甲醛

Recently, the DAS gene (DAS1) was cloned from the methylotrophic yeasts, C. boidinii and H. polymorpha.

DAS是一种依赖焦磷酸硫胺素的转酮醇酶，催化甲醛同化途径中的第一个反应。

The reaction mechanism was studied and the proposed methods were applied to the determination of SOD activity.Second, baded on sodium terephthalate trapping HO, an automated spectrofluorimetry for determining HO with flow injection analysis was developed. It was applied to the anti-oxidation determination of maize pollen polysaccharose and natural foods.

一设计合成了两种用于超氧阴离子自由基识别检测的荧光探针——香草醛缩-8-氨基喹啉和2-吡啶甲醛苯并噻唑啉，用普通荧光法和流动注射荧光法对超氧阴离子自由基进行分析测定，研究了反应机理，并将其用于超氧阴离子自由基和超氧化物歧化酶活性的测定。

A new method that formaldehyde in air is collected in canister, preconcentrated through 3-stage traps and analyzed by GC/MS is introduced in this paper. Characters such as detection limit, veracity, stability and region of linear response are investigated.

本文研究了采用SUMMA罐采样，三级冷阱预浓缩，GC/MS分析室内空气中甲醛的方法，并考察了该方法的检出下限、准确度、精密度、线性响应范围等方法特性。

Ultrafine copper powder s were prepared by direct reduction method with hydrazine hydrate and formaldehyde as composite reductive agent and glucose prereduction method,respectively.

分别采用水合肼-甲醛复合还原剂法以及葡萄糖预还原法制得了微米级的超细铜粉，并利用粉末X射线衍射以及扫描电镜对其进行了表征。

A corrosion inhibitor CH - 10 used in high temperature acid treatment was obtained by compounding this cationic Mannich base with propargyl alcohol.

针对Mannich碱型缓蚀剂存在的溶解性不好和缓蚀率不高等问题，以甲醛、环己酮和苯胺为原料，合成了一种Mannich碱型缓蚀剂CH-9，将其阳离子化后，再与丙炔醇复配，得到了阳离子型高温酸化缓蚀剂CH-10。

They were divided into two groups, and operated pulpotomy using formocresol and ferric sulfate respectively. The children were followed up after 6 months and 1 year. Successful rates of pulpotomy were summarized statistically.

选择3~5岁儿童的第一乳磨牙、4~6岁儿童的第二乳磨牙共45人，80颗乳磨牙深龋近髓的病例，随机分为两组，分别行甲醛甲酚和硫酸铁溶液牙髓切断，术后6个月及1年复查，分别统计两组成功率，比较两组的疗效差异。

Methods: 80 primary molars with deep caries close to the pulps were selected. They were divided into two groups, and operated pulpotomy using formocresol and ferric sulfate respectively. The children were followed up after 6 months and 1 year. Successful rates of pulpotomy were summarized statistically.

选择3~5岁儿童的第一乳磨牙、4~6岁儿童的第二乳磨牙共45人，80颗乳磨牙深龋近髓的病例，随机分为两组，分别行甲醛甲酚和硫酸铁溶液牙髓切断，术后6个月及1年复查，分别统计两组成功率，比较两组的疗效差异。

Four chalcones were synthesized by aldol condensation reaction of acetophenone or para-substituted acetophenones with 2-phenyl-1,2,3-triazol-4-carboxaldehyde, which reacted with three hydrazines in glacial acetic acid under refluxing to give a series of pyrazoline derivatives.

以2-苯基－1，2，3-三唑基－4-甲醛为原料，与苯乙酮［或取代苯乙酮(1a~1d)］发生羟醛缩合，生成相应的查尔酮(2a~2d)，再与不同的肼反应，合成了12种新的5位含2-苯基－1，2，3-三唑基的吡唑啉衍生物3a~3d，4a~4d，5a~5d。

The effects of ratio of formaldehyde to phenol r(subscript F/P, ratio of NaOH to phenol r(subscript NaOH/P and resinification temperature on chemical properties of liquefied wood resins were investigated.

考察不同甲醛与苯酚物质的量之比值r(下标 F/P、氢氧化钠与苯酚物质的量之比值r(下标 NaOH/P和树脂化温度对树脂理化性能的影响。

To broaden desert shrub new utilizing fields, accelerate desert shrub developing to the direction of high added-value and high benefit, the paper studied on the liquefaction of Salix, Caragana and Poplar in the presence of Phenol under sulfuric acid catalysis. The optimum processing parameters for Salix, Caragana and Poplar liquefaction and resinification were investigated. The effect of molar ratio of formaldehyde to liquefied products and NaOH to liquefied products on the character and glue strength of liquefied products resin was studied.

摘 要：为了开辟沙生灌木资源新的应用领域，促使沙生灌木资源的利用向高附加值、高效益的方向发展，本文以苯酚作液化剂，以稀硫酸作催化剂对沙柳、柠条和杨木进行液化实验，分析了反应温度、液比、催化剂用量及液化时间对液化反应的影响；并研究了沙柳、柠条和杨木液化产物树脂化合成工艺和配方，分析了不同的甲醛与液化产物摩尔比以及氢氧化钠与液化产物摩尔比对沙柳、柠条和杨木液化产物树脂的各项性能的影响。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。