PS/SiO2 particles with core-shell structure were synthesized by coating silica on surface of polystyrene(PS) colloidal particles.The reaction parameters,such as initial tetraethyl orthosilicate(TEOS) concentration,wat...PS/SiO2 particles with core-shell structure were synthesized by coating silica on surface of polystyrene(PS) colloidal particles.The reaction parameters,such as initial tetraethyl orthosilicate(TEOS) concentration,water concentration and reaction temperature,have been investigated to control the thickness of silica shells.The shell thickness was prepositional to the square root of the initial concentration of TEOS and first increased with increasing water concentration,reached a maximum at about 2.0 mol/L and then started decreasing beyond that concentration.It was also found that the shell thickness decreased firstly with the reaction temperature added,then tended to a constant.The so-synthesized PS/SiO2 core-shell particles were directly crystallized into 3-D ordered thin film,then sintered at 570℃ into the ordered macroporous thin film.Compared with the conditional method,the present approach avoids repeatedly filling the precursor in the templetes and save time more.展开更多
Photoanodic properties greatly determine the overall performance of quantum-dot-sensitized solar cells（QDSCs）. In the present report, the microdynamic behaviors of carriers in the nanocomposite thin-film, a Zn Se QD...Photoanodic properties greatly determine the overall performance of quantum-dot-sensitized solar cells（QDSCs）. In the present report, the microdynamic behaviors of carriers in the nanocomposite thin-film, a Zn Se QD-sensitized mesoporous La-doped nano-TiO2 thin-film, as a potential candidate for photoanode, are probed via nanosecond transient photovoltaic（TPV） spectroscopy. The results confirm that the L-Cys ligand has a dual function serving as a stabilizer and molecular linker. Large quantities of interface states are located at the energy level with a photoelectric threshold of1.58 eV and a quantum well（QW） depth of 0.67 eV. This QW depth is approximately 0.14 eV deeper than the depth of QW buried in the Zn Se QDs, and a deeper QW results in a higher quantum confinement energy. A strong quantum confinement effect of the interface state may be responsible for the excellent TPV characteristics of the photoanode. For example, the peak intensity of the TPV response of the QD-sensitized thin-film lasts a long time, from 9.40 × 10^（-7） s to 2.96 × 10^（-4） s,and the end time of the PTV response of the QD-sensitized thin-film is extended by approximately an order of magnitude compared with those of the TiO2 substrate and the QDs. The TPV characteristics of the QD-sensitized thin-film change from p-type to n-type for the QDs before and after sensitizing. These properties strongly depend on the extended diffusion length of the photogenerated carries and the reduced recombination rate of photogenerated electron-hole pairs, resulting in prolonged carrier lifetime and an increased level of electron injection into the TiO2 thin-film substrate.展开更多
Accurately obtaining the original information of an in-situ rock via coring is a significant guiding step for exploring and developing deep oil and gas resources.It is difficult for traditional coring technology and e...Accurately obtaining the original information of an in-situ rock via coring is a significant guiding step for exploring and developing deep oil and gas resources.It is difficult for traditional coring technology and equipment to preserve the original information in deep rocks.This study develops a technology for insitu substance-preserved(ISP),moisture-preserved(IMP),and light-preserved(ILP)coring.This technology stores the original information in real time by forming a solid sealing film on the in-situ sample during coring.This study designed the ISP-IMP-ILP-Coring process and tool.In addition,an ISP-IMP-ILPCoring process simulation system was developed.The effects of temperature,pressure,and film thickness on the quality of the in-situ film were investigated by performing in-situ film-forming simulation experiments.A solid sealing film with a thickness of 2-3 mm can be formed;it completely covers the core sample and has uniform thickness.The film maintains good ISP-IMP-ILP properties and can protect the core sample in the in-situ environment steadily.This study verifies the feasibility of“film formation during coring”technology and provides strong support for the engineering application of ISP-IMP-ILPCoring technology.展开更多
TixAl1-xN films have been prepared by RF reactive magnetron sputtering. X-ray diffraction results showed that TixAl1-xN thin films in this study were hexagonal wurtzite structure with the Ti content up to 0.18. X-ray ...TixAl1-xN films have been prepared by RF reactive magnetron sputtering. X-ray diffraction results showed that TixAl1-xN thin films in this study were hexagonal wurtzite structure with the Ti content up to 0.18. X-ray photoelectron spectrocopy studies provided that the Nls core-electron spectrum of TixAl1-xN thin film brodend with increasing Ti content, and the difference of the chemical shifts for Ti2p3/2 line between TiN and TixAl1-xN th77pj in film was 0.7 eV.展开更多
为了揭示敞口式离心喷嘴液膜填充及打开过程,采用两相界面追踪方法 VOF(volume of fluid)模拟了喷嘴内部及近喷口区域流动过程,计算得到的喷雾角和试验结果偏差不超过2%。计算结果表明:喷嘴内部填充过程中,自切向孔下游至喷嘴出口液膜...为了揭示敞口式离心喷嘴液膜填充及打开过程,采用两相界面追踪方法 VOF(volume of fluid)模拟了喷嘴内部及近喷口区域流动过程,计算得到的喷雾角和试验结果偏差不超过2%。计算结果表明:喷嘴内部填充过程中,自切向孔下游至喷嘴出口液膜厚度缓慢增加,在喷嘴出口处液膜厚度大幅度降低,呈非线性发展;相应地,切向孔截面空心涡经历了正方形-花瓣形-圆形的演化历程;喷口边缘处表面张力占主导,此时液膜较厚,因此液膜刚流出喷嘴时并没有立刻打开,而后变薄、失稳、脱落、破碎并部分聚合,随着时间推移,喷嘴出口液膜形态依次经历了铅笔形、洋葱形、郁金香形和完全发展形四种形态,与稳态下喷注压降改变时喷雾形态变化相一致。展开更多
基金Supported by the National Natural Science Foundation of China(No.:20221603)
文摘PS/SiO2 particles with core-shell structure were synthesized by coating silica on surface of polystyrene(PS) colloidal particles.The reaction parameters,such as initial tetraethyl orthosilicate(TEOS) concentration,water concentration and reaction temperature,have been investigated to control the thickness of silica shells.The shell thickness was prepositional to the square root of the initial concentration of TEOS and first increased with increasing water concentration,reached a maximum at about 2.0 mol/L and then started decreasing beyond that concentration.It was also found that the shell thickness decreased firstly with the reaction temperature added,then tended to a constant.The so-synthesized PS/SiO2 core-shell particles were directly crystallized into 3-D ordered thin film,then sintered at 570℃ into the ordered macroporous thin film.Compared with the conditional method,the present approach avoids repeatedly filling the precursor in the templetes and save time more.
基金supported by the Natural Science Foundation of Hebei Province,China(Grant Nos.E2013203296 and E2017203029)
文摘Photoanodic properties greatly determine the overall performance of quantum-dot-sensitized solar cells（QDSCs）. In the present report, the microdynamic behaviors of carriers in the nanocomposite thin-film, a Zn Se QD-sensitized mesoporous La-doped nano-TiO2 thin-film, as a potential candidate for photoanode, are probed via nanosecond transient photovoltaic（TPV） spectroscopy. The results confirm that the L-Cys ligand has a dual function serving as a stabilizer and molecular linker. Large quantities of interface states are located at the energy level with a photoelectric threshold of1.58 eV and a quantum well（QW） depth of 0.67 eV. This QW depth is approximately 0.14 eV deeper than the depth of QW buried in the Zn Se QDs, and a deeper QW results in a higher quantum confinement energy. A strong quantum confinement effect of the interface state may be responsible for the excellent TPV characteristics of the photoanode. For example, the peak intensity of the TPV response of the QD-sensitized thin-film lasts a long time, from 9.40 × 10^（-7） s to 2.96 × 10^（-4） s,and the end time of the PTV response of the QD-sensitized thin-film is extended by approximately an order of magnitude compared with those of the TiO2 substrate and the QDs. The TPV characteristics of the QD-sensitized thin-film change from p-type to n-type for the QDs before and after sensitizing. These properties strongly depend on the extended diffusion length of the photogenerated carries and the reduced recombination rate of photogenerated electron-hole pairs, resulting in prolonged carrier lifetime and an increased level of electron injection into the TiO2 thin-film substrate.
基金the National Natural Science Foundation of China(grant numbers 51827901,52004166)funded by the Program for Shenzhen Basic Research Program(General Program)(No.JCYJ20190808153416970)Guangdong Introducing Innovative and Enterpreneurial Teams(No.2019ZT08G315)
文摘Accurately obtaining the original information of an in-situ rock via coring is a significant guiding step for exploring and developing deep oil and gas resources.It is difficult for traditional coring technology and equipment to preserve the original information in deep rocks.This study develops a technology for insitu substance-preserved(ISP),moisture-preserved(IMP),and light-preserved(ILP)coring.This technology stores the original information in real time by forming a solid sealing film on the in-situ sample during coring.This study designed the ISP-IMP-ILP-Coring process and tool.In addition,an ISP-IMP-ILPCoring process simulation system was developed.The effects of temperature,pressure,and film thickness on the quality of the in-situ film were investigated by performing in-situ film-forming simulation experiments.A solid sealing film with a thickness of 2-3 mm can be formed;it completely covers the core sample and has uniform thickness.The film maintains good ISP-IMP-ILP properties and can protect the core sample in the in-situ environment steadily.This study verifies the feasibility of“film formation during coring”technology and provides strong support for the engineering application of ISP-IMP-ILPCoring technology.
基金This work was supported by the National Natural Science Foundation of China under grant No.10474074the Hubei Natural Science Foundation under grant No.2001ABB060.
文摘TixAl1-xN films have been prepared by RF reactive magnetron sputtering. X-ray diffraction results showed that TixAl1-xN thin films in this study were hexagonal wurtzite structure with the Ti content up to 0.18. X-ray photoelectron spectrocopy studies provided that the Nls core-electron spectrum of TixAl1-xN thin film brodend with increasing Ti content, and the difference of the chemical shifts for Ti2p3/2 line between TiN and TixAl1-xN th77pj in film was 0.7 eV.
文摘为了揭示敞口式离心喷嘴液膜填充及打开过程,采用两相界面追踪方法 VOF(volume of fluid)模拟了喷嘴内部及近喷口区域流动过程,计算得到的喷雾角和试验结果偏差不超过2%。计算结果表明:喷嘴内部填充过程中,自切向孔下游至喷嘴出口液膜厚度缓慢增加,在喷嘴出口处液膜厚度大幅度降低,呈非线性发展;相应地,切向孔截面空心涡经历了正方形-花瓣形-圆形的演化历程;喷口边缘处表面张力占主导,此时液膜较厚,因此液膜刚流出喷嘴时并没有立刻打开,而后变薄、失稳、脱落、破碎并部分聚合,随着时间推移,喷嘴出口液膜形态依次经历了铅笔形、洋葱形、郁金香形和完全发展形四种形态,与稳态下喷注压降改变时喷雾形态变化相一致。
基金supported by the National Key Basic Research Program of China(973)(2010CB635108,2011CBA00700)International Science and Technology Cooperation Program,China(2012DFA51210) National Natural Science Foundation of China(51203138,51273179)~~
