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971.
各种大气水汽输送气候计算方法的比较和讨论 总被引:4,自引:0,他引:4
比较瞬时法,平均法和逐层平均法3种水汽输送气候计算方案,发现它们的输送方向大致相同,输送量差异显著。瞬时法最准确;逐层平均法次之,但误差的年际波动较大,平均法虽然简单然而误差大。 相似文献
972.
沈健伟 《沉积与特提斯地质》1994,(4)
桂林地区晚泥盆世法门期末,海平面变化表现出高频率的特点,由此产生了5级旋回──PAC(punctuatedaggradationalcycles)。PAC是一种地层的幕式堆积方式,表现为间断加积的特点。本文讨论了桂林D/C界线层的PAC,并认为PAC中向上变浅之后出现的暴露面加上代表海水陡然加深的的页岩是短距离内不同相地层对比的极好标志,文中以额头村剖面新发现的可形刺:Pseudopolygnathusdentilineatus和Pseudopolygnathuscontraversus作为参照物,对额头村剖面和南边村剖面的PAC进行对比,从而提高浅水相D/C界线的精度。 相似文献
973.
The statistical relationship between the summer monsoon rainfall over all India, northwest India and peninsular India, onset
dates of monsoon and the index of mid latitude, (35° to 70°N) meridional circulation at 500 hPa level over different sectors
and hemisphere based on 19 years (1971–1989) data, have been examined. The results indicate that (i) the summer monsoon rainfalls
over all India, northwest India and peninsular India show a significant inverse relationship with the strength of meridional
index during previous January over sector 45°W to 90°E. (ii) The summer monsoon rainfalls over all India and peninsular India
show a significant inverse relationship with the strength of meridional index during previous December over sector 90°E to
160°E, (iii) The summer monsoon rainfall over northwest India shows a significant direct relationship with the meridional
index during previous May over sector 160°E to 45°W.
Significant negative relationships are also observed between the meridional circulation indices of previous October (sector
3 and 4), previous December (sectors 1, 3 and 4), previous winter season (sector 3 and 4) and the onset dates of summer monsoon
over India. The meridional circulation index thus can have some possible use for long range forecasting of monsoon rainfall
over all India, northwest India and peninsular India, as well as the onset dates of monsoon. 相似文献
974.
Luo Zhexian 《Acta Meteorologica Sinica》1994,8(1):60-71
The computational formulae are given for single-contour constant-value vortex motion influenced by the Coriolis force in the framework of contour dynamics,by which four numerical computations are performed,the result exhibiting their validity. 相似文献
975.
高温热水孔逸出气氡观测实验研究 总被引:3,自引:0,他引:3
本文通过在漳州龙师1#井开展的逸出气氡观测实验研究,认为逸出气氡作为新的地震前兆观测项目是可行的,可以进行平行样观测,同时可得到Rn气/Rn水比值,作为研究地下流体前兆的一个新的参数。并对应用电离法测量逸出气氡的连续自记观测技术进行了预研究试验。 相似文献
976.
977.
祁连山中段深部电性结构及潜在震源危险区的研究 总被引:3,自引:1,他引:3
位于青藏高原北缘的祁连山中段是地震十分活跃的地区之一。本课题采用MT重复测量方法,在该区建立的长约400km的剖面上进行监测。本文根据监测所获取的MT参数,从静态的角度探讨了该区深部电性结构及其电性横向变化特征,进而评估了该区的潜在震源区。研究发现,该区深部介质电性的物质特征有:1.部分地带呈现出剧烈的电性横向变化,2.具有极为发育的特殊增厚的壳内高导层地段,3具有高、低热流的过渡边缘地带,4.具有与活动大断裂相交汇的隐伏断裂构造的局部地段。近年来该区地震活动增强,数次中强地震都发生在具有上述特征的地带中,该地带将可能是祁连山中段的强震-大震潜在震源危险区。这四种电性特征将是潜在震源区的判别标志。 相似文献
978.
A highly sensitive and specific enzyme immunoassay (EIA) is described for the detection of the atrazine metabolite hydroxyatrazine. Polyclonal antibodies were raised in rabbits by immunization with a hapten-bovine serum albumin (BSA) conjugate containing 8 hapten residues per molecule of BSA. An EIA with a horseradish peroxidase (HRP) hapten tracer was optimized in microtitre plates. A concentration of 50% B/B0 was found at 0.10 μg/L for hydroxyatrazine. A limit of determination for hydroxyatrazine was reached at approximately 0.01 μg/L, i.e. well below the maximum concentration permitted by the EU guidelines for drinking water and the drinking water ordinance of the FRG. The assay did not require concentration or clean-up steps for drinking water or ground water samples. Validation experiments confirmed a good accuracy and precision. Hydroxyatrazine is reported to be the main atrazine metabolite found in soil samples. As organic solvents are usually employed for soil extraction, the influence of methanol as representative organic solvent on the assay was examined. Up to a concentration of 5% (v/v) methanol, the organic solvent did not affect the assay. 相似文献
979.
本文介绍了土壤样氦气测量方法勘查隐伏陷落柱及其找深部铀矿的简要原理和应用效果。通过对5个实例的氦异常特征研究,表明在陷落柱边缘及其中部氦含量变化明显;在隐伏铀矿体的垂直投影部位,地表有较好的氦异常。从而说明:用该法可为煤矿寻找隐伏的陷落柱,可以探测与成矿有关的岩溶塌陷构造,寻找铀矿及各种断裂构造,可以为各种受断裂控制的热液矿床指明远景地段,为勘探设计提供依据。 相似文献
980.
Stem wood of the Angiosperm Calluna vulgaris (Scotch heather), isolated at different depths from a selection of raised bog peat deposits, was chemically characterized using in-source pyrolysis mass spectrometry (Py-MS) and Curie-point pyrolysis gas chromatography mass spectrometry (Py-GC-MS). Light microscopy was performed to relate mass spectrometric characteristics with anatomical features. Peatified wood samples, isolated from increasing depth show a gradual decrease in carbohydrate content. This decrease in anatomically reflected in a selective removal of secondary cell wall material from the fibre-tracheids and wood parenchyma. During prolonged peatification a selective removal of hemicellulose sugars is observed, while a part of the cellulose fraction is preserved. This highly resistant cellulose is mainly located in the secondary cell walls of the vessels. The lignin macromolecule is preserved, but a gradual decrease in syringyl to guaiacyl ratio (S/G) is observed during peatification. Because no increase in catechol and phenolic compounds is observed, we conclude that S/G shifts are due to removal the of syringyl-rich secondary cell wall material and the retention of guaiacyl-rich compound middle lamella. Small chemical changes in the lignin macromolecule involve shifts in oxygen substitutions on the aliphatic side chains of the methoxyphenolics and the occurrence of aromatic acids. 相似文献