Background Intestinal oxidative stress serves as an endogenous host defense against the gut microbiota by increas-ing energy expenditure and therefore decreasing feed efficiency(FE).Several systems coordinately regula...Background Intestinal oxidative stress serves as an endogenous host defense against the gut microbiota by increas-ing energy expenditure and therefore decreasing feed efficiency(FE).Several systems coordinately regulate redox bal-ance,including the mitochondrial respiratory chain,nicotinamide adenine dinucleotide phosphate(NADPH)oxidase,and different antioxidants.However,it remains unclear which redox balance compartments in the intestine are crucial for determining FE.Results In this study,we first screened the key targets of different metabolites and redox balance-related gene expression in broiler ceca.We then constructed a mouse colitis model to explore malic acid(MA)ability to allevi-ate intestinal inflammation.We further used controlled release technology to coat MA and investigated its effects on the intestinal redox status and FE in vivo.Finally,we examined the underlying mechanism by which MA modulated redox status using a porcine intestinal epithelial cell jejunum 2(IPEC-J2)cell model in vitro.Our results demonstrated that the MA/malic enzyme 3(ME3)pathway may play an important role in reducing oxidative stress in the broiler cecum.In addition,colon infusion of MA attenuated inflammatory phenotypes in the dextran sulfate sodium salt(DSS)induced mouse colitis model.Then,dietary supplementation with controlled-release MA pellet(MAP)reduced the feed to gain(F/G)ratio and promoted chicken growth,with reduced oxidative stress and increased bacterial diver-sity.Finally,the in vitro IPEC-J2 cell model revealed that ME3 mediated the effect of MA on cellular oxidative stress.Conclusion In summary,our study firstly revealed the important role of the MA/ME3 system in the hindgut of broiler chickens for improving intestinal health and FE,which may also be crucial for the implications of colon inflammation associated diseases.展开更多
A novel Eu^(3+)-doped fluorapatite red phosphor Ca_(2)Y_(8)(BO_(4))_(2)(SiO_(4))_(4)F_(2)Eu^(3+)with pure phase was synthesized in this study.Density functional theory(DFT)calculation and diffuse reflection spectrum a...A novel Eu^(3+)-doped fluorapatite red phosphor Ca_(2)Y_(8)(BO_(4))_(2)(SiO_(4))_(4)F_(2)Eu^(3+)with pure phase was synthesized in this study.Density functional theory(DFT)calculation and diffuse reflection spectrum analysis reveal its potential as a matrix for phosphors excited by ultraviolet light.Eu^(3+)has a^(7)F_(0)→^(5)L_(6)transition at 394 nm,and the prepared phosphor exhibits a high emission intensity at 614 nm,which may be attributed to the^(5)D_(0)-^(7)F_(2)energy transition at the lower symmetry site of Eu^(3+).The optimal doping concentration of the phosphor is determined to be 11 mol%,with concentration quenching attributed to the exchange interaction mechanism.The overall color purity of the phosphor is up to 99.88%,with an internal quantum efficiency as high as 91.15%.Notably,Ca_(2)Y_(8)(BO_(4))_(2)(SiO_(4))_(4)F_(2):11 mol%Eu^(3+)(CYBSF:11 mol%Eu^(3+))phosphors exhibit good thermal stability,with a thermal quenching temperature(T1/2)of 552 K and the intensity of emission at 423 K still at 88.89%of that at 298 K.The activation energy of the phosphor is up to 0.30287 eV.Its comprehensive luminescence performance surpasses that of commercial red phosphor,making it suitable for near ultraviolet excited warm white light emitting diode(NUV-WLED)with a high color rendering index(Ra=82)and a correlated color temperature(CCT)of 4339 K.Moreover,the phosphor achieves latent fingerprint visualization and anti-counterfeiting ink on different material surfaces:glass,aluminum foil,plastic and paper.Overall,the fluorapatite CYBSF:11 mol%Eu^(3+)phosphor holds great potential for multimodal applications due to its high quantum efficiency and good thermal stability.展开更多
Contact detection is the most time-consuming stage in 3D discontinuous deformation analysis(3D-DDA)computation.Improving the efficiency of 3D-DDA is beneficial for its application in large-scale computing.In this stud...Contact detection is the most time-consuming stage in 3D discontinuous deformation analysis(3D-DDA)computation.Improving the efficiency of 3D-DDA is beneficial for its application in large-scale computing.In this study,aiming at the continuous-discontinuous simulation of 3D-DDA,a highly efficient contact detection strategy is proposed.Firstly,the global direct search(GDS)method is integrated into the 3D-DDA framework to address intricate contact scenarios.Subsequently,all geometric elements,including blocks,faces,edges,and vertices are divided into searchable and unsearchable parts.Contacts between unsearchable geometric elements would be directly inherited,while only searchable geometric elements are involved in contact detection.This strategy significantly reduces the number of geometric elements involved in contact detection,thereby markedly enhancing the computation efficiency.Several examples are adopted to demonstrate the accuracy and efficiency of the improved 3D-DDA method.The rock pillars with different mesh sizes are simulated under self-weight.The deformation and stress are consistent with the analytical results,and the smaller the mesh size,the higher the accuracy.The maximum speedup ratio is 38.46 for this case.Furthermore,the Brazilian splitting test on the discs with different flaws is conducted.The results show that the failure pattern of the samples is consistent with the results obtained by other methods and experiments,and the maximum speedup ratio is 266.73.Finally,a large-scale impact test is performed,and approximately 3.2 times enhanced efficiency is obtained.The proposed contact detection strategy significantly improves efficiency when the rock has not completely failed,which is more suitable for continuous-discontinuous simulation.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
Solid-state lighting is now developing toward high-power and super-brightness,but is largely limited by the lack of highly robust and efficient color conversion materials that can be survived from high-power or high-p...Solid-state lighting is now developing toward high-power and super-brightness,but is largely limited by the lack of highly robust and efficient color conversion materials that can be survived from high-power or high-power density excitation,typically the red-emitting ones.In this work,we fabricated highly effi-cient and pore-free Sr_(0.5)Ca_(0.5)AlSiN_(3)∶Eu^(2+)(SCASN)red-emitting ceramics by spark plasma sintering of fine phosphor powders.These fine phosphor powders were prepared by treating the commercial phosphors with high-energy ball-milling,centrifugation and acid washing,leading to a particle size of 2.55μm and an internal quantum efficiency as high as 74.0%under 450 nm excitation.The phosphor powders can be densified into SCASN ceramics without using sintering additives at a temperature as low as 1475℃,and the ceramics show an internal quantum efficiency of 75.3%,which is 50%higher than those ceram-ics fabricated with untreated commercial powders.When excited by a high-power blue LED at a current density of 4 A/mm^(2),the SCASN ceramics have a maximum luminous flux of 660 lm(i.e.,26 Mcd/m^(2)).The phosphor ceramics can also withstand a high laser power density of 15.7 W/mm^(2),and exhibit an output luminance of 188 Mcd/m^(2).This work provides a general method to prepare fine phosphor powders that enable to fabricate high efficiency phosphor ceramics used in high-power solid-state lighting.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
Solar steam generation(SSG)is widely regarded as one of the most sustainable technologies for seawater desalination.However,salt fouling severely compromises the evaporation performance and lifetime of evaporators,lim...Solar steam generation(SSG)is widely regarded as one of the most sustainable technologies for seawater desalination.However,salt fouling severely compromises the evaporation performance and lifetime of evaporators,limiting their practical applications.Herein,we propose a hierarchical salt-rejection(HSR)strategy to prevent salt precipitation during long-term evaporation while maintaining a rapid evaporation rate,even in high-salinity brine.The salt diffusion process is segmented into three steps—insulation,branching diffusion,and arterial transport—that significantly enhance the salt-resistance properties of the evaporator.Moreover,the HSR strategy overcomes the tradeoff between salt resistance and evaporation rate.Consequently,a high evaporation rate of 2.84 kg m^(-2) h^(-1),stable evaporation for 7 days cyclic tests in 20 wt%NaCl solution,and continuous operation for 170 h in natural seawater under 1 sun illumination were achieved.Compared with control evaporators,the HSR evaporator exhibited a>54%enhancement in total water evaporation mass during 24 h continuous evaporation in 20 wt%salt water.Furthermore,a water collection device equipped with the HSR evaporator realized a high water purification rate(1.1 kg m^(-2) h^(-1)),highlighting its potential for agricultural applications.展开更多
The lead-free perovskite solar cells(PSCs) have drawn a great deal of research interest due to the Pb toxicity of the lead halide perovskite.CHNHSnIis a viable alternative to CHNHPbX,because it has a narrower band gap...The lead-free perovskite solar cells(PSCs) have drawn a great deal of research interest due to the Pb toxicity of the lead halide perovskite.CHNHSnIis a viable alternative to CHNHPbX,because it has a narrower band gap of 1.3 eV and a wider visible absorption spectrum than the lead halide perovskite.The progress of fabricating tin iodide PSCs with good stability has stimulated the studies of these CHNHSnIbased cells greatly.In the paper,we study the influences of various parameters on the solar cell performance through theoretical analysis and device simulation.It is found in the simulation that the solar cell performance can be improved to some extent by adjusting the doping concentration of the perovskite absorption layer and the electron affinity of the buffer and HTM,while the reduction of the defect density of the perovskite absorption layer significantly improves the cell performance.By further optimizing the parameters of the doping concentration(1.3 × 10cm~3) and the defect density(1 × 10cm~3) of perovskite absorption layer,and the electron affinity of buffer(4.0 eV) and HTM(2.6 eV),we finally obtain some encouraging results of the Jof 31.59 mA/cm~2,Vof 0.92 V,FF of 79.99%,and PCE of 23.36%.The results show that the lead-free CHNHSnIPSC is a potential environmentally friendly solar cell with high efficiency.Improving the Snstability and reducing the defect density of CHNHSnIare key issues for the future research,which can be solved by improving the fabrication and encapsulation process of the cell.展开更多
Tb^3＋ and Ce^3＋ co-activated LiZnPO4 phosphors with high luminescence efficiency were synthesized by a high temperature solid-state reaction at 1000 ℃ for 3 h. The XRD patterns, photoluminescence spectra and SEM we...Tb^3＋ and Ce^3＋ co-activated LiZnPO4 phosphors with high luminescence efficiency were synthesized by a high temperature solid-state reaction at 1000 ℃ for 3 h. The XRD patterns, photoluminescence spectra and SEM were recorded and the effects ofTb^3＋and Ce^3＋ concentration, sintering condition on the luminescent properties of as-synthesized phosphors were investigated. The emission spectra under ultraviolet （200-300 nm） radiation showed a dominant peak at 543 nm attributed to the ^5D4→^7F5 transition of Tb^3＋, which was greatly enhanced by the co-doping of Ce^3＋, indicating that there occurred an efficient non-radiative energy transfer from Ce^3＋ to Th^3＋. The optimal doping concentrations of Tb^3＋ and Ce^3＋ were determined to be 9% and 10%, respectively.展开更多
A novel nanocomposite of Ni nanoparticles loaded on Mg-doped Al_(2)O_(3)(Ni/Mg-Al_(2)O_(3))was prepared.By photothermocatalytic CO_(2) reduction with methane(CRM)merely using focused UV-vis-IR illumination on Ni/Mg-Al...A novel nanocomposite of Ni nanoparticles loaded on Mg-doped Al_(2)O_(3)(Ni/Mg-Al_(2)O_(3))was prepared.By photothermocatalytic CO_(2) reduction with methane(CRM)merely using focused UV-vis-IR illumination on Ni/Mg-Al_(2)O_(3),high production rates of H_(2)(r_(H2),69.71 mmol min^(−1) g^(−1))and CO(rCO,74.57 mmol min^(−1) g^(−1))and an extremely large light-to-fuel efficiency(η,32.9%)are acquired.High rH2 and rCO(51.07 and 59.66 mmol min^(−1) g^(−1))and a largeη(32.5%)are acquired even by using focusedλ>560 nm vis-IR illumination.Ni/Mg-Al_(2)O_(3) shows good durability for photothermocatalytic CRM due to the side reaction of carbon deposition being enormously inhibited in comparison with a reference catalyst of Ni nanoparticles loaded on Al_(2)O_(3).The enormous carbon deposition inhibition is ascribed to the presence of a fence of CO_(2) molecules(strongly adsorbed on Mg-doped Al_(2)O_(3))around Ni nanoparticles,which block the polymerization and growth of carbon species to nanofibers by promoting the oxidation of carbon species formed by CH_(4) dissociation.The high photothermocatalytic activity of Ni/Mg-Al_(2)O_(3) arises from efficient light-driven thermocatalytic CRM.A photoactivation is found to considerably raise the photothermocatalytic activity of Ni/Mg-Al_(2)O_(3) because of the apparent activation energy(Ea)being substantially decreased upon focused illumination.The Ea reduction is associated with the rate-determining steps of CRM(e.g.,CH_(4) dissociation and the oxidation of carbon species)being accelerated upon focused illumination.展开更多
The average photoelectric conversion efficiency(PCE)of a bare mono crystalline silicon solar cell is 14.71%±0.03%under AM1.5.It decreases to 14.20%±0.005%when covering an un-doped flat glass on the solar cel...The average photoelectric conversion efficiency(PCE)of a bare mono crystalline silicon solar cell is 14.71%±0.03%under AM1.5.It decreases to 14.20%±0.005%when covering an un-doped flat glass on the solar cell,and it goes down to 14.10%±0.005%by using a 5 wt%Eu^3+doped glass.The absorptions of the Eu^3+doped CPM glass one-to-one match the excitation spectra at 362,381,393,400,413 and464 nm,which are related to the transitions of 7 F0→(5 D4,5 G2,5 L6,5 D3),7 F1→5 D3,and 7 F0→5 D2,respectively.In addition,a concave pyramid microstructure(CPM)is embedded in the glass surface to increase light transmittance.The average PCE increases to 14.61%±0.07%when a 5 wt%Eu^3+doped CPM glass covers on the silicon solar cell.Compared with the un-doped flat glass,a net increase of the PCE is0.41%,where the 0.16%increment of PCE is from the lighting trapping of the CPM structure,and the downshifting of near ultraviolet(NUV)light by Eu^3+ion donates the other 0.25%increment.It confirms that the as-prepared Eu^3+doped CPM glass has a good downshifting and antireflection function.展开更多
The replacement of small cations with bulkier organic cations containing long alkyl chains or benzene rings to form a thin two-dimensional(2D)perovskite passivation layer on three-dimensional(3D)perovskite(2D/3D)has b...The replacement of small cations with bulkier organic cations containing long alkyl chains or benzene rings to form a thin two-dimensional(2D)perovskite passivation layer on three-dimensional(3D)perovskite(2D/3D)has become a promising strategy for improving both the efficiency and stability of perovskite solar cells(PSCs).The 2 D layer defines the interfacial chemistry and physics at the 2D/3D bilayer and endows the 2D/3D structure with better chemical and thermal stability.Herein,2D/3D(CF_(3)-PEA)_(2) FA_(0.85)MA_(0.15)Pb_(2)I_(7)/FA_(0.85)MA_(0.15)PbI_(3) planar heterojunction perovskite was produced using a facile interfacial ion exchange process.The 2 D(CF_(3)-PEA)_(2) FA_(0.85)MA_(0.15)Pb_(2)I_(7) capping layer can not only passivate the FA_(0.85)MA_(0.15)PbI_(3) film but also act as super-hydrophobic layer to inhibit water diffusion and significantly enhance the stability.The 2D capping layer can also establish a unique graded band structure at the perovskite/Spiro-OMeTAD interface and lead to p-type doping for Spiro-OMeTAD layer which is beneficial for efficient charge transport.Optimized PSCs based on this 2D/3D heterojunction yield a champion power conversion efficiency(PCE)of 23.1%and improved stability.The device maintains 84%output for 2400 h aging under ambient environmental conditions without encapsulation,and maintains 81%for 200 h under illumination with encapsulation.This work will inspire the design of more fluorinated 2D perovskite interfaces for advanced photovoltaics and beyond.展开更多
The major enrichment type of shale oil in the Chang 7_(3) shale of Upper Triassic Yanchang Formation in the Ordos Basin is unknown.This paper analyzes the organic matter transformation ratio,hydrocarbon expulsion effi...The major enrichment type of shale oil in the Chang 7_(3) shale of Upper Triassic Yanchang Formation in the Ordos Basin is unknown.This paper analyzes the organic matter transformation ratio,hydrocarbon expulsion efficiency and roof/floor sealing conditions of the Chang 7_(3) shale,and evaluates the major enrichment type of shale oil in this interval.The average organic matter transformation ratio of the Chang 7_(3) shale is about 45%;in other words,more than 50%of the organic matters have not transformed to hydrocarbons,and the lower the maturity,the greater the proportion of untransformed organic matters.The cumulative hydrocarbon expulsion efficiency of the transformed hydrocarbon is 27.5% on average,and the total proportion of untransformed organic matters plus retained hydrocarbons is greater than 70%.The relative hydrocarbon expulsion efficiency of the Chang 7_(3) shale is 60%on average,that is,about 40% of hydrocarbons retain in the shale.The Chang 7_(3) shale corresponds to Chang 7_(1+2) and Chang 8 sandstones as the roof and floor,respectively,and is further overlaid by Chang 6 shale,where extensive low porosity and low permeability–tight oil reservoirs have formed in the parts with relatively good porosity and permeability.Moreover,the Chang 7_(3) shale is tested to be in a negative pressure system(the pressure coefficient of 0.80–0.85).Therefore,the roof/floor sealing conditions of the Chang 7_(3) shale are poor.The retained hydrocarbons appear mostly in absorbed status,with low mobility.It is concluded that the medium–high mature shale oil is not the major enrichment type of shale oil in the Chang 7_(3) shale,but there may be enrichment opportunity for shale oil with good mobility in the areas where the sealing conditions are good without faults and fractures and oil reservoirs are formed off Chang 7_(1+2),Chang 6 and Chang 8.Furthermore,low–medium mature shale oil is believed to have great potential and is the major enrichment type of shale oil in the Chang 7_(3) shale.It is recommended to prepare relevant in-situ conversion technologies by pilot test and figure out the resource availability and distribution.展开更多
Native orchid species of Singapore in their natural conditions experience stress from high irradiance, high temperatures and periods of extended low rainfall, which impact orchid plant physiology and lead to reduced g...Native orchid species of Singapore in their natural conditions experience stress from high irradiance, high temperatures and periods of extended low rainfall, which impact orchid plant physiology and lead to reduced growth and productivity. In this study, it was found that there was a reduction in photochemical efficiency of photosystem II (PSII) in 6 native orchid species under high light (HL) and Bulbophyllum membranaceum under low light (LL). There was chronic photoinhibition in these 6 orchid species over a period of 3 months after transplanting onto the tree trunks without watering and fertilization, especially in Coelogynes mayeriana and Bulbophyllum membranaceum under both HL and LL. This chronic photoinhibition caused by sustained period of water deficit in their natural conditions was later reversed by natural re-watering conditions from higher rainfall. These results indicate that water deficit has a greater impact on photosynthetic light utilization efficiency than excess light. The present study also showed that after natural rewatering, relative water content (RWC) of leaves and pseudobulbs generally increased. During the natural re-watering, total leaf area also gradually increased and reached maximum expansion after 7 weeks under both HL and LL, with some exceptions due to leaf abscission or decline in total leaf area, possibly a strategy for water conservation.展开更多
基金supported by the local innovative and research teams project of Guangdong province(2019BT02N630)national key research and development program(2022YFD1300401)+2 种基金Double first-class discipline promoting project(2023B10564001)National Natural Science Foundation of China(32272954)Natural Science Foundation of Guangdong Province,China(2024A1515013131).
文摘Background Intestinal oxidative stress serves as an endogenous host defense against the gut microbiota by increas-ing energy expenditure and therefore decreasing feed efficiency(FE).Several systems coordinately regulate redox bal-ance,including the mitochondrial respiratory chain,nicotinamide adenine dinucleotide phosphate(NADPH)oxidase,and different antioxidants.However,it remains unclear which redox balance compartments in the intestine are crucial for determining FE.Results In this study,we first screened the key targets of different metabolites and redox balance-related gene expression in broiler ceca.We then constructed a mouse colitis model to explore malic acid(MA)ability to allevi-ate intestinal inflammation.We further used controlled release technology to coat MA and investigated its effects on the intestinal redox status and FE in vivo.Finally,we examined the underlying mechanism by which MA modulated redox status using a porcine intestinal epithelial cell jejunum 2(IPEC-J2)cell model in vitro.Our results demonstrated that the MA/malic enzyme 3(ME3)pathway may play an important role in reducing oxidative stress in the broiler cecum.In addition,colon infusion of MA attenuated inflammatory phenotypes in the dextran sulfate sodium salt(DSS)induced mouse colitis model.Then,dietary supplementation with controlled-release MA pellet(MAP)reduced the feed to gain(F/G)ratio and promoted chicken growth,with reduced oxidative stress and increased bacterial diver-sity.Finally,the in vitro IPEC-J2 cell model revealed that ME3 mediated the effect of MA on cellular oxidative stress.Conclusion In summary,our study firstly revealed the important role of the MA/ME3 system in the hindgut of broiler chickens for improving intestinal health and FE,which may also be crucial for the implications of colon inflammation associated diseases.
基金supported by the National Natural Science Foundation of China(52372013)Natural Science Foundation of Shanghai(22ZR1460600)。
文摘A novel Eu^(3+)-doped fluorapatite red phosphor Ca_(2)Y_(8)(BO_(4))_(2)(SiO_(4))_(4)F_(2)Eu^(3+)with pure phase was synthesized in this study.Density functional theory(DFT)calculation and diffuse reflection spectrum analysis reveal its potential as a matrix for phosphors excited by ultraviolet light.Eu^(3+)has a^(7)F_(0)→^(5)L_(6)transition at 394 nm,and the prepared phosphor exhibits a high emission intensity at 614 nm,which may be attributed to the^(5)D_(0)-^(7)F_(2)energy transition at the lower symmetry site of Eu^(3+).The optimal doping concentration of the phosphor is determined to be 11 mol%,with concentration quenching attributed to the exchange interaction mechanism.The overall color purity of the phosphor is up to 99.88%,with an internal quantum efficiency as high as 91.15%.Notably,Ca_(2)Y_(8)(BO_(4))_(2)(SiO_(4))_(4)F_(2):11 mol%Eu^(3+)(CYBSF:11 mol%Eu^(3+))phosphors exhibit good thermal stability,with a thermal quenching temperature(T1/2)of 552 K and the intensity of emission at 423 K still at 88.89%of that at 298 K.The activation energy of the phosphor is up to 0.30287 eV.Its comprehensive luminescence performance surpasses that of commercial red phosphor,making it suitable for near ultraviolet excited warm white light emitting diode(NUV-WLED)with a high color rendering index(Ra=82)and a correlated color temperature(CCT)of 4339 K.Moreover,the phosphor achieves latent fingerprint visualization and anti-counterfeiting ink on different material surfaces:glass,aluminum foil,plastic and paper.Overall,the fluorapatite CYBSF:11 mol%Eu^(3+)phosphor holds great potential for multimodal applications due to its high quantum efficiency and good thermal stability.
基金financially supported by the National Key R&D Program of China(Grant No.2023YFC3081200)the National Natural Science Foundation of China(Grant Nos.U21A20159 and 52179117).
文摘Contact detection is the most time-consuming stage in 3D discontinuous deformation analysis(3D-DDA)computation.Improving the efficiency of 3D-DDA is beneficial for its application in large-scale computing.In this study,aiming at the continuous-discontinuous simulation of 3D-DDA,a highly efficient contact detection strategy is proposed.Firstly,the global direct search(GDS)method is integrated into the 3D-DDA framework to address intricate contact scenarios.Subsequently,all geometric elements,including blocks,faces,edges,and vertices are divided into searchable and unsearchable parts.Contacts between unsearchable geometric elements would be directly inherited,while only searchable geometric elements are involved in contact detection.This strategy significantly reduces the number of geometric elements involved in contact detection,thereby markedly enhancing the computation efficiency.Several examples are adopted to demonstrate the accuracy and efficiency of the improved 3D-DDA method.The rock pillars with different mesh sizes are simulated under self-weight.The deformation and stress are consistent with the analytical results,and the smaller the mesh size,the higher the accuracy.The maximum speedup ratio is 38.46 for this case.Furthermore,the Brazilian splitting test on the discs with different flaws is conducted.The results show that the failure pattern of the samples is consistent with the results obtained by other methods and experiments,and the maximum speedup ratio is 266.73.Finally,a large-scale impact test is performed,and approximately 3.2 times enhanced efficiency is obtained.The proposed contact detection strategy significantly improves efficiency when the rock has not completely failed,which is more suitable for continuous-discontinuous simulation.
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supported by the National Key Research and Development Program(MOST,No.2022YFE0108800)the National Natural Science Foundation of China(Nos.52272165,U2005213 and 52172157)the Major Science and Technology Projects of Xiamen Science and Technology Bureau(No.3502Z20231018).
文摘Solid-state lighting is now developing toward high-power and super-brightness,but is largely limited by the lack of highly robust and efficient color conversion materials that can be survived from high-power or high-power density excitation,typically the red-emitting ones.In this work,we fabricated highly effi-cient and pore-free Sr_(0.5)Ca_(0.5)AlSiN_(3)∶Eu^(2+)(SCASN)red-emitting ceramics by spark plasma sintering of fine phosphor powders.These fine phosphor powders were prepared by treating the commercial phosphors with high-energy ball-milling,centrifugation and acid washing,leading to a particle size of 2.55μm and an internal quantum efficiency as high as 74.0%under 450 nm excitation.The phosphor powders can be densified into SCASN ceramics without using sintering additives at a temperature as low as 1475℃,and the ceramics show an internal quantum efficiency of 75.3%,which is 50%higher than those ceram-ics fabricated with untreated commercial powders.When excited by a high-power blue LED at a current density of 4 A/mm^(2),the SCASN ceramics have a maximum luminous flux of 660 lm(i.e.,26 Mcd/m^(2)).The phosphor ceramics can also withstand a high laser power density of 15.7 W/mm^(2),and exhibit an output luminance of 188 Mcd/m^(2).This work provides a general method to prepare fine phosphor powders that enable to fabricate high efficiency phosphor ceramics used in high-power solid-state lighting.
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support provided by the Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone Shenzhen Park Project(HZQB-KCZYB-2020030)the Research Grants Council of Hong Kong(Project No:AoE/M-402/20.)+1 种基金the Open Project of Yunnan Precious Metals Laboratory Co.,Ltd(YPML-2023050248)the Hong Kong Innovation and Technology Commission via the Hong Kong Branch of National Precious Metals Material Engineering Research Center.
文摘Solar steam generation(SSG)is widely regarded as one of the most sustainable technologies for seawater desalination.However,salt fouling severely compromises the evaporation performance and lifetime of evaporators,limiting their practical applications.Herein,we propose a hierarchical salt-rejection(HSR)strategy to prevent salt precipitation during long-term evaporation while maintaining a rapid evaporation rate,even in high-salinity brine.The salt diffusion process is segmented into three steps—insulation,branching diffusion,and arterial transport—that significantly enhance the salt-resistance properties of the evaporator.Moreover,the HSR strategy overcomes the tradeoff between salt resistance and evaporation rate.Consequently,a high evaporation rate of 2.84 kg m^(-2) h^(-1),stable evaporation for 7 days cyclic tests in 20 wt%NaCl solution,and continuous operation for 170 h in natural seawater under 1 sun illumination were achieved.Compared with control evaporators,the HSR evaporator exhibited a>54%enhancement in total water evaporation mass during 24 h continuous evaporation in 20 wt%salt water.Furthermore,a water collection device equipped with the HSR evaporator realized a high water purification rate(1.1 kg m^(-2) h^(-1)),highlighting its potential for agricultural applications.
基金supported by the Graduate Student Education Teaching Reform Project,China(Grant No.JG201512)the Young Teachers Research Project of Yanshan University,China(Grant No.13LGB028)
文摘The lead-free perovskite solar cells(PSCs) have drawn a great deal of research interest due to the Pb toxicity of the lead halide perovskite.CHNHSnIis a viable alternative to CHNHPbX,because it has a narrower band gap of 1.3 eV and a wider visible absorption spectrum than the lead halide perovskite.The progress of fabricating tin iodide PSCs with good stability has stimulated the studies of these CHNHSnIbased cells greatly.In the paper,we study the influences of various parameters on the solar cell performance through theoretical analysis and device simulation.It is found in the simulation that the solar cell performance can be improved to some extent by adjusting the doping concentration of the perovskite absorption layer and the electron affinity of the buffer and HTM,while the reduction of the defect density of the perovskite absorption layer significantly improves the cell performance.By further optimizing the parameters of the doping concentration(1.3 × 10cm~3) and the defect density(1 × 10cm~3) of perovskite absorption layer,and the electron affinity of buffer(4.0 eV) and HTM(2.6 eV),we finally obtain some encouraging results of the Jof 31.59 mA/cm~2,Vof 0.92 V,FF of 79.99%,and PCE of 23.36%.The results show that the lead-free CHNHSnIPSC is a potential environmentally friendly solar cell with high efficiency.Improving the Snstability and reducing the defect density of CHNHSnIare key issues for the future research,which can be solved by improving the fabrication and encapsulation process of the cell.
基金Project supported by National High Technology Research and Development Program of China,863 Program (2010AA03A407,2010AA03A408)the Foundation of Training Academic and Technical Header for Main Majors of Jiang xi of China (2007GG00800)
文摘Tb^3＋ and Ce^3＋ co-activated LiZnPO4 phosphors with high luminescence efficiency were synthesized by a high temperature solid-state reaction at 1000 ℃ for 3 h. The XRD patterns, photoluminescence spectra and SEM were recorded and the effects ofTb^3＋and Ce^3＋ concentration, sintering condition on the luminescent properties of as-synthesized phosphors were investigated. The emission spectra under ultraviolet （200-300 nm） radiation showed a dominant peak at 543 nm attributed to the ^5D4→^7F5 transition of Tb^3＋, which was greatly enhanced by the co-doping of Ce^3＋, indicating that there occurred an efficient non-radiative energy transfer from Ce^3＋ to Th^3＋. The optimal doping concentrations of Tb^3＋ and Ce^3＋ were determined to be 9% and 10%, respectively.
基金supported by National Natural Science Foundation of China(21972109,21673168)DFT calculations were conducted at the Shanghai Supercomputer Center(SSC),China.
文摘A novel nanocomposite of Ni nanoparticles loaded on Mg-doped Al_(2)O_(3)(Ni/Mg-Al_(2)O_(3))was prepared.By photothermocatalytic CO_(2) reduction with methane(CRM)merely using focused UV-vis-IR illumination on Ni/Mg-Al_(2)O_(3),high production rates of H_(2)(r_(H2),69.71 mmol min^(−1) g^(−1))and CO(rCO,74.57 mmol min^(−1) g^(−1))and an extremely large light-to-fuel efficiency(η,32.9%)are acquired.High rH2 and rCO(51.07 and 59.66 mmol min^(−1) g^(−1))and a largeη(32.5%)are acquired even by using focusedλ>560 nm vis-IR illumination.Ni/Mg-Al_(2)O_(3) shows good durability for photothermocatalytic CRM due to the side reaction of carbon deposition being enormously inhibited in comparison with a reference catalyst of Ni nanoparticles loaded on Al_(2)O_(3).The enormous carbon deposition inhibition is ascribed to the presence of a fence of CO_(2) molecules(strongly adsorbed on Mg-doped Al_(2)O_(3))around Ni nanoparticles,which block the polymerization and growth of carbon species to nanofibers by promoting the oxidation of carbon species formed by CH_(4) dissociation.The high photothermocatalytic activity of Ni/Mg-Al_(2)O_(3) arises from efficient light-driven thermocatalytic CRM.A photoactivation is found to considerably raise the photothermocatalytic activity of Ni/Mg-Al_(2)O_(3) because of the apparent activation energy(Ea)being substantially decreased upon focused illumination.The Ea reduction is associated with the rate-determining steps of CRM(e.g.,CH_(4) dissociation and the oxidation of carbon species)being accelerated upon focused illumination.
基金Project supported by National"Double First-class"Construction Special Funding Project(0290-X2100502)。
文摘The average photoelectric conversion efficiency(PCE)of a bare mono crystalline silicon solar cell is 14.71%±0.03%under AM1.5.It decreases to 14.20%±0.005%when covering an un-doped flat glass on the solar cell,and it goes down to 14.10%±0.005%by using a 5 wt%Eu^3+doped glass.The absorptions of the Eu^3+doped CPM glass one-to-one match the excitation spectra at 362,381,393,400,413 and464 nm,which are related to the transitions of 7 F0→(5 D4,5 G2,5 L6,5 D3),7 F1→5 D3,and 7 F0→5 D2,respectively.In addition,a concave pyramid microstructure(CPM)is embedded in the glass surface to increase light transmittance.The average PCE increases to 14.61%±0.07%when a 5 wt%Eu^3+doped CPM glass covers on the silicon solar cell.Compared with the un-doped flat glass,a net increase of the PCE is0.41%,where the 0.16%increment of PCE is from the lighting trapping of the CPM structure,and the downshifting of near ultraviolet(NUV)light by Eu^3+ion donates the other 0.25%increment.It confirms that the as-prepared Eu^3+doped CPM glass has a good downshifting and antireflection function.
基金support from the National Natural Science Foundation of China(62074095)the National Key Research and Development Program of China(2016YFA0202403)+3 种基金the Fundamental Research Funds for the Central Universities(GK202002001)the 111 Project B(14041)the DNL Cooperation Fund CAS(DNL180311)support of the H2 cluster in Xi’an Jiaotong University。
文摘The replacement of small cations with bulkier organic cations containing long alkyl chains or benzene rings to form a thin two-dimensional(2D)perovskite passivation layer on three-dimensional(3D)perovskite(2D/3D)has become a promising strategy for improving both the efficiency and stability of perovskite solar cells(PSCs).The 2 D layer defines the interfacial chemistry and physics at the 2D/3D bilayer and endows the 2D/3D structure with better chemical and thermal stability.Herein,2D/3D(CF_(3)-PEA)_(2) FA_(0.85)MA_(0.15)Pb_(2)I_(7)/FA_(0.85)MA_(0.15)PbI_(3) planar heterojunction perovskite was produced using a facile interfacial ion exchange process.The 2 D(CF_(3)-PEA)_(2) FA_(0.85)MA_(0.15)Pb_(2)I_(7) capping layer can not only passivate the FA_(0.85)MA_(0.15)PbI_(3) film but also act as super-hydrophobic layer to inhibit water diffusion and significantly enhance the stability.The 2D capping layer can also establish a unique graded band structure at the perovskite/Spiro-OMeTAD interface and lead to p-type doping for Spiro-OMeTAD layer which is beneficial for efficient charge transport.Optimized PSCs based on this 2D/3D heterojunction yield a champion power conversion efficiency(PCE)of 23.1%and improved stability.The device maintains 84%output for 2400 h aging under ambient environmental conditions without encapsulation,and maintains 81%for 200 h under illumination with encapsulation.This work will inspire the design of more fluorinated 2D perovskite interfaces for advanced photovoltaics and beyond.
基金Supported by the National Natural Science Foundation of China(U22B6004).
文摘The major enrichment type of shale oil in the Chang 7_(3) shale of Upper Triassic Yanchang Formation in the Ordos Basin is unknown.This paper analyzes the organic matter transformation ratio,hydrocarbon expulsion efficiency and roof/floor sealing conditions of the Chang 7_(3) shale,and evaluates the major enrichment type of shale oil in this interval.The average organic matter transformation ratio of the Chang 7_(3) shale is about 45%;in other words,more than 50%of the organic matters have not transformed to hydrocarbons,and the lower the maturity,the greater the proportion of untransformed organic matters.The cumulative hydrocarbon expulsion efficiency of the transformed hydrocarbon is 27.5% on average,and the total proportion of untransformed organic matters plus retained hydrocarbons is greater than 70%.The relative hydrocarbon expulsion efficiency of the Chang 7_(3) shale is 60%on average,that is,about 40% of hydrocarbons retain in the shale.The Chang 7_(3) shale corresponds to Chang 7_(1+2) and Chang 8 sandstones as the roof and floor,respectively,and is further overlaid by Chang 6 shale,where extensive low porosity and low permeability–tight oil reservoirs have formed in the parts with relatively good porosity and permeability.Moreover,the Chang 7_(3) shale is tested to be in a negative pressure system(the pressure coefficient of 0.80–0.85).Therefore,the roof/floor sealing conditions of the Chang 7_(3) shale are poor.The retained hydrocarbons appear mostly in absorbed status,with low mobility.It is concluded that the medium–high mature shale oil is not the major enrichment type of shale oil in the Chang 7_(3) shale,but there may be enrichment opportunity for shale oil with good mobility in the areas where the sealing conditions are good without faults and fractures and oil reservoirs are formed off Chang 7_(1+2),Chang 6 and Chang 8.Furthermore,low–medium mature shale oil is believed to have great potential and is the major enrichment type of shale oil in the Chang 7_(3) shale.It is recommended to prepare relevant in-situ conversion technologies by pilot test and figure out the resource availability and distribution.
文摘Native orchid species of Singapore in their natural conditions experience stress from high irradiance, high temperatures and periods of extended low rainfall, which impact orchid plant physiology and lead to reduced growth and productivity. In this study, it was found that there was a reduction in photochemical efficiency of photosystem II (PSII) in 6 native orchid species under high light (HL) and Bulbophyllum membranaceum under low light (LL). There was chronic photoinhibition in these 6 orchid species over a period of 3 months after transplanting onto the tree trunks without watering and fertilization, especially in Coelogynes mayeriana and Bulbophyllum membranaceum under both HL and LL. This chronic photoinhibition caused by sustained period of water deficit in their natural conditions was later reversed by natural re-watering conditions from higher rainfall. These results indicate that water deficit has a greater impact on photosynthetic light utilization efficiency than excess light. The present study also showed that after natural rewatering, relative water content (RWC) of leaves and pseudobulbs generally increased. During the natural re-watering, total leaf area also gradually increased and reached maximum expansion after 7 weeks under both HL and LL, with some exceptions due to leaf abscission or decline in total leaf area, possibly a strategy for water conservation.
