糖果厂模型的最优化搜索方法

讨论了用两台装置搜索两个坏硬币的糖果厂模型C2,给出了一个测试过程t,使之与理论上的最优过程最多相差一次测试。     

Optimization of starch-based candy supplemented with date palm (Phoenix dactylifera) and tamarind (Tamarindus indica L.)

The various health challenges posed by conventional candies necessitate the development of health-promoting and phytochemicals supplemented varieties. The current study explored medicinal properties of date palm and tamarind in the formulation of a starch-based candy, using response surface method for the production optimization. Experimental design variables include the starch (90–100%), date palm (0–10%), and tamarind (0–10%), while the functional, phytochemical, and antioxidant properties were the responses. The candy modification response results are as follows: pH (2.80–3.00), crude fibre (4.41–6.43%), soluble sugar (91.69–126.96%), total titrable acidity (90.00–120.00%), total phenolics (0.039–0.063 mg GA/mL), total flavonoids (0.0006–0.001 mg RU/mL), vitamin C (0.362–0.516 mg/mL), hydroxyl radical scavenging activities (14.28–26.67%), 1, 1- diphenyl-2-picryhydrazyl (1.12–3.88%) and ferric reducing property (0.09–0.31 mg/mL). The experiments revealed that most of the nutritional properties of the candies increased favorably with the incorporation of date palm and tamarind pulps and decreasing starch content. Significant (p ≤ 0.05) interactive effects were revealed between the diverse variables. The experiments also revealed the positive influence of the date palm and tamarind fruit pulps on the functional, phytochemical, and antioxidant properties of starch-based candies; hence demonstrating the possibility of developing nutraceutical based-candies with a more beneficial health effect.     

A learning trajectory in Kindergarten and first grade students’ thinking of variable and use of variable notation to represent indeterminate quantities

Given the importance of understanding and using indeterminate quantities in algebraic thinking, the development of learning trajectories about how Kindergarten and first grade students understand variable and use variable notation in the context of algebraic expressions is critical. Based on an empirically developed learning trajectory, we analyzed children’s responses at three different points in a classroom teaching experiment. Our purpose was to describe levels of thinking among 16 students (eight in Kindergarten and eight in first grade). Our results revealed qualitative changes in the thinking about indeterminate quantities of most student participants. As students progressed through the experiment, we found that they advanced from what we characterized as a “Pre-variable” Level to a “Letters as representing indeterminate quantities as varying unknowns; explicit operations on indeterminate quantities” Level. Learning trajectories such as that developed here hold promise for informing the design of interventions that support young children’s early algebraic thinking.