The influence of magnesium and aluminum salts as impurities on the hydrolysis of titanyl sulfate was investigated.The degree of TiOSO4 conversion to hydrated titanium dioxide（HTD） and the particle size of HTD were m...The influence of magnesium and aluminum salts as impurities on the hydrolysis of titanyl sulfate was investigated.The degree of TiOSO4 conversion to hydrated titanium dioxide（HTD） and the particle size of HTD were measured as functions of the concentrations of MgSO4 and Al2（SO4）3 in the TiOSO4 solution.The Boltzmann growth model,which focuses on two main parameters,namely the concentrations of Mg2＋ and Al3＋（ρ（Mg2＋） and ρ（Al3＋）,respectively）,fits the data from the hydrolysis process well with R20.988.The samples were characterized by ICP,SEM,XRD,and laser particle size analyzer.It is found that the addition of Mg SO4 simultaneously improves the hydrolysis ratio and the hydrolysis rate,especially when F（the mass ratio of H2SO4 to TiO2） is high,hydrolysis ratio increases from 42.8% to 83.0%,whereas the addition of Al2（SO4）3 has negligible effect on the chemical kinetics of HTD precipitation during the hydrolysis process,hydrolysis ratio increases from 42.8% to 51.9%.An investigation on the particle size of HTD reveals that the addition of Mg SO4 and Al2（SO4）3 clearly increases the size of the crystallites and decreases the size of the aggregates.展开更多
The relationship between hydrolysis conditions and hydrous titania polymorphs obtained in a titanyl sulfate and sulfmic acid solu- tion was investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM...The relationship between hydrolysis conditions and hydrous titania polymorphs obtained in a titanyl sulfate and sulfmic acid solu- tion was investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and high-resolution transmission electron micros- copy （HRTEM）. The results revealed that the feeding rate of the titanyl sulfate stock solution, the concentration of sulfi.Lric acid, and the seed dosage of mtile crystal could significantly affect the hydrolysis rate, thus influencing the titania crystal phase. Hydrous TiO2 in the form of rutile, anatase, or the mixture of both could be obtained in solutions of low titanium concentrations and 2.5wt% to 15wt% sulfuric acid at 100℃. When the hydrolysis rate of titanitma expressed by TiOa was more than or equal to 0.04 g/（L.min）, the hydrolysate was almost phase-pure anatase, while the main phase state was rutile when the hydrolysis rate was less than or equal to 0.01 g/（L.min）. With the hy- drolysis rate between 0.02 and 0.03 g/（L.min）, the hydrolysate contained almost equal magnitude ofrutile and anatase. It seems that although rutile phase is thermodynamically stable in very acidic solutions, anatase is a kinetically stable phase.展开更多
To investigate the factors that influence treatment satisfaction after high-power potassium-titanyl-phosphate （KTP） laser vaporization of the prostate, we compared the characteristics between patients who were satis...To investigate the factors that influence treatment satisfaction after high-power potassium-titanyl-phosphate （KTP） laser vaporization of the prostate, we compared the characteristics between patients who were satisfied and those who were not satisfied. In all, 97 patients aged between 53-82 years （median age 67 years） underwent high-power KTP laser vaporization of the prostate for lower urinary tract symptoms due to benign prostatic hyperplasia. At 12 months postoperatively, 60 patients were satisfied with the treatment, whereas 37 were dissatisfied. Although there were no differences in International Prostate Symptom Score （IPSS） values at baseline, the satisfied group scored better in total IPSS at 1, 3, 6, and 12 months postoperatively （P 〈 0.05）. At baseline, the maximum flow rate （Qmax） was lower in the dissatisfied group and remained low throughout the follow-up period, with the exception of 1 month postoperatively （P 〈 0.05）, compared with the satisfied group. There were no differences in other objective data between the two groups, including post-void residual and the number of voids based on the frequency-volume charts. In a multivariate model, a higher bladder contractility index was associated with a greater likelihood of treatment satisfaction 12 months after high-power KTP laser vaporization （odds ratio 1.024, 95% confidence interval 1.001-1.048, P 〈 0.05）. Patients who were not satisfied following the surgery had a smaller improvement in subjective symptoms and Qmax. In addition, our findings suggest that the relative risk of treatment dissatisfaction following high-power KTP laser vaporization was increased in patients with weak detrusor contractility.展开更多
Ultralong titanyl phthalocyanine （TiOPc） sub-micron wires have been synthesized by a novel solution-based self- assembly method. By using different solvents, changing the mass concentration and the solvent vapor pre...Ultralong titanyl phthalocyanine （TiOPc） sub-micron wires have been synthesized by a novel solution-based self- assembly method. By using different solvents, changing the mass concentration and the solvent vapor pressure, the length and the shape of the wires can be adjusted. The mixed-phase properties of the TiOPc sub-micron wires were investigated by the ultraviolet-visible （UV-vis） absorption spectrum and X-ray diffraction. Organic transistors based on these wires were studied, which show the typical p-channel characteristics.展开更多
Photoelectrochemical(PEC)H_(2)O_(2)production through water oxidation reaction(WOR)is a promising strategy,however,designing highly efficient and selective photoanode materials remains challenging due to competitive r...Photoelectrochemical(PEC)H_(2)O_(2)production through water oxidation reaction(WOR)is a promising strategy,however,designing highly efficient and selective photoanode materials remains challenging due to competitive reaction pathways.Here,for highly enhanced PEC H_(2)O_(2)production,we present a conformal amorphous titanyl phosphate(a-TP)overlayer on nanoparticulate TiO_(2)surfaces,achieved via lysozyme-molded in-situ surface reforming.The a-TP overlayer modulates surface adsorption energies for reaction intermediates,favoring WOR for H_(2)O_(2)production over the competing O_(2)evolution reaction.Our density functional theory calculations reveal that a-TP/TiO_(2)exhibits a substantial energy uphill for the O·*formation pathway,which disfavors O_(2)evolution but promotes H_(2)O_(2)production.Additionally,the a-TP overlayer strengthens the built-in electric field,resulting in favorable kinetics.Consequently,a-TP/TiO_(2)exhibits 3.7-fold higher Faraday efficiency(FE)of 63%at 1.76 V vs.reversible hydrogen electrode(RHE)under 1 sun illumination,compared to bare TiO_(2)(17%),representing the highest FE among TiO_(2)-based WOR H_(2)O_(2)production systems.Employing the a-TP overlayer constitutes a promising strategy for controlling reaction pathways and achieving efficient solar-to-chemical energy conversion.展开更多
A number of publications containing structural data, characteristics of nonlinear optical properties of pure and doped crystals of potassium titanyl phosphate (KTP) family have been reviewed to analyze the structural ...A number of publications containing structural data, characteristics of nonlinear optical properties of pure and doped crystals of potassium titanyl phosphate (KTP) family have been reviewed to analyze the structural and symmetry conditionality of nonlinear optical properties of these crystals. The pseudosymmetric features of KTP-type crystals with respect to inversion are investigated. Specifically, pseudoinversion distribution maps are calculated;pseudoinversion extrema and coordinates of pseudoinversion centres are found;and the distributions of pure and doped KTP-type structures and their individual atomic sublattices over the degree of pseudoinversion are analyzed. A correlation between the characteristics of nonlinear optical properties of a number of crystals belonging to the KTP family and the degree of pseudoinversion of their atomic structures is demonstrated.展开更多
Barium titanate(BaTiO_(3))is an important ferroelectric and electronic ceramic material because of its outstanding dielectric and ferroelectric properties.The demand for BaTiO_(3) nanoparticles with adjustable particl...Barium titanate(BaTiO_(3))is an important ferroelectric and electronic ceramic material because of its outstanding dielectric and ferroelectric properties.The demand for BaTiO_(3) nanoparticles with adjustable particle size has increased extensively due to the miniaturization of electronic devices.The oxalate precipitation method is regarded as a highly attractive technology for fabricating BaTiO_(3) nanoparticles,as it enables large-scale production at a low cost.However,the calcination process is a crucial step that significantly influences the particle size and morphology of the obtained BaTiO_(3) nanoparticles.This study investigates the thermal decomposition mechanism and particle size regulation strategies during the calcination of barium titanyl oxalate tetrahydrate(BTOT)for fabricating BaTiO_(3) nanoparticles.The Kissinger-Akahira-Sunose(KAS)model is used to calculate the kinetic parameters of BTOT thermal decomposition process,and the results indicate that the decomposition process can be divided as four stages,with the average activation energy of 60.77,269.89,484.72,and 199.82 kJ/mol,respectively.The average activation energy reaches its maximum value in the third stage,indicating that the thermal decomposition reaction in this stage is more challenging to occur compared to the other stages.The gas release behaviors of H_(2)O,CO,and CO_(2) are analyzed on-line during the thermal decomposition of BTOT,and the overall reaction mechanism is proposed.Additionally,by adjusting the calcination parameters,the particle size of BaTiO_(3) could be effectively regulated within the range of 25-120 nm.Increasing the heating rate from 10 to 40 K/min decreases the average particle size of BaTiO_(3) from 62 to 44 nm.Extending the calcination time from 0 to 120 min increases the average particle size from 25 to 71 nm.Raising the terminal temperature from 1173 to 1273 K significantly increases the average particle size from 56 to 120 nm.Briefly,accelerating the heating rate,reducing the calcination time,and lowering the calcination temperature facilitate the fabrication of BaTiO_(3) with a smaller particle size and more uniform morphology.This study offers a robust theoretical framework and technical guidance for optimizing the process conditions for fabricating BaTiO_(3) nanoparticles via controlled thermal decomposition of BTOT,while also contributing to the advancement of related technological fields.展开更多
KTiOPO-4(KTP) crystal is a nonlinear optical material with superior properties. The KTP structure, point group mm2, is typified by the chemical form {K++}〔Ti 4+〕O(P 5+)O-4, where the curly brackets indicate nine or ...KTiOPO-4(KTP) crystal is a nonlinear optical material with superior properties. The KTP structure, point group mm2, is typified by the chemical form {K++}〔Ti 4+〕O(P 5+)O-4, where the curly brackets indicate nine or eightfold coordination, the square brackets sixfold octahedral coordination and the parentheses fourfold tetrahedral coordination. Different isovalent and aliovalent substitutions in a given structure is quite interesting. The KTP-type structure is extremely accommodating with respect to partial or complete isomorphous substitution which may be especially significant in optical devices such as waveguides. A monographic review of the structure-property relationship of KTP isomorphous substitution is briefly and precisely presented. It is shown that the properties of KTP are very sensitive to its structure. Among the composition, structure and properties of KTP-type crystal, the structure is the core because it is a link between the composition and properties.展开更多
基金Project(51090380)supported by the National Natural Science Foundation of ChinaProjects(2013CB632601,2013CB632604)supported by the National Basic Research Program of China
文摘The influence of magnesium and aluminum salts as impurities on the hydrolysis of titanyl sulfate was investigated.The degree of TiOSO4 conversion to hydrated titanium dioxide（HTD） and the particle size of HTD were measured as functions of the concentrations of MgSO4 and Al2（SO4）3 in the TiOSO4 solution.The Boltzmann growth model,which focuses on two main parameters,namely the concentrations of Mg2＋ and Al3＋（ρ（Mg2＋） and ρ（Al3＋）,respectively）,fits the data from the hydrolysis process well with R20.988.The samples were characterized by ICP,SEM,XRD,and laser particle size analyzer.It is found that the addition of Mg SO4 simultaneously improves the hydrolysis ratio and the hydrolysis rate,especially when F（the mass ratio of H2SO4 to TiO2） is high,hydrolysis ratio increases from 42.8% to 83.0%,whereas the addition of Al2（SO4）3 has negligible effect on the chemical kinetics of HTD precipitation during the hydrolysis process,hydrolysis ratio increases from 42.8% to 51.9%.An investigation on the particle size of HTD reveals that the addition of Mg SO4 and Al2（SO4）3 clearly increases the size of the crystallites and decreases the size of the aggregates.
基金financially supported by a grant from the Ph.D. Programs Foundation of the Ministry of Education of China (No.20070610125)
文摘The relationship between hydrolysis conditions and hydrous titania polymorphs obtained in a titanyl sulfate and sulfmic acid solu- tion was investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and high-resolution transmission electron micros- copy （HRTEM）. The results revealed that the feeding rate of the titanyl sulfate stock solution, the concentration of sulfi.Lric acid, and the seed dosage of mtile crystal could significantly affect the hydrolysis rate, thus influencing the titania crystal phase. Hydrous TiO2 in the form of rutile, anatase, or the mixture of both could be obtained in solutions of low titanium concentrations and 2.5wt% to 15wt% sulfuric acid at 100℃. When the hydrolysis rate of titanitma expressed by TiOa was more than or equal to 0.04 g/（L.min）, the hydrolysate was almost phase-pure anatase, while the main phase state was rutile when the hydrolysis rate was less than or equal to 0.01 g/（L.min）. With the hy- drolysis rate between 0.02 and 0.03 g/（L.min）, the hydrolysate contained almost equal magnitude ofrutile and anatase. It seems that although rutile phase is thermodynamically stable in very acidic solutions, anatase is a kinetically stable phase.
文摘To investigate the factors that influence treatment satisfaction after high-power potassium-titanyl-phosphate （KTP） laser vaporization of the prostate, we compared the characteristics between patients who were satisfied and those who were not satisfied. In all, 97 patients aged between 53-82 years （median age 67 years） underwent high-power KTP laser vaporization of the prostate for lower urinary tract symptoms due to benign prostatic hyperplasia. At 12 months postoperatively, 60 patients were satisfied with the treatment, whereas 37 were dissatisfied. Although there were no differences in International Prostate Symptom Score （IPSS） values at baseline, the satisfied group scored better in total IPSS at 1, 3, 6, and 12 months postoperatively （P 〈 0.05）. At baseline, the maximum flow rate （Qmax） was lower in the dissatisfied group and remained low throughout the follow-up period, with the exception of 1 month postoperatively （P 〈 0.05）, compared with the satisfied group. There were no differences in other objective data between the two groups, including post-void residual and the number of voids based on the frequency-volume charts. In a multivariate model, a higher bladder contractility index was associated with a greater likelihood of treatment satisfaction 12 months after high-power KTP laser vaporization （odds ratio 1.024, 95% confidence interval 1.001-1.048, P 〈 0.05）. Patients who were not satisfied following the surgery had a smaller improvement in subjective symptoms and Qmax. In addition, our findings suggest that the relative risk of treatment dissatisfaction following high-power KTP laser vaporization was increased in patients with weak detrusor contractility.
基金supported by the National Natural Science Foundation of China(Grant No.61176021)the Innovation Group Project from Shanghai EducationCommission,China
文摘Ultralong titanyl phthalocyanine （TiOPc） sub-micron wires have been synthesized by a novel solution-based self- assembly method. By using different solvents, changing the mass concentration and the solvent vapor pressure, the length and the shape of the wires can be adjusted. The mixed-phase properties of the TiOPc sub-micron wires were investigated by the ultraviolet-visible （UV-vis） absorption spectrum and X-ray diffraction. Organic transistors based on these wires were studied, which show the typical p-channel characteristics.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government,Ministry of Science and ICT(MSIT)(NRF-2020M3D1A2102837)the Korea Institute of Energy Technology Evaluation and Planning(KETEP)grant funded by the Korea government(MOTIE)(20214000000500,training program of CCUS for the green growth)。
文摘Photoelectrochemical(PEC)H_(2)O_(2)production through water oxidation reaction(WOR)is a promising strategy,however,designing highly efficient and selective photoanode materials remains challenging due to competitive reaction pathways.Here,for highly enhanced PEC H_(2)O_(2)production,we present a conformal amorphous titanyl phosphate(a-TP)overlayer on nanoparticulate TiO_(2)surfaces,achieved via lysozyme-molded in-situ surface reforming.The a-TP overlayer modulates surface adsorption energies for reaction intermediates,favoring WOR for H_(2)O_(2)production over the competing O_(2)evolution reaction.Our density functional theory calculations reveal that a-TP/TiO_(2)exhibits a substantial energy uphill for the O·*formation pathway,which disfavors O_(2)evolution but promotes H_(2)O_(2)production.Additionally,the a-TP overlayer strengthens the built-in electric field,resulting in favorable kinetics.Consequently,a-TP/TiO_(2)exhibits 3.7-fold higher Faraday efficiency(FE)of 63%at 1.76 V vs.reversible hydrogen electrode(RHE)under 1 sun illumination,compared to bare TiO_(2)(17%),representing the highest FE among TiO_(2)-based WOR H_(2)O_(2)production systems.Employing the a-TP overlayer constitutes a promising strategy for controlling reaction pathways and achieving efficient solar-to-chemical energy conversion.
文摘A number of publications containing structural data, characteristics of nonlinear optical properties of pure and doped crystals of potassium titanyl phosphate (KTP) family have been reviewed to analyze the structural and symmetry conditionality of nonlinear optical properties of these crystals. The pseudosymmetric features of KTP-type crystals with respect to inversion are investigated. Specifically, pseudoinversion distribution maps are calculated;pseudoinversion extrema and coordinates of pseudoinversion centres are found;and the distributions of pure and doped KTP-type structures and their individual atomic sublattices over the degree of pseudoinversion are analyzed. A correlation between the characteristics of nonlinear optical properties of a number of crystals belonging to the KTP family and the degree of pseudoinversion of their atomic structures is demonstrated.
文摘Barium titanate(BaTiO_(3))is an important ferroelectric and electronic ceramic material because of its outstanding dielectric and ferroelectric properties.The demand for BaTiO_(3) nanoparticles with adjustable particle size has increased extensively due to the miniaturization of electronic devices.The oxalate precipitation method is regarded as a highly attractive technology for fabricating BaTiO_(3) nanoparticles,as it enables large-scale production at a low cost.However,the calcination process is a crucial step that significantly influences the particle size and morphology of the obtained BaTiO_(3) nanoparticles.This study investigates the thermal decomposition mechanism and particle size regulation strategies during the calcination of barium titanyl oxalate tetrahydrate(BTOT)for fabricating BaTiO_(3) nanoparticles.The Kissinger-Akahira-Sunose(KAS)model is used to calculate the kinetic parameters of BTOT thermal decomposition process,and the results indicate that the decomposition process can be divided as four stages,with the average activation energy of 60.77,269.89,484.72,and 199.82 kJ/mol,respectively.The average activation energy reaches its maximum value in the third stage,indicating that the thermal decomposition reaction in this stage is more challenging to occur compared to the other stages.The gas release behaviors of H_(2)O,CO,and CO_(2) are analyzed on-line during the thermal decomposition of BTOT,and the overall reaction mechanism is proposed.Additionally,by adjusting the calcination parameters,the particle size of BaTiO_(3) could be effectively regulated within the range of 25-120 nm.Increasing the heating rate from 10 to 40 K/min decreases the average particle size of BaTiO_(3) from 62 to 44 nm.Extending the calcination time from 0 to 120 min increases the average particle size from 25 to 71 nm.Raising the terminal temperature from 1173 to 1273 K significantly increases the average particle size from 56 to 120 nm.Briefly,accelerating the heating rate,reducing the calcination time,and lowering the calcination temperature facilitate the fabrication of BaTiO_(3) with a smaller particle size and more uniform morphology.This study offers a robust theoretical framework and technical guidance for optimizing the process conditions for fabricating BaTiO_(3) nanoparticles via controlled thermal decomposition of BTOT,while also contributing to the advancement of related technological fields.
文摘KTiOPO-4(KTP) crystal is a nonlinear optical material with superior properties. The KTP structure, point group mm2, is typified by the chemical form {K++}〔Ti 4+〕O(P 5+)O-4, where the curly brackets indicate nine or eightfold coordination, the square brackets sixfold octahedral coordination and the parentheses fourfold tetrahedral coordination. Different isovalent and aliovalent substitutions in a given structure is quite interesting. The KTP-type structure is extremely accommodating with respect to partial or complete isomorphous substitution which may be especially significant in optical devices such as waveguides. A monographic review of the structure-property relationship of KTP isomorphous substitution is briefly and precisely presented. It is shown that the properties of KTP are very sensitive to its structure. Among the composition, structure and properties of KTP-type crystal, the structure is the core because it is a link between the composition and properties.
