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91.
胡昌苗  张微  冯峥  唐娉 《遥感学报》2014,18(2):267-286
全球地表覆盖遥感制图与关键技术研究项目要求对两个基准年度(2000年,2010年)的全球覆盖30 m分辨率遥感数据进行辐射处理,转换到地表反射率,数据以Landsat TM/ETM+为主,HJ-1A/B CCD数据为补充。海量数据中有些不适宜进行绝对大气校正,为了保证全球覆盖,对这些数据设计开发了一套自动的相对辐射处理及精度验证流程算法,利用相邻数据重叠区域进行相对辐射校正的方式,将数据由Oigital Number(DN)值直接转换为地表反射率,精度验证以MODIS地表反射率产品MOD09GA作为参考,比较对应波段数据的相对一致性,算法采用了图像分块处理技术及OpenMP加速技术提高效率,实际应用结果表明该算法流程可以满足项目对辐射处理精度、速度及自动化程度的要求。  相似文献   
92.
In this paper,a multistep finite difference scheme has been proposed,whose coefficients are determined taking into consideration compatibility and generalized quadratic conservation,as well as incorporating historical observation data.The schemes have three advantages:high-order accuracy in time,generalized square conservation,and smart use of historical observations.Numerical tests based on the one-dimensional linear advection equations suggest that reasonable consideration of accuracy,square conservation,and inclusion of historical observations is critical for good performance of a finite difference scheme.  相似文献   
93.
碳捕集与封存(CCS)技术作为解决全球气候变化问题的重要手段之一,能够有效减少CO2排放。中国作为碳排放大国,当前电力的主要来源仍是煤电,碳捕集(CC)改造在燃煤电厂中有很大的应用潜力。经济性对CC改造的部署至关重要。为此,本文计算了中国各省典型电厂CC改造前后的平准化度电成本,比较了不同省份的CO2捕集成本与CO2避免成本,分析了不同掺烧率下生物质掺烧结合碳捕集(bioenergy with carbon capture,BECC)改造的经济性。研究发现,CC改造会导致不同地区的燃煤电厂度电成本增加57.51%~93.38%。煤价较低的华北和西北地区(青海除外)CC改造经济性较好,BECC改造则更适合华中地区。建议在推进燃煤电厂CC和BECC改造时要充分考虑区域资源特点,完善碳市场建设,形成合理碳价以促进CC和BECC部署。  相似文献   
94.
北京石花洞位于房山花岗岩体边缘向形带的东北扬起端,与北京猿人遗址南北相望,地层均为奥陶系马家沟组石灰岩.洞内石笋记录了中更新世以来北京西山古环境的变化,可以建立第四纪石笋剖面.钙板的铀系年龄为334.99~366.74 ka,定名钙板组(Qp2g).粗犷石笋的铀系年龄为169 ~ 235 ka,粗犷石笋的电子自旋共振年龄为130~518ka,属中更新世沉积,定名云水洞组(Qp2y).杆状石笋的铀系年龄为14.9±2.1 ~ 100.3±11.1 ka,属晚更新世沉积,定名石花洞组(Qp3sh).在全新世石笋中,微层与微层之间存在厚约1μm的条带状纹线,是划分微层层数的标志,具有微层理的石笋14C年龄为0.58~ 2.50 ka,定名守备支洞组(Qhsh).  相似文献   
95.
An inexact stochastic fuzzy programming (ISFP) approach has been developed for the optimization of the industrial structure in resource-based city subjected to water resources under uncertainty in present study. The ISFP method incorporates the techniques of inexact stochastic programming and inexact fuzzy chance-constrained programming, where the uncertainties are expressed as interval, fuzzy sets, and probability distribution, respectively. Moreover, it can also examine the risk of violating fuzzy tolerance constraints. The developed method is subsequently employed in a realistic case for industrial development in the Jinchang city, Gansu province, China. The result can help to analyze whether the water resources carrying capacity of Jinchang can meet the need of local economic development plan under uncertainty and help decision maker to optimize the industry structure under water resource constraints to meet the maximum economic efficiency.  相似文献   
96.
A robust risk analysis method (RRAM) is developed for water resource decision making under uncertainty. This method incorporates interval-parameter programming and robust optimization within a stochastic programming framework. In the RRAM formulation, penalties are exercised with the recourse against any infeasibility, and robustness measures are introduced to examine the variability of the second stage costs which are above the expected levels. In this study, a number of weighting levels are considered which correspond to the robustness levels of risk control. Generally, a plan with a higher robust level would better resist from system risk. Thus, decision with a lower robust level can correspond to a higher risk of system failure. There is a tradeoff between system cost and system reliability. The RRAM is applied to a case of water resource management. The modeling results can help generate desired decision alternatives that will be particularly useful for risk-aversive decision makers in handling high-variability conditions. The results provide opportunities to managers to make decisions based on their own preferences on system stability and economy, and ensure that the management policies and plans be made with reasonable consideration of both system cost and risk.  相似文献   
97.
An inexact fuzzy-random-chance-constrained programming model (IFRCCMM) was developed for supporting regional air quality management under uncertainty. IFRCCMM was formulated through integrating interval linear programming within fuzzy-random-chance-constrained programming framework. It could deal with parameter uncertainties expressed as not only fuzzy random variables but also discrete intervals. Based on the stochastic and fuzzy chance-constrained programming algorithms, IFRCCMM was solved when constraints was satisfied under different satisfaction and violation levels of constraints, leading to interval solutions with different risk and cost implications. The proposed model was applied to a regional air quality management problem for demonstration. The obtained results indicated that the proposed model could effectively reflect uncertain components within air quality management system through employing multiple uncertainty-characterization techniques (in random, fuzzy and interval forms), and help decision makers analyze trade-offs between system economy and reliability. In fact, many types of solutions (i.e. conservative solutions with lower risks and optimistic solutions with higher risks) provided by IFRCCMM were suitable for local decision makers to make more applicable decision schemes according to their understanding and preference about the risk and economy. In addition, the modeling philosophy is general and applicable to many other environmental problems that may be complicated with multiple forms of uncertainties.  相似文献   
98.
A series of laboratory experiments were carried out in this study to investigate the remediation of phenanthrene contaminated soil using ultrasound and soil washing. The results indicated that ultrasound and soil washing could significantly enhance the remediation efficiency of each other. The performance of the combined ultrasonic and soil washing process was then investigated, and the impacts of four experimental variables including the initial concentration of phenanthrene in soil, sonication time, pH of washing solution, and washing flow rate were examined using an orthogonal experimental design method. The analysis of variance (ANOVA) of experimental results revealed that the initial phenanthrene concentration, sonication time and soil washing flow rate showed significant effects (P ≤ 0.05) on the remediation efficiency. A pseudo-first-order kinetics model was developed for describing the remediation process, and a maximum remediation efficiency of 69.5% was observed in the study after 20 min of treatment under the experimental conditions. Therefore, the results indicate that the combined ultrasonic and soil washing process could represent a promising technology for the effective remediation of phenanthrene contaminated soil.  相似文献   
99.
在湖北省京山县雁门口地区二叠世栖霞组上部的含泥灰岩中发现棘皮动物化石,其腔被不同形态微晶的草莓状黄铁矿充填,有正四面体、正六面体、五角十二面体和近球体。溶解氧与草莓状黄铁矿的形成过程有关,其浓度决定微晶的S/Fe。统计显示,黄铁矿的S/Fe平均值随微晶的边数增加而增加,所以,棘皮动物腔内草莓状黄铁矿形成由早及晚的次序为:近球体微晶,五角十二面体微晶,正六面体微晶,正四面体微晶的草莓状黄铁矿。同一环境中,黄铁矿微晶的S/Fe可用来指示形成次序。  相似文献   
100.
北京市平原区土壤中硒的含量和分布   总被引:13,自引:0,他引:13  
通过对北京平原土壤硒含量调查和研究,发现北京平原分布有高硒土壤,其特征为沿平原区西部山前断续出现,在北京市区零星分布。表层土壤硒含量为0.04~5.26 mg/kg,平均值为0.20 mg/kg,深层土壤硒含量为0.043~0.22mg/kg,平均值为0.081 mg/kg,总体趋势是硒在表层土壤富集;各类岩石中以炭质页岩中含硒量最高,北京西部富硒炭质页岩的风化可能为平原区土壤硒的来源。相关性分析表明,土壤中Se与有机质呈正相关性,有机质对表层土壤Se具有强烈的吸附与固定作用。  相似文献   
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