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61.
The impacts of blanket peatland management on water tables, near‐surface macropore flow and saturated hydraulic conductivity were investigated using automated dipwells and mini‐disc tension infiltrometers. Three neighbouring hillslopes which were undisturbed, drained and restored by drain blocking were studied. Mean water table depths at the undisturbed sites were slightly shallower than at the restored site and water tables at both sites were significantly shallower relative to the drained treatment. Through time, however, the water table at the restored treatment behaved in a markedly different way to that at the undisturbed site. Water tables reached the peat surface for only 2% of the time for the drained and restored treatments compared to 18% for the undisturbed treatment. The proportion of runoff flowing through macropores in the near‐surface layers of the peat was found to be large (≥60%) across all three treatments, yet functional macroporosity was found to be significantly greater in the undisturbed peat relative to the two other treatments. Meanwhile, saturated hydraulic conductivity was found to be significantly higher at the restored treatment relative to the two other treatments, with mean conductivities ca. 1.5 times greater, suggesting a form of heightened soil–water interaction. Combined, the results indicate that although restoration by ditch blocking may result in a relatively successful water table recovery, there may not be the full reinstatement of peatland hydrological processes. 相似文献
62.
Menşure Özgüven Bilge Şener Ilkay Orhan Nazım Şekeroğlu Muzaffer Kirpik Murat Kartal Ipek Peşin Zülküf Kaya 《Industrial Crops and Products》2008,27(1):60-64
Artemisia annua L. is an aromatic-antibacterial herb that destroys malarial parasites, lowers fevers and checks bleeding, and of which the secondary compound of interest is artemisinin. The objective of the present study was to determine yield, yield components and artemisinin content of A. annua L. grown under four nitrogen applications (0, 40, 80 and 120 kg ha−1) in the Çukurova region of Turkey in 2004 and 2005. Field trials were conducted at Çukurova University, Agricultural Faculty Field Crops Department. In the study, plant height, number of branches, fresh herbage yield, dry herbage yield, fresh leaf yield, dry leaf yield, essential oil content and artemisinin content (by high performance liquid chromatography, HPLC) were examined. By analysis of variance, nitrogen doses had no any statistical effect on the traits investigated except for artemisinin content. Artemisinin content of the dried leaves were significantly affected by nitrogen applications, which varied from 6.32 to 27.50 mg 100 g−1. Contents were from 120 and 80 kg ha−1 nitrogen for the years of 2004 and 2005, respectively. 相似文献
63.
Abstract – Relationships between fish length, otolith size, age and weight were assessed for a population of wild Australian smelt ( Retropinna semoni ) larvae and juveniles captured over a 4-year period to aid further interpretation of growth and condition during the early life history of the species. Nonlinear smoothed generalized additive models best described the fish–otolith size relationship during the larval and juvenile period, indicating that the proportionality between fish length and otolith size varies in relation to size. It is proposed that back-calculated predictions of fish size at a previous age or otolith size, accounting for individual variation is possible by assuming a body proportional hypothesis. Growth rate of larval and juvenile Australian smelt was best described using the Gompertz model that indicated a steady decline in growth rate after around 30 days of age. The allometric growth of larval and juvenile Australian smelt established from the length/weight relationship can subsequently be used to assess the condition of fish within this population using a relative condition or relative weight condition index. The results of the study have provided significant information to enable more precise growth reconstruction and condition assessment for the species in Australian lowland rivers. 相似文献
64.
Hemagglutination and hemagglutination inhibition of turkey red blood cells with Mycoplasma hyopneumoniae 总被引:2,自引:0,他引:2
T F Young B Z Erickson R F Ross Y Wannemuehler 《American journal of veterinary research》1989,50(7):1052-1055
The ability of Mycoplasma hyopneumoniae to agglutinate RBC was evaluated to develop an in vitro cytadsorption assay. Using swine RBC in a microtitration hemagglutination test, no agglutination or partial agglutination was detected. Comparison of RBC from various other species indicated that improved hemagglutination was obtained with RBC from turkeys. This hemagglutination was detected only when mycoplasma cells used in the assay had been frozen and thawed, heated at 50 C for 30 minutes, or treated with trypsin. Treatment of RBC with trypsin or neuraminidase enhanced hemagglutination. Possible surface lectin activity in M hyopneumoniae was evaluated by use of carbohydrates in a blocking assay; hemagglutination was not inhibited by any of 13 carbohydrates evaluated. Mycoplasma hyopneumoniae convalescent porcine serum and monoclonal antibodies against 2 M hyopneumoniae immunogens of molecular weights of 64,000 and 41,000 inhibited hemagglutination. 相似文献
65.
Sunflower cake (SC), horse bean (HB), and alfalfa meal (AM) were treated with rising doses of formaldehyde (F) from 0.0, 0.2 ... 2.0 g F per 100 g crude protein. We have followed the differences of crude protein solubility, its degradability and disappearance of dry matter in the rumen as well as the amount of reversible bonded F from the F dose. With AM it was found a significant influence of ADF on the degradability and on the amount of acid-labile bonded F and/or on the decrease of N solubility. From the total N content the share of soluble nitrogen decreased in SC by 31%, HB by 24%, and in AM only by 12.5%. With the increase of the F dose its protective effect on proteins against the degradability mainly in SC and HB also rose significantly. The degradability of AM protein was influenced more by the incubation time than by the effect of treatment. The degradability of the SC proteins fell from 95% with untreated to 27% treated with the maximum dose. With AM it fell slowly from 84% to 74% by the determination coefficient R2 = 0.77. It was observed a marked decrease in HB only from the dose of 1.28% F. The changes in dry matter disappearance were similar to the changes in crude protein degradability and to the changes of solubility in SC and AM. The in situ method proved very suitable for the determination of the extent of degradability of the feed proteins in the rumen. 相似文献
66.
B.W. Manktelow B.V.Sc. Ph.D. M.R.C.V.S. Dip.Microbiol. W.L. Porter B.V.M.S. M.R.C.V.S. N.Z. K.H.C. Lewis M.Agr.Sc. 《New Zealand veterinary journal》2013,61(12):245-248
A serological survey of 213 randomly chosen dairy farm residents in the Manawatu showed that 66 (34%) of the people who milked cows had leptospiral titres ≤ 1:24 by the Microscopic Agglutination Test. Forty-eight (72.7%) of these people had titres to hardjo, while 29 (43.9%) had titres to pomona. Dual hardjo/pomona titres occurred in 12 people. Ballum and Copenhageni accounted for 8% of the titres found. Women milkers and farm residents who did not milk were all serologically negative. A third of the seropositive milkers had a history of clinical leptospirosis. Other factors which significantly correlated with leptospiral titres included the time spent in the dairy shed during milking, the wearing of shorts, the keeping of pigs for sale, and the number of years the individual had been working on a dairy farm. The type of milking shed and the size of the herd were interrelated and both showed strong trends towards a correlation with serological prevalence. 相似文献
67.
W.J. Hartley M.R.C.V.S. Joan C. Kater B.V.Sc. E.D. Andrews M.Sc. A.N.Z.I.C. 《New Zealand veterinary journal》2013,61(5):118-120
Extract A great deal of evidence has now accumulated that immunity to helminth infection is acquired following natural exposure. Although this immunity is not absolute, animals that have been exposed to infection and survived are able to tolerate a much heavier intake of infective larvae than animals that have never been exposed. 相似文献
68.
The development and reversal of aeolian desertification have been widely recognised as the dominant causes of changes in the source areas of dust storms. The Alashan Plateau, which is near China's Hexi Corridor, is one of the major dust storm source regions in northern China. To investigate the relationship between climatic and anthropogenic factors and the development of aeolian desertification, we reconstructed the temporal and spatial evolution of aeolian desertification and the underlying processes from 1975 to 2007 using Landsat images and analysed the driving forces. The results show that aeolian desertified land in the study area covered 32 847·79 km2 in 2007, amounting to 11·3 per cent of the total area, with an initial period of desertification expansion from 1975 to 2000 and a reversal of desertification from 2000 to 2007. On the basis of the analysis of effects of climate changes and human activities in the region, aeolian desertification was principally driven by human activities in this area; climatic variations had little effect on the area of severe desertification. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
69.
Z Grabarevi? P Dzaja J Peri? V Serman Z Bidin H Mazija N Mas Z Mikulec K Culjak Z Simec B Njari 《Acta veterinaria Hungarica》1999,47(2):233-241
The work describes the effects of cimetidine on stress-induced gizzard erosions (Experiment A) and the influence of the long-term application (42 days) of the same drug on weight gain and feed consumption during broiler fattening (Experiment B). For Experiment A, 60 male, three-day-old chicks were divided into two groups: C (n = 30)--control chicks treated with 0.5 ml saline; CIM (n = 30)--chicks treated with cimetidine in a dose of 5 mg/kg body weight (b. w.) intragastrically. All chicks were stressed using a modified water-immersion stress method according to which the chicks, after 24 h of feed deprivation, were immersed in tap water (17 degrees C) for a few seconds. Under chloroform anaesthesia ten chicks from each group were killed 1, 2 and 3 h after the stressing. The morphometric analysis of gizzard erosion (GE) and histopathological examinations of gizzards were performed for each chick. In Experiment B, 32 one-day-old broilers of both sexes were used. The control group was untreated (n = 16) while the CIM group (n = 16) was fed the same diet supplemented with 10 mg of cimetidine per kilogram of feed throughout the fattening period (42 days). The results of Experiment A showed decreased mean length of the GE in the cimetidine-treated birds as compared with the GE lesions of the controls. In Experiment B, the treated chicks had reduced liveweight (1835.1 g), carcass weight (1474.6 g) and increased feed consumption (2115 g of feed per kilogram of weight gain) compared to the controls in which the same parameters were 1898.5 g, 1574.2 g and 1797 g, respectively. The results show that while stress-induced GE of chicks can be medicated pharmacologically, long-term application of the same substance impairs the results of fattening. 相似文献
70.