麦套春棉麦棉共生期水分变化动态研究

１９９２～１９９３年对麦套春棉麦棉共生期水分变化动态进行了研究。两年试验结果表明，４种套种方式共生期田间持水量变化动态均表现为：棉行间＞棉株间＞麦棉行间＞麦行间；在试验范围内麦棉间距≥０３０ｍ时，无论麦收前有无自然降雨，棉行间、棉株间持水量与纯作棉田（ＣＫ）差异不显著，而麦棉行间、麦行间持水量显著低于ＣＫ；３—２式和４—２式用水较为经济；套种田与ＣＫ持水量等同点分布区集中在距小麦边行０３０～０４０ｍ处，各套种方式麦棉间距以０３０ｍ为宜。     

礼貌的顺应性

从语境关系顺应、语言结构顺应、动态顺应、意识程度四个方面对礼貌现象的考察说明礼貌具有顺应性。礼貌的顺应性是指在交际活动中, 处于不同心理状态的交际者根据语境变化选择适宜的礼貌策略来表达自己的思想。忽视礼貌的顺应性是礼貌原则存在不足之处的根本原因。     

浑善达克沙地飞播区不同恢复阶段植物群落结构动态变化

为研究浑善达克沙地飞播区不同恢复阶段植物群落结构动态变化,揭示飞播后浑善达克沙地植被恢复的特点和变化规律,于2013—2017年在浑善达克沙地11个飞播区进行了植被调查试验,并从功能型角度出发,结合对应分析、关联度分析以及Mann-Kendall趋势分析等数据分析方法探讨了飞播区植被恢复的阶段性以及各功能型植物在群落中的地位和作用。结果显示:浑善达克沙地飞播区19 a恢复时间共分为3个恢复阶段,且飞播后,伴随恢复时间的推移,乔木、灌木半灌木、多年生杂类草、一/二年生杂类草、多年生豆科牧草、多年生禾草、一/二年生禾草7个功能型植物间的相互依赖程度逐渐减弱;随着恢复年限的增加,群落的稳定性逐渐增大。不同恢复阶段,植被恢复的主导功能型并不唯一,可在不同阶段进行适时管理,从而使植物群落的演替阶段和整体发展趋势更有利于退化沙地的植被恢复与重建。     

Tumbleweeds in the Western Australian cropping system: seed dispersal characteristics of Salsola australis

Salsola australis, like other agricultural weed species of the Salsola genus, produces a mobile seedbank. Aspects of this mobile seedbank were investigated in three field trials, including total seed production, rate of seed shedding, rate at which seeds lose germinability and the distance and directionality of plant movement. Total seed production was highly variable (ranging from 138 to 7734 seeds per plant), but was directly related to aboveground plant biomass at maturity. Following senescence, mature plants broke free of their root system and the wind driven plants moved considerable distances (1.6–1247.2 m). Half of the mobile plants moved <100 m, as they became entangled with other S. australis plants within the stand. Seed shedding commenced before the plants became mobile and increased with movement, but was also related to the aging and weathering processes experienced by stationary or mobile plants. All plants retained a proportion of their seed in spite of movement, weathering and ageing of the plants, although germinability of retained seed dropped to <2% after 2 months. Salsola australis engages in broad scale seed dispersal similar to that observed in other species of the Salsola genus, allowing this species to maintain a high rate of invasion and range expansion.     

含钛高炉渣水解制取钛白的动力学研究

在实验基础上确立了含钛高炉渣水解制取钛白过程中钛液ＴｉＯＳＯ４浓度随时间的变化关系，经数学分析建立了动力学方程并讨论了方程的适应性。为信水解过程听进一步研究和生产实践提供了数据。     

系统动力学方法在林分断面积生长模型中的应用

由于辽宁东部地区日本落叶松长期处于自然生长状态下,缺乏科学的经营管理,因而年平均生长量较低,亟待进行人为经营,加快其生长,增加后备资源。将系统动力学方法应用于日本落叶松断面积生长研究中,旨在对日本落叶松的生长进行准确的预测,从而为森林经理者合理经营提供理论指导。分别用传统方法和系统动力学的方法对断面积生长进行建模,并进行比较择优,同时用同一地区的30块样地模型进行了精度检验。结果表明,用系统动力学方法来模拟断面积生长规律简便易行,突破了以往传统模型的局限性,同时克服了传统模型繁琐复杂和参数较多的缺点,拟合效果理想。     

西兰花选择性采收作业平台识别切割装置设计与试验

针对当前人工采收西兰花存在季节性劳动力需求强、劳动强度大以及成本高等问题，该研究基于西兰花的农艺特性与形态特征设计了一种西兰花选择性采收作业平台，旨在能够实现对西兰花的自主识别切割作业。首先，该平台采用“识别-采收”一体化作业模式，通过对采收作业平台的关键部件进行设计与选型，建立了西兰花的视觉识别系统和定心切割机构。其次，根据西兰花茎秆与割刀之间的相互作用关系，采用对数螺线作为切割曲线设计了一种等滑切角割刀，确定了割刀滑切角40o、切割半径135 mm、割刀长度260 mm等关键切割参数。根据西兰花茎秆的材料属性参数，基于ANSYS Workbench/LS-DYNA软件对茎秆切割过程进行显式动力学仿真分析，以割刀刃角和转速为控制因子，以最大切割力为试验指标，利用正交试验优化设计，确定了茎秆切割过程的最优参数组合为割刀刃角20°、转速1 rad/s，在此参数下最大切割力为725.82 N，切割质量较优。最后，对采收作业平台进行性能试验，结果表明视觉系统能够有效识别自然环境下的成熟西兰花植株，检测效果良好；定心切割机构可快速平稳的切入并切断西兰花茎秆，切断表面平整光滑；采收作业平台整体漏收率在10%以下、检测准确率为90%、切茎合格率为88.9%，可满足西兰花选择性采收的作业需求。本研究可为西兰花选择性采收作业装备的设计开发提供理论参考和实际借鉴。     

Burial rates of surrogate seeds in arable fields

The probability of seed consumption by surface-dwelling predators depends on the duration of seed exposure on the soil surface. We investigated seed burial using painted ceramic beads as surrogate seeds. Fifty beads of three size classes each were applied to small arenas within crop fields and their fates were followed from August to October. New sets of beads were applied as soon as most beads had disappeared from the soil surface. Bead availability on the soil surface declined immediately after placement, and then declined steadily over time, with increased loss during rain and management practices. Smaller beads were incorporated into the soil/litter matrix more easily than larger beads. Bead burial differed considerably among crop environments, with more burial in forage crops (red clover, lucerne) than in row crops (soyabean, maize). The fact that seed availability differed among crop environments suggests that it can be manipulated to maximise predation risk.     

冬小麦亩产700kg土壤肥力与群体发展动态指标的研究

通过对亩产700kg超高产麦田连续多年多点跟踪调查分析研究,得出了在青岛市气象和生产条件下,实现亩产700kg超高产栽培的土壤肥力指标为有机质1.4%以上,碱解氮90mg/kg以上,速效磷35mg/kg以上,速效钾100mg/kg以上;施肥指标为有机肥3000kg/667m2,纯N 20kg/667m2,P2O510kg/667m2,K2O 10kg/667m2左右。产量构成因素指标为穗数54.2万/667m2,穗粒数35.7粒,千粒重43g;群体动态指标为基本苗13.8×104/667m2,冬前总茎数75.1×104/667m2,春季最大分蘖107.5×104/667m2左右。     

甘蓝大田中降解菌对氯氰菊酯的降解动态研究

在大田甘蓝地中,以从菜园土壤和菠菜叶片分离得到的氯氰菊酯降解菌株T-1和菌株Y-3为研究对象,采用气相色谱法检测,对降解菌降解氯氰菊酯的残留动态进行研究。结果表明:与对照相比,降解菌对氯氰菊酯的降解有促进作用;菌株Y-3和菌株T-1在土壤中对氯氰菊酯的降解动态基本类似,半衰期均为10d;具有内生性的菌株Y-3在甘蓝植株体内对氯氰菊酯降解效果较好,半衰期为7d。