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111.
波伏棱型羟基纤蛇纹石是波伏棱型纤蛇纹石矿物的新变种,本文报导它的吸收光谱、红外光谱、穆斯堡尔谱、电子顺磁共振谱和核磁共振谱。 研究表明,吸收光谱是Fe~(3 )和Fe~(2 )的晶场跃迁以及Fe~(2 )→Fe~(3 )的荷移跃迁引起的;红外光谱是OH和Si-O的伸缩振动、OH转动以及Mg-O和Si-O的弯曲振动引起的;穆斯堡尔谱是Fe~(2 )_(八面体)、Fe~(3 )_(八面体)和Fe~(3 )_(四面体)引起的;电子顺磁共振谱是Mn~(2 )_(八面体)、Fe~(3 )_(八面体)和Fe~(3 )_(四面体)引起的;核磁共振谱是管道水,镁八面体和硅氧四面体上的OH引起的;矿物加热到825℃时,结构开始破坏并出现镁橄榄石相。 此外,本文还解释了该蛇纹石颜色的本质,阐明了上述过渡金属离子和OH在该矿物中的结构环境。 相似文献
112.
P. C. Simon D. Gillotay N. Vanlaethem-Meuree J. Wisemberg 《Journal of Atmospheric Chemistry》1988,7(2):107-135
Absorption cross-sections of nine halomethanes (CCl4, CHCl3, CH2Cl2, CH3Cl, CFCl3, CF2Cl2, CF3Cl, CHFCl2, and CHF2Cl), measured between 174 and 250 nm for temperatures ranging from 225 to 295 K, are presented with uncertainties ranging from 2 to 4% and compared with previous determinations made for comparable temperature ranges.The largest temperature effect which takes place near the absorption threshold, decreases the absorption cross-section up to 50% for highly chlorinated methanes, but is negligible for molecules highly stabilized by hydrogen and/or fluorine. Extrapolated values for temperatures of aeronomical interest are presented, as well as parametrical formulas which give absorption cross-section values for given wavelength and temperature ranges. 相似文献
113.
矿石中金的在线固相萃取及缝管火焰原子吸收测定 总被引:3,自引:0,他引:3
介绍了将流动注射在线因相萃取预浓集与石英缝管火焰原子吸收相结合测定矿石中金的方法,用XAD-8吸附树脂填充的微型柱(100μl)在6ml/min的流速下,从0.5mol/LHCl介质的试样溶液中浓集金氯络合物,再用乙醇洗脱,最后由火焰原子吸收检测,在采样频率为103样/h的流速下灵敏度提高47倍,分析精度为1.3%,检出限为1.0μg/L;在65样/h的采样频率下灵敏度提高95倍,检出限可达0.7 相似文献
114.
This article summarizes work on multiple scattering based on models of media with randomly distributed scatterers. The scatterers are isotropic and statistically uniform. Measuring distance in terms of mean-free pathL
s and time in terms of the mean-free timesL
s/V, whereV is the velocity of scattered waves, we have more convenient dimensionless distance and time. It can be shown that after the dimensionless time equals 0.65 energy contributed from multiple scattering becomes predominant. Thus the later coda reflects the effect of multiple scattering rather than single scattering. Treating the seismic record, including starting and tail parts, as a whole, the diffusion theory predicts that at a dense distribution of scatterers and a small distance between source and receiver, codas reflect mainly intrinsicQ
i. Of course, this conclusion is coincident with the presumption of the diffusion theory,Q
s>Q
i. However, from a new integral equation of multiple scattering, which deals with the scattered waves and primary waves separately, the conclusion is similar but clearer. This article quotes the new expression for coda energy in two-dimensional space. It shows that if the receiver is close to the source, the coda decay reflects only intrinsicQ
i, then as the distance increases, effects of scatteringQ
s, are involved in the decay feature. The theoretical plots of coda decay show that it seems in most cases in the earthQ
i should not be smaller than one tenth ofQ
s.Project Sponsored by the Joint Earthquake Science Foundation of China. 相似文献
115.
叶蜡石、高岭石和迪开石的吸收光谱研究 总被引:3,自引:0,他引:3
对不同地区叶蜡石、高岭石、迪开石的吸收光谱测量及其高斯谱拟合说明,三各矿物的吸收光谱均由一个吸收边和三个吸收峰叠加而成。主吸收峰在562nm左右,峰高以迪开石为最大,高岭石次之,叶蜡石最低。同一地区不同颜色的叶蜡石,其主吸收峰位置随铁含量的增加向短波方向移动,相对峰高也随之增大。叶蜡石的颜色主要取决于主吸收峰的位置、高度和吸收边位置。可以认为,此吸收边为Fe^3 →O^2-荷移谱的低能拖尾部分,吸收峰则为铁离子的晶场谱带或晶场谱与Fe^2 →Fe^3 荷移的叠加。 相似文献
116.
新疆绿柱石宝石辐照致色机制的吸收光谱研究 总被引:1,自引:0,他引:1
本文对新疆阿尔泰天然淡蓝、浅蓝宝石级绿柱石辐照前后及退火处理伴随着颜色改变的吸收光谱等进行了分析讨论,认为天然淡蓝、浅蓝色绿柱石经~(60)Co-γ辐照变成黄绿色,其原因主要归因于遂道中Fe~(2-)向Fe~(3+)的转变和八面体中Fe~(3+)和配位体O~(2-)的电荷转移。 相似文献
117.
A. Waltrop S. K. Mitra A. I. Flossmann H. R. Pruppacher 《Journal of Atmospheric Chemistry》1991,12(1):1-17
An experimental study involving the Mainz vertical wind tunnel is described where the rate of SO2 removed from the air by freely suspended water drops was measured for SO2 concentrations in the gas phase ranging between 50 and 500 ppb, and for various H2O2 concentrations in the liquid phase. In a first set of experiments, the pH inside the SO2 absorbing drops was monitored by means of colour pH indicators added to the drops. In a second set of experiments, the amount of SO2 scavenged by the drops was determined as sulfate by an ionchromatograph after the drops had been removed from the vertical air stream of the wind tunnel after various times of exposure to SO2. The results of our experimental study were compared with the theoretical gas diffusion model of Walcek and Pruppacher which was reformulated for the case of SO2 concentrations in the ppbv(v) range for which the main resistance to diffusion lies in the gas phase surrounding the drop. Excellent agreement between experiment and theory was obtained. Encouraged by this agreement, the theory was used to investigate the rate of sulfate production inside a drop as a function of pH. The sulfate production rate, which includes transport and oxidation, was compared with the production rate based on bulk equilibrium, as cited in the literature. 相似文献
118.
119.
J. N. Desai 《Journal of Earth System Science》1984,93(3):189-200
The paper describes use of Fabry-Perot (fp) systems in spectroscopic studies of astronomy and earth’s upper atmosphere. Factors influencing the resolution, luminosity
and instrumental line shape offp spectrometer are discussed and the need for their optimization is emphasised, if desired luminosity gain is to be realised
in practice. Use offp as imaging spectrometer, scanning spectrometer and as a narrow band filter are illustrated. Tandemfp systems are briefly dealt with. 相似文献
120.
D. Perner U. Platt M. Trainer G. Hübler J. Drummond W. Junkermann J. Rudolph B. Schubert A. Volz D. H. Ehhalt K. J. Rumpel G. Helas 《Journal of Atmospheric Chemistry》1987,5(2):185-216
Using long path UV absorption spectroscopy we have measured OH concentrations close to the earth's surface. The OH values observed at two locations in Germany during 1980 through 1983 range from 0.7×106 to 3.2×106 cm-3. Simultaneously we measured the concentrations of O3, H2O, NO, NO2, CH4, CO, and the light non methane hydrocarbons. We also determined the photolysis rates of O3 and NO2. This allows calculations of OH using a zero dimensional time depdendent model. The modelled OH concentrations significantly exceed the measured values for low NO
x
concentrations. It is argued that additional, so far unidentified. HO
x
loss reactions must be responsible for that discrepancy. 相似文献