柱状纳米羟基磷灰石的制备和结构表征

以P2O5,Ca(NO3)2.4H2O为原料,无水乙醇为溶剂,通过调节pH值控制凝胶的形成,利用溶胶-凝胶/水热法制备柱状纳米羟基磷灰石(HAP).通过XRD、FTIR、电镜(TEM、SEM)等检测手段,对凝胶燃烧产物和经水热处理后的粉体相组成、形貌进行分析,探讨HAP晶体形成的原因.结果表明,利用溶胶-凝胶经低温燃烧后形成主晶相为纳米级的HAP,形状以柱状为主,经水热处理后,可得高纯度的HAP柱状晶体(100 nm×1800 nm),杂以少量粒状纳米粒子(30 nm×60 nm).     

β-磷酸三钙对玻璃基骨水泥显微结构的影响

以CaHPO4.2H2O和CaCO3为原料,采用固相反应法制备β-磷酸三钙(TCP),并将其掺加到玻璃基生物骨水泥中制成复合骨水泥,浸泡在人体模拟体液(SBF)中,研究其显微结构的变化.结果表明,通过湿式粉碎和固相反应法可以制得晶体发育良好、纯度高的-βTCP粉末;复合骨水泥试样中的-βTCP在SBF溶液的浸泡下会逐步降解,从而制得具有较高孔隙率的骨水泥.     

动物骨源灰分掺杂Na2O-CaO-SiO2系 硅灰石微晶玻璃结构与性能研究

采用烧结法制备了钠钙硅系硅灰石微晶玻璃,利用动物骨源灰分(骨灰)引入羟基磷灰石进行掺杂,研究了不同骨灰掺杂量对硅灰石微晶玻璃的烧结工艺、物相组成、微观结构和性能的影响。结果表明:随着骨灰质量分数的增加,玻璃软化温度逐渐升高,气孔率增加,显微硬度、抗压强度、收缩率、体积密度均逐渐降低,硅灰石的晶相含量逐渐减少,羟基磷灰石晶相含量增多;骨灰质量分数为40%时,样品中硅灰石为主晶相、羟基磷灰石为次晶相,显微硬度为484.5Hv0.1,抗压强度为221MPa,满足骨修复材料的需要。当掺杂60%和80%骨灰时,主晶相为磷酸三钙,次晶相为少量的硅灰石和羟基磷灰石。     

柠檬酸对溶胶-凝胶法制备羟基磷灰石粉体的影响

为改善以Ca(NO) 3·4H2 O和 (CH3O) 3PO为前驱体、采用溶胶凝胶法制备羟基磷灰石(HAP)粉体的颗粒较大 ,尝试加入螯合剂柠檬酸 (C6H8O7) ,研究其对HAP粉体特征的影响 .SEM结果显示柠檬酸的加入使得粉体粒度明显变小 ,进一步在TEM观察 ,可以发现HAP粉体尺寸约为 5 0nm .XRD和FTIR分析表明柠檬酸的加入可使更多的CO2 -3 以B型替代的方式进入HAP结构中 ,并引起HAP晶格微畸变     

CaO-SiO_2/PAA复合膜的制备及其体外生物活性

以四水合硝酸钙为钙源、正硅酸乙酯为硅源(按CaO/SiO2摩尔比1∶1),采用溶胶-凝胶法制备出CaO-SiO2生物玻璃溶胶.采用压力诱导的方法将CaO-SiO2溶胶注入多孔阳极氧化铝(PAA)的纳米孔道中,经550℃热处理,得到CaO-SiO2/PAA复合膜.所得样品在模拟体液(SBF)中分别浸泡1和7d,观察其表面诱导形成类骨磷灰石的能力.通过扫描电镜(SEM)、X射线能谱仪(EDS)、傅里叶变换红外衍射仪(FTIR)对浸泡前后样品的微观形貌和成分进行表征.试验结果表明:钙硅基生物活性材料能够装载在PAA的纳米孔道中,并且装载有钙硅基材料的PAA在SBF中浸泡后能诱导类骨磷灰石的生成.     

溶胶-凝胶法制备羟基磷灰石粉体化学机理分析

利用硝酸钙醇溶液和五氧化二磷醇溶液,通过溶胶-凝胶法,制备了羟基磷灰石（HAP）粉体．对前驱体和不同热处理温度的HAP粉体试样进行了FTIR与XRD测试分析,讨论分析了在溶胶-凝胶法制备HAP过程中HAP生成化学反应的机理．     

HPMC凝胶模板诱导羟基磷灰石的合成

以羟丙基甲基纤维素（hydroxypmpylmethyl cellulose,HPMC）水凝胶作为模板合成了羟基磷灰石．利用X射线粉末衍射（XRD）、扫描电子显微镜（SEM）和傅里叶变换红外光谱（FTIR）等检测手段对所得的产物进行了形貌与结构表征．结果表明：HPMC水凝胶模板可以诱导羟基磷灰石的形成;模板分子上的多羟基与磷灰石晶体有一定的相互作用,模板的疏水微区和凝胶网络结构为磷灰石的形成提供了微环境,也决定着磷灰石晶体的微观形貌．     

分散介质对电泳沉积生物陶瓷涂层的影响

采用湿法制备羟基磷灰石,并将其应用于不同分散介质进行电泳沉积羟基磷灰石生物陶瓷涂层,利用扫描电镜(SEM)、红外光谱(FTIR)以及X-射线衍射(XRD)对涂层的形貌和化学组成进行分析.实验结果表明,不同的分散介质对电泳沉积羟基磷灰石生物陶瓷涂层的组成和形貌起着决定作用.     

纳米掺锌羟基磷灰石的制备及抗菌性能

采用溶胶-凝胶-超临界CO2干燥法,制备了羟基磷灰石(HAP)和Zn/[Zn Ca]摩尔比γ为0～0.2的掺锌羟基磷灰石(ZnHAP)的纳米微粒.通过FTIR、XRD、TEM分析了锌的掺入对HAP结构、晶形及结晶度的影响;通过抑菌环和抗菌率实验,研究了HAP掺锌后大肠杆菌、金黄色葡萄球菌、乳酸杆菌的抗菌性能.结果表明:采用溶胶-凝胶-超临界CO2干燥法,可制备纳米HAP和纳米ZnHAP,锌可以部分取代钙掺入HAP的结构中;HAP掺入锌后其红外光谱特征吸收峰的振动频率增大,但吸收峰的强度及结晶度随γ增大而降低,晶形从短棒状变为针状;当试样抗菌浓度为0.1 g/mL时,纳米HAP及γ在0.04以下的纳米ZnHAP仅在动态作用下有抗菌作用;而γ在0.08以上时,无论是在静态还是动态作用下ZnHAP都具有抗菌作用,且抗菌性能随掺锌量的增加而提高.说明掺锌可以改善HAP的抗菌性能.     

低Ca/P比溶液电沉积羟基磷灰石涂层

电沉积羟基磷灰石涂层具有工艺简单、过程易控制、适于在复杂表面制备厚度均匀涂层的特点.沉积液Ca/P比(原子数分数)直接影响涂层中的物相组成与涂层形貌.作者采用电沉积与后续热处理相结合的工艺,用低Ca/P比溶液在金属钛表面沉积羟基磷灰石(HA)涂层.利用X射线衍射、透射电镜和扫描电镜分析了涂层中物相组成及后续热处理对涂层中物相和涂层形貌的影响.实验结果表明电压与电解液温度等工艺参数影响涂层中羟基磷灰石的含量以及沉积过程中晶体长大和形核方式.随电压与温度的升高,涂层中羟基磷灰石含量增加.在低温、高压下,电沉积过程以晶体长大为主,涂层薄而致密;在高温、低压下,电沉积过程以晶体形核为主,涂层厚而疏松.经500 ℃空气中热处理后,涂层基本转化为羟基磷灰石,其Ca/P比约为1.61.电沉积涂层由片状和条状物质组成;热处理后,形貌基本未改变,但颗粒因失水发生团聚.通过精确控制电压与电解液温度等参数,能获取内层致密外层疏松的理想梯度结构HA涂层材料,满足对生物植入体的多种要求.     

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.