制备了ZSM-5分子筛催化剂,将初始催化剂(Cat-0)先在700℃下水热处理4 h获得催化剂Cat-4,再于600℃下继续进行不同时间的水热处理,处理300 h获得的催化剂为Cat-300;采用NH3-TPD和27Al MAS NMR方法对经不同时间水热处理的催化剂进行表征,...制备了ZSM-5分子筛催化剂,将初始催化剂(Cat-0)先在700℃下水热处理4 h获得催化剂Cat-4,再于600℃下继续进行不同时间的水热处理,处理300 h获得的催化剂为Cat-300;采用NH3-TPD和27Al MAS NMR方法对经不同时间水热处理的催化剂进行表征,考察了Cat-4和Cat-300裂解石脑油的性能,以考察长期处于高温水热条件下ZSM-5分子筛催化剂性能的变化。实验结果表明,Cat-4的NH3-TPD酸量比Cat-0降低约70%,骨架铝含量从16.9%降至11.7%,非骨架铝含量从0.4%增至5.5%;Cat-300的酸量与Cat-4相比变化不明显,Cat-300的骨架铝含量比Cat-0降低62%,但骨架铝和非骨架铝含量之和基本不变;Cat-4和Cat-300裂解石脑油时,二者的裂解能力接近。长期处于高温水热条件下,ZSM-5分子筛的骨架结构虽然有所变化,但对其裂解石脑油能力的影响不大。展开更多
Many opioids-mediated responses, including the inhibition of forskolin-stimulated cyclic-AMP accumulation, the activation of an inwardly rectifying K^+ channel, and antinociception, are diminished by repeated exposure...Many opioids-mediated responses, including the inhibition of forskolin-stimulated cyclic-AMP accumulation, the activation of an inwardly rectifying K^+ channel, and antinociception, are diminished by repeated exposure to selective agonists. This loss of receptor sensitivity and function results in desensitization, down-regulation and the development of opiate tolerance. In our research, we are supposed to find out展开更多
Three pod lengths （ 10 cm, 10–20 cm and 20 cm） and 13 pre-sowing treatments were considered with four dates of collection （9 February, 19 February, 1 March and 11 March） to investigate their effect on germination...Three pod lengths （ 10 cm, 10–20 cm and 20 cm） and 13 pre-sowing treatments were considered with four dates of collection （9 February, 19 February, 1 March and 11 March） to investigate their effect on germination rate and growth of seedlings of Albizia lebbeck （L.） Benth. at Pundibari, West Bengal, India. The best time of pod collection was on 19 February as the germination rate of the seeds collected on this date was 92.5% without requiring any pre-sowing treatments. This clearly indicated that the seeds collected on 19 February were non-dormant, viable and physiologically mature. Significantly better seedling growth was also obtained when the seeds were sown on 19 February which was extracted from pods of length 10-20 cm. Application of thio-urea as a pre-treatment did not significantly enhanced seed germination rate, but its application in lower concentration （100 μL·L-1） resulted in better seedling growth and development.展开更多
文摘制备了ZSM-5分子筛催化剂,将初始催化剂(Cat-0)先在700℃下水热处理4 h获得催化剂Cat-4,再于600℃下继续进行不同时间的水热处理,处理300 h获得的催化剂为Cat-300;采用NH3-TPD和27Al MAS NMR方法对经不同时间水热处理的催化剂进行表征,考察了Cat-4和Cat-300裂解石脑油的性能,以考察长期处于高温水热条件下ZSM-5分子筛催化剂性能的变化。实验结果表明,Cat-4的NH3-TPD酸量比Cat-0降低约70%,骨架铝含量从16.9%降至11.7%,非骨架铝含量从0.4%增至5.5%;Cat-300的酸量与Cat-4相比变化不明显,Cat-300的骨架铝含量比Cat-0降低62%,但骨架铝和非骨架铝含量之和基本不变;Cat-4和Cat-300裂解石脑油时,二者的裂解能力接近。长期处于高温水热条件下,ZSM-5分子筛的骨架结构虽然有所变化,但对其裂解石脑油能力的影响不大。
文摘Many opioids-mediated responses, including the inhibition of forskolin-stimulated cyclic-AMP accumulation, the activation of an inwardly rectifying K^+ channel, and antinociception, are diminished by repeated exposure to selective agonists. This loss of receptor sensitivity and function results in desensitization, down-regulation and the development of opiate tolerance. In our research, we are supposed to find out
文摘Three pod lengths （ 10 cm, 10–20 cm and 20 cm） and 13 pre-sowing treatments were considered with four dates of collection （9 February, 19 February, 1 March and 11 March） to investigate their effect on germination rate and growth of seedlings of Albizia lebbeck （L.） Benth. at Pundibari, West Bengal, India. The best time of pod collection was on 19 February as the germination rate of the seeds collected on this date was 92.5% without requiring any pre-sowing treatments. This clearly indicated that the seeds collected on 19 February were non-dormant, viable and physiologically mature. Significantly better seedling growth was also obtained when the seeds were sown on 19 February which was extracted from pods of length 10-20 cm. Application of thio-urea as a pre-treatment did not significantly enhanced seed germination rate, but its application in lower concentration （100 μL·L-1） resulted in better seedling growth and development.
