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111.
Budong Qian Reinder De Jong Richard Warren Aston Chipanshi Harvey Hill 《Agricultural and Forest Meteorology》2009,149(6-7):1022-1031
A study to forecast regional spring wheat (Triticum aestivum L.) yields on the Canadian Prairies was conducted, based on simulated daily water use and soil water contents derived from the National Drought Model. Empirical linear regression models were calibrated from 1976 to 2006 spring wheat yield data for this purpose. Potential predictors assessed were mainly those indicators related to water stress conditions at different crop growth stages. Stepwise regression and cross-validation were employed for the selection of the predictors in multivariate linear regression models used for forecasting spring wheat yields from seeding to harvest. The cross-validated “forecasts” for 1976–2006, using data up to harvest, explained 77%, 64%, 63% and 70% of yield variances, respectively, for Alberta, Saskatchewan, Manitoba and the entire Prairie region. Root mean squared error of the “forecasts” ranged from 8% to 11% of the average yields. The prediction accuracy earlier in the season was often lower than later in the season. Usable prediction accuracy was found by the middle of the growing season (around heading or anthesis), but only marginally effective at seeding time, especially so for Saskatchewan. 相似文献
112.
Hak Jin Kim Yong Woo Kim In Sook Lee Jong Woon Song Yeon Joo Jeong Seon Hee Choi Kyung Un Choi Kuen Tak Suh Byung Mann Cho 《Acta veterinaria Scandinavica》2009,51(1):30
Background
To test the hypothesis that triolein emulsion will increase vascular permeability of skeletal muscle.Methods
Triolein emulsion was infused into the superficial femoral artery in rabbits (triolein group, n = 12). As a control, saline was infused (saline group, n = 18). Pre- and post-contrast T1-weighted MR images were obtained two hours after infusion. The MR images were qualitatively and quantitatively evaluated by assessing the contrast enhancement of the ipsilateral muscles. Histologic examination was performed in all rabbits.Results
The ipsilateral muscles of the rabbits in the triolein group showed contrast enhancement, as opposed to in the ipsilateral muscles of the rabbits in the saline group. The contrast enhancement of the lesions was statistically significant (p < 0.001). Histologic findings showed that most examination areas of the triolein and saline groups had a normal appearance.Conclusion
Rabbit thigh muscle revealed significantly increased vascular permeability with triolein emulsion; this was clearly demonstrated on the postcontrast MR images. 相似文献113.
Marian E.H. Bos Mirjam Nielen Guus Koch Annemarie Bouma Mart C.M. De Jong Arjan Stegeman 《Preventive veterinary medicine》2009,88(4):278-285
To optimize control of an avian influenza outbreak knowledge of within-flock transmission is needed. This study used field data to estimate the transmission rate parameter (β) and the influence of risk factors on within-flock transmission of highly pathogenic avian influenza (HPAI) H7N7 virus in the 2003 epidemic in The Netherlands. The estimation is based on back-calculation of daily mortality data to fit a susceptible-infectious-dead format, and these data were analysed with a generalized linear model. This back-calculation method took into account the uncertainty of the length of the latent period, the survival of an infection by some birds and the influence of farm characteristics. After analysing the fit of the different databases created by back-calculation, it could be concluded that an absence of the latency period provided the best fit. The transmission rate parameter (β) from these field data was estimated at 4.50 per infectious chicken per day (95% CI: 2.68–7.57), which was lower than what was reported from experimental data. In contrast to general belief, none of the studied risk factors (housing system, flock size, species, age of the birds in weeks and date of depopulation) had significant influence on the estimated β. 相似文献
114.
A 3-year-old, neutered male Persian cat with chronic ulcerative facial dermatitis was diagnosed with feline idiopathic facial dermatitis based on signalment, clinical history and diagnostic test results, including dermatohistopathological evaluation. Initial treatment started with 4 weeks of oral antifungal/antibiotic medication for severe secondary infectious dermatitis of Malassezia and bacteria. As the lesions gradually improved, the oral medication was withdrawn, leaving only 0.1% topical FK506 (tacrolimus) ointment for the remaining lesions. Topical treatment was administered just in case any new lesions developed. The patient has been managed effectively with topical tacrolimus and no side-effects were observed during treatment. Feline idiopathic facial dermatitis is known as a difficult dermatosis to manage successfully, but our experience suggests that it may respond to topical tacrolimus. 相似文献
115.
A melt-process was used to prepare high molecular weight Poly(vinyl chloride) (PVC) films without the use of a conventional
plasticizer and heat stabilizer. Rigid PVC powder was swollen with dimethylformamide containing 4∼10 vol% water to reduce
its melting temperature. The swollen powder was pressed at a relatively low temperature of 75∼125 °C to form a film shape,
and then washed and dried. The visible light transmittance, X-ray diffraction, density and the tensile properties of the resulting
films were examined to estimate the success or failure of film formation. The films could be produced by not only the melt-process
but also a compression-process using the rigid, highly swollen PVC powder. The resulting films had no voids, which are generally
observed in PVC products formed by a solution process. The minimum temperature for these processes decreased with decreasing
water content in the mixture: The minimum temperatures according to the water content in the mixture to produce faultless
films through the melt-process were 4 %–105 °C, 6 %–115 °C, 8 and 10 %–125 °C, while those through the compression process
were 4 %–95 °C, 6 and 8 %–105 °C, 10 %–115 °C. 相似文献
116.
The dynamics of the friction yarn formation process is described in terms of the dynamic behavior of the process state variables.
Production efficiency and product quality of friction spinning are influenced by these process state variables. This study
was performed with the intention of setting up a dynamic model based on mass balance in order to delineate the dynamic behavior
of the cross-sectional area of the in-process bundle on the friction drum surface and to attain the distribution profiles
of the cross-sectional area in transient state and in steady state as well. Then, simulation results were compared with those
of the experiment, while the input variation was used as a test signal. Theoretical model shows that the bundle thickness
on the friction drum has the dynamic characteristics of an integrating system with interval due to the finite length of the
input fleece zone, and is in good correspondence with the results of the experiment. A periodic change in the fleece feeding
rate led to the fact that there was a specific range of the fluctuation wavelength in the fleece feeding rate, whereas a change
in the in-process bundle thickness completely disappeared or became locally maximized in certain wavelength areas. This could
lead to a magnification or inaction of the perturbations with the corresponding wavelength in the bundle thickness; a bundle
thickness irregularity. Experiments also identified that the theoretical model accurately described the fiber accumulation
dynamics in a friction spinning process. 相似文献
117.
118.
Yong Hoon Lee Seungdon Lee Dong Hee Lee Sang Hye Ji Hyun Young Chang Sunggi Heu Jae Wook Hyun Dong-Soo Ra Eun Woo Park 《European journal of plant pathology / European Foundation for Plant Pathology》2008,120(1):97-102
Soil-borne cereal mosaic virus (SBCMV) causes a severe disease in susceptible cultivars of winter wheat. The virus is vectored by the soil-borne protist
Polymyxa graminis. Experiments were conducted to investigate whether SBCMV RNA2 could persist in seed from SBCMV-infected susceptible cultivars
of winter wheat. Over 7,000 seedlings were generated from seed collected from two cultivars of SBCMV-infected winter wheat.
Seedlings were grown in a glasshouse compartment and batch tested for the presence of SBCMV using real-time RT-PCR. The majority
of batches tested positive for SBCMV, indicating an RNA2 transmission rate of 1.8–9.4% in wheat. The presence of the virus
was confirmed by amplifying and sequencing a larger (400 bp) fragment of viral RNA2 in a sub-set of the seedlings testing
positive by real-time RT-PCR. Root extracts from this sub-set tested negative for P. graminis using real-time PCR. The implications for disease epidemiology of this virus are discussed.
The authors are British Civil Servants and as such their work is subject to British Crown Copyright. This means the exclusive
copyright for the article cannot be transferred. 相似文献
119.
120.
Chanseok Ryu Masahiko Suguri Michihisa Iida Mikio Umeda Chungkeun Lee 《Precision Agriculture》2011,12(3):378-394
In this study, protein content (PC) of brown rice before harvest was established by remote sensing (RS) and analyzed to select
the key management factors that cause variation of PC using a GIS database. The possibility of finding out the key management
factors using GreenNDVI was tested by combining RS and a GIS database. The study site was located at Yagi basin (Japan) and
PC for seven districts (85 fields) in 2006 and nine districts (73 fields) in 2007 was investigated by a rice grain taste analyzer.
There was spatial variability between districts and temporal variability within the same fields. PC was predicted by the average
of GreenNDVI at sampling points (Point GreenNDVI) and in the field (Field GreenNDVI). The accuracy of the Point GreenNDVI
model (r
2 > 0.424, RMSE < 0.256%) was better than for the Field GreenNDVI model (r
2 > 0.250, RMSE < 0.298%). A general-purpose model (r
2 = 0.392, RMSE = 0.255%) was established using 2 years data. In the GIS database, PC was separated into two parts to compare
the difference in PC between the upper (mean + 0.5SD) and lower (mean − 0.5SD) parts. Differences in PC were significant depending
on the effective cumulative temperature (ECT) from transplanting to harvest (Factor 4) in 2007 but not in 2006. Because of
the difference in ECT depending on vegetation term (from transplanting to sampling), PC was separated into two groups based
on the mean value of ECT as the upper (UMECT) and lower (LMECT) groups. In 2007, there were significant differences in PC
at LMECT group between upper and lower parts depending on the ECT from transplanting to last top-dressing (Factor 2), the
amount of nitrogen fertilizer at top-dressing (Factor 3) and Factor 4. When the farmers would have changed their field management,
it would have been possible to decrease protein contents. Using the combination of RS and GIS in 2006, it was possible to
select the key management factor by the difference in the Field GreenNDVI. 相似文献