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61.
真菌孢子烷烃生物标志物特征及其热演化试验的初步研究 总被引:1,自引:1,他引:1
以一种类似地层中无孔多胞孢的现代真菌链格孢属孢子为样品,研究真菌孢子的原生烃烷烃馏分生物标志物及其热解生烃特征。实验结果表明,真菌孢子样品原生烃类的烷烃馏分,主要由正烷烃、异构烷烃和链烯烃相成。正烷烃约占抽提物总量的0.18%、nC19,烷占正烷烃总量的24.1%。 相似文献
62.
This integrated study on the pressure–temperature–deformation‐time record of the Goszów light quartzites from the Młynowiec–Stronie Group (Sudety Mts., SW Poland) provides new data that improve our understanding of the structure and geodynamic development of the Orlica–Śnieżnik Dome (OSD) as a Gondwana‐derived unit involved in the formation of the Variscan orogen. The structural and metamorphic record of the Goszów light quartzites, when compared to the under‐ and overlying rock formations, indicates that the whole Młynowiec–Stronie Group in the eastern part of the Saxothuringian terrane functioned as a single, integral lithotectonic unit with no visible structural or metamorphic discontinuities. The sequence of structures and thermodynamic modelling indicate that the light quartzites underwent the same polyphase tectonometamorphic evolution as the adjacent rocks belonging to the Młynowiec–Stronie Group. The development of tight, N–S‐trending folds and axial penetrative metamorphic foliation was related to metamorphic progression from 500 °C to 640 °C at 6–7 kbar. Subsequently, under the retrogressive conditions below 540 °C, the foliation was reactivated as a result of subsequent N–S‐directed ductile shearing and extension. Therefore, the study of the light quartzites exemplifies the penetrative structures in the OSD, and the metamorphic foliation and N–S‐trending lineation are composite structures. The monazite metamorphic ages of ca. 364 Ma and 335 Ma may be related to the approximately E–W‐ and N–S‐oriented tectonic movements, respectively, which occurred during the amalgamation of the Saxothuringian terrane with Brunovistulia. In contrast, the previously unknown early Palaeozoic monazite age of ca. 494 Ma is interpreted as the protolith age of the light quartzites. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
63.
Geochemical and Sr–Nd isotopic constraints on the petrogenesis of the Goesan monzodiorite pluton in the central Okcheon belt,Korea
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The Permian–Triassic high pressure metamorphism and potassic magmatism in central Korea attest to the extension of the Dabie‐Sulu collision belt in central‐eastern China towards the Korean Peninsula and possibly the Japanese Islands. We present major and trace element and Sr–Nd isotope data for a ca. 230 Ma monzodiorite pluton emplaced in the Goesan area, central Okcheon belt, Korea. This pluton shows geochemical features comparable with those of the coeval monzonite–syenite–gabbro–mangerite suite documented recently in the Gyeonggi massif. The metaluminous and alkali–calcic signatures of the Goesan intrusives correspond to the Caledonian‐type post‐orogenic granitoids. The K2O/Na2O ratios of all analyzed samples are greater than 1, and are not correlative with their SiO2 contents. The enrichment of both large‐ion‐lithophile elements and highly compatible elements in the Goesan pluton is probably indicative of metasomatized mantle origin. The elemental fractionation in the source region must have occurred in the distant past, possibly the Paleoproterozoic, to generate significantly negative εNd(t) values (< –16). Chondrite‐normalized rare earth element patterns as well as Rb/Sr and Ba/Rb ranges suggest that the source consists of amphibole‐bearing rocks. Progressive decreases in negative Eu anomaly and Ba, Sr, Ni, Cr and V contents with increasing SiO2 contents reflect an important role of plagioclase, biotite and hornblende for the fractionation process. Zr is undersaturated in the potassic, metaluminous melt. The initial Sr–Nd isotopic compositions of the samples are correlated with their SiO2 contents, substantiating a role of crustal assimilation during the magmatic differentiation. The Sr–Nd elemental and isotopic modeling suggests that the Goesan pluton was initially slightly heterogeneous in its isotopic composition, and underwent concurrent assimilation and fractional crystallization. The occurrence of the Goesan pluton provides further evidence corroborating the amalgamation of allochthonous terranes within the Okcheon belt during the Permian–Triassic collisional orogeny. 相似文献
64.
17β-羟类固醇脱氢酶8(17β-HSD8)广泛分布在脊椎动物体内的多种组织中,调节类固醇激素代谢和脂肪酸代谢。本文采用荧光定量RT-PCR和原位杂交技术,对栉孔扇贝胚胎和幼虫中17β-HSD8mRNA的时空表达进行了分析。研究结果表明,栉孔扇贝17β-HSD8在未受精卵中高水平表达,受精卵和卵裂期胚胎中表达量显著下降,囊胚中的表达量显著提高。提示栉孔扇贝17β-HSD8是一个母源表达的基因,其合子基因在囊胚时期开始表达。原位杂交结果显示,17β-HSD8mRNA阳性信号在各发育阶段的胚胎和担轮幼虫中均匀分布,在D形幼虫中主要定位在内脏团附近,提示17β-HSD8可能参与起始器官发生。 相似文献
65.
以陵水17-2气田群开发为例,介绍具有储油和外输功能的半潜式平台在结构设计分析中的基本流程与方法。半潜式生产平台的结构设计分析流程为舱室划分、结构尺度规划设计、总体结构分析和关键连接部位的局部结构分析及特殊情况的结构分析。由于平台的储油和外输功能,平台设计压头和舱室布置等均与常规半潜式生产平台存在一定的特殊性。通过对流程和方法介绍,展现了各阶段设计中的具体方法和相应的特殊性。结果显示,通过特殊的舱室划分形式、结构设计和腐蚀余量考虑,平台结构能够满足储油和外输功能的要求。 相似文献
66.
自2003年开始,历时15余年,在山东省开展了深层土壤地球化学调查,深层土壤样品采样密度为1点/4km2,16 km2组合成1件分析样,分析测试Ag,As,Au,B等54项指标;在基本查明全省土壤地球化学基准值基础上,进一步以17市行政区为单元,统计并研究了其深层土壤地球化学参数,确定了山东省17市土壤地球化学基准值,为山东省17市基础地质研究及地质找矿与区划等提供了基础数据。 相似文献
67.
W.C. Seabergh 《Ocean Engineering》2010,37(1):48-58
A 1:50 scale physical model was constructed for the 17th Street Canal region, New Orleans, on the southern coast of Lake Pontchartrain, as part of the Interagency Performance Evaluation Task Force (IPET) study of Hurricane Katrina. The purpose of the 1350 m2 physical model that represented about 3.4 km2 of the local area was to aid in defining wave and water velocity conditions in the 17th Street Canal during the time period leading up to the breaching of the floodwall within the Canal. In the immediate period following this disaster, there were many hypothesis of failure put forth in the media. Some of these hypothesis indicated wave action may have been the underlying cause of the failure of the 17th Street Canal floodwall. Some performed numerical work with inappropriate boundary conditions, which indicated strong wave-generated currents may have caused erosion along the floodwalls. This physical model study indicated a number of wave-attenuating processes occurring as waves approached the location of the breach. Wave height reduction resulted due to: (1) refraction of wave energy over the shallower submerged land areas surrounding the harbor away from the canal; (2) reflection of energy off vertical walls in the region between the entrance to the canal near the Coast Guard Harbor and the bridge; and (3) interaction of the wave with the Hammond Highway bridge, including reflection and transmission loss. Wave heights near the lakeside of the bridge were 0.3-0.9 m in height, reduced from 1.8 to 2.7 m wave heights in the open lake. Waves on the south side of the bridge, near the breach, were further reduced to heights below 0.3 m. These results supported the conclusion that waves were not a significant factor for the 17th Street Canal floodwall failure. Other IPET investigations determined floodwall failure was of a geotechnical nature due to the high surge water level. The physical model also provided calibration information for numerical wave models. The effects of debris on flow and waves after the breach was formed were also investigated. 相似文献
68.
Minxue He Terri S. Hogue Kristie J. FranzSteven A. Margulis Jasper A. Vrugt 《Advances in water resources》2011,34(1):114-127
The National Weather Service (NWS) uses the SNOW17 model to forecast snow accumulation and ablation processes in snow-dominated watersheds nationwide. Successful application of the SNOW17 relies heavily on site-specific estimation of model parameters. The current study undertakes a comprehensive sensitivity and uncertainty analysis of SNOW17 model parameters using forcing and snow water equivalent (SWE) data from 12 sites with differing meteorological and geographic characteristics. The Generalized Sensitivity Analysis and the recently developed Differential Evolution Adaptive Metropolis (DREAM) algorithm are utilized to explore the parameter space and assess model parametric and predictive uncertainty. Results indicate that SNOW17 parameter sensitivity and uncertainty generally varies between sites. Of the six hydroclimatic characteristics studied, only air temperature shows strong correlation with the sensitivity and uncertainty ranges of two parameters, while precipitation is highly correlated with the uncertainty of one parameter. Posterior marginal distributions of two parameters are also shown to be site-dependent in terms of distribution type. The SNOW17 prediction ensembles generated by the DREAM-derived posterior parameter sets contain most of the observed SWE. The proposed uncertainty analysis provides posterior parameter information on parameter uncertainty and distribution types that can serve as a foundation for a data assimilation framework for hydrologic models. 相似文献
69.
70.
利用芳烃参数研究煤系烃源岩中重排藿烷成因 总被引:4,自引:1,他引:3
研究发现鄂尔多斯盆地部分地区上古生界煤系烃源岩存在较高丰度的17α(H)-重排藿烷和早洗脱重排藿烷,在对重排藿烷分布、组成特征及生标组成特征研究的基础上,应用芳烃参数对高丰度重排藿烷的成因进行了探讨。饱和烃生物标志物组成特征显示,高重排藿烷与陆源高等植物生源关系密切,主要在弱氧化沉积环境下演化形成。具有高-异常高丰度17α(H)-重排藿烷和早洗脱重排藿烷(C30*/C30H>0.2、C30E/C30H>0.1)的烃源岩二环+三环芳烃相对含量一般大于50%,四环、五环芳烃含量相对较低,普遍低于35%,未见芳香甾萜类,研究认为其生源主要为陆生高等植物;甲基菲指数MPI1、MPI2和甲基菲比值F1研究结果显示,Pr/Ph>1的弱氧化环境烃源岩17α(H)-重排藿烷和早洗脱重排藿烷在进入成熟阶段后开始大量形成,并随成熟度升高而增大;Pr/Ph<1还原环境下的烃源岩重排藿烷丰度相对较低,但在进入成熟阶段后仍有随成熟度升高而增大的趋势;三芴系列化合物参数表明,沉积环境的弱氧化性质对17α(H)-重排藿烷和早洗脱重排藿烷的形成有较大的影响,沼泽相沉积环境最有利于重排藿烷的形成。 相似文献