In the reply to the second problem, the author points out the fact that ordering the rational numbers and the empty sets produced by the interval nests of rational numbers, is the foundation of real number theory and the basic method to introduce irrational numbe.

In this article, especially after comparing Laozi s correlative thought to the concept of empty set in fractal theory, we acknowledge there exists metaphysical wisdom and foundation for post-modern generativism.

Study on the return of the empty containers;

It faces a problem of empty container allocation in the intemational maritime management.

In order to reduce the radiation heat loss during heat transfer in a fairly high temperature, two types of evacuated collector tubes with inner radiation shield were hereby put forward.

An idea about product factor of incidence is raised,the product factor of incidence is calculated and compared on the single horizontal aside solar evacuated collector tube and single tilted aside solar evacuated collector tube,a conclusion is obtained which tilted aside is better than horizontal aside,but it is limited to single tube.

In this paper, the design requirements and constructure speciality of pumping station for the solar evacuated collector tubes are reported.