基于激光反射的土壤表面粗糙度测量装置设计与试验

为了实时获取土壤表面粗糙度数据,设计了一种基于激光三角测距原理的土壤表面粗糙度专用测量装置.采用激光扫描测距仪测量微位移,其精度高、响应速度快,测距分辨力高达0.1 mm,显著提高了土壤表面粗糙度的测量精度;借助于光电编码盘和螺杆组合实现高精度扫描定位;PDA作为上位机,农田环境下具有方便携带,大容量存储数据和智能化实时处理功能等优点.     

线性旋转变压器研究

文章阐述了线性旋转变压器的工作原理,并对其基本结构、种类做了介绍,说明了线性旋转变压器的实用性。     

水蚀荒漠化的最大熵模糊优化评价模型

基于最大熵原理,应用模糊集合论中的隶属度等概念,综合考虑土地水蚀荒漠化评价的随机性和模糊性,定义加权广义距离表征待评价土地样本与标准样本的差异,建立了最大熵模糊优化评价模型。通过实例,选择沟谷密度、坡度、土壤厚度、土壤有机质和植被指数等五指标,给出土地样本的水蚀荒漠化最优分级;对比模糊综合评判,所建模型评价结果具有较小的Shannon熵,即分级决策具有较小的不确定性。     

单片机原理与接口技术实验教学体系改革与探索

当前的升学与就业形势对高校学生的要求越来越高,如何建立起一整套从基本验证到设计综合性以及创新性实验的新实验模式成为当务之急。通过对“单片机原理与接口技术实验”体系的改革,探索出了紧密结合物理学院实际的实验教学方法;在实验内容上,形成验证性、综合设计性和研究开发性的3个层次的全新的实验教学体系。     

论农村职教教师备课的原则和措施

分析了农村职业教育中教师备课的重要性,论述了教师备课时要遵循科学性、艺术性和实用性等原则,并强调备课的规范化,加强教学监督,从而提高教师备课水平,提高教学质量。     

一类带阻尼项的二阶强迫非线性微分方程的振动性判定准则

本文建立了二阶强迫非线性微分方程(r(t)ψ(t))|y′(t)|~(a-1)y′(t))′ P(t)ψ(y(t))|y′(t)|~(a-1)y′(t) q(t)f(y(t))=e(t),α＞1的振动性判定准则,其中t≥t_0．这些振动性非决定准则仅依赖于[t_0,∞)的子区间序列的性质。所得结果比Cak- mak and Tiryaki[1]及Li and Cheng[2]中结果适用更广泛。     

橘小实蝇引诱物质研究进展

综述了橘小实蝇引诱剂物质和引诱机制的研究进展,指出当前对引诱物质的研究主要集中在蛋白和化学物质以及植物源物质上,对引诱机理的研究也表现在对化学物质和营养物质的需求方面,植物源引诱物质将成为未来橘小实蝇研究的重点。     

Establishment of trees on mixtures of pulverized fuel ash and Gypsum. Part II: Nutrition and trace elements

Nutrients and trace elements were determined in the foliage of nine tree species grown in mixtures of pulverized fuel ash (PFA) and gypsum. No serious macronutrient deficiencies were observed. Treatments with PFA consistently increased foliar levels of boron, potassium and molybdenum, and the poor performance of some tree species in pure PFA was attributed to boron toxicity. Gypsum hindered the uptake of boron when mixed with PFA, however, and co-disposal of the two wastes could be used to minimize problems associated with boron toxicity.     

红肉猕猴桃果园管理技术概述

红肉猕猴桃是猕猴桃中的特色类群。红肉猕猴桃品种在消费市场需求旺盛,商业价值突出,商业栽培面积快速增加,但产业发展中的技术问题也日益突出。本文就红肉猕猴桃产业发展的基本环境和现状、果园生产的技术问题及解决方案等做一概述,以期为红肉猕猴桃产业健康持续发展提供建议。     

Grass mixtures for afforested opencast spoils in South Wales

An experiment that investigated the establishment of seven grass and legume seed mixes on opencast coal mining spoil in South Wales is described. After three years, mixtures containing Poa pratensis and Festuca rubra var. rubra were the most successful in covering the spoil; the ‘Johnson JR33’ seed mix proved the best of those commercially available that was tested. Tree growth was not detrimentally affected by the establishment of a grass ground cover. Erosion was not an important process at the experimental site, though slumping occurred locally from plough ridge to plough furrow.