近50年菏泽市暴雨气候特征

为了揭示菏泽市暴雨气候特征,笔者利用菏泽市9个气象站50年的暴雨资料进行了研究。选取1960—2009年历年3—11月菏泽市9个站的逐日（20:00—20:00）降水资料,采用多种统计方法分析菏泽市多年暴雨气候规律。结果表明：菏泽市暴雨年际变化及年代际变化离差较大,60年代暴雨较多,之后较少,2000年之后又呈增长趋势。并且在1974年和2003年发生明显突变。1974年以前和2003年以来暴雨发生次数较多,1975—2002年期间暴雨发生次数较少。暴雨发生有明显的区域性,区域分布呈东南向西北递减的趋势,并且南北易受不同系统影响。本研究对做好暴雨预报,开拓气象服务,防灾减灾有一定参考作用。     

过程能力分析法在卷烟烟支质量控制中的应用

根据数理统计的原理和方法,运用过程能力分析的方法,通过计算卷烟生产过程烟支质量过程能力指数,开展工序质量过程能力评价,及时了解各工序对卷烟品质的控制能力,确保烟支生产的稳定性,从而提高卷烟企业在市场中的竞争力。     

新型城镇化背景下长三角城市群产城融合路径探讨

产城融合是针对城镇化推进的形势和问题提出的新理念,作为产城融合进程中产业繁荣的投入要素和城市建设的服务对象,人的发展是产城融合的出发点和根本落脚点.因此在人本视角下以产-城-人系统协同发展为导向探究区域产城融合进程和路径具有重要意义.基于城市建设、产业发展和人的发展三者的内在作用机制,利用熵权法将长三角城市群的产城融合...     

浅谈人工栽培经济林的特点

从林木个体分化不明显、速生早实、产量较高等3个方面论述了人工栽培经济林的特点。     

长江经济带国家级自然保护区内社区居民现状与发展对策

中国自然保护区多处于地理位置偏僻的贫困落后地区,且在有关法律条文规定下,居民对保护区内资源利用受限,特别是核心区和缓冲区中众多的社区居民给自然保护区管理带来压力,自然保护区保护与社区经济发展之间的矛盾日益凸显。文中通过对重点区域长江经济带国家级自然保护区内居民现状进行调查和分析,探讨不同类型自然保护区内社区居民人口密度、经济水平和自然资源依赖程度的差异,并针对自然保护区内社区发展存在的主要问题包括人口众多、经济水平受限等,提出降低保护区内人口密度、多形式提高居民收入、发展生态旅游和加强可持续经营管理等建议。     

三峡库区坡地梨-旱稻农业模式生态经济分析

运用生态经济学原理对三峡库区坡地新建梨-旱稻复合系统的生态效益和经济效益进行了研究。结果表明:与清耕梨园相比,梨园间作旱稻并秸秆还田后,有良好的水土保持作用和改土培肥效果,同时能有效控制田间杂草,减少梨园病虫害的发生,消减非点源N污染负荷60.19 kg/hm2,非点源P污染负荷8.0kg/hm2。与单一系统相比,复合系统提高土地利用率44%,能量经济系数上升2%。研究结果表明:梨-旱稻复合系统是一种具有良好生态效益的高效种植模式,值得在库区大力推广。     

A family of segmented polynomial functions for modelling the border effect on the diameter growth of Ayous (Triplochiton scleroxylon K. Schum)

This paper introduces a family of four segmented (or grafted) polynomial functions for modelling the decrease in the diameter of Ayous (Triplochiton scleroxylon K. Schum) with distance from the border of the plantation. The functions, each comprising two segments of second degree or less, were fitted to data collected in the Cameroon rain forest. A comparative assessment of the fit was carried out using criteria such as mean deviation, root mean squared deviation, and fit index.

The border effect extended to 10 m inside the plantation where a 50% decrease in diameter occurred. Beyond that distance, the diameter appeared to be stable except for random variation. The estimated functions performed equally well as they all provided a good fit to the data, with a small bias. Most importantly, they proved to be flexible and thus adaptable to a wide variety of situations.

Recommendations are made concerning setting up a guard area and ways of improving the silviculture of Ayous. Also, the possibilities for an agrisilvipastoral system are explored.     

不同种源马尾松造林效果及经济效益对比分析

分不同地位指数级，对比分析了广西容县种源和贵州龙里种源马尾松人工林的林分结构和生长效果的差异。以现实林分蓄积量为基础，结合材种出材量（率）预测模型和研究区的技术经济指标，用动态分析方法进行了经济效果评价。结果表明，在贵州引种广西容县种源是可行的，在相同立地条件，容县种源林分生产力高于贵州龙里种源，树高、胸径、蓄积量分别高１５．０—２１．７％、５．４—１９．１％和２８—４０％。经济效益、净现值高３８．９６—６１．２８％和６９．７８—９１．７６％。两种源单株材积随林龄加大，差异增大，但增长百分比随之减少。经济效益、净现值、益本比均随地位指数的增大而加大。     

European forest accounting: general concepts and Austrian experiences

Within the European Union there exist three different frameworks for forest accounting at the national level. For purposes of the national accounts, the regulations of the European System of Integrated Economic Accounts (ESA) have to be observed. They require a distinction between forestry and logging and provide specific guidelines for the valuation of standing timber. In recognition of the special character of forests and forestry production, two satellite accounts are devoted to forestry: the Economic Accounts for Forestry (EAF) and the European Framework for Integrated Environmental and Economic Accounting for Forests (IEEAF). Although they were designed as complementary to the national accounts and refer to the same basic methodologies, the guidelines for forest accounting provided by the three manuals are not fully compatible. Just recently, a further integration and harmonization of the concepts for forest accounting has been proposed. Austria has implemented the valuation of the increment as an output of forestry as requested by ESA and produces the EAF tables on a regular basis. The possibilities for extending forest accounting to natural resource accounts for standing timber and the IEEAF have been investigated in terms of pilot studies. The Austrian experiences and results exemplify the problems and possible solutions associated with the adoption of the different European schemes. Data deficits and valuation issues restrict the significance of respective results to some degree, especially as regards forestry-specific extensions of the accounting schemes.     

大姚核桃经济价值及培育技术探讨

文章分析了大姚核桃的经济价值,并从营建原则、栽植要领、土壤管理、肥料管理、水分管理和健康护理方面论述其培育技术。