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Mendelson JR Lips KR Gagliardo RW Rabb GB Collins JP Diffendorfer JE Daszak P Ibáñez D R Zippel KC Lawson DP Wright KM Stuart SN Gascon C da Silva HR Burrowes PA Joglar RL La Marca E Lötters S du Preez LH Weldon C Hyatt A Rodriguez-Mahecha JV Hunt S Robertson H Lock B Raxworthy CJ Frost DR Lacy RC Alford RA Campbell JA Parra-Olea G Bolaños F Domingo JJ Halliday T Murphy JB Wake MH Coloma LA Kuzmin SL Price MS Howell KM Lau M Pethiyagoda R Boone M Lannoo MJ Blaustein AR Dobson A Griffiths RA 《Science (New York, N.Y.)》2006,313(5783):48
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Oxley DR Smith KB Alford JR Hibbing MV Miller JL Scalora M Hatemi PK Hibbing JR 《Science (New York, N.Y.)》2008,321(5896):1667-1670
Although political views have been thought to arise largely from individuals' experiences, recent research suggests that they may have a biological basis. We present evidence that variations in political attitudes correlate with physiological traits. In a group of 46 adult participants with strong political beliefs, individuals with measurably lower physical sensitivities to sudden noises and threatening visual images were more likely to support foreign aid, liberal immigration policies, pacifism, and gun control, whereas individuals displaying measurably higher physiological reactions to those same stimuli were more likely to favor defense spending, capital punishment, patriotism, and the Iraq War. Thus, the degree to which individuals are physiologically responsive to threat appears to indicate the degree to which they advocate policies that protect the existing social structure from both external (outgroup) and internal (norm-violator) threats. 相似文献
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In many forested wetlands of Louisiana, surface water quality is being deteriorated by nutrient input from adjacent agricultural production areas. This field study assesses the input of fertilizer N, applied to sugarcane fields, to forested wetlands. The potential use of natural abundance variations in 15N14N ratios for identification and tracing surface water N sources (NH 4 + - and NO3 --N) was evaluated. Runoff and surface water samples were collected from sugarcane fields and bordering forested wetlands (6 stations) over a 16 month period and analyzed for NH 4 + -N, NO 3 - -N, and associated NH 4 + -δ15N and NO 3 - -δ15N ratios. Fertilizer N draining into adjacent forested wetland was estimated to be only a small fraction of the amount applied. Concentrations of NH 4 + - and NO 3 - -N in the collected water samples were low and ranged from 0.02 to 1.79 mg L-1. Isotopic analysis revealed NH 4 + -δ15N and NO 3 - -δ15N means were distinctive and may have the potential to be used as tracers of N contamination. The mean NH 4 + -δ15N value was +18.6 ± 7.1‰ and the NO 3 - -δ15N mean was +8.3 ± 3.1‰. Anomalously high NO 3 - -δ15N values (>30‰) were attributed to denitrification. 相似文献
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Allelopathy as a mechanism of invasion in plant communities remains a debated topic, partly due to lack of techniques to measure allelochemical output and stability in the field. Evidence has arisen to support allelopathic mechanisms in several invasive knapweeds, including Russian knapweed. Previous studies have shown that a phytotoxin, 7,8-benzoflavone, is produced by Russian knapweed roots under soil-free conditions. Here we describe a high performance liquid chromatography (HPLC) method to detect this compound in soil and we present the first observations of this compound from Russian knapweed infested soils. 相似文献
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Donald Bergeron Rodney J. Bushway Richard H. Storch A. Randall Alford Alfred A. Bushway 《American Journal of Potato Research》1988,65(2):67-74
An enzyme which hydrolyzed a terminal rhamnose moiety from α-chaconine was extracted and partially purified from Colorado potato beetle (CPB) (Leptinotarsa decemlineata) larvae. This ammonium sulfate precipitated enzyme fraction resulted in nearly 97% metabolism of α-chaconine after a 144 hour incubation period at 42 C as determined by high performance liquid Chromatographic (HPLC) analysis. Approximately 81% of the metabolized α-chaconine was detected asβ 2-chaconine. The isolated enzyme fraction from CPB larvae exhibited no metabolism of α-solanine. Metabolism was also followed over time by thin layer chromatography (tlc). 相似文献
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