温室黄瓜发育期模拟模型的检验

针对作物生育期研究主要有3种方法:有效积温法、生理发育时间法和正弦指数函数法。试验选取不同温室不同茬口黄瓜的发育期数据和温室环境数据对3种发育期模拟模型方法进行验证。温室黄瓜发育期的预测结果表明,正弦指数函数法预测准确而稳定,回归估计标准误差(RMSE)在0.8~2.4d之间,以每日平均气温和每小时平均气温为输入值的生理发育时间法RMSE值分别在0.8~6.1和0.8~7.0d,有效积温法1.3~6.2d。基于以上验证结果,3种模拟预测发育期方法中,正弦指数函数法表现出较好的预测性和较强的机理性,适用于作物发育期的预测。     

Cultivation Influences on Soil Organic Carbon Associated with Texture in Seasonally Frozen Zones

[Objective] This study aimed to examine indicative roles of texture representing soil organic carbon presence and variability subsequent to cultivation under cold temperate climates with seasonal freeze-thaw events.[Method] Three chronosequences were selected for paired comparisons.Soil samples were collected at six depths with a 10 cm increment.Analysis of variance with general linear model and regression was performed for statistical analysis.[Result] In seasonally frozen soils where fragmentation of macroaggregates was stimulated,soil organic carbon level was positively associated with clay ＋ silt proportion due to a wider textural range,better than sole clay content.Exponential function better fitted the experimental data to present progressively increased effectiveness of clay ＋ silt content in maintaining carbon.Clay content explained 12％-41％ and 14％-43％ of variation via linear and exponential functions,respectively.Accordingly,clay ＋ silt content explained 47％-65％ and 46％-70％.[Conclusion] Texture reflected soil organic carbon occurrence as consequences of reclamation.For seasonally frozen soils with wider textural ranges,it is robust to adapt clay ＋ silt content as dependent variable and exponential function.The generated algorithms provided an available pathway to estimate soil organic carbon losses following cultivation and to evaluate soil fertility.     

枫杨种源苗期生长及生物量地理变异研究

对采自15个省区的55个枫杨种源种子在浙江安吉进行苗期试验。参试种源表现出明显的苗期生长差异，苗高的极差达163％，地径极差达180％，生物量极差达194％。种源苗高生长表现出明显的南－北纬向及垂直变异趋势，枫杨南部分布区及低海拔种源的高生长一般优于北部分布区和高海拔地区的种源。枫杨在长江中下游亚区、江南丘陵及华南亚区、漓江－湘江－洞庭湖水系、贵川陕西部亚区、北部亚区内表现出各自的亚区变异模式。根据苗高、地径及总生物量等主要性状，构建综合选择指数函数I＝0．1167X1（总干质量／g) 0.0750X2(苗高／cm)-0.1231X3(地径／cm)，并评选出6个苗期生长优良的种源，即江西南部的信丰，贵州东北部的思南，陕西中部的汉中，湖南洞庭湖的益阳，重庆的涪陵以及福建东北部的福安种源。     

盘式制动器摩擦特性的指数函数模型

以JF－132型汽车制动器试验台为试验设备，采用试验优化与回归分析技术，研究盘式制动器的准静态摩擦特性，以制动压力与初速度为试验因素，以制动力矩为试验指标，建立了盘式制动器摩擦特性的指数函数模型，并进行了统计检验。     

土壤溶质迁移的指数函数模型

边界层方法是描述土壤溶质迁移的简单方法,通过边界层距离与时间的关系可以估计溶质迁移参数。基于边界层方法,研究了土壤溶质迁移的数学模拟及相应参数估计问题。假定土壤溶质浓度剖面为指数函数,得到了描述溶质浓度分布的指数函数模型。各参数对边界层距离的影响分析表明,应选取较小的孔隙水流速度、短历时推求土壤溶质迁移参数;对不同模型预测土壤溶质分布进行比较,结果表明,在短距离处指数型解与精确解的误差比其它都要小。误差分析表明了指数函数模型的有效性和实用性。     

内蒙古草甸草原生物量碳分配格局

以中国北方草甸草原为研究对象,借助GIS等工具手段,在草地群落类型实测数据基础上,对内蒙古草甸草原的地上/地下生物量分配开展定量研究,主要结论如下:1)内蒙古草甸草原的生物量碳密度为660.43 g C/m²,其中地榆群落(460.63 g C/m²)具有最高的地上生物量碳密度,地榆群落(787.10 g C/m²)和五花草塘群落(776.22 g C/m²)具有最高的地下生物量碳密度,其他群落间则不存在显著性差异(P>0.05);2)温带草甸草原以16.60×10⁶ hm²的面积,贡献了111.20 Tg的生物量碳,其中地上生物量碳为27.57 Tg,地下生物量碳为83.63 Tg,根冠比(R∶S)为3.03;3)地下生物量沿土壤深度的分布可分为两种类型:线叶菊、芨芨草、野大麦、地榆、贝加尔针茅、苔草以及五花草塘群落属于“指数型”,其地下生物量主要分布在0~10 cm土壤层,且符合指数函数,该类型占据草原群落的主要部分;拂子茅、小叶锦鸡儿以及芦苇群落属于“抛物线”形,其地下生物量主要分布在0~10 cm和20~40 cm土壤层,该类别群落主要为灌木或半灌木,分布曲线不符合指数函数而符合二次函数。     

桑天牛有虫株率与平均虫口密度关系的研究

通过对１００块标准地资料的分析研究，得出桑天牛（ＡｐｒｉｏｎａｇｅｒｍａｒｉＨｏｐｅ）有虫株率与平均虫口密度之间关系，可用指数函数描述，从而给调查工作带来极大的方便。     

一族非线性色散偏微分方程的指数函数型和三角函数型精确解指数函数型和三角函数型精确解

利用辅助方程法和指数函数法,研究了由Degasperis,Holm 和Hone3人导出的一族非线性三阶扩散方 程.借助于Maple程序的辅助计算,获得了大量的指数函数型、双曲函数型和三角函数型精确解,这些精确解包 括孤立波解、扭子波解和周期波解,并分析和讨论了几种典型类型的精确解的动力学性质,给出了几种代表性精 确解的波形图.     

A New Function for Modelling Diameter Frequency Distribution in the Tropical Rain Forest of Xishuangbanna, Southwest of China

Permanent plots in the montane tropical rain forests in Xishuangbanna, southwest China, were established, and different empirical models, based on observation data of these plots in 1992, were built to model diameter frequency distributions.The focus of this study is on predicting accuracy of stem number in the larger diameter classes, which is much more important than that of the smallcr trees, from the view of forest management, and must be adequately considered in the modelling and estimate.There exist 3 traditional ways of modelling the diameter frequency distribution: the negative exponential function model, limiting line function model, and Weibull distribution model. In this study, a new model, named as the logarithmic J-shape function, together with the others, was experimented and was found as a more suitable model for modelling works in the tropical forests.     

广义Sierpinski垫上正交指数函数的个数

联系到扩张整矩阵和数字集M=[p1p4p60p2p50 0p3 ]D={[000],[100],[010],[001]的自仿测度μM,D是非谱测度.其中pi∈2Z+1(i=1,2,3);pi∈Z且|pi|>1(i=4,5,6);p2|p4且p3|pi(i=5,6).证明了在L2(μM,D)空间上最多存在4个相互正交的指数函数且4是最好估计.