中草药大黄小波变换的近红外光谱聚类分析

采用小波变换技术对近红外光谱压缩,减少训练时间,并以聚类法定性,以鉴别不同产地的大黄(Rheum palmatum L.).该方法可有效鉴别不同产地的大黄,与传统鉴别结果基本一致.结果表明,近红外漫反射光谱法作为一种快速简便的分析技术,可用于大黄等中草药的质量控制,为大黄的生药鉴定提供参考.     

在社会经济与森林资源因子约束下的我国林业区划研究——基于Kohonen网络聚类

在林业区划理论的指导下，根据林业统计年鉴公布的2009年的相关数据，本文选取社会经济因子与森林资源因子两方面的相关指标进行基于Kohone网络的聚类分析，以探究我国各地区林业产出与森林资源现状及两者之间的相关性。在社会经济与森林资源因子约束下，将全国区划为资源最充沛——林业较发达地区，资源较充沛——林业最发达地区，资源最匮乏——林业发展一般地区和资源较匮乏——林业欠发达地区四个区域。经过分析发现，产值最高的区域其资源不一定是最充沛的，相反，资源最匮乏的区域产值也不一定是最低的，两者之间没有绝对的正相关关系。     

参数可变自适应遗传算法在军事地形图矢量化中的应用

针对纸制军事地图矢量化问题进行研究，提出一种基于自适应遗传算法的军事地形图矢量化方法，并在生成新的个体后，增加个体修正操作，提高个体的适应度。在该算法中，提出一种即考虑进化代数对算法的影响，又考虑到每代不同个体适应度作用的自适应交叉概率和变异概率。通过与传统方法的实验比较，证明该方法的可用性和有效性。     

数字存储示波器特性及其应用

数字存储示波器是采用数字电路进行模/数转换，并通过存储器实现对触发前信号的记忆功能的一种具备存储功能新型示波器；此文尝试在分析数字存储示波器的原理和特性的基础上，对其在工程应用中应注意的问题进行分析。     

甜菜地下害虫抽样调查方法

综述了甜菜地下害虫抽样调查方法。     

Transect relascope sampling for assessing coarse woody debris: The case of a π/2 relascope angle

In transect relascope sampling, a wide‐angle relascope is used along survey lines for selecting a sample of objects that extend linearly in the plane, e.g. downed logs. The method is closely related to line intersect (intercept) sampling. In this article, a special case of the transect relascope technique is studied. Using a π/2 radian relascope angle, the method becomes invariant to the orientation of the line objects in the population. The reason is that the area of inclusion around objects, through which a survey line should pass for an object to be included, turns out to be circular. In analytical studies and Monte Carlo simulations, the cost‐efficiency of transect relascope and line intersect sampling is evaluated. It is found that transect relascope sampling is a competitive alternative to line intersect sampling in inventories of the total volume of coarse woody debris (in the form of downed logs) in forest compartments.     

Needle Collection Time for Nutrient Evaluation in Christmas Tree Production

Christmas tree needle sampling to evaluate nutrient need is an established practice. Data to support the recommended fall sampling time in Oregon and Washington were not found. In addition, the recommendation for needle sampling of Fraser fir in North Carolina was made without data from winter months. The goal for this article is to affirm or modify recommended needle sampling time. Needles of Douglas fir, Turkish fir, Nordmann fir, Noble fir, Grand fir, and Fraser fir Christmas trees were collected monthly for a year, dried, and analyzed for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and boron (B). No single period was found for any species when needle nutrient concentration was stable for all elements determined. Needle collection time was chosen by integrating cultural practices, likelihood of nutrient deficiency, and needle nutrient concentration changes for species grown in an area. Needle collection is recommended during February in western Oregon and Washington. The current sampling time, fall, is logical for Fraser fir Christmas tree production in North Carolina.     

Potential of weed seedbanks for managing weeds: a review of recent New Zealand research

Weed seedbanks are the primary source of weeds in cultivated soils. Some knowledge of the weed seedbank may therefore be appropriate for integrated weed management programs. It would also be very useful in planning herbicide programs and reducing the total herbicide use. However, a number of problems are inherent in the estimation of the seedbank size for arable weeds that usually have annual life cycles. In a long-term research project we have investigated the dynamics of weed seedbanks in corn fields for the past 8 years. Specific studies have included (i) developing cheap and efficient methods for estimating the weed seedbank; (ii) developing guidelines for efficient soil sampling (including the number and size of samples); (iii) influence of cultivation methods on weed seed distribution; (iv) mapping the spatial variability of the seedbank; (v) estimating the rate of seedbank decline for certain weed species; and (vi) assessing the potential of using the weed seed content in the soil to predict future weed problems. This paper reviews and summarizes the results of our research on the above aspects. The strong correlation between seedlings emerged in the greenhouse and seeds extracted in the laboratory for the most abundant weed species has demonstrated the potential for using the weed seed content of the soil to predict future weed infestations. The next step is to establish correlations with field emergence under commercial conditions using the sampling guidelines developed in our studies. Subsequently, we aim to offer the weed seedbank estimation as a commercial service to farmers for planning the most appropriate weed management options.     

新疆哈纳斯自然保护区地衣群落的聚类分析

我们根据多年的实地调查结果并采用聚类分析方法对分布在哈纳斯国家级自然保护区的地衣群落进行了研究。结果表明分布在该地区的地衣种类有 10 3种 ,他们分别属于 2 0科 ,4 0属。地衣物种形成了 6种群落。同时发现该地区地衣对基物形成专一性 ,它们的基物包括 :树皮、藓丛、藓土、草地、石面、地面、土层、石浮土等。     

小麦禾缢管蚜种群动态的研究

本文采用平均密度（X），聚块性指标（m/m）和有蚜株率（F）对小麦禾缢管蚜种群动态进行模糊聚类分析。找出了其种群消长的4个时期：点片发生期，始盛期，猖獗期和衰退期；防治重点应在始盛期，即瓢虫卵期，以达到经济有效，充分保护利用天敌的目的。