基于神经网络的压铸合金选择

在归纳总结压铸合金选择经验和知识的基础上 ,对压铸合金性能进行评价。采用BP神经网络方法建立了快捷的压铸合金材料选择系统 ,提出了一种将模糊化性能要求量化 ,增加训练样本集的方法。     

略论与电除尘器设计有关的几个问题

作者根据多年从事电除尘器工作的经验，提出了在设计、制造和调试中应充分考虑的诸如原始条件、设备参数选择、结构设计等影响电除尘器性能的各种因素，并从理论上进行分析和论证，以期通过讨论寻求最佳的设计方案和实践效果。     

制造抽油机驱动绳工艺探讨

着重介绍了冷挤压技术在制造抽油机驱动绳中的应用方法。同时解决了抽油机驱动绳不能同时受力 ;钢丝绳因加热而产生的局部材料内部组织变化造成驱动绳断裂等关键问题。     

羌塘高原美马错自然保护区的初步评价

拟建的羌塘高原美马错自然保护区是我国青藏高原高寒草原生态系统保存最完好的地区之一,区内含有野牦牛、藏野驴、藏羚等多种珍稀野生动物,其密度之高为西藏所仅见。该地区具有极高的自然保护价值,应作为代表青藏高原高寒草原生态系统的典型地区,列为国家级自然保护区。     

云南金鼎锌业有限公司新建项目选址评价

介绍了云南金鼎锌业有限公司新建项目选址周围地区环境概况和项目排污简况,从规划、对周围环境的影响、卫生防护距离设置、公众参与调查方面分析了选址的可行性,认为该项目选址可行。     

锡林浩特市可持续发展规划

首次提出锡林浩特市应以可持续发展的观点规划设计，这一规划将使使锡林浩特市以可持续方式扩大与发展，并使得位于这一地区的锡林郭勒草原自然保护区受到最小的影响。文中每项设计建议都根据现在的城市规则，经济发展和锡林郭勒自然保护区的关系得来，将对锡林浩特市的未来发展建设起到重要的参考价值。     

四方山、达尔滨湖自然保护区植被及植物区系组成

本文论述了四方山、达尔滨湖自然保护区植被生态条件、植被类型、植物类群组成、生活型组成、水分生态类型及区系地理成分等调查成果。     

西鄂尔多斯国家级自然保护区旅游开发的战略意义及可行性分析

西鄂尔多斯自然保护区是一个以保护古老残遗植物及草原向荒漠过渡的植被带和多样的生态系统为主要对象的综合性自然保护区。受传统资源开发模式的影响，生态环境十分脆弱，保护难度极大。西部大开发为这一区域旅游开发提供了机遇，通过旅游开发，建立新的经济开发模式，促使区域生态环境好转，以促进保护区的建设和发展。本文就该区域旅游开发的战略意义和可行性进行了探讨。     

The superseded female's dilemma: ultimate and proximate factors that influence guarding behaviour of the carpenter bee Xylocopa pubescens

Both solitary and primitively social nests of the facultatively social carpenter bee Xylocopa pubescens can be found throughout most of the breeding season. In social nests there is reproductive division of labour between a dominant forager and a guarding female. Two types of guarding females can be discerned: the young pre-reproductive guards, and older, formerly reproductive guards. The latter type of guard is found when, after a take-over of reproductive dominance either by a nestmate (mostly a daughter) or an intruder, the defeated female stays in the nest instead of leaving to try and found or usurp another nest. She is then manipulated into the role of a guard. The dominant female profits from the presence of the guard since she protects the nest against pollen robbery by conspecifics (Hogendoorn and Velthuis 1993). We have studied why superseded females might prefer to remain as a guard, rather than try their luck somewhere else. The hypotheses investigated pertain to (1) the difficulty for the defeated female of finding a new nest and of restarting reproductive activities due to (a) ecological constraints (nest and pollen shortage) and (b) the effect of age and wear on the defeated female; (2) the effects of guarding in terms of inclusive fitness. We found that superseded females remained as guards significantly more often when a nestmate (not necessarily close kin) took over reproductive dominance than when an intruder did so. Other factors associated with the decision of the defeated female to stay or leave were her age and the number of her own young still present after the supersedure. The probability of finding or constructing a new nest was lower for old than for young females. After finding a nest, old females produced less brood than young foundresses. As a result of these two factors old superseded females gained, in terms of inclusive fitness, by staying as guards, whereas young females profited from leaving the nest. We interpret these results as an indication that guarding behaviour has evolved due to kin selection. However, kin discrimination apparently did not occur. Therefore we conclude that in this species kin selection is not, in the proximate frame of reference, based on kin recognition and preference for helping kin. Correspondence to: K. Hogendoorn     

炼铁厂高炉原料仓料位计的选择与应用

高炉料仓环境条件恶劣，而高炉生产又要掌握料位情况。比较了2种料位计，最终选择了SA—2型料位计。