同时实验还发现，基于膨润土体系反应的转化率较高，且副产物总选择性维持于32%左右。

The experimental results showed that the conversion of lactic acid dehydration was higher than hectorite catalysts system, and the selectivity of by-products can be controlled around 32%.

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对于反应副产物而言，基于锂皂石所制备的催化剂其副产物总选择性为45%左右较自制SiO2所制备的固体催化剂有较大的改善。

For modified hectorite catalysts the selectivity of by-products could be controlled around 45%, which make a big advancement from solid catalysts synthesized by SiO2.

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集中供冷系统仿真数学模型的主要特点是压缩机可以根据蒸发器总负荷大小选择性开关不同的档位，相应的输入输出参数也随之改变。

And the capacities of compressor could be selected by on-off switch along with the change of burthen of evaporator, which is a main characteristic of the central refrigeration system model.

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