科技论文学术价值评价方法的探讨

探讨了科技论文学术质量评价方法和机制.列出了4大类评价方法,包括12种具体评价方法.按评价时间先后分类,把评价方法分为早期评价、中期评价和后期评价.     

地表水环境质量评价方法比较探讨

指出了地表水环境质量评价主要有单因子评价、污染指数评价和不确定性评价等方法。采用单因子评价、灰关联分析和内梅罗指数法对H市地表水环境质量作出了评价,共选择9个指标作为评价因子,分别对33个水质样品进行了评价,并将评价结果进行了对比。结果表明：3种评价方法的水质评价结果,在污染小的河流相差较大,在污染河流中较为接近。建议采用单因子评价和灰关联分析结合的评价方法对地表水环境质量进行评价。     

湿地评价研究概述

按照评价对象、评价内容和评价结果表达方式的不同对目前湿地评价研究作了分类,提出了湿地评价的3个基本阶段的技术路线和方法,详细分析了北美洲、欧洲、亚洲和中国等世界各地湿地评价研究进展情况,并且指出了进行湿地评价工作的意义。     

森林资源评价浅议

阐述了森林资源评价产生的渊源、历史背景及其基本理论;介绍了欧洲、北美、亚洲、世界组织等世界各地森林资源评价研究进展情况;并按照评价对象、评价内容的不同对目前森林资源评价研究作了分类;分析了森林可持续发展的评价指标体系的研究进展。     

森林健康评价研究综述

文章介绍了森林健康的概念及其评价的研究进展,指出了影响森林健康状况的病虫害因素,探讨了森林健康状况评价指标体系的构建、评价的模型与方法以及评价的结果等,同时也对森林健康评价的趋势进行了展望。     

基于GIS的森林资源评价系统研究与设计

基于研究建立了森林资源评价指标体系,通过将森林资源评价与地理信息系统平台相结合,分析并设计了基于G IS的森林资源评价系统.该系统为用户提供了G IS基本功能、数据管理、森林资源评价等功能服务,实现了直接在数据库中获取评价指标,进行计算机化的森林资源评价.评价结果可以直观地与实际的地理信息相联系,为森林资源管理决策提供支持.     

森林生态服务功能价值评价与监测

探讨了森林生态服务功能价值评价的重要性,分析了国内外森林生态服务功能评价的情况,论述了森林生态服务功能价值评价的研究进展,针对山西省的森林生态服务功能评价情况,提出了开展森林生态服务功能观测与评价的几点建议。     

森林火灾经济损失风险评价

在全球气候持续变暖的背景下,世界各国森林火灾发生的频次增多,造成的损失不断加重。本文介绍了我国森林火灾损失评价技术的研究现状,分析了我国森林火灾损失评价存在的问题,重点综述了适合我国国情和林情的评价分类、评价指标体系、评价方法、评价标准和评价系统,为科学准确评价森林火灾损失、正确评价森林防火工作提供了重要依据,对提高森林防火工作的规范化水平、推进生态文明建设将起到促进作用。     

高尔夫教练员教学素质评价方法探讨

为对高尔夫教练员的教学素质进行科学有效的评价,本文采用层次分析法对现有的评价体系进行了优化、改良,构建了一套涵盖面广、评价主体突出、易于推广的评价体系。选取某校的高尔夫专业高年级学生38人对现有评价方法、所提改良评价方法以及学生评教结果进行了对比,结果表明:优化后的评价方法在一定程度上有利于减少非重点要素的干扰与主观随意性,提高了评价结果的客观性与合理性。此外,精简后的评价体系更易于推广和执行。     

森林资源调查质量评价方法的研究

本文在确定了森林资源调查质量评价因子的基础上,定义了质量评价函数,然后从抽样理论出发,得出了评价函数值的估计值,提出了一套合乎实际的森林资源调查质量评价方法。     

Repair and strengthening of timber cantilever beams

This research aims to study the feasibility of repair and strengthening of timber cantilever beams used in historic buildings. It is conducted to investigate the feasibility of using different valid materials and techniques to repair and strengthen timber cantilever beams in new and historic timber buildings. The study is performed in terms of structural performance as well as historic and architectural values. An experimental program of several different materials and techniques is executed. The results are driven in terms of initial cracking load, crack propagation for the tested samples at different loading stages, deflection values, and failure load for each repaired or strengthened material and technique. The main variables are timber types (new and historic), repair and strengthening materials (steel plates, Glass Fiber Reinforced Polymer wrap, and Carbon Fiber Reinforced Polymer laminates), repair or strengthening techniques (near surface mounted and externally bonded system), and cantilever length (1000 and 1250?mm). Test results indicated that using steel plates, glass fiber wrap, and carbon fiber laminates increases the value of failure loads and decreases the deflection at both; repaired and strengthened timber cantilever beams compared to control beams.     

竹大片刨花板对竹材生物学特性的适应性

以云南四种典型材用丛生竹（龙竹、甜龙竹、黄竹和油勒竹）宏观构造、组织结构、主要物理力学性质和化学组份等竹材主要生物学特性的研究分析结果为依据,提出了竹大片刨花板的结构、制板工艺和设备与原料竹材生物学特性之间应有的适应性关系。继而,通过实验室系列化试验和工厂试生产,确定了竹大片刨花板的应有性能和最佳工艺条件包括竹大片刨花的最佳质量指标及其最佳制备条件。     

Comparative Study in Chemical Character and Fatty acid Compositions of Masked Civet''''s Fat and Nutria''''s Oil

IntroductionMaskedciVet(Paguma18vata),Mammalia,Viverridae,ismainlydiStributedinShanxi,Sichuan,Tibet,Yunnanprovinces,etc..Itsmeatisdeliciousandhasspecialflavor.Itiseasytoberaisedartificially,withhighproduCtivity.Nutria(MyocasterCOypus),Rodentia,Capromyidae,originatedinArgentina,Chili,etc.insouthAmerica.Itisakindofherbivoresfur-bearer.itsartificialraisinghassuchmeritsasdurablefurandlowcostandhighproduCtivity.MaskedcivetandnutriahavehigheconomicvalueandwideprospeCtofutilization.Atpresen…     

用苯芴酮萃取分光法测定微量锗

本文探讨了用苯芴酮萃取分光法测定微量锗的实验条件和步骤．结果表明，用此法测定微量锗灵敏度高、操作简便、准确，是测定微量锗的较好方法．可用于对植物和食品中的微量锗进行检测．     

自然保护区合作管理(共管)理论研究综述

自然保护区合作管理自20世纪80年代末期开始逐步兴起,在资源管理中被广泛使用。文章介绍了共管的含义、共管实施原则、分析框架和评价指标。从公共部门和私有部门的互动模式、集体行动类型的不同、政府和资源使用者的参与管理方式三个方面论述了共管的模式。分析了政府和社区在共管实施过程中的作用,指出共管仍面临着分权不够、合作中的文化障碍、组织类型简单和信息交流不充分、社区参与能力和认识能力不足等挑战。     

Chemical composition of wood and its connection with wood anatomy in Betula pubescens

ABSTRACT

The connection between chemical composition and anatomy of wood is poorly studied. Abiotic and biotic growth conditions affect the synthesis of structural compounds and the anatomy of wood at the same time as they affect growth. In this study, the wood chemical composition, and connections between wood chemistry and anatomy were studied in downy birch (Betula pubescens Ehrh.) grown on four growth sites possessing mineral and peat soils. Lignin, holocellulose, extractive and ash contents, and effective heating value were analysed and compared with libriform fibre double wall thickness and lumen diameter, vessel size and number, and ray and axial parenchyma numbers. Measured lignin and extractive contents were exceptionally high and holocellulose content low. Correlations between wood anatomy and effective heating value were partly different on different soils. Correlations between holocellulose and anatomy were the opposite of the correlations between other chemical compounds and anatomy. The significant correlations between chemical composition and anatomy were commonly opposite in trees grown on peat than in trees grown on mineral soil. Particularly, vessel characteristics and fibre wall thickness correlated significantly with wood chemistry in trees grown on mineral soil. The connections between wood anatomy and chemistry proved to be soil-dependent.     

Spatial patterns of Douglas-fir and aspen forest expansion

Spatial patterns, rates, and density of encroaching forests into adjacent grasslands have important implications for long-term land use management and resource planning. This study examines the effects of Douglas-fir (Pseudotsuga menzeisii) and aspen (Populus tremuloides) regeneration mechanisms on sucker and seedling spatial patterns, distance from adult trees, and density in encroaching forests. A total of 8,924 aspen suckers and 1,244 Douglas-fir seedlings were counted and mapped in 2,920 quadrats (5 m × 5 m) in 106 plots along a lower forest-grassland ecotone in the Centennial Valley, MT, USA. Sucker and seedling spatial patterns were analyzed using Morisita’s I index. Average sucker and seedling density per quadrat and distance from adult trees were estimated for each plot and compared between aspen-dominated plots and Douglas-fir-dominated plots using ANOVA tests. Aspen suckers were established in a clustered spatial pattern at a significantly higher density and a significantly shorter distance from the adult trees. In contrast, Douglas-fir seedlings were established in varying spatial patterns at a significantly lower density and a significantly greater distance from the adult trees. Forest encroachment into the adjacent grassland in the Centennial Valley is occurring in contrasting patterns and at varying rates and densities due to the difference in aspen and Douglas-fir regeneration mechanisms.     

气候因子对竹子生长的影响研究综述

竹子是集经济、生态和社会效益于一体的优良林种,是区域农村经济社会发展的重要资源和生态环境保护的重要屏障.温度、水分、光照、大气组分等的变化直接影响着竹子的生长发育和分布.该文从主要气候因子对竹子生物学特性、生态学特征及其分布和经济产出的影响研究现状进行了综述,提出了今后需要重点开展的相关研究内容.     

Modelling impacts of changes in carbon dioxide concentration,climate and nitrogen deposition on carbon sequestration by European forests and forest soils

Changes in the Earth's atmosphere are expected to influence the growth, and therefore, carbon accumulation of European forests. We identify three major changes: (1) a rise in carbon dioxide concentration, (2) climate change, resulting in higher temperatures and changes in precipitation and (3) a decrease in nitrogen deposition. We adjusted and applied the hydrological model Watbal, the soil model SMART2 and the vegetation model SUMO2 to asses the effect of expected changes in the period 1990 up to 2070 on the carbon accumulation in trees and soils of 166 European forest plots. The models were parameterized using measured soil and vegetation parameters and site-specific changes in temperature, precipitation and nitrogen deposition. The carbon dioxide concentration was assumed to rise uniformly across Europe. The results were compared to a reference scenario consisting of a constant CO₂ concentration and deposition scenario. The temperature and precipitation scenario was a repetition of the period between 1960 and 1990. All scenarios were compared to the reference scenario for biomass growth and carbon sequestration for both the soil and the trees.     

我国湿地保护管理现状与优化对策

我国湿地资源在全球占据重要地位, 在我国生物多样性保护与社会经济可持续发展方面发挥着重要作用。在总结我国湿地保护管理现状的基础上, 文中指出我国湿地保护管理方面存在着责权不清、管理机构不健全且有重叠、将湿地划为未利用地以及制度与机制有待完善等问题, 提出了优化我国湿地保护管理体制的建议, 以期为湿地相关立法提供依据, 并进一步促进我国湿地保护管理水平的整体提升。