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31.
Horst Falke 《International Journal of Earth Sciences》1955,43(2):350-351
Ohne Zusammenfassung 相似文献
32.
Horst Piller 《Contributions to Mineralogy and Petrology》1954,4(1-2):151-162
Zusammenfassung Es werden der qualitative Mineralbestand und die Korngrößen verteilung im Verwitterungsgrus des Granites vom Fliegenberg, westlich Thiersheim, angegeben. Während der mechanische Zerfall des Gesteins als relativ stark erkannt worden ist, sind keine nennenswerten chemischen Mineralumwandlungen festzustellen. Dadurch wird die vorteilhafte Untersuchung der Schwerminerale ermöglicht. Eine hervorragende Stellung nimmt der Apatit ein. Dieser ist nahezu frisch. Da er sick an anderer Stelle (Grus des Brockengranits) unter ähnlichen Verwitterungen als chemisch instabil erwiesen hat, wird die Verwitterung des Fliegenberggranites noch jüngeren rezenten Verwitterungseinflüssen zugeschrieben. Die restliche Schwermineralassoziation wird in dieWellssche Gruppe der pneumatolytischen Bildungen eingeordnet. Die Beobachtungen deuten auf eine geringe Tiefenstufe des hier aufgeschlossenen Teils vom Granitkörper und die besondere Anlage zu einer Grusbildung hin.Herrn Professor Dr.Carl W. Correns zum 60. Geburtstag gewidmet. 相似文献
33.
Nikolaus Gussone Gerald Langer Markus Geisen Blair A. Steel Ulf Riebesell 《Earth and Planetary Science Letters》2007,260(3-4):505-515
Four species of marine calcifying algae, the coccolithophores Calcidiscus leptoporus, Helicosphaera carteri, Syracosphaera pulchra and Umbilicosphaera foliosa were grown in laboratory cultures under temperatures varying between 14 and 23 °C, and one species, C. leptoporus, under varying [CO32−], ranging from 105 to 219 μmol/kg. Calcium isotope compositions of the coccoliths resemble in both absolute fractionation and temperature sensitivity previous calibrations of marine calcifying species e.g. Emiliania huxleyi (coccolithophores) and Orbulina universa (planktonic foraminifera) as well as inorganically precipitated CaCO3, but also reveal small species specific differences. In contrast to inorganically precipitated calcite, but similar to E. huxleyi and O. universa, the carbonate ion concentration of the medium has no statistically significant influence on the Ca isotope fractionation of C. leptoporus coccoliths; however, combined data of E. huxleyi and C. leptoporus indicate that the observed trends might be related to changes of the calcite saturation state of the medium. Since coccoliths constitute a significant portion of the global oceanic CaCO3 export production, the Ca isotope fractionation in these biogenic structures is important for defining the isotopic composition of the Ca sink of the ocean, one of the key parameters for modelling changes to the marine Ca budget over time. For the present ocean our results are in general agreement with the previously postulated and applied mean value of the oceanic Ca sink (Δsed) of about − 1.3‰, but the observed inter- and intra-species differences point to possible changes in Δsed through earth history, due to changing physico-chemical conditions of the ocean and shifts in floral and faunal assemblages. 相似文献
34.
Bertram Böhrer Horst Heidenreich Michael Schimmele Martin Schultze 《International Journal of Salt Lake Research》1998,7(3):235-260
Salt-laden groundwater inflows have formed monimolimnia in developing lakes of the abandoned opencast lignite mine Merseburg-Ost, Central Germany. Water-levels are still rising. To predict the future status of the lakes, two numerical models were developed. One was designed to predict groundwater flows, the second included limnophysical processes. The models were run in parallel and data exchange between them was performed every 1 to 10 years of model time. A trial of a 100-years prognosis was done. The results of surface salinity, mixing depth, and salinity profile are given. A sensitivity analysis yielded indications for the accuracy of the prediction. 相似文献
35.
A. N. Platonov A. N. Tarashchan K. Langer M. Andrut G. Partzsch S. S. Matsyuk 《Physics and Chemistry of Minerals》1998,25(3):203-212
A selected set of five different kyanite samples was analysed by electron microprobe and found to contain chromium between <0.001 and 0.055 per formula unit (pfu). Polarized electronic absorption spectroscopy on oriented single crystals,
R1, R2-sharp line luminescence and spectra of excitation of λ3- and λ4-components of R1-line of Cr3+-emission had the following results: (1) The Fe2+–Ti4+ charge transfer in c-parallel chains of edge connected M(1) and M(2) octahedra shows up in the electronic absorption spectra
as an almost exclusively c(||Z′)-polarized, very strong and broad band at 16000 cm−1 if <, in this case the only band in the spectrum, and at an invariably lower energy of 15400 cm−1 in crystals with ≥ . The energy difference is explained by an expansion of the Of–Ok, and Ob–Om edges, by which the M(1) and M(2) octahedra are interconnected (Burnham 1963), when Cr3+ substitutes for Al compared to the chromium-free case. (2) The Cr3+ is proven in two greatly differing crystal fields a and b, giving rise to two sets of bands, derived from the well known
dd transitions of Cr3+
4A2g→4T2g(F)(I), →4T1g(F)(II), and →4T1g(P)(III). Band energies in the two sets a and b, as obtained by absorption, A, and excitation, E, agree well: I: 17300(a, A),
17200(a, E), 16000(b, A), 16200(b, E); II: 24800(a, A), 24400(a, E); 22300(b, A), 22200(b, E); III: 28800(b,A) cm−1. Evaluation of crystal field parameters from the bands in the electronic spectra yield Dq(a)=1730 cm−1, Dq(b)=1600 cm−1, B(a)=790 cm−1, B(b)=620 cm−1 (errors ca. ±10 cm−1), again in agreement with values extracted from the λ3, λ4 excitation spectra. The CF-values of set a are close to those typical of Cr3+ substituting for Al in octahedra of other silicate minerals without constitutional OH− as for sapphirine, mantle garnets or beryl, and are, therefore, interpreted as caused by Cr3+ substituting for Al in some or all of the M(1) to M(4) octaheda of the kyanite structure, which are crystallographically
different but close in their mean Al–O distances, ranging from 1.896 to 1.919 A (Burnham 1963), and slight degrees of distortion.
Hence, band set a originates from substitutive Cr3+ in the kyanite structural matrix. The CF-data of Cr3+ type b, expecially B, resemble those of Cr3+ in oxides, especially of corundum type solid solutions or eskolaite. This may be interpreted by the assumption that a fraction
of the total chromium contents might be allocated in a precursor of a corundum type exsolution.
Received: 3 January 1997 / Revised, accepted: 2 May 1997 相似文献
36.
37.
Horst Stöckl 《Pure and Applied Geophysics》1980,118(2):1248-1271
Shallow strike slip earthquakes on vertical faults are modelled as two-dimensional antiplane strain ruptures in a uniformly prestressed homogeneous halfspace. Behind the rupture front, which is specified, the stress drops to a lower value. The elastodynamic boundary value problem is solved with a finite difference method. Several cases are studied, which include symmetric and one-directional rupture propagation, surface faulting, multiple events, variable rupture velocity, sticking and rebreaking of the fault plane. The time function of displacement, velocity and acceleration are interpreted as signals generated by events in the focus, namely starting, stopping and breaking through the surface of the rupture. The model explains peak velocity and peak acceleration in the near field of M5.5–6 earthquakes; which are typically about 0.2 m/s and 5 m/s2 at 10 km epicentral distance, if the rupture velocity is close to the shear wave velocity. Sticking of the fault does not alter the accelerograms significantly, but it increases the seismic moment in simple events and decreases it in multiple events.Contribution No. 226, Geophysical Institute, University of Karlsruhe. 相似文献
38.
39.
Horst Piller 《Mineralium Deposita》1966,1(3):175-192
By means of recently developed, photoelectric measuring equipment the reflectivity of ore-minerals can be determined under the microscope over a sufficiently large spectral range with such a degree of accuracy and reliability that the dispersion curves can be plotted. Quantitative coefficients for the corresponding reflection colours, as well as for the visual reflectivity, can be computed from these curves. After a short introduction the tristimulus values for some ore minerals are given, as can be calculated from known reflectivity values. The quantitative values are compared with the known qualitative values for colour and reflectivity impression and for the reflection pleochroism. It is shown that reflectivity and colour differences can be determined colorimetrically with at least the same accuracy as by an experienced observer. The following characteristics are emphasized as advantages of quantitative colorimetry: 1. the objective method of determination, 2. the unambiguity and reproducibility of colour and reflectivity characteristics, 3. the simple and internationally comprehensible terminology, 4. the possibility of cataloguing ore minerals according to a quantitative colour system, and 5. the fact that even a colour-blind microscopist can determine any colour with the same certainty as an experienced observer.
Standard Specification, published by the Deutscher Normenausschuß DIN 5033. Farbmessung (Measurement of Colour) 1962/64.
Paper on Instructions for Use, Messrs. CARL ZEISS, Oberkochen. The Principles of Colour Measurement, 50-669/I-e (1962). 相似文献
Zusammenfassung Mit neueren photoelektrischen Meßanordnungen ist das Reflexionsvermögen von Erzmineralen unter dem Mikroskop über einen ausreichend großen Spektralbereich so genau und sicher bestimmbar, daß man die maßgebenden Dispersionskurven konstruieren kann. Aus diesen lassen sich quantitative Maßzahlen für die entspr. Reflexionsfarben und für das visuelle Reflexionsvermögen errechnen. Nach kurzer Einführung werden die Farbwerte einiger Erzminerale angegeben, wie sie sich aus bekannten Reflexionswerten errechnen ließen. Die quantitativen Werte werden mit herkömmlichen qualitativen Angaben über Farb- und Reflexionseindruck und über den Reflexionspleochroismus verglichen, und es wird gezeigt, daß die Reflexions- und Farbdifferenzen mit mindestens derselben Genauigkeit farbmetrisch erfaßbar sind wie durch das Auge eines erfahrenen Beobachters. Als Vorteile werden herausgestellt: 1. das objektive Bestimmungsverfahren, 2. die Eindeutigkeit und Reproduzierbarkeit der Farb- und Reflexionscharakteristik, 3. die einfache und international verständliche Terminologie, 4. die Katalogisierbarkeit der Erzminerale nach einem quantitativen Farbsystem, 5. die Tatsache, daß sogar ein farbuntüchtiger Mikroskopiker jede Farbe mit der gleichen Sicherheit erfassen kann wie der erfahrene Beobachter.
Standard Specification, published by the Deutscher Normenausschuß DIN 5033. Farbmessung (Measurement of Colour) 1962/64.
Paper on Instructions for Use, Messrs. CARL ZEISS, Oberkochen. The Principles of Colour Measurement, 50-669/I-e (1962). 相似文献
40.
Mössbauer and polarized optical absorption spectra of the kyanite-related mineral yoderite were recorded. Mössbauer spectra of the purple (PY) and green yoderite (GY) from Mautia Hill, Tanzania, show that the bulk of the iron is Fe3+ in both varieties, with Fe2+/(Fe2++Fe3+) ratios near 0.05. Combining this result with new microprobe data for PY and with literature data for GY gives the crystallochemical formulae: $$\begin{gathered} ({\text{Mg}}_{{\text{1}}{\text{.95}}} {\text{Fe}}_{{\text{0}}{\text{.02}}}^{{\text{2 + }}} {\text{Mn}}_{{\text{0}}{\text{.01}}}^{{\text{2 + }}} {\text{Fe}}_{{\text{0}}{\text{.34}}}^{{\text{3 + }}} {\text{Mn}}_{{\text{0}}{\text{.07}}}^{{\text{3 + }}} {\text{Ti}}_{{\text{0}}{\text{.01}}} {\text{Al}}_{{\text{3}}{\text{.57}}} )_{5.97}^{[5,6]} \hfill \\ {\text{Al}}_{{\text{2}}{\text{.00}}}^{{\text{[5]}}} [({\text{Si}}_{{\text{3}}{\text{.98}}} {\text{P}}_{{\text{0}}{\text{.03}}} ){\text{O}}_{{\text{18}}{\text{.02}}} ({\text{OH)}}_{{\text{1}}{\text{.98}}} ] \hfill \\ \end{gathered}$$ and PY and $$\begin{gathered} ({\text{Mg}}_{{\text{1}}{\text{.98}}} {\text{Fe}}_{{\text{0}}{\text{.02}}}^{{\text{2 + }}} {\text{Mn}}_{{\text{< 0}}{\text{.001}}}^{{\text{2 + }}} {\text{Fe}}_{{\text{0}}{\text{.45}}}^{{\text{3 + }}} {\text{Ti}}_{{\text{0}}{\text{.01}}} {\text{Al}}_{{\text{3}}{\text{.56}}} )_{6.02}^{[5,6]} \hfill \\ {\text{Al}}_{{\text{2}}{\text{.00}}}^{{\text{[5]}}} [({\text{Si}}_{{\text{3}}{\text{.91}}} {\text{O}}_{{\text{17}}{\text{.73}}} {\text{(OH)}}_{{\text{2}}{\text{.27}}} ] \hfill \\ \end{gathered}$$ for GY. The Mössbauer spectra at room temperature contain one main doublet with isomer shifts and quadrupole splittings of 0.36 (PY), 0.38 (GY) and 1.00 (PY), 0.92 (GY) mm s?1, respectively. These values correspond to Fe3+ in six or five-fold coordination. The doublet components have anomalously large half widths indicating either accomodation of Fe3+ in more than one position (e.g., octahedraA1 and five coordinatedA2) or the yet unresolved superstructure. Besides strong absorption in the ultraviolet (UV) starting from about 25,000 cm?1, the polarized optical absorption spectra are dominated by strong bands around 16,500 and 21,000 cm?1 (PY) and a medium strong band at around 13,800 cm?1 (GY). Position and polarization of these bands, in combination with the UV absorption, explain the colour and pleochroism of the two varieties. The bands in question are assigned to homonuclear metal-to-metal charge transfer transitions: Mn2+(A1) Mn3+(A1′) ? Mn3+(A1) Mn2+(A1′) and Mn2+(A1) Mn3+(A2 ? Mn3+(A1) Mn2+(A2) in PY and Fe2+(A1) Fe3+(A1′) ? Fe3+(A1) Fe2+(A1′) in GY. The evidence for homonuclear Mn2+ Mn3+ charge transfer (CTF) is not quite clear and needs further study. Heteronuclear FeTi CTF does not contribute to the spectra. In PY, additional weak bands were resolved at energies around 17,700, 18,700, 21,000, and 21,900 cm?1 and assigned to Mn3+ in two positions. Weak bands around 10,000 cm?1 in both varieties are assigned to Fe2+ spin-alloweddd-transitions. Very weak and sharp bands, around 15,400, 16,400, 21,300, 22,100, 23,800, and 25,000 cm?1 are identified in GY and assigned to Fe3+ spin-forbiddendd-transitions. 相似文献