二-十进制

In contrast, dimerization and trimerization of NaH2PO4 are predicted to be the predominant initial reactions for the silica supported NaH2PO4 catalyst.

但是在硅胶负载的磷酸二氢钠上，磷酸二氢钠的二聚和三聚是缩合反应初始阶段的主要反应。

In contrast,dimerization and trimerization of NaH_2PO_4 are predicated to be the predominant initial reactions for the silica supported NaH_2PO_4 catalyst.

但是在二氧化硅负载的磷酸二氢钠上，磷酸二氢钠的二聚和三聚是缩合反应初始阶段的主要反应。

The discussion is focused on the feasibility of dimethyl ether used as a city gas and the price problem.

讨论了二甲醚生产的基本原理与工艺，介绍了二甲醚的主要燃料用途，重点讨论了二甲醚作为城镇燃气的可行性与价格问题。

In this paper, the catalyst and process of dimethyl ether from syngas were studied.

合成气一步法制二甲醚是近年来开发的一种新技术，相对于传统的两步法合成工艺，即先合成甲醇再脱水制二甲醚，合成气一步法合成二甲醚因其热力学上的有利性和经济上的合理性，成为C1化学研究的一个热点。

Seven types of dimetric drawing and three types of trimetric drawing are introducedby the author with an aim to help hasten the shift of the principles derived from varioustypes of dimetric and trimetric projections from the theoretical approach to the field ofpractical use,and to alleviate the embarrassing situation that only the simple methodscan be resorted to in drawing the pictorial projections by isometric drawing and cabinetdrawing.

为了使各种形式的正二测和正三测从理论研究转向实际应用，克服长期来人们在绘制轴测图时，多数只能采用正等测和斜二测等单调情况，以及提高绘图速度，本文推荐采用七种正二测和三种正三测，并设计一套绘制这十种正轴测的专用工具--轴测多角比例尺。本文提出一套近似作这十种正轴测坐标面上椭圆的方法和数据，使其既简便又准确。

The hydrogenation of crude dinitrobenzene is the best production technology of m-phenylenediamine .

介绍了我国间苯二胺的生产现状及工艺，指出采用粗品混合二硝基苯直接加氢是制备间苯二胺最好的方法，具有成本低、污染小等优点。

Effect of heat treatment on the ndcrophase separation of a segmented poly copolymer based on poly diol, 3, 5 dithyltoluene diandne and 4,4'-diphenylmethane diisocyanate has been studied bymeans of fourier transform infrared spectroscopy.

用傅里叶变换红外光谱方法研究了热处理对由聚环氧丙烷聚醚多元醇、3.5－二乙基甲苯二胺和4，4－二苯基甲烷二异氰酸酯组成的多嵌段聚氨酯脲的微相分离行为的影响。

The solubilities of ROK in several different solvents such as toluene, ether, THF and 2G were studied. Considering the influence of solvent on the microstructure of telomers, THF was determined to be the best solvent.In the system of n-BuLi/ROK/xylene/2G/olefin, the influence of ROK on diolefin anionic telomerization was investigated, and the result shows that the difference between butadiene system and isoprene system was little.

考察了不同ROK在甲苯、乙醚、四氢呋喃及二乙二醇二甲醚(2G)等不同溶剂中溶解能力，又考虑到溶剂对聚合物结构的影响，以及工业化的难易程度等方面，最终确定了ROK的最佳溶剂为THF。

A new type of spiro crosslinking agent,3,11 dimethylene 2,10 dione 1,4,9,12 tetraoxodispirobutadecane(2),was synthesized successfully.

合成了一种新型螺环环丙烯酸酯交联剂-3，11-二亚甲基-2，10-二酮-1，4，9，12-四氧二螺［4，2，4，2］十四烷（2）。

The paper reviewed the synthesis and production of the surfactant - dodecyl diphenyl ether sodium disulfonate .

介绍了十二烷基二苯醚二磺酸钠的合成及生产情况。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。