The influence of variable viscosity and double diffusion on the convective stability of a nanofluid flow in an inclined porous channel is investigated.The DarcyBrinkman model is used to characterize the fluid flow dyn...The influence of variable viscosity and double diffusion on the convective stability of a nanofluid flow in an inclined porous channel is investigated.The DarcyBrinkman model is used to characterize the fluid flow dynamics in porous materials.The analytical solutions are obtained for the unidirectional and completely developed flow.Based on a normal mode analysis,the generalized eigenvalue problem under a perturbed state is solved.The eigenvalue problem is then solved by the spectral method.Finally,the critical Rayleigh number with the corresponding wavenumber is evaluated at the assigned values of the other flow-governing parameters.The results show that increasing the Darcy number,the Lewis number,the Dufour parameter,or the Soret parameter increases the stability of the system,whereas increasing the inclination angle of the channel destabilizes the flow.Besides,the flow is the most unstable when the channel is vertically oriented.展开更多
Perovskite solar cells(PSCs)have made great advances in terms of power conversion efficiency(PCE),yet their subpar stability continues to hinder their commercialization.The interface between the perovskite layer and t...Perovskite solar cells(PSCs)have made great advances in terms of power conversion efficiency(PCE),yet their subpar stability continues to hinder their commercialization.The interface between the perovskite layer and the charge-carrier transporting layers plays a crucial role in undermining the stability of PSCs.In this work,we propose a strategy to stabilize high-performance PSCs with PCE over 23%by introducing a cesium-doped graphene oxide(GO-Cs)as an interlayer between the perovskite and hole-transporting material.The GO-Cs treated PSCs exhibit excellent operational stability with a projected T80(the time where the device PCE reduces to 80%of its initial value)of 2143 h of operation at the maximum powering point under one sun illumination.展开更多
The long-term dynamic evolution and underlying mechanisms of coastal landscape pattern stability,driven by strong anthropogenic interference and consequently climate change,are topics of major interest in national and...The long-term dynamic evolution and underlying mechanisms of coastal landscape pattern stability,driven by strong anthropogenic interference and consequently climate change,are topics of major interest in national and international scientific research.Guangdong Province,located in southeastern China,has been undergoing rapid urbanization over several decades.In this study,we quantitatively determined the scale threshold characteristics of coastal landscape pattern stability in Guangdong Province,from the dual perspective of spatial heterogeneity and spatial autocorrelation.An analysis of the spatiotemporal evolution of the coastal landscape was conducted after the optical scale was determined.Then,we applied the geodetector statistical method to quantitatively explore the mechanisms underlying coastal landscape pattern stability.Based on the inflection point of landscape metrics and the maximum value of the MoranⅠindex,the optimal scale for analyzing coastal landscape pattern stability in Guangdong Province was 240 m×240 m.Within the past several decades,coastal landscape pattern stability increased slightly and then decreased,with a turning point around 2005.The most significant variations in coastal landscape pattern stability were observed in the transition zone of rural-urban expansion.A q-statistics analysis showed that the explanatory power of paired factors was greater than that of a single driving factor;the paired factors with the greatest impact on coastal landscape pattern stability in Guangdong Province were the change in gross industrial output and change in average annual precipitation from 2010 to 2015,based on a q value of 0.604.These results will contribute to future efforts to achieve sustainable coastal development and provide a scientific basis and technical support for the rational planning and utilization of resources in large estuarine areas,including marine disaster prevention and seawall ecological restoration.展开更多
Objective:To analyze the enduring rotational steadiness of AcrySof IQ Toric intraocular lens(IOL)in cataract patients suffering from myopia in a long-term study.Methods:A retrospective study was conducted on a case se...Objective:To analyze the enduring rotational steadiness of AcrySof IQ Toric intraocular lens(IOL)in cataract patients suffering from myopia in a long-term study.Methods:A retrospective study was conducted on a case series involving 78 patients.A total of 120 eyes with an axial length(AL)ranging from 24-30 mm and corneal astigmatism≥1.50 D underwent implantation of AcrySof IQ Toric IOL guided by the version navigation system.The eyes were divided into two groups based on AL.Group A included 60 eyes with high myopia(AL≥26 mm),while Group B consisted of eyes with low to moderate myopia(24 mm≤AL<26 mm).Data on the preoperative AL were collected.Measurements were taken for residual astigmatism,the best corrected visual acuity(BCDVA),corneal astigmatism,and IOL rotation occurring between 24-and 48-months post-surgery.The percentage of eyes with an IOL rotation of under 5°and 10°was analyzed.Results:The mean length of follow-up times was recorded as 34.27±4.98,and the average rotation was 2.73±1.29°.Group A exhibited a slightly higher average rotation of 2.87±1.31°,compared to the rotation of 2.59±1.27°observed in Group B.At both the 24-36 month and 26-48 month post-operation marks,the degree of IOL rotation did not show a statistically significant difference between the two groups,with none of the patients experiencing a rotation exceeding 10°(P>0.05).The percentage of rotation degrees under 5°was recorded as 98.22%.After the procedure,the BCDVA was 0.1322±0.03 LogMAR.There was a substantial increase in theχvalue after the operation as compared to the pre-operativeχ^(2) value(χ^(2)=76.79).The standard deviation of preoperative corneal astigmatism was statistically significant(P<0.05)at 2.17±1.08 D.Following the surgical procedure,the remaining astigmatism was measured at 0.41±0.26 D.The data showed a notable gap in statistical significance(t=4.281,P<0.05).Conclusion:The AcrySof Toric IOL was a reliable solution for managing corneal astigmatism in cataract patients with myopia,demonstrating excellent long-term rotational stability.展开更多
The presence of defects and detrimental reactions at NiO_(x)/perovskite interface extremely limit the efficiency performance and long-term stability of the perovskite solar cells(PSCs) based on NiO_(x).Herein,an amphi...The presence of defects and detrimental reactions at NiO_(x)/perovskite interface extremely limit the efficiency performance and long-term stability of the perovskite solar cells(PSCs) based on NiO_(x).Herein,an amphipathic molecule Triton X100(Triton) is modified on the NiO_(x)surface.The hydrophilic chain of Triton as a Lewis base additive can coordinate with the Ni3+on the NiO_(x)surface which can passivate the interfacial defects and hinder the detrimental reactions at the NiO_(x)/perovskite interface.Additionally,the hydrophobic chain of Triton protrudes from the NiO_(x)surface to prevent moisture from penetrating into the NiO_(x)/perovskite interface.Consequently,the NiO_(x)/Triton-based devices(MAPbI3as absorbing layer) show superior moisture and thermal stability,retaining 88.4% and 64.3% of the initial power conversion efficiency after storage in air(40%-50% relative humidity(RH)) at 25 ℃ for 1070 h and in N2at 85℃ for 800 h,respectively.Moreover,the efficiency increases from 17.59% to 19.89% because of the passivation defect and enhanced hole-extraction capability.Besides,the NiO_(x)/Triton-based PSCs with Cs_(0.05)(MA_(0.15)FA_(0.85))_(0.95)Pb(I_(0.85)Br_(0.15))3perovskite as the light-absorbing layer also exhibits better moisture and thermal stability compared to the control devices,indicating the viability of our strategies.Of particular note,a champion PCE of 22.35% and 20.46% was achieved for small-area(0.1 cm^(2)) and large-area(1.2 cm^(2)) NiO_(x)/Triton-based devices,respectively.展开更多
In this work,we developed the PM6:Y6-based inverted structure organic photovoltaic(i-OPV)with improved power conversion efficiency(PCE)and long-term stability by resolving the origins of the performance deterioration....In this work,we developed the PM6:Y6-based inverted structure organic photovoltaic(i-OPV)with improved power conversion efficiency(PCE)and long-term stability by resolving the origins of the performance deterioration.The deep defects between the metal oxide-based electron transport layer and bulk-heterojunction photoactive layer interface were responsible for suboptimal PCE and facilitated degradation of devices.While the density of deep traps is increased during the storage of i-OPV,the penetrative oxygen-containing defects additionally generated shallow traps below the band-edge of Y6,causing an additional loss in the open-circuit voltage.The suppression of interfacial defects by chemical modification effectively improved the PCE and long-term stability of i-OPV.The modified i-OPV(mi-OPV)achieved a PCE of 17.42%,which is the highest value among the reported PM6:Y6-based i-OPV devices.Moreover,long-term stability was significantly improved:~90%and~80%retention of its initial PCE after 1200 h of air storage and illumination,respectively.展开更多
The subject of the present paper is to prove that the recently introduced conjecture of boundedness puts a ban over the view of stability as asymptotic property. This result comes in sharp contrast with the prescripti...The subject of the present paper is to prove that the recently introduced conjecture of boundedness puts a ban over the view of stability as asymptotic property. This result comes in sharp contrast with the prescription of the traditional thermodynamics and statistical physics which consider the existence of equilibrium as asymptotic property of all systems. The difference commences from the use of infinitesimal calculus as the basic implement for modelling by the latter while the primary premise of the conjecture of boundedness is sustaining the energy/matter/information permanently bounded and finite. The latter property overrules the infinitesimal calculus as the major implement of modelling because, among all, it is proven that the traditional one suffers unsoluble difficulties.展开更多
Although the efficiency of organic–inorganic hybrid halide perovskite solar cells has been improved rapidly, the intrinsic instability of perovskite materials restricts their commercial application. Here, an eco-frie...Although the efficiency of organic–inorganic hybrid halide perovskite solar cells has been improved rapidly, the intrinsic instability of perovskite materials restricts their commercial application. Here, an eco-friendly and low-cost organic polymer, cellulose acetate butyrate(CAB), was introduced to the grain boundaries and surfaces of perovskite, resulting in a high-quality and low-defect perovskite film with a nearly tenfold improvement in carrier lifetime. More importantly, the CAB-treated perovskite films have a well-matched energy level with the charge transport layers, thus suppressing carrier nonradiative recombination and carrier accumulation. As a result, the optimized CAB-based device achieved a champion efficiency of 21.5% compared to the control device(18.2%). Since the ester group in CAB bonds with Pb in perovskite, and the H and O in the hydroxyl group bond with the I and organic cations in perovskite,respectively, it will contribute to superior stability under heat, high humidity, and light soaking conditions. After aging under 35% humidity(relative humidity, RH) for 3300 h, the optimized device can still maintain more than 90% of the initial efficiency;it can also retain more than 90% of the initial efficiency after aging at 65 ℃, 65% RH, or light(AM 1.5G) for 500 h. This simple optimization strategy for perovskite stability could facilitate the commercial application of perovskite solar cells.展开更多
To provide a scientific basis for sustainable land management, a 20-year fertility experiment was conducted in Changwu County, Shaanxi Province, China to investigate the effects of long-term application of chemical fe...To provide a scientific basis for sustainable land management, a 20-year fertility experiment was conducted in Changwu County, Shaanxi Province, China to investigate the effects of long-term application of chemical fertilizers on wheat grain yield and yield stability on the Loess Plateau using regression and stability analysis. The experiment consisted of 17 fertilizer treatments, containing the combinations of different N and P levels, with three replications arranged in a randomized complete block design. Nitrogen fertilizer was applied as urea, and P was applied as calcium superphosphate. Fertilizer rates had a large effect on the response of wheat yield to fertilization. Phosphorus, combined with N, increased yield significantly （P 〈 0.01）. In the unfertilized control and the N or P sole application treatments, wheat yield had a declining trend although it was not statistically significant. Stability analysis combined with the trend analysis indicated that integrated use of fertilizer N and P was better than their sole application in increasing and sustaining the productivity of rainfed winter wheat.展开更多
An understanding of wheat yield and yield stability response to fertilization is important for sustainable wheat production. A 36-year long-term fertilization experiment was employed to evaluate the yield and yield st...An understanding of wheat yield and yield stability response to fertilization is important for sustainable wheat production. A 36-year long-term fertilization experiment was employed to evaluate the yield and yield stability of winter wheat. Five fertilization regimes were compared,including(1) CK, no fertilizer;(2) NPK, inorganic fertilizer only;(3) O, organic fertilizer only;(4)NPKO, 50% of NPK plus 50% of O, and(5) HNPKO, 80% of NPK plus 80% of O. The greatest yield increase was recorded in HNPKO, followed by NPKO, with O producing the lowest mean yield increase. Over the 36 years, the rate of wheat yield increase in fertilized plots ranged from95.31 kg ha-1 year-1 in the HNPKO to 138.65 kg ha-1 year-1 in the O. Yield stability analysis using the additive main effects and multiplicative interactions(AMMI) method assigned 62.3%, 26.3%,and 11.4% of sums of squares to fertilization effect, environmental effect, and fertilization ×environment interaction effect, respectively. The combination of inorganic and organic fertilization(NPKO and HNPKO) appeared to produce more stable yields than O or NPK, with lower coefficients of variation and AMMI stability value. However, wheat grown with O seemed to be the most susceptible to climate change and the least productive among the fertilized plots.Significant correlations of grain yield with soil properties and with mean air temperature were observed. These findings suggest that inorganic + organic fertilizer can increase wheat yield and its stability by improvement in soil fertility and reduction in variability to climate change.展开更多
Straw incorporation is a global common practice to improve soil fertility and rice yield.However,the effect of straw incorporation on rice yield stability is still unknown,especially under high fertilization level con...Straw incorporation is a global common practice to improve soil fertility and rice yield.However,the effect of straw incorporation on rice yield stability is still unknown,especially under high fertilization level conditions.Here,we reported the effect of straw returning on rice yield and yield stability under high fertilization levels in the rice–wheat system over nine years.The results showed that straw incorporation did not significantly affect the average rice yield of nine years.Straw incorporation reduced the coefficient of variation of rice yield by 25.8%and increased the sustainable yield index by 8.2%.The rice yield positively correlated with mean photosynthetically active radiation (PAR) of rice growth season and the effects of straw incorporation on rice yield depended on the PAR.Straw incorporation increased the rice yield by 5.4%in the low PAR years,whereas it did not affect the rice yield in the high PAR years.Long-term straw incorporation lowered soil bulk density but improved the soil organic matter,total N,available N,available P,and available K more strongly than straw removal.Our findings suggest that straw incorporation can increase rice yield stability through improving the resistance of rice plant growth to low PAR.展开更多
Tin halide perovskites(THPs)have received extensive attention due to their low toxicity and excellent optoelectronic properties,and are considered to be the most promising alternatives to develop efficient lead-free p...Tin halide perovskites(THPs)have received extensive attention due to their low toxicity and excellent optoelectronic properties,and are considered to be the most promising alternatives to develop efficient lead-free perovskite solar cells.However,due to the unique and inherent characteristics of Sn^(2+)being easily oxidized to Sn^(4+)and fast crystallization,tin perovskite solar cells(TPSCs)show relatively poor performance and stability,compared to the lead counterparts.Recently,the introduction of bulky organic spacers into three-dimensional(3D)THPs for dimensional regulation can not only prevent the intrusion of water and oxygen,but also inhibit the self-doping effect and ion migration.In this review,we will detail how dimensional regulation enables TPSCs with high performance and superior stability.First,we summarize the intrinsic properties of THPs and analyze the root causes of their poor performance and instability.Next,we discuss the specific structure and types of the dimensional regulation strategy.Then,the mechanism of dimensional regulation is discussed in detail,mainly from inhibiting the Sn^(2+)oxidation,optimizing crystallization,passivating defects,and improving energy level alignment.Finally,future challenges and prospects for dimensional regulation are elaborated to help researchers develop more efficient and stable TPSCs.展开更多
To investigate the dynamic characteristics and long-term dynamic stability of the new subgrade structure of medium-low-speed(MLS)maglevs,cyclic vibration tests were performed under natural and rainfall conditions,and ...To investigate the dynamic characteristics and long-term dynamic stability of the new subgrade structure of medium-low-speed(MLS)maglevs,cyclic vibration tests were performed under natural and rainfall conditions,and the dynamic response of the subgrade structure was monitored.The dynamic response attenuation characteristics along the depth direction of the subgrade were compared,and the distribution characteristics of the dynamic stress on the surface of the subgrade along the longitudinal direction of the line were analyzed.The critical dynamic stress and cumulative deformation were used as indicators to evaluate the long-term dynamic stability of the subgrade.Results show that water has a certain effect on the dynamic characteristics of the subgrade,and the dynamic stress and acceleration increase with the water content.With the dowel steel structure set between the rail-bearing beams,stress concentration at the end of the loaded beam can be prevented,and the diffusion distance of the dynamic stress along the longitudinal direction increases.The dynamic stress measured in the subgrade bed range is less than 1/5 of the critical dynamic stress.The postconstruction settlement of the subgrade after similarity ratio conversion is 3.94 mm and 7.72 mm under natural and rainfall conditions,respectively,and both values are less than the 30 mm limit,indicating that the MLS maglev subgrade structure has good long-term dynamic stability.展开更多
Callovo-Oxfordian(COx)claystone has been considered as a potential host rock for geological radioactive waste disposal in France(Cigéo project).During the exploitation phase(100 years),the stability of drifts(e.g...Callovo-Oxfordian(COx)claystone has been considered as a potential host rock for geological radioactive waste disposal in France(Cigéo project).During the exploitation phase(100 years),the stability of drifts(e.g.galleries/alveoli)within the disposal is assured by the liner,which includes two layers:concrete arch segment and compressible material.The latter exhibits a significant deformation capacity(about 50%)under low stress(<3 MPa).Although the response of these underground structures can be governed by complex thermo-hydro-mechanical coupling,the creep behavior of COx claystone has been considered as the main factor controlling the increase of stress state in the concrete liner and hence the long-term stability of drifts.Therefore,by focusing only on the purely mechanical behavior,this study aims at investigating the uncertainty effect of the COx claystone time-dependent properties on the stability of an alveolus of Cigéo during the exploitation period.To describe the creep behavior of COx claystone,we use Lemaitre’s viscoplastic model with three parameters whose uncertainties are identified from laboratory creep tests.For the reliability analysis,an extension of a well-known Kriging metamodeling technique is proposed to assess the exceedance probability of acceptable stress in the concrete liner of the alveolus.The open-source code Code_Aster is chosen for the direct numerical evaluations of the performance function.The Kriging-based reliability analysis elucidates the effect of the uncertainty of COx claystone on the long-term stability of the concrete liner.Moreover,the role of the compressible material layer between the concrete liner and the host rock is also highlighted.展开更多
All-inorganic CsPbI_(2)Br perovskite solar cells(PSCs)have received extensive research interests recently.Nevertheless,their low efficiency and poor long-term stability are still obstacles for further commercial appli...All-inorganic CsPbI_(2)Br perovskite solar cells(PSCs)have received extensive research interests recently.Nevertheless,their low efficiency and poor long-term stability are still obstacles for further commercial application.Herein,we demonstrate that high efficiency and exceptional long-term stability are realized by incorporating gadolinium(III)chloride(GdCl_(3))into the CsPbI_(2)Br perovskite film.The incorporation of GdCl_(3) enhances the Goldschmidt tolerance factor of CsPbI_(2)Br perovskite,yielding a dense perovskite film with small grains,thus the a-phase CsPbI_(2)Br is remarkably stabilized.Additionally,it is found that the GdCl_(3)-incorporated perovskite film achieves suppressed charge recombination and appropriate energy level alignment compared with the pristine CsPbI_(2)Br film.The noticeable increment in efficiency from14.01%(control PSC)to 16.24%is achieved for GdCl_(3)-incorporated PSC.Moreover,the nonencapsulated GdCl_(3)-incorporated PSC exhibits excellent environmental and thermal stability,remaining over 91%or90%of the original efficiency after 1200 h aging at 40%relative humidity or 480 h heating at 85℃ in nitrogen glove box respectively.The encapsulated GdCl_(3)-incorporated PSC presents an improved operational stability with over 88%of initial efficiency under maximum power point(MPP)tracking at 45℃ for1000 h.This work presents an effective ion-incorporation approach for boosting efficiency and long-term stability of all-inorganic PSCs.展开更多
Nonlinear stability of the motionless double-diffusive solution of the problem of an infinite horizontal fluid layer saturated porous medium is studied. The layer is heated and salted from below. By introducing two ba...Nonlinear stability of the motionless double-diffusive solution of the problem of an infinite horizontal fluid layer saturated porous medium is studied. The layer is heated and salted from below. By introducing two balance fields and through defining new energy functionals it is proved that for CLe ≥ R, Le ≤ 1 the motionless double-diffusive solution is always stable and for CLe < R, Le < 1 the solution is globally exponentially and nonlinearly stable whenever R < 4π~2+ Le C, where Le, C and R are the Lewis number, Rayleigh number for solute and heat, respectively. Moreover, the nonlinear stability proved here is global and exponential, and the stabilizing effect of the concentration is also proved.展开更多
Long-term stability of large-span caverns is a challenging issue for design and construction of underground rock engineering.The Heidong cavern group consisting of 21 caverns was constructed about 1400 years ago for q...Long-term stability of large-span caverns is a challenging issue for design and construction of underground rock engineering.The Heidong cavern group consisting of 21 caverns was constructed about 1400 years ago for quarrying in massive Cretaceous tuff.The cavern No.5 of the Heidong cavern group is characterized by an unsupported span up to 92 m,with the overburden thickness of only 3-25 m.To analyze its long-term stability,a detailed investigation was conducted to obtain its geometry and rock mass characteristics,and to monitor surrounding rock displacements.Based on field survey and laboratory tests,numerical simulations were performed using the finite difference code FLAC;.The analysis results revealed that for the long-term stability of the cavern No.5,some major factors should be carefully considered,such as cavern excavation method in hard massive rocks,site investigation using trial pits,tools like short iron chisel and hammer for manual excavation,geometric dome roof,and waste rocks within abutment or on the floor.The highlights of the technologies obtained from this large-scale ancient underground project can provide reference for other similar project excavations in practice.展开更多
Based on the analysis of the basic characteristics for the gob site in Northern Shaanxi Province and the room and pillar mining way about coal mine, the variety rule of the coal beds below the site was studied by the ...Based on the analysis of the basic characteristics for the gob site in Northern Shaanxi Province and the room and pillar mining way about coal mine, the variety rule of the coal beds below the site was studied by the using of FEM during the process of coal mining. The statuses of the stresses and strains and the varieties of the plastic area were simulated in the whole rock and coal pillars. The characters of stresses and deformation of the gob area of the coalmine were analyzed and evaluated after the site built in weathering. Moreover, the long-term stability of the gob area was predicted. As a result, the deformation of the gob area under the site is not been finished, and there is the danger that the gob site will collapsing as a whole; therefore, relative measures must be taken.展开更多
Gas–solid separation fluidized bed is a typical method for coal separation without water utilization.Geldart A particles is also considered as the ideal dense medium to strengthen separation efficiency.Fluidization s...Gas–solid separation fluidized bed is a typical method for coal separation without water utilization.Geldart A particles is also considered as the ideal dense medium to strengthen separation efficiency.Fluidization stability reflects the bed pressure fluctuations and the distribution of bubble and emulsion phases,affecting the separation performance.And the main frequency of pressure fluctuations can directly reflect the degree of pressure fluctuations.Therefore,the detailed fluidization stability is analyzed combined the method of standard deviation of pressure fluctuations,power spectral density,etc.,for Geldart A particles.The results showed that maintaining an appropriate gas velocity resulted in an average bed pressure of around 2000 Pa.The main frequency is mainly concentrated around 1–1.5 Hz.Finally,a prediction model of the main frequency of pressure fluctuations is established,and the error can be controlled within±0.15.The investigation further proved the stable fluidization of Geldart A particles and provides a method for predicting the main frequency of pressure fluctuations in the gas–solid separation fluidized bed.展开更多
文摘The influence of variable viscosity and double diffusion on the convective stability of a nanofluid flow in an inclined porous channel is investigated.The DarcyBrinkman model is used to characterize the fluid flow dynamics in porous materials.The analytical solutions are obtained for the unidirectional and completely developed flow.Based on a normal mode analysis,the generalized eigenvalue problem under a perturbed state is solved.The eigenvalue problem is then solved by the spectral method.Finally,the critical Rayleigh number with the corresponding wavenumber is evaluated at the assigned values of the other flow-governing parameters.The results show that increasing the Darcy number,the Lewis number,the Dufour parameter,or the Soret parameter increases the stability of the system,whereas increasing the inclination angle of the channel destabilizes the flow.Besides,the flow is the most unstable when the channel is vertically oriented.
基金King Abdulaziz City for Science and Technology (KACST) for the fellowshipfunding from the European Union’s Horizon 2020 research and innovation program GRAPHENE Flagship Core 3 under agreement No.: 881603+2 种基金funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sk?odowska-Curie grant agreement No. 945363funding from the Shanghai Pujiang Program (22PJ1401200)the National Natural Science Foundation of China (No. 52302229)
文摘Perovskite solar cells(PSCs)have made great advances in terms of power conversion efficiency(PCE),yet their subpar stability continues to hinder their commercialization.The interface between the perovskite layer and the charge-carrier transporting layers plays a crucial role in undermining the stability of PSCs.In this work,we propose a strategy to stabilize high-performance PSCs with PCE over 23%by introducing a cesium-doped graphene oxide(GO-Cs)as an interlayer between the perovskite and hole-transporting material.The GO-Cs treated PSCs exhibit excellent operational stability with a projected T80(the time where the device PCE reduces to 80%of its initial value)of 2143 h of operation at the maximum powering point under one sun illumination.
基金The National Natural Science Foundation of China under contract Nos 42201104 and 42071123the China Postdoctoral Research Foundation under contract No.2023M730758.
文摘The long-term dynamic evolution and underlying mechanisms of coastal landscape pattern stability,driven by strong anthropogenic interference and consequently climate change,are topics of major interest in national and international scientific research.Guangdong Province,located in southeastern China,has been undergoing rapid urbanization over several decades.In this study,we quantitatively determined the scale threshold characteristics of coastal landscape pattern stability in Guangdong Province,from the dual perspective of spatial heterogeneity and spatial autocorrelation.An analysis of the spatiotemporal evolution of the coastal landscape was conducted after the optical scale was determined.Then,we applied the geodetector statistical method to quantitatively explore the mechanisms underlying coastal landscape pattern stability.Based on the inflection point of landscape metrics and the maximum value of the MoranⅠindex,the optimal scale for analyzing coastal landscape pattern stability in Guangdong Province was 240 m×240 m.Within the past several decades,coastal landscape pattern stability increased slightly and then decreased,with a turning point around 2005.The most significant variations in coastal landscape pattern stability were observed in the transition zone of rural-urban expansion.A q-statistics analysis showed that the explanatory power of paired factors was greater than that of a single driving factor;the paired factors with the greatest impact on coastal landscape pattern stability in Guangdong Province were the change in gross industrial output and change in average annual precipitation from 2010 to 2015,based on a q value of 0.604.These results will contribute to future efforts to achieve sustainable coastal development and provide a scientific basis and technical support for the rational planning and utilization of resources in large estuarine areas,including marine disaster prevention and seawall ecological restoration.
基金This study was funded by a research grant from Alcon(IIT#68022037)Subject of Medical and Health Research in Heilongjiang Province(20230707020332).
文摘Objective:To analyze the enduring rotational steadiness of AcrySof IQ Toric intraocular lens(IOL)in cataract patients suffering from myopia in a long-term study.Methods:A retrospective study was conducted on a case series involving 78 patients.A total of 120 eyes with an axial length(AL)ranging from 24-30 mm and corneal astigmatism≥1.50 D underwent implantation of AcrySof IQ Toric IOL guided by the version navigation system.The eyes were divided into two groups based on AL.Group A included 60 eyes with high myopia(AL≥26 mm),while Group B consisted of eyes with low to moderate myopia(24 mm≤AL<26 mm).Data on the preoperative AL were collected.Measurements were taken for residual astigmatism,the best corrected visual acuity(BCDVA),corneal astigmatism,and IOL rotation occurring between 24-and 48-months post-surgery.The percentage of eyes with an IOL rotation of under 5°and 10°was analyzed.Results:The mean length of follow-up times was recorded as 34.27±4.98,and the average rotation was 2.73±1.29°.Group A exhibited a slightly higher average rotation of 2.87±1.31°,compared to the rotation of 2.59±1.27°observed in Group B.At both the 24-36 month and 26-48 month post-operation marks,the degree of IOL rotation did not show a statistically significant difference between the two groups,with none of the patients experiencing a rotation exceeding 10°(P>0.05).The percentage of rotation degrees under 5°was recorded as 98.22%.After the procedure,the BCDVA was 0.1322±0.03 LogMAR.There was a substantial increase in theχvalue after the operation as compared to the pre-operativeχ^(2) value(χ^(2)=76.79).The standard deviation of preoperative corneal astigmatism was statistically significant(P<0.05)at 2.17±1.08 D.Following the surgical procedure,the remaining astigmatism was measured at 0.41±0.26 D.The data showed a notable gap in statistical significance(t=4.281,P<0.05).Conclusion:The AcrySof Toric IOL was a reliable solution for managing corneal astigmatism in cataract patients with myopia,demonstrating excellent long-term rotational stability.
基金supported by the National Key Research and Development Program of China(2018YFA0208701)the National Natural Science Foundation of China(21773308)+7 种基金the Research Funds of Renmin University of China(2017030013,201903020 and 20XNH059)the Fundamental Research Funds for Central Universities(China)supported by the Solar Energy Research Institute of Singapore(SERIS) at the National University of Singapore(NUS)supported by NUSthe National Research Foundation Singapore(NRF)the Energy Market Authority of Singapore(EMA)the Singapore Economic Development Board(EDB)the financial support from the China Scholarship Council(CSC) funding。
文摘The presence of defects and detrimental reactions at NiO_(x)/perovskite interface extremely limit the efficiency performance and long-term stability of the perovskite solar cells(PSCs) based on NiO_(x).Herein,an amphipathic molecule Triton X100(Triton) is modified on the NiO_(x)surface.The hydrophilic chain of Triton as a Lewis base additive can coordinate with the Ni3+on the NiO_(x)surface which can passivate the interfacial defects and hinder the detrimental reactions at the NiO_(x)/perovskite interface.Additionally,the hydrophobic chain of Triton protrudes from the NiO_(x)surface to prevent moisture from penetrating into the NiO_(x)/perovskite interface.Consequently,the NiO_(x)/Triton-based devices(MAPbI3as absorbing layer) show superior moisture and thermal stability,retaining 88.4% and 64.3% of the initial power conversion efficiency after storage in air(40%-50% relative humidity(RH)) at 25 ℃ for 1070 h and in N2at 85℃ for 800 h,respectively.Moreover,the efficiency increases from 17.59% to 19.89% because of the passivation defect and enhanced hole-extraction capability.Besides,the NiO_(x)/Triton-based PSCs with Cs_(0.05)(MA_(0.15)FA_(0.85))_(0.95)Pb(I_(0.85)Br_(0.15))3perovskite as the light-absorbing layer also exhibits better moisture and thermal stability compared to the control devices,indicating the viability of our strategies.Of particular note,a champion PCE of 22.35% and 20.46% was achieved for small-area(0.1 cm^(2)) and large-area(1.2 cm^(2)) NiO_(x)/Triton-based devices,respectively.
基金supported by a National Research Foundation of Korea(grant#:2020R1A2C1003929,2019R1A6A1A11053838,2020M1A2A2080746,2021M2E8A1044198,2016R1A5A1012966,2021M3H4A1A03051379).
文摘In this work,we developed the PM6:Y6-based inverted structure organic photovoltaic(i-OPV)with improved power conversion efficiency(PCE)and long-term stability by resolving the origins of the performance deterioration.The deep defects between the metal oxide-based electron transport layer and bulk-heterojunction photoactive layer interface were responsible for suboptimal PCE and facilitated degradation of devices.While the density of deep traps is increased during the storage of i-OPV,the penetrative oxygen-containing defects additionally generated shallow traps below the band-edge of Y6,causing an additional loss in the open-circuit voltage.The suppression of interfacial defects by chemical modification effectively improved the PCE and long-term stability of i-OPV.The modified i-OPV(mi-OPV)achieved a PCE of 17.42%,which is the highest value among the reported PM6:Y6-based i-OPV devices.Moreover,long-term stability was significantly improved:~90%and~80%retention of its initial PCE after 1200 h of air storage and illumination,respectively.
文摘The subject of the present paper is to prove that the recently introduced conjecture of boundedness puts a ban over the view of stability as asymptotic property. This result comes in sharp contrast with the prescription of the traditional thermodynamics and statistical physics which consider the existence of equilibrium as asymptotic property of all systems. The difference commences from the use of infinitesimal calculus as the basic implement for modelling by the latter while the primary premise of the conjecture of boundedness is sustaining the energy/matter/information permanently bounded and finite. The latter property overrules the infinitesimal calculus as the major implement of modelling because, among all, it is proven that the traditional one suffers unsoluble difficulties.
基金supported by the National Key Research and Development Program of China (2020YFA07150002018YFB1503100)the Suzhou Fangsheng FS-300 for research support。
文摘Although the efficiency of organic–inorganic hybrid halide perovskite solar cells has been improved rapidly, the intrinsic instability of perovskite materials restricts their commercial application. Here, an eco-friendly and low-cost organic polymer, cellulose acetate butyrate(CAB), was introduced to the grain boundaries and surfaces of perovskite, resulting in a high-quality and low-defect perovskite film with a nearly tenfold improvement in carrier lifetime. More importantly, the CAB-treated perovskite films have a well-matched energy level with the charge transport layers, thus suppressing carrier nonradiative recombination and carrier accumulation. As a result, the optimized CAB-based device achieved a champion efficiency of 21.5% compared to the control device(18.2%). Since the ester group in CAB bonds with Pb in perovskite, and the H and O in the hydroxyl group bond with the I and organic cations in perovskite,respectively, it will contribute to superior stability under heat, high humidity, and light soaking conditions. After aging under 35% humidity(relative humidity, RH) for 3300 h, the optimized device can still maintain more than 90% of the initial efficiency;it can also retain more than 90% of the initial efficiency after aging at 65 ℃, 65% RH, or light(AM 1.5G) for 500 h. This simple optimization strategy for perovskite stability could facilitate the commercial application of perovskite solar cells.
基金Project supported by the Agricultural Development Program of the Chinese Academy of Sciences (No. KSCX1-YWN1504)the West Light Foundation of the Chinese Academy of Sciences (No. 2005404)the National Natural Science Foundation of China (Nos. 50479065 and 40601041).
文摘To provide a scientific basis for sustainable land management, a 20-year fertility experiment was conducted in Changwu County, Shaanxi Province, China to investigate the effects of long-term application of chemical fertilizers on wheat grain yield and yield stability on the Loess Plateau using regression and stability analysis. The experiment consisted of 17 fertilizer treatments, containing the combinations of different N and P levels, with three replications arranged in a randomized complete block design. Nitrogen fertilizer was applied as urea, and P was applied as calcium superphosphate. Fertilizer rates had a large effect on the response of wheat yield to fertilization. Phosphorus, combined with N, increased yield significantly （P 〈 0.01）. In the unfertilized control and the N or P sole application treatments, wheat yield had a declining trend although it was not statistically significant. Stability analysis combined with the trend analysis indicated that integrated use of fertilizer N and P was better than their sole application in increasing and sustaining the productivity of rainfed winter wheat.
基金supported by the National Key Research and Development Program of China(2016YFD0300803)the Special Fund for Agro-scientific Research in the Public Interest(201503116-10)+1 种基金the Agricultural Science and Technology Innovation Program(CAAS-XTCX2016019-03 and Y2016XT01-03)the Science and Technology Major Project of Anhui Province(16030701099)
文摘An understanding of wheat yield and yield stability response to fertilization is important for sustainable wheat production. A 36-year long-term fertilization experiment was employed to evaluate the yield and yield stability of winter wheat. Five fertilization regimes were compared,including(1) CK, no fertilizer;(2) NPK, inorganic fertilizer only;(3) O, organic fertilizer only;(4)NPKO, 50% of NPK plus 50% of O, and(5) HNPKO, 80% of NPK plus 80% of O. The greatest yield increase was recorded in HNPKO, followed by NPKO, with O producing the lowest mean yield increase. Over the 36 years, the rate of wheat yield increase in fertilized plots ranged from95.31 kg ha-1 year-1 in the HNPKO to 138.65 kg ha-1 year-1 in the O. Yield stability analysis using the additive main effects and multiplicative interactions(AMMI) method assigned 62.3%, 26.3%,and 11.4% of sums of squares to fertilization effect, environmental effect, and fertilization ×environment interaction effect, respectively. The combination of inorganic and organic fertilization(NPKO and HNPKO) appeared to produce more stable yields than O or NPK, with lower coefficients of variation and AMMI stability value. However, wheat grown with O seemed to be the most susceptible to climate change and the least productive among the fertilized plots.Significant correlations of grain yield with soil properties and with mean air temperature were observed. These findings suggest that inorganic + organic fertilizer can increase wheat yield and its stability by improvement in soil fertility and reduction in variability to climate change.
基金the National Key Research and Development Program of China (2017YFD0301203, 2017YFD0300100, and 2018YFD0300803)Jiangsu Agriculture Science and Technology Innovation Fund (CX(18)1002)。
文摘Straw incorporation is a global common practice to improve soil fertility and rice yield.However,the effect of straw incorporation on rice yield stability is still unknown,especially under high fertilization level conditions.Here,we reported the effect of straw returning on rice yield and yield stability under high fertilization levels in the rice–wheat system over nine years.The results showed that straw incorporation did not significantly affect the average rice yield of nine years.Straw incorporation reduced the coefficient of variation of rice yield by 25.8%and increased the sustainable yield index by 8.2%.The rice yield positively correlated with mean photosynthetically active radiation (PAR) of rice growth season and the effects of straw incorporation on rice yield depended on the PAR.Straw incorporation increased the rice yield by 5.4%in the low PAR years,whereas it did not affect the rice yield in the high PAR years.Long-term straw incorporation lowered soil bulk density but improved the soil organic matter,total N,available N,available P,and available K more strongly than straw removal.Our findings suggest that straw incorporation can increase rice yield stability through improving the resistance of rice plant growth to low PAR.
基金financially supported by the National Natural Science Foundation of China(51702038)the Science&Technology Department of Sichuan Province(2020YFG0061)+2 种基金the Recruitment Program for Young Professionalsthe National Key Research and Development Program of China(2017YFA0206600)the National Natural Science Foundation of China(51773045,21772030,51922032,21961160720)for financial support。
文摘Tin halide perovskites(THPs)have received extensive attention due to their low toxicity and excellent optoelectronic properties,and are considered to be the most promising alternatives to develop efficient lead-free perovskite solar cells.However,due to the unique and inherent characteristics of Sn^(2+)being easily oxidized to Sn^(4+)and fast crystallization,tin perovskite solar cells(TPSCs)show relatively poor performance and stability,compared to the lead counterparts.Recently,the introduction of bulky organic spacers into three-dimensional(3D)THPs for dimensional regulation can not only prevent the intrusion of water and oxygen,but also inhibit the self-doping effect and ion migration.In this review,we will detail how dimensional regulation enables TPSCs with high performance and superior stability.First,we summarize the intrinsic properties of THPs and analyze the root causes of their poor performance and instability.Next,we discuss the specific structure and types of the dimensional regulation strategy.Then,the mechanism of dimensional regulation is discussed in detail,mainly from inhibiting the Sn^(2+)oxidation,optimizing crystallization,passivating defects,and improving energy level alignment.Finally,future challenges and prospects for dimensional regulation are elaborated to help researchers develop more efficient and stable TPSCs.
基金supported by the 2018 Major Science and Technology Project of China Railway Construction Corporation Limited(No.2018-A01)the National Natural Science Foundation of China(No.51978588).
文摘To investigate the dynamic characteristics and long-term dynamic stability of the new subgrade structure of medium-low-speed(MLS)maglevs,cyclic vibration tests were performed under natural and rainfall conditions,and the dynamic response of the subgrade structure was monitored.The dynamic response attenuation characteristics along the depth direction of the subgrade were compared,and the distribution characteristics of the dynamic stress on the surface of the subgrade along the longitudinal direction of the line were analyzed.The critical dynamic stress and cumulative deformation were used as indicators to evaluate the long-term dynamic stability of the subgrade.Results show that water has a certain effect on the dynamic characteristics of the subgrade,and the dynamic stress and acceleration increase with the water content.With the dowel steel structure set between the rail-bearing beams,stress concentration at the end of the loaded beam can be prevented,and the diffusion distance of the dynamic stress along the longitudinal direction increases.The dynamic stress measured in the subgrade bed range is less than 1/5 of the critical dynamic stress.The postconstruction settlement of the subgrade after similarity ratio conversion is 3.94 mm and 7.72 mm under natural and rainfall conditions,respectively,and both values are less than the 30 mm limit,indicating that the MLS maglev subgrade structure has good long-term dynamic stability.
文摘Callovo-Oxfordian(COx)claystone has been considered as a potential host rock for geological radioactive waste disposal in France(Cigéo project).During the exploitation phase(100 years),the stability of drifts(e.g.galleries/alveoli)within the disposal is assured by the liner,which includes two layers:concrete arch segment and compressible material.The latter exhibits a significant deformation capacity(about 50%)under low stress(<3 MPa).Although the response of these underground structures can be governed by complex thermo-hydro-mechanical coupling,the creep behavior of COx claystone has been considered as the main factor controlling the increase of stress state in the concrete liner and hence the long-term stability of drifts.Therefore,by focusing only on the purely mechanical behavior,this study aims at investigating the uncertainty effect of the COx claystone time-dependent properties on the stability of an alveolus of Cigéo during the exploitation period.To describe the creep behavior of COx claystone,we use Lemaitre’s viscoplastic model with three parameters whose uncertainties are identified from laboratory creep tests.For the reliability analysis,an extension of a well-known Kriging metamodeling technique is proposed to assess the exceedance probability of acceptable stress in the concrete liner of the alveolus.The open-source code Code_Aster is chosen for the direct numerical evaluations of the performance function.The Kriging-based reliability analysis elucidates the effect of the uncertainty of COx claystone on the long-term stability of the concrete liner.Moreover,the role of the compressible material layer between the concrete liner and the host rock is also highlighted.
基金supported by the National Natural Science Foundation of China(52172237,52072228)the Shaanxi International Cooperational Project(2020KWZ-018)+1 种基金the Research Fund of the State Key Laboratory of Solidification Processing(NPU),China(Grant No.2021-QZ-02)the Fundamental Research Funds for the Central Universities(3102019JC005)。
文摘All-inorganic CsPbI_(2)Br perovskite solar cells(PSCs)have received extensive research interests recently.Nevertheless,their low efficiency and poor long-term stability are still obstacles for further commercial application.Herein,we demonstrate that high efficiency and exceptional long-term stability are realized by incorporating gadolinium(III)chloride(GdCl_(3))into the CsPbI_(2)Br perovskite film.The incorporation of GdCl_(3) enhances the Goldschmidt tolerance factor of CsPbI_(2)Br perovskite,yielding a dense perovskite film with small grains,thus the a-phase CsPbI_(2)Br is remarkably stabilized.Additionally,it is found that the GdCl_(3)-incorporated perovskite film achieves suppressed charge recombination and appropriate energy level alignment compared with the pristine CsPbI_(2)Br film.The noticeable increment in efficiency from14.01%(control PSC)to 16.24%is achieved for GdCl_(3)-incorporated PSC.Moreover,the nonencapsulated GdCl_(3)-incorporated PSC exhibits excellent environmental and thermal stability,remaining over 91%or90%of the original efficiency after 1200 h aging at 40%relative humidity or 480 h heating at 85℃ in nitrogen glove box respectively.The encapsulated GdCl_(3)-incorporated PSC presents an improved operational stability with over 88%of initial efficiency under maximum power point(MPP)tracking at 45℃ for1000 h.This work presents an effective ion-incorporation approach for boosting efficiency and long-term stability of all-inorganic PSCs.
基金supported by National Natural Science Foundation Project(41671229)
文摘Nonlinear stability of the motionless double-diffusive solution of the problem of an infinite horizontal fluid layer saturated porous medium is studied. The layer is heated and salted from below. By introducing two balance fields and through defining new energy functionals it is proved that for CLe ≥ R, Le ≤ 1 the motionless double-diffusive solution is always stable and for CLe < R, Le < 1 the solution is globally exponentially and nonlinearly stable whenever R < 4π~2+ Le C, where Le, C and R are the Lewis number, Rayleigh number for solute and heat, respectively. Moreover, the nonlinear stability proved here is global and exponential, and the stabilizing effect of the concentration is also proved.
基金financial support by the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology(Grant No.SKLGP2011K007)the Key Research Program of the Chinese Academy of Sciences(KZZD-EW05-02)the National Natural Science Foundation of China (Nos.41372324,40972198 and 41172269)
文摘Long-term stability of large-span caverns is a challenging issue for design and construction of underground rock engineering.The Heidong cavern group consisting of 21 caverns was constructed about 1400 years ago for quarrying in massive Cretaceous tuff.The cavern No.5 of the Heidong cavern group is characterized by an unsupported span up to 92 m,with the overburden thickness of only 3-25 m.To analyze its long-term stability,a detailed investigation was conducted to obtain its geometry and rock mass characteristics,and to monitor surrounding rock displacements.Based on field survey and laboratory tests,numerical simulations were performed using the finite difference code FLAC;.The analysis results revealed that for the long-term stability of the cavern No.5,some major factors should be carefully considered,such as cavern excavation method in hard massive rocks,site investigation using trial pits,tools like short iron chisel and hammer for manual excavation,geometric dome roof,and waste rocks within abutment or on the floor.The highlights of the technologies obtained from this large-scale ancient underground project can provide reference for other similar project excavations in practice.
文摘Based on the analysis of the basic characteristics for the gob site in Northern Shaanxi Province and the room and pillar mining way about coal mine, the variety rule of the coal beds below the site was studied by the using of FEM during the process of coal mining. The statuses of the stresses and strains and the varieties of the plastic area were simulated in the whole rock and coal pillars. The characters of stresses and deformation of the gob area of the coalmine were analyzed and evaluated after the site built in weathering. Moreover, the long-term stability of the gob area was predicted. As a result, the deformation of the gob area under the site is not been finished, and there is the danger that the gob site will collapsing as a whole; therefore, relative measures must be taken.
基金National Natural Science Foundation of China(grant Nos.52220105008,52261135540)China National Funds for Distinguished Young Scientists(grant No.52125403)+1 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province(grant No.SJCX23_1302)the Graduate Innovation Program of China University of Mining and Technology(grant No.2023WLJCRCZL081).
文摘Gas–solid separation fluidized bed is a typical method for coal separation without water utilization.Geldart A particles is also considered as the ideal dense medium to strengthen separation efficiency.Fluidization stability reflects the bed pressure fluctuations and the distribution of bubble and emulsion phases,affecting the separation performance.And the main frequency of pressure fluctuations can directly reflect the degree of pressure fluctuations.Therefore,the detailed fluidization stability is analyzed combined the method of standard deviation of pressure fluctuations,power spectral density,etc.,for Geldart A particles.The results showed that maintaining an appropriate gas velocity resulted in an average bed pressure of around 2000 Pa.The main frequency is mainly concentrated around 1–1.5 Hz.Finally,a prediction model of the main frequency of pressure fluctuations is established,and the error can be controlled within±0.15.The investigation further proved the stable fluidization of Geldart A particles and provides a method for predicting the main frequency of pressure fluctuations in the gas–solid separation fluidized bed.
