硝酸

The reaction between acridine yellow and nitrite nitrogen in acid medium was studied.

利用在酸性介质中，吖啶黄与亚硝酸根反应并在波长436 nm处的吸光度与亚硝酸根浓度呈线性关系，提出并建立了测定亚硝酸盐氮的新方法。

The number of autoterophic bacteria were significantly lower than the heterotrophic bacteria. Majority of 21 strains of heterotrophic bacteria that isolated from water body were Pseudomonas. Majority of 25 strains of heterotrophic bacteria isolated from sediment were bacillus, microccus and Pseudomonas.Three genus of autotrophic bacteria were sulphuret bacteria, nitrify bacteria and nitrosobacteria that were capable of oxidizing H2S, S, FeS, oxidizing NH3 to NO2 and NO2 to NO3 respectively.

试验稚鳖池水中共分离出21株异养细菌，其中优势菌为假单胞杆菌属细菌；底泥中共分离出25株异养细菌，其中优势菌为芽胞杆菌属细菌，微球菌属细菌假单胞菌属细菌，三种自养细菌分别为具有氧化硫化氢、元素硫或硫化亚铁的硫细菌；具有氧化氨为亚硝酸的亚硝化细菌和能将亚硝酸进一步转化成硝酸的硝化细菌。

The sludge age in the reactor is large, so that nitrobacteria and nitrosomonas live together. The nitrogen removal via nitrite was possible mainly because the activity of nitrobacteria was inhibited rather than rushed out in number.

反应器内的污泥龄较长，硝酸菌和亚硝酸菌长期共存，发生短程硝化反硝化主要因为硝酸菌的活性受到抑制，而不是数量上受到淘汰。

Highquality hydrogen for industry uses,dilute nitric acid,refined nitric acid,calcium nitrate tetrahydrate,calcium nitrate dihydrate,corrugated metal structured packing,catalyst for polyethylene,ultrahighmolecular weight polyethylene,15N labelled compounds,purificants of petrochemical industry,highmolecular flame retardants,molecular sieve desiccant,chemical machinery and equipment,separation equipment for chemical industry,testing and monitoring analyzers,detectors and equipment.

工业用优质氢，优质硝酸，硝酸钙，硝酸钙，金属规整波纹填料，聚乙烯催化剂，超高分子量聚乙烯，N15标记化合物，石化净化剂，高分子材料阻燃剂，分子筛干燥剂，化工机械和设备，化工分离设备，化工检测设备。

The result shows: in 0~360 kg/hm^2 fertilizer can improve the plant height, dry matter accumulation of maize, nitrogen accumulation, root vigor, leaf nitrate reeducates activity, chlorophyll content and yield, meanwhile the leaves' nitrate reeducates activity, dry matter accumulation and the final output of wheat, root activity and other indicators were significantly correlated; Cultivating under the same conditions and dropping the fertilizer amount from 360 kg/hm^2 to 315 kg/hm^2, the dry matter accumulation will be increased, the roots vigor and leaf nitrate reeducates activity will be strengthened, but the yield are not obviously different in the same treatment.

结果表明：在0~360kg/hm^2的施肥范围内，肥料能显著增加玉米植株的株高、干物质积累盆、叶绿素含量和籽粒产量，提高根系活力、叶片硝酸还原酶活性；同时硝酸还原酶活性、干物质积累量、根系活力和叶绿素含量等指标与玉米最终产量呈显著正相关；在相同的栽培条件下，将施肥量从360kg/hm^2降至315kg/hm^2，植株的于物质积累量增加、根系活力、叶片硝酸还原酶活性增强，但处理间籽粒产量无显著差异。

Passive film was formed onto the surface of stainless steel in nitric acid solution.

在90℃温度均匀腐蚀条件下，经过40天后，321不锈钢样品在低酸度的硝酸铀酰溶液中的腐蚀速率小于0.04g／m〓。h，铀酰离子以六水硝酸铀酰的形式吸附于321不锈钢表面，在含氯离子和次氯酸根离子的硝酸铀酰溶液中，321不锈钢发生了点蚀，出现了点蚀坑。

Influence of fluorine on filtration of acidinsoluble matter, crystal and filtration of calcium nitrate , ammonia neutralization of mother liquor and evaporation process of slurry are discussed based on its increasing slurry viscosity, growing fine crystal and troubling filtration in production of nitrophosphate by nitric acid decomposing phosphate rock.

介绍在硝酸分解磷矿生产硝酸磷肥的过程中，杂质氟对酸不溶物过滤、硝酸钙结晶及过滤、母液的氨中和及料浆蒸发过程的影响。

The recovery of tin and nitric acid from the spent solder stripper, and the feasibility of recovering nitric acid were investigated by determining diffusion dialysis coefficient of the dialysis membrane for different spent liquor including iron,copper and tin.

通过考察铁盐、铜盐和亚锡盐对硝酸扩散系数的影响研究了采用扩散渗析法从废退锡液中回收硝酸的可行性，实际样品的研究表明，扩散渗析法回收硝酸的回收率在70％以上。

One was that one molecule of nitrous acid di-rectly reacted with DMA,and the other was that two molecules of nitrous acid reacted first to yield nitrogen trioxide,which then reacted with DMA.

计算结果表明，DMA与亚硝酸间接反应的活化能比直接反应的低约55kJ/mol，由此可推断DMA与亚硝酸生成NDMA的反应是以两分子的亚硝酸先生成ONNO2再亚硝化DMA为主要反应途径。

The optimum parameters of chemical passivation in citric acid solution were 4%citric acid, 65°C, 15min, and the time of re-treat in 50%HNO_3 was 11min.

硝酸电化学钝化的较优工艺为：硝酸浓度10％，800mV恒电位阳极极化，25℃左右，时间15min；柠檬酸化学钝化的较优工艺为：柠檬酸浓度4％，温度65℃，钝化时间15min，浓硝酸后处理11min。

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。