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1.
Maximumlikelihoodspectrumestimationmethodanditsapplicationinseismo┐magnet┐icrelationXIAO-PINGZENG1)(曾小苹),YUN-FANGLIN1)(林云芳),...  相似文献   

2.
Simultaneousinversionofvelocitydistribu┐tionandinterfacepositionsSONG-LINLI1)(李松林)NING-YUANWU2)(吴宁远)ZHAN-LONGSONG1)(宋占隆)JIN-...  相似文献   

3.
Featuresofisostaticgravityanomalyandseis┐micactivityintheCentralAsianregionSHENG-MINGFANG1)(方盛明)RUIFENG2)(冯锐)CHANG-ZHENGTIAN...  相似文献   

4.
TheQvaluevariationsinthepreparingpro┐cesofrockruptureBINWANG1)(王彬),ZHAO-YONGXU1)(许昭永),JIN-MINGZHAO1)(赵晋明)YI-LIHU2)(胡毅力)1)Sei...  相似文献   

5.
Anapproachondynamicearthquakepredic┐tionbygeoresistivitymeasurementsHONG-KUIZHANG1))(张洪魁),QI-XINGSHEN2)(沈启兴),WEIWU1)(吴卫)YU-L...  相似文献   

6.
Numericalanalysisoftheinteractionofsoil┐structureunderearthquakeloadingGEN-DEZHANG1)(章根德)SHU-CHENGNING2)(宁书成)1)InstituteofMe...  相似文献   

7.
Research Note     
Comprehensiveindicesofearlyjudgementforearthquakesequencetypebypaternrecogni┐tionCUI-YINGZHOU1)(周翠英),YU-XIAZHANG2)(张宇霞),HONG...  相似文献   

8.
Themedium┐andshort┐termpredictionmethodsofstrongearthquakesbasedonneu┐ralnetworkZHI-QIANGHAN(韩志强)BI-QUANWANG(王碧泉)Instituteof...  相似文献   

9.
Long┐andintermediate┐termseismicpoten┐tialofFen┐Weiseismicbelt:activefaultdataapplicationJINGLIU(刘静)andLIANG-MOUWANG(汪良谋)Ins...  相似文献   

10.
Crustalstructureandaccuratehypocenterde┐terminationalongtheLongmenshanfaultzoneZHUZHAO1)(赵珠)JUNFAN1)(范军)SI-HUAZHENG2)(郑斯华)AK...  相似文献   

11.
Mechanism of satellitic thermo-infrared brightness temperature and temperature increaming is studied. Experiments are made with a gas sample taken around the epicenter area. The gas ample is pmved to contain green house gases such as CH4, and CO2 which have increased by tens of thousands of times. In addition, lab research slso pmes that CH4, and CO2 can obtain energy under the action of transient electric field and release heat, thus reeulting in a temperature increase of 2–6°C. Also a brief account of practices since 1990 is given; altogether 40 short-tenn and impending earthquake predictions have been made, with 9 precise ones whose three main factors of an earthquake are clearly depicted, and 12 fairly good ones. These predictions include 3 earthquakes ofM.⩾ 7, 4 ofM.⩾ 6.0 and the rest are mundM. 5.0. Yet there are earthquakes left out of prediction. Finally the evolutionwy processing characters of satellitic thermo-infrared brightness temperature and temperature increase before the Lijiang earthquake on Feb. 3, 1996 and Tangshan earthquake on April 14, 1998 are introduced in detail. The conclusion makes a study on the regularities of connection among time, space and stress when there appears the satellitic thermal-inlinred brightness tempera- and temperature increasing anomaly. Project supported by the State 863 High-Tech Project (Grant No. 863-2-7-4-18)  相似文献   

12.
An electric furnace with oxygen-fugacity control was constructed. Oxygen partial pressure inside the furnace is controlled by flowing H2 and CO2 gas mixtures in different ratios. The system is set up inside a three-layer permalloy shield and a solenoid coil to produce an axial magnetic field. Oxygen fugacities are directly measured by an yttriadoped zirconia probe. The difference between the predicted and measured values of fugacities was small at 1,200°C, but a substantial discrepancy was observed at 780°C. Thermoremanent magnetization (TRM) was produced in various gas mixtures by heating the samples of recent basaltic lavas of Oshima (Japan) and Hawaii to 600 or 800°C for 1 h and cooling in a 0.4-Oe field. In general, the TRM is larger when produced in an oxidizing atmosphere and smaller in a reducing atmosphere. Alternating field demagnetization shows that the coercivity is also increased (decreased) when the TRM is acquired in oxidizing (reducing) conditions. However, these properties depend also on the previous heat treatments of the samples.  相似文献   

13.
Entrapped biogenic gas in peat can greatly affect peatland biogeochemical and hydrological processes by altering volumetric water content, peat buoyancy, and ‘saturated’ hydraulic conductivity, and by generating over‐pressure zones. These over‐pressure zones further affect hydraulic gradients which influence water and nutrient flow direction and rate. The dynamics of entrapped gas are of global interest because the loss of this gas to the atmosphere via ebullition (bubbling) is likely the dominant transport mechanism of methane (CH4) to the atmosphere from peatlands, which are the largest natural terrestrial source per annum of atmospheric CH4. We investigated the relationship between atmospheric pressure and temperature on volumetric gas content (VGC) and CH4 ebullition using a laboratory peat core incubation experiment. Peat cores were incubated at three temperatures (one core at 4 °C, three cores at 11 °C, and one core at 20 °C) in sealed PVC cylinders, instrumented to measure VGC, pore‐water CH4 concentrations, and ebullition (volume and CH4 concentrations). Ebullition events primarily occurred (71% of the time) during periods of falling atmospheric pressure. The duration of the drop in atmospheric pressure had a larger control on ebullition volume than the magnitude of the drop. VGC in the 20 °C core increased from the onset of the experiment and reached a fluctuating but time‐averaged constant level between experiment day 30 and 115. The change in VGC was low for the 11 °C cores for the initial period of the experiment but showed large increases when the growth chamber temperature increased to 20 °C due to a malfunction. The core maintained at 4 °C showed only a small increase in entrapped gas content throughout the experiment. The 20 °C core showed the largest increase in VGC. The increases in VGC occurred despite pore‐water concentrations of CH4 being below the equilibrium solubility level. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

14.
The Dongfang 13-1 is located in the diapiric structure belt of the Yinggehai Basin. The formation pressure of its main gas reservoir in the Miocene Huangliu Formation is up to 54.6 MPa(pressure coefficient=1.91) and the temperature is as high as 143°C(geothermal gradient 4.36°C/100 m), indicating that it is a typical high-temperature and overpressured gas reservoir. The natural gas is interpreted to be coal-type gas derived from the Miocene mature source rocks containing type II2-III kerogens as evidenced by high dryness index of up to 0.98 and heavy carbon isotopes, i.e., the δ13C1 ranging from -30.76‰ to -37.52‰ and δ13C2 ranging from -25.02‰ to -25.62‰. The high temperature and overpressured Miocene petroleum system is related mainly to diapir in the Yinggehai Basin and contains more pore water in the overpressured reservoirs due to undercompaction process. The experimental and calculated results show that the solubility of natural gas in formation water is as high as 10.5 m3/m3 under the temperature and pressure conditions of the Sanya Formation, indicating that at least part of the gas may migrate in the form of water-soluble phase. Meanwhile, the abundant gas source in the Basin makes it possible for the rapid saturation of natural gas in formation water and exsolution of soluble gas. Therefore, the main elements controlling formation of the Dongfang 13-1 gas pool include that(1) the diapir activities and accompanying changes in temperature and pressure accelerate the water-soluble gas exsolution and release a lot of free gas;(2) submarine fan fine sandstone in the Huangliu Formation provides good gas-water segregation and accumulation space; and(3) the overlying overpressured mud rocks act as effective caps. The accumulation mechanism reveals that the high temperatural and high pressure structure belt near the diapir structures has a good potential for large and medium-sized gas field exploration.  相似文献   

15.
Thermal diffusivity, k, of three lunar rocks (10049 and 10069; Type A, Apollo 11 and 14311; Apollo 14) and a terrestrial basalt (alkaline olivine basalt, Oki-do?go, Japan) was measured under one atmosphere and in vacuum conditions (10?3 ~ 10?5 mmHg) in the temperature range from 85 to 850°K. The semi-empirical curve of k =A + B/T +CT3 is fitted to the data in each condition. The porosity of rocks strongly affects the thermal diffusivity at low temperature ( T ? 500°K) in vacuum condition. At 150°K, thermal diffusivity of lunar rocks with porosity of 5.5% (10049) and 11% (10069) at one atmosphere is about 1.7 and 3.2 times of that in vacuum, respectively. The difference between the values at one atmosphere and those in vacuum decreases as the temperature increases. Measurements of k should be made at gas pressures at least lower than 10?3 mmHg to estimate the value under lunar surface conditions.  相似文献   

16.
A field gas chromatograph, built in 1978, was used in the field to directly analyse volcanic gases before water vapor condensation. Tested in Vulcano (Italy), Kilauea (Hawaii) and Merapi (Indonesia), this field measurement technique provides the actual composition of the volcanic gas mixture. The technique avoids the depletion of sulfur gases and the dissolution of the acid gases in the condensed water during the cooling. Thus the mixture of H2S and SO2 in fumarolic and high temperature gases (up to 819°C) in equilibrium at the emission temperature was examined.  相似文献   

17.
In recent years, much work on the natural gas de- struction in carbonate reservoirs has been carried out at home and abroad. The classification of source rocks, the estimation of natural gas resource and the explora-tion of gas reservoirs can be related to the determina-tion of the geochemical depth limit for natural gas. On the basis of reaction kinetics and lab simulation ex- periments, the kerogen decomposition proceeds, sub-stantially, to completion at more than 5% vitrinite re-flectance[1…  相似文献   

18.
Experiments were made on 58 sediment samples from four sites(1244,1245,1250 and 1251) of ODP204 at five temperature points(25,35,45,55 and 65℃) to simulate methane production from hydrate-bearing sediments.Simulation results from site 1244 show that the gas components consist mainly of methane and carbon dioxide,and heavy hydrocarbons more than C2+ cannot be detected.This site also gives results,similar to those from the other three,that the methane production is controlled by experimental temperatures,gene...  相似文献   

19.
Two comparative simulation experiments(a normal atmospheric-pressure opening system and a 20 MPa closed system)were conducted to study the geochemical evolution of n-alkane,sterane,and terpane biomarkers in the process of oil cracking into gas under different pressures.With an initial experimental temperature set at 300°C,the temperature was increased to 650°C at a heating rate of 30°C/h.The products were tested every 50°C starting at 300°C,and a pressure of 20 MPa was achieved using a water column.The low-maturity crude oil sample was from the Paleogene system in the Dongying sag in eastern China.The threshold temperature obtained for the primary oil cracking process in both pressure systems was 450°C.Before the oil was cracked into gas,some components,including macromolecular n-alkanes,were cracked into medium-or small-sized n-alkanes.The secondary oil cracking of heavy hydrocarbon gases of C2–5to methane mainly occurred between 550°C to 650°C,and the parameters Ln(C1/C2)and Ln(C1/C3),as well as the dry coefficients,increased.Overpressure inhibited the oil cracking process.In the 20 MPa system,the oil conversion rate decreased,the temperature threshold for gas generation rose,and oil cracking was inhibited.Compared with the normal pressure system,high-carbon n-alkanes and other compounds in the 20 MPa pressure system were reserved.Furthermore,the parameters∑C21-/∑22+,Ln(C1/C2),and Ln(C1/C3),as well as the dry coefficients,decreased within the main temperature range.During secondary oil cracking(550°C to 600°C),the Ph/nC18and Pr/nC17decreased.High pressure influenced the evolution of the biomarkers Ts and Tm,C31homohopane,C29sterane,and their related maturity parameters to different extents during oil cracking under different temperature ranges.  相似文献   

20.
The dehydration melting of the natural rock at high pressure is important to investigating the magma formation in the earth’s interior. Since the 1970s, a lot of geological scientists have paid more atten- tion to the dehydration melting of the natural rock[1―5]. Previous experiments of dehydration melting and observations of fieldwork argued that the dehy- dration melting of the rock was probably the most important fashion for the melting of the lower crust rock[6―12]. The genesis of most …  相似文献   

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