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1.
提出了一条从银杏叶中分离、纯化聚戊烯醇类化合物的工艺路线,对工艺中主要分离、纯化单元进行了研究。实验结果表明,用廉价的石油醚为萃取剂,萃取物经水解、大孔树脂吸附和硅胶柱层析,油状产物中聚戊烯醇类化合物含量超过95%,聚戊烯醇类化合物得率为50%,回收率为95.7%,整个工艺过程简单,易于工业放大。  相似文献   

2.
以硅胶为载体,制备了负载型的Cs2.5H0.5PWl2O40催化剂,将该催化剂用于乙酸与1—丁烯的酯化反应和叔戊烯与甲酵的醚化反应,考察了其活性组分负载量、载体硅胶性质和焙烧温度对催化剂性能的影响.研究了催化剂用量、反应温度、反应压力、n(1—丁烯)/n(乙酸)、反应时间等反应条件对酯化反应中乙酸转化率的影响.与其他类型催化剂的醚化活性进行了对比,并进行了Cs2.5H0.5PWl2O40/SiO2催化剂的醚化稳定性实验.结果表明,以低钠硅胶为载体,在活性组分负载量为40%,焙烧温度为300—400℃时制备的Cs2.5H0.5PWl2O40/SiO2催化剂具有较高的催化活性.随着负载量增大,催化剂孔径、孔容和比表面积减小,而催化活性先增加后减小.在反应温度120℃、压力1.5MPa、n(1—丁烯)/n(乙酸)比3.0、催化剂用量4%、反应时间7h的条件下进行酯化反应,乙酸的转化率为87.36%.在反应温度80℃、压力1.0MPa、n(甲酵)/n(叔戊烯)比1.1、LHSV为1h^-1的条件下进行醚化反应,叔戊烯的转化率为68.57%.制备的新型Cs2.5H0.5PWl2O40/SiO2催化剂对于乙酸与1—丁烯的直接酯化反应和叔戊烯与甲酵的醚化反应具有良好的活性与选择性,催化剂寿命长.因此,Cs2.5H0.5PWl2O40/SiO2是一种理想的乙酸与烯烃直接酯化和叔戊烯与甲酵醚化反应的催化剂.  相似文献   

3.
【目的】探究生境对银杏(Ginkgo biloba)叶中聚戊烯醇、可溶性糖、可溶性蛋白和类脂4类代谢产物积累的影响,探索影响代谢产物积累的主要立地因子,为银杏栽培提供理论依据。【方法】采用随机区组试验设计,方差分析、多重比较、相关性分析和逐步回归分析等方法,研究雌株和雄株银杏在7个生境下叶中聚戊烯醇、可溶性糖、蛋白质和类脂等变化规律。【结果】来自不同生境银杏叶中聚戊烯醇、可溶性糖、蛋白质和类脂的含量存在显著差异(P<0.05),来自石家庄地区叶中聚戊烯醇、可溶性糖、可溶性蛋白和类脂的含量最高;聚戊烯醇含量与类脂含量呈极显著正相关关系(P<0.01),但与蛋白质含量呈显著负相关关系(P<0.05);平均最暖月气温是影响银杏叶中聚戊烯醇、可溶性糖、可溶性蛋白和类脂积累的关键环境因子,此外日照时长和土壤中P、K含量对其的积累也具有较大的影响。【结论】环境因素会显著影响银杏叶中代谢产物的含量,温暖的生境有助于聚戊烯醇等类脂类物质的合成与积累。  相似文献   

4.
鸡屎藤鲜品挥发油化学成分的研究   总被引:3,自引:1,他引:3  
用水蒸气蒸馏法提取鸡屎藤鲜品的挥发油,所得到的挥发油用气相色谱/质谱(GC/MS)法分离并分析鉴定其成分及相对含量,共鉴定出27个化合物,所鉴定的组分占挥发性成分总冷面积的99.98%,鸡屎藤鲜品挥发油的主要化学成分是乙酸(31.14%)、2—甲基—2—丁烯—1—醇(3.32%)、糠醛(7.49%)、3—吱喃甲醇(6.10%)、3—甲硫基丙醛(0.61%)、氧化芳樟醇(8.54%)、反式氧化芳樟醇(10.37%)、芳樟醇(3.93%)、异佛尔酮(1.90%)、5—甲基—6,7—二氢—5(H)—环戊并吡嗪(0.72%)、环氧里哪醇(1.00%)、异冰片(6.35%)、β—葑醇(7.30%)等.  相似文献   

5.
灰绿黄堇挥发性成分的分析研究   总被引:2,自引:0,他引:2  
采用水蒸气蒸馏法提取,同时采用毛细管气相色谱质谱联用法对灰绿黄堇挥发性化学成分进行了分析研究.经毛细管色谱分离出13个峰,并且确认了所含的全部化合物.用气相色谱面积归一化法测定了各成分的相对百分含量.其主要化学成分为:3.7—二甲基—1.6—辛二烯—3—醇(46.80%);2—氨基苯甲酸—3.7—二甲基—1,6—辛二烯—3—酯(11.90%);4—甲基—1—(1—甲基乙基)—3—环己烯—1—醇(10.66%);α—松油醇(8.31%)等,上述4种化合物的含量占全油的77.67%.为进—步开发利用提供了科学依据。  相似文献   

6.
利用剩余活性污泥水解蛋白质制备蛋白质泡沫灭火剂的研究   总被引:12,自引:2,他引:12  
将武汉市水质净化厂剩余活性污泥,经过酸、碱水解以制备水解蛋白质,结果表明:酸法水解比碱法效果好,经过pH为1.0、水解温度为121℃、水解时间4h的水解后,用Follin酚法测定其蛋白质含量为59.2%(干污泥),而碱法水解时(pH为11.5—12.5,水解时间为2—6h),其水解液无法过滤,因而有待进一步研究或不能采用;将酸解液过滤并浓缩,经过适当配制后,测试其灭火特性,结果表明:粘度、沉淀物、发泡倍数、90%火焰控制时间、灭火时间、抗烧时间等均达到中华人民共和国公共安全行业标准(GA219—1999).  相似文献   

7.
采用硅胶柱色谱及HPLC等分离方法对狼毒大戟正己烷提取物进行分离纯化,得到5个三萜类化合物,依据波谱数据分析鉴定它们的结构分别为:羽扇豆醇(1),butyrospermol(2),异巴耳三萜醇(3),δ-amyrin(4),24-亚甲基环阿尔廷醇(5)。其中,化合物3和4为首次从该植物中分离得到。  相似文献   

8.
采用硅胶柱色谱及HPLC等分离方法对苹果树皮正己烷提取物进行分离纯化,得到6个单体化合物,依据波谱数据分析鉴它们的结构分别为:木栓酮(1),羽扇豆醇(2),3-β-齐墩果醇(3),软脂酸(4),3-β-齐墩果醇-18-烯(5),β-谷甾醇(6)。其中化合物3, 4,5为首次从苹果属植物中分离得到,化合物1为首次从该植物中分离得到。  相似文献   

9.
采用HPLC法,对银杏叶的提取物进行了指纹图谱研究:使用Waters Nova-Pak C18(Φ3.9×150 mm,4 μm)色谱柱,流动相为0.2%磷酸水溶液和乙腈,二元梯度洗脱,流速1.0 mL/min,柱温34℃,检测波长为310 nm和355 nm. 利用该法对两种不同厂家生产的银杏叶提取物,以及自制银杏叶醇提物、水提物进行了检测,取得了满意的效果. 该法操作简单、稳定性、精密度高,可作为各类银杏叶原料、中间产物及银杏叶提取物产品的质量控制依据.  相似文献   

10.
2-烃基-2,2-二烯丙基乙酸类化合物的新法合成   总被引:2,自引:0,他引:2  
以2位烃基取代乙酸为起始原料,与烯丙基氯反应成酯后,在氢化钠的催化作用下进行C1aisen重排反应得到4—戊烯酸类化合物,再经酯化和C1aisen重排反应得到2—烃基—2,2—二烯丙基乙酸类化合物,4步反应收率为15.4%一53.5%。  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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