置换

Based on this model, a new crypt structure called completely nonsingular matrix based substitution permutation network is designed.

基于这一模型，设计了一个称为基于全非奇异矩阵的代替置换网络的密码结构。

Objective To compare the myocardial protection effects of cold blood cardioplegia and cold crystalloid cardioplegia in patients undergoing valve replacement surgery.

目的 比较冷血液停跳液和冷晶体停跳液在心脏瓣膜置换手术中的心肌保护效果。

As to cyclic codes over finite chain rings, we study their stucture and develop the Fourier Transform method to finite chain rings. The permutation groups of cyclic codes and their extended codes are investigated using their Mattson-Solomn polynomials.

对于有限链环上的循环码，我们研究了它们的结构，并把傅立叶变换的方法推广到有限链环，用循环码的Mattson-Solomn多项式对循环码及其扩展码的置换群进行了研究。

First, two preprocess algorithms are designed to decompose a communication request set into some continuous cyclic sequences. Then the permutation group is used to represent the ring network with fixed converters and an algorithm is proposed to classify the wavelength channels into some groups.Based on these on these ideas,a wavelength assignment algorithm is presented.For an optical ring with any fixed conversion mode,the algorithm can giv a good assignment scheme.

首先，提出了两个对环网上的请求集合预处理的算法，这两个算法可以将请求集合分解成一些连续的循环序列；然后，采用置换群来描述具有固定波长转换器的光环网，基于这种数学表示，提出了对环网上的波长信道进行分解的算法；基于这些算法，进一步提出了一个波长分配算法，该算法对于环形光网上的任意固定转换模式都能给出一个较好的波长分配方案。

Several important relations are studied between the girth condition and the ACE (approximated cycle extrinsic message degree) spectrum of the QC-LDPC (quasi-cyclic low-density parity-check) codes, where the PCM (parity-check matrices) are defined by the base-matrix and expanded by the cyclic permutation matrices.

研究了基于置换阵的QC-LDPC码圈长分布、ACE分布与对应的基矩阵结构之间的关系。

Objective To investigate the clinical effect and safety of Dacron heart patch in the exchange surgery of hydroxyapatite implant.

目的 探讨心脏涤纶补片在羟基磷灰石义眼台置换术中应用的临床效果。

The tower high about 6 meters, put the brewing water to the deaeration tower to oxygenate directly, adopt CO2 permutation, while completed the deaeration, the deaeration water also to achieve the partial carbonation goal.

塔高约6米，直接将酿造水进入脱氧塔进行脱氧，采用CO2置换，在完成脱氧的同时脱氧水也达到了部分碳酸化目的。

Hydroxyl octanoic acid(1) was synthesized from heptaldehyde by a four-step reaction of nucleophilic substitution,displacement reaction,acid hydrolysis and deaminization.

以正庚醛为原料，经过亲核取代、置换反应、酸水解及碱化脱氨等4步反应合成了制备3，6-二己基-1，4-二氧杂-2，5-二酮的中间体——α-羟基辛酸(1)；1经对甲苯磺酸催化脱水得辛交酯。

However, survival came at a steep price with the debilitation of my family's financial foundation with medical expenses.

1989年，我父亲意外的决定去追寻他的梦想，这对他的家庭而言是极为不切实际的，他决定脱离在台湾学院所学的观光事业专业而从事一个彻底不同和看起来较不顺利的路途，投入陶瓷学习两年半後在1992年，在中国他发生了重大车祸，外科太夫当时曾表示90%他将不能恢复行走是因整个股骨全部碎裂，舆痛苦博击的他历经了大的手术，医生们置换了所有的股骨，术後他表现极乐观及强壮，慢慢的走向复原。

In tracing such moves Tuleda pretend, first, to decentralize the conditions by which signs and symbols become fixed and static.

在这个过程中，这些面变成话语被迫以不停的置换复位的方式迁移或移动的接触区域或场所。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐