查询词典 nitrogen-free

The phytoplankton community was mainly composed of Cyanophyceae, Euglenophyceae, Bacillariophyceae, and Chlorophyceae, and the dominant species were Oscillatoria subtillissima, Dactylococcopsis irregularis, Euglena caudata, Melosira granulata, Cyclotella meneghiniana, Chlorella vulgaris, and Scenedesmus quadricauda. The main environmental factors affecting the distribution of phytoplankton species in July were ammonium-nitrogen, dissolved oxygen, water temperature, and total phosphorus, while those in September were pH, water temperature, dissolved oxygen, transparency, and total nitrogen. Water transparency and zooplankton were the main factors affecting the biomass of Cryptophyceae, Pyrrophyceae, and Bacillariophyceae; while nitrogen, phosphorous, and dissolved oxygen were the main factors affecting the biomass of Cyanophyceae, Euglenophyceae, and Chlorophyceae.

结果表明：调查期间共鉴定出浮游植物384种，隶属于8门，浮游植物密度范围为2.01×105～57.60×105 cells·L-1；群落组成以蓝藻、裸藻、硅藻和绿藻为主，主要优势种有细微颤藻、无常蓝纤维藻、尾裸藻、颗粒直链藻、梅尼小环藻、普通小球藻、四尾栅藻等；7月影响浮游植物分布的主要环境因子依次为铵态氮、溶解氧、水温和总磷，而9月的pH值、水温、溶解氧、透明度和总氮含量对浮游植物的分布产生影响较大；其中，透明度和浮游动物量是影响隐藻、甲藻和硅藻藻类生物量的主要环境因子，而蓝藻、裸藻、绿藻主要受水体氮磷营养盐浓度和溶解氧的影响。

The paper reviews home and overseas research works on exhumation and use of nitrogen-fixing resource, genetics engineering of nitrogen fixation, and biochemistry of nitrogenase and chemical modeling of biological nitrogen fixation, and describe the prospect of biological nitrog...

本文从固氮资源的发掘和利用、固氮的遗传工程以及固氮酶生物化学和化学模拟生物固氮三方面对国内外的研究进展进行了全面的阐述，并对生物固氮研究的前景进行了展望。

Highter nitrogen, potassium and magnesium levels decreased the absorber of nitrogen, potassium and magnesium.4 Mutual effects of N- K, N—Mg and K-Mg had positive compound effect on the yield and fecula contents of pumpkin when nitrogen, potassium and magnesium were at proper level.

氮—钾、氮—镁、钾—镁互作对南瓜产量和淀粉含量在适当水平表现为正互作效应，而在高水平下表现为负互作效应。

The soil had great population of bacteria, but the fungi quantity is excessive which may cause the multiplication of germina. As base-fertilizer, the slowed-release fatty had positive influence on soil fast-effect nutrient, but the organism quality is small, the soil enzyme activity with microorganism activity both low. Soil EC, total nitrogen, available nitrogen, available phosphorus and organic matters were significantly negative related to the soil pH. Soil total nitrogen was positive significantly related to soil available nutrient.

土壤中pH值与土壤EC值、土壤全氮、速效氮、速效磷、有机质含量呈显著负相关，土壤全氮含量与土壤速效养分含量有极显著正相关关系，而且土壤有机质含量与土壤速效养分之间也有相互促进的作用，所以土壤养分的平衡效果非常重要，有机肥处理后土壤养分全面，肥力较高。

In nitrogen and phosphorus mixed pollution water, in thewater that the concentration of nitrogen is 21mg/L and the concentration of phosphorus is155mg/L, Eichharnia crassipes and Hosta ventricosa can grow normally. In the water that theconcentration of nitrogen is 210mg/L and the concentration of phosphorus is 31mg/L, thephysiological indicators of Hosta ventricosa is good but the physiological indicators of Eichhomiacrassipes is worse than the other treatment and the root of Eichharnia crassipes was rot when itwas planted in the 7th day, and on the 11th day the plants wilt symptoms, it noted that thistreatment affected the growth of Eichharnia crassipes.

在氮磷复合污染的水体中，凤眼莲和紫萼玉簪在氮浓度21mg／L，磷浓度155mg／L水体中都能够正常生长，而在氮浓度210mg／L，磷浓度31mg／L水体中，紫萼玉簪生长正常，而凤眼莲的生理指标比在其它处理中要差，并且凤眼莲在种植的第7天出现根部腐烂，11天时植株枯萎的症状，说明氮浓度210mg／L，磷浓度31mg／L复合污染在一定程度上影响植物的正常生长。

The results showed that: the influence of the aquaculture process on aquaculture water determined by type of aquaculture; the influence of aquaculture process on the water temperature, salinity and pH value were not wide.the descent of pH value was related to feed coefficients ; the dissolve oxygen of water in outfall was lower than the water in infall,but the concentration still maintained at the saturation level, is mainly affected by density of aquaculture ,rate of feed and artificial measures of increasing oxygen ;the major form of inorganic nitrogen was nitrate-N;the concentration of inorganic nitrogen and the organic matter tended to increase ,but the ammonium to decline ,this was relation with density of aquaculture ,rate of feed and variation of the different inorganic nitrogen form ; concentration of phosphate-P was low in outfall of pond , related with phosphate-P precipitating, as flowing water speed slowly in outfall;This phenomenon that the total number of bacteria and coli form group of water in outfall was lower than the water in infall , this caused by measures of sterilization and disinfection .

结果表明：养殖过程对水体影响与养殖类型有关。养殖过程对水体的水温、盐度和pH影响不大； pH下降与饲料系数高有关；溶解氧含量排水口比进水口低，但仍维持在饱和状态，与养殖密度、投饵率和人工增氧有关。硝酸氮是无机氮的主要存在形式，无机氮和有机物含量有升高趋势，氨氮有下降的趋势，与养殖密度，投饵率和各种无机氮之间的相互转换有关。活性磷酸盐含量在排水口含量下降，与排水口流水速度慢，磷酸盐沉淀有关。生物指标细菌总数和大肠杆菌总数在排水口比进水口低现象普遍存在，这与养殖场杀菌消毒等措施有关。

A pot experiment with twenty-three open-pollinated Liriodendron chinense families from Liping of Guizhou at two nitrogen levels was conducted to investigate family variation and inheritance of nitrogen absorption and utilization efficiency related to nitrogen supply.

选用来自贵州黎平马褂木优良种源的23个优树自由授粉家系，设置低N和高N2种N素水平的盆栽试验，以研究马褂木N素吸收和利用效率的家系遗传变异及N素水平的影响。

The pathogen grew well on the media using glucose, sucrose, fructose, maltose, rhamnose or soluble starch as carbon sources. Galactose, xylose, mannite or sorbose was not beneficial for the growth of the pathogen, however. The media with only organic or inorganic nitrogen sources were not suitable for the pathogen growth although organic nitrogen sources were better than inorganic nitrogen sources. The pathogen could also infect Allium cepa L., A. fistulosum L. and A. odorum L. under artificial inoculation conditions.

在碳源中，以对葡萄糖、蔗糖、果糖、麦芽糖、鼠李糖和淀粉的利用为佳，而半乳糖、山梨糖、甘露醇、木糖和菊糖不利病菌的生长；有机氮源优于无机氮源，但单独应用有机或无机氮作为营养均不适于此病菌的生长；在人工接种条件下，病菌可侵染葱、洋葱和韭等葱属植物。

Nitrogen narcosis (or nitrogen euphoria or raptures of the deep):Effects of breathing nitrogen under increased pressure.

氮麻醉：在压力增高的条件下吸入氮气所产生的生理效应。

Nitrogen narcosis (or nitrogen euphoria or rapture s of the deep):Effects of breathing nitrogen under increased pressure.

氮麻醉：在压力增高的条件下吸入氮气所产生的生理效应。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。