共查询到20条相似文献,搜索用时 93 毫秒
3.
4.
《中国石油和化工标准与质量》2017,(16)
大渡河是川西水系的重要组成部分,其干流流向呈"L"形展布,在流经石棉时由南北向急转为东西向,形成了反常的河谷流路。本文在分析大渡河流域的地质背景后,提出大渡河干流河流袭夺的证据,并对其地质形成条件进行探讨。 相似文献
5.
6.
7.
陶瓷彩绘装饰一直是最具有代表性和突出艺术成就的一个重要表现形式,它会让更多的艺术形式形成独有的艺术风格展现在瓷器上.本文主要通过对动物基本形体结构的认知、丝毛技法的运用以及背景的创作进行了分析与研究. 相似文献
8.
在火焰原子吸收分析的原子化过程中形成的固体颗粒对光的散射以及基体分子对光的吸收统称为背景吸收,它叠加在待测原子真实吸收之上产生正干扰,待测试液和标准试液物理性质的差异又会产生物理干扰,这两种干扰往往同时存在,给分析带来很大的误差。现讨论利用标准加人法消除物理干扰的功能和双谱线扣背景法扣除背景干扰的原理,可以同时将两种干扰消除,本方法很适用于无扣除背景干扰功能的普通火焰原子吸收分光光度计对于高盐度水质中微量元素的检测。 相似文献
9.
10.
11.
12.
13.
采用了两种不同的商业BaTiO3纳米粉体(以下称为s-1#粉和s-2#粉)进行水系流延成型及烧结研究。首先对这两种粉体进行表征,通过SEM观察两种粉体的平均粒径为100nm,球形;通过X荧光元素分析,获得其所含元素的对比;然后对其进行水系流延成型,在1300℃烧结,两种粉体所获得的晶相均为立方相;通过XRD分析s-2#粉及其烧结体的衍射峰,发现由于烧结过程中Sr的固溶使得烧结体相对于粉体的衍射峰向高角度偏移;SEM观察s-1#粉烧结体发现,有异常晶粒长大现象并对其不同区域进行能谱分析,结果表明,硅含量是导致烧结体异常晶粒长大的主要原因。 相似文献
14.
15.
16.
D. Precht E. Frede H. Hagemeister H. Timmen 《European Journal of Lipid Science and Technology》1985,87(3):117-126
Variations of Cow's Milk Fat as Affected by Feeding with Special Consideration of Regulation Mechanisms of Fat Metabolism Milk fat composition is highly affected by the conditions of feeding, which again may have considerable consequences for the quality of several dairy products. In order to establish possible variations in physical and chemical properties of the milk fat as depending on the nutritional status of the cow, a small herd of cows was successively subjected to different defined feeding conditions (barn feeding, pasture feeding, energy deficit). The investigations indicated that from barn feeding to pasture feeding to energy deficit the proportions of oleic acid and of long chain triglycerides increased and the proportions of short and medium chain fatty acids and triglycerides decreased. In spite of highly differing fat compositions relatively constant values for the viscosity and the average triglyceride molecular weight were obtained; also various characteristics from the melting and solidification curves were nearly identical. The solid/liquid ratios approached at higher temperatures. These results point to the existence of regulation mechanisms, in the course of which the flow and melting properties are kept within the required narrow ranges by an opposite behaviour of the proportions of short chain fatty acids and oleic acid. With pasture feeding, compared with barn feeding, all oleic acid isomers and linoleic acid increased, with energy deficit the proportions of these acids are at the low level of barn feeding. These results as well as the continuous decrease of the cholesterol content from barn to pasture to energy deficit are explained on the basis of the different pathways of fat metabolism; deficit are explained on the basis of the different pathways of fat metabolism; furthermore the proportions of trans C18: 1 acids are discussed in connection with the milk fat content. The milk fat globules are particularly large and unstable at the period of energy deficit. Consequently, quality deterioration of whipping cream (creaming, plug formation) and other dairy products (lipolysis) can be expected. 相似文献
17.
论述了粉体性能、压制工具在技术陶瓷成型中的主要作用,阐述了各种缺陷的产生原因和克服方法。 相似文献
18.
19.
介绍塑料波纹管极易损坏的成波块成型面的简易修复方法。所设计的夹具、刀具用于修复波纹管模具成型面,可克服排屑、进刀及成对模块轴向稳合等诸多困难。成型面轴向、径向稳合均能达到原设计要求。 相似文献