We have prepared the 2-（quinolin-8-yloxy）-acetic acid and characterized it by infrared and Raman spectroscopies in the solid phase. The Density Functional Theory （DFT） method, together with the 6-31G^＊ and 6-311...We have prepared the 2-（quinolin-8-yloxy）-acetic acid and characterized it by infrared and Raman spectroscopies in the solid phase. The Density Functional Theory （DFT） method, together with the 6-31G^＊ and 6-311＋＋ G^＊＊ basis sets, show that three stable molecules, for the anhydrous and monohydrated compounds were theoretically determined in the gas phase, and that probably the two more stable conformations are present in the solid phase of the monohydrated compound. The harmonic vibrational wavenumbers for the optimized geometries were calculated at B3LYP/6-31G^＊and B3LYP/6-311＋＋G^＊＊ levels. For a complete assignment of all the observed bands in the vibrational spectra the DFT calculations were combined with Pulay＇s scaled quantum mechanical force field （SQMFF） methodology in order to fit the theoretical Wavenumber values to the experimental ones. The characteristics of the electronic delocalization of all structures of both forms were performed by using natural bond orbital （NBO）, while the corresponding topological properties of electronic charge density are analysed by employing Bader＇s atoms in molecules theory （AIM）.展开更多
Eight rare earth metal （ Ⅲ ） complexes with 2- （ （（4,6-dimethyl）-2-pyrimidinyl） thio）-acetic acid, LnL3· n H2O [HL = 2-（（（4,6-dimethyl）-2-pyrimidinyl）thio）-acetic acid; Ln = La, Ce, Pr, Nd, Sm Eu, ...Eight rare earth metal （ Ⅲ ） complexes with 2- （ （（4,6-dimethyl）-2-pyrimidinyl） thio）-acetic acid, LnL3· n H2O [HL = 2-（（（4,6-dimethyl）-2-pyrimidinyl）thio）-acetic acid; Ln = La, Ce, Pr, Nd, Sm Eu, Gd, Tb; n = 4 or 5], were prepared and characterized by elemental analysis, complexometric titration, thermal analysis, conductivity, IR and ^1H- NMR. The results reveal that carboxyl group of the hgand coordinates with rare earth ions in bidentate mode after deprotonated. The water molecules exist as crystal water in the complexes. The anti-tumour activities of HL and some complexes were tested by both the MTT and SRB methods. The results show that the suppression ratios of some complexes against the tested tumour cells （HL-60 human leukemia cell lines, BGC-823 human gastric carcinoma cell lines, hela human cervix adenocarcinoma cell lines and Bel-7402 human hepatic carcinoma cell lines） are superior to HL.展开更多
As is known to all, nitrogen not only plays an important role in the industrial development of human society but also plays an important part in the proteins that constitute the essence of life[1]. In 1910, the Haber-...As is known to all, nitrogen not only plays an important role in the industrial development of human society but also plays an important part in the proteins that constitute the essence of life[1]. In 1910, the Haber-Bosch process was first used to synthesize ammonia.展开更多
The influences of catalyst concentration, reaction temperature and pressure, feed rate, and water content on the liquid phase oxidation of 2,6-diisopropylnaphthalene to 2,6-naphthalenedicarboxylic acid (2,6-NDCA)were ...The influences of catalyst concentration, reaction temperature and pressure, feed rate, and water content on the liquid phase oxidation of 2,6-diisopropylnaphthalene to 2,6-naphthalenedicarboxylic acid (2,6-NDCA)were studied in a 1 L titanium reactor using air as oxidant, acetic acid as solvent, and a Co-Mn-Br mixture as catalyst, and the optimum operation conditions were obtained in the experimental range.Meanwhile, the promotor effects of individual CO2 and Ni 2+ and their combined use on the activity of Co-Mn-Br catalyst were discussed.Based on the results of the batch experiments, a continuous process for making 2,6-NDCA was developed.The yield of 2,6-NDCA increased from 69% to 73% and the purity of 2,6-NDCA could be up to 95% with the increasing of reaction time.展开更多
Cerium‐based catalysts are very attractive for the catalytic abatement of nitrogen oxides(NOx)emitted from stationary sources.However,the main challenge is still achieving satisfactory catalytic activity in the low‐...Cerium‐based catalysts are very attractive for the catalytic abatement of nitrogen oxides(NOx)emitted from stationary sources.However,the main challenge is still achieving satisfactory catalytic activity in the low‐temperature range and tolerance to SO2 poisoning.In the present work,two series of Mo‐modified CeO_(2)catalysts were respectively obtained through a wet impregnation method(Mo‐CeO_(2))and a co‐precipitation method(MoCe‐cp),and the roles of the Mo species were systematically investigated.Activity tests showed that the Mo‐CeO_(2)catalyst displayed much higher NO conversion at low temperature and anti‐SO2 ability than MoCe‐cp.The optimal Mo‐CeO_(2)catalyst displayed over 80%NO elimination efficiency even at 150°C and remarkable SO2 resistance at 250°C(nearly no activity loss after 40 h test).The characterization results indicated that the introduced Mo species were highly dispersed on the Mo‐CeO_(2)catalyst surface,thereby providing more Brønsted acid sites and inhibiting the formation of stable adsorbed NOx species.These factors synergistically promote the selective catalytic reduction(SCR)reaction in accordance with the Eley‐Rideal(E‐R)reaction path on the Mo‐CeO_(2)catalyst.Additionally,the molybdenum surface could protect CeO_(2)from SO2 poisoning;thus,the reducibility of the Mo‐CeO_(2)catalyst declined slightly to an adequate level after sulfation.The results in this work indicate that surface modification with Mo species may be a simple method of developing highly efficient cerium‐based SCR catalysts with superior SO2 durability.展开更多
A new europium(Ⅲ)complex containing(4-Methyl-2-oxo-2 H-chromen-7-yloxy)-acetic acid moiety(CMMC)was synthesized,characterized,and confirmed as antitumor agent and fluorescent probe.The spectroscopic measurements of ...A new europium(Ⅲ)complex containing(4-Methyl-2-oxo-2 H-chromen-7-yloxy)-acetic acid moiety(CMMC)was synthesized,characterized,and confirmed as antitumor agent and fluorescent probe.The spectroscopic measurements of Eu(Ⅲ)in the presence of CMMC were obtained in different solvents.The results show that the strongest Eu(Ⅲ)emission bands were monitored in iso-propyl alcohol while the weakest Eu(Ⅲ)emission band was observed in acetonitrile.The interaction of Eu(Ⅲ)-(CMMC)2 complex with DNA was monitored using absorption and emission techniques.From fluorescence titration measurements,the binding constants of DNA with Eu(Ⅲ)-(CMMC)_2 complex were found to be 1.04×10~5 L·mol^(-1) in Tris-HCl and 1.17×10~7 L·mol^(-1) in DMSO-Tris-HCl buffer(9∶1 V/V).Hypochromism was observed from the absorption titration experiment which indicates the intercalation of Eu(Ⅲ)-complex between the base pair of DNA.This result further confirmed by fluorescent Ethidium bromide displacement assay.The fluorescence calibration curve was used for the determination of DNA with LOD of 1.2 ng in DMSO-Tris-HCl buffer(9∶1 V/V)and 5 ng in Tris-HCl buffer.The preliminary antitumor investigation shows promising cytotoxicity against MDA-MB-231,MCF-7(mammary cancer),and PC-3(prostate carcinoma)cell lines with IC50 values of 40.63,25.42 and 30.25μmol·L^(-1),respectively.展开更多
All-inorganic CsPbI_(2)Br perovskite with suitable bandgap and excellent thermal stability has been reported as the most promising candidate for efficient perovskite solar cells (PSCs). However, the high annealing tem...All-inorganic CsPbI_(2)Br perovskite with suitable bandgap and excellent thermal stability has been reported as the most promising candidate for efficient perovskite solar cells (PSCs). However, the high annealing temperature (> 250 ℃) and poor stability of α-CsPbI_(2)Br greatly limit the future application in photovoltaic field. Herein, a facile method is reported to prepare α-CsPbI_(2)Br perovskite film with high stability at low temperature (70 ℃) by incorporating a small amount of γ-aminobutyric acid (GABA) in the precursor solutions. The devices exhibit reproducible photovoltaic performance with a champion efficiency up to 15.16%, along with the excellent stability, maintaining more than 80% of its initial efficiency after stored in ambient condition for 600 h without any encapsulation. Most importantly, the method enables fabrication of semitransparent CsPbI_(2)Br PSCs with a PCE of 6.76%, as well as an average visible transparency (AVT) of 25.38%. To the best of our knowledge, this is the first attempt to apply CsPbI_(2)Br to the semitransparent solar cells.展开更多
In this work, the effectiveness of V2O5-WO3/TiO2 catalysts modified with different CeO2 contents by impregnation and co-precipitation methods on the selective catalytic reduction of NOxby NH3 have been studied compara...In this work, the effectiveness of V2O5-WO3/TiO2 catalysts modified with different CeO2 contents by impregnation and co-precipitation methods on the selective catalytic reduction of NOxby NH3 have been studied comparatively by various experimental techniques. The results showed that the NO conversion of V2O5-WO3/CeO2-TiO2 catalysts modified by co-precipitation method obviously increased with the Ce doping contents in the studied range below 20%（All Ce contents are in mass fractions）, but the NO conversion of V2O5-WO3/CeO2/TiO2 catalysts modified by impregnation methods was lower than V2O5-WO3/CeO2-TiO2 catalysts especially beyond 2.5% Ce doping contents. The V2O5-WO3/CeO2-TiO2 catalysts showed better SCR activity, wider reaction window, and higher sulfur and water resistance. The characterization results elucidated that the modified catalysts by co-precipitation method exhibited higher specific surface area, much better dispersity of Ce component, more Ce^（3＋）species and more Br？nsted acid sites than that by impregnation. The vacancies caused by more Ce^（3＋）species were favorable for more NO oxidation to NO2, and the interaction between Ce species and WOxspecies generated more Br？nsted acid sites. It could be supposed that dispersed Ce Oxspecies and WOxspecies offered more second active centers respectively to adsorb oxygen and activate ammonia as co-catalysis to the primary active center of V ions, thus facilitated the better SCR activity of modified V2O5-WO3/CeO2-TiO2 catalysts by coprecipitation methods. The co-precipitation methods with Ce component were more suitable for production of modified commercial V2O5-WO3/TiO2 catalysts.展开更多
文摘We have prepared the 2-（quinolin-8-yloxy）-acetic acid and characterized it by infrared and Raman spectroscopies in the solid phase. The Density Functional Theory （DFT） method, together with the 6-31G^＊ and 6-311＋＋ G^＊＊ basis sets, show that three stable molecules, for the anhydrous and monohydrated compounds were theoretically determined in the gas phase, and that probably the two more stable conformations are present in the solid phase of the monohydrated compound. The harmonic vibrational wavenumbers for the optimized geometries were calculated at B3LYP/6-31G^＊and B3LYP/6-311＋＋G^＊＊ levels. For a complete assignment of all the observed bands in the vibrational spectra the DFT calculations were combined with Pulay＇s scaled quantum mechanical force field （SQMFF） methodology in order to fit the theoretical Wavenumber values to the experimental ones. The characteristics of the electronic delocalization of all structures of both forms were performed by using natural bond orbital （NBO）, while the corresponding topological properties of electronic charge density are analysed by employing Bader＇s atoms in molecules theory （AIM）.
文摘Eight rare earth metal （ Ⅲ ） complexes with 2- （ （（4,6-dimethyl）-2-pyrimidinyl） thio）-acetic acid, LnL3· n H2O [HL = 2-（（（4,6-dimethyl）-2-pyrimidinyl）thio）-acetic acid; Ln = La, Ce, Pr, Nd, Sm Eu, Gd, Tb; n = 4 or 5], were prepared and characterized by elemental analysis, complexometric titration, thermal analysis, conductivity, IR and ^1H- NMR. The results reveal that carboxyl group of the hgand coordinates with rare earth ions in bidentate mode after deprotonated. The water molecules exist as crystal water in the complexes. The anti-tumour activities of HL and some complexes were tested by both the MTT and SRB methods. The results show that the suppression ratios of some complexes against the tested tumour cells （HL-60 human leukemia cell lines, BGC-823 human gastric carcinoma cell lines, hela human cervix adenocarcinoma cell lines and Bel-7402 human hepatic carcinoma cell lines） are superior to HL.
基金supported by the National Key R&D Program of China(2017YFA0208300 and 2017YFA0700104)the National Natural Science Foundation of China(21671180 and 21406184)+2 种基金the Chengdu International Science and Technology Cooperation Fund(2020GH0200069HZ)the funding support from CAS Fujian Institute of Innovationfinancially supported by the DNL Cooperation Fund(DNL201918)。
文摘As is known to all, nitrogen not only plays an important role in the industrial development of human society but also plays an important part in the proteins that constitute the essence of life[1]. In 1910, the Haber-Bosch process was first used to synthesize ammonia.
文摘The influences of catalyst concentration, reaction temperature and pressure, feed rate, and water content on the liquid phase oxidation of 2,6-diisopropylnaphthalene to 2,6-naphthalenedicarboxylic acid (2,6-NDCA)were studied in a 1 L titanium reactor using air as oxidant, acetic acid as solvent, and a Co-Mn-Br mixture as catalyst, and the optimum operation conditions were obtained in the experimental range.Meanwhile, the promotor effects of individual CO2 and Ni 2+ and their combined use on the activity of Co-Mn-Br catalyst were discussed.Based on the results of the batch experiments, a continuous process for making 2,6-NDCA was developed.The yield of 2,6-NDCA increased from 69% to 73% and the purity of 2,6-NDCA could be up to 95% with the increasing of reaction time.
文摘Cerium‐based catalysts are very attractive for the catalytic abatement of nitrogen oxides(NOx)emitted from stationary sources.However,the main challenge is still achieving satisfactory catalytic activity in the low‐temperature range and tolerance to SO2 poisoning.In the present work,two series of Mo‐modified CeO_(2)catalysts were respectively obtained through a wet impregnation method(Mo‐CeO_(2))and a co‐precipitation method(MoCe‐cp),and the roles of the Mo species were systematically investigated.Activity tests showed that the Mo‐CeO_(2)catalyst displayed much higher NO conversion at low temperature and anti‐SO2 ability than MoCe‐cp.The optimal Mo‐CeO_(2)catalyst displayed over 80%NO elimination efficiency even at 150°C and remarkable SO2 resistance at 250°C(nearly no activity loss after 40 h test).The characterization results indicated that the introduced Mo species were highly dispersed on the Mo‐CeO_(2)catalyst surface,thereby providing more Brønsted acid sites and inhibiting the formation of stable adsorbed NOx species.These factors synergistically promote the selective catalytic reduction(SCR)reaction in accordance with the Eley‐Rideal(E‐R)reaction path on the Mo‐CeO_(2)catalyst.Additionally,the molybdenum surface could protect CeO_(2)from SO2 poisoning;thus,the reducibility of the Mo‐CeO_(2)catalyst declined slightly to an adequate level after sulfation.The results in this work indicate that surface modification with Mo species may be a simple method of developing highly efficient cerium‐based SCR catalysts with superior SO2 durability.
基金supported by grants 4590/1434 by Deanship of Scientific Resea rch at Taibah University in Saudi Arabia for financial assistance
文摘A new europium(Ⅲ)complex containing(4-Methyl-2-oxo-2 H-chromen-7-yloxy)-acetic acid moiety(CMMC)was synthesized,characterized,and confirmed as antitumor agent and fluorescent probe.The spectroscopic measurements of Eu(Ⅲ)in the presence of CMMC were obtained in different solvents.The results show that the strongest Eu(Ⅲ)emission bands were monitored in iso-propyl alcohol while the weakest Eu(Ⅲ)emission band was observed in acetonitrile.The interaction of Eu(Ⅲ)-(CMMC)2 complex with DNA was monitored using absorption and emission techniques.From fluorescence titration measurements,the binding constants of DNA with Eu(Ⅲ)-(CMMC)_2 complex were found to be 1.04×10~5 L·mol^(-1) in Tris-HCl and 1.17×10~7 L·mol^(-1) in DMSO-Tris-HCl buffer(9∶1 V/V).Hypochromism was observed from the absorption titration experiment which indicates the intercalation of Eu(Ⅲ)-complex between the base pair of DNA.This result further confirmed by fluorescent Ethidium bromide displacement assay.The fluorescence calibration curve was used for the determination of DNA with LOD of 1.2 ng in DMSO-Tris-HCl buffer(9∶1 V/V)and 5 ng in Tris-HCl buffer.The preliminary antitumor investigation shows promising cytotoxicity against MDA-MB-231,MCF-7(mammary cancer),and PC-3(prostate carcinoma)cell lines with IC50 values of 40.63,25.42 and 30.25μmol·L^(-1),respectively.
基金financial support from the Taishan Scholar Project of Shandong Province (No. tsqn201812098)the Shandong Provincial Natural Science Foundation (Nos. ZR2020MF103,ZR2019MF057 and ZR2019MA066)National Natural Science Foundation of China (No. 21701080)。
文摘All-inorganic CsPbI_(2)Br perovskite with suitable bandgap and excellent thermal stability has been reported as the most promising candidate for efficient perovskite solar cells (PSCs). However, the high annealing temperature (> 250 ℃) and poor stability of α-CsPbI_(2)Br greatly limit the future application in photovoltaic field. Herein, a facile method is reported to prepare α-CsPbI_(2)Br perovskite film with high stability at low temperature (70 ℃) by incorporating a small amount of γ-aminobutyric acid (GABA) in the precursor solutions. The devices exhibit reproducible photovoltaic performance with a champion efficiency up to 15.16%, along with the excellent stability, maintaining more than 80% of its initial efficiency after stored in ambient condition for 600 h without any encapsulation. Most importantly, the method enables fabrication of semitransparent CsPbI_(2)Br PSCs with a PCE of 6.76%, as well as an average visible transparency (AVT) of 25.38%. To the best of our knowledge, this is the first attempt to apply CsPbI_(2)Br to the semitransparent solar cells.
基金Project supported by the Guangxi Natural Science Foundation(2014GXNSFAA118057)Guangxi Science and Technology Planning Project(AB16380276)
文摘In this work, the effectiveness of V2O5-WO3/TiO2 catalysts modified with different CeO2 contents by impregnation and co-precipitation methods on the selective catalytic reduction of NOxby NH3 have been studied comparatively by various experimental techniques. The results showed that the NO conversion of V2O5-WO3/CeO2-TiO2 catalysts modified by co-precipitation method obviously increased with the Ce doping contents in the studied range below 20%（All Ce contents are in mass fractions）, but the NO conversion of V2O5-WO3/CeO2/TiO2 catalysts modified by impregnation methods was lower than V2O5-WO3/CeO2-TiO2 catalysts especially beyond 2.5% Ce doping contents. The V2O5-WO3/CeO2-TiO2 catalysts showed better SCR activity, wider reaction window, and higher sulfur and water resistance. The characterization results elucidated that the modified catalysts by co-precipitation method exhibited higher specific surface area, much better dispersity of Ce component, more Ce^（3＋）species and more Br？nsted acid sites than that by impregnation. The vacancies caused by more Ce^（3＋）species were favorable for more NO oxidation to NO2, and the interaction between Ce species and WOxspecies generated more Br？nsted acid sites. It could be supposed that dispersed Ce Oxspecies and WOxspecies offered more second active centers respectively to adsorb oxygen and activate ammonia as co-catalysis to the primary active center of V ions, thus facilitated the better SCR activity of modified V2O5-WO3/CeO2-TiO2 catalysts by coprecipitation methods. The co-precipitation methods with Ce component were more suitable for production of modified commercial V2O5-WO3/TiO2 catalysts.
