疲劳试验研究进展

疲劳学已成为一门重要科学学科，对其研究具有极其重要的现实意义。目前，疲劳学的前沿方向是随机疲劳理论、混沌疲劳以及复合材料疲劳寿命估算。疲劳试验是进行疲劳学研究的不可或缺的条件，同样产品的疲劳寿命估计离不开疲劳试验，最后介绍了目前疲劳试验机的研究方向。     

铆接钢桥剩余寿命与使用安全评估方法

基于疲劳累积损伤和断裂力学理论，建立了能表征铆接钢桥疲劳破坏行为的确定性评估方法．进而基于铆接钢桥的疲劳随机损伤演化机理，针对铆接结构多破坏模式和铆接多成分、多构件的疲劳失效特点，建立了能反映铆接钢桥脆断和韧断疲劳破坏机制的构件概率疲劳模型和系统疲劳可靠性分析模型．基于Monte-Carlo算法，进行铆接钢桥构件和结构系统疲劳断裂失效概率的计算，并编制了用于铆接钢桥系统疲劳可靠性分析的大型程序系统．     

海洋石油工程中的疲劳问题

分析了海洋环境条件下疲劳寿命的随机性与模糊性因素。给出了模糊随机海浪谱及其载荷谱的制作方法，提出了模糊疲劳损伤评价及模糊疲劳可靠性的分析方法，研究了疲劳寿命的估算模式与模型，形成了应用模糊概率断裂与损伤力学解决海洋石油工程中疲劳问题的较系统的理论。此外，还探讨了就腐蚀疲劳，随机冰载荷作用下的低温疲劳等特殊问题，以及减缓与抑制金属疲劳等问题。     

金属疲劳断裂过程中的尖点突变模型

基于疲劳断裂过程中存在着突变现象的观点，对系统（由疲劳试样和疲劳试验机所组成）在疲劳断裂过程中的变化情况作了深入研究，建立了疲劳断裂过程中尖点突变的模型，并通过理论分析获得了疲劳断裂过程中突变发生的条件．     

躯体性疲劳机制研究的进展与思考

通过文献综述法简要总结了躯体性疲劳的概念、研究历史及现状，介绍了中枢疲劳和外周疲劳的可能机制，简要探讨了中枢疲劳和外周疲劳的关系。目前，疲劳研究采用了生物化学、生物电、微透析、基因表达等技术，已经深入到亚细胞、分子、质子和基因水平。研究结果表明，中枢疲劳的概念的内涵和外延未必妥当，中枢疲劳和外周疲劳之间有复杂的关系。为了阐明疲劳机理、实现抗疲劳、消除疲劳、增强体质的目标，未来的研究既要从微观水平对运动疲劳进行评定，也要从整体生物电的角度深入研究疲劳产生的可能机制。     

浅谈大学生如何选择消除运动性疲劳的方法

运动性疲劳是运动训练中常出现的一种生理现象（过度疲劳除外），根据超量恢复理论、应激理论和运动训练理论，运动水平的提高就是疲劳一超量恢复一再疲劳一再超量恢复的过程。因此，在运动训练中出现疲劳是很正常的。但疲劳如果不能及时消除，疲劳积累会对机体产生不良影响，将会影响运动员的运动训练安排和健康。能否尽快消除疲劳，连续、合理和有规律地安排训练，是运动训练所面临的一个重要问题。因此，如何采取有效的疲劳消除方法就显得极为重要。本文具体介绍了如何消除运动性疲劳的方法，指导同学们正确选择消除运动性疲劳的方法，使其能尽快消除疲劳，连续、合理和有规律地安排训练，为取得好成绩打下良好的基础。     

模糊可靠性疲劳寿命的分析与计算

针对随机栽荷下构件疲劳寿命预估中的可靠性问题，在模糊累积损伤疲劳寿命计算模型的基础上，根据恒幅疲劳寿命的分布及试验参数，依可靠性理论，导出了恒幅载荷下构件的可靠度工作寿命的数学方程，从而建立了承受随机载荷的构件的模糊可靠度疲劳寿命计算模型，同时还导出了传统累积损伤计算方法下可靠度疲劳寿命计算模型。采用这两种模型，通过实测载荷谱，对构件的可靠度疲劳寿命进行了预估，并与实际安全寿命进行比较。结果表明，所建立的模糊可靠度疲劳寿命计算模型预估的安全寿命与实际安全寿命相当吻合，相对误差仅为2．12％，传统可靠度疲劳寿命计算模型的预估误差为99．27％。     

机械零件的疲劳强度设计

根据现有的疲劳理论及Ｍｉｎｅｒ理论，定义了能反映影响疲劳损伤的主要因素的应力循环的一次循环的疲劳损伤量δ和零件的疲劳损伤累积强度Ｋ，建立了一种疲劳损伤累积理论的新表达方法。用该方法可以方便地进行常规疲劳计算，计算结果令人满意。     

金属材料热机械疲劳试验研究的现状

详细论述了金属材料的热机械疲劳试验与研究现状，分析了金属材料的热机械疲劳特性，讨论了热机械疲劳试验方法，并提出了目前热机械疲劳试验与研究中存在的问题，以及热机械疲劳研究领域的研究方向。     

钢筋混凝土吊车梁钢筋疲劳可靠度分析

基于吊车载荷随机数学模型和钢筋的疲劳试验结果，进行了吊车梁钢筋的疲劳累积损伤概率分析，提出了钢筋混凝土吊车梁的钢筋疲劳可靠性分析和疲劳寿命估计方法     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.