A spinnable zirconium solution was obtained by heating the aqueous solution that contains ZrOCl 2 .8H 2 O, Y(NO 3 ) 3 .6H 2 O, H 2 O 2 and CH 3 COOH under a reduced pressure in a rotary evaporator. The preparation of the sol, possible structure of PZA, idealized formation process of PZA, firing schedule of the gel fiber, phase transformation of ZrO 2 and characterization of the fibers were discussed in this article. The green fibers and those sintered at different temperatures were characterized by thermogravimetry-differential thermal analysis (TG-DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopic (SEM) techniques. After calcined at 1200 o C, zirconia fibers with cubic phase were obtained by the addition of 6 mol% Y 2 O 3 . The diameters of the zirconium oxide fiber were 5-7 m, and the grain size was about 20-30 nm. The activation energy for grain growth of zirconia fiber was estimated to be 24.18 kJ.mol -1 . IntroductionZirconia fibers have attracted much attention in science and technology during the last decades because of its high melting temperature (2750 o C), high dielectric constant, refractive index and hardness, and low thermal conductivity (2 W.m -1 K -1 ) .1 Due to these prominent properties, zirconia fibers exhibit wide applications in two major areas: as reinforcement of metals and ceramics and high temperature insulating materials. 2 The main methods of making zirconia fibers are: 3 impregnation of organic polymer fibers with zirconium salt solutions; 4 spinning of organic polymer fibers from polymer solutions containing zirconium salts or fine zirconia powders; 5, 6 spinning of sol solutions prepared by sol-gel processing of inorganic zirconium salt or zirconium alkoxide. 7,8 The present spinning techniques for preparing zirconia fibers include rotational centrifugal spinning, dry spinning, blow spinning and electrospinning. Rotational centrifugal spinning can meet the mass production requirement of zirconia fibers due to its fiberizing efficiency. Dry spinning is a better method to produce continuous zirconia fibers, and electrospinning is a method that can produce zirconia nanofibers.Sol-gel combined rotational centrifugal spinning technique is a better method for manufacturing zirconia fibers. This technique involved three steps: preparation of a spinnable sol with suitable organic precursor; spinning of the solution to obtain fibers of organic composite; calcination of the composite fibers to obtain final oxide fibers.

Abstract. In order to reduce the apple damage of extrusion and collision caused by machine during apple picking, study law of apple damage is necessary. A compressive test is carried out on precision micro controlled electronic universal testing machine, red apple of Fuji type at mature state as the test material. Through analyzing mechanical characteristics of apple compression, the mechanical model is established. By calculating, obtained compressive elastic modulus of apple is 2.091MPa, the maximum elastic limit is 0.130MPa, and the elastic modulus of compression remained at the scope of 5~7MPa. When the stress value of Apple reaches its yield limit 0.125MPa, the deformation of apple is accelerated. This study can be used to make a reasonable prediction of mechanical damage of apple.