Effects of Enhanced UV-B Radiation on N2O Emission in a Soil-Winter Wheat System     

Zhenghua Hu  Jingyan Jiang  Shutao Chen  Qiaohui Liu  Chuanpo Niu 《Water, air, and soil pollution》2010,213(1-4):493-499

An outdoor pot experiments was conducted to investigate the effects of enhanced ultraviolet-B (UV-B) radiation on nitrous oxide (N₂O) emissions from soil-winter wheat systems. The enhanced UV-B radiation treatments were simulated by 20% increase in its intensity. N₂O fluxes were measured with a static opaque chamber-gas chromatograph method. The results showed that enhanced UV-B radiation did not change the seasonal patterns of N₂O emissions. Compared to the controls, the enhanced UV-B radiation reduced N₂O fluxes by 16.4% (p?=?0.015) during the elongation-booting stage, while it had no significant effects on N₂O fluxes in the turning-green and heading-maturity phases. During the turning green-overall heading span, the accumulative N₂O was largely decreased by the enhanced UV-B radiation (p?<?0.05). From the overall heading to maturity, however, the effects of enhanced UV-B on N₂O emissions were not pronounced (p?>?0.10). At the elongation-booting stage, enhanced UV-B increased soluble proteins content in leaves, NO ₃ ^- -N and NO ₄ ⁺ -N content in rhizosphere soil, and soil microbial biomass C (C _mic) and N (N _mic; p?<?0.05), as well as microbial biomass C:N ratio changing from 5.0 to 6.8. Our findings suggest that the effects of enhanced UV-B radiation on N₂O emissions differed with winter wheat developmental stages. To assess the overall effects of enhanced UV-B radiation on N₂O emissions from agroecosystems, nevertheless, more field measurements deserve to be carried out in various cropping systems.  相似文献   

Flow injection chemiluminescence determination of sudan I in hot chilli sauce     

Liu Y  Song Z  Dong F  Zhang L 《Journal of agricultural and food chemistry》2007,55(3):614-617

A chemiluminescence method based on the luminol-H2O2 system with flow injection technology was proposed for the determination of sudan I in hot chilli sauce. It was found that sudan I could enhance chemiluminescence intensity generated from the luminol-H2O2 system. The increment of chemiluminescence intensity was proportional to the concentration of sudan I, giving a calibration graph linear over the concentration from 10 pg mL-1 to 7 ng mL-1 (R 2 = 0.9980) with the detection limit of 3 pg mL-1 (3sigma) and the quantification limit of 7.5 pg mL-1. At a flow rate of 2.0 mL min-1, one analysis cycle, including sampling and washing, could be accomplished in 60 s with a relative standard deviation of <5.0%. The method has been applied successfully to the determination of sudan I in Pixian douban, Golden Mark guilin chilli sauce, and Golden Mark satay sauce, and the recovery was 90.6-110.0%.  相似文献   

谈公路沥青混凝土摊铺的自动找平     

张正华  王锡殿  李立昌 《森林工程》2001,17(2):41-43

本谈了沥青混凝土摊铺自动找平控制各环节的数学模型，并利用计算机语言对其进行了仿真和绘制了图形，同时讨论了个别控制参数对其摊铺的影响，这为选择合理的控制参数提供理论依据。  相似文献   

猪胚胎移植中同期发情母猪的内分泌研究     

蔡正华  冯书堂  陶涛    吴兰欣  刘殿魁 《黑龙江动物繁殖》1996,(2)

〗本研究选用猪胚胎移植的３头供体母猪，依次用前列腺素（ＰＧ），孕马血清促性腺激素（ＰＭＳＧ）和人绒毛膜促性腺激素（ＨＣＧ）作同期发情和超数排卵处理，于处理第１１天做剖腹手术采集胚胎，在整个处理过程中多次采血，监测了血清中孕酮（Ｐ４），雌二醇（Ｅ２），促黄体素（ＬＨ）和硫酸雌酮（Ｅ１Ｓ）四种激素浓度的变化，并据此来讨论同期发情和超数排卵处理成功和失败的原因。  相似文献   

pBⅠ121载体酶切位点添加及拟南芥Na~+/H~+逆向转运蛋白基因表达载体的构建     

张俊莲  王蒂  张金文  陈正华 《分子植物育种》2006,(6)

对pBI121载体GUS基因后的终止子序列(SacⅠ-EcoRⅠ)通过PCR扩增法进行了酶切位点的添加,即在SacⅠ后添加了XhoⅠ、在EcoRⅠ前添加了KpnⅠ。序列分析发现,两个酶切位点的添加是成功的,但扩增的终止子序列与原序列的同源性间有差异,即有4个碱基发生了变异,特别是第17个碱基位点出现了缺失。利用绿色荧光蛋白(GFP)对添加酶切位点载体进行了终止子活性的检测,结果发现,它与携带GFP的pBI121载体一样,GFP基因能正常表达,说明pBI121载体终止子序列酶切位点的添加是成功的。利用改造后的载体(pBI121-GZ)构建了CaMV35S启动子驱动AtNHX1基因的植物表达载体。  相似文献   

棉花群体干物质生产与分配的数学模型研究   总被引：6，自引：0，他引：6  

赵中华  刘德章 《棉花学报》1997,(1)

在１９９１～１９９３年棉花高产优质与生态环境因子关系研究的基础上，利用作物生长模拟分析的方法和大量试验资料及相关的气象资料，建立了棉花群体干物质生产与分配的数学模型。该模型包括：叶面积动态，光合生产，干物质积累和分配子模型。所建模型经检验，具有较好的模拟性能，可用于指导棉花生产。  相似文献   

枫泾和长白母猪对初情期前注射黄体素释放激素类似物(LRH-A_2)的反应     

王瑞祥  蔡正华  焦淑贤  赵尚吉  廖述人 《畜牧兽医学报》1991,(2)

进行两个试验,研究了初情期前不同日龄的枫泾和长白母猪LRH-A_2诱导的LH水平和不同剂量的LRH-A_2对LH水平的影响。结果表明,77日龄枫泾猪,85和202日龄长白猪在诱导前血清中LH含量分别为1.70±0.17、0.74±0.10和1.40±0.14ng/ml,前二者和后二者间的差异极为明显(P<0.001)。除枫泾猪的5μg和10μg剂量外,其余各剂量在注射5分钟后血清中LH含量均显著高于注射前的LH值(P<0.005～0.001)。枫泾猪诱导的LH峰值与LRH-A_2的剂量无关,而长白猪的峰值出现时间和峰值高低均因剂量而异。诱导的LH值随初情期前的小母猪日龄而变化。枫泾猪和长白猪诱导的LH峰值出现的日龄分别为30和60天,峰值分别为5.55±0.63和16.14±2.74ng/ml,差异极明显(P<0.005)。枫泾猪在30～60和75～90日龄时诱导的LH值分别显著低于长白猪在60和95日龄的诱导值,但接近初情期时,两猪种间的差异则变得不明显。可结论如下:甾体激素的负反馈机制,枫泾和长白猪分别在30和60日龄开始建立,并在初情期时达到完善。  相似文献   

快冷多元准晶形成条件的研究     

肖觉民  吴力军 《湖南农业大学学报(自然科学版)》1993,20(4)

  相似文献   

五针松组起源中国     

彭镇华 《安徽农业大学学报》1999,26(1):1-8

中国植物种质资源丰富,是世界许多物种起源中心。据五针松组树脂道分析,认为华山松为五针松２６个树种原始种,故五针权组起源中心。五针松组亲缘关系与地缘关系高度一致性,证明泛大陆时亚洲东侧与北美侧是联成一体,并非是其东西外侧。美国西部竞有８个同一树脂道类型五针松树种,表明其西海岸外曾有岛屿,是基因隔离的结果。  相似文献   

玉米杂交种蜡熟后籽粒自然脱水速率差异分析   总被引：10，自引：1，他引：10  

金益  王振华 《东北农业大学学报》1997,28(1):29-32

分析了黑龙江省主栽的８个玉米杂交种蜡熟后１０ｄ内籽粒在田间自然条件下脱水干燥的速率。结果以东农２４９最快，达１．１１７％／ｄ，合玉１５和四单１９最慢，分别为０．４２３％／ｄ和０．５７０％／ｄ。影响蜡熟后籽粒脱水快慢的既有外部气象原因，也有杂交种本身的原因，如籽粒类型、苞叶长短和松紧等。  相似文献