A reflective faceted structure is proposed to reshaping an incoherent light beam into two focalized spots-To obtain the desired irradiance distribution on a detector,custom optimization function is written,and the two...A reflective faceted structure is proposed to reshaping an incoherent light beam into two focalized spots-To obtain the desired irradiance distribution on a detector,custom optimization function is written,and the two dimensional tilt angles of each facet are optimized automatically in a pure non-sequential mode in Zemax OpticStudio 16.The result is also confirmed inside LightTools&2 from Synopsys.For measuring the quality of the optimization result in the case of two spots focalization,four factors including efficiency on the detector,uniformity,the root mean square error and the correlation coefficient are calculated.These four factors are used to evaluate the influence of several parameters on the irradiance distribution.These parameters include the incidence angle,the divergence angle,the facet size,the source type and the resolution of the facet angular positions.Finally,an analysis of those parameters is made and the performance of this type of component is demonstrated.展开更多
Electron collision as well as its controlling lies in the core of study on nonsequential double ionization(NSDI).A single collision occurred in a convergent time is important to disclose the essential features of the ...Electron collision as well as its controlling lies in the core of study on nonsequential double ionization(NSDI).A single collision occurred in a convergent time is important to disclose the essential features of the electron correlation.However,it is difficult to form such a collision.By using counterrotating circular two-color(CRTC)laser fields,we show that a single electron collision can be achieved in a convergent time and a net electron correlation is set up within the sub-femtosecond time scale in the NSDI process of Ar atoms.The proposed method is also valid for other atoms,provided that one chooses the frequency and intensity of the CRTC field according to a scaling law.展开更多
Hubble tension between the local measurement and global observation has been a key problem in cosmology.In this paper,we consider the quintessence scalar field,phantom field and quintom field as the dark energy to rec...Hubble tension between the local measurement and global observation has been a key problem in cosmology.In this paper,we consider the quintessence scalar field,phantom field and quintom field as the dark energy to reconcile this problem.Different from most previous work,we start from the dimensionless equation of state(w)of dark energy,not a parameterization of potential.The combined analysis shows that observational data sets favor Hubble constant H0=71.3-0.917+0.854 km s^(-1)Mpc^(-1),which can reconcile Hubble tension within 1.20σ.We also perform a Bayes factor analysis using the MCEvidence code,and confirm that the phantom scalar field is still the most effective.To investigate the reason of Hubble tension,we analyze the density parameter.The comparison shows that the scalar fields provide a slightly largerΩbh2 and smallerΩch2 than the standardΛCDM model.We finally analyze a possible reason of Hubble tension from the kinematic acceleration?.We find an interesting physical phenomenon.The acceleration a in these scalar fields are similar as theΛCDM model at about redshift z>0.5.However,they increase and deviate from each other at low redshift,especially in the near future.Only the?in phantom scalar field will decrease in the future.展开更多
Mobile manipulators are used in a variety of fields because of their flexibility and maneuverability.The path planning capability of the mobile manipulator is one of the important indicators to evaluate the performanc...Mobile manipulators are used in a variety of fields because of their flexibility and maneuverability.The path planning capability of the mobile manipulator is one of the important indicators to evaluate the performance of the manipulator,but it is greatly challenged in the face of maps with narrow channel.To address the problem,an improved hierarchical motion planner(IHMP)is proposed,which consists of a two-dimensional(2D)path planner for the mobile base,and a three-dimensional(3D)trajectory planner for the on-board manipulator.Firstly,a hybrid sampling strategy is proposed,which can reduce invalid nodes of the generated probabilistic roadmap.Bridge test is used to locate the narrow channel areas,and a Gaussian sampler is deployed in these areas and the boundaries.Meanwhile,a random sampler is deployed in the rest areas.Trajectory planner for on-board manipulator is to generate a collision-free and safe trajectory in the narrow channel with collaboration of the 2D path planner.The experimental results show that IHMP is effective for mobile manipulator motion planning in complex static environments,especially in narrow channel.展开更多
Developing a cotton fabric sensing layer with good waterproofness and breathability via a low-cost and eco-friendly method is increasingly important for the construction of comfortable and wearable electronic devices....Developing a cotton fabric sensing layer with good waterproofness and breathability via a low-cost and eco-friendly method is increasingly important for the construction of comfortable and wearable electronic devices.Herein,a waterproof and breathable cotton fabric composite decorated by reduced graphene oxide(rGO)and carbon nanotube(CNT),Cotton/rGO/CNT,is reported by a facile solution infiltration method,and we adopt such Cotton/rGO/CNT composite to develop a layer-by-layer structured multifunctional flexible sensor,enabling the high-sensitivity detection of pressure and temperature stimulus.Particularly,the multifunctional flexible sensor exhibits a high response toward tiny pressure,demonstrating salient superiority in the continuous and reliable monitoring of human physiological information.Concerning temperature sensing,a good linear response for the temperatures ranging from 28 to 40℃ is achieved by the multifunctional flexible sensor and gives rise to be successfully applied to the non-contact real-time monitoring of human respiration signal.Finally,an array consisting of multifunctional flexible sensors further demonstrates its feasibility in perceiving and mapping the pressure and temperature information of contact objects.This work provides a feasible strategy for designing cotton-based sensing layers that can effectively resist liquid water penetration and allow water vapor transmission,and offers reasonable insight for constructing comfort and multifunctional wearable electronics.展开更多
Two-dimensional(2 D) Te nanosheets were successfully fabricated through the liquid-phase exfoliation(LPE) method. The nonlinear optical properties of 2 D Te nanosheets were studied by the open-aperture Z-scan techniqu...Two-dimensional(2 D) Te nanosheets were successfully fabricated through the liquid-phase exfoliation(LPE) method. The nonlinear optical properties of 2 D Te nanosheets were studied by the open-aperture Z-scan technique. Furthermore, the continuous wave mode-locked Nd:YVO4 laser was successfully realized by using 2 D Te as a saturable absorber(SA) for the first time, to the best of our knowledge. Ultrashort pulses as short as 5.8 ps were obtained at 1064.3 nm with an output power of 851 m W. This primary investigation indicates that the 2 D Te SA is a promising photonic device in the fields of ultrafast solid-state lasers.展开更多
Ti_(3)CN,as a typical hetero-MXene,has attracted tremendous attention for its unique properties.However,its ultrafast photonics applications are still rare.Here,the few-layer Ti_(3)CN MXene was successfully prepared b...Ti_(3)CN,as a typical hetero-MXene,has attracted tremendous attention for its unique properties.However,its ultrafast photonics applications are still rare.Here,the few-layer Ti_(3)CN MXene was successfully prepared by selective etching and molecular delamination technique.The nonlinear optical response of few-layer Ti_(3)CN MXene at 640 nm was studied using the open-aperture Z-scan technique.The asprepared Ti_(3)CN MXene sample exhibited excellent nonlinear saturable absorption characteristics,resulting in the nonlinear absorption coefficient b of4.05×10^(-2)cm/GW,which was one order of magnitude larger than that of black phosphorus(BP)and molybdenum disulfide(MoS_(2)).For the optical modulation applications of few-layer Ti_(3)CN MXene,passively Q-switched(PQS)solid-state visible lasers based on Ti_(3)CN saturable absorber(SA)at 522 nm,607 nm,639 nm,and 721 nm were successfully realized.Furthermore,a Ti_(3)CN-based stable passively mode-locked Pr:YLF red laser was also successfully achieved with a pulse duration of 30 ps,and the corresponding repetition rate was 73.1 MHz.The optical modulation device based on few-layer Ti_(3)CN MXene shows good performance.Our work demonstrates that the tremendous prospects of the few-layer Ti_(3)CN MXene as a visible optical modulation device in ultrafast photonics applications.展开更多
In this study,we constructed ten dark energy models to test whether they can reconcile the Hubble tension and how much it is affected by parameterization.To establish a fair test,the models are diverse,encompassing fr...In this study,we constructed ten dark energy models to test whether they can reconcile the Hubble tension and how much it is affected by parameterization.To establish a fair test,the models are diverse,encompassing fractional,logarithmic,exponential,and inverse exponential forms as well as several non-parameterized models.The dataset we used includes the NPIPE pipeline of cosmic microwave background(CMB)power-spectrum data from Planck2020,Pantheon+samples from Supernovae Type la,and baryon acoustic oscillations.The MCMC calculations imply dark energy transferring from w<-1 to w>-1 for the four parameterized dark energy models.However,these models cannot adequately reconcile the Hubble tension.Notably,we found that phantom-like dark energy with w<-1 can achieve the greatest reduction in the Hubble tension to 0.1808o.However,AIC analysis indicates that this alleviation is at the cost of high AIC.We also investigated the effect of constructions on the derivative of the equation of state dw/da,cosmic density parameter,CMB power spectrum C^(TT),and mater spectra P(k).We also found that the Hubble tension may be related to the reionization process.展开更多
Recently,van der Waals heterostructures(vdWHs)constructed by transition-metal dichalcogenides(TMDCs)have come under the research spotlight owing to their excellent capabilities,multiple functionalities,and innovative ...Recently,van der Waals heterostructures(vdWHs)constructed by transition-metal dichalcogenides(TMDCs)have come under the research spotlight owing to their excellent capabilities,multiple functionalities,and innovative architecture for advanced optoelectronic devices.Herein,novel heterojunction photodetectors composed of monolayer molybdenum disulfide(MoS2)and few-layer rhenium selenide(ReSe_(2))are explored for ultra-fast and polarization detection.Owing to the enhanced light-matter interactions and type-II band alignment of the ReSe_(2)/MoS_(2) heterostructure,the photodetector exhibits impressive performances at 638 nm in terms of a high on/off ratio~104,large photoresponsivity~3.52 A/W,high specific detectivity~1011 Jones,and large 3 dB frequency of 65.7 kHz.In addition,ultrafast rise/decay times(5.0/9.1 ms)are obtained under pulsed incident light contributed to the built-in electric field at the heterointerface,demonstrating a result one or two orders of magnitude faster than the currently reported values of group VII-TMDCs based photodetectors.Beyond the conventional photodetection,this photodetector also displays polarization detection capability with sensitivity 1.35.Such Re-based vdWHs provide superior platforms for the realization of ultra-fast and polarization-sensitive photodetection in broadband spectrum.展开更多
As"molecular bridge,"coupling agents can not only realize the covalent connection of composites,but also affect their properties,thus affecting the properties of devices based on them.Herein,leveraging diffe...As"molecular bridge,"coupling agents can not only realize the covalent connection of composites,but also affect their properties,thus affecting the properties of devices based on them.Herein,leveraging differences in charge conduction properties of the(3-aminopropyl)trimethoxysilane and 5,10,15,20-tetrakis(4-aminophenyl)-21H,23H-porphine caused by conjugacy structural differences,two kinds of layerby-layer assembled smart carbon materials with different electrical properties are obtained at the same reduction temperature.The two graphene ultrathin films are then“planted”on Si/SiO2 substrates,respectively,as semiconductor layer and source/drain electrodes to fabricate an ultra-stable all-graphene field effect transistor(AG-FET).Enabled by the covalent functionalized configuration and the functionally diverse of coupling agents,the AG-FET obtained by this simple method won the high electrical characteristics,the hole,electron mobility,and the shelflife could reach 3.79 cm2/(V·s),3.78 cm2/(V·s),and 18months,respectively.In addition,good material stability and excellent device structure endow the device exceptional stability,electrical stability,and solvent resistance,improving its application prospect in solution phase sensing/detection.Such characteristics could be used to sense,transduce,and respond to external stimuli,especially in solution phase to monitor the important analytes,such as Hg^(2+)in a flowing sewage environment.We believe that such easy-to-manufacture AG-FETs with ultrahigh performance and ultrahigh stability could also show great application prospects in other significant fields.展开更多
基金supported by Natural Science Foundation of Shandong Province,China(No.ZR2019BF033).
文摘A reflective faceted structure is proposed to reshaping an incoherent light beam into two focalized spots-To obtain the desired irradiance distribution on a detector,custom optimization function is written,and the two dimensional tilt angles of each facet are optimized automatically in a pure non-sequential mode in Zemax OpticStudio 16.The result is also confirmed inside LightTools&2 from Synopsys.For measuring the quality of the optimization result in the case of two spots focalization,four factors including efficiency on the detector,uniformity,the root mean square error and the correlation coefficient are calculated.These four factors are used to evaluate the influence of several parameters on the irradiance distribution.These parameters include the incidence angle,the divergence angle,the facet size,the source type and the resolution of the facet angular positions.Finally,an analysis of those parameters is made and the performance of this type of component is demonstrated.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61475168,11674231,and 61575124)。
文摘Electron collision as well as its controlling lies in the core of study on nonsequential double ionization(NSDI).A single collision occurred in a convergent time is important to disclose the essential features of the electron correlation.However,it is difficult to form such a collision.By using counterrotating circular two-color(CRTC)laser fields,we show that a single electron collision can be achieved in a convergent time and a net electron correlation is set up within the sub-femtosecond time scale in the NSDI process of Ar atoms.The proposed method is also valid for other atoms,provided that one chooses the frequency and intensity of the CRTC field according to a scaling law.
基金Ming-Jian Zhang is supported by the Natural Science Foundation of Shandong Province(Grant No.ZR2021MA075)Li Chen is supported by the Natural Science Foundation of Shandong Province(Grant No.ZR2019MA033)。
文摘Hubble tension between the local measurement and global observation has been a key problem in cosmology.In this paper,we consider the quintessence scalar field,phantom field and quintom field as the dark energy to reconcile this problem.Different from most previous work,we start from the dimensionless equation of state(w)of dark energy,not a parameterization of potential.The combined analysis shows that observational data sets favor Hubble constant H0=71.3-0.917+0.854 km s^(-1)Mpc^(-1),which can reconcile Hubble tension within 1.20σ.We also perform a Bayes factor analysis using the MCEvidence code,and confirm that the phantom scalar field is still the most effective.To investigate the reason of Hubble tension,we analyze the density parameter.The comparison shows that the scalar fields provide a slightly largerΩbh2 and smallerΩch2 than the standardΛCDM model.We finally analyze a possible reason of Hubble tension from the kinematic acceleration?.We find an interesting physical phenomenon.The acceleration a in these scalar fields are similar as theΛCDM model at about redshift z>0.5.However,they increase and deviate from each other at low redshift,especially in the near future.Only the?in phantom scalar field will decrease in the future.
文摘Mobile manipulators are used in a variety of fields because of their flexibility and maneuverability.The path planning capability of the mobile manipulator is one of the important indicators to evaluate the performance of the manipulator,but it is greatly challenged in the face of maps with narrow channel.To address the problem,an improved hierarchical motion planner(IHMP)is proposed,which consists of a two-dimensional(2D)path planner for the mobile base,and a three-dimensional(3D)trajectory planner for the on-board manipulator.Firstly,a hybrid sampling strategy is proposed,which can reduce invalid nodes of the generated probabilistic roadmap.Bridge test is used to locate the narrow channel areas,and a Gaussian sampler is deployed in these areas and the boundaries.Meanwhile,a random sampler is deployed in the rest areas.Trajectory planner for on-board manipulator is to generate a collision-free and safe trajectory in the narrow channel with collaboration of the 2D path planner.The experimental results show that IHMP is effective for mobile manipulator motion planning in complex static environments,especially in narrow channel.
基金supported by the National Natural Science Foundation of China(Nos.62174068,61805101,62005095,61888102,and 62104080)Shandong Provincial Natural Science Foundation of China(Nos.ZR2019BF013 and ZR2020QF105)Rizhao City Key Research and Development Program under Grant(No.2021ZDYF010102).
文摘Developing a cotton fabric sensing layer with good waterproofness and breathability via a low-cost and eco-friendly method is increasingly important for the construction of comfortable and wearable electronic devices.Herein,a waterproof and breathable cotton fabric composite decorated by reduced graphene oxide(rGO)and carbon nanotube(CNT),Cotton/rGO/CNT,is reported by a facile solution infiltration method,and we adopt such Cotton/rGO/CNT composite to develop a layer-by-layer structured multifunctional flexible sensor,enabling the high-sensitivity detection of pressure and temperature stimulus.Particularly,the multifunctional flexible sensor exhibits a high response toward tiny pressure,demonstrating salient superiority in the continuous and reliable monitoring of human physiological information.Concerning temperature sensing,a good linear response for the temperatures ranging from 28 to 40℃ is achieved by the multifunctional flexible sensor and gives rise to be successfully applied to the non-contact real-time monitoring of human respiration signal.Finally,an array consisting of multifunctional flexible sensors further demonstrates its feasibility in perceiving and mapping the pressure and temperature information of contact objects.This work provides a feasible strategy for designing cotton-based sensing layers that can effectively resist liquid water penetration and allow water vapor transmission,and offers reasonable insight for constructing comfort and multifunctional wearable electronics.
基金supported by the National Natural Science Foundation of China (Nos. 12004208, 51302285, 61675217, and 61975221)Natural Science Foundation of Shanghai (No. 19ZR1479300)+3 种基金Key Research Program of Frontier Science of CAS (No. QYZDB-SSW-JSC041)Program of Shanghai Academic Research Leader (No. 17XD1403900)Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDB16030700)Key Laboratory of Optoelectronic Information Technology, Ministry of Education (Tianjin University)。
文摘Two-dimensional(2 D) Te nanosheets were successfully fabricated through the liquid-phase exfoliation(LPE) method. The nonlinear optical properties of 2 D Te nanosheets were studied by the open-aperture Z-scan technique. Furthermore, the continuous wave mode-locked Nd:YVO4 laser was successfully realized by using 2 D Te as a saturable absorber(SA) for the first time, to the best of our knowledge. Ultrashort pulses as short as 5.8 ps were obtained at 1064.3 nm with an output power of 851 m W. This primary investigation indicates that the 2 D Te SA is a promising photonic device in the fields of ultrafast solid-state lasers.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.12004208 and 62005177)the Natural Science Foundation of Shandong Province of China(Grant No.ZR2021QF128)+2 种基金the Qilu University of Technology(Shandong Academy of Sciences)Education and Industry Integration and Innovation Pilot(Grant Nos.2022PY022 and 2022JBZ01-04)The author also thanks to support and funding of King Khalid University through Research Center for Advanced Materials Science(RCAMS)(Grant No:RCAMS/KKU/008/21).
文摘Ti_(3)CN,as a typical hetero-MXene,has attracted tremendous attention for its unique properties.However,its ultrafast photonics applications are still rare.Here,the few-layer Ti_(3)CN MXene was successfully prepared by selective etching and molecular delamination technique.The nonlinear optical response of few-layer Ti_(3)CN MXene at 640 nm was studied using the open-aperture Z-scan technique.The asprepared Ti_(3)CN MXene sample exhibited excellent nonlinear saturable absorption characteristics,resulting in the nonlinear absorption coefficient b of4.05×10^(-2)cm/GW,which was one order of magnitude larger than that of black phosphorus(BP)and molybdenum disulfide(MoS_(2)).For the optical modulation applications of few-layer Ti_(3)CN MXene,passively Q-switched(PQS)solid-state visible lasers based on Ti_(3)CN saturable absorber(SA)at 522 nm,607 nm,639 nm,and 721 nm were successfully realized.Furthermore,a Ti_(3)CN-based stable passively mode-locked Pr:YLF red laser was also successfully achieved with a pulse duration of 30 ps,and the corresponding repetition rate was 73.1 MHz.The optical modulation device based on few-layer Ti_(3)CN MXene shows good performance.Our work demonstrates that the tremendous prospects of the few-layer Ti_(3)CN MXene as a visible optical modulation device in ultrafast photonics applications.
基金Supported by the Natural Science Foundation of Shandong Province,China(ZR2021MA075)the Talent Research Project of Qilu University of Technology(2023RCKY029)Supported by the Natural Science Foundation of Shandong Province,China(ZR2019MA033)。
文摘In this study,we constructed ten dark energy models to test whether they can reconcile the Hubble tension and how much it is affected by parameterization.To establish a fair test,the models are diverse,encompassing fractional,logarithmic,exponential,and inverse exponential forms as well as several non-parameterized models.The dataset we used includes the NPIPE pipeline of cosmic microwave background(CMB)power-spectrum data from Planck2020,Pantheon+samples from Supernovae Type la,and baryon acoustic oscillations.The MCMC calculations imply dark energy transferring from w<-1 to w>-1 for the four parameterized dark energy models.However,these models cannot adequately reconcile the Hubble tension.Notably,we found that phantom-like dark energy with w<-1 can achieve the greatest reduction in the Hubble tension to 0.1808o.However,AIC analysis indicates that this alleviation is at the cost of high AIC.We also investigated the effect of constructions on the derivative of the equation of state dw/da,cosmic density parameter,CMB power spectrum C^(TT),and mater spectra P(k).We also found that the Hubble tension may be related to the reionization process.
基金supported by the National Natural Science Foundation of China(61804086)National Natural Science Foundation of Shandong Province(ZR2021MA033).
文摘Recently,van der Waals heterostructures(vdWHs)constructed by transition-metal dichalcogenides(TMDCs)have come under the research spotlight owing to their excellent capabilities,multiple functionalities,and innovative architecture for advanced optoelectronic devices.Herein,novel heterojunction photodetectors composed of monolayer molybdenum disulfide(MoS2)and few-layer rhenium selenide(ReSe_(2))are explored for ultra-fast and polarization detection.Owing to the enhanced light-matter interactions and type-II band alignment of the ReSe_(2)/MoS_(2) heterostructure,the photodetector exhibits impressive performances at 638 nm in terms of a high on/off ratio~104,large photoresponsivity~3.52 A/W,high specific detectivity~1011 Jones,and large 3 dB frequency of 65.7 kHz.In addition,ultrafast rise/decay times(5.0/9.1 ms)are obtained under pulsed incident light contributed to the built-in electric field at the heterointerface,demonstrating a result one or two orders of magnitude faster than the currently reported values of group VII-TMDCs based photodetectors.Beyond the conventional photodetection,this photodetector also displays polarization detection capability with sensitivity 1.35.Such Re-based vdWHs provide superior platforms for the realization of ultra-fast and polarization-sensitive photodetection in broadband spectrum.
基金supported by the Joint Funds of the National Natural Science Foundation of China(U22A20140)the Independent Cultivation Program of Innovation Team of Ji’nan City(2019GXRC011)the National Natural Science Foundation of China(62001189)。
基金supported by the National Natural Science Foundation of China(Grant No.51902131)Natural Science Foundation of Shandong province(Grant No.ZR2019BEM006)+1 种基金National Key Research and Development Program of China(Grant No.2017YFB0405400)Major Innovation Projects in Shandong Province(2018YFJH0503).
文摘As"molecular bridge,"coupling agents can not only realize the covalent connection of composites,but also affect their properties,thus affecting the properties of devices based on them.Herein,leveraging differences in charge conduction properties of the(3-aminopropyl)trimethoxysilane and 5,10,15,20-tetrakis(4-aminophenyl)-21H,23H-porphine caused by conjugacy structural differences,two kinds of layerby-layer assembled smart carbon materials with different electrical properties are obtained at the same reduction temperature.The two graphene ultrathin films are then“planted”on Si/SiO2 substrates,respectively,as semiconductor layer and source/drain electrodes to fabricate an ultra-stable all-graphene field effect transistor(AG-FET).Enabled by the covalent functionalized configuration and the functionally diverse of coupling agents,the AG-FET obtained by this simple method won the high electrical characteristics,the hole,electron mobility,and the shelflife could reach 3.79 cm2/(V·s),3.78 cm2/(V·s),and 18months,respectively.In addition,good material stability and excellent device structure endow the device exceptional stability,electrical stability,and solvent resistance,improving its application prospect in solution phase sensing/detection.Such characteristics could be used to sense,transduce,and respond to external stimuli,especially in solution phase to monitor the important analytes,such as Hg^(2+)in a flowing sewage environment.We believe that such easy-to-manufacture AG-FETs with ultrahigh performance and ultrahigh stability could also show great application prospects in other significant fields.
