建平县暴雨时空特征分析

利用1953-2013年的逐日降水资料,分析了建平县暴雨的年际变化特征。对该地区产生暴雨的环流形势和天气系统进行了归纳和分析,得出了影响该地区产生暴雨的大尺度环流天气形势,并根据数值预报产品进行物理量诊断分析,从中选取预报因子和预报指标,再结合建平当地特殊地形综合进行分析,最后总结出形成建平气候特点的暴雨预报,为提高当地暴雨天气预报准确率提供了参考。     

平原区浅层水水位预报模型应用成果与讨论

本文从一个水文地质实体模型概念化入手，建立了描述地下水运动的数学模型。计算模型及参数反演模型。介绍了模型应用成果，就地下水水位变化对降雨入渗补给量、潜水蒸发量等潜水垂向水量交替强度的影响进行了探讨，并对地下水数值模型参数确定中校验函数的灵敏度问题作了讨论。     

Effects of feedbacks and seed rain on ecotone patterns

Ecotones can be abrupt changes in vegetation on gradual abiotic gradients, such as some treelines, and so have been considered as potential indicators of response to climatic change and regulators of fluxes across landscapes. Factors of positive feedback for growth and establishment and seed rain from source areas have been suggested as playing a role in such patterns and dynamics. The effects of variation in feedback strength and seed rain on the abrupt pattern have not, however, been assessed. A spatially explicit computer simulation is used to represent an ecotone as might occur at a mountain treeline. The steepness of the abiotic gradient determines the general location of the treeline, while the strength of feedback determines how abrupt it is. Increased seed rain and seedling survival modify the dominant patterns by creating patches of krummholz or small seedings. The feedbacks are spatially autocorrelated and so create waves of mortality and regeneration on the simulated slopes comparable to dynamics observed on some mountains. These dynamics may mean that the pattern at the ecotone at any point in time is ephemeral and may respond differently to environmental change.     

Grain Yield and Drought Resistance Indices of Oat Cultivars in Field Rain Shelter and Laboratory Experiments

Oat cultivars (n = 22) varying in origin were examined in laboratory and field tests at Svalöv and Ultuna, Sweden, in 1985 and 1986. Comparisons were made between drought resistance characteristics of juvenile plants and drought responses in yield of crops grown in field. By using automatic, movable rain shelters in combination with drip irrigation systems, both high and low irrigation regimes could be effected in the field experiments.
Black oat cultivars were more stable under water deficiency conditions, particularly on sandy soil. They possessed the highest drought resistance indices both in the laboratory and field. Modern white oat cultivars were found to be most drought sensitive.
Drought resistance index (DRI) and seminal root length (RL), as assessed in seedling stage, were strongly correlated with field drought susceptibility index (S). It is suggested that DRI and RL could be used as selection criteria to increase drought resistance of oats.     

模拟酸雨对春小麦开花期叶片光合特性及产量的影响

本试验采用pH为1.5、2.5、3.5、4.5和5.6的模拟酸雨在春小麦开花期对其进行喷淋,测定不同pH模拟酸雨处理后春小麦叶片的光合参数与春小麦产量.研究结果表明:随着酸雨pH的下降,春小麦叶片净光合速率下降了24.20％～58.23％,气孔导度下降了35.90％ ～ 58.37％,蒸腾速率下降了36.70％ ～ 56.69％,胞间CO2浓度上升了73.26％～101.06％,叶绿素相对含量下降了1.96％ ～ 15.99％,产量下降了12.54％～32.53％.酸雨对春小麦叶片光合特性的影响随酸雨的氢离子浓度增大而愈显著.酸雨pH与净光合速率、蒸腾速率、气孔导度、叶绿素相对含量及春小麦最终产量均呈极显著正相关,与胞间CO2浓度呈显著负相关.     

酸雨胁迫对木荷和青冈幼苗土壤脲酶活性的影响

[目的]为了对外界因素引起的土壤环境变化提供预警。[方法]以亚热带常绿阔叶林木荷(Schima superb)、青冈(Cyclobalanopsisglauca)幼苗及无植物对照土壤体系为研究对象,研究酸雨胁迫下土壤脲酶活性的动态变化。[结果]在不同酸雨梯度的长期胁迫下,土壤脲酶活性变化有很好的季节性规律,表现为夏季明显高于春季和秋季的特点,且不同季节差异在0.01水平显著。土壤脲酶活性的最大值都出现在2009年8月,最低值出现在2007年春季。在重度酸雨pH 2.5处理下,木荷土壤脲酶活性初期无明显变化规律,后期与CK(pH 5.6)相比无显著差异;青冈土壤脲酶活性变化是促进,无明显变化,试验后期有显著的抑制作用(P0.05);无植物对照开始无明显规律,然后促进,后期显著抑制了土壤脲酶活性(P0.05)。在中度酸雨pH 4.0处理下,试验初期无明显变化规律,后期显著促进了木荷土壤脲酶活性(P0.05),显著抑制青冈土壤脲酶的活性(P0.05),无植物对照土壤脲酶活性仅在酸雨喷淋的第3年夏季有显著抑制作用(P0.05)。[结论]了解酸雨胁迫对土壤酶活性的影响需要对各种生态环境、植被、土壤因子长期的测定。     

2011年秋季连阴雨对周口市作物生长影响及对策

利用周口市夏玉米、大豆、棉花定点观测地段数据,结合大田调查情况,分析2011年9月5～20日周口市连阴雨对该市作物生长的影响情况,并提出生产建议。结果表明,此次连阴雨伴随低温寡照不利天气条件,此时周口市秋作物正处于产量形成的关键时期,秋季连阴雨不利于作物光合作用和灌浆进行,造成玉米出现早衰、百粒重下降、产量下降、收获期推迟,大豆产量稍受影响、发育期推迟,棉花品质较差、产量较低、发育期受影响较小。针对此次过程的影响结合周口市当地的实际,提出相应的对策,以期对以后的秋季连阴雨天气的防范工作有所帮助。     

小麦面团拉伸参数和吹泡参数相关性研究

小麦经粒径分选与比重分选后,不同粒径及不同容重大小的小麦籽粒拉伸参数与吹泡参数存在差异,分析两组参数的相关性,从而揭示针对不同品质等级的小麦,两套评价指标各自的特点及两者存在的深层次联系。研究结果表明:针对拉伸参数,粒径分布在2.2～2.4cm的小麦拉伸面积和拉伸阻力平均值分别为23.7cm2和108.3EU,而到粒径分布在3.0～3.2cm的小麦拉伸面积和拉伸阻力降到13cm2和64.6EU,粒径增大,拉伸面积和拉伸阻力下降;吹泡参数随着粒径的增大其变化规律不明显。2组参数对应容重的变化规律不明显。对2组参数进行相关性分析表明两者的关联度较高,但拉伸参数可以更全面地描述受雨害小麦的加工特性。     

闽东穆阳水蜜桃避雨栽培技术

根据宁德市农业科学研究所对穆阳水蜜桃进行避雨栽培的试验、研究结果,总结以遮盖避雨栽培为主的配套栽培技术。     

呼和浩特市一次久旱转暴雨过程分析

应用常规资料、T639数值预报产品资料和physic实况资料,对2011年8月14日呼和浩特市久旱转雨过程的环流演变及各种物理量场特征进行诊断分析。结果表明:干旱期呼和浩特市上空长期维持稳定的"西高东低"环流型;大尺度环流形势的调整,特别是中纬度环流形势向"东高西低"转变,是久旱转雨的必要条件。进一步分析发现,这次暴雨过程与典型的西太平洋副高西伸北抬,副高外围的西南暖湿气流增强、低空急流、低涡切变和不稳定层结的发展等有关。久旱转雨降水主要产生在低层高能舌、水汽辐合带及低层辐合、高层辐散的上升气流区内。