浅议林区交流配电网安全性措施

本论述了林区交流配电网络安全性的措施，供电线路型式，安全性的含义，保证安全性的措施。     

贯彻GB5226．1-2002标准 提高木工机床产品安全性能

我国木工机床电气安全执行的标准是GB5226.1-2002,它和欧盟标准EN60204-1均等同采用IEC60204-1,亦即贯彻好国家标准GB5226.1-2002,也就同时满足了国际标准和欧洲标准对木工机床电气设备安全性的要求.本文分析了导致木工机床不安全的因素,从电气安全结构及电气安全试验等方面介绍了GB5226.1-2002对木工机床的要求,并提出了提高木工机床电气安全性的措施.     

单片机系统抗干扰措施

单片机在控制领域已经被广泛地应用,对其可靠性要求也越来越高,其中系统抗干扰性能是可靠性的重要指标.可通过硬件和软件两种措施,提高单片机的抗干扰性,通常根据实际情况将两种措施有效地结合起来,才能取得较好的抗干扰效果.本文以国内使用最为普遍的51单片机为基础,根据自身使用单片机的经验,从硬件和软件两个方面,介绍了单片机的多种抗干扰方法.硬件抗干扰主要解决单片机受外界因素的影响,而软件抗干扰主要保证程序的正确执行和数据的安全性.     

浅谈市政道路绿化

市政道路是城市中具有重要地位的空间环境,市政道路绿化是公路建设的一个重要组成部分.它对于提高交通安全性和舒适性,缓解公路车辆通行给公路沿线居民带来的不良影响,保护城市原有自然环境和改善生活环境质量等都具有极其重要的意义.笔者根据自身工作实际,试图从市政道路绿化的作用,目前存在的主要问题、改进措施及未来市政道路绿化发展方向等方面,阐述市政道路绿化对于完善城市功能、提高城市品位等方面的巨大作用.     

楼宇建设工程电气接地与监理要点

通过对建筑工程电气接地系统的分析,论述了现代化楼宇建筑采取的建筑电气安全性技术措施,并对其施工质量提出了几项监理要点。     

电力工程施工管理和运行状态检修的研究

为保证电力线路运行的安全性和可靠性,除了要做好电力工程施工管理,保证电力工程线路的设计和施工满足各种安全性和可靠性的指标外,还要采取有力措施,保证电力线路的运行、检修、诊断等。为此,笔者根据多年在电力行业的工作经验,对这两方面的工作进行了分析研究,仅供参考。     

高等级公路桥头跳车原理分析与预防措施

随着公路交通事业的迅速发展,桥头跳车问题已经成为高速公路和城市道路的常见病害之一,严重地影响行车的舒适性和安全性.引起桥头跳车的主要原因有不均均匀沉降,刚度突变和车速与车辆本身的抗振性能.就高等级公路而言,主要是柔性道路与刚性结构物之间的连接处发生错台,导致行车时发生桥头跳车现象.在车辆荷载、结构自重和自然因素作用下,桥梁与道路同时发生沉降,但两者的沉降量有很大差异,道路的沉降量远大于桥梁的沉降量,形成发生桥头跳车的错台.如何有效地控制桥头跳车,保证高速公路运营的安全性和舒适性已越来越引起人们的重视.从工程实践中出发,首先分析高等级公路桥头跳车的原因,然后从台背地基的处理、台背路基的填筑、设置道路与桥梁过渡措施等几个方面提出避免桥头跳车的预防措施,其结论可供道路工程设计施工参考.     

砖茶中氟的饮用安全性研究现状

砖茶是边疆少数民族地区日常饮食中不可或缺的一部分.因其氟含量很高,导致相当一部分饮用砖茶的人出现了氟中毒症状.本文对氟与人体健康的关系、边疆少数民族地区饮用砖茶与摄氟量的情况、砖茶氟在释放过程中的影响因素及其与人体摄氟量的关系、降氟措施等研究现状进行了综述,并对砖茶氟饮用安全性研究中存在的部分问题及今后的研究方向进行了...     

花椒的无公害防控

本文通过调研和实践,提出应从加大安全宣传、实行质量安全监管、加强农业防控、合理使用化学农药等项措施出发,从而保证花椒食用的安全性。     

提高煤矿供电系统可靠性的措施

煤矿作为我国的支柱型能源,在其开采过程中安全是生产的第一要素。尤其近年来,随着煤矿工作量的逐年增加,供电系统的安全性和可靠性直接关系到煤矿工作人员的生命安全。文章阐述了提高煤矿供电系统可靠性的意义,分析了煤矿供电系统中的现存问题,并且有针对性地提出了具体的改进措施,以期加强煤矿供电系统的安全性及可靠性。     

基于网络嵌入性的我国东北国有林区知识转移机理

文中从社会网络视角分析我国东北国有林区职工、家庭及林业企业知识转移的过程和影响因素,以期通过社会关系和网络结构促进林业企业转型。应用知识转移基本理论构建东北国有林区多层次知识转移理论模型,在此基础上从社会网络视角分析林区职工、家庭和林业企业3个层面的知识转移机理。研究表明:增强林区知识转移个体与利益相关者的联系程度、占据更多的结构洞位置以及提高个体网络中心度和凝聚程度有利于知识获取和内化;林区待岗职工与利益相关者的弱联系有利于其获得更多就业机会;国有森工企业由于过度嵌入社会网络,知识内化和创新动力不足。     

利用辽宁省森林生态网络构筑生态防火网络体系的思考

立足辽宁省森林生态网络体系的"点(中心城镇)"、"线(河流线、海岸线、铁路线、公路线、防护林带)"、"面(主要林区)"系统,综合考虑各地的自然、经济条件、林分状况、火险等级等实际,探讨利用河流、山脊、沟壑等自然条件和林道网、防护林带等森林生态网络元素构筑完整的封闭式生态防火网络体系.文中具体阐述了生态防火网络的设计原则与框架,提出加强领导,落实责任,依靠科技,提高水平,强化管理,完善政策等生态防火网络建设的保障措施.     

林区通信网的组建方法

本文论述了林区各场所通信设备组合运用的方法 ,对偏远山区通信发展起到快速普及作用。经实践证明 ,这种手段的组合是适合林区各场所通信网的最佳途径。     

对推进安徽现代林业建设的思考

现代林业建设是林业发展方向的必然选择。论述了现代林业建设的迫切性及现代林业的主要理论 ,从实际出发 ,阐明了安徽林业“点”、“线”、“面”建设的重点 ,并就安徽现代林业建设中关于万里绿色长廊工程 ,林业发展规划及调查设计技术标准 ,森林经营方式 ,林业产业体系建设 ,建设森林生态网络体系框架 ,创造现代林业建设的良好外部环境等方面提出建议。     

全国森林火险预报系统的研究与运行

森林火险预报对于加强森林防火工作,保护森林资源有重要的意义。当前我国各级气象部门发布的森林火险天气预报和一些地区发布的森林火险预报的空间位置较粗略、时效性较差,不能满足各级森林防火工作的实际需求。作者引入信息技术,在网络和GIS平台上建立森林火险预报系统,试图解     

北京城市森林体黍的建设与发展

文章从北京推进宜发达地区城市、生态城市建设的角度,总结了北京城市森林建设历程和坚持生态优先、因地制宜、以人为本3点主要做法。客观分析了目前北京城市森林体系在落实发展理念上、在建设质量上、在实施过程中存在的矛盾和问题,     

Key structural forest connectors can be identified by combining landscape spatial pattern and network analyses

Conservation and enhancement of ecological connectivity is widely recognized as one of the key objectives of forest landscape management. However, practical difficulties still exist due to the lack of pragmatic and operational methodologies that can be efficiently applied for these purposes within the scope of a forest management plan. Here we present the novel integration of two recent approaches for analyzing forest structural connectivity that offers considerable synergies and potential relevant benefits for forest planning at a variety of scales. We combine the morphological analysis of forest spatial patterns with recent indices for the analysis of landscape network connectivity based on the concept of measuring habitat availability (reachability) at the landscape scale. The combination of these approaches in a single integrated workflow embraces from (1) the diagnosis and characterization at the pixel level of the forest spatial patterns and their individual constituents, which are mainly the core habitat areas and the structural connectors (bridges) between them, to (2) the assessment of their individual importance to uphold ecological fluxes as irreplaceable providers of structural connectivity. We present and show different analytical possibilities within the integrated workflow from where the manager can choose depending on the planning targets and on the characteristics of the ecological processes of interest. We illustrate the application of the combined approach in two forested areas in Central Spain with different scales and management contexts, in which the structural connectivity between forest habitat areas needs to be sustained. Our assessment was able to discriminate and highlight a concise subset of cores and bridges that concentrated most of the contribution to the overall connectivity and functioning of the forest habitat network. This provides clear guidelines on where the conservation management efforts should be targeted, allowing for many alternative areas where the rest of the management objectives and activities can be accommodated as required by the multifunctionality of forest resources. The proposed integrated approach can equally serve to identify (a) those forest areas that play a crucial role to sustain ecological fluxes that are to be promoted by management, such as the dispersal of native biota or (b) those sites where the spread of wildfires or invasive species can be halted more effectively. The potential of the proposed methodology to inform and guide forestry decisions is reinforced by the availability of the required analytical tools (Guidos and Conefor Sensinode) as freeware software packages.     

Chinese Forest Ecosystem Research Network and Its Development

1INTRODUCTIONAsanimportant,internationallyusedmethodofstudyingandunveilingthestructureofanecosystemanditsfunctionalchanginglaws,long-termfixed-observationisanirreplaceableresearchmethodologyofestablishingecosystemobservationsitesontypicallynaturalormanualecosystem-regions,inthelongtermobservinginafixedplacethedynamicchangingpatternsandprocessesoftheecosystemsconstitution,structure,bio-productivity,nutrientscycling,watercyclingandenergyutilization,etc.;undertheinterferenceofnaturalcondition…     

Temporal mapping of deforestation and forest degradation in Nepal: Applications to forest conservation

Deforestation and forest degradation are associated and progressive processes resulting in the conversion of forest area into a mosaic of mature forest fragments, pasture, and degraded habitat. Monitoring of forest landscape spatial structures has been recommended to detect degenerative trends in forest conditions. GIS and remote sensing play an important role in the generation of such data to identify degraded and deforested areas as well as potential areas for conservation. In this study we analyzed forest degradation and deforestation trends in Chitwan district in Nepal, which contains key habitat elements for wildlife in the region. An artificial neural network was used to predict forest canopy density in five classes using Landsat images of the year 2001. Forest canopy density was predicted with 82% overall accuracy. Except riverine forest, forest area of all other forest types was reduced. Terai Shorea robusta forest, which has high commercial value, showed a loss of 23% between 1976 and 1989 and an overall loss of 15% forest covers between the year 1976 and 2001. Deforestation and forest degradation disproportionately reduced the sizes of the different forest types, a finding that has important management implications. The maps presented in this article could be useful to prioritize limited resources for conservation.     

Spatially explicit assessment of forest road suitability for timber extraction and hauling in Switzerland

Efficient forest management, and wood production in particular, requires a forest road network of appropriate density and bearing capacity. The road network affects the choice of a suitable extraction method and the length of the transport route from the forest, while the road standard defines the truck type that can be used.

We evaluate the forest road network’s economic suitability for harvesting operations in the entire Swiss forest, an area of about 13,000 km² covering a range of topographies, based on the Swiss National Forest Inventory’s (NFI) forest road dataset. This dataset is based on information from an interview survey with the local forest services and includes all forest roads in Switzerland capable of carrying trucks. Extraction options and hauling routes are analysed together; thus, the entire logging process is examined.

Model results include maps of the most suitable extraction method; extraction costs; hauling costs; and a suitability map based on a combination of the results. While the larger part of the Swiss forest is classified as “suitable” for economic harvesting operations, significant portions also fall into the “limited suitability” and “not suitable” categories. Our analysis provides an objective, country-wide, spatially explicit assessment of timber accessibility. The resulting suitability map helps identify areas where timber harvesting is economic using the current forest road network, and where it is not. The model results can be used in road network planning and management, for example, by comparing road-network re-design scenarios, and compared to the spatial distribution of available wood volume.