例谈数学课堂中“生本时间”的设置策略

走进课堂不难发现这样的现象:为了不影响预定教学任务的完成,有些教师不愿给学生多提供一些动脑、动口、动手的时间和空间;总想让学生少走弯路,不犯错误,急于给足条件、点明思路、唠叨引导;总想把问题当时解决,不想留一些有价值的问题给学生去探究。这些观念和行为是对学生学习体验权的削弱。因此,科学地设置"生本时间"就显得非常有意义。

Learning by Doing Effect in North South Trade under the Global Value Chains： An Empirical Analysis of Various Industries in the U.S.

This paper studies the division of labor and economic development under global value chains in North South trade by mainly investigating the changes of production hours and cost per unit along with more and more output and increasing trade value in several industries in the U.S., because the U. S. is at the leading position in the division of labor by global value chains. The empirical evidence reveals that more international outsourcing, there will be more detailed division of labor, and the industry unit production time and production cost will show more declining trend year by year. This is consistent with that the global value chains and the outsourcing play more and more important roles in the international division of labor and economic growth in both developed and developing countries, and helps explain the integration of workforce across countries in the global value chains.

Long Work Hours and Work-Life Balance in Korea and Japan

This study examines long work hours and work-life balance in relation to wage level, workaholism, and consumerism in both Korea and Japan. Findings of this study can be summarized as follows. First, the hypothesis that the wages and working hours have positive but differential effects depending on wage level categories are supported. Second, effects of cultural factors, such as workaholism and consumerism, on long work hours, however, are not significant in both countries. Third, for Korean manual workers, the probability of working long hours is high, but the level of time scarcity is low; but the effect of union membership on long work hours is not significant in both Korea and Japan. Fourth, the hypothesis that negative effects of long work hours and time scarcity on satisfaction with work-life balance are supported. These findings suggest that an increase in wage for non-regular workers and a minimum wage are required to reduce working hours. In addition, they also suggest that reducing working hours, overtime work in particular, and wage gap are crucial to raising the level of satisfaction with work-life balance in both Korea and Japan.

Study of Synthetic Process of Vitamin C

[ Objective] The aim was to find optimum reaction conditions for synthetic process of Vitamin C. [ Method] Vitamin C sodium was used as raw material to prepare vitamin C through acidification, separation, desalination, recovery and purification. The impact of reaction time, tempera-ture, feedstock molar ratio and water content on the yield of vitamin C were investigated in the experiment. [Result] The optimum reaction condi- tions for synthetic process of Vitamin C were as follows： in the acidification test, reaction time 120 min, temperature 20 -30 ℃, the molar ratio be-tween hydrochloric acid and Vitamin C sodium 1 ： 1 and water content 41.0%. Under the above condition, the purity and yield of vitamin C reach 99.80% and 94.74% respectively. [Conclusion] The process can decrease consumption, enhance quality and recover of the product, improve the environmental pollution, shorten processing periods and reduce production cost. Thus, the process is suitable for industrialization. Key words Vitamin C; Vitamin C sodium; Acidification; China

The Straight-Line Depreciation Method Used by Selected Companies and Educational Institutions in the Philippines

The straight-line method in computing for depreciation expense is the prevailing method used in the Philippines. This paper aims to determine the rationale behind the use of this method. The objective of the study is to determine the length of time within which the depreciation method is used, reasons in using the method, the rate of depreciation used by the companies, and the effects of the depreciation expense on their operating expenses. It also determines if the companies＇ decisions to use the straight-line method are influenced by the factors mentioned by Reynolds （196 I）----expected amount of services over the life of assets, the amount and timing of operating costs, the decline in the physical efficiency of the assets, and the rate of return--and if they considered capital investments and tax reduction in using this method. The study shows that companies and educational institutions use the straight-line method of computing depreciation expenses, because it is easy to use in computing the depreciation expenses, in comparing with previous years＇ computations, and in keeping track of the expenses. It is also convenient for tax administration and financial reporting. The rate of depreciation used varies, because the companies and educational institutions use their past experiences in determining the life of fixed assets. The percentage of depreciation to the operating expenses also varies. The companies and educational institutions adhered to the factors mentioned by Reynolds （1961） in choosing the straight-line method of depreciation. The companies did not consider reduction of tax in using the straight-line method.