The aging process of pure copper precursors and copper-zinc binary precursorswere studied by XRD, TG-DTG and TPR techniques. The catalytic activity and stability of CuO/ZnOwere tested using fixed-bed flow reactor, and...The aging process of pure copper precursors and copper-zinc binary precursorswere studied by XRD, TG-DTG and TPR techniques. The catalytic activity and stability of CuO/ZnOwere tested using fixed-bed flow reactor, and the physical properties of the catalysts and Cuspecies were characterized with N_2 adsorption and N_2O passivation method, respectively. For theCu-Zn binary system prepared at the precipitating condition of pH=8.0 and temperature=80℃, theinitial phase was a mixture of copper nitrate hydroxide Cu_2(NO_3)(OH)_3, georgeite and hydrozinciteZn_5(CO_3)_2(OH)_6. By increasing the duration of its aging time, the phase of Cu_2(NO_3)(OH)_2first transited to georgeite, and then interdiffused into Zn_5(CO_3)_2(OH)_6 and resulted in two newphases: rosasite (Cu,Zn)_2CO_3(OH)_2 and au-richalcite (Zn,Cu)_5(CO_3)_2(OH)_6. The former phasewas much easier to be formed than the latter one, while the latter phase was more responsible forthe activity of methanol synthesis than the former one. It is found that the composition andstructure of the precursors altered obviously after the colour transition point. The experimentalresults showed that methanol synthesis is a structure-sensitive catalytic reaction.展开更多
文摘The aging process of pure copper precursors and copper-zinc binary precursorswere studied by XRD, TG-DTG and TPR techniques. The catalytic activity and stability of CuO/ZnOwere tested using fixed-bed flow reactor, and the physical properties of the catalysts and Cuspecies were characterized with N_2 adsorption and N_2O passivation method, respectively. For theCu-Zn binary system prepared at the precipitating condition of pH=8.0 and temperature=80℃, theinitial phase was a mixture of copper nitrate hydroxide Cu_2(NO_3)(OH)_3, georgeite and hydrozinciteZn_5(CO_3)_2(OH)_6. By increasing the duration of its aging time, the phase of Cu_2(NO_3)(OH)_2first transited to georgeite, and then interdiffused into Zn_5(CO_3)_2(OH)_6 and resulted in two newphases: rosasite (Cu,Zn)_2CO_3(OH)_2 and au-richalcite (Zn,Cu)_5(CO_3)_2(OH)_6. The former phasewas much easier to be formed than the latter one, while the latter phase was more responsible forthe activity of methanol synthesis than the former one. It is found that the composition andstructure of the precursors altered obviously after the colour transition point. The experimentalresults showed that methanol synthesis is a structure-sensitive catalytic reaction.
文摘目的：探讨精神分裂症患者返回抑制及认知功能的受损害状况。方法将11例精神分裂症患者设为患者组，10例健康志愿者设为对照组，采用北京大学何淑嫦老师提供的 EXP＿E‐motion‐detetion‐face2‐Square程序进行测试分析。结果患者组线索开始呈现到靶子的时间间隔在880 m s时，线索化位置对刺激的反应时间显著滞后于非线索化位置（ P＜0．01）；对照组在不同线索开始呈现到靶子的时间间隔水平，所有线索化位置对刺激的反应时间均显著滞后于非线索化位置的反应时间（P＜0．01）。患者组和对照组在不同线索开始呈现到靶子的时间间隔水平的不同线索化内容靶刺激的反应时间比较差异均无显著性（P＞0．05）。结论精神分裂症患者存在返回抑制，且出现的时间滞后于健康人。
