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51.
52.
天然气水合物的地热研究进展 总被引:8,自引:0,他引:8
天然气水合物的地热研究在以下几个方面都取得了重要进展,热流与似海底反射层的关系,水合物稳定带的研究;水合物热物理参数的确定;水合物形成过程中的热状态;热导率的应用,指出了今后水合物的地热学研究方向。 相似文献
53.
H. O. Prtner B. Berdal R. Blust O. Brix A. Colosimo B. De Wachter A. Giuliani T. Johansen T. Fischer R. Knust G. Lannig G. Naevdal A. Nedenes G. Nyhammer F. J. Sartoris I. Serendero P. Sirabella S. Thorkildsen M. Zakhartsev 《Continental Shelf Research》2001,21(18-19)
Effects of global warming on animal distribution and performance become visible in many marine ecosystems. The present study was designed to develop a concept for a cause and effect understanding with respect to temperature changes and to explain ecological findings based on physiological processes. The concept is based on a wide comparison of invertebrate and fish species with a special focus on recent data obtained in two model species of fish. These fish species are both characterized by northern and southern distribution limits in the North Atlantic: eelpout (Zoarces viviparus), as a typical non-migrating inhabitant of the coastal zone and the cod (Gadus morhua), as a typical inhabitant of the continental shelf with a high importance for fisheries.Mathematical modelling demonstrates a clear significant correlation between climate induced temperature fluctuations and the recruitment of cod stocks. Growth performance in cod is optimal at temperatures close to 10°C, regardless of the population investigated in a latitudinal cline. However, temperature specific growth rates decrease at higher latitudes. Also, fecundity is less in White Sea than in North and Baltic Sea cod or eelpout populations. These findings suggest that a cold-induced shift in energy budget occurs which is unfavorable for growth performance and fecundity. Thermal tolerance limits shift depending on latitude and are characterized by oxygen limitation at both low or high temperatures. Oxygen supply to tissues is optimized at low temperature by a shift in hemoglobin isoforms and oxygen binding properties to lower affinities and higher unloading potential. Protective stimulation of heat shock protein synthesis was not observed.According to a recent model of thermal tolerance the downward shift of tolerance limits during cold adaptation is associated with rising mitochondrial densities and, thus, aerobic capacity and performance in the cold, especially in eurythermal species. At the same time the costs of mitochondrial maintenance reflected by mitochondrial proton leakage should rise leaving a lower energy fraction for growth and reproduction. The preliminary conclusion can be drawn that warming will cause a northern shift of distribution limits for both species with a rise in growth performance and fecundity larger than expected from the Q10 effect in the north and lower growth or even extinction of the species in the south. Such a shift may heavily affect fishing activities in the North Sea. 相似文献
54.
The heat capacity of natural chamosite (XFe=0.889) and clinochlore (XFe=0.116) were measured by differential scanning calorimetry (DSC). The samples were characterised by X-ray diffraction, microprobe analysis and Mössbauer spectroscopy. DSC measurements between 143 and 623?K were made following the procedure of Bosenick et?al. (1996). The fitted data for natural chamosite (CA) in J?mol?1?K?1 give: C p,CA = 1224.3–10.685?×?103?×?T ??0.5???6.4389?× 106?×T ??2?+?8.0279?×?108?×?T ??3 and for the natural clinochlore (CE): C p,CE = 1200.5–10.908?×?103?×T ??0.5?? 5.6941?×?106?×?T ??2?+?7.1166?×?108?×?T ??3. The corrected C p-polynomial for pure end-member chamosite (Fe5Al)[Si3AlO10](OH)8 is C p,CAcor = 1248.3–11.116?× 103?×?T ??0.5???5.1623?×?106?×?T ??2?+?7.1867?×?108×T ??3 and the corrected C p-polynomial for pure end-member clinochlore (Mg5Al)[Si3AlO10](OH)8 is C p,CEcor = 1191.3–10.665?×?103?×?T ??0.5???6.5136?×?106?×?T ??2?+ 7.7206?×?108?×?T ??3. The corrected C p-polynomial for clinochlore is in excellent agreement with that in the internally consistent data sets of Berman (1988) and Holland and Powell (1998). The derived C p-polynomial for chamosite (C p,CAcor) leads to a 4.4% higher heat capacity, at 300?K, compared to that estimated by Holland and Powell (1998) based on a summation method. The corrected C p-polynomial (C p,CAcor) is, however, in excellent agreement with the computed C p-polynomial given by Saccocia and Seyfried (1993), thus supporting the reliability of Berman and Brown's (1985) estimation method of heat capacities. 相似文献
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56.
1987—1988年,在塔里木盆地北部的库车一轮台地区进行了热流测量,取得了西北地区的首批热流值。研究区在地质上属雅克拉一轮台基岩隆起带,巨厚的中新生界陆相碎屑岩不整合于古生界及前古生界基岩之上。西段雅克拉地区在深约5400m 的不整面之下为下古生界碳酸盐岩,上覆厚仅数十米的侏罗系及厚约5300m 以上的下白垩统一第四系,在侏罗系及下白垩统之间有一沉积间断。 相似文献
57.
58.
Martin?SchmidEmail author Andreas?Lorke Alfred?Wüest Michel?Halbwachs Gregory?Tanyileke 《Ocean Dynamics》2003,53(3):288-301
To prevent the recurrence of a disastrous eruption of carbon dioxide (CO2) from Lake Nyos, a degassing plan has been set up for the lake. Since there are concerns that the degassing of the lake may reduce the stability of the density stratification, there is an urgent need for a simulation tool to predict the evolution of the lake stratification in different scenarios. This paper describes the development of a numerical model to predict the CO2 and dissolved solids concentrations, and the temperature structure as well as the stability of the water column of Lake Nyos. The model is tested with profiles of CO2 concentrations and temperature taken in the years 1986 to 1996. It reproduces well the general mixing patterns observed in the lake. However, the intensity of the mixing tends to be overestimated in the epilimnion and underestimated in the monimolimnion. The overestimation of the mixing depth in the epilimnion is caused either by the parameterization of the k-epsilon model, or by the uncertainty in the calculation of the surface heat fluxes. The simulated mixing depth is highly sensitive to the surface heat fluxes, and errors in the mixing depth propagate from one year to the following. A precise simulation of the mixolimnion deepening therefore requires high accuracy in the meteorological forcing and the parameterization of the heat fluxes. Neither the meteorological data nor the formulae for the calculation of the heat fluxes are available with the necessary precision. Consequently, it will be indispensable to consider different forcing scenarios in the safety analysis in order to obtain robust boundary conditions for safe degassing. The input of temperature and CO2 to the lake bottom can be adequately simulated for the years 1986 to 1996 with a constant sublacustrine source of 18 l s–1 with a CO2 concentration of 0.395 mol l–1 and a temperature of 26 °C. The results of this study indicate that the model needs to be calibrated with more detailed field data before using it for its final purpose: the prediction of the stability and the safety of Lake Nyos during the degassing process.Responsible Editor: Hans Burchard 相似文献
59.
用1989~1998年上海逐日4次气象观测资料,应用美国特拉华大学的SSC天气分类方法确定逐日天气类型,形成了10年逐日天气类型日历。并通过天气类型与死亡率的对比分析,确定MT+类型是上海地区形成热浪的“侵人型”气团,是具有最高死亡率的天气类型。采用逐步回归方法建立了MT+类型下因受热浪侵袭而超正常死亡数的回归方程。在此基础上建立了上海热浪与健康监测预警系统。通过1999年气象和死亡实况资料检验,系统对热浪及因此引起的死亡具有较好的监测和预警效果。 相似文献
60.
Mantle heat flow and thermal structure of the northern block of Southern Granulite Terrain, India 总被引:1,自引:0,他引:1
Continental shield regions are normally characterized by low-to-moderate mantle heat flow. Archaean Dharwar craton of the Indian continental shield also follows the similar global pattern. However, some recent studies have inferred significantly higher mantle heat flow for the Proterozoic northern block of Southern Granulite Terrain (SGT) in the immediate vicinity of the Dharwar craton by assuming that the radiogenic elements depleted exposed granulites constitute the 45-km-thick crust. In this study, we use four-layered model of the crustal structure revealed by integrated geophysical studies along a geo-transect in this region to estimate the mantle heat flow. The results indicate that: (i) the mantle heat flow of the northern block of SGT is 17 ± 2 mW/m2, supporting the global pattern, and (ii) the lateral variability of 10–12 mW/m2 in the surface heat flow within the block is of crustal origin. In terms of temperature, the Moho beneath the eastern Salem–Namakkal region appears to be at 80–100 °C higher temperature than that beneath the western Avinashi region. 相似文献