This paper analyses and evaluates the rich natural cold resource in North China and proposes the ways of preserving the natural cold resource in winter for the preservation of fresh agricultural products.

The winter in the northern China is very cold and long, which has rich natural cold resource.

Preliminary study on technology for ice-making using natural cold resource based on heat pipe;

Charging and discharging of a seasonal soil cool storage system using natural cold source;

The test result shows that in north China it is feasible to lower temperature through mechanical ventilation on proper occasions, particularly taking advantage of the natural cold source in winter can decrease ventilation cost.

A leap of epistemology sustainable development on natural resources and environment;

On natural resources development and transportation construction in northwest China;

Preliminary study on natural resources of Anoectochilus roxburghii;

This paper introduced the nature resources of temperature,illumination,precipitation and ground soils in Shaanxi province's tobacco leaf production zone at first,and then it had been analyzed and evaluated according to the condition demanding of climate and soils that is regard to high quality flue-cured tobacco growth.

This thesis starts from the technological research environment, analyzes the kinds of resources and resource elements obtained in the Yuan Long-ping s technological innovation, puts forward the three resources involved in the technological innovation: technological resources、 society resources and nature resources.

Preliminary study on natural resource of Potentilla anserina L.;

Analysis on the dominance of natural resource in three sugarcane productive bases;

Natural resource and regional economic growth:a summary;