置换

METHODS From May 2004 to Feb 2005, 40 mitral valve disease or double valve cases underwent valve replacement in shanghai chest hospital randomly enrolled in this study, randomly separated into two groups, 20 cases each..

2004年5月至2005年2月，二尖瓣置换术或二尖瓣与主动脉瓣联合置换术的患者40例，每组20例；对照组不做任何形式的超滤；试验组ECC中行零平衡超滤，超滤量约60 ml/kg，平均3 417 ml／人。

The process and kinetics of CH4 replacement from CH4 hydrate formed in sodium dodecyl sulfate system by using pressurized CO2 was observed with a self-designed device at temperatures of 271.2, 273.2 and 276.0 K and at pressures of 2.8, 3.25 MPa.

在自行设计的反应装置中考察了2.8MPa和3.25MPa压力下，温度271.2、273.2和276.0K时CO2气体置换十二烷基硫酸钠体系CH4水合物中CH4的置换过程。

The processes of CH4 recovery from CH4 hydrate formed in sodium dodecyl sulfate system and pure water system using pressurized CO2 were observed with self-designed device at temperatures ranging from 271.2 K to 276.0 K and at a constant pressure of 3.25 MPa.

本文在自行设计的反应装置中考察了3.25MPa压力下，温度271.2K，273.2K和276.0K时CO2气体置换十二烷基硫酸钠体系和纯水体系CH4水合物中CH4的置换过程。

This study carried out a lab tests on the whole process of CH4 recovery from CH4 hydrate formed in sodium dodecyl sulfate system and pure water system by using the pressurized CO2 in a selfdesigned device observed under a constant pressure of 3.25 MPa and the temperatures of 271.2 K, 273.2 K, and 276.0 K respectively.

在自行设计的反应装置中考察了3.25 MPa压力下，温度271.2 K、273.2 K和276.0 K时CO2气体置换十二烷基硫酸钠体系和纯水体系CH4水合物中CH4的置换过程。

The study status on the preparation process of various methods to prepare silver-coated copper powder and the powder's properties were overviewed.

综述了制备银包铜粉各种方法的制备工艺及银包铜粉性能的研究现状，这些方法包括置换法、化学还原法、置换与化学沉积复合法及熔融雾化法。

Overall, the study included 81,856 patients with a total knee replacement and 106,254 patients with a total hip replacement.

本研究包括81856名全膝关节置换术病人和106254名全髋关节置换术病人。

OBJECTIVE: To summarize classification of knee joint, techniques of knee replacement surgery and complications following replacement.

目的：对膝关节假体的分类、膝关节置换手术技巧及其置换后并发症等方面进行归纳总结。

Then we put more efforts on some expressions, enumerations and constructions of orthomorphic permutations, an...

最后着重研究了正形置换的表示、构造、计数以及如何将线性正形置换非线性化等问题。

This paper presents a variable substitution-permutation network cryptosystem The system controls the input and output of complete involutions by key, and gets many different substitutions.

可变置换控制的代替—置换网络密码系统利用密钥控制完全对合的输入输出，得到大量不同的代替。

8Ps for native and NaBH〓 chemically modified reaction centers, and the transfer process from H〓 to the final electron acceptor Q〓 occurs in about hundreds of picoseconds. On the other hand, the energy transfer from excited B was obviously slowed down in the pheophytin-exchanged RC. By considering the change of free energy of ion pair P〓Phe〓, it could be expected there might exist alternative pathway of charge separation and electron transfer in pigment-exchanged reaction center. In addition, the influence of acid environment on the ultrafast dynamics of reaction center was also experimentally observed, which shows an evident difference from that of in native RC, and further investigation should be carried out to elucidate the origination.

在色素置换后的反应中心中，以B为起点的能量传递较天然RC的情况明显减慢，约在450fs左右，考虑到置换后的反应中心中P的自由能有所提高以及其仍然保持的光化学活性，这一较慢的能量传递也可能预示着还存在着其它的能量传递通道；另外，还对酸性处理的反应中心中的超快光动力学过程进行了尝试性的研究，发现由于色素分子的聚集以及蛋白环境的改变，BChl分子的激发态动力学过程有着明显不同于天然反应中心的情况。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。