purity 四级六级

The students are asked to prove the purity of copper.

要求学生们检验铜纯度。

She was a woman of purity and goodness.

她纯洁善良妇女。

Probity and purity will command respect everywhere.

为人正派到处受人尊敬。

The white colour is a symbol of purity.

白色纯洁象征。

?So long as he is spared to us, gladly shall we sit at his feet to learn from him the sublime precepts of purity, unworldliness, spirituality, and inebriation in the love of God.

只要他不伤害我们，我们会兴地坐在他脚上听着他崇纯洁、超尘脱俗和灵性，还有对神陶醉爱。

The indium sesquioxide with over 99% purity can be prepared by a decomposition of nitric acid. The method was characterized by fewer equipments, simple operation, low cost and quick yield.

采用硝酸分法可制取纯度于99%三氧化二铟.本法具有设备少、操作简单、成本低、见效快等优点.

Because the mature tissue of velvetleaf contains lots of secondary metabolites such as alkaloid and phenolic, it is difficult to obtain high purity DNA from mature tissue of velvetleaf.

摘要青麻成熟组织中酚类、黄酮类等次生代谢物较多，要从中取出纯度DNA比较困难。

The improvement of the purity of fluorene is not dependent on the removal of acenaphthene and dibenzofuran, but dependent on the separation of other impurities.

芴纯度主要不依赖苊、氧芴去除,而其它杂质分离。

Certified reference material of the high-purity silicasol was prepared by removing impurity ions from the high purity silicasol according to the ion exchange resin.

采用离子交换法实现了纯硅溶胶主成分与众多杂质离子分离,并制备了纯硅溶胶标准物质。

Ethyl phenylacrylate intermediate bringing a double bond was introduced first,which is subsequently transformed into triketone and then DCM was obtained with high purity.

采用具有烯烃骨架β-苯基丙烯酸酯为中间体先引入双键,再经过三酮合环制备乙烯基吡喃。

High purity titanium sesquioxide was obtained by the reaction of high purity hydrogen and titanium dioxide in the presence of titanium tetrachloride.

用纯氢和纯二氧化钛，在四氯化钛存在下，可以得到纯三氧化二钛。

The results showed that the purity of Zincite as product was more than 99.6%in according with the requirements of grade A products.

试验结果表明,其产品氧化锌纯度可达99.6%以上,符合级品要求。

The mixture was refined by sodium sulfide and sodium hydroxide to afford an O,O-diethyl thiophosphoryl chloride at a purity of 99%.

该粗品通过精制工艺改进,采用硫化钠和氢氧化钠混合物进行处理,得到纯度≥99%O,O-二乙基硫代磷酰氯。

Heptanone with purity being 98.5% was synthesized by ethyl acetoacetate.The yield is 58.9%,and its application in the related fields were discussed.

用乙酰乙酸乙酯法合成了2-庚酮,总得率为58.9%,纯度为98.5%.介绍了2-庚酮在相关领域中应用.

Thus, Gramine was prepared from Indole by condensatallizafion, the purity of Gramine was 98% , and the yield was 95% .

报道了芦竹碱新合成方法,由吲哚与甲醛和二甲胺缩合而制得芦竹碱,经重结晶后其含量为98％。

Use in the dark color: standard color is adopted terse white, which possesses qualities of austerity, bluffness and purity.

深色环境中应用：标准色采用简洁白色，朴素、坦率、纯正白色特性。

Therefore,it is important to control strictly reaction conditions for removing cystine's mesoisomer and making L-cystine of high optical purity.

严格控制反应条件，分离除去内消旋胱氨酸制取光学纯度L-胱氨酸重要措施。

Its advantages include high purity of carotin crystal, low acidity of the oil solution of carotin and stable quality.

本发明获得胡萝卜素晶体纯度，胡萝卜素油溶品酸价低、质量稳定。

High purity amygdalin was obtained from apricot kernel by the process of enzyme destruction, defatting, solvents extraction and recrystallization.

苦杏仁经灭酶、脱脂、萃取、重结晶,制得纯苦杏仁苷。

Carbon tetrabromide was prepared from acetone and sodium hypobromite by adding tetrabutylammonium bromide.The yield and purity were very satisfactory.

向次溴酸钠溶液中滴加适量丙酮,在四丁基溴化铵催化下,产率得到四溴化碳。