甲烷

Hydrogen bonding in hard segment domains of segmented polyester polyurethaneurea based on 4,4'-diphenylmethane diisocyanate, ethylene diamine and polybutylene adipate(M. W. 1975 and M. W. 1228) was studied by means of IR spectroscopy.

用红外光谱法对基於4，4'-二苯基甲烷二异氰酸酯、乙二胺和聚己二酸丁二醇酯（分子量分别为1975和1228）的两系列嵌段聚酯型聚脲氨酯硬段微区中的氢键化进行了研究。

In this paper, a series of low cross-linking polyurethanes are synthesized using polycaprolacton or polybutamethylene adipate or polyethylene-propylene adipate, MDI and glycerin. Their mechanical, thermal and dynamical properties and shape memory function are studied.

采用聚己二酸乙丙二醇酯、聚己二酸丁二醇酯、聚己内酯和 4，4'-二苯基甲烷二异氰酸酯为原料，以丙三醇为交联剂合成了一系列低度交联的聚氨酯，讨论了组成、配比等对性能的影响，比较了它们和线型聚氨酯在性能上的差别。

The optimal coefficient of excess air was related to the mass flow rate of methane and wall temperature.

甲烷质量流量、壁面温度与最佳过量空气系数之间具有一定的变化关系。

But as industry booms on earth, greenhouse gases, like carbon dioxide and methane, are released into the air—and trap more and more of the sun's energy in, so the earth's temperature rises.

但是由于地球上工业的迅速发展，诸如二氧化碳和甲烷之类的温室气体被释放到空气中――从而又把越来越多的太阳能聚集回地球，地球温度因此而升高。

In the light of the complex, high-level and non-linear feature of the mathematical model which describe the transport of the coalbed methane, this paper study the fully-implicit solving method of the mathematical model in detail. Based on the complexity of the algebraic equations which are formed eventually, according to the alternating direction implicit difference pattern, this paper use the iterative method and the fully main element Gauss-Jordan eliminating method to solve equations, which is to use the iterative method to determine coefficient matrix and use the fully main element Gauss-Jordan method to solve th linear algebraic equation group, at the same time of studying the solving method of the mathematical model, according to the devising requirement of FORTRAN77 program structure, this paper draw up computer program and form the corresponding computer model, and verify the validity and reliability of the model in theory by operating the model.

重点研究了模型内、外边界及有关参数的处理，针对描述煤层甲烷运移的数学模型是一个复杂、高阶非线性数学模型的特点，详细研究了模型的全隐式求解方法，根据最后形成的代数方程组的复杂性，按交替方向隐式差分格式，采用迭代与全选主元高斯约当消去法相结合的方法求解方程：即确定系数矩阵采用迭代法，求解线性方程组时采用全选主元高斯约当消去法，在研究模型解法的同时按FORTRAN结构化程序设计的要求，编制计算机程序，形成相应的CBMRS计算机模型，并通过模型的运行从理论上证明了模型的正确性与可靠性。

It was found that cyclic peptide 23shows higher transport activity for the studied alkali and alkaline-earth metal ions thancompound 24, which is related to the backbone flexibility of the cyclic peptides.

研究了在这两种环肽的存在下，碱金属和碱土金属离子穿越二氯甲烷液膜的过程。

The composition of Jupiter is 75% hydrogen and 25% helium by mass, with traces of ammonia, water and methane.

木星的组成是75％，氢和氦25％的质量与氨，水和甲烷的痕迹。

The atmosphere they create has a combination of gases such as hydrogen, water, ammonia, methane, and carbon dioxide.

他们创造的大气是由诸如氢、水、氨、甲烷和二氧化碳混合而成的气体。

The process is anaerobic, meaning it excludes oxygen, and Mr.

甲烷的产生过程是厌氧的，也就是要隔绝氧气。

Since methane is a potent greenhouse gas, things would have got very hot very quickly, to the detriment of any big animal that could not shed heat easily.

由于甲烷是一种效果强烈的温室气体，被此侵蚀的物质会急速地变热，即使身躯庞大的动物也无法摆脱，最终也只有毁灭的结局。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。