An Ecological Basis for Managing Giant Sequoia Ecosystems

A strategy for management of giant sequoia groves is formulated using a conceptual framework for ecosystem management recently developed by Region Five of the USDA Forest Service. The framework includes physical, biological, and social dimensions. Environmental indicators and reference variability for key ecosystem elements are discussed in this paper. The selected ecosystem elements include: 1) attitudes, beliefs, and values; 2) economics and subsistence; 3) stream channel morphology; 4) sediment; 5) water; 6) fire; 7) organic debris; and 8) vegetation mosaic. Recommendations are made for the attributes of environmental indicators that characterize these elements. These elements and associated indicators will define and control management activities for the protection, preservation, and restoration of national forest giant sequoia ecosystems.     

括苍山地区中生代火山旋回划分

本文通过对区内中生代火山活动具有代表性的一系列火山机构的剖析,在厘定火山地层层序的基础上,根据统一的旋回划分原则,划分出黄坦、山头郑、上张、塘上等四个火山旋回,分析了各火山旋回与区域构造运动的关系,并与前人划分的旋回作了对比。     

Spatial relationships and matrilineal kinship in African savanna elephant (Loxodonta africana) clans

African savanna elephants, Loxodonta africana, live in stable family groups consisting of adult females and their dependent offspring. During the dry season, clans consisting of several family groups typically share a common home range. We compared spatial relationships and mitochondrial DNA (mtDNA) haplotypes among 14 adult female elephants within 3 clans during the dry season in northern Zimbabwe. Spatial relationships were studied by radio-tracking. Home-range similarity was quantified by correlating the estimated utilization distributions of all pairs of elephants. Clans were identified by cluster analysis of the home-range similarity values. All three clans contained at least two of the five mtDNA haplotypes that were found, indicating that clan members are not necessarily matrilineally related. Within clans, home ranges of elephants with the same haplotype were not significantly more similar to each other than those of elephants with different haplotypes. Most elephants within each clan used their shared home ranges independently of each other: the distribution of distances between their positions at any given time did not differ from the distribution expected by chance. However, 8 out of the 26 within-clan pairs exhibited long-term coordination of space use by remaining within known hearing distance of each others low-frequency calls significantly more often than expected by chance. At least four of these coordinated pairs consisted of animals in different family groups. Elephants in three of the four different-family pairs whose movements were coordinated had different haplotypes. Further research is needed to determine the relationship between these coordinated movements and conventionally defined bond-group behavior.Electronic Supplementary Material Supplementary material is available in the online version of this article at .Communicated by C. Nunn     

大型构件试品实施振动试验时的若干问题探讨

大型构件试品振动试验是一项比较复杂的工程试验，它除了同通常振动试验一样进行准备外，由于它的体型大、质量大、重心高且多偏置、振型复杂等特点，还必须进行针对性的试验可行性、试验安全性及振动控制方法的论证和选择，才能使试验顺利进行且万无一失。本文通过作者实践中总结积累的经验，阐述论证的内容和选择的方法，希望起一个抛砖引玉的作用，以期引起试验同行的关注。     

直接空冷技术原理与组成

文章介绍了发展直接空冷系统的意义和必要性,直接空冷系统的工作原理、组成和特点.     

城市污水回用于循环冷却水的探讨

对国内外城市污水回用循环冷却水的实践进行了详述，针对国内城市污水水质，推荐污水水质回用标准，并确立相应的工艺流程，期间还讨论了城市二级处理污水回用时要注意的问题。     

采用先进水处理技术实现污水全面回用

抚顺石化公司洗化厂采用污水深度处理技术和先进的循环水处理技术-AEC及DIANIO（DⅡ），使大量污水作为补水水源，回用于循环水场、卫生冲洗、绿化等中水设施，创造了较好的节水减排效果。     

逆流式冷却塔噪声污染防治

该文介绍了逆流式冷却塔运行原理及噪声扰民治理的实例。并提出相应的措施。     

大型冷却塔噪声综合控制技术

大型冷却塔运行时有其特殊的环境要求 ,噪声治理有一定难度。现以南通某化工企业大型冷却塔噪声治理为例 ,对其位置、结构、机理和特性进行了探讨 ,阐述了一整套实用的控制措施。结果表明 ,方案严密、结构紧凑、造价低、降噪效果明显 ,该技术适用于同类型噪声的治理     

罗茨鼓风机的噪声治理

针对罗茨鼓风机的噪声特性,采用“负压冷却隔声间”隔声,并设计出重型隔声墙板以适应低频隔声的要求。