珠子草中的一种木脂素的选择性去甲基化反应

选择性去甲基反应在天然产物的修饰、转化和合成中有重要的意义.以珠子草中分离提纯的木脂索Phyllanthin为原料,采用AlCl3/(CH3)2S/CH2Cl2体系在0℃条件下对其进行O-选择性去甲基化反应,得到目标产物,并利用FT-IR、1H-NMR和13C-NMR对其化学结构进行表征.结果表明,Phyllanthin在C-9a的位置上发生了选择性去甲基化反应.     

水杉叶中木脂素类化合物的研究

水杉（Metasequoia glyptostroboides Hu et Cheng）叶风干粉碎后用甲醇提取,利用硅胶柱 层析、MCI柱层析、Sephadex LH-20凝胶柱层析及HPLC等分离技术对其化学成分进行分离纯化, 得到6个化合物,经波谱解析和对其理化性质进行对比,鉴定为1个降木脂素和5个木脂素,分别是 salicifoliol （1）、lariciresinol 9′-benzoate （2）、（-）-hinokinin （3）、meridinol （4）、8-hydroxypluviatolide （5）和（-）-matairesinol （6）。化合物1、2、5为首次从该植物中分离得到。     

樟树叶化学成分研究

为研究樟属植物香樟树叶的化学成分,运用正相和反相硅胶柱层析、半制备型高效液相色谱法对樟树叶提取分离纯化,用波谱技术鉴定其结构.结果表明：从该植物中分离得到5个化合物,其中1个为木脂素类化合物,4个为黄酮苷类化合物,分别为（8R,8＇R）-3,3＇,4,4＇-四甲氧基-9-氧代-8-8＇,9-O-9＇-木脂素（I）,槲皮素-3-Ο-α-L-鼠李糖苷（II）,山奈酚-3-Ο-β-D-葡萄糖基（6→1）-α-L-鼠李糖苷（III）,芦丁（IV）,槲皮素-3-Ο-β-D-葡萄糖苷（V）.     

毛细管电泳-电化学检测测定野菊花中的黄酮类化合物

采用毛细管电泳-电化学检测测定了野菊花中3种黄酮类化合物(刺槐素、槲皮素和木犀草素)的含量.研究了检测电位、运行缓冲溶液浓度和pH值,分离电压和进样时间对分离和检测的影响.以微碳圆盘电极(Ф=0.5 mm)为工作电极,检测电位为+0.95 V(vs.Ag/AgCl),以pH=8.00的50 mmol/L Na2B4O7~100mmol/L NaH2PO4缓冲液为运行液,当分离电压为21 kV时,3种黄酮类化合物在16 min内完全分离.刺槐素、槲皮素和木犀草素的线性范围分别为0.73~22.2、0.23~16.0和0.29~18.2μg/mL;检出限(S/N=3)分别为0.36、0.16和0.08μg/mL.该方法已成功地应用于野菊花中3种黄酮类化合物的测定.     

红车轴草异黄酮化合物的分离鉴定

对国产红车轴草（Trifolium pratense L.）乙醇提取物的乙酸乙酯部分进行化学成分研究。采用溶剂处理和各种色谱方法从中分离得到了8个异黄酮化合物,并利用波谱技术鉴定了结构。这8个化合物分别为樱黄素、德鸢尾素、鹰嘴豆芽素A、芒柄花素、红车轴草素、染料木素、毛蕊异黄酮和大豆素。     

玉兰花蕾骈双四氢呋喃型木脂素成分研究

为研究辛夷(Magnolia denudata)木脂素类的化学成分.采用硅胶、反相硅胶柱色谱和制备高效液相色谱技术进行分离纯化.从辛夷氯仿提取部位中分离得到8个骈双四氢呋喃型木脂素,分别为丁香脂素syringaresinol (1),kobusin (2),medioresinol (3),松脂醇二甲醚pinoresinol dimethy ether (4),木兰脂素magnolin (5),里立脂素B二甲醚 lirioresinol B dimethyl ether (6),辛夷脂素fargesin (7), epimagnolin B (8),各化合物结构分别通过化学方法和1H NMR、13C NMR、MS等波谱学方法鉴定.     

不同提取方法对五味子中木脂素成分提取率的影响

目的比较3种不同方法提取五味子中木脂素类成分的含量.方法分别用大孔吸附树脂法、超临界CO_2流体萃取法和超声提取法对五味子中木脂素成分进行提取,采用高效液相色谱法测定五味子中7种主要木脂素的含量.结果大孔吸附树脂法、超临界CO_2流体萃取法和超声提取法的五味子木脂素提取率分别为1.09%,1.89%和1.80%.结论通过对比发现,3种提取方法中超临界CO_2流体萃取法提取的北五味子木脂素含量较高.     

来自藏药植物迷芹的一种辛细醚型新木脂素

采用柱分离技术首次从迷果从芹植物中分离一种木脂素Acoradin,经UV,IR,MS及NMR分析得知其分结构式为：2R,2R'－二甲－1S,1'S－二（2,4,5－三甲氧基苯基）环丁烷。     

毛头牛蒡子总木脂素含量测定

文章测定毛头牛蒡子中总木脂素的含量。利用紫外分光光度计,以牛蒡苷为对照品,在280nm波长下测定总木脂素含量。对照品牛蒡苷在0．0207～0．1101mg／mL（r=0．9992）浓度范围内吸光度与浓度呈良好的线性关系,平均加样回收率98．3％,RSD=1．8％（n=5）。总木脂素平均含量为244mg／g,RSD=2．9％（n=5）。紫外分光光度法测定总木脂素含量,简单,稳定可靠,重现性好。     

水竹叶的化学成分

采用硅胶、 聚酰胺和Sephadex LH-20等柱层析方法, 首次从水竹叶乙醇提取物中分离得到4种化合物. 利用核磁共振氢谱和碳谱等波谱鉴定为木犀草素（luteolin, 1）、 异牡荆苷（isovitexin, 2）、 异荭草苷（isoorientin, 3）和荭草苷（orientin, 4）.     

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.     

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.     

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.