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71.
Genetic engineering of plant volatile terpenoids: effects on a herbivore,a predator and a parasitoid
Martine Kos Benyamin Houshyani Aart‐Jan Overeem Harro J Bouwmeester Berhane T Weldegergis Joop JA van Loon Marcel Dicke Louise EM Vet 《Pest management science》2013,69(2):302-311
BACKGROUND: Most insect‐resistant transgenic crops employ toxins to control pests. A novel approach is to enhance the effectiveness of natural enemies by genetic engineering of the biosynthesis of volatile organic compounds (VOCs). Before the commercialisation of such transgenic plants can be pursued, detailed fundamental studies of their effects on herbivores and their natural enemies are necessary. The linalool/nerolidol synthase gene FaNES1 was constitutively expressed from strawberry in three Arabidopsis thaliana accessions, and the behaviour of the aphid Brevicoryne brassicae L., the parasitoid Diaeretiella rapae McIntosh and the predator Episyrphus balteatus de Geer was studied. RESULTS: Transgenic FaNES1‐expressing plants emitted (E)‐nerolidol and larger amounts of (E)‐DMNT and linalool. Brevicoryne brassicae was repelled by the transgenic lines of two of the accessions, whereas its performance was not affected. Diaeretiella rapae preferred aphid‐infested transgenic plants over aphid‐infested wild‐type plants for two of the accessions. In contrast, female E. balteatus predators did not differentiate between aphid‐infested transgenic or wild‐type plants. CONCLUSION: The results indicate that the genetic engineering of plants to modify their emission of VOCs holds considerable promise for facilitating biological control of herbivores. Validation for crop plants is a necessary next step to assess the usefulness of modified volatile emission in integrated pest management. Copyright © 2012 Society of Chemical Industry 相似文献
72.
73.
Modifications of trout (Oncorhynchus mykiss) muscle proteins by preslaughter activity 总被引:2,自引:0,他引:2
Morzel M Chambon C Lefèvre F Paboeuf G Laville E 《Journal of agricultural and food chemistry》2006,54(8):2997-3001
The effect of two different preslaughter procedures (limited or 15-min intense muscular activity) on muscle trout proteins was investigated. Muscle was sampled 45 min and 24 h post-mortem, proteins were separated using two-dimensional electrophoresis, and spots of interest were tentatively identified by MALDI-TOF spectrometry. Twenty-nine and 4 spots were differentially represented between the two groups of fish at 45 min and 24 h post-mortem, respectively. Spots that could be identified corresponded mainly to proteins involved in energy-producing pathways (triosephosphate isomerase, enolase, pyruvate dehydrogenase) or to structural proteins (desmin, cap-Z, myosin heavy chain fragment). Persistent under-representation of desmin, a key cytoskeletal protein, in fish submitted to intense muscular activity suggests that such a preslaughter treatment can have an effect on post-mortem muscle integrity. 相似文献
74.
Mateus ML Rouvet M Gumy JC Liardon R 《Journal of agricultural and food chemistry》2007,55(8):2979-2984
Three complementary techniques were used in this study to investigate the physical changes during wetting of roasted and ground coffee. Scanning electron microscopy (SEM) was found to provide indirect evidence of the presence of liquid water in the coffee particles. The effect of wetting on coffee closed porosity was studied by helium pycnometry, and finally, particle sizing was used to determine the swelling kinetics of coffee after wetting. Due to the solubilization of compounds, the presence of liquid water could be detected in the coffee cells by SEM. The technique was then used to investigate different water contents; for example, for roasted and ground coffee containing 1 g of water per gram of coffee on a dry basis, liquid water was present in cells only at the periphery of approximately 1.0 mm diameter particles. Coffee closed porosity decreased with increasing water content, as evidenced by pycnometry. For roasted and ground coffee containing 1 g of water per gram of coffee, results showed a closed porosity lower that 0.1 cm3/g ( approximately 20% of the closed porosity measured in dry particles). The decrease of closed porosity may be attributed to both (1) water filling cells' lumen and (2) plasticization of cell wall polymers, resulting in the matrix relaxation and increase of helium accessibility to the pores. Water binding to the matrix polymers was further investigated by calorimetric measurements. The integration of the endothermic peak of freezing water showed that approximately 0.15 g of water/g of coffee is nonfreezable water, that is, water bound to the matrix polymers. Finally, the use of particle sizing showed that the average volume of the coffee particles with 1 g of water/g of coffee increased by up to 20-23% at 10-15 min following wetting. Moisture diffusion coefficients in coffee particles [( approximately 2-3) x 10(-11) m2 s(-1)] were approximated by fitting the swelling curves with a model of diffusion. The observed results may give information about homogeneity and the physical state of water in wetted roasted coffee and thus increase the understanding of the mechanisms of molecular mass transfer during extraction. 相似文献
75.
Effect of human activities on bearded vulture behaviour and breeding success in the French Pyrenees 总被引:1,自引:0,他引:1
The bearded vulture is a threatened species for which human disturbance has been suggested as an important factor potentially influencing breeding success. Additionally, disturbance remains one of the few factors that is possible to control through directed policy. We evaluated the effect of human activities on the behaviour and breeding success of bearded vultures breeding in the French Pyrenees. Human activities influenced bearded vulture behaviour (primarily through a decrease in nest attendance), but this effect varied in relation to the type of activities and the distance to the nest. Very noisy activities and hunting most frequently provoked nest unattendance even when occurring far (>1.5 km) from the nest. People on foot or cars/planes only affected bearded vulture behaviour if close (<500-700 m) to the nest. We also found a significant relationship between human activities and vulture breeding success: the probability of failure increased with the frequency of human activities. In particular, there was a significant relationship between the probability of failure and the frequency of very noisy activities. We discuss the implications of our results for management schemes and conservation of this species. 相似文献
76.
77.
Neudörffer A Bonnefont-Rousselot D Legrand A Fleury MB Largeron M 《Journal of agricultural and food chemistry》2004,52(7):2084-2091
The electrochemical oxidation potential of a series of monomeric and dimeric 4-hydroxycinnamic ethyl ester derivatives has been compared with their antioxidant activity toward copper-catalyzed human low-density lipoproteins (LDL) oxidation. Within the series of monomeric hydroxycinnamate derivatives, both oxidation potential and IC50 values decreased in the following order: sinapate > ferulate > p-coumarate. Among the 4-hydroxycinnamate dehydrodimer derivatives, noncyclized 8-8 diphenol dehydrodimers followed the same aforementioned sequence order and were found to be better antioxidants than their monomer counterparts. A good correlation between the inhibitory concentration and the oxidation potential was established among all these derivatives. However, a significantly deviating behavior was observed with the 8-5 dihydrobenzofuran and the 8-8 dihydronaphthol cyclic dehydrodimers, which showed lower activities toward copper-catalyzed human LDL, although their oxidation potentials remained very close to those of the noncyclized 8-8 dehydrodimers. Conversely, in the Trolox equivalent antioxidant capacity (TEAC) assay system, the 8-8 dihydronaphthol dehydrodimers were found to be the most efficient free-radical scavengers. Finally, in the series of dehydrodimers studied, it could be concluded that, whatever the in vitro test system used, (a) all dehydrodimer derivatives tested could contribute efficiently to the overall intake of antioxidants in the diet and (b) a low oxidation potential value was in favor of a satisfactory antioxidant activity. 相似文献
78.
Annelies Vercauteren Isabelle De Dobbelaere Erik Van Bockstaele Martine Maes Kurt Heungens 《European journal of plant pathology / European Foundation for Plant Pathology》2011,129(4):621-635
Phytophthora ramorum, a recently described North American and European pathogen, has three clonal lineages. The NA1 and NA2 lineages are found
in North American forests and nurseries, while the EU1 lineage appears mainly in European nurseries. P. ramorum is heterothallic, having two mating types A1 and A2. All NA1 and NA2 isolates are of A2 mating type. When first collected,
all EU1 isolates were of A1 mating type, with the exception of one A2 isolate collected in Belgium in 2002. Screening 410
other Belgian isolates for mating type revealed two additional EU1-A2 isolates collected in 2002 and 2003. PCR-RFLP, AFLP
and SSR markers were used to determine the nature of the mating type change. The three isolates show no indications of sexual
recombination or mitotic crossing over, indicating that mutation or mitotic gene conversion is the most likely explanation
for the mating type change. We compared the pathogenicity and sporulation characteristics of the EU1-A2 isolates to those
of EU1-A1 and NA1-A2 isolates on four host plants. Despite small differences in pathogenicity on some hosts, the EU1-A2 isolates
were similarly aggressive to each other and to the EU1-A1 isolates and more aggressive than the NA1-A2 isolates. Sporulation
characteristics were also comparable among EU1-A2 isolates and between EU1-A1 and EU1-A2 isolates, except for EU1-A2 isolate
BBA 26/02. The limited genotypic and phenotypic differences between EU1-A2 isolates probably evolved after the mating type
change, which may have occurred several years before the isolates were detected. There are strong indications that the EU1-A2
population has been eradicated from Belgium. 相似文献
79.
80.
The Cost of Off-Flavor 总被引:1,自引:0,他引:1
Carole R. Engle Gayle L. Pounds Martine van der Ploeg 《Journal of the World Aquaculture Society》1995,26(3):297-306
Off-flavor problems in farm-raised catfish Ictalurus punctatus increase production costs and pose inventory management problems for catfish farmers. Multiperiod mathematical programming techniques were used to test the effect of 16 different off-flavor scenarios on expected net returns above variable cost with and without cash flow restrictions. The patterns of off-flavor incidence had less effect on farm profits than whether or not fish are off-flavor during certain key months of the year. To be feasible, systems designed to purge off-flavor from catfish would need to cost less than $0.05 to $0.06/kg (if cash flow is not a consideration) or $0.04/kg to $0.25/ke (with cash flow considerations). 相似文献