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981.
Reid G. Palmer Paola T. Perez Evelyn Ortiz-Perez Fouad Maalouf María José Suso 《Euphytica》2009,170(1-2):35-52
Breeders are encouraged to develop breeding approaches that strive to integrate food production into the healthy functioning of agro-ecosystems. In the case of legumes, this approach should preserve bee fauna by providing suitable floral resources within the crops themselves. In parallel, legume breeding for sustainable agriculture is linked to the development of environmental services. Foraging places and nesting sites for solitary and social bees are some of the ecological services provided for legumes. Crops with floral attractiveness and rewards for insects can be used to enhance pollinator conservation as well as crop yield and yield stability. We analyze how understanding crop-pollinator relationships (CPR) can contribute to the production of high-yielding and pollinator-friendly varieties by examining: (1) The status of knowledge on mating systems and floral traits; (2) The contribution of CPR understanding to plant breeding for both hybrid-seed production and open-pollinated population improvement. 相似文献
982.
Arciniegas A Pérez-Castorena AL Maldonado J Avila G Villaseñor JL Romo de Vivar A 《Fitoterapia》2008,79(1):47-52
The new eremophilanolide 1, the known eremophilane derivatives 2 and 3, already described as part of mixtures, the known compounds hyperin, 2'-acetylhyperin and two calenduladiol esters were isolated from Roldana lineolata. Their structures were determined by spectroscopic methods. Compounds 1 and 2 as well as their acetylated and oxidized derivatives were tested against several fungi strains. Eremophilanolide 1 showed a mild activity against Trichophyton mentagrophytes. 相似文献
983.
Changes in land use in the Orinoco lowlands affect the daily trends of energy and water vapor fluxes. We analyzed these fluxes along a disturbance gradient beginning from a cultivated tall-grass Andropogon field (S1) and extending over three savanna sites with increasing woody cover over herbaceous vegetation. The savanna sites encompass a herbaceous savanna (S2), a tree savanna (S3) and a woodland savanna (S4). In the wet season, there were differences in the radiation budget: seasonally averaged albedo for S1 (0.17) exceeded that of S2-S4 (0.13-0.14). Eddy covariance fluxes indicate that the partitioning of the daily net radiation (Rn) into sensible and latent heat (lambda E) fluxes depends on land use. During the wet season, evapotranspiration (i.e., lambda E) over the S1-S4 sites accounted for a variable fraction of Rn (i.e., 0.75, 0.52, 0.67 and 0.68, respectively). Therefore, the Bowen ratio was typically below 1. As the dry season progressed, the lambda E/Rn ratio decreased markedly with increasing air and canopy temperatures and air humidity mole fraction deficit. The maximum evaporation rate over the S1-S4 sites was 3.2, 2.5, 3.5 and 4.1 mm day(-1), respectively, and the annual values were 721, 538, 771 and 732 mm year(-1), respectively, equivalent to 49, 65, 52 and 88% of the rainfall. Soil water content fell from a maximum above 0.28 in the wet season to 0.030, 0.026, 0.030 and 0.028 m(3) m(-3) at sites S1-S4, respectively, in the dry season. Leaf area index was greatly reduced as herbaceous vegetation dried out. 相似文献
984.
Suzanna Lettens Jos Van Orshoven Dominique Perrtn Bas Van Wesemael Bart Muys 《Annals of Forest Science》2008,65(6):604-604
985.
Maria João Gaspar José Luís Louzada Alexandre Aguiar Maria Helena Almeida 《Annals of Forest Science》2008,65(7):703-703
- ? It is essential to understand how characteristics are related to each other in breeding programmes to select wood properties, in order to avoid that, in selecting for one trait, we are negatively affecting another. Moreover, measuring wood properties is time consuming and expensive.
- ? This study assesses genetic and phenotypic correlations between wood density components and spiral grain of 46 half-sib families of Pinus pinaster in seventeen-year-old trees.
- ? Results showed that genetic correlations for all wood density components were higher than corresponding phenotypic correlations. Furthermore, all wood density components were highly genetically correlated with ring density, and also closely associated among themselves. Results showed a higher genetic correlation of ring density with earlywood density (r g = 0.96) than with latewood density r g = 0.79). A moderate to high positive genetic correlation was found between spiral grain and wood density characteristics (0.29–0.61).
- ? We conclude that ring density (overall wood density) can be improved by increasing either earlywood density, latewood percent, or both of these traits, and spiral grain can be modify in future plantations.
986.
Virginia Hernández-Santana José Martínez-Fernández Carlos Morán Ana Cano 《European Journal of Forest Research》2008,127(5):369-378
In the present study, carried out from 2004 to 2006, leaf and stem water potential and stem water content were measured in
Quercus pyrenaica Willd. individuals in an experimental forested catchment located in Central Western Spain under Mediterranean subhumid conditions.
These indicators of tree water status were compared with soil moisture contents measured in the same area from 0 to 1 m depth
and from 0 to 2.5 m depth during the last year of the study. The objectives were to clarify the seasonal and year-to-year
variations in tree water status, to examine applicability of stem water content as useful water stress indicator and to discuss
how deep soil water and root uptake contribute to survival during the long dry summer. Seasonal variations in the tree variables
measured revealed a typical pattern, with maximum values at the end of spring followed by a progressive decline during the
summer drought in response to the decrease in soil water content (almost exhausted at 0–100 cm depth). The relatively high
values and the non-significant variation in predawn leaf water potentials (except for 2005, which was exceptionally dry) indicate
that no clear water stress situations occurred. This may be explained in terms of a progressive absorption of water from the
deeper layers. The results also suggest that the stem water content is a more sensitive indicator of long-term water limitation
than the other variables measured. 相似文献
987.
Daily evapotranspiration estimates from extrapolating instantaneous airborne remote sensing ET values 总被引:1,自引:1,他引:0
José L. Chávez Christopher M. U. Neale John H. Prueger William P. Kustas 《Irrigation Science》2008,27(1):67-81
In this study, six extrapolation methods have been compared for their ability to estimate daily crop evapotranspiration (ETd) from instantaneous latent heat flux estimates derived from digital airborne multispectral remote sensing imagery. Data used
in this study were collected during an experiment on corn and soybean fields, covering an area of approximately 12 × 22 km,
near Ames, Iowa. ETd estimation errors for all six methods and both crops varied from −5.7 ± 4.8% (MBE ± RMSE) to 26.0 ± 15.8%. Extrapolated ETd values based on the evaporative fraction (EF) method better compared to eddy covariance measured ET values. This method reported
an average corn ETd estimate error of −0.3 mm day−1, with a corresponding error standard deviation of 0.2 mm day−1, i.e., about 5.7 ± 4.8% average under prediction when compared to average ETd values derived from eddy covariance energy balance systems. A solar radiation-based ET extrapolation method performed relatively
well with ETd estimation error of 2.2 ± 10.1% for both crops. An alfalfa reference ET-based extrapolation fraction method (ETrF) yielded an overall ETd overestimation of about 4.0 ± 10.0% for both crops. It is recommended that the average daily soil heat flux not be neglected
in the calculation of ETd when utilizing method EF. These results validate the use of the airborne multispectral RS-based ET methodology for the estimation
of instantaneous ET and its extrapolation to ETd. In addition, all methods need to be further tested under a variety of vegetation surface homogeneity, crop growth stage,
environmental and climatological conditions.
相似文献
José L. Chávez (Corresponding author)Email: |
Christopher M. U. NealeEmail: |
John H. PruegerEmail: |
William P. KustasEmail: |
988.
Molecular markers linked to the <Emphasis Type="Italic">fin</Emphasis> gene controlling determinate growth habit in common bean 总被引:1,自引:1,他引:0
Astrid Pañeda Cristina Rodríguez-Suárez Ana Campa Juan José Ferreira Ramón Giraldez 《Euphytica》2008,160(2):241-248
The S-genotypes of 16 apricot (Prunus armeniaca L.) cultivars native to China were determined by the S-allele PCR approach and the results were confirmed by cross-pollination tests among these cultivars. Primer combination EM-PC2consFD + EM-PC3consR,
based on the conserved regions C2 and C3 of Rosaceous
S-RNase genes, was the most useful primer combination for identifying Chinese apricot S-alleles. Twelve S-RNase alleles were identified using this primer combination, and they were defined as follows: S
9 was 657 bp, S
10 was 266 bp, S
11 was 464 bp, S
12 was 360 bp, S
13 was 401 bp, S
14 was 492 bp, S
15 was 469 bp, S
16 was 481 bp, S
17 was 487 bp, S
18 was 1337 bp, S
19 was 546 bp and S
20 was 1934 bp. S
11–S
20 were new S-RNase genes deposited in GenBank under accession numbers DQ868316, DQ870628-DQ870634, EF133689 and EF160078, respectively.
Our findings contribute to a more efficient breeding program of Chinese apricot and further studies on the S-RNase genes. 相似文献
989.
M. Manuel Robles-González Víctor Manuel Medina-Urrutia José Joaquín Velázquez-Monreal June Simpson 《Euphytica》2008,161(3):401-411
The Mexican lime industry is interested in developing lime cultivars with improved characteristics for fresh and processing
markets. The objective of this study was to determine the field performance and genetic molecular differences among four new
Mexican lime [Citrus aurantifolia (Christm) Swingle] clonal selections compared to traditional thorny Mexican lime under the dry tropical conditions of Mexico.
Tree growth, production, fruit quality, and molecular markers of the traditional thorny Mexican lime (MLT) cultivar were compared to the following lime selections:
thornless Mexican lime (MLTS), seedless Mexican lime (MLS), ML 12-8, and ML 20-3. After 10 years of evaluation MLS showed
the highest and MLTS the lowest tree growth. Most of the genotypes covered the soil surface area assigned to tree growth since
they were 7 years old. Only the less vigorous MLTS required 9 years to cover the same space. MLT was the most productive selection
(165 kg/tree/year, mean of 8 years of evaluation). MLS was the less productive (81 kg/tree in the same period of time). MLTS,
ML 12-8, and ML 20-3 produced intermediate yields. Acidity and total soluble solids among the selections were very similar.
However, MLS had the higher juice content and the lower seed number. The MLS selection is attractive for export market due
to these characteristics. AFLP studies confirmed genetic differences among the five lime selections. Nevertheless, all five
selections shared many bands as expected. 相似文献
990.
Angustias Márquez-Lema José M. Fernández-Martínez Begoña Pérez-Vich Leonardo Velasco 《Euphytica》2008,164(2):365-375
The presence of high levels of sinigrin in the seeds represents a serious constraint for the commercial utilisation of Ethiopian
mustard (Brassica carinata A. Braun) meal. The objective of this research was the introgression of genes for low glucosinolate content from B. juncea into B. carinata. BC1F1 seed from crosses between double zero B. juncea line Heera and B. carinata line N2-142 was produced. Simultaneous selection for B. carinata phenotype and low glucosinolate content was conducted from BC1F2 to BC1F4 plant generations. Forty-three BC1F4 derived lines were selected and subject to a detailed phenotypic and molecular evaluation to identify lines with low glucosinolate
content and genetic proximity to B. carinata. Sixteen phenotypic traits and 80 SSR markers were used. Eight BC1F4 derived lines were very close to N2-142 both at the phenotypic and molecular level. Three of them, with average glucosinolate
contents from 52 to 61 micromoles g−1, compared to 35 micromoles g−1 for Heera and 86 micromoles g−1 for N2-142, were selected and evaluated in two additional environments, resulting in average glucosinolate contents from
43 to 56 micromoles g−1, compared to 29 micromoles g−1 for Heera and 84 micromoles g−1 for N2-142. The best line (BCH-1773), with a glucosinolate profile made up of sinigrin (>95%) and a chromosome number of
2n = 34, was further evaluated in two environments (field and pots in open-air conditions). Average glucosinolate contents over
the four environments included in this research were 42, 31 and 74 micromoles g−1 for BCH-1773, Heera and N2-142, respectively. These are the lowest stable levels of glucosinolates reported so far in B. carinata. 相似文献