Multidimensional integration and multifunctional com-ponent assembly have been greatly explored in recent years to extend Moore’s Law of modern microelectronics.However,this inevitably exac-erbates the inhomogeneity ...Multidimensional integration and multifunctional com-ponent assembly have been greatly explored in recent years to extend Moore’s Law of modern microelectronics.However,this inevitably exac-erbates the inhomogeneity of temperature distribution in microsystems,making precise temperature control for electronic components extremely challenging.Herein,we report an on-chip micro temperature controller including a pair of thermoelectric legs with a total area of 50×50μm^(2),which are fabricated from dense and flat freestanding Bi2Te3-based ther-moelectric nano films deposited on a newly developed nano graphene oxide membrane substrate.Its tunable equivalent thermal resistance is controlled by electrical currents to achieve energy-efficient temperature control for low-power electronics.A large cooling temperature difference of 44.5 K at 380 K is achieved with a power consumption of only 445μW,resulting in an ultrahigh temperature control capability over 100 K mW^(-1).Moreover,an ultra-fast cooling rate exceeding 2000 K s^(-1) and excellent reliability of up to 1 million cycles are observed.Our proposed on-chip temperature controller is expected to enable further miniaturization and multifunctional integration on a single chip for microelectronics.展开更多
Here, large-scale and uniform hexagonal zinc oxide(ZnO) nanosheet films were deposited onto indium tin oxide(ITO)-coated transparent conducting glass substrates via a facile galvanic displacement deposition process. C...Here, large-scale and uniform hexagonal zinc oxide(ZnO) nanosheet films were deposited onto indium tin oxide(ITO)-coated transparent conducting glass substrates via a facile galvanic displacement deposition process. Compared with other commonly used solution methods, this process avoids high temperature and electric power as well as supporting agents to make it simple and cost-effective. The as-fabricated ZnO nanosheet films have uniform hexagonal wurtzite structure. The photoelectrochemical(PEC) cell based on ZnO nanosheet film/ITO photoelectrode was also fabricated and its performance was improved by optimizing the solution concentration. A higher photocurrent density of*500 l A cm^(-2)under AM 1.5 G simulated illumination of 100 m W cm^(-2)with zero bias potential(vs. Ag/AgCl electrode) was obtained, which may ascribe to the increased surface-to-volume ratio of disordered Zn O nanosheet arrays. Our developed method may be used to deposit other oxide semiconductors, and the Zn O nanosheet film/ITO PEC cell can be used to design low-cost optoelectronic and photoelectrochemical devices.展开更多
In order to clarify the influence of methane concentration and deposition time on self-organized nano-multilayers,three serial copper-carbon films have been prepared at various methane concentrations with different de...In order to clarify the influence of methane concentration and deposition time on self-organized nano-multilayers,three serial copper-carbon films have been prepared at various methane concentrations with different deposition times using a facile magnetron sputtering deposition system. The ratios of methane concentration(CH4/Ar+CH4) used in the experiments are 20%, 40%, and 60%, and the deposition times are 5 minutes, 20 minutes, and 40 minutes, respectively.Despite the difference in the growth conditions, self-organizing multilayered copper-carbon films are prepared at different deposition times by changing methane concentration. The film composition and microstructure are investigated by x-ray photoelectron spectroscopy(XPS), x-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), and high-resolution transmission electron microscopy(HRTEM). By comparing the composition and microstructure of three serial films, the optimal growth conditions and compositions for self-organizing nano-multilayers in copper-carbon film are acquired. The results demonstrate that the self-organized nano-multilayered structure prefers to form in two conditions during the deposition process. One is that the methane should be curbed at low concentration for long deposition time,and the other condition is that the methane should be controlled at high concentration for short deposition time. In particular, nano-multilayered structure is self-organized in the copper-carbon film with copper concentration of 10-25 at.%.Furthermore, an interesting microstructure transition phenomenon is observed in copper-carbon films, that is, the nanomultilayered structure is gradually replaced by a nano-composite structure with deposition time and finally covered by amorphous carbon.展开更多
The nonlinear dynamic characteristics and optimal control of a giant magnetostrictive film （GMF）-shaped memory alloy （SMA） composite plate subjected to in-plane stochastic excitation are studied. GMF is prepared b...The nonlinear dynamic characteristics and optimal control of a giant magnetostrictive film （GMF）-shaped memory alloy （SMA） composite plate subjected to in-plane stochastic excitation are studied. GMF is prepared based on an SMA plate, and combined into a GMF-SMA composite plate. The Van der Pol item is improved to explain the hysteretic phenomena of GMF and SMA, and the nonlinear dynamics model of a GMF-SMA composite cantilever plate subjected to in-plane stochastic excitation is developed. The stochastic stability of the system is analyzed, and the steady-state probability density function of the dynamic response of the system is obtained. The condition of stochastic Hopf bifurcation is discussed, the reliability function of the system is provided, and then the probability density of the first-passage time is given. Finally, the stochastic optimal control strategy is proposed by the stochastic dynamic programming method. Numerical simulation shows that the stability of the trivial solution varies with bifurcation parameters, and stochastic Hopf bifurcation appears in the process; the system＇s reliability is improved through stochastic optimal control, and the first- passage time is delayed. A GMF-SMA composite plate combines the advantages of GMF and SMA, and can reduce vibration through passive control and active control effectively. The results are helpful for the engineering applications of GMF-SMA composite plates.展开更多
Three-dimensional(3D)micro-jet printing is a droplet deposition technique based on liquid-phase materials.To improve the deposition density and performance of energetic films with micro/nanoscale on an energetic chip,...Three-dimensional(3D)micro-jet printing is a droplet deposition technique based on liquid-phase materials.To improve the deposition density and performance of energetic films with micro/nanoscale on an energetic chip,polydopamine(PDA)was utilized as a linker bridge to induce the in-situ self-assembly of CL-20-based energetic film via 3D micro-jet printing.The self-assembly was extensively characterized by confocal laser scanning microscopy(CLSM),SEM,power-XRD,XPS,and DSC.The performance of the self-assembled film was verified by the mechanical properties and detonation properties,and a possible self-assembly mechanism in the layer-by-layer micro-jet printing process was proposed.The results indicated PDA-induced self-assembly enhanced the physical entanglement between the binders and energetic crystal,reduced the porosity from 15.87%to 11.28%,and improved the elastic modulus and the detonation performance of the CL-20-based energetic film.This work proposes a novel and promising energetic film design and fabrication strategy to enhance the interaction between the energetic composite layers in the micro-jet printing process.展开更多
Numerical and experimental investigation results on the magnetohydrodynamics（MHD） film flows along flat and curved bottom surfaces are summarized in this study. A simplified modeling has been developed to study the ...Numerical and experimental investigation results on the magnetohydrodynamics（MHD） film flows along flat and curved bottom surfaces are summarized in this study. A simplified modeling has been developed to study the liquid metal MHD film state, which has been validated by the existing experimental results. Numerical results on how the inlet velocity（V）, the chute width（W） and the inlet film thickness（d0） affect the MHD film flow state are obtained. MHD stability analysis results are also provided in this study. The results show that strong magnetic fields make the stable V decrease several times compared to the case with no magnetic field,especially small radial magnetic fields（Bn） will have a significant impact on the MHD film flow state. Based on the above numerical and MHD stability analysis results flow control methods are proposed for flat and curved MHD film flows. For curved film flow we firstly proposed a new multi-layers MHD film flow system with a solid metal mesh to get the stable MHD film flows along the curved bottom surface. Experiments on flat and curved MHD film flows are also carried out and some firstly observed results are achieved.展开更多
In the application of polymer gels to profile control and water shutoff,the gelation time will directly determine whether the gel can"go further"in the formation,but the most of the methods for delaying gel ...In the application of polymer gels to profile control and water shutoff,the gelation time will directly determine whether the gel can"go further"in the formation,but the most of the methods for delaying gel gelation time are complicated or have low responsiveness.There is an urgent need for an effective method for delaying gel gelation time with intelligent response.Inspired by the slow-release effect of drug capsules,this paper uses the self-assembly effect of gas-phase hydrophobic SiO_(2) in aqueous solution as a capsule to prepare an intelligent responsive self-assembled micro-nanocapsules.The capsule slowly releases the cross-linking agent under the stimulation of external conditions such as temperature and pH value,thus delaying gel gelation time.When the pH value is 2 and the concentration of gas-phase hydrophobic SiO_(2) particles is 10%,the gelation time of the capsule gel system at 30,60,90,and 120℃is12.5,13.2,15.2,and 21.1 times longer than that of the gel system without containing capsule,respectively.Compared with other methods,the yield stress of the gel without containing capsules was 78 Pa,and the yield stress after the addition of capsules was 322 Pa.The intelligent responsive self-assembled micronanocapsules prepared by gas-phase hydrophobic silica nanoparticles can not only delay the gel gelation time,but also increase the gel strength.The slow release of cross-linking agent from capsule provides an effective method for prolongating the gelation time of polymer gels.展开更多
The CuO_x thin film photocathodes were deposited on F-doped Sn O_2 (FTO)transparent conducting glasses by alternating current(AC)magnetron reactive sputtering under different Ar:O_2 ratios.The advantage of this deposi...The CuO_x thin film photocathodes were deposited on F-doped Sn O_2 (FTO)transparent conducting glasses by alternating current(AC)magnetron reactive sputtering under different Ar:O_2 ratios.The advantage of this deposited method is that it can deposit a CuO_x thin film uniformly and rapidly with large scale.From the photoelectrochemical(PEC)properties of these CuO_x photocathodes,it can be found that the CuO_x photocathode with Ar/O_2 30:7 provide a photocurrent density ofà3.2 m A cm^(à2)under a bias potentialà0.5 V(vs.Ag/Ag Cl),which was found to be twice higher than that of Ar/O_2 with 30:5.A detailed characterization on the structure,morphology and electrochemical properties of these CuO_x thin film photocathodes was carried out,and it is found that the improved PEC performance of CuO_x semiconductor photocathode with Ar/O_230:7 attributed to the less defects in it,indicating that this Ar/O_230:7 is an optimized condition for excellent CuO_x semiconductor photocathode fabrication.展开更多
We present a self-assembly method to prepare array nano-wires of colloidal CdSe quantum dots on a substrate of porous Al2 O3 film modified by gold nanoparticles. The photoluminescence(PL) spectra of nanowires are in s...We present a self-assembly method to prepare array nano-wires of colloidal CdSe quantum dots on a substrate of porous Al2 O3 film modified by gold nanoparticles. The photoluminescence(PL) spectra of nanowires are in situ measured by using a scanning near-field optical microscopy(SNOM) probe tip with 100-nm aperture on the scanning near-field optical microscope. The results show that the binding sites from the edge of porous Al2 O3 nanopores are combined with the carboxyl of CdSe quantum dots’ surface to form an array of CdSe nanowires in the process of losing background solvent because of the gold nanoparticles filling the nano-holes of porous Al2 O3 film. Compared with the area of nonself-assembled nano-wire, the fluorescence on the Al2 O3/Au/CdSe interface is significantly enhanced in the self-assembly nano-wire regions due to the electron transfer conductor effect of the gold nanoparticles’ surface. In addition, its full width at half maximum(FWHM) is also obviously widened. The method of enhancing fluorescence and energy transfer can widely be applied to photodetector, photocatalysis, optical display, optical sensing, and biomedical imaging, and so on.展开更多
The spontaneously generated electrical charge of a droplet dispensed from conventional pipetting is undesirable and unpredictable for most experiments that use pipetting.Hence,a method for controlling and removing the...The spontaneously generated electrical charge of a droplet dispensed from conventional pipetting is undesirable and unpredictable for most experiments that use pipetting.Hence,a method for controlling and removing the electrical charge needs to be developed.In this study,by using the electrode-deposited pipet tip(E-pipet tip),the charge-controlling system is newly developed and the electrical charge of a droplet is precisely controlled.The effect of electrolyte concentration and volume of the transferred solution to the electrical charge of a dispensed droplet is theoretically and experimentally investigated by using the equivalent capacitor model.Furthermore,a proof-of-concept example of the self-alignment and self-assembly of sequentially dispensed multiple droplets is demonstrated as one of the potential applications.Given that the electrical charge of the various aqueous droplets can be precisely and simply controlled,the fabricated E-pipet tip can be broadly utilized not only as a general charge-controlling platform of aqueous droplets but also as a powerful tool to explore fundamental scientific research regarding electrical charge of a droplet,such as the surface oscillation and evaporation of charged droplets.展开更多
An efficient interface modification is introduced to improve the performance of polymeric thin film transistors. This efficient interface modification is first achieved by 4-fluorothiophenol（4-FTP） self-assembled mo...An efficient interface modification is introduced to improve the performance of polymeric thin film transistors. This efficient interface modification is first achieved by 4-fluorothiophenol（4-FTP） self-assembled monolayers（SAM） to chemically treat the silver source–drain（S/D） contacts while the silicon oxide（SiO2） dielectric interface is further primed by either hexamethyldisilazane（HMDS） or octyltrichlorosilane（OTS-C8）. Results show that contact resistance is the dominant factor that limits the field effect mobility of the PTDPPTFT4 transistors. With proper surface modification applied to both the dielectric surface and the bottom contacts, the field effect mobilities of the bottom-gate bottom-contact PTDPPTFT4 transistors were significantly improved from 0.15 cm^2·V^-1·s^-1 to 0.91 cm^2·V^-1·s^-1.展开更多
当前AI工具存在自动化程度过高、人类控制不足造成生成结果可控性差的问题,成为其应用于专业影视创作的主要壁垒。本文通过总结自主视频生成流程“墨池”(Inkstone)设计与应用中的经验,结合人工智能(AI)与自动化领域的有意义人类控制(Me...当前AI工具存在自动化程度过高、人类控制不足造成生成结果可控性差的问题,成为其应用于专业影视创作的主要壁垒。本文通过总结自主视频生成流程“墨池”(Inkstone)设计与应用中的经验,结合人工智能(AI)与自动化领域的有意义人类控制(Meaningful Human Con⁃trol,MHC)概念,对比了三种不同的自动化工具设计思路,分析了基于MHC的AI影视创作流程和工具开发具体方式,以及目前加强人类控制的若干可行技术路径。研究表明,加强AI训练和生成过程中的MHC,有望在发挥AI工具优势的前提下,对生成内容进行准确控制,从而使创作能够体现艺术家意图,适应专业影视创作需求。展开更多
基金The authors thank D.Berger,D.Hofmann and C.Kupka in IFW Dresden for helpful technical support.H.R.acknowledges funding from the DFG(Deutsche Forschungsgemeinschaft)within grant number RE3973/1-1.Q.J.,H.R.and K.N.conceived the work.With the support from N.Y.and X.J.,Q.J.and T.G.fabricated the thermoelectric films and conducted the structural and compositional characterizations.Q.J.prepared microchips and fabricated the on-chip micro temperature controllers.Q.J.and N.P.carried out the temperature-dependent material and device performance measurements.Q.J.and H.R.performed the simulation and analytical calculations.Q.J.,H.R.and K.N.wrote the manuscript with input from the other coauthors.All the authors discussed the results and commented on the manuscript.
文摘Multidimensional integration and multifunctional com-ponent assembly have been greatly explored in recent years to extend Moore’s Law of modern microelectronics.However,this inevitably exac-erbates the inhomogeneity of temperature distribution in microsystems,making precise temperature control for electronic components extremely challenging.Herein,we report an on-chip micro temperature controller including a pair of thermoelectric legs with a total area of 50×50μm^(2),which are fabricated from dense and flat freestanding Bi2Te3-based ther-moelectric nano films deposited on a newly developed nano graphene oxide membrane substrate.Its tunable equivalent thermal resistance is controlled by electrical currents to achieve energy-efficient temperature control for low-power electronics.A large cooling temperature difference of 44.5 K at 380 K is achieved with a power consumption of only 445μW,resulting in an ultrahigh temperature control capability over 100 K mW^(-1).Moreover,an ultra-fast cooling rate exceeding 2000 K s^(-1) and excellent reliability of up to 1 million cycles are observed.Our proposed on-chip temperature controller is expected to enable further miniaturization and multifunctional integration on a single chip for microelectronics.
基金supported by the National Major Basic Research Project of 2012CB934302the National 863 Program2011AA050518+1 种基金the Natural Science Foundation of China(Grant No.1117419711574203 and 61234005)
文摘Here, large-scale and uniform hexagonal zinc oxide(ZnO) nanosheet films were deposited onto indium tin oxide(ITO)-coated transparent conducting glass substrates via a facile galvanic displacement deposition process. Compared with other commonly used solution methods, this process avoids high temperature and electric power as well as supporting agents to make it simple and cost-effective. The as-fabricated ZnO nanosheet films have uniform hexagonal wurtzite structure. The photoelectrochemical(PEC) cell based on ZnO nanosheet film/ITO photoelectrode was also fabricated and its performance was improved by optimizing the solution concentration. A higher photocurrent density of*500 l A cm^(-2)under AM 1.5 G simulated illumination of 100 m W cm^(-2)with zero bias potential(vs. Ag/AgCl electrode) was obtained, which may ascribe to the increased surface-to-volume ratio of disordered Zn O nanosheet arrays. Our developed method may be used to deposit other oxide semiconductors, and the Zn O nanosheet film/ITO PEC cell can be used to design low-cost optoelectronic and photoelectrochemical devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.51472250,U1637204,and 51775537)
文摘In order to clarify the influence of methane concentration and deposition time on self-organized nano-multilayers,three serial copper-carbon films have been prepared at various methane concentrations with different deposition times using a facile magnetron sputtering deposition system. The ratios of methane concentration(CH4/Ar+CH4) used in the experiments are 20%, 40%, and 60%, and the deposition times are 5 minutes, 20 minutes, and 40 minutes, respectively.Despite the difference in the growth conditions, self-organizing multilayered copper-carbon films are prepared at different deposition times by changing methane concentration. The film composition and microstructure are investigated by x-ray photoelectron spectroscopy(XPS), x-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), and high-resolution transmission electron microscopy(HRTEM). By comparing the composition and microstructure of three serial films, the optimal growth conditions and compositions for self-organizing nano-multilayers in copper-carbon film are acquired. The results demonstrate that the self-organized nano-multilayered structure prefers to form in two conditions during the deposition process. One is that the methane should be curbed at low concentration for long deposition time,and the other condition is that the methane should be controlled at high concentration for short deposition time. In particular, nano-multilayered structure is self-organized in the copper-carbon film with copper concentration of 10-25 at.%.Furthermore, an interesting microstructure transition phenomenon is observed in copper-carbon films, that is, the nanomultilayered structure is gradually replaced by a nano-composite structure with deposition time and finally covered by amorphous carbon.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11272229 and 11302144)the Ph.D.Programs Foundation of the Ministry of Education of China(Grant No.20120032120006)the Tianjin Research Program of Application Foundation and Advanced Technology,China(Grant No.13JCYBJC17900)
文摘The nonlinear dynamic characteristics and optimal control of a giant magnetostrictive film （GMF）-shaped memory alloy （SMA） composite plate subjected to in-plane stochastic excitation are studied. GMF is prepared based on an SMA plate, and combined into a GMF-SMA composite plate. The Van der Pol item is improved to explain the hysteretic phenomena of GMF and SMA, and the nonlinear dynamics model of a GMF-SMA composite cantilever plate subjected to in-plane stochastic excitation is developed. The stochastic stability of the system is analyzed, and the steady-state probability density function of the dynamic response of the system is obtained. The condition of stochastic Hopf bifurcation is discussed, the reliability function of the system is provided, and then the probability density of the first-passage time is given. Finally, the stochastic optimal control strategy is proposed by the stochastic dynamic programming method. Numerical simulation shows that the stability of the trivial solution varies with bifurcation parameters, and stochastic Hopf bifurcation appears in the process; the system＇s reliability is improved through stochastic optimal control, and the first- passage time is delayed. A GMF-SMA composite plate combines the advantages of GMF and SMA, and can reduce vibration through passive control and active control effectively. The results are helpful for the engineering applications of GMF-SMA composite plates.
文摘Three-dimensional(3D)micro-jet printing is a droplet deposition technique based on liquid-phase materials.To improve the deposition density and performance of energetic films with micro/nanoscale on an energetic chip,polydopamine(PDA)was utilized as a linker bridge to induce the in-situ self-assembly of CL-20-based energetic film via 3D micro-jet printing.The self-assembly was extensively characterized by confocal laser scanning microscopy(CLSM),SEM,power-XRD,XPS,and DSC.The performance of the self-assembled film was verified by the mechanical properties and detonation properties,and a possible self-assembly mechanism in the layer-by-layer micro-jet printing process was proposed.The results indicated PDA-induced self-assembly enhanced the physical entanglement between the binders and energetic crystal,reduced the porosity from 15.87%to 11.28%,and improved the elastic modulus and the detonation performance of the CL-20-based energetic film.This work proposes a novel and promising energetic film design and fabrication strategy to enhance the interaction between the energetic composite layers in the micro-jet printing process.
基金supported by the National Magnetic Confinement Fusion Science Program of China(Nos.2014GB125003 and 2013GB114002)National Natural Science Foundation of China(No.11105044)
文摘Numerical and experimental investigation results on the magnetohydrodynamics（MHD） film flows along flat and curved bottom surfaces are summarized in this study. A simplified modeling has been developed to study the liquid metal MHD film state, which has been validated by the existing experimental results. Numerical results on how the inlet velocity（V）, the chute width（W） and the inlet film thickness（d0） affect the MHD film flow state are obtained. MHD stability analysis results are also provided in this study. The results show that strong magnetic fields make the stable V decrease several times compared to the case with no magnetic field,especially small radial magnetic fields（Bn） will have a significant impact on the MHD film flow state. Based on the above numerical and MHD stability analysis results flow control methods are proposed for flat and curved MHD film flows. For curved film flow we firstly proposed a new multi-layers MHD film flow system with a solid metal mesh to get the stable MHD film flows along the curved bottom surface. Experiments on flat and curved MHD film flows are also carried out and some firstly observed results are achieved.
基金support and funding from the National Natural Science Foundation of China (No.52174047)Sinopec Project (No.P21063-3)。
文摘In the application of polymer gels to profile control and water shutoff,the gelation time will directly determine whether the gel can"go further"in the formation,but the most of the methods for delaying gel gelation time are complicated or have low responsiveness.There is an urgent need for an effective method for delaying gel gelation time with intelligent response.Inspired by the slow-release effect of drug capsules,this paper uses the self-assembly effect of gas-phase hydrophobic SiO_(2) in aqueous solution as a capsule to prepare an intelligent responsive self-assembled micro-nanocapsules.The capsule slowly releases the cross-linking agent under the stimulation of external conditions such as temperature and pH value,thus delaying gel gelation time.When the pH value is 2 and the concentration of gas-phase hydrophobic SiO_(2) particles is 10%,the gelation time of the capsule gel system at 30,60,90,and 120℃is12.5,13.2,15.2,and 21.1 times longer than that of the gel system without containing capsule,respectively.Compared with other methods,the yield stress of the gel without containing capsules was 78 Pa,and the yield stress after the addition of capsules was 322 Pa.The intelligent responsive self-assembled micronanocapsules prepared by gas-phase hydrophobic silica nanoparticles can not only delay the gel gelation time,but also increase the gel strength.The slow release of cross-linking agent from capsule provides an effective method for prolongating the gelation time of polymer gels.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 41506093)
文摘The CuO_x thin film photocathodes were deposited on F-doped Sn O_2 (FTO)transparent conducting glasses by alternating current(AC)magnetron reactive sputtering under different Ar:O_2 ratios.The advantage of this deposited method is that it can deposit a CuO_x thin film uniformly and rapidly with large scale.From the photoelectrochemical(PEC)properties of these CuO_x photocathodes,it can be found that the CuO_x photocathode with Ar/O_2 30:7 provide a photocurrent density ofà3.2 m A cm^(à2)under a bias potentialà0.5 V(vs.Ag/Ag Cl),which was found to be twice higher than that of Ar/O_2 with 30:5.A detailed characterization on the structure,morphology and electrochemical properties of these CuO_x thin film photocathodes was carried out,and it is found that the improved PEC performance of CuO_x semiconductor photocathode with Ar/O_230:7 attributed to the less defects in it,indicating that this Ar/O_230:7 is an optimized condition for excellent CuO_x semiconductor photocathode fabrication.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61741505 and 61865002)the Guizhou Provincial Science and Technology Support Plan,China(Grant No QKHZ [2017]2887)+3 种基金the Guiding Local Science and Technology Development Plan of the Central Government of China(Grant No.QKZYD [2017]4004)the Guizhou Province Education and Teaching Reform for Graduate Student(Grant No.QJYH-JG [2016]15)the Guizhou University Introduces Talent Projects,China(Grant No.2016002)the Talents of Guizhou Municipal Science and Technology Cooperation Platform,China(Grant No.[2018]5781)
文摘We present a self-assembly method to prepare array nano-wires of colloidal CdSe quantum dots on a substrate of porous Al2 O3 film modified by gold nanoparticles. The photoluminescence(PL) spectra of nanowires are in situ measured by using a scanning near-field optical microscopy(SNOM) probe tip with 100-nm aperture on the scanning near-field optical microscope. The results show that the binding sites from the edge of porous Al2 O3 nanopores are combined with the carboxyl of CdSe quantum dots’ surface to form an array of CdSe nanowires in the process of losing background solvent because of the gold nanoparticles filling the nano-holes of porous Al2 O3 film. Compared with the area of nonself-assembled nano-wire, the fluorescence on the Al2 O3/Au/CdSe interface is significantly enhanced in the self-assembly nano-wire regions due to the electron transfer conductor effect of the gold nanoparticles’ surface. In addition, its full width at half maximum(FWHM) is also obviously widened. The method of enhancing fluorescence and energy transfer can widely be applied to photodetector, photocatalysis, optical display, optical sensing, and biomedical imaging, and so on.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIP).(No.2014R1A2A1A010065272011-0030075+1 种基金2012R1A2A2A06047424)supported by the convergence technology development program for bionic arm through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT&Future Planning(No.2014M3C1B2048632)
文摘The spontaneously generated electrical charge of a droplet dispensed from conventional pipetting is undesirable and unpredictable for most experiments that use pipetting.Hence,a method for controlling and removing the electrical charge needs to be developed.In this study,by using the electrode-deposited pipet tip(E-pipet tip),the charge-controlling system is newly developed and the electrical charge of a droplet is precisely controlled.The effect of electrolyte concentration and volume of the transferred solution to the electrical charge of a dispensed droplet is theoretically and experimentally investigated by using the equivalent capacitor model.Furthermore,a proof-of-concept example of the self-alignment and self-assembly of sequentially dispensed multiple droplets is demonstrated as one of the potential applications.Given that the electrical charge of the various aqueous droplets can be precisely and simply controlled,the fabricated E-pipet tip can be broadly utilized not only as a general charge-controlling platform of aqueous droplets but also as a powerful tool to explore fundamental scientific research regarding electrical charge of a droplet,such as the surface oscillation and evaporation of charged droplets.
基金Project supported by the National Basic Research Program of China(Grant No.2013CB328803)
文摘An efficient interface modification is introduced to improve the performance of polymeric thin film transistors. This efficient interface modification is first achieved by 4-fluorothiophenol（4-FTP） self-assembled monolayers（SAM） to chemically treat the silver source–drain（S/D） contacts while the silicon oxide（SiO2） dielectric interface is further primed by either hexamethyldisilazane（HMDS） or octyltrichlorosilane（OTS-C8）. Results show that contact resistance is the dominant factor that limits the field effect mobility of the PTDPPTFT4 transistors. With proper surface modification applied to both the dielectric surface and the bottom contacts, the field effect mobilities of the bottom-gate bottom-contact PTDPPTFT4 transistors were significantly improved from 0.15 cm^2·V^-1·s^-1 to 0.91 cm^2·V^-1·s^-1.
文摘当前AI工具存在自动化程度过高、人类控制不足造成生成结果可控性差的问题,成为其应用于专业影视创作的主要壁垒。本文通过总结自主视频生成流程“墨池”(Inkstone)设计与应用中的经验,结合人工智能(AI)与自动化领域的有意义人类控制(Meaningful Human Con⁃trol,MHC)概念,对比了三种不同的自动化工具设计思路,分析了基于MHC的AI影视创作流程和工具开发具体方式,以及目前加强人类控制的若干可行技术路径。研究表明,加强AI训练和生成过程中的MHC,有望在发挥AI工具优势的前提下,对生成内容进行准确控制,从而使创作能够体现艺术家意图,适应专业影视创作需求。
