超细晶粒WC—Co硬质合金的收缩与晶粒长大

采用复合烧结工艺（真空烧结＋热等静压烧结）制备超细晶粒ＷＣ－Ｃｏ硬质合金，研究了烧结过程中的超细合金的收缩及晶粒长大行为。结果表明，在常规的固相烧结阶段，局部微区内的液相烧结使超细晶粒ＷＣ－Ｃｏ硬质合金的收缩及晶粒长大行为不同于普通晶粒硬质合金。在此阶段，ＷＣ晶粒出现较严重的早期晶粒长大现象，导致合金的收缩占总体收缩量的９０％以上。     

机械合金化制备WC—Co纳米硬质合金

本文利用机械合金化技术研究了ＷＣ－Ｃｏ的合金化过程,成功地制备出纳米ＷＣ－Ｃｏ合金粉末,通过真空烧结成型工艺获得了平均晶粒度小于２００ｎｍ的ＷＣ－Ｃｏ硬质合金,其硬度达到１７．４ｋＮ／ｍｍ２,烧结密度为１０．９ｇ／ｃｍ３．对纳米ＷＣ－Ｃｏ粉末的烧结工艺作了初步探讨,通过添加少量的ＶＣ能有效地抑制烧结过程中晶粒的长大．     

热－力循环对热处理硬质合金钴相结构的影响

用Ｇｌｅｅｂｌｅ－１５００动态应力应变／热模拟试验机对ＷＣ－２０％Ｃｏ（质量分数）热处理硬质合金进行热－力循环实验，借助ＸＲＤ技术分析计算了合金中钴粘结相的相组成，并在ＳＥＭ下观察了合金的微观组织，结果表明：合金经热－力循环后，钴相中面心β－Ｃｏ含量降低，密排六方ａ－Ｃｏ含量相应升高；热处理合金钴相中面心钻相对体积百分含量下降的程度低于常规烧结合金。热处理硬质合金制品使用寿命的提高与合金中钴相相结构动态变化程度有关。     

钨─钴混合氧化物直接气相还原／碳化相变过程

用ＸＲＤ和ＳＥＭ对钨－钴混合氧化物（Ｗ２０Ｏ５８＋Ｃｏ３Ｏ４）的氢还原及在不同组成的Ｈ２／ＣＨ４混合气体中的碳化过程进行了研究．结果表明，在８５０℃以上氢还原产物是α－Ｗ＋Ｃｏ３Ｗ＋Ｃｏ７Ｗ６三相混合物．纯蓝钨（Ｗ２０Ｏ５８）或钨－钴混合氧化物都能在较低的温度下（９００～１０００℃）被甲烷气相碳化成ＷＣ，碳化速度和游离碳的析出均与碳化温度及Ｈ４／ＣＨ４混合气相的组成有关．作者给出了最佳的碳化工艺条件     

Y_2O_3在WC－8Ni硬质合金中的作用

本文研究了在ＷＣ－８Ｎｉ合金中添加微量Ｙ２Ｏ３制得ＹＮＲ８新型硬质合金，测试结果表明Ｙ２Ｏ３的加入明显提高了ＷＣ－８Ｎｉ合金的抗弯强度和耐磨性，最大提高幅度分别可达５０．４％、８２．７％，ＹＮＲ８合金达到并超过ＹＧ８（ＷＣ－８Ｃｏ）硬质合金的物理机械性能，并对ＹＮＲ８合金作了显微结构分析，探讨了稀土在ＷＣ－８Ｎｉ合金中的作用机理     

Y2O3在WC—8Ni硬质合金中的作用

本文研究了在ＷＣ－８Ｎｉ合金中添加微量Ｙ２Ｏ３制得ＹＮＲ８新型硬质合金，测试结果表明Ｙ２Ｏ３的加入明显提高ＷＣ－８Ｎｉ合金的抗弯强度和耐磨性、最大提高幅度分别可达５０．４％、８２．７％ＹＮＲ８合金达到并超过ＹＧ８（ＷＣ－８Ｃｏ）硬质合金的物理机械性能，并对ＹＮＲ８合金作了显微结构分析，探讨了稀土在ＷＣ－８Ｎｉ合金中的作用机理。     

W-Cu合金中Cu相纯度对热导的影响

为了探讨提高ＷＣｕ合金热导（ＴＣ值）的途径,采用４种不同纯度的铜,用熔渗工艺制备Ｗ１５Ｃｕ（质量分数,％）复合材料试样,并用ＣＯ２激光仪测试熔渗试样的ＴＣ值．研究发现,铜相纯度的微小变化对ＷＣｕ合金的ＴＣ值产生重大影响．并对铜相纯度影响ＷＣｕ合金ＴＣ值的机制进行分析和探讨．实验证明,用９９．９％的铜,并用适当的熔渗工艺,可以得到ＴＣ值为２００Ｗ·ｍ－１·Ｋ－１的Ｗ１５Ｃｕ合金．     

Fe-Cr-Mo-C 系粉末压坯烧结致密化机理

研究了烧结温度对Ｆｅ－Ｃｒ－Ｍｏ－Ｃ系试样密度及性能的影响,探讨了实现烧结致密化的机理．结果表明,采用真空烧结工艺,在１１６０～１２６０℃范围内,Ｆｅ－（１３～２０）Ｃｒ－１．５Ｍｏ－（１．８～３．６）Ｃ粉末压块可实现液相烧结致密化,制得密度大于７．３ｇ／ｃｍ３,硬度ＨＲＡ７０以上的高Ｃｒ烧结铁基材料．适宜的液相烧结温度随Ｃ含量增加而降低．     

超音速火焰喷涂WC—Co涂层结构的研究

用Ｘ射线衍射研究超音速火焰喷涂ＷＣ－Ｃｏ涂层的结构及其影响因素的结果表明，超音速火焰喷涂过程中，ＷＣ的分解也会发生，但受ＷＣ－Ｃｏ喷少粉末结构的影响很大。当粉末中的结合相为复合碳化钨（如Ｃｏ３Ｗ３Ｃ，Ｃｏ６Ｗ６Ｃ）而非金属钴时，ＷＣ最容易发生分解，依赖于燃气的种类，将分解为Ｗ２Ｃ或金属钨。钴包覆ＷＣ型粉末喷制的涂层结构明确显示了涂层中Ｃｏ－Ｗ－Ｃ非晶态相的形成。Ｃｏ－Ｗ－Ｃ三元非晶合金经结晶化热处     

铁镍代钴新型硬质合金的组织和性能

研究了热处理对粘结剂质量分数为１０％的ＷＣ－（Ｆｅ，Ｃｏ，Ｎｉ）合金组织和性能的影响，结果表明：淬火－回火过程中，硬质相ＷＣ的形态、大小和分布基本上没有变化，但粘结相的结构有变化；烧结态粘结相为马氏体和少量残留奥氏体组成；淬火处理使烧结态合金中的残留奥氏体量减小；淬火后回火，粘结相中出现逆转变回火奥氏体；随回火温度升高，逆转变回火奥氏体增加。文中还讨论了烧结态粘结相中马氏体的形成和逆转变回火奥氏体产生的原因，以及不同回火处理态合金中逆转变回火奥氏体与合金性能的关系。     

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.     

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.     

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).     

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.