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131.
本文在深入调研上海市集中测绘成果管理系统的基础上,通过对系统的建立与长期维护的总结,简要的介绍了系统实现的功能与系统架构,总结了系统建设过程中的思路与做法。着重阐述了系统在整合测绘处理与成果管理、保持基础数据的现势性方面所取得的成果,总结了系统在建设与使用过程中的优缺点,为其它地区建立或改造测绘成果系统提供借鉴。 相似文献
132.
R. Sridhar T. Thangaradjou L. Kannan S. Astalakshmi 《Journal of the Indian Society of Remote Sensing》2010,38(3):565-575
Coastal resources viz., coral reefs, seagrasses, mangroves, and coastal land features viz., sandy beach, mudflats and salt
pan/aquaculture ponds were classified and assessed in the Palk Bay region of the south-east coast of India using IRS LISS
III satellite image (1996, 2000, 2002 and 2004). The study recorded an areal coverage of 286.95 ha of reef area during 2004,
which is 177.54 ha lesser than that of the reef area of 1996. The reef vegetation composed mainly of seaweeds has gained over
29.44 ha during the same period. Likewise, sand over reef area has also increased alarmingly i.e. 120.34 ha between 1996 and
2004. The seagrass beds of Munaikkadu region of the Palk Bay are comparatively protected and have gained over 7.5 ha between
1996 and 2004. It has been found that both the dense (2.99 ha) and sparse (36.45 ha) mangroves have gained their areal coverage
considerably between 1996 and 2004. Whereas in Devipattinam region, many anthropogenic pressures are exerted only on the seagrass
resources which has led to the reduction of over 785.5 ha of dense seagrass beds between 1996 and 2004. The study clearly
indicated that the resources are under the pressures of low to high threats, especially the coral reefs and seagrasses, if
the pressures continue, coastal resources of the Palk Bay may face serious threats of destruction in this part of the Bay
in the years to come. 相似文献
133.
This paper focuses on the hypothesis of stability in the mechanisms of spatial dependence that are usually employed in spatial
econometric models. We propose a specification strategy for which the first step is to solve a local estimation algorithm,
called the Zoom estimation. The aim of this stage is to detect problems of heterogeneity in the parameters and to identify
the regimes. Then we resort to a battery of formal Lagrange Multipliers to test the assumption of stability in the processes
of spatial dependence. The alternative hypothesis consists of the existence of several regimes in these parameters. A small
Monte Carlo serves to confirm the behaviour of this strategy in a context of finite size samples. As an illustration, we solve
an application to the case of the hypothesis of convergence for the per capita income in the European regions. Our results
reveal the existence of a strong Centre-Periphery dichotomy in which instability extends to all the elements (coefficients
of regression as well as parameters of spatial dependence) that intervene in a classical conditional β-convergence model. 相似文献
134.
A GPS-Supported Gravity Survey in the Amazon of Ecuador 总被引:1,自引:0,他引:1
Mamadou Balde Jeremy Fishman Carlos L. V. Aiken Mohamed Abdel-Salam Mauricio F. de la Fuente 《GPS Solutions》1999,2(3):3-17
The growing importance and effectiveness of the Global Positioning System (GPS) in positioning geophysical surveys is now
well established. In Ecuador's Amazon basin the use of GPS was the determining factor in the successful completion of a gravity
survey carried out in 1994. Over 500 gravity stations, spaced from 1 to 5 km apart and positioned by GPS, were collected in
the jungle environment in the country's southeast, where the preexisting data, of variable and unknown quality, were mostly
confined to areas along the major rivers. This station densification, which includes the reoccupation of selected points,
contributed to increase the gravity coverage; it also allowed us to evaluate and correct 1100 preexisting data points in the
area, so that the different surveys can be merged. The composite data set is used for a geologic analysis of the study area,
where previously unknown structures are discovered. ? 1999 John Wiley & Sons, Inc. 相似文献
135.
Addressing climate change requires the synergy of technological, behavioural and market mechanisms. This article proposes a policy framework that integrates the three, deploying personal carbon trading as a key element within a policy portfolio to reduce personal carbon footprints. It draws on policy and human motivation literatures that address the behavioural changes that may be needed in the context of a long-term threat such as climate change. This proposal builds on an analysis of the British Columbia carbon tax, international examples of carbon pricing instruments and strategies for behavioural change such as social networks, loyalty management, mobile apps and gamification. Interviews were conducted with experts in financial services, energy conservation and clean technology, as well as with specialists in climate, health and taxation policy. Their input, together with a review of the theoretical literature and practical case studies, informed the proposed design of a Carbon, Health and Saving System for promoting individual engagement and collective action by linking long-term climate mitigation measures with short-term personal and social goals, including health, recreation and social reinforcement.Policy RelevanceThis article identifies areas for climate policy innovation and recommends policies that can support, promote and enable personal carbon budgeting and collective action. Although this study is focused on British Columbia, both the input provided by key opinion leaders and the proposed framework are applicable to other jurisdictions.This policy proposal shows how personal carbon trading could work in the context of a Canadian province with an existing climate mitigation policy. It also specifies a minimum viable product approach to establishing the economic, social and technological foundations for personal carbon trading.The Carbon, Health and Saving System identifies the technologies and stakeholders needed to implement personal carbon trading, and offers the possibility of motivating a widespread conscious human response in the event that carbon taxation proves insufficient to generate economic adaptation in a changing climate. 相似文献
136.
The complex variables boundary element method (CVBEM) is used to study interaction between a circular opening and fractures originating from its boundary in a piecewise homogeneous plane. A new complex hypersingular equation for piecewise homogeneous media with a circular opening is obtained. The equation is solved using the CVBEM technique with circular and straight boundary elements and polynomial approximations (with square root asymptotics for crack tip elements) for the unknown functions. The algorithm is verified through comparison with known semi‐analytical and numerical solutions that involve interaction between a circular opening and specific systems of cracks or other openings. New numerical results concerning the interaction of the circular opening with the cracks and circular inclusions are presented. The method is applied to an important problem in the petroleum industry: modelling propagation of hydraulic fractures in the vicinity of a borehole. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
137.
X. Lana M. D. Martínez A. Burgueño C. Serra J. Martín-Vide L. Gómez 《Theoretical and Applied Climatology》2008,91(1-4):99-116
Summary Daily pluviometric records of 43 meteorological stations across the Iberian Peninsula have permitted a detailed analysis of
dry spell patterns for the period 1951–2000 by distinguishing daily amount thresholds of 0.1, 1.0, 5.0 and 10.0 mm/day. The
analyses are based on three annual series, namely the number of dry spells, N, the average dry spell length, L, and the extreme dry spell length, L
max. First, the statistical significance of local trends for the annual series of N, L and L
max has been investigated by means of the Mann-Kendall test and significant field trends have been established by means of Monte
Carlo simulations. Clear signs of negative field trends are detected for N (1.0 and 10.0 mm/day) and L (0.1 mm/day). Second, the Weibull model fits well the empirical distributions of dry spell lengths for all the rain gauges,
whatever the daily amount threshold, with a well ranged spatial distribution of their parameters u and k. On the basis of the Weibull distribution, return period maps for 2, 5, 10, 25 and 50 years have been obtained for dry spell
lengths with respect to the four daily threshold levels. While for 0.1 and 1.0 mm/day the longest dry spells are expected
at the south of the Iberian Peninsula, for 5.0 and 10.0 mm/day they are mostly detected at the southeast. Finally, the elapsed
time between consecutive dry spells has been analysed by considering the same rain amount thresholds and different dry spell
lengths at increasing intervals of 10 days. This analysis makes evident a significant negative field trend of the elapsed
time between consecutive dry spells of lengths ranging from 10 to 20 days for daily amount thresholds of 1.0, 5.0 and 10.0 mm/day.
Authors’ addresses: X. Lana, C. Serra, Departament de Física i Enginyeria Nuclear, ETSEIB, Universitat Politècnica de Catalunya,
Av. Diagonal 647 planta 11, 08028 Barcelona, Spain; M. D. Marínez, Departament de Física Aplicada, Universitat Politècnica
de Catalunya, 08028 Barcelona, Spain; A. Burgue?o, Departament de Meteorologia i Astronomia, Universitat de Barcelona, 08028
Barcelona, Spain; J. Martín-Vide, L. Gómez, Grup de Climatologia, Universitat de Barcelona, 08028 Barcelona, Spain. 相似文献
138.
S. Pradhan V. K. Sehgal K. K. Bandyopadhyay R. N. Sahoo P. Panigrahi C. M. Parihar S. L. Jat 《Journal of the Indian Society of Remote Sensing》2018,46(2):321-326
The best and commonly used ground-based sensor to monitor crop growth, ASD FieldSpecPro Spectroradiometer (Analytical Spectral Devices, Boulder, CO, USA) is a passive sensor, which can be used under adequate light condition. However, now-a-days active sensors such as GreenSeeker? (GS) handheld crop response (Trimble Agriculture division, USA) are used for monitoring crop growth and are flexible in terms of timeliness and illumination conditions besides being cheaper than the ASD. Before its wide use, the suitability and accuracy of GS should be assessed by comparing the NDVI measured by this instrument with that by ASD, under diverse wheat growing conditions of India. Keeping this in view, the present experiment was undertaken with the following objectives: (1) to find out the temporal variation of NDVI measured both by ASD and GS treatments, (2) to find out relationship between the NDVI measured through ASD and GS and, (3) to evaluate the suitability of GS for NDVI measurements. It was observed that the numerical value of NDVI as measured by GS was always significantly (P < 0.05) lower than that measured by ASD for all the experiments under study. The NDVI-ASD and NDVI-GS were significantly positively correlated (P < 0.01) with the correlation coefficients being +0.94, +0.88 and +0.87 for irrigation and nitrogen experiment, irrigation and cultivars experiment, and tillage, residue and nitrogen experiments, respectively. Further, the regression equation developed between the NDVI-ASD and NDVI-GS: [NDVI-GS = 1.070 × (NDVI-ASD ? 0.292] can be successfully used to compute the NDVI of ASD from that computed by GS. 相似文献
139.
Kathleen M. Baker Andrew C. Johnson Caitlin N. Callahan Heather L. Petcovic 《制图学和地理信息科学》2016,43(2):176-187
Topographic maps and aerial photographs are particularly useful when geoscientists are faced with fieldwork tasks such as selecting paths for observation, establishing sampling schemes, or defining field regions. These types of images are crucial in bedrock geologic mapping, a cognitively complex field-based problem-solving task. Geologic mapping requires the geologist to correctly identify rock types and three-dimensional bedrock structures from often partial or poor-quality outcrop data while navigating through unfamiliar terrain. This paper compares the walked routes of novice to expert geologists working in the field (n = 66) with the results of a route planning and navigation survey of a similar population of geologists (n = 77). Results show clearly that those geologists with previous mapping experience make quick and decisive determinations about field areas from available imagery and maps, regardless of whether they are or not physically present in the field area. Recognition of geologic features enabled experts to form and verbalize a specific plan for travel through a landscape based on those features. Novices were less likely to develop specific travel route plans and were less likely to identify critical landscape cues from aerial photographs. 相似文献
140.
以大连市中山区的遥感和建筑等多源数据为基础,结合单窗算法和相关分析方法,研究分析了2002—2014年研究区的地表温度空间分异特征及地表温度与建筑密度的相关性。研究结果表明:(1)2002—2014年地表温度高温区域多分布在中山区西北部、解放路和中南路的沿线,且温度增加明显,东北部由于填海造陆温度明显升高;(2)高密度和较高密度的地块主要分布在青泥洼天津街商业区,大部分低、较低、中密度地块分布在解放路和中南路沿线;(3)2002年、2014年,地表温度与建筑密度呈现中等相关性,相关系数分别为0.514、0.537。 相似文献