羧甲基纤维素接枝丙烯酸钠高吸水性树脂的合成与性能

根据自由基聚合和接枝共聚的机理 ,以过硫酸铵为引发剂 ,用羧甲基纤维素接枝丙烯酸钠制得高吸水性树脂 ,并且详细考察了原料配比和引发剂用量对接枝共聚物性能的影响 .实验结果表明 ,该接枝聚合物是一种较好的超强吸水材料 ,它吸自来水和盐水的量都远远大于其它吸水材料 .其吸去离子水为 1 0 0 0 g/g,吸 0 .9%的盐水为 1 4 0～ 1 6 0 g/g,且保水性能好 .     

超声辐照纤维素基高吸水树脂的合成

采用超声辐照技术,以羧甲基纤维素、丙烯酸为主要原料,合成了纤维素基高吸水树脂并对其合成工艺及性能进行了研究.主要考察了超声功率、反应温度、丙烯酸中和度、交联剂用量、溶剂用量等因素对产品吸水能力的影响.运用正交分析法,采用正交表L16 (45)分析了各因素对吸水树脂性能的影响,确定了最佳工艺条件,在此基础上合成的产品,其吸水倍率为925 g/g,吸盐水倍率为95 g/g,并有很好的持续保水能力和较快的吸水速率.红外及扫描电镜测试结果表明,丙烯酸成功接枝在羧甲基纤维素的主链上,且该吸水树脂具有疏松多孔的三维网状结构.     

羧甲基纤维素接枝丙烯酸复合材料的制备及对Cr(VI)的吸附研究

以过硫酸钾为引发剂,N,N'-亚甲基双丙烯酰胺为交联剂,采用自由基聚合法使羧甲基纤维素与丙烯酸进行接枝共聚,制备了一种羧甲基纤维素接枝聚丙烯酸Cr(VI)吸附材料,研究了原料配比、pH、溶液浓度、吸附时间和温度对吸附性能的影响。结果表明：羧甲基纤维素与丙烯酸的质量比为3:17、PH=4.5时复合材料表现出最佳吸附性能;吸附时间为2h时,吸附率大于95%。     

羧甲基纤维素接枝丙烯酸复合材料的制备及对Cr(Ⅵ)的吸附研究

以过硫酸钾为引发剂,N,N’—亚甲基双丙烯酰胺为交联剂,采用自由基聚合法使羧甲基纤维素与丙烯酸进行接枝共聚,制备了一种羧甲基纤维素接枝聚丙烯酸Cr(Ⅵ)吸附材料,研究了原料配比、pH、溶液浓度、吸附时间和温度对吸附性能的影响。结果表明:羧甲基纤维素与丙烯酸的质量比为3:17、pH=4.5时复合材料表现出最佳吸附性能;吸附时间为2h时,吸附率大于95%。     

纤维素系高吸水性树脂的制备工艺及其发展方向

介绍了纤维素接枝丙烯酸、丙烯酰胺、丙烯腈不同单体制备高吸性树脂的工艺,论述了改善其耐盐性、提高其吸水速率和吸水强度的几种方法,并预测了该领域今后的发展方向.     

纤维素接枝高吸水性树脂的合成与性能

采用反相悬浮聚合方法制备羧甲基纤维素接枝丙烯酸高吸水性材料,并详细考察原料配比,油水比、引发剂、分散剂,中和度,反应温度和反应对接枝共聚物性能的影响。     

纤维素接枝聚合反应的研究

用高锰酸钾为引发剂，将纤维与丙烯酸进行接枝聚合，研究接枝聚合反应工艺条件对接率的影响。结果表明：高锰酸钾浓度，预处理温度和时间，硫酸浓度，丙烯酸浓度，反应温度和时间均与接枝率有关；反庆中选择高锰酸浓度0.003mol/L，预处理温度60℃和时间10min，硫酸浓度0.2mol/L，丙烯酸浓度2mol/L，反应温度60℃和时间5h，纤维素接率可达35％。     

羧甲基纤维素接枝丙烯酸掺杂聚苯胺对Pb(II)的吸附研究

以过硫酸钾为引发剂,N,N’-亚甲基双丙烯酰胺为交联剂,采用自由基聚合法使羧甲基纤维素与丙烯酸进行接枝共聚并掺杂聚苯胺,应用于Pb(Ⅱ)的吸附研究,考察了原料配比、pH、溶液浓度、吸附时间对吸附性能的影响。结果表明:羧甲基纤维素、丙烯酸和聚苯胺的质量比为2∶3∶1、pH=6时复合材料表现出最佳吸附性能;吸附时间为45 min时,吸附率大于97%。     

沸石/羧甲基纤维素接枝丙烯酰胺复合型保水剂的制备

在沸石的存在下,以N,N-亚甲基双丙烯酰胺作交联剂,以过硫酸钾为引发剂,羧甲基纤维素(CMC)与丙烯酸(AA)、丙烯酰胺(AM)进行接枝共聚反应,合成接枝纤维素/沸石复合保水剂.采用红外光谱表征复合保水剂的微观特征,研究纤维素与单体的配比、沸石添加量、交联剂用量、引发剂用量、中和度及单体质量比对吸水率的影响,测试复合材料的吸水速率和保水性.结果表明:当沸石、CMC、引发剂、交联剂用量分别占单体质量的20%、3%、0.7%、0.04%,AA与AM质量比为5,中和度为77%时,复合保水剂吸自来水倍率达434 g/g,对生理盐水溶液的吸水倍率达71 g/g.     

超声波辅助纤维素与丙烯酸的固相接枝研究

研究在超声波辅助的条件下硝酸铈铵引发微晶纤维素与丙烯酸固相接枝共聚,考察了在未中和的条件下超声时间、引发剂用量、交联剂用量、纤维素与单体的比例对产物吸自来水倍率的影响,利用TG、IR、SEM表征接枝物的结构和性能。结果表明纤维素能够被硝酸铈铵固相引发接枝,接枝效果良好,通过扫描电镜可以看出,接枝物表面没有明显的界面。     

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).     

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.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.