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Mixed oxide β-ZrWMoO8-containing composites with monoclinic zirconia (m-ZrO2) were prepared in search for zero thermal expansion ceramics over a wide temperature range. Thermomechanical analyzer (TMA) results indicate that the thermal expansion coefficients of the β-ZrWMoO8-containing composites decrease with increasing amount of β-ZrWMoO8 and that the composite with 50 wt. % β-ZrWMoO8 and 50 wt. % m-ZrO2 exhibits near-zero thermal expansion from 30 to about 600oC. However, its relative density is low. The addition of a small amount of Al(NO3)3.9H2O as a sintering aid increases the density (possibly because the Al3+ ion promotes sintering and densification) while affecting the structure and thermal expansion only insignificantly.

Cu/Sc2W3O12 metal-based composites with controlled coefficients of thermal expansion (CTEs) were successfully prepared via powder metallurgic method. The effects of Sc2W3O12 content, sintering temperature and sintering time on the thermal expansion properties were investigated in this paper. The results indicated that the optimum sintering temperature was 600℃. Increasing sintering temperature can promote the density of the Cu/Sc2W3O12 composite, but Cu-W alloy formed in the composite when sintering temperature rose to 700℃. The lowest CTEs of Cu/Sc2W3O12 composite can be controlled to 2.1×10-6K-1, which is matched with the value of Si (2.5×10-6K-1 ).

Two of the difficult problems China faces in the final years of this century are those of maintaining stability and deepening reform. There is a compatibility between these two political goals—unless reform is deepened, it will be difficult for China to enjoy long-term stability. But there is also a contradiction between them—it would not be possible to deepen reform without touching on certain vested interests, and yet, once you touch certain vested interests, you are likely to create some measure of instability. In fact, it may even be said that in China today, the masses and the elite are more attentive to political and economic stability than they have been in the past, and the argument that "China simply cannot be chaotic" [the title of a popular book—Ed.] has struck a rather deep chord with the Chinese people. All of China's Asian neighbors and the major Western countries hope that stability will be maintained in China, and that turmoil in China can be avoided. Nevertheless, for us to be able to und...