变甲醛

Adding Cr in the catalyst enhances the selectivity to benzaldehyde (from 85.6 to 91.2％ at 400℃). Cu or Ti is very beneficial for the hydrogenation of methyl benzoate to toluene or the hydrogenolysis of methyl benzoate.

Cr调变的催化剂提高了甲醛选择性(在400℃，从85.6提高到为91.2％)，Cu和Ti调变的催化剂则显示较高的苯甲酸甲酯深度加氢活性，即氢解活性。

This work, concentrated on the asymmetric allylation of aldehydes controlled by different chiral auxiliaries prepared from rotational pure tartaric acid, can be divided into three parts.The first part aims to review the developments of chiral drugs and asymmetric synthesis, from which derived the present research topic backgrounds and works.Synthesis and applications of allylation from aldehydes are the second part of the thesis. By optimizing the reaction conditions, such as solvents, temperature, time and chiral auxiliaries like N,N\'-dibenzyl tartamide, N,N\'-p-dimethylphenyl tartamide, N,N\'-o-dimethylphenyl tartamide, N,N\'-o-dichlorophenyl tartamide, N,N\'-a-dinaphyl tartamide, N,N\'-dicyclohexyl tartamide and N,N\'-diphenyl tartamide, ideal experimenttal conditions are obtained according to HPLC monitoring, as well as the auxiliaries\' recoveries experiments. Starting from benzaldehyde and 3-bromopropaldehyde, N,N\'-dibenzyl tartamide is considered the best auxiliary in this reaction.

本文介绍了醛的不对称烯丙基化反应，以光学纯酒石酸为原料，研究了不同构型手性配体在醛的烯丙基化反应中的立体选择性，全文共分三部分十个章节：第一部分对当前手性药物和手性技术进行了概述，并由此展开了本文的研究背景和任务；第二部分为有机合成部分，对醛的不对称烯丙基化反应进行了深入探讨，以苯甲醛为原料对反应条件进行优化，在优化的反应条件下对制备的七种可回收手性酰胺配体(N-苄基酒石酸二酰胺、N-对甲苯基酒石酸二酰胺、N-邻甲苯基酒石酸二酰胺、N-邻氯苯基酒石酸二酰胺、N-a-萘基酒石酸二酰胺、N-环己基酒石酸二酰胺和N-苯基酒石酸二酰胺)进行筛选，优化配体回收实验条件，最终确定出N-苄基酒石酸二酰胺在苯甲醛的不对称烯丙基化反应中具有较大优越性，结晶回收的手性配体光学纯度保持不变。

The stereochemical structures of two new compounds, 5-(3-chlorophenyl)-2-furfur-aldehyde-N-4-methylphenyloxyacetylhydrazone and 5-(3-chlorophenyl)-2-furfuraldehyde-N-4-nitrophenyloxyacetylhydrazone, were determined by DPFGSE-NOE experiments performed in DMSO-d\-6 at 25 ℃ and variable-temperature ~1H NMR The ~1H chemical shifts of the compounds were completely assigned at 25 ℃ and 90

利用变温实验和DPFGSE NOE实验，确定了 5 (3 氯苯基) 2 呋喃甲醛 N 4 甲基苯氧乙酰腙和5 (3 氯苯基) 2 呋喃甲醛 N 4 硝基苯氧乙酰腙两个新化合物25 ℃时在二甲基亚砜中的空间构型，并对这两个新化合物在 25 ℃和 90 ℃时的质子的化学位移进行了全归属。

Fans into formaldehyde sulfoxylate can make it tough, Smoothness and delicious, not white.

使用&甲醛次硫酸氢钠&能改善食品的外观和口感，粉丝放入甲醛次硫酸氢钠可使其变得韧性好、爽滑可口、不易煮烂。

Nickel sulfate was the most frequent sensitizer, followed by Thimerosal, Potassium dichromate, Fragrance mix and Formaldehyde. Frequencies of contact allergy to Thiuram mix, Mercapto mix, Imidazolidinyl urea, and bronopol were relatively low.

结果： 1 129 例受试者中，阳性反应747例，阳性反应率较高的变应原依次是：硫酸镍、硫柳汞、重铬酸钾、芳香混合物、甲醛，阳性反应率较低的变应原有：秋兰姆混合物、硫氢基混合物、咪唑烷基尿素、溴硝丙二醇。

The experiment results showed that, the MnO_2 particles scattered uniformally after milled for 6h, the average diameter was 300nm, which loaded on the surface of fiber in flat successfully. The removal efficiencies to HCHO of MnO_2 milled for 6h was up to 94.07% after 72h, the removal efficiencies increased with the content of MnO_2 loaded, its increased after treated with DMF, or so was 7%.

实验结果表明，研磨6h的MnO_2粉末分散均匀，平均粒径可达300nm，以平铺的形式均匀地负载于纤维上，效果比较理想；随着吸附时间的延长，研磨6h的MnO_2粉末反应72h对甲醛的去除率达94.07％；活性炭／腈氯纶负载MnO_2纤维对甲醛的去除率比未负载的明显提高；随着纳米MnO_2负载量的增大，甲醛的去除率变大，用DMF处理后的纤维对甲醛的去除率有所提高，大约提高7％。

Through practice we know that when the thickness of polyformaldehyde layer is proper (excluding the thickness of polyformaldehyde between the large-grained copper powder and screw copper nails), it has a good comprehensive ability of load-bearing, friction and wear endurance and creep resistance.

我们通过实践了解到，聚甲醛层在适宜的厚度适宜（不含嵌入到大颗粒铜粉及螺旋铜钉间隙内聚甲醛厚度）时，其承载能力、摩擦磨损性能和抗蠕变能力的综合特性较好。

Through practice we know that when the thickness of polyformaldehyde layer is proper (excluding the thickness of polyformaldehyde between the large-grained copper powder and screw copper nails), it has a good comprehensive ability of load-bearing, friction and wear endurance and creep resistance.

我们通过实践了解到，聚甲醛层在适宜的厚度时（不含嵌入到大颗粒铜粉及螺旋铜钉间隙聚甲醛厚度，其承载能力、摩擦磨损性能和抗蠕变能力的综合特性较好。

The degree of hydrogenation of methyl benzoate might be controled by adding the promoters and changing the nano-size of ZnO. For hydrogenation of methyl benzoate to benzaldehyde, the active-structure of a catalyst should be modified to decrease the absorption of benzaldehyde on the surface of it, because benzaldehyde absorbed is hydrogenated easily. Using 30-40％ZnO/γ-Al〓O〓 or Li-30％ZnO/γ-Al〓O〓, a higher selectivity to benzaldehyde is obtained. Hydrogenolysis of methyl benzoate to toluene or benzene is carried out effectively using a catalyst modified. For instance, 45.3％ selectivity to benzene and 100％ conversion of methyl benzoate at 420℃ was obtained over 10％ZnO/MCM-41 with the nano-size particles of ZnO (2.4nm).

也可以通过助催化剂的添加和活性组分的纳米化，并根据苯甲酸甲酯多步加氢反应的特点实行加氢深度的调控：苯甲酸甲酯选择性加氢制苯甲醛中，由于苯甲醛容易进一步加氢，需要对活性结构进行调变，以减弱苯甲醛的吸附，使用30-40％ZnO/γ-Al〓O〓催化剂或Li调变的Li-30％ZnO/γ-Al〓O〓催化剂，可获得较高的苯甲酸甲酯加氢制苯甲醛的活性；采用同样的方式，苯甲酸甲酯选择性氢解为甲苯或苯也获得了较好的结果，如使用ZnO纳米化的10％ZnO/MCM-41催化剂，在420℃，可获得45.3％的苯选择性，苯甲酸甲酯完全转化。

Melamine formaldehyde resin was used to encapsulate a phase change material which melt point is 20℃ by in situ polymerization.

采用原位聚合法用三聚氰胺甲醛树脂包覆一种相变点为24℃相变材料A，制得相变储热微胶囊。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。