查询词典 formaldehyde

The regularities of the influence of various factors includingreaction temperature,reaction time,the ratio of formaldehyde to acetaldehyde,the quantity of alkali and the concentration of formaldehyde on the yieldsof pentaerythritol and dipentaerythritol were studied.

通过单因素实验，考察了反应温度、反应时间、甲醛与乙醛的配比等因素对单、双季戊四醇收率的影响。

Four new compounds,substituted-benzyloxyindole-3-formaldehyde-(4′-nitro) phenylhydrazone ,were synthesized by the condensation of 4-nitrophenylhydrazine with substituted-benzyloxyindole-3-formaldehyde in ethanol.

以取代苄氧基吲哚-3-甲醛和4-硝基苯肼为原料，乙醇为溶剂，通过缩合脱水反应合成了4个新化合物——取代苄氧基吲哚-3-甲醛-(4′-硝基)苯腙，其结构经1H NMR，IR，MS和元素分析表征。

The resol phenol-formaldehyde adhesive could be prepared from liquefied wood (wood: phenol=1:2) in phenol at r(subscript F/P) 1.8, r(subscript NaOH/P) 0.7 and resinification temperature 80℃. The physical properties of the poplar three-layer plywood bonded with LWR were similar to those with normal PF resins and also satisfied the demands of I level. Free formaldehyde content of plywood (0.1 mg/L) was lower than the E0 level set by GB/T 9846-2004 Plywood.

结果表明，采用料液比为1：2的液化物，F1.8，r0.7，树脂化温度80℃条件下合成的杉木液化物树脂压制的杨木三层胶合板满足I类胶合板强度要求，各项物理力学性能与常规PF树脂压制的板材相当，板材的甲醛释放量为0.1mg/L，远低于GB/T 9846-2004《胶合板》中的E0级要求。

It can meet the measurement requirements of general food samples for formaldehyde and sodium formaldehyde sulfoxylate.

可满足一般食品样品中甲醛和吊白块测定的要求。

Sodium formaldehyde sulfoxylate can break down into formaldehyde and sulfur dioxide in process of using.

吊白块在使用过程中会分解出甲醛和二氧化硫，先用乙酸铅试纸法[1]对样品进行定性筛选，可疑样品再用分光光度法[2]测量甲醛的含量，判断是否含有吊白块。

While four sample treatments tested for different samples formaldehyde or formaldehyde sodium sulfoxylate content measured.

同时试验了四种样品处理方法，可用于不同样品中甲醛或吊白块含量的测定。

Food analysis, Formaldehyde, sodium formaldehyde sulfoxylate, Sample treatment

食品分析；甲醛；吊白块；样品处理

A clean production technology of sodium sulfoxylate formaldehyde by one-step process with sodium pyrosulfite ,zinc powder and formaldehyde as raw materials was studied in detail.

详细研究了以焦亚硫酸钠、锌粉和甲醛为原料，一步法合成甲醛合次硫酸氢钠的清洁生产工艺，其最佳操作条件为：焦亚硫酸钠与锌粉物质的量比约1∶2.5，焦亚硫酸钠与甲醛物质的量比约1∶2.1，亚硫酸氢钠溶液的pH 3.3~3.6，活化温度≤45℃，最高温度97~102℃，高温反应时间

Results: good standard linear curve, r = 0.9998; minimum checking limited to: 0.28μg formaldehyde, or 1.4μg sodium formaldehyde sulfoxylate; Variation coefficient 2.0%.

结果：标准曲线线性良好，r = 0.9998；最低检出限为：0.28μg甲醛，或1.4μg吊白块；变异系数为2.0 %。

This apparatus can be used to determine the formaldehyde, Sodium formaldehyde sulfoxylate , nitrite ,nitrate ,sulfur dioxide and pesticide residue in food rapidly and quantitatively by spectrophotometry..

仪器采用分光光度法，快速定量检测食品中甲醛、吊白块、亚硝酸盐、硝酸盐、二氧化硫和农药残留，适用于食品生产企业、农业生产基地、农业市场、质量监督、卫生防疫等部门。

It's not quite as simple as that.

并没有那么容易。

It debuted in 1992 in Japan and the United Kingdom, and 1993 in the United States.

它首次亮相于1992年在日本和英国，在美国1993年。