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141.
Tomei PE Uncini Manganelli RE Flamini G Cioni PL Morelli I 《Journal of agricultural and food chemistry》2003,51(12):3614-3617
The essential oil obtained by hydrodistillation of the fresh aerial parts of Mentha microphylla C. Kock (Lamiaceae) collected on the Gennargentu Mountains (Sardinia, Italy) has been investigated by gas chromatography (GC) and GC/mass spectrometry (MS). The main constituents that resulted were pulegone (34.1%), piperitenone oxide (32.9%), and piperitenone (11.3%). The presence of small amounts of compounds such as ethyl hexanoate, 1-octen-3-ol, nonanal, and ethyl 2-methylbutanoate could justify the particular odorous profile of the plant, resembling the aroma of milk and other dairy products such as mozzarella. 相似文献
142.
Mondello L Casilli A Tranchida PQ Cicero L Dugo P Dugo G 《Journal of agricultural and food chemistry》2003,51(19):5602-5606
This investigation concerns the application of fast GC in the analysis of essential oils. These are complex matrixes that usually undergo GC separation with conventional methods involving long columns, slow programmed temperature rates, and consequently, a high cost in terms of time. Fast GC techniques are based on the use of narrow bore capillary columns that allow the achievement of high-speed separations on complex samples while maintaining excellent resolution. This work saw the application of two methods on five different citrus essential oils and the comparison of all the results obtained. 相似文献
143.
Di Cesare LF Forni E Viscardi D Nani RC 《Journal of agricultural and food chemistry》2003,51(12):3575-3581
Basil (Ocimum basilicum L.) leaves were dried using a microwave oven at atmospheric pressure or two traditional methods: air-drying at 50 degrees C and freeze-drying. The microwave-drying was carried out at different powers and times on raw basil leaves, while for air and freeze-drying techniques, both raw and blanched leaves were used. The raw and dried basil was analyzed for selected aroma compounds by gas chromatography/mass spectrometry-selected-ion-monitoring, the chlorophyll a and b by HPLC and the color by a reflected-light colorimeter. For dried samples microwaved for 1 min at 270, 2 min at 440, 1 min at 650, and 1 min at 1100 W, the percentage retentions of the characteristic volatile compounds (eucalyptol, linalool, eugenol, and methyl eugenol) were higher than in the samples dried by traditional methods, with the exception of freeze-dried unblenched basil. Microwave drying allowed a larger retention of chlorophyll pigments than air-drying and freeze-drying (with or without blanching) and preserved the color of the raw basil. Microwave drying requires a much shorter treatment and implied the simultaneous blanching of the material. 相似文献
144.
In the last 40 years, Italy has seen important changes: human pressure is increasing in flat and coastal areas while internal mountainous areas are being abandoned and naturally reforested. These changes have substantial impacts on the biodiversity of the region but no conservation strategy has ever explicitly considered them, and no systematic assessment of the existing protected areas has been carried out. We used a combination of distribution models and extents of occurrence to perform a gap analysis and an irreplaceability analysis. We evaluated the effectiveness of the protected areas for the conservation of terrestrial vertebrates, and we identified regions, species, and strategies that appear to be priorities for expanding and consolidating the existing network. The existing protected areas cannot be considered fully representative, and this is especially true for Sardinia where many of the gap species are located. The Alps and the Apennines represent the strongholds of species diversity, but most of the species of conservation interest are concentrated in the Mediterranean part of the peninsula, as well as in small areas of the plains, where human pressure is higher. Biodiversity and human presence are functionally linked through traditional agriculture and pasture and the only option for conservation is that of considering human presence and activities as an integral part of the system. In a human dominated landscape, protected areas must be planned and managed in conjunction with the matrix in which they are embedded and in the context of the environmental history of the region. 相似文献
145.
The depletion of oxygen and the use of high energy cost electron acceptors for mineralisation processes are considered as one of the main reasons limiting degradation rates in aquatic organic-rich ecosystems. In this research the effect of two different biostimulation oxygen-releasing protocols were investigated using extracellular β-glucosidase activity rates. Organic-rich sediment and water was collected from the harbour of Genoa (Italy, North-Western Mediterranean) and oxygenation was generated either by positioning air tubes into the overlying water, or by placing oxygen release compounds (ORC) directly into the sediment, in laboratory microcosms. The increase in enzymatic activity was significant in the water compartment of the oxygenated microcosms (ANOVA, p<0.05) and greater for the ORC treatment. In particular, in the water, air tubes caused an increase in the β-glucosidase activity during the first 24 h (from 18.1 nmol l−1 h−1 (T=0, before the treatment) to 50.9 nmol l−1 h−1 (T=24 h)), while ORC induced a β-glucosidase activity increase over the whole period (from 12.4 nmol l−1 h−1 (T=0) to 63.7 nmol l−1 h−1 (T=60 d)) together with a reduction in carbohydrate (from 1.91 mg l−1 (T=0) to 0.76 mg l−1 (T=60 d)) and a sedimentary pH increase (from 8.04 (T=0) to 8.22 (T=60 d)). The response to ORC treatment in the overlying water was also evident in the potential carbohydrate turnover rate, decreasing from 0.86 h (T=0) to 0.06 h (T=60 d) and cell specific enzymatic activity, increasing from 3.8 (T=0) to 22.8 nmol l−1 h−1 cell−1 (T=60 d). A less marked change was observed in the sediment.This research shows that the supply of oxygen directly into the sediment rather than water aeration is a better way of naturally enhancing enzymatic degradation rates in organic-rich marine ecosystems. The marked effect observed in the water following the sediment treatment suggests the occurring of a close association of decomposition processes within water and sediment compartments. 相似文献
146.
Fuzzi Sandro Orsi Giordano Bonforte Giuseppe Zardini Bruno Franchini Pier Luigi 《Water, air, and soil pollution》1997,93(1-4):383-394
The study of fog water chemical composition and the contribution of fog droplets to total chemical deposition has become a relevant environmental subject over the past few years. This paper describes a fog water collector suitable for deposition network operation, due to its complete automation and to the facility of remote acquisition of sampling information. Sampling of fog droplets on teflon strings is activated by an optical fog detector according to a particular protocol operated by a microprocessor controller. Multiple sample collection, also microprocessor controlled, is possible with this instrument. The problem of fog droplet sampling in sub-freezing conditions is overcome using a sampling schedule implemented by the microprocessor controller which alternates between sampling periods and stand-by periods during which melting of the rime collected on the strings is allowed. Field tests on the reliability and reproducibility of the sampling operations are presented in the paper. Side by side operation of the fog collector with a PVM-100 fog liquid water content meter shows that the amount of water per unit volume of air collected by the sampling instrument is proportional to the fog liquid water content averaged over the period of an entire fog event. 相似文献
147.
BACKGROUND: The correlation between pesticide residue levels and formulation of an active substance is often not considered, even if it is reasonable to expect some differences arising from behaviour during dilution and spraying, from adhesion to plant and from degradation. An experimental study to investigate the magnitude of tebuconazole residues as a function of different tebuconazole formulated products was carried out in Italy. The fungicide was applied as wettable powder (WP) and water‐dispersible granule (WG) formulations to peach, plum, apricot and nectarine orchards, on four different sites. The fruit samples gained from the field trials were quantitatively analysed by gas chromatography with a nitrogen phosphorus detector (GC/NPD) for tebuconazole residues. RESULTS: Tebuconazole residues in the fruits gained from the plot treated with the WP formulation, 14 days after application, were in the range 0.01–0.07 mg kg?1, while corresponding residues in the plot treated with the WG formulation were in the range 0.01–0.06 mg kg?1. CONCLUSION: No significant differences in the residue levels of tebuconazole could be observed between the trials conducted with the WP and the WG formulation. Copyright © 2009 Society of Chemical Industry 相似文献
148.
Giuseppe Firrao Luigi Carraro Emanuela Gobbi Romano Locci 《European journal of plant pathology / European Foundation for Plant Pathology》1996,102(9):817-822
Red clover (Trifolium pratense) and Ladino clover (Trifolium repens) plants showing phytoplasma-associated symptoms (yellowing/reddening, virescence and phyllody) have been recovered in Friuli-Venezia Giulia, Italy. Using AluI RFLP analysis of PCR amplified 16S rDNA we showed that the disease can be caused independently by two phylogenetically distinct phytoplasmas. One of them showed the very typical 16S rDNA RFLP pattern of the agent of Clover Phyllody in Canada (CCPh). The 16S rDNA of the other phytoplasma (Italian Clover Phyllody phytoplasma, ICPhp) has been PCR amplified, cloned and sequenced. The sequence revealed high similarity (>98%) with phytoplasmas belonging to the X disease cluster, which includes organisms not reported to cause phyllody on their hosts. The analysis by AluI RFLP of the PCR amplified pathogen 16S rDNA from other herbaceous plants (Crepis biennis, Taraxacum officinale, Leucanthemum vulgare) collected nearby with phytoplasma-associated symptoms showed similar patterns. Southern blot hybridization of their EcoRI digested total DNA revealed identical RFLP patterns, suggesting that the causative agent may be the same organism.Abbreviations PCR
Polymerase Chain Reaction
- rDNA
gene for the small subunit ribosomal RNA
- RFLP
Restriction Fragment Length Polymorphism 相似文献
149.
Manna L Reale S Viola E Vitale F Foglia Manzillo V Pavone LM Michele PL Caracappa S Gravino AE 《Veterinary parasitology》2006,142(3-4):271-280
The factors responsible for the clinical progress of visceral leishmaniasis (VL) in dogs have not been yet established. The starting hypothesis was the possibility of associating the changing level of a specific type of cytokines with the evolution of the infection towards infection-manifested disease or resistant behaviour. For this purpose the authors have established a connection between Leishmania load, cytokine mRNA accumulation, and the progression of the disease in naturally infected asymptomatic dogs. We made use of real-time (RT) PCR system to detect the expression of cytokine mRNA levels during all the phases of the infection. In particular, we measured the amount of parasites in samples such as blood, lymph nodes and skin, and the expression levels of IFN-gamma, IL-2, IL-4, IL-10, IL-12 and IL-18 cytokines in the blood. We employed different targeted real-time PCR assay on 40 naturally infected dogs, initially asymptomatic; 20 of these progressed to overt disease, and the 20 remaining dogs remained asymptomatic throughout the period of study (2 years). Two other groups included: 20 naturally infected dogs with clinical signs of VL, and 20 healthy dogs living in a non-endemic area. All these animals were employed as positive and negative controls, respectively. The overall results obtained demonstrate that the simultaneous evaluation of parasites and cytokine levels represents a reliable tool for predicting disease development, and thus for choosing the best treatment for the asymptomatic form of the disease. 相似文献
150.
Cardoso D Guerra FF Peiró JR Perri SH Nogueira GP 《Canadian journal of veterinary research》2011,75(3):237-240
Changes in luteinizing hormone (LH) secretion after 17β-estradiol (E(2)) injection were evaluated during sexual maturation in 10 prepubertal Nelore heifers. Heifers were divided into 2 groups: intact (I) and ovariectomized (OVX). 17β-estradiol (2 μg/kg) was administered to both groups at 10, 13, and 17 mo of age. Only at 10 mo of age was there a greater mean LH concentration in OVX heifers (1.33 ± 0.29 ng/mL) compared with the I group (0.57 ± 0.15 ng/mL). At 13 and 17 mo of age there was no significant difference between the 2 groups in any of the evaluated variables (number of peaks, total peak area, greatest peak area, and time to greatest peak occurrence). This suggests a decrease in negative E(2) feedback associated with an increase in positive feedback to LH secretion during sexual maturation, and these were likely the key factors that determined the time of first ovulation in Nelore heifers. 相似文献