The present study focuses on the flow of a yield-stress(Bingham)nanofluid,consisting of suspended Fe3O4 nanoparticles,subjected to a magnetic field in a backward-facing step duct(BFS)configuration.The duct is equipped...The present study focuses on the flow of a yield-stress(Bingham)nanofluid,consisting of suspended Fe3O4 nanoparticles,subjected to a magnetic field in a backward-facing step duct(BFS)configuration.The duct is equipped with a cylindrical obstacle,where the lower wall is kept at a constant temperature.The yield-stress nanofluid enters this duct at a cold temperature with fully developed velocity.The aim of the present investigation is to explore the influence of flow velocity(Re=10 to 200),nanoparticle concentration(ϕ=0 to 0.1),magnetic field intensity(Ha=0 to 100),and its inclination angle(γ=0 to 90)and nanofluid yield stress(Bn=0 to 20)on the thermal and hydrodynamic efficiency inside the backward-facing step.The numerical results have been obtained by resolving the momentum and energy balance equations using the Galerkin finite element method.The obtained results have indicated that an increase in Reynolds number and nanoparticle volume fraction enhances heat transfer.In contrast,a significant reduction is observed with an increase in Hartmann and Bingham numbers,resulting in quasi-immobilization of the fluid under the magnetic influence and radical solidification of this type of fluid,accompanied by the suppression of the vortex zone downstream of the cylindrical obstacle.This study sheds light on the complexity of this magnetically influenced fluid,with potential implications in various engineering and materials science fields.展开更多
With the proliferation of online services and applications,adopting Single Sign-On(SSO)mechanisms has become increasingly prevalent.SSO enables users to authenticate once and gain access to multiple services,eliminati...With the proliferation of online services and applications,adopting Single Sign-On(SSO)mechanisms has become increasingly prevalent.SSO enables users to authenticate once and gain access to multiple services,eliminating the need to provide their credentials repeatedly.However,this convenience raises concerns about user security and privacy.The increasing reliance on SSO and its potential risks make it imperative to comprehensively review the various SSO security and privacy threats,identify gaps in existing systems,and explore effective mitigation solutions.This need motivated the first systematic literature review(SLR)of SSO security and privacy,conducted in this paper.The SLR is performed based on rigorous structured research methodology with specific inclusion/exclusion criteria and focuses specifically on the Web environment.Furthermore,it encompasses a meticulous examination and thematic synthesis of 88 relevant publications selected out of 2315 journal articles and conference/proceeding papers published between 2017 and 2024 from reputable academic databases.The SLR highlights critical security and privacy threats relating to SSO systems,reveals significant gaps in existing countermeasures,and emphasizes the need for more comprehensive protection mechanisms.The findings of this SLR will serve as an invaluable resource for scientists and developers interested in enhancing the security and privacy preservation of SSO and designing more efficient and robust SSO systems,thus contributing to the development of the authentication technologies field.展开更多
Road construction in Africa is faced with a shortage of quality materials, leading to delays and increased costs. Traditional materials, such as clay soils of the bar soil type, have inadequate properties for pavement...Road construction in Africa is faced with a shortage of quality materials, leading to delays and increased costs. Traditional materials, such as clay soils of the bar soil type, have inadequate properties for pavement sub-base layers, particularly in terms of bearing capacity. This study explores a composite material combining bar soil and bamboo fibers to improve the mechanical performance of bar soil, offering a sustainable and cost-effective solution. The Tori-Bossito bar soil was characterised by particle size analysis, Atterberg limits, Proctor compaction tests and the California Bearing Ratio (CBR). The results show that this material is a class A2 sandy-clay soil with a CBR of 18, which is insufficient for foundation layers requiring a CBR of over 30. To improve its performance, Sèmè-Kpodji bamboo fibers, 30 to 100 microns in diameter and 3 to 5 cm long, were incorporated at rates of 0.9% to 2.7%. The optimum mix, with 2.4% fiber, has a CBR of 35, a dry density of 1.92 t/m3 and a moisture content of 12.4%. This reinforced material is suitable as a base course for low-traffic roadways.展开更多
Over the last few years, many studies have been published using modern network analysis of the brain. Researchers and practical doctors alike should understand this method and its results on the brain evaluation at re...Over the last few years, many studies have been published using modern network analysis of the brain. Researchers and practical doctors alike should understand this method and its results on the brain evaluation at rest, during activation and in brain disease. The studies are noninvasive and usually performed with elecroencephalographic, magnetoencephalographic, magnetic resonance imaging and diffusion tensor imaging brain recordings. Different tools for analysis have been developed, although the methods are in their early stages. The results of these analyses are of special value. Studies of these tools in schizophrenia are important because widespread and local network disturbances can be evaluated by assessing integration, segregation and several structural and functional properties. With the help of network analyses, the main findings in schizophrenia are lower optimum network organization, less efficiently wired networks, less local clustering, less hierarchical organization and signs of disconnection. There are only about twenty five relevant papers on the subject today. Only a few years of study of these methods have produced interesting results and it appears promising that the development of these methods will present important knowledge for both the preclinical signs of schizophrenia and the methods' therapeutic effects.展开更多
In the solid state cathodoluminescence （SSCL）, organic materials were excited by hot electrons accelerated in silicon oxide （SiO2） layer under alternating current （AC）. In this paper exciton behaviours were anal...In the solid state cathodoluminescence （SSCL）, organic materials were excited by hot electrons accelerated in silicon oxide （SiO2） layer under alternating current （AC）. In this paper exciton behaviours were analysed by using transient spectra under different driving voltages. The threshold voltages of SSCL and exciton ionization were obtained from the transient spectra. The recombination radiation occurred when the driving voltage went beyond the threshold voltage of exciton ionization. From the transient spectrum of two kinds of luminescence （exciton emission and recombination radiation）, it was demonstrated that recombination radiation should benefit from the exciton ionization.展开更多
Objective: To assess knowledge and behaviour related to toxoplasmosis which remains a neglected disease in Morocco.Methods: Observational investigations were conducted among 600 pregnant women from Essaouira Province....Objective: To assess knowledge and behaviour related to toxoplasmosis which remains a neglected disease in Morocco.Methods: Observational investigations were conducted among 600 pregnant women from Essaouira Province.The interview items covered respondents' knowledge of the disease, its preventive practices and risk behaviours.Results: A total of 22/600 women had already carried out the anti-toxoplasmosis test, while, 96% have never done any screening of anti-Toxoplasma antibodies.Only 16/600 women have good information about the disease, its mode of transmission and its complications in both the fetus and his mother.Although most women adopt a healthy diet, the consumption of raw or undercooked meat is far to be considered as a risk factor, along with other potential factors that may foster the acquisition of the disease, such as possessing a domestic cat, educational status and knowledge of the disease.However, in this study, contact with soil was revealed the most important risk factor(P = 0.045), followed by the hygiene conditions after handling raw meat(P = 0.048).Conclusion: The underestimation of the Toxoplasma gondii sero-prevalence in Essaouira Province can be explained by the absence of toxoplasmosis serology in health institutions, as well as the gap of knowledge about the disease by local population.展开更多
This work focuses on the valorization of local materials.The rock that is granite,a material used in construction thanks to its mechanical resistance,is the subject of our study.The granite of the commune of Savè...This work focuses on the valorization of local materials.The rock that is granite,a material used in construction thanks to its mechanical resistance,is the subject of our study.The granite of the commune of Savè,made it possible to appreciate the thermal behavior of this rock studied with a view to its use as a building material.To this end,a thermal diffusivity measurement test was carried out on this material.Thus,we made samples which were then connected to a data acquisition box via thermocouples.A Python script is used to ensure the collection of temperature values over time.From this thermal diffusivity test carried out on the granite taken from the Savèbreasts,we obtained an average diffusivity a=5.84×10^(-6)m^(2)/s.As a result,the thermal effusivity and the heat capacity of the material were determined having respectively the value 1,351.09 J/(K·m^(2)·s^(1/2))and 547,945.21 J/(m^(3)·K).These different results highlight a thermal characterization of Savègranites as a relevant material in the design and construction of an energy-efficient eco-housing.展开更多
This paper proposes a numerical method for the study of ventilation efficiency in buildings. The developed model is validated with the experimental results of Nielsen who tested the isothermal flow in a scaled model o...This paper proposes a numerical method for the study of ventilation efficiency in buildings. The developed model is validated with the experimental results of Nielsen who tested the isothermal flow in a scaled model of a ventilated room. A zonal method is used to predict airflow patterns in the same ventilated room. The different equations governing the flow in the room were coded in Matlab for different operating conditions, different zonal configurations of the room and different number of cells （control volumes）. The efficiency of the ventilation was determined by calculating the number of ACH （air changes per hour） for each cell. The present results show the importance of the inlet air flow rate, the space resolution and the jet inlet dimensions on the determination of air quality.展开更多
To install a tower solar power plant,the receiver is a key part for storing heat.There are two categories of receivers:surface receivers and volumetric receivers.To produce pressurized air at very high temperatures,th...To install a tower solar power plant,the receiver is a key part for storing heat.There are two categories of receivers:surface receivers and volumetric receivers.To produce pressurized air at very high temperatures,the volumetric receiver is indicated.Thus,it allows the air to be heated up to 1100˚C[1]allowing good efficiency to be achieved.We present here the dynamic modeling of a volumetric solar receiver with pressurized air.The absorber used is designed with ceramic material(terracotta)and a parallelepiped shape called a honeycomb absorber.In our case,the circular cells have a diameter of 3mm and are separated from each other by a distance of 3 mm.The symmetrical character allows us to reduce the calculation domains to an elementary cell representative of their structure.We use the finite element method of the Comsol 5.3a calculation code for the numerical resolution.Our results thus show that with a pressure of 10 bars and an air inlet temperature of 398K˚C for a mass air flow rate of 0.3 kg/s,we obtain an air outlet temperature of around 1000 K,which is sufficient to supply a combustion chamber and drive an alternator.展开更多
In natural photosynthesis,compartmentalized protein networks spatially orchestrate light-driven electron transfer for CO_(2)activation,offering a blueprint for artificial systems.Herein,we report the design and synthe...In natural photosynthesis,compartmentalized protein networks spatially orchestrate light-driven electron transfer for CO_(2)activation,offering a blueprint for artificial systems.Herein,we report the design and synthesis of a molecular compartmentalized photocatalyst for photocatalytic CO_(2)overall conversion,in which a nickel-substituted polyoxometalate(NiPOM)is confined within the inner channels of carbon nanotubes(CNTs),while Fe-porphyrin derivatives(FeTCPPOMe)are anchored onto the CNT exterior viaπ-πinteractions.This unique inside-outside configuration creates a highly ordered,vectorial electron transfer pathway whereby photoexcited electrons are generated at the FeTCPPOMe sites,swiftly injected into the CNT and then directly delivered to the encapsulated NiPOM.Under simulated solar illumination,the FeTCPPOMe-NiPOM@CNT composite exhibits good photocatalytic CO_(2)reduction performance,achieving a CO production rate of 42.7μmol g^(−1)h^(−1)with a 100%CO selectivity.In-situ DRIFTS,quasi in-situ XPS and in-situ illuminated Kelvin probe force microscopy(KPFM)combined with density functional theory calculations clearly elucidated the photoinduced electron transfer pathway.This work demonstrates that strategic nanoscale confinement and hierarchical assembly can dramatically enhance charge transport and catalytic efficiency,offering a promising blueprint for next-generation CO_(2)photoreduction systems.展开更多
The X-ray fluorescence(XRF)core-scanned Rb/Sr ratios of lake sediments have been widely used as a proxy for chemical weathering intensity and past climate change.However,some factors could affect Rb/Sr ratios,causing ...The X-ray fluorescence(XRF)core-scanned Rb/Sr ratios of lake sediments have been widely used as a proxy for chemical weathering intensity and past climate change.However,some factors could affect Rb/Sr ratios,causing misinterpretation and limiting its application.In this study,we present a high-resolution XRF core-scanned Rb/Sr record of core ZB13-C1 from the Zoige Basin in the eastern Tibetan Plateau.To validate its application,we correlated this record with the chemical index of alteration(CIA)and other paleoclimatic proxies.Our results showed that(1)the core-scanned Rb/Sr ratios and CIA were reliable proxies of chemical weathering intensity in fine-grained sedimentary sequences;(2)the low values of corescanned Rb/Sr ratios and CIA were significantly correlated with high total organic carbon content,arboreal pollen content,carbonate content,and C/N ratios,confirming its reliability as a proxy for the Asian summer monsoon intensity;(3)the corescanned Rb/Sr ratios at core depths of 25–0.3 and 56–47 m were unable to reliably reflect chemical weathering intensity due to both the grain-size effect and the low test accuracy.Our study highlights the need for mutual verification of multiple indicators before accurately applying Rb/Sr as a paleoclimatic proxy in other similar study areas.展开更多
Indium phosphide(InP)nanowires(NWs)have attracted significant attention due to their exotic properties that are different from the bulk counterparts,and have been widely used for light generation,amplification,detecti...Indium phosphide(InP)nanowires(NWs)have attracted significant attention due to their exotic properties that are different from the bulk counterparts,and have been widely used for light generation,amplification,detection,modulation,and switching,etc.Here,high-quality InP NWs were directly grown on a quartz substrate by the Au-nanoparticle assisted vapor-liquid-solid method.We thoroughly studied their nonlinear optical absorption properties at 1.06μm by the open-aperture Z-scan method.Interestingly,a transition phenomenon from satu-rable absorption(SA)to reverse saturable absorption(RSA)was observed with the increase of the incident laser intensity.In the analysis,we found that the effective nonlinear absorption cofficient(βeff-10^2 cm/MW)under the SA process was 3 orders of magnitude larger than that during the RSA processes.Furthermore,the SA proper-ties of InP NWs were experimentally verified by using them as a saturable absorber for a passively Q-switched Nd:YVO4 solid-state laser at 1.06μm,where the shortest pulse width of 462 ns and largest single pulse energy of 1.32μJ were obtained.Moreover,the ultrafast carrier relaxation dynamics were basically studied,and the intraband and inter-band ultrafast carrier relaxation times of 8.1 and 63.8 ps,respectively,were measured by a degenerate pump-probe method with the probe laser of 800 nm.These results well demonstrate the nonlinear optical absorption properties,which show the excellent light manipulating capabilities of InP NWs and pave a way for their applications in ultrafast nanophotonic devices.展开更多
To display the distribution characteristics of turbulence eddy under condition of complex terrain in Loess Plateau,and to enhance the precision of turbulence measurements,the research of turbulence ergodicity is consi...To display the distribution characteristics of turbulence eddy under condition of complex terrain in Loess Plateau,and to enhance the precision of turbulence measurements,the research of turbulence ergodicity is considered to be the prior section of the experiment.With the statistics of single-site turbulence measurements obtained in Baimiao Tableland,Ping Liang,Gan Su,analysis result shows that not only the turbulence with scale less than 10 min,which can easily satisfy the ergodicity,the tableland terrain can also be a major cause of the coherent structure of periodic,large-scale turbulence;compared to which for the turbulence above the flat underlying surface,the distribution of 10–40 min,large-scale turbulence in the tableland region tends to be more steady and,thus,can also satisfy the ergodicity easily.Under the condition of extremely unstable stratification,the wind is comparatively low in speed and features distinctly large-scale,periodical fluctuation,and with the trend of smooth increase in temperature,large-scale wind turbulence and temperature turbulence both tend to satisfy ergodicity.In comparison,under the condition of extremely stable stratification,the aperiodicity of large-scale wind turbulence and temperature turbulence caused by intermittency is comparatively strong,and the turbulence cannot satisfy ergodicity easily.展开更多
Self-assembled supramolecular structures with efficient singlet oxygen(1O2)-generation ability are expected to enable photocatalytic oxidation reactions.Herein,we use two photosensitizers,perylene diimide and benzothi...Self-assembled supramolecular structures with efficient singlet oxygen(1O2)-generation ability are expected to enable photocatalytic oxidation reactions.Herein,we use two photosensitizers,perylene diimide and benzothiadiazole derivative,as the boards to prepare two barrel-shaped metallacages viametal-coordination-driven self-assembly.展开更多
The production of coal-based solid waste(CBSW)from coal mining operations poses a significant threat to the ecological environment in mining regions.This research addresses the proper management of CBSW accumulation b...The production of coal-based solid waste(CBSW)from coal mining operations poses a significant threat to the ecological environment in mining regions.This research addresses the proper management of CBSW accumulation by utilizing coal gangue,fly ash,and gasification slag as primary materials for backfill preparation.This study focused on evaluating the early uniaxial compressive strength and fluidity of the backfill while investigating the changing characteristics of early compressive strength,fluidity,and microstructure during the early age of backfill development.Findings showed that the slurry fluidity significantly decreased as the mass concentration increased,whereas factors such as the aggregate-cement mass ratio,fine aggregate content,and fiber content demonstrated no noticeable impact on slurry fluidity.Notably,the early compressive strength of the backfill decreased significantly with an increase in the aggregate-cement mass ratio;however,increases in the mass concentration and fine aggregate content effectively enhanced the early compressive strength of the backfill,serving as key influencing factors.The inclusion of fiber significantly enhanced the early compressive strength of the backfill,with the optimal fiber concentration determined to be∼0.2wt%.Furthermore,increasing the mass concentration or fine aggregate content alleviated the negative impacts of higher aggregate-cement mass ratios on early compressive strength.However,it must be noted that an elevated fine aggregate content may reduce the reinforcing effects of mass concentration on early compressive strength.This leads to enlarged void structures in the samples,whereas increasing the fine aggregate content reduces the void size and range,thereby improving the early compressive strength of the backfill.展开更多
Many people affected by fragile X syndrome(FXS)and autism spectrum disorders have sensory processing deficits,such as hypersensitivity to auditory,tactile,and visual stimuli.Like FXS in humans,loss of Fmr1 in rodents ...Many people affected by fragile X syndrome(FXS)and autism spectrum disorders have sensory processing deficits,such as hypersensitivity to auditory,tactile,and visual stimuli.Like FXS in humans,loss of Fmr1 in rodents also cause sensory,behavioral,and cognitive deficits.However,the neural mechanisms underlying sensory impairment,especially vision impairment,remain unclear.It remains elusive whether the visual processing deficits originate from corrupted inputs,impaired perception in the primary sensory cortex,or altered integration in the higher cortex,and there is no effective treatment.In this study,we used a genetic knockout mouse model(Fmr1^(KO)),in vivo imaging,and behavioral measurements to show that the loss of Fmr1 impaired signal processing in the primary visual cortex(V1).Specifically,Fmr1^(KO) mice showed enhanced responses to low-intensity stimuli but normal responses to high-intensity stimuli.This abnormality was accompanied by enhancements in local network connectivity in V1 microcircuits and increased dendritic complexity of V1 neurons.These effects were ameliorated by the acute application of GABAA receptor activators,which enhanced the activity of inhibitory neurons,or by reintroducing Fmr1 gene expression in knockout V1 neurons in both juvenile and young-adult mice.Overall,V1 plays an important role in the visual abnormalities of Fmr1^(KO) mice and it could be possible to rescue the sensory disturbances in developed FXS and autism patients.展开更多
文摘The present study focuses on the flow of a yield-stress(Bingham)nanofluid,consisting of suspended Fe3O4 nanoparticles,subjected to a magnetic field in a backward-facing step duct(BFS)configuration.The duct is equipped with a cylindrical obstacle,where the lower wall is kept at a constant temperature.The yield-stress nanofluid enters this duct at a cold temperature with fully developed velocity.The aim of the present investigation is to explore the influence of flow velocity(Re=10 to 200),nanoparticle concentration(ϕ=0 to 0.1),magnetic field intensity(Ha=0 to 100),and its inclination angle(γ=0 to 90)and nanofluid yield stress(Bn=0 to 20)on the thermal and hydrodynamic efficiency inside the backward-facing step.The numerical results have been obtained by resolving the momentum and energy balance equations using the Galerkin finite element method.The obtained results have indicated that an increase in Reynolds number and nanoparticle volume fraction enhances heat transfer.In contrast,a significant reduction is observed with an increase in Hartmann and Bingham numbers,resulting in quasi-immobilization of the fluid under the magnetic influence and radical solidification of this type of fluid,accompanied by the suppression of the vortex zone downstream of the cylindrical obstacle.This study sheds light on the complexity of this magnetically influenced fluid,with potential implications in various engineering and materials science fields.
文摘With the proliferation of online services and applications,adopting Single Sign-On(SSO)mechanisms has become increasingly prevalent.SSO enables users to authenticate once and gain access to multiple services,eliminating the need to provide their credentials repeatedly.However,this convenience raises concerns about user security and privacy.The increasing reliance on SSO and its potential risks make it imperative to comprehensively review the various SSO security and privacy threats,identify gaps in existing systems,and explore effective mitigation solutions.This need motivated the first systematic literature review(SLR)of SSO security and privacy,conducted in this paper.The SLR is performed based on rigorous structured research methodology with specific inclusion/exclusion criteria and focuses specifically on the Web environment.Furthermore,it encompasses a meticulous examination and thematic synthesis of 88 relevant publications selected out of 2315 journal articles and conference/proceeding papers published between 2017 and 2024 from reputable academic databases.The SLR highlights critical security and privacy threats relating to SSO systems,reveals significant gaps in existing countermeasures,and emphasizes the need for more comprehensive protection mechanisms.The findings of this SLR will serve as an invaluable resource for scientists and developers interested in enhancing the security and privacy preservation of SSO and designing more efficient and robust SSO systems,thus contributing to the development of the authentication technologies field.
文摘Road construction in Africa is faced with a shortage of quality materials, leading to delays and increased costs. Traditional materials, such as clay soils of the bar soil type, have inadequate properties for pavement sub-base layers, particularly in terms of bearing capacity. This study explores a composite material combining bar soil and bamboo fibers to improve the mechanical performance of bar soil, offering a sustainable and cost-effective solution. The Tori-Bossito bar soil was characterised by particle size analysis, Atterberg limits, Proctor compaction tests and the California Bearing Ratio (CBR). The results show that this material is a class A2 sandy-clay soil with a CBR of 18, which is insufficient for foundation layers requiring a CBR of over 30. To improve its performance, Sèmè-Kpodji bamboo fibers, 30 to 100 microns in diameter and 3 to 5 cm long, were incorporated at rates of 0.9% to 2.7%. The optimum mix, with 2.4% fiber, has a CBR of 35, a dry density of 1.92 t/m3 and a moisture content of 12.4%. This reinforced material is suitable as a base course for low-traffic roadways.
文摘Over the last few years, many studies have been published using modern network analysis of the brain. Researchers and practical doctors alike should understand this method and its results on the brain evaluation at rest, during activation and in brain disease. The studies are noninvasive and usually performed with elecroencephalographic, magnetoencephalographic, magnetic resonance imaging and diffusion tensor imaging brain recordings. Different tools for analysis have been developed, although the methods are in their early stages. The results of these analyses are of special value. Studies of these tools in schizophrenia are important because widespread and local network disturbances can be evaluated by assessing integration, segregation and several structural and functional properties. With the help of network analyses, the main findings in schizophrenia are lower optimum network organization, less efficiently wired networks, less local clustering, less hierarchical organization and signs of disconnection. There are only about twenty five relevant papers on the subject today. Only a few years of study of these methods have produced interesting results and it appears promising that the development of these methods will present important knowledge for both the preclinical signs of schizophrenia and the methods' therapeutic effects.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10374001, 10434030 and 60576016）, State Key Development Program for Basic Research of China （Grant No 2003CB314707）, the Excellent Doctor＇s Science and Technology Innovation Foundation of Beijing Jiaotong University of China （48011）.
文摘In the solid state cathodoluminescence （SSCL）, organic materials were excited by hot electrons accelerated in silicon oxide （SiO2） layer under alternating current （AC）. In this paper exciton behaviours were analysed by using transient spectra under different driving voltages. The threshold voltages of SSCL and exciton ionization were obtained from the transient spectra. The recombination radiation occurred when the driving voltage went beyond the threshold voltage of exciton ionization. From the transient spectrum of two kinds of luminescence （exciton emission and recombination radiation）, it was demonstrated that recombination radiation should benefit from the exciton ionization.
文摘Objective: To assess knowledge and behaviour related to toxoplasmosis which remains a neglected disease in Morocco.Methods: Observational investigations were conducted among 600 pregnant women from Essaouira Province.The interview items covered respondents' knowledge of the disease, its preventive practices and risk behaviours.Results: A total of 22/600 women had already carried out the anti-toxoplasmosis test, while, 96% have never done any screening of anti-Toxoplasma antibodies.Only 16/600 women have good information about the disease, its mode of transmission and its complications in both the fetus and his mother.Although most women adopt a healthy diet, the consumption of raw or undercooked meat is far to be considered as a risk factor, along with other potential factors that may foster the acquisition of the disease, such as possessing a domestic cat, educational status and knowledge of the disease.However, in this study, contact with soil was revealed the most important risk factor(P = 0.045), followed by the hygiene conditions after handling raw meat(P = 0.048).Conclusion: The underestimation of the Toxoplasma gondii sero-prevalence in Essaouira Province can be explained by the absence of toxoplasmosis serology in health institutions, as well as the gap of knowledge about the disease by local population.
文摘This work focuses on the valorization of local materials.The rock that is granite,a material used in construction thanks to its mechanical resistance,is the subject of our study.The granite of the commune of Savè,made it possible to appreciate the thermal behavior of this rock studied with a view to its use as a building material.To this end,a thermal diffusivity measurement test was carried out on this material.Thus,we made samples which were then connected to a data acquisition box via thermocouples.A Python script is used to ensure the collection of temperature values over time.From this thermal diffusivity test carried out on the granite taken from the Savèbreasts,we obtained an average diffusivity a=5.84×10^(-6)m^(2)/s.As a result,the thermal effusivity and the heat capacity of the material were determined having respectively the value 1,351.09 J/(K·m^(2)·s^(1/2))and 547,945.21 J/(m^(3)·K).These different results highlight a thermal characterization of Savègranites as a relevant material in the design and construction of an energy-efficient eco-housing.
文摘This paper proposes a numerical method for the study of ventilation efficiency in buildings. The developed model is validated with the experimental results of Nielsen who tested the isothermal flow in a scaled model of a ventilated room. A zonal method is used to predict airflow patterns in the same ventilated room. The different equations governing the flow in the room were coded in Matlab for different operating conditions, different zonal configurations of the room and different number of cells （control volumes）. The efficiency of the ventilation was determined by calculating the number of ACH （air changes per hour） for each cell. The present results show the importance of the inlet air flow rate, the space resolution and the jet inlet dimensions on the determination of air quality.
文摘To install a tower solar power plant,the receiver is a key part for storing heat.There are two categories of receivers:surface receivers and volumetric receivers.To produce pressurized air at very high temperatures,the volumetric receiver is indicated.Thus,it allows the air to be heated up to 1100˚C[1]allowing good efficiency to be achieved.We present here the dynamic modeling of a volumetric solar receiver with pressurized air.The absorber used is designed with ceramic material(terracotta)and a parallelepiped shape called a honeycomb absorber.In our case,the circular cells have a diameter of 3mm and are separated from each other by a distance of 3 mm.The symmetrical character allows us to reduce the calculation domains to an elementary cell representative of their structure.We use the finite element method of the Comsol 5.3a calculation code for the numerical resolution.Our results thus show that with a pressure of 10 bars and an air inlet temperature of 398K˚C for a mass air flow rate of 0.3 kg/s,we obtain an air outlet temperature of around 1000 K,which is sufficient to supply a combustion chamber and drive an alternator.
基金supported by the National Natural Science Foundation of China(22472071,22075119,and 22209017)the Natural Science Foundation of Gansu Province(21JR7RA440)the Fundamental Research Funds for the Central Universities(lzuibky2024-ou01)。
文摘In natural photosynthesis,compartmentalized protein networks spatially orchestrate light-driven electron transfer for CO_(2)activation,offering a blueprint for artificial systems.Herein,we report the design and synthesis of a molecular compartmentalized photocatalyst for photocatalytic CO_(2)overall conversion,in which a nickel-substituted polyoxometalate(NiPOM)is confined within the inner channels of carbon nanotubes(CNTs),while Fe-porphyrin derivatives(FeTCPPOMe)are anchored onto the CNT exterior viaπ-πinteractions.This unique inside-outside configuration creates a highly ordered,vectorial electron transfer pathway whereby photoexcited electrons are generated at the FeTCPPOMe sites,swiftly injected into the CNT and then directly delivered to the encapsulated NiPOM.Under simulated solar illumination,the FeTCPPOMe-NiPOM@CNT composite exhibits good photocatalytic CO_(2)reduction performance,achieving a CO production rate of 42.7μmol g^(−1)h^(−1)with a 100%CO selectivity.In-situ DRIFTS,quasi in-situ XPS and in-situ illuminated Kelvin probe force microscopy(KPFM)combined with density functional theory calculations clearly elucidated the photoinduced electron transfer pathway.This work demonstrates that strategic nanoscale confinement and hierarchical assembly can dramatically enhance charge transport and catalytic efficiency,offering a promising blueprint for next-generation CO_(2)photoreduction systems.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA20070101)the National Natural Science Foundation of China(Grant Nos.41690113&41888101)the National Key Research and Development Program of China(Grant No.2016YFA0600501)。
文摘The X-ray fluorescence(XRF)core-scanned Rb/Sr ratios of lake sediments have been widely used as a proxy for chemical weathering intensity and past climate change.However,some factors could affect Rb/Sr ratios,causing misinterpretation and limiting its application.In this study,we present a high-resolution XRF core-scanned Rb/Sr record of core ZB13-C1 from the Zoige Basin in the eastern Tibetan Plateau.To validate its application,we correlated this record with the chemical index of alteration(CIA)and other paleoclimatic proxies.Our results showed that(1)the core-scanned Rb/Sr ratios and CIA were reliable proxies of chemical weathering intensity in fine-grained sedimentary sequences;(2)the low values of corescanned Rb/Sr ratios and CIA were significantly correlated with high total organic carbon content,arboreal pollen content,carbonate content,and C/N ratios,confirming its reliability as a proxy for the Asian summer monsoon intensity;(3)the corescanned Rb/Sr ratios at core depths of 25–0.3 and 56–47 m were unable to reliably reflect chemical weathering intensity due to both the grain-size effect and the low test accuracy.Our study highlights the need for mutual verification of multiple indicators before accurately applying Rb/Sr as a paleoclimatic proxy in other similar study areas.
基金National Natural Science Foundation of China(61575110,61675116,61975095)Department of Science and Technology of Shandong Province(2017WLJH48)+3 种基金Shandong University(2020QNQT)Academy of Finland Photonics Flagship PREIN(320167)Walter AhLströmin SäätiöNokia.
文摘Indium phosphide(InP)nanowires(NWs)have attracted significant attention due to their exotic properties that are different from the bulk counterparts,and have been widely used for light generation,amplification,detection,modulation,and switching,etc.Here,high-quality InP NWs were directly grown on a quartz substrate by the Au-nanoparticle assisted vapor-liquid-solid method.We thoroughly studied their nonlinear optical absorption properties at 1.06μm by the open-aperture Z-scan method.Interestingly,a transition phenomenon from satu-rable absorption(SA)to reverse saturable absorption(RSA)was observed with the increase of the incident laser intensity.In the analysis,we found that the effective nonlinear absorption cofficient(βeff-10^2 cm/MW)under the SA process was 3 orders of magnitude larger than that during the RSA processes.Furthermore,the SA proper-ties of InP NWs were experimentally verified by using them as a saturable absorber for a passively Q-switched Nd:YVO4 solid-state laser at 1.06μm,where the shortest pulse width of 462 ns and largest single pulse energy of 1.32μJ were obtained.Moreover,the ultrafast carrier relaxation dynamics were basically studied,and the intraband and inter-band ultrafast carrier relaxation times of 8.1 and 63.8 ps,respectively,were measured by a degenerate pump-probe method with the probe laser of 800 nm.These results well demonstrate the nonlinear optical absorption properties,which show the excellent light manipulating capabilities of InP NWs and pave a way for their applications in ultrafast nanophotonic devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.41675014&91437103)the Gansu Science and Technology Program(Grant No.18JR2RA005)。
文摘To display the distribution characteristics of turbulence eddy under condition of complex terrain in Loess Plateau,and to enhance the precision of turbulence measurements,the research of turbulence ergodicity is considered to be the prior section of the experiment.With the statistics of single-site turbulence measurements obtained in Baimiao Tableland,Ping Liang,Gan Su,analysis result shows that not only the turbulence with scale less than 10 min,which can easily satisfy the ergodicity,the tableland terrain can also be a major cause of the coherent structure of periodic,large-scale turbulence;compared to which for the turbulence above the flat underlying surface,the distribution of 10–40 min,large-scale turbulence in the tableland region tends to be more steady and,thus,can also satisfy the ergodicity easily.Under the condition of extremely unstable stratification,the wind is comparatively low in speed and features distinctly large-scale,periodical fluctuation,and with the trend of smooth increase in temperature,large-scale wind turbulence and temperature turbulence both tend to satisfy ergodicity.In comparison,under the condition of extremely stable stratification,the aperiodicity of large-scale wind turbulence and temperature turbulence caused by intermittency is comparatively strong,and the turbulence cannot satisfy ergodicity easily.
文摘Self-assembled supramolecular structures with efficient singlet oxygen(1O2)-generation ability are expected to enable photocatalytic oxidation reactions.Herein,we use two photosensitizers,perylene diimide and benzothiadiazole derivative,as the boards to prepare two barrel-shaped metallacages viametal-coordination-driven self-assembly.
基金Open Fund of Anhui University of Science and Technology Engineering Laboratory for Safe and Precise Coal Mining(No.ESCMMP202402)China Postdoctoral Science Foundation(Nos.2024M750015,2024T170912,and 2023M733481)+2 种基金Key Laboratory of Xinjiang Coal Resources Green Mining,Ministry of Education(No.KLXGY-KB2418)Anhui University of Science and Technology Talent Introduction Research Fund(No.2023yjrc106)National Natural Science Foundation of China(Nos.42402287 and 52130402).
文摘The production of coal-based solid waste(CBSW)from coal mining operations poses a significant threat to the ecological environment in mining regions.This research addresses the proper management of CBSW accumulation by utilizing coal gangue,fly ash,and gasification slag as primary materials for backfill preparation.This study focused on evaluating the early uniaxial compressive strength and fluidity of the backfill while investigating the changing characteristics of early compressive strength,fluidity,and microstructure during the early age of backfill development.Findings showed that the slurry fluidity significantly decreased as the mass concentration increased,whereas factors such as the aggregate-cement mass ratio,fine aggregate content,and fiber content demonstrated no noticeable impact on slurry fluidity.Notably,the early compressive strength of the backfill decreased significantly with an increase in the aggregate-cement mass ratio;however,increases in the mass concentration and fine aggregate content effectively enhanced the early compressive strength of the backfill,serving as key influencing factors.The inclusion of fiber significantly enhanced the early compressive strength of the backfill,with the optimal fiber concentration determined to be∼0.2wt%.Furthermore,increasing the mass concentration or fine aggregate content alleviated the negative impacts of higher aggregate-cement mass ratios on early compressive strength.However,it must be noted that an elevated fine aggregate content may reduce the reinforcing effects of mass concentration on early compressive strength.This leads to enlarged void structures in the samples,whereas increasing the fine aggregate content reduces the void size and range,thereby improving the early compressive strength of the backfill.
文摘Many people affected by fragile X syndrome(FXS)and autism spectrum disorders have sensory processing deficits,such as hypersensitivity to auditory,tactile,and visual stimuli.Like FXS in humans,loss of Fmr1 in rodents also cause sensory,behavioral,and cognitive deficits.However,the neural mechanisms underlying sensory impairment,especially vision impairment,remain unclear.It remains elusive whether the visual processing deficits originate from corrupted inputs,impaired perception in the primary sensory cortex,or altered integration in the higher cortex,and there is no effective treatment.In this study,we used a genetic knockout mouse model(Fmr1^(KO)),in vivo imaging,and behavioral measurements to show that the loss of Fmr1 impaired signal processing in the primary visual cortex(V1).Specifically,Fmr1^(KO) mice showed enhanced responses to low-intensity stimuli but normal responses to high-intensity stimuli.This abnormality was accompanied by enhancements in local network connectivity in V1 microcircuits and increased dendritic complexity of V1 neurons.These effects were ameliorated by the acute application of GABAA receptor activators,which enhanced the activity of inhibitory neurons,or by reintroducing Fmr1 gene expression in knockout V1 neurons in both juvenile and young-adult mice.Overall,V1 plays an important role in the visual abnormalities of Fmr1^(KO) mice and it could be possible to rescue the sensory disturbances in developed FXS and autism patients.
