Dear Editor： Therapeutically active metabolite contents in a med- icinal plant vary in nature, which may impact on its therapeutic efficacy. Bergenia （Saxifragaceae） is an evergreen perennial herb widely distribut...Dear Editor： Therapeutically active metabolite contents in a med- icinal plant vary in nature, which may impact on its therapeutic efficacy. Bergenia （Saxifragaceae） is an evergreen perennial herb widely distributed in Central and East Asia with about 30 species reported worldwide. It grows at a range of altitudes from the Khasia hills at 400 feet to the temperate Himalayas from Kashmir to Bhutan at 7,000-10,000 feet. Its distribution over a wide range of altitudinal zones makes it a good candidate for studying variations in its metabolic profiles under different climatic conditions. Bergenin （C-glycoside of 4-O-methyl gallic acid） has been identified as a potent active secondary metabolite in Bergenia and other therapeutically active constituents including, among others, gallic acid （3,4,5 trihydroxybenzoic acid）, （＋） catechin, and gallicin （Fig. 1）.展开更多
It is recognized that the nucleate pool boiling data available in literature are mainly related to four known correlations, each differs from the other by a varying magnitude of constant coefficients, depending on res...It is recognized that the nucleate pool boiling data available in literature are mainly related to four known correlations, each differs from the other by a varying magnitude of constant coefficients, depending on restrictive experimental conditions. The present work is concerned in developing an empirically generalized correlation, which covers the entire range of nucleate boiling with a minimum possible deviation from experimental data. The least squares multiple regression technique is used to evaluate the best coefficient value used in the correlations. An empirical correlation that fits a broader scope of available data has been developed by a non-linear solution technique leading to the following equation: where the coefficients R1 and R3 both represent the effect of surface-liquid combination. They are assessed independently for the used surface material and liquid.展开更多
文摘Dear Editor： Therapeutically active metabolite contents in a med- icinal plant vary in nature, which may impact on its therapeutic efficacy. Bergenia （Saxifragaceae） is an evergreen perennial herb widely distributed in Central and East Asia with about 30 species reported worldwide. It grows at a range of altitudes from the Khasia hills at 400 feet to the temperate Himalayas from Kashmir to Bhutan at 7,000-10,000 feet. Its distribution over a wide range of altitudinal zones makes it a good candidate for studying variations in its metabolic profiles under different climatic conditions. Bergenin （C-glycoside of 4-O-methyl gallic acid） has been identified as a potent active secondary metabolite in Bergenia and other therapeutically active constituents including, among others, gallic acid （3,4,5 trihydroxybenzoic acid）, （＋） catechin, and gallicin （Fig. 1）.
文摘It is recognized that the nucleate pool boiling data available in literature are mainly related to four known correlations, each differs from the other by a varying magnitude of constant coefficients, depending on restrictive experimental conditions. The present work is concerned in developing an empirically generalized correlation, which covers the entire range of nucleate boiling with a minimum possible deviation from experimental data. The least squares multiple regression technique is used to evaluate the best coefficient value used in the correlations. An empirical correlation that fits a broader scope of available data has been developed by a non-linear solution technique leading to the following equation: where the coefficients R1 and R3 both represent the effect of surface-liquid combination. They are assessed independently for the used surface material and liquid.
