The next step in the transition to environmentally safer refrigerants is phaseout of R-22. It is the most widely used refrigerant, both in the United Statess and on a global basis. Its application range in residential...The next step in the transition to environmentally safer refrigerants is phaseout of R-22. It is the most widely used refrigerant, both in the United Statess and on a global basis. Its application range in residential, commercial, industrial, and transport systems is broader than for any other refrigerant and spans cooling capacities from 2 kW to 33 MW(1/2 to 9,500 refrigeration tons, RT). The specific replacements depend on the applications.展开更多
为解决氟利昂制冷剂对臭氧层破坏和气候变暖潜能值高的缺陷,基于热管技术,该文设计了一套分离式低温热管蓄冷装置,用新型无氟制冷剂HCR-22替代传统制冷剂R-22,以蓄冷量为指标,研究了2种制冷剂在不同的充液率和冷凝/蒸发段面积比条件下...为解决氟利昂制冷剂对臭氧层破坏和气候变暖潜能值高的缺陷,基于热管技术,该文设计了一套分离式低温热管蓄冷装置,用新型无氟制冷剂HCR-22替代传统制冷剂R-22,以蓄冷量为指标,研究了2种制冷剂在不同的充液率和冷凝/蒸发段面积比条件下的蓄冷效果。试验结果表明:HCR-22用于低温热管的最佳充液率为80%,与R-22相同;热管模组运行70h时,HCR-22和R-22的蓄冷量分别为16230.52和16252.09 k J;最佳充液时,HCR-22用于低温热管的最优冷凝/蒸发段面积比为2.8:1,小于R-22时的3:1;HCR-22与R-22在相变传热中有近乎相同的传热稳定性,但制冷剂的用量仅为R-22的1/3。该研究为新型无氟制冷剂HCR-22替代传统制冷剂R-22提供了依据和技术支持,对低温热管的推广应用提供保障。展开更多
Objective To study the chemical constituents in the dried roots of Panax notoginseng.Methods The constituents were isolated and purified with chromatographic methods.Their structures were elucidated by spectroscopic m...Objective To study the chemical constituents in the dried roots of Panax notoginseng.Methods The constituents were isolated and purified with chromatographic methods.Their structures were elucidated by spectroscopic methods（1D,2D NMR,UV,IR,[α]D,and HRESI-TOF-MS）and chemical analyses.Results Twenty saponins including 20（S）-ginsenoside Rh1（1）,6-O-β-D-（6′-acetyl）-glucopyranosyl-24-ene-dammar-3β,6α,12β,20S-tetraol（2）,ginseno-side Rf（3）,notoginsenoside R2（4）,ginsenoside Rg2（5）,ginsenoside Rg1（6）,notoginsenoside Rt（7）,koryoginsenoside R1（8）,6-O-（β-D-glucopyranosyl）-20-O-（β-D-xylopyranosyl）-3β,6α,12β,20（S）-tetrahydroxy-dammar-24-ene（9）,pseudoginsenoside Rt3（10）,notoginsenoside R1（11）,ginsenoside Re（12）,notoginsenoside N（13）,ginsenoside F1（14）,ginsenoside U（15）,ginsenoside Rk3（16）,3β,12β-dihydroxydammar-（E）-20（22）,24-diene-6-O-β-D-xylopyranosyl-（1→2）-β-D-glucopyranoside（17）,ginsenoside Rh4（18）,pseudoginsenoside Rt5（19）,and vinaginsenoside R22（20）were obtained.Conclusion Compounds 2,19,and 20 are isolated from this species for the first time.The 1H-NMR data of compound 19 and1H-NMR and 13C-NMR data of compound 20 are first reported.Meanwhile,the NMR data ofβ-D-xylopyranosyl group in compound 9 is corrected.展开更多
文摘The next step in the transition to environmentally safer refrigerants is phaseout of R-22. It is the most widely used refrigerant, both in the United Statess and on a global basis. Its application range in residential, commercial, industrial, and transport systems is broader than for any other refrigerant and spans cooling capacities from 2 kW to 33 MW(1/2 to 9,500 refrigeration tons, RT). The specific replacements depend on the applications.
文摘为解决氟利昂制冷剂对臭氧层破坏和气候变暖潜能值高的缺陷,基于热管技术,该文设计了一套分离式低温热管蓄冷装置,用新型无氟制冷剂HCR-22替代传统制冷剂R-22,以蓄冷量为指标,研究了2种制冷剂在不同的充液率和冷凝/蒸发段面积比条件下的蓄冷效果。试验结果表明:HCR-22用于低温热管的最佳充液率为80%,与R-22相同;热管模组运行70h时,HCR-22和R-22的蓄冷量分别为16230.52和16252.09 k J;最佳充液时,HCR-22用于低温热管的最优冷凝/蒸发段面积比为2.8:1,小于R-22时的3:1;HCR-22与R-22在相变传热中有近乎相同的传热稳定性,但制冷剂的用量仅为R-22的1/3。该研究为新型无氟制冷剂HCR-22替代传统制冷剂R-22提供了依据和技术支持,对低温热管的推广应用提供保障。
基金Fund: Important Drug Development Fund, Ministry of Science and Technology of China (2012ZX09101201-002)Research Fund for the Doctoral Program of Higher Education of China (20121210110007)
文摘Objective To study the chemical constituents in the dried roots of Panax notoginseng.Methods The constituents were isolated and purified with chromatographic methods.Their structures were elucidated by spectroscopic methods（1D,2D NMR,UV,IR,[α]D,and HRESI-TOF-MS）and chemical analyses.Results Twenty saponins including 20（S）-ginsenoside Rh1（1）,6-O-β-D-（6′-acetyl）-glucopyranosyl-24-ene-dammar-3β,6α,12β,20S-tetraol（2）,ginseno-side Rf（3）,notoginsenoside R2（4）,ginsenoside Rg2（5）,ginsenoside Rg1（6）,notoginsenoside Rt（7）,koryoginsenoside R1（8）,6-O-（β-D-glucopyranosyl）-20-O-（β-D-xylopyranosyl）-3β,6α,12β,20（S）-tetrahydroxy-dammar-24-ene（9）,pseudoginsenoside Rt3（10）,notoginsenoside R1（11）,ginsenoside Re（12）,notoginsenoside N（13）,ginsenoside F1（14）,ginsenoside U（15）,ginsenoside Rk3（16）,3β,12β-dihydroxydammar-（E）-20（22）,24-diene-6-O-β-D-xylopyranosyl-（1→2）-β-D-glucopyranoside（17）,ginsenoside Rh4（18）,pseudoginsenoside Rt5（19）,and vinaginsenoside R22（20）were obtained.Conclusion Compounds 2,19,and 20 are isolated from this species for the first time.The 1H-NMR data of compound 19 and1H-NMR and 13C-NMR data of compound 20 are first reported.Meanwhile,the NMR data ofβ-D-xylopyranosyl group in compound 9 is corrected.
