秦巴山区土壤中钾素状况的分析及补钾措施

始于20年前的土壤普查查明，陕西省耕地速效钾平均146mg/kg，作为粮油基地的关中地区更高于此，这就掩盖了秦巴山区缺押的严重性。当时秦巴山地缺钾已占40％，随着耕作水平提高和产量增长，秦巴山区耕地缺钾面积已接近80％。事实证明，缺钾已成为秦巴山区粮食增产的瓶颈 。分析了秦巴耕地缺钾的原因和钾肥肥效，提出了相应的补钾方略。     

微生物活性指标: 重金属污染下的土壤质量敏感指标

Physicochemical properties, total and DTPA (diethylenetriaminepentaacetic acid)-extractable Cu, Zn, Pb and Cd contents, microbial biomass carbon (C) content and the organic C mineralization rate of the soils in a long-term trace metal-contaminated paddy region of Guangdong, China were determined to assess the sensitivity of microbial indices to moderately metal-contaminated paddy soils. The mean contents of total Cu, Zn, Pb and Cd were 251, 250, 171, and 2.4 mg kg^-1 respectively. DTPA-extractablc metals were correlated positively and significantly with total metals, CEC, and organic C (except for DTPA-extractable Cd), while they were negatively and highly significantly correlated with pH, total Fe and Mn. Metal stress resulted in relatively low ratios of microbial biomass C to organic C and in remarkable inhibition of the microbial metabolic quotient and C minera]ization rate, which eventually led to increases in soil organic C and C/N. Moreover, microbial respiratory activity showed a stronger correlation to DTPA-extractable metals than to total metal content. Likewise, in the acid paddy soils some "linked" microbial activity indices, such as metabolic quotient and ratios of basal respiration to organic C, especially during initial incubation, were found to be more sensitive indicators of soil trace metal contamination than microbial biomass C or basal respiration alone.     

森林资源二类调查中MapInfo应用技巧探讨

MapInfo是一款著名的地理信息管理桌面系统,具有小巧灵活、使用简单、功能强大、价格适中的特点,非常适合森林资源二类调查中使用;通过合理定制工作流程、快捷键定义、快速配准、建立小班图层、MapBasic编程等技巧的应用,更能得心应手、简捷有效地处理小班信息。     

城市排水管道系统规划设计的研究

本文的研究对象为城市排水管道,主要探讨了城市排水管道的规划设计思路。首先探讨了城市排水管道的作用,其次论述了城市排水管道规划设计的具体内容,最后结合未来的发展趋势给出了城市污水资源优化的思路和城市雨水利用的具体措施。     

作物主动汲水技术内涵与研究进展

持续创新农田灌溉技术，有利于应对农业水资源短缺、耕地资源不足，也是确保中国粮食安全的重要技术基础。该研究提出了"作物主动汲水"（Crop Initiative Draw Water，CIDW）概念，并分析其得以实现的基本条件是：土壤水非饱和性、外界水水势始终小于大气压、外界水和作物根系的距离有效性、高效的水势能差转化界面。综合文献划分出了压力势差（Pressure Potential Difference, P-CIDW)、渗透势差 (Osmotic Potential Difference, O-CIDW)和重力势差作物主动汲水（Gravitational Potential Difference，G-CIDW）等3种形式的CIDW，并分析了它们的势能特征和基本实现途径。进一步，从硬件设备技术、作物表现、水盐运移与分布、土壤生境等几个方面，重点综述了P-CIDW的研究进展。近十多年来的研究表明，相比漫灌、沟灌、滴灌等传统灌溉技术，适宜参数的P-CIDW能够显著地提高作物产量与水分利用效率、养分吸收和肥料利用率、根际土壤酶活性和微生物多样性、水肥耦合效应，明显地影响了作物生理生化指标、土壤养分有效性和养分空间分布；土壤质地及其剖面构型显著地影响了P-CIDW下的水盐运移与分布；利用初始土壤含水率和基质势、渗水器导水率、供水压力以及时间等参数，可以半机理半经验地估测P-CIDW的累积入渗量。最后展望了CIDW研究的未来，认为，土壤水分-作物关系的基础理论急需要突破、研发高效的势能转化界面材料仍然是发展CIDW技术的关键任务、尽快制定P-CIDW技术标准、P-CIDW控压方法还需要革命性的创新。     

Effect of controllable drawbead on the formability of high strength steel box

With the application of simulation technology and orthogonal test, the effects of controllable drawbead on the formability of HSS (high strength steel) box are researched through the simulation of HSS box with 6 different drawbead shapes and 3 different drawbead trajectories. Use the limit drawing height as the evaluate indicator, it is proofed that the controllable drawbead can improve the formability of HSS by analyzing the result data that three types of controllable drawbead trajectories indicators are bigger than the immovable ones. And the 2nd trajectory, ascent—halt—descent is determined as the optimal type. The improve scales of straight drawbeads is better than the oblique drawbead, whereas the latter ones have better target. The main influence factors are obtained by range analysis. At last the reason that accounts for controllable drawbead can improve the formability is got the answer by the forming force analysis.     

对实施"全民健身计划纲要"之健身器材的研究

全民健身计划纲要的实施给体育健身器材市场带来了无限的商机,重要的是体育健身器材是深入持久地推动国民健身强体、增加体育人口、提高生活质量的重要保证.运用问卷、访问和资料法,对健身器材的发展现状、健身器材发展中的相关因素与存在的主要问题以及未来发展的趋势做了分析,并对健身器材的研制、开发提出了未来的设想.     

基于单CCD曲面测量方法

该测量方法是在三坐标测量机上,建立基于单CCD的自由曲面视觉测量系统;利用CCD测量被测物体表面的曲面特征;采用基于矩形细分的未知曲面测量规划方法,智能指导高精度测头测量,以便快速、准确地获取被测物体表面的大量测量数据.最后通过试验验证了该测量系统的可行性.     

在CAD中对二维机械制图和三维机械制图定义的探讨

对CAD二维机械制图和三维机械制图的定义进行讨论，提出了CAD三视图，CAD轴测图，CAD测剖视图的定义观点。     

淮河流域中上游圩区治理分区除涝设计探讨

在淮河流域的干、支流中上游沿岸圩区 ,分区除涝方法是排涝及时、缩短下游淹没时间 ,充分发挥除涝工程效益的方法。分区降涝互不窜排 ,运行简便 ,除低农业生产成本 ,减轻农民负担 ,达到减灾免灾之目的