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1.
报导适用于根霉乳酸生产菌筛选的酸性淀粉培养基富集培养法和KMnO4-KBr平板筛选法。用上述富集培养方法可使土样中产酸菌的筛出率提高70%,而利用KMnO4-KBr平板筛选法则使乳酸生产菌的直接检出成为可能。  相似文献   

2.
引言我們在进行锗中少数载流子~*寿命的测量工作中,共采用了四种測量方法:“光电导衰退法”“双脉冲法”“曼納电桥法”“光磁效应法”。这些测量寿命的基本方法,不但适用于锗,也适用于其它半导体材料。利用光电导衰法”“双脉冲法”可以测量硅中少子的寿命。用“光磁效应”可以测量小于0.1微秒的短寿命,比較适用于  相似文献   

3.
采用光电反射式的光路,通过对纳米金层析试条光电信号的信息处理提取特征参量,并采用支持向量机建立纳米金层析试条特征参量与甲胎蛋白浓度之间的拟合模型,建立金免疫层析试条甲胎蛋白定量方法.金免疫层析试条定量系统与化学发光法对比试验数据结果相关系数r=0.967,P<0.000 1,两种检测方法线性相关,测定数据变异系数(CV)小于6%.实验结果表明该金免疫层析定量系统适用于甲胎蛋白的快速、准确、定量测定,具有一定的临床诊断价值.  相似文献   

4.
石灰软化工艺通常用来去除硬度和磷酸盐。可以利用一些软件模型对其过程进行模拟,这些模型是建立在试验中得到的平衡常数的基础上的。这些“伪平衡常数”是源自国外的市政污水的数据,大部分是美国的数据。以石灰法处理北京高碑店污水处理厂的出水的数据作为基础,研究美国电力研究所(EPRI)的SOFTEN4的适用性。SOFTEN4模拟结果发现需要对模型进行一定调整,使其适用于中国水质。  相似文献   

5.
分别应用ConA激活的小鼠胸腺细胞增殖法和脾细胞增殖法对样品内白细胞介素-2(IL-2)的活性进行生物学测定.细胞增殖状况以3H-TdR掺入强度显示,并对实验条件进行了探讨.结果表明;添加氢化考的松(HC)的胸腺细胞法适用于检测培养物上清内的IL-2活性,其实验操作较脾细胞法更为省时省事  相似文献   

6.
本文以油菜和稗草为试材,以100ppm的处理浓度,测定并比较了1,4,2-二氮磷杂环戊-5-(硫)酮类4个通式40个衍生物的除草活性,结果发现,这些衍生物大多数对油菜的活性高于稗草,表明它们具有明显的选择杀革特性,同时还发现不同通式的大多数衍生物其化学结构与除草活性之间具有不同的构效关系.  相似文献   

7.
本文以油菜和稗草为试材,以100ppm的处理浓度,测定并比较了1,4,2-二氮磷杂环戊-5-(硫)酮类4个通式40个衍生物的除草活性,结果发现,这些衍生物大多数对油菜的活性高于稗草,表明它们具有明显的选择杀草特性,同时还发现不同通式的大多数衍生物其化学结构与除草活性之间具有不同的构效关系。  相似文献   

8.
目的:建立肝组织输液传染性病毒DNA(TTVDNA)的原位杂交检测技术,探讨TTVDNA在肝组织中的分布。方法:采用PCR扩增法,分别合成地高辛标记的Gla、G2b两种亚型的双链TTVDNA探针。同时应用两型探针对22例血清学检查无甲-庚型肝炎病毒感染的肝病患者肝组织TTVDNA进行原位杂交检测,并将检测结果与巢式PCR法检测配对血清TTVDNA的结果进行比较。结果:原位杂交阳性信号主要定位于肝细胞核,少数位于胞浆。22例肝病患者肝组织标本中TTVDNA原位杂交阳性率68.2%(15/22),其中慢性肝炎、肝硬化、肝细胞癌患者中原位杂交阳性率83.3%(15/18),4例肝破裂、肝良性肿瘤患者TTVDNA原位杂交检测皆为阴性。配对血清TTVDNA阳性率63.6%(14/22)。血清与肝组织TTVDNA检测符合率86.4%(19/22)。结论:双探针原位杂交检测具有较高的特异性和灵敏性,有助于肝病病因的分析。TTVDNA在慢性肝炎、肝硬化、肝细胞癌的肝组织中检出率较高,提示TTV可能与这些肝病有关。  相似文献   

9.
报告一种新的植物生长抑制剂生物活性鉴定法一油菜(Brassica campestrisL)下胚轴试法,该试法以浸渍法处理吸涨2h的油菜种子,26℃黑暗保温53h后测定结果,以10μg/ml的检测浓度可将10种已知抑制剂的活性准确多分开来。检测ABA、S07和S08的线性浓度范围均为0.001~1μg/mL,PP333为0.1~1μg/mL。它与某些经典试法的反应灵敏度相当或更高,且更加简便快速。  相似文献   

10.
提出一种建立现场回弹法测强曲线的方法,此方法将制定通用(或专用)曲线的大量实验室数据所提供的共性信息和现场钻芯及同条件试块所得到的个性信息有效地融合,利用极大似然原理得到现场回弹测强曲线.通过利用原有的数据信息,有效扩展了现场试验数据的样本量;通过将共性信息和个性信息的融合,使现场测强曲线不仅体现出混凝土强度和回弹值之间的一般关系,同时还能适应于特定工程的实际情况.工程实践表明,利用本文方法建立的现场回弹测强曲线推定混凝土强度值的精度较高.此方法不仅适用回弹法检测混凝土结构强度,还能在其它领域中应用.  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.
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   

14.
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   

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.
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   

17.
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   

18.
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   

19.
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   

20.
1 Rise of studies on climate change's effects on biodiversity
Until the 1980s, climate change and biodiversity were studied as two independent disciplines for more than a century. In 1992, the Ecological Society of America's annual report named climate change, biodiversity, and the sustainable ecological system as the three major global environmental issues of the twenty-first century [1].  相似文献   

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