Results 51 to 60 of about 3,307 (154)

采煤塌陷对风沙区土壤理化性质影响的研究

open access: yesShuitu Baochi Xuebao, 2006
为了研究采煤塌陷对风沙区土壤理化性质的影响,为干旱和半干旱风沙区采煤塌陷地的复垦工作提供理论依据,本文运用土壤学基本理论和方法,测定、计算了毛乌素沙地东南缘补连塔煤矿塌陷区和非塌陷区的土壤机械组成、容重、孔隙度、田间持水量、饱和导水率和养分等指标。方差分析结果表明:与非塌陷区相比,塌陷沙丘物理性粘粒含量明显减少,尤其地表10 cm处;塌陷沙丘顶部和中部土壤容重和孔隙度没有明显变化,而沙丘底部和丘间低地土壤容重明显降低,孔隙度明显增大;塌陷沙丘0~40 cm内土壤容重和孔隙度无明显变化,但40~100 ...
王健   +4 more
doaj   +2 more sources

选择性填充光子晶体光纤的高灵敏温度传感

open access: yesGuangtongxin yanjiu, 2016
为了研制具有更高灵敏特性的温度传感器,文章提出利用光子带隙效应,在PCF(光子晶体光纤)中选择性填充热敏液体实现高灵敏温度传感。应用全矢量平面波展开法计算光纤带隙,带隙及其宽度随温度规律性漂移。当在包层空气孔中选择不同位置和结构填充热敏液体时,发现仅填充内层空气孔时,带隙随温度漂移造成的变化率最大。当在包层第一层空气孔中填充热敏液体,晶格周期Λ=9μm,空气填充率分别选取d/Λ=0.9和d/Λ=0.5时,带隙边界波长检测和带隙宽度检测的温度灵敏度分别可达到22.07和7.01nm ...
尤承杰, 施伟华
doaj  

[[alternative]]Cross-Flow Filtration of Soft Colloids [PDF]

open access: yes
計畫編號:NSC89-2214-E032-004研究期間:199908~200007研究經費:819,000[[sponsorship ...
黃國楨
core  

地下水引發自由端順向坡土體滑動特性分析 [PDF]

open access: yes, 2014
Retrogressive sliding can be observed in groundwater-induced landslides. The major inducing factor of this phenomenon is the fluidization in the down-hillslope and the soil of the bottom-layers.
Chun-Hung Wu   +5 more
core  

Spontaneous combustion characteristics of hydrothermal eroded coal in deep mining [PDF]

open access: yes
In the process of deep mining, the temperature of mine water is significantly higher than that of shallow coal seams. The erosion of high-temperature hydrothermal fluids affects the physical and chemical characteristics of coal, which in turn affects its
Daimin HU   +5 more
core   +1 more source

江西大岗山3种林型土壤水分物理性质研究

open access: yesShuitu Baochi Xuebao, 2008
对江西大岗山林区常绿阔叶林、杉木人工林和毛竹林土壤的容重、孔隙度、持水量和贮水量等物理性质进行了研究。结果表明:(1)常绿阔叶林、毛竹林和杉木人工林的土壤容重均随深度的增加而增加。在0~80 cm的土层中,杉木人工林、常绿阔叶林和毛竹林的土壤容重分别为1.29 g/cm3,1.24 g/cm3和1.20 g/cm3。(2)随土层深度的增加,3种林型土壤的总孔隙度、毛管孔隙度、饱和持水量和毛管持水量均逐渐降低。(3)在0~80 cm的土层中,常绿阔叶林的土壤总孔隙度和非毛管孔隙度最大,毛竹林次之 ...
王燕   +5 more
doaj  

[[alternative]]Mechanism of Microfiltration of Hand to Filter Slurries(II) [PDF]

open access: yes
計畫編號:NSC90-2214-E032-002研究期間:200108~200210研究經費:794,000[[sponsorship ...
黃國楨
core  

[[alternative]]The Study on Thermal and Fluid Technology of Micro Coolers(III) [PDF]

open access: yes
計畫編號:NSC90-2218-E032-014研究期間:200108~200207研究經費:372,000[[sponsorship ...
杜文謙
core  

Effect of holding time on microstructure of secondary carbonized briquette and strengthening of mechanical-seepage characteristics [PDF]

open access: yes
Physical simulation test is an effective method of occurrence mechanism and prevention and control of coal mine gas disasters. At present, the mechanical strength and permeability of briquette materials used in coal mine gas disasters physical simulation
Guoliang CAI   +4 more
core   +1 more source

退化第四纪红粘土重建森林模式及其土壤恢复研究

open access: yesShuitu Baochi Xuebao, 2004
以江西严重退化第四纪红粘土为研究对象,选择其中9种模式重建的林龄10年的森林,调查土壤理化性状,结果表明:(1)土壤有机质、全N、速效N、全P、速效P明显增加,而且增加幅度最大的是有机质;土壤全钾、有效钾都较大程度提高。(2)土壤有机质、全氮浓度随土层深度明显下降,有效磷、有效钾、有效氮浓度则随土层深度平缓下降,全磷、全钾浓度随土层变化不明显。(3)各重建森林模式的土壤容重、非毛管孔隙度也呈较大幅度降低;毛管持水量、毛管孔隙度呈不同幅度增加;不同重建模式总孔隙度变化的差异较大。
刘苑秋 杜天真 郭晓敏 杨国平 罗良兴
doaj   +2 more sources

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