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Two trials were completed to investigate the effects of luprostiol in swine. The first trial was to evaluate parturition induced by various dosages of luprostiol compared with those of lutalyse or vehicle. Sows were assigned by random allotment to one of the following treatments on Day 112 of gestation: Group A, control (0 mg luprostiol); Group B (1.88 mg luprostiol); Group C (3.75 mg luprostiol); Group D (7.5 mg luprostiol); Group E (15 mg luprostiol); Group F (10 mg lutalyse). All prostaglandin-treated groups farrowed earlier than the controls (P<0.05), with Groups D (26.3 h), E (31.0 h) and F (25.8 h) having the shortest treatment-to-first-pig intervals, and Groups A (76.0 h), B (54.4 h) and C (40.0 h) having the longest intervals. Luprostiol-treated sows had the shortest farrowing time (P<0.05; range = 3.2 to 3.9 h). Significant differences were found for the time (min) between births: Group A (32.1), Group B (28.4), Group F (35.5) took longer than Group C (20.2), Group D (21.0) and Group E (21.6). In a second trial, 20 crossbred pregnant sows received either vehicle or luprostiol (7.5 mg) on Day 112 of gestation. Progesterone concentrations declined rapidly (P<0.05) in luprotiol treated females but were unchanged in control females during the 24-h collection period. The results of these trials show 7.5 mg luprostiol to be the most effective dose for inducing farrowing. 相似文献
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High concentrations of dimethyl sulfoxide (DMSO) have been shown to cause gross structural changes in collagen fibers in vitro. As endometrial fibrosis is a major cause of infertility in mares, the effect of serial DMSO infusions on periglandular fibrosis of Category II endometria was investigated. Initially, six mares with Category I endometria were serially infused with DMSO to determine whether such therapy would incite fibrosis. Four mares, serially infused with saline, served as controls in each experiment. One hundred milliliters of 75% DMSO was infused initially, followed by the same volume of 25% DMSO daily for 6 d. Endometrial biopsies obtained 21 d after the last infusion displayed no significant difference in the incidence of periglandular fibrosis when compared with the Day 0 biopsies. Examination of treated uteri at necropsy showed no gross evidence of adhesions or ulcerations. 相似文献
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Modifications of extracellular electric and ionic gradients preceding the transition from tip growth to isodiametric expansion in the apical cell of the fern gametophyte 总被引:1,自引:0,他引:1
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Fern (Onoclea sensibilis L.) gametophytes exposed to blue light are induced to undergo a morphological transition from a tip-growing filament to a planar prothallus. Extracellular measurements of electric currents and localized ion activities around the apical cell of 8 to 10 day-old gametophytes were made with a vibrating probe and ion selective electrodes. In darkness, we observed exit current densities of an average of 75 nanoamperes per square centimeter near the tip and 2 to 15 nanoamperes per square centimeter along the lateral walls of this cell. Measurements with ion selective electrodes for H+, K+, and Ca2+ showed that this cell was bounded by a thin layer of medium that was depleted in K+ and Ca2+ and exhibited a lower pH than the bulk solution. Both the K+ and Ca2+ depletion zones and the zone of higher acidity were particularly pronounced at the tip end of the cell; the pH at 2 micrometers from the tip was nearly 0.5 units more acid than the bulk medium at pH 6. Disruption of steady state, external gradients with media that contained lower concentrations of H+, K+, Ca2+, or Cl− produced certain differences in the rates of restoration of particular ion zones, raising the possibility that some of the ion migrations are interdependent. Within 15 minutes after irradiation with blue light, current leaving the tip declined to levels which were indistinguishable from those leaving the lateral walls and there was a rapid lowering in the rates of tip acidification and K+ depletion near the tip. The rapid dissipation of both the longitudinally aligned electrical field and the tip-localized asymmetries in external cation distribution in blue light suggest that loss of electrical polarity in this tip growing cell may be an initial step in the chain of events which govern changes in cell shape. 相似文献
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银缕梅属——中国金缕梅科一新属 总被引:14,自引:1,他引:13
在研究中国稀有濒危植物过程中,通过三年观察,作者发现小叶金缕梅绝无花瓣,无疑应从金缕梅族中分出,其形态特征又明显与无花瓣的蚊母树族和弗特吉族各属有差别,故成立新属——银缕梅属。 相似文献
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Immunological comparison of the in vitro and in vivo labeled victorin binding protein from susceptible oats 总被引:2,自引:0,他引:2
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The fungus Cochliobolus victoriae causes victoria blight of oats and produces the host-specific toxin victorin. The reaction of oats to the fungus and its toxin is controlled by a single dominant gene whose product has been hypothesized to function as the site of action (receptor) of the toxin in susceptible oat genotypes. Previously, using a biologically active 125I derivative of the toxin, we identified a 100 kilodalton victorin-binding protein (VBP) which binds victorin in a ligand-specific manner and binds in vivo only in susceptible oat genotypes. However, a VBP in both the susceptible and resistant oat genotypes was identified by in vitro binding experiments. One interpretation of the lack of genotype-specific binding in vitro is that the 100 kilodalton protein detected in vitro is not the same 100 kilodalton protein detected in vivo. To clarify the relationship between the 100 kilodalton protein(s) labeled in vivo and in vitro, we developed antisera to the in vitro-labeled VBP from the susceptible genotype and demonstrated that these preparations react with the in vivo-labeled VBP from the susceptible genotype. This finding coupled with previous observations strongly suggest that the VBP observed in vivo is the same protein detected in vitro. Furthermore, the results support our previous observations which suggest that the VBPs labeled in vitro in susceptible and resistant genotypes are closely related or identical. 相似文献
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外源蜕皮激素对蓖麻蚕蛹发育的效应 总被引:2,自引:1,他引:1
本文报道蓖麻蚕蛹在室温28℃下的卵巢发育过程,以及外源20-羟基蜕皮酮对蚕蛹发育的影响。正常蛹在任何发育期内注射20-羟基蜕皮酮后,全部仍羽化成蛾,但蛹期延长约1至4天。无脑蛹经注射后出现蛹——蛾的变态,发育情况因剂量而不同:注射0.1微克后约有半数蛹发育成蛾;注射2微克羽化率较高,卵巢管的发育也最好;4微克或更高的注射量能使全部蛹发育成蛾,但卵巢管多少有些不正常。注射量超过5微克时,蛾体较小,颜色浅黄,没有或只有很少的鳞片。蛹的发育天数随剂量的增大而减少。经外源20-羟基蜕皮酮处理后,无论是有脑蛾或是无脑蛾的卵粒都明显地比正常蛾的卵粒大。当超过一定的注射量时,注射量越大,蚕蛾的自动蜕壳能力越差。 相似文献