豫西传统地坑窑小气候特征及其热舒适性评价     

白婧羽  杜田恬  田芸溪  刘建军 《西北林学院学报》2021,36(3):252-259

为探究豫西地区地坑窑的热舒适性及影响成因,在冬季和夏季对河南三门峡市曲村的生土地坑窑进行室内外热环境监测,选取相同位置的地上普通砖房建筑作为对照,利用人体热舒适模型对两者室内外热环境和舒适度进行定量分析、对比与评价。结果表明,冬季地坑窑室内空气温度高于地面普通建筑4.16℃,黑球温度高于地面建筑5.17℃,夏季窑室内平均空气温度低于地面建筑3.1℃,黑球温度低4.06℃;冬夏两季地坑窑室内热舒适均优于地上普通建筑,测量期间夏季和冬季窑室内分别有100%和44%的时间处于舒适范围,地面砖房建筑内分别有22%和11%的时间处于舒适范围,其中,夏季热舒适优于冬季;空气温度是影响窑洞室内热舒适的首要因素,黑球温度是影响室外院落热舒适的首要因素;但冬季窑洞内部保温性能较低,夏季通风不畅,室内湿度高达71.97%,冬季窑洞室内温度是更加急需改善的缺陷。  相似文献   

木材检验技术在木材运输中的应用探讨     

凃光华 《广东林业科技》2014,30(1):64-68

文章介绍了木材检验技术在木材运输中的作用与地位,分析了木材运输中常见的木材检验技术误区,阐述了由此引起的责任风险或者造成的危害,并依据现行木材检验标准规定,针对性地提出了规范的木材检验技术操作要领。  相似文献   

正交胶合木应用及发展前景   总被引：1，自引：0，他引：1  

付红梅  王志强 《林业机械与木工设备》2014,(3):4-7,10

介绍了一种新型的工程木产品-正交胶合木的定义、特点、国外发展现状及生产工艺,并指出了正交胶合木在国内的发展前景。  相似文献   

勐腊县珍贵用材林发展可行性研究及树种规划概述     

黄海燕  戴益源  孙亚丽 《林业资源管理》2014,(5):107-114

通过对珍贵用材林发展的概述、市场需求和产业发展趋势的分析,论述了勐腊县珍贵用材林产业发展的迫切性和可行性。在此基础上,针对勐腊县的实际情况,就发展珍贵用材林所用树种及种植技术进行设计规划。  相似文献   

Supply consequences of subsidizing thinning activities in Sweden     

《Scandinavian Journal of Forest Research》2012,27(1-4):379-386

This paper is an attempt to measure the supply consequences of the thinning subsidy which was in operation during the cutting season 1979/80. The econometric analyses are based on a questionnaire to a sample of 2500 private non‐industrial forest owners, which was produced by the official Swedish investigation SOU 1981:81. The analyses show that it is questionable whether the subsidy did affect the total cut. The estimates of the supply increase range from an average of zero to 122 m³/owner. As a by‐product we obtain estimates of the price elasticity of the private non‐industrial forest owners supply curve. These estimates range from 0.63 to 1.69.  相似文献   

Multivariate product adapted grading of Scots Pine sawn timber for an industrial customer,part 2: Robustness to disturbances     

《Wood material science & engineering》2013,8(6):420-427

ABSTRACT

Holistic-subjective automatic grading (HSAG) of sawn timber by an industrial customer's product outcome is possible through the use of multivariate partial least squares discriminant analysis (PLS-DA), shown by part one of this two-part study. This second part of the study aimed at testing the robustness to disturbances of such an HSAG system when grading Scots Pine sawn timber partially covered in dust. The set of 308 clean planks from part one of this study, and a set of 310 dusty planks, that by being stored inside a sawmill accumulated a layer of dust, were used. Cameras scanned each plank in a sawmill's automatic sorting system that detected selected feature variables. The planks were then split and processed at a planing mill, and the product grade was correlated to the measured feature variables by partial least squares regression. Prediction models were tested using 5-fold cross-validation in four tests and compared to the reference result of part one of this study. The tests showed that the product adapted HSAG could grade dusty planks with similar or lower grading accuracy compared to grading clean planks. In tests grading dusty planks, the disturbing effect of the dust was difficult to capture through training.  相似文献   

STABILIZATION OF DUNE SAND AT BORGO BONSIGNORE IN SICILY / STABILISASIE VAN DUINSAND BY BORGO BONSIGNORE IN SICILIE     

P. J. LE ROUX 《Southern Forests》2013,75(1):44-46

The methods employed and the results achieved in stabilizing an area of about 225 ha dune sand is described. The techniques employed in allowing tree species to become established are mentioned and are illustrated by various plates  相似文献   

木材内部腐朽特征识别专家系统   总被引：4，自引：4，他引：0  

杨学春 《森林工程》2004,20(1):14-15

简单介绍了专家系统在林业上的应用 ,详细阐述了木材内部腐朽特征识别专家系统的设计过程。该系统可以为合理造材 ,提高木材的经济价值提供依据。  相似文献   

五道河林场次生用材林龄级结构调整及评价   总被引：1，自引：0，他引：1  

亢新刚  黄庆丰 《北京林业大学学报》2001,23(3):52-55

龄级结构是森林结构中最重要的结构之一 .该文对河北省五道河林场的次生用材林的龄级结构用数学规划方法进行了调整 ,并用欧氏距离和平衡率 2方法对龄级结构调整的结果进行了评价 ,效果良好  相似文献   

湖南省森林公益效能的经济评价Ⅰ森林的木材生产效益与水源涵养效益     

康文星  田大伦 《中南林业科技大学学报(自然科学版)》2001,21(3):13-17

根据多年定位测定的数据以及<湖南省森林资源主要数据汇编>、<湖南省农业区划(8)>和湖南省水利厅有关资料,对湖南省森林的木材生产效益和水源涵养效益进行计量评估,结果表明,湖南省现有的森林每年生长木材488.7675万m3,年平均生产木材效益24.44亿圆,而其森林的水源涵养效益中,森林贮水功能效益9.84亿圆,防洪效益3.68亿圆,枯水期增加的水资源利用效益26.73亿圆.其涵养水源总效益共计40.25亿圆,是木材效益的1.65倍,同时,即使是灌草坡地调节水分的能力也明显高于裸地,因此.从水文学观点出发,对于难以造林的山坡、山顶,要注意灌木林的保护和经营,使其发挥更好的防水功能.  相似文献