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81.
水—经济空间关系是干旱区与半干旱区水资源研究的热点,揭示水—经济空间分布演变规律和因果关系,可为优化水资源合理配置、合理部署产业结构调整政策提供理论和决策参考。研究应用水足迹理论,核算新疆各地州1991—2015年农作物水足迹,结合信息熵值理论分析新疆各地州农作物水足迹、国内生产总值、第一产业增加值其熵值的空间演变规律及因果关系。结果表明:新疆农作物水足迹与第一产业增加值、国内生产总值空间演变整体向着均衡有序的方向发展,水—经济的空间不均衡性逐步缩小;新疆农作物水足迹显著影响其第一产业增加值空间演变,影响期1~5 a,农业经济空间分布受农业用水空间分布的长期制约;农作物水足迹和国内生产总值没有空间演变因果关系,全疆经济发展向着第二产业、第三产发展转型,农业经济不再显著影响全疆经济发展。 相似文献
82.
83.
区域尺度精细化水动力数值模拟是解决大量工程、地质、环境等问题的重要手段。水动力荷载的直接冲击是近海近岸结构物、设施破坏的主要动力因素。本文章旨在介绍Boussinesq-GreenNaghdi有旋非静压水动力模型及其在区域尺度灾害性海浪的非静压水动力荷载分析和风险分布评价上的应用。这套模型利用了Boussinesq量纲和Green-Naghdi加权积分的结构。速度和压力被用多项式假设来表达和非线性重排法的应用,有效地提高了模型性能,避免了无旋假设的使用,更好地模拟计算了右旋流速和非静态压力场等复杂水动力参数。模拟重现美国和菲律宾沿海台风浪过程,深入分析非静压海浪荷载作用机理,计算海浪荷载的时空分布,与巨石迁移和结构物损坏的调查数据进行对比验证,构建海浪荷载与区域结构物破坏程度分布的相关性,量化各项影响要素如流速、浪高、结构物特征等的风险权重,通过回归分析法推导基于多影响要素的区域海浪风险参数化定量评价方法。为非静压相位解析有旋水动力理论和海浪灾害机理的科学探索提供原创性基础。为沿海人类活动、区域规划、工程设计、防灾减灾等提供科学指导。 相似文献
84.
Zhu Xiaobin Xu Weihai Wang Xinting Huang Xinping Deng Liping Kang Xinglun Jiang Zhigang Ma Xuli 《中国海洋湖沼学报》2005,23(1):39-42
Heavy metals pollution in Jiaozhou Bay was studied inRuditapes. philippinarum, a bioindicator of seawater pollution. Heavy metals in soda industry wastes “white mud” were also studied. Comparison of
microwave digestion method with general digestion method revealed that microwave digestion is superior to general digestion
in precision, recovery, digestion speed and efficiency, etc. Cd concentration in HongdaoR. philippinarum samples exceeded the national standard by 0.046 mg/kg, that of Yinghai sample by 0.02 mg/kg, and that of Hongshiya sample
by 0.22 mg/kg. Sample Pb concentration in Hongshiya was found to exceed the national standard by 0.02 mg/kg. However the heavy
metals concentration inR. philippinarum near the Qingdao Alkaline Factory was complied with the standard. This was proved byPenaeus chinensis culture experiment. Therefore, the possible contamination source may come from other land areas.
This study is supported by Project 973 (NO.2002CB 412402), and key project of the Chinese Academy of Sciences (Grant NO.KJCX315W-215). 相似文献
85.
Fluids double-fracturing genetic mechanism and mineralization of gold-copper of the breccia pipe at Qibaoshan in Shandong Province 总被引:9,自引:0,他引:9
XU Xingwang CAI Xinping QIN Dajun WANG Jie LIANG Guanghe Zhang Xiaoyun LIU Lijin 《中国科学D辑(英文版)》2000,43(2):113-121
After studying the characteristics and special texture of the fluidogenous tectonics, mineral assemblage in the cemented vein
between breccia and their special distribution, and stress analyzing the joint structures in and around the breccia pipe,
it is found that the observed phenomena are caused by a new tectonic dynamic mechanics of fluid—double-fracturing caused by
temperature and pressure of fluids and pulsating expansion. Under the actions of thermal stress and the pressure of fluids,
thermal cracks and joints that developed along parts of the thermal cracks formed systematically in the rocks. Under these
conditions, up-arching fracture zones that pulsatively expanded upward and cylindrical pressing breccia body were formed.
Rocks at the peak of the pyramidal fractures zone break down instantly. Where the difference between pressure of fluids and
the overburden pressure exceeded greatly the competence of the rocks, fluid junctions occurred and the velocity of the fluid
flow increased as a result. Explosive body expanded upward in the shape of an inverse cone, cone-like explosive breccia body
and cover-like shattering breccia body located on the upper part of the breccia pipe were ultimately formed. Gold-rich fluids
were enriched and mineralized near the boiling surface in the lower part of the inverse cone-like explosive breccia body where
temperature and pressure decreased rapidly, while copper-rich fluids were enriched and mineralized in the junction area where
temperature and pressure were relatively high. 相似文献
86.
乌鲁木齐河流域不同水体中的氧稳定同位素 总被引:1,自引:0,他引:1
The variations of the stable oxygen isotope in different water mediums in Urumqi River Basin, China, are analyzed. The stable oxygen isotope in precipitation has marked temperature effect either under synoptic or seasonal scale at the head of Urumqi River. The linear regression equations of δ^18O against temperature are δ^18O=-0.94T-12.38 and δ^18O=1.29T-13.05 under the two time scales, respectively. The relatively large δ^18O/temperature slopes show the strong sensitivity of δ^18O in precipitation to temperature variation at the head of Urumqi River. According to the analyses on the δ^18O in precipitation sampled at three stations with different altitudes along Urumqi River, altitude effect is notable in the drainage basin. The δ^18O/altitude gradients have distinct differences: the gradient from Urumqi to Yuejinqiao is merely -0.054‰/hm, but -0.192‰/hm from Yuejinqiao to Daxigou, almost increasing by 2.6 times over the former. No altitude effect is found in surface firn the east branch of Glacier No. 1 at the head of Urumqi River, showing that precipitation in the glacier is from the cloud cluster with the same condensation level. Influenced by strong ablation and evaporation, the δ^18O in surface firn increases with increasing altitude sometimes. Survey has found that the δ^18O in meltwater at the terminus of Glacier No. 1 and in stream water at Total Control have the similar change trend with the former all smaller than the latter, which displays the different runoff recharges, and all mirror the regime of temperature in the same term basicallv. 相似文献
87.
88.
Eco-environmental change detection by using remote sensing and GIS techniques: a case study Basrah province, south part of Iraq 总被引:3,自引:1,他引:2
This study examines the temporal and spatial dynamics of eco-environment degradation processes and change detection as evident from land use survey datasets (1990–2003) for the Basrah province, Iraq was taken as a case. Using a combination of techniques of RS, GIS, and GPS, the study identifies five prominent eco-environment degradation processes, namely: desertification, secondary salinization, urbanization, vegetation degradation, and loss of wetlands. Rates of conversion were calculated and distribution patterns were mapped with the aid of GIS. The results suggest that wind erosion was the dominant cause of eco-environment degradation in more than half of the study area. Coupled with this were increases in salinization processes, affecting 17.6% of the land area in 2003. Overall, severe eco-environment degradation was noticed to be the dominant eco-environment degradation grade (61.9% of total area), followed by moderate eco-environment degradation (18.9% of total area) in 2003. Incorporation of both natural and anthropogenic factors in the analysis provided realistic assessment of the risk of land degradation. The study area, in general, is exposed to a high-risk of eco-environment degradation. 相似文献
89.
Peiyan Sun Zhenhui Gao Lixin Cao Xinping Wang Qing Zhou Yuhui Zhao Guangmei Li 《中国海洋大学学报(英文版)》2011,10(1):35-41
In recent years, oil spill accidents occur frequently in the marine area of China. Finding out the spilled oil source is a
key step in the relevant investigation. In this paper, a step-by-step fingerprinting identification method was used in a spilled
oil accident in the Bohai Sea in 2002. Advanced chemical fingerprinting and data interpretation techniques were used to characterize
the chemical composition and determine the possible sources of two spilled oil samples. The original gas chromatography -flame
ionization detection (GC-FID) chromatogram of saturated hydrocarbons was compared. The gas chromatography-mass spectrometry
(GC/MS) chromatograms of aromatic hydrocarbons terpane and sterane, n-alkane and poly-aromatic hydrocarbons (PAHs) were analyzed. The correlation analysis on diagnostic ratios was performed with
Student’s t-test. It is found that the oil fingerprinting of the spilled oil (designated as sz1) from the polluted sand beach
was identical with the suspected oil (designated as ky1) from a nearby crude oil refinery factory. They both showed the fingerprinting
character of mixed oil. The oil fingerprinting of the spilled oil (designated as ms1) collected from the port was significantly
different from oil ky1 and oil sz1 and was with a lubricating oil fingerprint character. The identification result not only
gave support for the spilled oil investigation, but also served as an example for studying spilled oil accidents. 相似文献
90.
INFLUENCEOFSEA-AIRINTERACTIONONTHEDISCHARGEOFFLOODSEASONINTHEUPPERREACHESOFTHECHANGJIANGRIVERZhangXinping(章新平)(LanzhouInstitu... 相似文献