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431.
432.
Caroline Onfroy Alain Baranger Bernard Tivoli 《European journal of plant pathology / European Foundation for Plant Pathology》2007,119(1):13-27
The expression of partial resistance in pea to ascochyta blight (caused by Mycosphaerella pinodes) was studied in a detached stipule assay by quantifying two resistance components (fleck coalescence and lesion expansion)
using the method of point inoculation of stipules. Factors determining optimal conditions for the observation of partial resistance
are spore concentration, the age of the fungal culture prior to spore harvest and the pathogenicity of the isolate used for
testing. Partial resistance was not expressed when spore concentration was high or when the selected isolate was aggressive.
Furthermore, assessments of components of partial resistance were highly correlated with disease severity in a seedling test.
A screening protocol was developed based on inoculations of detached stipules to study partial resistance in pea. To simplify
the rating process, a more comprehensive disease rating scale which took into account fleck coalescence and lesion expansion
was tested by screening a large number of genotypes. 相似文献
433.
Benoît Moury Kahsay Gebre Selassie Georges Marchoux Anne-Marie Daubèze Alain Palloix 《European journal of plant pathology / European Foundation for Plant Pathology》1998,104(5):489-498
The tomato spotted wilt virus resistance in pepper conferred by the Tsw gene is less stable at 32 °C continuous temperature. Continuous high temperatures for at least nine days lead to systemic spread and necrotic symptoms in plants that are totally resistant at a lower temperature (22 °C). We show that continuous high temperatures destabilize this resistance in young plants, but older inoculated plants rarely develop systemic symptoms. Populations segregating for the Tsw gene showed that heterozygosity at the Tsw locus increased the chance of inoculated seedlings to develop systemic necrotic symptoms. Genetic background was less significantly involved in the thermosensitivity of the resistant response. As a consequence, it would be preferable to grow cultivars homozygous at the Tsw locus in high temperature conditions. 相似文献
434.
435.
Objective To evaluate the use and complications of a penetrating keratoprosthesis implantation in the management of corneal opacification in dogs. Methods A retrospective clinical study describes the indications for the surgical technique utilized and the outcomes of this procedure in 20 eyes of 19 dogs with blindness of corneal origin. A successful surgical outcome was defined as a clear keratoprosthesis optic and improvement or restoration of functional vision over a follow‐up period ranging from at least 8 months to a maximum of 7 years. Results Eyes with total corneal opacification resulting from chronic superficial keratitis (n = 11), keratoconjunctivitis sicca (n = 5), endothelial dystrophy (n = 3) and chemical burn (n = 1) were treated by unilateral (n = 18) or bilateral (n = 1) full‐thickness implantation of a keratoprosthesis. Keratoprostheses were retained in 15 eyes (75%) which regained vision to the date of reporting. Among these eyes, six had uncomplicated postoperative course, five developed retroprosthetic membranes and four developed granulation tissue over the optic of the keratoprostheses. These complications were successfully removed surgically in the nine eyes. The five remaining eyes (25%) developed serious early postoperative complications, for which enucleation had to be performed. Conclusion In keratopathies in which the corneal opacification could not be treated by standard medical or surgical procedures, this keratoprosthesis appears to be promising to restore vision in chronic superficial keratitis and deep corneal dystrophy. It appears to have a poor prognosis in keratoconjunctivitis sicca in brachycephalic dogs. The post operative complications retro‐prosthetic membranes and granulomatous overgrowth could be treated well. 相似文献
436.
Catherine Ky-Dembele Jules Bayala Antoine Kalinganire Fatoumata Tata Traoré Bréhima Koné Alain Olivier 《Southern Forests》2016,78(3):193-199
Pterocarpus santalinoides is a multipurpose tree species, native to Africa and South America. However, excessive pruning for fodder is jeopardising its seed production leading to poor regeneration in the Sahel region. Efficient vegetative propagation techniques may overcome this concern. To address this issue, four experiments were conducted to determine the effects of substrate (Experiment 1), cutting type (Experiments 2 and 3), genotype (Experiment 4) and auxins (Experiments 1, 2, and 4) on rooting ability in a non-mist propagating unit in Mali. Among the four tested substrates, no significant differences were found in rooting parameters, including the percentage of rooted cuttings, the number of roots and secondary roots per rooted cutting, and the length of the longest root per rooted cutting. Semi-hardwood cuttings rooted significantly better than softwood cuttings with a higher percentage of rooted cuttings (31.7?±?6.5% vs. 9.2?±?2.7%), greater number of roots (8.2?±?4.8 vs 1.5?±?0.7), greater number of secondary roots (16.7?±?4.2 vs 4.6?±?1.8) and longer root length (17.8?±?12.0?cm vs 2.3?±?1.0?cm) per rooted cutting. In addition, one-node cuttings cut below the second and third nodes, respectively, had the highest rooting success (88% and 90%, respectively) followed by cuttings cut below the fourth node (68%) and the first node (62%). Significant differences in the percentage of rooted cuttings were found among 12 randomly selected genotypes with rooting varying from 2% to 75%.The results also showed that auxin application, especially IBA, had a significant effect on rooting success, the number of roots and secondary roots per rooted cutting. Single-node cuttings, and cuttings of 10?cm length with multiple softwood and semi-hardwood nodes, can be used with or without auxin treatment for successful clonal propagation of P. santalinoides. The results of the present study indicated that P. santalinoides is amenable to clonal propagation using low-cost propagators and sand-based rooting media. 相似文献
437.
Philippe Abbal Jean-Marie Sablayrolles Éric Matzner-Lober Jean-Michel Boursiquot Cedric Baudrit Alain Carbonneau 《Journal of Agricultural, Biological & Environmental Statistics》2016,21(1):131-151
We propose here a decision support system for vine growers to assess the quality of a vineyard to be planted. The quality of a vineyard is defined by the probability of possible profitability of the wine sales he is able to produce. The model, based on a Bayesian network (BN), takes into account environment and the parameters defining vineyard status with their associated interactions. BN are widely used for knowledge representation and reasoning under uncertainty in natural resource management. There is a rising interest in BN as tools for ecological and agronomic modelling. Data were collected from knowledge of vine-growing experts. We developed a C# computer program predicting the likely quality of a vineyard. The model has been validated on existing vineyards with prediction ability around 75 %. This system should ease assessments of the likely impact of the choices and decisions of vine growers on the quality of new vineyards to be planted in any part of the world. No such model has been developed before for vine growers. 相似文献
438.
The plant minimal exchangeable K (EPl,min) defines the lower accessible limit of the most available pool of soil K to plants. It is also an index of long‐term K reserve in soils. However, its estimation by the classical method of exhaustion cropping is laborious. This study aimed at comparing EPl,min values obtained by the exhaustion cropping method with EPl,min values estimated by an alternative approach based on the cationic exchange capacity (CEC) of the infinitely high selective sites for K (i.e., always saturated with K) in the K‐Ca exchange (EK‐Ca,min). A set of 45 soil samples, corresponding to the various fertilization K treatments of 15 long‐term K fertilization trials, was used in this study. The selected soil samples presented a wide range of texture, CEC, and exchangeable K. The plant minimal exchangeable K was found more or less independent of the K treatment, whereas EK‐Ca,min increased when the soil exchangeable K content increased. The plant minimal exchangeable K was systematically lower than EK‐Ca,min, showing that EK‐Ca,min is at least partially available to the plant. Hence, EK‐Ca,min is not a surrogate of EPl,min. Conversely, the plant minimal exchangeable K was strongly, positively correlated to soil CEC (measured at soil pH; r2 = 0.90***). This soil property can consequently be used as a proxy of EPl,min. 相似文献
439.
Jean-Charles Bénézet Andréa Stanojlovic-Davidovic Anne BergeretLaurent Ferry Alain Crespy 《Industrial Crops and Products》2012,37(1):435-440
Biodegradable foams made from potato starch and natural fibres were obtained by extrusion. The effects of varying origins of these fibres on foam properties were studied, as well the relationships between their properties and the foam microstructure. The addition of fibres increased the expansion index and led to a significant reduction in water adsorption of starch foams, generally improving foam properties. The mechanical properties of the foams were affected by both relative humidity (RH) of storage and foam formulation. In general, as the RH increased, the foam strength decreased. The formulation presenting the best mechanical properties contained 10 wt% hemp fibre and had a maximal resistance of 4.14 MPa and a modulus of 228 MPa, corresponding to a more compact and dense microstructure. 相似文献
440.