海相碳酸盐岩碳同位素地层学研究中存在的问题及建议——以二叠系研究为例

以二叠系碳同位素地层学研究为例,在有条件控制的实验模拟基础上发现：1）采集到的地质样品一般都是不同碳酸盐矿物的混合样品,这些不同碳酸盐矿物具有不同的碳氧同位素比值（δ13C和δ18O）;2）自然露头和采石场剖面样品的无机碳氧稳定同位素组成会在可预见的时间内发生足以影响研究结果的淋滤交代作用;3）利用地层中碳酸盐样品的δ...     

频谱分析法在反演造山带地形高差演化中的应用——以中国大别山、米仓山和美国内华达山脉为例

近年来迅速发展的低温热年代学已极大改善了人们对地壳内(1～6 km)隆升和剥蚀过程的认识.然而在实际工作中,样品的采集除了受到气候、地理环境等恶劣条件的制约以外,在对低温热年代学数据进行解释或以此计算造山带的隆升剥露速率时,使用的一些有关近地表热结构的假定条件通常是不科学的,如将易受地表起伏影响的地热等温线形态考虑成水...     

工业化进程中能源的演变与勘探地球物理学的发展

论述了三次工业革命过程中的能源演变规律及其对勘探地球物理学发展的推动作用和我国工业化进程中的能源形态及我国勘探地球物理学的发展。认为勘探地球物理学的发展与社会工业化进程、能源结构变化密切相关;勘探地球物理学的发展具有与时俱进性,能创造巨大的经济效益,在世界能源和我国国家建设的特殊时期中有战略地位,并将面临从＂找矿型＂转变成为＂社会型＂的学科的必经之路。     

Impacts of diverted freshwater on dissolved organic matter and microbial communities in Barataria Bay, Louisiana, U.S.A

Here we present results of an initial assessment of the impacts of a water diversion event on the concentrations and chemical composition of dissolved organic matter (DOM) and bacterioplankton community composition in Barataria Bay, Louisiana U.S.A, an important estuary within the Mississippi River Delta complex. Concentrations and spectral properties of DOM, as reflected by UV/visible absorbance and fluorescence, were strikingly similar at 26 sites sampled along transects near two western and two eastern areas of Barataria Bay in July and September 2010. In September 2010, dissolved organic carbon (DOC) was significantly higher (568.1-1043 μM C, x=755.6+/-117.7 μM C, n=14) than in July 2010 (249.1-577.1 μM C, x=383.7+/-98.31 μM C, n=14); conversely, Abs254 was consistently higher at every site in July (0.105-0.314) than in September (0.080-0.221), averaging 0.24±0.06 in July and 0.15±0.04 in September. Fluorescence data via the fluorescence index (FI450/500) revealed that only 30% (8 of 26) of the July samples had an FI450/500 above 1.36, compared to 96% (25 of 26) for the September samples. This indicates a more terrestrial origin for the July DOM. Bacterioplankton from eastern sites differed in composition from bacterioplankon in western sites in July. These differences appeared to result from reduced salinities caused by the freshwater diversion. Bacterioplankton communities in September differed from those in July, but no spatial structure was observed. Thus, the trends in bacterioplankton and DOM were likely due to changes in water masses (e.g., input of Mississippi River water in July and a return to estuarine waters in September). Discharge of water from the Davis Pond Freshwater Diversion (DPFD) through Barataria Bay may have partially mitigated some adverse effects of the oil spill, inasmuch as DOM is concerned.     

多离子成分空间等离子体中斜传播波的混杂共振：（Ⅱ）实验观测与波模识别

在分析ＡＲＣＳ３探空火箭记录到的由人工离子束激发的低频等离子波的特征和激发机制的过程中，提出了多离子成分冷等离子体中的一般混杂共振和一般混杂波的概念，给出了斜向传播冷等离子体波的混杂共振条件．在上述理论的基础上，考虑了电子、氧离子、氦离子和人工氩离子束的贡献，计算出ＡＲＣＳ３实验条件下的等离子体介电函数，并用等离子体波模识别的方法，识别出频率在１８０Ｈｚ。附近的最强波峰乃是Ｏ＋－Ｈｅ＋双离子混杂波．     

水平冲击矛钻进轨迹理论分析

本文首先对被研究对象水平冲击予及土体做了若干假设，并在此基础上建立起力学模型，然后找出研究对象所有受力并对它们进行分析，简化，最后从力学角度对水平冲击矛钻进轨迹进行了分析。     

静压注浆在房屋基础加固中的应用

由于房屋基础下覆地基存在软弱层，临近桩基施工抽水所引起的地基不均匀沉降导致房屋出现开裂现象，通过静压注浆的方法将地基进行加固，阻止裂隙了的发育，并将地面抬高，使裂纹有所吻合，取得较好的效果。