Non-random nectar unloading interactions between foragers and their receivers in the honeybee hive

Nectar acquisition in the honeybee Apis mellifera is a partitioned task in which foragers gather nectar and bring it to the hive, where nest mates unload via trophallaxis (i.e. mouth-to-mouth transfer) the collected food for further storage. Because forager mates exploit different feeding places simultaneously, this study addresses the question of whether nectar unloading interactions between foragers and hive-bees are established randomly, as it is commonly assumed. Two groups of foragers were trained to exploit a different scented food source for 5 days. We recorded their trophallaxes with hive-mates, marking the latter ones according to the forager group they were unloading. We found non-random probabilities for the occurrence of trophallaxes between experimental foragers and hive-bees, instead, we found that trophallactic interactions were more likely to involve groups of individuals which had formerly interacted orally. We propose that olfactory cues present in the transferred nectar promoted the observed bias, and we discuss this bias in the context of the organization of nectar acquisition: a partitioned task carried out in a decentralized insect society.     

Quantitative structure - activity study on the reductivedehalogenation potency of the halogenated aromatics

Ｑｕａｎｔｉｔａｔｉｖｅｓｔｒｕｃｔｕｒｅ－ａｃｔｉｖｉｔｙｓｔｕｄｙｏｎｔｈｅｒｅｄｕｃｔｉｖｅｄｅｈａｌｏｇｅｎａｔｉｏｎｐｏｔｅｎｃｙｏｆｔｈｅｈａｌｏｇｅｎａｔｅｄａｒｏｍａｔｉｃｓＨｕａｎｇＱｉｎｇｇｕｏ；ＷａｎｇＬｉａｎｓｈｅｎｇ；Ｈａｎ...     

Effect of acid precipitation on leaching of nutritionsand aluminium from forest soils

ＥｆｆｅｃｔｏｆａｃｉｄｐｒｅｃｉｐｉｔａｔｉｏｎｏｎｌｅａｃｈｉｎｇｏｆｎｕｔｒｉｔｉｏｎｓａｎｄａｌｕｍｉｎｉｕｍｆｒｏｍｆｏｒｅｓｔｓｏｉｌｓＤａｉＺｈａｏｈｕａ；ＬｉａｏＢｏｈａｎ；ＷａｎｇＺｈｉｈａｉＷａｎｇＸｉｎｇｊｕｎ；ＬｉｕＹｕｎｘｉ...     

安大略基拉尼公园及实验湖泊区浮游生物群落对酸化的响应及其恢复过程

人们普遍推测控制SO2排放可以促进加拿大、美国和欧洲的酸化淡水湖泊的恢复.本文研究了1998～2000年间靠近安大略省基拉尼公园的22个湖泊(pH值范围4.5～7.7)的浮游生物群落变化,将结果与安大略省西北的实验湖泊区(ELA)人工酸化(pH值从6.7降至4.5)又恢复(pH升至6.0)的南302号湖的数据进行了对比,以评价酸化后的恢复效果.根据历史记录,基拉尼地区数个湖泊的pH值由先前酸化的5.0～5.5反弹到6.0.浮游生物量与pH不相关,但其物种的丰富度与pH值间呈显著相关.将所得到的物种多样性数据与历史数据加以组合,可观察到其中6个湖泊中的恢复轨迹.相关分析表明:pH值得到提高后,其中几个湖泊的浮游生物群落开始向中性环境中的典型群落转化.     

Synthesis and structure-activity relationship of diene modified analogs of<Emphasis Type="Italic"> Matsucoccus</Emphasis> sex pheromones

The biological activity of the Matsucoccus spp. sex pheromones and diene modified analogs has been tested in forests of Israel and Portugal in order to explore the structure-activity relationship of the pine bast scale pheromone/kairomone system. The response of the adult predatory bugs, Elatophilus hebraicus and E. crassicornis and of the brown lacewing, Hemerobius stigma is more selective than that of the conspecific Matsucoccus males. The removal of the terminal methyl group from the diene terminus of both pheromones 1 and 2 eliminates all kairomonal activity but retains moderate pheromonal activity. Addition of a methyl group to the diene terminus of pheromones 1 and 2 sustains full pheromonal and kairomonal activities of the Elatophilus spp. but eliminates entirely the kairomonal activity of H. stigma. Subtle designed alterations in the structure of the diene group, typical of all Matsucoccus pheromones, change the mode of the kairomonal activity markedly.     

环境及环境科学的哲学概观

从哲学层次上考察环境和环境科学有关问题，对环境问题的根本解决与环境科学的发展具有世界观与方法论上的指导意义。环境是一个哲学范畴，是主体活动赖于进行的自然、社会、人文条件的总和。环境哲学承认环境的价值因素，引入环境价值系统，实行自然资源的有偿使用。环境哲学将伦理观引入自然环境之中，倡导人类须规范其行为、尊重自然环境有其存在与发展的权利。环境哲学寻求从根本上解决人类自身发展的道路。     

再论含金硫化物矿物中能否存在负价金问题──答李九玲等同志

本文从讨论金属结合能何以具有表面化学位移的原因开始,从金属团簇的一般性质出发,论证了金属结合能自尺寸大于1nm的团簇到金属微粒再到块体金属具有连续过渡性;金属结合能与粒径R呈正相关;与1／R具线性负相关关系,认为金微粒或团簇具有1．1eV以上的结合能负位移是可能的。并指出李九玲等同志在“评<含金硫化物矿物中不可能存在负价金>”一文中引用的某些衬底材料上的金团簇呈现结合能正位移的数据是由于这些金困簇已与其衬底材料发生了键合作用造成的,它们不能作为否定金属结合能位移与粒径呈正相关的依据。同时,笔者从“化学结合金”在氰化过程中并未被氧化成正离子金判断,它不应是负价金。并由同质并能位移与粒径可具负相关关系推论,“化学结合金”应是合企硫化物矿物中可存在的少量微粒碲金矿、碲金银矿等中的正离子金。笔者强调在讨论企的价态问题时应采用Allred－Rochow电负性数据而非常用的Pauling电负性数据,并再次指出含金硫化物矿物中不可能有负价金存在。     

活性污泥法的多变量最优控制Ⅲ.限制最高和同时限制平均与最高出水BOD浓度

在前文的基础上,进一步研究了更常用的在限制最高和同时限制平均与最高出水有机物浓度两种排放标准的约束条件下,使其运行费用最省的最优周期控制问题.计算结果都表明,最优控制变量QW和DO的变化规律都尽可能使其满足约束条件和节省运行费用,但是,当进水负荷变化幅度非常大时,任何控制也难于使出水水质达标,而运行费用还会大幅度增大.相对而言,同时限制平均与最高出水BOD浓度是更合理的排放标准,它既有利于污水处理厂的运行管理又能有效地保护受纳水体.初始状态S(0)对最优控制的影响不大.而X(0)的影响较大,在本研究中,X(0)的最优值在2400-2600mg/L范围内.