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121.
J.M. Afonso D. Montero L. Robaina N. Astorga M.S. Izquierdo R. Ginés 《Fish physiology and biochemistry》2000,22(2):159-163
Skeletal deformities constitute a major problem for aquaculture industry by decreasing the final value of the fish. An analysis of skeletal malformations in 11,640 fish was performed considering families and triplicates per family. Thirtynine different skeletal abnormalities were detected, such as lordosis, vertebral fusion, absence of one or both operculum, bent-jaw, etc. Moreover, a new unusual complex spinal column deformity consisting of a consecutive repetition of lordosis, scoliosis and kyphosis (LSK) from the head to the caudal fin was described. This syndrome was statistically associated with the family structure (Z2H–family,LSK=3.49; p<0.05). The incidence of this deformity was 0.2% in the whole population, and 6.5% within the affected family (2H). The environmental and genetic causes are discussed. 相似文献
122.
Gregorio Arone Constantino Calderón Silvia Moreno Eulogio J. Bedmar 《Biology and Fertility of Soils》2014,50(1):185-190
Peasants of the Quechua region of the Peruvian Andes use chacras to grow maize (Zea mays) in innate association with bur clover (Medicago hispida). From a total of 25 bacterial strains isolated from root nodules of bur clover grown in soils from chacras in Allpas (Acobamba, Peru) 7 clustered into 6 Repetitive extragenic palindromic-polymerase chain reactions (REP–PCR) groups. The nearly complete 16S rRNA gene sequence from the representative strains AP1, AP15, AP28, AP29, AP37, and AP70 showed they were closely related to members of the genus Ensifer of the Alphaproteobacteria. Sequencing of the housekeeping atpD, glnII, and recA and the symbiotic nodC genes from each of the six strains revealed they all were similar to those of strains included in Ensifer medicae. The remaining 18 strains were distributed into 8 REP–PCR groups and analyses of the 16S rRNA gene sequences showed that the isolates belong to several phylogenetic groups, being closely related to species of genera Kaistia, Pseudomonas, Achromobacter, Stenotrophomonas, Xanthomonas, Sphyngopyxis, Duganella, and Rheinheimera. 相似文献
123.
Luara Castilho Pereira Leonardo Balbinot Gregorio Nolazco Matus Herly Carlos Teixeira Dias Kelly Cristina Tonello 《林业研究》2021,42(6):2301-2311
Although the scientific knowledge about some associations between physical parameters of the soil is con-solidated,studies focused on investigating the dynamics... 相似文献
124.
Liz Ota John Herbohn Steve Harrison Nestor Gregorio Vera Lex Engel 《Agroforestry Systems》2018,92(6):1597-1609
Systematic mapping studies provide a snapshot of the literature based on systematic literature searches. In this systematic mapping study, the original research that links reforestation and livelihoods in the tropics was mapped and analysed to identify the trends, biases and gaps in the literature. In total, 339 papers from 92 journals were identified. Agroforestry Systems was the journal in which articles were most frequently published, and Cameroon and Indonesia the most frequently studied countries. The greatest number of authors came from the USA, and authors were most commonly affiliated with ICRAF. A limited collaboration between research groups in the tropical regions was identified. Anthropology and Social Sciences were the most frequent areas of research, especially in Africa. Latin America had more technical studies and more publications discussing payment for environmental services than the other regions. Based on the temporal analysis of the main terms in abstracts of the publications included, it was found that agriculture-related terms and terms related to the human component in the landscape were consistently prevalent in the literature relating reforestation and livelihoods throughout time. Agroforestry systems were especially important in small-scale reforestation and livelihoods. Trends, biases and gaps were discussed. Broader cooperation between tropical regions and between clusters of authors would be beneficial for research and practice. 相似文献
125.
Eyad Atalah Carmen María Hernández‐Cruz Eneko Ganuza Tibiabin Benítez‐Santana Rachid Ganga Javier Roo Daniel Montero Marisol Izquierdo 《Aquaculture Research》2011,42(9):1261-1268
Together with docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), arachidonic acid (ARA) is being considered to be an essential fatty acid in marine fish larval diets. The objective of the present study was to determine the importance of dietary ARA levels for larval European sea bass performance, when EPA and DHA are also present in the diet. Eighteen‐day‐old larvae were fed, for 14 days, gelatine‐based microdiets containing the following ARA levels: 0.3%, 0.6% or 1.2%. Elevation of dietary ARA up to 1.2% showed a positive correlation with larval survival and a significant improvement in the specific growth rates, body weight and total length. Arachidonic acid was efficiently incorporated into larval lipids, even at a higher proportion than that in the diets. Increased accumulation of ARA did not affect the incorporation of DHA or EPA from the diet into larval total lipids. A significant positive correlation was found between dietary ARA levels and survival after handling stress, indicating the importance of this fatty acid in sea bass larvae response to acute stressors. The results show the importance of ARA for sea bass larvae, but higher dietary levels should be tested to determine whether there is a negative effect of ARA in sea bass as reported for other species. 相似文献
126.
Characterization of extracellular products from an isolate of Vibrio harveyi recovered from diseased post-larval Penaeus vannamei (Bonne) 总被引:2,自引:0,他引:2
Vibrio harveyi recovered from diseased post-larval Penaeus vannamei produced a thermostable exotoxin, which was lethal to Dublin Bay prawns, Nephrops norvegicus L., when injected intramuscularly. The extracellular products (ECPs) concentrated from tryptone soya broth supplemented with 1% (w/v) sodium chloride or from cellophane overlays on marine 2216E agar with incubation at 15, 22 and 27 °C were toxic, with the lethal dose 50% of the crude ECPs estimated to be 4.4 μgprotein prawn−1. Proteolytic, haemolytic and cytotoxic activities were detected, although the occurrence and quantity of these activities were influenced by cultural conditions. The ECPs which had been heated (100 °C for 10 min) or digested with protease K produced the same pathology as crude, untreated ECPs. Western blotting demonstrated that all the ECP preparations contained low molecular weight lipopolysaccharides, which may constitute the lethal toxin of V. harveyi. 相似文献
127.
High-quality seedlings are a prerequisite for successful forestry and agroforestry expansion in developing countries. Unfortunately, in the central Philippines, as supplies of timber from native forest have diminished in recent years, the expansion in planting of timber trees has been retarded by sub-optimal production of seedlings from small-scale nurseries. To address this problem, an extension program supported by the Australian Centre for International Agricultural Research (ACIAR) has attempted to improve the quality of seedlings produced in home nurseries, by assisting smallholders to raise and out-plant seedlings. A complementary program undertaken as part of the Community Agricultural Technology Program (CATP) has attempted to provide community workers and managers of small-scale nurseries with the benefit of recent ACIAR nursery research. Extended assistance in the ACIAR program addressed smallholders’ low self-efficacy in nursery technology and was successful in assisting them to grow high quality seedlings. A limited program of assistance was relatively unsuccessful. Evaluation of the CATP program showed that prior to the training, CATP participants were unfamiliar with some aspects of basic nursery technology. Consequently, they may have been unable to provide competent advice to smallholders. This implies that—as with the ACIAR training—extended training and follow-up assistance may be the key to improving the quality of seedlings for forestry and agroforestry expansion in the central Philippines. 相似文献
128.
129.
Improving postharvest resistance in fruits by external application of trans-resveratrol 总被引:2,自引:0,他引:2
Gonzalez Ureña A Orea JM Montero C Jiménez JB González JL Sánchez A Dorado M 《Journal of agricultural and food chemistry》2003,51(1):82-89
As it is well-known, one of the main problems of modern agriculture is the postharvest fruit losses due to pathogen's attack and natural senescence during storage. Well established solutions to improve this situation, such as, for example, storage under controlled conditions and the use of synthetic pesticides, are not free of problems due to human health risks and environmental effects caused by chemical pesticides. A new strategy to solve these problems consists of developing methods to improve the natural plant resistance by using, upon their identification, the plant's own defense molecules, in other words, applying methods based on the plant's own natural processes of pest suppression to control spoilage. This requires the identification of components of the natural defense response in plants, which, in turn, demands highly sensitive, fast, and versatile analytical methods especially for trace, nonvolatile, compounds. In this work a laser-based technique has been applied for screening the postharvest elicitation of resveratrol by Botrytis cinerea in grapes. Besides antifungal character, resveratrol is known to present important antioxidant properties, which could also have positive effects on fruit conservation during storage. Consequently, several experiments were carried out in which exogenous application of resveratrol to several fruits maintained their postharvest quality. The quality of both resveratrol-treated and untreated fruits has been studied by the assessment of the biochemical composition and sensory analysis. Indeed, the present work demonstrates that the external application of resveratrol does not alter the sensorial and biochemical properties of the fruit. 相似文献
130.