Latitudinal distribution of CO2 and CH4 on the route of the Chinese Arctic Research Expedition 2003     

张东启  徐建中  汤洁  温民 《极地研究(英文版)》2006,17(2):124-129

1 Introduction From July 10th to September 26, 2003,“Xuelong”scientific expedition icebreaker executed the 2nd Chinese Arctic Research Expedition (CHINARE2003). The voyage star- ted from Shanghai to Dalian via Yellow Sea and Bo Hai and the cruising rout…  相似文献   

PCI接口12通道2-16位可调DAC卡设计     

李辉  郑明雄  蒋朝根 《成都信息工程学院学报》2006,21(2):229-233

介绍了PCI接口芯片CH365和AVR单片机Megal28的工作原理，利用PWM（Pulse-Width Modulation脉宽调制）设计DAC卡的基本理论，详细讨论了利用CH365和Megal28实现PCI接口的12路多位接口卡的原理和方法，给出了软硬件设计的关键步骤和技术，并讨论了PWM输出的滤波电路。  相似文献   

三峡澎溪河水域CO₂与CH₄年总通量估算   总被引：1，自引：0，他引：1       下载免费PDF全文

李哲  白镭  蒋滔  郭劲松  刘静 《水科学进展》2013,24(4):551-559

以2010年6月~2011年5月三峡澎溪河回水区CO₂与CH₄通量监测数据为基础,参考澎溪河高阳平湖水域全年4次的24 h昼夜连续跟踪观测结果,对每月各采样点的日通量值进行估算。提出了水下地形划分法和环境因素控制法,将各采样点日通量数据外延至整个回水区水域,并估算了澎溪河回水区水域CO₂与CH₄年总通量值。研究期间,澎溪河回水区全年各采样点CO₂通量均值为(3.05±0.46)mmol/(m2·h);CH₄为(0.050 1±0.009 6)mmol/(m2·h)。以水下地形法为基础,该水域全年CO₂和CH₄总通量分别为40 060.5 t和540.9 t;以环境因素控制法为基础,全年CO₂与CH₄总通量分别为39 073.0 t和467.2 t。以环境要素控制法为参考,该水域CO₂全年平均释放强度为43.26 mmol/(m2·d),在全球水库数据序列中处于中等略偏高水平,CH₄全年平均释放强度为1.42 mmol/(m2·d),在全球水库序列中处于中等水平。  相似文献   

煤层气井压裂难易程度预测方法——以韩城区块为例     

贡玉军  郭大立  李铁军  李曙光  曾晓慧  计勇 《煤田地质与勘探》2012,40(2):23-27

预测煤层气井的压裂难易程度是制定煤层气井压裂方案的关键问题。目前,国内外还没有形成完善的压裂预测方法。以韩城区块煤层气井的压裂为例,通过测井资料和现场压裂数据,利用SPSS统计分析软件,运用多元逐步回归分析方法进行拟合,得到了煤层气井压裂难易程度预测公式。经过检验,发现该公式预测效果较好,具有一定的参考价值。   相似文献   

Hydropower – A Green Energy? Tropical Reservoirs and Greenhouse Gas Emissions     

Günter Gunkel 《洁净——土壤、空气、水》2009,37(9):726-734

Reservoirs are man‐made lakes that severely impact on river ecosystems, and in addition, the new lake ecosystem can be damaged by several processes. Thus, the benefits of a reservoir, including energy production and flood control, must be measured against their impact on nature. New investigations point out that shallow and tropical reservoirs have high emission rates of the greenhouse gases CO₂ and CH₄. The methane emissions contribute strongly to climate change because CH₄ has a 25 times higher global warming potential than CO₂. The pathways for its production include ebullition, diffuse emission via the water‐air interface, and degassing in turbines and downstream of the reservoir in the spillway and the initial river stretch. Greenhouse gas emissions are promoted by a eutrophic state of the reservoir, and, with higher trophic levels, anaerobic conditions occur with the emission of CH₄. This means that a qualitative and quantitative jump in greenhouse gas emissions takes place. Available data from Petit Saut, French Guinea, provides a first quantification of these pathways. A simple evaluation of the global warming potential of a reservoir can be undertaken using the energy density, the ratio of the reservoir surface and the hydropower capacity; this parameter is mainly determined by the reservoir's morphometry but not by the hydropower capacity. Energy densities of some reservoirs are given and it is clearly seen that some reservoirs have a global warming potential higher than that of coal use for energy production.  相似文献   

Synthesis of a Carbon Molecular Sieve from Broom Corn Stalk via Carbon Deposition of Methane for the Selective Separation of a CO2/CH4 Mixture          下载免费PDF全文

Fatemeh Banisheykholeslami  Ali Asghar Ghoreyshi  Maedeh Mohammadi  Kasra Pirzadeh 《洁净——土壤、空气、水》2015,43(7):1084-1092

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土壤含水量与温度对羊草、大针茅典型草原土壤—植物系统温室气体收支影响的初步研究   总被引：12，自引：0，他引：12  

杜睿  陈冠雄  吕达仁  王庚辰 《气候与环境研究》1997,2(3):273-279

本研究首次以我国内蒙古典型草原生态系统为研究对象,以密闭箱法对土壤－植物系统与大气间Ｎ２Ｏ和ＣＨ４气体交换进行了原位观测研究,通过结合实验室模拟实验研究表明,土壤含水量和温度对草原土壤－植物系统温室气体（Ｎ２Ｏ和ＣＨ４）排放通量有着重要的影响。在一定范围内,土壤含水量增加促进草原生态系统Ｎ２Ｏ排放和ＣＨ４吸收作用。温度升高促进草原生态系统Ｎ２Ｏ排放,但对ＣＨ４吸收的影响作用不明显。  相似文献   

Circumstellar matter in the symbiotic binary CH cyg during its current outburst     

A. Skopal  M. F. Bode  M. Bryce  J. Meaburn  S. Tamura 《Astrophysics and Space Science》1995,224(1-2):559-560

We present optical high-resolution spectroscopy and UBV photometry of the symbiotic binary CH Cyg during the current outburst which began in 1992 February.  相似文献   

The symbiotic star CH Cygni II. The ejecta from the 19982000 active phase     

S. P. S. Eyres  M. F. Bode  A. Skopal  M. M. Crocker  R. J. Davis  A. R. Taylor  M. Teodorani  L. Errico  A. A. Vittone  V. G. Elkin 《Monthly notices of the Royal Astronomical Society》2002,335(3):526-538

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气体（CH4、H2S、CO2）在水溶液中的溶解度模型     

段振豪  卫清 《地质学报》2011,85(7):1079-1093

本文介绍一个通过状态方程和特定粒子相互作用理论建立起来的气体在水溶液中的溶解度模型,用以计算气体(CH4、H2S、CO2)在纯水和含盐水溶液中的溶解度、流体包裹体的均一条件、成矿热液沸腾、流体不混溶性、水合物形成条件、CO2地质储藏量等.该模型不仅重现了上百套实验数据(约8000多个数据点),而且具有很强的外延能力.因...  相似文献