甲醛

Firstly, the reactivity of benzaldehyde is studied utilizing the autoclave designed by us in near-critical water.

通过对苯甲醛在近临界水中反应后产物的分析检测认为，苯甲醛在有限的温度范围内微量的发生了Cannizzaro反应，并同时伴随有苯甲醛自身的羟醛缩合反应等其他副反应的发生。

The flame retarding mechanism of MCA on POM was that formaldehyde and formate acid were absorbed by melamine resulting from melamine cyanurate pyrolysis and temperature of burning materials was reduced because melamine cyanurate sublimation absorbed heat and thermalplastic polyurethane absorbed formaldehyde and enhanced stability of POM composites.

热失重、红外和气质联用分析表明，MCA／TPU复合阻燃剂对聚甲醛的阻燃作用是由于三聚氰胺氰尿酸盐高温分解并吸热，降低材料燃烧区域的温度；另一方面MCA高温分解生成的三聚氰胺可吸收聚甲醛分解产生的甲醛和甲酸；此外，TPU可提高聚阻燃甲醛的热稳定性，有利于阻燃。

The optimun technological conditions were studied on the synthesis of 9-flourenylmethanal by the reaction of flouren and ethyl formate , and the synthesis of 9-flourenylmethanol by the reaction of 9-flourenylmethanal and methanal with sodium ethylate as catalyst.

研究了乙醇钠为催化剂，由芴与甲酸乙酯合成芴甲醛，再由芴甲醛与甲醛合成苯甲醇的工艺条件，结果表明：合成芴甲醛时，当芴为 16g时，催化剂乙醇钠 4 。

In acidic condition, the extractive form waste water in hardboard production reacts with extra amount of formaldehyde at 1-5∶1 (formaldehyde : solid extractive, based on weight) to prepare extractive-formaldehydecomplex, then urea or phenol is added into the solution of this complex and reacts with unreacted formaldehyde to form a new adhesive system.

利用纤维板生产中废水提取物与过量甲醛(甲醛溶液与粉状废水提取物的重量比为1～5：1)在酸性条件下可制成纤维板废水提取物-甲醛复合体，此种复合体反应液中的过量甲醛再用尿素或苯酚吸收，从而制成尿素改性纤维板废液胶。

Formaldehyde is absorbed by an acidic saturated solution of 2,4-dinitrophenyl hydrazine and converted to its hydrazone; the hydrazone is then extracted with CS2 and quantitated by GC.

利用尾气中的甲醛与2，4-二硝基苯肼酸性饱和溶液反应生成甲醛腙的特性，通过检测甲醛腙的浓度来检测尾气中的甲醛含量。

The statistical comparison was used chi-square test between the methanal or hydrochloric acid abdominal cavity injection method and Galili's method.

结果 大鼠在腹腔注射1%甲醛与0.5%盐酸后均100%发生肠粘连，注射0.5%甲醛的大鼠肠粘连的发生率为87.5%，且0.5%盐酸，1%甲醛，0.5%甲醛腹腔注射法与Galili法相比，差异无显著性。

The production technique of polyoxymethylene can be divided into homopolymer technique and copolymer technique. In this project, copolymer technique will be applied.

聚甲醛生产工艺有均聚甲醛和共聚甲醛两种，本项目拟采用共聚甲醛工艺技术。

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％。

The forming process for the high-strength, steel-base modified polyformaldehyde composite material in five-laver structure is to melt modified polyformaldehyde by heating and roll to make the melt polyformaldehyde permeate into the gaps gaps between the large-grained spherical copper powder and screw copper nails.

四层结构的钢基铜塑复合材料的成型过程，是将改性聚甲醛加热熔化，经轧制，使熔融的聚甲醛渗透到大颗粒球形铜粉的间隙中，解决了三层材料复合过程中，熔融的聚甲醛水平流动性强过垂直方向的渗透性，造成了结合强度低的缺陷，使聚甲醛层与铜粉及基体结合更牢固，提高了其承载和抗剪切的能力。

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。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。