1000 How much heat is energy equal to?

Generally, energy is joule and heat is calorie. The ratio is: Joule: Calories = 1:4. 1, 1000 Joule is about 244 calories.

As the legal unit of food calories, joules are widely used in Europe, while calories are used in the United States. Although Joule is the legal unit in China, calories are still widely used in Chinese mainland and Taiwan Province provinces due to tradition.

Most of us associate calories with what we eat or drink, such as "This soda contains 200 calories". In fact, the calories listed on food packaging are calories, and the capital letter C is also marked, which is equivalent to the heat required to raise 1 000 grams of water from 14.5 degrees Celsius to 15.5 degrees Celsius at1atmospheric pressure, which is about equal to the internal energy of 4 186 joules. ?

Joule fever

Take capillary electrophoresis as an example: capillary electrophoresis needs electric field to do work, and when there is electric field to do work, it will produce heat, which is Joule heat. According to its degree, this Joule heat can form different temperature gradients, and even cause solution convection and bubbles. Bubbles will interrupt electrophoresis, while temperature gradient and convection will greatly reduce the separation efficiency? .

In traditional electrophoresis, in order to avoid convection, cellulose, gel and other non-flowing or non-flowing substances are used as electrophoresis support media, which is actually a "blocking" method? .

On the contrary, in capillary electrophoresis, the strategy of eliminating "source" is adopted, that is, reducing the inner diameter of capillary to speed up heat dissipation to overcome Joule thermal effect. It can be predicted that the heat dissipation capacity and separation effect of different capillaries will be different, so it will be very useful to infer the heat dissipation performance or temperature distribution of capillaries in the electrophoresis process in advance.