Water-evaporation-induced electricity generation shows great application prospect due to the volt-level voltage induced by natural water evaporation in ambient environment.Increasing investigations have been conducted...Water-evaporation-induced electricity generation shows great application prospect due to the volt-level voltage induced by natural water evaporation in ambient environment.Increasing investigations have been conducted on water-evaporation-induced electricity in different materials,surface treatments,working mechanisms and wide ranges of practical applications.However,to further enhance the electricity output remains a great challenge.In this study,we fabricated porous carbon black films with isosceles trapezoid shapes to generate water-evaporation-induced electricity,in contrast with the widely used rectangle samples.We found that an isosceles trapezoid film produces two different voltages by inversing the film,because of different flow rates and capillary heights after inversion.The ratio of these voltages varies with the length of longer base when lengths of shorter base and heights are fixed,and the maximum ratio can reach 1.77:1 in our study.This work shows the importance of geometry design in improving the output voltage.展开更多
The effects of radio frequency(RF)atmospheric pressure(AP)He/H_(2)plasma and thermal treatment on the hydrogenation of TiO_(2)thin films were investigated and compared in this work.The color of the original TiO_(2)fil...The effects of radio frequency(RF)atmospheric pressure(AP)He/H_(2)plasma and thermal treatment on the hydrogenation of TiO_(2)thin films were investigated and compared in this work.The color of the original TiO_(2)film changes from white to black after being hydrogenated in He/H_(2)plasma at160 W(gas temperature~381℃)within 5 min,while the color of the thermally treated TiO_(2)film did not change significantly even in pure H_(2)or He/H_(2)atmosphere with higher temperature(470℃)and longer time(30 min).This indicated that a more effective hydrogenation reaction happened through RF AP He/H_(2)plasma treatment than through pure H_(2)or He/H_(2)thermal treatment.The color change of TiO_(2)film was measured based on the Commission Internationale d’Eclairage L*a*b*color space system.Hydrogenated TiO_(2)film displayed improved visible light absorption with increased plasma power.The morphology of the cauliflower-like nanoparticles of the TiO_(2)film surface remained unchanged after plasma processing.X-ray photoelectron spectroscopy results showed that the contents of Ti3+species and Ti-OH bonds in the plasma-hydrogenated black TiO_(2)increased compared with those in the thermally treated TiO_(2).X-ray diffraction(XRD)patterns and Raman spectra indicated that plasma would destroy the crystal structure of the TiO_(2)surface layer,while thermal annealing would increase the overall crystallinity.The different trends of XRD and Raman spectra results suggested that plasma modification on the TiO_(2)surface layer is more drastic than on its inner layer,which was also consistent with transmission electron microscopy results.Optical emission spectra results suggest that numerous active species were generated during RF AP He/H_(2)plasma processing,while there were no peaks detected from thermal processing.A possible mechanism for the TiO_(2)hydrogenation process by plasma has been proposed.Numerous active species were generated in the bulk plasma region,accelerated in the sheath region,and bumped toward the TiO_(2)film,which will react with the TiO_(2)surface to form OVs and disordered layers.This leads to the tailoring of the band gap of black TiO_(2)and causes its light absorption to extend into the visible region.展开更多
We discuss the entropy of the Garfinkle-Horowitz-Strominger dilaton black hole by using the thin film brick-wallmodel,and the entropy obtained is proportional to the horizon area of the black hole confirming the Beken...We discuss the entropy of the Garfinkle-Horowitz-Strominger dilaton black hole by using the thin film brick-wallmodel,and the entropy obtained is proportional to the horizon area of the black hole confirming the Bekenstein-Hawking'sarea-entropy formula.Then,by comparing with the original brick-wall method,we find that the resultobtained by the thin film method is more reasonable avoiding some drawbacks,such as little mass approximation,neglecting logarithm term,and taking the term L^3 as a contribution of the vacuum surrounding the black bole,and thephysical meaning of the entropy is more clearer.展开更多
By the statistical entropy of the Dirac field of the static spherically symmetric black hole, the result is obtained that the radiation energy flux of the black hole is proportional to the quartic of the temperature o...By the statistical entropy of the Dirac field of the static spherically symmetric black hole, the result is obtained that the radiation energy flux of the black hole is proportional to the quartic of the temperature of its event horizon. That is, the thermal radiation of the black hole always satisfies the generalised Stenfan-Boltzmann law. The derived generalised Stenfan-Boltzmann coefficient is no longer a constant. When the cut-off distance and the thin film thickness are both fixed, it is a proportional coefficient related to the space-time metric near the event horizon and the average radial effusion velocity of the radiation particles from the thin film. Finally, the radiation energy fluxes and the radiation powers of the Schwarzschild black hole and the Reissner-NordstrSm black hole are derived, separately.展开更多
Using entropy density of Dirac field near the event horizon of a rectilinear non-uniformly accelerating Kinnersley black hole, the law for the thermal radiation of black hole is studied and the instantaneous radiation...Using entropy density of Dirac field near the event horizon of a rectilinear non-uniformly accelerating Kinnersley black hole, the law for the thermal radiation of black hole is studied and the instantaneous radiation energy density is obtained. It is found that the instantaneous radiation energy density of a black hole is always proportional to the quartic of the temperature on event horizon in the same direction. That is to say, the thermal radiation of a black hole always satisfies the generalized Stefan-Boltzmann law. In addition, the derived generalized Stefan Boltzmann coefficient is no longer a constant, but a dynamic coefficient related to the space-time metric near the event horizon and the changing rate of the event horizon in black holes.展开更多
以壳聚糖(chitosan,CS)、海藻酸钠(sodium alginate,SA)为成膜基材,通过添加黑苹果果皮花青素(black apple peel anthocyanin,BAA)提取物制备智能指示膜(CS-SA-BAA薄膜),并将其应用于虾新鲜度监测。分析比较BAA提取物添加量对复合薄膜...以壳聚糖(chitosan,CS)、海藻酸钠(sodium alginate,SA)为成膜基材,通过添加黑苹果果皮花青素(black apple peel anthocyanin,BAA)提取物制备智能指示膜(CS-SA-BAA薄膜),并将其应用于虾新鲜度监测。分析比较BAA提取物添加量对复合薄膜微观形貌、厚度、颜色、机械性能、水分质量分数、紫外线透过率等的影响;并进一步研究利用复合薄膜监测虾新鲜度的可行性。结果表明:添加BAA提取物到复合薄膜中使组分之间发生了相互作用,BAA提取物在复合薄膜中分散良好,且复合薄膜机械性能得到显著提升,水分质量分数和紫外线透过率下降。此外,BAA提取物在pH 1~14范围内颜色由红色变为黄色,对酸碱度有明显响应,含有15%BAA提取物的复合薄膜对pH值敏感,可将其应用于虾新鲜度指示。在4℃下贮藏的第5天,虾的总挥发性盐基氮含量和pH值超过了虾的腐败阈值,表明虾已经腐败,同时复合薄膜的颜色由最初的红色变为深灰色。因此,CS-SA复合膜可作为良好的载体固定BAA以制备智能指示膜,用于虾新鲜度监测。展开更多
基金the National Key Research and Development Program of China(Grant No.2019YFA0705400)the National Natural Science Foundation of China(Grant No.51535005)+2 种基金the Research Fund of State Key Laboratory of Mechanics and Control of Mechanical Structures(Grant Nos.MCMS-I-0418K01 and MCMS-I-0419K01)the Fundamental Research Funds for the Central Universities(Grant Nos.NZ2020001,NC2018001,NP2019301 and NJ2019002)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Water-evaporation-induced electricity generation shows great application prospect due to the volt-level voltage induced by natural water evaporation in ambient environment.Increasing investigations have been conducted on water-evaporation-induced electricity in different materials,surface treatments,working mechanisms and wide ranges of practical applications.However,to further enhance the electricity output remains a great challenge.In this study,we fabricated porous carbon black films with isosceles trapezoid shapes to generate water-evaporation-induced electricity,in contrast with the widely used rectangle samples.We found that an isosceles trapezoid film produces two different voltages by inversing the film,because of different flow rates and capillary heights after inversion.The ratio of these voltages varies with the length of longer base when lengths of shorter base and heights are fixed,and the maximum ratio can reach 1.77:1 in our study.This work shows the importance of geometry design in improving the output voltage.
基金financially supported by National Natural Science Foundation of China(Nos.12075054,12205040,12175036,11875104)。
文摘The effects of radio frequency(RF)atmospheric pressure(AP)He/H_(2)plasma and thermal treatment on the hydrogenation of TiO_(2)thin films were investigated and compared in this work.The color of the original TiO_(2)film changes from white to black after being hydrogenated in He/H_(2)plasma at160 W(gas temperature~381℃)within 5 min,while the color of the thermally treated TiO_(2)film did not change significantly even in pure H_(2)or He/H_(2)atmosphere with higher temperature(470℃)and longer time(30 min).This indicated that a more effective hydrogenation reaction happened through RF AP He/H_(2)plasma treatment than through pure H_(2)or He/H_(2)thermal treatment.The color change of TiO_(2)film was measured based on the Commission Internationale d’Eclairage L*a*b*color space system.Hydrogenated TiO_(2)film displayed improved visible light absorption with increased plasma power.The morphology of the cauliflower-like nanoparticles of the TiO_(2)film surface remained unchanged after plasma processing.X-ray photoelectron spectroscopy results showed that the contents of Ti3+species and Ti-OH bonds in the plasma-hydrogenated black TiO_(2)increased compared with those in the thermally treated TiO_(2).X-ray diffraction(XRD)patterns and Raman spectra indicated that plasma would destroy the crystal structure of the TiO_(2)surface layer,while thermal annealing would increase the overall crystallinity.The different trends of XRD and Raman spectra results suggested that plasma modification on the TiO_(2)surface layer is more drastic than on its inner layer,which was also consistent with transmission electron microscopy results.Optical emission spectra results suggest that numerous active species were generated during RF AP He/H_(2)plasma processing,while there were no peaks detected from thermal processing.A possible mechanism for the TiO_(2)hydrogenation process by plasma has been proposed.Numerous active species were generated in the bulk plasma region,accelerated in the sheath region,and bumped toward the TiO_(2)film,which will react with the TiO_(2)surface to form OVs and disordered layers.This leads to the tailoring of the band gap of black TiO_(2)and causes its light absorption to extend into the visible region.
基金Supported by the National Natural Science Foundation of China under Grant No.10573004
文摘We discuss the entropy of the Garfinkle-Horowitz-Strominger dilaton black hole by using the thin film brick-wallmodel,and the entropy obtained is proportional to the horizon area of the black hole confirming the Bekenstein-Hawking'sarea-entropy formula.Then,by comparing with the original brick-wall method,we find that the resultobtained by the thin film method is more reasonable avoiding some drawbacks,such as little mass approximation,neglecting logarithm term,and taking the term L^3 as a contribution of the vacuum surrounding the black bole,and thephysical meaning of the entropy is more clearer.
基金supported by the National Natural Science Foundation of China (Grant No.10773002)the Technology Planning Project of Education Bureau of Shandong Province,China (Grant No.J07WJ49)
文摘By the statistical entropy of the Dirac field of the static spherically symmetric black hole, the result is obtained that the radiation energy flux of the black hole is proportional to the quartic of the temperature of its event horizon. That is, the thermal radiation of the black hole always satisfies the generalised Stenfan-Boltzmann law. The derived generalised Stenfan-Boltzmann coefficient is no longer a constant. When the cut-off distance and the thin film thickness are both fixed, it is a proportional coefficient related to the space-time metric near the event horizon and the average radial effusion velocity of the radiation particles from the thin film. Finally, the radiation energy fluxes and the radiation powers of the Schwarzschild black hole and the Reissner-NordstrSm black hole are derived, separately.
基金supported by the National Natural Science Foundation of China (Grant No 10773002)the Technology Planning Project of Education Bureau of Shandong Province, China (Grant No J07WJ49)
文摘Using entropy density of Dirac field near the event horizon of a rectilinear non-uniformly accelerating Kinnersley black hole, the law for the thermal radiation of black hole is studied and the instantaneous radiation energy density is obtained. It is found that the instantaneous radiation energy density of a black hole is always proportional to the quartic of the temperature on event horizon in the same direction. That is to say, the thermal radiation of a black hole always satisfies the generalized Stefan-Boltzmann law. In addition, the derived generalized Stefan Boltzmann coefficient is no longer a constant, but a dynamic coefficient related to the space-time metric near the event horizon and the changing rate of the event horizon in black holes.
