Titanic acid nanotubes(H_(2)Ti_(2)O_(4)(OH)_(2))were surface-modified with cetyl alcohol through dehydration reaction because of existence of Ti–OH.The modified nanotubes were characterized by transmission electron m...Titanic acid nanotubes(H_(2)Ti_(2)O_(4)(OH)_(2))were surface-modified with cetyl alcohol through dehydration reaction because of existence of Ti–OH.The modified nanotubes were characterized by transmission electron microscopy(TEM),Fourier Transform Infrared(FT-IR)spectrometry and pho-toluminescence(PL)spectra.The results indicate that the modified nanotubes can be easily dis-persed into organic solvent such as chloroform and toluene in contrast with the unmodified nanotubes,which makes it easier to be assembled by LB technique.Moreover,the Ti-O-CH_(2)(CH_(2))_(14)CH_(3) on the surface of the nanotubes can hinder the adsorption of water and consequently the photoluminescence property of the nanotubes can be stabilized.Even though kept in humid condition or in air for a long time,the modified nanotubes also maintain the special photoluminescence property in the visible region.展开更多
Supporting sustainable green energy systems,there is a big demand gap for grid energy storage.Sodiumion storage,especially sodium-ion batteries(SIBs),have advanced significantly and are now emerging as a feasible alte...Supporting sustainable green energy systems,there is a big demand gap for grid energy storage.Sodiumion storage,especially sodium-ion batteries(SIBs),have advanced significantly and are now emerging as a feasible alternative to the lithium-ion batteries equivalent in large-scale energy storage due to their natural abundance and prospective inexpensive cost.Among various anode materials of SIBs,beneficial properties,such as outstanding stability,great abundance,and environmental friendliness,make sodium titanates(NTOs),one of the most promising anode materials for the rechargeable SIBs.Nevertheless,there are still enormous challenges in application of NTO,owing to its low intrinsic electronic conductivity and collapse of structure.The research on NTOs is still in its infancy;there are few conclusive reviews about the specific function of various modification methods.Herein,we summarize the typical strategies of optimization and analysis the fine structures and fabrication methods of NTO anodes combined with the application of in situ characterization techniques.Our work provides effective guidance for promoting the continuous development,equipping NTOs in safety-critical systems,and lays a foundation for the development of NTO-anode materials in SIBs.展开更多
The severe erosion and inadequate mechanical strength are prominent challenges for high-energy gun propellants.To address it,novel PTW@PDA composites was prepared by polydopamine(PDA)-modifying onto potassium titanate...The severe erosion and inadequate mechanical strength are prominent challenges for high-energy gun propellants.To address it,novel PTW@PDA composites was prepared by polydopamine(PDA)-modifying onto potassium titanate whisker(PTW,K_(2)Ti_(6)O_(13)),and after was incorporated into gun propellant as erosion-reducing and mechanical-reinforcing fillers.The interfacial characterizations results indicated that as-prepared PTW@PDA composites exhibits an enhanced surface compatible with propellant matrix,thereby facilitating their dispersion into propellants more effectively than raw PTW materials.Compared to original propellants,PTW@PDA-modified propellants exhibited significant less erosion,with a Ti-Kbased protective coating being detected on the eroded steel.And 0.5 wt%and 1.0 wt%addition of PTW@PDA significantly improved impact,compressive and tensile strength of propellants.Despite the inevitably reduction in relative force,PTW@PDA slightly increase propellant burning rate while exerting little adverse impact on propellant dynamic activity.This strategy can provide a promising alternative to develop high-energy gun propellant with less erosion and more mechanical strength.展开更多
The debut of Titanic:The Artifact Exhibition at the Guangdong Museum not only marks the first time artifacts from the RMS Titanic have been叩enly showcased in China,its also organizer Premier Exhibition Inc/s largest ...The debut of Titanic:The Artifact Exhibition at the Guangdong Museum not only marks the first time artifacts from the RMS Titanic have been叩enly showcased in China,its also organizer Premier Exhibition Inc/s largest show in history,with more than 300 relics displayed across 20,000 square feet of space.This month,we went behind the scenes and chatted with one of the curators,Ou Yan,to see what visitors can expect.展开更多
【选注者言:春节的爆竹声,连绵不断,甚至延续到半夜,到凌晨。我失眠了,但心情却并不坏。爆竹一声除旧,桃符万户更新!现在是凌晨两点,英语称之为small hours,我披衣起身,打开电脑,在网上浏览起来。读到一篇短文,令我精神抖擞,睡意全消。...【选注者言:春节的爆竹声,连绵不断,甚至延续到半夜,到凌晨。我失眠了,但心情却并不坏。爆竹一声除旧,桃符万户更新!现在是凌晨两点,英语称之为small hours,我披衣起身,打开电脑,在网上浏览起来。读到一篇短文,令我精神抖擞,睡意全消。泰坦尼克巨轮已经沉没87个寒暑了,人们还在银幕上演绎她的故事,观者垂泪;人们还在聆听她的汽笛声,听众伤感。我是一个英语教师,细品本文,觉得本文造句非常讲究,用的大多是“拖泥带水”的长句,作者很懂修辞,这种“欲休还说”的句式不是很好地衬托渲染了今人怀旧时的那种缠绵悱恻的心绪吗?比如下句就很典型,我读之再三: When they were made the whistles weighed 750 pounds(340 kg)and could be heard more than 10 miles(16 km)away, according to the St. Paul Convention and Visitors Bureau, which hosted Saturday's event. 编辑先生,读者同志,不知你们是否同意我的以上分析。如果你们不同意,那么,是不是我过于善感了?】展开更多
Solid oxide electrolysis cell(SOEC) could be a potential technology to afford chemical storage of renewable electricity by converting water and carbon dioxide.In this work,we present the Ni-doped layered perovskite ox...Solid oxide electrolysis cell(SOEC) could be a potential technology to afford chemical storage of renewable electricity by converting water and carbon dioxide.In this work,we present the Ni-doped layered perovskite oxides,(La_(4)Sr_(n-4))_(0.9)Ti_(0.9n)Ni_(0.1n)O_(3n+2) with n=5,8,and 12(LSTNn) for application as catalysts of CO_(2) electrolysis with the exsolution of Ni nanoparticles through a simple in-situ growth method.It is found that the density,size,and distribution of exsolved Ni nanoparticles are determined by the number of n in LSTNn due to the different stack structures of TiO_6 octahedra along the c axis.The Ni doping in LSTNn significantly improved the electrochemical activity by increasing oxygen vacancies,and the Ni metallic nanoparticles afford much more active sites.The results show that LSTNn cathodes can successfully be manipulated the activity by controlling both the n number and Ni exsolution.Among these LSTNn(n=5,8,and 12),LSTN8 renders a higher activity for electrolysis of CO_(2) with a current density of 1.50A cm^(-2)@2.0 V at 800℃ It is clear from these results that the number of n in(La_(4)Sr_(n-4))_(0.9)Ti_(0.9n)Ni_(0.1n)O_(3n+2)with Ni-doping is a key factor in controlling the electrochemical performance and catalytic activity in SOEC.展开更多
Tetragonal barium titanate was synthesized from barium hydroxide octahydrate and titanium tetrachloride through a simple one-step hydrothermal method.The effect of different solvents on the crystal structure and morph...Tetragonal barium titanate was synthesized from barium hydroxide octahydrate and titanium tetrachloride through a simple one-step hydrothermal method.The effect of different solvents on the crystal structure and morphology of barium titanate nanoparticles during the hy-drothermal process was investigated.Except for ethylene glycol/water solvent,impurity-free barium titanate was synthesized in pure water,methanol/water,ethanol/water,and isopropyl alcohol/water mixed solvents.Compared with other alcohols,ethanol promotes the formation of a tetragonal structure.In addition,characterization studies confirm that particles synthesized in methanol/water,ethanol/water,and isopropyl al-cohol/water mixed solvents are smaller in size than those synthesized in pure water.In the case of alcohol-containing solvents,the particle size decreases in the order of isopropanol,ethanol,and methanol.Among all the media used in this study,ethanol/water is considered the optimum reaction media for barium titanate with high tetragonality(defined as the ratio of two lattice parameters c and a,c/a=1.0088)and small aver-age particle size(82 nm),which indicates its great application potential in multilayer ceramic capacitors.展开更多
Traditional wastewater mostly contains pharmaceutical ingredients. Therefore, the wastewater must be completely free from antibiotics before its release into the environment. In the present study, photocatalytic degra...Traditional wastewater mostly contains pharmaceutical ingredients. Therefore, the wastewater must be completely free from antibiotics before its release into the environment. In the present study, photocatalytic degradation was done to investigate the removal efficiency of Oxytetracycline Dihydrate (OTC) using ZnO, ZnO/3%BaTiO<sub>3</sub> (3 BZ), ZnO/18%BaTiO<sub>3</sub> (18 BZ), ZnO/ 33%BaTiO3 (33 BZ) and ZnO/48%BaTiO<sub>3</sub> (48 BZ) under UV light. After the exposure time of 420 min, about 99.57% and 97.87% of OTC was degraded using ZnO and 3 BZ respectively. Further, increasing the amount of BaTiO<sub>3</sub> in ZnO prolongs the degradation time. Therefore, faster efficiency was found using ZnO nanoparticles. The observed reaction rate constant using ZnO was 0.00933 min<sup>-1</sup> which decreased to 0.00532 min<sup>-1</sup> using 48 BZ, indicating the decrease of reaction rate for increasing the amount of BaTiO<sub>3</sub>. Hence, the use of ZnO photocatalyst is anticipated to be a promising technique for the photocatalytic degradation of contaminated wastewater with oxytetracycline antibiotics using UV light.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.90306010 and 20371015)State Key Basic Research'973'Plan of China(Grant No.2002CCC02700).
文摘Titanic acid nanotubes(H_(2)Ti_(2)O_(4)(OH)_(2))were surface-modified with cetyl alcohol through dehydration reaction because of existence of Ti–OH.The modified nanotubes were characterized by transmission electron microscopy(TEM),Fourier Transform Infrared(FT-IR)spectrometry and pho-toluminescence(PL)spectra.The results indicate that the modified nanotubes can be easily dis-persed into organic solvent such as chloroform and toluene in contrast with the unmodified nanotubes,which makes it easier to be assembled by LB technique.Moreover,the Ti-O-CH_(2)(CH_(2))_(14)CH_(3) on the surface of the nanotubes can hinder the adsorption of water and consequently the photoluminescence property of the nanotubes can be stabilized.Even though kept in humid condition or in air for a long time,the modified nanotubes also maintain the special photoluminescence property in the visible region.
基金supported by projects from the National Natural Science Foundation of China(U20A20145)the Open Project of State Key Laboratory of Environment-friendly Energy Materials(20kfhg07)+6 种基金Distinguished Young Foundation of Sichuan Province(2020JDJQ0027)2020 Strategic Cooperation Project between Sichuan University and the Zigong Municipal People's Government(2020CDZG-09)State Key Laboratory of Polymer Materials Engineering(sklpme2020-3-02)Sichuan Provincial Department of Science and Technology(2020YFG0471,2020YFG0022,2022YFG0124)Sichuan Province Science and Technology Achievement Transfer and Transformation Project(21ZHSF0111)Sichuan University Postdoctoral Interdisciplinary Innovation Fund(2021SCU12084)Start-up funding of Chemistry and Chemical Engineering Guangdong Laboratory(2122010)。
文摘Supporting sustainable green energy systems,there is a big demand gap for grid energy storage.Sodiumion storage,especially sodium-ion batteries(SIBs),have advanced significantly and are now emerging as a feasible alternative to the lithium-ion batteries equivalent in large-scale energy storage due to their natural abundance and prospective inexpensive cost.Among various anode materials of SIBs,beneficial properties,such as outstanding stability,great abundance,and environmental friendliness,make sodium titanates(NTOs),one of the most promising anode materials for the rechargeable SIBs.Nevertheless,there are still enormous challenges in application of NTO,owing to its low intrinsic electronic conductivity and collapse of structure.The research on NTOs is still in its infancy;there are few conclusive reviews about the specific function of various modification methods.Herein,we summarize the typical strategies of optimization and analysis the fine structures and fabrication methods of NTO anodes combined with the application of in situ characterization techniques.Our work provides effective guidance for promoting the continuous development,equipping NTOs in safety-critical systems,and lays a foundation for the development of NTO-anode materials in SIBs.
基金the support of the instrument and equipment fund of the Key Laboratory of Special Energy,Ministry of Education,Nanjing University of Science and Technology,China.
文摘The severe erosion and inadequate mechanical strength are prominent challenges for high-energy gun propellants.To address it,novel PTW@PDA composites was prepared by polydopamine(PDA)-modifying onto potassium titanate whisker(PTW,K_(2)Ti_(6)O_(13)),and after was incorporated into gun propellant as erosion-reducing and mechanical-reinforcing fillers.The interfacial characterizations results indicated that as-prepared PTW@PDA composites exhibits an enhanced surface compatible with propellant matrix,thereby facilitating their dispersion into propellants more effectively than raw PTW materials.Compared to original propellants,PTW@PDA-modified propellants exhibited significant less erosion,with a Ti-Kbased protective coating being detected on the eroded steel.And 0.5 wt%and 1.0 wt%addition of PTW@PDA significantly improved impact,compressive and tensile strength of propellants.Despite the inevitably reduction in relative force,PTW@PDA slightly increase propellant burning rate while exerting little adverse impact on propellant dynamic activity.This strategy can provide a promising alternative to develop high-energy gun propellant with less erosion and more mechanical strength.
文摘The debut of Titanic:The Artifact Exhibition at the Guangdong Museum not only marks the first time artifacts from the RMS Titanic have been叩enly showcased in China,its also organizer Premier Exhibition Inc/s largest show in history,with more than 300 relics displayed across 20,000 square feet of space.This month,we went behind the scenes and chatted with one of the curators,Ou Yan,to see what visitors can expect.
文摘【选注者言:春节的爆竹声,连绵不断,甚至延续到半夜,到凌晨。我失眠了,但心情却并不坏。爆竹一声除旧,桃符万户更新!现在是凌晨两点,英语称之为small hours,我披衣起身,打开电脑,在网上浏览起来。读到一篇短文,令我精神抖擞,睡意全消。泰坦尼克巨轮已经沉没87个寒暑了,人们还在银幕上演绎她的故事,观者垂泪;人们还在聆听她的汽笛声,听众伤感。我是一个英语教师,细品本文,觉得本文造句非常讲究,用的大多是“拖泥带水”的长句,作者很懂修辞,这种“欲休还说”的句式不是很好地衬托渲染了今人怀旧时的那种缠绵悱恻的心绪吗?比如下句就很典型,我读之再三: When they were made the whistles weighed 750 pounds(340 kg)and could be heard more than 10 miles(16 km)away, according to the St. Paul Convention and Visitors Bureau, which hosted Saturday's event. 编辑先生,读者同志,不知你们是否同意我的以上分析。如果你们不同意,那么,是不是我过于善感了?】
基金supported by the National Natural Science Foundation of China (51877173)the Key R&D Project of Shaanxi Province (2023-YBGY-057)+1 种基金the State Key Laboratory of Electrical Insulation and Power Equipment (EIPE22314, EIPE22306)the Natural Science Basic Research Program of Shaanxi (2023-JC-QN-0483)。
文摘Solid oxide electrolysis cell(SOEC) could be a potential technology to afford chemical storage of renewable electricity by converting water and carbon dioxide.In this work,we present the Ni-doped layered perovskite oxides,(La_(4)Sr_(n-4))_(0.9)Ti_(0.9n)Ni_(0.1n)O_(3n+2) with n=5,8,and 12(LSTNn) for application as catalysts of CO_(2) electrolysis with the exsolution of Ni nanoparticles through a simple in-situ growth method.It is found that the density,size,and distribution of exsolved Ni nanoparticles are determined by the number of n in LSTNn due to the different stack structures of TiO_6 octahedra along the c axis.The Ni doping in LSTNn significantly improved the electrochemical activity by increasing oxygen vacancies,and the Ni metallic nanoparticles afford much more active sites.The results show that LSTNn cathodes can successfully be manipulated the activity by controlling both the n number and Ni exsolution.Among these LSTNn(n=5,8,and 12),LSTN8 renders a higher activity for electrolysis of CO_(2) with a current density of 1.50A cm^(-2)@2.0 V at 800℃ It is clear from these results that the number of n in(La_(4)Sr_(n-4))_(0.9)Ti_(0.9n)Ni_(0.1n)O_(3n+2)with Ni-doping is a key factor in controlling the electrochemical performance and catalytic activity in SOEC.
基金supported by Chongqing Newcent New Materials Co.,Ltd.,China (No.2021GKF-0708).
文摘Tetragonal barium titanate was synthesized from barium hydroxide octahydrate and titanium tetrachloride through a simple one-step hydrothermal method.The effect of different solvents on the crystal structure and morphology of barium titanate nanoparticles during the hy-drothermal process was investigated.Except for ethylene glycol/water solvent,impurity-free barium titanate was synthesized in pure water,methanol/water,ethanol/water,and isopropyl alcohol/water mixed solvents.Compared with other alcohols,ethanol promotes the formation of a tetragonal structure.In addition,characterization studies confirm that particles synthesized in methanol/water,ethanol/water,and isopropyl al-cohol/water mixed solvents are smaller in size than those synthesized in pure water.In the case of alcohol-containing solvents,the particle size decreases in the order of isopropanol,ethanol,and methanol.Among all the media used in this study,ethanol/water is considered the optimum reaction media for barium titanate with high tetragonality(defined as the ratio of two lattice parameters c and a,c/a=1.0088)and small aver-age particle size(82 nm),which indicates its great application potential in multilayer ceramic capacitors.
文摘Traditional wastewater mostly contains pharmaceutical ingredients. Therefore, the wastewater must be completely free from antibiotics before its release into the environment. In the present study, photocatalytic degradation was done to investigate the removal efficiency of Oxytetracycline Dihydrate (OTC) using ZnO, ZnO/3%BaTiO<sub>3</sub> (3 BZ), ZnO/18%BaTiO<sub>3</sub> (18 BZ), ZnO/ 33%BaTiO3 (33 BZ) and ZnO/48%BaTiO<sub>3</sub> (48 BZ) under UV light. After the exposure time of 420 min, about 99.57% and 97.87% of OTC was degraded using ZnO and 3 BZ respectively. Further, increasing the amount of BaTiO<sub>3</sub> in ZnO prolongs the degradation time. Therefore, faster efficiency was found using ZnO nanoparticles. The observed reaction rate constant using ZnO was 0.00933 min<sup>-1</sup> which decreased to 0.00532 min<sup>-1</sup> using 48 BZ, indicating the decrease of reaction rate for increasing the amount of BaTiO<sub>3</sub>. Hence, the use of ZnO photocatalyst is anticipated to be a promising technique for the photocatalytic degradation of contaminated wastewater with oxytetracycline antibiotics using UV light.