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销接式索夹几何参数精确计算方法研究
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作者 杨洋 曾瑞祥 《公路交通技术》 2022年第6期51-57,共7页
为达到桥梁景观效果,越来越多的悬索桥采用空间缆索设计形式,其主缆和吊杆处于三维空间中,索夹在设计和施工阶段产生的误差,会使结构不能在理想成桥状态下工作,长期作用下,可引起吊杆疲劳断裂。为此,采用空间向量几何和柔性索计算方法,... 为达到桥梁景观效果,越来越多的悬索桥采用空间缆索设计形式,其主缆和吊杆处于三维空间中,索夹在设计和施工阶段产生的误差,会使结构不能在理想成桥状态下工作,长期作用下,可引起吊杆疲劳断裂。为此,采用空间向量几何和柔性索计算方法,研究销接式索夹的几何参数计算。研究结果表明:空间向量几何和柔性索计算方法用于索夹参数计算,可降低索夹几何误差,满足桥梁工程设计要求。 展开更多
关键词 桥梁工程 空间缆
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销接式索夹悬索桥成桥线形的高精度计算方法 被引量:6
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作者 罗凌峰 单德山 +1 位作者 陈奉民 陈品诣 《工程力学》 EI CSCD 北大核心 2021年第8期133-144,共12页
由于已有方法对索鞍和索夹的影响考虑不够全面,提出一种求解悬索桥目标成桥状态的高精度方法。该方法通过计入索鞍与主缆间的摩擦影响,全面考虑主缆与索鞍的接触问题,根据分段悬链线方程、闭合条件以及索鞍处主缆的力学平衡关系,分别推... 由于已有方法对索鞍和索夹的影响考虑不够全面,提出一种求解悬索桥目标成桥状态的高精度方法。该方法通过计入索鞍与主缆间的摩擦影响,全面考虑主缆与索鞍的接触问题,根据分段悬链线方程、闭合条件以及索鞍处主缆的力学平衡关系,分别推导得出中、边跨缆索系统的目标函数,采用Nelder-Mead算法求解函数以确定目标成桥状态。该求解过程自适应地计入了销接式索夹的影响,从而得到可靠的吊索钢丝下料长度和主缆无应力长度。以笋溪河大桥作为工程算例,将所提方法的计算结果与该桥设计值进行对比,验证了该文方法的可靠性。 展开更多
关键词 桥梁工程 Nelder-Mead算法 主缆
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中国遗书收集制度述略 被引量:1
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作者 曾主陶 《求索》 CSSCI 北大核心 1989年第1期124-126,共3页
遗书收集制度是我国古代文献管理制度的重要内容。所谓遗书,一是指前人著作留于后世者,二是指散佚于民间之书。中国古代的遗书收集,既包括前人留于后世之著作,又包括散佚于民间之著作。公元前206年,刘邦率军入咸阳,萧何尽收秦丞相府律... 遗书收集制度是我国古代文献管理制度的重要内容。所谓遗书,一是指前人著作留于后世者,二是指散佚于民间之书。中国古代的遗书收集,既包括前人留于后世之著作,又包括散佚于民间之著作。公元前206年,刘邦率军入咸阳,萧何尽收秦丞相府律令图书,实际上已开遗书收集之先河。汉惠帝时,废除“挟书之律”,汉武帝正式建藏书之策、置写书之官、开献书之路,使遗书收集制度化。据现有文献记载,自汉代至鸦片战争之前,我国较大规模的遗书收集活动达114次之多。计汉代7次、魏晋南北朝17次、隋代2次、唐代10次。 展开更多
关键词 遗书 献书 接索 馆阁 牛弘 史馆 图书 制度 修纂 藏书
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A new approach for effectively determining fracture network connec- tions in fractured rocks using R tree indexing 被引量:2
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作者 LIU Hua-mei WANG Ming-yu SONG Xian-feng 《Journal of Coal Science & Engineering(China)》 2011年第4期401-407,共7页
Determinations of fracture network connections would help the investigators remove those "meaningless" no-flow-passing fractures, providing an updated and more effective fracture network that could considerably impr... Determinations of fracture network connections would help the investigators remove those "meaningless" no-flow-passing fractures, providing an updated and more effective fracture network that could considerably improve the computation efficiency in the pertinent numerical simulations of fluid flow and solute transport. The effective algorithms with higher computational efficiency are needed to accomplish this task in large-scale fractured rock masses. A new approach using R tree indexing was proposed for determining fracture connection in 3D stochastically distributed fracture network. By com- paring with the traditional exhaustion algorithm, it was observed that from the simulation results, this approach was much more effective; and the more the fractures were investigated, the more obvious the advantages of the approach were. Furthermore, it was indicated that the runtime used for creating the R tree indexing has a major part in the total of the runtime used for calculating Minimum Bounding Rectangles (MBRs), creating the R tree indexing, precisely finding out fracture intersections, and identifying flow paths, which are four important steps to determine fracture connections. This proposed approach for the determination of fracture connections in three-dimensional fractured rocks are expected to provide efficient preprocessing and critical database for practically accomplishing numerical computation of fluid flow and solute transport in large-scale fractured rock masses. 展开更多
关键词 fracture network connection fractured rooks R tree indexing
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Approach in High Precision Topic-Specific Resource Discovery on the Web
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作者 YeWei-guo LuZheng-ding 《Wuhan University Journal of Natural Sciences》 EI CAS 2004年第1期41-45,共5页
The Internet presents numerous sources of useful information nowadays. However, these resources are drowning under the dynamic Web, so accurate finding user-specific information is very difficult. In this paper we dis... The Internet presents numerous sources of useful information nowadays. However, these resources are drowning under the dynamic Web, so accurate finding user-specific information is very difficult. In this paper we discuss a Semantic Graph Web Search (SGWS) algorithm in topic-specific resource discovery on the Web. This method combines the use of hyperlinks, characteristics of Web graph and semantic term weights. We implement the algorithm to find Chinese medical information from the Internet. Our study showed that it has better precision than traditional IR (Information Retrieval) methods and traditional search engines. Key words HITS - evolution web graph - power law distribution - context analysis CLC number TP 391 - TP 393 Foundation item: Supported by the National High-Performance Computation Fund (00303)Biography: Ye Wei-guo (1970-), male, Ph. D candidate, research direction: Web information mining, network security, artificial intelligence. 展开更多
关键词 HITS evolution web graph power law distribution context analysis
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Key technology for construction of connection between steel pylonand concrete pile cap of middle pylon of Taizhou Bridge 被引量:1
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作者 Sun Yuxiang Zhang Hong +2 位作者 Xiao Wenfu Huang Tao You Xinpeng 《Engineering Sciences》 EI 2012年第3期8-11,共4页
Taizhou Bridge is a suspension bridge with three pylons and two 1 080 m main spans. The middle pylon is a steel frame with longitudinal herringbone shape and lateral gate shape. The connection between steel pylon and ... Taizhou Bridge is a suspension bridge with three pylons and two 1 080 m main spans. The middle pylon is a steel frame with longitudinal herringbone shape and lateral gate shape. The connection between steel pylon and concrete pile cap is a key part to transfer the huge inner force from the pylon to the foundation. Its construction quality is a critical factor to the overall structural loading of the whole bridge ; therefore the contact ratio between the bearing steel plate of pylon and concrete pile cap is required to be over 75 %. The inclined joint surface in two directions, longitudinally at 39/1 920 and laterally at 1/4, posted a challenge to the construction work. A procedure test was carried out to find an optimal construction method by comparison, and finally the post-injection method was selected as it can meet the requirement of concrete strength and contact ratio at the connection. The successful application of the post-injection method in Taizhou Bridge can nrovide an examnle and reference for similar nroiects in the future. 展开更多
关键词 middle pylon CONNECTION steel pylon concrete pile cap contact ratio post-injection method
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Analysis of tensioned membrane structures considering cable sliding 被引量:4
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作者 宋昌永 《Journal of Zhejiang University Science》 EI CSCD 2003年第6期672-682,共11页
In routine design of tensioned membrane structures, the membrane is generally modeled using space membrane elements and the cables by space cable elements, with no sliding allowed between the membrane and the cables. ... In routine design of tensioned membrane structures, the membrane is generally modeled using space membrane elements and the cables by space cable elements, with no sliding allowed between the membrane and the cables. On the other hand, large deflections are expected and sliding between the membrane and the cables is inevitable. In the present paper, the general finite element code ABAQUS was employed to investigate the influence of cable sliding on membrane surface on the structural behavior. Three analysis models were devised to fulfill this purpose: (1) The membrane element shares nodes with the cable element; (2) The cable can slide on the membrane surface freely (without friction) and (3) The cable can slide on the membrane surface, but with friction between the cable and the membrane. The sliding problem is modeled using a surface - based contact algorithm. The results from three analysis models are compared, showing that cable sliding has only little influence on the structure shape and on the stress distributions in the membrane. The main influence of cable sliding may be its effect on the dynamic behavior of tensioned membrane structures. 展开更多
关键词 Membrane structures Shape finding Cutting pattern Cables Contact simulation
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An Effective Management of Personal Paper Outcome Using Open Service
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作者 Heeseok Choi Wonkyun Joo Minwoo Park Kiseok Choi Jaesoo Kim 《Computer Technology and Application》 2013年第8期400-403,共4页
Abstract: Open collaboration-based R&D (research and development) has become an important issue recently. Researchers' performance is necessary to be understood by analyzing researchers' paper outcome. To drive ... Abstract: Open collaboration-based R&D (research and development) has become an important issue recently. Researchers' performance is necessary to be understood by analyzing researchers' paper outcome. To drive successful outcomes and co-research, researchers' paper outcome should be autonomously established. Therefore we propose an approach to manage and update easily paper outcome of researchers. The proposed approach makes researchers search their paper using the Google Scholar's opened API (application program interface) and update their outcome. Since researchers autonomously can establish the list of their own papers in our service using open service, researchers' personal outcome can be efficiently managed. 展开更多
关键词 Open R&D research outcome research performance R&D planning.
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The Theory of Internet Finance 被引量:9
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作者 谢平 邹传伟 《China Economist》 2013年第2期18-26,共9页
Internet based technologies, such as mobile payments, social networks, search engines and cloud computation, will lead to a paradigm shift in financial sector. Beside indirect financing via commercial banks and direct... Internet based technologies, such as mobile payments, social networks, search engines and cloud computation, will lead to a paradigm shift in financial sector. Beside indirect financing via commercial banks and direct financing through security markets, a third way to conduct financial activities will emerge, which we call "internet finance'" This paper presents a detailed analysis of payment, information processing and resource allocation under internet finance. 展开更多
关键词 internet finance mobile payments social networks search engines cloudcomputation
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On Application of Computer-based Corpora in Translation
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作者 Shangyi WU 《International Journal of Technology Management》 2015年第2期1-3,共3页
Authors of papers to proceedings have to type these in a form suitable for direct photographic reproduction bthrough the research methods about analyzing computer corpus translation and inter-language research methods... Authors of papers to proceedings have to type these in a form suitable for direct photographic reproduction bthrough the research methods about analyzing computer corpus translation and inter-language research methods, and through comparison analysis about three of more thaxL four hundred thousand words, link adverbs in Chinese and English corpus and its corresponding Chinese word retrieval results, and make a detailed description of the characteristic for Chinese English learners and native English speakers, and thus provides an application example to study corpus in translation. 展开更多
关键词 computer corpus Inter-language Style consciousness TRANSLATION
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Comparative Study on the E-waste Recycling Systems in Japan and China 被引量:1
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作者 Kayoko Y amamloto Bi Bo 《Journal of Environmental Science and Engineering(A)》 2013年第7期427-439,共13页
This study aims to identify processes, current situations and issues of recycling systems for four home appliances, namely, air conditioners, television receivers, refrigerators, and washing machines, among e-wastes i... This study aims to identify processes, current situations and issues of recycling systems for four home appliances, namely, air conditioners, television receivers, refrigerators, and washing machines, among e-wastes in China and Japan for understanding and comparison of their characteristics. In accordance with results of a literature search, review of information disclosed online, and questionnaire survey conducted, the findings of this study are summarized in the following two points: (1) The results show that in Japan most of the home appliances mentioned above have been collected through home appliance recycling tickets, resulting in an issue of "requiring some effort" in treatment and recycling stages, and most plants have contracted out their e-waste recycling; (2) It is found out that advantages of the recycling system in Japan include easiness to monitor concrete data and thorough environmental friendliness ensured while its disadvantages include illegal dumping and export. It becomes apparent that advantages of the recycling system in China include a high reuse rate, low treatment cost, and fewer illegal dumping while its disadvantages include less safe reused products, environmental pollution caused by e-waste treatment, illegal import and difficulty in obtaining data. 展开更多
关键词 E-WASTE recycling systems home appliances Japan and China.
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Using hot-vapor bypass for pressure control in distillation columns
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作者 Stefano Ciannella Arthur Siqueira Damasceno +3 位作者 Icaro Caze Nunes Gilvan Wanderley de Farias Neto Wagner Brandao Ramos Romildo Pereira Brito 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第1期144-151,共8页
Distillation column control is widely explored in literature due to its complexity and importance in chemical and petrochemical industries. In this process, pressure represents one of the most important variables to b... Distillation column control is widely explored in literature due to its complexity and importance in chemical and petrochemical industries. In this process, pressure represents one of the most important variables to be controlled. However, there are few studies about how pressure affects the dynamic behavior of distillation columns and most research on distillation column control involve direct manipulation of cooling fluid through the condenser. Nevertheless, such an approach demands constant changes in cooling fluid flowrates that are commonly by the order of tons per hour, which can be difficult to work or even unfeasible in a real plant. Furthermore, this strategy is usually avoided, as it can cause fouling and corrosion acceleration. The hot-vapor bypass strategy fits well as a solution for these issues, eliminating the need to dynamically manipulate cooling fluid flowrates in the condensation unit. This work presents the modeling and simulation of a conventional distillation column for the separation of water and ethanol, in which a comparative study between a conventional pressure control and a control using hot-vapor bypass was performed. The main results were obtained through dynamic simulations which considered various disturbances in the feed stream, and demonstrated superior performance by the hot-vapor bypass system over the usual scheme proposed in literature, while evaluating the lntegral Absolute Error (IAE) norm as the control performance index. 展开更多
关键词 Distillation Pressure control Hot-vapor bypass
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A unified model of bidirectional reflectance distribution function for the vegetation canopy 被引量:6
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作者 XU XiRu FAN WenJie +2 位作者 LI JuCai ZHAO Peng CHEN GaoXing 《Science China Earth Sciences》 SCIE EI CAS CSCD 2017年第3期463-477,共15页
An accurate and operational bidirectional reflectance distribution function (BDRF) canopy model is the basis of quantitative vegetation remote sensing. The canopy reflectance should be approximated as the sum of the... An accurate and operational bidirectional reflectance distribution function (BDRF) canopy model is the basis of quantitative vegetation remote sensing. The canopy reflectance should be approximated as the sum of the single scattering reflectance arising from the sun, pl, and the multiple scattering reflectance arising from the canopy, fin, as their directional characteristics are dramatically different. Based on the existing BRDF model, we obtain a new analytical expression of ρ1 and ρm in this paper, which is suitable for different illumination conditions and different vegetation canopies. According to the geometrical optic model at the leaf scale, the anisotropy of ρ1 can be ascribed to the geometry of the object, sun and the sensor, multiple scale clumping, and the fraction of direct solar radiation and diffuse sky radiation. Then, we parameterize the area ratios of four components: the sunlit foliage, sunlit ground, shadow foliage and shadow ground based on a Poisson distribution, and develop a new approximate analytical single scattering reflectance model. Assuming G=0.5, a recollision probability theory based scattering model is developed which considers the effects of diffuse sky radiation, scattering inside the canopy and rebounds between the canopy and soil. Validation using ground measurements of maize and black spruce forest proves the reliability of the model. 展开更多
关键词 Vegetation BRDF Unified model Clumping Index Proportion of direct solar radiation and diffuse sky radiation Recollision probability
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Low-temperature thermoplastic welding of metallic glass ribbons for in-space manufacturing 被引量:2
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作者 Chaoqun Liao Ming Liu +9 位作者 Qi Zhang Wen Dong Rui Zhao Bobo Li Zhiwei Jiao Jian Song Wei Yao Shaofan Zhao Haiyang Bai Wei-Hua Wang 《Science China Materials》 SCIE EI CAS CSCD 2021年第4期979-986,共8页
In-space manufacturing is an emerging and promising research field in space industry,which benefits the development of space explorations.Owing to the microgravity,high vacuum and complexity of the space environment,a... In-space manufacturing is an emerging and promising research field in space industry,which benefits the development of space explorations.Owing to the microgravity,high vacuum and complexity of the space environment,a special manufacturing strategy for alloys is highly demanded for the in-space manufacturing.Herein,a lowtemperature thermoplastic metallic welding method was proposed and employed for La-based metallic glass ribbons.With the sandwiched structures of La-and Zr-based ribbons,the welded samples exhibit a competitive fracture strength and an increased tensile strain than those of the welded la-based samples due to the second phase strengthening.This suggests that metallic glass is an ideal material candidate for in-space manufacturing,and can be well manufactured at a nonmelting state with good mechanical performances.In addition,the thermoplastic manufacturing method can also feature a moderate processing time window.In general,this work presents the promising potential of low-temperature thermoplastic welding strategy for in-space manufacturing of metallic materials. 展开更多
关键词 in-space manufacturing metallic glasses thermoplastic welding mechanical properties
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Predicted Modulated Differential Rates for Direct WIMP Searches at Low Energy Transfers
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作者 J.D.Vergados 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第3期504-514,共11页
The differential event rate for direct detection of dark matter,both the time averaged and the modulated one due to the motion of the Earth,are discussed.The calculations focus on relatively light cold dark matter can... The differential event rate for direct detection of dark matter,both the time averaged and the modulated one due to the motion of the Earth,are discussed.The calculations focus on relatively light cold dark matter candidates (WIMP) and low energy transfers.It is shown that for sufficiently light WIMPs the extraction of relatively large nucleon cross sections is possible.Furthermore for some WIMP masses the modulation amplitude may change sign,meaning that,in such a case,the maximum rate may occur six months later than naively expected.This effect can be exploited to yield information about the mass of the dark matter candidate,if and when the observation of the modulation of the event rate is established. 展开更多
关键词 dark matter WIMP direct detection WIMP-nucleus scattering event rates MODULATION
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