首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
探讨毛细管电泳对B族维生素的分离分析的最佳电泳条件,结果表明:胶束电动力学毛细管色谱是分离分析B族维生素的一种有效的毛细管电泳操作模式;不同缓冲液及其PH对分离造果影响很大,100mmol/L硼酸钠缓冲液(PH8.5)比较适合B族维生素的分离分析;毛细管温度、运行电压对分离也有较大影响,在35cm*50μm未涂渍石英毛细管条件下,采用PH8.5,附加50mmol/L SDS对分离也有较大影响,在3  相似文献   

2.
非衍生化毛细管气相色谱法分析雄性激素的研究   总被引:1,自引:0,他引:1  
本文研究了典型雄激素睾酮和甲基睾酮毛细管气相色谱不经衍生反应直接测定的可行性以及影响检测灵敏度的各种因素。注样器320℃、柱温265℃、4mOV-101毛细管短柱、FID检测器,恒温和程序升温均可直接测定上述化合物,捡出限分别为2ng和1.5ng。  相似文献   

3.
中华大蟾蜍肺毛细血管的扫描电镜观察   总被引:3,自引:0,他引:3  
用扫描电镜观察了ABS丁酮溶液灌注的中华大蟾蜍肺毛细胞管构筑情况,其肺壁被内面的施工网状隔膜分隔成许多小室-肺泡;在网状隔膜,肺泡壁上均有丰富的毛细血管,且相互吻合成单层密集网;肺泡毛细血管网眼多,由五边形的毛细管环构成,毛细血管直径9.53-16.73μm,网眼孔径91.7-25.18μm;在毛细血管铸型上有明显的内皮细胞核的压迹。  相似文献   

4.
研究了用毛细管区带电泳法快速分离检测甲基安非他明和安非他明的方法.在350 m m ol/L(pH 3.1) 的磷酸盐缓冲体系中,上述两种组分可在6 m in 内完全分离.以紫外检测器在195 nm 处检测安非他明和甲基安非他明,14 次平行测定的相对标准偏差RSD分别为3.1% 和2.2% ,在5×10- 6- 500×- 6的范围内,安非他明和甲基安非他明均有较好的线性(r > 0.999),结果表明该方法在较大的范围内有良好的线性关系和较好的重现性.  相似文献   

5.
毛细管电泳法研究低能离子对甜菊糖苷成分的影响   总被引:1,自引:0,他引:1  
经能量为75KeV,剂量为10^14ions/cm^2的氮、碳离子处理的甜菊种子及未处理的甜菊种子,栽培成苗后取叶片,提取糖苷后在相同的条件下进行毛细管电泳定量检测,研究氮,碳离子处理后主要糖苷成分Stevioside和Rebaudioside含量的变化。  相似文献   

6.
在低渗透多孔介质中,由于孔隙半径小而不能忽略毛细管压力对油气体系相平衡的影响。针对这一问题。建立了考虑毛细管压力的相平衡计算模型。利用K值多组分模型(KCOM-PVT)软件中的相态模拟计算模块。对一个实际凝析气藏中油气体系的毛细管压力,露点压力和恒组成膨胀过程中反凝析液量进行了模拟计算,论证了毛细管压力对凝析气体系相平衡的影响程度,计算结果表明,润湿性决定毛细管压力对凝析气体系相态行为影响的方式,当润湿角θ为0-π/2时,油气体系的上露点压力上升,恒组成膨胀过程中反凝析液量增加;当润湿角θ为π/2-π时,其变化趋势相反,毛细管半径和界面张力决定毛细管压力对凝析气体系相态行为影响的强弱,只有当毛细管半径低于10^-5cm时,毛细管压力对油气体系相平衡的影响才变得明显。  相似文献   

7.
在激波管中,同不同长度不同管径的毛细管测量了阶跃压力信号,分析了毛细管长度和管径对阶压力信号响应的影响。实验结果对用毛细管测量非定常压力,具有较为重要的参考价值。  相似文献   

8.
制冷系统的蒸发温度、制冷量、输入功率、性能系数随毛细管的改变而变化,其工作特性对整个系统而言显得十分重要的。因此对毛细管的流动过程建立了质量、能量和动量守恒特性方程,以熵最大原则建立了临界流状态下毛细管出口临界状态的参数关联式,分析计算了进口压力和毛细管内径对出口临界参数的影响,并与标准试验毛细管曲线进行了对比,结果表明,该模型在一定参数范围内与实际状况吻合。  相似文献   

9.
应用色谱分离理论,综合考虑了分子扩散、进样量、能量耗散等因素对高效毛细管电泳分离的影响,建立了高效毛细管电泳分离模型。研究了电压、溶液浓度、进样量、毛细管管径等因素对理论极高度的影响,并与模型计算结果进行了比较。结果表明,所提出的模型能够较好地描绘高效毛细管电泳的分离机理,该模型可作为优化操作条件和进行放大设计的基础。在此基础上,应用高效毛细管电泳技术对生物产品进行了分离,以探讨该技术在生物领域的应用。  相似文献   

10.
用毛细管流变仪研究了磺化摩尔分数为2.27×10-2的磺化聚苯乙烯的熔体流变性能.结果表明,聚苯乙烯磺化后熔体的假塑性增大,当温度从225℃升至255℃,其非牛顿指数从0.46升至0.68.在该温度范围内磺化聚苯乙烯熔体粘流活化能(平均约为126kJ/mol)明显大于聚苯乙烯(99.4kJ/m2),这主要是由于离子交联作用使链段迁移更加困难所致  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.
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   

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.
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   

15.
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   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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   

19.
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.  相似文献   

20.
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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号