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Knoevenagel condensation reaction of aromatic aldehydes with active methylene compounds like ethyl cyanoacetate proceeds smoothly in water in the presence of 8mol% of diammonium hydrogen phosphate and 2mol% TEBA.

醛与活泼亚甲基化合物的 Knoevenagel 反应是有机合成中广泛应用的形成碳碳键的重要方法，该反应一般是弱碱性催化剂存在下完成的，如各类胺、脲[1]等，Lerwis酸[2]、杂多酸[3]、氨基酸[4]等也可用于催化该反应。

The use of carbon monoxide from coal or natural gas to produce dialkyl oxalate is an important research area in C1 chemical technology. The chemical reactions and performance in the coupling reaction system for synthesis of diethyl oxalate from carbon monoxide and ethyl nitrite were tested in the presence of hydrogen under the typical coupling reaction conditions.

摘 要：实验研究了在氢气存在下，一氧化碳与亚硝酸乙酯偶联合成草酸二乙酯反应体系在典型操作条件下的化学反应和反应性能，结果表明氢气只与反应体系中的亚硝酸乙酯反应生成乙醇。

With the completion of one phase of the project, the largest producer in Guangzhou in the presence of large shopping centres Dika Avignon City Campaign will be officially opened in August this year, the world of building materials tycoon Oubeide Guangzhou is the only flagship store opened by the end of this year.

随着一期工程的完工，率先进驻的广州最大体育用品购物中心迪卡侬大型运动城将于今年8月正式开业，世界建材巨头欧倍德广州唯一旗舰店也将于今年年底开业。

In the presence of sodium as catalyst, the ester exchange reaction between methyl dimethoxy acetate and cephalotaxine produced cephalotaxine dimethoxy acetate, which was then hydrolyzed in dilute hydrochloric acid. Spectrum analysis showed one of hydrolytic products was cephalotaxinone.

本文报导己二甲氧基乙酸甲酮和三尖杉碱在金属钠催化下，直接进行酯交换反应生成二甲氧基乙酸三尖杉酯，后者在稀盐酸中水解，水解产物之一经光谱分析碳定为三尖杉酮碱。

PGF(subscript 2α) did not potentiate insulin secretion stimulated by 16.5mmolL^(-1) glucose when NIT-1β cells were in depolarized condition in the presence of 60mmolL^(-1) KCl and 250μmolL^(-1) diazoxide or pretreated with chloride channel blocker 4,4'-diisothiocyanatostithene-2,2'-disulfonic acid.

促进细胞膜去极化在PGF(下标 2α)增强胰岛素分泌中起着重要作用。

Fresh algal extracts prepared in 0.5 M HCl were neutralised, purified on a SPE column (RP-18, Merck), lyophilised in the presence of 1 mM dithiothreitol to prevent the formation of disulphide bridges and stored at -/20℃.

食藻提取物中拟定0.5米盐酸被瓦解，纯化的固相萃取柱（RP-18， Merck），lyophilised，在场的1毫米二硫苏糖醇，以防止形成二硫键桥梁和储存在-/20℃。

N-Butyl stearate was synthesized in high yield by esterification of n- butyl alcohol with stearic acid in the presence of ammonium ferric sulfate dodecahydrate.

在十二水合硫酸铁铵存在下，正丁醇和硬脂酸发生酯化反应，高收率地合成了硬脂酸正丁酯。

Here, we point out that, within the frame of general relativity, the basic astrophysical equations are Einstein equation, Boltzmann equation of the distribution function of real matter in the presence of electromagnetical field in curved spacetime, Maxwell equation and the equation of radiative transfer of Stokes parameter of photons in curved spacetime.

这里，我们指出，在广义相对论框架下，天体物理基本方程为Einstein场方程，弯曲时空中实物质分布函数所满足的含有电磁场的Boltzmann方程，弯曲时空中Maxwell方程组和弯曲时空中光子Stokes参量所满足的辐射转移方程。

By time-varying filtering, we realize the signal selectivity and interference suppression, especially for the signals with time-varying power spectrum. It is shown herein that conventional eigenstructure based methods are lower dimensional special case of the time-frequency subspace fitting method. The closed-form array response estimation algorithms for blind source separation in wireless communication is also developed in the dissertation by exploiting the data structure of second-order statistics of the array output in the presence of multipath. The proposed method achieves array response estimation with little constraint on signal property and propagation environment such as scatters or angular spread. Moreover, the array utilized here can be of arbitrary geometry and even uncalibrated. Since the closed-form solution is obtained, no misconvergency may occur and large amount of computation can be saved. The equivalent feed model and corresponding optimization designation are proposed to realize the downlink multi-user selective transmission. By coherent and non-coherent superposition of the electromagnetical field, multiple beams can be formed using a single array, so that each co-channel user signal is transmitted in each beam and will not interfered with each other. The proposed system scheme implements the digital beamforming and the channel allocation in the base band, therefore is suitable for the utilization of the radio software technology. The feasibility and effectiveness of the proposed model are proved by the RF experiment.

在窄带条件下，GSC－SSF方法还可以提高阵列的虚拟孔径，从而提高估计的性能；可以证明，Cyclic DOA 和SC-SSF方法可看作该方法的特例或近似； 3、提出了二维GSC－SSF方法和宽带谱相关DOA矩阵方法，利用信号的循环平稳特性解决了宽带条件下二维 DOA 估计问题，并具有阵元数少、计算量较小的特点； 4、提出了时频子空间拟合和宽带时频DOA估计算法，将联合时频分析的理论和方法引入到阵列信号的空间谱估计研究中，利用时变滤波实现信号选择性测向和干扰抑制，特别适合于谱时变信号；可以证明传统特征结构法可看作是时频子空间拟合方法的特例； 5、提出了多用户环境下阵列响应的估计方法——CARE方法，该方法对信号结构和传播参数（主要是散射源分布与角度散布）的约束较少，适用于各种几何结构的阵列甚至未校准的阵列，能够直接得到阵列响应的闭式解，因此计算量小、稳健性好，不存在收敛问题； 6、提出了针对多用户下行选择性发送的阵列等效激励模型、优化设计方法及其系统实现方案，通过空间场的相干叠加与非相干叠加使得单一阵列能够形成多个波束，并保证各波束内的用户信号各不相同且相互干扰最小；其系统方案具有在基带实现数字波束成形、信道分配并便于软件无线电实现的特点，其有效性已得到外场实测数据的证实。

A fully ethoxy-terminated polymethylsilsesquioxane has been prepared via a dehydration ethanolysis reaction between absolute ethanol and an ordered ladder-like HO-Me-T, which improved long-term storage stability of HO-Me-T. Meanwhile, EtO-Me-T can still participate in the cross-linking reaction with hydroxy-terminated PDMS in the presence of catalyst.

利用含端羟基的LPS与无水乙醇之间的催化脱水反应合成了一种乙氧基为末端基团的活性梯形聚甲基倍半硅氧烷，有效地改善该类聚合物的长期稳定性；同时，该乙氧基封端聚合物仍然具有活性，可以代替常用的正硅酸乙酯与羟基硅油进行交联反应。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。