查询词典 n-heneicosane

A selective and mild PS-DIB/ionic-liquid immobilized 2, 2, 6, 6-tetramethyl-piperidin-4-ol-N-oxyl catalytic oxidation procedure of alcohols to the corresponding aldehydes and ketones in ionic liquid BF4 at room temperature was developed. The oxidant PS-DIB was prepared via the iodation and acetylation of polystyrene resin. For the preparation of the ionic-liquid immobilized TeMPO catalyst, 4-(2, 2, 6, 6-Tetramethyl-1-oxyl-4-piperidoxyl)butyl bromide was first synthesized from TeMPO and 1, 4-dibromobutane.

将聚苯乙烯树脂先碘化再乙酰基化，制得了负载型二乙酰氧碘苯作为氧化剂。2， 2， 6， 6-四甲基－N-氧自由基哌啶醇与1， 4-二溴丁烷反应生成4-溴丁氧基－2， 2， 6， 6-四甲基－哌啶－1-氧化物，再与N-甲基咪唑发生季铵化反应，生成的溴化季铵盐与四氟硼酸钠进行离子交换制得氟硼酸型2， 2， 6， 6-四甲基－N-氧自由基哌啶负载离子液体。

For different polynomials g, if the characteristic polynomial of a n matrix A is irreducible, then we get some theorems to determine matrix equations g =A solvable; if it is reducible, then, to see n-dimension space vectors M over a field F as F-module, we use module theory to determine these equations solvable such that it is simpler and clearer to investigate these questions.

对于不同多项式g，当n阶矩阵A的特征多项式为不可约的，我们给出了矩阵方程g=A有解的判定定理；当A的特征多项式为可约的，把域F上的n维线性空间M作为由A导出的F -模，我们利用模论知识来决定矩阵方程g=A有解性，从而使这一问题变了简单，研究思路更加清晰。

Anchor points based Isometric Embedding under least square error criterion has a time complexity of O n log( n , and after obtained geodesic distances it has linear time complexity for embedded points and can be fully realized in parallel.

基于锚点集的最小平方误差等距嵌入算法AIE具有O n log( n 的时间复杂性，而且在获得测地线距离后的计算时间复杂度达到对嵌入点数的线性关系，且可以完全并行实现。

The cascade of reversible logic gate network with n inputs and n outputs forms a group isomorphic to the symmetric group S2.

n输入n输出可逆逻辑门的级联构成一个群，它与对称群S2同构。

When n〓: n〓=1: 35, the type of adsorption isotherm transformed from Ⅱ to Ⅳ.

当n〓：n〓=1：35，吸附等温线的类型由Ⅱ型向Ⅳ型转化。

Position of low air jet stream: 23°N—28°N,105°E—115°E

低空急流带位置：23°N—28°N，105°E—115°E之间

Adopting generalized Jordan block and algebra equivalence transform method, all of the transfer functions at different load points can be transformed to state-space description with time variable. The steady robustness of three different mode of control systems were researched by mathematic analysis. It shows that: for the high order inertia controlled object with the characteristic of nonlinear and time-variable that described by the set of transfer functions, the Luenberger function observer established according to its any algebra equivalence state-space description, if some conditions can be met, there would be a matrix of T with n′n satisfied the Sylvester matrix equation TA- FT=GC.

采用广义约当块及代数等价变换方法，可将分段的传递函数描述转换为变参数的状态空间描述，对3种典型控制系统的稳定鲁棒性所进行的理论研究表明，对同一组传递函数描述的具有非线性和时变特性的高阶惯性受控对象，依据其任一代数等价的状态空间描述所构建的Luenberger函数观测器，在满足一定的条件时，存在n′n解阵T满足Sylvester矩阵方程TA- FT=GC。

In this paper, the Lagrange interpolation formula asked a class function expression question, the determination function to the higher mathematics in the elementary mathematics in some value scope question, the equality proof question, the multinomial factorisation question, to ask to have the Finite series to pass the formula question, the certificate any n function at will n+1 different spots function value maximum value minimal problem and so on six aspects should serve as the simple introduction, and has separately made the comparison with these six aspects elementary mathematics method, thus solved some operation problems in elementary mathematics.

摘要本文对高等数学中Lagrange插值公式在初等数学中的求一类函数表达式问题、确定函数在某点的取值范围问题、恒等式的证明问题、多项式的因式分解问题、求有穷数列的通项公式问题、证明任一n次函数的随意的n+1个两两不同点的函数值的最大值的最小值问题等六个方面的应用作了简单介绍，并与这六个方面的初等数学方法分别作了比较，从而解决一些初等数学中的运算问题。

Both the protection and deprotective group methods for the amino-group on side chain of a new N-pivot lariat crown ether were studied comparatively.

研究了一种新的氮支套素冠醚侧链上氨基的保护和脱保护基方法，结果表明，由过量乙二胺与对甲苯磺酰氯反应得到的单保护乙二胺（N－对甲苯磺酰基乙二胺4a），经N－烷基化环化反应，然后在氢化铝锂存在下脱除保护基，即可制得最佳产率的N－（2－氨基已基）单氮杂－12－冠－4（1）。

Firstly, we prove a proposition : the leading coefficient regarded as a polynomial in q~n, q~(1/2 of the recurrence is not equal to zero for all n ≥ [m/2] + 1, where m is the degree in q~(1/2) of the leading coefficient.

首先，我们证明了一个命题：迭代关系的首项系数关于q~n，q~(1/2的多项式对所有的n≥1[m/2]+1均不为零，其中m为首项系数中q~(1/2)的次数。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。