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Claire N. Lieske James H. Clark Howard G. Meyer John R. Lowe 《Pesticide biochemistry and physiology》1980,13(3):205-212
This paper constitutes the first report on the spontaneous reactivation of a cholinesterase following inhibition by an organophosphinate. The spontaneous reactivation of eel acetylcholinesterase following inhibition by p-nitrophenyl diphenylphosphinate (DPP), p-nitrophenyl methyl(phenyl)phosphinate (MPP), and p-nitrophenyl dimethylphosphinate (DMP) at 25.0°C in 0.10 M 3-(N-morpholino)propanesulfonic acid buffer of pH 7.60 reflected the following order of activity: MPP > DPP > DMP. Hydrolysis studies of the phosphinate esters under these conditions exhibited the same order of reactivity. Kinetic studies on the spontaneous reactivation of methyl(phenyl)phosphinylated eel acetylcholinesterase at pH 7.60 and pH 9.10 showed a 100% recovery of enzymatic activity, thus demonstrating the absence of aging. The absence of aging was further supported by oxime-induced reactivation studies. 相似文献
997.
The study reviews and discusses functional aspects of the so-called "acid mantle" of the integumentum commune of domesticated mammals and birds. The problems referred to are closely related to the skin surface-pH and different factors influencing this phenomenon (chemical composition of the skin surface film, secretory activity of apocrine tubular glands, structure of the microflora, lack of skin glands in birds). It becomes evident, that an "acid mantle" of the skin of domesticated animals cannot be verified, and that normal skin-pH (medium values weakly acid to alkaline) exerts no microbicidal effects. Integumental antimicrobial properties may rather be connected with free fatty acids as decomposition products of skin lipids. 相似文献
998.
Induced systemic resistance in Trichoderma harzianum T39 biocontrol of Botrytis cinerea 总被引:11,自引:0,他引:11
Geert De Meyer Joseph Bigirimana Yigal Elad Monica Höfte 《European journal of plant pathology / European Foundation for Plant Pathology》1998,104(3):279-286
Biocontrol of Botrytis cinerea with Trichoderma spp. is generally believed to result from direct interaction of the biocontrol agent with the pathogen or from a Trichoderma-induced change in environmental conditions that affects B. cinerea development. In this work we provide arguments for the participation of induced plant defence in T. harzianum T39 control of B. cinerea. In tomato, lettuce, pepper, bean and tobacco, T. harzianum T39 application at sites spatially separated from the B. cinerea inoculation resulted in a 25–100%percnt; reduction of grey mould symptoms, caused by a delay or suppression of spreading lesion formation. Given the spatial separation of both micro-organisms, this effect was attributed to the induction of systemic resistance by T. harzianum T39. The observation that in bean the effect of T. harzianum T39 was similar to that of the rhizobacterium Pseudomonas aeruginosa KMPCH, a reference strain for the induction of systemic resistance, confirmed this hypothesis. Since B. cinerea control on tobacco leaves sprayed with T. harzianum T39 was similar to the control on leaves from T. harzianum T39 soil-treated plants, induction of plant defence might also participate in biocontrol on treated leaves. 相似文献
999.
Evaluation of possible methods to reduce pain associated with electroejaculation in bulls. 总被引:3,自引:1,他引:2 下载免费PDF全文
W L Mosure R A Meyer J Gudmundson A D Barth 《The Canadian veterinary journal. La revue veterinaire canadienne》1998,39(8):504-506
Heart rate changes were recorded in attempt to objectively measure pain associated with 6 methods of semen collection, including transrectal massage, conventional electroejaculation, and electroejaculation after either intrarectal lidocaine, epidural lidocaine, epidural xylazine, or intravenous xylazine. Epidural anesthesia with lidocaine or xylazine tended to result in smaller heart rate changes. 相似文献
1000.
Habitat for wide-ranging species should be addressed at multiple scales to fully understand factors that limit populations.
The marbled murrelet (Brachyramphus marmoratus), a threatened seabird, forages on the ocean and nests inland in large trees. We developed statistical relationships between
murrelet use (occupancy and abundance) and habitat variables quantified across many spatial scales (statewide to local) and
two time periods in California and southern Oregon, USA. We also addressed (1) if old-growth forest fragmentation was negatively
associated with murrelet use, and (2) if some nesting areas are more important than others due to their proximity to high
quality marine habitat. Most landscapes used for nesting were restricted to low elevation areas with frequent fog. Birds were
most abundant in unfragmented old-growth forests located within a matrix of mature second-growth forest. Murrelets were less
likely to occupy old-growth habitat if it was isolated (> 5 km) from other nesting murrelets. We found a time lag in response
to fragmentation, where at least a few years were required before birds abandoned fragmented forests. Compared to landscapes
with little tono murrelet use, landscapes with many murrelets were closer to the ocean's bays, river mouths, sandy shores,
submarine canyons, and marine waters with consistently high primary productivity. Within local landscapes (≤ 800ha), inland
factors limited bird abundance, but at the broadest landscape scale studied (3200 ha), proximity to marine habitat was most
limiting. Management should focus on protecting or creating large, contiguous old-growth forest stands, especially in low-elevation
areas near productive marine habitat.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献