11 research outputs found

    Response of Photosynthetic Apparatus to Different Irradiance in Flag Leaves of High-Yielding Winter Wheat PH01-35 Grown under Low Light Conditions

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    为了解弱光下生长的小麦叶片在不同光强下PS II和光合电子传递链的工作状态,解释其突然转入强光下时发生光抑制和光破坏的原因,以PH01-35为材料,采用大田人工遮光的方法,测定了小麦旗叶叶绿素含量、光合特性参数及快速光曲线。弱光处理15 d后,旗叶叶绿素含量明显上升,净光合速率、光补偿点、光饱和点、表观量子效率、羧化效率均出现不同程度的下降。与250μMOl M-2 S-1的弱光适应3 H相比,1 200μMOl M-2 S-1的强光适应3 H后,弱光下生长叶片的快速光曲线初始斜率下降幅度较大,曲线下降部分的斜率、最大相对电子传递速率、半饱和光强的上升幅度均小于自然光下生长的叶片,光能利用能力较低,其非光化学猝灭系数nPQ也明显低于自然光下生长的叶片,为自然光下生长叶片的87.5%。弱光下生长的小麦叶片光能吸收能力增强,但较低的光能利用能力和过剩光能耗散能力是其转入自然强光后易发生光抑制甚至光破坏的主要原因。To further explain the mechanism of photoinhibition and light damage in wheat(Triticum aestivum L.) leaves when it was suddenly transferred from low light to high light conditions,the responses of photosynthetic apparatus in shaded leaves of the high-yielding winter wheat line,PH01-35,were examined using chlorophyll fluorescence and gas exchange techniques.After 15-day shading,the chlorophyll content increased greatly,but the net photosynthetic rate(Pn),light compensation point(LCP),light saturation point(LSP),apparent quantum yield(AQY),and carboxylation efficiency(CE) all decreased.Compared with leaves grown in full sunlight,the initial slope(α),decline slope(β),maximum relative electron transport rate(rETRmax),and minimum saturating irradiance(Ek) of rapid light curves in leaves grown in low light were lower when the plant was transferred from low light intensity of 250 μmol m-2 s-1 to high light intensity of 1 200 μmol m-2 s-1.Non photochemical quenching(NPQ) in leaves grown in low light was significantly lower than that in leaves grown in full sunlight,indicating that the ability of light use and thermal energy dissipation was limited in leaves grown in low light.The wheat leaves grown in low light were more suscepti-ble to photoinhibition due to low CO2 assimilation and photoprotective ability,such as xanthophylls cycle-dependent dissipation of excessive energy,despite the better energy absorbability in low light conditions.山东省农业良种工程重大课题(鲁农良种字[2006]6号)资

    北山造山带公婆泉岩浆弧的组成、时代及其大地构造意义

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    反应条件对Ni-Mo/TiO_2-Al_2O_3催化剂上噻吩加氢脱硫的影响

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    采用溶胶-凝胶技术,从Al2O3载体的表面改性出发,制备了TiO2-Al2O3复合载体,用此改性载体制备了NiMo/TiO2-Al2O3催化剂;在中压固定床微反装置上考察了反应条件对噻吩加氢脱硫活性的影响。结果表明,在反应温度260~270℃、氢分压3.0MPa、空速3.0~5.0h^-1及氢油体积比480~550条件下,噻吩的转化率可达100%

    杆状病毒表达EV71病毒样颗粒的装配、制备纯化与鉴定

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    将EV71P1和3CD基因片段克隆入同一杆状病毒穿梭质粒Bacmid中,构建出重组杆状病毒表达质粒Bac-mid-P1-3CD;脂质体介导其转染Sf9昆虫细胞获得共表达P1和3CD的重组杆状病毒(AcMNPV-P1-3CD)。用IFA和Western-blot法对表达产物进行鉴定和分析。电镜结果显示P1经3CD切割装配成了大小约为27nm的类球形颗粒(即EV71VLPs)。进一步分析影响杆状病毒表达系统的因素以对表达条件进行优化,结果显示MOI值和时间均可影响目的蛋白的表达,其中时间是主要因素。选择优化后条件利用无血清培养基对贴壁Sf9细胞在多层细胞培养器中进行VLPs的大量表达,密度梯度离心法纯化,SDS-PAGE结果可见三条大小约为39kD、34kD和26kD的VP1、VP0和VP3特异性条带。纯化后EV71VLPs颗粒结构完好,为下一步EV71蛋白结构的基础研究和基因工程疫苗的研究奠定了基础

    反应条件对Ni-Mo/TiO_2-Al_2O_3催化剂上噻吩加氢脱硫的影响

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    采用溶胶-凝胶技术,从Al2O3载体的表面改性出发,制备了TiO2-Al2O3复合载体,用此改性载体制备了NiMo/TiO2-Al2O3催化剂;在中压固定床微反装置上考察了反应条件对噻吩加氢脱硫活性的影响。结果表明,在反应温度260~270℃、氢分压3.0MPa、空速3.0~5.0h^-1及氢油体积比480~550条件下,噻吩的转化率可达100%

    新疆塔里木盆地北部碳酸盐岩欠平衡钻井技术研究

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    该课题根据碳酸盐岩储层的特点,提出了欠平衡钻井设备配置方案并进行了实施;建立了欠平衡钻井参数计算机数学模型,确定了塔北碳酸盐岩储层欠平衡钻井参数控制范围,研究了欠平衡压力与立管压力、排量之间的关系;制定了塔北碳酸盐岩储层欠平衡钻井施工方案,形成了现场操作的压井方法和井控技术;研制出低胶聚黄钻井液和无固相盐水聚合物钻井液两套适合塔北地区碳酸盐岩特征的欠平衡钻井液体系。在发现产层、保护油气层、解决严重井漏等工程复杂问题和提高机械钻速方面取得显著效果。该课题圆满完成了“九五”国家科技攻关计划规定的研究任务,成规压力碳酸盐岩储层欠平衡钻井达到国内领先水平

    JUNO Sensitivity on Proton Decay pνˉK+p\to \bar\nu K^+ Searches

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    The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in pνˉK+p\to \bar\nu K^+ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via pνˉK+p\to \bar\nu K^+ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is 9.6×10339.6 \times 10^{33} years, competitive with the current best limits on the proton lifetime in this channel

    JUNO sensitivity on proton decay pνK+p → νK^{+} searches

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