Photoheranostics have emerged as a promising tool for cancer theranostics owing to their real-time feedback on treatment and their precise diagnosis.Among them,how to improve the photothermal conversion efficiency(PCE...Photoheranostics have emerged as a promising tool for cancer theranostics owing to their real-time feedback on treatment and their precise diagnosis.Among them,how to improve the photothermal conversion efficiency(PCE)of phototheranostic agents(PTAs)is the key factor for phototheranostic systems.Herein,we provided an efficient method to improve PCE and constructed a biocompatible nano-material ICR-Qu@NH_(2)-Fe_(3)O_(4)@PEG(QNFP)by combing near-infrared second region(NIR-Ⅱ)molecular dye ICR-Qu and amino-modified magnetic nanoparticles and then encapsulated by DSPE-m PEG2000.QNFP exhibited excellent performance for photothermal therapy with a high PCE of 95.6%.Both in vitro and in vivo experiments indicated that QNFP could inhibit the growth of tumors under laser irradiation with low toxicity and realized real-time NIR-Ⅱfiuorescent imaging of tumors.In general,we realized a simple but efficient method to improve the PCE of NIR-Ⅱmolecular dye without reduce its quantum yield,which is an ideal choice for cancer diagnosis and treatment.展开更多
The redox couple of I^(0)/I^(-)in aqueous rechargeable iodine–zinc(I^(2)-Zn)batteries is a promising energy storage resource since it is safe and cost-effective,and provides steady output voltage.However,the cycle li...The redox couple of I^(0)/I^(-)in aqueous rechargeable iodine–zinc(I^(2)-Zn)batteries is a promising energy storage resource since it is safe and cost-effective,and provides steady output voltage.However,the cycle life and efficiency of these batteries remain unsatisfactory due to the uncontrolled shuttling of polyiodide(I_(3)^(-)and I_(5)^(-))and side reactions on the Zn anode.Starch is a very low-cost and widely sourced food used daily around the world.“Starch turns blue when it encounters iodine”is a classic chemical reaction,which results from the unique structure of the helix starch molecule–iodine complex.Inspired by this,we employ starch to confine the shuttling of polyiodide,and thus,the I^(0)/I^(-)conversion efficiency of an I^(2)-Zn battery is clearly enhanced.According to the detailed characterizations and theoretical DFT calculation results,the enhancement of I^(0)/I^(-)conversion efficiency is mainly originated from the strong bonding between the charged products of I_(3)^(-)and I_(5)^(-)and the rich hydroxyl groups in starch.This work provides inspiration for the rational design of high-performance and low-cost I^(2)-Zn in AZIBs.展开更多
Mg_(3)Sb_(2)-based thermoelectric materials have been the focus of widespread investigations as promising candidates for the harvesting of waste heat.Interface stability and service performance are key points for the ...Mg_(3)Sb_(2)-based thermoelectric materials have been the focus of widespread investigations as promising candidates for the harvesting of waste heat.Interface stability and service performance are key points for the commercial applications of these materials.We utilized Mg_(4.3)Sb_(3)Ni as a barrier layer to improve the thermal stability of Mg 3 Sb 2-based devices.However,its intrinsic high resistivity contributed nega-tively to the desired performance of the device.In this work,we investigated two other Mg-Sb-Ni ternary phases,MgSbNi and MgSbNi_(2),as new barrier layer materials to connect with Mg_(3.2)Sb_(2)Y_(0.05).The results show that the efficiency of the Mg_(1.2)SbNi/Mg_(3.2)Sb_(2)Y_(0.05)/Mg_(1.2)SbNi joint is increased by 33%relative to the higher Mg-content barriers due to lower resistivity.The system exhibited good interfacial compatibility and showed little change with aging at 673 K for 20 days.展开更多
Photovoltaic(PV)power generation is highly regarded for its capability to transform solar energy into electrical power.However,in real-world applications,PV modules are prone to issues such as increased self-heating a...Photovoltaic(PV)power generation is highly regarded for its capability to transform solar energy into electrical power.However,in real-world applications,PV modules are prone to issues such as increased self-heating and surface dust accumulation,which contribute to a reduction in photoelectric conversion efficiency.Furthermore,elevated temperatures can adversely affect the components’operational longevity.To augment the efficiency and extend the lifespan of PV modules,it is crucial to implement cooling strategies and periodic surface dust removal.In this research,we introduce a composite PV module design that amalgamates a hygroscopic hydrogel with self-cleaning attributes.The design incorporates a superhydrophobic polydimethylsiloxane(PDMS)film as its exposed surface layer and employs a PAM-CaCl2-SiC hygroscopic hydrogel for rear cooling.This arrangement is intended to facilitate efficient surface self-cleaning and passive cooling of the composite PV module.Experimental studies were conducted to evaluate the performance of this innovative composite PV module design,and the results showed that the composite PV panel had an increase of about 1.39%in power generation compared to an ordinary PV panel in the spring of Shenzhen,China.展开更多
With the aim to enhance the energy conversion efficiency of the rainbow shape piezoelectric transducer, an analysis model of energy conversion efficiency is established based on the elastic mechanics theory and piezoe...With the aim to enhance the energy conversion efficiency of the rainbow shape piezoelectric transducer, an analysis model of energy conversion efficiency is established based on the elastic mechanics theory and piezoelectricity theory. It can be found that the energy conversion efficiency of the rainbow shape piezoelectric transducer mainly depends on its shape parameters and ma- terial properties from the analysis model. Simulation results show that there is an optimal length ratio to generate maximum en- ergy conversion efficiency and the optimal length ratios and energy conversion efficiencies of beryllium bronze substrate trans- ducer and steel substrate transducer are （0.65, 2.21%） and （0.65, 1.64%） respectively. The optimal thickness ratios and energy conversion efficieneies of beryllium bronze substrate transducer and steel substrate transducer are （1.16, 2.56%） and （1.49, 1.57%） respectively. With the increase of width ratio and initial curvature radius, both the energy conversion efficiencies de- crease. Moreover, beryllium bronze flexible substrate transducer is superior to the steel flexible substrate transducer.展开更多
In this study,an optical setup for generating terahertz(THz)pulses through a two-color femtosecond laser filament was carefully designed to achieve a precise overlap of two-color laser pulses in space and time.β-bari...In this study,an optical setup for generating terahertz(THz)pulses through a two-color femtosecond laser filament was carefully designed to achieve a precise overlap of two-color laser pulses in space and time.β-barium borate(BBO),α-BBO,and a dual-wavelength plate were used to compensate the phase delay of the two-color lasers.Tilting ofα-BBO could further realize the precise spatial overlap of the two beams by counteracting the walk-off effect.The maximum out-put THz pulse energy reached 21μJ in argon gas when using a commercial Ti:sapphire laser with a pulse energy of 6 mJ at a 1 kHz repetition rate.The corresponding conversion efficiency exceeded 0.35%.展开更多
The present study proposed a floating multi-body wave energy converter composed of a floating central platform,multiple oscillating bodies and multiple actuating arms. The relative motions between the oscillating bodi...The present study proposed a floating multi-body wave energy converter composed of a floating central platform,multiple oscillating bodies and multiple actuating arms. The relative motions between the oscillating bodies and the floating central platform capture multi-point wave energy simultaneously. The converter was simplified as a forced vibration system with three degrees of freedom, namely two heave motions and one rotational motion. The expressions of the amplitude-frequency response and the wave energy capture width were deduced from the motion equations of the converter. Based on the built mathematical model, the effects of the PTO damping coefficient, the PTO elastic coefficient, the connection length between the oscillating body and central platform, and the total number of oscillating bodies on the performance of the wave energy converter were investigated. Numerical results indicate that the dynamical properties and the energy conversion efficiency are related not only to the incident wave circle frequency but also to the converter’s physical parameters and interior PTO coefficients. By adjusting the connection length, higher wave energy absorption efficiencies can be obtained. More oscillating bodies installed result in more stable floating central platform and higher wave energy conversion efficiency.展开更多
The electrochemical conversion of carbon dioxide(CO_(2))has been attracting increasingly research interest in the past decade,with the ultimate goal of utilizing electricity from renewable energy to realize carbon neu...The electrochemical conversion of carbon dioxide(CO_(2))has been attracting increasingly research interest in the past decade,with the ultimate goal of utilizing electricity from renewable energy to realize carbon neutrality,as well as economic and energy benefits.Nonetheless,the capture and concentrating of CO_(2) cost a substantial portion of energy,while almost all the reported researches showed CO_(2) electroreduction under high concentrations of(typically pure)CO_(2) reactants,and only very few recent studies have investigated the capability of applying low CO_(2) concentrations(such as~10%in flue gases).In this work,we first demonstrated the electroreduction of 0.03%CO_(2)(in helium)in a homemade gas‐phase electrochemical electrolyzer,using a low‐cost copper(Cu)or nanoscale copper(nano‐Cu)catalyst.Mixed with steam,the gas‐phase CO_(2) was directly delivered onto the gas‐solid interface with the Cu catalyst and reduced to CO,without the need/constraint of being adsorbed by aqueous solution or alkaline electrolytes.By tuning the catalyst and experi‐mental parameters,the conversion efficiency of CO_(2) reached as high as~95%.Furthermore,we demonstrated the direct electroreduction of 0.04%CO_(2) from real air sample with an optimized conversion efficiency of~79%,suggesting a promising perspective of the electroreduction ap‐proach toward direct CO_(2) conversion.展开更多
Conversion efficiency of soft X-ray from 0.35μm pulse laser-irradiated aluminium planar target at laser intensities 10^13- 10^15 W/cm^2 on the Xingguang-Ⅱ facility （laser energy 5 - 90 J, focal spot - Φ 200μm ful...Conversion efficiency of soft X-ray from 0.35μm pulse laser-irradiated aluminium planar target at laser intensities 10^13- 10^15 W/cm^2 on the Xingguang-Ⅱ facility （laser energy 5 - 90 J, focal spot - Φ 200μm full width of half maximun （FWHM） 400 - 800 ps） was measured. A simple model was given to explain soft X-ray conversion efficiency. In this model, because of the heat conduction from the laser-heated spot, the conversion was very small at lower irradiance limit, while at higher limit it was bounded by the energy lost in blow off plasma. Consequently, at the laser intensity around 2×10^14 W/cm^2 , the X-ray conversion efficiency reaches a maximum.展开更多
It is well known that temperature acts negatively on practically all the parameters of photovoltaic solar cells. Also, the solar cells which are subjected to particularly very high temperatures are the light concentra...It is well known that temperature acts negatively on practically all the parameters of photovoltaic solar cells. Also, the solar cells which are subjected to particularly very high temperatures are the light concentration solar cells and are used in light concentration photovoltaic systems (<i><span style="font-family:Verdana;">CPV</span></i><span style="font-family:Verdana;">). In fact, the significant heating of these solar cells is due to the concentration of the solar flux which arrives on them. Light concentration solar cells appear as solar cells under strong influences of heating and temperature. It is therefore necessary to take into account temperature effect on light concentration solar cells performances in order to obtain realistic results. </span><span style="font-family:""><span style="font-family:Verdana;">This one-dimensional study of a crystalline silicon solar cell under light concentration takes into account electrons concentration gradient electric field in the determination of the continuity equation of minority carriers in the base. To determine excess minority carrier’s density, the effects of temperature on the diffusion and mobility of electrons and holes, on the intrinsic concentration of electrons, on carrier’s generation rate as well as on width of band gap have also been taken into account. The results show that an increase of temperature improves diffusion parameters and leads to an increase of the short-circuit photocurrent density. However, an increase of temperature leads to a significant decrease in open-circuit photovoltage, maximum electric power and conversion efficiency. The results also show that the operating point and the maximum power point (</span><i><span style="font-family:Verdana;">MPP</span></i><span style="font-family:Verdana;">) moves to the open circuit when the cell temperature increases.</span></span>展开更多
The food consumption and ecological conversion efficiency of a species marine pelagic andsmall size fish, Hyporhamphus sajori, were determined by using in situ stomach content method presented by Eggers. The results s...The food consumption and ecological conversion efficiency of a species marine pelagic andsmall size fish, Hyporhamphus sajori, were determined by using in situ stomach content method presented by Eggers. The results showed that: (1) the fish was taken in food all day, so empty-stomach rate was very low, taking up about 4.5% of the total determined fish number. However, the fish still has significant daily feeding rhythm. A feeding peak was found 0:00 o'clock at night, but feeding level was always high in the daytime; (2) relationship between instantaneous food content in stomach and corresponding time could be described as S_t = a · e (-b·t). There was not significant difference of instantaneous gastric evacuation rate between two determinations, with average value being 0.13 × 10^(-2) g/ (g' h) (wet weight); (3) the daily food consumption tended to change in irregular waving form, with average value being (10.16Xl0^(-2)±1.19xl0(-2) g/ (g·d) (wet weight) or (55.56 × 10(-2) ±6.51 × 10^(-2) kJ/ (g·d). The wave distance is constant and about 14 d, but the wave height changed largely; (4) actual determining value of daily growth rate was 3.24 × 10^(-2)g/ (g·d) (wet weight) or 12.91 × 10^(-2)kJ/ (g·d), from which 31.89% (wet weight) or 23.24% kJ of ecological conversion efficiency could be obtained.展开更多
The maximum power conversion efficiencies of the top-emitting,oxide-confined,two-dimensional integrated 2×2 and4×4 vertical-cavity surface-emitting laser（VCSEL） arrays with the oxide-apertures of 6 μm,16 ...The maximum power conversion efficiencies of the top-emitting,oxide-confined,two-dimensional integrated 2×2 and4×4 vertical-cavity surface-emitting laser（VCSEL） arrays with the oxide-apertures of 6 μm,16 μm,19 μm,26 μm,29 μm,36 μm,39 μm,and 46 urn are fabricated and characterized,respectively.The maximum power conversion efficiencies increase rapidly with the augment of oxide-aperture at the beginning and then decrease slowly.A maximum value of27.91%at an oxide-aperture of 18.6 μm is achieved by simulation.The experimental data are well consistent with the simulation results,which are analyzed by utilizing an empirical model.展开更多
Simple arguments are used to construct a model to explain the extreme ultraviolet radiation conversion efficiency(EUV-CE) of a tin-based droplet target laser produced plasmas by calculating the laser absorption effici...Simple arguments are used to construct a model to explain the extreme ultraviolet radiation conversion efficiency(EUV-CE) of a tin-based droplet target laser produced plasmas by calculating the laser absorption efficiency,radiation efficiency,and spectral efficiency.The dependence of drive laser pulse duration and laser intensity on EUV-CE is investigated.The results show that at some appropriate laser intensity,where the sum energy of the thermal conduction,out-off band radiation and plasma plume kinetic losses is at a minimum,the EUV-CE should reach a maximum.The EUV-CE predicted by the present simple model is also compared with the available experimental and simulation data and a fair agreement between them is found.展开更多
We report on fabrication and photovoltaic characteristics of InxGa1-xN/GaN multiple quantum well solar cells with different indium compositions and barrier thicknesses. The as-grown samples are characterized by high- ...We report on fabrication and photovoltaic characteristics of InxGa1-xN/GaN multiple quantum well solar cells with different indium compositions and barrier thicknesses. The as-grown samples are characterized by high- resolution x-ray diffraction and reciprocal space mapping. The results show that the sample with a thick barrier thickness （lO.Onm） and high indium composition （0.23） has better crystalline quality. In addition, the dark current density-voltage （J-V） measurement of this device shows a significant decrease of leakage current, which leads to high open-circuit voltage Vow. Through the J-V characteristics under an Air Mass 1.5 Global （AM 1.5 G） illumination, this device exhibits a Voc of 1.89 V, a short-circuit current density Ysc of 3.92mA/cm2 and a fill factor of 50.96%. As a result, the conversion efficiency （77） is enhanced to be 3.77% in comparison with other devices.展开更多
Ramp-up experiments by means of lower hybrid wave on HT-7 superconducting tokamak have been performed and analyzed. A ramp-up rate of over 300 kA/s is obtained and a conversion efficiency of over 1.0% has been achieve...Ramp-up experiments by means of lower hybrid wave on HT-7 superconducting tokamak have been performed and analyzed. A ramp-up rate of over 300 kA/s is obtained and a conversion efficiency of over 1.0% has been achieved during the ramp-up phase. The study of the dependence of conversion efficiency on plasma density shows that the conversion efficiency is affected by the driven current, which is mainly dominated by the competition of impurity concentration with wave accessibility condition. In addition, the effect of current profile may play an important role in determining the conversion efficiency.展开更多
A three-dimensional approach to the effect of magnetic field incidence angle on electrical power and conversion efficiency is performed on a front-illuminated polycrystalline silicon bifacial solar cell. A solution of...A three-dimensional approach to the effect of magnetic field incidence angle on electrical power and conversion efficiency is performed on a front-illuminated polycrystalline silicon bifacial solar cell. A solution of the continuity equation allowed us to present the equations of photocurrent density, photovoltage and electric power. The influence of the angle of incidence of the magnetic field on the photocurrent density, the photovoltage and the electric power has been studied. The curves of electrical power versus dynamic junction velocity were used to extract the values of maximum electrical power and dynamic junction velocity and to calculate those of conversion efficiency. From this study, it is found that the conversion efficiency values increase with the angle of incidence of the magnetic field.展开更多
Efficient CO_(2) electroreduction requires catalysts for enhanced energy conversion efficiency and carbon product selectivity with low overpotential,in consideration of the interference of competitive H_(2) evolution ...Efficient CO_(2) electroreduction requires catalysts for enhanced energy conversion efficiency and carbon product selectivity with low overpotential,in consideration of the interference of competitive H_(2) evolution reaction and complex intermediate species involved.We proposed that adaptive electronic structures based on dynamic mixed-valence interconversion would facilitate electron transfer and intermediate turnover during the catalysis,ensuring high activity,selectivity,and durability.Herein,a novel mixed-valence Cu-based metal-organic framework was prepared using an electron-rich linker for electrocatalytic reduction of CO_(2).The designed material delivered a remarkable Faradaic efficiency of 99.2%for C_(1) liquid fuels at a low reduction potential of -0.1 V versus reversible hydrogen electrode,considerably higher than that of the commercial copper foam and competitive to the Cu-based electrocatalysts reported.The experimental data and theoretical calculations verified the Cu(Ⅰ)/Cu(Ⅱ)interconversion and the much higher energy barrier of H2 evolution than carbon product generation.Such a feasible strategy,simultaneously improving energy conversion efficiency,carbon product selectivity,and structural robustness,provides great insights into rational catalyst customization for sustainable CO_(2) conversion.展开更多
The development of photothermal agents with high photothermal conversion efficiency(PCE)and long ab-sorption wavelengths is crucial for safe and effective anti-cancer treatment.However,achieving these advantages often...The development of photothermal agents with high photothermal conversion efficiency(PCE)and long ab-sorption wavelengths is crucial for safe and effective anti-cancer treatment.However,achieving these advantages often requires precise molecular design and complex synthetic procedures.In this study,we present a simple,precise,and effective method for fabricating photothermal agents with high PCE using long wavelength exci-tation.This approach involves linking two electron-donating components,diphenylamine(DPA),and an electron-withdrawing squaraine(SQ),via aπ-bridge thiophene(T).The resulting D-π-A-π-D structure leads to a red-shifted absorption band.Within the DTS structure,DPA functions as a molecular rotor,T serves as a coplanar backbone,and SQ promotes J aggregation.When DTS nanoparticles(NPs)are fabricated using an amphiphilic nano-carrier,the maximum absorption wavelength shifts from 701 to 803 nm.This shift is accompanied by reduced fluorescence and an exceptionally high PCE of 86.0%.Both in vitro and in vivo assessments confirm that DTS NPs exhibit strong potential for photothermal antitumor therapy.Overall,this strategy offers a valuable framework for designing photothermal agents with clinical applications in mind,offering a simpler and more efficient approach to achieving high PCE and long absorption wavelengths.展开更多
The research on the conversion efficiency of"Green Mountains into Clear Water"(Green)and"Gold and silver Mountains"(Gold)is of great significance to promote the coordination between natural resourc...The research on the conversion efficiency of"Green Mountains into Clear Water"(Green)and"Gold and silver Mountains"(Gold)is of great significance to promote the coordination between natural resource conservation in national park and the local economic and social development.This paper pays attention to the linking role of ecosystem services in different stages of the conversion process between the Green and Gold.Based on the twostage division,this paper constructs the accounting framework for conversion efficiency of Green and Gold.That is,the comprehensive conversion efficiency of Green and Gold is decomposed into the I-stage efficiency of ecological inputs conversion to Green and the II-stage efficiency of ecosystem services conversion to economic output.Furthermore,the Qilian Mountain National Park in China and its surrounding area Zhangye City,is taken as an example.Using a two-stage non-oriented super-efficiency network EBM model and panel data from 2007 to 2018 to empirically analysis the dynamic evolution characteristics of the conversion efficiency of Green and Gold.Based on this,the heterogeneity improvement strategy is proposed.The results show that:(1)the comprehensive efficiency of the Two Mountains conversion in Zhangye City decreased first and then increased.The highest was 1.715 in 2007;the lowest was 1.367 in 2012;since 2012,the development has gradually improved.The main reason for the decrease in the comprehensive efficiency from 2007 to 2012 is the lower conversion efficiency in IIstage.(2)Spatial difference analysis shows that the areas with low the comprehensive efficiency were concentrated in Sunan,Minle,and Shandan Counties along the Qilian Mountains.The comprehensive efficiency was 0.406,0.489 and 0.482 respectively.The key to improving the comprehensive efficiency of Sunan County and Minle County is II-stage,while the focus of improving Shandan County is I-stage.(3)Redundancy analysis found that the main factor affecting the comprehensive efficiency of the Two Mountains conversion is insufficient output.In the future,we should focus on expanding effective pathways for the Two Mountains conversion and innovating institutional mechanisms for realizing ecological value.展开更多
Quantum dots(QDs)can modulate the solar spectrum through the down-conversion mechanism to better match the spectral response of solar cells.Following previous work,this paper first tested the response of QD solar cell...Quantum dots(QDs)can modulate the solar spectrum through the down-conversion mechanism to better match the spectral response of solar cells.Following previous work,this paper first tested the response of QD solar cells to specific monochromatic light,and found that QDs can effectively improve the photoelectric conversion efficiency(PCE)in the ultraviolet(UV)band by comparison.Then the photoelectric properties of the QD solar cells are tested under the air-mass 1.5(AM1.5)and air-mass 0(AM0)spectra.The experimental results show that because the absorption band of QDs is in the UV region,the space solar cells in the AM0 spectrum can obtain better PCE after coating QDs.The research results show the technical route of space solar cells with down-conversion mechanism,and put forward an important direction for the application of space solar photovoltaic(PV)technology,and have a good application prospect.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.U21A20308,22077088)Foundation from Science and Technology Major Project of Tibetan Autonomous Region of China(No.XZ202201ZD0001G)Foundation from Science and Technology Department of Sichuan Province(No.2021ZHCG0025)。
文摘Photoheranostics have emerged as a promising tool for cancer theranostics owing to their real-time feedback on treatment and their precise diagnosis.Among them,how to improve the photothermal conversion efficiency(PCE)of phototheranostic agents(PTAs)is the key factor for phototheranostic systems.Herein,we provided an efficient method to improve PCE and constructed a biocompatible nano-material ICR-Qu@NH_(2)-Fe_(3)O_(4)@PEG(QNFP)by combing near-infrared second region(NIR-Ⅱ)molecular dye ICR-Qu and amino-modified magnetic nanoparticles and then encapsulated by DSPE-m PEG2000.QNFP exhibited excellent performance for photothermal therapy with a high PCE of 95.6%.Both in vitro and in vivo experiments indicated that QNFP could inhibit the growth of tumors under laser irradiation with low toxicity and realized real-time NIR-Ⅱfiuorescent imaging of tumors.In general,we realized a simple but efficient method to improve the PCE of NIR-Ⅱmolecular dye without reduce its quantum yield,which is an ideal choice for cancer diagnosis and treatment.
基金financially supported by the National Natural Science Foundation of China(Nos.U20A20246 and 51872108)the Fundamental Research Funds for the Central Universitiesthe Advanced Talents Incubation Program of Hebei University(521100221039)
文摘The redox couple of I^(0)/I^(-)in aqueous rechargeable iodine–zinc(I^(2)-Zn)batteries is a promising energy storage resource since it is safe and cost-effective,and provides steady output voltage.However,the cycle life and efficiency of these batteries remain unsatisfactory due to the uncontrolled shuttling of polyiodide(I_(3)^(-)and I_(5)^(-))and side reactions on the Zn anode.Starch is a very low-cost and widely sourced food used daily around the world.“Starch turns blue when it encounters iodine”is a classic chemical reaction,which results from the unique structure of the helix starch molecule–iodine complex.Inspired by this,we employ starch to confine the shuttling of polyiodide,and thus,the I^(0)/I^(-)conversion efficiency of an I^(2)-Zn battery is clearly enhanced.According to the detailed characterizations and theoretical DFT calculation results,the enhancement of I^(0)/I^(-)conversion efficiency is mainly originated from the strong bonding between the charged products of I_(3)^(-)and I_(5)^(-)and the rich hydroxyl groups in starch.This work provides inspiration for the rational design of high-performance and low-cost I^(2)-Zn in AZIBs.
基金supported by the National Science Foundation of China(Grant No.52202277)the Special Project of Science and Technology Cooperation and Exchange of Shanxi Province(Grant No.202104041101007).
文摘Mg_(3)Sb_(2)-based thermoelectric materials have been the focus of widespread investigations as promising candidates for the harvesting of waste heat.Interface stability and service performance are key points for the commercial applications of these materials.We utilized Mg_(4.3)Sb_(3)Ni as a barrier layer to improve the thermal stability of Mg 3 Sb 2-based devices.However,its intrinsic high resistivity contributed nega-tively to the desired performance of the device.In this work,we investigated two other Mg-Sb-Ni ternary phases,MgSbNi and MgSbNi_(2),as new barrier layer materials to connect with Mg_(3.2)Sb_(2)Y_(0.05).The results show that the efficiency of the Mg_(1.2)SbNi/Mg_(3.2)Sb_(2)Y_(0.05)/Mg_(1.2)SbNi joint is increased by 33%relative to the higher Mg-content barriers due to lower resistivity.The system exhibited good interfacial compatibility and showed little change with aging at 673 K for 20 days.
基金supported by grants from the Shenzhen Science and Technology Innovation Commission(JCYJ20190808111407284,JCYJ20220531103409021)supported by the National Natural Science Foundation of China(22102104).
文摘Photovoltaic(PV)power generation is highly regarded for its capability to transform solar energy into electrical power.However,in real-world applications,PV modules are prone to issues such as increased self-heating and surface dust accumulation,which contribute to a reduction in photoelectric conversion efficiency.Furthermore,elevated temperatures can adversely affect the components’operational longevity.To augment the efficiency and extend the lifespan of PV modules,it is crucial to implement cooling strategies and periodic surface dust removal.In this research,we introduce a composite PV module design that amalgamates a hygroscopic hydrogel with self-cleaning attributes.The design incorporates a superhydrophobic polydimethylsiloxane(PDMS)film as its exposed surface layer and employs a PAM-CaCl2-SiC hygroscopic hydrogel for rear cooling.This arrangement is intended to facilitate efficient surface self-cleaning and passive cooling of the composite PV module.Experimental studies were conducted to evaluate the performance of this innovative composite PV module design,and the results showed that the composite PV panel had an increase of about 1.39%in power generation compared to an ordinary PV panel in the spring of Shenzhen,China.
基金National Natural Science Foundation of China (10972 102)Research Fund for the Doctoral Program of Higher Education of China (200802870007)Technology Research and Development Program of Jiangsu Province (BE2009163)
文摘With the aim to enhance the energy conversion efficiency of the rainbow shape piezoelectric transducer, an analysis model of energy conversion efficiency is established based on the elastic mechanics theory and piezoelectricity theory. It can be found that the energy conversion efficiency of the rainbow shape piezoelectric transducer mainly depends on its shape parameters and ma- terial properties from the analysis model. Simulation results show that there is an optimal length ratio to generate maximum en- ergy conversion efficiency and the optimal length ratios and energy conversion efficiencies of beryllium bronze substrate trans- ducer and steel substrate transducer are （0.65, 2.21%） and （0.65, 1.64%） respectively. The optimal thickness ratios and energy conversion efficieneies of beryllium bronze substrate transducer and steel substrate transducer are （1.16, 2.56%） and （1.49, 1.57%） respectively. With the increase of width ratio and initial curvature radius, both the energy conversion efficiencies de- crease. Moreover, beryllium bronze flexible substrate transducer is superior to the steel flexible substrate transducer.
基金National Natural Science Foundation of China(12061131010,12074198)Russian Science Foundation(21-49-00023).
文摘In this study,an optical setup for generating terahertz(THz)pulses through a two-color femtosecond laser filament was carefully designed to achieve a precise overlap of two-color laser pulses in space and time.β-barium borate(BBO),α-BBO,and a dual-wavelength plate were used to compensate the phase delay of the two-color lasers.Tilting ofα-BBO could further realize the precise spatial overlap of the two beams by counteracting the walk-off effect.The maximum out-put THz pulse energy reached 21μJ in argon gas when using a commercial Ti:sapphire laser with a pulse energy of 6 mJ at a 1 kHz repetition rate.The corresponding conversion efficiency exceeded 0.35%.
基金financially supported by the National Natural Science Foundation of China(Grant No.51779104)the Natural Science Foundation of Fujian Province,China(Grant Nos.2016J01247 and 2016J01245)+1 种基金the New Century Talent Support Program of Fujian Province,China(Grant No.JA13170)the Foreign Cooperation Program of Fujian Province,China(Grant No.2016I010003)
文摘The present study proposed a floating multi-body wave energy converter composed of a floating central platform,multiple oscillating bodies and multiple actuating arms. The relative motions between the oscillating bodies and the floating central platform capture multi-point wave energy simultaneously. The converter was simplified as a forced vibration system with three degrees of freedom, namely two heave motions and one rotational motion. The expressions of the amplitude-frequency response and the wave energy capture width were deduced from the motion equations of the converter. Based on the built mathematical model, the effects of the PTO damping coefficient, the PTO elastic coefficient, the connection length between the oscillating body and central platform, and the total number of oscillating bodies on the performance of the wave energy converter were investigated. Numerical results indicate that the dynamical properties and the energy conversion efficiency are related not only to the incident wave circle frequency but also to the converter’s physical parameters and interior PTO coefficients. By adjusting the connection length, higher wave energy absorption efficiencies can be obtained. More oscillating bodies installed result in more stable floating central platform and higher wave energy conversion efficiency.
文摘The electrochemical conversion of carbon dioxide(CO_(2))has been attracting increasingly research interest in the past decade,with the ultimate goal of utilizing electricity from renewable energy to realize carbon neutrality,as well as economic and energy benefits.Nonetheless,the capture and concentrating of CO_(2) cost a substantial portion of energy,while almost all the reported researches showed CO_(2) electroreduction under high concentrations of(typically pure)CO_(2) reactants,and only very few recent studies have investigated the capability of applying low CO_(2) concentrations(such as~10%in flue gases).In this work,we first demonstrated the electroreduction of 0.03%CO_(2)(in helium)in a homemade gas‐phase electrochemical electrolyzer,using a low‐cost copper(Cu)or nanoscale copper(nano‐Cu)catalyst.Mixed with steam,the gas‐phase CO_(2) was directly delivered onto the gas‐solid interface with the Cu catalyst and reduced to CO,without the need/constraint of being adsorbed by aqueous solution or alkaline electrolytes.By tuning the catalyst and experi‐mental parameters,the conversion efficiency of CO_(2) reached as high as~95%.Furthermore,we demonstrated the direct electroreduction of 0.04%CO_(2) from real air sample with an optimized conversion efficiency of~79%,suggesting a promising perspective of the electroreduction ap‐proach toward direct CO_(2) conversion.
基金Project suppoted by Shanghai Leading Academic Discipline Foundation （Grant No. T0104）, and Science Foundation of Shanghai Mtmicipal Commission of Education （Grant No. 214680）
文摘Conversion efficiency of soft X-ray from 0.35μm pulse laser-irradiated aluminium planar target at laser intensities 10^13- 10^15 W/cm^2 on the Xingguang-Ⅱ facility （laser energy 5 - 90 J, focal spot - Φ 200μm full width of half maximun （FWHM） 400 - 800 ps） was measured. A simple model was given to explain soft X-ray conversion efficiency. In this model, because of the heat conduction from the laser-heated spot, the conversion was very small at lower irradiance limit, while at higher limit it was bounded by the energy lost in blow off plasma. Consequently, at the laser intensity around 2×10^14 W/cm^2 , the X-ray conversion efficiency reaches a maximum.
文摘It is well known that temperature acts negatively on practically all the parameters of photovoltaic solar cells. Also, the solar cells which are subjected to particularly very high temperatures are the light concentration solar cells and are used in light concentration photovoltaic systems (<i><span style="font-family:Verdana;">CPV</span></i><span style="font-family:Verdana;">). In fact, the significant heating of these solar cells is due to the concentration of the solar flux which arrives on them. Light concentration solar cells appear as solar cells under strong influences of heating and temperature. It is therefore necessary to take into account temperature effect on light concentration solar cells performances in order to obtain realistic results. </span><span style="font-family:""><span style="font-family:Verdana;">This one-dimensional study of a crystalline silicon solar cell under light concentration takes into account electrons concentration gradient electric field in the determination of the continuity equation of minority carriers in the base. To determine excess minority carrier’s density, the effects of temperature on the diffusion and mobility of electrons and holes, on the intrinsic concentration of electrons, on carrier’s generation rate as well as on width of band gap have also been taken into account. The results show that an increase of temperature improves diffusion parameters and leads to an increase of the short-circuit photocurrent density. However, an increase of temperature leads to a significant decrease in open-circuit photovoltage, maximum electric power and conversion efficiency. The results also show that the operating point and the maximum power point (</span><i><span style="font-family:Verdana;">MPP</span></i><span style="font-family:Verdana;">) moves to the open circuit when the cell temperature increases.</span></span>
基金This study was supported by the DevelopmentProgramming Program of National Major Basic Research of China un- der contract No.G19990437.
文摘The food consumption and ecological conversion efficiency of a species marine pelagic andsmall size fish, Hyporhamphus sajori, were determined by using in situ stomach content method presented by Eggers. The results showed that: (1) the fish was taken in food all day, so empty-stomach rate was very low, taking up about 4.5% of the total determined fish number. However, the fish still has significant daily feeding rhythm. A feeding peak was found 0:00 o'clock at night, but feeding level was always high in the daytime; (2) relationship between instantaneous food content in stomach and corresponding time could be described as S_t = a · e (-b·t). There was not significant difference of instantaneous gastric evacuation rate between two determinations, with average value being 0.13 × 10^(-2) g/ (g' h) (wet weight); (3) the daily food consumption tended to change in irregular waving form, with average value being (10.16Xl0^(-2)±1.19xl0(-2) g/ (g·d) (wet weight) or (55.56 × 10(-2) ±6.51 × 10^(-2) kJ/ (g·d). The wave distance is constant and about 14 d, but the wave height changed largely; (4) actual determining value of daily growth rate was 3.24 × 10^(-2)g/ (g·d) (wet weight) or 12.91 × 10^(-2)kJ/ (g·d), from which 31.89% (wet weight) or 23.24% kJ of ecological conversion efficiency could be obtained.
基金supported by the National Natural Science Foundation of China(Grant Nos.61222501 and 61335004)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20111103110019)
文摘The maximum power conversion efficiencies of the top-emitting,oxide-confined,two-dimensional integrated 2×2 and4×4 vertical-cavity surface-emitting laser（VCSEL） arrays with the oxide-apertures of 6 μm,16 μm,19 μm,26 μm,29 μm,36 μm,39 μm,and 46 urn are fabricated and characterized,respectively.The maximum power conversion efficiencies increase rapidly with the augment of oxide-aperture at the beginning and then decrease slowly.A maximum value of27.91%at an oxide-aperture of 18.6 μm is achieved by simulation.The experimental data are well consistent with the simulation results,which are analyzed by utilizing an empirical model.
基金Supported by the National Natural Science Foundation of China under Grant No. 61078024
文摘Simple arguments are used to construct a model to explain the extreme ultraviolet radiation conversion efficiency(EUV-CE) of a tin-based droplet target laser produced plasmas by calculating the laser absorption efficiency,radiation efficiency,and spectral efficiency.The dependence of drive laser pulse duration and laser intensity on EUV-CE is investigated.The results show that at some appropriate laser intensity,where the sum energy of the thermal conduction,out-off band radiation and plasma plume kinetic losses is at a minimum,the EUV-CE should reach a maximum.The EUV-CE predicted by the present simple model is also compared with the available experimental and simulation data and a fair agreement between them is found.
基金Supported by the National Basic Research Program of China(No 2012CB619303)the National High-Technology Research and Development Program of China(No 2011AA050514)
文摘We report on fabrication and photovoltaic characteristics of InxGa1-xN/GaN multiple quantum well solar cells with different indium compositions and barrier thicknesses. The as-grown samples are characterized by high- resolution x-ray diffraction and reciprocal space mapping. The results show that the sample with a thick barrier thickness （lO.Onm） and high indium composition （0.23） has better crystalline quality. In addition, the dark current density-voltage （J-V） measurement of this device shows a significant decrease of leakage current, which leads to high open-circuit voltage Vow. Through the J-V characteristics under an Air Mass 1.5 Global （AM 1.5 G） illumination, this device exhibits a Voc of 1.89 V, a short-circuit current density Ysc of 3.92mA/cm2 and a fill factor of 50.96%. As a result, the conversion efficiency （77） is enhanced to be 3.77% in comparison with other devices.
文摘Ramp-up experiments by means of lower hybrid wave on HT-7 superconducting tokamak have been performed and analyzed. A ramp-up rate of over 300 kA/s is obtained and a conversion efficiency of over 1.0% has been achieved during the ramp-up phase. The study of the dependence of conversion efficiency on plasma density shows that the conversion efficiency is affected by the driven current, which is mainly dominated by the competition of impurity concentration with wave accessibility condition. In addition, the effect of current profile may play an important role in determining the conversion efficiency.
文摘A three-dimensional approach to the effect of magnetic field incidence angle on electrical power and conversion efficiency is performed on a front-illuminated polycrystalline silicon bifacial solar cell. A solution of the continuity equation allowed us to present the equations of photocurrent density, photovoltage and electric power. The influence of the angle of incidence of the magnetic field on the photocurrent density, the photovoltage and the electric power has been studied. The curves of electrical power versus dynamic junction velocity were used to extract the values of maximum electrical power and dynamic junction velocity and to calculate those of conversion efficiency. From this study, it is found that the conversion efficiency values increase with the angle of incidence of the magnetic field.
基金granted by the National Natural Science Foundation of China(Nos.22376161 and 52373216)the National Key Research and Development Program of China(No.2022YFE0110500)the Fundamental Research Funds for the Central Universities of China.
文摘Efficient CO_(2) electroreduction requires catalysts for enhanced energy conversion efficiency and carbon product selectivity with low overpotential,in consideration of the interference of competitive H_(2) evolution reaction and complex intermediate species involved.We proposed that adaptive electronic structures based on dynamic mixed-valence interconversion would facilitate electron transfer and intermediate turnover during the catalysis,ensuring high activity,selectivity,and durability.Herein,a novel mixed-valence Cu-based metal-organic framework was prepared using an electron-rich linker for electrocatalytic reduction of CO_(2).The designed material delivered a remarkable Faradaic efficiency of 99.2%for C_(1) liquid fuels at a low reduction potential of -0.1 V versus reversible hydrogen electrode,considerably higher than that of the commercial copper foam and competitive to the Cu-based electrocatalysts reported.The experimental data and theoretical calculations verified the Cu(Ⅰ)/Cu(Ⅱ)interconversion and the much higher energy barrier of H2 evolution than carbon product generation.Such a feasible strategy,simultaneously improving energy conversion efficiency,carbon product selectivity,and structural robustness,provides great insights into rational catalyst customization for sustainable CO_(2) conversion.
基金supported by the National Natural Science Foundation of China(32101129,52103230,32101124)Shenzhen Basic Research Special(Natural Science Fund)basic research surface project(No.JCYJ20210324113006017)+1 种基金Guangdong basic and Applied Basic Research Fund Regional Joint Fund Project(key project)(No.2020B1515120091)China Postdoctoral Science Foundation(2021M691440).
文摘The development of photothermal agents with high photothermal conversion efficiency(PCE)and long ab-sorption wavelengths is crucial for safe and effective anti-cancer treatment.However,achieving these advantages often requires precise molecular design and complex synthetic procedures.In this study,we present a simple,precise,and effective method for fabricating photothermal agents with high PCE using long wavelength exci-tation.This approach involves linking two electron-donating components,diphenylamine(DPA),and an electron-withdrawing squaraine(SQ),via aπ-bridge thiophene(T).The resulting D-π-A-π-D structure leads to a red-shifted absorption band.Within the DTS structure,DPA functions as a molecular rotor,T serves as a coplanar backbone,and SQ promotes J aggregation.When DTS nanoparticles(NPs)are fabricated using an amphiphilic nano-carrier,the maximum absorption wavelength shifts from 701 to 803 nm.This shift is accompanied by reduced fluorescence and an exceptionally high PCE of 86.0%.Both in vitro and in vivo assessments confirm that DTS NPs exhibit strong potential for photothermal antitumor therapy.Overall,this strategy offers a valuable framework for designing photothermal agents with clinical applications in mind,offering a simpler and more efficient approach to achieving high PCE and long absorption wavelengths.
基金funded by National Natural Science Foundation of China(Grant No.:42461046)the Postdoctoral Science Foundation of China(Grant No.:2020M673641XB).
文摘The research on the conversion efficiency of"Green Mountains into Clear Water"(Green)and"Gold and silver Mountains"(Gold)is of great significance to promote the coordination between natural resource conservation in national park and the local economic and social development.This paper pays attention to the linking role of ecosystem services in different stages of the conversion process between the Green and Gold.Based on the twostage division,this paper constructs the accounting framework for conversion efficiency of Green and Gold.That is,the comprehensive conversion efficiency of Green and Gold is decomposed into the I-stage efficiency of ecological inputs conversion to Green and the II-stage efficiency of ecosystem services conversion to economic output.Furthermore,the Qilian Mountain National Park in China and its surrounding area Zhangye City,is taken as an example.Using a two-stage non-oriented super-efficiency network EBM model and panel data from 2007 to 2018 to empirically analysis the dynamic evolution characteristics of the conversion efficiency of Green and Gold.Based on this,the heterogeneity improvement strategy is proposed.The results show that:(1)the comprehensive efficiency of the Two Mountains conversion in Zhangye City decreased first and then increased.The highest was 1.715 in 2007;the lowest was 1.367 in 2012;since 2012,the development has gradually improved.The main reason for the decrease in the comprehensive efficiency from 2007 to 2012 is the lower conversion efficiency in IIstage.(2)Spatial difference analysis shows that the areas with low the comprehensive efficiency were concentrated in Sunan,Minle,and Shandan Counties along the Qilian Mountains.The comprehensive efficiency was 0.406,0.489 and 0.482 respectively.The key to improving the comprehensive efficiency of Sunan County and Minle County is II-stage,while the focus of improving Shandan County is I-stage.(3)Redundancy analysis found that the main factor affecting the comprehensive efficiency of the Two Mountains conversion is insufficient output.In the future,we should focus on expanding effective pathways for the Two Mountains conversion and innovating institutional mechanisms for realizing ecological value.
基金supported by the Science&Technology Development Fund of Tianjin Education Commission for Higher Education(No.2022KJ133).
文摘Quantum dots(QDs)can modulate the solar spectrum through the down-conversion mechanism to better match the spectral response of solar cells.Following previous work,this paper first tested the response of QD solar cells to specific monochromatic light,and found that QDs can effectively improve the photoelectric conversion efficiency(PCE)in the ultraviolet(UV)band by comparison.Then the photoelectric properties of the QD solar cells are tested under the air-mass 1.5(AM1.5)and air-mass 0(AM0)spectra.The experimental results show that because the absorption band of QDs is in the UV region,the space solar cells in the AM0 spectrum can obtain better PCE after coating QDs.The research results show the technical route of space solar cells with down-conversion mechanism,and put forward an important direction for the application of space solar photovoltaic(PV)technology,and have a good application prospect.
