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1.
Deep sea drilling in the Central Gulf of California, a young and active spreading centre, shows that the high heat flow typical of these regions causes extensive alteration of sediment organic matter, especially near sills and above magma chambers where hydrothermal activity is concentrated. Even on the nearby passive margin, where there are no sills, heat flow is moderately high and hydrocarbon generation has begun in immature sequences. Migrating light hydrocarbons are detected especially where hydrothermal activity is concentrated. Thermogenic methane is more widespread, though not in the passive margin bordering the spreading centre. Despite the incidence of hydrocarbon generation and migration, the amounts of hydrocarbons involved are relatively small and apparently do not lead to commercially significant accumulations of petroleum.The organic matter in these sediments is mostly marine because the Gulf of California generally has low runoff from land and highly productive surface waters. Turbidites rich in terrigenous organic material are locally abundant in the mainly pelagic section in the Guaymas Basin. The highest concentrations of organic matter are found in laminated diatomites deposited on the Guaymas passive margin within the oxygen minimum zone.  相似文献   
2.
基于Y1井煤系烃源岩样品微量元素分析、煤岩显微组分及热解测试结果,结合小波分析的米氏旋回划分结果,系统研究了崖南凹陷Y1井崖三段煤系烃源岩特征及发育规律。研究表明:①以104和260尺度结合岩芯沉积序列及地球化学测试结果,将崖三段划分为2个中期和5个短期米氏旋回,垂向上表现为旋回厚度及烃源岩比例向上增大的趋势,中期旋回上部为烃源岩优势发育层位,其中ⅠA2、ⅠA3和ⅠB2为煤系烃源岩发育的优势旋回;②煤系烃源岩有机显微组分表现为富镜质组、贫惰质组、贫壳质组+腐泥组,镜质组含量为44%~100%,平均为83%,以基质镜质体及镜屑体为主,烃源岩类型以Ⅲ型(腐殖型)有机质为主,少量为Ⅱ2型(腐泥-腐殖型)有机质,烃源岩以产气为主,其成熟度较低,Ro值平均为1.12%,处于生烃阶段初期;③煤系烃源岩发育受多种因素控制,其中断陷盆地向坳陷盆地的转化时期是成煤的关键构造时期、强烈进积作用使得煤系烃源岩保存不全、区域海平面上升时期是成煤的关键时期、短期旋回小波曲线右偏拐点处为煤系烃源岩相对发育层位。  相似文献   
3.
The carbonaceous chondrite meteorites are fragments of asteroids that have remained relatively unprocessed since the formation of the Solar System 4.56 billion years ago. The major organic component in these meteorites is a macromolecular phase that is resistant to solvent extraction. The information contained within macromolecular material can be accessed by degradative techniques such as pyrolysis. Hydropyrolysis refers to pyrolysis assisted by high hydrogen gas pressures and a dispersed sulphided molybdenum catalyst. Hydropyrolysis of the Murchison macromolecular material successfully releases much greater quantities of hydrocarbons than traditional pyrolysis techniques (twofold greater than hydrous pyrolysis) including significant amounts of high molecular weight polyaromatic hydrocarbons (PAH) such as phenanthrene, carbazole, fluoranthene, pyrene, chrysene, perylene, benzoperylene and coronene units with varying degrees of alkylation. When hydropyrolysis products are collected using a silica trap immersed in liquid nitrogen, the technique enables the solubilisation and retention of compounds with a wide range of volatilities (i.e. benzene to coronene). This report describes the hydropyrolysis method and the information it can provide about meteorite macromolecular material constitution.  相似文献   
4.
Fifteen recent sediment samples from the offshore Orinoco Delta, Venezuela, were separated by sieving and pipette analysis into seven size fractions ranging from 4ø to 10ø, in 1 ø units. Total organic carbon was determined for each size fraction and the organic matter characterized by pyrolysis and pyrolysis-gas chromatography. The sediments average 0.98% organic matter with somewhat higher values nearshore. Nearshore sediments also had higher organic contents in the coarsest fractions and a decrease in organic matter from coarse to fine sediment fractions. Sediments from further offshore generally show the highest organic contents in the finer fractions. Pyrolysis showed a low bitumen content and confirmed that the kerogen was dominantly terrestrial and gas prone. The observed trends were attributed to sorting of organic matter by its physical characteristics, with the denser, coarse-grained material settling out nearshore and the Finer-grained material being carried further from shore and settling out with finer-grained sediments.  相似文献   
5.
This study is the first attempt which provides information regarding the bulk and quantitative pyrolysis results of the Chia Gara Formation from the Kurdistan region, northern Iraq. Ten representative early-mature to mature samples from the Chia Gara Formation were investigated for TOC contents, Rock Eval pyrolysis, pyrolysis-GC and bulk kinetic parameters. These analyses were used to characterize the petroleum generated during thermal maturation of the Chia Gara source rock and to clarify the quantity of the organic matter and its effect on the timing of petroleum generation.Pyrolysis HI data identified two organic facies with different petroleum generation characteristics; Type II–III kerogen with HI values of >250 mg HC/g TOC, and Type III kerogen with HI values < 100 mg HC/g TOC. These types of kerogen can generate liquid HCs and gas. This is supported by the products of pyrolysis–gas chromatography (Py–GC) analysis of the extracted rock samples. Pyrolysis products show a dominance of a marine organic matter with variable contributions from terrestrial organic matter (Types II–III and III kerogen), and produces mainly paraffinic-naphthenic-aromatic low wax oils with condensate and gas.Bulk kinetic analysis of the Chia Gara source rock indicates a heterogeneous organic matter assemblage, typical of restricted marine environments in general. The activation energy distributions reveal relatively broad and high values, ranging from 40 to 64 kcal/mol with pre-exponential factors varying from 2.2835 E+12/sec to 4.0920 E+13/sec. The predicted petroleum formation temperature of onset (TR 10%) temperatures ranges from 110 to 135 °C, and peak generation temperatures (geological Tmax) between 137 °C and 152 °C. The peak generation temperatures reach a transformation ratio in the range of 42–50% TR, thus the Chia Gara source rock could have generated and expelled significant quantities of petroleum hydrocarbons in the Kurdistan of Iraq.  相似文献   
6.
A suite of seep samples from the vicinity of the Marco Polo field in the Green Canyon area of the Gulf of Mexico provides an exceptional opportunity to study the impact of interference from sediment background organic matter and alteration by biodegradation on thermogenic hydrocarbons from seafloor seeps. These seep samples contain a range in both the concentration of seeped hydrocarbons present and level of biodegradation experienced. In addition, the subsurface oil that sources the seepage was available for comparison.  相似文献   
7.
Biomass char (BC) deriving from fast pyrolysis of biomass was a potential adsorption material due to its relative high fixed‐carbon content and the inherent porous structures. Adsorption of phosphate from aqueous solution by BC was investigated in this paper. The results showed that the adsorption capacity of BC was dependent on pyrolysis conditions, such as temperature and holding time. The maximum adsorption capacity for phosphate was approximately 15.11 mg g?1 at 298 K. The pseudo‐second order model of the adsorption kinetics indicated that the adsorption process was complex and several mechanisms were involved. Equilibrium isotherm was satisfactorily followed the Freundlich isotherm model. The KF value in Freundlich equation gradually increased with elevating temperature. Moreover, the thermodynamic constants: ΔG0, ΔH0, and ΔS0 were evaluated as ?6.49 kJ mol?1 (at 298 K), 13.41 kJ mol?1, and 66.70 J mol?1 K?1, respectively. Phosphate adsorption onto BC was spontaneous and endothermic. As a waste, BC was a potentially attractive adsorbent for phosphate removal from aqueous solution with low cost and high capability.  相似文献   
8.
应用高压封闭体系,对海相碳酸盐岩干酪根进行了热裂解模拟实验,并从气态烃、非气态烃产率及碳同位素演化特征等方面,探讨了海相碳酸盐岩烃源岩干酪根作为气源的生气机理。在模拟实验基础上,结合专用Kinetics软件求取碳酸盐岩烃源岩干酪根裂解产气动力学参数(活化能和指前因子),并将模拟实验结果外推至地质条件下,探讨其动力学模型的实际应用。结果表明,在该地质条件下,甲烷在EasyRo为0.9%时进入主生气期(转化率为10%),2.9%时主生气期结束(转化率为90%)。乙烷至戊烷在EasyRo为1.1%时进入主生气期(转化率10%),2.7%时主生气期结束(转化率90%)。该研究成果为我国海相碳酸盐岩裂解气的判识、资源评价提供了可靠的实验依据。  相似文献   
9.
The authors Present the effects of the total organic carbon( TOCinert )during Pyrolysis and how it overall affects the estimates of the hydrocarbon index( HI)using the cross Plot S2 vs. TOC graPh. A to...  相似文献   
10.
Open-system non-isothermal pyrolysis up to 1,200°C in combination with elemental analysis was used to study the thermal liberation of molecular nitrogen (N2) from sedimentary rocks and kerogen concentrates of Palaeozoic age from the Central European Basin system and an Eocene shale (Liaohe Basin, China) with a high content (36%) of ammonium feldspar (buddingtonite). The N/Corg (atomic) ratios of the kerogen concentrates ranged from 0.005 to 0.014, which represents the range commonly observed for coals. Bulk N/Corg ratios of the Palaeozoic shales extended from 0.035 to 0.108, indicating the presence of significant amounts of inorganic nitrogen. Namurian A and A-B (CnA; CnA-B) samples typically exhibited the earliest onset of N2 generation with intense, characteristic peaks around 600°C. N2 liberation from the buddingtonite-rich sample occurred at higher temperatures, with a broad peak around 700°C. Pyrograms of the kerogen concentrates showed no or strongly reduced N2 generation in the 500–700°C range. On-line isotope-specific analysis of the pyrolytically liberated N2 on one sample revealed a variability of ∼10‰ in the δ15N values and a steady increase in δ15N with temperature during the main phase of N2 generation.  相似文献   
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