基于新标准的高速公路超高计算方法

本论文研究新的《公路工程设计规范》和《公路工程设计标准》条件下,高速公路超高值的确定,缓和曲线长度的计算方法以及超高过渡段内不同的旋转阶段超高值的设计方法,并给出了相应的计算公式。     

山区公路路线设计经验总结

对山区公路路线设计中线形标准、曲线间最小直线长度、超高值、缓和曲线长度与超高过渡段等进行分析与探讨。     

山区公路路线设计的经验总结

对山区公路路线设计中线形标准、曲线间最小直线长度、超高值、缓和曲线长度与超高过渡段等进行分析与探讨.     

高速公路超高设计方法的研究

研究了高速公路缓和曲线长度的确定方法，通过高速公路断面迭加图和超高过渡轨迹图，并研究了超高过渡段内不同的旋转阶段、不同硬路肩宽度和坡度情况下超高值的计算公式，为高速公路超高计算提供了理论依据。     

山区公路路线设计的几点体会

本文对山区公路路线设计中线形标准、曲线间最小直线长度、超高值、缓和曲线长度与超高过渡段等进行分析，有一定参考价值。     

重大件运输公路平曲线最大超高横坡分析

在水电站进场道路规划设计阶段以及重大件运输前,需要分析计算相关道路的适应性和通过性,本文针对公路平曲线超高问题,对重大件运输汽车能适应的最大超高横坡进行了研究,提出了重大件运输公路平曲线最大超高横坡计算方法,推导了计算公式,并进行了实例计算。     

超高缓和段的设计理论在道桥施工中的应用

本文将超高缓和段的设计理论应用于道桥施工中。取得了良好的行车效果。文中所述超高缓和段的设计过程及应用举例。可供道桥施工单位技术人员参考使用。     

超高过渡段起点位置确定方法的浅析

】针对平曲线中圆曲线半径较大,缓和曲线较长时而引起的超高渐变率过小的情况,怎样在缓和曲线内确定合适的区段来完成超高的过渡？作者通过理论上的分析,提出了超高过渡段起点位置确定的方法。     

浅谈高等级公路缓和曲线采用长度问题

本文就作者在实际设计工作中,对影响高等级公路缓和曲线长度的因素和不同条件下缓和曲线长度采用问题进行了论述。     

缓和曲线在高等级公路设计中的应用

本文对高等级公路平面设计中缓和曲线长度的影响因素进行了分析说明,并对设计中如何合理确定缓和曲线长度提出了具体方法。     

高等级公路路线设计中缓和曲线采用长度的研究

本文对高等级公路设计中经常遇到的缓和曲线采用长度问题,根据国内外高等级公路设计的新概念,从理论和实践上进行了阐述,对提高公路的设计水平提出具体意见。     

Formulae of Tree Height Curve and Volume Curve Derived from Theory of Column Buckling

InttoductionIn~al,thecuverofrelahonshipbetWeenthetreehaighandthediameteratbreastheight(dbh)isconSderedasheightdbhcurveorastreeheightcurve(h-d).Therearebomethodstosetuptheformulaeoftrpeheightcurvfoneisgraphjcmethod,theotherismathemahcalequahonbyselechngapp…     

Analyzing dynamic curve widening on forest roads

Forest roads require important design specifications to ensure all-season access for various vehicles. Long and heavy log trucks can face serious maneuvering problems on forest roads due to insufficient amount of area to the left for road widening on horizontal curves. In order to provide safe and continuous shipment and transportation,appropriate curve widening areas should be provided for long vehicles along horizontal curves. In this study, a statistical model was developed to provide curve-widening solutions for long trucks(e.g., those with 18 wheels) considering various curve radius and deflection angles. The dynamic curve widening feature of Plateia 2013 program was employed to calculate curve widening for the specified vehicle. During the solution process, nine different horizontal curve diameters from 10 to 50 m(by 5 m intervals)and 17 different deflection angles from 90° to 170°(by 5°intervals) were evaluated to run horizontal curve-widening analysis. Using a multiple regression model, we made suitable predictions about curve widening. The curvewidening areas decrease as the horizontal curve radius increases, while increasing the deflection angle on horizontal curves increases curve widening areas. Clearly, the computer-based dynamic curve widening model developed in this study can be effectively used in determining optimum widening for horizontal curves by evaluating the number of alternatives that fit geometrical specifications and vehicle types.     

原木截面形状的二次B样条曲线拟合

描述了一种模拟原木截面形状的新方法。用自行研制的MQK3102原木形状识别机测得原木截面上的有限离散样点,利用二次B样条参数曲线拟合方法对这些点进行拟合。该方法能较好地模拟出原木截面的真实形状,样点数量要求不多,计算速度快,前一段曲线的计算结果不影响后面的计算,避免了由累计误差引起的图形失真。将其运用到原木长度方向上的多个采样截面,可近似模拟出原木的整体外形,从而为原木的优化下锯提供参考模型。图4参9。     

浅谈简易目测曲线法

本文介绍了目测曲线的具体方法，认为目测曲线法使用方法，掌握，目测曲线是在弧线上进行实测，道影伐开工程量注，可以充分利用地形进行实测。．     

Plant hormesis and Shelford's tolerance law curve

Shelford's law of tolerance is illustrated by a bell-shaped curve depicting the relationship between environmental factor/factors' intensity and its favorability for species or populations.It is a fundamental basis of ecology when considering the regularities of environment impacts on living systems,and applies in plant biology,agriculture and forestry to manage resistance to environmental limiting factors and to enhance productivity.In recent years,the concept of hormesis has been increasingly used to study the dose-response relationships in living organisms of different complexities,including plants.This requires the need for an analysis of the relationships between the hormetic dose-response model and the classical understanding of plant reactions to environments in terms of Shelford's law of tolerance.This paper analyses various dimensions of the relationships between the hormetic model and Shelford's tolerance law curve under the influence of natural environmental factors on plants,which are limiting for plants both in deficiency and excess.The analysis has shown that Shelford's curve and hormetic model do not contradict but instead complement each other.The hormetic response of plants is localized in the stress zone of the Shelford's curve when adaptive mechanisms are disabled within the ecological optimum.At the same time,in a species range,the ecological optimum is the most favorable combination of all or at least the most important environmental factors,each of which usually deviates slightly from its optimal value.Adaptive mechanisms cannot be completely disabled in the optimum,and hormesis covers optimum and stress zones.Hormesis can modify the plant tolerance range to environmental factors by preconditioning and makes limits of plant tolerance to environmental factors flexible to a certain extent.In turn,as a result of tolerance range evolution,quantitative characteristics of hormesis(width and magnitude of hormetic zone) as well as the range of stimulating doses,may significantly differ in various plant species and even populations and intra-population groups,including plants at different development stages.Using hormetic preconditioning for managing plant resistance to environmental limiting factors provides an important perspective for increasing the productivity of woody plants in forestry.     

Analysis of cyclic vacuum drying curve

The objective of this research was to analyze the cyclic vacuum drying curve within one cycle. Red oak specimens of two different groups, square in cross-section, were used. Group one was comprised of four different thicknesses (2.54, 3.81, 5.08, and 6.35 cm) with a length of 25.4 cm and group two was comprised of three different lengths (12.7, 25.4, and 38.1 cm) with the thickness of 2.54 cm. The specimens were heated to 60°C in the heating oven and then dried in the vacuum oven at 18 mm Hg. The vacuum oven was at room temperature (20°C). The vacuum pump was kept running for 140 min. It was found that the cyclic vacuum drying curve consisted of two distinct parts. The fast drying period lasted about 10 to 15 min. The slow drying period occurred when the pressure inside wood approached the ambient pressure. Most of the moisture was removed during the fast drying period.     

福建柏人工林地位指数曲线模型的研究

利用福建柏人工林优势木树干解析材料,选择McDill——Amateis生长方程建立多形地位指数曲线模型。结果表明：McDill——Amateis方程能够很好地描述福建柏人工林优势高生长规律,是研制多形地位指数曲线的一个理想的生长方程,在森林立地质量评价中有实际应用的价值。     

The monotony preserving QO‐spline as a taper curve

A monotony preserving quadratic spline interpolating at a given point set can be constructed by the so‐called QO‐algorithm. The quality of QO‐splines, which are taper curves constructed by using this algorithm, is investigated. A comparison was made using the program of McAllister & Roulier which produces a shape preserving taper curve by using quadratic splines, too. Tests done on a representative sample tree material indicate that the QO‐spline is in general a better taper curve than the one produced by the program of McAllister & Roulier even if the difference may be small in certain cases.