全文获取类型
收费全文 | 130篇 |
免费 | 3篇 |
国内免费 | 1篇 |
专业分类
测绘学 | 16篇 |
大气科学 | 1篇 |
地球物理 | 10篇 |
地质学 | 47篇 |
海洋学 | 5篇 |
天文学 | 52篇 |
自然地理 | 3篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 4篇 |
2017年 | 2篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 7篇 |
2011年 | 4篇 |
2010年 | 5篇 |
2009年 | 9篇 |
2008年 | 4篇 |
2007年 | 1篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1992年 | 3篇 |
1991年 | 7篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 8篇 |
1984年 | 2篇 |
1983年 | 7篇 |
1982年 | 1篇 |
1979年 | 7篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1969年 | 2篇 |
排序方式: 共有134条查询结果,搜索用时 31 毫秒
71.
We present here the examples that show how fusing data from hyperspectral sensors with data from high spatial resolution sensors can enhance overall road detection accuracy. The fusion of hyperspectral and high spatial resolution data combines their superior respective spectral and spatial information. IKONOS (MSS) and Hyperion images were fused using the principal component analysis (PCA) method. The approach for road extraction integrates multiresolution segmentation and object oriented classification. Road extraction is done from an IKONOS (MSS) image and a Hyperion and IKONOS (MSS) merged image and comparisons are made depending on accuracy and quality measures such as completeness and correctness. This article also emphasises the types of roads which are giving better accuracy of extraction after fusion with hyperspectral image. This can vary because of types of material and condition of roads. The methodology was applied on roads of Dehradun, India. 相似文献
72.
George Mathew Archana Nair T. K. Gundu Rao Kanchan Pande 《Journal of Earth System Science》2009,118(4):391-404
Thermal infrared spectroscopy is a powerful technique for the compositional analysis of geological materials. The spectral
feature in the mid-IR region is diagnostic of the mineralogy and spectral signatures of mixtures of minerals that add linearly,
and therefore, can be used as an important tool to determine the mineralogy of rocks in the laboratory and remotely for planetary
exploration. The greatest challenge in the emission measurement lies in the measurement of the weak thermal photons emitted
from geological materials in a laboratory setup, and accurately records the temperature of the rock sample. The present work
pertains to the details of a new Thermal Emission Spectrometer (TES) laboratory that has been developed under the ISRO Planetary
Science and Exploration (PLANEX) programme, for emission related mineralogical investigations of planetary surfaces. The focus
of the paper is on the acquisition and calibration technique for obtaining emissivity, and the deconvolution procedure to
obtain the modal abundances of the thermal emission spectra in the range of 6–25 μm using Fourier Transform Infrared (FTIR)
spectroscopy. The basic technique is adopted from the work of Ruff et al (1997). This laboratory at the Department of Earth Sciences, IIT-Bombay is currently developing pure end mineral library
of mineral particulates (<65 μm), and adding new end members to the existing ASU spectral library. The paper argues the need
for considering Lunar Orbiter Thermal Emission Spectrometer (LOTES) for future Indian Moon mission programme (Chandrayan-II)
to determine evidences of varied lithologies on the lunar surface. 相似文献
73.
The visibility in the umbral ultraviolet spectrum of the O2 Schumann-Runge absorption band system has been explored. It is found that the band system may be visible in high dispersion sunspot spectrum. 相似文献
74.
Comparison of “argon” absolute age determinations of crystalline rocks of the “Crystalline Nappe” (Kumar, 1971, unpublished Ph. D. thesis) and of the “root-zone” (Jaspa granite) has led to an important conclusion concerning the interpretation of the development of the “crystalline nappe” and its rejuvenation. 相似文献
75.
Kanchan Pande 《Journal of Earth System Science》2002,111(2):115-115
A review of the available radiometric and paleomagnetic data from the Deccan Flood Basalt Province (DFBP) suggests that the
volcanism was episodic in nature and probably continued over an extended duration from 69 Ma to 63 Ma between 31R and 28N.
It is likely that the most intense pulse of volcanism at 66.9 ± 0.2 Ma preceded the Cretaceous Tertiary Boundary (KTB, 65.2
± 0.2Ma) events by R∼1.7Ma. The magnetostratigraphic record in the Deccan lava pile is incomplete and it is therefore possible
that the lava flows constituting the reverse polarity sequence were erupted in more than one reversed magnetic chron. 相似文献
76.
77.
Attitude motion of spinning axisymmetric satellites in presence of gravity-gradient and solar radiation pressure torques is studied analytically. The approximate closed-form solution developed for the nonlinear, nonautonomous, coupled fourth-order system proves to be an excellent tool in locating periodic solutions of the system in both circular and noncircular orbits. The variational stability of the periodic motion is examined using the Floquet theory. The resonance analysis suggests the existence of critical combinations of system parameters leading to large amplitude oscillations.
相似文献78.
Y. P. Patil S. H. Pawar A. R. Pande P. S. Dhote A. N. Gokarn 《International Journal of Environmental Science and Technology》2018,15(10):2269-2272
Studies in managing harmful parthenium weed by converting it into active charcoal have been described in this paper. Cheaply available calcium chloride has been used as a catalyst for the pyrolysis of parthenium weed. Although this preliminary study is limited to the use of two temperatures of pyrolysis with three ratios of catalyst to biomass, the results show ample scope for suggesting the use of active charcoal obtained for pollution abatement of effluents containing special kind of constituents, like large-size molecules. 相似文献
79.
A numerical model is proposed to analyse elastic as well as elastoplastic behaviour of stone-column reinforced foundations. The stone-columns are assumed to be dispersed within the in situ soil and a homogenization technique is invoked to establish equivalent material properties for in situ soil and stone-column composite. The difficulties encountered in carrying out elastoplastic analyses of composite materials are overcome by adopting a separate yield function for each of the constituent materials and a sub-iteration procedure within an implicit backward Euler stress integration scheme. In the proposed procedure, equilibrium as well as kinematic conditions implied in the homogenization procedure are satisfied for both elastic as well as elastoplastic stress states. The proposed model is implemented in an axi-symmetric finite element code and numerical prediction is made for the behaviour of model circular footings resting on stone-column reinforced foundations. This prediction indicates good agreement with experimental observation. Finally, a new scheme in which the length of stone-column is variable is proposed and its behaviour is examined through a numerical example. © 1998 John Wiley & Sons, Ltd. 相似文献
80.
Poonam S. Tiwari H. Pande Ashwini Kumar Pandey 《Journal of the Indian Society of Remote Sensing》2009,37(2):223-231
Automatic road extraction from remotely sensed images has been an active research in urban area during last few decades. But
such study becomes difficult in urban environment due to mix of natural and man-made features. This research explores methodology
for semiautomatic extraction of urban roads. An integrated approach of airborne laser scanning (ALS) altimetry and high-resolution
data has been used to extract road and differentiate them from flyovers. Object oriented fuzzy rule based approach classifies
roads from high resolution satellite images. Complete road network is extracted with the combination of ALS and high-resolution
data. The results show that an integration of LiDAR data and IKONOS data gives better accuracy for automatic road extraction.
The method was applied on urban area of Amsterdam, The Netherlands. 相似文献