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排序方式: 共有318条查询结果,搜索用时 15 毫秒
91.
Domínguez-Crespo Miguel A. Sánchez-Hernández Z. Erika Torres-Huerta Aidé M. Negrete-Rodríguez Ma. de la Luz X. Conde-Barajas Eloy Flores-Vela Abelardo 《Water, air, and soil pollution》2012,223(2):915-931
In order to enhance the removal of heavy metals such as Ni, Cu, Zn and Cd from wastewater, different cow dung/sewage sludge
ratios were tested to assess the effect of these metals on the adaptability of Eisenia fetida earthworms to the treatment process carried out in a typical plant located in Tamaulipas, Mexico. Two experimental water
treatment setups were proposed. The first set of experiments was planned to determine the adequate sewage sludge/cow dung
ratio(s), whereas the second arrangement was designed to evaluate the growth performance and fecundity of the earthworms under
high heavy metal concentrations. To achieve the objectives, the experiments were conducted for 90 days under controlled environmental
conditions. Maximum worm biomass and growth rates were attained in samples containing 25 wt.% of sewage sludge. Weight and
mortality of worms were significantly affected by the high levels of heavy metals, making difficult the metal accumulation
in the worm tissues. 相似文献
92.
Erika Sato Yuko Suga Chihiro Kisaki Koki Toyota Kazuto Miyake Atsushi Takada 《Soil Science and Plant Nutrition》2013,59(2):213-222
Abstract The humus composition was analyzed and the humic acid characterized by UV and visible absorption spectroscopy in order to investigate the rotting and maturing process of city refuse compost according to the method of Kumada et al. During the composting process, the following findings were obtained: (1) the HT value was almost constant, but the HE/HT ratio varied somewhat, (2) HA increased with decrease in FA, and the PQ value so increased clearly, (3) the shoulder-like absorption at a wavelength near 270 nm weakened, and (4) the RF value of humic acid increased, whereas the Δ log K value seldom varied. The IR spectrum of humic acid gradually changed as follows: (1) the absorption band in the 1700-1600 cm-1 region and in the 1550-1500 cm-1 region increased slightly, (2) the band in the 1100-1000 cm-1 region decreased, and (3) the bands at 835 and 710 cm-1 com pletely disappeared. On the whole, the shape of the IR spectrum of the city refuse compost became featureless. These changes were probably due to the oxidation which occurred in the composting process. 相似文献
93.
94.
Erika Valéria Saliba Albuquerque Poliene Martins Costa Ana Cristina Meneses Mendes Gomes Marcilene Santos Antonio Alves Pereira Michel Nicole Diana Fernandez Maria Fatima Grossi-de-Sa 《European journal of plant pathology / European Foundation for Plant Pathology》2010,127(3):365-373
Root-knot nematodes (RKN) are obligate parasite species of the genus Meloidogyne that cause great losses in Arabica coffee (Coffea arabica L.) plantations. Identification of resistant genotypes would facilitate the improvement of coffee varieties aiming at an
environmental friendly and costless nematode control. In this work, the C. arabica genotype ‘UFV 408-28’ was found to be resistant to the most destructive RKN species M. incognita. Pathogenicity assays indicated that the highly aggressive populations of M. incognita races 1, 2 and 3 were not able to successfully reproduce on ‘UFV 408-28’ roots and displayed a low gall index (GI = 2). An
average reduction of 87% reduction of the M. incognita population was observed on ‘UFV 408-28’ when compared to the susceptible cultivar ‘IAC 15’. By contrast, ‘UFV 408-28’ was
susceptible to the related species M. exigua and M. paranaensis (GI = 5 and 4, respectively). Histological observations performed on sections of UFV408-28 roots infected with M. incognita race 1 showed that nematode infection could be blocked right after penetration or during migration and establishment stages,
at 6 days, 7 days and 8 days after infection (DAI). Fluorescence and bright field microscopy observations showed that root
cells surrounding the nematodes exhibited HR-like features such as accumulation of phenolic compounds and a necrotic cell
aspect. In the susceptible ‘IAC 15’ roots, 6 DAI, feeding sites contained giant cells with a dense cytoplasm. Necrotic cells
were never observed throughout the entire infection cycle. The HR-like phenotype observed in the ‘UFV 408-28’—M. incognita interaction suggests that the coffee resistance may be mediated by a R-gene based immunity system and may therefore provide new insights for understanding the molecular basis of RKN resistance
in perennial crops. 相似文献
95.
Merchant SS Prochnik SE Vallon O Harris EH Karpowicz SJ Witman GB Terry A Salamov A Fritz-Laylin LK Maréchal-Drouard L Marshall WF Qu LH Nelson DR Sanderfoot AA Spalding MH Kapitonov VV Ren Q Ferris P Lindquist E Shapiro H Lucas SM Grimwood J Schmutz J Cardol P Cerutti H Chanfreau G Chen CL Cognat V Croft MT Dent R Dutcher S Fernández E Fukuzawa H González-Ballester D González-Halphen D Hallmann A Hanikenne M Hippler M Inwood W Jabbari K Kalanon M Kuras R Lefebvre PA Lemaire SD Lobanov AV 《Science (New York, N.Y.)》2007,318(5848):245-250
Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as the structure, assembly, and function of eukaryotic flagella (cilia), which were inherited from the common ancestor of plants and animals, but lost in land plants. We sequenced the approximately 120-megabase nuclear genome of Chlamydomonas and performed comparative phylogenomic analyses, identifying genes encoding uncharacterized proteins that are likely associated with the function and biogenesis of chloroplasts or eukaryotic flagella. Analyses of the Chlamydomonas genome advance our understanding of the ancestral eukaryotic cell, reveal previously unknown genes associated with photosynthetic and flagellar functions, and establish links between ciliopathy and the composition and function of flagella. 相似文献
96.
Erika M. Stein Sara G. Tajú Patrícia A. Miyasato Rafaela P. de Freitas Lenita de F. Tallarico Guilherme S. dos Santos Giovana L. F. Luiz Henrique K. Rofatto Fbio N. V. da Silva Pio Colepicolo Arthur L. Macedo Carlos A. Carollo Eliana Nakano 《Marine drugs》2021,19(5)
Schistosomiasis is a parasitic disease that affects more than 250 million people. The treatment is limited to praziquantel and the control of the intermediate host with the highly toxic molluscicidal niclosamide. Marine algae are a poorly explored and promising alternative that can provide lead compounds, and the use of multivariate analysis could contribute to quicker discovery. As part of our search for new natural compounds with which to control schistosomiasis, we screened 45 crude extracts obtained from 37 Brazilian seaweed species for their molluscicidal activity against Biomphalaria glabrata embryos and schistosomicidal activities against Schistosoma mansoni. Two sets of extracts were taxonomically grouped for metabolomic analysis. The extracts were analyzed by GC–MS, and the data were subjected to Pattern Hunter and Pearson correlation tests. Overall, 22 species (60%) showed activity in at least one of the two models. Multivariate analysis pointed towards 3 hits against B. glabrata veliger embryos in the Laurencia/Laurenciella set, 5 hits against B. glabrata blastula embryos, and 31 against S. mansoni in the Ochrophyta set. Preliminary annotations suggested some compounds such as triquinane alcohols, prenylated guaianes, dichotomanes, and xenianes. Despite the putative identification, this work presents potential candidates and can guide future isolation and identification. 相似文献
97.
Cristian R Bulboa Juan E Macchiavello Eurico C Oliveira & Erika Fonck 《Aquaculture Research》2005,36(11):1069-1074
Chondracanthus chamissoi is an important source of carrageenan in Chile. Presently, all the production is harvested from wild populations. This study reports the first attempt to cultivate C. chamissoi. Experiments were conducted with female gametophytic and sporophytic thalli by inserting them among braids of a 7 mm polypropylene rope. Inoculated ropes were placed at 1, 3 and 5 m depths in two sheltered bays in northern Chile. The fronds adapted well to cultivation and grew at all the depths tested, although the greatest increase in biomass was observed at 1 m depth. On a yearly cycle, higher biomass increases were observed in autumn and winter months compared with the spring and summer. We believe that by adapting the cultivation methodology, this species could be cultivated year round. 相似文献
98.
Cumming Duan Stephen J. Duguay Erika M. Plisetskaya 《Fish physiology and biochemistry》1993,11(1-6):371-379
To examine the hormonal and nutritional regulation of insulin-like growth factor I (IGF-I) mRNA expression, a sequence-specific
solution hybridization/RNase protection assay for coho salmon IGF-I mRNA was developed. This assay is both rapid and sensitive
and has low inter- (less than 15%) and intra-assay variations (less than 5%). Using this assay, the tissue distribution of
IGF-I mRNA and effects of growth hormone (GH), prolactin (PRL) and somatolactin (SL) on hepatic IGF-I mRNA expression in coho
salmon were examined in vivo. Liver had the highest IGF-I mRNA level of 16 pg/μg DNA. Significant amounts of IGF-I mRNA were also found in all other tissues
examined (intestine 4.1, kidney 3.8, gill arch 2.4, brain 2.4, ovary 2.3, muscle 2.1, spleen 1.7 and fat 1.1 pg/μg DNA). Injection
of coho salmon GH at doses of 0.1 and 1 μg/g body weight significantly increased the hepatic IGF-I mRNA levels in a dose-dependent
manner. Injection of coho salmon SL, a recently discovered member of the GH/PRL family, stimulated the IGF-I mRNA expression
at the higher dose (1 μg/g), whereas coho salmon PRL had no effect at either dose. Concentration-dependent stimulation by
coho salmon GH was also obtained in vitro in primary culture of salmon hepatocytes in concentrations ranging from 0.01 to 1 μg/ml. These results indicate that IGF-I
mRNA expression occurs in a variety of tissues in coho salmon, and that at least the hepatic expression is under the regulation
of GH and possibly other hormones. The sequence-specific assay established in the present study can be used for accurate quantitation
of IGF-I mRNA in salmonid species, and can contribute to a better understanding of the physiology of IGF-I in salmonids.
Résumé Afin d'étudier les régulations homronales et nutritionnelles de l'expression des ARNm de l'IGF-I (insulin-like growth factor I), un dosage spécifique par hybridation en solution des ARNm d'IGF-I de saumon coho et protégé des RNases, a été développé. Ce dosage, à la fois rapide et sensible, présente un faible coefficient de variation inter- (< 15%) et intra- (< 5%) dosage. L'étude de la distribution tissulaire des ARNm de l'IGF-I et des effets de l'hormone de croissance (GH), de la prolactine (Prl) et de la somatolactine (SI) sur l'expression hépatique des ARNm de l'IGF-I, a été entreprise in vivo chez le saumon coho en utilisant ce dosage. Le foie présente les plus grandes quantités d'ARNm d'IGF-I (16 pg/μg d'ADN). Des quantités significatives d'ARNm d'IGF-I ont été également détectées dans tous les autres tissus étudiés (intestin 4,1; rein 3,8; branchie 2,4; ovaire 2,3; muscle 2,1; rate 1,7 et graisse 1,1 pg/μg d'ADN). L'injection à des saumons coho, de GH à des doses de 0,1 et 1 μg/g de poids vif, augmente significativement et de manière dose dépendante les niveaux hépatiques d'ARNm d'IGF-I. L'injection de SI de saumon coho, un membre récemment découvert de la famille GH/Prl, stimule avec la plus haute dose utilisée, l'expression des ARNm d'IGF-I alors que la Prl n'a aucun effet. La GH augmente de manière dose dépendante (0,01–1 μg/ml) l'expression in vitro des ARNm d'IGF-I par des ARNm d'IGF-I par des hépatocytes de saumon coho en culture. Ces résultats indiquent que, chez le saumon coho, l'expression des ARNm d'IGF-I est présente dans le nombreaux tissus et que, l'expression hépatique est, au moins en partie, régulée par la GH et peut-être par d'autres hormones. Le dosage par séquence spécifique mise au point dans le présent travail, peut-être utilisé pour la quantification précise des ARNm, d'IGF-I de salmonidés et devrait permettre une meilleure connaissance de la physiologie de L'IGF-I chez les salmonidés.相似文献
99.
Gossip is a form of affective information about who is friend and who is foe. We show that gossip does not influence only how a face is evaluated--it affects whether a face is seen in the first place. In two experiments, neutral faces were paired with negative, positive, or neutral gossip and were then presented alone in a binocular rivalry paradigm (faces were presented to one eye, houses to the other). In both studies, faces previously paired with negative (but not positive or neutral) gossip dominated longer in visual consciousness. These findings demonstrate that gossip, as a potent form of social affective learning, can influence vision in a completely top-down manner, independent of the basic structural features of a face. 相似文献
100.
Harada K Okada E Shimizu T Kataoka Y Sawada T Takahashi T 《Comparative immunology, microbiology and infectious diseases》2012,35(2):139-144
In this study, fecal Escherichia coli isolates (n=188) from 34 dog-owner pairs and 26 healthy control humans (2 isolates per individual) were tested for susceptibility to 6 antimicrobials and screened for virulence genes. Genetic diversity between canine and owner isolates was evaluated by pulsed-field gel electrophoresis (PFGE). Canine isolates exhibited significantly different rates of resistance to four and two antimicrobials, compared to control and owner isolates, respectively. Of the genes examined, the prevalence of sfa, hly, and cnf genes in canine isolates were higher than in control isolates, but not than in owner isolates. These results suggest that characteristics of owner isolates are somewhat similar to canine isolates, compared to isolates from non-dog owners. In addition, PFGE analysis revealed that transfer of E. coli between owners and their dogs had occurred within 3/34 (8.8%) households. Considering the effects of dog ownership on the population of E. coli isolates from owners, further epidemiological studies are required. 相似文献