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391.
东西的小说创作,尤其是20世纪90年代中期以后的相当一部分作品,在主题思想和叙述策略上均具有鲜明的后现代倾向,足以形成其独特的艺术方式.以后现代主义文学与叙事学的相关理论,从东西小说创作的叙事手法和叙述语言等方面出发,试图对东西小说独特的叙事艺术予以解读.  相似文献   
392.
为研究2022年门源MS6.9地震的发震构造及构造应力场特征,文章先搜集了1月8—30日M≥1.9地震事件的P波初动符号,基于P波初动极性反演震源机制解的方法,得出66个地震的震源机制解,参考水平应变花面应变对地震震源机制的划分原则进行分类,虽然震源机制分布类型较广,但走滑类震源机制超过半数,表明此次地震序列以走滑为主;然后基于得到的震源机制解,利用网格搜索法反演该区构造应力场,得到研究区内呈NEE-SWW向挤压,NNW-SSE向拉张;主震震源机制P和T轴与所处的应力区应力方向相近;最后模拟研究了主震震源机制与应力体系的关系,得到此次地震是在构造应力场作用下沿最优节面破裂的,可视其为该区域应变能积累后的一次正常释放。该研究对后续的发震机制和地球动力学分析具有参考意义。  相似文献   
393.
394.
This paper proposes a simplified analytical solution considering non-Darcian and wellbore storage effect to investigate the pumping flow in a confined aquifer with barrier and recharge boundaries. The mathematical modelling for the pumping-induced flow in aquifers with different boundaries is developed by employing image-well theory with the superposition principle, of which the non-Darcian effect is characterized by Izbash’s equation. The solutions are derived by Boltzmann and dimensionless transformations. Then, the non-Darcian effect and wellbore storage are especially investigated according to the proposed solution. The results show that the aquifer boundaries have non-negligible effects on pumping, and ignoring the wellbore storage can lead to an over-estimation of the drawdown in the first 10 minutes of pumping. The higher the degree of non-Darcian, the smaller the drawdown.  相似文献   
395.
The semi-arid region, as a key part of global land, plays an important role in climate change. In the process of modern climate change, the semi-arid region is significantly affected by local human activities, showing remarkable expansion and obvious decadal variations. In this paper, we summarized the studies of the land-atmosphere interaction in the semi-arid regions in recent years, and major land surface observation plans. We put emphasis on energy balance, water cycle, carbon cycle in land-atmosphere interaction of climate change, and their performance in historical simulation and future prediction. The prediction results illustrate that new character of land-atmosphere interaction will appear as the drying of drylands in the future. Therefore, it is necessary to deepen the understanding of land-atmosphere interaction and move forward energetically on research in regional climate from different aspects.  相似文献   
396.
This paper describes seismic velocity tomography applied to the investigation and assessment of karst collapse hazards to facilitate accurate characterization of geological conditions of karst sinkhole formation. In the survey areas of Xiamao, Guangzhou, China, and Huangchi, Foshan, China, seismic velocity tomography was used to explore the structures of rock and soil associated with karst collapse. The results show that sand intercalated with clay or clay intercalated with soft soil dominates the cover of these two areas. The overburden is 20–33 m thick and underlain by Carboniferous limestone. In the limestone, there are well-developed karst caves and cracks as well as highly fluctuating bedrock surfaces. The seismic velocities are less than 2500 m/s in the cover, 2500–4500 m/s in the karst fracture zones and caves of Xiamao, and 1500–2000 m/s in the Huangchi collapse area. The karst fracture zones, relief of bedrock surfaces, and variations of soil thicknesses revealed by seismic velocity tomography are well constrained and in agreement with those in the drilling borehole profiles. This paper demonstrates that seismic velocity tomography can delineate anomalies of rock and soil with the advantages of speed, intuitive images, and high resolution.  相似文献   
397.
The microtremor horizontal-to-vertical spectral ratio (HVSR, or H/V spectral ratio) method is an effective tool for detecting sediment thickness. Firstly, single-station microtremor measurements were taken beside 52 boreholes located in Pearl River Delta, China. Sediment thicknesses revealed by those boreholes range from 7.9 to 39.6 m. Then, those microtremor data were analyzed using HVSR method, and peak frequency of each site was extracted. According to those peak frequencies of HVSR and corresponding sediment thicknesses, the frequency-to-thickness fitting (fZ) equation which is suitable for Pearl River Delta area was established. And this equation was compared with several fitting equations derived from different regions by other researchers. Finally, this fitting equation was applied in a collapse area in Guangzhou city to estimate site sediment thickness. Compared with data from five boreholes in this collapse area, the consistency between estimated sediment thickness and real value was relatively good. Karst sinkholes are generally located in regions where thickness of sediments is shallow. Therefore, the method described in this paper can provide support for delineating potential collapse areas.  相似文献   
398.
The Global Lagrangian Atmospheric Dispersion Model (GLADIM) is described. GLADIM is based on the global trajectory model, which had been developed earlier and uses fields of weather parameters from different atmospheric reanalysis centers for calculations of trajectories of air mass that include trace gases. GLADIM includes the parameterization of turbulent diffusion and allows the forward calculation of concentrations of atmospheric tracers at nodes of a global regular grid when a source is specified. Thus, GLADIM can be used for the forward simulation of pollutant propagation (volcanic ash, radionuclides, and so on). Working in the reverse direction, GLADIM allows the detection of remote sources that mainly contribute to the tracer concentration at an observation point. This property of Lagrangian models is widely used for data analysis and the reverse modeling of emission sources of a pollutant specified. In this work we describe the model and some results of its validation through a comparison with results of a similar model and observation data.  相似文献   
399.
位于宁芜矿集区南部钟姑矿田内的和睦山铁矿床是长江中下游成矿带内的一个典型的中型玢岩铁矿床,其主矿体呈似层状或透镜状产于闪长(玢)岩体与中-上三叠统地层接触带及其附近的灰岩中。近矿围岩蚀变矿化强烈,并具有显著的分带特征。岩(矿)相学研究表明,该矿床的形成经历了成矿前期(钠长石阶段)、主成矿期(阳起石-磷灰石-Ⅰ型磁铁矿阶段、浅闪石-金云母-Ⅱ型磁铁矿阶段和赤铁矿阶段)和成矿后期(石英-黄铁矿阶段和碳酸盐阶段)。矿物学研究表明,热液浅闪石较早阶段阳起石更富Al和Na、而贫Si;晚阶段Ⅱ型磁铁矿较早阶段Ⅰ型磁铁矿更富Ti和Al、而贫Mg。由岩体到矿体方向,金云母中Mg O含量逐渐富集,而Fe O和Ti O2含量逐渐降低,说明浅闪石-金云母-Ⅱ型磁铁矿阶段的成矿温度高于阳起石-磷灰石-Ⅰ型磁铁矿阶段,且阳起石-磷灰石-Ⅰ型磁铁矿阶段成矿热液在演化过程中,温度是逐渐降低的。综合研究表明,和睦山铁矿床为中-高温气液交代充填成因,Ⅰ型磁铁矿的形成以热液交代作用为主,Ⅱ型磁铁矿的生成则以热液充填作用为主,钠化对铁的活化和迁移起了重要作用。  相似文献   
400.
叙述了FAST(500m口径球面射电望远镜)30m模型L-波段馈源的设计、制作和性能测试过程。馈源的设计仿真使用了HFSS软件,并选用纸板或塑料板和铝箔胶带,通过手工操作完成馈源制作。馈源的性能通过测试表明满足FAST30m模型天文观测的需要。文中采用的HFSS软件仿真及手工制作馈源的方式不失为形式简单的馈源的模型制作的一种快速、经济和有效的方法。这种方法对相近的工作有一定的参考价值。  相似文献   
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