查询词典 nitrogen cycle

It is conducive to uptake soil nitrogen for flue-tobacco on dryland soil with maize-tobacco rotation before topping (60 days after transplanting) and uptake soil nitrogen for flue-tobacco on paddy soil with rice-tobacco rotation after topping.2 The nitrogen utilization efficiency of rapeseed cake, rice straw and rape straw were 19.5%, 15.5%, 8.1% respectively, and the inorganic fertilizer nitrogen utilization efficiency were 41.1%, 42.7% and 35.7% under the combined application of organic additives and inorganic nitrogen fertilizer. The contribution rate of rapeseed cake, rice straw, rape straw to accumulated nitrogen of flue-cured tobacco were 1.0%, 2.4%, 2.7% respectively by the combined application of organic additives and nitrogen fertilizer. Flue-cured tobacco for organic nitrogen absorption meet with the nitrogen needs laws of high-quality tobacco, indicating that the combined application organic additives and inorganic nitrogen fertilizer reduces the nicotine content of tobacco, an increase of sugar/nicotine ratio and improved the quality of tobacco. In which the role of rice and rape straw is greater than the rapeseed cake can be used as measures to lower nicotine.3 Nitrogen accumulation in flue-cured tobacco with the total nitrogen input was a significant positive correlation during the growth stage of flue-cured tobacco. The total nitrogen input for the 156.3-405.5kg.hm-2, in which the soil nitrogen mineralization capacity account for 22.6%-54.3%, with an average of 34.5%, that is, soil nitrogen mineralization accounted for 1/3 of the total nitrogen input.

旱地轮作土壤有利于烤烟生长前期对土壤氮素的吸收，水旱轮作土壤增加了烤烟生长后期对土壤氮的吸收。2在有机添加物与无机氮肥配施条件下，烤烟对有机添加物中氮的吸收规律基本符合优质烟的需氮规律，其中烤烟对菜籽饼肥、稻草秸秆、油菜秸秆所含氮素的利用率分别为19.5%、15.5%、8.1%，所配施无机氮肥的利用率分别为41.1%、42.7%和35.7%，菜籽饼肥、稻草秸秆、油菜秸秆对烤烟氮素累积量的贡献分别为1.0%、2.4%、2.7%。3不同轮作方式及添加有机物条件下氮素平衡结果显示，烤烟生长期间的氮输入总量为156.3-405.5kg.hm-2，其中矿化氮量为输入总氮量的22.6%-54.3%，平均为34.5%，约为输入总氮量的1/3；肥料氮的利用率为31.4%-42.7%；植烟土壤氮素表观损失率在37.5%-57.2%，平均为46.9%，约为输入总氮量的一半。

The results show that though the strain is growing slower in the nitrogen-free medium than in the nitrogen-containing medium, the content of capsular polysaccharides produced by the strain in the nitrogen-free medium is higher than those in the nitrogen-containing medium, the content of capsular polysaccharides produced by the strain in the nitrogen-free medium is higher than those in the nitrogen-containing medium. The capsular polysaccharides produced by the strain in the culture which contains different mineral powders will reach the highest content on the third or the fourth day in its growing period. The strain's capability of releasing potassium from k-feldspar and biotite in the nitrogen-containing medium is higher than that in the nitrogen-free medium because in the nitrogen-free medium, the strain and its production of glucoprotein are less than those in the nitrogen-containing medium.

结果表明，尽管该菌在无氮培养条件下的菌体数量远小于有氮培养条件，但无氮培养条件下所提取的细菌多糖多于在有氮条件下培养所提取的细菌多糖；胶质芽孢杆菌在以添加钾长石粉或黑云母粉制作的无氮培养基中生长可形成大量多糖，采用丙酮法进行细菌培养液多糖提取，发现细菌培养的第3天所提多糖含量最高；胶质芽孢杆菌在以添加钾长石粉或黑云母粉制作的有氮培养基中生长亦可形成较多的多糖，且在细菌培养的第4天所提多糖含量最高；胶质芽孢杆菌在有氮条件下对含钾矿物的释钾率高于在无氮条件下的释钾率，这可能与该菌在有氮条件下生长更快、可产生较多菌体细胞有关。

Because of nitrogen, the value of IAA/ABA、GA3/ABA、(IAA+GA3+ZR)/ABA in grain promoted at seed filling stage and at the mature stage.6、The adjustment of nitrogen levels on carbon and nitrogen metabolism.Nitrogen reduced the C/N in leaves and stem. When the nitrogen rate was 50 kg/hm2, the effect on stem was obvious. When the nitrogen rate was 100 kg/hm2, the effect on leaves was obvious. The C/N in roots lower before seed filling stage and the effect was not obvious after seed filling stage.7、Effect of nitrogen levels on yield traitsPlant height, pods per plant and full grain number were increased and bottom-pod height and podded node were decreased by applying nitrogen.

施氮在鼓粒期、成熟期均提高了子粒中IAA/ABA、GA3/ABA、(IAA+GA3+ZR)/ABA的值。6、氮素水平对大豆碳氮代谢的调节施氮降低了叶片和茎秆中C/N的比值，施氮量为50 kg/hm2时，对茎秆作用效果明显，施氮量为100 kg/hm2时，对叶片效果明显；施氮降低了根系鼓粒期前的C/N比值，而鼓粒期后作用效果不明显。7、氮素水平对产量性状的影响施氮增加了大豆的株高、株荚数、饱满粒数，降低大豆的结荚高度、结荚结位。

The results showed that the grain yield of winter wheat with two-irrigation was higher than that with one-irrigation with the same nitrogen application rate and method. Compared to one-irrigation,the grain number per spike in two-irrigation was higher,the 1000-grain weight was lower, the water wastage was higher, but the WUE was lower. The yield was not affected significantly by nitrogen rates and the methods. Within the nitrogen rate of 157.5-295.5kg/hm2, the lower NUPE and Nitrogen Productivity declined with nitrogen rate increasing. NHI was not lower than the others at the lowest nitrogen rate of 157.5kg/hm2. The accumulation of NO3--N in soil was significantly and positively correlated with the nitrogen application rate. NO3--N in one-irrigation was distributed mainly in the top layer (0-80cm), but it was inverse in two-irrigation.

结果表明，施氮量和施氮方式相同时春浇二水冬小麦的产量高于春浇一水，二水穗粒数较一水高，千粒重则低于一水，一水耗水量较少，水分利用效率明显高于二水；同一水分下不同施肥量及施肥方式对产量的影响差异不显著，同一施肥方式下在157.5-295.5kg/hm2范围内，施肥量越大，氮素生理效率和氮肥生产力越低，施氮157.5kg/hm2时，氮收获指数均处在最高或较高水平；土壤硝态氮残留量与施氮量呈显著正相关，成熟期一水条件下土壤中硝态氮主要集中在上层(0~80cm)，二水条件下则主要分布在中下层。

The critical nitrogen content in heading period was used to calculate the biggest accumulation quantity of nitrogen. The latent distribution index of leaf and stem, which was the variety heredity parameter, were used to distinguish the difference in nitrogen assignment in different varieties. The dynamic content of the nitrogen accumulation before anthesis could be described with a Richards model. The dynamic content of the nitrogen remobilization in leaf with leaf area index could be described with a power model, and the nitrogen absorption of grain from soil with dry weight could be described with a power model. The dynamic content of nitrogen density in stem and spike with physiological development time could be described with a nonlinear model.

模型利用抽穗期植株临界含氮量来表达氮素最大积累量，引入叶片潜在分配指数和茎鞘潜在分配指数2个品种遗传参数来区别不同品种在器官间的氮素分配差异，采用Richards方程来描述大麦花前氮素积累动态变化；采用指数函数方程来描述叶片氮的转移量随叶面积指数的动态变化以及籽粒从土壤中吸收的氮量随干物重的动态变化；采用非线性函数方程描述茎鞘和穗部的氮浓度随生理发育时间的动态变化。

The result showed there existed significant differences among families in seedling growth, dry matter accumulation, leaf shape as well as root parameters at high and low nitrogen levels. Remarkable reduction in seedling height, dry matter accumulation, leaf and root parameters were observed under low nitrogen stress, whereas larger proportion of photosynthesis production was allocated into roots to promote nitrogen absorption. Family variation in seeding growth, leaf and root parameters were increased under low nitrogen stress in comparison with high nitrogen level, which would be benefit to discriminate superior L. chinense families with high nitrogen efficiency. Nitrogen efficiency of different L.

结果表明：不同氮素水平下，马褂木苗的生长、干物质积累、叶片和根系等性状皆存在显著的家系遗传差异；低氮胁迫将显著抑制马褂木苗叶片发育和根系生长，影响苗高生长和干物质积累，但低氮素水平下生产的光合产物则较多地分配至地下根系部分以促进对氮素的吸收利用；与高氮处理比较，低氮胁迫加大了苗木生长、叶片和根系参数等家系遗传分化，有利于鉴别高氮效率的马褂木优良家系。

The effects and mechanism of GABAergic neurons, NOergic neurons, opioid peptide and cyclic adenosine monophosphate in the nucleus reticularis thalami on sleep-wakefulness cycle of rats and the effects and mechanism of the 5-HTergic nerve fibers project from the nucleus raphes dorsalis to RT on sleep-wakefulness cycle of rats were investigated with the methods of brain stereotaxic, nucleus spile, microinjection and polysomngraphy.1. The effects of GABAergic neurons in RT on sleep-wakefulness cycle of rats1.1 Microinjection of 3-mercaptopropionic acid (3-MP, a kind of glutamate decarboxylase inhibitor) into RT. On the day of microinjection, sleep only decreased a litter. On the second day, sleep marked decreased and wakefulness marked increased. On the third and fourth day, sleep and wakefulness stages resumed to normal.1.2 Microinjection of gamma-amino butyric acid (GABA 1.0μg) into RT enhanced sleep and reduced wakefulness compared with control; while microinjection of L-glutamate (L-Glu, 0.2μg) decreased sleep and increased wakefulness; microinjection of bicuculline (BIC, 1.0μg), a GABAA receptor antagonist, enhanced wakefulness and reduced sleep; microinjection of baclofen (BAC, 1.0μg), GABAB receptor agonist, had the same effects as GABA.2. The effects of NOergic neurons in RT on sleep-wakefulness cycle of rats2.1 Microinjection of L-arginine (L-Arg, 0.5μg) into RT decreased sleep compared with control, but there were on statistaical difference between L-Arg group and control; while microinjection of sodium nitroprusside (SNP, 0.2μg), a NO donor into RT, sleep marked decreased and wakefulness marked increased. Microinjection of nitric oxide synthase inhibitor, N-nitro-L-arginine (L-NNA, 2.0μg) into RT enhanced sleep and reduced wakefulness.2.2 After simultaneous microinjection of L-NNA (2.0μg) and SNP (0.2μg) into RT, SNP abolished the sleep-promoting effect of L-NNA compared with L-NNA group; after simultaneous microinjection of L-NNA (2.0μg) and L-Arg(0.5μg) into RT, we found that L-NNA could not blocked the wakefulness-promoting effect of L-Arg.3. The effects of opioid peptide in RT on sleep-wakefulness cycle of rats3.1 Microinjection of morphine sulfate (MOR, 1.0μg) into RT increased wakefulness and decreased sleep compared with control; while microinjection of naloxone hydrochloride (NAL, 1.0μg), the antagonist of opiate receptors, into RT, enhanced sleep and reduced wakefulness.3.2 After simultaneous microinjection of MOR (1.0μg) and NAL (1.0μg) into RT, the wakefulness-promoting effect of MOR and the sleep-promoting effect of NAL were not observed compared with control.4. The effects of cAMP in RT on sleep-wakefulness cycle of rats Microinjection of cAMP (1.0μg) into RT increased sleep and decreased wakefulness compared with control; microinjection of methylene blue (MB,1.0μg) into RT enhanced sleep and reduced wakefulness compared with control.5. The effects of the 5-HTergic nerve fibers project from DRN to RT on sleep-wakefulness cycle of rats5.1 When L-Glu (0.2μg) was microinjected into DRN and normal sodium (NS,1.0μg) was microinjected into bilateral RT. We found that sleep was decreased and wakefulness was increased compared with control; when L-Glu (0.2μg) was microinjected into DRN and methysergide (MS,1.0μg), a non-selective 5-HT antagonist, was microinjected into bilateral RT, We found that sleep was enhanced and wakefulness was reduced compared with L-Glu group.5.2 When p-chlorophenylalanine (PCPA, 10μg) was microinjected into DRN and NS (1.0μg) was microinjected into bilateral RT, We found that sleep was increased and wakefulness was decreased compared with control; microinjection of 5-hydroxytryptaphan (5-HTP, 1.0μg), which can convert to 5-HT by the enzyme tryptophane hydroxylase and enhance 5-HT into bilateral RT, could block the effect of microinjection of PCPA into DRN on sleep-wakefulness cycle.

本研究采用脑立体定位、核团插管、微量注射、多导睡眠描记等方法，研究丘脑网状核(nucleus reticularis thalami，RT)中γ-氨基丁酸(gamma-amino butyric acid ，GABA)能神经元、一氧化氮(nitrogen monoxidum，NO)能神经元、阿片肽类神经递质、环一磷酸腺苷(cyclic adenosine monophosphate，cAMP)及中缝背核(nucleus raphes dorsalis，DRN)至RT的5-羟色胺(5-hydroxytryptamine，5-HT)能神经纤维投射对大鼠睡眠-觉醒周期的影响及其作用机制。1 RT内GABA能神经元对大鼠睡眠-觉醒周期的影响1.1大鼠RT内微量注射GABA合成关键酶抑制剂3-巯基丙酸(3-MP，5μg)，注射当天睡眠时间略有减少，第二日睡眠时间显著减少，觉醒时间明显增多，第三、四日睡眠和觉醒时间逐渐恢复至正常。1.2大鼠RT内微量注射GABA受体激动剂GABA( 1.0μg)后，与生理盐水组比较，睡眠时间增加，觉醒时间减少；而RT内微量注射L-谷氨酸(glutamic acid， L-Glu， 0.2μg)后，睡眠时间减少，觉醒时间增加；RT内微量注射GABAA受体阻断剂荷包牡丹碱(bicuculline，BIC，1.0μg)后，睡眠时间减少，觉醒时间增加；RT内微量注射GABAB受体激动剂氯苯氨丁酸(baclofen，BAC，1.0μg)后，产生了与GABA相似的促睡眠效果。2 RT内NO能神经元对大鼠睡眠-觉醒周期的影响2.1大鼠RT内微量注射NO的前体L-精氨酸(L-Arg，0.5μg)后，与生理盐水组对比，睡眠时间略有减少，但无显著性意义；而RT内微量注射NO的供体硝普钠(Sodium Nitroprusside，SNP，0.2μg)后可明显增加觉醒时间，缩短睡眠时间；微量注射一氧化氮合酶抑制剂L-硝基精氨酸(L-arginine，L-NNA，2.0μg)后，引起睡眠时间增多，觉醒时间减少。2.2大鼠RT内同时微量注射L-NNA(2.0μg)和SNP(0.2μg)后与L-NNA组比较发现SNP逆转了L-NNA的促睡眠作用；RT内同时微量注射L-NNA(2.0μg)和L-Arg(0.5μg)后，与L-NNA(2.0μg)组比较发现L-Arg可以增加觉醒而缩短睡眠，其促觉醒作用未能被NOS的抑制剂L-NNA所逆转。3 RT内阿片肽对大鼠睡眠-觉醒周期的影响3.1大鼠RT内微量注射硫酸吗啡(morphine sulfate，MOR，1.0μg)后与生理盐水组对比，睡眠时间减少而觉醒时间增加； RT内微量注射阿片肽受体拮抗剂盐酸纳洛酮(naloxone hydrochloride，NAL，1.0μg)后与生理盐水组比较，睡眠时间增加而觉醒时间减少。3.2大鼠RT内同时微量注射MOR(1.0μg)和NAL(1.0μg)后，与生理盐水组对比，原有的MOR促觉醒效果和NAL的促睡眠效果都没有表现。4 RT内环一磷酸腺苷信使对大鼠睡眠-觉醒周期的影响大鼠RT内微量注射cAMP(1.0μg)后与NS(1.0μg)组比较，睡眠时间增多而觉醒时间减少；RT内微量注射亚甲蓝(methylene blue，MB，1.0μg)后，与NS组比较，睡眠时间增多而觉醒时间减少。5中缝背核投射到丘脑网状核的5-羟色胺能神经纤维对大鼠睡眠-觉醒周期的影响5.1大鼠DRN内微量注射L-Glu(0.2μg)，同时在双侧RT内微量注射NS (1.0μg)后，与对照组(DRN和双侧RT注射NS， 0.2μg)比较，睡眠时间减少，觉醒时间增多；大鼠DRN内微量注射L-Glu(0.2μg)，同时在双侧RT内微量注射二甲基麦角新碱(methysergide， MS， 1.0μg )后，与对照组(DRN注射L-Glu 0.2μg，双侧RT注射NS 1.0μg)比较，睡眠时间增多，觉醒时间减少。5.2大鼠DRN内微量注射对氯苯丙氨酸(p-chlorophenylalanine，PCPA，10μg)，同时在双侧RT内微量注射NS (1.0μg)后，与对照组(DRN和双侧RT注射NS， 1.0μg)比较，睡眠时间增多，觉醒时间减少；大鼠DRN内微量注射PCPA(10μg)，产生睡眠增多效应后，在双侧RT内微量注射5-羟色胺酸(5-hydroxytryptaphan ， 5-HTP， 1.0μg )后，与对照组(DRN注射PCPA 10μg，双侧RT注射NS 1.0μg)比较，睡眠时间减少，觉醒时间增多。

All the results indicated that Brazilian sugarcane also had a nitrogen-fixing capacity in Guangxi, Mo was propitious to regulate nitrogenase activity of nitrogen-fixing bacteria in sugarcane under nitrogenous conditions, and promoted nitrogen fixing; while under non nitrogenous conditions, it was unpropitious to regulate the nitrogen activity and inhibited nitrogen fixation of nitrogen-fixing bacteria.

上述结果说明：巴西甘蔗在本地也具有一定的固氮能力；在不缺氮条件下，钼处理较利于调节甘蔗体内固氮菌的固氮酶活性，促进其固氮；而在缺氮条件下，钼处理不利于调节甘蔗体内固氮菌的固氮酶活性，抑制其固氮作用。

Our work reported here are aiming at improving nitrogen and water use efficiency in wheat/maize, faba bean/maize, pea/maize and soybean/maize intercropping through field experiment.The main results obtained were as the following:(1) Land equivalent ratio was greater than 1.0 for faba bean (Viciafaba L.)/maize (Zea mays L.) intercropping regardless of nitrogen fertilizer application or not. Based on grain yields production, LER of pea (Pisum sativum L.)/maize intercropping was over 1.0 in spite of nitrogen fertilizer application, while LER was higher than 1.0 only when nitrogen fertilizer was applied based on biomass production. However, LER in soybean (Glycine max L.)/maize intercropping was smaller than 1.0 both nitrogen applicationa and no nitrogen application. In wheat Triticum aestivum L.

本文通过田间试验，对小麦／玉米、蚕豆／玉米、大豆／玉米和豌豆／玉米间作种植下作物对氮素和水分利用的影响进行了系统比较，获得的主要结果如下：(1)蚕豆／玉米间作的土地当量比都大于1；豌豆／玉米间作以籽粒产量为基础的LER无论施氮还是不施氮都大于1，而以生物学产量为基础的LER只有施用氮肥时才大于1；大豆／玉米间作无论施氮还是不施氮LER均小于1。

Four nitrogen addition treatments i.e, null nitrogen level, low nitrogen level (LN, 50 kg N hm-2 a-1), moderate nitrogen level (MN,100 kg N hm-2 a-1) and high nitrogen level (HN, 150 kg N hm-2 a-1), were established in the forest. All nitrogen treatments were carried out in triplicates.

通过原位进行低氮(LN， 50 kg N· hm-2· a-1)、中氮(MN， 100 kg N· hm-2· a-1)和高氮(HN， 150 kg N· hm-2· a-1)处理，研究了川南天然常绿阔叶林土壤酶活性特征及其对模拟N沉降的响应。

Must have Coordination and negotiation skill, flexible ideas, and be punctilious person.

必须具备较好的协调与谈判能力，头脑灵活，工作认真仔细

Result: 18 patients are all with simple eye.The pigment mole lies in nasal and temple sides of the ball conjunctiva,in which 2 lie in lacrimal caruncle and semilunar plica.

结果：18例患者均为单眼，色素痣大多数位于内外侧睑裂部球结膜面，2例位于泪阜及半月皱襞，经激光治疗后，10例色素痣消失，有5例行再次激光后消失，2例行第三次激光后消失，1例第四次激光后消失。