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111.
Bioavailability of triazine herbicides in a sandy soil profile 总被引:1,自引:0,他引:1
Carsten S. Jacobsen Nir Shapir Lene O. Jensen Einar H. Jensen Réne K. Juhler Jens C. Streibig Ralphi T. Mandelbaum Arne Helweg 《Biology and Fertility of Soils》2001,33(6):501-506
The bioavailability of atrazine was evaluated in a Danish soil profile (Drengsted) using a combination of soil sorption, transport and mineralisation methods as well as inoculation using Pseudomonas ADP. Sorption of atrazine decreased markedly with depth as indicated by Kd values of 5.2 l kg-1 for the upper soil and 0.1 l kg-1 for the subsoils. The transport of atrazine was evaluated using soil TLC plates and the resulting Rf values were 0.1 for the upper soil and 0.9 for the subsoil. Only a relatively small amount of atrazine leached through undisturbed soil columns taken from the upper 60 cm. Inoculating with Pseudomonas strain ADP (1᎒6 CFU g-1 dry weight soil) revealed that the degradation of 0.01 ppm atrazine was fully completed (80% mineralisation) within 10 days in the subsoil, while it reached less than 15% in the upper soil. Over a period of 500 days, a total mineralisation of 37% of added atrazine in the upper soil was found (2 mg kg-1 incubated at 20° C). However, in the subsurface soil where 0.02 mg kg-1 of atrazine was incubated at 10°C, the degradation was slower, only reaching about 12%. Terbuthylazine mineralisation was found to be temperature-dependent and low (less than 5%) in the upper soil and very much lower in the subsoil. Desethylterbuthylazine was the most frequently found metabolite. Finally, Pseudomonas strain ADP inoculated into soils from different depths increased the mineralisation of terbuthylazine dramatically. Modelling using a "two-compartment model" indicated that desorption of terbuthylazine is the limiting step for its mineralisation. 相似文献
112.
Yanjun Xie Callum A. S. Hill Zefang Xiao Carsten Mai Holger Militz 《Wood Science and Technology》2011,45(1):49-61
The dynamic water vapour sorption properties of Scots pine (Pinus sylvestris L.) wood samples were studied to investigate the modifying effects of glutaraldehyde. Pine sapwood was treated with solutions
of glutaraldehyde and a catalyst (magnesium chloride) to obtain weight per cent gains of 0.5, 8.6, 15.5, and 21.0%, respectively.
The sorption behaviour of untreated and treated wood was measured using a Dynamic Vapour Sorption apparatus. The results showed
considerable reduction in equilibrium moisture content of wood and the corresponding equilibrium time at each target relative
humidity (RH) due to glutaraldehyde treatment. The moisture adsorption and desorption rates of modified and unmodified wood
were generally faster in the low RH range (up to approximate 20%) than in the high range. Modification primarily reduced the
adsorption and desorption rates over the high RH range of 20–95%. Glutaraldehyde modification resulted in a reduction in sorption
hysteresis due to the loss of elasticity of cell walls. 相似文献
113.
Jiang W Yun D Saleh L Barr EW Xing G Hoffart LM Maslak MA Krebs C Bollinger JM 《Science (New York, N.Y.)》2007,316(5828):1188-1191
In a conventional class I ribonucleotide reductase (RNR), a diiron(II/II) cofactor in the R2 subunit reacts with oxygen to produce a diiron(III/IV) intermediate, which generates a stable tyrosyl radical (Y*). The Y* reversibly oxidizes a cysteine residue in the R1 subunit to a cysteinyl radical (C*), which abstracts the 3'-hydrogen of the substrate to initiate its reduction. The RNR from Chlamydia trachomatis lacks the Y*, and it had been proposed that the diiron(III/IV) complex in R2 directly generates the C* in R1. By enzyme activity measurements and spectroscopic methods, we show that this RNR actually uses a previously unknown stable manganese(IV)/iron(III) cofactor for radical initiation. 相似文献
114.
Lisa G Hohmann Christina Weimann Carsten Scheper Georg Erhardt Sven Knig 《Journal of animal science》2020,98(10)
The objectives of this study were to investigate milk casein polymorphisms in dams and to determine the impacts of maternal casein genotypes on growth traits of their sucking calves. Milk samples from 433 dams of the breeds German Angus (GA) and German Simmental (GS) were typed at the milk protein loci α s1-casein (αs1-CN), β-casein (β-CN), α s2-casein (αs2-CN), and κ-casein (κ-CN) via isoelectric focusing. Associations between casein genotypes in maternal milk with growth traits of their 1,872 calves were analyzed until the age of weaning using linear mixed models, considering either genotypes of individual casein loci (model 1) or composite α s1-β-α s2-κ-CN genotypes within the casein cluster (model 2). Besides environmental effects such as sex, age of the dam, and calving year-season, genetic effects (breed group and maternal and paternal effects) were considered in statistical models. The composite casein genotype BBǀA2A2ǀAAǀAB (order of genes on bovine chromosome 6: α s1-ǀβ-ǀα s2-ǀκ-CN) was associated with greater average daily weight gains (ADG) and heavier age-adjusted weaning weights (WW) of calves (P < 0.05). The effects of composite genotypes on birth weight of calves were similar (P > 0.05; model 2). With regard to individual casein loci, greater ADG and WW were observed for calves from dams with the genotypes κ-CN BB and α s1-CN BB, respectively (P < 0.05; model 1). Age-adjusted WW was largest for calves from dams carrying the κ-CN genotype BB (215 kg) compared with calves representing the maternal AB and AA genotypes (both 204 kg). Results from the present study suggested selectable casein genotypes due to their nutritional value of milk (value in terms of offspring performances), offering new perspectives for breeding strategies in beef cattle to improve preweaning calf performance. 相似文献
115.
Nitzsche Kai Nils Kleeberg Andreas Hoffmann Carsten Merz Christoph Premke Katrin Gessler Arthur Sommer Michael Kayler Zachary E. 《Journal of Soils and Sediments》2022,22(3):994-1009
Journal of Soils and Sediments - Kettle holes are small inland water bodies known to be dominated by terrigenous material; however, the processes and structures that drive the enrichment and... 相似文献
116.
Andre Shih DVM DACVA Herbert W. Maisenbacher DVM DACVIM Carsten Bandt DVM DACVECC Carolina Ricco DVM MS DACVA James Bailey DVM DACVA Jess Rivera BS Amara Estrada DVM DACVIM 《Journal of Veterinary Emergency and Critical Care》2011,21(4):321-327
Objective – To determine if metatarsal artery pressure (COmet) is comparable to femoral artery pressure (COfem) as the input for transpulmonary pulse contour analysis (PiCCO) in anesthetized dogs, using the lithium dilution method (LiDCO) as a standard for cardiac output (CO) measurement. Design – Prospective randomized study. Setting – University research laboratory. Animals – Ten healthy purpose‐bred mixed breed dogs were anesthetized and instrumented to measure direct blood pressure, heart rate, arterial blood gases, and CO. Interventions – The CO was measured using LiDCO and PiCCO techniques. Animals had their right femoral and left distal metatarsal artery catheterized for proximal (COfem) and distal (COmet) PiCCO analysis, respectively. Measurements were obtained from each animal during low, normal, and high CO states by changing amount of inhalant anesthetics and heart rate. Measurements were converted to CO indexed to body weigh (CIBW=CO/kg) for statistical analysis. Agreement was determined using Bland and Altman analysis and concordance correlation coefficients. Measurements and Main Results – Thirty paired measurements were taken. The LiDCO CIBW (± SD) was 68.7 ± 30.3, 176.0 ± 53.0, and 211.1 ± 76.5 mL/kg/min during low, normal, and high CO states, respectively. There was a significant effect of CIBW state on bias and relative bias with COmet (P<0.001 and P=0.003, respectively). Bias of the COmet method (± SD) was ?116.6 (70.5), 20.1(76.4), and 91.3 (92.0) mL/kg/min at low, normal, and high CIBW, respectively. Bias of the COfem (± SD) was ?20.3 (19.0), 8.6 (70.9), and ?2.9 (83.0) mL/kg/min at low, normal, and high CIBW, respectively. The mean relative bias for COfem was ?6.7 ± 44% (limits of agreements: ?81.2 to 67.9%). Conclusion – Compared with lithium dilution, the pulse contour analysis provides a good estimation of CO, but requires femoral artery catheterization in anesthetized dogs. 相似文献
117.
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119.
Hogerheijde MR Bergin EA Brinch C Cleeves LI Fogel JK Blake GA Dominik C Lis DC Melnick G Neufeld D Panić O Pearson JC Kristensen L Yildiz UA van Dishoeck EF 《Science (New York, N.Y.)》2011,334(6054):338-340
Icy bodies may have delivered the oceans to the early Earth, yet little is known about water in the ice-dominated regions of extrasolar planet-forming disks. The Heterodyne Instrument for the Far-Infrared on board the Herschel Space Observatory has detected emission lines from both spin isomers of cold water vapor from the disk around the young star TW Hydrae. This water vapor likely originates from ice-coated solids near the disk surface, hinting at a water ice reservoir equivalent to several thousand Earth oceans in mass. The water's ortho-to-para ratio falls well below that of solar system comets, suggesting that comets contain heterogeneous ice mixtures collected across the entire solar nebula during the early stages of planetary birth. 相似文献
120.
A cognitive hierarchy framework was used for understanding the impact of two wildlife value orientations (WVO), domination and mutualism, on anti-angling sentiments in Germany. We also explored anthropomorphism (i.e., attribution of sentience and pain perception to animals), attitudes toward animal rights, and attitudes toward recreational and catch-and-release angling as constructs that might mediate the influence of WVO on the support for a ban on recreational angling. Data from 1,043 randomly selected persons were analyzed using structural equation modeling. Results supported the suitability of WVO to explain the moral acceptability of recreational fishing mediated by animal rights ideology. We found little effect of anthropomorphism on attitudes toward recreational fishing. We conclude that convincingly answering the question of whether or not fish feel pain is unlikely to alter the social climate related to recreational fishing. By contrast, an increase of mutualism WVO in Germany is likely to elevate negative resentment to recreational fishing. 相似文献