查询词典 chemical method

A method for preparing D-valine from L-valine by racemization and chemical resolution is presented.

介绍了L 缬氨酸经消旋化及化学拆分制备D 缬氨酸的方法。

X-ray radiography, X-ray radioscopy and X-ray computed tomography were performed to the C preforms and C/SiC composites made by chemical vapor infiltration method. Elementary research of the simulation of X-ray nondestructive testing of C preforms and C/SiC composites was conducted. The main contents and conclusions are summarized as follows:(1) The equivalent absorption coefficients of graphite and SiC to Al (KAl/sic, KAI/C) were measured. It was found that in 35-45KV, KAl/sic=1.1~1.2 and KAl/c=0.08~0.12. That means X-ray radiography was much less sensitive to fiber defects than to SiC matrix. It was suggested that Al Image Quality Indicator would be used to evaluate the quality of X-ray radiographs of C/SiC.

本文选择X射线照相、X射线实时成像和X射线CT等三种方法对C纤维预制体及C／SiC复合材料进行了检测和研究，并对C／SiC复合材料X射线检测的计算机模拟做了初步的探索，主要研究内容和结果如下：(1)测定了C和SiC的X射线照相等效系数，在35～45KV的条件下，Al对SiC的等效系数K_为1.1～1.2，Al对C的等效系数K_为0.08～0.12，所以X照相射线检测C／SiC对C纤维缺陷不敏感，而对SiC基体缺陷敏感。

THE MAIN DISADVANTAGE OF THIS METHOD IS THAT DRY CHEMICAL HAS NO COOLING EFFECT AND FIRES MAY REFLASH AFTER THEY APPEAR TO HAVE BEEN OF SATISFACTORILY EXTINGUISHED.

乙类火警可以用乾化学剂扑救，但其弊处是没有冷却效果，火很容易复燃，最有效的是以乾化学剂为第一线救火扑灭剂，再跟著使用泡沫或雾化喷水。

Electrical conductivity relaxation method was used to determine the oxygen chemical diffusion coefficients .

采用电导弛豫法测定了样品的氧化学扩散系数。

Electrical conductivity relaxation method was used to determine the oxygen chemical diffusion coefficients D～.

采用电导弛豫法测定了样品的氧化学扩散系数。

NBR/modified montmorillonite and NR/HMMT nanocomposites were prepared by the mixing intercalation method with the monomers resorcin and hexamethylenetetramine complex . XRD and TEM showed that the interlayer spacing of HMMT had got much larger with RH addition and the layers of HMMT had dispersed in rubber matrix on nanometers. FTIR and crosslinking density results explained that chemical reaction had occurred between RH and rubber in the course of vulcanization, which improved the crosslinking density of rubber and enhanced the interaction between the rubber and HMMT.

采用单体混炼插层法，引入间苯二酚-六次甲基四胺的络合物，制备了橡胶／改性蒙脱土插层纳米复合材料。X-射线衍射分析表明：RH的加入使蒙脱土层间距不断扩大；TEM观察到无机片层在橡胶基体中纳米级分散；FTIR和交联密度的分析发现，在硫化过程中RH与橡胶发生化学键合反应，同时与改性蒙脱土相互作用，使得体系交联密度提高。

Adopt orthogonal experimental design to optimize chemical technology of detaching safrole and refining citral from Zhejiang volatile oil;use compacting method to prepare soft capsule and research making craft condition;use gas chromatography to Zhejiang volatile oil, take off poisonous oil an...

采用正交试验设计对用化学法从者姜挥发油中除去黄樟醚及精制柠檬醛进行工艺优选；采用压制法制备软胶囊，研究制备工艺条件；用气相色谱法对者姜挥发油、脱毒油和者姜心脑康软胶囊进行质量控制，建立质量标准。

The method and principle of variable angle sample spinning NMR were introduced. In presence of both quadrupole and chemical shift interactions, VASS NMR computer simulation was performed.

2介绍了变角样品旋转NMR方法和原理，及解决同时考虑半整数四极核四极作用和化学位移作用以及两种作用张量主轴不重合情况下的VASS NMR拟谱问题。

Savary used method of separation medium fungi, France BIOMERIEUX application of automatic identification systems on the EXPRESSION fungi for biological and chemical identification and drug sensitivity.

用沙氏培养基分离真菌，应用法国BIOMERIEUX的EXPRESSION自动鉴定系统对真菌进行生化及药敏鉴定。

A new algorithm, which is called "rank method", for the judgment of the thermodynamic self-consistency of an electrochemical/chemical reactions system has been developed.

介绍了一种判断电化学/化学反应体系热力学自洽性的新方法-"秩法"。

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％。