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171.
172.
Fumonisins were monitored in corn grain collected from Bt hybrids grown in 107 locations across the United States in 2000-2002. Bt corn hybrids contain the Cry1Ab protein from Bacillus thuringiensis that controls European corn borers and other stalk-boring pests. Fumonisin levels were frequently lower in grain from Bt hybrids grown in field trials under conditions of natural (FACT trials) or manual insect infestation (university trials). Over three years of FACT trials, there were 126/210 comparisons when fumonisin levels in grain from control hybrids were >2 ppm, exceeding U.S. FDA guidance levels of 2 ppm for human food. Grain from Bt hybrids was at or below 2 ppm of fumonisins for 58 of the 126 comparisons. The use of Bt hybrids can increase the percentage of corn grain that would be suitable for use in food and feed.  相似文献   
173.
Owing to the importance of snowfall to water supplies in the western United States, governmentagencies regularly collect data on snow water equivalent (the amount of water in snow) over this region. Several differentmeasurementsystem, of possibly different levels of accuracy and reliability, are in operation: snow courses, snow telemetry, aerial markers, and airborne gamma radiation. Data are available at more than 2,000 distinct sites, dating back a variable number of years (in a few cases to 1910). Historically, these data have been used primarily to generate flood forecasts, and short-term (intra-annual) predictions of streamflow and water supply. However, they also have potential for addressing the possible effects of long-term climate change on snowpack accumulations and seasonal water supplies. We presenta Bayesian spatio-temporalanalysis of the combined snow water equivalent (SWE) data from all four systems that all ows for systematic differences in accuracy and reliability. The primary objectives of our analysis are (1) to estimate the long-term temporal trend in SWE over the western U.S. and characterizehow this trend variesspatially, with quantifiable estimates of variability, and (2) to investigate whether there are systematic differences in the accuracy and reliability of the four measurement systems. We find substantial evidence of a decreasing temporal trend in SWE in the Pacific North west and northern Rockies, but no evidence of a trend in the intermountain region and southern Rockies. Our analysis also indicates that some of the systems differ significantly with respect to their accuracy and reliability.  相似文献   
174.
Summary The genetic affinities between the cultivated artichoke Cynara cardunculus L. var. scolymus (L.) Flori (= C. scolymus L.) and its wild relatives were tested by means of a crossing programme. The following wild taxa were involved: (i) wild cardoon C. carcundulus L. var. sylvestris (Lamk) Fiori, (ii) C. syriaca Boiss., (iii) C. cornigera Lindley, (iv) C. algarbiensis Cosson, (v) C. baetica (Spreng.) Pau (= C. alba Boiss.), and (vi) C. humilis L. Only the wild cardoon was found to be fully cross-compatible and fully infertile with the crop. In contrast, all other five wild Cynara species turned to be almost fully-or fully-cross-incompatible with the crop, and the few interspecific F1 hybrids recovered were partly or almost fully sterile. These finds establish the wild cardoon as the wild ancestor of the cultivated vegetable.  相似文献   
175.
Genetic strategies aimed at improving general immune competence (IC) have the potential to reduce the incidence and severity of disease in beef production systems, with resulting benefits of improved animal health and welfare and reduced reliance on antibiotics to prevent and treat disease. Implementation of such strategies first requires that methodologies be developed to phenotype animals for IC and demonstration that these phenotypes are associated with health outcomes. We have developed a methodology to identify IC phenotypes in beef steers during the yard weaning period, which is both practical to apply on-farm and does not restrict the future sale of tested animals. In the current study, a total of 838 Angus steers, previously IC phenotyped at weaning, were categorized as low (n = 98), average (n = 653), or high (n = 88) for the IC phenotype. Detailed health and productivity data were collected on all steers during feedlot finishing, and associations between IC phenotype, health outcomes, and productivity were investigated. A favorable association between IC phenotype and number of mortalities during feedlot finishing was observed with higher mortalities recorded in low IC steers (6.1%) as compared with average (1.2%, P < 0.001) or high (0%, P = 0.018) IC steers. Disease incidence was numerically highest in low IC steers (15.3 cases/100 animals) and similar in average IC steers (10.1 cases/100 animals) and high IC steers (10.2 cases/100 animals); however, differences between groups were not significant. No significant influence of IC phenotype on average daily gain was observed, suggesting that selection for improved IC is unlikely to incur a significant penalty to production. The potential economic benefits of selecting for IC in the feedlot production environment were calculated. Health-associated costs were calculated as the sum of lost production costs, lost capital investment costs, and disease treatment costs. Based on these calculations, health-associated costs were estimated at AUS$103/head in low IC steers, AUS$25/head in average IC steers, and AUS$4/head in high IC steers, respectively. These findings suggest that selection for IC has the potential to reduce mortalities during feedlot finishing and, as a consequence, improve the health and welfare of cattle in the feedlot production environment and reduce health-associated costs incurred by feedlot operators.  相似文献   
176.
When resources are limited, use of cattle owned and maintained by cooperators to conduct beef cattle breeding research in the Southern Region can be a feasible alternative to the traditional policy of using experiment station cattle. Former students, former experiment station employees, extension personnel, institutional personnel, or tribal personnel can serve as suitable cooperators or can aid in locating potential cooperators. Several problems can be associated with cooperative work; however, the two most obvious are 1) only a limited number of researchable questions can be addressed and 2) complete experimental control over the cattle is seldom achieved. The procedure has the primary advantage that in most cases all or at least the greatest portion of the expense of owning and maintaining the cow herd is borne by the cooperator.  相似文献   
177.
Tyrosine kinase inhibitors are widely utilized in veterinary oncology for the treatment of mast cell and solid tumours. In man, these drugs are associated with thyroid dysfunction: however, to date only one study has investigated this in dogs. The aim of this study was to prospectively assess thyroid function in a group of dogs with cancer receiving toceranib. Thirty‐four dogs were prospectively enrolled at two referral hospitals into two groups; those receiving toceranib with prednisolone and those receiving toceranib alone. Total thyroxine (TT4) and thyroid stimulating hormone (TSH) was monitored at regular time points during treatment. Follow‐up data was available for 19 dogs. Overall, 12 incidences of elevated TSH occurred but none of these dogs had concurrent low TT4 concentrations. There was a significant difference in median TSH at week six compared with baseline. Hypothyroidism was not diagnosed in any patient during the study period. Patient drop‐out was higher than anticipated which prevented the assessment of longer term toceranib administration on thyroid function. Toceranib therapy was not associated with hypothyroidism in this study but did result in elevations in TSH which confirms what has been previously reported. Toceranib should be considered to cause thyroid dysfunction in dogs and monitoring is advised.  相似文献   
178.
Coronary heart disease (CHD) is a major cause of death in Western countries. We used genome-wide association scanning to identify a 58-kilobase interval on chromosome 9p21 that was consistently associated with CHD in six independent samples (more than 23,000 participants) from four Caucasian populations. This interval, which is located near the CDKN2A and CDKN2B genes, contains no annotated genes and is not associated with established CHD risk factors such as plasma lipoproteins, hypertension, or diabetes. Homozygotes for the risk allele make up 20 to 25% of Caucasians and have a approximately 30 to 40% increased risk of CHD.  相似文献   
179.
Protein is the second most abundant constituent in the rice grain next to starch. Association analysis for protein concentration in brown rice was performed using a “mini‐core” collection, which represents the germplasm diversity found in the USDA rice world collection. Protein concentration was determined in replicated trials conducted in two southern U.S. locations, and association mapping was performed by using 157 genomewide DNA markers. Protein concentration ranged from 5.4 to 11.9% among the 202 accessions. Protein variation owing to accession and accession × location interaction were highly significant. Ample variation was seen within each subpopulation by ancestry, as well as within the 14 geographic regions where the accessions originated. Accessions from Eastern Europe had the highest level of protein. Ten markers on eight chromosomes were significantly associated with protein concentration. Five of these markers occurred near known protein precursor genes or quantitative trait loci, and the other five markers were novel for the association with protein concentration in rice. The germplasm and genetic markers identified in this study will assist breeders in developing cultivars tailored for applications requiring specific protein concentration in the rice grain. The research results contribute to the potential discovery of novel rice storage protein pathways in the endosperm.  相似文献   
180.
In many situations, information on stem diameters inside bark (dib) are more desirable than on diameters outside bark (dob). However, obtaining dib measurements is usually expensive, time-consuming, and prone to significant measurement errors when done on standing trees. Many bark thickness equations have been proposed to estimate the dibs of standing trees. In this study, we compared several commonly used bark thickness equations for seven conifer species in the Acadian Region of North America. Mixed-effects modeling techniques were employed to fit linear and non-linear bark thickness equations. We found the equation proposed by Cao and Pepper (South J Appl Forestry 10:220?C224, 1986; Eq. 5) performed significantly better than other equations for most of our study species. The Cao and Pepper (South J Appl Forestry 10:220?C224, 1986) equation is a function of dob, relative height in the stem, tree height, and the ratio of dib to dob at breast height. The mean absolute bias was found to be reduced up to 74% compared with using a fixed ratio approach employed in the widely used Northeastern variant of the Forest Vegetation Simulator (FVS-NE) growth and yield model. Leave-one-out cross validation was further performed to determine the location of suitable prior measurements in the prediction process for three of the most well-behaved equations. Results show that no unified prior measurement can provide best predictive abilities across all species as the choice of prior dib measurements depends on both species and bark thickness equations.  相似文献   
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