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GENERALIZED JACOBI SPECTRAL GALERKIN METHOD FOR FRACTIONAL-ORDER VOLTERRA INTEGRO-DIFFERENTIAL EQUATIONS WITH WEAKLY SINGULAR KERNELS

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Journal of Computational Mathematics 2024年第2期42卷 355-371页

作者： Yanping chen Zhenrong chen Yunqing Huang School of Mathematical Sciences South China Normal UniversityGuangzhou 510631China Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan UniversityXiangtan 411105China

For fractional Volterra integro-differential equations(FVIDEs)with weakly singular kernels,this paper proposes a generalized Jacobi spectral Galerkin *** basis functions for the provided method are selected generalized Jacobi functions(GJFs),which can be utilized as natural basis functions of spectral methods for weakly singular FVIDEs when appropriately *** developed method's spectral rate of convergence is determined using the L^(∞)-norm and the weighted L^(2)-*** results indicate the usefulness of the proposed method.

关键词： Generalized Jacobi spectral Galerkin method Fractional-order Volterra integ-ro-differential equations Weakly singular kernels Convergence analysis

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中国水泥出口贸易的隐含环境影响核算

复旦学报（自然科学版） 2022年第4期61卷 485-494页

作者：徐晓臻黄蓓佳苑静陈妍希上海理工大学环境与建筑学院上海200093

本研究旨在核算中国水泥出口贸易的隐含环境影响,为国际贸易环境污染转移的评估提供更加贴近实际生产的研究思路,也为国家制定水泥出口贸易相关政策提供参考。采用线性回归法估算水泥出口省份的生产工艺结构,结合全生命周期方法评价分... 详细信息

本研究旨在核算中国水泥出口贸易的隐含环境影响,为国际贸易环境污染转移的评估提供更加贴近实际生产的研究思路,也为国家制定水泥出口贸易相关政策提供参考。采用线性回归法估算水泥出口省份的生产工艺结构,结合全生命周期方法评价分析不同水泥生产技术的环境影响,并基于以上信息核算中国水泥出口贸易的隐含环境负荷。研究结果显示,2005年—2014年间山东和江苏是中国水泥出口主要省份,各省水泥窑技术从立窑和其他回转窑逐渐向新型干法水泥窑工艺转变,也带来了显著的环境效益。水泥生产主要的环境影响包括化石能源消耗、气候变化、光化学臭氧形成、颗粒物形成、陆地酸化。本研究强调了工业产品在生产地的技术水平对产品出口贸易隐含环境影响的重要性,同时其也受到贸易政策、市场需求等因素的影响。

关键词：水泥出口国际贸易水泥生产工艺全生命周期隐含环境影响

Deformation-based longitudinal equivalent stiffness beam model for shield tunnel and its application in seismic deformation method

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Underground Space 2024年第4期17卷 280-299页

作者： Pingliang chen Ping Geng Junbo chen Qi Yang Key Laboratory of Transportation Tunnel Engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China State Key Laboratory of Intelligent Geotechnics and Tunnelling Chengdu 610031China Technology Center of Sichuan Road&Bridge Group Co. LtdChengdu 610041China

In the longitudinal seismic deformation method for shield tunnels,one of the most commonly used is the longitudinal equivalent stiffness beam model(LES)for simulating the mechanical behavior of the *** this model,axial deformation and bending deformation are independent,so the equivalent stiffness is a constant ***,the actual situation is that axial deformation and bending deformation occur simultaneously,which is not considered in *** present,we are not clear about the effect on the calculation results when axial deformation and bending deformation occur ***,in this paper,we improve the traditional LES by taking the relative deformation as a load and considering the coordinated deformation of axial and bending degrees of *** improved model is called DNLES,and its neutral axis equations are an explicit ***,we propose an iterative algorithm to solve the calculation model of the DNLES-based longitudinal seismic deformation *** a calculation example,we find that the internal forces based on LES are notably underestimated than those of DNLES in the compression bending zone,while are overestimated in the tension bending *** considering the combined effect,the maximum bending moment reached 13.7 times that of the LES model,and the axial pressure and tension were about 1.14 and 0.96 times,*** analysis reveals the coordinated deformation process in the axial and bending directions of the shield tunnel,which leads to a consequent change in equivalent *** explains why,in the longitudinal seismic deformation method,the traditional LES may result in unreasonable calculation results.

关键词： Shield tunnel Longitudinal seismic deformation method Longitudinal equivalent stiffness beam Combined axial and bending deformation

Recent Advances in Nickel Catalyzed Carbonylative Reactions via the Insertion of Carbon Monoxide

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Chinese Journal of Chemistry 2024年第2期42卷 177-189页

作者： Xinzhou chen Gang chen Zhong Lian Department of Dermatology State Key Laboratory of Biotherapy and Cancer CenterWest China HospitalSichuan UniversityChengduSichuan 610041China

Carbonyl compounds have attracted considerable attention due to their extensive applications in drug ***,they are important synthetic intermediates for the construction of carbon-carbon and carbon-heteroatom ***-metal-catalyzed carbonylation via the insertion of co is one of the most efficient and straightforward strategies to access carbonyl ***,most of the transition-metal-catalyzed carbonylative reactions require expensive and toxic noble-metal ***,there is a growing demand for the exploration of nickel-catalyzed carbonylative reactions via the insertion of CO due to the earth abundance and low cost of *** with the well-established palladium-catalyzed carbonylative reactions,nickel-catalyzed analogous transformations have been relatively *** is primarily because CO strongly binds to nickel,often resulting in catalyst *** recent years,some research groups have focused on using CO surrogates or NN_(2) pincer nickel catalyst to circumvent the formation of Ni(CO)_(4).Nickel-catalyzed carbonylation has been applied in the construction of carbonyl-containing compounds,such as ketones,carboxylic acids,thioesters,acyl chloride and carboxamides.

关键词： Carbonylation Nickel catalysis Carbon monoxide C1 chemistry Carbonyl-containing compounds

High-Level Security Dimension Evaluation of Blockchain BaaS System and Key Technology

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China Communications 2024年第6期21卷 176-191页

作者： chen Wanfa Zheng Qing’an chen Shuzhen Fu Hongyi chen Liang Fujian Police College Fuzhou 350007China Computer Science and Information Security Management Department Fujian Police CollegeFuzhou 350007China Fujian Province Key Laboratory for Digital Network Crime Supervision and Prevention Fuzhou 350007China Beijing University of Posts and Telecommunications Beijing 100876China Fujian Provincial Prison Administration Fuzhou 350002China

In recent years,blockchain technology integration and application has gradually become an important driving force for new technological innovation and industrial *** blockchain technology and applications are developing rapidly,the emerging security risks and obstacles have gradually become *** can still find security issues in blockchain systems and conduct attacks,causing increasing losses from network attacks every *** response to the current demand for blockchain application security detection and assessment in all industries,and the insufficient coverage of existing detection technologies such as smart contract detectiontechnology,this paper proposes a blockchain core technology security assessment system model,and studies the relevant detection and assessment key technologies and systems.A security assessment scheme based on a smart contract and consensus mechanism detection scheme is *** the underlying blockchain architecture supports the traceability of detection results using super ***,the functionality and performance of the system were tested,and the test results show that the model and solutions proposed in this paper have good feasibility.

关键词： blockchain security consensus mechanis smart contract

Blockchain-based immunization against kleptographic attacks

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Science China(Information Sciences) 2024年第7期67卷 172-183页

作者： Changsong JIANG Chunxiang XU Jie chen Kefei chen School of Computer Science and Engineering University of Electronic Science and Technology of China Yangtze Delta Region Institute (Huzhou) University of Electronic Science and Technology of China Department of Mathematics Hangzhou Normal University

Adversarial implementations of cryptographic primitives called kleptographic attacks cause the leakage of secret information. Subliminal channel attacks are one of the kleptographic attacks. In such attacks, backdoors are embedded in implementations of randomized algorithms to elaborately control randomness generation, such that the secrets will be leaked from biased outputs. To thwart subliminal channel attacks, double-splitting is a feasible solution, which splits the randomness generator of a randomized algorithm into two independent generators. In this paper, we instantiate double-splitting to propose a secure randomness generation algorithm dubbed SRG using two physically independent generators: ordinary and public randomness generators. Based on public blockchains, we construct the public randomness generator,which can be verified publicly. Hashes of a sufficient number of consecutive blocks that are newly confirmed on a blockchain are used to produce public randomness. In SRG, outputs from the two generators are taken as inputs of an immunization function. SRG accomplishes immunization against subliminal channel ***, we discuss the application strategies of SRG for symmetric and public-key encryption.

关键词： kleptographic attacks subliminal channel blockchain immunization randomized algorithm

基于计算机辅助术前计划的胫骨远端内侧单钢板结合拉力螺钉治疗pilon骨折

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中华骨科杂志 2019年第9期39卷 543-549页

作者：强敏菲张坤陈雁西贾小阳陈松王暑光王雄同济大学附属东方医院创伤骨科上海200120

目的探讨基于计算机辅助术前计划的胫骨远端内侧单钢板结合拉力螺钉治疗pilon骨折的疗效。方法回顾性分析2013年1月至2016年12月,应用胫骨远端内侧钢板结合拉力螺钉治疗27例pilon骨折患者资料,男16例,女11例;年龄21~67岁,平均47.7岁;按A... 详细信息

目的探讨基于计算机辅助术前计划的胫骨远端内侧单钢板结合拉力螺钉治疗pilon骨折的疗效。方法回顾性分析2013年1月至2016年12月,应用胫骨远端内侧钢板结合拉力螺钉治疗27例pilon骨折患者资料,男16例,女11例;年龄21~67岁,平均47.7岁;按AO/OTA分型,均为43-C型;按Rüedi-Allgower分型:Ⅱ型5例,Ⅲ型22例;其中19例合并腓骨骨折。所有病例术前均采用计算机辅助术前计划进行损伤细节分析、骨折模拟复位、虚拟手术评估。记录术前计划所需时间,评估术前计划在术中的实现情况;记录手术时间、术中出血量及术前、术后踝关节活动度。末次随访采用美国足踝外科协会(American Orthopaedic Foot and Ankle Society,AOFAS)踝-后足评分、视觉模拟评分(visual analogue scale,VAS)评估临床疗效。结果计算机辅助术前设计总耗时平均25.8 min(范围,14~30 min)。所有患者术前设计方案在术中均顺利实施,平均手术时间(138.5±27.0)min,术中出血量(225.9±87.0)ml。27例患者均获得随访,随访时间12~27个月,平均(18.6±4.1)个月。末次随访时,踝关节活动度较术前明显改善;AOFAS踝-后足评分平均为(82.9±12.1)分,VAS评分为(2.7±1.6)分,均较术前明显改善,术前及术后比较差异均有统计学意义(t=-19.358,7.720;均P<0.001)。结论采用计算机辅助术前计划系统操作可高效、便捷、快速制定pilon骨折的虚拟手术计划,同时可在术中有效辅助精准实施胫骨内侧单钢板结合拉力螺钉治疗C型pilon骨折,并取得满意的临床疗效。

关键词：胫骨骨折骨折固定术,内内固定器计算机辅助设计成像,三维

Goal-Oriented Control Systems(GOCS):From HOW to WHAT

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 816-819页

作者： Wen-Hua chen the Department of Aeronautical and Automotive Engineering Loughborough UniversityLeicestershireLE113TUU.K.

Brief:New control theory is required to underpin safe design and deployment of future highly automated systems to deal with uncertain environments and complicated tasks,enabled by AI and other advanced ***-Oriented Control Systems offer potential to transform the control system design from currently instructing a control system how to perform a task to specifying what is to be achieved.

关键词： automated instru system

From ore to MOF: A case of MIL-100(Fe) production from iron ore concentrates

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Progress in Natural Science:Materials International 2024年第1期34卷 66-73页

作者： Miao Chang Chiyao Tang Chong-chen Wang chen Zhao Beijing Key Laboratory of Functional Materials for Building Structure and Environment Remediation School of Environment and Energy Engineering Beijing University of Civil Engineering and Architecture

Within this work, iron ore concentrates instead of elemental iron Fe0and iron salts like Fe（NO3）3and FeCl3were selected as iron source to prepare MIL-100（Fe）(labeled as MIL-100（Fe）-ore). The corresponding synthesis cost is reduced to half of the MIL-100（Fe） produced from elemental iron and iron salts. As well, the unreacted iron ore concentrates can be easily separated from the as-prepared MIL-100（Fe）-ore by magnetic to facilitate the purification process, free of the strong acids to wash the residual iron. The as-obtained MIL-100（Fe）-ore with Langmuir surface area up to 2281.6 m2g-1displayed long-term chemical stability. Furthermore, the sorption capacity of MIL-100（Fe）-ore towards malachite green（MG） is up to 522.3 mg g-1at 25℃ and initial pH = 3.2, higher than that of MIL-100（Fe） yielded by conventional hydrothermal process. Finally, the production cost and life cycle assessment of MIL-100（Fe）-ore were compared with other traditional production procedures. The results revealed that our work greatly reduced the synthesis cost and enhanced the environmental sustainability.

关键词： Metal-organic framework Iron ore concentrates Adsorption Life cycle assessment