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991.
Stone R 《Science (New York, N.Y.)》2002,298(5594):728-731
992.
993.
Stone R 《Science (New York, N.Y.)》2007,318(5856):1537-1538
994.
995.
Stone EC Cummings AC Loooper MD Selesnick RS Lal N McDonald FB Trainor JH Chenette DL 《Science (New York, N.Y.)》1989,246(4936):1489-1494
The Voyager 2 cosmic ray system (CRS) measured significant fluxes of energetic [>/=1 megaelectron volt (MeV)] trapped electrons and protons in the magnetosphere of Neptune. The intensities are maximum near a magnetic L shell of 7, decreasing closer to the planet because of absorption by satellites and rings. In the region of the inner satellites of Neptune, the radiation belts have a complicated structure, which provides some constraints on the magnetic field geometry of the inner magnetosphere. Electron phase-space densities have a positive radial gradient, indicating that they diffuse inward from a source in the outer magnetosphere. Electron spectra from 1 to 5 MeV are generally well represented by power laws with indices near 6, which harden in the region of peak flux to power law indices of 4 to 5. Protons have significantly lower fluxes than electrons throughout the magnetosphere, with large anisotropies due to radial intensity gradients. The radiation belts resemble those of Uranus to the extent allowed by the different locations of the satellites, which limit the flux at each planet. 相似文献
996.
Stone RG 《Science (New York, N.Y.)》1987,235(4790):800a
997.
Utada AS Lorenceau E Link DR Kaplan PD Stone HA Weitz DA 《Science (New York, N.Y.)》2005,308(5721):537-541
Double emulsions are highly structured fluids consisting of emulsion drops that contain smaller droplets inside. Although double emulsions are potentially of commercial value, traditional fabrication by means of two emulsification steps leads to very ill-controlled structuring. Using a microcapillary device, we fabricated double emulsions that contained a single internal droplet in a core-shell geometry. We show that the droplet size can be quantitatively predicted from the flow profiles of the fluids. The double emulsions were used to generate encapsulation structures by manipulating the properties of the fluid that makes up the shell. The high degree of control afforded by this method and the completely separate fluid streams make this a flexible and promising technique. 相似文献
998.
Elizabeth Finnis 《Agriculture and Human Values》2007,24(3):343-353
Using a case study from the Kolli Hills, India, I suggest that political ecology provides a useful theoretical basis for considering
localized dietary transitions in rural, agricultural communities in developing countries. By examining the reasons for the
near-disappearance of local minor millets as staple foods in three small-farmer communities, I argue that an explicit, actor-oriented
analysis allows for an integration of food issues with considerations of environmental circumstances, local aspirations, and
labor concerns. That is, an agricultural shift that abandons minor millets as a food resource reflects environmental changes
and household economic aspirations. Such an analysis has implications for the creation of practical food security projects
through the recognition and incorporation of small-farmer experiences, voices, and priorities. This research was undertaken
through ethnographic fieldwork, using semi-structured interviews and participant observation as the primary methods.
Elizabeth
Finnis obtained her PhD from McMaster University in Canada and is currently a post-doctoral fellow in the Department of Anthropology
and the Centre for Society, Technology, and Development at McGill University. 相似文献
999.
Kameshwari Pothukuchi Rayman Mohamed David A. Gebben 《Agriculture and Human Values》2008,25(3):319-332
This paper provides a conceptual framework to explain why disparities may exist in food safety code compliance by food stores
in different neighborhoods. Explanations include market dynamics, community characteristics, retailer attributes, inspector
characteristics, and enforcement approaches, and interactions among the factors. A preliminary and limited empirical test
of some of these relationships in Detroit, Michigan shows a higher rate of food safety violations by stores in poorer neighborhoods
and in neighborhoods with higher concentrations of African-American residents. Stores inspected by female inspectors also
scored higher numbers of critical violations, suggesting a need for greater examination of the social relations associated
with enforcement interactions in food safety studies.
Kameshwari Pothukuchi PhD, is Associate Professor of Urban Planning at Wayne State University. She conducts research on issues related to urban food security, including grocery stores, community gardens, and community and regional food planning. A policy guide on community and regional food planning, co-authored by her, was recently adopted by the American Planning Association (). Rayman Mohamed PhD, is Assistant Professor of Urban Planning at Wayne State University. He conducts research on land use and environmental planning. His recent articles examine decision making by developers, the economics of conservation subdivisions, and the relationship between sprawl and the costs of infrastructure. David A. Gebben is a graduate student of agricultural economics and a research assistant in the Global Urban Studies Program at Michigan State University. 相似文献
Kameshwari PothukuchiEmail: |
Kameshwari Pothukuchi PhD, is Associate Professor of Urban Planning at Wayne State University. She conducts research on issues related to urban food security, including grocery stores, community gardens, and community and regional food planning. A policy guide on community and regional food planning, co-authored by her, was recently adopted by the American Planning Association (). Rayman Mohamed PhD, is Assistant Professor of Urban Planning at Wayne State University. He conducts research on land use and environmental planning. His recent articles examine decision making by developers, the economics of conservation subdivisions, and the relationship between sprawl and the costs of infrastructure. David A. Gebben is a graduate student of agricultural economics and a research assistant in the Global Urban Studies Program at Michigan State University. 相似文献
1000.
In face of rising flood losses globally, the approach of “living with floods,” rather than relying on structural measures
for flood control and prevention, is acquiring greater resonance in diverse socioeconomic contexts. In the Lerma Valley in
the state of Mexico, rapid industrialization, population growth, and the declining value of agricultural products are driving
livelihood and land use change, exposing increasing numbers of people to flooding. However, data collected in two case studies
of farm communities affected by flooding in 2003 illustrate that the concept of flood as agricultural “hazard” has been relatively
recently constructed through public intervention in river management and disaster compensation. While farming still represents
subsistence value to rural households, increasingly rural communities are relying on non-farm income and alternative livelihood
strategies. In this context, defining flooding in rural areas as a private hazard for which individuals are entitled to public
protection may be counterproductive. A different approach, in which farmers’ long acceptance of periodic flooding is combined
with valuing agricultural land for ecoservices, may enable a more sustainable future for the region’s population.
Hallie Eakin received her doctorate in Geography and Regional Development from the University of Arizona in 2002. She is currently an assistant professor at the University of California, Santa Barbara. As a postdoctoral researcher at the Center of Atmospheric Sciences of the National Autonomous University of Mexico in Mexico City, she continued to work on issues related to economic globalization, agricultural change, and rural vulnerability to climate in the context of several comparative international projects involving case studies in Mexico, Argentina, Guatemala, and Honduras. Her articles on this research have been published in World Development, the Journal of Environment and Development, Climatic Change, Global Environmental Change and Physical Geography. Her book Weathering Risk in Rural Mexico, based on her research on agricultural adaptation to neoliberal reforms and climatic variability in central Mexico, was released by the University of Arizona Press in 2006. Kirsten Appendini has a doctorate in Agricultural Economics from the National Autonomous University of Mexico (UNAM). She currently is a researcher and professor on the faculty of the Center for Economic Studies (Centro de Estudios Económicos) at the Colegio de México in Mexico City. She has published widely on issues of agrarian change, rural poverty, food security, and food policy in Mexico. Her book on Mexican maize policy, De la milpa a los tortibonos: La restructración de la política alimentaria en México (Colmex 2001) is now on its second edition. She has also served as a consultant to the UN Food and Agriculture Organization and several bilateral development agencies. 相似文献
Hallie EakinEmail: |
Hallie Eakin received her doctorate in Geography and Regional Development from the University of Arizona in 2002. She is currently an assistant professor at the University of California, Santa Barbara. As a postdoctoral researcher at the Center of Atmospheric Sciences of the National Autonomous University of Mexico in Mexico City, she continued to work on issues related to economic globalization, agricultural change, and rural vulnerability to climate in the context of several comparative international projects involving case studies in Mexico, Argentina, Guatemala, and Honduras. Her articles on this research have been published in World Development, the Journal of Environment and Development, Climatic Change, Global Environmental Change and Physical Geography. Her book Weathering Risk in Rural Mexico, based on her research on agricultural adaptation to neoliberal reforms and climatic variability in central Mexico, was released by the University of Arizona Press in 2006. Kirsten Appendini has a doctorate in Agricultural Economics from the National Autonomous University of Mexico (UNAM). She currently is a researcher and professor on the faculty of the Center for Economic Studies (Centro de Estudios Económicos) at the Colegio de México in Mexico City. She has published widely on issues of agrarian change, rural poverty, food security, and food policy in Mexico. Her book on Mexican maize policy, De la milpa a los tortibonos: La restructración de la política alimentaria en México (Colmex 2001) is now on its second edition. She has also served as a consultant to the UN Food and Agriculture Organization and several bilateral development agencies. 相似文献