公路网狭义总容量理论及模型

提出了一个关于计算公路公路网规划狭义总容量的理论及其应用模式，它是交通工程学中关于路段和交叉口通行能力的概念在公路网上的推广与延伸。将交通量划分为区域内部流量和外部流量，并分别给予计算，最后，还对本理论的应用前景进行了初探。     

多熟制春玉米两段覆膜种植的生产潜力及高产技术优化研究

根据农业系统工程原理 ,运用采用 D-饱和最优回归设计方法 ,研究了长江下游沿江稻田生态条件下春玉米两段覆膜这一新型种植方式的生产潜力和技术优化问题 ,建立了产量函数数学模型。结果表明 :春玉米两段覆膜种植方式综合技术措施下的最大生产潜力 ;Ymax=62 6.0 8kg/ 667m2 ;产量 5 5 0 kg/ 667m2 以上的农艺组合为 :每 667m2 的种植密度 5 2 78～ 5 991株 ,氮肥施用量 (纯 N) 2 88.6～ 3 5 2 .3 5 kg·hm- 2 ,乙烯利的化控浓度 (3 0 4.6～ 498.0 )× 1 0 - 6 ;对其产量影响的程度依次为种植密度 >氮肥 >化控。     

Uncertainty in simulated nitrate leaching due to uncertainty in input data. A case study

Abstract. Deterministic leaching models are used to estimate regional losses of nitrate from agricultural land to the environment. The estimated leaching losses are associated with uncertainty arising from uncertainty in the input data used. In the present case study we have assessed this uncertainty by use of Monte Carlo analysis, using the Latin hypercube sampling technique. Input data have preferably been adopted from publicly available data. Data which could not be retrieved from the databases was assessed by guided estimates or based on local data. The estimated annual leaching loss from the study region was around 106 kg N ha⁻¹, which is in agreement with previous findings. The uncertainty in the leaching expressed in terms of coefficients of variation (CV) depended on the agricultural practices. CV's for arable farm rotations, cattle farm rotations, and pig farm rotations were around 20, 30 and 40%, respectively. Breakdown of the total uncertainty into contributions of different error sources did not isolate one single all important source.     

Prediction of spatial soil property information from ancillary sensor data using ordinary linear regression: Model derivations, residual assumptions and model validation tests

Geospatial measurements of ancillary sensor data, such as bulk soil electrical conductivity or remotely sensed imagery data, are commonly used to characterize spatial variation in soil or crop properties. Geostatistical techniques like kriging with external drift or regression kriging are often used to calibrate geospatial sensor data to specific soil or crop properties. More traditional statistical methods such as ordinary linear regression models are also commonly used. Unfortunately, some soil scientists see these as competing and unrelated modeling approaches and are unaware of their relationship. In this article we review the connection between the ordinary linear regression model and the more comprehensive geostatistical mixed linear model and describe when and under what conditions ordinary linear regression models represent valid spatial prediction models. The formulas for the ordinary linear regression model parameter estimates and best linear unbiased predictions are derived from the geostatistical mixed linear model under two different residual error assumptions; i.e., strictly uncorrelated (SU) residuals and effectively uncorrelated (EU) residuals. The theoretically optimal (best linear unbiased) and computable (linear unbiased) predictions and variance estimates derived under the EU error assumption are examined in detail. Statistical tests for detecting spatial correlation in LR model residuals are also reviewed, in addition to three LR model validation tests derived from classical linear modeling theory. Two case studies are presented that highlight and demonstrate the various parameter estimation, response variable prediction and model validation techniques discussed in this article.     

济南市城市居住区外部环境空间的评价

选取尽可能全面且有代表性的指标，构建评价体系，选择各时期品质较高或获奖的济南市的18个居住小区进行实地调查问卷，然后利用层次分析法确定出各指标的权重，最后应用模糊数学方法进行评价．结果表明：所选取的18个居住区的外部空间处于一般水平；外部空间环境总体布局构成、室外场所空间的设置和各类景素小空间的构建等3个一级指标评价处于一般水平；整个济南市居住区外部环境空间是属于较差或者很差的状况．     

胶凝原油管道再启动研究进展

介绍了国内外学者对胶凝原油管道再启动问题的认识,指出了现有启动模型的不足,认为通过试验的方式研究胶凝原油停输再启动的问题,可以为输油管道设计过程中管材的选择、管道允许停输时间的确定和最小启动压力的预测提供科学依据.     

数字图书馆建设及其运行模式研究

本文简要讨论了数字图书馆信息资源采集、加工、整合、存储、发布和开发利用系统等的主要内容框架.根据国内外数字图书馆研究现状,论述了不同数字图书馆的建设模式、发展特点及其主要功能.     

模糊数学法在甘蔗制糖行业清洁生产评价中的应用

将模糊数学法的基本理论和方法运用到甘蔗制糖行业清洁生产评价当中,结果表明：运用模糊综合评判法对清洁生产水平进行评价是一种比较科学的方法,能够将评价中各种影响因素共存的复杂性简要化,一定程度上削减主观偏好对评价结果的影响,有效克服单指标方法的片面性.该评价方法可操作性较强,准确性较高,对甘蔗制糖行业清洁生产评价有一定的指导和参考作用.     

花生冠层APAR和FAPAR高光谱遥感估测模型研究

为了快速、无损监测花生生长发育，建立整个生育期内花生冠层吸收性光合有效辐射（APAR）和光合有 效辐射吸收系数（FAPAR）的高光谱遥感估测模型，本试验利用高光谱遥感技术，测定沈阳地区5种不同生态类型的 花生冠层光谱数据，同期获取APAR、FAPAR；并对原始光谱数据进行logρ、1/ρ、ρ′变换，构建6种植被指数，分别与 APAR和FAPAR进行Pearson相关分析，并建立估测模型，对模型进行检验与评价。研究结果表明：4种变换形式的 光谱数据中最优波段与APAR 和FAPAR 均达极显著相关（r≥0.3969，P<0.01），以ρ′在759nm 波段处与APAR（r= 0.7574）和FAPAR（r=0.6276）的相关性最好，ρ′759nm处的高光谱参数与APAR、FAPAR建立的估测方程y = 797.3846 e271.4883x（R=0.5512，P<0.01；RE=0.1213）和y =0.756e85.21x（R=0.4204，P<0.01，RE=0.0788）拟合系数最高、预测精度较 好，估测效果很好。比值植被指数（RVI）、差值植被指数（DVI）、归一化植被指数（NDVI）、复归一化差值植被指数 （RDVI）、垂直植被指数（PVI）和修改土壤调整植被指数（MSAVI）这6种植被指数的最优波段与APAR的相关性优 于与FAPAR的相关性，MSAVI[723,761]与APAR所建立的对数函数y = 1554ln（x）+ 1631（R=0.7566，P<0.01；RE= 0.0870）和RDVI[731,764]与FAPAR建立的多项式函数y = 1.027x2 + 0.713x + 0.729（R=0.6194，P<0.01；RE=0.0699） 的模拟值和实测值均达到了极显著、预测精度较高，MSAVI对APAR和RDVI对FAPAR估测效果很好。一阶微分光 谱和植被指数可以较好地估测花生冠层APAR和FAPAR。     

基于生态适宜性分析的平原煤矿县生态空间优化

煤矿区塌陷为难点的生态问题已经成为制约平原煤矿地区社会、经济、生态可持续发展的阻力。本文从自然生态、特征限制、人为干扰3个层面构建平原煤矿地区生态适宜性综合分析体系,以山东省郓城县为研究区域分析生态适宜度,在此基础上引入最小累计阻力模型分析研究区生态网络,并以乡镇为单元提出优化建议,提升郓城县生态适宜度,稳固生态网络。结果表明:当前研究区生态适宜度5等级分区面积呈现正态分布,但分布极不均匀,最适宜区集中于县域北侧,最不适宜区集中于县域中南部的塌陷水域和塌陷深度较深的地区;生态网络主要集中于西北部区域,南部和中部相对欠缺。并针对现状对各等级分区结果实施不同的建设策略,并对生态网络结构的优化建议,从而为郓城县的生态修复建设和生态保护建设提供方向。