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
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
A nonfused ring electron acceptor(NFREA),designated as TT-Ph-C6,has been synthesized with the aim of enhancing the power conversion efficiency(PCE)of organic solar cells(OSCs).By integrating asymmetric phenylalkylamin...A nonfused ring electron acceptor(NFREA),designated as TT-Ph-C6,has been synthesized with the aim of enhancing the power conversion efficiency(PCE)of organic solar cells(OSCs).By integrating asymmetric phenylalkylamino side groups,TT-Ph-C6 demonstrates excellent solubility and its crystal structure exhibits compact packing structures with a three-dimensional molecular stacking network.These structural attributes markedly promote exciton diffusion and charge carrier mobility,particularly advantageous for the fabrication of thick-film devices.TT-Ph-C6-based devices have attained a PCE of 18.01%at a film thickness of 100 nm,and even at a film thickness of 300 nm,the PCE remains at 14.64%,surpassing that of devices based on 2BTh-2F.These remarkable properties position TT-Ph-C6 as a highly promising NFREA material for boosting the efficiency of OSCs.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
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
All polymer solar cells(all-PSCs)promise mechanically-flexible and morphologically-stable organic photovoltaics and have aroused increased interests very recently.However,due to their disorderly conformation structure...All polymer solar cells(all-PSCs)promise mechanically-flexible and morphologically-stable organic photovoltaics and have aroused increased interests very recently.However,due to their disorderly conformation structures within the photoactive film,inefficient charge generation and carrier transport are observed which lead to inferior photovoltaic performance compared to smaller molecular acceptor-based photovoltaics.Here,by diluting PM6 with a cutting-edge polymeric acceptor PY-IT and diluting PY-IT with PM6 or D18,donor-dominating or acceptor-dominating heterojunctions were prepared.Synchrotron X-ray and multiple spectrometer techniques reveal that the diluted heterojunctions receive increased structural order,translating to enhanced carrier mobility,improved exciton diffusion length,and suppressed non-radiative recombination loss during the power conversion.As the results,the corresponding PM6+1%PY-IT/PY-IT+1%D18 and PM6+1%PY-IT/PY-IT+1%PM6 devices fabricated by layer-by-layer deposition received superior power conversion efficiency(PCE)of 19.4%and 18.8%respectively,along with enhanced operational lifetimes in air,outperforming the PCE of 17.5%in the PM6/PY-IT reference device.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
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
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
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
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
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
Trap-assisted charge recombination is one of the primary limitationsof restricting the performance of organic solar cells. However, effectivelyreducing the presence of traps in the photoactive layer remains challengin...Trap-assisted charge recombination is one of the primary limitationsof restricting the performance of organic solar cells. However, effectivelyreducing the presence of traps in the photoactive layer remains challenging.Herein, wide bandgap polymer donor PTzBI-dF is demonstrated as an effectivemodulator for enhancing the crystallinity of the bulk heterojunction active layerscomposed of D18 derivatives blended with Y6, leading to dense and orderedmolecular packings, and thus, improves photoluminescence quenching properties.As a result, the photovoltaic devices exhibit reduced trap-assisted charge recombinationlosses, achieving an optimized power conversion efficiency of over 19%.Besides the efficiency enhancement, the devices comprised of PTzBI-dF as athird component simultaneously attain decreased current leakage, improved chargecarrier mobilities, and suppressed bimolecular charge recombination, leading toreduced energy losses. The advanced crystalline structures induced by PTzBI-dFand its characteristics, such as well-aligned energy level, and complementaryabsorption spectra, are ascribed to the promising performance improvements.Our findings suggest that donor phase engineering is a feasible approach to tuning the molecular packings in the active layer, providingguidelines for designing effective morphology modulators for high-performance organic solar cells.展开更多
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Financial support from the National Natural Science Foundation of China(22375024,21975031,21734009,51933001,22109080,and 52173174)the Natural Science Foundation of Shandong Province(No.ZR2022YQ45)+2 种基金the Taishan Scholars Program(Nos.tstp20221121 and tsqnz20221134)The Beijing Natural Science Foundation(No.2244073)supported by State Key Laboratory of Bio-Fibers and Eco-Textiles(Qingdao University)(RZ2200002821)is acknowledged.
文摘A nonfused ring electron acceptor(NFREA),designated as TT-Ph-C6,has been synthesized with the aim of enhancing the power conversion efficiency(PCE)of organic solar cells(OSCs).By integrating asymmetric phenylalkylamino side groups,TT-Ph-C6 demonstrates excellent solubility and its crystal structure exhibits compact packing structures with a three-dimensional molecular stacking network.These structural attributes markedly promote exciton diffusion and charge carrier mobility,particularly advantageous for the fabrication of thick-film devices.TT-Ph-C6-based devices have attained a PCE of 18.01%at a film thickness of 100 nm,and even at a film thickness of 300 nm,the PCE remains at 14.64%,surpassing that of devices based on 2BTh-2F.These remarkable properties position TT-Ph-C6 as a highly promising NFREA material for boosting the efficiency of OSCs.
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.
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supported by the Key Research and Development Program of Hubei Province(2023BAB116)the National Natural Science Foundation of China(52203238,52273196,52073221)the Fundamental Research Funds for the Central Universities of China(WUT:2021III016JC).
文摘All polymer solar cells(all-PSCs)promise mechanically-flexible and morphologically-stable organic photovoltaics and have aroused increased interests very recently.However,due to their disorderly conformation structures within the photoactive film,inefficient charge generation and carrier transport are observed which lead to inferior photovoltaic performance compared to smaller molecular acceptor-based photovoltaics.Here,by diluting PM6 with a cutting-edge polymeric acceptor PY-IT and diluting PY-IT with PM6 or D18,donor-dominating or acceptor-dominating heterojunctions were prepared.Synchrotron X-ray and multiple spectrometer techniques reveal that the diluted heterojunctions receive increased structural order,translating to enhanced carrier mobility,improved exciton diffusion length,and suppressed non-radiative recombination loss during the power conversion.As the results,the corresponding PM6+1%PY-IT/PY-IT+1%D18 and PM6+1%PY-IT/PY-IT+1%PM6 devices fabricated by layer-by-layer deposition received superior power conversion efficiency(PCE)of 19.4%and 18.8%respectively,along with enhanced operational lifetimes in air,outperforming the PCE of 17.5%in the PM6/PY-IT reference device.
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.
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 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 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.
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.
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support from the National Natural Science Foundation of China(62275057)the Guangxi Natural Science Foundation(2023GXNSFFA026004 and 2022GXNSFDA035066)+2 种基金the Innovation Project of Guangxi Graduate Education(YCBZ2024034)Natural Science Foundation of Ningbo under grant(2022J149)Natural Science Foundation of Ningbo under grant(2022A-230-G)
文摘Trap-assisted charge recombination is one of the primary limitationsof restricting the performance of organic solar cells. However, effectivelyreducing the presence of traps in the photoactive layer remains challenging.Herein, wide bandgap polymer donor PTzBI-dF is demonstrated as an effectivemodulator for enhancing the crystallinity of the bulk heterojunction active layerscomposed of D18 derivatives blended with Y6, leading to dense and orderedmolecular packings, and thus, improves photoluminescence quenching properties.As a result, the photovoltaic devices exhibit reduced trap-assisted charge recombinationlosses, achieving an optimized power conversion efficiency of over 19%.Besides the efficiency enhancement, the devices comprised of PTzBI-dF as athird component simultaneously attain decreased current leakage, improved chargecarrier mobilities, and suppressed bimolecular charge recombination, leading toreduced energy losses. The advanced crystalline structures induced by PTzBI-dFand its characteristics, such as well-aligned energy level, and complementaryabsorption spectra, are ascribed to the promising performance improvements.Our findings suggest that donor phase engineering is a feasible approach to tuning the molecular packings in the active layer, providingguidelines for designing effective morphology modulators for high-performance organic solar cells.
