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111.
首都圈地区跨断层流动形变监测场地优化布设探讨   总被引:2,自引:0,他引:2  
依据跨断层流动形变测量规范,兼顾监测场地的可控性和均匀性、监测服务目的以及活动断裂的地震易发性等,探讨了首都圈地区跨断层流动形变监测场地的优化布设。  相似文献   
112.
树基沟铜锌矿床是太古宙花岗-绿岩带中与火山岩有关的块状硫化物矿床(VMS)。本次对赋矿围岩黑云斜长角闪片麻岩开展了锆石LA-ICP-MS U-Pb定年,主量元素、微量元素和Hf同位素分析。锆石U-Pb定年结果表明,黑云斜长角闪片麻岩原岩结晶年龄为(2 549.4±5.6) Ma,可近似代表树基沟铜锌矿床成矿时代。地球化学研究表明,岩石富集大离子亲石元素(LILE)、亏损高场强元素(HFSE)、轻稀土富集、重稀土亏损,为一套岛弧环境的火山沉积岩。黑云斜长角闪片麻岩εHft)值为5.0~8.7,单阶段模式年龄TDM 1值为2 527~2 649 Ma,指示其源区主要亏损地幔物质,树基沟地区可能存在新太古代地壳增生事件。结合前人研究成果,认为树基沟铜锌矿床成矿于板块俯冲环境,地幔部分熔融形成富含贱金属岩浆向上运移、汇聚、喷发、固结成岩,后经海水淋滤下渗成矿元素富集二次喷发成矿,并经后期鞍山运动变质变形作用的产物。  相似文献   
113.
The great M_S8.0 Wenchuan earthquake on May 12,2008 was generated by abrupt faulting in the Yingxiu-Beichuan fault along the Longmenshan fault zone. The earthquake not only produced surface ruptures along the Yingxiu-Beichuan and Guanxian-Jiangyou faults,but also surface ruptures,arching of highway pavement,sand-boils and waterspouts in various degrees in areas such as Shifang and Mianzhu on the Chengdu Plain. To understand the shallow geological structures under the surface rupture zone,a 6350m long high-resolution shallow seismic reflection profile in near-EW direction was performed. This profile is located at Shigu town,Shifang city,where a suspected earthquake surface rupture zone was discovered. In this study,a group interval of 3m,shotpoint interval of 18m,and a 300-channel 25-fold observation system were used. In consideration of both near-surface reflections and dipping interface imaging,we adopted the split-spread geometry and asymmetrical zero-offset receiving technique. To better suppress random-noise and raise the signal-to-noise ratio of seismic data,30 times vertical stacking of vibrator signals was made for each common-shot gather after correlation of individual records. By using the above work method and spread geometry,we obtained high-resolution images of structures in the depth range of 15m~800m after data processing. The result shows the existence of buried thrust faults thrusting to the plain area and back-thrust faults under the surface rupture zone. It also shows that the activity of the buried thrust faults may be the main cause for folding and deformation in near-surface strata and coseismic surface rupturing.  相似文献   
114.
A M S 6.8 earthquake occurred on October 5,2008 in the Wuqia region in Xinjiang.The macroseismic epicenter is situated in the Nula village of the Kyrghyz Republic,7km southwest of the Wuqia Yierkeshitan Port in Xinjiang.The epicenter intensity is Ⅷ degrees (outside borders).The areas of intensity Ⅶ and Ⅵ are 7354km 2 and 1031km 2,respectively.This seismic event is related with movement of the NE-trending Kzikeaerkate fault belt.Buildings in the earthquake-stricken area were damaged or affected to a certain extent by this earthquake,accompanied with some phenomena of geological disaster.  相似文献   
115.
Optimum delay interval design in delay blasting   总被引:2,自引:0,他引:2  
The major concern of this research is the reduction of blast vibrations at certain points of foremost importance. A procedure for optimum delay interval design, considering detonation time errors of the electric detonators, was proposed. Using the relationship between the peak particle velocity (PPV) and the delay at certain points of interest which was calculated by means of a computer program by simulating the superposition of the vibration waves emitted from each borehole, one can usually select the optimal delay interval in order to minimize the PPV. But due to the variations in the actual delay caused by the detonation time errors, the expected PPV usually not only depends on the nominal delay but also on the sensitivity of the PPV. Therefore, the selection of the optimum time interval for a delay blast should be based on both the optimum as well as several sub-optimal time intervals as candidates. In addition, the detonation time errors should be taken into consideration. Also, a new design concept, called 'combined delay blasting', which uses electronic detonators, is proposed to further reduce the PPV at the points of interest. Estimated vibration time histories based on this concept and their PPVs indicated considerably favorable results.  相似文献   
116.
Pore structure characteristics are important to oil and gas exploration in complex low-permeability reservoirs. Using multifractal theory and nuclear magnetic resonance (NMR), we studied the pore structure of low-permeability sandstone rocks from the 4th Member (ES4) of the Shahejie Formation in the south slope of the Dongying Sag. We used the existing pore structure data from petrophysics, core slices, and mercury injection tests to classify the pore structure into three categories and five subcategories. Then, the T2 spectra of samples with different pore structures were interpolated, and the one- and three-dimensional fractal dimensions and the multifractal spectrum were obtained. Parameters α (intensity of singularity) and f (α) (density of distribution) were extracted from the multifractal spectra. The differences in the three fractal dimensions suggest that the pore structure types correlate with α and f (α). The results calculated based on the multifractal spectrum is consistent with that of the core slices and mercury injection. Finally, the proposed method was applied to an actual logging profile to evaluate the pore structure of low-permeability sandstone reservoirs.  相似文献   
117.
李博  王鹏皓  卢军炯  王寇 《海洋与湖沼》2019,50(6):1161-1167
本文基于2016年长江口海域(舟山绿华山)的连续观测数据,分析了该海域水文环境要素分布,并估算了溶解氧跨跃层垂向输运。本次观测发现,水体的温度、盐度和溶解氧剖面具有明显的分层结构,三者跃层具有相同的变化趋势且主要受潮流变化影响。通过计算,得到跃层浮性频率的平方(N2)在10–3—10–2/s2之间,剪切的平方(S2)介于10–5—10–2/s2。潮流活动会激发水体剪切不稳定促进水体中溶解氧的垂向交换。最后,采用简化的一维溶解氧垂向输运模型,得到观测周期内跨跃层输运的溶解氧的含量为4.75mmol/(m2·d),佐证层化是长江口海域出现氧亏损现象的主要原因之一。  相似文献   
118.
Kou  Hailei  Jing  Hao  Wu  Chuangzhou  Ni  Pengpeng  Wang  Yiyi  Horpibulsuk  Suksun 《Acta Geotechnica》2022,17(5):1859-1877

Improving the engineering properties of low-strength soft clay in an environmentally friendly way becomes a challenge in coastal areas. Conventional ground treatment techniques for marine clay using cement can cause significant environmental pollution. In this study, the potential use of industrial waste residue-based binder (IWRB), a silicate-based chemical modified by a powdery polymer, as a substitute for Portland cement (PC) is investigated. Collected marine clay was treated with various IWRB-to-PC ratios (0:8, 4:4, 2:6 and 8:0 wt. %) to measure the mechanical properties, through unconfined compression (UC) test and one-dimensional consolidation (ODC) test, and the microstructural and mineralogical characters, through scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetry analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). The strength and the deformation of specimens treated with mixed IWRB and PC in a ratio of 1:1 were similar to those improved with PC alone, but the toughness was significantly improved. The microstructural results demonstrated that the cementitious compounds (C–S–H and C–A–S–H) increased significantly in the early curing stage of marine clay treated with IWRB, contributing to the improvement of mechanical properties. It is suggested that IWRB can be an effective substitute for PC to reduce the cost and environmental pollution.

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119.
利用2012—2018年鸭梨花芽发育实景观测照片,精准判定每个鸭梨花芽发育物候期节点发生时间,以此为依据统计鸭梨花芽每个发育物候期的气象要素数据,以物候期为单位分析气象影响因子对花芽发育过程的影响。研究表明:温度在鸭梨花芽发育各阶段起主导作用,筛选出鸭梨花芽萌发到始花、开绽到始花、露蕾到始花3个时段日平均气温≥0℃活动积温和≥3℃有效积温,作为制作鸭梨始花期预报的积温指标计算鸭梨开花日期,得到"积温对比预报法";经2016—2018年应用检验:预报时效10~12d时预报结果与鸭梨开花实况误差在1~2d以内,预报时效7d时预报结果与鸭梨开花实况完全吻合。本研究克服了传统植物花期预报研究因花前物候资料匮乏、不能进行花前发育期分析的缺陷,并把"中长期天气预报产品"引入了花期预报方法的使用,为植物花期预报研究方法提供了新思路。  相似文献   
120.
基于D-InSAR技术的伊朗巴姆地震地表形变监测   总被引:1,自引:1,他引:0  
以伊朗巴姆地区为例,对伊朗巴姆地震造成的地表形变进行了差分干涉测量,得到了垂直向的同震三维形变场,并运用GIS三维分析技术对形变场进行了分析。实验结果表明,地震在巴姆城市的东侧造成了较大形变,在西侧也产生了微量形变。巴姆城市北部地块沉降,南部地块隆起。同时在巴姆城市南部可明显看到地震造成的断层。实验结果验证了基于C波段的SAR数据的D-InSAR技术在干燥地区监测地表形变方面的可行性。本文对产生去相关效应的原因进行了解释,认为对于干燥少植被的地区干涉效果较好。并指出,如果能够通过技术进步提高雷达干涉测量的精度并降低观测成本,同时将该技术与GPS、GIS等技术相结合,从而更好地研究形变机理,这将对地质灾害的研究产生重大意义。  相似文献   
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