不同剂型高效氯氟氰菊酯对大型溞的毒性效应

为明确剂型对农药制剂毒性的影响,参照《化学农药环境安全评价试验准则》的方法,测定了高效氯氟氰菊酯乳油、脲醛树脂微胶囊悬浮剂、聚脲微胶囊悬浮剂和水乳剂3种剂型4种制剂对大型溞的急性毒性,并对其体长、摄食等亚急性毒性指标进行了比较.结果表明,加工成不同剂型均会提高药剂的毒性,高效氯氟氰菊酯原药对大型溞的48 h-EC50为2.50×10-3mg·L-1,乳油、脲醛树脂微胶囊悬浮剂、聚脲微胶囊悬浮剂和水乳剂3种剂型的4种制剂的48 h-EC50分别为8.04×10-4、6.25×10-4、1.56×10-3、1.65×10-3mg·L-1,且毒性随暴露时间延长而明显增加.亚急性毒性试验结果显示,当浓度为1.00×10-4mg·L-1时,3种剂型的4种制剂均会对体长、摄食等亚急性指标产生影响,且不同剂型的高效氯氟氰菊酯对大型溞体长的影响强弱顺序为:脲醛树脂微胶囊悬浮剂乳油聚脲微胶囊悬浮剂水乳剂,对摄食的影响为:乳油脲醛树脂微胶囊悬浮剂聚脲微胶囊悬浮剂水乳剂.     

特殊人工环境下电子战装备的防护

简述了烟尘环境、核环境、电磁辐射环境和生化有毒沾染环境等4种特殊人工环境对电子战装备的影响,重点对电子战装备在各种特殊人工环境下的防护措施作了一些探讨。最后指出开展这方面研究的重要性。     

浅谈电子对抗装备的综合标准化问题

由我军电子对抗装备存在的可靠性差,故障率高,维修保障困难,军事经济效益低等问题,引出装备的标准化、模块化、通用化存在着一定的缺陷,阐明了标准化工作对电子对抗装备研制和生产的重要意义,最后提出了综合标准化的理论,并就电子对抗装备的综合标准化提出了几点看法。     

电子战装备在戈壁沙漠地区的防护

首先阐述了装备在戈壁沙漠地区防护的必要性和重要性．然后描述了戈壁沙漠地区的环境特点,并较具体地给出了戈壁沙漠地区的恶劣环境对电子战装备性能造成的不良影响。针对戈壁沙漠地区的恶劣环境对电子战装备造成的不良影响,给出了较具体的防护措施和日常维护的建议。     

复杂电磁环境下电子对抗装备野战化保障探讨

从当前电子对抗装备野战化保障的实际出发,首先简要、定性地分析了电子对抗装备当前所面临的电磁环境,提出了电子对抗部队实现装备保障野战化必须提升野战装备指挥、野战装备维修、野战器材供应及野战装备防护等"四个能力".在此基础上,进一步阐明了电子对抗装备野战化保障需把握的问题.     

Elevated atmospheric CO2 and drought effects on leaf gas exchange properties of barley

Atmospheric CO₂ concentration (C_a) is rising, predicted to cause global warming, and alter precipitation patterns. During 1994, spring barley (Hordeum vulgare L. cv. Alexis) was grown in a strip-split-plot experimental design to determine the effects that the main plot C_a treatments [A: Ambient at 370 μmol (CO₂) mol⁻¹; E: Enriched with free-air CO₂ enrichment (FACE) at ∼550 μmol (CO₂) mol⁻¹] had on several gas exchange properties of fully expanded sunlit primary leaves. The interacting strip-split-plot irrigation treatments were Dry or Wet [50% (D) or 100% (W) replacement of potential evapotranspiration] at ample nitrogen (261 kg N ha⁻¹) and phosphorous (29 kg P ha⁻¹) fertility. Elevated C_a facilitated drought avoidance by reducing stomatal conductance (g_s) by 34% that conserved water and enabled stomata to remain open for a longer period into a drought. This resulted in a 28% reduction in drought-induced midafternoon depression in net assimilation rate (A). Elevated C_a increased A by 37% under Dry and 23% under Wet. Any reduction in A under Wet conditions occurred because of nonstomatal limitations, whereas under Dry it occurred because of stomatal limitations. Elevated C_a increased the diurnal integral of A (A′) that resulted in an increase in the seasonal-long integral of A′ (A″) for barley leaves by 12% (P = 0.14) under both Dry and Wet - 650, 730, 905 and 1020 ± 65 g (C) m⁻² y⁻¹ for AD, ED, AW and EW treatments, respectively. Elevated C_a increased season-long average dry weight (DW_S; crown, shoots) by 14% (P = 0.02), whereas deficit irrigation reduced DW_S by 7% (P = 0.06), although these values may have been affected by a short but severe pea aphid [Acyrthosiphon pisum (Harris)] infestation. Hence, an elevated-C_a-based improvement in gas exchange properties enhanced growth of a barley crop.