Variations of specific leaf area and nutrients of Chinese caragana in the Loess Plateau region suffering both wind and water erosions

通过对黄土高原水蚀风蚀交错区主要生长月份柠条锦鸡儿(Caragana korshinlii Kom.)叶片比叶面积(SLA)和矿质元素含量的测定,探讨其对生境条件及生长时间的响应规律,结果表明:不同生境柠条锦鸡儿叶片SLA随生长月份的变化趋势基本一致,但变化差异不显著;不同生境叶片有机碳(C)含量变化差异不显著;叶片全氮(N)含量、全钾(K)含量对生长月份的变化响应明显,变异幅度较大,而随生境条件发生的变异较小;叶片全磷(P)含量在不同生境随着生长月份发生的变异较大。不同生境叶片N/P随月份发生的变异较大、C/P的变异较小;叶片C/N、C/K在不同生境间无明显差异,但均随生长月份而产生较大变化,叶片N、P、K的含量与SLA相关性不明显。所以,生境条件和生长时间是柠条锦鸡儿叶片结构特性和养分组成发生变化的重要原因,其叶片比叶面积与矿质养分含量受外界环境因子和自身发育状况的共同调控

施肥滴灌加速滴头堵塞风险与诱发机制研究

以2 种内镶片式迷宫流道滴头为研究对象，采用数学分析方法、扫描电镜/能谱分析技术( SEM-EDS) 和X 射 线衍射技术( XＲD) 对不同水溶性肥料滴灌后滴头流量、堵塞物表面微形貌及其化学组分进行多角度分析，研究肥 料特性和流道结构对滴头堵塞过程的影响效应。结果表明: 肥料特性是决定堵塞类型和诱发风险的重要因素 ( P ＜ 0. 01) ，流道结构对堵塞的影响需双重考虑结构尺寸及结构类型; 当施肥质量分数小于等于0. 5% 时，施肥加 速滴头堵塞的效果较小且与肥料类型关系不大，当施肥质量分数在0. 5% ～ 2. 0% 之间时，各肥料滴灌适用性由大 到小依次为: 磷肥、尿素、钾肥、复合肥，当施肥质量分数在2. 0% ～ 3. 0% 之间时，尿素滴灌滴头流量降幅为 10. 26%，显著高于施加磷肥( 7. 85%) 、钾肥( 4. 07%) 和复合肥( 2. 74%) ; 施加尿素滴灌诱发滴头堵塞主要物质的 形成机理为分子态尿素析出物与水中悬浮颗粒物形成团聚体在较差流体的运动粘度下造成的物理堵塞，磷肥主要 为吸附作用加速肥料杂质团聚沉淀的物理、化学堵塞，硫酸钾施肥滴灌主要为离子交换形成的钙、镁沉淀导致流道 壁面糙度升高、过水断面减小的化学堵塞过程，复合肥诱发滴头堵塞风险最低。施肥滴灌存在诱发或者加速滴头 堵塞的风险，但不同肥料诱发滴头堵塞主要物质的形成机理不同，加速堵塞的风险也不同，故对于不同的肥料类型 宜采用不同的抗堵塞管理策略。</p

硫酸钾对浑水滴灌滴头堵塞的影响

【Objective】 In order to provide reference for the implementation of water and fertilizer integrated drip irrigation, this study evaluated the effects of potassium sulfate on the clogging of the drip in fertigation with muddy water such as the Yellow River water. 【Method】Three kinds of sediment content（1.0，1.5 and 2.0 g/L） and three kinds of potassium sulfate mass concentration（10，20 and 30 g/L）were arranged. A kind of intermittent irrigation clogging experiment was designed, the changes of average relative flow rate and coefficient of uniformity of the drip were calculated. After that period, the siltation&rsquo;s characteristics and structure of the runner block had been analyzed by field emission scanning electron microscopy. Lastly, the dripper output sediment and deposition sediment were collected and analyzed. 【Result】Adding potassium sulfate into muddy water accelerates the clogging of dripper, and the higher potassium sulfate mass concentration was, the more obvious the effect of accelerating the clogging was. When potassium sulfate mass concentration was 30 g/L, the effective irrigation times of different sediment content, which were 1.0, 1.5 and 2.0 g/L, reduced by 4 times, 9 times and 8 times respectively and the clogging rate increased by 30%&mdash;35%. Potassium sulfate increased the conductivity significantly, the conductivity of muddy water was 0.16 ms.cm-1 when there was no fertilization, and however the conductivity which potassium sulfate mass concentration of 30 g/L was about 25 ms/cm. The potassium sulfate mass concentration has a certain effect on the clogging position of the dripper, which has little effect on the inlet&#39;s clogging and has a great effect on the channel block. The potassium sulfate mass concentration was 10, 20and 30 g/L, and the total number of blocked flow blockage was increased by 7, 18 and 17 respectively than without fertilizer. Potassium sulfate changes the conductivity of irrigation water, affecting sulfate precipitation and resulting in dripper clogging. After the application of potassium sulfate, the sediment in the water is easy to adsorb K+, which increases the agglomeration between the sediment particles, resulting in the increase of the complexity of surface structure of the clogging and the compactness and stability of the clogging material. After applying potassium sulfate in muddy water, the proportion of silt and clay in the output sediment is larger than that in the capillary, and the proportion of sand is less than the deposition sediment in the pipe. The fractal dimension of siltation sediment was negatively correlated with the relative flow rate.【Conclusion】If using the potassium sulfate fertilizer for drip irrigation, people should reduce the potassium sulfate concentration below 10 g/L, in order to slow the dripper clogging.;【目的】分析引黄灌溉过程中肥料硫酸钾对滴头堵塞的影响，为水肥一体化滴灌的实施提供参考。【方法】分别配置了3种含沙量（1.0，1.5和2.0 g/L）和3种硫酸钾质量浓度（10，20和30 g/L）进行间歇灌水堵塞试验，计算滴头的平均相对流量和灌水均匀度，利用场发射扫描电镜分析流道堵塞物结构，收集并分析滴头输出泥沙和毛管淤积泥沙的机械组成。【结果】施加硫酸钾后浑水滴灌滴头堵塞出现加速现象，硫酸钾质量浓度越大，加速堵塞作用越明显。当硫酸钾质量浓度为30 g/L时，含沙量为1.0，1.5和2.0 g/L处理的有效灌水次数分别较未施肥处理减少4，9和8次，滴头堵塞率较未施肥处理增加30%~35%；施加硫酸钾显著增大了水的电导率，未施加硫酸钾的浑水电导率约为0.16 ms/cm，硫酸钾质量浓度为30 g/L时，含钾浑水的电导率为25.19 ms/cm。硫酸钾质量浓度对滴头堵塞的位置有一定影响，对滴头进水口堵塞影响较小，对滴头流道堵塞影响较大,当硫酸钾质量浓度为10，20和30 g/L时，流道堵塞滴头数比未施肥处理分别增加了7、18和17个。硫酸钾改变了灌溉水的电导率，易产生硫酸盐沉淀而造成滴头堵塞。施加硫酸钾肥后，浑水中泥沙颗粒易吸附K+，增加了泥沙颗粒之间的团聚，导致堵塞物表面结构复杂程度提高，堵塞物致密性和稳定性增强；浑水中施加硫酸钾肥后，输出泥沙中粉砂和黏粒比例较毛管淤积泥沙大，砂粒比例则较毛管淤积泥沙少，淤积泥沙的分形维数与平均相对流量呈显著负相关。【结论】选用硫酸钾滴灌时，硫酸钾质量浓度应小于10 g/L，以减缓其对滴头堵塞的影响。</p

在量子分子动力学模型中与N，Z有关的宏观势对碎片形成的影响

基于ＱｕａｎｔｕｍＭｏｌｅｃｕｌａｒＤｙｎａｍｉｃｓ（ＱＭＤ）模型，在Ｓｋｙｒｍｅ类型势，Ｙｕｋａｗａ和库仑相互作用势外，又考虑了与碎片集团的中子、质子数相关的宏观势，即波滴模型中的对称能再加上壳修正能和对修正能．这样的考虑改善了中能重离子反应中集团形成的合理结构。Based on the QMD model, in addition to the Skyrme-type, Yukawa and Coulomb interactions, a macroscopic potential, which is dependent on the neutron andproton number N,Z of the cluster and consists of the symmetrical energy of liquiddrop model and shell and pairing correction energies, has been taken into account.It improved the reasonable structure of the cluster formation in heavy ion reactionswith intermediate energy.中国科学院理论物理学科特别支持费部分资

米非司酮对雄性小鼠繁殖抑制作用研究/Effects of mifepristone (RU-486) on reproductive success in male mice[J]

为确定米非司酮抑制雄性小鼠繁殖的有效剂量及其生理机制,以不同浓度米非司酮油溶液灌胃给药,测定了各组雄性小鼠的体重.器官、精子活力及激素等生理指标和繁殖能力.结果表明:不同剂量米非司酮处理对雄性小鼠体重、睾丸鲜重和附睾鲜重无显著影响,对精子数量和活动性影响主要在高剂量时较强,而随着剂量增加,精子的存活率显著降低且畸形率显著增加；高浓度米非司酮可导致雄鼠血清LH上升和睾酮浓度降低:随米非司酮剂量增加,小鼠繁殖成功率呈下降趋势,且显著减少子代数量,但不影响繁殖个体的胎仔数及幼体存活和发育.米非司酮对雄鼠繁殖具有一定的抑制作用,作用机理在于降低精子存活率和增加畸形率,因此具有鼠类两性不育剂的开发应用潜力

不同剂量米非司酮对雌性小鼠繁殖的影响/Effects of mifepristone at different doses on reproduction of female mice[J]

为确定米非司酮抑制害鼠繁殖的效力及适宜剂量,每2周对雌鼠灌服不同剂量的米非司酮1次,检测给药期间和停药后小鼠繁殖及幼鼠的生长状况.结果发现,给药期间米非司酮抑制小鼠繁殖效果存在一定的量效关系.按体重小于1.25 mg/kg剂量的米非司酮对小鼠繁殖无显著抑制作用；2.5 mg/kg以上剂量能降低小鼠的产仔率；5 mg/kg剂量能显著降低产仔率和胎仔数；10 mg/kg以上剂量能使小鼠完全不育.停药后雌鼠繁殖能力的恢复与之前用药剂量负相关,给药组第一胎平均胎仔数仍显著少于对照组,且第一胎分娩时间也被延迟；至第二胎时平均胎仔数趋于恢复.该结果表明多次给予米非司酮能够有效抑制雌鼠繁殖,停药后仍有一定的持效期,因此具有作为害鼠不育剂的良好潜力

准噶尔盆地南缘水资源合理配置及高效利用技术研究

一、任务来源： 国家科技支撑计划项目“准噶尔盆地南缘水资源合理配置及高效利用技术研究”,课题编号为2007BAC17B02。 二、技术原理及性能指标： 本项目成果主要应用于水资源领域;技术原理为通过对准噶尔盆地南缘水资源总量及变化趋势的研究,分析评价水资源开发潜力;研究准噶尔盆地南缘自然植被和绿洲防护林的生态需水量,对区域自然植被保育和人工植被建植进行水分调控;开发利用区域非常规水资源,提出非常规水资源安全性评价指标,提出非常规水资源高效利用技术规程;确定准噶尔盆地南缘重要区域中天然水循环通量和人工水循环通量的基本比例,对区域水资源进行合理配置,实现水资源开发利用..