全文获取类型
收费全文 | 93篇 |
免费 | 2篇 |
出版年
2016年 | 1篇 |
2013年 | 3篇 |
2012年 | 3篇 |
2011年 | 1篇 |
2010年 | 8篇 |
2009年 | 5篇 |
2007年 | 2篇 |
2005年 | 2篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1998年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1987年 | 3篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 17篇 |
1974年 | 1篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1966年 | 1篇 |
1959年 | 3篇 |
1958年 | 2篇 |
1957年 | 1篇 |
1956年 | 8篇 |
1955年 | 3篇 |
1954年 | 1篇 |
1953年 | 1篇 |
1951年 | 3篇 |
1950年 | 3篇 |
1949年 | 2篇 |
排序方式: 共有95条查询结果,搜索用时 15 毫秒
31.
32.
33.
34.
35.
36.
37.
SARAH L. O'BRIEN JULIE D. JASTROW DAVID A. GRIMLEY MIQUEL A. GONZALEZ‐MELER 《Global Change Biology》2010,16(9):2573-2588
Revitalization of degraded landscapes may provide sinks for rising atmospheric CO2, especially in reconstructed prairies where substantial belowground productivity is coupled with large soil organic carbon (SOC) deficits after many decades of cultivation. The restoration process also provides opportunities to study the often‐elusive factors that regulate soil processes. Although the precise mechanisms that govern the rate of SOC accrual are unclear, factors such as soil moisture or vegetation type may influence the net accrual rate by affecting the balance between organic matter inputs and decomposition. A resampling approach was used to assess the control that soil moisture and plant community type each exert on SOC and total nitrogen (TN) accumulation in restored grasslands. Five plots that varied in drainage were sampled at least four times over two decades to assess SOC, TN, and C4‐ and C3‐derived C. We found that higher long‐term soil moisture, characterized by low soil magnetic susceptibility, promoted SOC and TN accrual, with twice the SOC and three times the TN gain in seasonally saturated prairies compared with mesic prairies. Vegetation also influenced SOC and TN recovery, as accrual was faster in the prairies compared with C3‐only grassland, and C4‐derived C accrual correlated strongly to total SOC accrual but C3‐C did not. High SOC accumulation at the surface (0–10 cm) combined with losses at depth (10–20 cm) suggested these soils are recovering the highly stratified profiles typical of remnant prairies. Our results suggest that local hydrology and plant community are critical drivers of SOC and TN recovery in restored grasslands. Because these factors and the way they affect SOC are susceptible to modification by climate change, we contend that predictions of the C‐sequestration performance of restored grasslands must account for projected climatic changes on both soil moisture and the seasonal productivity of C4 and C3 plants. 相似文献
38.
MARCELO J. ALFONZO ESTHER PEÑA DE AGUILAR ALBA GUEVARA DE MURILLO SINAÍ SÁNCHEZ DE VILLARROEL RAMONA GONZALEZ DE ALFONZO ADOLFO BORGES 《Journal of receptor and signal transduction research》2013,33(4):269-297
A G protein-coupled natriuretic peptide-guanylyl cyclase receptor-B (NPR-B) located in plasma membranes from bovine tracheal smooth muscle shows complex kinetics and regulation. NPR-B was activated by natriuretic peptides (CNP-53 > ANP-28) at the ligand extracellular domain, stimulated by Gq-protein activators, such as mastoparan, and inhibited by Gi-sensitive chloride, interacting at the juxtamembrane domain. The kinase homology domain was evaluated by the ATP inhibition of Mn2+-activated NPR-B, which was partially reversed by mastoparan. The catalytic domain was studied by kinetics of Mn2+/Mg2+ and GTP, and the catalytic effect with GTP analogues with modifications of the /γ phosphates and ribose moieties. Most NPR-B biochemical properties remained after detergent solubilization but the mastoparan activation and chloride inhibition of NPR-B disappeared. Our results indicate that NPR-B is a highly regulated nano-machinery with domains acting at cross-talk points with other signal transducing cascades initiated by G protein-coupled receptors and affected by intracellular ligands such as chloride, Mn2+, Mg2+, ATP, and GTP. 相似文献
39.
A. GLORIA‐SORIA D. A. KELLNER J. E. BROWN C. GONZALEZ‐ACOSTA B. KAMGANG J. LUTWAMA J. R. POWELL 《Medical and veterinary entomology》2016,30(2):235-240
The mosquito Stegomyia aegypti (= Aedes aegypti) (Diptera: Culicidae) is the primary vector of viruses that cause yellow fever, dengue and Chikungunya fever. In the absence of effective vaccines, the reduction of these diseases relies on vector control strategies. The success of these strategies is tightly linked to the population dynamics of target populations. In the present study, 14 collections from St. aegypti populations separated by periods of 1–13 years were analysed to determine their temporal genetic stability. Although temporal structure is discernible in most populations, the degree of temporal differentiation is dependent on the population and does not obscure the geographic structure of the various populations. The results suggest that performing detailed studies in the years prior to and after population reduction‐ or modification‐based control interventions at each target field site may be useful in assessing the probability of success. 相似文献
40.