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41.
The acaricidal activity of methanolic extracts from 40 oriental medicinal plant species and a steam distillate of Cinnamomum camphora towards poultry house-collected adult Dermanyssus gallinae De Geer was examined using direct contact and vapour phase toxicity bioassays. Results were compared with those of 15 acaricides currently used. In filter paper contact toxicity bioassays using adult D. gallinae, C. camphora steam distillate (0.0051 mgcm(-2)) was the most toxic material, followed by extracts from Asarum sieboldii var. seoulens whole plant, Eugenia caryophyllata flower bud and Mentha arvensis var. piperascens whole plant (0.0063-0.0072 mgcm(-2)), based upon 24h LD(50) values. The acaricidal activity of these four plant preparations was almost comparable to that of profenofos (LD(50), 0.003 mgcm(-2)) but less effective than dichlorvos (LD(50), 0.0004 mgcm(-2)). The toxicity of Illicium verum fruit and Lysimachia davurica leaf extracts (0.09 mgcm(-2)) was almost comparable to that of benfuracarb, prothiofos, propoxur and fenthion (0.053-0.070mgcm(-2)). In vapour phase toxicity tests, these plant preparations were more effective in closed containers than in open ones, indicating that the mode of delivery of these plant extracts was largely a result of action in the vapour phase. Plants described herein merit further study as potential D. gallinae control agents. 相似文献
42.
This study examined the expression of three isoforms of nitric oxide synthase (NOS) in the testes of pigs. Immunohistochemical studies demonstrated the presence of nNOS, eNOS and iNOS in interstitial cells, primary spermatocytes and spermatids. Positive immunoreactions for eNOS and iNOS were detected in peritubular myoid cells. Some vascular endothelial cells were positive for nNOS and eNOS. The expression of nitrotyrosine was detected in interstitial cells. In addition, the histochemical study revealed that all the interstitial cells were stained positively for NADPH-diaphorase, although some spermatids and vascular endothelial cells displayed moderate enzymatic activity. These findings suggest that three isoforms of NOS are expressed in the testis of pig and that they play important roles in the biology of interstitial cells that produce testosterone, as well as in spermatogenesis in the seminiferous tubules. 相似文献
43.
S H Chae I H Jeong D H Choi J W Oh Y J Ahn 《Journal of agricultural and food chemistry》1999,47(3):934-938
The growth-inhibiting activity of Coptis japonica (Makino) root-derived materials toward eight human intestinal bacteria was examined using an impregnated paper disk method and compared to that of four commercially available isoquinoline alkaloids [berberine sulfate (BS), berberine iodide (BI), palmatine chloride (PC), and palmatine sulfate(PS)], as well as that of Thea sinensis leaf-derived epigallocatechin gallate (EGCG). The biologically active constituents of the Coptis extract were characterized as the isoquinoline alkaloids berberine chloride (BC), palmatine iodide (PI), and coptisine chloride (CC) by spectral analysis. The growth responses varied with both chemical and bacterial strain used. In a test using 500 microg/disk, BC and PI produced a clear inhibitory effect against Bifidobacterium longum, Bifidobacterium bifidum, Clostridium perfringens, and Clostridium paraputrificum, whereas weak or no inhibition was observed in Bifidobacterium adolescentis, Lactobacillus acidophilus, Lactobacillus casei, and Escherichia coli. At 1000 microg/ disk, CC revealed weak or no growth inhibition toward all test bacteria, whereas EGCG exhibited weak growth inhibition against only C. perfringens and C. paraputrificum. Among various isoquinoline alkaloids, BC exhibited more potent inhibitory activity toward C. perfringens than BI and BS, whereas the inhibitory effect was more pronounced in PI compared to PC and PS. The Coptis root-derived materials did not promote growth of B. longum and C. perfringens. 相似文献
44.
Sang G. Lee Soon I. Kim Young J. Ahn Joon B. Kim Boum Y. Lee 《Pest management science》1997,49(2):119-124
The larvicidal component from sawdust of Thujopsis dolabrata var. hondai (Family Cupressaceae) against the pine needle gall midge (Thecodiplosis japonensis) was isolated by chromatographic techniques and characterized by spectral analysis as carvacrol. In a laboratory study using the impregnated filter paper method, carvacrol was more toxic to T. japonensis larvae than β-thujaplicine, cedrol, α-terpinol, thujone or thymol. In field studies with soil injections of carvacrol, this compound exhibited potent larvicidal activity, suggesting that this activity might be attributable to fumigant action. In a test with trunk implantation, a mixture of carvacrol and phosphamidon (0·15+0·15 ml cm-1 diameter at breast height) revealed much more potent larvicidal activity than phosphamidon alone (0·3 ml cm-1 DBH) in spite of little or no larvicidal activity of carvacrol alone (0·3 ml cm-1 DBH), indicating a possible synergistic effect. As a naturally occurring insecticide, carvacrol could be useful as a new preventive agent against damage caused by T. japonensis. © 1997 SCI. 相似文献
45.
Dong-Gyun Kim Yu-Ri Kim Eun-Young Kim Hyun Min Cho Sun-Hee Ahn In-Soo Kong 《Fisheries Science》2010,76(5):803-810
Vibrio anguillarum is a major pathogenic bacterium that causes vibriosis and septicemia in fish and shellfish. In this study, we identified the groESL genes, which encode bacterial chaperonins, from V. anguillarum. The groE gene cluster consisted of a 291-bp groES gene, a 69-bp intergenic spacer region, and a 1,635-bp groEL gene order. Sequence analysis with the groESL gene of Vibrio species exhibited that the groEL gene was more species-specific and suitable than the groES gene for V. anguillarum detection. Owing to the difficulty in distinguishing V. anguillarum from the closely related V. ordalii, we compared the sequences of groEL from V. anguillarum and the groEL homolog hsp60 from V. ordalii, in order to design a primer set based on a region dissimilar between the two. PCR with the groEL primer set produced a clear 195-bp amplicon in six serotypes of V. anguillarum, whereas 23 Vibrio species of 39 samples, including V. ordalii, and 10 species of enteric bacteria gave no bands. PCR using the groEL primers also amplified a unique product from V. anguillarum-infected flounder and oyster tissues. These results demonstrate that the groEL-target PCR assay is a sensitive and species-specific tool for the detection of V. anguillarum infection. 相似文献
46.
Although thermally conductive composites that can efficiently dissipate the heat generated from electronic devices are in high demand, most neat polymers used as matrix materials are problematic because they have poor thermal conductivities. The low thermal conductivity of polymeric materials is caused by structural defects; therefore, it can be improved by increasing the orientational regularity of the polymer chains. Here, main-chain liquid crystalline polymers (LCPs) were designed and synthesized to investigate the effects of liquid crystallinity-induced structural regularity on the thermal conductivity of the polymers. In addition, an in-situ polymerization method was devised for commercial applicability, and the thermal conductivity of the obtained polymer was compared to that of a conventionally polymerized polymer having the same structure. The designed polymers exhibited thermotropic liquid crystalline characteristics, and the polymer with longer spacers between the rigid segments showed relatively higher thermal conductivity exceeding 0.5 W·m-1· K-1 after sample preparation by injection molding. In addition, X-ray diffraction analysis revealed that the differences in the thermal conductivity, depending on the molding temperature during specimen preparation, were caused by variations in chain orientation within the same polymer. Based on the obtained results, it was concluded that LCPs are strong candidate matrix materials for thermally conductive composites; the suggested in-situ polymerization method could be applied practically to the polymerization of polyester-type LCPs. 相似文献
47.
Toxicity of Lavandula angustifolia oil constituents and spray formulations to insecticide‐susceptible and pyrethroid‐resistant Plutella xylostella and its endoparasitoid Cotesia glomerata 下载免费PDF全文
48.
Larvicidal activity of Magnolia denudata seed hydrodistillate constituents and related compounds and liquid formulations towards two susceptible and two wild mosquito species 下载免费PDF全文
49.
Carbon nanotube (CNT)/magnetite (Fe3O4) nanocomposites were successfully fabricated by nanocoating. When the CNT/Fe3O4 nanocomposites were added to a carbonyl (CI) based magnetorheological fluid (MRF), the magnetic rheological properties of
the MRF were enhanced. Such enhancement in magnetic rheological properties of the CI-CNT/Fe3O4 MRF is considered to be attributable to both the superparamagnetic property of the magnetic layer covering the CNT surface
and the high length to diameter ratio of the CNT/Fe3O4 nanocomposite. Impact properties for CI-CNT/Fe3O4 MRF treated Kevlar fabrics were also tested, and improved impact properties were observed with external magnetic fields compared
to CI-MRF treated Kevlar fabrics. 相似文献
50.
Moon-Young Kim Jae-Jun Ahn Kashif Akram Gui-Ran Kim Mi-Seon Jeong Ji-Young Kwak 《Journal Of Aquatic Food Product Technology》2013,22(3):299-306
ABSTRACTRadiation-specific luminescence properties in irradiated dried-fishery products (pollack, little pollack, clams, and shrimp) were investigated at different dose levels (0–10 kGy). Photostimulated luminescence (PSL) analysis of whole samples was effective for dried clams and shrimp, while low PSL sensitivity was observed in dried pollack and little pollack. Thermoluminescence (TL) analysis was conducted after isolation of silicate minerals, in which the two methods of mineral isolation—density separation and acid hydrolysis—were compared. Irradiated samples were easily distinguishable through the strong TL glow curves, with maximum peaks in temperature range of 150–250°C. TL ratios (TL1/TL2) were < 0.1 for nonirradiated samples, while > 0.1 for irradiated. There was a clear effect of applied irradiation dose, with a negligible effect of the method used for mineral separation. The mineral composition showed that feldspar and quartz minerals were mainly responsible for the well-characterized luminescence behavior upon irradiation. 相似文献