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41.
福建晚更新世海侵问题探讨 总被引:1,自引:0,他引:1
福建沿海在晚更新世大约距今90—80ka、70—60ka、44—39ka和34—20ka期间分别发生过4次海侵。最末一次海侵(距今34—20Ka)期间有过明显的海面下降波动,时间大约在距今28ka前后。 相似文献
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1998年夏季南海水团分析 总被引:8,自引:0,他引:8
根据 1 998年夏季“南海季风试验 ( SCSMEX)”期间所获的 CTD资料 ,使用系统聚类、Fuzzy模式聚类、Bayes判别分析和 Fuzzy分析等水团分析方法 ,对南海水体的结构和水团配置状况等进行了分析 ,划出了南海存在的 9个主要水团 ,并对各水团的温、盐度特征进行了初析。在调查期间 ,南海本地水 (南海水 )几乎控制了整个调查海区 ,而黑潮水仅出现在台湾岛的西南海域 ;海水强烈混合发生在吕宋海峡附近 ;在中南半岛以东和吕宋岛以西海域 ,表层水明显下沉 ;在南海东南部可能有来自苏禄海的海水 ,其温、盐度特征类似于吕宋海峡中的黑潮水 相似文献
44.
利用在九江-瑞昌MS5.7地震震中附近架设的丁家山台(DJS)、狮子洞台(SZD)和武蛟台(WUJ)的地震波形资料,采用S波分裂系统分析方法,对余震进行了S波分裂分析。结果表明,震中距较小、台站附近断层分布复杂的丁家山台(DJS)的慢波时间延迟相对较大,快波偏振方向不太集中。台站附近断裂分布单一的武蛟台(WUJ)快波偏振优势方向与断裂走向角度相差约35°,与区域主压应力方向也不一致。台站附近无断层通过的狮子洞台(SZD)快波偏振优势方向接近区域主压应力方向。慢波时间延迟大小与震源深度没有明显的规律性关系。 相似文献
45.
Jun Guo Jianzhong Zhou Lixiang Song Qiang Zou Xiaofan Zeng 《Stochastic Environmental Research and Risk Assessment (SERRA)》2013,27(4):985-1004
Assessment of parameter and predictive uncertainty of hydrologic models is an essential part in the field of hydrology. However, during the past decades, research related to hydrologic model uncertainty is mostly done with conceptual models. As is accepted that uncertainty in model predictions arises from measurement errors associated with the system input and output, from model structural errors and from problems with parameter estimation. Unfortunately, non-conceptual models, such as black-box models, also suffer from these problems. In this paper, we take the artificial neural network (ANN) rainfall-runoff model as an example, and the Shuffled Complex Evolution Metropolis algorithm (SCEM-UA) is employed to analysis the parameter and predictive uncertainty of this model. Furthermore, based on the results of uncertainty assessment, we finally arrive at a simpler incomplete-connection artificial neural network (ICANN) model as well as with better performance compared to original ANN rainfall-runoff model. These results not only indicate that SCEM-UA can be a useful tool for uncertainty analysis of ANN model, but also prove that uncertainty does exist in ANN rainfall-runoff model. Additionally, in some way, it presents that the ICANN model is with smaller uncertainty than the original ANN model. 相似文献
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48.
Zeng Jingjing Qu Jiansheng Pei Huijuan Dong Liping Liao Qin Liu Yanfei Zhang Zhiqiang 《地球科学进展》2015,30(11):1210-1217
The international climate change negotiation has been carried out over 20 years. The issue of climate change has shifted from a scientific question into a complex political matter which is related to the sustainable development of mankind. Based on the overview of major processes and stages of international climate conferences, this paper analyzed the key measures that major countries have taken to address climate change, as well as the primary tasks of Paris climate conference and recent international actions. The recent international climate policy issues were also analyzed in order to provide suggestions for China’s activel participation in the development of a new round of international climate change system. 相似文献
49.
Mingguo Zeng 《中国地球化学学报》2010,29(4):431-437
The 2008-05-12 Wenchuan mud-volcano-earthquake was accompanied with eruption of a huge volume of gas and stone, revealing
that earthquakes generally result from instant reverse phase explosion of supercritical water (SCW) at the supercritical point.
In the deep parts of the crust and mantle there still exists a large amount of supercritical water equivalent in order of
magnitude to that of the Earth’s hydrosphere. Soft fluids which exist in the MOHO at the top of the upper mantle are the so-called
deep supercritical fluids (SCWD). Supercritical water (SCW) has n×103 times strong capability to dissolve gas. Its viscosity is extremely low and its diffusivity is extremely strong. Therefore,
it can naturally migrate toward a region with relatively negative pressure. In the steep break zone of the MOHO at the 57–65
km depth beneath the earthquake belt, due to mutation of overburden pressure, SCWD can automatically separate out CaSiO3 and other inorganic salts, evolving into the SCW (H2O-CO2-CH4O system. In going upwards to the 10–20-km depth of the crust SCW will be accumulated as an earthquake-pregnant reservoir
in the broken terrain. The phase-transition heat of SCW is estimated at 606.62 kJ/kg and the reverse phasing kinetic energy
is 2350.8 kJ/kg. When automatic exhaust at the time of decompression reaches the critical pressure (Pc), the instant explosion
reverse phase will be normal-state air water. It will release a huge volume of energy and high-kinetic-energy gas which has
been expanded by a factor of 1000, leading to the breaking of the country rocks overlying the earthquake-pregnant reservoir,
thus giving rise to a Ms 8.0 earthquake. As a result, there were formed eruptive and air-driven (pneumatic) debris flows whose
volumatric flow rate reaches n×1014 m3/s, and their force greatly exceeds the power of INT explosive of the same equivalent value. 相似文献
50.
浅层地下水氟的溶解/沉淀作用的定量研究 总被引:12,自引:0,他引:12
以河北邢台山前平原浅层高氟地下水为例,根据氟的化学热力学分析,确定了控制浅层地下水中氟迁移和富集的固相沉淀物,以及不同化学类型的浅层地下水中含氟固相沉淀物的溶解/沉淀条件;利用浅层地下水化学平衡反应模型和PHREEQE软件,确定了氟化的稳定区域,计算了氟化钙的饱和指数.研究结果表明,在浅层高氟地下水的整个形成过程中,都表现为氟由固相转入水相的趋势,有利于氟的迁移和富集 相似文献