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11.
Aerial Photographs of 1:50,000 scale pertaining to Tons Catchment were used for generating a land use map showing cultivated lands, forests land, grass land, barren land with rock outcrops, snow and glaciers. The area was divided into 4 altitudinal Zones. More than 81% lies above 3000 m height and should be left for natural regeneration. Cultivated land occupies 4.97% of the area and is concentrated below 3000 m altitudinal zone and lies along river courses and on river terraces. Distribution of forest lands in altitudinal zone indicates that percent area covered under forest is higher than the average distribution of forest as reported by Seth (1978). Grass and open scrub, barren Innd with rock outcrops, glaciers and snow covered areas occupy 6.8%, 18.1%, 16.5% and 28.0% respectively.  相似文献   
12.
Book review     
Sea Surveying, edited by Alan Ingham (London: John Wiley & Sons, 1975), 2 volumes, 306 and 233 pp., hardcover, $49.50.  相似文献   
13.
Himalayan mountain system is distinguished globally for a rich biodiversity and for its role in regulating the climate of the South Asia.Traditional crop-livestock mixed farming in the Himalaya is highly dependent on forests for fodder and manure prepared from forest leaf litter and livestock excreta. Apart from sustaining farm production, forests provide a variety of other tangible and intangible benefits, which are critical for sustainable livelihood of not only 115 million mountain people, but also many more people living in the adjoining plains. Extension of agricultural landuse coupled with replacement of traditional staple food crops by cash crops and of multipurpose agroforestry trees by fruit trees are widespread changes. Cultivation of Fagopyrum esculentum,Fagopyrum tataricum, Panicum miliaceum, Setaria italica and Pisum arvense has been almost abandoned. Increasing stress on cash crops is driven by a socio-cultural change from subsistence to market economy facilitated by improvement in accessibility and supply of staple food grains at subsidized price by the government. Farmers have gained substantial economic benefits from cash crops. However, loss of agrobiodiversity implies more risks to local livelihood in the events of downfall in market price/demand of cash crops, termination of supply of staple food grains at subsidized price, pest outbreaks in a cash crop dominated homogeneous landscape and abnormal climate years. Indigenous innovations enabling improvement in farm economy by conserving and/enhancing agrobiodiversity do exist, but are highly localized. The changes in agrobiodiversity are such that soil loss and run-off from the croplands have dramatically increased together with increase in local pressure on forests. As farm productivity is maintained with forest-based inputs, continued depletion of forest resources will result in poor economic returns from agriculture to local people,apart from loss of global benefits from Himalayan forests. Interventions including improvement in traditional manure and management of on-farm trees,participatory development of agroforestry in degraded forest lands and policies favoring economic benefits to local people from non-timber forest products could reduce the risks of decline in agricultural biodiversity and associated threats to livelihoods and Himalayan ecosystems.  相似文献   
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Resource use efficiency analyses of village ecosystem are necessary for effective and efficient planning of resource utilization. This paper deals with economic and energy input-output analyses of different components of village ecosystem in representative buffer zone villages, which are practicing transhumance and settled way of lifestyles in Nanda Devi Biosphere Reserve (NDBR) of Garhwal Himalaya. While the villages practicing transhumance used various natural resources spatially segregated,the villages practicing settled way of lifestyle have to manage resources from a limited spatial area through rotation and varied extraction intensities. Forests subsidized the production activity in both type of villages and the per capita resource extractions were found to be greater in tran~humance village than settled village. Though crops provided maximum energy, in terms of economic criteria, animal husbandry played important role in both settled and transhumance villages. As villages representing both the situations showed different ways of adjustments to the conservation oriented land use changes, management authority needs to address the eco-development plans fulfilling the aspirations of all people traditionally using the resources of the Reserve to reduce the conflicts and encourage their participation in the conservation of the area.  相似文献   
17.
This study investigated land use/land cover change (LULCC) dynamics using temporal satellite images and spatial statistical cluster analysis approaches in order to identify potential LULCC hot spots in the Pune region. LULCC hot spot classes defined as new, progressive and non-progressive were derived from Gi* scores. Results indicate that progressive hot spots have experienced high growth in terms of urban built-up areas (20.67% in 1972–1992 and 19.44% in 1992–2012), industrial areas (0.73% in 1972–1992 and 3.46% in 1992–2012) and fallow lands (4.35% in 1972–1992 and ?6.38% in 1992–2012). It was also noticed that about 28.26% of areas near the city were identified as new hot spots after 1992. Hence, non-significant change areas were identified as non-progressive after 1992. The study demonstrated that LULCC hot spot mapping through the integrated spatial statistical approach was an effective approach for analysing the direction, rate, spatial pattern and spatial relationship of LULCC.  相似文献   
18.
The chemical composition of 2188 terrestrial igneous rocks ranging from ultrabasic to granitic composition was analyzed statistically using the method of factor analysis (principal components). The resultant first and second factors were: $$\begin{gathered} {\text{ }}F_1 = 0.933{\text{ Na}}_{\text{2}} {\text{O + 0}}{\text{.143 SiO}}_{\text{2}} + 0.206{\text{ K}}_{\text{2}} {\text{O}} - 0.346{\text{ CaO}} - 0.263{\text{ MgO}} - \hfill \\ .203{\text{ FeO}} \pm \cdot \cdot \cdot \hfill \\ {\text{ }}F_2 = 0.979{\text{ Al}}_{\text{2}} {\text{O}}_{\text{3}} - 0.269{\text{ MgO}} - 0.151{\text{ SiO}}_{\text{2}} - 0.112{\text{ FeO}} \pm \cdot \cdot \cdot \hfill \\ \end{gathered} $$ where oxides are in weight percent. A plot of the first factor against the second results in a useful igneous variation diagram. When the compositions of the 2188 terrestrial rocks and 604 lunar rocks are plotted on this diagram, the two groups of rocks are clearly separated within an albite-anorthite-forsterite-fayalite-quartz polygon. None of the terrestrial differentiation trends are significant for lunar rocks. The major difference in the chemistry of lunar and terrestrial rocks lies in the former being albite poor. Removal of most of the albite from the compositions of terrestrial layered intrusives such as the Skaergaard results in an excellent match between the compositions of the two groups of rocks. Albite subtracted compositions of Skaergaard rocks in particular cover the entire range of chemical variation in the lunar rocks. The statistical results prompt us to speculate further on the similarity of the moon and Skaergaard. We note that the average composition of the moon (Wanke et al., 1974) is similar to the albite subtracted composition of the Skaergaard magma. The lunar crust and a significant part of the lunar interior may match the albite subtracted and somewhat Mg enriched Skaergaard magma.  相似文献   
19.
The enstatite-diopside solvus presents certain interesting thermodynamic and crystal-structural problems. The solvus may be considered as parts of two solvi one with the ortho-structure and the other with clino-structure. By assuming the standard free energy change for the two reactions (MgMgSi2O6)opx ? (MgMgSi2O6)cpx and (CaMgSi2O6) opx ? (CaMgSi2O6) cpx as 500 and 1 000 to 3 000 cal/mol respectively, it is possible to calculate the regular solution parameter W for orthopyroxene and clinopyroxene. These W's essentially refer to mixing on M2 sites. The expression for the equilibrium constant by assuming ideal mixing for Fe-Mg, Fe-Ca and non-ideal mixing for Ca-Mg on binary M1 and ternary M2 sites is given by 1 $$K_a = \frac{{X_{{\text{Mg - cpx}}}^{{\text{M1}}} X_{{\text{Mg - cpx}}}^{{\text{M2}}} \exp \left[ {\frac{{W_{{\text{cpx}}} }}{{RT}}\left\{ {X_{{\text{Ca - cpx}}}^{{\text{M2}}} \left( {X_{{\text{Ca - cpx}}}^{{\text{M2}}} + X_{{\text{Fe - cpx}}}^{{\text{M2}}} } \right)} \right\}} \right]}}{{X_{{\text{Mg - cpx}}}^{{\text{M1}}} X_{{\text{Mg - opx}}}^{{\text{M2}}} \exp \left[ {\frac{{W_{{\text{cpx}}} }}{{RT}}\left\{ {X_{{\text{Ca - opx}}}^{{\text{M2}}} \left( {X_{{\text{Ca - opx}}}^{{\text{M2}}} + X_{{\text{Fe - opx}}}^{{\text{M2}}} } \right)} \right\}} \right]}}$$ where X's are site occupancies, R is 1.987 and T is temperature in oK. Temperature of pyroxene crystallization may be estimated by substituting for T in the above equation until the equation ?RT In K a=500 is satisfied. The shortcomings of this method are the incomplete standard free energy data on the end member components and the absence of site occupancy data in pyroxenes at high temperatures. The assumed free energy data do, however, show the possible extent of inaccuracy in temperature estimates resulting from the neglect of Mg-Ca non ideality.  相似文献   
20.
Abstract

During May 1985, a comprehensive GPS and acoustic navigation data set was collected off the Monterey, California coast. Three types of GPS units, a LORAN‐C, and a Miniranger operated concurrently with an OCEANO acoustic system to resolve state‐of‐the‐art accuracies for at‐sea geodetic positioning. This report details the acoustic system which displayed baseline errors of only ±0.25 m over distances to 2600 m. Unfiltered point‐to‐point acoustic navigation errors had a standard deviation of ± 1.25 m, which included ship motion errors in addition to surveying errors. Ninety percent of the stations had navigation standard deviations below ±0.75 m The experiment showed that sub‐meter acoustic surveying is the state‐of‐the‐art.  相似文献   
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