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971.
水文现代化建设指导意见   总被引:5,自引:4,他引:5  
2005年2月25日,“水文现代化建设指导意见”以水利部文件(水文[2005]70号)下发到各流域机构、各省(自治区、直辖市)水利(水务)厅(局),各计划单列市水利(水务)局、新疆生产建设兵团水利局。该指导意见下发一年来起到了较好效果,为使基层水文职工和有关高校、科研单位水文科技人员更好地了解指导意见内容,现将指导意见全文转载,供有关水文科技人员学习与参考。  相似文献   
972.
张建云  章树安 《水文》2006,26(3):10-12
本文简要介绍了《水文现代化建设指导意见》的主要内容;深入论述了水文现代化建设的必要性、原则和要着重处理的关系;从站网、测验、信息处理和应用,以及信息社会公众服务等方面存在的问题进行了较全面的分析;并结合我国的实际,对稳步推进水文现代建设主要任务提出了具体意见。  相似文献   
973.
梁家志  章四龙 《水文》2006,26(3):60-62
近几年来,随着计算机、网络、地理信息系统等高新技术在水文情报预报领域里的推广应用,全国水文情报预报业务系统得到很大的发展,相继开发建设了满足业务需求的业务系统。本文主要介绍了水文情报预报业务系统,包括查询系统、会商系统和洪水预报系统等。  相似文献   
974.
呼伦湖水面蒸发及水量平衡估计   总被引:4,自引:1,他引:4  
李翀  马巍  叶柏生  廖文根 《水文》2006,26(5):41-44
为重建水文资料缺乏的呼伦湖流域的水文序列,本研究基于长期的气象观测记录,采用彭曼公式估计了湖泊的水面蒸发,并建立一个两参数月水量平衡模型模拟湖周的入流,通过水量平衡计算,模拟了湖泊月水量、水位变化,重建了42年(1961-2002)的呼伦湖区水文序列。模拟的水位变化趋势与实际比较接近,误差较小,模拟精度较好。所重建的42年呼伦湖水文序列,可为该区域的水资源评价管理提供科学依据。  相似文献   
975.
党新成  李新贤  高建芳 《水文》2006,26(5):89-90,82
论述了新疆玛纳斯河流域自然地理、气候及河流概况,降雨、径流和泥沙的时空分布规律,从降水、径流、洪水、泥沙、水质等方面分析了该流域的水文与环境特征。  相似文献   
976.
荒漠地区生物土壤结皮的水文物理特征分析   总被引:15,自引:0,他引:15       下载免费PDF全文
通过室内压力陶土板系统测定土壤含水率与基质势的关系与Star-1土壤水分物理特征测定系统确定非饱和土壤水力传导度的方法,结合应用van Genuchten公式模拟,分析了位于腾格里沙漠东南缘包兰铁路沙坡头段人工生态防护体系生物土壤结皮的水文物理特征,确定了其水分特征曲线、非饱和土壤水力传导度、非饱和弥散系数,并与原始沙丘沙进行比较。结果表明,生物土壤结皮的持水能力是沙丘沙的3~9倍。当土壤基质势在-1~-3 000 cm的较高范围变化时,生物土壤结皮平均非饱和水力传导度低于沙丘沙(约为12%);而当土壤基质势在-3 000~-15 000 cm的较低范围变化时,沙丘沙的平均非饱和水力传导度又大大低于生物土壤结皮(约为91.0%)。正是由于生物土壤结皮特殊的质地与结构,使其非饱和水力传导度随着土壤基质势的降低,以及土壤含水量的减少,而趋于增大。与原始沙丘沙比较,生物土壤结皮独特的水文物理特点决定了它对荒漠地区土壤微生境的改善与促进作用,特别是通常情况下的高持水能力与低土壤基质势条件下的较高非饱和水力传导度,能够提高浅层土壤水分的有效性,有利于人工生态防护体系主要组分浅根系灌木、草本植物与小型土壤动物的生存繁衍。  相似文献   
977.
《中国地球化学学报》2006,25(B08):236-236
It is still disputed in the scientific community whether it is possible to trace a direct link or even proportionality between mercury (Hg) anthropogenic loadings to lake ecosystems and resulting methylmercury (MeHg) levels found in fish tissues. We present here the exemplary case of the Baihua Reservoir, located on the Maotiahoe River, near Guiyang (Guizhou, China). Baihua was impacted for many years by Hg-contaminated effluents from industrial source. While sedimentary profiles exhibit extreme enrichment in sedimentary Hg burden, fish species harvested from the reservoir still present low Hg levels. Thus we propose here that in the case of Hg, loading does not tell it all and one must take it into account the net methylation capacity of lake ecosystems and its ability to efficiently bioaccumulate MeHg along the trophic web.  相似文献   
978.
Detailed time-series studies on the major ion geochemistry of tropical peninsular Indian rivers are lacking. In this backdrop, a small stretch of the Godavari River, globally ranking 32nd in terms of total discharge, is chosen for sampling at its mouth. The objectives are: (1) to understand the natural and anthropogenic sources controlling the major ion chemistry of the Godavari River at Rajahmundry, (2) processes controlling the temporal variations in major ions over a period of two years, (3) comparison of total dissolved solid (TDS) fluxes and weathering rates at Godavari River with other major tropical rivers. A total of 47 surface samples were collected, bimonthly, at five stations in the Godavari at Rajahmundry spaced over a distance of 6 km for a period of two years. Water samples were collected in pre-cleaned PP bottles. Parameters like temperature, pH, conductivity, dissolved oxygen, alkalinity were measured on-site. Samples collected for analysis of major ions were processed within a few hours of collection by filtering through 0.45 mm pore size millipore filters. Filtered water samples for major ions were transported to the laboratory in cleaned 250 mL PP bottles. Sodium and K were measured on a Flame Photometer, Ca and Mg on a Flame Atomic Absorption Spectrophotometer, Cl, NO3, SO4 by Ion Chromatography and SiO2 on a spectrophotometer. Chemical weathering of rocks controls the major ion chemistry of the Godavari River at its mouth as indicated by the alkaline nature of the river and dominant presence of Ca, Mg and HCO3 ions. Ca/Mg and Na/Mg ratios point its source to a mixture of lithological assemblages of basalt, granite-granodiorite,  相似文献   
979.
Sr isotope studies of surficial waters have highlighted that differences in the ^87Sr/^86Sr ratio and Sr concentration are primarily caused by mixing of waters of various origins with specific isotopic and chemical characteristics, resulting from water-rock interaction processes. In this paper we reported the first Sr isotopic ratios, coupled with water chemistry, the measurement was carried out on samples related to (1) the Amo River (Tuscany, central-northern Italy), between the source and the mouth, (2) the most important tributaries and to (3) the thermal water discharges seeping out in the southern part of the basin. The main goals are: a) to use the ^87Sr/^86Sr ratio as a discriminative parameter of source areas, b) to define its variation along both the main course and principal tributaries, and c) to estimate the effects of the mixing process of the different end-embers. The outcropping rocks in the Amo River Basin are predominantly sedimentary, mainly made up of Mesozoic limestones, Oligocene sandstones and Plio-Pleistocene marine-lacustrine formations. Triassic and Mesosinian evaporites crop out in the Elsa and Era reaches, whereas Paleozoic quartzitic formations occur in the Mrs. Pisani area. Strontium isotopic composition is generally controlled by lithology and does not seem to be affected by anthropic input and flow rate. The ^87Sr/^86Sr ratios in the Arno Basin vary between 0.707963 and 0.712743, the highest ratios being related to waters circulating in the Palezoic rocks and Oligocene sandstone formations. Less radiogenic values pertain to the Elsa and Era tributaries where contributions related to the dissolution of evaporitic sequences, and mixing processes with the thermal discharges have been distinguished. The tributaries show that water samples in the pristine area have higher ^87Sr/^86Sr ratios than the respective tributaries from which water samples were collected near the confluence. Eventually, water samples collected along the Arno River, close to the mouth, tend to have Sr isotopic ratios similar to those of the present seawater.  相似文献   
980.
The sorption of aqueous cadmium on carbonate-hydroxyapatite (CHap) is a complicated non-homogeneous solid/water reaction, From kinetic point of view, it can be described by two stages: at the earlier stage, reaction rate is so fast that its kinetic course is intricate, and at the later stage, the rate of reaction becomes slow and the process of reaction accords with one order reaction kinetic equation. Experimental results show that the relationship between reaction rate constant kl and temperature T accords to Arrhenius Equation, and the activation energy of sorption (Ea) is 6.075 J/mol and frequency factor (A) is 220 s^-1. At the same time, reaction rate constant kl increases with decreasing Cd^2+ initial concentration, on the contrary, with increasing pH and CHap dosage.  相似文献   
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