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91.
Five Standardbred trotters were trained on a treadmill 3 times as week for 12 weeks by intervals of draft loaded exercise. The draft load was 34 kilopond and the velocity approximately 7 m/sec -1. Standardized exercise tests with sequentially increasing speed were performed before, and after 4, 8 and 11 weeks of training. No significant effects of training were seen on heart rate response to exercise or on total blood volume, red cell volume and plasma volume when related to bodyweight, whereas less blood lactate (p<0.05) was accumulated. Blood lactate response to exercise may therefore be valuable for monitoring metabolic adaptations to training by draft loaded exercise.  相似文献   
92.
Anna V. Eggertsdóttir  DVM  PhD    Øyvind Stigen  DVM  PhD    Lars Lønaas  DVM  PhD    Marianne Langeland  DVM  PhD    Morten Devor  DVM    Gunvor Vibe-Petersen  DVM  PhD    Thomas Eriksen  DVM  PhD 《Veterinary surgery : VS》2001,30(6):546-551
OBJECTIVE: To compare the recurrence rate of acute gastric dilatation with or without volvulus (GDV) after circumcostal gastropexy (CCGP) or gastrocolopexy (GCP) in dogs. STUDY DESIGN: A prospective, double-blind, multicenter, randomized, controlled, clinical trial with two groups (A and B). ANIMALS: Fifty-four client-owned dogs presented for treatment of GDV. METHODS: Dogs with acute GDV that had not previously had a gastropexy performed were included. The preoperative treatment before gastropexy was standardized. A CCGP was performed on dogs in group A, and a GCP was performed on dogs in group B. Postoperative treatment was standardized, but deviation did occur according to the special needs of particular patients. A minimal follow-up time of 180 days was required for dogs not excluded from the study. The median follow-up time in group A was 700 days; in group B, it was 400 days. The occurrence of abdominal pain and gastrointestinal problems after surgery were recorded by the owners. RESULTS: There was no significant difference in the recurrence rate of GDV between the two groups. At the end of the study, the recurrence rate was 9% and 20% in group A and in group B, respectively. CONCLUSIONS: Both surgical techniques are effective in preventing recurrence of GDV.  相似文献   
93.
Syringocystadenoma papilliferum, a hamartoma with mostly sweat gland, but also follicular infundibular elements, is described on the flank and head of two young cats. Clinically, lesions were cutaneous plaques characterized by irregular but sharply demarcated borders and a roughened, hyperpigmented surface. Complete surgical excision in one case was curative. Histologically, the lesion was limited to the superficial dermis and consisted of coalescing units of proliferating sweat glands. The proliferation was tubular or papillary, and may have been epitrichial, opening within dilated hypertrophied follicular infundibuli, or atrichial. Three types of epithelium were observed, recapitulating the formation of the follicular-sweat gland unit with infundibular, ductal and secretory epithelia. The glands reacted positively for alpha cytokeratin 8 and were supported by fibrous tissue with a plasmacytic, lymphocytic and neutrophilic infiltrate. As in humans, this lesion may be classified within the hamartoma-nevus-type category.  相似文献   
94.
95.
Nitrogen efficiency is a complex trait. Identification of secondary plant traits correlating with N efficiency would facilitate the breeding for N‐efficient cultivars. Sixteen tropical maize cultivars differing in grain yield at low N supply (N efficiency) under field conditions in Zimbabwe exhibited a significant negative correlation between N efficiency and leaf senescence during grain filling. The same cultivars were studied for leaf senescence under N deficiency in a short‐term nutrient‐solution experiment. Leaf chlorophyll contents as estimated by SPAD values and photosynthesis rates were used as measures for leaf senescence. Cultivars differed both in SPAD values and photosynthesis rates of the older leaves during N deprivation. Significant negative correlations were found between SPAD values, photosynthesis rates in the nutrient‐solution experiment, and leaf‐senescence scores in the field experiments, and positive correlations were found between photosynthesis rates and grain yield under low‐N conditions in the field. Relationships between physiological root parameters, which were also investigated in the nutrient‐solution experiment, and N uptake or grain yield of the cultivars in the field could not be established. It is concluded, that the assessment of the capacity of a genotype to maintain a higher photosynthetic capacity of older leaves during N deficiency–induced senescence at the seedling stage is a suitable selection parameter for the N efficiency of tropical maize cultivars.  相似文献   
96.
The aim of this study was to investigate the possible influence of surface topographical features on the spatial variability of glyphosate degradation and some microbial characteristics in sandy loam soil. Soil samples were taken from the ploughed layer across an agricultural field after seedbed preparation for grain (Grue site), and down to 1 m depth under a ridge tilled field (Målselv site), both sites having similar soil textural characteristics (sandy loam soil). Laboratory experiments were performed looking at glyphosate mineralization and soil microbial activity at the Grue site, as well as microbial biomass, activity and substrate utilization patterns at the Målselv site. Microbial biomass and activity decreased, and substrate utilization patterns changed with increasing soil depth, reflecting naturally occurring changes in quantity and quality of soil organic carbon. Further, our results show that considerable spatial heterogeneity in the degradation rate of glyphosate and general carbon utilization exists even across small areas within a single agricultural field. This horizontal variability was observed over several spatial scales, and could not be clearly explained. It evidently arose from differences in environmental factors affecting microbial activity and growth, and topographical features controlling redistribution of water and matter flow patterns were correlated to the investigated soil microbial variables.  相似文献   
97.
This work investigates whether Fourier transform infrared spectroscopy (FTIR), in combination with multivariate analysis, can distinguish extra virgin olive oils from different producing countries. Duplicate spectra were collected from 60 oils from four European countries. Two approaches to data analysis were used as follows: first, the "whole spectrum" method of partial least squares (PLS) followed by distance-based linear discriminant analysis (LDA) applied to the PLS scores, and second, a genetic algorithm (GA) for variate selection from the raw data, followed by LDA applied to the selected subset. The PLS-LDA approach produced a cross-validation success rate of 96%, whereas the GA-LDA approach achieved a 100% cross-validation success rate, from subsets comprising only eight variates. Neither the selected variate nor the whole spectrum approach was able to offer insight into the origin of the discrimination in biochemical terms. However, FTIR analysis is rapid, and this work shows that it has the required discriminatory power to potentially offer a "black box" method of screening oils to verify their country of origin.  相似文献   
98.
A new, resource-efficient, herbarium-based method for estimating temporal frequency changes in species, especially of non-vascular plants and fungi, is presented. It is based on a reference data set for the temporal distribution of general collecting activity for the organism group and geographical area of interest. The reference data set includes the collecting year of 650-1000 randomly selected herbarium specimens. The technique relies on the assumption that the temporal distribution of herbarium collections reflects the collecting activity in a region. The temporal distribution of collections of example species is compared with that of the reference data set to correct for the collecting intensity. Thus, cases that are explained by changes in general collecting frequency can be separated from those where other causes are likely. Species of the latter category need to be examined individually in order to assess whether the actual causes for the detected frequency variations are due to environmental changes or other factors. The present method provides a tool to assess actual increases and decreases of moderately frequent to common taxa, to aid in tracing predicted or unpredicted changes in nature.  相似文献   
99.
Abstract

The strategy to mitigate phosphorus (P) losses in areas of arable cropping in Norway has focused on measures to reduce erosion. Risk assessment of erosion has formed the basis for implementation of the measures. The soil P content has increased during recent decades, motivating an evaluation of its effect on P transfer in the landscape. The present study describes the spatial variability of runoff P concentrations from an agricultural dominated catchment (4.5 km2), representative for agriculture in south-eastern Norway. The concentrations of suspended sediments (SS), total P (TP) and dissolved reactive P (DRP) in runoff from 22 subcatchments (0.3–263 ha) during one year (monthly and during runoff-events) were evaluated. Contributions from point sources were 38 kg TP yr?1 compared to a total P loss of 685 kg yr?1 from the whole catchment. During low flow, mean diffuse TP concentration in runoff from subcatchments varied from 28 to 382 µg l?1. The mean low flow TP concentration was 39 µg l?1 from the housing area (only diffuse runoff) and 33 µg l?1 from the forested area. During high flow the highest diffuse TP concentration was measured in an area with high erosion risk and high soil P status. At the subcatchment level the transfer of SS varied from 25 to 175% of the whole catchment SS transfer. Correspondingly for TP, the transfer varied from 50 to 260% of the whole catchment TP transfer. For each of five agricultural subcatchments the slope of the relationship between TP and SS concentrations reflected the mean soil P status of the subcatchment. Erosion risk estimates were closely related to the SS concentration (R2=0.83). The study illustrates that soil P status in addition to soil erosion is an important factor for P transfer.  相似文献   
100.
Abstract

Two experiments were conducted to study the effects of different forage crops on productivity and some egg quality parameters of small flocks of organic laying hens fed whole wheat or concentrates. Each experiment was carried out in a split plot design with two different forage crops and two types of supplementary feed (typical concentrate for organic layers versus whole wheat) with three replications. In the first experiment the tested forage crops were of a well-established grass/clover and a mixture of forbs (Fagopyrum esculentum, Phacelia tanacetifolia and Linum usitatissimum). In the second experiment the tested forage crops were a well-established grass/clover and chicory (Cichorium intybus cv. Grassland Puna). The results on productivity and egg quality suggest that laying hens consume large amounts of foraging material when accessible. In nutrient restricted hens (wheat-fed) the forage may yield a substantial contribution to the requirements of amino acids and metabolizable energy although productivity parameters and measurements on dry matter in albumen showed that wheat-fed hens, on a short-term basis, were not able to fully compensate for the lack of protein and amino acids by increased foraging. Of the forage crops investigated especially chicory seems to contribute to the nutrition of the hens. Measurements on eggshell parameters showed that oyster shells together with foraging material were sufficient to meet the hens’ calcium requirements. Yolk colour clearly revealed that laying hens consume large quantities of green fodder irrespective of the type of supplementary feed. Yolk colour from hens with access to chicory tended to be darker, of a redder and less yellow hue compared with grass/clover fed hens, which is considered a positive quality.  相似文献   
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