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831.
文章采用GPS-RTK技术进行2016年金山三岛滩涂水下地形测量,绘制金山三岛滩涂水下地形云图,并与2014年和2015年滩涂水下地形测量结果进行对比,得出以下结论:金山三岛连线左右1km之内的地形起伏变化大,小金山岛南北侧各有一条深坑,大小金山岛之间有一条贯穿东西向的深槽,它的形成与涨落潮流不一致以及人为活动有关,大金山岛与浮山岛之间有一类似山脊样的地形,浮山岛南侧也有一深坑存在。近3年金山三岛滩涂水下地形变化不大,局部小范围内有淤积和冲刷。定期对三岛滩涂水下地形进行测量可以掌握其变化规律,为管理部门提供管理基础资料。 相似文献
832.
通过对莺歌海盆地D1-1底辟区中深层高温超压带与浅层正常压力带、压力过渡带天然气的组成、碳同位素特征差异的对比分析,结合底辟活动特征,研究了天然气藏的形成过程和天然气组分的分布规律。研究结果表明:(1)D1-1底辟核部区和底辟波及区中深层天然气成藏过程有差异,主要受底辟活动影响程度的控制。底辟核部区中深层气藏的形成过程为早期成藏、后期破坏并再次充注;底辟波及区中深层气藏的形成则为早期成藏,后期改造较弱,成熟煤型原生气藏保存较好。(2)D1-1底辟核部区和底辟波及区中深层天然气组分、碳同位素分布有明显规律;随距底辟核部距离的增大,其甲烷含量升高,二氧化碳含量降低,甲烷碳同位素变轻(成熟度降低),二氧化碳碳同位素也变轻,底辟核部区富集无机成因CO2,至底辟波及区则以有机成因CO2为主。 相似文献
833.
云南富乐厂铅锌矿床是滇东北矿集区东南部的典型矿床之一。在矿区进行大比例尺构造填图的基础上,运用构造成矿动力学的理论和方法,筛选典型断裂构造进行力学性质的鉴定,对不同期次、不同方向的断裂特征进行了系统阐述,初步划分了构造期次,总结了构造体系。认为该区断裂经历了晋宁期-澄江期近东西向的挤压作用,印支期-燕山早期北西-南东向挤压作用及后期燕山中晚期-喜马拉雅期的北东-南西向挤压作用的过程。晋宁-澄江期构造作用为该区成矿提供了有利的地质背景,印支期-燕山早期为该矿成矿主期,北东向压扭性断裂和北西向的扭张性断裂使得流体充填、富集成矿;后期近东西向的扭性断裂为破矿构造。通过矿区构造与成矿关系的研究,为隐伏矿预测与深部勘查提供了依据。 相似文献
834.
835.
以唐山市中心区土地利用为例,在分析研究区土地利用现状的基础上,综合研究影响城市土地利用潜力的因素,设计了评价流程,构建了土地利用潜力评价的指标体系和评价模型。结果显示,中心区总面积11 479.27hm2,其中无容量土地、容量完全损失土地、未利用的土地、低度利用的土地、合理利用的土地、过度利用的土地6种潜力类型的土地面积分别占总面积的27.86%,6.43%,5.69%,23.64%,28.62%,7.76%,土地利用率偏低,有很大的挖潜空间。通过对唐山市中心区城市土地利用潜力的评价,不仅为中心区的城市建设和土地利用提供依据,也为城市土地利用潜力评价的推广和应用提供方法和思路。 相似文献
836.
837.
包头市九原区土地利用现状与可持续发展研究 总被引:2,自引:0,他引:2
以包头市九原区为研究对象,根据其近几年来的土地详查数据,对各种地类的情况做出统计,总结出该区的土地利用情况,分析其现状特点,指出当前土地利用中主要存在的问题,提出一些相应的研究对策。 相似文献
838.
S. C. Khosla M. L. Nagori S. R. Jakhar A. S. Rathore 《Journal of the Geological Society of India》2009,73(5):724-732
Except for the east coast of Andhra Pradesh, the Deccan Inter-trappean sedimentary beds of Peninsular India have been long
known to yield non-marine microfauna, mainly ostracods. These have been extensively described from different localities of
Madhya Pradesh, Maharashtra, Karnataka, Andhra Pradesh, Gujarat and Rajasthan states. Occurrence of mixed microfaunal association
of marine, brackish water and non-marine foraminifers and ostracods is being recorded from these beds from Jhilmili, Chhindwara
district, Madhya Pradesh. It comprises at least two or more planktonic foraminifer species, and one brackish water and 17
non-marine ostracod species. The brackish water ostracod, Neocyprideis raoi (Jain, 1978) has been previously recorded in great profusion from the Inter-trappean beds of Duddukuru, West Godavari District,
Andhra Pradesh, which have been assigned Early Palaeocene age (Khosla and Nagori, 2002). Presence of molt stages of the bulk
of non-marine and brackish water ostracods in the Inter-trappean beds of Jhilmili is suggestive that they were inhabitants
of low mesohaline inland pool/lake. The planktonic foraminifers were carried to this pool/lake by a marine transgression probably
from the east coast of India through the Trans Deccan Straits. 相似文献
839.
P. Conde Bueno E. Bellido J. A. Martín Rubí R. Jiménez Ballesta 《Environmental Geology》2009,56(5):815-824
Mercury (Hg) is one of the elements with increasing environmental significance. A total of 22 samples (soils, rocks and gels)
were collected along a 6 km transect around the Valdeazogues River valley in the southwest of the Iberian Peninsula (Almadén,
Spain). Samples were characterized by different soil types of depositional sequences associated with mining tailings, type
and system tracts: 15 surface soil samples included in the transect; 3 of a Haploxerept soil profile developed on slates;
2 of quartzite and slates rocks (reference rocks in the area). Moreover, two of a gel substance (in the lower tract of the
river). Soil samples were analyzed for Hg, Cu, Ni, Cr, V, Pb, Cd and As, as well as for organic matter, pH abrasion and calcium
carbonate content. All samples were collected from the Almadén mining district. The level of occurrence of the elements (especially
Hg) and the effect of some properties on its concentration distributions were investigated. The total mercury contents varied
in the range 7,315–3.44 mg kg−1. The mean concentration of total mercury in soils and rocks was 477.03 mg kg−1dry mass. This value is very high compared to the regional background value of other areas. Only rarely is it higher than
1%: in one sample (7,315 mg kg−1) it was almost eight times in comparison with the affected zones, with a high value of 1,000 mg kg−1. Significant differences between samples were found in the total content of mercury. A large percentage of the samples registered
detectable levels of V, Cr, Ni, Pb, As and Cu. Cd readings were below the detectable range for all samples tested. Cr mean
concentration was 216.95 mg kg−1 (minimun concentration 86, maximun 358); V mean concentration was 119.09 mg kg−1 (minimun concentration 69, maximun 1,209); As mean concentration was 51.24 mg kg−1 (minimun 13.3 and maximun 319.4); Ni mean concentration was 45.64 mg kg−1 (minimun concentration 21.2 and maximun 125.6); Cu mean concentration was 33.25 mg kg−1 (minimun concentration 19.3 and maximun 135); Pb mean concentration was 15.19 mg kg−1 (minimun 1.12 and maximun 1013). Metal distribution generally showed spatial variability ascribed to significant anthropogenic
perturbation by mining tailing type. Hg showed vertical profile characterized by surface enrichment, with concentrations in
the upper layer (93.7–82.2 mg kg−1 in front of 3.4 of the rock value) exceeding, in several occasions, the background value. The results obtained denote a potential
toxicity of some heavy metals in some of the studied samples. Water-soluble mercury could enter the aquatic system and accumulate
in sediments. Mercury and other heavy metals contamination depended on the duration and intensity of mining activities. 相似文献
840.