层次差异消除法镇定一类非线性组合大系统

引进相似变换，以减少或消除子系统间的层次差异，提出了一层次差异消除准则，进而运用比较原理和矩阵指数性质，建立了非线性关联子系统矩阵特征与系统稳定性之间的关系，将一类具有非线性系统的镇定问题转换成经典的特征值配置问题。本文仅需假定系统的非线性（可能含不确定性）成分具范数界，不必要求其范数满足匹配条件。数值例子表明所出的方法的有效性，并与相关成果进行了比较。     

南昌地区樟树蚧虫种类的考察

南昌地区危害樟树的蚧虫种类经过考察鉴定后,得知有6种,其中以黑蜕白轮蚧,糠片盾蚧分布广、危害烈.为了便于控制,特对其进行空间分布型测定,结果均属聚集分布型,服从于负二项分布.     

Effects of feedbacks and seed rain on ecotone patterns

Ecotones can be abrupt changes in vegetation on gradual abiotic gradients, such as some treelines, and so have been considered as potential indicators of response to climatic change and regulators of fluxes across landscapes. Factors of positive feedback for growth and establishment and seed rain from source areas have been suggested as playing a role in such patterns and dynamics. The effects of variation in feedback strength and seed rain on the abrupt pattern have not, however, been assessed. A spatially explicit computer simulation is used to represent an ecotone as might occur at a mountain treeline. The steepness of the abiotic gradient determines the general location of the treeline, while the strength of feedback determines how abrupt it is. Increased seed rain and seedling survival modify the dominant patterns by creating patches of krummholz or small seedings. The feedbacks are spatially autocorrelated and so create waves of mortality and regeneration on the simulated slopes comparable to dynamics observed on some mountains. These dynamics may mean that the pattern at the ecotone at any point in time is ephemeral and may respond differently to environmental change.     

多级提水过程中PLC对水泵叶片角度的控制

在贮水池的提水过程中，利用PLC自动控制水泵叶片角度的大小，从而自动控制排水量，达到节省人力和电能以及排水稳定的目的。     

Human-mediated vegetation switches as processes in landscape ecology

Switches are processes in which there is positive feedback between vegetation and environment. Landscape features can be created and modified by switches. The concept has previously been used with physical factors and non-human animals as the switch mediator, i.e. the factor which the vegetation modifies and which in turn affects the vegetation. Here, the switch concept is extended to include some types of human behaviour as possible switch mediators. With this extension, the switch concept can explain the impact on the landscape of some types of human behaviour. Examples are given of the behaviour of mower drivers, mowing up to a boundary which they create and/or maintain, and of walkers trampling tracks which they create and/or maintain. Other possibilities are discussed briefly. It is concluded that the concept of a human-mediated switch can unify the study of human behaviour, vegetation processes and landscape ecology.     

旅游活动对森林生态系统结构和功能的负面影响

自1950年代以来，森林旅游业发展迅速，大量的游客涌入森林给森林生态系统带来了巨大的压力和严重影响。从生态系统演替、物种组成、营养结构、物质循环、能量流动、信息传递等方面探讨了旅游活动对森林生态系统的影响，并对减小旅游干扰对森林生态系统的破坏，实现森林生态系统健康、可持续地发展提出了一些建议。     

水帘过滤负压抽风对兔舍小气候和家兔的影响

[目的]探讨水帘过滤负压纵向通风调节室内小气候的可行性,为标准化兔舍设计提供依据。[方法]选用水帘过滤负压抽风兔舍和室内放置轴流通风机兔舍各一栋,在开启有关设备时测定室内温度、湿度、氨气浓度、空气流速的变化,统计对比母兔的繁殖仔兔数、死亡数、投入产出指标。[结果]试验兔舍与对照兔舍的温度差异显著(P<0.05),氨气浓度差异极显著(P<0.01),母兔的繁殖率明显提高,死亡数、单位生产成本明显降低。[结论]水帘降温纵向抽风可以有效控制室内小气候,是一种能兼顾降温与通风且单位生产成本较低的方法,值得在南方兔舍设计中推广。     

乙醇发酵分离耦合过程中负压对酵母代谢的影响

研究了负压对酵母繁殖力、酵母形态、发酵性能、发酵副产物等的影响,结果表明:通过平板和显微镜观察,发现负压对酵母的繁殖力和形态有一定的影响;抽样的最大乙醇浓度、乙醇生产力比对照高;抽压过程中有一部分糖被消耗转化为菌体的维持能;并根据发酵结果,对菌体生长、糖消耗、CO2生成、乙醇生成进行了曲线拟合。     

包头市区冬春季负氧离子浓度变化与气象要素关系初探

文章利用2011年11月至2012年5月包头市逐日负氧离子实况资料,分析了负氧离子冬春季、月和日变化特征及其与相关气象要素的关系。结果表明:包头市负氧离子浓度具有明显的季节、月和日变化,春季负氧离子浓度明显高于冬季,月平均最小浓度值出现在1月,最大浓度值出现在5月,夜间负氧离子浓度高于白天;负氧离子浓度变化与相关气象要素关系密切:月平均浓度与月平均气温、降水量呈正相关。     

分层法在卷烟质量改进方面的应用

运用分层法及直方图对消费者反馈的质量问题进行了统计分析,对卷烟生产企业在寻求质量改进中找到了一些原因和解决方法。结果表明：（1）卷烟品牌的价位影响消费者对卷烟包装质量的关注程度,越是高端品牌,顾客关注度越高,反馈越高;反之,低端品牌顾客质量关注度越低。（2）卷烟质量缺陷主要集中在条装和盒装,可以通过技术手段加大设备投入进行质量控制。