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991.
Takanori Imai Sousuke Inoue Naomi Ohdaira Yasuyuki Matsushita Rie Suzuki Mariko Sakurai José Manoel Henriques de Jesus Salete Kiyoka Ozaki Zenesio Finger Kazuhiko Fukushima 《Journal of Wood Science》2008,54(6):470-475
Heartwood extracts from Amazonian trees cumaru-ferro (Dipteryx odorata), jatoba (Hymenaea courbaril), and guarita (Astronium lecointei) exhibit antioxidant activities comparable with that of α-tocopherol, a well-known antioxidant. This article reports the characterization of the antioxidant compounds in the extracts
of the three heartwoods. Silica gel column chromatography of the cumaru-ferro EtOAc extract yielded (−)-(3R)-7,2′,3′-trihydroxy-4′-methoxyisoflavan and (+)-(3R)-8,2′,3′-trihydroxy-7,4′-dimethoxyisoflavan. Silica gel column chromatography followed by preparative high-performance liquid
chromatography of the jatoba EtOAc extract yielded (−)-fisetinidol and (+)-trans-taxifolin. Chemical structures were assigned using electron-ionization mass spectrometry, 1H and 13C nuclear magnetic resonance (NMR) spectroscopy including nuclear Overhauser effect spectroscopy (NOESY), as well as optical
rotation and circular dichroism. Gas chromatography-mass spectrometry demonstrated that the isolated compounds were predominant
in the EtOAc extracts. In the guarita EtOAc extract, catechin and gallic acid were identified by comparing their retention
times and mass fragmentation patterns with those of authentic samples. Antioxidant activity determined by the 1,1-diphenyl-2-picrylhydrazyl
assay demonstrated that all these compounds had activities comparable with that of α-tocopherol.
Part of this report was presented at the 57th Annual Meeting of the Japan Wood Research Society, Hiroshima, August 2007 相似文献
992.
Toru Taniguchi Yasunori Ohmiya Manabu Kurita Miyoko Tsubomura Teiji Kondo Yong Woo Park Kei’ichi Baba Takahisa Hayashi 《Journal of Wood Science》2008,54(5):408-413
We performed biosafety assessments of transgenic poplars prior to field trials. Constitutive expression of the Aspergillus aculeatus xyloglucanase in Populus alba increased the cellulose content and specific gravity of its stem, the leaves of which were visibly greener, thicker, and
smaller than those of the wild-type plant. Although the young transgenic poplars grew faster than the wild type in a growth
chamber, there was no distinguishable difference in growth between the poplars when they were placed in a special screened
greenhouse. Allelopathic tests showed that the transgenic poplars do not produce harmful substances. Based on all the biosafety
assessments and the scientific literature on poplar species, we came to the conclusion that transgenic poplars probably do
not disturb the biological diversity of the surrounding environment, even when they are submitted to field trials. 相似文献
993.
Wook Kang Chun-Won Kang Woo Yang Chung Chang-Deuk Eom Hwanmyeong Yeo 《Journal of Wood Science》2008,54(5):343-348
This study was undertaken to estimate the effect of openings between cell walls on combined bound water and water vapor diffusion
in wood. Using a newly developed model, the radial and tangential moisture diffusion coefficients can be predicted depending
on the opening area. The new model explicitly involves a term for water vapor diffusion through the openings, as well as a
term for the combined diffusion of bound water and water vapor. A classical model developed by Stamm and Choong had higher
longitudinal moisture diffusion coefficients than that in the parallel model at higher moisture content, which is inconsistent
with the Wiener bound rule. The new model suggested in this article is useful for analyzing the experimental results and understanding
the variability of the diffusion coefficients. 相似文献
994.
Effect of temperature and compression on the mechanical behavior of steam-treated wood 总被引:2,自引:0,他引:2
The mechanical behavior of steamed spruce wood changes dramatically with compression along the grain, the change being much more moderate perpendicular to the grain. The stiffness decrement due to increased temperature is greatest in the tangential material direction. The stiffness decrement due to compression is greatest along the grain. Compression to 80% compressive strain at 131°C inverts the order of the material directions regarding stiffness, the stiffness being the least along the grain. Plastic strain due to compression is greater at higher temperatures. The compression-induced decrement of stiffness along the grain is greater at higher temperatures, but the off-axis decrement of stiffness is less at higher temperatures. 相似文献
995.
This paper describes the use by family forest landowners of educational programs provided by Washington State University Cooperative
Extension (WSUCE), and the associated use of technical assistance programs provided by state and federal agencies and the
private sector. Approximately 100,000 family forest owners controlled 19% or over 1.2 M ha of Washington’s forestland and
accounted for 29% of the timber harvested in the state on a volume basis in 1998. A variety of public and private assistance
and education programs are available to encourage and help family forest owners manage their forests. In 1999 a mail survey
was conducted to evaluate use and effectiveness of Washington’s family forest assistance and education programs. Over half
of the 872 responding family forest landowners had contact with an extension educator, program or educational material, and
about three quarters of these respondents gave an overall rating of the usefulness of extension programs and materials as
good or excellent. Respondents attending WSUCE forestry educational programs have larger median land ownership size, are older,
have owned their forests longer, have a higher rate of absentee ownership, and are better educated than non-users. They are
more likely to actively manage their forests for timber production and exhibit a clearer understanding of the multiple-use
capabilities of their forests. 相似文献
996.
A study was conducted with the objective of obtaining a profile of farmers who have participated in the Farm Partnership Scheme
in Ireland. This scheme is a joint venture between Coillte (The Irish Forestry Board) and farmers. Under the terms of the
scheme, Coillte is responsible for the establishment, management and harvesting of the forest plantation on the farmer’s land.
The farmer retains ownership of the land, receives premium payments and shares in the harvesting profits. Fifty farmers who
joined the Farm Partnership Scheme between 1993–1997 were interviewed in 1999 and a detailed questionnaire was completed.
Survey results indicate that the typical farm partner was male, married and aged 50 years or older. Over half of those surveyed
had an off-farm job. The most popular reason for farmers opting to participate in the Farm Partnership Scheme was that they
did not have sufficient time to undertake the establishment and management of a forest plantation themselves. The average
size of forest established under the scheme was 23.7 ha, with Sitka spruce the most popular species planted. The average annual
payment under the scheme was €8077. For 46% of those surveyed, the returns from the Farm Partnership Scheme comprised all
of their farm income. 相似文献
997.
Tree planting for poverty reduction in less-favoured areas of the Ethiopian highlands 总被引:1,自引:0,他引:1
This paper assesses the potential impact of planting of eucalypt trees as a strategy to reduce poverty in a less-favoured
area of the highlands of Ethiopia. Results from simulations with a bio-economic model for a less-favoured case study area
in the highlands are combined with survey data at community, household and plot level to assess how general the results of
the bio-economic model are. Application of the bio-economic model shows clearly that land degradation, population growth,
stagnant technology and drought threaten food security. Household welfare and land quality are deteriorating rapidly in the
area and interventions are urgently needed to avoid human disaster. Planting of eucalypts on land unsuitable for crop production
may substantially increase household incomes if market outlets for trees can be found. Tree planting will not have severe
negative effects on food production or land conservation. A policy combining promotion of tree planting and conservation of
cropland may achieve win-win benefits in terms of increased household incomes as well as more sustainable land-use. Analysis
of survey data from the Amhara Region of Ethiopia reveals that there is a large area of land that is unsuitable for crop production
located close to all-weather roads in the less-favoured areas of the region. Few trees have been planted on this type of land
up to now. The past policy seems to have discouraged tree planting except on homestead plots that are more suitable for food
crops.
This paper reports part of the IFPRI/ILRI project ‘Policies for Sustainable Land Management in the East African Highlands’.
These two agencies have provided funds and logistical support for the work. The Norwegian Ministry of Foreign Affairs has
provided funds for this research in the Amhara Region in Ethiopia. The authors also draw on earlier work funded by Research
Council of Norway. Any correspondence should be directed to the first author. 相似文献
998.
FLORES, the Forest Land Oriented Resource Envisioning System, is a framework to facilitate quantitative modelling of ecological,
economic and social issues at the landscape scale. This issue ofSmall-scale Forest Economics, Management and Policy describes the evolution of FLORES from a concept to a series of models calibrated for diverse locations, and documents the
lessons learned.
The idea to construct and use landscape-scale models of the forest frontier, based on simulating household decisions and land
use at a spatial scale close to the field level, arose from a desire to add rigour to land-use policy research at CIFOR, the
Center for International Forestry Research (Vanclay 1995). This simulation modelling approach to addressing interdisciplinary
issues, where people are strongly interacting with forest resources, became known as FLORES, the Forest Land Oriented Resource
Envisioning System (Vanclay 1998). Muetzelfeldtet al. (1998) constructed a simple prototype of a FLORES model to illustrate the concept and demonstrate the ability of a system-dynamics
modelling environment to animate such a model (Muetzelfeldt and Taylor 1997, 2001, Muetzelfeldt and Massheder 2003). In 1999,
FLORES became a reality, when 50 scientists from diverse disciplines met in Bukittinggi, Indonesia to construct the first
FLORES model styled on this prototype (CIFOR 1999, Vanclayet al. 2003).
The research reported in this special issue was made possible by generous financial support from the Department for International
Development (UK), the European Community, the Asian Development Bank (under RETA 5812) and the Center for International Forestry
Research. The views expressed herein are those of the authors alone. We would like to thank the following people who have
assisted in the production of this special issue by acting as anonymous referees for these and other papers: Andy Warner,
Brendan Moran, Bruno Verbist, Chris Dake, Chris Legg, Doug Sheil, Euan Mason, Francois Bousquet, Frank Vanclay, Geoff Slaughter,
James Gambiza, John Herbohn, John Poulsen, Jungho Suh, Mike Spilsbury, Paul Phillips, Paul van Gardingen, Phil Norman, Philip
Nyhus, Roger Wheate, Ross Sigley, Steve Harrison and Tom Evans. Thanks also to the editorial staff, especially Steve Harrison,
John Herbohn and Jungho Suh, for making this special issue possible. 相似文献
999.
Mandy Haggith Ravi Prabhu Happyson Mudavanhu Frank Matose Tendayi Mutimukuru Richard Nyirenda Wavell Standa-Gunda 《Small-Scale Forestry》2003,2(2):155-169
This paper explores the challenge of defining the scope of a systems model, emphasising three aspects: boundary, granularity
and conceptual scope. The significance of these is illustrated by reference to a model of land-use decisions made in villages
bordering on the Mafungautsi forest in Zimbabwe. The purpose of this model was to help policy players (Forestry Commission
staff, non-governmental organisations, researchers and local people) to understand the impact of policy interventions on local
people’s livelihoods. Scoping decisions that were made in building the Mafungautsi model were deliberately liberal, to encompass
the interests of all participants in the modelling process. These decisions now present a range of serious challenges: the
difficulty of model calibration, the computational expense of running simulations, and the difficulty for new users to understand
the model. Facilitators of modelling teams need to consider the serious implications of giving everyone what they want and
including all participants’ ideas in a model. In the long run, it may be better to be tough and reject many suggestions at
the outset. The former approach is unlikely to lead to a tractable model, while the latter may ultimately offer greater satisfaction
for all.
We are grateful to the UK’s Department for International Development (DFID) and the European Community for financial support
of this project. Thanks also to all of the ACM team who have contributed ideas on the process and content of the modelling
work and who make it fun to undertake collaborative research. Thanks also to the participants in the Zimbabwe FLAC workshops
for their input into the specification of the Mafungautsi model. Finally thanks to Robert Muetzelfeldt, Jasper Taylor, Jonathan
Massheder, Fergus Sinclair and Jerry Vanclay for helping us to ride on the FLORES bandwagon. 相似文献
1000.
BYUNBong-Kyu YANShan-chun LICheng-de 《林业研究》2003,14(3):210-212
Genus Eurydoxa Filipjev in China is reviewed and noted for the first time. Based on the present study, two species are recognized, including rhodopa Diakonoff and advena Filipjev. All available information for the species is reviewed and provided. 相似文献