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231.
Determination of different agronomical properties including soil-related parameters for enhanced canola (Brassica napus L.) production can be of great significance. Hence, the objectives were to determine the effects of different tillage systems, canola cultivars and different planting dates on: (i) canola yield and oil, and (ii) soil moisture and microbial carbon (C) and nitrogen (N). Two field experiments were planned as split-plot experiments in three replicates. The main plots were different tillage systems including no-tillage (NT), minimum tillage (MT) and conventional tillage (CT), and the subplots were the combination of different canola cultivars (PF and Hyola 401) and different planting dates (PD): 8 and 23 September and 7 October. Soil moisture under CT and PF was significantly less than that of MT and NT, and Hyola 401, respectively. Carbon and N microbial biomass was the highest at NT and on the first PD. The tillage method and planting date also significantly affected canola yield, oil content and the amount, and the number of earthworms. We may conclude that although the amount of yield was the highest at CT, it may be more agronomically sustainable to plant canola under NT or MT earlier during the autumn growing season.  相似文献   
232.
The presence of cycles characterizes all economic systems, but economic cycles have differentiated spatial impacts. Some regions have broader cycles with respect to the country, while others tend to be less responsive to shocks and hence have narrower cycles. Being exposed to broader cycles, that is, greater volatility, may increase the strain on a regional economic system. This paper investigates the different responsiveness to cyclical forces and volatility of regions in the long run. It does so by using quarterly employment data for the Nuts2 Italian regions over almost 40 years before and during the period 1978–2016. Explored in particular are the cross-regional variations in employment volatility and the reasons for the patterns observed, as well as whether they have changed the following different macroeconomic policy regimes. The paper identifies the break dates of different regimes, and these regime changes will be related to policy modifications, such as the implementation of the European Monetary Union. The determinants of this regional volatility appear to be quite stable, so that the changes in volatility are explained by how these determinants have changed overtime and how they are unevenly distributed in space. In particular, the lagging regions of the country suffer, in addition to lower production and income, from higher volatility due to a structure which is weaker and more unstable. Volatility can hence be an additional issue for lagging regions.  相似文献   
233.
234.
Abstract

A field experiment was conducted at Ste. Anne de Bellevue, Quebec during the growing seasons of 2002 and 2003, to study the effect of Nod factor treatments, applied at specific growth stages, on photosynthesis and biomass accumulation by soybean grown under two tillage systems (conventional tillage, no-tillage). Spray application of Nod factors increased photosynthesis at the four fully expanded trifoliate leaves and full bloom growth stages under no-tillage and conventional tillage; they increased plant biomass at the beginning seed filling stage. Nod factor treatment did not affect yield in 2002, due to severe drought during the reproductive period. In 2003, Nod factor application increased yield under conventional tillage but not under no-tillage, and this may have been due to the negative effect of no-tillage on plant growth on the clay-loam soil at the experimental site. This study indicated that responses to Nod factors are affected by environmental conditions, and that Nod factors may be useful when applied to soybean grown under conventional tillage.  相似文献   
235.
Modeling water flow and solute transport in vadose zone requires knowledge of soil hydraulic properties, which are water retention and hydraulic conductivity curves. As an alternative to direct measurement, indirect determination of these functions from basic soil properties using pedotransfer functions (PTFs) has attracted the attention of researchers in a variety of fields such as soil scientists, hydrologists, and agricultural and environmental engineers. In this study, PTFs for point and parametric (van Genuchten's parameters) estimation of soil hydraulic parameters from basic soil properties such as particle-size distribution, bulk density, and three different pore sizes were developed and validated using artificial neural network (ANN) and multiple-linear regression methods and the predictive capabilities of the two methods was compared using some evaluation criteria. Total of 195 soil samples was divided into two groups as 130 for the development and 65 for the validation of PTFs. Although the differences between the two methods were not statistically significant (p > 0.05), regression predicted point and parametric variables of soil hydraulic parameters better than ANN. Both methods had lower accuracy in parametric predictions than in point predictions. Accuracy of the predictions was evaluated by the coefficient of determination (R2) and the root mean square error (RMSE) between the measured and predicted parameter values. The R2 and RMSE varied from 0.637 to 0.979 and from 0.013 to 0.938 for regression, and varied from 0.444 to 0.952 and from 0.020 to 3.511 for ANN, respectively. Even though regression performs insignificantly better than ANN in this case, ANN produces promising results and its advantages can be utilized by developing or using new algorithms in future studies.  相似文献   
236.
The quality of crude hazelnut oil extracted from Tombul (Round) hazelnut, grown in the Giresun province of Turkey, was determined by measuring lipid classes, fatty acids, and fat soluble bioactives (tocopherols and phytosterols). Oxygen uptake, peroxide value, thiobarbituric acid reactive substances, and alpha-tocopherol levels of stripped and crude hazelnut oils in bulk and oil-in-water (o/w) emulsion systems were also evaluated as indices of lipid oxidation over a 21 day storage period at 60 degrees C in the dark. The total lipid content of Tombul hazelnut was 61.2%, of which 98.8% were nonpolar and 1.2% polar constituents. Triacylglycerols were the major nonpolar lipid class and contributed nearly 100% to the total amount. Phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol were the most abundant polar lipids, respectively. Sixteen fatty acids were identified, among which oleic acid contributed 82.7% to the total, followed by linoleic, palmitic, and stearic acids. Unsaturated fatty acids accounted for 92.2% of the total fatty acids present. Among oil soluble bioactives, alpha-tocopherol (38.2 mg/100 g) and beta-sitosterol (105.5 mg/100 g) were predominant in hazelnut oil and comprised 88 and 93% of the total tocopherols and phytosterols present, respectively. The results also showed that both stripped and crude hazelnut oils were more stable in terms of lipid oxidation in the bulk oil as compared to those in an o/w emulsion.  相似文献   
237.
The effect of different host plants including cabbage, cauliflower, mustard, radish, and broccoli on biological parameters of Pieris brassicae (L.) was studied in the laboratory at 28°C, 65 ± 5% RH and 12L:12D photoperiod. Duration of each life stage, longevity, the intrinsic rate of natural increase (r m), net reproductive rate (R 0), mean generation time (T), doubling time (DT), and finite rate of increase (λ) of the cabbage white butterfly on the different cole crops were estimated. Differences in fertility life table parameters of the P. brassicae among host plants were analyzed using pseudo-values, which were produced by Jackknife re-sampling. The results indicating that cabbage might be the most suitable food for P. brassicae due to the shorter development time (16 days), longer adult longevity (12 and 9 days for female and male, respectively), higher fecundity (281 eggs/female), higher intrinsic rate of natural increase (0.1156 females/female/day), lower doubling time (6.00), lower larval mortality (70.33%), and higher yield of adult (30%). Therefore, it can be concluded from the present study that P. brassicae prefers cabbage for fast and healthy development with low larval mortality and highest number of adult yield than other cole crops.  相似文献   
238.
Gibberellins production by soil fungi received little attention, although substantial work has been carried out on other growth promoting aspects of soil borne fungi. We investigated gibberellins production and growth promoting capacity of a novel fungal strain of Neosartorya, which was isolated from the roots of Chinese cabbage (Bassica rapa L. ssp. pekinensis). Fungal culture filtrates (CF) obtained from pure cultures of 16 endophytic fungi were bioassayed on Waito-C, in order to investigate plant growth promoting capacity of these fungi. The fungal isolate CC-8 induced maximum shoot length of Waito-C (13.0 cm) as compared to control treatments. In a separate experiment, the CF of fungus CC-8 significantly promoted plant length and biomass of Chinese cabbage. The fungal CF also increased endogenous bioactive GA1 and GA4 contents of Chinese cabbage. Gibberellin analysis of CF of CC-8 showed presence of both physiologically active and non active gibberellins in higher concentrations (GA1, 1.42 ng/ml; GA3, 5.93 ng/ml; GA4, 11.36 ng/ml; GA7, 3.25 ng/ml; GA9, 0.79 ng/ml; GA15, 1.18 ng/ml). The culture filtrate of CC-8 produced higher amounts of GA3, GA4, GA7 and GA9 than wild type Fusarium fujikuroi, a well known gibberellins producing fungus. The fungal isolate CC-8 was later identified as a new strain of Neosartorya species on the basis of traditional and advance molecular techniques.  相似文献   
239.
A study was conducted to evaluate four different probiotic levels, using diets supplemented with 0 (control), 0.1%, 0.2%, 0.3% or 0.5% of organic-green culture-zs (probiotic). The cockerels of 6-weeks old were randomly divided into 15 separate floor pens each comprising 25 birds and three pens (replicates) per treatment group following completely randomized design. At 12 weeks of age BW and feed to gain ratio (FCR) were determined. At the end of 42 days of experiment, nine birds per treatment were sacrificed to evaluate carcass characteristics, abdominal fat contents and the internal organs. Blood haemato-biochemical parameters were also determined. Haemagglutination inhibition antibody titres against Newcastle disease virus and lymphoid organs weight/body weight ratio were also determined. The BW of birds fed 0.2-0.5% of probiotic was significantly greater than birds fed without probiotic diet. Similarly, better FCR was observed in birds those fed diets of high level of probiotic. There was no mortality recorded at higher levels of probiotics. Differences in carcass characteristics, organs weight, meat composition, haematological values and HDL and LDL concentrations among all the diets were non-significant. However, abdominal fat contents reduced significantly in supplemented groups in relation to control and cholesterol contents were reduced significantly in 0.3% or 0.5% supplemented groups in relation to control. Feeding levels of 0.2-0.5% of probiotic, did positively affect the immune system within the parameters measured. It may be concluded that performance, blood chemistry and immunity against disease in cockerels could be maintained when supplementing 0.3% or 0.5% level of probiotic incorporated in crossbred cockerel's diets.  相似文献   
240.
绿液预处理对麦草化学成分及酶水解糖化的影响   总被引:1,自引:0,他引:1  
主要探讨在不同温度、用碱量和硫化度条件下绿液预处理对麦草化学成分及酶水解效率的影响。随着预处理用碱量和硫化度的提高木质素的脱除率增加,但同时也加剧了碳水化合物的降解,导致麦草浆得率下降。绿液预处理废液的pH值小于9.5,弱碱介质可以减少碳水化合物的降解,同时避免禾草原料含量较高的硅溶解在黑液中,有利于废液的碱回收利用。预处理后浆料经过由纤维素酶、木聚糖酶和β-葡萄糖苷酶组合而成的混合酶液水解,纤维素酶用量从5 FPU/g增加到10 FPU/g时,总糖得率及转化率显著增加。在酶用量为10 FPU/g条件下经过48 h的酶水解后,温度130℃、用碱量8%、硫化度40%条件下的预处理浆料总糖得率达到最大值43%,总糖转化率为73.1%。  相似文献   
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