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21.
OBJECTIVE: To determine whether the bispectral index (BIS) can be used as an indicator of degree of CNS depression in isoflurane-anesthetized horses. ANIMALS: 10 Standardbred and 6 Norwegian cold-blooded trotter stallions admitted for routine castration. PROCEDURE: A 2-channel referential electrode configuration was used to record EEG for calculation of BIS by the EEG monitor. The BIS was calculated before (awake) and after (sedated) administration of detomidine (0.01 mg/kg of body weight, IV) and butorphanol (0.01 mg/kg, IV). Anesthesia was induced with ketamine hydrochloride (2.5 mg/kg, IV) and diazepam (0.04 mg/kg, IV) and maintained with isoflurane delivered in oxygen. The BIS was calculated after 30 minutes of equilibration at an end-tidal isoflurane concentration of 1.4% (n = 8) or 1.9% (8) and recorded continuously during surgery. RESULTS: Bispectral index was significantly less in sedated and anesthetized horses, compared with awake horses. However, BIS was not significantly different between sedated and anesthetized horses. Mean BIS in horses anesthetized at 1.9% isoflurane was significantly greater, compared with horses anesthetized at an end-tidal concentration of 1.4%. Four horses in the 1.4% group moved during surgery, and BIS increased immediately prior to movement in 2 of these horses. CONCLUSIONS AND CLINICAL RELEVANCE: BIS is not a precise indicator of degree of CNS depression in isoflurane-anesthetized horses. Thus, determination of BIS may not be a useful technique for monitoring anesthetic depth in isoflurane-anesthetized horses. 相似文献
22.
Dorn C Schroeter A Helmuth R 《Berliner und Münchener tier?rztliche Wochenschrift》2002,115(7-8):252-258
The National Salmonella Reference Laboratory (NRL-Salm) of the Federal Institute for Health Protection of Consumers and Veterinary Medicine receives putative Salmonella isolates originating from animals, food, feed and the environment for typing. This report summarises the results of the sero- and phagetyping studies. In livestock S. Typhimurium DT 104 with 24% and S. Enteritidis PT 4 with 9% of all isolations predominate like in the human isolates. These sero- and phagetypes are frequently isolated from food as well and consequently can reach the consumer via the food chain. 相似文献
23.
ABSTRACT A leaf spot disease with unknown etiology has become more pronounced in spring and winter barley in Germany in recent years. The symptoms are similar to net blotch and Ramularia leaf spots, but the causal agents of these diseases are not identified. The symptom expression varied much on cultivars. Cultivars most affected by the disease of both spring and winter barley showed a significantly higher level of superoxide (O(2) ) production and lipid peroxidation (malondialdehyde), but a lower level of antioxidant potential expressed as superoxide dismutase (SOD) activity, catalase activity, and integral water-soluble antioxidant capacity (ACW) than insensitive cultivars. A high positive correlation between O(2) production and leaf spot development between ear emergence and milk ripeness was established in the most sensitive winter barley cv. Anoa (r(2) = 0.9622) and spring barley cv. Barke (r(2) = 0.9434). Leaf H(2)O(2) levels increased with the severity of leaf spots. The histochemical localization of O(2) and H(2)O(2) in the tissues adjacent to leaf spots indicated that these two active oxygen species (AOS) are involved in the formation of leaf spots. Reduction of symptom severity by applying strobilurin and azole fungicides was always associated with elevated SOD activity and ACW content and suppressed O(2) production. However, peroxidase activities were significantly higher in sensitive cultivars and in more severely affected tissues and decreased by applying fungicides. Thus, it is assumed that a possible genetic mechanism based on the imbalanced AOS metabolism contributes to formation of physiological leaf spots. 相似文献
24.
Julie M. Steed Andreas Baierl Bruce D. L. Fitt 《European journal of plant pathology / European Foundation for Plant Pathology》2007,118(4):359-373
In winter oilseed rape experiments at Rothamsted in 2000/01 to 2002/03 growing seasons, the severity of phoma stem canker
epidemics in summer depended on the timing of phoma leaf spot epidemics in the previous autumn, and hence on the timing of
Leptosphaeria maculans ascospore release. The first major release of L. maculans ascospores was earlier in 2000 (26 September) and 2001 (18 September) than in 2002 (21 October). Consequently, the autumn
phoma leaf spot epidemic was also earlier in 2000 and 2001 than in 2002. The resulting stem canker epidemics were severe by
harvest (July) in 2001 and 2002 but not in 2003. No correlation was found between the severity or duration of phoma leaf spotting
(lesion days or lesion °C-days) and the subsequent severity of phoma stem canker epidemics. Rates of leaf production and loss
were similar in the three growing seasons. Out of ca. 25 leaves produced on plants during each season, leaf numbers 10–14 generally remained on plants for the longest. Treatment
with flusilazole + carbendazim in autumn decreased the severity of phoma leaf spotting for several weeks after treatment,
decreased the severity of stem canker the following summer and increased yield significantly in 2001 and 2002 but not in 2003.
The most effective timings for flusilazole + carbendazim application were when leaves 7–11 were present on most plants and
at least 10% of plants were affected by phoma leaf spot. Two half-dose applications of fungicide reduced phoma stem canker
and increased yield more than a single full dose application when phoma leaf spot epidemics were early (<800 °C-days after
sowing). 相似文献
25.
Andreas Kofoet Mathias Fink 《European journal of plant pathology / European Foundation for Plant Pathology》2007,117(4):369-381
Epidemics of Peronospora parasitica are strongly affected by temperature and air moisture, and the interaction of these factors. Because a significant percentage
of radish plants are grown in greenhouses, it may be possible to influence epidemics by altering the greenhouse climate. The
objective of this study was to test the hypothesis that epidemics of P. parasitica can be modelled by the effects of air temperature and moisture in the greenhouse. Such a model could then be used to analyse
greenhouse climate control strategies with regard to managing downy mildew. Five radish crops were grown under greenhouse
conditions with set-points for heating and ventilation intended to obtain favourable conditions for disease development during
the first part of the growing cycle. Subsequent to this first phase, unfavourable conditions were set until harvest. Disease
incidence was measured once a week until the radishes reached marketable size. In addition, experiments were carried out in
growth chambers in which inoculated plants were subjected to air temperatures between 8 and 27°C, and disease incidence and
sporulation intensity were measured. Data from these two experiments were then used to estimate model parameters. In this
model, the interactions of air temperature (T) and water vapour saturation deficit (SD) were adequately described by a multiplicative
relationship. The simulated epidemics by the fitted model were highly correlated with the observed epidemics (r = 0.91, R
2 = 0.83, n = 29). Parameter estimates indicated that T of ca. 20°C and SD < 0.03 hPa resulted in the highest rates of disease development
and that the rate was zero when SD > 2.0 hPa. Both experimental data and simulations showed that epidemics of P. parasitica can be effectively controlled by managing the greenhouse climate. 相似文献
26.
Andreas H. Hasler Robert J. Washabau 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1997,11(6):313-318
We have previously shown that cisapride, a substituted piperidinyl benzamide, stimulates contraction of healthy feline colonic smooth muscle. The purpose of the present investigation was to determine the effect of cisapride on feline idiopathic megacolonic smooth muscle function. Longitudinal smooth muscle strips from ascending and descending colon were obtained from cats with idiopathic megacolon, suspended in a 1.5 mM Ca2+-HEPES buffer solution (37°C, 100% O2, pH 7.4), attached to isometric force transducers, and stretched to optimal muscle length (L0). Control responses were obtained at each muscle site with acetylcholine (10–8 to 10 4 M), substance P (10–11 to 10-7 M), or potassium chloride (10 to 80 mM). Muscles were then stimulated with cumulative (10–9 to 10–6 M) doses of cisapride in the absence or presence of tetrodotoxin (10–6 M) and atropine (10–6 M), or in a 0 calcium HEPES buffer solution. In cats with idiopathic megacolon, cisapride stimulated contractions of longitudinal smooth muscle from both the ascending and the descending colon. Cisapride-induced contractions were similar in magnitude to those induced by substance P and acetylcholine in the ascending colon, but were less than those observed in the descending colon. Cisapride-induced contractions in megacolonic smooth muscle were only partially inhibited by tetrodotoxin and atropine, but were virtually abolished by removal of extracellular calcium. We concluded that cisapride-induced contractions of feline megacolonic smooth muscle are largely smooth muscle mediated and dependent on influx of extracellular calcium. Cisapride-induced contractions in megacolonic smooth muscle are only partially dependent on enteric cholinergic nerves. Thus, cisapride may be useful in the treatment of cats with idiopathic megacolon. 相似文献
27.
Somatic embryos of Norway spruce (Picea abies (L.) Karst.) differentiate from proembryogenic masses (PEMs), which are subject to autodestruction through programmed cell death. In PEMs, somatic embryo formation and activation of programmed cell death are interrelated processes. We sought to determine if activation of programmed cell death in PEMs is caused by genetic aberrations during somatic embryogenesis. Based on the finding that withdrawal of auxin and cytokinin induces programmed cell death in PEMs, 1-week-old cell suspensions were cultured in medium either with or without auxin and cytokinin and then transferred to maturation medium containing abscisic acid. We analyzed the stability of three nuclear simple sequence repeat (SSR) microsatellite markers at successive stages of somatic embryogenesis in two cell lines. There were no mutations at the SSR loci at any of the successive developmental stages from PEMs to cotyledonary embryos, irrespective of whether or not the proliferation medium in which cell suspensions had been cultured contained auxin or cytokinin. The morphologies of plants regenerated from the cultures were similar, although withdrawal of auxin and cytokinin significantly stimulated the yield of both embryos and plants. We conclude, therefore, that the high genetic stability of somatic embryos in Norway spruce is unaffected by the induction of programmed cell death caused by withdrawal of auxin and cytokinin. 相似文献
28.
29.
Jürg Andreas Stückelberger Hans Rudolf Heinimann Edouard Charles Burlet 《European Journal of Forest Research》2006,125(4):377-390
Cost estimation is probably the most decisive factor in the process of computer-aided, preliminary planning for low-volume road networks. However, the cost of construction is normally assumed to be route-independent for a specific project area, resulting in sub-optimal layouts. This is especially true for mountainous terrain and in areas with unstable subsoil. Here, we present a model for more accurately estimating spatial variability in road life-cycle costs, based on terrain surface properties as well as geological properties of the subsoil. This parametric model incorporates four structural components: embankment, retaining structures, pavement, and drainage and stream-crossing structures. It is linked to a geo-database that allows users to derive location-specific parameter values as input. In applying this model, we have demonstrated that variability in costs ranges widely for mountainous areas, with the most expensive construction being approximately five times greater there than on more favorable sites. This variability strongly affects the optimal layout of a road network. First, when location-specific slope gradients are considered, costs are reduced by about 17% from those calculated via currently available engineering practices; when both slope gradient and geotechnical formations are included, those costs are decreased by about 20%. Second, the length of the road network is increased by about 4% and 10% respectively, compared with current practices. 相似文献
30.
Harald Dinkelmeyer Johannes Lehmann Andreas Renck Lucerina Trujillo Jose Pereira da Silva Jr Gerhard Gebauer Klaus Kaiser 《Agroforestry Systems》2003,57(3):213-224
Mixed tree cropping systems have been proposed for sustainable nutrient management in the humid tropics. Yet, the nutrient interactions between intercropped trees have not been addressed sufficiently. In the present study we compare the temporal and spatial patterns of the uptake of applied 15N by four different tree crops in a mixed tree cropping system on a Xanthic Ferralsol in central Amazônia, Brazil, during one year. Most of the N uptake occurred during the first two weeks. Very little N was recovered by peach palm (Bactris gasipaes), more by cupuassu (Theobroma grandiflorum) and annatto (Bixa orellana) and most by Brazil nut (Bertholletia excelsa). Due to tree pruning the total accumulation of applied 15N in the above-ground biomass of annatto decreased throughout the year. It remained constant in cupuassu and peach palm and increased in Brazil nut. Brazil nut showed an extensive root activity and took up more fertilizer N applied to neighboring trees than from the one applied under its own canopy in contrast to the other three tree crops. Therefore, trees with wide-spread root systems may not need to receive N fertilizer directly but can take up N applied to other trees in the mixed cropping system. This means that such trees may effectively decrease N leaching when intercropped with trees that have dormant periods or places with low N uptake, but also exert considerable resource competition.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献