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121.
Brüning P Haase I Matissek R Fischer M 《Journal of agricultural and food chemistry》2011,59(22):11910-11917
According to German food guidelines, almonds are the only oilseed ingredient allowed for the production of marzipan. Persipan is a marzipan surrogate in which the almonds are replaced by apricot or peach kernels. Cross-contamination of marzipan products with persipan may occur if both products are produced using the same production line. Adulterations or dilutions, respectively, of marzipan with other plant-derived products, for example, lupine or pea, have also been found. Almond and apricot plants are closely related. Consequently, classical analytical methods for the identification/differentiation often fail or are not sensitive enough to quantify apricot concentrations below 1%. Polymerase chain reaction (PCR)-based methods have been shown to enable the differentiation of closely related plant species in the past. These methods are characterized by high specificity and low detection limits. Isolation methods were developed and evaluated especially with respect to the matrix marzipan in terms of yield, purity, integrity, and amplificability of the isolated DNA. For the reliable detection of apricot, peach, pea, bean, lupine, soy, cashew, pistachio, and chickpea, qualitative standard and duplex PCR methods were developed and established. The applicability of these methods was tested by cross-reaction studies and analysis of spiked raw pastes. Contaminations at the level of 0.1% could be detected. 相似文献
122.
E E McConnell G W Lucier R C Rumbaugh P W Albro D J Harvan J R Hass M W Harris 《Science (New York, N.Y.)》1984,223(4640):1077-1079
Soil environmentally contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was given by gavage to guinea pigs and rats. The development of a characteristic clinicopathologic syndrome in guinea pigs, the induction of aryl hydrocarbon hydroxylase in rats, and the presence of TCDD in the livers of both species show that TCDD in soil exhibits high biological availability after ingestion. 相似文献
123.
Bechtluft P van Leeuwen RG Tyreman M Tomkiewicz D Nouwen N Tepper HL Driessen AJ Tans SJ 《Science (New York, N.Y.)》2007,318(5855):1458-1461
How chaperone interactions affect protein folding pathways is a central problem in biology. With the use of optical tweezers and all-atom molecular dynamics simulations, we studied the effect of chaperone SecB on the folding and unfolding pathways of maltose binding protein (MBP) at the single-molecule level. In the absence of SecB, we find that the MBP polypeptide first collapses into a molten globulelike compacted state and then folds into a stable core structure onto which several alpha helices are finally wrapped. Interactions with SecB completely prevent stable tertiary contacts in the core structure but have no detectable effect on the folding of the external alpha helices. It appears that SecB only binds to the extended or molten globulelike structure and retains MBP in this latter state. Thus during MBP translocation, no energy is required to disrupt stable tertiary interactions. 相似文献
124.
Wild P Farhan H McEwan DG Wagner S Rogov VV Brady NR Richter B Korac J Waidmann O Choudhary C Dötsch V Bumann D Dikic I 《Science (New York, N.Y.)》2011,333(6039):228-233
Selective autophagy can be mediated via receptor molecules that link specific cargoes to the autophagosomal membranes decorated by ubiquitin-like microtubule-associated protein light chain 3 (LC3) modifiers. Although several autophagy receptors have been identified, little is known about mechanisms controlling their functions in vivo. In this work, we found that phosphorylation of an autophagy receptor, optineurin, promoted selective autophagy of ubiquitin-coated cytosolic Salmonella enterica. The protein kinase TANK binding kinase 1 (TBK1) phosphorylated optineurin on serine-177, enhancing LC3 binding affinity and autophagic clearance of cytosolic Salmonella. Conversely, ubiquitin- or LC3-binding optineurin mutants and silencing of optineurin or TBK1 impaired Salmonella autophagy, resulting in increased intracellular bacterial proliferation. We propose that phosphorylation of autophagy receptors might be a general mechanism for regulation of cargo-selective autophagy. 相似文献
125.
Weis P 《Science (New York, N.Y.)》2002,298(5601):2109-2110
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127.
Recombinant human tumor necrosis factor-alpha: effects on proliferation of normal and transformed cells in vitro 总被引:118,自引:0,他引:118
B J Sugarman B B Aggarwal P E Hass I S Figari M A Palladino H M Shepard 《Science (New York, N.Y.)》1985,230(4728):943-945
Modulation of the growth of human and murine cell lines in vitro by recombinant human tumor necrosis factor-alpha (rTNF-alpha) and recombinant human interferon-gamma (rIFN-gamma) was investigated. rTNF-alpha had cytostatic or cytolytic effects on only some tumor cell lines. When administered together with rIFN-gamma, rTNF-alpha showed enhanced antiproliferative effects on a subset of the cell lines tested. In contrast to its effects on sensitive tumor cells, rTNF-alpha augmented the growth of normal diploid fibroblasts. Variations in the proliferative response induced by rTNF-alpha were apparently not due to differences in either the number of binding sites per cell or their affinity for rTNF-alpha. These observations indicate that the effects of rTNF-alpha on cell growth are not limited to tumor cells, but rather that this protein may have a broad spectrum of activities in vivo. 相似文献
128.
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130.
Patrick Hildebrandt Philipp Kirchlechner Andreas Hahn Thomas Knoke Rodrigo Mujica H. 《European Journal of Forest Research》2010,129(5):935-946
Financial assessment in forestry is characterized by considerable impacts of risk factors due to large time horizons. Accounting
for the risk of timber price fluctuation mixtures of Rauli (Nothofagus alpina, P. et E., OERST.) and Douglas fir (Pseudotsuga menziesii, Mirb.) have been evaluated by different approaches. The data were taken from plantations in Southern Chile between 39°10′
and 39°50′ south latitude. Increments have been modelled in order to calculate possible financial returns and changed volume
growth has been taken into consideration for mixtures of large blocks and single-tree mixtures of both species. The optimum
proportions of both species varied depending on the different perspectives of the financial assessment: first, the effects
of diversification shown by classical portfolio approach were low; second, the integration of moderate risk aversion of the
decision maker resulted in predominance of stands with high proportions of Douglas fir, but optimum proportions of Rauli increased
with higher degrees of risk aversion. The maximization of the expected surplus in relation to the fluctuation of net present
values (NPVs) (Sharpe ratio) resulted in even higher optimum proportions of Rauli. However, mixed stands proved more advantageous
in contrast to the financial assessment without consideration of the risk factor timber price fluctuation (maximization of
NPV). Finally, the integration of further risk factors can have impacts on the results as well as the integration of further
effects of single-tree mixtures. Both lacks of information should be investigated for more extensive assessments in the future. 相似文献