春大豆鼓粒至成熟期水分胁迫对结实和产量的影响

揭示春大豆后期干旱对产量形成的影响规律,为开展夏秋干旱评估和抗旱灌溉提供科学依据。于2017年和2018年在吉林省中部开展大豆鼓粒—成熟期农田水分控制试验,设7个土壤水分处理和1个自然雨养处理,观测土壤湿度、结荚率、空秕荚率、百粒重及产量。采用回归方法分析土壤湿度对大豆产量性状的影响。结果表明：在田间持水量以下,大豆粒重和产量与鼓粒—成熟期间耕层土壤水分线性正相关,结荚数和空秕荚率与土壤水分呈二次函数关系。鼓粒—成熟期间0—30 cm土层土壤湿度每下降1个百分点,大豆结荚数和有效荚数分别下降3.1和3.7个百分点,相对百粒重和相对单产分别下降0.8和1.5个百分点,空秕荚率上升9.3个百分点。大豆鼓粒—成熟期比较喜水,但也有较强的耐旱能力,土壤湿度22%—23%之间大豆荚数多、空秕荚少、籽粒重、产量高。大豆鼓粒—成熟期轻旱、中旱、重旱和特旱的土壤相对湿度指标分别为66%—75%、57%—65%、50%—56%和50%以下,对应的减产率分别为5%—10%、11%—15%、16%—20%和20%以上。与以往指标比较,本试验重旱、特旱指标明显大于凋萎湿度,更符合大豆水分生理规律,可用于春大豆鼓粒—成熟期干旱影响定量评估。     

南黄海春秋季大型底栖动物分布现状

根据 2 0 0 0年 1 0月和 2 0 0 1年 3月在 1 2 1°— 1 2 5°E、33°— 36°N海域范围内的 1 7个取样站采集的 482号采泥样品和 5 4 6号拖网样品共计 2 72种动物 ,经实验室鉴定、称重、计数、计算 ,分析研究了南黄海海域大型底栖动物在春季和秋季的分布状况。结果表明 ,在 2 72种大型底栖生物中 ,多毛类 84种 ,软体动物 76种 ,甲壳动物 83种 ,棘皮动物 2 9种。从分析结果看 ,春季和秋季大型底栖生物的栖息密度没有明显的差异 ,而生物量却变化很大 ,秋季的生物量远高于春季。这与底栖生物在春季繁殖 ,多为幼体或低龄个体 ,而秋季基本长大成熟有关。与 1 95 9— 1 960年的全国海洋综合调查对南黄海底栖生物的调查结果比较 ,表明当前该海域大型底栖生物的分布格局和生态学特点没有根本的改变 ,但春季的生物量较 1 95 9年低     

Perennial phenology patterns and ecological traits of Dixidae (Insecta,Diptera) in lotic habitats of a barrage lake system

Dixidae (Insecta, Diptera) are an interesting ecological component in freshwater ecosystems. They are merolimnic insects with larvae and pupae living in aquatic habitats while adults live in terrestrial habitats in close proximity to water. The goals of this study were to determine the phenology patterns of Dixidae and what influences them, to analyse their preference for microhabitats, and to determine the main ecological factors that have an influence on the composition of Dixidae. Adult Dixidae were collected monthly in the period from 2007 to 2008 at 10 sites, from 2009 to 2010 at four sites, and from 2011 to 2014 at three sites in the Plitvice Lakes National Park. Adult specimens were collected using pyramid-type emergence traps. A total of 1271 Dixidae were collected during eight years of study belonging to five species of the genus Dixa. Dixa submaculata was most abundant species at the spring and upper reach of Bijela rijeka Stream and the upper reach of Crna rijeka Stream. Dixa nebulosa was most numerous at the Kozjak-Milanovac tufa barrier site. Dixa puberula was the dominant species at the rest of the sites. Dixa puberula and Dixa submaculata were univoltine, bivoltine or trivoltine, depending on the site, while Dixa nebulosa was only univoltine. The highest diversity was recorded at the tufa barrier Kozjak-Milanovac, and the highest number of species, four species, was found at the upper reach of the Crna rijeka Stream. The greatest number of specimens was recorded at the Labudovac tufa barrier, 128 specimens in 2014. Water temperature is the main ecological factor that influences the phenology of Dixidae at the tufa barriers and lower streams. Discharge affected the abundance of Dixidae. Dixa puberula prefers moss as a substrate and a faster water velocity.     

张家口矾山泉水氡资料变化特征分析

深入研究了矾山泉水氡资料的趋势变化和年变化特征,对水氡与气温的正相关特性进行了分析,并对该泉水氡资料的映震能力作了统计分析。结果表明,矾山泉水氡资料从长期到中短期的异常变化与本区的中强地震活动有较好的对应关系,根据中短期异常可作出6个月以内中等地震发生的概率为68.70%。     

辽宁省春季透雨集合预报误差分析

利用2016—2018年4月1日至6月30日三个全球数值预报业务中心(CMA、ECMWF和NCEP)的24 h降水集合预报资料和辽宁省降水观测资料,采用TS评分、预报偏差B、Talagrand分布以及BS评分等方法对辽宁省春季透雨(4—6月)CMA、ECMWF和NCEP三套全球集合预报结果进行对比分析.结果表明:三个集...     

乌鲁木齐10号泉水汞短临前兆特征探讨

从１０号泉地下水汞的地球化学特性入手,结合近５年来１０次震例,分析并初步总结了地下水水泵的短临前兆特征,水泵的短临异常的出现往往是突发性的;汞异常形态特征基本上具有一定重复性的正异常,仅有个别地震时出现负异常。映震范围;对５级以下地震,水汞异常范围约在６００ｋｍ以内,对５级地上地震,水汞异常范围约在３５０ｋｍ以内;对个别７级以上地震可能映震范围接近１０００ｋｍ。汞异常时间与发震;在前兆近场,往往在     

豫东平原春季干旱对冬小麦产量结构的影响

春季干旱对冬小麦产量结构的影响因干旱出现时段不同而异;在拔节期前出现干旱,对小麦产量结构影响较轻;拔节期以后影响程度最重。采取灌溉、蓄水保墒、选用抗旱小麦良种等技术措施,能有效地预防干旱或减轻干旱造成的损失。     

Vertical distribution of primary producers and zooplankton grazers during different phases of the Arctic spring bloom

During a circumnavigation of the Svalbard archipelago in May 2006, simultaneous marine environmental (meteorology, heat flux, ocean turbulence, irradiance) and biological (phytoplankton and zooplankton biomass/species) data were sampled at selected stations. The zooplankton data were supplemented by high-resolution, high-speed VPR sampling down to 100 m depth at most stations. We were able to sample different phases of the phytoplankton spring bloom in Arctic as well as in Atlantic waters, and the stations represented different situations with respect to irradiance, turbulence and water-column stability. Phytoplankton growth and depth distribution were physically controlled, while zooplankton distributions were affected by biological parameters and turbulence. Development of the zooplankton followed the phytoplankton bloom phase, which was progressing in a direction from west to east in the waters north of Svalbard, and southwards in the Barents Sea. Our results also showed that the zooplankton did not avoid Phaeocystis pouchetii colonies, which have earlier been described as toxic. Despite an early retreat of the ice this year there was no apparent mismatch between the phytoplankton bloom and the dominant mesozooplankton, Calanus spp.     

沈阳桃仙机场春季冷锋型雷暴与冷锋型大风合成对比分析

以1996～2005年逐年沈阳桃仙国际机场春季雷暴的天气演变过程相似资料为依据,采用合成方法,选取4个典型冷锋雷暴个例进行分析。结果表明:蒙古气旋前部的暖平流、大范围正涡度区和正涡度平流导致了我国沈阳地区不稳定层结的建立和加强;高空辐散和低空辐合为雷暴天气的发生和加强创造了动力抬升条件;高空具有高湿位势涡度值的干冷空气叠加在低层扰动上,有利于不稳定层结的加强和降水发生。与相似形势下只产生春季大风而未产生雷暴的4次大风个例天气过程的合成对比分析,结果显示:冷锋的伸展方向及沈阳上空深厚的辐散层和低空湿位势涡度的不同分布可能是产生雷暴和大风不同天气现象的主要成因。     

华南热带气旋特大暴雨的统计特征

根据珠江三角洲１９７６－１９８３年３－５月逐日天气资料和广州０８时探空资料，采用对比度分析方法，研究了本地区春季龙卷发生的环境条件，并与非龙卷局地强风暴发生的环境条件作了比较，结果表明，龙卷发生的有利环境条件对流层深层气层中气压低风速大、层结不稳定、低层高温高湿和中下层位势不稳定，定性上与局地强风暴的条件基本相同，其中对流层深厚气层中更强的强的低压辐合、更不稳定的层结和更大的水平动量是局地强风暴进