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It can obtain a strong learning algorithm by combining a series of weak learning algorithms through some rules, but it tends to overfit in the presence of highly noise samples.

但是，Adaboost在有高噪音样本的情况下，有可能发生过配现象，该文在Adaboost算法的基础上，对其权值更新规则做了改进，并结合PCA进行人脸检测。

An oxidative halogenation process involving contacting a reactant hydrocarbon selected from methane, a halogenated C1 hydrocarbon, or a mixture thereof with a source of halogen and, preferably, a source of oxygen in the presence of a rare earth halide or rare earth oxyhalide catalyst, so as to form a halogenated C1 hydrocarbon having a greater number of halogen substituents as compared with the reactant hydrocarbon.

一种氧化卤化方法，包括使一种选自甲烷、卤代C1烃、或其混合物的反应剂烃与卤素源和优选的氧源，在稀土卤化物或稀土卤氧化物催化剂存在下，进行接触，从而形成一种卤代C1烃产物，它较所述反应剂烃具有更多数目的卤素取代基。

Cycloserine was produced using L-serine methyl ester hydrochloride as raw material. L-serine methyl ester hydrochloride was chloridized with phosphorus pentachloride to afford 2-amino-3-chloride propanic acid methyl ester hydrochloride, which was cyclized with hydroxylamine in the presence of alkali to give cycloserine.

以L-丝氨酸甲酯盐酸盐为原料制备了环丝氨酸。L-丝氨酸甲酯盐酸盐和五氯化磷在氯仿溶剂中进行氯代反应生成2-氨基-3-氯丙氨酸甲酯盐酸盐，后者和羟胺在碱性溶液中发生环合反应得到环丝氨酸。

Efficient conversion of pentaerythrite with carbonyl compounds,aldehyde or ketone,to the corresponding pentaerythritol dialdehyde or diketone compounds in the presence of ammonium hydrogen sulfate under microwave irradiation without solvent was described.

无溶剂微波照射下，通过硫酸氢铵催化季戊四醇和醛、酮反应合成了季戊四醇双缩醛、酮化合物。通过IR和1HNMR对产物结构进行了表征，研究了反应条件对产率的影响，最佳反应条件为微波照射功率750 W，照射时间1.5 min

MethodsVanillin was used as colour developing reagent in the presence of perchloric acid.

方法利用在高氯酸的条件下香草醛-冰醋酸与三萜酸的反应测定总三萜酸。

In the presence of O〓, peroxyl radicals formed under neutral condition are either directly oxidized to non-aromatic acids, or forms aromatic intermediates, which are further oxidized to non-aromatic acids; peroxyl radicals formed under alkaline conditions are directly oxidized to non-aromatic acids.

有氧状态下的羟基自由基氧化体系中，过氧自由基在氧气的催化作用下既可开环形成有机酸，也可形成4-氯邻苯二酚和对苯二酚，进而氧化开环成有机酸，并最终矿化；碱性条件下的过氧自由基则直接开环降解。

The reaction was run in aqueous diethyl ether at 30℃ for 24h under the catalysis of bakers' yeast, which preincubated for 2h in the presence of phenacyl chloride.

实验结果表明，乙醚为适宜反应介质，适宜pH为中性；反应初始水含量和初始底物浓度分别以w(H2O)=30g/L、c=5 mmol/L为佳。

A catalytic kinetic spectrophotometric method has been established for the determination of trace Mn, based on the catalytic action of Mnon the oxidation - reduction reaction between KIO4 and KI in the presence of 1, 10 -phenanthroline and in HAc-NaAc buffer solution.

本文研究了HAc－NaAc缓冲溶液中，在1，10—菲啰啉激活作用下，锰对KIO4－KI氧化还原反应的催化动力学条件，建立了催化动力学光度法测定痕量锰的方法。

This thesis is constituted by four parts: In the first part a summarization is given on the main total synthetic methods of isoflavones, for example, deoxybenzoin method which generally involves two steps wherein a phenol is reacted in the presence of a Lewis acid with phenylacetic acid to generate an intermediate deoxybenzoin which is then cyclized with a one carbon electrophile.

本论文主要工作包括四部分：第一章综述了近年来全合成异黄酮的主要方法：脱氧安息香法，是以多羟基苯酚与苯乙酸或苯乙腈在Lewis酸存在下，反应生成中间体脱氧安息香，然后再与亲电碳试剂进行关环反应生成异黄酮。

In Chapter 3, the separation of Fe〓, Co〓, Ni〓, Zn〓, Cu〓 by CE in the presence of imidazole or phenylamine as UV-absorbing background electrolyte and α-hydroxybutyric acid as the complexing agent with indirect UV absorbance was investigated.

在第三章，研究了以咪唑或苯甲胺为背景吸收电解质，α-羟基异丁酸为络合剂，采用毛细管离子电泳间接紫外法测定了镍矿石中Ni，Co，Cu的含量。

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。