Another Source of Atmospheric Methane

The atmospheric concentration of methane is steadily increasin.Lacking of precise estimates of source and sink strengths for the atmospheric methane severely limits the current understanding of the global methane cycle.Agood budget of atmospheric methane can enhance our understanding of the global carbon cycle and global climate change,The known estimates of the main source and sink strengths are gresented in this paper,In terms of carbon isotopic studies,it is evidenced that the earth‘s primodial methane,which was trapped in the earth during its formation,may be another source of methane,with extensive,earth‘s degassing which is calleld the “breathing“ process of the earth and played an important role in the formation of the promitive atmosphere,large amounts of methane were carried from the deep interior to the surface and then found its way into the atmosphere.     

跨孔条件下椭球模型的视电阻率异常特征

在跨孔条件下，利用积分方程法计算了孔区内外不同位置、不同产状的三维椭球体模型视电阻率异常。根据所得的典型数值模拟结果，借助视电阻率异常信息剖面图，对异常进行研究，总结了异常特征及其变化规律，并以此为基础分析和认识了其他模型的异常特征。     

Coal-generated oil in Tuha Basin

The Turpan-Harmi (abbreviated to Tuha below) Basin is a typical basin of coal-generated oil accumulation in China. The Middle-Lower Jurassic coal measures are considered the main source beds. Hence, both desmocollinite and suberinite are considered the contributors for coal-generated oil. Principal geochemical features of the crude oil in the Tuha Basin are rich in alkanes (70%—80%), high pristane/phytane ratio (6—8), abundant heavy carbon isotope (δ¹³C PDB= -26%–-23%) and absolute GP sterane predominance. The hydrocarbon generation process from the coal series is characterized by multistages, early generation and early expulsion.     

AN APPARENT TEMPERATURE MODEL BASED ON THERMAL EQUILIBRIUM

In this paper,a comprehensive analysis and review of the advances in the research of human body comfort degree is made.Based on the studies of human thermal equilibrium theories contributed by previous researchers,different apparent temperature models corresponding to different environments are set up in accordance with the current situation and the characteristics of metabolism in different groups of people in China.After case studies and comparison with present dominant human body comfort degree statistical models,it is proved that the apparent temperature models have high rationality and wide adaptability.Furthermore,the comfort scaling standard according to apparent temperature is suggested,which is suitable for the middle latitude regions in China.     

VICARIOUS RADIOMETRIC CALIBRATION OF SATELLITE FY-ID SENSORS AT VISIBLE AND NEAR INFRARED CHANNELS

For the problem of in-flight test site radiometric calibration for the FY-1D Meteorological Satellite onboard sensor's visible and near infrared channels,this paper described the calibration method,satellite-ground synchronous observation data acquired at China Dunhuang Calibration Test Site,parameter derivation and radiative transfer computation during the calibration,and the calibration result analysis.At FY-1D seven channels (with central wavelength at Channels 1:630 nm,2:865 nm;6:1610 nm;7:455 nm,8:505 nm;9:555 nm;10:932 nm),calibration coefficients obtained during the ground site calibration were compared with that respectively of prelaunch calibration.It is demonstrated that results of FY-1D onboard two sensors' (A and B) at channels 1,2,6 and 10 were close to pre-calibration,and the absolute difference of Gobi desert reflectance computed using test site and pre-launch calibration coefficients was no more than 2%. At other channels,large pre-launch calibration errors resulted in a poor consistency between the test site and pre-launch calibration.The errors can be corrected by the test site calibration results. Based on a rough estimation,the overall error of the calibration was about 6%. The paper also presented the in-flight vicarious calibration at the visible and near infrared channels of FY-1C sensor A which was launched in 1999 and has been put into operational mode since 2002.The results exhibit that FY-1C sensor's response has 23% attenuation at Channels 7 and 8,while only minor degradation at the other channels was found. During the mission,calibrations were also conducted at NOAA-17's Channels 1 and 2 (1:430-830 nm,2:500-1072 nm).A very good consistency has been achieved between the test site and pre-launched calibration results.     

贵州百花湖分层晚期有机质降解过程与溶解N2O循环

百花湖是一个具有季节性分层的富营养小型湖泊,在秋季湖水倒转期经常发生水质恶化事件,碳氮循环出现异常。文章研究特选择在秋初,湖泊分层开始消失时,测定了湖水中不同深度的N₂O,CH₄,CO₂,有机和无机碳同位素以及其他化学参数变化。结果发现:采样时百花湖在约6m和16m深度附近出现了两个温度不连续层(SDL和PDL),并影响到有机颗粒的沉降和分解。相对而言,有较多的有机质在这两个层内发生降解,但降解的途径有所不同,上部主要是有氧降解,下部则主要是无氧降解过程。N₂O的产生和消耗与有机质的降解过程完全对应:PDL层以上,ΔN₂O与AOU的线性关系反映了N₂O主要形成于硝化作用;PDL层以下反硝化作用导致N₂O严重不饱和;PDL内位于硝化作用和反硝化作用过渡带的N₂O峰,显然是硝化与反硝化联合作用的结果。PDL层内较大的CH₄浓度变化梯度,说明嗜甲烷细菌可能通过氧化NH+4贡献了部分N₂O。百花湖秋、冬季表层湖水N₂O都是过饱和的,都是大气N₂O的源,依据分子扩散模型计算湖泊N₂O的释放通量在12～14μmol/m·day之间,秋、冬季没有明显的差别。秋季底层湖水的反硝化作用是湖泊N₂O的汇,其消耗通量与表层的释放通量基本相当。     

冻融试验对土中含水量分布的影响

The silty clay and silty loam are two typical soil types obtained from two test sites along the Qinghai-Tibet railway. The two types of soil have been designed various initial dry densities, water eontents, temperature conditions in repeated freezing and thawing tests with free access to water at the bottom. Afterfreeze-thaw cycles, the moisture content in the freeze-thaw zone increases more than that in the unfrozen zone to the peak approximately at the top of the samples. With comparison of the water contents in the frozen and thawed states, the moisture content in the upper freeze-thaw zone in the frozen state is greater than that in the thawed state, while that in unfrozen zone in the frozen state is smaller than that in the thawed state. Within the region of the frost front, the water content in frozen state is smaller than that in thawed state. These findings help to study the freeze-thaw mechanisms deeply and perfect the forecasting module of moisture transferring in freeze-thaw cycles.     

渍水麦田土壤水分动态模型研究

根据土壤水分平衡原理，建立了一个反映土壤渍水、可与小麦生长模型耦合的土壤水分动态模型，尤其考虑了因地下水位较浅而引起的毛管上升水量和土壤导水率的变化对土壤含水量的影响。采用盆栽小麦水分试验资料验证了日蒸散量的模拟值，利用湖北荆州农业气象试验站和江苏金坛农业气象试验站的土壤水分历史资料对建立的模型进行了综合测试和验证，结果表明:蒸散量、地下水位和0～50 cm土壤含水量的模拟值与实测值具有较好的一致性，模型能可靠地预测多雨和渍水地区麦田土壤水分的变化动态     

SSM/I资料反演大范围地表湿度试验

利用SSM/ I遥感数据, 结合2002年汛期“973”外场观测资料及T106资料, 借助微波辐射传输正演模型, 通过物理反演原理提取SSM/ I低频19 GHz通道像元平均地表微波比辐射率, 然后利用地表微波辐射模型, 估算SSM/ I像元的地表湿度信息。以2002年8月中旬发生在长江流域的暴雨天气过程为例, 将反演得到的地表湿度信息与地面观测到的降水信息进行对比分析, 并与地面的洪涝特征进行对比分析, 得到了与地面降水观测结果较为一致的对比结果。     

区域地球化学数据的归一化处理及应用

介绍了一种简单的勘查地球化学数据调整方法———归一化,该方法采用各批或各区块差异数据的平均值或中位数的衬值乘以参照值以获得元素的视含量,用于调整不同分析批次之间的系统误差,或不同背景区数据的差异;用2个实例详细介绍了该方法的应用效果。