2500 2500 2100 L 2100 1.:L8203 1700 LY293 1700 1350℃ L+Cu20 1300 L1C120 L&2CuO 1300 10?5℃ -L+Y2CU2O5- 100气 a2Cu04*L*203 900 900 L82CuO4CHo Y2Cu205+ Y2Cu295+Y20 2Cu2Os La2CuO4 500 0 0 40 60 80100 500L 0 20 40 60 80100 Cuo mol% La203 Cuo mol% Y203 Fig.1 Phase diagram of Cuo-LaaO3 Fig.2 Phase diagram of Cuo-Y2O3 binary system binary system -Calculated, -Calculated, Experimental, Experimental, Decomposition of Cuo .Decomposition of Cuo Using the same method,the CuO-Y203 and CuO-Nd2O3 binary phase diagrams as shown in Fig,2(a)and Fig.3(4)have been constructed very recently.Up to now,superconductivitity has been found in most of the RE- Ba-Cu-C systems (RE=rare earths except Ce,Pr,Tb and Pm).As a syste- matic research work,we plan to construct the phase diagrams of all CuO- RE2O;(RE:rare earths)systems using this method. 2 BaB204-based Systems Many metaborates have potential nonlinear optical properties.For example, barium metaborate is an excellent ultraviolet SHG (Second Harmonic Generator) material.Obviously,the study of the phase diagrams of metaborate systems is significant for the utilization of new metaborate materials and better under- standing of their physico-chemical properties. As one of the systematical study of metaborate phase diagrams,the phase diagrams of the BaB2O.-Na2B2O-K2B2O system and its subsystems were constructed by combination of computer calculation and limited experimental measurements. 156尸卜卜 洲 击抢 工 弋 ‘ 从 ， 州 一 工 “ “ 。 ‘ 干 习 ‘ 叫 二 」 盛琦 弋 月 ， ， ‘ ’ “ …… “ 十 。 ‘ 卜 压 口 。卜 ， 位 一 扭 — ， 五 一 — ， ， ， 垃 ， 一 一 月 〔 〔 〕 ， 几 ， ， 且沼月 ︸扫几 一 一 扭 ， 、 一 · ， 了， 一 · 了 了 ， ‘ 一 一