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1.
锗对铁皮石斛原球茎的生长及抗氧化酶系的影响   总被引:4,自引:0,他引:4  
研究了不同浓度的锗(GeO2)对组培铁皮石斛原球茎的鲜重、可溶性蛋白质、叶绿素含量以及保护酶系统(SOD,CAT,POD)活性的影响.结果表明:适宜浓度的GeO2(5.00mg/L)能够显著增加铁皮石斛原球茎的鲜重,提高可溶性蛋白质和叶绿素含量,使SOD、CAT活性明显升高,而POD的活性则呈现缓慢的下降趋势.由此可见,培养基中添加5.00mg/L的锗时,对铁皮石斛原球茎的生长是有明显促进作用的.  相似文献   

2.
采用正交试验设计方法对马鞭石斛多糖提取工艺进行优化分析.结果表明提取次数、料液比和离心时间分别是在脱单糖、水提和醇沉工艺流程中的主要影响因素;其最佳脱单糖工艺是乙醇浓度(95%)、料液比(1:20)、提取时间(10min)和提取次数(3次);最佳多糖水提工艺是料液比(1:30)、提取时间(60min)、提取次数(1次)和粉碎度(0.25mm);醇沉最佳工艺条件是离心时间(10min)、乙醇浓度(90%)、醇沉时间(30min)和醇沉次数为3次.石斛多糖提取工艺复杂,涉及到很多影响因素,要想获得高纯度、高提取率和低成本石斛多糖,还需要进一步深入研究.  相似文献   

3.
为了解石斛(Dendrobium)花朵的挥发性成分,本文以罗河石斛(D.lohohense)、球花石斛(D.thyrsiflorum)、喇叭唇石斛(D.lituiflorum)、紫瓣石斛(D.parishii)、黄石斛(D.catenatum)和始兴石斛(D.shixingense)的花朵为材料,采用固相微萃取法(SPME)结合气相色谱-质谱联用(GC-MS)技术分析6种石斛花朵的挥发性成分的种类及其相对含量。结果显示:(1)从6种石斛花朵中共鉴别出106种挥发性物质,主要成分为萜烯类、烷烃类、酯类等;6种石斛均含有萜烯类和烷烃类,其中罗河石斛中萜烯类成分相对含量较高(88.68%),球花石斛中烷烃类成分相对含量较高(72.38%)。(2) 6种石斛花朵均含有十甲基环戊硅氧烷,并且该成分在球花石斛、紫瓣石斛、黄石斛和始兴石斛中的相对含量较高,分别为22.04%、25.86%、20.58%和21.66%。(3)罗河石斛花中的α-蒎烯、β-水芹烯和D-柠檬烯相对含量较高,分别为26.66%、22.96%和13.77%;罗勒烯在喇叭唇石斛中的相对含量高达73.98%。综上,6种石斛花朵中挥发性成分种类和含量不尽相同,个别石斛花朵的特征性挥发性成分可能是其独特香味来源之一。研究结果对香型石斛种类的选育及其衍生产品的开发具有重要参考价值。  相似文献   

4.
赤水旺隆金钗石斛(Dnobile-Lindl),俗称吊兰花,兰科石斛属革本植物,是一味常用的名贵药材,金钗石解中提取出来的化合物具有抗人体肺癌、人体卵巢腺癌和人体前髓细胞白血病的作用。金钗石斛以茎为药,性寒、味甘,具有益味生津、滋阴清热等功效,用于治疗伤津、口干烦渴、病后虚热.舌光少苔、食少十呕、目暗不明等症状,金钗石斛含有石斛碱(dendvobine),用鲜品或干品煮沸后直接饮用。石斛因多年过渡乱采而不栽,资源严重枯竭,保护石斛野生资源和扩大石斛栽培刻不容缓,1999年赤水市政府从云南引进一批金钗而斛扩大栽培获得成功。经过5年的努力,现已建立赤水市旺隆镇石斛基地1000亩,总结出了一套适合赤水地区金钗石斛栽培及管理的技术。  相似文献   

5.
目的:建立石斛滨蒿内酯的含量测定方法并测定不同品种石斛滨蒿内酯的含量.方法:Kromasil C18柱(4.6mm×250mm,5μm),柱温25℃.流动相乙腈.水(20:80),检测波长343nm,流速1mL.min^-1.结果:滨蒿内酯的平均回收率为100.2%.RSD为0.9%.不同石斛品种滨蒿内酯的含量多数未检测到,球花石斛中含有0.35mg.g^-1(购于五块石药材市场).结论:本方法简便、准确、重复性好,所测样品中球花石斛中含有滨蒿内酯,可以作为控制球花石斛材质量的方法之一.  相似文献   

6.
为科学、合理地开发利用雅长铁皮石斛(Yachang''s Dendrobium officinale)资源,本研究对其原生种和选育种的基本营养成分、氨基酸和矿质元素进行测定,并采用氨基酸比值系数法对两种铁皮石斛进行营养价值评价。研究结果表明:两种铁皮石斛中共检测出4种常量元素和6种微量元素。除了B、Fe以外,原生种中的4种常量元素(Na、Mg、K、Ca)和4种微量元素(Zn、Mn、Cu、Se)含量均显著高于选育种。两种铁皮石斛中均以K的含量最高,分别为4 430、3 650 mg/kg,且都表现出“高钾低钠”的特点,原生种中K含量约是Na含量的103.5倍,选育种约为187.2倍。两种铁皮石斛共检测出16种氨基酸,包括6种必需氨基酸(EAA),4种鲜味氨基酸(DAA),8种苦味氨基酸(BAA)和9种药用氨基酸(MAA)。原生种和选育种氨基酸总量(TAA)分别为0.85、0.68 g/100 g。原生种氨基酸总量、必需氨基酸总量、药用氨基酸总量均显著高于选育种,两种铁皮石斛的第一限制氨基酸均为蛋氨酸+半胱氨酸(Met+Cys)。两种铁皮石斛的必需氨基酸营养价值差距不大,其必需氨基酸比值系数分(SRC)分别为54.9(原生种)、56.2(选育种)。在基本营养成分方面,原生种中除粗纤维和粗蛋白的含量显著高于选育种之外,其他成分含量的差异性均不显著。综上,雅长铁皮石斛原生种在基本营养成分、矿质元素和氨基酸含量方面均优于选育种,其中矿质元素含量的差异最大。因此,原生种的整体营养价值高于选育种。  相似文献   

7.
《宝鸡文理学院学报(自然科学版)》(J.Baoji Univ.Arts&Sci.(Nat.Sci.Ed.))是由宝鸡文理学院主办的综合性自然科学学术季刊.先后被美国MR、CMP、MathSciNet、CA;德国ZBI、俄罗斯P)K等国际检索系统列为收录刊源,同时也被国内多种文摘杂志列为收录对象,是中国知网(CNKI)、万方数据库以及维普数据库等多种媒体的全文录入期刊。本刊为中国高校特色科技期刊、中国期刊方阵“双效期刊”、陕西省科学技术类特色期刊。  相似文献   

8.
比较了铁皮石斛、大苞鞘石斛和金钗石斛3种石斛茎段粗多糖、精多糖(除蛋白多糖)和多糖组分(过层析柱多糖分离组分)对DPPH、OH和O-2 3种自由基的离体抗氧化活性. 结果表明:随着多糖纯度增强和质量浓度的提高,抗氧化效果均显著增强,在12 g/L时,处理效果最佳,铁皮石斛多糖组分(DOPP-I)、大苞鞘石斛多糖组分(DWPP-I)和金钗石斛多糖组分(DNPP-I)对DPPH自由基的清除率均在75%以上,对OH自由基的清除率在 84%以上,且显著优于Vc (Vitamin c),但3种多糖组分间差异不显著;3种石斛多糖对O-2自由基的清除能力显著低于Vc,但DWPP-I的清除能力显著高于DOPP-I和DNPP-I. 总之,大苞鞘石斛多糖组分DWPP-I的抗氧化能力略优于铁皮石斛和金钗石斛.  相似文献   

9.
霍山石斛(Dendrobiumhuoshaneuse)是我国石斛属植物中一个特有物种,也是我国传统、名贵石斛类中药材中享有国际声誉的一种药材,为稀世之品,并有“软黄金”之称。它最早被记载于清代赵学敏所著《本草纲目拾遗》及其弟赵学楷所著《百草镜》中。据赵学楷记述道:“石斛近时有一种形  相似文献   

10.
药理学(pharmacology)是研究药物与机体相互作用及其规律和作用机制的一门学科,主要指研究使用化学物质治疗疾病时引起机体机能变化机制及机体对药物处置的学问。德国人施米德贝尔(O.schmiedeberg.1838~1921)首创的实验药理学成为近代药理学的基础。而药理学在我国的发展也有着悠久的历史,早在先秦著作《诗经》、《山海经》和《五十二病方》等医药典籍中都记载了多种动植物药物;  相似文献   

11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
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   

14.
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。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
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   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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