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131.
Silke Dachbrodt-Saaydeh 《Gesunde Pflanzen》2018,70(3):147-153
The reduction of risks associated with plant protection products is the main goal of the National Action Plan on sustainable use of plant protection products. One further goal is the use of plant protection products according to the necessary minimum. This aim serves also as an indicator with the target that 95% of pesticide applications are within the necessary minimum. For this purpose, the data from the Reference Farm Network on the intensity of pesticide use are assessed. With the current study we summarize the result for arable crops over the ten-year project period and investigate in detail the assessments from 2014 until 2016. The results show, that the majority of pesticide treatments are evaluated within the necessary minimum. Deviations occur especially for fungicide and insecticide treatments. Other factors, such as regional weather and pest or disease occurrence, production specific factors as well as farmers’ decision processes additionally influence the annual pesticide use intensity and the necessary minimum. Existing technologies, decision support systems and recommendations from advisory service should be better exploited in order to minimize those deviations. 相似文献
132.
Inversion of a canopy reflectance model using hyperspectral imagery for monitoring wheat growth and estimating yield 总被引:2,自引:0,他引:2
Silke Migdall Heike Bach Jans Bobert Marc Wehrhan Wolfram Mauser 《Precision Agriculture》2009,10(6):508-524
Applications of hyperspectral remote sensing data to derive relevant properties for precision agriculture are described. Green
leaf area index, fraction of senescent material and grain yield are retrieved from the hyperspectral data. Two sensors were
used to obtain these data; the airborne visible/infrared imaging spectrometer AVIS and the space-borne compact high-resolution
imaging spectrometer CHRIS; they show the applicability of the methods to different spatial scales. In addition, the bi-directional
observation capability of the CHRIS sensor is used to derive information about the average leaf angle of the canopies which
are used to link canopy structure with phenological development. Derivation of the canopy properties, green leaf area index
and fraction of senescent material was done with the radiative transfer model, SLC (soil–leaf–canopy). The results were used
as input into the crop growth model PROMET-V to calculate grain yield. Two years of data from the German research project
preagro are presented. 相似文献
133.
Wolfgang Merbach Edith Mirus Günther Knof Rainer Remus Silke Ruppel Rolf Russow Andreas Gransee Joachim Schulze 《植物养料与土壤学杂志》1999,162(4):373-383
The root-borne C- and N-flux in the plant/soil system was studied by determining the 14C- or 15N-balances in pot trials with soil as a substrate (14CO2- or 15NH3-application to the shoots, comparison of sterile and nonsterile treatments for quantification of root-borne substances). The following results were obtained: 1. The amount of (primary) root-borne carbon compounds released into soil was (besides root respiration) 11—20% of net-CO2-assimilation or 13—32% of the 14C incorporated into the plants (= 1 t C · ha—1). 5—6% of 15N assimilated by the plants were released as root-borne N compounds (= 15 kg N · ha—1). 2. A considerable portion of the root-borne C (about 6% = 600 kg C · ha—1) was found in the rooted soil zone at the end of the experiments (rhizodeposition). 3. (Primary) root-borne C and N compounds found in immediate vicinity of the roots (about 60—80%) were mainly water soluble, whereas most of the C and N compounds found in a greater distance were water insoluble. The water soluble exudates consisted mainly of neutral (carbohydrates) and acid fractions (organic acids). The basic fraction (amino acids) made up a small portion only. 4. The root-borne C and N compounds influenced the nutrient balance of soil and plant directly and/or indirectly via microbes (depending on species, variety and nutritional status of plants). 5. Microbes stimulated the release of C- and N-compounds, but rapidly respired 65—85% of the root-borne C-compounds, thereby putting a burden on the C-budget of the “host” plant. 6. It could be shown by the example of hup+ Rhizobium meliloti strains (tested by 3H2-incorporation) and the wheat-Serratia-association, that energy efficient microbenplant systems can improve plant performance. 相似文献
134.
Steffi Fritsche Xingxing Wang Lars Nichelmann Ida Suppanz Silke Hadenfeldt Jessica Endrigkeit Jinling Meng Christian Jung 《Plant Breeding》2014,133(4):470-479
Brassica napus L. is one of the most important oilseed crops in the world. Improving oil quality by increasing vitamin E content is a major target of rapeseed breeding. Vitamin E compounds, or tocopherols, are lipid‐soluble antioxidants that are essential nutrients for mammals. In this study, we report the characterization of rapeseed orthologs of the Arabidopsis tocopherol genes VTE1, VTE2 and PDS1. For each gene, at least two homologous sequences were found, and their expression was analysed in different tissues from three rapeseed genotypes. Genetic complementation experiments demonstrated that BnaX.VTE1.b and BnaA.VTE2.b homologs are capable of recovering seed γ‐tocopherol in Arabidopsis mutants. Overexpression of the genes in Arabidopsis Col‐0 shifted the seed tocopherol composition towards higher α‐tocopherol without increasing the total tocopherol content. To address the functionality of BnPDS1 sequences, we performed overexpression tests in Escherichia coli and enzymatic activity analyses. Overall, our results show that the identified sequences from rapeseed are functional orthologs of the Arabidopsis VTE genes and thus have considerable potential as molecular markers for selecting rapeseed with improved seed oil quality. 相似文献
135.
Hatchery cultivation of the common cockle (Cerastoderma edule L.): from conditioning to grow‐out
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Anna Elisabeth Pronker Frank Peene Silke Donner Sander Wijnhoven Pieter Geijsen Peter Bossier Nancy Marie Nevejan 《Aquaculture Research》2015,46(2):302-312
This study describes for the first time the cultivation of Cerastoderma edule on a commercial scale. A protocol to grow F2 generation cockles was developed, which led to fine‐tuning experiments for broodstock conditioning and spat growth. Broodstock animals were conditioned with diets of Isochrysis galbana (T‐Iso) or Tetraselmis suecica, whereas a third group was not fed. The best diet, T. suecica, induced 12 females out of 100 animals to spawn a total of 3 380 000 eggs. The non‐fed group did not spawn. Cockle spat (4.9 ± 1.0 mm) grew best when given a mixed diet of C. muelleri, T‐Iso and Sceletonema costatum, or a mixture of P. tricornutum and S. costatum at a concentration of 240 cells μl?1 day?1, resulting in a tripling of their wet weight after 14 days. The impact of density, burrowing substrate and food availability on cockle spat growth (41 days old, 5.6 ± 1.2 mm) was studied for 11 weeks. Best results were obtained by culturing spat at ad libitum food conditions at 500 ind m?2, resulting in an average growth rate of 168 μm day?1, an average final size of 19.0 ± 1.9 mm and a total final biomass of 1040 g m?2. 相似文献
136.
137.
Climate change with increasing temperature and ocean acidification (OA) poses risks for marine ecosystems. According to Pörtner and Farrell [1], synergistic effects of elevated temperature and CO2-induced OA on energy metabolism will narrow the thermal tolerance window of marine ectothermal animals. To test this hypothesis, we investigated the effect of an acute temperature rise on energy metabolism of the oyster, Crassostrea gigas chronically exposed to elevated CO2 levels (partial pressure of CO2 in the seawater ~0.15 kPa, seawater pH ~ 7.7). Within one month of incubation at elevated Pco2 and 15 °C hemolymph pH fell (pHe = 7.1 ± 0.2 (CO2-group) vs. 7.6 ± 0.1 (control)) and Peco2 values in hemolymph increased (0.5 ± 0.2 kPa (CO2-group) vs. 0.2 ± 0.04 kPa (control)). Slightly but significantly elevated bicarbonate concentrations in the hemolymph of CO2-incubated oysters ([HCO− 3]e = 1.8 ± 0.3 mM (CO2-group) vs. 1.3 ± 0.1 mM (control)) indicate only minimal regulation of extracellular acid-base status. At the acclimation temperature of 15 °C the OA-induced decrease in pHe did not lead to metabolic depression in oysters as standard metabolism rates (SMR) of CO2-exposed oysters were similar to controls. Upon acute warming SMR rose in both groups, but displayed a stronger increase in the CO2-incubated group. Investigation in isolated gill cells revealed a similar temperaturedependence of respiration between groups. Furthermore, the fraction of cellular energy demand for ion regulation via Na+/K+-ATPase was not affected by chronic hypercapnia or temperature. Metabolic profiling using 1H-NMR spectroscopy revealed substantial changes in some tissues following OA exposure at 15 °C. In mantle tissue alanine and ATP levels decreased significantly whereas an increase in succinate levels was observed in gill tissue. These findings suggest shifts in metabolic pathways following OA-exposure. Our study confirms that OA affects energy metabolism in oysters and suggests that climate change may affect populations of sessile coastal invertebrates such as mollusks. 相似文献
138.
Peiffer Stefan Beierkuhnlein Carl Sandhage-Hofmann Alexandra Kaupenjohann Martin Bär Silke 《Water, air, and soil pollution》1997,94(3-4):401-416
A field study was performed on the effects of acid mine leachate from slate mine tailings seeping into a small river passing through the tailings. Before entering the tailings the river water has high alkalinity which neutralizes acidity upon mixing with leachate within the tailings. Donwstreams of the tailings the pH of the river water ranges about pH = 8, the water contains high concentrations of sulfate (≈1500 μmol/1 and particulate bound aluminium (≈80 μmol/I), but low concentrations of dissolved aluminium (≈3 μmol/1). It is therefore assumed that AI(OH)3 colloids are precipitated during the neutralisation process and transported out of the tailings. The concentration of particulate bound aluminium along the river shows a strong correlation with the concentration of sulfate, which indicates that particulate bound aluminium is conservative. It therefore seems that under dry weather conditions (under most of the sampling was performed) no chemical retention mechanism exists which confines the distribution of aluminium to a restricted part of the catchment area. In contrast, the white river sediment is rich in both aluminium and sulfate, which suggests the temporary formation of aluminium hydroxosulfate minerals. Favorable (i.e. acidic) conditions may prevail at high discharges where the acidity accumulated in the tailings is flushed into the river with its subsequent acidification. 相似文献
139.
Does long-term farmyard manure fertilization affect short-term nitrogen mineralization from farmyard manure? 总被引:2,自引:0,他引:2
Leif Nett Sven Averesch Silke Ruppel Jörg Rühlmann Carmen Feller Eckhard George Matthias Fink 《Biology and Fertility of Soils》2010,46(2):159-167
One of the challenges in organic farming systems is to match nitrogen (N) mineralization from organic fertilizers and crop
demand for N. The mineralization rate of organic N is mainly determined by the chemical composition of the organic matter
being decomposed and the activity of the soil microflora. It has been shown that long-term organic fertilization can affect
soil microbial biomass (MB), the microbial community structure, and the activity of enzymes involved in the decomposition
of organic matter, but whether this has an impact on short-term N mineralization from recently applied organic substances
is not yet clear. Here, we sampled soils from a long-term field experiment, which had either not been fertilized, or fertilized
with 30 or 60 t ha−1 year−1 of farmyard manure (FYM) since 1989. These soil samples were used in a 10-week pot experiment with or without addition of
FYM before starting (recent fertilization). At the start and end of this experiment, soil MB, microbial basal respiration,
total plant N, and mineral soil N content were measured, and a simplified N balance was calculated. Although the different
treatments used in the long-term experiment induced significant differences in soil MB, as well as total soil C and N contents,
the total N mineralization from FYM was not significantly affected by soil fertilization history. The amount of N released
from FYM and not immobilized by soil microflora was about twice as high in the soil that had been fertilized with 60 t ha−1 year−1 of FYM as compared with the non-fertilized soil (p < 0.05). 相似文献
140.