Ammonium dinitramide(ADN)is a new type of green energetic oxidizer with excellent energy density and low pollution combustion characteristics.However,the strong hygroscopicity has a significant impact on its practical...Ammonium dinitramide(ADN)is a new type of green energetic oxidizer with excellent energy density and low pollution combustion characteristics.However,the strong hygroscopicity has a significant impact on its practical application.To assist in the research on moisture-proof modification of ADN materials,an innovative hygroscopic modeling approach was proposed to evaluate the hygroscopicity of ADN at various temperatures and humidities.By investigating the diffusion coefficient of water molecules in molecular dynamics processes,a visual insight into the hygroscopic process of ADN was gained.Furthermore,analyzing the non-covalent interactions between ADN and water molecules,the hygroscopicity of ADN could be evaluated qualitatively and quantitatively.The energy analysis revealed that electrostatic forces play a dominant role in the process of water adsorption by ADN,whereas van der Waals forces impede it.As a whole,the simulation results show that ADN presents the following hygroscopic law:At temperatures ranging from 273 K to 373 K and relative humidity(RH)from 10%to 100%,the hygroscopicity of ADN generally shows an increasing trend with the rise in temperature and humidity based on the results of three simulations.According to the non-hygroscopic point(298 K,52%RH)of ADN obtained by experiment in the literature,a non-hygroscopic range of temperature and humidity for ADN can be depicted when the simulation results in relative hygroscopicity is less than or equal to 17%.This study can provide effective strategies for screening anti-hygroscopic modified materials of ADN.展开更多
The sedative compounds in two traditional Chinese medicines were studied. These compounds are present in the medicinal herbs “Zao Ren” and “Lu Lu Tong”. The samples were first extracted by ethanol and pre-treated ...The sedative compounds in two traditional Chinese medicines were studied. These compounds are present in the medicinal herbs “Zao Ren” and “Lu Lu Tong”. The samples were first extracted by ethanol and pre-treated by ultrasonic wave, and then they were separated and qualitatively analyzed by high-resolution GC-EI-MS and High Performance Liquid Chromatography (HPLC) systems. We have found that the Chinese herb medicines “Zao Ren” contained clonazepam (120 ppm), whereas “Lu Lu Tong” Chinese drug contained estazolam (270 ppm). The Analytical measurements were done by using three different diagnostic indices using the GC-retention time of the GC-EI-MS total –ion–chromatogram;single stage EI-MS analysis identification and from the measurements of the retention time in the HPLC.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.22375098,21805139 and 12102194)the Joint Funds of the National Natural Science Foundation of China(Grant No.U2141202)Young Elite Scientists Sponsorship Program by CAST(Grant No.2021QNRC001).
文摘Ammonium dinitramide(ADN)is a new type of green energetic oxidizer with excellent energy density and low pollution combustion characteristics.However,the strong hygroscopicity has a significant impact on its practical application.To assist in the research on moisture-proof modification of ADN materials,an innovative hygroscopic modeling approach was proposed to evaluate the hygroscopicity of ADN at various temperatures and humidities.By investigating the diffusion coefficient of water molecules in molecular dynamics processes,a visual insight into the hygroscopic process of ADN was gained.Furthermore,analyzing the non-covalent interactions between ADN and water molecules,the hygroscopicity of ADN could be evaluated qualitatively and quantitatively.The energy analysis revealed that electrostatic forces play a dominant role in the process of water adsorption by ADN,whereas van der Waals forces impede it.As a whole,the simulation results show that ADN presents the following hygroscopic law:At temperatures ranging from 273 K to 373 K and relative humidity(RH)from 10%to 100%,the hygroscopicity of ADN generally shows an increasing trend with the rise in temperature and humidity based on the results of three simulations.According to the non-hygroscopic point(298 K,52%RH)of ADN obtained by experiment in the literature,a non-hygroscopic range of temperature and humidity for ADN can be depicted when the simulation results in relative hygroscopicity is less than or equal to 17%.This study can provide effective strategies for screening anti-hygroscopic modified materials of ADN.
文摘The sedative compounds in two traditional Chinese medicines were studied. These compounds are present in the medicinal herbs “Zao Ren” and “Lu Lu Tong”. The samples were first extracted by ethanol and pre-treated by ultrasonic wave, and then they were separated and qualitatively analyzed by high-resolution GC-EI-MS and High Performance Liquid Chromatography (HPLC) systems. We have found that the Chinese herb medicines “Zao Ren” contained clonazepam (120 ppm), whereas “Lu Lu Tong” Chinese drug contained estazolam (270 ppm). The Analytical measurements were done by using three different diagnostic indices using the GC-retention time of the GC-EI-MS total –ion–chromatogram;single stage EI-MS analysis identification and from the measurements of the retention time in the HPLC.
