Are forests potential landscape barriers for foraging bumblebees? Landscape scale experiments with Bombus terrestris agg. and Bombus pascuorum (Hymenoptera, Apidae)

Habitat fragmentation is generally considered to have detrimental effects on insect movement and associated pollen flow between plant populations. Against this background the role of forests as potential barriers for foraging bumblebees of the species Bombus terrestris agg. and Bombus pascuorum was studied in different experiments. Bombus terrestris agg. workers were found foraging at distances of up to 2.2 km from their nests. B. terrestris agg. as well as B. pascuorum individuals crossed 600 m of forestland between floral mass resources (Phacelia tanacetifolia, Helianthus annuus), although in general a high degree of site fidelity was observed. B. pascuorum workers accepted artificial floral resources within the forest, whereas the minor use of resources below forest canopy observed for B. terrestris agg. possibly indicates a preference for direct forage flights, probably leading above the forest canopy. Our results warn against experiments with genetically modified crop species with potential bumblebee pollination (e.g. Brassica napus), in which an isolating effect of forests is assumed.     

土壤冻结对麦田水分运动的初步研究

观测研究了在初冬冻融过程中麦田土壤水分的变化。结果三次冻融过程中0～20cm耕层土壤不结冻的覆盖处理含水量平均减少2．4％，而冻结的自然状态土壤含水量平均增加0．5％，每次冻结过程土壤含水比不冻结处理平均相对增加2．9％，0～san的表层土壤每次冻结过程土壤含水比不冻结处理平均相对增加2．63％。因此，冬季灌溉不能仅根据干旱天数来决定，分析冬季麦田水分状况，需考虑冻结对水分运动的影响。     

2013年鲁西南地区一次暴雨天气过程分析

利用常规天气图资料、观测资料和NCEP 1°×1°再分析资料对2013年5月25~27日鲁西南暴雨天气过程进行分析,结果表明,强降水发生在高空急流轴右后方低空急流轴的左前方以及江淮气旋顶端;充沛的水汽条件、相对湿度从地面到300 h Pa均达到饱和,低层辐合高层辐散导致强烈的上升运动触发了强降水;高低空急流的耦合和地面气旋配合较好;大气散度、涡度和垂直速度中心与暴雨落区有较好的对应关系;此次暴雨主要是由层状混合性云系造成的。     

论戊戌时期湖南新旧派儒学观的分歧

对待儒学的态度不同,是引发戊戌变法时期湖南新旧之争的重要原因之一。激进维新派为了回应西方文化的侵略,同时也为了宣传变法思想,提出了“保教”的主张,并在恢复真孔教的名义下,对儒学进行了改造,体现出一种保教尊孔的精神。由此引发了青年学子对传统儒学价值的怀疑,造成了儒学信仰危机。保守派坚持对儒学传统的继承,维护儒学的知识体系———经学,体现出一种尊经翼教的思想。新旧两派儒学观的分歧,折射出儒学在近代社会变迁局势下的困境。     

Diel and seasonal utilization of home ranges in a small lake by smallmouth bass (Micropterus dolomieui)

Abstract– Diel and seasonal movements of 9 smallmouth bass were monitored by ultrasonic tracking for 1–1.5 years in a small gravel pit lake in northeastern Illinois. Each fish had several home ranges over the study period. Males established home ranges around a nesting site in May and June. During the summer months, smallmouth bass had diurnal, nocturnal, diurnal and nocturnal home ranges. The fish exhibited 2 types of behavior when they were within their home ranges. They were either motionless, which generally occurred on the nocturnal home ranges, or they swam slowly about their home ranges. Rapid directional swimming movements occurred when fish were swimming across the lake or moving between home ranges. The home ranges were transitory. The average size of the reproductive (male) home range was 0.07 hectare; 0.12 hectare for nocturnal home ranges; 0.18 hectare for diurnal home range; and 0.20 for diurnal-nocturnal home range. Generally, reproductive and nocturnal home ranges were smaller; other types could be as small as these but were often larger. However, there was no significant difference in home range sizes.     

社会主义现实主义经典《创业史》

长期住在农村的柳青亲身经历了合作化运动的过程,深刻认识到农业合作化道路对改变小农经济的历史命运的重要意义。他的《创业史》以非凡的气势、精巧的构思、生动的人物形象回答了中国农村为什么会发生社会主义革命和这次革命是怎样进行的问题,是社会主义现实主义最杰出的典范作品。     

眼动技术在现代家具创新设计中的应用研究

眼动技术在平面设计和心理学研究领域已有广泛的应用,可以进行平面优化设计评估和视觉心理学探究,在家具设计领域应用还比较少见。近几年中国家具企业越来越重视家具的创新性设计,为此以座椅靠背搭脑的造型的评价为例,介绍了眼动技术在家具视觉因素评价方面的应用,并在此基础上探讨了家具创新的新方法和心思路。试验研究表明,注视时间、平均注视时间、注视次数、首视点次数、综合热点图以及注视模式等视觉行为评价指标不仅能够较好地反映家具视觉元素对人体生理、心理的影响,还可以将家具各视觉因素的程度及分布在家具上比较直观地反映出来。     

紫薇花柱运动的观察与研究

花柱运动直接影响着柱头在花中的位置以及柱头和花药之间的相对距离,与植物授粉密切相关。根据紫薇物候现象,分时段拍照观察。研究发现,紫薇的花柱运动具有卷曲性,花柱卷曲发生在中部,分为花柱上举型和花柱下垂型两种类型,且均发生在凌晨5:00左右。花柱运动的深入研究使我们对紫薇花的授粉习性有了更深入地了解,可为紫薇育种提供重要的理论依据。     

滴灌条件下杨树人工林土壤的水分运移

采用田间土壤剖面观测法,对北京永定河故道沙地上地表滴灌栽培的杨树人工林的土壤水分运移规律进行研究,在滴头流量恒定为4 L·h-1的条件下,试验和测定不同滴灌时长和停灌后土壤湿润锋的运移距离和土壤湿润体的形态.结果表明:土壤湿润锋随着滴灌时长的增加在垂直和水平方向上的运移距离逐渐增大,每增加1h滴灌时长,土壤湿润锋的垂直运移距离的增幅逐渐减小,水平运移距离的增幅则大小不一;在各时长滴灌停灌后,土壤湿润锋将继续在垂直方向和水平方向上运移1～3h,在垂直方向上的继续运移距离为2～10 cm,除在土壤最深处的水平继续运移距离明显较大外,在各土壤深处水平方向上的继续运移距离为1 ～ 10 cm;在持续滴灌1～6 h后,土壤湿润锋最终可以垂直运移到36 ～ 69 cm,水平运移到32～57 cm,持续滴灌3～4h后即可在0～40 cm土层内形成以滴头为圆心,半径30～ 40 cm的土壤湿润体;持续滴灌1～3h后土壤湿润体形态为逐渐增大的扁半椭球体,持续滴灌4～6h后土壤湿润体形态为逐渐增大的长半椭球体.     

Movement patterns of Lichia amia (Teleostei: Carangidae): results from a long-term cooperative tagging project in South Africa

Understanding fish movement patterns and migrations is important for fisheries management as well as the identification and conservation of critical habitats. Data collected by the Oceanographic Research Institute's Cooperative Fish Tagging Project (ORI-CFTP) were used to describe the large-scale movement patterns of Lichia amia along the South African coastline. A total of 10 762 L. amia were tagged between 1984 and 2012, of which 744 (7%) were recaptured. Most tagging effort, mainly on juvenile and subadult individuals, took place along the south-eastern (i.e. Eastern Cape) and south-western (i.e. Western Cape) regions of the country during summer. Conversely, more L. amia were tagged and recaptured (mostly adults) during winter and spring (July to November) along the north-east coast (i.e. KwaZulu-Natal). Movements (dispersal distance in kilometres) by juveniles were restricted and largely confined to estuaries within the south-eastern and south-western regions of the country. There was a significant effect of fish size on distance moved (ANOVA: p<0.001), with evidence of a distinct seasonal (winter) longshore migration by adults to KwaZulu-Natal. The consequences of juvenile residency in estuarine habitats and high recapture rate of adults during a directed, seasonal spawning migration are discussed in light of improving current fisheries management.