JT6120乘客座椅靠背曲线静态舒适性评价研究

The aim of this research was to evaluate a passenger seat of a new type bus in terms of eomfort. A fuzzy set model of multistage comfort scale (MCS) was adopted to the assessment of comfort, together with the techniques of human backshape and EMG measures     

海南椴生长特性及苗木培育的初步研究

本文论述了海南椴幼年期生长特性，年生长节律，苗期生长规律以及苗木繁育技术。用ｌｏｇｌｓｔｉｃ方程拟合，找出高和直径生长的最优回归方程。     

龙井市农村经济灰色关联度分析

利用灰色系统理论中灰色关联度分析的方法，龙井市近几年来农村经济分3个层次进行了系统、全面的分析。     

BR农用荧光灯补光育苗的研究

对黄瓜、番茄在育苗前期进行短时间的人工补光有明显促进生长的效果。农用荧光灯(BR)的补光效果优于日光型荧光灯(W)。早春育苗进行人工补光的时间以下午自然光照强度稍高于光补偿点、叶片气孔尚未关闭之前为好,呼和浩特、包头3月份16:00、4月份17:00开始补光为宜。补光的光强度在500～800lx 效果明显。光源距幼苗的距离以10cm 为宜。     

Fractal dimension estimates of a fragmented landscape: sources of variability

Although often seen as a scale-independent measure, we show that the fractal dimension of the forest cover of the Cazaville Region changes with spatial scale. Sources of variability in the estimation of fractal dimensions are multiple. First, the measured phenomenon does not always show the properties of a pure fractal for all scales, but rather exhibits local self-similarity within certain scale ranges. Moreover, some sampling components such as area of sampling unit, the use of a transect in the estimation of the variability of a plane, the location, and the orientation of a transect all affect, to different degrees, the estimation of the fractal dimension. This paper assesses the relative importance of these components in the estimation of the fractal dimension of the spatial distribution of woodlots in a fragmented landscape. Results show that different sources of variability should be considered when comparing fractal dimensions from different studies or regions.     

Effects of changing spatial scale on acoustic observations of patchiness in the Gulf Stream

We examine the influence of spatial scale on studies of nektonic patchiness at the north edge of the Gulf Stream by altering the grain size of acoustic cross sections and applying a patch-finding algorithm. From original pictures of 180 pixels deep by 540–1260 pixels long, we averaged depth and length, to give 9 scales ranging from fine grain (1 m vertical × 25 m horizontal sized pixels) to coarse grain (12 m × 300 m sized pixels). Measures of overall echo intensity within patches were the most predictable and showed little change with scale. Measures of variability of the echo within patches showed simple negative trends with scale and were best measured at fine spatial scales. Patch size and shape related variables have a more complex relationship with scale with differences between day and night transects more pronounced at intermediate scales. This suggests behavioral patch forming mechanisms within the nekton occur at a specific grain size (4 m vertical × 100 m horizontal) within the Gulf Stream front.     

基于不同尺度的干旱区城市景观生态研究--以陕西榆林市为例

从区域与城市两个尺度水平 ,对毛乌素沙漠南缘的榆林市城市景观进行研究认为 :在大尺度水平上 ,区域景观生态特征对城市景观特征具有一定的控制作用 ,而城市景观强大的功能流对区域景观产生干扰作用。城市景观的空间扩展与演化 ,既受区域景观特征的影响 ,也是区域景观演化的一个有机构成部分 ;在小尺度空间上 ,景观功能区、景观斑块与廊道的格局与功能 ,对城市景观格局动态以及维持城市景观多样的生态功能具有重要意义。在不同的利益追求下形成的景观文化 ,将深刻地影响到区域与城市景观演化的方向与过程。     

乡村生态学研究的尺度与等级特征

乡村生态学 ( Village ecology)的尺度和等级特征依赖一定空间区域 ,不同尺度所研究村落的特征也不尽相同 ,空间尺度的大小很大程度上决定于所研究村落的复杂性、稳定性及特征。在特定的空间尺度下 ,乡村的组成要素随着时间尺度的变化而变化 ,但变化速率受空间尺度大小的制约。乡村生态学研究具有等级结构 ,空间尺度决定所研究单元的等级位置。行政村 (中心村 )和自然村 (自然屯 )是乡村生态学研究的基本尺度     

Spatio-temporal modelling of broad scale heterogeneity in soil moisture content: a basis for an ecologically meaningful classification of soil landscapes

We describe the classification of landscapes characterised bymineral soil using a model that calculates soil moisture availability on amonthly basis. Scotland is used as a case study area. The model uses potentialsoil moisture deficit, estimated using broad scale (40 × 40 km)climate patterns, in conjunction with meteorological station measurements toobtain finer scale values of climatic soil moisture deficit. Point estimates ofsoil available water are obtained for soil characteristics using appropriatepedotransfer functions, and geostatistical techniques are used to upscale theresults and interpolate to a 1-km grid. Known heterogeneityin soil physical characteristics is used to provide local corrections to thepotential soil moisture deficit, estimated using the climatic variables above.Temporal profiles of monthly water content are modelled for each1-km location and classified into six classes usingunsupervised cluster analysis. The spatial distribution of these classesreflects regional variations in the availability of moisture and energy, onwhich finer-grained topographic patterns are superimposed. In the case study,the broad scale spatial heterogeneity of heathlands and grasslands on mineralsoils in Scotland is shown to be strongly related to the soil moistureclassification. The results can be used in studies investigating the patternsofdistribution of communities at the landscape and regional scale.This revised version was published online in May 2005 with corrections to the Cover Date.     

农村肉狗绿色养殖模式刍议

近年来，农村肉狗养殖成为农民增收致富新的亮点，但也存在着一些误区。本文就农村肉狗养殖现状，分析了存在的主要问题，并提出绿色养殖肉狗的建议与对策。