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101.
Zafrilla P Ferreres F Tomás-Barberán FA 《Journal of agricultural and food chemistry》2001,49(8):3651-3655
From red raspberries, ellagic acid, its 4-arabinoside, its 4' (4' '-acetyl) arabinoside, and its 4' (4' '-acetyl)xyloside, as well as quercetin and kaempferol 3-glucosides, were identified. In addition, two unidentified ellagic acid derivatives were detected. The free radical scavenging activity of the ellagic acid derivatives was evaluated by using the DPPH method and compared to that of Trolox. All of the isolated compounds showed antioxidant activity. The effect of processing to obtain jams on raspberry phenolics was evaluated. The flavonol content decreased slightly with processing and more markedly during storage of the jams. The ellagic acid derivatives, with the exception of ellagic acid itself, remained quite stable with processing and during 6 months of jam storage. The content of free ellagic acid increased 3-fold during the storage period. The initial content (10 mg/kg of fresh weight of raspberries) increased 2-fold with processing, and it continued increasing up to 35 mg/kg after 1 month of storage of the jam. Then a slight decrease was observed until 6 months of storage had elapsed. The increase observed in ellagic acid could be explained by a release of ellagic acid from ellagitannins with the thermal treatment. 相似文献
102.
Postharvest induction modeling method using UV irradiation pulses for obtaining resveratrol-enriched table grapes: a new "functional" fruit? 总被引:4,自引:0,他引:4
Cantos E Espín JC Tomás-Barberán FA 《Journal of agricultural and food chemistry》2001,49(10):5052-5058
A modeling method for the induction of resveratrol synthesis by UV irradiation pulses in Napoleon table grapes is proposed. The method is based on the combination of four main parameters: irradiation power (IW), irradiation time (IT), irradiation distance (ID), and number of elapsed days to achieve the highest resveratrol accumulation (D(m)). Maximum resveratrol content (11-fold higher than untreated grapes) was achieved using the combination: IW = 510 W, IT = 30 s, ID = 40 cm, and D(m) = 3 days. Sensory characteristics and main features of irradiated grapes (color, weight, firmness, flavor, size, ripening index and vitamin C content) remained unaltered after 1 week of storage. UV induction signal migrated to the hidden side of the grape skin with a delay of 3 days as compared to the directly irradiated side. Phenolic compounds were not detected in Napoleon grape flesh. Resveratrol content per standard serving (200 g) of irradiated grape was about 3 mg, an amount more than 10-fold higher than that of untreated Napoleon grapes. This means that a serving of irradiated grape (unpeeled) could supply the resveratrol content equivalent to 3 glasses of a red wine with high resveratrol content ( approximately 1 mg/glass). Therefore, controlled UV irradiation pulses are useful as a simple postharvest treatment (and alternative to genetic engineering) to obtain possible "functional" grapes (with enhanced health-promoting properties) as a dietary source of high resveratrol content. 相似文献
103.
Effect of postharvest storage and processing on the antioxidant constituents (flavonoids and vitamin C) of fresh-cut spinach 总被引:7,自引:0,他引:7
Gil MI Ferreres F Tomás-Barberán FA 《Journal of agricultural and food chemistry》1999,47(6):2213-2217
The effect of modified atmosphere packaging (MAP) and cooking on the flavonoids and vitamin C content (ascorbic + dehydroascorbic acid; AA + DHAA) of fresh-cut spinach was evaluated. The total flavonoid content (approximately 1000 mg kg(-)(1) f.w.) remained quite constant during storage in both air and MAP atmospheres, while vitamin C (750 mg kg(-)(1)f.w.) was better preserved in MAP-stored spinach. AA was transformed to DHAA during storage, and its concentration was higher in MAP-stored tissues. The free-radical scavenging activity of the isolated flavonoids was tested, and only those flavonoids with either a dihydroxyl grouping or acylated with ferulic acid showed significant activity. A decrease in the total antioxidant activity was observed during storage, particularly important in MAP-stored spinach. The higher content of DHAA and lower content of both AA and antioxidant flavonoids in the MAP-stored samples could explain this antioxidant activity decrease. Boiling extracted 50% of total flavonoids and 60% vitamin C in the cooking water. However, flavonoid glucuronides were extracted more in the cooking water than the other glycosides. The vitamin C content of the cooked tissue was higher in those samples stored in MAP. 相似文献
104.
FTIR study of glyphosate-copper complexes 总被引:4,自引:0,他引:4
Complexes of the herbicide glyphosate (GPS) and the heavy metal Cu were studied by infrared spectroscopy under controlled pH, in order to know the mechanisms involved in the formation of these complexes. In CuGPS(-), the IR spectrum shows participation of the carboxylate and phosphonic moieties of the GPS molecule. The formation of the complex produces a lower symmetry in the phosphonate group because of loss of the resonance situation of PO(3)(2)(-) groups, with a subsequent split of their absorption bands. Carboxylate groups are participating by forming unidentate complexes. No conclusion is reached about the involvement of the amino group, but previous EPR findings indicate coordination of GPS to Cu via nitrogen. Consequently, glyphosate in this complex functions with a tridentate character by forming two chelate rings. A study of the CuGPSH species was not possible due to overlapping of its absorption bands with those of free GPS species. 相似文献
105.
Until recently, demonstration of infectious pancreatic necrosis was conditioned by the isolation of virus. By means of the immunofluorescence method it is possible to make a rapid and accurate diagnosis, as well as to determine the development of infection. In acute cases, the virus in fry was demonstrated mainly in the cytoplasm of epithelial cells of guts; in Pd1-2 trout, the virus was proved in the cytoplasm of epithelial cells of primary kidney tubules and in the cytoplasm of epithelial cells of pancreatic acini. In all cases the virus occurrence demonstrated by immunofluorescence was in correlation with the results achieved by cultivation methods. 相似文献
106.
Resolution of a Left Ureteral Stone Using Electrohydraulic Lithotripsy in a Thoroughbred Colt 总被引:1,自引:0,他引:1
Lynn D. Rodger Gary P. Carlson Michael E. Moran Tom B. Yarbrough John R. Pascoe Jay A. Reynolds 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1995,9(4):280-282
A 3-year-old Thoroughbred colt was presented for evaluation of azotemia and anorexia. Physical examination revealed a ureterolith in the left ureter, approximately 10 cm from the bladder, which was thought to obstruct urine flow by approximately 90% when viewed cystoscopically. Ultrasonographic examination of both kidneys revealed indistinct corticomedullary junctions, and the right kidney was more hyperechoic. A percutaneous biopsy of the right kidney revealed chronic interstitial nephritis with marked interstitial medullary fibrosis. Medical therapy consisting of IV fluids, sodium chloride PO, and ammonium chloride PO was initiated. Ureteroscopic electrohydraulic lithotripsy via a perineal urethrostomy was used to successfully remove the stone. Klebsiella oxytoca , which responded to oral enrofloxacin therapy, was cultured from the urine after surgery. Azotemia resolved and the horse resumed training. 相似文献
107.
The metabolism of amino acids and urea in an isolated perfused wall of sheep rumen was studied by the method of organ perfusion, using 3 kinds of perfusate. In experiments with semisynthetic perfusate containing urea (SPurea) the levels of lysine, valine, glutamic acid and alanine increased at a simultaneous decrease of levels of leucine, arginine, aspartic acid, threonine and methionine. In perfusions with the semisynthetic medium without urea (SP) the levels of lysine, valine, phenylalanine, isoleucine, glutamic acid, glycine and alanine increased, the level of threonine dropped. In perfusions with whole autologous blood (KP) the levels of valine, glutamic acid and alanine increased, the level of arginine decreased. The level of urea decreased sharply at using SPurea and KP, however, the equal cumulation of ammonia (200-400 mumol x 1(-1)) was found in all three types of perfusate after 2-hr perfusion. Moreover, in experiments with SP a low level of urea was found already after 5-min. of perfusion. The results of the experiments suggest that the rumen wall is capable of producing amino acids also without the contents of rumen, and that independently on the presence or absence of urea as a nitrogen source. 相似文献
108.
109.
110.
Porter TE 《Domestic animal endocrinology》2005,29(1):52-62
Anterior pituitary somatotroph differentiation occurs during chick embryonic and rat fetal development. A number of findings support the hypothesis that differentiation of these growth hormone (GH) producing cells in the chick and the rat is regulated by adrenal glucocorticoids and thyroid hormones. Somatotroph differentiation can be induced in cultures of chick embryonic and rat fetal pituitary cells with adrenal glucocorticoids and this effect can be modulated by concomitant treatment with thyroid hormones. Plasma levels of thyroid hormones, corticosterone and adrenocorticotropic hormone increase during development, consistent with the ontogeny of somatotrophs. Treatment of chick embryos or rat fetuses with glucocorticoids in vivo induces premature somatotroph differentiation, indicating that the adrenal gland, and ultimately anterior pituitary corticotrophs, may function to regulate pituitary GH cell differentiation during development. Administration of thyroid hormones in vivo also increases somatotrophs prematurely, and administration of the thyroid hormone synthesis inhibitor methimazole inhibits somatotroph differentiation in vivo, suggesting that endogenous thyroid hormone synthesis contributes to normal somatotroph differentiation. Our working model for the regulation of somatotroph differentiation during normal development includes modulation by elements of the hypothalamo-pituitary-adrenal and hypothalamo-pituitary-thyroid axes. Additional research is reviewed defining the mechanism of action for these peripheral hormones in induction of pituitary GH gene expression during development. 相似文献