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91.
Design of a surface alloy catalyst for steam reforming   总被引:1,自引:0,他引:1  
Detailed studies of elementary chemical processes on well-characterized single crystal surfaces have contributed substantially to the understanding of heterogeneous catalysis. Insight into the structure of surface alloys combined with an understanding of the relation between the surface composition and reactivity is shown to lead directly to new ideas for catalyst design. The feasibility of such an approach is illustrated by the synthesis, characterization, and tests of a high-surface area gold-nickel catalyst for steam reforming.  相似文献   
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Background

Microcytic anemia is common in dogs with a congenital portosystemic shunt (cPSS) and typically resolves after surgical attenuation of the anomalous vessel. However, the pathophysiology of the microcytic anemia remains poorly understood. Hepcidin has been a key role in controlling iron transport in both humans and animals and in mediating anemia of inflammatory disease in humans. The role of hepcidin in the development of microcytic anemia in dogs with a cPSS has not been examined.

Hypothesis

To determine whether hepatic hepcidin mRNA expression decreases, while red blood cell count (RBC) and mean corpuscular volume (MCV) increase in dogs after surgical attenuation of a cPSS.

Animals

Eighteen client‐owned dogs with confirmed cPSS undergoing surgical attenuation.

Method

Prospective study. Red blood cell count (RBC) and mean corpuscular volume (MCV), together with hepatic gene expression of hepcidin, were measured in dogs before and after partial attenuation of a cPSS.

Results

There was a significant increase in both RBC (median pre 6.17 × 1012/L, median post 7.08 × 1012/L, P < .001) and MCV (median pre 61.5fl, median post 65.5fl, P = .006) after partial surgical attenuation of the cPSS. Despite the increase in both measured red blood cell parameters, hepatic gene expression of hepcidin remained unchanged.

Conclusions and Clinical Importance

This study found no evidence that dysregulated production of hepcidin was associated with anemia in dogs with a cPSS.  相似文献   
95.
An experiment was conducted to determine growth performance, carcass characteristics, and fat quality of growing-finishing pigs fed diets based on short-season corn hybrids. Twenty-four individually housed, Cotswold, growing pigs with an initial BW of 41.4 (SD = 1.4) kg were blocked by BW and sex and randomly allotted from within block to 1 of 3 diets to give 8 replicate pigs per diet. Experimental diets consisted of a control based on barley and 2 diets based on corn as the main energy sources. A 3-phase feeding program for 20 to 50 kg (phase I), 50 to 80 kg (phase II), and 80 to 110 kg (phase III) of BW was used. Diets for each phase contained approximately 3.5 Mcal/kg of DE, with total lysine of 0.95, 0.75, and 0.64% in phase I, II, and III diets, respectively. Average daily gain, ADFI, and G:F were monitored weekly during each phase. Pigs were slaughtered after reaching a minimum BW of 100 kg to determine carcass characteristics. There were no effects of diet on ADG, ADFI, and G:F (0.45 +/- 0.02, 0.34 +/- 0.02, and 0.31 +/- 0.02 for phase I, II, and III, respectively). Carcass length, dressing percent, LM area, loin depth, backfat thickness, belly firmness, and L*, b*, and a* fat color were not different across dietary treatments. Pigs fed one corn variety had no differences in fatty acid profile with barley-fed pigs, whereas those fed the other variety of corn had a greater (P < 0.05) concentration of PUFA in their backfat. The results indicate that growth performance, carcass characteristics, and fat quality of pigs fed diets based on short-season corn hybrids and those fed the barley-based diet were not different.  相似文献   
96.
OBJECTIVE: To investigate the effect of cyclosporine (2 or 5 mg/kg every 24 hours) on perianal fistulae (PAF) lesions. STUDY DESIGN: Blinded randomized, prospective trial. ANIMALS: Dogs (n = 20) with perianal fistulae. METHODS: Dogs were randomly assigned to administration of either 2 mg/kg (n = 10) or 5 mg/kg (n=10) of cyclosporine orally every 24 hours for 8 weeks. Lesion surface area was measured, lesion severity was graded using a visual analog scale, and the presence and severity of clinical signs recorded every 2 weeks. RESULTS: Lesion variables were significantly reduced in both groups after 8 weeks and owners also reported a reduction in clinical sign severity. The 5 mg/kg dose rate significantly accelerated lesion resolution compared with 2 mg/kg. In the 2 mg/kg group, 20% of dogs had complete resolution of clinical signs and 10% had resolution of lesions. In the 5 mg/kg group, 40% of dogs had complete resolution of clinical signs and 60% had resolution of lesions. CONCLUSIONS: A dose rate of 5 mg/kg every 24 hours was more effective at reducing the surface area and severity of PAF lesions than 2 mg/kg every 24 hours but less effective at resolving PAF lesions than previous studies using dose rates > or =5 mg/kg every 12 hours. CLINICAL RELEVANCE: Cyclosporine at 5 mg/kg every 24 hours may be useful for the palliation of PAF lesions.  相似文献   
97.
Summary A genetic diversity analysis in a collection of 171 non-restorer lines of sorghum (Sorghum bicolor (L.) Moench) using D2 technique and canonical variate analysis indicated that considerable variation in grain yield has been added to the collection by the addition of lines derived from random mating populations. The efficiency of D2 and canonical variate techniques in distinguishing extremely diverse genotypes was confirmed. However, the two techniques showed weak correspondence in their clusters. The F1 hybrids of 15 diverse lines exhibited no relationship between heterosis or per se performance of crosses and diversity in their parents. Therefore, traditional plant breeding methods are being advocated.Approved by ICRISAT as Journal Article no. 435.  相似文献   
98.
Soil-arthropod and earthworm densities (number m−2) were higher (P < 0.05) under no-tillage than conventional tillage practices. Enchytraeid worms were higher in conventional tillage. Two predaceous groups, ground beetles (Carabidae: Coleoptera) and spiders (Araneae), comprised more than one-half of all soil macroarthropods collected. All major microarthropod suborders (Oribatids, Prostigmatids, Mesostigmatids, and the order Collembola) were higher (P < 0.01) under no-tillage than conventional tillage. High soil-arthropod and earthworm densities under no-tillage systems suggest an expanded and beneficial involvement for these soil fauna in crop-residue-decomposition processes.  相似文献   
99.
Summary Herbicide combinations of paraquat, glyphosate, alachlor, linuron, fluazifopbutyl, aciflurofen, and bentazon were investigated for their impact on soil arthropod population dynamics and surface wheat straw decomposition (weight loss) within a North Carolina coastal plain agroecosystem. Herbicides were applied twice (preemergence and mid-bloom) at recommended field rates to soybeans no-till planted into wheat residue. Separate measurements were made for surface crop residue and soil-dwelling (0–3 cm depth) arthropods. Decomposition of herbicide (glyphosate) and nonherbicide-treated wheat straw residue was compared using mesh bag techniques. Decay rate constants were estimated for glyphosate and nonherbicide-treated wheat straw residue by fitting a two-component model to the data. Comparison of soil microarthropod numbers from herbicide and nonherbicide treatments showed no consistent trend, suggesting that abiotic factors such as soil temperature and moisture were probably more significant than herbicide effects in regulating soil microarthropod number and activity. Herbicides had no effect on soil macroarthropod number or activity until late in the season when macroarthropods were most abundant under weedy, no-tillage conditions. Moist soil and litter, low soil temperature, floral diversity, and high weed-seed availability probably enhanced macroarthropod numbers in nonherbicide treatments. Decomposition (ash-free weight loss) of nonherbicided, surface crop residues was more rapid than herbicide (glyphosate) treated, indicating that herbicide effects occur at the decomposer as well as producer level of agroecosystems.Paper No. 9957 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, NC 27695-7601, USA  相似文献   
100.
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