平菇津平90特性及栽培技术   总被引：1，自引：1，他引：1  

班立桐  谷荣祥  高燕  王文治 《天津农业科学》2001,7(2):36-37

介绍了平菇菌种津平 90的特征特性、生长条件及其高产栽培技术。  相似文献   

Rotation and Magnetism of Earth's Inner Core   总被引：1，自引：0，他引：1  

GA Glatzmaier  PH Roberts 《Science (New York, N.Y.)》1996,274(5294):1887-1891

Three-dimensional numerical simulations of the geodynamo suggest that a super- rotation of Earth's solid inner core relative to the mantle is maintained by magnetic coupling between the inner core and an eastward thermal wind in the fluid outer core. This mechanism, which is analogous to a synchronous motor, also plays a fundamental role in the generation of Earth's magnetic field.  相似文献   

The effect of exposure to the atomic bombs on pregnancy termination in Hiroshima and Nagasaki: preliminary report     

NEEL JV  SCHULL WJ  McDONALD DJ  MORTON NE  KODANI M  TAKESHIMA K  ANDERSON RC  WOOD J  BREWER R  WRIGHT S  YAMAZAKI J  SUZUKI M  KITAMURA S 《Science (New York, N.Y.)》1953,118(3071):537-541

  相似文献   

The Anglesey lakes,Wales, UK — Changes in trophic status of three standing waters as inferred from diatom transfer functions and their implications for conservation     

H. BENNION  C. A. DUIGAN  E. Y. HAWORTH  T. E. H. ALLOTT  N. J. ANDERSON  S. JUGGINS  D. T. MONTEITH 《水产资源保护:海洋与淡水生态系统》1996,6(2):81-92

1. A diatom-phosphorus (P) transfer function was applied to fossil diatom assemblages in sediment cores from three Anglesey lakes of conservation importance, in order to reconstruct quantitatively the recent history of total P (TP) concentrations for each lake. The results indicate that all three lakes have been eutrophic throughout the period represented by the cores. 2. The model suggests that Llyn Coron and Llyn Dinam experienced gradual increases in TP concentration (core base to 20 cm), followed by marked, rapid increases from the time represented by a sediment depth of 20 cm (early 1970s for Llyn Coron), most probably associated with agricultural intensification. 3. A recent decline in TP concentration at Llyn Coron and Llyn Dinam, associated with reductions in external P loading, is indicated by the model, although current levels are still considerably higher than those estimated for the base of the cores (Dinam: current=112 μg L⁻¹; base=65 μg L⁻¹, and Coron: current=156 μg L⁻¹; base=70 μg L⁻¹). 4. No clear changes in diatom-inferred TP concentration were observed for Llyn Penrhyn over the 70 year period represented by the core. However, the reconstruction for this lake is inaccurate because: (a) the sediment record appears to be disturbed, and (b) unlike Llyn Coron and Llyn Dinam, diatom preservation and modern analogues are poor, and the present TP concentration (>1 mg L⁻¹) is beyond the TP range of the model. 5. Continued control of the external TP loads from agricultural sources is essential to prevent further increases in lake TP concentrations at Llyn Coron and Llyn Dinam. Given the problems with the Llyn Penrhyn data, it is not possible to draw any firm conclusions regarding future site management. However, the impact of the recent installation of a phosphate stripping plant at the local sewage works should be monitored, to identify whether a reduction in external P loading results in a decrease in epilimnetic TP concentrations, and in turn whether this causes changes to the biological community structure of the lake.  相似文献   

原子吸收分光光度法测定植物中微量元素的研究   总被引：3，自引：1，他引：3  

高淑云 《农业科学与技术》2008,9(2):6-9

采用原子分光光度法测定牛蒡、银杏、银杏叶和大蒜中Se、Cd、Pb含量,以期为该法用于植物微量元素测定提供参考。  相似文献