共查询到20条相似文献,搜索用时 140 毫秒
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多次复合剂不但能驱避鸟鼠危害,提高出苗率,还能促进苗高、地径的生长。山杏采用多效复合剂处理后直播造林,每公顷减少鼠类危害126穴,出苗率平均提高9.6%;苗高、地径平均分别提高24%和38%。一次造林成功,达到规程标准。 相似文献
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如何使种子田间出苗率接近室内发芽率王枝梅种子检验的目的是评价种子的播种价值,也是在种子商品贸易中作出的质量保证。历年来,有不少消费者反映买回去的种子田间出苗率太低,与种子销售部门提供的发芽率有明显差异。这不仅给消费者造成了很大的经济损失,而且给种子销... 相似文献
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播种深度和土壤质地对麻黄种子发芽出土影响极显著,其中播深与出苗率呈极显著负相关,出苗率随覆土厚度的降低出苗量显著增加,以覆土0.5~1.0cm覆土最好,土质与出苗率的影响呈显著正相关,出苗数随土壤的疏松和颗粒增大出苗率迅速增大。 相似文献
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The rate of thermal degradation of wood as a function of the extent of heat-bath treatment was investigated. At both 150°C
and 170°C, the rate of degradation increased along with increasing relative humidity in the heating atmosphere. However, up
to intermediate relative humidity (in the vicinity of 50%), the higher the temperature, the less was the effect of increasing
relative humidity on the degradation rate. Furthermore, the greater the relative humidity, the less was the effect of increasing
temperature on the degradation rate. On the other hand, between intermediate relative humidity and water-saturated conditions,
the effect of increasing relative humidity on the degradation rate was the same regardless of the temperature, and the effect
of increasing temperature on the degradation rate was the same regardless of the relative humidity. In moist conditions, significant
thermal degradation occurred at temperatures as low as 150°C. 相似文献
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双江县华山松球蚜发生数量研究 总被引:3,自引:0,他引:3
华山松球蚜以成虫和若虫群集在华山松嫩枝,梢,针叶上吸食汁液。温度和湿度对华山松球蚜的发生影响较大;相对湿度在58%-70%,危害严重,相对湿度在75%以上时,华山松球蚜数量减少;5月为发生危害高峰期。 相似文献
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以河南科技学院东区校园的3种人工植物群落及裸地(对照)为对象,通过对群落内一些气象要素的实地观测,比较详尽的分析研究了这几种植物群落的园林生态效应。结果表明:(1)植物群落内的光照度、地表(0 cm)温度、表层(-5.0 cm)土壤温度、空气温度、空气湿度的日变化曲线与对照(裸地)日变化曲线相似。(2)混合草坪—黄杨—国槐群落(草灌乔)在3种观测的植物群落中,其生态效应最为明显。与对照(裸地)相比,它的遮光率、地表(0 cm)的平均降温率、表层(-5.0 cm)土温的平均降温率、气温平均降温率、平均增湿效应分别为36.3%、34.7%、18.9%、6.9%、13.9%;桐树林群落(草乔)次之,而混合草坪—黄杨群落(草灌)为最低。据此,提出了优化校园园林生态系统结构的措施。 相似文献
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沙地建立平欧杂种榛园初期,通过在防护林带内种植玉米等高秆作物试验,结果表明:榛园建园初期,在防护林带内种植玉米等高秆作物并保留茎秆,可增强林带的防护能力,大幅度提高造林成活率和保存率,减少抽条现象的发生,减轻风沙对幼树的为害,促进树木的生长。玉米防护带可降低风速,减少园内的水分蒸发,提高了温湿度,有利于改善榛树授粉条件,延长了授粉时间。 相似文献
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As a measure of estimating humidity control capacity of materials in an airtight room under sinusoidal temperature variation,
we used the Cb value, which is the ratio of the range of variation in relative humidity in a steel box lined with the material of interest
to the range in an empty steel box. In order to clarify the factors that affect the Cb value, we focused on both the temperature variation rate and the area that is lined in the box. It was found that changing
the rate of temperature variation over one period strongly affected the Cb value, although the amplitude of temperature variation did not. We further noticed that the difference between the time when
peak temperature was reached and the time when peak absolute humidity was reached (peak time difference), was found to be
useful for estimating the humidity control capacity of materials. Knowing the difference between the phase when peak temperature
was reached and the phase when peak absolute humidity was reached (phase angle difference) was also useful. Because the Cb value was affected by both the variation period and the lined area in the box, we can draw a contour diagram of the period
and the lined area for materials to give an overview of the humidity control capacity of a material. The materials of primary
interest in this study were Japanese cedar and porous ceramics. 相似文献
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分析对大型结构损伤识别产生影响的环境因素及其影响机理,以海洋平台及其所处海洋环境为例,定量分析结构在温度、湿度、附着海洋生物、附连水质量和潮汐等因素改变的情况下结构模态参数的变化。 相似文献
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选择城阳区13种地被植物,进行植物吸热降温效益的测定与计算。结果表明:蔷薇、黄花鸢尾、火棘、五叶地锦日蒸腾释水量和日蒸腾吸热量较高,是较好的吸热降温树种,而大叶黄杨、金叶女贞较低。灌木地被单位叶面积蒸腾吸热量明显高于藤本和草本地被。 相似文献