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Reductive denitrification of nitrate by scrap iron filings 被引量:2
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作者 郝志伟 徐新华 汪大翚 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE EI CAS CSCD 2005年第3期182-186,共5页
Reduction of nitrate by zero-valent iron is a highly exergonic reaction that has long been known to occur. Use of scrap iron filings (SIF) as the PRB (Permeable Reactive Barrier) material can be used to recycle certai... Reduction of nitrate by zero-valent iron is a highly exergonic reaction that has long been known to occur. Use of scrap iron filings (SIF) as the PRB (Permeable Reactive Barrier) material can be used to recycle certain by-products, and identify cheaper replacements for expensive conventional PRB materials, especially pure metallic iron. The feasibility of reductive denitrification of nitrate by SIF was studied by batch experiments. Operational parameters such as pH value, SIF dosage and initial concentration of nitrate were investigated. The removal efficiency of nitrate reached 80% under the conditions of pH of 2.5, nitrate initial con- centration of 45 mg/L and SIF dosage of 100 g/L within 4 h. Results indicated that nitrate removal is inversely related to pH. Low pH value condition favors for the nitrate transformation. Different from the results of others who studied nitrate reduction using iron powder, we found that there was a lag time before nitrate reduction occurs, even at low pH. Finally, the possible mechanism of nitrate reduction by Fe0 is discussed. 展开更多
关键词 DENITRIFICATION Scrap iron filings (SIF) Zero-valent iron NITRATE MECHANISM
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Effects of Steel Fibers and Iron Filings on Thermal and Mechanical Properties of Concrete for Energy Storage Application
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作者 A.A. Adeyanju K. Manohar 《Journal of Minerals and Materials Characterization and Engineering》 2011年第15期1429-1448,共20页
An experimental study on the thermal properties of iron filings and steel-fiber-reinforced concrete for solar/thermal energy storage application is presented in this report. It takes into account the results of measur... An experimental study on the thermal properties of iron filings and steel-fiber-reinforced concrete for solar/thermal energy storage application is presented in this report. It takes into account the results of measurements of thermal conductivity, thermal resistivity, thermal diffusivity and the results of compressive strength, density as well as energy storage capacity calculated from the knowledge of the above measured parameters. The experimental testing method is described as well: based upon the linear heat source theory, it requires the use of a special probe to be inserted into the sample. The experimentation was forwarded to test concrete aggregate mixtures with three different sizes and same quantity of steel fibers;two different quantities of iron filings and one plain concrete. The measurements were carried out from the pouring time of cubic samples and were ended up when hardened conditions were achieved. The results indicate that the steel fibers and iron filings have influence on the thermal and mechanical properties of the concretes tested, thus the iron filings and steel fibers reinforced concrete is suitable for better solar/thermal energy storage due to an increase in storage capacity over plain concrete. 展开更多
关键词 Steel FIBER IRON filings REINFORCED CONCRETE Thermal properties LINEAR HEAT sourcetheory.
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ZTE Attains Global No.1 Spot for PCT Patent Filings
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作者 ZTE Corporation 《ZTE Communications》 2012年第1期F0002-F0002,共1页
According to the website of the World Intellectual Property Organization, ZTE filed for 2826 applications in 2011. The company moved up from its No. 2 spot in 2010 The statistics also show consistent growth in the num... According to the website of the World Intellectual Property Organization, ZTE filed for 2826 applications in 2011. The company moved up from its No. 2 spot in 2010 The statistics also show consistent growth in the number of international patents that ZTE has filed over the past five years. The number of patents ZTE filed for grew more than 50 per cent yearonyear in 2011. 展开更多
关键词 ZTE Attains Global No.1 Spot for PCT Patent filings PCT
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An Innovative Approach Using TKN-Cryptology for Identifying the Replay Assault
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作者 Syeda Wajiha Zahra Muhammad Nadeem +6 位作者 Ali Arshad Saman Riaz Muhammad Abu Bakr Ashit Kumar Dutta Zaid Alzaid Badr Almutairi Sultan Almotairi 《Computers, Materials & Continua》 SCIE EI 2024年第1期589-616,共28页
Various organizations store data online rather than on physical servers.As the number of user’s data stored in cloud servers increases,the attack rate to access data from cloud servers also increases.Different resear... Various organizations store data online rather than on physical servers.As the number of user’s data stored in cloud servers increases,the attack rate to access data from cloud servers also increases.Different researchers worked on different algorithms to protect cloud data from replay attacks.None of the papers used a technique that simultaneously detects a full-message and partial-message replay attack.This study presents the development of a TKN(Text,Key and Name)cryptographic algorithm aimed at protecting data from replay attacks.The program employs distinct ways to encrypt plain text[P],a user-defined Key[K],and a Secret Code[N].The novelty of the TKN cryptographic algorithm is that the bit value of each text is linked to another value with the help of the proposed algorithm,and the length of the cipher text obtained is twice the length of the original text.In the scenario that an attacker executes a replay attack on the cloud server,engages in cryptanalysis,or manipulates any data,it will result in automated modification of all associated values inside the backend.This mechanism has the benefit of enhancing the detectability of replay attacks.Nevertheless,the attacker cannot access data not included in any of the papers,regardless of how effective the attack strategy is.At the end of paper,the proposed algorithm’s novelty will be compared with different algorithms,and it will be discussed how far the proposed algorithm is better than all other algorithms. 展开更多
关键词 Replay attack MALWARE message attack file encryption CRYPTOLOGY data security
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Enhancing PDF Malware Detection through Logistic Model Trees
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作者 Muhammad Binsawad 《Computers, Materials & Continua》 SCIE EI 2024年第3期3645-3663,共19页
Malware is an ever-present and dynamic threat to networks and computer systems in cybersecurity,and because of its complexity and evasiveness,it is challenging to identify using traditional signature-based detection a... Malware is an ever-present and dynamic threat to networks and computer systems in cybersecurity,and because of its complexity and evasiveness,it is challenging to identify using traditional signature-based detection approaches.The study article discusses the growing danger to cybersecurity that malware hidden in PDF files poses,highlighting the shortcomings of conventional detection techniques and the difficulties presented by adversarial methodologies.The article presents a new method that improves PDF virus detection by using document analysis and a Logistic Model Tree.Using a dataset from the Canadian Institute for Cybersecurity,a comparative analysis is carried out with well-known machine learning models,such as Credal Decision Tree,Naïve Bayes,Average One Dependency Estimator,Locally Weighted Learning,and Stochastic Gradient Descent.Beyond traditional structural and JavaScript-centric PDF analysis,the research makes a substantial contribution to the area by boosting precision and resilience in malware detection.The use of Logistic Model Tree,a thorough feature selection approach,and increased focus on PDF file attributes all contribute to the efficiency of PDF virus detection.The paper emphasizes Logistic Model Tree’s critical role in tackling increasing cybersecurity threats and proposes a viable answer to practical issues in the sector.The results reveal that the Logistic Model Tree is superior,with improved accuracy of 97.46%when compared to benchmark models,demonstrating its usefulness in addressing the ever-changing threat landscape. 展开更多
关键词 Malware detection PDF files logistic model tree feature selection CYBERSECURITY
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Making waste profitable: Efficient recovery of metallic iron from jarosite residues
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作者 Songshan Zhou Yunhui Han +11 位作者 Rong Huang Yin Huang Qingyuan Dong Haiyin Gang Jinchuan Qin Xi Yu Xiangfei Zeng Wenxing Cao Jiqin Wang Shaoqin Chen Rong Wang Mengjun Chen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第7期66-76,共11页
To address the hazardous by-product of zinc smelting and resource utilization of jarosite residue,this study applies an electric field-assisted hot acid treatment to completely recycle iron(Fe).This innovative approac... To address the hazardous by-product of zinc smelting and resource utilization of jarosite residue,this study applies an electric field-assisted hot acid treatment to completely recycle iron(Fe).This innovative approach aims to enhance the leaching efficiency of Fe from jarosite residue.The introduction of an electric field changes the charge distribution on the surface of the particles to enhance ions and electrons exchange and promotes the collision between particles to strengthen reaction kinetics.Based on the above,the leaching efficiency of Fe in jarosite under sulfuric acid attack has improved observably.The result shows that Fe leaching efficiency reaches 98.83%,which is increased by 28%under the optimal experimental conditions:current density of 30 mA·cm^(-2),H_(2)SO_(4) concentration of 1.5 mol·L^(-1),solid-liquid ratio of 70 g·L^(-1),temperature of 80℃ and time of 12 h.Leaching kinetics calculations show that the apparent activation energy is 16.97 kJ·mol^(-1) and the leaching of jarosite residue is controlled by a mixture of chemical reaction and diffusion,as well as the temperature and concentration of the leaching solution have an influence on leaching.This work provides a feasible idea for the efficient leaching of Fe from jarosite residue. 展开更多
关键词 Jarosite residue Electric filed Leaching kinetics
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Molecular Dynamics, Physical Properties, Diffusion Coefficients and Activation Energy of the Lithium Oxide (Li-O) and Sodium Oxide (Na-O) Electrolyte (Cathode)
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作者 Alain Second Dzabana Honguelet Abel Dominique Eboungabeka Timothée Nsongo 《Advances in Materials Physics and Chemistry》 CAS 2024年第9期213-234,共22页
This work is a simulation model with the LAMMPS calculation code of an electrode based on alkali metal oxides (lithium, sodium and potassium) using the Lennard Jones potential. For a multiplicity of 8*8*8, we studied ... This work is a simulation model with the LAMMPS calculation code of an electrode based on alkali metal oxides (lithium, sodium and potassium) using the Lennard Jones potential. For a multiplicity of 8*8*8, we studied a gap-free model using molecular dynamics. Physical quantities such as volume and pressure of the Na-O and Li-O systems exhibit similar behaviors around the thermodynamic ensembles NPT and NVE. However, for the Na2O system, at a minimum temperature value, we observe a range of total energy values;in contrast, for the Li2O system, a minimum energy corresponds to a range of temperatures. Finally, for physicochemical properties, we studied the diffusion coefficient and activation energy of lithium and potassium oxides around their melting temperatures. The order of magnitude of the diffusion coefficients is given by the relation Dli-O >DNa-O for the multiplicity 8*8*8, while for the activation energy, the order is well reversed EaNa-O > EaLi-O. 展开更多
关键词 Molecular Dynamics Diffusion Coefficients Activation Energy Lithium Oxide Sodium Oxide Lennard Jones Potential Data File Atomic and Charge Models CATHODE LAMMPS
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更正
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作者 《汽车电器》 2024年第3期11-11,共1页
尊敬的各位读者:因作者笔误,2024年第1期第73页《基于车载以太网的HIL实时仿真测试平台的研究及应用》前言第2行中的“FlexFile”应改成“FlexRay”。2024年第2期第33页《基于车载以太网DolP协议的研究及其在商用车中的应用》前言第3行... 尊敬的各位读者:因作者笔误,2024年第1期第73页《基于车载以太网的HIL实时仿真测试平台的研究及应用》前言第2行中的“FlexFile”应改成“FlexRay”。2024年第2期第33页《基于车载以太网DolP协议的研究及其在商用车中的应用》前言第3行中的“FlexFile”应改成“FlexRay”。 展开更多
关键词 车载以太网 商用车 仿真测试平台 FLEX 行中 FILE
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China’s IP protection spurs growth of foreign patent filings
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《中国专利与商标》 2020年第2期104-104,共1页
Japan,the United States and Germany topped the list of the most patent filings in China in 2019,according to the China’s National Intellectual Property Administration(CNIPA).Market entities from 186 countries and reg... Japan,the United States and Germany topped the list of the most patent filings in China in 2019,according to the China’s National Intellectual Property Administration(CNIPA).Market entities from 186 countries and regions applied for patents and trademarks in China in 2019.Japan. 展开更多
关键词 PROTECTION spurs GROWTH FOREIGN PATENT filings
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Scrap Iron Filings assisted nitrate and phosphate removal in low C/N waters using mixed microbial culture
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作者 Sanjena Narayanasamydamodaran Jian’e Zuo +1 位作者 Haiteng Ren Nawnit Kumar 《Frontiers of Environmental Science & Engineering》 SCIE EI CSCD 2021年第4期215-228,共14页
This study focuses on identifying the factors under which mixed microbial seeds assist bio-chemical denitrification when Scrap Iron Filings(SIF)are used as electron donors and adsorbents in low C/N ratio waters.Batch ... This study focuses on identifying the factors under which mixed microbial seeds assist bio-chemical denitrification when Scrap Iron Filings(SIF)are used as electron donors and adsorbents in low C/N ratio waters.Batch studies were conducted in abiotic and biotic reactors containing fresh and aged SIF under different dissolved oxygen concentrations with NO_(3)^(-)−N and/or PO_(4)^(3−)influent(s)and their nitrate/phosphate removal and by-product formations were studied.Batch reactors were seeded with a homogenized mixed microbial inoculum procured from natural sludges which were enriched over 6 months under denitrifying conditions in the presence of SIF.Results indicated that when influent containing 40 mg/L of NO_(3)^(-)−N was treated with 5 g SIF,79.9%nitrate reduction was observed in 8 days abiotically and 100%removal was accomplished in 20 days when the reactor was seeded.Both abiotic and seeded reactors removed more than 92%PO_(4)^(3−)under high DO conditions in 12 days.Abiotic and biochemical removal of NO_(3)^(-)−N and abiotic removal of PO_(4)^(3−)were higher under independent NO_(3)^(-)−N/PO_(4)^(3−)loading,while 99%PO_(4)^(3−)was removed biochemically under combined NO_(3)^(-)−N and PO_(4)^(3−)loading.This study furthers the understandings of nitrate and phosphate removal in Zero Valent Iron(ZVI)assisted mixed microbial systems to encourage the application of SIF-supported bio-chemical processes in the simultaneous removals of these pollutants. 展开更多
关键词 Scrap iron filing Nitrate removal Phosphate removal Mixed culture denitrification Zero valent iron
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基于知识图谱的医院医疗专家档案信息化管理 被引量:1
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作者 张红 周荻然 钱玉锦 《中国卫生资源》 CSCD 北大核心 2023年第6期721-724,730,共5页
随着大数据、云计算、人工智能及语义网等信息技术的日趋成熟,基于数据驱动的信息挖掘及信息资源整合成为各领域信息化探索的方向,也推动档案领域管理方法的创新。面对内容庞杂的医院医疗专家档案信息资源,研究运用人工智能及语义分析... 随着大数据、云计算、人工智能及语义网等信息技术的日趋成熟,基于数据驱动的信息挖掘及信息资源整合成为各领域信息化探索的方向,也推动档案领域管理方法的创新。面对内容庞杂的医院医疗专家档案信息资源,研究运用人工智能及语义分析等技术,进行信息挖掘,通过本体建模、知识抽取、知识融合等,构建以医院医疗专家档案为中心的知识图谱,不仅能进一步实现医疗专家档案的信息化管理,也可为顺应信息化时代智慧医院的发展趋势,推进医疗领域人才建设、医疗事业高质量发展服务。 展开更多
关键词 知识图谱knowledge graph 医疗专家档案medical expert file 信息化informatization 知识管理knowledge management 智慧医院intelligent hospital
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文物信息系统数据管理方法研究 被引量:2
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作者 高国庆 李光亚 +2 位作者 张超 胡雅妮 韩晓东 《工业控制计算机》 2023年第3期110-112,共3页
针对当前文物信息系统在文件上传过程中存在的文件接收不全、文字乱码、传输无法随时终止等缺陷,研究了一种效率更高的文件上传解决方案。首先,该方案基于FTP协议对文件上传的可控性,保证了目录文件的完整传输,其次,通过断点续传技术解... 针对当前文物信息系统在文件上传过程中存在的文件接收不全、文字乱码、传输无法随时终止等缺陷,研究了一种效率更高的文件上传解决方案。首先,该方案基于FTP协议对文件上传的可控性,保证了目录文件的完整传输,其次,通过断点续传技术解决了服务端大文件传输时的中断响应问题;最后利用ConcurrentQueue分段存储技术和文件复位技术优化了客户端接收文件的完整性和精准度。经过大量测试,所提方案能有效修复了文物信息系统中关于文件传输功能的漏洞,提高文件上传效率。 展开更多
关键词 file transfer protocol 文件上传 分段存储 解决方案 信息系统
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Electronic Auction Scheme Based on Smart Contract and IPFS 被引量:1
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作者 WU Xiaohua LIU Huan +1 位作者 WU Fengheng ZHANG Ke 《计算机工程》 CAS CSCD 北大核心 2023年第2期181-190,共10页
Sealed-bid auctions are a vital transaction tool in the e-commerce field.Traditional centralized auction schemes typically result in severe threats to data integrity,information transparency,and traceability owing to ... Sealed-bid auctions are a vital transaction tool in the e-commerce field.Traditional centralized auction schemes typically result in severe threats to data integrity,information transparency,and traceability owing to their excessive reliance on third parties,and blockchain-based auction schemes generally suffer from high storage costs and are deficient in functional and architectural design.To solve these problems,this study presents a sealed-bid auction scheme that removes the third-party based on an Ethereum smart contract,ensuring data integrity,openness,and transparency in the execution process.The commitment mechanism and distributed storage system help to significantly reduce the user’s storage cost and protect the privacy of user bids.For the functional design,this study introduces a fulltext-retrieval and dispute-processing module for commodities,which reduces the defects existing in the functional module design of existing auction systems.Furthermore,a prototype auction system on the Ethereum test chain is built to validate the proposed scheme.Experiments show that compared with traditional storage methods,indirect storage based on a distributed storage system of texts and images can reduce the storage cost by at least 50%while ensuring data integrity.Finally,the gas cost at each stage of the auction scheme and the time required for the full-text retrieval of products are recorded to evaluate the scheme performance and analyze the test results. 展开更多
关键词 sealed bid auction Ethereum smart contract commitment Interplanetary File System(IPFS)
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Regional unconformities and their controls on hydrocarbon accumulation in Sichuan Basin, sW China 被引量:1
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作者 YANG Weij WEI Guoqi +7 位作者 WU Saijun XIE Wuren JIN Hui ZENG Fuying HAO Cuiguo BAI Zhuangzhuang SU Yiqing LI Rong 《Petroleum Exploration and Development》 SCIE 2023年第3期573-587,共15页
Based on outcrop,seismic and drilling data,the main regional unconformities in the Sichuan Basin and their controls on hydrocarbon accumulation were systematically studied.Three findings are obtained.First,six regiona... Based on outcrop,seismic and drilling data,the main regional unconformities in the Sichuan Basin and their controls on hydrocarbon accumulation were systematically studied.Three findings are obtained.First,six regional stratigraphic unconformities are mainly developed in the Sichuan Basin,from the bottom up which are between pre-Sinian and Sinian,between Sinian and Cambrian,between pre-Permian and Permian,between middle and upper Permian,between middle and upper Triassic,and between Triassic and Jurassic.Especially,16 of 21l conventional(and tight)gas fields discovered are believed to have formed in relation to regional unconformities.Second,regional unconformity mainly controls hydrocarbon accumulation from five aspects:(1)The porosity and permeability of reservoirs under the unconformity are improved through weathering crust karstification to form large-scale karst reservoirs;(2)Good source-reservoir-caprock assemblage can form near the unconformity,which provides a basis for forming large gas field;(3)Regional unconformity may lead to stratigraphic pinch-out and rugged ancient landform,giving rise to a large area of stratigraphic and lithologic trap groups;(4)Regional unconformity provides a dominant channel for lateral migration of oil and gas;and(5)Regional unconformity is conducive to large-scale accumulation of oil and gas.Third,the areas related to regional unconformities are the exploration focus of large gas fields in the Sichuan Basin.The pre-Sinian is found with source rocks,reservoir rocks and other favorable conditions for the formation of large gas fields,and presents a large exploration potential.Thus,it is expected to be an important strategic replacement. 展开更多
关键词 UNCONFORMITY large gas filed Sichuan Basin karst reservoir hydrocarbon accumulation control exploration potential
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NRT FILES镍钛根管锉预备对弯曲根管应力分布的仿真分析 被引量:1
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作者 蒋谊芳 蔡绮敏 +3 位作者 初政一 秦敏 申煜荣 顾远平 《中国组织工程研究》 CAS 北大核心 2023年第7期1038-1042,共5页
背景:在根管治疗中,镍钛合金器械常因应力超过金属塑性变形的弹性极限或在根管弯曲处重复弯曲导致镍钛合金疲劳断裂。目的:探索新型镍钛锉NRT FILES在作为根管预备材料时对根管内壁存在的应力分布,明确应力集中区域。方法:利用Solidwork... 背景:在根管治疗中,镍钛合金器械常因应力超过金属塑性变形的弹性极限或在根管弯曲处重复弯曲导致镍钛合金疲劳断裂。目的:探索新型镍钛锉NRT FILES在作为根管预备材料时对根管内壁存在的应力分布,明确应力集中区域。方法:利用Solidworks软件对NRT FILES进行三维建模,模拟还原器械在真实口腔环境中存在的状态。建立6组根管简化模型:①弯曲角度30°、弯曲半径5 mm、根尖弯曲;②弯曲角度30°、弯曲半径5 mm、根中弯曲;③弯曲角度30°、弯曲半径2 mm、根尖弯曲;④弯曲角度30°、弯曲半径2 mm、根中弯曲;⑤弯曲角度45°、弯曲半径5 mm、根尖弯曲;⑥弯曲角度45°、弯曲半径2 mm、根尖弯曲。将根管简化模型与根管锉模型进行组配,对根管内壁受力点及应力分布情况进行分析。结果与结论:①-⑥组根管锉最大应力分别为1 185,1 354,1 371,1 678,1 335,2 557 MPa,最大应变分别为0.010 36,0.013 54,0.013 79,0.016 48,0.013 45,0.022 03;根管弯曲部位的不同会影响根管锉所承受的应力大小,因此在根管治疗中,根管锉沿着根管越往下,根管锉与根管接触的半径越大、刚性越差,根管锉所承受的应力越大越容易发生断裂;根管弯曲半径越小,根管锉承受的应力越大;根管弯曲角度越小,根管锉所承受的应力越大。在根尖弯曲部位,根管锉在根管弯曲半径小的弯曲根管需要承受更大的应力,根管锉更容易发生断裂;同理,在根中弯曲部位,根管锉在根管弯曲半径小的弯曲根管亦承受更大的应力,因此要格外注意根管的弯曲程度,以此来选择合适的根管锉进行根管治疗。 展开更多
关键词 弯曲根管 NRT FILES镍钛锉 根管预备 应力分布 有限元分析
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长三角医疗卫生领域行政规范性文件协作备案机制的构建 被引量:1
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作者 李幸祥 《中国卫生资源》 CSCD 北大核心 2023年第2期150-156,共7页
长三角医疗卫生领域行政规范性文件的协作制定,对于推动实现医疗卫生领域的一体化具有重要的现实意义。与之伴随的突出问题是,对此类跨行政区划协作制定的行政规范性文件如何进行备案审查。建议将长三角相关省市政府或卫生健康部门拟制... 长三角医疗卫生领域行政规范性文件的协作制定,对于推动实现医疗卫生领域的一体化具有重要的现实意义。与之伴随的突出问题是,对此类跨行政区划协作制定的行政规范性文件如何进行备案审查。建议将长三角相关省市政府或卫生健康部门拟制为行政联合体,将相关省市的备案机关拟制为备案联合体,由行政联合体向备案联合体报送备案。受委托的备案机关代表备案联合体对文件的制定主体、程序、内容进行审查后,由相关省市的备案机关联合出具备案审查意见。 展开更多
关键词 长三角Yangtze River Delta 医疗卫生health care 行政规范性文件administrative normative document 协作备案cooperative filing
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Automated File Labeling for Heterogeneous Files Organization Using Machine Learning
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作者 Sagheer Abbas Syed Ali Raza +4 位作者 MAKhan Muhammad Adnan Khan Atta-ur-Rahman Kiran Sultan Amir Mosavi 《Computers, Materials & Continua》 SCIE EI 2023年第2期3263-3278,共16页
File labeling techniques have a long history in analyzing the anthological trends in computational linguistics.The situation becomes worse in the case of files downloaded into systems from the Internet.Currently,most ... File labeling techniques have a long history in analyzing the anthological trends in computational linguistics.The situation becomes worse in the case of files downloaded into systems from the Internet.Currently,most users either have to change file names manually or leave a meaningless name of the files,which increases the time to search required files and results in redundancy and duplications of user files.Currently,no significant work is done on automated file labeling during the organization of heterogeneous user files.A few attempts have been made in topic modeling.However,one major drawback of current topic modeling approaches is better results.They rely on specific language types and domain similarity of the data.In this research,machine learning approaches have been employed to analyze and extract the information from heterogeneous corpus.A different file labeling technique has also been used to get the meaningful and`cohesive topic of the files.The results show that the proposed methodology can generate relevant and context-sensitive names for heterogeneous data files and provide additional insight into automated file labeling in operating systems. 展开更多
关键词 Automated file labeling file organization machine learning topic modeling
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Enhanced Best Fit Algorithm for Merging Small Files
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作者 Adnan Ali Nada Masood Mirza Mohamad Khairi Ishak 《Computer Systems Science & Engineering》 SCIE EI 2023年第7期913-928,共16页
In the Big Data era,numerous sources and environments generate massive amounts of data.This enormous amount of data necessitates specialized advanced tools and procedures that effectively evaluate the information and ... In the Big Data era,numerous sources and environments generate massive amounts of data.This enormous amount of data necessitates specialized advanced tools and procedures that effectively evaluate the information and anticipate decisions for future changes.Hadoop is used to process this kind of data.It is known to handle vast volumes of data more efficiently than tiny amounts,which results in inefficiency in the framework.This study proposes a novel solution to the problem by applying the Enhanced Best Fit Merging algorithm(EBFM)that merges files depending on predefined parameters(type and size).Implementing this algorithm will ensure that the maximum amount of the block size and the generated file size will be in the same range.Its primary goal is to dynamically merge files with the stated criteria based on the file type to guarantee the efficacy and efficiency of the established system.This procedure takes place before the files are available for the Hadoop framework.Additionally,the files generated by the system are named with specific keywords to ensure there is no data loss(file overwrite).The proposed approach guarantees the generation of the fewest possible large files,which reduces the input/output memory burden and corresponds to the Hadoop framework’s effectiveness.The findings show that the proposed technique enhances the framework’s performance by approximately 64%while comparing all other potential performance-impairing variables.The proposed approach is implementable in any environment that uses the Hadoop framework,not limited to smart cities,real-time data analysis,etc. 展开更多
关键词 Big data Hadoop MapReduce small file HDFS
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A Wrapping Encryption Based on Double Randomness Mechanism
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作者 Yi-Li Huang Fang-Yie Leu +2 位作者 Ruey-Kai Sheu Jung-Chun Liu Chi-Jan Huang 《Computers, Materials & Continua》 SCIE EI 2023年第10期1143-1164,共22页
Currently,data security mainly relies on password(PW)or system channel key(SKCH)to encrypt data before they are sent,no matter whether in broadband networks,the 5th generation(5G)mobile communications,satellite commun... Currently,data security mainly relies on password(PW)or system channel key(SKCH)to encrypt data before they are sent,no matter whether in broadband networks,the 5th generation(5G)mobile communications,satellite communications,and so on.In these environments,a fixed password or channel key(e.g.,PW/SKCH)is often adopted to encrypt different data,resulting in security risks since thisPW/SKCH may be solved after hackers collect a huge amount of encrypted data.Actually,the most popularly used security mechanism Advanced Encryption Standard(AES)has its own problems,e.g.,several rounds have been solved.On the other hand,if data protected by the same PW/SKCH at different time points can derive different data encryption parameters,the system’s security level will be then greatly enhanced.Therefore,in this study,a security scheme,named Wrapping Encryption Based on Double Randomness Mechanism(WEBDR),is proposed by integrating a password key(or a system channel key)and an Initialization Vector(IV)to generate an Initial Encryption Key(IEK).Also,an Accumulated Shifting Substitution(ASS)function and a three-dimensional encryption method are adopted to produce a set of keys.Two randomness encryption mechanisms are developed.The first generates system sub-keys and calculates the length of the first pseudo-random numbers by employing IEK for providing subsequent encryption/decryption.The second produces a random encryption key and a sequence of internal feedback codes and computes the length of the second pseudo-random numbers for encrypting delivered messages.A wrapped mechanism is further utilized to pack a ciphertext file so that a wrapped ciphertext file,rather than the ciphertext,will be produced and then transmitted to its destination.The findings are as follows.Our theoretic analyses and simulations demonstrate that the security of the WEBDR in cloud communication has achieved its practical security.Also,AES requires 176 times exclusive OR(XOR)operations for both encryption and decryption,while the WEBDR consumes only 3 operations.That is why the WEBDR is 6.7∼7.09 times faster than the AES,thus more suitable for replacing the AES to protect data transmitted between a cloud system and its users. 展开更多
关键词 Initial encryption key accumulated shifting substitution three-dimensional operation wrapped ciphertext file
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High-Imperceptibility Data Hiding Scheme for JPEG Images Based on Direction Modification
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作者 Li Liu Jing Li +2 位作者 Yingchun Wu Chin-Chen Chang Anhong Wang 《Computer Systems Science & Engineering》 SCIE EI 2023年第11期1415-1431,共17页
Data hiding(DH)is an important technology for securely transmitting secret data in networks,and has increasing become a research hotspot throughout the world.However,for Joint photographic experts group(JPEG)images,it... Data hiding(DH)is an important technology for securely transmitting secret data in networks,and has increasing become a research hotspot throughout the world.However,for Joint photographic experts group(JPEG)images,it is difficult to balance the contradiction among embedded capacity,visual quality and the file size increment in existing data hiding schemes.Thus,to deal with this problem,a high-imperceptibility data hiding for JPEG images is proposed based on direction modification.First,this proposed scheme sorts all of the quantized discrete cosine transform(DCT)block in ascending order according to the number of non-consecutive-zero alternating current(AC)coefficients.Then it selects non-consecutive-zero AC coefficients with absolute values less than or equal to 1 at the same frequency position in two adjacent blocks for pairing.Finally,the 2-bit secret data can be embedded into a coefficient-pair by using the filled reference matrix and the designed direction modification rules.The experiment was conducted on 5 standard test images and 1000 images of BOSSbase dataset,respectively.The experimental results showed that the visual quality of the proposed scheme was improved by 1∼4 dB compared with the comparison schemes,and the file size increment was reduced at most to 15%of the comparison schemes. 展开更多
关键词 Data hiding JPEG images coefficient-pair direction modification file size increment
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