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141.
A major factor affecting spring canola (Brassica napus) production in Canada is killing frosts during seedling development in the spring and seed maturation in the fall. The objective
of this study was to explore the possibility of producing spring canola lines with mutations that have altered biochemical
pathways that increase cold tolerance. The approach was to generate UV point mutations in cultured microspores followed by
chemical in vitro selection of individual mutant microspores or embryos resulting in measurable alterations to various biochemical
pathways with elevated levels of key defense signaling molecules such as, salicylic acid (SA), p-Fluoro-d,l-Phenyl Alanine (FPA), and jasmonic acid (JA). In addition, since proline (Pro) is known to protect plant tissues in the cold-induced
osmotic stress pathway, mutants that overproduce Pro were selected in vitro by using three Pro analogues: hydroxyproline (HP),
azetidine-2-carboxylate (A2C); and, 3,4-dehydro-d,l-proline (DP). Of the 329 in vitro selected mutant embryos produced, 74 were identified with significant cold tolerance compared
to their donor parents through indoor freezer tests at −6°C, and 19 had better winter field survival than winter canola checks. All chemically selected mutant doubled haploids with increased
cold tolerance compared well with parent lines for all seed quality and agronomic parameters. Development of increased frost
tolerant cultivars should allow for spring canola to be produced in western Canada without compromising seed quality. 相似文献
142.
Lloyd C. Irland 《European Journal of Forest Research》2010,129(5):777-786
The UN’s Millennium Development Goals (MDGs) and other regional and national policy commitments have motivated an upsurge
of interest in concepts and practical methods for monitoring forest conditions and trends at very wide geographic scales.
Two approaches to sustainability assessment at a global level are reviewed here. One consists of monitoring change in forest
conditions over time—the so-called Criteria and Indicators (C&I) approach. Another approach compares nations at a given point
in time. An example is the Yale Environmental Performance Index (EPI). Both approaches yield insights. It is widely recognized,
though, that severe data weaknesses afflict forest information over much of the world. These weaknesses include weak or absent
information on wood consumption in many regions, poor area estimates, and weak or absent information on key ecological conditions
in forests. The purpose of this essay is to introduce these efforts at global assessment, and to argue that an entirely new
discipline is needed to supply the information needed. The focus of this new discipline would be to design an ecologically
based set of definitions for forest and related ecosystems, and then to build and implement the optimum combination of satellite
measurements, air photo interpretation, and field plot measurements needed to measure world forest resource conditions and
trends. Examples of this new approach are already appearing. This argument is addressed to members of the global forest policy
community concerned with assessment, and to scientists, technologists, and managers in the many technical fields already engaged
on one or another aspect of measuring and monitoring forest conditions at a national and regional scale. 相似文献
143.
Pascale Affolter Ulf Büntgen Jan Esper Andreas Rigling Pascale Weber Jürg Luterbacher David Frank 《European Journal of Forest Research》2010,129(3):289-298
Tree rings from the Alpine area have been widely used to reconstruct variations in summer temperature. In contrast, estimates
of changes in the hydrological cycle are rather scarce. In order to detect altitudinal and species-specific patterns of growth
responses to anomalous dry and wet conditions, a large network of 53 tree-ring width site chronologies along the Rhone valley
(Valais, Switzerland) covering the 1751–2005 period was compiled and analyzed. A total of 1,605 measurement series from four
conifer species—pine, larch, spruce, fir—were detrended to allow inter-annual to multi-decadal scale variability to be preserved.
Site chronologies were combined to four altitudinal (colline: <800 m asl, sub-montane: 800–1,000 m asl, montane: 1,000–1,450 m
asl, sub-alpine: >1,450 m asl) and species-specific mean time-series. These records were compared with temperature, precipitation,
and drought (scPDSI) data. Among the altitudinal records, the colline chronologies showed highest correlation with June precipitation
and scPDSI (0.5 and 0.7). Altitudinal effects, via control on climatic conditions, were superimposed upon species-specific
characteristics in affecting tree growth and response to moisture variations. In particular, species-specific differences
affected the significance level of drought response, with decreasing drought sensitivity towards higher elevations. Growth
conditions were found to be optimal at ~1,300 m asl, with precipitation/drought limiting tree growth below and temperature
above. Common years of extreme drought and low growth for the colline sites occurred in 1921, 1944, 1976, 1992, and 1998.
Our results demonstrate the potential of lower elevation conifers for reconstructing long-term changes in Alpine hydro-climate. 相似文献
144.
145.
146.
Xiaoliang Xiang Shuju Ning Xia Jiang Xiaogui Gong Renlei Zhu Lanfang Zhu Daozhi Wei 《Frontiers of Agriculture in China》2010,4(4):416-421
An efficient protein extraction method for two-dimensional gel electrophoresis (2-DE) from plant samples is usually challenging due to the low protein content and high level of interfering compounds. Proteomic analyses of rice (Oryza sativa L.) roots are limited by the lack of an efficient protein extraction method. To establish an effective protocol of protein extraction suitable for 2-DE analysis in rice roots, we evaluated three protein extraction methods (trichloroacetic acid [TCA]/acetone, Mg/NP-40/TCA, and tris-base/acetone). Our results showed that the Mg/NP-40/TCA extraction method had the highest protein yield and is the best resolution of protein separation among the three methods. The TCA/acetone method exhibited clear protein profiles and detected more protein spots with the highest intensity in the region of high Mr (above 45 kDa) than the other methods. However, this method was unable to detect proteins with low-Mr (less than 24.0 kDa). The Tris-base/acetone method showed the poorest resolution of protein separation. Our results suggest that the Mg/NP-40/TCA method was the most effective among the three methods and may provide enhanced proteomic information for rice and other crop roots. 相似文献
147.
Leland L. Glenna Raymond A. JussaumeJr. Julie C. Dawson 《Agriculture and Human Values》2011,28(2):213-224
Science and technology studies (STS) research challenges the concept of technological determinism by investigating how the
end users of a technology influence that technology’s trajectory. STS critiques of determinism are needed in studies of agricultural
technology. However, we contend that focusing on the agency of end users may mask the role of political-economic factors which
influence technology developments and applications. This paper seeks to mesh STS insights with political-economic perspectives
by accounting for relationships between availability of diverse technologies, variations in political-economic structures,
and farmer interests and characteristics. We present the results of an analysis on the recent development of three wheat varieties:
(a) a wheat variety that was modified genetically to tolerate the herbicide glyphosate, (b) wheat varieties with characteristics
selected to serve specific markets, (c) and emerging research and development of perennial wheat varieties. Using data obtained
through a survey of wheat growers in Washington State, we analyzed whether farmer interest in these three clusters of wheat
varieties was associated with distinct individual characteristics and attitudes and whether those characteristics and attitudes
are consistent with political economic structures. Although our analysis did not allow us to assess the degree of direct influence
that farmers have on the technological development trajectory for these types of wheat, we were able to document variation
in technological alternatives and farmer characteristics related to different political-economic trends. 相似文献
148.
149.
Daniel R. Block Michael Thompson Jill Euken Toni Liquori Frank Fear Sherill Baldwin 《Agriculture and Human Values》2008,25(3):379-388
Engagement happens when academics and non-academics form partnerships to create mutual understanding, and then take action
together. An example is the “value web” work associated with W. K. Kellogg Foundation’s Food Systems Higher Education–Community
Partnership. Partners nationally work on local food systems development by building value webs. “Value chains,” a concept
with considerable currency in the private sector, involves creating non-hierarchical relationships among otherwise disparate
actors and entities to achieve collective common goals. The value web concept is extended herein by separating the values
of the web itself, such as the value of collaboration, from values “in” the web, such as credence values associated with a
product or service. By sharing and discussing case examples of work underway around the United States, the authors make a
case for employing the value webs concept to represent a strategy for local food systems development, specifically, and for
higher education–community partnerships, generally.
Daniel R. Block is an associate professor of geography and coordinator of the Frederick Blum Neighborhood Assistance Center at Chicago State University. His current research focuses on food access issues in urban environments, particularly in Chicago. Michael Thompson is an assistant professor at Oregon State University, and a Seafood and Fisheries specialist for Oregon Sea Grant Extension. Primary areas of research include fisheries management, seafood quality/handling, and seafood product development. Jill Euken is an industrial specialist for biobased products for Iowa State University Extension/CIRAS, and deputy director, ISU Bioeconomy Institute. She was part of the steering team for the Iowa Value Chain Partnership for Sustainable Agriculture and led the Bioeconomy Working Group. Toni Liquori is a nutritionist, teacher and food activist with a long time interest in the design, implementation, and evaluation of school-based intervention programs and coalition building for activism around food related issues, as well as teaching and training in public health. Frank Fear is senior associate dean, College of Agriculture and Natural Resources; and professor, in the Department of Community, Agriculture, Recreation and Resources Studies; and Senior Outreach Fellow at Michigan State University. He is lead author of Coming to Critical Engagement (University Press of America, 2006), an analysis of the engagement movement in higher education; and recently completed two terms as president of the Greater Lansing Food Bank. Sherill Baldwin is ecology director at Mercy Center at Madison, Connecticut, a spiritual retreat and conference center. She previously provided consulting services to CitySeed, Inc. in New Haven (CT) and to Frank Fear and the W. K. Kellogg Foundation for a community learning project related to sustainable food systems. She has an MS in Resource Development from Michigan State University and a BA in Solid Waste Management from the University of Massachusetts. 相似文献
Daniel R. BlockEmail: |
Daniel R. Block is an associate professor of geography and coordinator of the Frederick Blum Neighborhood Assistance Center at Chicago State University. His current research focuses on food access issues in urban environments, particularly in Chicago. Michael Thompson is an assistant professor at Oregon State University, and a Seafood and Fisheries specialist for Oregon Sea Grant Extension. Primary areas of research include fisheries management, seafood quality/handling, and seafood product development. Jill Euken is an industrial specialist for biobased products for Iowa State University Extension/CIRAS, and deputy director, ISU Bioeconomy Institute. She was part of the steering team for the Iowa Value Chain Partnership for Sustainable Agriculture and led the Bioeconomy Working Group. Toni Liquori is a nutritionist, teacher and food activist with a long time interest in the design, implementation, and evaluation of school-based intervention programs and coalition building for activism around food related issues, as well as teaching and training in public health. Frank Fear is senior associate dean, College of Agriculture and Natural Resources; and professor, in the Department of Community, Agriculture, Recreation and Resources Studies; and Senior Outreach Fellow at Michigan State University. He is lead author of Coming to Critical Engagement (University Press of America, 2006), an analysis of the engagement movement in higher education; and recently completed two terms as president of the Greater Lansing Food Bank. Sherill Baldwin is ecology director at Mercy Center at Madison, Connecticut, a spiritual retreat and conference center. She previously provided consulting services to CitySeed, Inc. in New Haven (CT) and to Frank Fear and the W. K. Kellogg Foundation for a community learning project related to sustainable food systems. She has an MS in Resource Development from Michigan State University and a BA in Solid Waste Management from the University of Massachusetts. 相似文献
150.
Daniel Coq-Huelva Bolier Torres-Navarrete Carlos Bueno-Suárez 《Agriculture and Human Values》2018,35(1):163-179
This article explores the role of conventions in the normalization of cocoa production in Ecuadorian Amazonia. Convention theory provides key theoretical tools for understanding coordination among agents. However, conventions must be understood as cultural constructions with a strong Eurocentric background that must be substantially modified in originally non-European contexts. A creative application of convention theory can partially overcome bifurcation among Western and non-Western rationalities. First, it shows that Western values and forms of coordination are heterogeneous, conflictive and opposing. Second, it provides key insight for understanding the transformation of subaltern subjectivities generated from non-Western rationalities that are closely associated with subjugated knowledges. Third, in applying the concept of compromise, it allows one to understand cognitive hybridization and coordination among indigenous and Western agents and thus the complexities of processes of resistance, subversion and empowerment carried by indigenous communities. This article is focused on how cocoa production in Ecuadorian Amazonia serves as an example of the confluence and coordination of indigenous (using the concept of “Good Living” or Sumak Kawsay) and Western conventions. The assertion of Sumak Kawsay is understood as a relevant transformation of Ecuadorian post-colonial relations. It is shown that relevant industrial upgrading processes are justified by, among others, Sumak Kawsay repertoires. Additionally, dialogue on knowledge and compromise among conventions, and especially concerning Sumak Kawsay and the market, have been key facets shaping the development of a differentiated quality strand that has promoted relevant changes in the subaltern positioning of indigenous farmers in the cocoa commodity chain. 相似文献