硝酸

The nitrocellulose filter s are then placed on wet filter paper containing alkali, which denatures the DNA

再将硝酸纤维素滤膜置于含碱的湿滤纸上，碱的作用是使DNA变性。

NO3(superscript -) is deoxidized into NO2(superscript -) by nitrate reductase.

在硝酸还原酶的作用下，硝酸盐被还原为亚硝酸盐。

NO3- is deoxidized into NO2- by nitrate reductase.

在硝酸还原酶的作用下，硝酸盐被还原为亚硝酸盐。

Compounds 3a-3d, 4a-4d, 5a-5d, 6a-6e and 7a-7e were prepared with a new efficient method, in which the aromatic amines were diazotized with isoamyl nitrite in EtONa/EtOH under refluxing condition, and mono -, bis -and tetrakis -substituted calix [4] arenes were obtained respectively as main product by diazo-coupling in different molar ratio to calix [4] arene.

一，提出了一个有效的新方法合成含有芳香偶氮基团的杯[4]芳烃衍生物3a-3d；4a-4d；5a-5d；6a-6e和7a-7e：即在非水溶剂乙醇中用亚硝酸异戊酯，在强碱乙醇钠存在下对芳香胺进行重氮化，得到芳香重氮酸盐沉淀，过滤，然后加入杯[4]芳烃的四氢呋喃溶液，通入CO〓气体调节溶液的pH值为7-9，使其发生偶联反应。

Methods: 2ethyl aniline was used as starting material of the synthesis and was processed by acetic anhydride acylation, strong nitric acid nitraction at low temperature, and desacyl synthesis to produce 2ethyl5nitro aniline. The product was then synthesized to 3methyl6nitro1Hindazole by using ringclosing reaction in the presence of NaNO2, and then ethylated to obtain 2,3diethyl6 nitro2Hindazole. The latter compound was then reduced by SnCl2/Hcl to get target compound 2,3diethyl6nitro2Hindazole.

以2乙基苯胺为原料经醋酐酰化、浓硝酸低温硝化及去酰基保护合成2乙基5硝基苯胺，后用亚硝酸钠关环得3甲基6硝基1H吲唑，经硫酸二甲酯甲基化得2，3二甲基6硝基2H吲唑，最后用氯化亚锡将其还原得到目标产物，通过1H NMR确定结构与目标产物一致。

Methods: 2-ethyl aniline was used as starting material of the synthesis and was processed by acetic anhydride acylation, strong nitric acid nitraction at low temperature, and desacyl synthesis to produce 2-ethyl-5-nitro aniline. The product was then synthesized to 3-methyl-6-nitro-lH-indazole by using ring-closing reaction in the presence of NaNO2, and then ethylated to obtain 2, 3-diethyl-6- nitro-2H-indazole. The latter compound was then reduced by SnC12/Hcl to get target compound 2, 3-diethyl-6-nitro-2H-indazole.

以2-乙基苯胺为原料经醋酐酰化、浓硝酸低温硝化及去酰基保护合成2-乙基－5-硝基苯胺，后用亚硝酸钠关环得3-甲基－6-硝基－1H-吲唑，经硫酸二甲酯甲基化得2，3-二甲基－6-硝基－2H-吲唑，最后用氯化亚锡将其还原得到目标产物，通过1HNMR确定结构与目标产物一致。

The green body's bending strength was 3.916MPa after jelling and drying under special temperature and time using nitric acid as a curing agent.

以硝酸为固化剂在一定的温度及时间内胶凝固化并干燥，可以得到抗弯强度为3.916MPa的生坯。

It indicates that the damage or amorpho-tization takes place-within crystalline lamellae rather on their surface.

经硝酸腐蚀的试样，其凝胶渗透色谱测得的数均分子量，随着辐照剂量的增加而增加，表明晶区内分子数减少。

It can transport all kinds of temperature and deepnesses unorgan acid such as nitric ,sulfuric,hydrochloric acid,organ acid,strong alkali,weak alkali,salt solution,different liquidized oil chemical products,organ compounds and others erosive liquid .

该型泵可输送各种温度和浓度的硝酸、硫酸、盐酸、和磷酸等无机酸和有机酸；各种温度和浓度下的氢氧化钠和碳酸钠等碱性溶液各种盐溶液；各种液态石油化工产品、有机化合物，以及其他有腐蚀性的液体。

The 3,4-dimethoxybenzene was nitrated by mixed acid of HNO3-H2SO4 under the reaction temperature of 0~5℃. 3,4-dimethoxynitroben-zene was obtained by filtration, and its yield reached over 97%.

在0~5℃低温条件下，以硝酸和硫酸按比例配成的混酸进行硝化，反应结束后过滤得到3，4-二甲氧基硝基苯，该步反应的收率有97%。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。