We have studied the property of single-walled ZnO nanotubes with adsorbed water molecules, and theo- retically designed a new sensor for detecting water molecules using single-waJ1ed ZnO nanotubes using a combination ...We have studied the property of single-walled ZnO nanotubes with adsorbed water molecules, and theo- retically designed a new sensor for detecting water molecules using single-waJ1ed ZnO nanotubes using a combination of density functional theory and the non-equilibrium Green＇s function method. Details of the geometric structures and adsorption energies of the H2O molecules on the ZnO nanotube surface have been investigated, Our computational results demonstrate that the formation of hydrogen bonding between the H2O molecules and the ZnO nanotube, and adsorption energies of the H2O molecules on the ZnO nanotube are larger than the adsorption energies of other gas molecules present in the atmospheric environment. Moreover, the current-voltage curves of the ZnO nanotube with and without H2O molecules adsorbed on its surface are calculated, the results of which showed that the H2O molecules form stable adsorption configurations that could lead to the decrease in current. These results suggest that the single-walled ZnO nanotubes are able to detect and monitor the presence of H2O molecules by applying bias voltages.展开更多
以酸洗废硫酸和H_2O_2组成的氧化体系,降解农药废水中的COD。采用Box-Behnken试验设计,以COD去除率为响应值,考察了废硫酸投加量、H_2O_2投加量以及反应时间的单独作用和交互影响,通过建立COD降解率数学模型预测酸洗废硫酸/H_2O_2氧化...以酸洗废硫酸和H_2O_2组成的氧化体系,降解农药废水中的COD。采用Box-Behnken试验设计,以COD去除率为响应值,考察了废硫酸投加量、H_2O_2投加量以及反应时间的单独作用和交互影响,通过建立COD降解率数学模型预测酸洗废硫酸/H_2O_2氧化体系的最佳氧化参数。结果表明,在废硫酸添加量为14.17 m L/L、H_2O_2添加量为1.47 m L/L、反应时间为55.9 min时,COD降解率存在最大值,为47.79%,在该条件下进行7次试验对模型预测结果进行验证,7次试验的COD降解率平均值为47.52%,与预测值相差0.56%,与拟合模型的预测值基本相符,该模型能够较好地解释酸洗废硫酸/H_2O_2氧化工艺。此外,对7次试验出水中Pb、Cr也进行了检测,7次试验出水中均未检测出Pb、Cr元素,因此,酸洗废硫酸中存在的微量重金属元素不会对最终出水水质产生影响。表明酸洗废硫酸/H_2O_2氧化体系用于农药废水处理工艺是可行的。展开更多
Quantum chemical calculations are performed to study the reactions of OH and ozone with- out and with water to estimate whether the single water molecule can decrease the energy barrier of the OH radical reaction with...Quantum chemical calculations are performed to study the reactions of OH and ozone with- out and with water to estimate whether the single water molecule can decrease the energy barrier of the OH radical reaction with ozone. The calculated results demonstrate that the single water molecule can reduce the activated barrier of the naked OH＋Oa reaction with the value of about 4.18 kJ/mol. In addition, the transition state theory is carried out to determine whether the single water molecule could enhance the rate constant of the OH＋O3 reaction. The computed kinetic data indicate that the rate of the ozone reaction with the formed complexes between OH and water is much slower than that of the OH＋O3 reaction, whereas the rate constant of OH reaction with the formed H20---Oa complex is 2 times greater than that of the naked OH radical with ozone reaction. However, these processes in the atmosphere are not important because the reactions can not compete well with the naked reaction of OH with ozone under atmospheric condition.展开更多
以L aC l3.7H2O替代传统液体无机酸为催化剂,以合成异丁酸正丁酯为探针反应考察催化酯化反应的优化条件,并在此条件下合成了多种异丁酸酯,比较了不同催化剂对催化合成异丁酸正丁酯的影响。实验结果表明,L aC l3.7H2O对酯化反应具有良好...以L aC l3.7H2O替代传统液体无机酸为催化剂,以合成异丁酸正丁酯为探针反应考察催化酯化反应的优化条件,并在此条件下合成了多种异丁酸酯,比较了不同催化剂对催化合成异丁酸正丁酯的影响。实验结果表明,L aC l3.7H2O对酯化反应具有良好的催化活性,并能避免液体无机酸催化剂所引起的弊端,异丁酸正丁酯的酯化率可达96.5%。且催化剂易回收,反应后处理简单,无废酸排放,是一种环境友好型催化剂。展开更多
The selective catalytic reduction （SCR） activities of the MoO3 doped V/WTi catalysts prepared by the incipient wetness impregnation method at low temperature were investigated. The results showed that the addition o...The selective catalytic reduction （SCR） activities of the MoO3 doped V/WTi catalysts prepared by the incipient wetness impregnation method at low temperature were investigated. The results showed that the addition of MoO3 could enhance the NOx conversion at low temperature and the best SCR activity was obtained when the dosage of MoO3 reached 5 wt.%. The NH3-TPD and DRIFTS experiments indicated that the addition of MoO3 changed the type and number of acid sites on the surface of catalysts and reaction activities of acid sites were altered at the same time. The redox capacity and amount of active oxygen species got improved for V3Mo5/WTi catalyst, which could be confirmed by the H2-TPR and transient response experiments. Water vapor inhibited the NOx conversion at low temperature. Deposition of ammonium sulfate or bisulfate might be main reason for the loss of catalytic activity in the presence of SO2 at low temperature. Choosing the suitable NH3/NO ratio and elevation of reaction temperature both could weaken the influence of SO2 on the SCR activity of the V3MoSAFTi catalyst. Thermal treatment of the deactivated catalyst at 350℃ could get the low temperature activity recovered. The decrease of GHSV improved the deNOx efficiency at low temperature and we speculated that the rational technological process and operation parameters could contribute to the application of this kind of catalysts in real industrial environment.展开更多
Raman peaks of various hydrates in the H20-NaCl-CaCl2 system have been previously identified, but a quantitative relationship between the Raman peaks and XNaCl （i.e.,NaCl/ （NaCl＋CaCl2）） has not been established, ...Raman peaks of various hydrates in the H20-NaCl-CaCl2 system have been previously identified, but a quantitative relationship between the Raman peaks and XNaCl （i.e.,NaCl/ （NaCl＋CaCl2）） has not been established, mainly due to the difficulty to freeze the solutions. This problem was solved by adding alumina powder to the solutions to facilitate nucleation of crystals. Cryogenic （-185℃） Raman spectroscopic studies of alumina-spiced solutions indicate that XNaCl is linearly correlated with the total peak area fraction of hydrohalite. Capsules of solutions made from silica capillary were prepared to simulate fluid inclusions. Most of these artificial fluid inclusions could not be totally frozen even at temperatures as low as -185℃, and the total peak area fraction of hydrohalite is not correlated linearly with XNaCI. However, the degree of deviation （△XNaCl） from the linear correlation established earlier is related to the amount of residual solution, which is reflected by the ratio （r） of the baseline ＂bump＂ area, resulting from the interstitial unfrozen brine near 3435 cm^-1, and the total hydrate peak area between 3350 and 3600 cm^-1. A linear correlation between △XNaCl and r is established to estimate XNaCl from cryogenic Raman spectroscopic analysis for fluid inclusions.展开更多
以5,5′-联四唑-1,1′-二羟基二水化合物（H2BTO·2H2O）和2-甲基咪唑为原料合成了一种新的5,5′-联四唑-1,1′-二氧-2-甲基咪唑含能离子盐（M2BTO）。采用X-射线单晶衍射、FT-IR、1 H NMR、13 C NMR和元素分析进行了结构表征;利用...以5,5′-联四唑-1,1′-二羟基二水化合物（H2BTO·2H2O）和2-甲基咪唑为原料合成了一种新的5,5′-联四唑-1,1′-二氧-2-甲基咪唑含能离子盐（M2BTO）。采用X-射线单晶衍射、FT-IR、1 H NMR、13 C NMR和元素分析进行了结构表征;利用差示扫描量热分析（DSC）和热重-微分热重分析（TG-DTG）研究了该含能离子盐的热分解过程及其非等温分解反应动力学;利用Kamlet-Jacobs经验公式对其爆速、爆压参数进行了理论计算;采用WL-1型撞击感度测试仪测定了M2BTO的特性落高H50;采用Kissinger法和Ozawa法计算了其反应活化能。结果表明,M2BTO晶体属于三斜晶系,P-1空间群,晶胞参数为：a=0.538 60（5）nm,b=0.726 76（6）nm,c=1.111 49（11）nm,V=401.00（6）×10^-3nm3,ρ=1.534g/cm3,Z=1;M2BTO分解峰值温度为542.1K,TG曲线上只存在一个失重阶段,该阶段位于503.5-568.2K,失重为78.2%,表明其有较好的热稳定性;表观活化能为134.7kJ/mol（Kissinger法）和136.7kJ/mol（Ozawa法）,二者一致性较好,指前因子1n（A/s-1）=29.33;其爆速、爆压的理论计算值分别为7 104m/s、20.23GPa,特性落高（H50）大于61.0cm。展开更多
Studies of the non-isothermal decomposition of barium2,4,6-trinitroresorecinate monohydrate,Ba(TNR)·H 2 O,were carried out by means of TG-DTA,DSC and IR.The thermal decomposition mechanism and associated ki-netic...Studies of the non-isothermal decomposition of barium2,4,6-trinitroresorecinate monohydrate,Ba(TNR)·H 2 O,were carried out by means of TG-DTA,DSC and IR.The thermal decomposition mechanism and associated ki-netics were investigated.The kinetic parameters were obtained from an analysis of the DSC curves by integral and differential methods.The most probable kinetic model function of the dehydration reaction of Ba(TNR)·H 2 O was suggested by comparison of the kinetic parameters.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.11174214the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20090181110080
文摘We have studied the property of single-walled ZnO nanotubes with adsorbed water molecules, and theo- retically designed a new sensor for detecting water molecules using single-waJ1ed ZnO nanotubes using a combination of density functional theory and the non-equilibrium Green＇s function method. Details of the geometric structures and adsorption energies of the H2O molecules on the ZnO nanotube surface have been investigated, Our computational results demonstrate that the formation of hydrogen bonding between the H2O molecules and the ZnO nanotube, and adsorption energies of the H2O molecules on the ZnO nanotube are larger than the adsorption energies of other gas molecules present in the atmospheric environment. Moreover, the current-voltage curves of the ZnO nanotube with and without H2O molecules adsorbed on its surface are calculated, the results of which showed that the H2O molecules form stable adsorption configurations that could lead to the decrease in current. These results suggest that the single-walled ZnO nanotubes are able to detect and monitor the presence of H2O molecules by applying bias voltages.
文摘以酸洗废硫酸和H_2O_2组成的氧化体系,降解农药废水中的COD。采用Box-Behnken试验设计,以COD去除率为响应值,考察了废硫酸投加量、H_2O_2投加量以及反应时间的单独作用和交互影响,通过建立COD降解率数学模型预测酸洗废硫酸/H_2O_2氧化体系的最佳氧化参数。结果表明,在废硫酸添加量为14.17 m L/L、H_2O_2添加量为1.47 m L/L、反应时间为55.9 min时,COD降解率存在最大值,为47.79%,在该条件下进行7次试验对模型预测结果进行验证,7次试验的COD降解率平均值为47.52%,与预测值相差0.56%,与拟合模型的预测值基本相符,该模型能够较好地解释酸洗废硫酸/H_2O_2氧化工艺。此外,对7次试验出水中Pb、Cr也进行了检测,7次试验出水中均未检测出Pb、Cr元素,因此,酸洗废硫酸中存在的微量重金属元素不会对最终出水水质产生影响。表明酸洗废硫酸/H_2O_2氧化体系用于农药废水处理工艺是可行的。
基金This work was supported by the National Natural Science Foundation of China （No.10865003） and the Science and Technology Foundation of GuiZhou Province, China （No.[201112107）. We thank the Key Laboratory of Guizhou High Performance Computational Chemistry for computer time.
文摘Quantum chemical calculations are performed to study the reactions of OH and ozone with- out and with water to estimate whether the single water molecule can decrease the energy barrier of the OH radical reaction with ozone. The calculated results demonstrate that the single water molecule can reduce the activated barrier of the naked OH＋Oa reaction with the value of about 4.18 kJ/mol. In addition, the transition state theory is carried out to determine whether the single water molecule could enhance the rate constant of the OH＋O3 reaction. The computed kinetic data indicate that the rate of the ozone reaction with the formed complexes between OH and water is much slower than that of the OH＋O3 reaction, whereas the rate constant of OH reaction with the formed H20---Oa complex is 2 times greater than that of the naked OH radical with ozone reaction. However, these processes in the atmosphere are not important because the reactions can not compete well with the naked reaction of OH with ozone under atmospheric condition.
文摘以L aC l3.7H2O替代传统液体无机酸为催化剂,以合成异丁酸正丁酯为探针反应考察催化酯化反应的优化条件,并在此条件下合成了多种异丁酸酯,比较了不同催化剂对催化合成异丁酸正丁酯的影响。实验结果表明,L aC l3.7H2O对酯化反应具有良好的催化活性,并能避免液体无机酸催化剂所引起的弊端,异丁酸正丁酯的酯化率可达96.5%。且催化剂易回收,反应后处理简单,无废酸排放,是一种环境友好型催化剂。
基金financially supported by the Policy-induced Project of Jiangsu Province for the Industry-UniversityResearch Cooperation (BY2015070-21)the Natural Science Fund Program of Jiangsu Province (BK20150749)
文摘The selective catalytic reduction （SCR） activities of the MoO3 doped V/WTi catalysts prepared by the incipient wetness impregnation method at low temperature were investigated. The results showed that the addition of MoO3 could enhance the NOx conversion at low temperature and the best SCR activity was obtained when the dosage of MoO3 reached 5 wt.%. The NH3-TPD and DRIFTS experiments indicated that the addition of MoO3 changed the type and number of acid sites on the surface of catalysts and reaction activities of acid sites were altered at the same time. The redox capacity and amount of active oxygen species got improved for V3Mo5/WTi catalyst, which could be confirmed by the H2-TPR and transient response experiments. Water vapor inhibited the NOx conversion at low temperature. Deposition of ammonium sulfate or bisulfate might be main reason for the loss of catalytic activity in the presence of SO2 at low temperature. Choosing the suitable NH3/NO ratio and elevation of reaction temperature both could weaken the influence of SO2 on the SCR activity of the V3MoSAFTi catalyst. Thermal treatment of the deactivated catalyst at 350℃ could get the low temperature activity recovered. The decrease of GHSV improved the deNOx efficiency at low temperature and we speculated that the rational technological process and operation parameters could contribute to the application of this kind of catalysts in real industrial environment.
基金supported by an NSERC-Discovery grant(to Chi)in part by the Knowledge Innovation Program of Chinese Academy of Sciences(SIDSSE201302)
文摘Raman peaks of various hydrates in the H20-NaCl-CaCl2 system have been previously identified, but a quantitative relationship between the Raman peaks and XNaCl （i.e.,NaCl/ （NaCl＋CaCl2）） has not been established, mainly due to the difficulty to freeze the solutions. This problem was solved by adding alumina powder to the solutions to facilitate nucleation of crystals. Cryogenic （-185℃） Raman spectroscopic studies of alumina-spiced solutions indicate that XNaCl is linearly correlated with the total peak area fraction of hydrohalite. Capsules of solutions made from silica capillary were prepared to simulate fluid inclusions. Most of these artificial fluid inclusions could not be totally frozen even at temperatures as low as -185℃, and the total peak area fraction of hydrohalite is not correlated linearly with XNaCI. However, the degree of deviation （△XNaCl） from the linear correlation established earlier is related to the amount of residual solution, which is reflected by the ratio （r） of the baseline ＂bump＂ area, resulting from the interstitial unfrozen brine near 3435 cm^-1, and the total hydrate peak area between 3350 and 3600 cm^-1. A linear correlation between △XNaCl and r is established to estimate XNaCl from cryogenic Raman spectroscopic analysis for fluid inclusions.
文摘以5,5′-联四唑-1,1′-二羟基二水化合物（H2BTO·2H2O）和2-甲基咪唑为原料合成了一种新的5,5′-联四唑-1,1′-二氧-2-甲基咪唑含能离子盐（M2BTO）。采用X-射线单晶衍射、FT-IR、1 H NMR、13 C NMR和元素分析进行了结构表征;利用差示扫描量热分析（DSC）和热重-微分热重分析（TG-DTG）研究了该含能离子盐的热分解过程及其非等温分解反应动力学;利用Kamlet-Jacobs经验公式对其爆速、爆压参数进行了理论计算;采用WL-1型撞击感度测试仪测定了M2BTO的特性落高H50;采用Kissinger法和Ozawa法计算了其反应活化能。结果表明,M2BTO晶体属于三斜晶系,P-1空间群,晶胞参数为：a=0.538 60（5）nm,b=0.726 76（6）nm,c=1.111 49（11）nm,V=401.00（6）×10^-3nm3,ρ=1.534g/cm3,Z=1;M2BTO分解峰值温度为542.1K,TG曲线上只存在一个失重阶段,该阶段位于503.5-568.2K,失重为78.2%,表明其有较好的热稳定性;表观活化能为134.7kJ/mol（Kissinger法）和136.7kJ/mol（Ozawa法）,二者一致性较好,指前因子1n（A/s-1）=29.33;其爆速、爆压的理论计算值分别为7 104m/s、20.23GPa,特性落高（H50）大于61.0cm。
文摘Studies of the non-isothermal decomposition of barium2,4,6-trinitroresorecinate monohydrate,Ba(TNR)·H 2 O,were carried out by means of TG-DTA,DSC and IR.The thermal decomposition mechanism and associated ki-netics were investigated.The kinetic parameters were obtained from an analysis of the DSC curves by integral and differential methods.The most probable kinetic model function of the dehydration reaction of Ba(TNR)·H 2 O was suggested by comparison of the kinetic parameters.
