials offer a vast design space for achieving nonlinear constitutive relations.This is facilitated by switching between different patterns under deformation.However,the related inverse design problem is quite challenging,due to the lack of appropriate mathematical formulation and the convergence issue in the post-buckling analysis of intermediate designs.In this work,periodic unit cells are explicitly described by the moving morphable voids method and effectively analyzed by eliminating the degrees of freedom in void regions.Furthermore,by exploring the Pareto frontiers between error and cost,an inverse design formulation is proposed for unit cells.This formulation aims to achieve a prescribed constitutive curve and is validated through numerical examples and experimental results.The design approach presented here can be extended to the inverse design of other types of mechanical metamaterials with prescribed nonlinear effective properties. 展开更多
关键词 METAMATERIAL Pattern-transformation Constitutive curve Inverse design
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Why do not accounting graduates want to become accountants?
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作者 Noraini Mohd Nasir Erlane K. Ghani Jamaliah Said 《Journal of Modern Accounting and Auditing》 2009年第5期59-65,共7页
This study searches the reasons why accounting graduates do not want to become members of the Malaysian Institute of Accountants (MIA) and accountants. Ten participants were interviewed. An analysis of their intervi... This study searches the reasons why accounting graduates do not want to become members of the Malaysian Institute of Accountants (MIA) and accountants. Ten participants were interviewed. An analysis of their interview transcripts, using the constant comparative method, discloses the following reasons why they do not register as members: no added benefits to current employment, difficulty in filling in the application forms, high cost of membership and lack of ambition to become accountants. The findings of this study provide insights to the professional accounting bodies and academics on the accounting graduates' lack of interest to become accountants. 展开更多
关键词 accountantS accounting graduates MIA membership
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Machine learning for membrane design and discovery 被引量:1
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作者 Haoyu Yin Muzi Xu +4 位作者 Zhiyao Luo Xiaotian Bi Jiali Li Sui Zhang Xiaonan Wang 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第1期54-70,共17页
Membrane technologies are becoming increasingly versatile and helpful today for sustainable development.Machine Learning(ML),an essential branch of artificial intelligence(AI),has substantially impacted the research an... Membrane technologies are becoming increasingly versatile and helpful today for sustainable development.Machine Learning(ML),an essential branch of artificial intelligence(AI),has substantially impacted the research and development norm of new materials for energy and environment.This review provides an overview and perspectives on ML methodologies and their applications in membrane design and dis-covery.A brief overview of membrane technologies isfirst provided with the current bottlenecks and potential solutions.Through an appli-cations-based perspective of AI-aided membrane design and discovery,we further show how ML strategies are applied to the membrane discovery cycle(including membrane material design,membrane application,membrane process design,and knowledge extraction),in various membrane systems,ranging from gas,liquid,and fuel cell separation membranes.Furthermore,the best practices of integrating ML methods and specific application targets in membrane design and discovery are presented with an ideal paradigm proposed.The challenges to be addressed and prospects of AI applications in membrane discovery are also highlighted in the end. 展开更多
关键词 Machine learning Membranes AI for Membrane DATA-DRIVEN design
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Perception of Forensic Accountants About Elaboration of Free Judicial Expertise in Brazil
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作者 Anna Paula Leal de Sousa Idalberto Jos6 das Neves Jfinior Helder Bueno Leal 《Journal of Modern Accounting and Auditing》 2012年第8期1126-1139,共14页
The Article 23 in the Universal Declaration of Human Rights mentions that all work must have a fair and favorable remuneration. However, in Brazil, the State uses the free legal aid as a way of minimizing the social a... The Article 23 in the Universal Declaration of Human Rights mentions that all work must have a fair and favorable remuneration. However, in Brazil, the State uses the free legal aid as a way of minimizing the social and economic inequality, making it possible for the needy to have access to justice. Through the free legal aid, the litigant is exempted from payment of fees and legal expenses and court, thus, transferring the burden of work to professionals who assist in the judicial process. So, the magistrate can appoint an expert accountant to assist him in the trial of the legal question when the proof requires accounting knowledge. In this way, this article discusses the accounting expertise that is free of charge from the perception of expert accountants. The authors had applied questionnaires in August and September in 2008, and obtained 131 responses and 2,859 data. From this research, the authors observed that the majority of respondents when solicited to work with the possibility of non-payment attended the demand, and believed that this would contribute to society and assist the magistrate. 展开更多
关键词 forensic accounting forensic accountant's honorarium free expertise
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Accountant and Accounting beyond Jokes:an Analysis of Cartoons(1925-2003)
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作者 Ana Paula Paulino da Costa +2 位作者 Elionor Weffort Joanília Neide de Sales Cia JosilmarCordenonssi Cia 《Journal of Business Administration Research》 2020年第1期19-31,共13页
The main purpose of our paper is to identify and analyse the underlying stereotype attributes concerning accountant,accounting and users through cartoons.Doing so,we aim to capture insights of how this spectrum of soc... The main purpose of our paper is to identify and analyse the underlying stereotype attributes concerning accountant,accounting and users through cartoons.Doing so,we aim to capture insights of how this spectrum of society perceives actors involved on accounting issues.Our study also differs from others as our period of analysis is long,79 years,from 1925 to 2003.As we have the advantage of a long period and a popular non-professional database,we can work with multiple actors as accountant,accounting and users,instead of focusing on single one.And the richness of database also allowed splitting these main actors in 7 actors.In order to capture stereotype nuances of multiple actors from a cartoon database,we use discourse analysis method that has been used on other studies of identity but not to study accounting issues.As cartoons are composed by images and texts to give a message,it is richer to analyze discourse beyond images and texts.Our results are mainly consistent with previous studies although we found some different results when considering different periods of time as well new findings about tax actors such as taxpayers,tax agent and tax accounting. 展开更多
关键词 accountant accountING STEREOTYPES Cartoons Popularculture
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Deep Insight of Design,Mechanism,and Cancer Theranostic Strategy of Nanozymes 被引量:1
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作者 Lu Yang Shuming Dong +6 位作者 Shili Gai Dan Yang He Ding Lili Feng Guixin Yang Ziaur Rehman Piaoping Yang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第2期165-217,共53页
Since the discovery of enzyme-like activity of Fe3O4 nanoparticles in 2007,nanozymes are becoming the promising substitutes for natural enzymes due to their advantages of high catalytic activity,low cost,mild reaction... Since the discovery of enzyme-like activity of Fe3O4 nanoparticles in 2007,nanozymes are becoming the promising substitutes for natural enzymes due to their advantages of high catalytic activity,low cost,mild reaction conditions,good stability,and suitable for large-scale production.Recently,with the cross fusion of nanomedicine and nanocatalysis,nanozyme-based theranostic strategies attract great attention,since the enzymatic reactions can be triggered in the tumor microenvironment to achieve good curative effect with substrate specificity and low side effects.Thus,various nanozymes have been developed and used for tumor therapy.In this review,more than 270 research articles are discussed systematically to present progress in the past five years.First,the discovery and development of nanozymes are summarized.Second,classification and catalytic mechanism of nanozymes are discussed.Third,activity prediction and rational design of nanozymes are focused by highlighting the methods of density functional theory,machine learning,biomimetic and chemical design.Then,synergistic theranostic strategy of nanozymes are introduced.Finally,current challenges and future prospects of nanozymes used for tumor theranostic are outlined,including selectivity,biosafety,repeatability and stability,in-depth catalytic mechanism,predicting and evaluating activities. 展开更多
关键词 Nanozymes Classification Prediction and design Catalytic mechanism Tumor theranostics
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Electrolyte Design for Low‑Temperature Li‑Metal Batteries:Challenges and Prospects 被引量:1
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作者 Siyu Sun Kehan Wang +3 位作者 Zhanglian Hong Mingjia Zhi Kai Zhang Jijian Xu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第2期365-382,共18页
Electrolyte design holds the greatest opportunity for the development of batteries that are capable of sub-zero temperature operation.To get the most energy storage out of the battery at low temperatures,improvements ... Electrolyte design holds the greatest opportunity for the development of batteries that are capable of sub-zero temperature operation.To get the most energy storage out of the battery at low temperatures,improvements in electrolyte chemistry need to be coupled with optimized electrode materials and tailored electrolyte/electrode interphases.Herein,this review critically outlines electrolytes’limiting factors,including reduced ionic conductivity,large de-solvation energy,sluggish charge transfer,and slow Li-ion transportation across the electrolyte/electrode interphases,which affect the low-temperature performance of Li-metal batteries.Detailed theoretical derivations that explain the explicit influence of temperature on battery performance are presented to deepen understanding.Emerging improvement strategies from the aspects of electrolyte design and electrolyte/electrode interphase engineering are summarized and rigorously compared.Perspectives on future research are proposed to guide the ongoing exploration for better low-temperature Li-metal batteries. 展开更多
关键词 Solid electrolyte interphase Li metal Low temperature Electrolyte design BATTERIES
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Design,test,and verification of in-situ condition preserved coring and analysis system in lunar-based simulation environment 被引量:1
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作者 Haichun Hao Mingzhong Gao +10 位作者 Yan Wu Zheng Gao Yongcheng Li Xuemin Zhou Peng Chu Xuan Wang Jiahua Li Lang Zhou Jie Song Tianxiang Ao Yikun Yang 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第9期1259-1272,共14页
The lunar surface and its deep layers contain abundant resources and valuable information resources,the exploration and exploitation of which are important for the sustainable development of the human economy and soci... The lunar surface and its deep layers contain abundant resources and valuable information resources,the exploration and exploitation of which are important for the sustainable development of the human economy and society.Technological exploration and research in the field of deep space science,especially lunar-based exploration,is a scientific strategy that has been pursued in China and worldwide.Drilling and sampling are key to accurate exploration of the desirable characteristics of deep lunar resources.In this study,an in-situ condition preserved coring(ICP-Coring)and analysis system,which can be used to test drilling tools and develop effective sampling strategies,was designed.The key features of the system include:(1)capability to replicate the extreme temperature fluctuations of the lunar environment(-185 to 200℃)with intelligent temperature control;(2)ability to maintain a vacuum environment at a scale of 10^(-3) Pa,both under unloaded conditions within Ф580 mm×1000 mm test chamber,and under loaded conditions using Ф400 mm×800 mm lunar rock simulant;(3)application of axial pressures up to 4 MPa and confining pressures up to 3.5 MPa;(4)sample rotation at any angle with a maximum sampling length of 800 mm;and(5)multiple modes of rotary-percussive drilling,controlled by penetration speed and weight on bit(WOB).Experimental studies on the drilling characteristics in the lunar rock simulant-loaded state under different drill bit-percussive-vacuum environment configurations were conducted.The results show that the outgassing rate of the lunar soil simulant is greater than that of the lunar rock simulant and that a low-temperature environment contributes to a reduced vacuum of the lunar-based simulated environment.The rotary-percussive drilling method effectively shortens the sampling time.With increasing sampling depth,the temperature rise of the drilling tools tends to rapidly increase,followed by slow growth or steady fluctuations.The temperature rise energy accumulation of the drill bits under vacuum is more significant than that under atmospheric pressure,approximately 1.47 times higher.The real-time monitored drilling pressure,penetration speed and rotary torque during drilling serve as parameters for discriminating the drilling status.The results of this research can provide a scientific basis for returning samples from lunar rock in extreme lunar-based environments. 展开更多
关键词 Lunar-based Large temperature difference Vacuum Drilling and coring System design
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Molecular Mechanism and Molecular Design of Lubricating Oil Antioxidants 被引量:1
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作者 Su Shuo Long Jun +2 位作者 Duan Qinghua Zhou Han Zhao Yi 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS CSCD 2024年第2期135-145,共11页
To overcome the limitations of traditional experimental“trial and error”methods in lubricant additive design,a new molecular design method based on molecular structure parameters is established here.The molecular me... To overcome the limitations of traditional experimental“trial and error”methods in lubricant additive design,a new molecular design method based on molecular structure parameters is established here.The molecular mechanism of the antioxidant reaction of hindered phenol,diphenylamine,and alkyl sulfide are studied via molecular simulations.Calculation results show that the strong electron-donating ability and high hydrogen-donating activity of the antioxidant molecule and the low hydrogen-abstracting activity of free radicals formed after dehydrogenation are the internal molecular causes of the shielding of phenol and diphenylamine from scavenging peroxy free radicals,and the strong electron-donating ability is the internal molecular cause of the high activity of thioether in decomposing alkyl hydrogen peroxide.Based on this antioxidant molecular mechanism,a molecular design rule of antioxidant is proposed,namely“high EHOMO,large Q(S),low bond dissociation energy BDE(O—H)and BDE(N—H)”.Two new antioxidants,PAS-I and PAS-II,are designed and prepared by chemical bonding of hindered phenol,diphenylamine,and sulfur atoms.Experimental results show that these antioxidants both have excellent antioxidant effects in lubricating oil,and that PAS-II is the superior antioxidant,consistent with theoretical predictions. 展开更多
关键词 lubricating oil ANTIOXIDANT molecular mechanism molecular design antioxidant performance
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