高纯银杏黄酮水解条件研究

在已有文献的基础上,对纯度大于85%的银杏黄酮水解条件作了优化,主要研究了水解介质的组成和质液比两个不确定因素.水解液组成为:V(CH3OH):V(HCl)=45:5,质液比为w(黄酮):V(水解液)=1 g:65 mL.为水解HPLC法测定高纯度银杏黄酮及银杏黄酮甙元槲皮素、山奈酚、异鼠李素的生产提供了优化条件.     

不同地区银杏花粉黄酮和内酯含量的差异性

以15个不同地区百年左右的银杏雄树花粉为材料,用高效液相色谱法(HPLC)检测了银杏花粉中黄酮和内酯的含量.结果表明:银杏花粉主要含有以山奈素为母核的黄酮醇苷,以槲皮素和异鼠李素为母核的黄酮苷的含量相对较少,银杏花粉总黄酮含量平均为20.44 mg/g;还发现银杏花粉中的内酯成分为银杏内酯A,其含量平均在2.22 mg/g;不同地区间银杏花粉之间的黄酮和内酯含量差异显著.相关分析表明,不同地区银杏花粉之间黄酮和内酯含量的差异与气候地理因子的相关性不显著.初步筛选出黄酮和内酯含量较高的重庆01、广德01、北京01、康县01等4个单株作为备选的优良单株.     

钼酸钠-分光光度法测定银杏黄酮的含量

提出了钼酸钠-分光光度法测定药物制剂中银杏黄酮含量的新方法.该法是基于银杏黄酮能与钼酸钠反应生成黄色钼酸酯,此物质在266 nm处有最大吸收.吸光度与银杏黄酮浓度之间的关系式为:A=0.017 1C 0.001 4,其中C的浓度范围为4.0～50.0 μg/mL,r=0.999 8,平均回收率为99.6%.     

培养条件对银杏悬浮培养细胞黄酮合成影响研究

对12个不同品种的银杏树幼叶及其诱导的愈伤组织进行了银杏黄酮含量测定，发现其存在较大差异．梅核品种幼叶黄酮含量最高，为3．32％，大白果品种幼叶黄酮含量最低，为0.84％；梅核品种幼叶愈伤组织黄酮含量最高，达1．26％，岭南品种幼叶愈伤组织黄酮含量最低，为0.22％．选取生长旺盛、银杏黄酮含量高的愈伤组织在B5液体培养基中进行了银杏细胞悬浮培养，研究了多种条件对银杏细胞生长和银杏黄酮含量的影响．结果表明，在150mL培养瓶中装有50mL培养液，接种量为鲜质量30—40g/L，对培养细胞给予3000—40001x的光照、以蔗糖为碳源最有利于黄酮的合成，以葡萄糖为碳源则最有利于细胞生长．HPLC检测结果显示，银杏悬浮培养细胞中银杏黄酮含量可达细胞干质量的2．82％．     

高纯银杏黄酮水解条件研究

在已有文献的基础上，对纯度大于85％的银杏黄酮水解条件作了优化，主要研究了水解介质的组成和质液比两个不确定因素．水解液组成为：V(CH3OH)：V(HC1)=45：5，质液比为w(黄酮)：y(水解液)=1g：65mL．为水解HPLC法测定高纯度银杏黄酮及银杏黄酮甙元槲皮素、山奈酚、异鼠李素的生产提供了优化条件．     

溶剂热法从银杏叶中提取银杏黄酮的研究

采用溶剂热法提取银杏黄酮,利用高效液相色谱进行含量分析,通过正交实验对影响提取率的主要因素进行了考察。研究结果表明溶剂热法提取银杏黄酮的最佳条件为：乙醇体积分数70%,溶剂体积对样品质量比为40mL/g,热处理温度和时间为90℃下加热3h。与传统的热回流提取法相比,溶剂热法在提取银杏黄酮时具有提取率高、操作简便、无污染等优点。     

银杏提取物对内皮细胞产生NO,MDA和SOD的影响

比较了几种不同银杏提取物的物理性质和药效.用HPLC法测定了不同银杏提取物中黄酮的含量,以内皮细胞为作用对象,用联胺对内皮细胞进行氧化损伤,同时用不同银杏提取物对内皮细胞进行保护,24 h后测定细胞上清液中NO,MDA和SOD的含量.结果显示几种银杏黄酮提取物对内皮细胞因联胺损伤而降低的NO具有恢复能力,可以提高细胞的SOD含量,但对MDA的分泌影响不大.结果表明银杏提取物有效成分含量变化对药效的影响较大.     

银杏资源的开发利用

银杏(Ginkgo biloba)又名白果树或公孙树,是一种极为古老的裸子植物,为中生代晚期冰川时期的幸存者,绵延至今它已在地球上生存了1亿多年,所以有“活化石”之称。我国可谓银杏的故乡,银杏约占世界银杏资源的3/4以上,年产白果约7000～8000吨;银杏干叶2万多吨。现今这种孑遗植物每年以2000～2500万株的递增速度发展着。 银杏叶中含有银杏双黄酮等8种黄酮化合物,     

缺氧胁迫小细胞团法选育高产黄酮苷悬浮细胞系

以银杏优良品种的种苗诱导愈伤组织,考察了B5,sH,MS,White4种培养基对银杏愈伤组织生长性状和黄酮苷合成能力的影响,采用缺氧胁迫小细胞团法从愈伤组织中筛选高产黄酮苷的细胞系,并对细胞系在悬浮培养时的条件进行了优化.结果表明TZG-1培养周期18d,生长指数为4.12,黄酮苷含量为1.25％,比愈伤组织提高了257.1％;Ms培养基有利于形成质地松软的愈伤组织,当培养基中NH4+与NO3-的浓度比为20.3/39.4或10.3/29.1,蔗糖质量浓度为30g/L或40g/L,pH值为5.6～6.0时,有利于细胞生长和黄酮苷合成.     

溶剂萃取法脱除银杏酸工艺研究

通过溶剂萃取法脱除银杏叶提取物中的有害成分银杏酸,以银杏黄酮、银杏内酯和银杏酸的分配比为指标,考察了水相pH值、乙醇体积分数、有机相等对分配比的影响,优化了溶剂萃取法脱除银杏酸的工艺参数。结果表明,以pH值2.0、体积分数40%的乙醇为下相,正己烷为上相时,可有效脱除银杏叶提取物中的银杏酸,并且最大限度保留银杏黄酮和银杏内酯等活性成分。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

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.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

A computer generator for randomly layered structures

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

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.