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1.
研究了水热体系下以哌嗪为模板剂的Ω沸石的合成规律,并与传统合成Ω沸石的模板剂四甲基氢氧化铵(TMAOH)进行了比较.实验结果表明:在Ω沸石的合成体系中,两种模板剂的结构导向作用不尽相同,在100 ℃哌嗪没有结构导向作用,在150 ℃才能够合成Ω沸石.而TMAOH的作用恰好相反,在100 ℃就能够合成Ω沸石,在150 ℃仅能够合成ANA沸石.用哌嗪做模板剂,所合成样品的相对结晶度高于用TMAOH合成的样品.  相似文献   

2.
分别以白炭黑(Ⅰ)和硅溶胶(Ⅱ)为硅源,在(TPA)2O-Na2O-SiO2-H2O体系(TPA为四丙基铵)中,反应温度为60℃,合成了高结晶度纯硅沸石.用扫描电子显微镜(SEM)法测得的晶粒大小分别为0.20μm(Ⅰ)和0.45μm(Ⅱ);用粉末X射线衍射(XRD)线宽法测得的晶粒大小为0.02μm.与高温(180℃)合成的硅沸石样品相比较,低温合成的微细晶粒硅沸石样品已具备纳米级材料的若干特性.微细晶粒硅沸石的正己烷吸附量和比表面都非常大.XRD谱,红外吸收光谱(FT-IR),29Si魔角固体核磁共振(29SiMASNMR)和热重分析(TG/DTG/DTA)的研究证明,微细晶粒硅沸石的结构破坏温度和单斜/正交对称性相转变温度明显地比高温合成的硅沸石低,硅羟基缺陷也明显地增加.0.20~0.45μm的微细晶粒硅沸石的比表面几乎与胶体质点相同,它的外表面积达100m2/g,中孔容积为0.10~0.12ml/g,平均孔径为2.6~2.7nm.这表明微细晶粒硅沸石实际上是纳米质点的结合体.  相似文献   

3.
利用聚苯乙烯-丙烯酸(PSA)共聚物胶粒为模板,采用控制沉降和原位聚合的方法首先合成PSA@Fe2O4/聚砒咯(PPy)复合核壳粒子;将去核后得到的Fe3O4/PPy空心胶囊进一步热解炭化,制备了单分散Fe3O4/Carbon空心胶囊.样品物相及结构经X射线衍射仪(XRD)、透射电子显微镜(TEM)和扫描电子显微镜(SEM)表征.超导量子干涉仪(SQUID)测定结果显示,碳胶囊样品呈超顺磁性.N2气吸附测试结果显示磁性碳胶囊的比表面积BET为98m^2/g.以Fe3O4/Carbon磁性空心胶囊对抗癌药物阿霉素进行负载后,体外模拟释放实验结果显示胶囊具有良好的药物缓释性能.  相似文献   

4.
分别以白炭黑和硅溶胶为硅源,在(TPA)2O-Na2O-SiO2-H2O体系中,反应温度为60℃.,合成了高结晶度纯硅沸石,用扫描电子显微镜法测得的晶业大小分别为0.20μm和0.45μm;用粉末X射线衍射线宽法测得的晶粒大小为0.02μm。与高温合成的硅沸石样品相比较,低温合成的微细晶粒硅沸石样品已具备纳米级产若干特性。  相似文献   

5.
报道了以硅沸石(Silicalite)为原料,添加结晶模板剂TPABr(4-n-丙基溴铵)以及碱源(NaOH)等,利用水热合成法成功地合成了高硅含量、疏水性硅沸石膜.同时探讨了硅沸石膜对各种含醇水溶液的渗透气化分离特性.研究结果表明:对乙醇/水溶液,供给液乙醇浓度4.7%(wt)时,透过液乙醇浓度达到76%(wt)以上,分离系数αe/w)达65以上;对酒精发酵液,供给液乙醇浓度4.8%(wt)时,透过液乙醇浓度达到82%(wt)以上,分离系数α(e/w)高达90以上.充分说明了所合成的硅沸石膜对酒精水溶液具有非常高的分离效果.  相似文献   

6.
无机胺合成ZSM—5沸石分子筛   总被引:8,自引:0,他引:8  
利用氨水为模板剂合成了ZSM-5沸石分子筛,研究了合成温度和时间对分子筛合成的影响。实验表明,在142~177℃范围内,以氨水为模板剂都可以合成出ZSM-5沸石分子筛。合成温度越低,所需时间越长,同时以XRD为手段,对分别以氨水和正丙胺为模板剂合成的ZSM-5沸石分子筛的结构进行了比较。  相似文献   

7.
树形分子为模板低温制备纳米硫化锌空心球   总被引:4,自引:0,他引:4  
利用3.5代端酯基PAMAM树形分子(G3.5-COOCH3)为模板,低温下成功制备了纳米硫化锌空心球,用透射电子显微镜(TEM)、X射线粉末衍射(XRD)及紫外吸收光谱等手段对合成样品的形貌、结构及性能进行了表征.TEM结果显示,ZnS空心球的直径在80~100nm范围左右,其壳层的厚度约为20~30nm.树形分子的农度对产物的最终形貌和结构均有很大的影响.并讨论了空心球结构形成的可能模板机理.  相似文献   

8.
介孔空心微球的合成对于获得优良的吸附剂, 催化剂和药物缓释剂具有十分重要的意义. 采用十二胺(DDA)为主模板剂, 聚乙二醇1000(PEG1000)为辅助模板剂, 成功地合成出了具有介孔孔壁的, 比表面积可高达951.23 m2/g 的空心二氧化硅微球. 考察了温度, 浓度, 溶剂等合成条件对合成的介孔空心微球的结构及形貌的影响, 实验结果表明合成温度及溶剂对合成的材料的结构及形貌具有显著的影响. 不同比例的醇水混合体系用做溶剂时, 可得到形貌及有序度完全不同的物质. 最佳的合成温度约为30-40℃, 低于该温度时, 合成的样品难以形成空心球结构, 而高于该温度时, 空心球结构将受到破坏. 此外, 模板剂的浓度也对合成样品的结构具有重要的影响.  相似文献   

9.
在大孔α—Al2O3陶瓷管栽体上采用晶种预涂层法在澄清溶液体系中水热合成了Silicalite-1型沸石膜,用SEM和XRD表征了晶种、晶种涂层后载体和成膜后沸石膜的结构、晶形变化、晶相结构等成膜情况,并初步考查了两种不同温度(130℃和160℃)下生长成膜的结构变化.结果表明:制备的品种呈椭球形、晶粒小(约100nm)而均匀、纯度高.适合作晶种涂层成膜;所用载体孔径大而不均匀、表面粗糙而不平整,但经品种涂层后表面可形成一层厚度均匀、光滑的晶种层,再水热晶化时有利于成膜.所得膜连续、清晰无裂缺,载体、晶种层和沸石膜层之间相互结合紧密;连续晶种层改善了载体表面的性能。有利于连续Silicalite—1沸石膜的形成;合成温度不同,沸石晶粒在载体表面生长的方向不同,所形成的膜微观结构也不同.该合成方法能适合其他不同类型沸石膜的制备.  相似文献   

10.
用化学分析、粉末X射线衍射、傅里叶红外吸收光谱、热失重及差热分析、13C魔角固体核磁交叉极化(CP)及高功率去偶(HPDEC)谱对由模板分子四甲基乙基二胺(TMEDA)导向合成的高硅沸石ZSM-5、ZSM-35及丝光沸石进行研究,揭示了该模板分子在沸石孔道中的位置、运动状态及模板分子与骨架的相互作用.  相似文献   

11.
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.  相似文献   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
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。  相似文献   

14.
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  相似文献   

15.
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  相似文献   

16.
17.
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.  相似文献   

18.
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).  相似文献   

19.
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.  相似文献   

20.
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.  相似文献   

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