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带凸台无底缸体零件的多向模锻工艺研究
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作者 葛苏 任杰 张家伟 《热加工工艺》 北大核心 2024年第1期143-147,154,共6页
为了保证气缸、液压缸在服役过程中的可靠性和稳定性,其毛坯必须采用锻件。针对带凸台无底缸体零件内部中空、外侧带有凸起的结构特点,制定其锻件图。通过对比坯料填充模腔的成形过程、锻造载荷、锻件应变分布、锻件温度分布、模具温度... 为了保证气缸、液压缸在服役过程中的可靠性和稳定性,其毛坯必须采用锻件。针对带凸台无底缸体零件内部中空、外侧带有凸起的结构特点,制定其锻件图。通过对比坯料填充模腔的成形过程、锻造载荷、锻件应变分布、锻件温度分布、模具温度分布,对4种多向模锻方案进行了有限元模拟研究,得出了最佳多向模锻操作方案。按照此方案设计模具和试验,成形出尺寸合格的缸体锻件。 展开更多
关键词 带凸缸体 多向模锻 无飞边 斜度小
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中国大气本底基准观象台概述
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作者 张晓春 朱庆斌 +2 位作者 季秉法 汤洁 温玉璞 《青海气象》 1995年第3期55-58,共4页
中国大气本底基准观象台自正式挂牌运行至今,已经工作了一年多时间了,本文在本底台一周年之际,介绍本底台的任务及现有的观测项目。一年来,本底台的工作得到了国内外专家的肯定和赞扬,它将以新的姿态迎接新的挑战。
关键词 大气本 观象 瓦里关山 基准 二氧化碳 监测项目 世界气象组织 大气成份 底台 人类活动
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港珠澳大桥浅水区非通航孔桥预制承台及底节墩身围堰封底施工技术
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作者 康平 陈山亭 《科技创新与应用》 2021年第7期17-21,共5页
港珠澳大桥浅水区非通航孔桥预制承台及底节墩身采用无内支撑双壁锁口钢套箱围堰施工,围堰采用分块插打拼装成整体,围堰拔除及倒运采用整体拔除、整体下沉方案。其中,复杂海况条件及地质情况下,围堰基坑开挖、清基、封底是技术难点和重... 港珠澳大桥浅水区非通航孔桥预制承台及底节墩身采用无内支撑双壁锁口钢套箱围堰施工,围堰采用分块插打拼装成整体,围堰拔除及倒运采用整体拔除、整体下沉方案。其中,复杂海况条件及地质情况下,围堰基坑开挖、清基、封底是技术难点和重点,控制着承台的安装总时间,必须严格把控。文章对相关工艺进行了总结,特别对围堰内填砂及基底土层承载力试验进行了介绍。 展开更多
关键词 港珠澳大桥 浅水区非通航孔 预制承节墩身 围堰 开挖 填砂 土层承载力试验
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防止机车锅炉底圈滑台裂纹的措施
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作者 房文彦 《铁道机车车辆工人》 1995年第7期8-9,共2页
机车入厂检修时,底圈滑台安装处出现裂纹现象时有发生,焊修后多数还裂或变形较大。不仅增加了工作量和劳动强度,还影响机车的下沉座炉,造成生产不均衡。 锅炉底圈滑台安装处左右各四孔通过锥度螺栓与滑台相连,产生的裂纹都是从左右边缘... 机车入厂检修时,底圈滑台安装处出现裂纹现象时有发生,焊修后多数还裂或变形较大。不仅增加了工作量和劳动强度,还影响机车的下沉座炉,造成生产不均衡。 锅炉底圈滑台安装处左右各四孔通过锥度螺栓与滑台相连,产生的裂纹都是从左右边缘部裂开并向内延伸的。裂纹位置如图1所示。为防止裂纹的产生可采取如下措施。 (1)在检修中为弥补设计制造的不足。 展开更多
关键词 机车 锅炉 圈滑 裂纹 防止措施
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毛泽东诗七首
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作者 许渊冲 《解放军外国语学院学报》 CSSCI 1989年第3期20-26,共7页
云开衡岳积阴止,天马凤凰春树里.年少峥嵘屈贾才,山川奇气曾钟此.
关键词 毛泽东 云开 COMMAND 凤凰 马衣 好八连 层峰 音联 底台 天渊
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一种新颖的房地产营销策划法
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作者 小禹 《中外房地产导报》 1995年第15期27-27,共1页
“M—M”是Magnifying Mar-ket的缩写,英文含义为“放大营销市场”,旨在利用有市场推广能力的网络机构,并配合新闻媒体的立体宣传,达到扩大市场的目的。 “M—M”市场推广法,最先由美国著名的广告运动策略家丹·舒尔茨提出,94年底... “M—M”是Magnifying Mar-ket的缩写,英文含义为“放大营销市场”,旨在利用有市场推广能力的网络机构,并配合新闻媒体的立体宣传,达到扩大市场的目的。 “M—M”市场推广法,最先由美国著名的广告运动策略家丹·舒尔茨提出,94年底台湾的专业房地产广告商将“M—M”市场推广法导入房地产营销,获得巨大成功。 展开更多
关键词 房地产营销策划 市场推广 房地产商 网络机 广告运动 底台 大营销 房地产广告 获得巨大成功 扩大市场
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科学管理原则在实践中的应用
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作者 符春阁 《青海气象》 1997年第3期48-49,共2页
本文应用科学管理原则,统筹安排各项工作,对于有效地发挥人、财、物等各方面的作用,不断提高工作效率,保质保量地完成中国大气本底基准观象台的监测任务,进行了有益的探索。
关键词 科学管理原则 工作人员 底台 监测仪器 工作效率 瓦里关山 大气本 管理工作 业务工作 监测工作
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Niches of dominant fish in the waters surrounding the Taishan Islands, China 被引量:2
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作者 杨璐 陈杰 +5 位作者 杨圣云 钟慧琪 鞠培龙 杨顺良 孙芹芹 陈明茹 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2016年第4期697-708,共12页
An index of relative importance(IRI) was employed to screen for dominant fish in the waters surrounding the Taishan Islands, China, using data from four seasonal trawl surveys undertaken between 2012 and 2013. Niche b... An index of relative importance(IRI) was employed to screen for dominant fish in the waters surrounding the Taishan Islands, China, using data from four seasonal trawl surveys undertaken between 2012 and 2013. Niche breadth and niche overlap were measured using the Feinsinger and Morisita-Horn indices, respectively, and the characteristics and seasonal variations in the niches of dominant fish were assessed via non-metric multidimensional scaling(NMDS) and cluster analysis. A total of 80 fish species, including 16 dominant species, were recorded. Only A mblychaeturichthys hexanema was dominant in all seasons. According to niche breadth values and NMDS, the 16 dominant species were grouped into the following three types:(1) wide niche breadth species, including Cynoglossus macrolepidotus, A. hexanema, and Trypauchen vagina, among others;(2) medium niche breadth species, including Setipinna taty and Johnius belangerii; and(3) narrow niche breadth species, including A trobucca nibe and Coilia mystus. Most species with a wider niche breadth were demersal fish with a lower swimming capability and even distribution. The niche breadth of migrating fish was narrower than that of settled fish. At a given spatial scale, fish with stronger swimming capabilities had a narrower niche breadth. Niche overlap, which is associated with niche specialization, ranged from 0.000 to 0.886 and had an annual mean value of 0.314. In summer and autumn, niche overlap was relatively high within species of the Sciaenidae family and within species of the Gobiidae in autumn. Dif ferences in thermophily, feeding habits, food organism abundance/distribution and predator-prey relationships af fected the niche overlap of fish in this area. Cluster analysis revealed that species with the narrowest niche breadth and lowest niche overlap values usually displayed lower aggregation and greater distribution dif ferences compared with other species. 展开更多
关键词 Taishan Islands dominant fish niche breadth niche overlap niche specialization
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Deep Seismic Exploration in the Taiwan Straits: The HX9 Survey Line Experiment and Preliminary Results
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作者 Yan Pei Zhang Yifeng +1 位作者 Li Puchun Wang Sun 《Earthquake Research in China》 CSCD 2015年第4期459-469,共11页
By using an offshore large volume air-gun seismic source, onshore seismic stations( including mobile stations and permanent stations) and ocean bottom seismometers,a deep seismic exploration experiment was carried out... By using an offshore large volume air-gun seismic source, onshore seismic stations( including mobile stations and permanent stations) and ocean bottom seismometers,a deep seismic exploration experiment was carried out for the first time in the Taiwan Straits. Results show that seismic stations can receive seismic signals from the air-gun arrays of the "YANPING Ⅱ"scientific investigation ship from as far as 280 km away.Tens of thousands of high quality seismic data items were obtained successfully and different types of P-wave seismic phases were identified. A one-dimensional crustal structure model of the survey profile HX9 shows that the crustal structure,which is reflected by Pc and Pm P reflection waves from two velocity discontinuities and basement refraction wave( Pg) constitutes the basic characteristic of the crustal structure in this region. The depths of Conrad discontinuity and Moho discontinuity are respectively16. 0km- 17. 5km and 28. 0km- 29. 5km. 展开更多
关键词 Taiwan Straits Deep seismic exploration Air-gun seismic source Crustal structure
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A bottom-up method for module-based product platform development through mapping,clustering and matching analysis
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作者 张萌 李国喜 +2 位作者 曹建平 龚京忠 吴宝中 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第3期623-635,共13页
Designing product platform could be an effective and efficient solution for manufacturing firms. Product platforms enable firms to provide increased product variety for the marketplace with as little variety between p... Designing product platform could be an effective and efficient solution for manufacturing firms. Product platforms enable firms to provide increased product variety for the marketplace with as little variety between products as possible. Developed consumer products and modules within a firm can further be investigated to find out the possibility of product platform creation. A bottom-up method is proposed for module-based product platform through mapping, clustering and matching analysis. The framework and the parametric model of the method are presented, which consist of three steps:(1) mapping parameters from existing product families to functional modules,(2) clustering the modules within existing module families based on their parameters so as to generate module clusters, and selecting the satisfactory module clusters based on commonality, and(3) matching the parameters of the module clusters to the functional modules in order to capture platform elements. In addition, the parameter matching criterion and mismatching treatment are put forward to ensure the effectiveness of the platform process, while standardization and serialization of the platform element are presented. A design case of the belt conveyor is studied to demonstrate the feasibility of the proposed method. 展开更多
关键词 product platform development bottom-up method MAPPING CLUSTERING MATCHING
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隧洞全圆针梁式钢模台车混凝土衬砌施工 被引量:2
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作者 葛慧聪 《河南水利与南水北调》 2016年第1期65-66,共2页
在隧洞工程中,探索和掌握全圆全断面针梁式钢模台车混凝土衬砌施工技术,尤其是底模设计创新技术,不但能大幅度缩短工期,节约施工成本,而且对提高混凝土衬砌外观质量起着至关重要的作用。文章从钢模台车就位调整、混凝土衬砌浇筑、钢模... 在隧洞工程中,探索和掌握全圆全断面针梁式钢模台车混凝土衬砌施工技术,尤其是底模设计创新技术,不但能大幅度缩短工期,节约施工成本,而且对提高混凝土衬砌外观质量起着至关重要的作用。文章从钢模台车就位调整、混凝土衬砌浇筑、钢模台车脱模行走等三个主要工艺流程,重点介绍了底模设计创新技术、全圆全断面针梁式钢模台车混凝土衬砌施工技术。 展开更多
关键词 钢模车混凝土衬砌 模设计创新 外观质量
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Origin of Taiwan Canyon and its effects on deepwater sediment 被引量:2
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作者 XU Shang WANG YingMin +4 位作者 PENG XueChao ZOU HuaYao QIU Yan GONG ChengLin ZHUO HaiTeng 《Science China Earth Sciences》 SCIE EI CAS 2014年第11期2769-2780,共12页
The continental slope of the Taiwan Shoal, which has cultivated numerous submarine canyons, is located in a passive conti- nental margin environment. However, the trend of the Taiwan Canyon, with its 45° intersec... The continental slope of the Taiwan Shoal, which has cultivated numerous submarine canyons, is located in a passive conti- nental margin environment. However, the trend of the Taiwan Canyon, with its 45° intersection angle, is obviously different from that of the erosion valley downward along the continental slope. A distinct break is present in the lower segment of the Taiwan Canyon, which then extends from west to east parallel to the continental slope until finally joining the Manila Trench. By utilizing multiple-beam water depth data, high-resolution seismic data, and sediment cores, this study describes the topo- graphic characteristics of the Taiwan Canyon and provides a preliminary discussion on the origin of the Taiwan Canyon and its effect on deepwater sediment. The terrain, landform, and sediment of the Taiwan Canyon exhibit segmentation characteristics. The upper segment is characterized primarily by erosion, downward cutting with a V shape, and wide development of sliding, slumping, and other gravity flow types. The middle segment is characterized mostly by U-shaped erosion-sedimentation transi- tion and development of an inner levee. The lower segment is characterized primarily by sedimentation and development of a sediment wave. The bottom current has a significant reworking effect on the interior sediments of the canyon and forms re- worked sands. The formation and evolution of the Taiwan Canyon is closely related to sediment supply, gravity sliding (slumping), faulting activities, and submarine impaling. Given the sufficient terrigenous clastic supply, the sediments along the continental shelf edge continuously proceed seaward; gliding and slumping in the front edge provide driving forces for the formation of the canyon. Faulting activities result in stratum crushing, and the gravity flow takes priority in eroding the relatively fragile stratum. Thus, the direction of the extension of the canyon crosses the surrounding erosion valley obliquely. Seamounts are formed through submarine impaling. Owing to seamount blocking, the lower segment of the canyon is turned toward the east-west direction. Large amounts of sediments overflow at the turning, formin~ sediment waves. 展开更多
关键词 deepwater sediment gravity flow sediment waves Taiwan Canyon MORPHOLOGY
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