共查询到20条相似文献，搜索用时 375 毫秒
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以油松、华山松为试验树种,进行了不同移植时间采取不同技术措施移植。结果表明,春季移植最佳;秋季喷施植物蒸腾抑制剂、树体输液以及夏季移植后遮阳都可以提高移植成活率15%~28%。 相似文献
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指出了中国北方农村广泛使用火炕进行采暖,但传统火炕存在空气污染和热效率比低下的问题。提出了一种新型的太阳能炕并建立了动态数值模型。基于该数学模型,以特定气象参数为条件,研究了太阳能炕的蓄热特性和炕表面温度特性。结果表明:在炕表面温度一定的条件下(25℃),房间空气温度波动非常小,炕内水管表面温度不超过40℃。因此太阳能热水很适合作为炕的加热热源。另外,炕的蓄热质量对房间温度影响较大,合适的蓄热质量能保证晚上炕没有加热的情况下,房间空气温度仍然处在舒适的范围。 相似文献
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为探讨银杏壮苗培育技术,于１９９６年进行了银杏有育苗试验研究,结果表明,选择有胚率高的大粒种子进行播种,易发芽出苗,且苗木粗壮,育苗对宜选择排水好的圃地进行育苗,苗床宜高,沟深应在２５ｃｍ以上,播种后即用地膜覆盖,能提高出苗率,提早出苗,提高生长量,夏季高温时,用塑料遮阳纱遮阳,可防止苗木曝晒,提高苗木保存率,促进苗木生长。 相似文献
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太湖流域位于我国长江中下游平原河网地区,是受全球气候变化和人类活动影响最显著的地区之一。该文利用太湖流域范围内的21个气象站点的长期观测资料,运用趋势系数、气候倾向率等方法分析了该区域的气候时空变化规律。结果表明,1958—2017年该区气温有显著上升趋势,平均气温以0.293℃/10a幅度升高。各月气温均呈上升趋势,但是冬、春季升温最为剧烈,达0.362℃/10a;夏、秋季最弱,为0.222℃/10a。由于最冷月平均温度升高比最热月大,所以导致气温年较差减少。气温升高存在显著的区域差异,东部地区增温剧烈,气温倾向率大于0.4℃/10a;最小的气温倾向率位于西南部地区,小于0.25℃/10a。流域降水总体呈增加趋势,平均年降水量倾向率为3.026mm/10a,东部地区和无锡、常州地区降水增加显著。全球变化及城市化的影响是导致流域气温和降水地区差异的主要原因。 相似文献
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当今世界几乎所有建筑都依靠机械性措施来维持室内舒适度,造成了能源危机、全球变暖等环境问题。于是人们开始回归传统,希望通过研究传统民居自身是如何通过被动性设计来适应地域气候的,来寻找出路。基于山西省晋中市太谷县气候特点,从空间设计、材料应用、技术应用、结构设计几个方面对三多堂进行气候适应性分析,寻求地域气候和传统民居之间的耦合关系,构建太谷县传统民居的气候适应性设计语言模式:主宅坐北朝南;适宜厚度的维护结构;向内型封闭空间;逐渐升高的台基;南大北无的窗洞;夏笼布冬窗纸;火炕。 相似文献
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文中介绍了一种新型工程竹产品——正交胶合竹（CLB）。已有试验对CLB墙体在稳态传热过程下的保温性能进行了探究，为进一步研究CLB墙体在室外综合温度周期性变化作用下的传热过程并探究采用CLB墙体的竹结构房屋的能耗情况，通过建立在稳态传热过程下CLB墙体的有限元模型并与已有试验结果对比验证了其有效性，从而进一步建立了受到室外综合温度作用下的5种墙体模型，以此分析CLB墙体在非稳态传热条件下的保温性能以及不同保温方式对于CLB墙体保温性能的影响，最后通过DeST对CLB墙体房屋进行能耗分析。结果表明：研究建筑墙体受到的温度作用时，太阳辐射引起的当量温度不应忽视；CLB墙体拥有优越的保温性能，采用CLB墙体的建筑室内热环境稳定；无论夏季或冬季，保温层最合理的位置在CLB墙体的外侧；围护墙体采用CLB墙体的竹结构能够达到江苏省居住建筑节能率65%的水平。 相似文献
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A disk-trenching experiment in thesub-boreal spruce zone of central British Columbia,Canada, established three plots (0.12 to 0.26 ha each)with trenches running east–west, and another threeplots with north–south trenches. Approximately 200Pinus contorta Dougl. seedlings were planted ineach of 13 microsites: berm, hinge, and trenchpositions in each of north, south, east, and westaspects, and in untreated locations between furrows.Soil temperature and soil moisture of representativemicrosites were monitored for 3 years; seedlingdiameter, height, and vigour were monitored annuallyfor ten growing seasons. Based on tenth-year stemvolumes, performance on south-, east-, and west-facingmicrosites was significantly greater than onnorth-facing or untreated microsites. Superior growthwas noted on all berm and hinge positions other thanthose facing north. Microsites identified as best inyear 5 were also best in year 10. On east-, south- orwest-facing berm positions, stem volume averaged 47%to 54% greater than that of control seedlings in year5, but had suffered greater mortality. Seedlings oneast-, south- or west-facing hinges were 46% to 61%(year 5), or 36% to 47% (year 10) larger thancontrol seedlings. Both east–west and north–southdisk-trenching treatments are useful for increasingseedling growth, with planting spot selection beingmore important overall than trench orientation. Thestand-level effectiveness of north–south disktrenching was greatest, because the creation of coolnorth-facing microsites was avoided. 相似文献
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This survey was conducted from 2005 to 2008 regarding the thermal environment of three types of experimental houses—a wood and mud composite wall type (Type WM), a mud wall type (Type M), and an insulated wall type (Type I). To reveal the influence of the wall composition of wooden houses on the indoor thermal environment, each experimental house was constructed on the same site. As a result, under natural indoor air temperatures, the monthly average indoor air temperature level and the time ratio of indoor air temperature surpassing the outdoor air temperature were in the following order: Type I > Type WM > Type M. Type WM exhibited the highest phase shift of air temperature, indicating that the insulation performance and heat capacity affect the phase shift of air temperature. The equalization of indoor air temperature through the suppression of the increase in the indoor air temperature of Type M is likely caused by low insulation performance and large thermal capacity. The time fluctuations in electric consumption by air conditioning and indoor–outdoor air temperature differences of each experimental house over 1 day indicated that a building’s thermal load and the thermal capacity are related. 相似文献
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为探索城市森林环境空气负氧离子水平,2016年9月至2017年8月,采用便携式负离子监测仪对湖南省森林植物园不同林分森林环境空气负氧离子浓度进行了观测,根据获取的资料分析了湖南省森林植物园空气负氧离子的季、月和日变化特征,以及空气负氧离子与气象因子的相关关系。结果表明:湖南省森林植物园负氧离子浓度年平均值为845个·cm-3;季变化中,其最大值出现在夏季,平均949个·cm-3,最小值出现在冬季,平均440个·cm-3;月变化中,其最大值出现在8月,平均1 071个·cm-3,最小值出现在1月,平均310个·cm-3;在日变化中,上午06:00—07:00空气负氧离子浓度最高,平均1 600个·cm-3,中午12:00—13:00最低,平均620个·cm-3。温度与负氧离子浓度表现出正相关,而湿度与负氧离子浓度表现出负相关。针叶林的空气负氧离子浓度要高于阔叶林。 相似文献
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lntroductionThepIantingofFraxiusm8ndShurfoabeganatShangzhi,Kedong,YianandFujincountiesofHei-longjiangProvincein196o'.Ash(hainusmand-shurica)andlarch(LarisgmehnI),AshandKoreanpine(PinuskoraiensiS)mixedstandwereremainednow,whichwereartificial,orformedbyplantingAshatterpIantingpureconiferousforest,orinducedbyestablishingeffectareainnaturalashforest.TherearemanyreferencesonthegrowthofashmixedstandinChina.Butinthepast,thestudyoftherela-tionshipbetWeentheincreasinggrowthofmixedstandwithdiffe… 相似文献
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In this study,the durability of rubber wood(Hevea brasiliensis) which was thermally treated at 170,185,200,and 215℃for 3 h respectively was investigated.The results showed that the durability of heat-treated rubber wood was improved,and the improvement became more obvious with the increase of the treating temperature. When treated at 185℃or lower temperature,the decay resistance of treated wood had no significant improvement.The lowest weight losses were 21.6%and 6.8%after attack by brown rot fungi(Gloeophyllum trabeum) and white rot fungi (Coriolus versicolor) respectively,which were reached by the specimens treated at 215℃.Their resistance to mold fungi was not improved,but the heat-treated wood performed better than untreated wood when both were painted.In field test,the heat-treated specimens exhibited no advantage in termite resistance compared to untreated. 相似文献
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研究木粉/高密度聚乙烯(WF/HDPE)复合材在不同朝向的自然老化条件下使用时颜色与表面化学成分的变化,并分析采用光稳定剂、抗氧剂和颜料作为防老化剂的效果.户外使用的木粉/HDPE复合材在夏天暴晒1个月颜色就会发生明显变化,南面和东面更加显著,红外分析表明:复合材料表面C=O增加、木材指数下降,有氧化现象发生.人工加速稳定老化检测结果表明:与抗氧剂和光稳定剂相比,颜料的使用对减小变色有明显作用,但颜料、抗氧剂和光老化剂3种助剂对延缓WF/HDPE复合材的抗弯性能下降没有起到明显作用. 相似文献
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指出了居家环境一直为人们普遍关注,建筑室内氡污染主要来源于建筑物地基及周围表层土壤、建筑材料、家用燃气、生活用水、室外空气、地下深部的氡6类,然而按世界平均水平计算,来源于建筑物地基及周围土壤的氡浓度约占室内氡浓度的60.4%,故针对腾冲县火山地质博物馆建筑地基及周围土壤氡浓度进行了检测和分析,提出了相应的建议,以更好的服务于游客。 相似文献