Wood Chemical Modification: the State of the Art of Technologies and Commercialization Process of SiO2 Gels Impregnation Wood by Lowry Method Impregnation Process of Thermochromic Functional Poplar Veneer Effect of Different Drying Methods on the Liquid Impregnation of Chinese Fir Plantation Wood Controlling Factors of Wood Permeability and Its Improving Measures Research on Moisture-Resistance of Finish Foil Impregnated with UMF Resin STUDY ON THE IMPREGNATION OF PHENOL RESIN IN CHINESE FIR AND ITS IMPROVEMENT