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1.
长白山野生树舌子实体经分离纯化获得另两个以甘露糖为主的多糖 F_B和 F_c。经超离心,电流泳 sepharose 4B 凝胶柱层析等检验.表明二者皆为均一多糖。经G.C..高碘酸氧化,Smith 降解,部份酸水解,甲基化分析,I.R,G·C-M.S 试验等表明:F_B 是由1→3甘露糖残基构成主链,分支点及分支比例均较大;F_c是由1→6和1→4甘露糖构成主链,分支较少。  相似文献   

2.
树舌、茯苓多糖的提取分离及组成   总被引:17,自引:1,他引:16  
对树舌(Ganoderma apparatus)、茯苓(poria cocos)多糖的提取、纯化和单糖的组成成分进行了研究.认为树舌子实体和茯苓菌核经热水提取、脱色和乙醇沉淀分别得到相应多糖(树舌多糖Ga,茯苓多糖Pc)粗品,多糖粗品经脱蛋白,乙醇分级沉淀、Sephadex G-15葡聚糖凝胶柱层析纯化得Ga-1、Ga-2、Ga-3和Pc -1、Pc -2、Pc -3 3个级分,并应用薄板层析技术,确定树舌多糖3个级分均由葡萄糖、树胶醛糖、甘露糖、果糖及一种未知单糖组成,茯苓多糖3个级分均由葡萄糖、甘露糖、核糖及一种未知单糖组成.  相似文献   

3.
含壬二酸—尿素包结物的组成物可作为美白化妆料,对雀班、色黑有减轻作用。例一、其成份为: 1.液体石蜡 5.0份 2.凡士林 2.0份 3.蜂蜡 0.8份 4.山梨梨醇酐单硬脂酸酯 0.8份 5.聚氧化乙烯十六酯(20E、D) 1.2份 6.甲基蛋氨酸 0.2份 7.羧基乙烯聚合物(1%水溶液) 20.份 8.氢氧化钾 0.1份 9.精制水 63.2份 10.壬二酸—尿素包结物 2.0份 11.丙二醇 5.0份  相似文献   

4.
根据2016—2018年海阳市信息船的渔捞日志,对海阳市近海渔业资源组成进行分析,结果表明渔获量较高的月份多集中在3—5月份和9—11月份,春汛和秋汛明显;共发现渔获物29种,隶属于17目24科29属,3年全是优势种的种类只有鳀,2年是优势种的种类有黄鮟鱇、蓝点马鲛、青鳞小沙丁、口虾蛄和海蜇,优势种年间更替较明显.秋季多样性指数(0. 30~1. 53)和丰富度指数(0. 57~1. 51)均较高.春季多样性指数(0~0. 94)和均匀度指数(0. 63~1. 00)较高,春季多样性指数低于秋季.秋季各月渔业资源群落结构相似性较高.  相似文献   

5.
本文在已给出的K—M矩阵U(λ_1,λ_2)基础上,研究了衰变过程B→Kl+l~-+X.三代情形,分支比主要依赖 m+且不确定性很小.四代情形时,比值可有较大增长,我们讨论了分支比与相位φ_(ij)以及质量m_(tt)之间的关系,特别是λ_2对分支比的影响十分显著.  相似文献   

6.
1.S表示|z|<1中正則且單葉的函數f(z)=z+a_2z~2+…的全體所成之族。∑表示在區域|ζ|>1中半純且單葉的函數F(ζ)=ζ+α_0+(a_1/ζ)+…的全體所成之族。 設f(z)/f'(0)∈S,且當|z|<1時|f(z)|<1。當f'(0)≥T,(01上是正則,單葉的,  相似文献   

7.
抽象距离空间的秩的概念   总被引:18,自引:0,他引:18  
引言“距离几何”的基本思想应当說在上一世纪末已經由比利时的Tilly明确提出了。Tilly引进的半度量(Semi—Metric)的概念后經Fréchet发展成为(在增加了三角形不等式之后)度量和度量空間(Metric Space)的重要概念。作为几何学的一个分支而言,距离几何(Distance Geometry)的真正基础是由K.Menger于1928年—1931年间的四篇論文中奠定的。在Menger工作的基础上,这一几何分支于30—40年代有一些发展,例如可参看L.M.Blumenthal的专著《Theory and  相似文献   

8.
本文为提交1985年国际轻子光子会议论文的一部分,文中计算了 SU(2)_L×SU(2)_R××U(1)_(L R)弱电理论中新规范玻色子的衰变宽度和分支比.结果表明:具有丢失能量的衰变模式可达20—30%的分支比。  相似文献   

9.
用两步热重法(用样量小于10mg)快速测定干酪根的无水无灰基.固定碳含量(F_c),并与固态~13CNMR法测定的芳碳率(F_A)相比较,得到关联公式.两步热重法的原理是,第一步:在惰性气氛(N_2)下.将干酪根升温至110℃,测出水分失重.于110~900℃热解并测出挥发分失重;第二步:在900℃下将N_2切换成空气.燃烧至恒重测固定碳重,残渣为灰分.本文还结合干酪根有机碳的质量系数法,定量评价了襄9井生油岩油气生成量和生油气潜量.  相似文献   

10.
高粘合强度的导电树脂化合物这种树脂化合物含有两种聚丁二烯衍生物(A)、一种至少有一个双键的可聚合单体(B)、一种能产生自由基的聚合催化剂(C)、以及导电剂(如金、银、铜等)(D)。这几种组分的重量混合比为100份A:25—1000份B:0.2—15份C:10—85份D。这种化  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.
王慧 《科技信息》2008,(10):240-240
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.  相似文献   

14.
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.  相似文献   

15.
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   

16.
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   

17.
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   

18.
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   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

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