黄土丘陵区不同立地条件沙棘水分特征与生物量研究

研究了峁顶、阳坡、阴坡三种立地类型条件下的沙棘蒸腾特性，观测了环境因子、沙棘叶的蒸腾速率（Ｔｒ）以及植株生物量，以水分为主分析不同立地条件下沙棘生产力产生差异的生理生态学原因。结果表明：阳坡沙棘总蒸腾量较大，但在黄土高原土壤含水量较低的情况下，沙棘组织失水过多，自身很难维持正常的代谢水平，对生物产量的累积不利；相反阴坡沙棘蒸腾日变化较平缓，组织失水少能维持正常的代谢水平，生物量累积较多

Effect of Anti-oxidation Marttor to Protective Function on Cell Membrane of Seabuckthorn Leaf under PEG Osmotic Stress

以沙棘叶片为材料 ,研究了外源抗氧化物质 Vc、VE、β-胡萝卜素等对 PEG渗透胁迫下细胞膜的保护作用。结果表明 :加入外源 Vc、β-胡萝卜素能有效保护膜系统 ,使膜透性和丙二醛在胁迫条件下增加小于对照 ,尤其在胁迫前期作用明显 ,而对叶绿素的保护作用在后期表现更突出 ,使叶绿素含量维持在较高水平 ;外源 VE 对防止膜透性增加作用不大 ,对减低丙二醛含量与保护叶绿素方面有所贡献。同时也证明沙棘叶片内 Vc在渗透胁迫下含量下降 ,而 Pro含量显著升高。证明这些物质是构成沙棘抗旱性的重要基础

Changes of Endogenous Hormone of Sea buckthorn in Dormancy Stage and Sprout Period under Soil Water Stress and Exogenous GA_3 Regulation

研究了２年生中国沙棘（Ｈｉｐｐｏｐｈａｅ ｒｈａｍｎｏｉｄｓ）在土壤干旱胁迫下苗木含水量、内源激素水平与萌芽率关系以及萌芽关键期喷施外源ＧＡ３的作用。结果表明：土壤干旱胁迫使冬季休眠与春季萌芽期苗木含水量、内源ＧＡ１／３降低，内源ＡＢＡ明显提高，ＧＡ１／３ＡＢＡ下降，达到萌动所需的调控阈值的时间延迟，重度干旱下苗木萌芽延迟约２５ｄ，且萌芽后的枝生长十分缓慢；中度干旱下苗木萌芽延迟１０ｄ，萌芽后生长亦有所抑制。喷施８０ｍｇ／Ｌ外源ＧＡ３溶液可有效提高重度干旱下苗木内源ＧＡ１／３，降低ＡＢＡ含量，使ＧＡ１／３／ＡＢＡ提高，促进苗木提早萌芽及萌芽后生长；在适宜水分及中度干旱下，沙棘苗木外施ＧＡ３对萌芽及其生长作用不明显

Relationships between water and productivity of seabuckthorn (Hippophae) in different habitats of the Loess Plateau, China

对黄土高原丘陵沟壑区不同立地条件下的沙棘生产力与水分关系作了初步研究 .结果表明 ,5种立地条件下的沙棘蒸腾变化趋势不尽相同 .半阴坡清晨蒸腾较强烈 ,其它几种立地蒸腾较弱 .随着太阳辐射角度的变化和不同立地土壤含水量的差异 ,阴坡、阳坡上午蒸腾呈下降趋势 ,峁顶变化较平稳 .至中午12 :0 0半阴坡蒸腾达最大值 .从午后蒸腾趋势可看出 ,除阴坡外 ,其余各立地蒸腾均不同程度地下降 ,尤其半阴坡下降幅度最大 .阳坡蒸腾速率始终处在较低的水平 .沙棘蒸腾大小顺序为半阴坡 >阴坡 >半阳坡 >峁顶 >阳坡 .黄土高原半干旱地区沙棘蒸腾与光照强度没有直接的相关性 ,与相对湿度相关性显著 .不同立地条件导致了沙棘生物量的差异 ,阴坡生物量要显著高于半阴坡、半阳坡和峁

Water relation and growth of seabuckthorn and poplar under different soil water content

在盆栽条件下对杨树、沙棘进行了 3种土壤水分处理 ,研究结果表明 :沙棘的叶含水率在同一土壤水分下比杨树高 ,而水势低 ,说明沙棘叶的抗旱保水能力强于杨树 ;沙棘单叶的光合速率能够长时间维持在较高的水平 ,蒸腾速率却并非如此。杨树无论在生长初期 ,还是生长中期其单叶 WUE均高于沙棘。以新生枝生物量 /耗水总量计算的整体 WUE在 3种土壤水分条件下 ,杨树的 WUE分别是沙棘的 2 .4倍、2 .3倍、2倍 ,其差异达极显著水平 ,但在 3种土壤水分条件下 2个树种都以中度亏缺下的水分利用率最高。整个生长季节处在严重干旱下的杨树和沙棘的生长均受到显著影响 ,沙棘生长受干旱影响程度小于杨树 ,从整个生长趋势上看杨树适宜于良好水分下的生长 ,沙棘在适宜水分和中度亏缺下均可良好生

干旱多风环境下沙棘移栽苗木致死机理与成活率的提高

研究了水分胁迫下沙棘苗木萌芽过程中体内水分状况与ABA累积的关系 ,土壤含水量和风速对沙棘苗木含水量和水势有明显的影响 ,当定植后根系土层的土壤含水量低于 14 .5 % ,风速达到 6m/s,可使苗体含水量占干重比值小于 1.2 ,水势小于 - 2 .5Mpa,芽和韧皮中ABA含量与苗体组织含水量、萌芽率及成活率呈显著负相关 ;在干旱多风条件下苗木成活率显著降低 ,即使少量成活的苗木幼芽生长缓慢。在干旱多风条件下沙棘造林宜采取截干、埋苗造林 ,避免苗木自身过度失水而降低成活率和成活后的生长 ,因此 ,可以显著提高造林成活率

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

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 $p\to \bar\nu K^+$ 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 $p\to \bar\nu K^+$ 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 $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ 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 suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies