They recommend revised limits for the concentration of selected air pollutants: particulate matter (PM), ozone (O3), nitrogen dioxide (NO2) and sulfur dioxide (SO2), applicable across all WHO regions.
它们为下述选定的空气污染物的浓度限值提出了修订：可吸入颗粒物(PM)、臭氧(o3)、二氧化氮(NO2)和二氧化硫(SO2)，适用于世卫组织所有区域。
The concentration of nitrogen trifluoride in the atmosphere is about 0.5 part per trillion, making it very hard to measure.
大气中三氟化氮的浓度大约为0.5万亿分之一(ppt)，使得它很难测定。
With the increasing of oil migration effects, the concentration of nitrogen compounds decreased whereas the ratios of shielded nitrogen compounds to exposed or semi-shielded ones increased.
随着运移作用的加强，含氮化合物绝对浓度下降，“屏蔽”型与“暴露”型或“半屏蔽”型化合物的比值增加。
The broth contained high concentration of amino nitrogen and fungal polysaccharide.
该发酵液含有较高的氨基态氮，香菇多糖。
The results showed that starch as carbon source, and casein and soybean powder as nitrogen source, o methoxyphenol and vanillin of suitable concentration had good influence on laccase production.
结果表明，淀粉作碳源、干酪素作氮源有利于漆酶的分泌，适宜浓度的愈创木酚和香兰素等对漆酶的产生有一定的作用；
So water-retaining agents could mix urea and low concentration potassium in process of production, and we can study complex water-retaining agents which compose the nitrogen and potassium too.
因此，在生产过程中可以考虑保水剂与尿素和低浓度的钾肥混合施用，也可以进行赋氮肥、钾肥的复合型保水剂研究。
To exclude higher oxygen concentration in an equipment with an potential source of ignition we use Nitrogen to dilute the air in the vessel.
避免设备内氧气浓度过高以及火源的存在，使用氮气稀释釜内空气。
Effect of nitrogen and ammonia content on the nitriding rate, the microstructure, nitrogen concentration and hardness distribution of the nitriding case were studied.
研究氨气和氮气混合气氛的成分对渗氮速率的影响，测定了渗氮层的显微组织、渗氮层氮浓度分布及有关力学性能。
Under this experiment condition, the light compensation point and light saturation point of the two species didn't show regularity with the change in nitrogen concentration in water.
在本实验条件下，这两种供试植物的光合补偿点和光合饱和点随氮浓度的变化没有表现出规律性。
It was showed that the mean concentration and accumulated amounts of runoff losses of nitrogen were highly correlated with N-application rates.
结果显示，随施氮量增加，农田径流液中氮素的平均浓度和氮素径流累积流失量提高，两者间呈显著正相关。
The time of dynamic nitrogen adjustment were determined by regular patterns or by the comprehensive evaluation of soil mineral nitrogen concentration and rice population status.
氮素动态调控时期由高产栽培常用的追肥时期或根据水稻群体状况与土壤矿质态氮浓度综合判断确定，追氮量由模型计算获得。
Change of phosphorus and nitrogen concentration in the leakage loss.
渗漏流失氮磷浓度的变化。
The concentration of ammonium nitrogen in horizontal migration decreased with the increase in unsaturated soil water diffusivity in power function.
铵态氮水平运移的浓度受非饱和土壤水扩散率的影响，并随非饱和土壤水扩散率的升高而呈幂函数曲线下降。
The COD, ammonia and total nitrogen (TN) removal efficiency were studied in the paper at low DO concentration in a pilot-scale A/O nitrogen removal plant treating domestic wastewater.
应用A/O中试装置处理实际生活污水，研究了低DO浓度下系统对有机物、氨氮和总氮的去除效果。
This inhibiting effect was due chiefly to the concentration of combined nitrogen.
化合态氮的抑制作用与浓度密切相关。
The concentration of nitrogen and ammonia has no effect on purging efficiency.
氨氮浓度的高低对吹脱效率影响不大。
The process transfers to the Marine high concentration of phosphate nitrogen and iron, which stimulate the growth of the phytoplankton.
这一过程向海洋传送了高浓度的磷酸盐、氮和铁，从而刺激了浮游植物的生长。
This paper reports the effect of DCD in seedling stage to soil microorganism of bacteria, mold and actinomycetes, and the concentration changes of both ammonium nitrogen and nitrate nitrogen in soil.
实验研究了双氰胺在玉米苗期对土壤微生物细菌、霉菌和放线菌的影响，及对土壤中铵态氮和硝态氮贮量变化的影响。
The results indicate that the normal operation of reactor only needs the lower concentration of carbon source and nitrogen source to obtain perfect result.
结果表明，较低浓度的碳源和氮源即可维持反应器的正常运行，达到理想的脱色效果；
Nitrogen release characteristic of Dianchi lake sediment and the nitrogen nutrients concentration of overlying water body was studied through simulating cultivation.
通过模拟培养，研究了底泥氮营养的释放及上覆水体中氮营养的浓度变化特征。
The effect of nitrogen on growth, total alkaloids concentration and total alkaloids yield of Sophora flavescens was studied.
结果表明，施用氮肥对苦参生长以及苦参总碱含量均有显著促进效应。
Bean cake was the best nitrogen source, and their optimal mass concentration for Bacillus sp. X18 and X10-1-2 were 4 % and 1 %, respectively.
两株菌的最佳氮源均为豆饼，X18的最佳豆饼质量分数为4%，而X10 - 1 - 2的最佳豆饼质量分数为1%。
The methanolic extract obtained from shellfish sample should be dried under nitrogen, keeping the concentration of methanol below 4%.
利用甲醇进行贝类样品的提取后需要进行氮气吹干，样品检测液中的甲醇浓度必须低于4%。
Nitrogen has great effects on the plant photosynthesis, organic matter decomposition, carbon allocation and the responses of ecosystem when the atmospheric CO2 concentration increases.
氮素可限制植物光合、有机质分解、同化产物的分配以及生态系统对大气co2浓度升高的响应。
The kinetic model of the nitrification of garbage percolate is different from that of sewage with low-concentration of ammonia nitrogen.
垃圾渗滤液硝化动力学模型不同于低浓度氨氮废水硝化动力学模型。
The pot experiment indicated that different strains symbiotic nitrogen fixation efficiency and the ammonium molybdate concentration were related.
盆栽试验表明，不同菌株共生固氮的有效性与钼酸铵浓度相关。
From the investigations, lack of nitrogen and phosphorus, oxygen deficiency in aeration basin of SBR, high concentration of sulfide in the wastewater is found.
调查分析得知该厂印染废水存在氮、磷缺乏现象，SBR曝气池存在缺氧现象，废水中硫化物含量较高。
From the investigations, lack of nitrogen and phosphorus, oxygen deficiency in aeration basin of SBR, high concentration of sulfide in the wastewater is found.
调查分析得知该厂印染废水存在氮、磷缺乏现象，SBR曝气池存在缺氧现象，废水中硫化物含量较高。
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