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81.
We evaluated the applicability of a simple passive sampling method to quantify HNO3(g) in ambient air. The method has the advantages of not only ease of operation but also low cost. A sampling velocity of 214 m day?1 was determined based on the concentration of HNO3(g) measured by the four-stage filter-pack method at nine sites located within a 250?×?250-km area in Japan. This sampling velocity was applied at sites located outside of area to verify the applicability and accuracy of the simple passive sampling method. The variation in the results for the application of the sampling velocity ranged from 0.39 to 0.95. The simple passive sampling method should be applied to sites with different meteorological conditions, and the obtained data should be used to obtain more significant information and/or to indicate the need for further developments in the methodology.  相似文献   
82.
83.
The optical isomers, (R)-1(α-methylbenzyl)-3-p-tolylurea ((R)-MBU) and (S)-1-(α-methylbenzyl)-3-p-tolylurea ((S)MBU), which are analogues of daimuron [1-(α,α-dimethylbenzyl)-3-p-tolylurea], a herbicide for Cyperaceae weeds and a safener for paddy rice, exhibited different biological responses. These two physiological properties of daimuron were observed separately in (R)-MBU and (S)-MBU. Only (R)-MBU had herbicidal activity against Cyperaceae weeds, while the (S)-isomer was a more effective safener against bensulfuron-methyl (BSM) injury of rice seedlings than was (R)-MBU. (S)-MBU promoted root growth of rice seedlings, but the (R)-enantiomer inhibited root growth. (S)-MBU was a more potent inhibitor than (R)-MBU on PS II reaction of spinach broken chloroplasts. Furthermore, (S)-MBU and (R)-MBU showed cross intergenus selective phytotoxicity among the Gramineae plants, Oryza sativa L. (rice, cv. Tsukinohikari, japonica), Triticum aestivum L. (wheat, cv. Norin No. 61) and Echinochloa crusgalli var. frumentacea Wight, on root growth inhibition in the dark.  相似文献   
84.
OBJECTIVE: To determine the role of platelet activating factor (PAF) in lipopolysaccharide (LPS)-induced thrombocytopenia and neutropenia in dogs. ANIMALS: 42 dogs. PROCEDURES: Blood samples were obtained from dogs given LPS (40 microg/kg of body weight; n = 16), PAF (1 microg/kg; 6), PAF (5 microg/kg/h for 90 minutes; 4), or physiologic saline (0.9% NaCl) solution (0.1 ml/kg/h for 90 minutes; 3) IV to monitor changes in blood cell counts, using automated counters and blood smears stained with Giemsa. Blood samples were also obtained from dogs given LPS (40 microg/kg) that had (n = 5) or had not (6) been treated beforehand with TCV-309, a potent PAF antagonist. Concentration of PAF in blood was determined by use of 125I-radioimmunoassay in dogs given LPS at 1 mg/kg (n = 3) and 40 microg/kg (9). RESULTS: Thrombocytopenia and neutropenia were found in all dogs except those given saline solution. The LPS-induced thrombocytopenia was significantly suppressed by prior treatment with TCV-309. The PAF concentrations increased markedly 1 hour after injection of 1 mg/kg of LPS and increased slightly but significantly 10 minutes after injection of 40 microg/kg of LPS. CONCLUSION AND CLINICAL RELEVANCE: PAF plays an important role in the development of LPS-induced thrombocytopenia and neutropenia in dogs. Control of PAF production, PAF-induced effects, or both may be important in the treatment of dogs with gram-negative bacterial infections and associated thrombocytopenia and neutropenia.  相似文献   
85.
Leaves of tomato and barley were inoculated with conidia of Blumeria graminis f. sp. hordei race 1 (R1) or Oidium neolycopersici (KTP-01) to observe cytological responses in search of resistance to powdery mildew. Both conidia formed appressoria at similar rates on tomato or barley leaves, indicating that no resistance was expressed during the prepenetration stage of these fungi. On R1-inoculated tomato leaves, appressoria penetrated the papillae, but subsequent haustorium formation was inhibited by hypersensitive necrosis in the invaded epidermal cells. On the other hand, KTP-01 (pathogenic to tomato leaves) successfully developed functional haustoria in epidermal cells to elongate secondary hyphae, although the hyphal elongation from some conidia was later suppressed by delayed hypersensitive necrosis in some haustorium-harboring epidermal cells. Thus, the present study indicated that the resistance of tomato to powdery mildew fungi was associated with a hypersensitive response in invaded epidermal cells but not the prevention of fungal penetration through host papilla.  相似文献   
86.
Conidiogenesis by Oidium neolycopersici KTP-01 on tomato leaves was vitally monitored with a high-fidelity digital microscope. Conidiophores were initially formed 3 days after inoculation and then elongated to a maximum length within at least 12h. The apical part was split into two cells after two successive septations, accompanied by apical expansion. These cells subsequently developed into primary and secondary conidia. An additional septation at the stem portion of the conidiophores produced a generative and a foot cell. Subsequent conidiation occurred during repeated cycles of splitting of the generative cell, maturation of the apical cell into a conidium, and abstriction of the conidium. To our knowledge, this report is the first on the developmental process of conidiogenesis by powdery mildew on host leaves as revealed with the digital microscope.  相似文献   
87.
88.
A comparison of the expression of surface membrane antigens between dendritic cells (DC) derived from Peyer's patch macrophages (DPP-DC) of non-infected and Toxoplasma gondii (T. gondii) infected mice was performed. C57BL/6J mice aged 6-8 weeks of both sexes were infected orally with a 0.5 ml suspension containing 2 x 10(4) bradyzoites of the Beverley strain of T. gondii, sacrificed on day 8 and DC generated using discrete Peyer's patch macrophages (DPP-M?) as progenitor cells. When a comparison of the expression of surface membrane antigens between the antigen presenting cells (APC) obtained from discrete Peyer's patches of non-infected and T. gondii infected mice was carried out, no significant differences were observed in the macrophage progenitor and DC populations expression of F4/80, DEC-205, CD11c, CD80 (B7-1) and CD34. However, a significant decrease in MHC class II antigen levels and a down regulation of the co-stimulatory molecule CD86 (B7-2) were noted. B7-1 appeared to be the dominant co-stimulatory ligand, whereas B7-2, which was down regulated during T. gondii infection, had a weak expression. Taken together, these results may help clarify the role of DC in the complex network regulating surface membrane antigens, as well as, their capacity for antigen uptake, processing and presentation during toxoplasmosis.  相似文献   
89.
FS-L3 cells, originating from porcine kidney, were used for propagation of Hemagglutinating encephalomyelitis virus (HEV) and development of a virus neutralizing (VN) test. Sera of pigs, rats, cows and dogs had VN activities to HEV. On the other hand, sera of mice, rabbits, goats, sheep, horses, cats, chickens, hamsters and human did not have measurable VN activities, although these sera had high HI activities. Our results support the idea that the VN is a more reliable measure of HEV infection than the conventionally used HI test.  相似文献   
90.
The infectivity of a Japanese isolate of tomato powdery mildew, Oidium neolycopersici KTP-01, to tomato cultivars was examined using a resistant cultivar Grace bred in The Netherlands to O. lycopersici, which was recently proposed to be renamed O. neolycopersici. Grace was severely infected with KTP-01, and its susceptibility was similar to that on susceptible tomato cultivars Moneymaker and Ponderosa, suggesting that KTP-01 differs in pathogenicity on tomatoes from those of European and American isolates.  相似文献   
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