共查询到20条相似文献，搜索用时 125 毫秒
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指出了物理方法防治甘肃鼢鼠具有对人、畜和环境安全的特点。利用接洞式鼢鼠活捕器、彭林地弓箭、银恒快速捕鼠器和环形捕鼠荚在每个标准地分别布设相同的数量,连续捕杀72 h,计算了捕获效率。然后,从捕鼠器配件组成数量、携带便利性、操作的难易程度、捕杀精准度、捕捉鼢鼠数量、对环境的保护和单价7个方面进行评价。 相似文献
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西和县油松飞播区中华鼢鼠危害严重，损失惨重。此鼠一年两代，３～４月写７～９月繁殖，４～５月和９～１０月为全年活动盛期。利用这两个有利的期，采取弓箭捕杀和磷化铝片药剂熏杀结合进行防治，灭鼠效果很好。 相似文献
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西和县油松飞播区中华鼢鼠危害严重，损失惨重。此鼠一年两代，３－４月与７－９月繁殖，４－５月和９－１０月为全年活动盛期。利用这两个有利时期，采取弓箭捕杀和磷化铝片药剂熏杀结合进行防治，灭鼠效果很好。 相似文献
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物理机械防治鼢鼠是人工采用物理机械技术防治的方法。对于林区鼢鼠的大面积防治，目前主要是使用化学灭鼠剂，但无论哪种药剂都不能百分之百的杀灭害鼠，必然会有部分抗药性较强或施药不到的残余鼠继续繁殖，几年后又会造成严重危害。如果化防之后再以器械补充捕杀，或化防与器械捕杀综合 相似文献
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本项试验在进行了中华鼢鼠生物学特性及生态习性观察的基础上，开展了树木幼苗期保护、灭鼠药剂筛选以及器械捕杀试验。其结果表明：生产防治采用药液浇灌保护油松幼苗；洞内投放鼢鼠灵、ＰＸ－气体麻醉灭鼠剂、ＴＬＢ－灭鼠剂毒饵诱杀；鼠敌烟弹窒息灭鼠以及放置弓型夹捕杀都有较好的防治效果。用于生产，获大面积应用成功。本文还提出了鼢鼠综合防治建议及设计，有重要生产指导价值。 相似文献
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为降低海东林区内高原鼢鼠Myospalax baileyi对林木的危害程度,提高林分质量,通过造林整地、施用药剂、人工捕杀的方法总结出一套合理有效治理高原鼢鼠的防治措施。本试验在造林前采用3种方式进行整地,其中水平沟整地对鼢鼠的防治效果最好。在整地的基础上,分别施用雷公藤甲素颗粒剂、地芬·硫酸钡饵剂及莪术醇成品饵剂,雷公藤甲素防效最佳,同时结合人工捕杀,防治效果达81.82%。故水平沟整地后喷施0.025 mg/kg雷公藤甲素辅以人工捕杀是防治高原鼢鼠较为合理的方案。 相似文献
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Kana Yamashita Yasuhiko Hirakawa Shuetsu Saito Hiroshi Nakatani Motoyoshi Ikeda 《Journal of Wood Science》2011,57(5):363-370
To evaluate the bow variation in boxed-heart square timber of sugi (Cryptomeria japonica), bows from kiln-dried timber for five sugi cultivars with different longitudinal shrinkage trends were compared for two
stem heights. Two general trends were observed, depending on the cultivar: (1) either the bow was larger at the lower than
at the upper part of the stem, or (2) the bows at the lower and the upper parts of the stem were similar. In timber that had
larger bow values, the gradients of longitudinal shrinkage were large across the radius and along the length of the timber.
There was a positive relationship between the bow and longitudinal shrinkage. These results suggest that the bow variation
between the timbers was caused by a variation in longitudinal shrinkage, which was affected by the microfibril angle. Furthermore,
the bow was inversely proportional to the modulus of elasticity, which suggests that timber with a low modulus of elasticity
is susceptible to a large bow due to large longitudinal shrinkage. 相似文献
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竹层积材的非均匀性与纵向曲翘 总被引：1，自引：0，他引：1
讨论竹材与竹层积材非均匀性和纵向曲翘行为,由于竹篾的几何尺寸和组坯方式决定了竹层积材的非均匀性和随机性,从而决定了其非对称性。参照英国有关标准,测试了竹层压板的纵向曲翘行为。结果表明:材料有可能发生超过结构材要求的纵向曲翘。今后在建立有关标准时应增加相关条目。 相似文献
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王朗林区人工缺苞箭竹亚层数量特征及其模型刘兴良，向性明（四川省林业科学研究院成都６１００８１）关键词四川王朗，亚高山暗针叶林，亚建群层，缺苞箭竹，大熊猫，仿真造林缺苞箭竹（Ｆａｒｇｅｓｉａｄｅｎｕｄａｔａ）是四川王朗林区亚高山暗针叶林下亚建群层的主要... 相似文献
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ZHOU Yongdong** JIANG Xiaomei PIAO Chenghan Research Institute of Wood Industry Chinese Academy of Forestry Beijing P.R.China 《中国林业科技(英文版)》2006,5(3):17-21
INTRODUCTION Eucalyptus plantations have been important plantations in South China for its fast-growth rate. And the overall planted area is beyond 1.6 million ha, mainly distributed in the provinces of Guangdong, Guangxi, Yunnan, Fujian, etc. But, the main utilization is limited to wood chips currently. Along with the natural forest protection policy implementation, the wood resource has transferred from the natural forest to plantation forests, and the value-added application of plant… 相似文献
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Kana Yamashita Yasuhiko Hirakawa Shuetsu Saito Hiroshi Nakatani Motoyoshi Ikeda Masamitsu Ohta 《Journal of Wood Science》2014,60(1):1-11
The effect of cross-sectional dimensions on bow and surface checking were investigated, using the boxed-heart square timber of two sugi cultivars with dimensions 80, 120, and 140 mm and length 1.9 m taken at two different heights above the ground. The smaller cross-sectional timber tended to have larger bow, less surface checking, and larger dimensional shrinkage. However, the drying defects were different between the cultivars and sampling heights, depending on the shrinkage properties of the juvenile wood and the heartwood proportion in the core part of the stem. The bow was larger in the smaller cross-sectional timber in which the longitudinal shrinkage was large in the juvenile wood. Surface checking was more prominent in larger cross-sectional timber containing sapwood in its outer part, which suggested the surface checking was induced by drying stress, owing to large moisture gradients between the heartwood and sapwood. The cross-dimensional shrinkage of the timber was larger in timber with larger tangential shrinkage. 相似文献
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青藏高原退耕还林(草)地鼠害防治技术研究 总被引：9，自引：1，他引：9
在退耕还林草地设置鼠害防治试验示范小区，运用铗日法和化学药剂克鼠星对地上鼠进行防治试验。运用灭鼠雷、人工地箭及窒息灭鼠弹对地下鼠进行防治试验的结果表明：鼠药最佳投放时间应为每年的3—4月，灭鼠雷和人工地箭灭鼠率分别是70．8％和75．4％。 相似文献
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中华鼢鼠防治技术研究 总被引：2，自引：0，他引：2
通过4种药剂毒饵防治的对比研究和人工地箭防治,结果表明,溴敌隆毒饵不仅防治效果较好(86.7%),且属第二代抗凝血杀鼠剂,对其他动物低毒,不产生二次中毒现象;人工地箭的防治效果为62.7%~81.3%,平均74%,都是目前防治中华鼢鼠的较佳方法。 相似文献
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Multiple regression equations of compressive strength on linearand quadratic terms of top diameter, length, moisture content,number of rings at the top, and maximum bow have been fittedto data collected in a survey of the strength of pitprops cutfrom home-grown conifers. The resulting equations have providedadequate estimates of the strengths of home-grown pitprops forgiven combinations of size, moisture content, rate of growth,and degree of bow. 相似文献
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Pernambuco (Guilandina echinata Spreng. syn Caesalpinia echinata Lam.), which has been used for a material of violin bows, was compared with substitutable wood species from the viewpoint of processing properties and durability. The properties required for bow material are discussed. The shearing strength of pernambuco was higher than that of the other wood species at the same specific gravity. High shearing strength seems to be effective for preventing damage to the head (top part) of the bow. The presence of extractives affects the thermal softening of wood material, but ease of handling and permanent retention of form are not particularly superior for pernambuco, although it does have a high extractives content. A peculiarly low loss tangent (tan S) of pernambuco can probably be attributed to the large amount of extractives, rather than the mean microfibril angle.Part of this report was presented at the 46th Annual Meeting of the Japan Wood Research Society in Kumamoto, April 1996. 相似文献
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Magnus Fredriksson Olof Broman Fredrik Persson Ann Axelsson Pedro Ah Shenga 《Wood material science & engineering》2014,9(1):31-39
With the development of scanning technology in sawmills, it is possible to optimise log rotational position when sawing. However, choosing a different rotational position than horns down might be detrimental for the board shape after drying, especially for curved logs. Thus, there is a need to investigate at what level of log curve it is possible to freely rotate logs without causing board warp. This study was carried out through a test sawing that was conducted at a sawmill situated in the middle of Sweden. The tests were made on 177 Norway spruce logs, with varying amount of curve. Half of the logs were sawn in the horns-down position, half were sawn rotated perpendicular to horns down. Log shape and warp of the dried boards were measured. The results indicated a relationship between board spring, log curve and choice of rotational position. Furthermore, board bow was related to log curve but not rotational position. It can be concluded that for straight logs, with a bow height of less than 15 mm, an unconventional rotational position does not cause excess spring in the boards. Bow and twist are not affected by the rotational position at all. 相似文献