日式插花中花意匠的基本理论与运用实例

对现代较为流行的日本花道主流插花流派小原流进行了分析,对小原流的基础理论花意匠进行了探讨,对花意匠的插花形式和花型,以及日式花道的精神进行了阐述,以期对我国现代插花艺术提供有益借鉴。     

木材干燥过程的Elman神经网络模型研究

[目的]研究木材干燥过程的Elman神经网络模型。[方法]在人工神经网络理论的基础上,选用Elman神经网络建立木材干燥过程模型。针对木材干燥过程的特点,Elman神经网络利用木材干燥过程材堆的温度、湿度以及对应的木材含水率建立模型。[结果]通过实际干燥过程数据对模型的准确度进行验证,结果表明Elman神经网络利用少量数据就可以建立模型,并且模型预测精度高,对数据的联想记忆和优化能力强。[结论]Elman神经网络建立的木材干燥过程模型准确,对于提高木材干燥过程的控制水平具有重要研究意义。     

Influence of protein content on spaghetti cooking quality

Water sorption tests on three different types of laboratory-made spaghettis were conducted at 100 °C to study the influence of protein content on hydration kinetics during cooking and overcooking and on quality characteristics. In particular, the weight, diameter and length of spaghetti strands were monitored over a 20 min period. The different hydration behaviours of the spaghettis were analyzed using a mathematical model that quantitatively resolved the hydration process into the controlling factors (i.e. water diffusion, macromolecular matrix relaxation kinetics, and ‘residual deformation’ release kinetics). Only small differences were observed within the range of protein contents (12.7–15.5%) investigated. In particular, spaghetti stickiness decreased as protein content increased. Moreover, samples with intermediate protein contents showed the highest water diffusion coefficients.     

Effects of reforestation on the hydrological function of a small watershed in the Three Gorges Reservoir Area

For vegetation communities with hydrological function in the Three Gorges Reservoir Area, the storm event distributed hydrological model Precipitation-Runoff Modeling System (PRMS)-Storm was built based on modular modeling system developed by the US Geological Survey, and was employed to study the effects of forests on peak flows in the Xiangshuixi forest watershed in the Three Gorges Reservoir Area. The results showed that: 1) this simulation study suggested that PRMS-Storm can meet the second level national flood prediction standards of China for simulating storm events of small forest watersheds, and can issue flood forecasting; 2) hydrological functions of different vegetation communities were evaluated, and three simulation scenarios were arranged: mixed conifer-broadleaf forests (scenario 1), broad-leaved forests (scenario 2), and general forests arrangement (scenario 3); 3) the well-arranged forest scenarios can reduce over 20% of surface runoff, result in an increase of over 16% in subsurface flow, and decrease peak flow by 20.8%, 9.6%, and 18.9%, respectively. The reduction of peak flow rates was significant when rainfall peak was higher than 0.8 mm/min, especially for short-term rainfall events. In general, we found that scenarios 1 and 3 were preferable for reducing peak flow rates and volumes in the reforestation practices in the study region, and scenario 1 was better than scenario 3, so the mixed conifer-broadleaf forests had the best hydrological function. __________ Translated from Journal of Beijing Forestry University, 2006, 28(5): 42–51 [译自: 北京林业大学学报]     

Modeling forage growth in a Midwest USA silvopastoral system

Tree effects on understory pasture growth in a silvopastoral system were modeled by explicit simulation of tree canopy light and rainfall interception, evapotranspiration, and nutrient uptake. The algorithms to model these effects were incorporated into a multispecies grazing simulation model, GRASIM, to form the Silvopasture GRASIM model (SGRASIM). The new model was evaluated using forage biomass data and soil moisture data collected from a silvopasture field experiment with black walnut (Juglans nigra L.). The SGRASIM model performed well in simulating the growth of three competing dominant forage species (orchardgrass [Dactylis glomerata L.], Kentucky bluegrass [Poa pratensis L.], and tall fescue [Festuca arundinacea (Schreb.)] in the pasture both under tree canopy and in open pasture (linear regression of observed on simulated biomass for the species gave r ² values above 0.97). Model growth parameters for forage under tree canopy, compared with those for an open pasture, bear testament to the shading effects from the forest canopy in terms of reduced photosynthetic efficiency, increased leaf area ratio, and photosynthate partitioned to aboveground biomass. The new model reasonably followed the soil moisture time series in the upper soil layer (0–30 cm), where the bulk of the forage roots reside.     

造型植物及其在园林绿化中的应用

本文介绍了造型植物的定义及其研究进展,并以珠海长隆园林景观中造型植物为例,浅谈了造型植物在国内应用情况,对造型植物的应用提出了建议,认为应该在植物引种、开拓应用范围、丰富植物种类,降低生产成本等方面加强研究。     

面向对象的多轴车辆建模与仿真

利用面向对象的Modelica语言开发的应用程序Dymola,将计算机的可视化技术和参数化造型与建模能力结合,采用模块化的建模方法,对某8×8车辆建立起整车模型,并在此基础上对其阶跃输入下的动态响应进行仿真计算。     

在不同环境条件下优质蛋白玉米品种的物候期模型

传统农业研究方法的结果通常具有地域性, 且周期长, 且投入大, 用作物生长模型模拟技术, 是解决这一问题的理想方法. 为了用CERES玉米生长模型预测栽培管理措施对不同品种生长发育的影响, 在泰国北部清迈大学农学院的多熟种植中心(北纬18°47′, 东经99°57′, 海拔300m)进行品种×播种期的双因素试验, 参试种为:Across 8763(     

中尺度地形对暴雨降水影响的数值模拟研究

利用PSU／NCAR的中尺度模式MM4就1991年7月2日江淮暴雨进行模拟研究,主要考察了中尺度地形对暴雨降水的影响。在模拟工作中,人为地将模式地形中长江中游的大别山地区及其紧邻地域的海拔高度降为50m以下,而并不改变大尺度环境的各要素场。数值试验结果表明,地形的改变使中尺度暴雨中心位置和强度发生了变化。但是局地地形的改变也只在有限区域内对局地中尺度降水系统产生影响。     

Ultraviolet-B radiation in a row-crop canopy: an extended 1-D model

A decrease in stratospheric ozone may result in a serious threat to plants, since biologically active short-wavelength ultraviolet-B (UV-B 280–320 nm) radiation will increase even with a relatively small decrease in ozone. Numerous investigations have demonstrated that the effect of UV-B enhancements on plants includes reduction in grain yield, alteration in species competition, susceptibility to disease, and changes in plant structure and pigmentation. To determine the physiological effects on plants of any increases in UV-B radiation, the irradiances at the potential sensitive plant surface need to be known. A number of radiative transfer models exist but because of the importance of sky diffuse radiation to the global UV-B irradiance, models designed to estimate photosynthetically active radiation or total solar radiation may not accurately model the UV-B. This paper compares spatially and temporally averaged measurements of the UV-B canopy transmittance of a relatively dense maize canopy (sky view: 0.27°) to the estimations of two one-dimensional models differing mainly in the handling of sky radiance. The model that considered the distribution of sky radiance tended to underestimate the canopy transmittance, the model that assumed an isotropic sky radiance distribution tended to overestimate the canopy transmittance. However, the assumption concerning the sky radiance distribution accounted for only about 0.01 of the model error. Consequently, the sky radiance distribution is probably not important in modeling such dense crop canopies. The model that overestimated transmittance and had the generally larger errors, a modified Meyers model, used the assumption of uniform leaf angle distribution, whereas in the other model, designated the UVRT model, leaf angle distributions were estimated by sample measurements. Generally this model would be satisfactory in describing the statistically average UV-B irradiance conditions in the canopy. This model may also be applied to other dense plant canopies including forests.