The seed shadow of oak ( Quercus liaotungensis Koidz.) was investigated in a broad_leaved deciduous forest in Dongling Mountain in 1997. The seed rain patterns under oak tree crown for three out of four oak trees fit...The seed shadow of oak ( Quercus liaotungensis Koidz.) was investigated in a broad_leaved deciduous forest in Dongling Mountain in 1997. The seed rain patterns under oak tree crown for three out of four oak trees fit quadratic distribution, with high coefficients of determination. For each of the four trees selected in this study the seed rain size estimated from the viable acorns collected from the traps deployed under the crown was low, ranging from 26 to 259. For each of the four oak trees, the average density of the seed rain under oak tree crown ranged from 0.76 to 7.26 seeds/m 2. The average seed rain density estimated from the acorns in the traps deployed randomly in the field was 1.57 seeds/m 2. After all viable acorns fell, the acorn ground density estimated from the acorns in the quadrats was 0.13 seeds/m 2, but no viable acorns were found on the ground under the tree crown of the four oak trees, although the area under the crown was over 5 folds than the area of the combined quadrats. These results indicated that a large number of acorns was removed or predated by vertebrates once the acorns fell on the ground and acorns predation was more intensive in the sites directly under the parent trees than the sites away from the parent trees; this supports the distance_dependent hypothesis. Of the total acorns of all four oak trees, the viable acorns only accounted for 18.1%, and 17.8% for acorns infected by insect larvae, 12.1% for immature acorns, 3.6% for decayed acorns, and the acorns predated by rodent directly in the crown was the highest, accounting for 48.4%. The proportion of acorns predated by animals including vertebrates and invertebrates amounts up to 78.3%, indicating that acorn predation by animals is a limiting factor affecting acorn survival before seed dispersal. The sustained time of viable acorn fall ranged from September 8 to October 3 for the four oak trees, with the peak between 16th and 26th September. The number of acorns was not significantly different among the four directions around the trunk base.展开更多
Two new compounds, named lyciumlignan D(1) and lyciumphenyl propanoid A(2), along with seven known compounds, were isolated from the root bark of Lycium chinense. Their structures were elucidated using spectroscopic d...Two new compounds, named lyciumlignan D(1) and lyciumphenyl propanoid A(2), along with seven known compounds, were isolated from the root bark of Lycium chinense. Their structures were elucidated using spectroscopic data(UV, IR, HR-ESI-MS, 1D and 2D NMR, CD), as well as by comparison with those of the literature. Compounds 3–9 were isolated from this genus for the first time. In the in vitro assay, compounds 3, 6, and 7 exhibited stronger anti-inflammatory effects than the positive control curcumin at a concentration of 10 μmol/L.展开更多
This article presents a general form of the estimator for identifying dispersion effects from unreplicated two-level factorial experiments,and shows that the widely used estimators such as the BH,MH,and AMH estimators...This article presents a general form of the estimator for identifying dispersion effects from unreplicated two-level factorial experiments,and shows that the widely used estimators such as the BH,MH,and AMH estimators are all special cases of the proposed one,designated as the G estimator.The unbiased condition of the G estimator is proved,and a lower bound of variance of the G estimator is provided.A simulation based on a realistic design illustrates the variation of the variance and MSE(mean square error) of the G estimator on different coefficients.This estimator may be more flexible and has better performance than other methods such as the BH and MH estimators by appropriately selecting the coefficients.展开更多
Few studies have to date gone behind the scenes to unveil the hidden metaphor-metonymy structure underpinning the input hypothesis （ Krashen 1981 ） despite overt attention paid to it over the years. In an effort to ...Few studies have to date gone behind the scenes to unveil the hidden metaphor-metonymy structure underpinning the input hypothesis （ Krashen 1981 ） despite overt attention paid to it over the years. In an effort to use a fine-grained metaphor-analysis approach（ e. g. , Lakoffand Johnson 1980, 1999） to revisit the input hypothesis, this study looks into its thrust--the causal effect of comprehensible input upon comprehension--in the hope of charting out its hidden organization. By discovering a theme of CAUSATION pivoted on space-based metaphors and metonyrnies, the present study brings to relief two fallacies committed in the input hypothesis. First, the heavy dependence on the prototypicaUy physical-spatial hierarchy leads to a red-herring fallacy, whose inconsistency defies rather than supports its statement about comprehensible input as the overriding cause. Second, although there is no denying that comprehensible input is a significant source of language gains, to enthrone it as the sole causal variable to the exclusion of all the other important variables, especially the agency of the 1.2 learner who should have been positioned in the spotlight in the first place, is another fallacy of immense magnitude.展开更多
文摘The seed shadow of oak ( Quercus liaotungensis Koidz.) was investigated in a broad_leaved deciduous forest in Dongling Mountain in 1997. The seed rain patterns under oak tree crown for three out of four oak trees fit quadratic distribution, with high coefficients of determination. For each of the four trees selected in this study the seed rain size estimated from the viable acorns collected from the traps deployed under the crown was low, ranging from 26 to 259. For each of the four oak trees, the average density of the seed rain under oak tree crown ranged from 0.76 to 7.26 seeds/m 2. The average seed rain density estimated from the acorns in the traps deployed randomly in the field was 1.57 seeds/m 2. After all viable acorns fell, the acorn ground density estimated from the acorns in the quadrats was 0.13 seeds/m 2, but no viable acorns were found on the ground under the tree crown of the four oak trees, although the area under the crown was over 5 folds than the area of the combined quadrats. These results indicated that a large number of acorns was removed or predated by vertebrates once the acorns fell on the ground and acorns predation was more intensive in the sites directly under the parent trees than the sites away from the parent trees; this supports the distance_dependent hypothesis. Of the total acorns of all four oak trees, the viable acorns only accounted for 18.1%, and 17.8% for acorns infected by insect larvae, 12.1% for immature acorns, 3.6% for decayed acorns, and the acorns predated by rodent directly in the crown was the highest, accounting for 48.4%. The proportion of acorns predated by animals including vertebrates and invertebrates amounts up to 78.3%, indicating that acorn predation by animals is a limiting factor affecting acorn survival before seed dispersal. The sustained time of viable acorn fall ranged from September 8 to October 3 for the four oak trees, with the peak between 16th and 26th September. The number of acorns was not significantly different among the four directions around the trunk base.
基金financially supported by the National Natural Science Foundation of China(No.81303207)CAMS Innovation Fund for Medical Sciences(CIFMS,No.2016-I2M-1-007)
文摘Two new compounds, named lyciumlignan D(1) and lyciumphenyl propanoid A(2), along with seven known compounds, were isolated from the root bark of Lycium chinense. Their structures were elucidated using spectroscopic data(UV, IR, HR-ESI-MS, 1D and 2D NMR, CD), as well as by comparison with those of the literature. Compounds 3–9 were isolated from this genus for the first time. In the in vitro assay, compounds 3, 6, and 7 exhibited stronger anti-inflammatory effects than the positive control curcumin at a concentration of 10 μmol/L.
基金supported by the National Natural Science Fund of China under Grant No.61503228Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi under Grant No.2015106
文摘This article presents a general form of the estimator for identifying dispersion effects from unreplicated two-level factorial experiments,and shows that the widely used estimators such as the BH,MH,and AMH estimators are all special cases of the proposed one,designated as the G estimator.The unbiased condition of the G estimator is proved,and a lower bound of variance of the G estimator is provided.A simulation based on a realistic design illustrates the variation of the variance and MSE(mean square error) of the G estimator on different coefficients.This estimator may be more flexible and has better performance than other methods such as the BH and MH estimators by appropriately selecting the coefficients.
文摘Few studies have to date gone behind the scenes to unveil the hidden metaphor-metonymy structure underpinning the input hypothesis （ Krashen 1981 ） despite overt attention paid to it over the years. In an effort to use a fine-grained metaphor-analysis approach（ e. g. , Lakoffand Johnson 1980, 1999） to revisit the input hypothesis, this study looks into its thrust--the causal effect of comprehensible input upon comprehension--in the hope of charting out its hidden organization. By discovering a theme of CAUSATION pivoted on space-based metaphors and metonyrnies, the present study brings to relief two fallacies committed in the input hypothesis. First, the heavy dependence on the prototypicaUy physical-spatial hierarchy leads to a red-herring fallacy, whose inconsistency defies rather than supports its statement about comprehensible input as the overriding cause. Second, although there is no denying that comprehensible input is a significant source of language gains, to enthrone it as the sole causal variable to the exclusion of all the other important variables, especially the agency of the 1.2 learner who should have been positioned in the spotlight in the first place, is another fallacy of immense magnitude.
