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991.
A large autochthonic soil of preoligocene age from lower devonian schist of the Eifel Paleosols of Mesozoic-Tertiary age and their sediments are very important for the reconstruction of the landscape history in the area of the Rhenish Massiv. But stratigraphically determined, as well as autochthonous soils with exact analytical datas scarcely exist. Therefore a thick, autochthonous profile of a red fossil soil rich in clay was investigated. It consists of a concretion zone, mottled clay zone and a pallid zone above a 30 m thick saprolithe zone from bleached Devonian clay and silt shales with sandstone layers. Stratigraphical investigations of the superficial layers improve a pre-Oligocene age of soil formation. Results of soil analysis show an absolute accumulation of red coloured Fe oxides in the upper horizons and an intensive formation of kaolinite from chlorites and micas. Quartz underwent solution only in the finest fractions. Desilication did not proceed so far, that gibbsite could be formed. Therefore the molar SiO2 : Al2O3 ratio of the clay fraction does not decrease below 2. Erosion of formerly existing, stronger weathered horizons can't be excluded. According to the FAO-UNESCO soil map of the world and the Soil Taxonomy the criteria for Oxisols and Ferralsols are closely fulfilled. By the systematic of the Federal Republic of Germany the palesol is to be classified as a red-plastosol. 相似文献
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996.
Degradation of 14 C-labeled Diazinon in the rat 总被引:1,自引:0,他引:1
997.
试验研究不同早稻品种灌浆期高温胁迫后根系生理差异结果表明,高温对不同水稻品种根系超氧化物歧化酶、过氧化物酶、过氧化氢酶活性均有影响,但对耐热型品种的影响显著小于热敏感品种,耐热型品种在高温胁迫后保护酶活性能较快恢复并接近对照水平;高温胁迫对耐热型水稻品种根系α-萘胺氧化力无影响,但热敏感品种根系氧化力明显下降,故根系α-萘胺氧化力可作为根系耐热指标之一。 相似文献
998.
Aro TL Larmo PS Bäckman CH Kallio HP Tahvonen RL 《Journal of agricultural and food chemistry》2005,53(5):1482-1488
The fatty acid composition and contents of fat and fat-soluble vitamins of three salted products prepared from Icelandic herring were analyzed. The effects of storage on the products over their shelf life, 6 or 12 months, were investigated. The average oil content of salted, gutted herring and salted fillets in vacuum remained constant, 17 and 12% of wet weight, respectively. In the pickled product the oil content decreased during the 12 months of storage from 13 to 12%. The composition of the products was typical for herring, the most abundant fatty acids being oleic (18:1n-9), palmitic (16:0), cetoleic (22:1n-11), and gadoleic (20:1n-9) acids. Monounsaturated acids constituted clearly the main group with a proportion of >50% of all fatty acids. Eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) comprised together >12% of all fatty acids. During storage, some hydrolysis of triacylglycerol (TAG) occurred, causing a slight reduction in practically all esterified fatty acids. In none of the three products was the loss of polyunsaturated fatty acids from TAG greater than the loss of saturated ones, indicating that the loss of EPA and DHA was not due to oxidation. After packing, the average content of vitamins A, D, and E in the products varied between 27 and 87 microg/100 g (wet weight), between 17-28 microg/100 g (wet weight), and between 77-120 microg/100 g (wet weight), respectively. During storage, the level of vitamin A decreased significantly, whereas no loss of vitamin D was observed. The content of vitamin E was low in all products and showed wide variation. When compared to the recommended daily intake, it could be concluded that the products investigated were good and stable sources of long-chain n-3 fatty acids (EPA, DHA) and vitamin D. 相似文献
999.
G. Benckiser R. Eilts A. Linn H. -J. Lorch E. Sümer A. Weiske F. Wenzhöfer 《Biology and Fertility of Soils》1996,23(3):257-265
Nitrous oxide emissions, nitrate, water-soluble carbon and biological O2 demand (BOD5) were quantified in different cropping systems fertilized with varying amounts of nitrogen (clayey loam, October 1991 to May 1992), in an aerated tank (March 1993 to March 1994), and in the nitrification-denitrification unit (March to July 1994) of a municipal waste water treatment plant. In addition, the N2O present in the soil body at different depths was determined (February to July 1994). N2O was emitted by all cropping systems (mean releases 0.13–0.35 mg N2O m-2 h-1), and all the units of the domestic waste water treatment plant (aerated tank 0–6.2 mg N2O m-2 h-1, nitrification tank 0–204,3 mg N2O m-2, h-1, denitrifying unit 0–2.2 mg N2O m-2 h-1). During the N2O-sampling periods estimated amounts of 0.9, 1.5, 2.4 and 1.4 kg N2O–N ha-1, respectively, were released by the cropping systems. The aerated, nitrifying and denitrifying tanks of the municipal waste water treatment plant released mean amounts of 9.1, 71.6 and 1.8 g N2O–N m-2, respectively, during the sampling periods.The N2O emission were significantly positively correlated with nitrate concentrations in the field plots which received no N fertilizer and with the nitrogen content of the aerated sludge tank that received almost exclusively N in the form of NH
4
+
. Available carbon, in contrast, was significantly negatively correlated with the N2O emitted in the soil fertilized with 80 kg N ha-1 year. The significant negative correlation between the emitted N2O and the carbon to nitrate ratio indicates that the lower the carbon to nitrate ratio the higher the amount of N2O released. Increasing N2O emissions seem to occur at electron donorto-acceptor ratios (CH2O or BOD5-to-nitrate ratios) below 50 in the cropping systems and below 1200–1400 in the waste water treatment plant. The trapped N2O in the soil body down to a depth of 90 cm demonstrates that agricultural production systems seem to contain a considerable pool of N2O which may be reduced to N2 on its way to the atmosphere, which may be transported to other environments or which may be released at sometime in the future.Dedicated to Professor J.C.G. Ottow on the occasion of his 60th birthday 相似文献
1000.
J H Gould S C Hight G H Alvarez C E Nelson S G Capar 《Journal of the Association of Official Analytical Chemists》1990,73(3):401-404
Use of lead glazes on ceramicware and the release of lead from finished glazes are reviewed. Single units of ceramicware with initial lead leach levels from less than 0.1 to 470 micrograms/mL were subjected to multiple automatic dishwashings with intermediate scrubbing of the ware by plastic fiber pads. Ware was periodically leached with 4% acetic acid solution at room temperature for 24 h, and the solutions were analyzed for lead. Release of lead under these conditions is discussed. Results indicated that neither passive leachings nor multiple dishwashings and scrubbings can predict future lead-release characteristics of glazes and decorations. 相似文献