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1.
改性木素的阻垢性能研究   总被引:2,自引:0,他引:2  
采用自由基反应 ,对木素进行枝改性 ,合成羧酸型木素 (LA)阻垢剂。利用静态阻垢法测定和比较LA与一些常用阻垢剂的阻垢率。结果表明 ,LA阻垢性能良好 ,当LA用量为10mg/L ,阻垢率达 85 2 %。根据三因子二次回归正交设计实验 ,定量研究了阻垢率与溶液中阻垢剂LA用量、Ca2 含量和 pH值之间的关系 ,得到的回归方程能较好拟合实验测定结果 ,可用于合成产物LA阻垢性能和确定其适用条件的研究。  相似文献   

2.
合成了马来酸一丙烯酸共聚物阻垢剂,对引发剂用量、溶剂水量、催化剂用量以及反应温度等影响反应结果的主要因素,通过实验进行优选。结果表明:在马来酸酐50份、丙烯酸11份固定的条件下。采用引发剂25份、溶剂水15份、催化剂0.03份、反应温度100℃、反应时间4h,合成的共聚物阻垢效果最佳。静态阻垢性能测试结果(按照Q/SYDQ0833-2002标准进行评价),阻垢率达82.5%。其效果优于马来酸单聚物,且成本低于1:1摩尔比的马丙共聚物。  相似文献   

3.
以马来酸酐、丙烯酸和丙烯酰胺为原料在水相中合成了三元共聚物阻垢剂,研究了单体配比、引发剂用量等条件对共聚物阻垢性能的影响,探讨了阻垢率与共聚物用量、 Ca2+ 质量浓度、温度的关系。  相似文献   

4.
采用溶液聚合的方法,将淀粉和壳聚糖与丙烯酸接枝制备了高溶胀性接枝共聚物.研究了淀粉和壳聚糖配比、引发剂用量、交联剂用量、丙烯酸中和度、反应温度及反应时间等因素对接枝产物溶胀度的影响规律.结果表明,当淀粉和壳聚糖配比为8:1,引发剂用量为0.5%、交联剂用量为0.02%、丙烯酸中和度为80%、反应温度为50℃、反应时间为2 h时,该凝胶材料在蒸馏水中溶胀度接近800.  相似文献   

5.
引发剂对木质素磺酸盐接枝丙烯酸的影响   总被引:1,自引:0,他引:1  
研究了三种常用引发体系对木质素磺酸盐接枝丙烯酸反应的影响;通过比较三种接枝共聚产物的接枝率和阻垢性能,得出选用Fe^2+-H2O2为该合成反应的引发体系较优的结论。  相似文献   

6.
以丙烯酸(AA)为接枝单体,甲苯、乙酸乙酯为溶剂,BPO为引发剂,在氯丁橡胶(CR)上进行接枝共聚,制备出CR/AA二元接枝共聚物(CR-g-AA)胶粘剂.探讨了反应温度、反应时间、原料配比和引发剂用量等对接枝率和产物性能的影响,并用TG/DSC对接枝共聚物进行了表征.结果表明,反应温度85℃、反应时间4 h、引发剂用量为CR质量的0.9%~1.2%、CR与AA的质量比为15/100时,单体转化率达到70%、接枝率为56.8%,产物的180°剥离强度达到5.7 kN.m-1.  相似文献   

7.
介绍了一种制备无规聚丙烯和丙烯酸接枝共聚物的方法,并着重讨论了接枝共聚合反应条件对丙烯酸接枝量的影响,即温度,引发剂用量,单体用量对丙烯酸接枝量的影响。  相似文献   

8.
EA/BA/AN/VAC四元共聚物接枝改性天然橡胶的研究   总被引:7,自引:2,他引:5  
研究了 EA/ BA/ AN/ VAC四元共聚物接枝改性天然橡胶的制备过程中 ,反应温度、引发剂用量、反应时间及单体浓度对接枝聚合反应的影响。结果表明 :采用乳液聚合方法 ,以 KPS/ SHS氧化 -还原体系为引发剂 ,反应温度 6 0~ 70℃ ,引发剂用量1 .3% ,反应时间 2 .5 h为适宜的合成条件。红外光谱证实了接枝共聚物的生成  相似文献   

9.
利用丙烯酸生产废水中的丙烯酸,在一定条件下发生聚合反应生成聚丙烯酸阻垢剂。通过测定不同条件下合成的阻垢剂的阻垢率,确定了引发剂(过硫酸铵、亚硫酸氢钠)投加量、反应时间、温度对生成的聚丙烯酸阻垢性能的影响。研究结果表明:引发剂过硫酸铵投加量为1.8g·L^-1,亚硫酸氢钠投加量为0.82g·L^-1,反应时间为100min,温度90℃,此条件下聚合反应后废水具有良好的阻垢效果,阻垢率为91.3%。  相似文献   

10.
以质量分数为65%的氯化锌水溶液为反应介质、过硫酸钾为引发剂,研究了微晶纤维素(MCC)与丙烯酸(AA)的均相接枝共聚反应,考察了引发剂用量、引发时间、接枝共聚时间、单体用量等因素对接枝率的影响,并用FT-IR、XRD和TGA分析了接枝前后微晶纤维素的特性.结果表明:当引发剂与MCC的质量比为1∶2、单体与MCC的质量比为5∶1、引发时间为10 min、接枝共聚时间为8 h、共聚温度为60℃时,接枝率达20.3%;随接枝时间的延长,接枝产物粒径呈减小趋势,电位呈增加趋势;接枝后的产物在1729cm-1处有CO的吸收峰,说明接枝上了丙烯酸单体;接枝后MCC的结晶度及热分解温度均降低.  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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