试论精确农业及我国行动对策

精确农业是超前性的农业新技术。由于精确农业充分地利用了作物、土壤和病虫害的空间和时间变化量来进行耕作和田间管理,因而,取得的经济和环境边际效益非常显著。结合我国国情,研究发展适用的精确农业技术体系、应用体系不仅是必要的,而且是可能的。精确农业的研究与发展将有助于我国人口、资源与环境方面重大问题的解决,有助于农业资源的高效利用和农业环境保护。为了适应精确农业应用,作为核心技术的地理信息系统（ＧＩＳ）技术也应在界面、功能、可操作性、信息源、实时性和处理速度等方面进行改进,深入研究多层次集成系统     

内燃机螺帽径向夹持下料模和镦挤孔模具设计

根据轴向应力对棒料剪断方式及其断口形状的影响,设计了对螺帽锻造所用热轧棒料能进行精密剪切下料的新型结构的径向支持下料模具.采取增加下六角冲头与凹模的配合长度及配合精度的导向方法,设计了在80吨非标压力机上锻带孔螺帽的成形模具.给出了两种模具的试验结果.     

自动跟踪动压平衡烟尘采样仪的研制

ＧＭ１００Ｃ动压平衡自动跟踪烟尘采样仪,跟踪精度高,响应时间快,无需换孔板,只要拨动波段开关就可换采样嘴。     

基于G1-VPRS-MIE多层次灰色理论的引水明渠运行风险评价

引水明渠的安全运行风险评价对减少和预防其在输水运行过程中的灾害发生、提高其在运营期间的社会经济效益具有重要的意义。为了对引水明渠在运行期间的风险进行合理赋权和评价,通过科学合理的方法构建了多指标参数的明渠运行风险影响因素指标体系,包括主体结构风险、自然风险、水污染风险、组织管理风险和运行调度风险5个风险因子子系统及20个二级指标在内的评价指标体系;运用G1和VPRS法分别确定各指标的主观权重和客观权重,结合MIE理论优化指标权重;根据明渠工程的运行特点,选取多层次灰色理论计算引水明渠运行风险值,并根据相关规范和安全风险评价实践确定风险评价等级。将该模型应用于引大入秦工程中,结果表明:采用序关系分析法(G1法)和变精度粗糙集理论(VPRS)并结合最小信息熵原理(MIE)的权重确定方法(G1-VPRS-MIE),不但避免了层次分析法过度依赖专家的主观经验、克服了粗糙集理论在边界刻画的局限性,而且弥补了主观和客观方法相结合的不足;对于指标权重的确定更加客观合理,既能满足所得权重的客观性,也能保证评估结果具有一定的解释性,同时能够减少单一权重计算的偏差;多层次灰色评价模型对于引水明渠安全运行风险等级的确定较为有效,并得出其风险等级为中等偏高,与实际情况一致。研究成果为引水明渠工程安全运行提供了一定的参考,同时可为类似气候环境的引水明渠区域规划、设计、施工提供有效的借鉴。     

异烟酸-吡唑啉酮光度法测定地表水中氰化物的质量控制指标研究

通过对大量监测数据进行统计分析,获得异烟酸-吡唑啉酮光度法（HJ484—2009）测定水中氰化物质量控制评定指标。研究表明：样品浓度在0．05～0．3mg／L范围内时,建议控制室内相对标准偏差≤3％,室间相对标准偏差≤10％;样品浓度小于等于0．05mg／L时,建议控制相对偏差≤10％;样品浓度大于0．05mg／L时,...     

Optimizing model for land use/land cover retrieval from remote sensing imagery based on variable precision rough sets

The suitable spectral mode in remote sensing is often desirable to facilitate the inversion of ecological environment and landscape. This paper put forward an optimizing model based on variable precision rough sets (VPRS) for the land cover discrimination in wetland inventory. In the case study of Lake Baiyangdian which has important ecological functions to the northern China, this model is established successfully according to the domain-experts knowledge. The procedure is as follows. First step is data collection, including remote-sensing data (e.g., Landsat-5 TM bands), the digitized relief maps, and statistical yearbooks. Second, the remote sensing imagery (RSI) and relief maps are co-registered into the same resolution. Third, a condition set, including various attributes is derived from spectral bands, band math or ratio indices based on previous studies, at the same time, the decision set is derived from true land types after investigation and validation. Then, the remote sensing decision table (RSDT) is constructed by linking condition set with decision set according to the sequential pixels in RSI. Fourth, we create one forward greedy searching algorithm based on VPRS to handle this RSDT. After adjusting parameters such as β and knowledge granularity diameter (KGD), we obtain the stable optimized results. Comparative experiments and evaluation show that the discrimination or retrieval accuracy of VPRS model is satisfying (overall accuracy: 87.32% and KHAT: 0.84) and better than original data. Moreover, data dimension has been decreased dramatically (from 12 to 3) and key attributes found by the model may be useful for specific retrieval in wetland inventories.     

Dance precision of <Emphasis Type="Italic">Apis florea</Emphasis>—clues to the evolution of the honeybee dance language?

All honeybee species make use of the waggle dance to communicate the direction and distance to both food sources and potential new nest sites. When foraging, all species face an identical problem: conveying information about profitable floral patches. However, profound differences in nesting biology (some nest in cavities while others nest in the open, often on a branch or a cliff face) may mean that species have different requirements when dancing to advertise new nest sites. In cavity nesting species, nest sites are a precise location in the landscape: usually a small opening leading to a cavity in a hollow tree. Dances for cavities therefore need to be as precise as possible. In contrast, when the potential nest site comprises a tree or perhaps seven a patch of trees, precision is less necessary. Similarly, when a food patch is advertised, dances need not be very precise, as floral patches are often large, unless they are so far away that recruits need more precise information to be able to locate them. In this paper, we study the dance precision of the open-nesting red dwarf bee Apis florea. By comparing the precision of dances for food sources and nest sites, we show that A. florea workers dance with the same imprecision irrespective of context. This is in sharp contrast with the cavity-nesting Apis mellifera that increases the precision of its dance when advertising a potential new home. We suggest that our results are in accordance with the hypothesis that the honeybees’ dance communication initially evolved to convey information about new nest sites and was only later adapted for the context of foraging.     

基于预测有效度一致的城市生活垃圾产生量预测

提出了基于预测有效度一致的城市生活垃圾产生量最优组合预测模型,该模型在组合预测之前利用Kendall一致性检验法对参加组合的单项预测模型值的拟合精度进行一致性检验,在通过检验之后再利用方差倒数法求解最优组合权重,建立组合预测模型。通过实例分析,表明其预测精度高于参加组合的各单项模型预测值,在城市生活垃圾产生量的预测工作中有一定的应用价值。     

计算机辅助法兰类锻件计算

此文分析了常见几种法兰锻件图特点,给出了法兰锻件图上各圆角圆心坐标及圆弧和相邻线段的切点坐标及法兰锻件体积计算公式,并进—步采用计算机辅助计算锻件体积,提高了计算精度并大大减轻了手工计算的繁重劳动。     

链条滚子精密成形新工艺

针对链条滚子成形存在的问题,提出了一种利用棒料以冷挤压成形为主,在连续模中进行多个工序连续成形的精密成形工艺方案,从而提高了材料的利用率和工厂的经济效益。