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521.
Walsh T McClellan JM McCarthy SE Addington AM Pierce SB Cooper GM Nord AS Kusenda M Malhotra D Bhandari A Stray SM Rippey CF Roccanova P Makarov V Lakshmi B Findling RL Sikich L Stromberg T Merriman B Gogtay N Butler P Eckstrand K Noory L Gochman P Long R Chen Z Davis S Baker C Eichler EE Meltzer PS Nelson SF Singleton AB Lee MK Rapoport JL King MC Sebat J 《Science (New York, N.Y.)》2008,320(5875):539-543
Schizophrenia is a devastating neurodevelopmental disorder whose genetic influences remain elusive. We hypothesize that individually rare structural variants contribute to the illness. Microdeletions and microduplications >100 kilobases were identified by microarray comparative genomic hybridization of genomic DNA from 150 individuals with schizophrenia and 268 ancestry-matched controls. All variants were validated by high-resolution platforms. Novel deletions and duplications of genes were present in 5% of controls versus 15% of cases and 20% of young-onset cases, both highly significant differences. The association was independently replicated in patients with childhood-onset schizophrenia as compared with their parents. Mutations in cases disrupted genes disproportionately from signaling networks controlling neurodevelopment, including neuregulin and glutamate pathways. These results suggest that multiple, individually rare mutations altering genes in neurodevelopmental pathways contribute to schizophrenia. 相似文献
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As monkeys perform schedules containing several trials with a visual cue indicating reward proximity, their error rates decrease as the number of remaining trials decreases, suggesting that their motivation and/or reward expectancy increases as the reward approaches. About one-third of single neurons recorded in the anterior cingulate cortex of monkeys during these reward schedules had responses that progressively changed strength with reward expectancy, an effect that disappeared when the cue was random. Alterations of this progression could be the basis for the changes from normal that are reported in anterior cingulate population activity for obsessive-compulsive disorder and drug abuse, conditions characterized by disturbances in reward expectancy. 相似文献
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Jiang L Althoff EA Clemente FR Doyle L Röthlisberger D Zanghellini A Gallaher JL Betker JL Tanaka F Barbas CF Hilvert D Houk KN Stoddard BL Baker D 《Science (New York, N.Y.)》2008,319(5868):1387-1391
The creation of enzymes capable of catalyzing any desired chemical reaction is a grand challenge for computational protein design. Using new algorithms that rely on hashing techniques to construct active sites for multistep reactions, we designed retro-aldolases that use four different catalytic motifs to catalyze the breaking of a carbon-carbon bond in a nonnatural substrate. Of the 72 designs that were experimentally characterized, 32, spanning a range of protein folds, had detectable retro-aldolase activity. Designs that used an explicit water molecule to mediate proton shuffling were significantly more successful, with rate accelerations of up to four orders of magnitude and multiple turnovers, than those involving charged side-chain networks. The atomic accuracy of the design process was confirmed by the x-ray crystal structure of active designs embedded in two protein scaffolds, both of which were nearly superimposable on the design model. 相似文献
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Heritability of spotted wilt resistance in a Florida‐EP™ “113”‐derived peanut (Arachis hypogaea) population 下载免费PDF全文
Yu‐Chien Tseng Barry L. Tillman Salvador A. Gezan Jianping Wang Diane L. Rowland 《Plant Breeding》2018,137(4):614-620
Spotted wilt, caused by tomato spotted wilt virus (TSWV), is a major disease of peanut (Arachis hypogaea ) in the south‐eastern United States. Cultivar resistance is the most important factor in disease control. However, spotted wilt resistance in current cultivars still carries risk in the absence of other practices when disease is severe. In contrast, a newly developed cultivar, Florida‐EP? “113,” has demonstrated excellent resistance even when spotted wilt is severe. Information on heritability of this resistance can help breeders better utilize it in breeding. F2‐derived populations from the cross Florida‐EP? “113”/Georgia Valencia were developed and tested in field experiments in Florida from 2012 to 2014. Disease symptoms were evaluated visually, and the frequency of TSWV infection was measured by ImmunoStrip®. Heritability estimated from ImmunoStrip® was higher (0.66) compared to visual ratings (0.48). Genetic correlations among evaluation methods (r A = 0.92–0.99) and environments (r B = 0.86–0.99) were high. These results indicate that resistance in Florida‐EP? “113” is highly heritable and that selection in a high disease risk environment is feasible without significant erosion of genetic gain. 相似文献
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Aynalem Dilla Philip J. Smethurst Karen Barry David Parsons Mekuria Denboba 《Agroforestry Systems》2018,92(6):1699-1709
A number of agroforestry models have been developed to simulate growth outcomes based on the interactions between components of agroforestry systems. A major component of this interaction is the impact of shade from trees on crop growth and yield. Capability in the agricultural production systems simulator (APSIM) model to simulate the impacts of shading on crop performance could be particularly useful, as the model is already widely used to simulate agricultural crop production. To quantify and simulate the impacts of shading on maize performance without trees, a field experiment was conducted at Melkassa Agricultural Research Centre, Ethiopia. The treatments contained three levels of shading intensity that reduced incident radiation by 0 (control), 50 and 75% using shade cloth. Data from a similar field experiment at Machakos Research Station, Kenya, with 0, 25 and 50% shading were also used for simulation. APSIM adequately simulated maize grain yield (r2 = 0.97) and total above-ground biomass (r2 = 0.95) in the control and in the 50% treatments at Melkassa, and likewise in the control (r2 = 0.99), 25% (r2 = 0.90) and 50% (r2 = 0.98) treatments at Machakos. Similarly, APSIM effectively predicted Leaf Area Index attained at the flowering (r2 = 0.90) and maturity (r2 = 0.94) stages. However, APSIM under-estimated maize biomass and yield at 75% shading. In conclusion, the model can be reliably employed to simulate maize productivity in agroforestry systems with up to 50% shading, but caution is required at higher levels of shading. 相似文献
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Christopher Hedstrom David Lowenstein Heather Andrews Barry Bai Nik Wiman 《Journal of pest science》2017,90(4):1169-1179
Trissolcus japonicus is an egg parasitoid of Halyomorpha halys, brown marmorated stink bug, a severe agricultural pest in the USA. T. japonicus is being evaluated in quarantine as a classical biological control agent to manage H. halys populations in the USA. To determine T. japonicus’ potential for successful management of the pest, we performed a series of no-choice and paired-host-range tests, evaluating parasitism and host recognition in ten nontarget insects. In laboratory no-choice tests, T. japonicus successfully parasitized egg masses of seven Pentatomidae native to Oregon in addition to H. halys. Mean parasitism proportions of egg masses were greater than 40% in two species, B. dimidiata and H. abbreviatus, and were statistically similar to parasitism of H. halys. However, paired-host tests identified higher proportions of parasitized H. halys egg masses compared to four other pentatomids. T. japonicus was equally attracted to volatiles produced by H. halys and other pentatomids but demonstrated significantly longer arrestment response time on surfaces with H. halys contact kairomones. Although host acceptance patterns were similar between stink bug species, our results suggest a greater potential for parasitoid development in H. halys eggs compared to the native pentatomids. During host-range testing, we detected field populations of T. japonicus at 11 sites in Portland, OR, indicating an unintentional introduction and establishment. Further work is needed to characterize its nontarget activity and dispersal patterns in areas where H. halys causes economic damage in Oregon. 相似文献