查询词典 nitrogen

The invention relates to a process for producing polyethylene terephthalate 1, 3-propanediol, which comprises the following steps: using titanic acid ester as major catalyst, using germanium compounds and cobalt compounds as synergic catalyst, conducting esterification reaction for poly terephthalic acid and 1, 3-propanediol according to the molar 1:1.05-2.2 under the nitrogen pressure of 0.1-0.4MPa and 230-265 DEG C, or conducting ester exchanging reaction for poly terephthalic acid and 1, 3-propanediol according to the molar ratio 1:1.8-2.2 in 160-220 DEG C, decompressing reaction to high vacuum 10-150Pa, wherein the final temperature of reaction is 265-275 DEG C, recovering to normal pressure with nitrogen to obtain the PTT product.

本发明涉及一种生产聚对苯二甲酸1，3-丙二醇酯的方法，采用以钛酸酯为主催化剂，锗化合物和钴化合物为协同催化剂，对苯二甲酸二甲酯和1，3-丙二醇按摩尔1∶1.05-2.2，在0.1-0.4MPa氮气压力和230-265℃下进行酯化反应，或对苯二甲酸二甲酯和1，3-丙二醇按摩尔比1∶1.8-2.2，在160-220℃进行酯交换反应，将反应减压至高真空10-150Pa，反应终温在265-275℃，用氮气恢复到常压，得到本PTT产品；大大缩短了反应时间，直接聚合制备特性粘度在0.7-1.05dL/g的PTT切片，使反应产物色相良好，PTT产品可用于纤维加工及工程塑料领域。

The dosage of nitrogen-potassium topdressing 225 kg/hm^2 were relatively better, nitrogen-potassium topdressing had better application value.

结论］氮钾追肥以225 kg/hm^2较好，具有较好的应用价值。

Field experiments were conducted to study effects of nitrogen application rate and ratio of base and topdressing on nitrogen utilization, grain yield, and grain protein content in winter wheat using 15N tracer technique.

在大田栽培条件下，运用15N示踪技术研究了不同施氮量和底追肥比例对小麦氮素利用和子粒产量及蛋白质含量的影响。

The correlation of the total nitrogen and the reducing sugar content was very significant negative, of the total nitrogen and the nicotine content was significant positive.

总氮与还原糖含量呈极显著负相关，与烟碱含量呈极显著正相关。

This paper presents the development and the actual state of nitrogen trifluoride in China,analyzed the market of nitrogen trifluoride and give the advice.

综述了我国三氟化氮的发展和现状，分析了市场形势，并提出了三氟化氮今后发展的对策。

Using field experiment and chemical analysis,the yield and nitrate content of various organ in tumorous stem mustard under different forms of nitrogen and different nitrogen levels were studied.

采用田间试验和化验分析等方法，研究了不同形态氮、不同氮水平下，茎瘤芥各器官产量和硝酸盐含量的变化特征。

Compared to the other carbon and nitrogen sources studied, sucrose and malt extract were found to be the suitable carbon/nitrogen sources. The decolorization efficiency of Cerrena unicolor Y5002 to orange G was similar at different orange G concentration below 500mg/L; however, alizarin red inhibited the decolorization reaction at the concentration of 400mg/L or above 400mg/L.

对一色齿毛菌Cerrena unicolor Y5002的液体培养脱色条件进行了研究，其最适碳源和氮源分别为蔗糖和麦芽浸粉；在不同橙黄G浓度下均获得较高的脱色率，因此浓度为500mg/L的橙黄G未对该菌的脱色能力产生抑制作用，而浓度为400mg/L茜素红则对其脱色作用产生明显抑制。

The Simpson and Shannon-Weiner indices of aquatic plant diversity were both significantly positively correlated with catalase, protease and invertase, and negatively correlated with urase, soil organic matter and total nitrogen. Similarly, soil organic matter and total nitrogen were negatively correlated with catalase, protease and invertase but positively correlated with urase.

植物α多样性指数(辛普森、香浓-维纳指数)与湿地土壤有机质、全氮含量呈负相关，与土壤过氧化氢酶、蛋白酶、蔗糖酶活性呈正相关，与脲酶活性呈负相关；土壤有机质、全氮含量与过氧化氢酶、蛋白酶、蔗糖酶活性呈一致负相关，与脲酶活性则成正相关。

A series of nitrogen fixation characteristics, such as nodule nitrogen fixation activity, nodule ureide content and young stem ureide content were studied in the same latitude and differently evolutionary types of soybean.

本试验研究了中国同一纬度不同进化类型大豆主要生育时期的根瘤固氮酶活性、根瘤酰脲含量和幼茎段酰脲含量。

For example, one volume of liquid nitrogen at atmospheric pressure vaporize s to 694 volumes of nitrogen gas at 68 F (20 C).

例如，一个大气压下的单位体积的液态氮在68°F(20°C)时蒸发成694个单位体积的氮气。

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。