高效液相色谱法和光度法测定苯酚的对比

分别对液相色谱法和4-氨基安替比林分光光度法,测定苯酚的精密度、检测限及准确度等,进行对比和分析.结果表明:色谱法和光度法精密度和准确度均较高,但光度法操作简便且检出限较低,费用少,建议作为酚醛胶木制品苯酚释放的定量方法.     

精准农业技术系统集成在新疆棉花种植中的应用

根据新疆生产建设兵团农业机械化、集约化、规模化生产的特点，结合新疆兵团棉花种植的实际情况和基础条件，利用GIS、RS、GPS、ES、MS等最新技术在棉花精准种植试验区开展研究工作。跟踪国内外精准农业的最新研究发展水平，在数字农业技术创新的基础上，整合国内已有的研究成果，利用信息技术对新疆现有的农业生产设备进行组装配套，研制、开发、集成具有新疆特色的数字农业技术体系与推广模式，进行规模化应用示范。在农田信息采集、处理和实施系统3个方面进行棉花精准种植信息系统集成研究，取得了初步成果：利用自主开发与引进的硬件平台，组装集成的配套技术体系，在棉花的精准播种、节水灌溉、变量施肥、病虫害预测预报与防治、长势监测等产前、产中管理决策中应用，形成一套适宜新疆的先进成熟的棉花生产管理智能化决策系统，同时与变量作业机具组装配套进行示范，该成果可为新疆及其它地区棉花精准种植提供参考模式，具有重大的推广意义，市场前景广阔。     

精密施肥机的研究与应用

对国内外现有施肥技术现状进行了调研，结合中国的国情,研究开发出了实用可靠高精密度的施肥机系统。该系统主要由主控制器、高精度的EC、pH传感器，液压水表阀门、压力调节阀、压力计、过滤器、肥料泵等元件组成，在灌溉施肥过程中，肥料泵以微量的脉冲注肥，可以保证精确的肥料施用剂量。该施肥机采用模块化设计，具有结构简单可靠、适用范围广、控制精度高、界面友好等优点，实现了对作物的高产优质栽培所需要的合理营养供给。     

Error analysis of worm grinding wheel precise dressing by diamond roller with straight profile

In worm grinding wheel dressing with diamond roller, using straight line instead of theoretical curve of roller will result in dressing error. Method of the precise dressing is studied, while the mathematical model is presented. Theoretical curve of diamond roller is calculated based on the space meshing theory and helicoid equation of worm grinding wheel. The fitting error between the theoretical curve and approximate straight line which is obtained by the theoretical curve is calculated. The dressing error on normal section of worm grinding wheel is analyzed. The case study of a kind of worm grinding wheel with single head shows that the dressing error increases with diameter decreasing of worm grinding wheel and diamond roller, while the variation of diamond roller’s diameter makes little contribution. The validity of worm grinding wheel dressing using straight line diamond roller is proved, and the algorithm can be used as guidance in practice.     

手持GPS测量面积的精度分析

介绍了手持GPS在森林资源调查、工程造林中林地面积测量的精度,选择已知面积作为测量对象,对测量误差及其精度进行分析计算,结果表明:手持GPS测量林地面积的精度能够满足林业中的应用要求.     

罗盘导线定位及其精度分析

为解决森林调查中罗盘定位的精度问题,利用全站仪具有测量边长和角度精度高的特点,将其测量值作为真值.用罗盘仪对其值进行重复观测,进行比较研究,通过间接平差,得出罗盘仪测量边长和竖角的精度,由此推导出罗盘导线和罗盘测树高的精度.试验表明,1 km罗盘支导线最弱点的中误差达3 m,罗盘测树高的相对精度达5%.这个精度能够满足林业上的测量要求.由此可见,用罗盘进行辅助定位,是一种理想手段.     

提高植物叶片面积测量精度的方法

介绍了用CCD（Charge Coupled Device) 提高植物叶片面积测量精度的方法，分析了采用不同的图像获取设备时影响测量精度的各种因素。讨论了使用数码相机时消除线性几何畸变影响的方法，使利用数码相机实现非破坏性测量真正走向了实用化。     

新疆精准农业的发展策略

通过对在新疆发展精准农业技术的利弊分析，提出了适合于新疆的精准农业技术的应用发展策略。为适应农业生产的高产、高效和可持续发展，精准农业技术的推广应用势在必行。     

Providing Precision Farming Education Through Conferences and Workshops

In response to rapidly growing interest in precision farming, universities and others have developed numerous educational programs. Many of these events are multi-day conferences and workshops as these venues provide the time necessary for attendees to learn about the many technologies, analysis approaches, and management strategies that make up precision farming. The Washington State University Western Precision Agriculture Conference, the Assiniboine Community College Precision Agriculture Conference and the University of Nebraska–Lincoln Crop Modeling for Environment-Specific Management Workshop exemplify these types of educational programs. The Western Precision Agriculture Conference uses a traditional format where the audience primarily listens to presentations. The Assiniboine Community College Precision Agriculture Conference provides a mixture of presentations and hands-on sessions where attendees actually use precision farming tools or develop site-specific management plans. Finally, those who attend the University of Nebraska–Lincoln Crop Modeling for Environment-Specific Management Workshop complete exercises related to each topic and presentation. Because a conference or workshop brings many experts together for a short period of time, organizers of all three events have tried to capture conference content for later use in other educational programs. Their approaches to this include videotaping interviews of conference speakers and assembling software and data used during the conference on compact disk. Given the multidisciplinary nature of precision farming, conferences and workshops that utilize multiple expert presenters such as those discussed in this paper are among the best sources of precision farming education.     

Weed Detection Using Canopy Reflection

For site-specific application of herbicides, automatic detection and evaluation of weeds is desirable. Since reflectance of crop, weeds and soil differs in the visual and near infrared wavelengths, there is potential for using reflection measurements at different wavelengths to distinguish between them. Reflectance spectra of crop and weed canopies were used to evaluate the possibilities of weed detection with reflection measurements in laboratory circumstances. Sugarbeet and maize and 7 weed species were included in the measurements. Classification into crop and weeds was possible in laboratory tests, using a limited number of wavelength band ratios. Crop and weed spectra could be separated with more than 97% correct classification. Field measurements of crop and weed reflection were conducted for testing spectral weed detection. Canopy reflection was measured with a line spectrograph in the wavelength range from 480 to 820 nm (visual to near infrared) with ambient light. The discriminant model uses a limited number of narrow wavelength bands. Over 90% of crop and weed spectra can be identified correctly, when the discriminant model is specific to the prevailing light conditions.