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Characterization of machine tools and measurement system for micromilling 预览
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作者 Andrea Abeni Matteo Lancini Aldo Attansio 《纳米技术与精密工程(英文)》 CAS CSCD 2019年第1期23-28,共6页
Technological progress has led to increased demand for small components with tiny features,which cannot be achieved through conventional machining.Industrial application of processes based on microcutting is limited b... Technological progress has led to increased demand for small components with tiny features,which cannot be achieved through conventional machining.Industrial application of processes based on microcutting is limited by some issues concerning the geometrical scale.The process performance is significantly affected by millingmachine,tool holder,tool,workpiecematerialmicrostructure,workpiece fixtures,and process parameters.At present,an ultimate micromachining assessment procedure is not available.This study aims to propose and conduct an experiment on a testing procedure for micromilling.The set up to be implemented and the output to be considered are defined and described.Threemajor stages are identified:estimation of the effective bandwidth of the load cell–tool holder system,the millingmachine natural frequency measurement,and micromilling test execution.The entire procedure is performed,and its robustness is demonstrated. 展开更多
关键词 MICROMILLING Machine TOOL performance test TOOL run-out FORCE ANALYSIS MODAL ANALYSIS
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Contactless Microwave Detection of Shubnikov–De Haas Oscillations in Three-Dimensional Dirac Semimetal ZrTe5
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作者 武敏 张红伟 +7 位作者 朱相德 陆建伟 郑国林 高文帅 韩玉岩 周建辉 宁伟 田明亮 《中国物理快报:英文版》 SCIE CAS CSCD 2019年第6期49-52,共4页
We report Shubnikov–de Haas(SdH)oscillations of a three-dimensional(3D) Dirac semimetal candidate of layered material ZrTe5 single crystals through contactless electron spin resonance(ESR)measurements with the magnet... We report Shubnikov–de Haas(SdH)oscillations of a three-dimensional(3D) Dirac semimetal candidate of layered material ZrTe5 single crystals through contactless electron spin resonance(ESR)measurements with the magnetic field up to 1.4 T.The ESR signals manifest remarkably anisotropic characteristics with respect to the direction of the magnetic field,indicating an anisotropic Fermi surface in ZrTe5.Further experiments demonstrate that the ZrTe5 single crystals have the signature of massless Dirac fermions with nontrivialBerry phase,key evidence for 3D Dirac/Weyl fermions.Moreover,the onset of quantum oscillation of our ZrTe5 crystals revealed by the ESR can be derived down to 0.2 T,much smaller than the onset of SdH oscillation determined by conventional magnetoresistance measurements.Therefore,ESR measurement is a powerful tool to study the topologically nontrivial electronic structure in Dirac/Weyl semimetals and other topological materials with low bulk carrier density. 展开更多
关键词 DIRAC MICROWAVE Haas ESR SPIN down tool our
如何改善提升发动机油底壳清洁度 预览
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作者 吴能武 闫翔 王瑞平 《内燃机》 2019年第1期15-18,共4页
质量管理是企业管理的核心内容,在汽油发动机制造业显得尤为重要,要提升发动机产品质量的整体水平,就要确保发动机润滑系统良好,油底壳清洁度却是发动机润滑系统的测量指标.
关键词 滤膜杂质 检测 刀具 清洗 改善提升
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基圆大于齿根圆渐开线刀具设计加工 预览
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作者 唐清松 《工具技术》 2019年第3期94-96,共3页
介绍了基圆大于齿根圆渐开线刀具的设计原理及数控花键磨床砂轮修整器CAM软件进行二次开发,并实现了此类刀具的齿形磨削加工。
关键词 渐开线 刀具 CAM二次开发 VB
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Effects of postweld aging on the microstructure and properties of bobbin tool friction stir-welded 6082-T6 aluminum alloy 预览
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作者 Yu-peng Li Da-qian Sun +1 位作者 Wen-biao Gong Liang Liu 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2019年第7期849-857,共9页
Samples of 6082-T6 aluminum alloy were subjected to bobbin tool friction stir welding (BT-FSW), and the joints were treated by postweld natural aging (PWNA) and postweld artificial aging (PWAA). The microstructure, mi... Samples of 6082-T6 aluminum alloy were subjected to bobbin tool friction stir welding (BT-FSW), and the joints were treated by postweld natural aging (PWNA) and postweld artificial aging (PWAA). The microstructure, microhardness, and tensile properties of the aged and as-welded specimens were investigated. Transmission electron microscopy (TEM) observations revealed that a large number of Guinier–Preston (GP) zones precipitated in the form of a network on the stir zone (SZ) after PWNA for 60 d, and a large number of β'' phases precipitated in the matrix for after PWAA for 6 h. As the aging time increased, the microhardness of the SZ and the thermomechanically affected zone (TMAZ) increased significantly, and the hardness of the SZ after PWAA for 6 h was close to that of the base metal (BM). With increasing PWNA time, the strength and strain increased slightly. When the PWAA time increased, the strength clearly increased, with a maximum value of 279.9 MPa after 6 h, while the strain decreased. 展开更多
关键词 postweld AGING aluminum alloys BOBBIN TOOL FRICTION STIR welding microstructure properties
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Chromosomal deletions mediated by CRISPR/Cas9 in Helicoverpa armigera
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作者 Ming-Hui Jin Yu-Tao Xiao +3 位作者 Ying Cheng Jie Hu Chao-Bin Xue Kong-Ming Wu 《昆虫科学:英文版》 SCIE CAS CSCD 2019年第6期1029-1036,共8页
Helicoverpa armigera, cotton bollworm, is one of the most disastrous pests worldwide, threatening various food and economic crops. Functional genomic tools may provide efficient approaches for its management. The clus... Helicoverpa armigera, cotton bollworm, is one of the most disastrous pests worldwide, threatening various food and economic crops. Functional genomic tools may provide efficient approaches for its management. The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system, dependent on a single guide RNA (sgRNA), has been used to induce indels for targeted mutagenesis in cotton bollworm. However, genomic deletions may be more desirable to disrupt the function of noncoding genes or regulatory sequences. By injecting two sgRNAs with Cas9 protein targeting different exons, we obtained predictable genomic deletions of several hundred bases. We achieved this type of modification with different combinations of sgRNA pairs, including HaCad and HaABCC2. Our finding indicated that CRISPR/Cas9 can be used as an efficient tool to engineer genomes with chromosomal deletion in H. armigera. 展开更多
关键词 CHROMOSOMAL DELETION CRISPR/Cas9 genome EDITING tool HELICOVERPA ARMIGERA KNOCKOUT sgRNAs
高温作业下专用服装设计分析 预览
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作者 张倩倩 张坤 《科技创新导报》 2019年第7期133-134,共2页
在高温环境下工作时,人们需要穿着专用服装以避免灼伤。专用服装通常由三层织物材料构成,记为I、II、III层,其中I层与外界环境接触,III层与皮肤之间还存在空隙,将此空隙记为IV层。为设计这种专用服装,将体内温度控制在37℃的假人放置在... 在高温环境下工作时,人们需要穿着专用服装以避免灼伤。专用服装通常由三层织物材料构成,记为I、II、III层,其中I层与外界环境接触,III层与皮肤之间还存在空隙,将此空隙记为IV层。为设计这种专用服装,将体内温度控制在37℃的假人放置在实验室的高温环境中,对环境温度为75℃、II层厚度为6mm、IV层厚度为5mm、工作时间为90min的情形开展实验,测量得到假人皮肤外侧的温度。为了降低研发成本、缩短研发周期,可以通过数学建模确定假人皮肤外侧的温度变化情况,并解决相关问题。 展开更多
关键词 热传导微分方程模型 CURVE FITTING Tool 非线性规划 目标规划模型 专用服装
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WC-Re复合搅拌头设计及其制造工艺研究 预览
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作者 张嘉波 邹鑫 +2 位作者 陈滨熹 唐普洪 陈科 《制造技术与机床》 北大核心 2019年第6期97-102,共6页
针对高温搅拌摩擦焊接过程中搅拌针和轴肩失效形式和程度不一致,以及现有的用于高温搅拌摩擦焊接搅拌头制造的材料的成本过高问题。提出了一种复合材料搅拌头的设计。搅拌针采用WC-Re合金,轴肩采用WC-Co合金,两部分用圆锥面连接。通过... 针对高温搅拌摩擦焊接过程中搅拌针和轴肩失效形式和程度不一致,以及现有的用于高温搅拌摩擦焊接搅拌头制造的材料的成本过高问题。提出了一种复合材料搅拌头的设计。搅拌针采用WC-Re合金,轴肩采用WC-Co合金,两部分用圆锥面连接。通过数值计算得出适中锥度,针对WC-Re合金与WC-Co合金在电火花加工过程中腐蚀速率不一致所形成的凸台特征,提出了该搅拌头的三级制造工艺。使用试制的搅拌头进行焊接试验,试验结果表明本搅拌头结构合理,能适应搅拌摩擦焊接过程中的高温高压力复变环境。 展开更多
关键词 搅拌摩擦焊机 搅拌头 复合 高温
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Tool-path generation for industrial robotic surface-based application
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作者 He Lyu Yue Liu +2 位作者 Jiao-Yang Guo He-Ming Zhang Ze-Xiang Li 《先进制造进展:英文版》 CAS CSCD 2019年第1期64-72,共9页
Industrial robots are widely used in various applications such as machining, painting, and welding. There is a pressing need for a fast and straightforward robot programming method, especially for surface-based tasks.... Industrial robots are widely used in various applications such as machining, painting, and welding. There is a pressing need for a fast and straightforward robot programming method, especially for surface-based tasks. At present, these tasks are time-consuming and expensive, and it requires an experienced and skilled operator to program the robot for a specific task. Hence, it is essential to automate the tool-path generation in order to eliminate the manual planning. This challenging research has attracted great attention from both industry and academia. In this paper, a tool-path generation method based on a mesh model is introduced. The bounding box tree and kdtree are adopted in the algorithm to derive the tool path. In addition, the algorithm is integrated into an offline robot programming system offering a comprehensive solution for robot modeling, simulation, as well as tool-path generation. Finally, a milling experiment is performed by creating tool paths on the surface thereby demonstrating the effectiveness of the system. 展开更多
关键词 Industrial ROBOT TOOL PATH GENERATION Simulation INTELLIGENT MANUFACTURING
Particle Removal Mechanism of High Volume Fraction SiCp/Al Composites by Single Diamond Grit Tool
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作者 DU Jinguang MING Wuyi +3 位作者 CAO Yang MA Jun HE Wenbin LI Xiaoke 《武汉理工大学学报:材料科学英文版》 SCIE EI CAS 2019年第2期324-331,共8页
Particle removal mechanism was presented during machining particle SiC/Al composites with diamond grinding tool. The relevant removal modes and their mechanisms were discussed considering the impact and squeezing effe... Particle removal mechanism was presented during machining particle SiC/Al composites with diamond grinding tool. The relevant removal modes and their mechanisms were discussed considering the impact and squeezing effect of diamond grit on the SiC particle. The experimental results show that the aluminum matrix has larger plastic deformation, so the aluminum mixed with the surplus SiC particles is cut from the surface. The SiC particles can be removed in multiple ways, such as broken/fractured, micro cracks, shearing and pulled out, etc. More particles removed by shearing, and less particles removed by fractured during material removal progress can produce a better machined surface. 展开更多
关键词 SICP/AL composites SiC particle removal MECHANISM GRINDING TOOL
人工智能环境常用工具配置与技巧 预览
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作者 韩庆生 王爱玲 +1 位作者 张景 张锦仓 《教育教学论坛》 2019年第27期93-94,共2页
利用Python语言开展人工智能研究,Jupyter notebook作为一个Web编辑器,支持运行超过40种编程语言,包括:数据清理和转换,数值模拟,统计建模,机器学习等,本文主要介绍了安装配置参数,以及在windows和linux环境下,远程桌面、文件共享等方... 利用Python语言开展人工智能研究,Jupyter notebook作为一个Web编辑器,支持运行超过40种编程语言,包括:数据清理和转换,数值模拟,统计建模,机器学习等,本文主要介绍了安装配置参数,以及在windows和linux环境下,远程桌面、文件共享等方面的一些使用技巧和方法,为人工智能环境的搭建提供可以借鉴的经验。 展开更多
关键词 人工智能 工具 配置与技巧
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想象、现实、工具:基于人工智能文艺创作的多重思考 预览
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作者 杜彬彬 《科教导刊》 2019年第2期51-52,63共3页
当下对于人工智能文艺创作的想象带有一定的科幻色彩,但也有人基于文艺创作中的复杂性精神活动,对人工智能文艺创作保持警觉。从社会现实运用角度出发,就会发现科学技术上的人工“智能”与文艺创作意义上“人工智能”,其实有很大的差异... 当下对于人工智能文艺创作的想象带有一定的科幻色彩,但也有人基于文艺创作中的复杂性精神活动,对人工智能文艺创作保持警觉。从社会现实运用角度出发,就会发现科学技术上的人工“智能”与文艺创作意义上“人工智能”,其实有很大的差异,这在根本上说明了人工智能的工具性。 展开更多
关键词 想象 现象 工具 人工智能 文艺创作
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“马克思机器思想”及其当代伦理启示 预览
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作者 刘宝杰 《长沙理工大学学报:社会科学版》 2019年第4期19-24,共6页
马克思系统阐述机器的生成、发展与创新,阐明分工与机器的关系,界定机器的构成要素,厘清机器与工具的区别,历时性梳理了机器的演进,提出机器“器官延长论”。马克思深刻揭示出资本主义生产方式运用机器的实质,探究机器运用带来的劳动异... 马克思系统阐述机器的生成、发展与创新,阐明分工与机器的关系,界定机器的构成要素,厘清机器与工具的区别,历时性梳理了机器的演进,提出机器“器官延长论”。马克思深刻揭示出资本主义生产方式运用机器的实质,探究机器运用带来的劳动异化、相对过剩人口等社会伦理后果。马克思机器思想为当下机器伦理问题的解答提供了可能的途径,机器伦理的实质是机器使用及设计过程中衍生出的伦理问题,机器伦理问题的回答不能停留于对机器本身的关注,而需回到社会实践语境中来。 展开更多
关键词 马克思机器思想 机器 工具 机器伦理 智能机器
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某乡镇垃圾回收站冬季环卫作业细菌污染情况抽样调查
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作者 黄晋 李荣宗 罗彩凤 《中国校医》 2019年第5期323-324,339共3页
目的分析东莞市塘厦镇中型垃圾回收站冬季细菌污染情况。方法以东莞市塘厦镇数量居多的中型垃圾回收站为研究对象,以细菌总数、大肠菌群、沙门氏菌的检测为卫生学指标,采用多阶段随机抽样选取研究站点;以入选站点全体工人为研究人群,检... 目的分析东莞市塘厦镇中型垃圾回收站冬季细菌污染情况。方法以东莞市塘厦镇数量居多的中型垃圾回收站为研究对象,以细菌总数、大肠菌群、沙门氏菌的检测为卫生学指标,采用多阶段随机抽样选取研究站点;以入选站点全体工人为研究人群,检测工人手掌、清洁工具和运输车辆的手掌握持部件表面污染程度,同时检验站内空气及垃圾渗漏液,分析受污染情况。结果 3家中型垃圾回收站纳入研究范围,对站内物体表面、环卫作业人员手部、回收站空气检测均未发现大肠菌群和沙门氏菌。对站内物体表面检测,电动车垃圾桶检出细菌总数最多为5 cfu/cm^2;环卫作业人员手部洗手后细菌总数最高值为9 cfu/cm^2,而未洗手前检出细菌总数为250 cfu/cm^2。对3个垃圾站点站内值班房、垃圾压缩机、站内工具存放间空气进行检查,发现3个站点中垃圾压缩机中细菌总数污染最严重,A站点15 cfu/cm^2,B站点17 cfu/cm^2,C站点13 cfu/cm^2。垃圾渗漏液细菌总数均高达1 000 cfu/mL。且检出大肠菌群、沙门氏菌及霉菌。结论冬季环卫作业细菌污染防护重点应在环卫工人手部,并对垃圾渗漏液进行及时处理,降低感染风险。 展开更多
关键词 垃圾处理 回收 季节/冬 细菌污染 手表面 用具
浅论建筑工程竣工测量的内容和技术要领 预览
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作者 杨亮升 《城市建筑》 2019年第8期160-161,共2页
改革开放以来,我国城市化进程不断加快,建筑工程的数量日益增多,工程的规模也越来越大。如何保证建筑工程的质量,促进建筑行业的发展,是时代赋予人们的新的课题。本文从原则、内容和技术要领三方面,对建筑工程竣工测量进行了分析,希望... 改革开放以来,我国城市化进程不断加快,建筑工程的数量日益增多,工程的规模也越来越大。如何保证建筑工程的质量,促进建筑行业的发展,是时代赋予人们的新的课题。本文从原则、内容和技术要领三方面,对建筑工程竣工测量进行了分析,希望能够为相关的工作提供一定的参考。 展开更多
关键词 建筑工程 竣工测量 地下管线 工具
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Experimental Study on Wear Characteristics of PCBN Tool with Variable Chamfered Edge
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作者 Tao Chen Lixing Song +1 位作者 Suyan Li Xianli Liu 《中国机械工程学报:英文版》 SCIE EI CAS CSCD 2019年第3期89-97,共9页
Owing to heavy dynamic and thermal loads, PCBN tools are seriously worn during hard cutting, which largely constrains the improvement of their machining performance. Therein, the chamfered structure of a cutting edge ... Owing to heavy dynamic and thermal loads, PCBN tools are seriously worn during hard cutting, which largely constrains the improvement of their machining performance. Therein, the chamfered structure of a cutting edge has a notable influence on the tool wear. Thus, a comparative study was carried out on the wear morphology and wear mechanism of PCBN tools with either a variable chamfered edge or an invariable chamfered edge. The results indicate that, for a PCBN tool with a variable chamfered edge, the rake wear area is far from the cutting edge and slowly extends toward it. A shallow large-area crater wear occurs on the rake face, and the flank wear area has a long triangular shape with a smaller wear area and width, and the cutting edge remains in a good state during the cutting process. In contrast, for a PCBN tool with an invariable chamfered edge, a deep small-area crater appears on the rake face, and the wear area is close to the cutting edge and quickly extends toward it. Thus, it is easy for chips to accumulate in the crater, resulting in large-area and high-speed wear on the flank face. In addition, the tool shows a weak wear resistance. In the initial wear stage, the rake wear mechanism of the two cutting tools is a mixture of abrasive, oxidation, and other types of wear, whereas their flank wear mechanism is dominated by abrasive wear. With an aggravation of the tool wear, the oxidation and diffusion wear mechanism are both increasingly strengthened. The rake wear of the cutter with a variable chamfered edge showed an obvious increase in the oxidation and diffusion wear, as did the flank wear of the cutter with an invariable chamfered edge. This study revealed the wear mechanism of the PCBN tool with a variable chamfered edge and provided theoretical and technological support for its popularization and application in the machining of high-hardness materials. 展开更多
关键词 HARD CUTTING VARIABLE chamfered EDGE PCBN tool WEAR morphology WEAR mechanism
From Chats to Cash Social media is a new nifty marketing tool to boost startups
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作者 Wang Jun 《北京周报:英文版》 2019年第24期38-39,共2页
Hey Tea,the new tea shop chain phe-nomenon specializing in cheese-topped tea and fruit tea.is famous,especially on social media,for the serpentine queues of customers patiently awaiting their turn to order.Be it in Be... Hey Tea,the new tea shop chain phe-nomenon specializing in cheese-topped tea and fruit tea.is famous,especially on social media,for the serpentine queues of customers patiently awaiting their turn to order.Be it in Beijing or Shanghai or even Guangzhou in Guangdong Province in south China,it may take four to five hours to get a cup of tea but buyers'enthusiasm never seems to flag. 展开更多
关键词 CASH SOCIAL MEDIA MARKETING TOOL
通过联合数据管理实现增值
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作者 Giari Fiorucci 《现代制造》 2019年第15期48-51,共4页
2017汉诺威EMO展会上展出了c-Com开放型云平台,包括“Tool Dashboard”,“Dynamic Order Optimizer”、“Reconditioning Management”和“MachineRun-Off”等四个模块以及相关的App。平台背后的企业c-Com GmbH公司期待着在加工环节中... 2017汉诺威EMO展会上展出了c-Com开放型云平台,包括“Tool Dashboard”,“Dynamic Order Optimizer”、“Reconditioning Management”和“MachineRun-Off”等四个模块以及相关的App。平台背后的企业c-Com GmbH公司期待着在加工环节中对刀具和C类部件进行一种创新、透明和合作式的数据管理。c-Com可采用SaaS技术解决方案(软件服务)与供应商和用户对日常工作和相关项目进行数据分享和管理。 展开更多
关键词 数据管理 OPTIMIZER DYNAMIC GmbH公司 TOOL 日常工作 软件服务 aS技术
面部除皱术效果评价工具的探讨
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作者 汪曲胜 《智慧健康》 2019年第20期93-94,共2页
伴随着年龄的增长,人体各种组织将发生不同程度的老化,而面颈部的皮肤松弛正是人体老化的外在且最易暴露的表现。本文的目的既是探讨目前国内外对面部除皱术术后疗效评定的主观及客观工具的应用研究,也是为今后在临床上使用最合理的面... 伴随着年龄的增长,人体各种组织将发生不同程度的老化,而面颈部的皮肤松弛正是人体老化的外在且最易暴露的表现。本文的目的既是探讨目前国内外对面部除皱术术后疗效评定的主观及客观工具的应用研究,也是为今后在临床上使用最合理的面部除皱术疗效评估方式提供参考。 展开更多
关键词 面部除皱术 面部老化 疗效评价 工具
井下压裂暂堵工具用可溶金属材料研究进展 预览
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作者 黄传艳 李双贵 +4 位作者 李林涛 万小勇 李冬梅 席君杰 王小红 《石油矿场机械》 2019年第1期68-72,共5页
可溶金属材料制备的井下暂堵工具在压裂施工中的应用,极大地提高了非常规油气井压裂施工效率及技术经济指标。综述了井下暂堵工具用可溶金属材料的性能要求,镁基胞状结构、铝基掺杂结构可溶合金材料的设计思路及制备工艺,介质中Cl^-浓度... 可溶金属材料制备的井下暂堵工具在压裂施工中的应用,极大地提高了非常规油气井压裂施工效率及技术经济指标。综述了井下暂堵工具用可溶金属材料的性能要求,镁基胞状结构、铝基掺杂结构可溶合金材料的设计思路及制备工艺,介质中Cl^-浓度、HCl浓度及介质温度对可溶金属材料溶解速度的影响规律。针对我国特有的高Cl^-浓度、高HCl浓度及高温介质,研发溶解速度可控的可溶金属是当前井下暂堵工具材料的发展方向。 展开更多
关键词 压裂 工具 材料
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