多孔羟基磷灰石生物陶瓷的研究现状与进展

羟基磷灰石生物陶瓷与人体的无机组成和晶体结构相似 ,具有良好的生物活性和生物相容性 .多孔羟基磷灰石生物陶瓷 ,其相互连通的微孔有利于组织液的微循环并为羟基磷灰石深部的新生骨提供营养 ,促进纤维组织和新生骨的结合和生长 ,是一种性能优异的硬骨组织替代材料 .近年来 ,发明了一系列制备多孔羟基磷灰石陶瓷的方法 ,如有机泡沫浸渍法、添加造孔剂法、快速成型法等 .对于多孔羟基磷灰石生物陶瓷的研究 ,注重研究孔尺寸对多孔体与组织之间相互关系的影响 ,并逐步实现了对多孔体孔径的控制 .本文综述了多孔羟基磷灰石生物陶瓷的制备工艺、生物特性和发展趋势 .     

磷酸钙生物陶瓷涂层制备及其研究进展

羟基磷灰石是哺乳动物体内硬组织的主要无机成分 ,人工合成的羟基磷灰石具有优良的生物相容性和生物活性 但是纯的羟基磷灰石脆性大 ,强度较低 钛及钛合金等医用金属材料具有较好的强度、韧性和优良的加工性能 ,但是生物相容性差 金属基体羟基磷灰石涂层材料兼备金属材料优良的力学性能和生物陶瓷材料的生物特性 ,备受材料领域和医学领域学者的关注 涂层与基体的界面结合强度及涂层材料植入后的稳定性 ,是目前研究的热点和难点 简要评述了羟基磷灰石涂层的制备技术 ,介绍了近年来的研究进展 ,对提高结合强度和植入稳定性的方法进行了归纳     

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.     

磷酸钙生物陶瓷

磷酸钙生物陶瓷材料包括磷酸三钙（β－TCP）和羟基磷灰石（HA）,具有较好的生物相容性和生物活性,本文总结了磷酸钙生物陶瓷材料的制备方法和力学性能研究的最新进展,指出溶液沉淀法和溶胶凝胶法是目前优先使用的精细磷酸钙陶瓷粉末制备工艺,由于磷酸陶瓷的韧性较低,必须对它进行补强增韧,以扩大在临床中的应用范围。     

注浆成型法制备多孔羟基磷灰石生物陶瓷

通过一系列实验,研究了注浆成型法制备多孔羟基磷灰石生物陶瓷和添加高温粘结剂对陶瓷的力学性能影响.对制品进行抗压强度和气孔率的测试观察.结果表明:羟基磷灰石在高温下烧结出现微观结构的变化,并伴有体积收缩.高温粘结剂对羟基磷灰石烧结体的力学性能有影响.     

电泳沉积羟基磷灰石生物陶瓷涂层的研究

用异丙醇作为分散介质，对电泳沉积羟基磷灰石生物陶瓷涂层进行了系统研究，经过制备稳定的悬浮液、电泳沉积，高温烧结等过程，在Ti6A14V合金上得到表面均匀的羟基磷灰石生物陶瓷涂层，用X射线衍射（XRD）和扫描电镜（SEM）等技术对羟基磷灰石颗粒的物相和沉积层的表面进行了表征，研究了电泳时间与电泳沉积量和电流密度，电泳沉积量和电泳电压之间的相互关系，并讨论了这些实验参数对电泳沉积过程的影响。     

HAP生物活性陶瓷的结构稳定性与力学性能

探讨了羟基磷灰石生物活性陶瓷的制备工艺对材料结构稳定性及力学性能的影响。采用化学共沉淀法合成羟基磷灰石粉料，采用注浆成型、热压烧结及热等级压后烧结等工艺制备羟基磷灰石颌面骨材料。经结构分析、力学性能测试及显微结构观察，认为该材料具有满足于临床应用的物理性能。     

羟基磷灰石的制备方法及应用研究

羟基磷灰石作为磷酸钙的一种，它具有优异的生物活性、热稳定性及离子交换能力，是一种理想的多功能材料.随着对羟基磷灰石研究的不断深入，其制备方法及应用领域得以大幅拓展.文章就羟基磷灰石理化性质和结构组成作以综述，阐述了其制备工艺以及在力学、生物医学，吸附、催化剂、载体材料等领域的应用研究，并对其发展前景进行展望.     

废弃贝壳制备纳米带状羟基磷灰石的研究

本研究探索了利用废弃贝壳制备生物活性材料羟基磷灰石的工艺路径。采用水浴加热的方法,以贝壳粉为原料、磷酸氢二氨为磷源,尿素为添加剂,成功制备出高纯相、尺寸均匀可控的纳米带状羟基磷灰石。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、红外光谱(FTIR)等方法表征产物的晶相组成及形貌。XRD分析结果显示:贝壳中的碳酸钙已经完全转化为羟基磷灰石;SEM分析结果表明:采用水浴法合成得到的羟基磷灰石为纳米级别的带状结构;FTIR表征检测到羟基磷灰石中的羟基,进一步验证产物为羟基磷灰石。本研究解决了废弃贝壳环境污染的问题,同时降低了羟基磷灰石的制备成本。     

PVA/HA复合水凝胶的制备及性能研究

采用模板法制备了微孔羟基磷灰石,采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)对其结构进行了表征。同时,制备了聚乙烯醇/微孔羟基磷灰石复合水凝胶和聚乙烯醇/纳米羟基磷灰石复合水凝胶。测试了聚乙烯醇/羟基磷灰石复合水凝胶的含水率和力学性能。实验表明,合成的羟基磷灰石具有微孔结构,复合水凝胶含水率可达到60%以上,羟基磷灰石的加入使复合材料的拉伸强度、断裂伸长率都得到了较大提高,可用于人造软骨,是一种很有开发前景的生物医用材料。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

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.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

A computer generator for randomly layered structures

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

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

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。     

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.     

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

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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