胶合木国产化生产线关键设备

简述了胶合木的基本概念,根据胶合木生产工艺流程介绍了目前国产化生产线及其关键设备。对胶合木生产线的发展及应用前景进行了分析与展望。     

冬收小麦生育特性的研究

江汉平原的亚热带气候生态条件,对于常规冬小麦的后期生长发育不利,有利于冬收小麦的栽培。由于冬收小麦各生育阶段能得到较好的生态条件,所以比常规冬小麦增产,有栽培价值。     

闽江开展木材船运研究

本文通过对木材水运和陆运及木材船运和排运之间的对比分析研究，阐述了闽江开展木材船运的重大经济意义．同时提出了闽江木材船运适宜的工艺类型和设备以及提高木材船运经济效益的有效途径．     

基于GIS的矿井机电设备管理信息系统开发研究

针对目前矿井机电设备管理中存在的问题．特别是井下设备移动频繁的特点，介绍了基于GIS的矿井机电设备管理信息系统的功能，重点介绍了GIS系统的二次开发技术，对于GIS应用系统的开发具有一定的参考价值。     

基于超声波传播特性的液态食品质量检测系统研制

研制了一个适用于液态食品超声波传播特性检测的装置，利用超声脉冲发射和接收测定液态食品的超声传播速度、声衰减和声阻抗。声速检测采用比较法，相对误差小于0.5%。利用声传播途径通过方程计算声衰减和声阻抗，计算中考虑了传播过程的声反射和声透射，结果具有一定的准确性。利用该装置研究发现苹果汁饮料中原果汁浓度与声速有良好的线性相关，具较好的实用性，可以应用于食品质量的超声检测。     

移动式采摘机器人研究现状与进展

采摘机器人是21世纪精准农业的重要装备之一，是未来智能农业机械的发展方向。移动式采摘机器人由机械手、末端执行器、移动机构、机器视觉系统以及控制系统等构成。机械手的结构形式和自由度直接影响采摘机器人智能控制的复杂性、作业的灵活性和精度。移动机构的自主导航和机器视觉系统解决采摘机器人的自主行走和目标定位，是整个机器人系统的核心和关键。该文对移动式采摘机器人的研究现状进行综合，提出目前采摘机器人技术发展中面临的技术难题及相应的对策，包括采用开放式控制系统。     

SCS模型在小型集水区降雨径流计算中的应用

用SCS降水－径流模型对陕北、渭北多个小型集水区降雨径流量进行了分析与计算。结果表明：SCS降水－径流模型考虑了径流与土壤特性和土地利用情况的关系,简单易行,所需参数少,是一种较好的小型集水区径流计算方法,可用于小流域、沟道等小型集水区可集雨量的计算。该文还分析了模型参数与陕北、渭北土壤分区特征的关系,确定了陕北、渭北不同分区的模型参数。     

Community patterns generated by human harvesting on Chilean shores: a review

1. The Chilean rocky coast has been exploited for food by coastal gatherers for at least 8500 years BP and probably was an important factor in how prehistoric people were able to colonize the South Americas Pacific Rim. The main species targeted in the past were the same as those today except that now the gatherers are resident and the fishing activity is more intense and persistent. 2. With many pertinent studies from around the world having been published on this topic, mostly conducted in Marine Reserves, this review tries to identify the main patterns that can help us recognize, in the Chilean intertidal, the degree of exploitation on wave exposed and wave protected rocky shore habitats. 3. Three clear patterns were identified depending on the trophic level adopted by the human gatherers in the food chain of the intertidal zone. First, when the humans act as herbivores, collecting the large laminarian Durvillaea antarctica, adult plants disappear from the accessible sites, especially the midlittoral, semi‐exposed and exposed habitats. 4. Second, when humans harvest the ecologically important herbivorous archeogastropoda Fissurella spp., this results in the red alga Mazzaella laminarioides covering almost 100% of the midlittoral rocks. Third, when humans become top predators by collecting the muricid carnivore Concholepas concholepas, then bivalves, mainly Perumytilus purpuratus, cover the rocks in multiple layers. 5. These patterns contribute to the evaluation of the state of conservation of the Chilean rocky intertidal shores, especially because the north and the south are beginning to be connected by a new coastal road. Thus it is necessary to evaluate urgently, on a large spatial scale, the state of conservation of these communities, in order to help select the appropriate places for establishing Marine Reserves. Copyright © 2001 John Wiley & Sons, Ltd.     

Land-use legacy of historical tree harvesting for charcoal production in a semi-arid woodland

Historical processes may have longer lasting effects in arid forest and woodlands because of slow rates of succession. We investigated the influence of historical tree harvesting upon contemporary spatial dynamics of pinyon-juniper woodland in the western United States. Despite intensive and widespread harvesting of woodland by the charcoal industry during the late 19th century, the role of afforestation has seldom been addressed as a potential mechanism for the dramatic expansion of pinyon-juniper woodlands over the past century. Spatial models of disturbance processes are one way to ascertain effects of such historical influences. We developed a process-based spatial model to estimate the historical tree harvest pressure according to a parsimonious set of rules and constraints. The model used a convection-diffusion approach that incorporated the influences of topography, transportation, and mining production. We used a combination of field-surveyed, archaeological, historical, and GIS data sets to calibrate, validate, and compare the alternative mathematical models. Model results were consistent with the historical harvest evidence (AUC > 0.66), with high harvest intensity closer to the mining districts, quickly decreasing at the maximum distance of influence. Performance was improved by including the local terrain. Harvesting initially showed radial patterns emanating from the significant mining districts, and then gradually expanded northward with development of the railway system. Our spatial modeling approach provides a means to assess the pattern and magnitude of historical tree harvesting in semi-arid woodlands. The general approach can be applied to explore the importance of other historical disturbance and cultural processes, whose effects may no longer be evident, in forests and woodlands worldwide.     

沼液无害化处理与利用成套设备工艺技术

针对目前循环农业生产中沼液有害重金属超标以及沼液管网系统产气爆管,沼渣、厌氧菌落群堵管等问题,导致农用沼液难以利用的现状,研究开发出了一种沼液无害化处理与利用的成套设备。该设备包括沼液无害化处理与肥水一体灌溉装置两部分,具有重金属脱除容易、管网自动排气防爆、防堵塞及肥水一体化灌溉功能,有效提高了沼液沼渣利用率,实现农业...