In Bachelard＇s thought, the understanding ＂of the other＂ in scientific thought is given usually by means of empirical or rational discourse. However, it is not unusual to realize the emphasis of scientific thought ...In Bachelard＇s thought, the understanding ＂of the other＂ in scientific thought is given usually by means of empirical or rational discourse. However, it is not unusual to realize the emphasis of scientific thought as rationally justifiable. Certainly, the dynamics of scientific thought throughout history has not been indifferent to other possibilities of epistemological construction. We cannot escape the facts： Science needs linguistic devices to strengthen its principles and criteria for validation. The aim of this paper is to answer, based on a new conception of metaphor, under what conditions metaphor can be a ＂physical metaphor＂ and the extent to which the symbolism in general brings a special light gain of sense to the understanding of physical reality that surrounds us.展开更多
The joint European Space Agency and Chinese Academy of Sciences Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission will explore global dynamics of the magnetosphere under varying solar wind and interplane...The joint European Space Agency and Chinese Academy of Sciences Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission will explore global dynamics of the magnetosphere under varying solar wind and interplanetary magnetic field conditions,and simultaneously monitor the auroral response of the Northern Hemisphere ionosphere.Combining these large-scale responses with medium and fine-scale measurements at a variety of cadences by additional ground-based and space-based instruments will enable a much greater scientific impact beyond the original goals of the SMILE mission.Here,we describe current community efforts to prepare for SMILE,and the benefits and context various experiments that have explicitly expressed support for SMILE can offer.A dedicated group of international scientists representing many different experiment types and geographical locations,the Ground-based and Additional Science Working Group,is facilitating these efforts.Preparations include constructing an online SMILE Data Fusion Facility,the discussion of particular or special modes for experiments such as coherent and incoherent scatter radar,and the consideration of particular observing strategies and spacecraft conjunctions.We anticipate growing interest and community engagement with the SMILE mission,and we welcome novel ideas and insights from the solar-terrestrial community.展开更多
In order to explore the mechanism of improving the surface wettability of low-energy polytetrafluoroethylene(PTFE)by new extended surfactants,five kinds of extended anionic surfactants with different numbers of oxypro...In order to explore the mechanism of improving the surface wettability of low-energy polytetrafluoroethylene(PTFE)by new extended surfactants,five kinds of extended anionic surfactants with different numbers of oxypropylene(PO)and oxyethylene(EO),octadecyl-(PO)_(m)-(EO)_(n)-sodium carboxylate(C_(18)PO_(m)EO_(n)C,m=5,10,15,n=5,10,15),were studied.The surface tension and contact angle of C_(18)PO_(m)EO_(n)C solution with different concentrations were measured,and the adhesion tension,PTFE-water interfacial tension,and adhesion work were calculated.It was found that the extended surfactant molecules adsorb on the surface of the solution and the PTFE-liquid interface simultaneously when the concentration is lower than the critical micelle concentration(cmc),and there was a linear relationship between surface tension and adhesion tension.The adsorption amount of C_(18)PO_(m)EO_(n)C at the PTFE-water interface was significantly lower than that on the surface of the solution.As the concentration increases above cmc,semi-micelle aggregates on the surface of PTFE are formed by C_(18)PO_(m)EO_(n)C molecules through hydrophobic interaction,and the hydrophilic group faces the solution to modify the surface of PTFE with high efficiency.展开更多
Purpose-Weathering steel has excellent resistance to atmospheric corrosion,but still faces complex environmental corrosion problems during long-term operation.This paper mainly studies the corrosion problem of weather...Purpose-Weathering steel has excellent resistance to atmospheric corrosion,but still faces complex environmental corrosion problems during long-term operation.This paper mainly studies the corrosion problem of weather resistant steel materials for railway freight car bodies with a load capacity of 70 tons.Design/methodology/approach-The paper analyzes the corrosion characteristics of weather resistant steel materials for truck bodies through macroscopic and microscopic methods including metallographic microscopy,scanning electron microscopy,energy dispersive spectroscopy and X-ray diffraction.Electrochemical analysis shows that the rust layer on the surface of weathering steel changes the surface state of the material,and also proves that weathering steel used in trucks undergoes electrochemical corrosion under atmospheric corrosion.At the same time,ion chromatography technology is used to study the corrosive ions mainly present in the residual liquid and foam solution inside the vehicle body.Findings-The corrosion of truck body materials is mainly electrochemical corrosion,and the corrosion of door materials is more obvious than that of other parts.The corrosion products are mainly Fe oxides and hydroxides.There are high concentrations of Cl-and SO42-ions in the residual liquid and foam solution at the bottom of the freight car,which are the main factors causing corrosion of the railway freight car body.Originality/value-The foam adhesive around the door panel is in a moist state for a long time,and corrosive ions will accelerate the electrochemical corrosion of the weather resistant steel material of the door panel.Therefore,the corrosion of the cargo door panel is more severe than other components.展开更多
Detecting internal defects,particularly voids behind linings,is critical for ensuring the structural integrity of aging high-speed rail(HSR)tunnel networks.While ground-penetrating radar(GPR)is widely employed,systema...Detecting internal defects,particularly voids behind linings,is critical for ensuring the structural integrity of aging high-speed rail(HSR)tunnel networks.While ground-penetrating radar(GPR)is widely employed,systematic quantification of performance boundaries for air-coupled(A-CGPR)and ground-coupled(G-CGPR)systems within the complex electromagnetic environment of multilayer reinforced HSR tunnels remains limited.This study establishes physics-based quantitative performance limits for A-CGPR and G-CGPR through rigorously validated GPRMax finite-difference time-domain(FDTD)simulations and comprehensive field validation over a 300 m operational HSR tunnel section.Key performance metrics were quantified as functions of:(a)detection distance(A-CGPR:2.0–4.5 m;G-CGPR:≤0.1 m),(b)antenna frequency(A-CGPR:300 MHz;G-CGPR:400/900 MHz),(c)reinforcement configuration(unreinforced,single-layer,multilayer rebar),and(d)void geometry(axial length:0.1–1.0 m;radial depth:0.1–0.5 m).Key findings demonstrate:a.A-CGPR(300 MHz):Reliably detects axial voids≥0.3 m at distances≤3 m in minimally reinforced(single-layer rebar)linings(field R2=0.89).Performance degrades significantly at distances>3 m(>60%signal attenuation at 4.5 m)or under multilayer rebar interference,causing 25%–40%accuracy loss for voids<0.3 m.Optimal distance:2.0–2.5 m.b.G-CGPR(900 MHz):Achieves<5%size measurement error for axial voids≥0.1 m and radial voids≥0.2 m in unreinforced linings.Resolution degrades under multilayer reinforcement due to severe signal attenuation,increasing axial void detection error to 10%–20%for voids≥0.3 m and constraining radial size measurement.c.Synergistic Framework:A hybrid inspection protocol is proposed,integrating A-CGPR(20 km/h)for rapid large-area screening and targeted G-CGPR(3 km/h)for high-resolution verification of identified anomalies.This framework enhances NDT efficiency while reducing estimated lifecycle inspection costs by 34%compared to G-CGPR alone.This research provides the first physics-derived quantitative detection thresholds for A-CGPR and G-CGPR in multi-rebar HSR tunnels,validated through field-correlated simulations.Future work will focus on multi-frequency antenna arrays and deep learning algorithms to mitigate reinforcement interference.The established performance boundaries and hybrid framework offer critical guidance for optimizing tunnel lining inspection strategies in extensive HSR networks.展开更多
Photocatalysis is a promising technology for purification of indoor air by oxidation of volatile organic compounds.This study provides a comprehensive analysis of the adsorption and photo-oxidation of surface-adsorbed...Photocatalysis is a promising technology for purification of indoor air by oxidation of volatile organic compounds.This study provides a comprehensive analysis of the adsorption and photo-oxidation of surface-adsorbed acetone on three SrTiO_(3)morphologies:cubes(for which exclusively{100}facets are exposed),{110}-truncated cubes,and{100}-truncated rhombic dodecahedrons,respectively,all prepared by hydrothermal synthesis.In situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy shows that cubic crystals contain a high quantity of surface-OH groups,enabling significant quantities of adsorbed acetone in the form ofη^(1)-enolate when exposed to gas phase acetone.Contrary,{110}facets exhibit fewer surface-OH groups,resulting in relatively small quantities of adsorbedη^(1)-acetone,without observable quantities of enolate.Interestingly,acetate and formate signatures appear in the spectra of cubic,surfaceη^(1)-enolate containing,SrTiO_(3)upon illumination,while besides acetate and formate,the formation of(surface)formaldehyde was observed on truncated cubes,and dodecahedrons,by conversion of adsorbedη^(1)-acetone.Time-Resolved Photoluminescence studies demonstrate that the lifetimes of photogenerated charge carriers vary with crystal morphology.The shortest carrier lifetime(τ_(1)=33±0.1 ps)was observed in{110}-truncated cube SrTiO_(3),likely due to a relatively strong built-in electric field promoting electron transport to{100}facets and hole transport to{110}facets.The second lifetime(τ_(2)=259±1 ps)was also the shortest for this morphology,possibly due to a higher amount of surface trap states.Our results demonstrate that SrTiO_(3)crystal morphology can be tuned to optimize performance in photocatalytic oxidation.展开更多
This study aimed to quantify the carbon footprint of the National University of Juliaca(UNAJ)for the year 2023,in order to identify the main sources of greenhouse gas(GHG)emissions and provide a foundation for impleme...This study aimed to quantify the carbon footprint of the National University of Juliaca(UNAJ)for the year 2023,in order to identify the main sources of greenhouse gas(GHG)emissions and provide a foundation for implementing sustainable policies.The methodology was based on the greenhouse gas inventory approach outlined in ISO 14064-1,applying the operational control method to measure both direct and indirect emissions.Data on energy consumption,transportation,and purchased goods and services were collected using digital tools and surveys,and emissions were calculated in metric tons of CO_(2)equivalent(tCO_(2)e).The results indicate that UNAJ’s total carbon footprint in 2023 was 1,461.03 tCO_(2)e,with per capita emissions of 0.47 tCO_(2)e per person.The main sources of emissions were transportation,accounting for 75.88%of total emissions,followed by the consumption of goods and services(14.29%)and energy use(5.12%).Despite limitations in solid waste management,the study makes a valuable contribution to the development of sustainability strategies,emphasizing the urgent need for sustainable mobility policies,energy efficiency measures,and the adoption of responsible procurement practices.Furthermore,it highlights the importance of achieving carbon neutrality at UNAJ as a key objective in mitigating its environmental impact.The findings provide relevant insights from the Peruvian context and offer a basis for analyzing emissions at local universities,with practical implications for enhancing environmental management in higher education institutions.展开更多
AIM:To characterize the ocular surface characteristics in the Nepalese population across all age groups who have used digital screens for extended durations over several years.METHODS:In a cross-sectional,observationa...AIM:To characterize the ocular surface characteristics in the Nepalese population across all age groups who have used digital screens for extended durations over several years.METHODS:In a cross-sectional,observational study,144 digital screen users were assessed for dry eye disease(DED)using subjective and objective measures.The Ocular Surface Disease Index(OSDI)Questionnaire evaluated symptoms,followed by clinical assessments,including slit lamp biomicroscopy,tear breakup time(TBUT),Oxford Scheme grading,and Schirmer I test.DED was diagnosed if a patient had an OSDI score over 13 and at least two clinical signs(OSDI,Schirmer I test,or ocular staining).The prevalence of DED was calculated based on the proportion of patients meeting these criteria.RESULTS:Of the 144 participants(mean age:34.6±15.2y),78(54.2%)were female.The use of digital screens varied between 2-8h(mean duration:4.1±2.7h)per day.The mean OSDI score,TBUT score,and the Schirmer I scores were 22.7±10.5(max-min:24.4-20.9),6.8±4.2s(max-min:7.5-6.1),and 12.3±4.6 mm(max-min:13.1-11.5)respectively with 95%confidence interval(β=1.96),and a two-tailed statistical significance level of 5%(α=0.05).With increased screen use,TBUT shortened and OSDI scores increased significantly(P<0.01),though Schirmer I scores were unaffected(P>0.05).The prevalence of DED ranged from 6.3%to 22.9%in those using screens for more than 2h,with an overall prevalence of 67.4%among digital screen users.CONCLUSION:There is a significant association between prolonged use of digital screens and clinical markers of dry eye signs and symptoms.展开更多
Despite continuous progress made on the taxonomy of the genus Tropidophorus, the Lao Water Skink, T. laotus, is only known from brief descriptions of its syntypes in historical literature. Here we designate a lectotyp...Despite continuous progress made on the taxonomy of the genus Tropidophorus, the Lao Water Skink, T. laotus, is only known from brief descriptions of its syntypes in historical literature. Here we designate a lectotype and paralectotype of the species, redescribe the species based on the type series and newly collected topotypes, provide the first colored photographs of taxonomically-verified individuals, and estimate its phylogenetic position using mitochondrial DNA data for the first time.Using these comparable data, we confirm that the previously identified “T. berdmorei” population from southern Yunnan Province, China, represents a distinct new species that is closely related and morphologically similar to T. laotus, but differs from true T. laotus by having considerable genetic divergence(4.7%–4.8% for 12S, 3.2%–4.2% for 16S)and distinct morphological characters(e.g., undivided frontonasal scales and a distinct color pattern of the throat). The southern Yunnan population is therefore described as a new species. With the above newly acquired data, we update the checklist and the provincial-level distribution of the genus Tropidophorus in China and compile an updated key to all recognized species of the genus from China and Indochina.展开更多
The intermittent nature of solar irradiance is a critical constraint for the realization of continuous photocatalytic hydrogen evolution,thus urging the development of more powerful systems persistently active after i...The intermittent nature of solar irradiance is a critical constraint for the realization of continuous photocatalytic hydrogen evolution,thus urging the development of more powerful systems persistently active after illumination.This limitation is bypassed in round-the-clock photocatalytic architectures,which incorporate advanced charge storage to de-correlate pho-ton absorption and catalytic turnover time scales.The strategies involve defect-mediated trap states,multi-electron redox processes,radical-dependent stabilization,and an interfacial charge pool in Faradaic junctions to work together,leading to extended hydrogen evolution reaction(HER)in the dark.Long afterglow phosphorescent materials(e.g.,Sr_(2)MgSi_(2)O_(7):Eu^(2+),Dy^(3+))incorporated in heterojunction architectures with type II or Z-scheme band alignments can also promote fast charge separation for energy storage and subsequently enable controlled release after light quenching by the phosphorescent emis-sion.Advances in band-structure engineering,plasmonic coupling,and redox-active interfacial design result in systems with extraordinary stability and catalytic activity under natural day-night cycles.These stable photocatalytic systems off er a fundamentally new strategy for effi cient and environmentally benign sunlight-driven fuel production,meeting both per-formance and sustainability challenges to renewable energy technologies.展开更多
A review of the systemic acute phase reaction with major cytokines involved, and the hepatic metabolic changes, negative and positive acute phase proteins (APPs) with function and associated pathology is given. It app...A review of the systemic acute phase reaction with major cytokines involved, and the hepatic metabolic changes, negative and positive acute phase proteins (APPs) with function and associated pathology is given. It appears that APPs represent appropriate analytes for assessment of animal health. Whereas they represent non-specific markers as biological effect reactants, they can be used for assessing nutritional deficits and reactive processes, especially when positive and negative acute phase variables are combined in an index. When such acute phase index is applied to separate healthy animals from animals with some disease, much better results are obtained than with single analytes and statistically acceptable results for culling individual animals may be reached. Unfortunately at present no cheap, comprehensive and easy to use system is available for assessing various acute phase proteins in serum or blood samples at the same time. Protein microarray or fluid phase microchip technology may satisfy this need; and permit simultaneous analysis of numerous analytes in the same small volume sample and enable integration of information derived from systemic reactivity and nutrition with disease specific variables. Applying such technology may help to solve health problems in various countries not only in animal husbandry but also in human populations.展开更多
In many second-rotation Pinus radiata forest planta-tions, there has been a steady trend towards wider tree spacing and an increased rate of application of P fertiliser. Under these regimes, the potential for understo...In many second-rotation Pinus radiata forest planta-tions, there has been a steady trend towards wider tree spacing and an increased rate of application of P fertiliser. Under these regimes, the potential for understory growth is expected to in-crease through increased light and greater nutrient resources. Therefore, understory vegetation could become a more signifi-cant component of P cycling in P. radiata forests than under closely-spaced stands. Studies have shown that growth rates and survival of trees is reduced in the presence of understory vegeta-tion due to the competition of understory vegetation with trees. Other studies have suggested that understory vegetation might have beneficial effects on nutrient cycling and conservation within forest stands. This review discusses the significance of understory vegetation in radiata pine forest stands, especially their role in enhancing or reducing P availability to forest trees.展开更多
Potassium （K^＋） is an essential macronutrient for all living organisms and large amounts are required for plant growth and development. In many regions of Asia K＋-fertilization has been neglected and soils have be...Potassium （K^＋） is an essential macronutrient for all living organisms and large amounts are required for plant growth and development. In many regions of Asia K＋-fertilization has been neglected and soils have become K＋-depleted. K＋- deficiency in the field diminishes not only crop production but also leads to environmental problems due to inefficient usage and leaching of nitrate. Consequences of K^＋-deficiency on crop production range from decreased biomass, nutritional quality and taste of the crops to inferior harvest and storage properties, as well as increased susceptibility to disease. Effects of K^＋-deficiency on plant physiology include decreased photosynthetic rate, impaired tissue allocation of sugars and amino acids, decreased protein synthesis.展开更多
A large unified hybrid network model with a variable speed growth （LUHNM-VSG） is proposed as third model of the unified hybrid network theoretical framework （UHNTF）. A hybrid growth ratio vg of deterministic linki...A large unified hybrid network model with a variable speed growth （LUHNM-VSG） is proposed as third model of the unified hybrid network theoretical framework （UHNTF）. A hybrid growth ratio vg of deterministic linking number to random linking number and variable speed growth index a are introduced in it. The main effects of vg and a on topological transition features of the LUHNM-VSC are revealed. For comparison with the other models, we construct a type of the network complexity pyramid with seven levels, in which from the bottom level-1 to the top level-7 of the pyramid simplicity-universality is increasing but complexity-diversity is decreasing. The transition relations between them depend on matching of four hybrid ratios （dr, fd, gr, vg）. Thus the most of network models can be investigated in the unification way via four hybrid ratios （dr, fd, gr, vg）. The LUHNM-VSG as the level-1 of the pyramid is much better and closer to description of real-world networks as well as has potential application.展开更多
文摘In Bachelard＇s thought, the understanding ＂of the other＂ in scientific thought is given usually by means of empirical or rational discourse. However, it is not unusual to realize the emphasis of scientific thought as rationally justifiable. Certainly, the dynamics of scientific thought throughout history has not been indifferent to other possibilities of epistemological construction. We cannot escape the facts： Science needs linguistic devices to strengthen its principles and criteria for validation. The aim of this paper is to answer, based on a new conception of metaphor, under what conditions metaphor can be a ＂physical metaphor＂ and the extent to which the symbolism in general brings a special light gain of sense to the understanding of physical reality that surrounds us.
基金supported by Royal Society grant DHFR1211068funded by UKSA+14 种基金STFCSTFC grant ST/M001083/1funded by STFC grant ST/W00089X/1supported by NERC grant NE/W003309/1(E3d)funded by NERC grant NE/V000748/1support from NERC grants NE/V015133/1,NE/R016038/1(BAS magnetometers),and grants NE/R01700X/1 and NE/R015848/1(EISCAT)supported by NERC grant NE/T000937/1NSFC grants 42174208 and 41821003supported by the Research Council of Norway grant 223252PRODEX arrangement 4000123238 from the European Space Agencysupport of the AUTUMN East-West magnetometer network by the Canadian Space Agencysupported by NASA’s Heliophysics U.S.Participating Investigator Programsupport from grant NSF AGS 2027210supported by grant Dnr:2020-00106 from the Swedish National Space Agencysupported by the German Research Foundation(DFG)under number KR 4375/2-1 within SPP"Dynamic Earth"。
文摘The joint European Space Agency and Chinese Academy of Sciences Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission will explore global dynamics of the magnetosphere under varying solar wind and interplanetary magnetic field conditions,and simultaneously monitor the auroral response of the Northern Hemisphere ionosphere.Combining these large-scale responses with medium and fine-scale measurements at a variety of cadences by additional ground-based and space-based instruments will enable a much greater scientific impact beyond the original goals of the SMILE mission.Here,we describe current community efforts to prepare for SMILE,and the benefits and context various experiments that have explicitly expressed support for SMILE can offer.A dedicated group of international scientists representing many different experiment types and geographical locations,the Ground-based and Additional Science Working Group,is facilitating these efforts.Preparations include constructing an online SMILE Data Fusion Facility,the discussion of particular or special modes for experiments such as coherent and incoherent scatter radar,and the consideration of particular observing strategies and spacecraft conjunctions.We anticipate growing interest and community engagement with the SMILE mission,and we welcome novel ideas and insights from the solar-terrestrial community.
文摘In order to explore the mechanism of improving the surface wettability of low-energy polytetrafluoroethylene(PTFE)by new extended surfactants,five kinds of extended anionic surfactants with different numbers of oxypropylene(PO)and oxyethylene(EO),octadecyl-(PO)_(m)-(EO)_(n)-sodium carboxylate(C_(18)PO_(m)EO_(n)C,m=5,10,15,n=5,10,15),were studied.The surface tension and contact angle of C_(18)PO_(m)EO_(n)C solution with different concentrations were measured,and the adhesion tension,PTFE-water interfacial tension,and adhesion work were calculated.It was found that the extended surfactant molecules adsorb on the surface of the solution and the PTFE-liquid interface simultaneously when the concentration is lower than the critical micelle concentration(cmc),and there was a linear relationship between surface tension and adhesion tension.The adsorption amount of C_(18)PO_(m)EO_(n)C at the PTFE-water interface was significantly lower than that on the surface of the solution.As the concentration increases above cmc,semi-micelle aggregates on the surface of PTFE are formed by C_(18)PO_(m)EO_(n)C molecules through hydrophobic interaction,and the hydrophilic group faces the solution to modify the surface of PTFE with high efficiency.
基金supported by Research and Development Plan of China Railway Group(N2023J065).
文摘Purpose-Weathering steel has excellent resistance to atmospheric corrosion,but still faces complex environmental corrosion problems during long-term operation.This paper mainly studies the corrosion problem of weather resistant steel materials for railway freight car bodies with a load capacity of 70 tons.Design/methodology/approach-The paper analyzes the corrosion characteristics of weather resistant steel materials for truck bodies through macroscopic and microscopic methods including metallographic microscopy,scanning electron microscopy,energy dispersive spectroscopy and X-ray diffraction.Electrochemical analysis shows that the rust layer on the surface of weathering steel changes the surface state of the material,and also proves that weathering steel used in trucks undergoes electrochemical corrosion under atmospheric corrosion.At the same time,ion chromatography technology is used to study the corrosive ions mainly present in the residual liquid and foam solution inside the vehicle body.Findings-The corrosion of truck body materials is mainly electrochemical corrosion,and the corrosion of door materials is more obvious than that of other parts.The corrosion products are mainly Fe oxides and hydroxides.There are high concentrations of Cl-and SO42-ions in the residual liquid and foam solution at the bottom of the freight car,which are the main factors causing corrosion of the railway freight car body.Originality/value-The foam adhesive around the door panel is in a moist state for a long time,and corrosive ions will accelerate the electrochemical corrosion of the weather resistant steel material of the door panel.Therefore,the corrosion of the cargo door panel is more severe than other components.
基金funded by the Key Project of Science&Technology Research ofChina Academy of Railway Sciences,grant number 2023YJ022.
文摘Detecting internal defects,particularly voids behind linings,is critical for ensuring the structural integrity of aging high-speed rail(HSR)tunnel networks.While ground-penetrating radar(GPR)is widely employed,systematic quantification of performance boundaries for air-coupled(A-CGPR)and ground-coupled(G-CGPR)systems within the complex electromagnetic environment of multilayer reinforced HSR tunnels remains limited.This study establishes physics-based quantitative performance limits for A-CGPR and G-CGPR through rigorously validated GPRMax finite-difference time-domain(FDTD)simulations and comprehensive field validation over a 300 m operational HSR tunnel section.Key performance metrics were quantified as functions of:(a)detection distance(A-CGPR:2.0–4.5 m;G-CGPR:≤0.1 m),(b)antenna frequency(A-CGPR:300 MHz;G-CGPR:400/900 MHz),(c)reinforcement configuration(unreinforced,single-layer,multilayer rebar),and(d)void geometry(axial length:0.1–1.0 m;radial depth:0.1–0.5 m).Key findings demonstrate:a.A-CGPR(300 MHz):Reliably detects axial voids≥0.3 m at distances≤3 m in minimally reinforced(single-layer rebar)linings(field R2=0.89).Performance degrades significantly at distances>3 m(>60%signal attenuation at 4.5 m)or under multilayer rebar interference,causing 25%–40%accuracy loss for voids<0.3 m.Optimal distance:2.0–2.5 m.b.G-CGPR(900 MHz):Achieves<5%size measurement error for axial voids≥0.1 m and radial voids≥0.2 m in unreinforced linings.Resolution degrades under multilayer reinforcement due to severe signal attenuation,increasing axial void detection error to 10%–20%for voids≥0.3 m and constraining radial size measurement.c.Synergistic Framework:A hybrid inspection protocol is proposed,integrating A-CGPR(20 km/h)for rapid large-area screening and targeted G-CGPR(3 km/h)for high-resolution verification of identified anomalies.This framework enhances NDT efficiency while reducing estimated lifecycle inspection costs by 34%compared to G-CGPR alone.This research provides the first physics-derived quantitative detection thresholds for A-CGPR and G-CGPR in multi-rebar HSR tunnels,validated through field-correlated simulations.Future work will focus on multi-frequency antenna arrays and deep learning algorithms to mitigate reinforcement interference.The established performance boundaries and hybrid framework offer critical guidance for optimizing tunnel lining inspection strategies in extensive HSR networks.
基金Advanced Research Center for Chemical Building Blocks,ARC CBBC,which is co-foundedco-financed by the Dutch Research Council(NWO)and the Netherlands Ministry of Economic Affairs and Climate Policy.
文摘Photocatalysis is a promising technology for purification of indoor air by oxidation of volatile organic compounds.This study provides a comprehensive analysis of the adsorption and photo-oxidation of surface-adsorbed acetone on three SrTiO_(3)morphologies:cubes(for which exclusively{100}facets are exposed),{110}-truncated cubes,and{100}-truncated rhombic dodecahedrons,respectively,all prepared by hydrothermal synthesis.In situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy shows that cubic crystals contain a high quantity of surface-OH groups,enabling significant quantities of adsorbed acetone in the form ofη^(1)-enolate when exposed to gas phase acetone.Contrary,{110}facets exhibit fewer surface-OH groups,resulting in relatively small quantities of adsorbedη^(1)-acetone,without observable quantities of enolate.Interestingly,acetate and formate signatures appear in the spectra of cubic,surfaceη^(1)-enolate containing,SrTiO_(3)upon illumination,while besides acetate and formate,the formation of(surface)formaldehyde was observed on truncated cubes,and dodecahedrons,by conversion of adsorbedη^(1)-acetone.Time-Resolved Photoluminescence studies demonstrate that the lifetimes of photogenerated charge carriers vary with crystal morphology.The shortest carrier lifetime(τ_(1)=33±0.1 ps)was observed in{110}-truncated cube SrTiO_(3),likely due to a relatively strong built-in electric field promoting electron transport to{100}facets and hole transport to{110}facets.The second lifetime(τ_(2)=259±1 ps)was also the shortest for this morphology,possibly due to a higher amount of surface trap states.Our results demonstrate that SrTiO_(3)crystal morphology can be tuned to optimize performance in photocatalytic oxidation.
文摘This study aimed to quantify the carbon footprint of the National University of Juliaca(UNAJ)for the year 2023,in order to identify the main sources of greenhouse gas(GHG)emissions and provide a foundation for implementing sustainable policies.The methodology was based on the greenhouse gas inventory approach outlined in ISO 14064-1,applying the operational control method to measure both direct and indirect emissions.Data on energy consumption,transportation,and purchased goods and services were collected using digital tools and surveys,and emissions were calculated in metric tons of CO_(2)equivalent(tCO_(2)e).The results indicate that UNAJ’s total carbon footprint in 2023 was 1,461.03 tCO_(2)e,with per capita emissions of 0.47 tCO_(2)e per person.The main sources of emissions were transportation,accounting for 75.88%of total emissions,followed by the consumption of goods and services(14.29%)and energy use(5.12%).Despite limitations in solid waste management,the study makes a valuable contribution to the development of sustainability strategies,emphasizing the urgent need for sustainable mobility policies,energy efficiency measures,and the adoption of responsible procurement practices.Furthermore,it highlights the importance of achieving carbon neutrality at UNAJ as a key objective in mitigating its environmental impact.The findings provide relevant insights from the Peruvian context and offer a basis for analyzing emissions at local universities,with practical implications for enhancing environmental management in higher education institutions.
文摘AIM:To characterize the ocular surface characteristics in the Nepalese population across all age groups who have used digital screens for extended durations over several years.METHODS:In a cross-sectional,observational study,144 digital screen users were assessed for dry eye disease(DED)using subjective and objective measures.The Ocular Surface Disease Index(OSDI)Questionnaire evaluated symptoms,followed by clinical assessments,including slit lamp biomicroscopy,tear breakup time(TBUT),Oxford Scheme grading,and Schirmer I test.DED was diagnosed if a patient had an OSDI score over 13 and at least two clinical signs(OSDI,Schirmer I test,or ocular staining).The prevalence of DED was calculated based on the proportion of patients meeting these criteria.RESULTS:Of the 144 participants(mean age:34.6±15.2y),78(54.2%)were female.The use of digital screens varied between 2-8h(mean duration:4.1±2.7h)per day.The mean OSDI score,TBUT score,and the Schirmer I scores were 22.7±10.5(max-min:24.4-20.9),6.8±4.2s(max-min:7.5-6.1),and 12.3±4.6 mm(max-min:13.1-11.5)respectively with 95%confidence interval(β=1.96),and a two-tailed statistical significance level of 5%(α=0.05).With increased screen use,TBUT shortened and OSDI scores increased significantly(P<0.01),though Schirmer I scores were unaffected(P>0.05).The prevalence of DED ranged from 6.3%to 22.9%in those using screens for more than 2h,with an overall prevalence of 67.4%among digital screen users.CONCLUSION:There is a significant association between prolonged use of digital screens and clinical markers of dry eye signs and symptoms.
基金support by the National Science Foundation of China (32130015)Yunnan Revitalization Talent Support Program Yunling Scholar Project+7 种基金the Animal Branch of the Germplasm Bank of Wild Species, Chinese Academy of Sciences (the Large Research Infrastructure Funding) to Jing CHE,Biological Resources Programme, Chinese Academy of SciencesYunnan Revitalization Talent Support Program Young Talent ProjectCAS Special Research Assistant (SRA) ProgramProgram of Yunnan Forestry and Grassland Administration (2022GF258D-10)Small Grant Program for New Records and Rediscoveries of Rare Species by Tencent FoundationShanshui Conservation Center to Kai WANGU.S. National Science Foundation (grant DEB1145922)the Partnerships for Enhanced Engagement in Research (PEER) Science program (grant PGA-2000003545), which is a partnership between the U.S. Agency for International Development (USAID) and the U.S. National Science Foundation to Bryan L. STUART。
文摘Despite continuous progress made on the taxonomy of the genus Tropidophorus, the Lao Water Skink, T. laotus, is only known from brief descriptions of its syntypes in historical literature. Here we designate a lectotype and paralectotype of the species, redescribe the species based on the type series and newly collected topotypes, provide the first colored photographs of taxonomically-verified individuals, and estimate its phylogenetic position using mitochondrial DNA data for the first time.Using these comparable data, we confirm that the previously identified “T. berdmorei” population from southern Yunnan Province, China, represents a distinct new species that is closely related and morphologically similar to T. laotus, but differs from true T. laotus by having considerable genetic divergence(4.7%–4.8% for 12S, 3.2%–4.2% for 16S)and distinct morphological characters(e.g., undivided frontonasal scales and a distinct color pattern of the throat). The southern Yunnan population is therefore described as a new species. With the above newly acquired data, we update the checklist and the provincial-level distribution of the genus Tropidophorus in China and compile an updated key to all recognized species of the genus from China and Indochina.
基金Nguyen Tat Thanh University,Ho Chi Minh city,Vietnam,for supporting this study
文摘The intermittent nature of solar irradiance is a critical constraint for the realization of continuous photocatalytic hydrogen evolution,thus urging the development of more powerful systems persistently active after illumination.This limitation is bypassed in round-the-clock photocatalytic architectures,which incorporate advanced charge storage to de-correlate pho-ton absorption and catalytic turnover time scales.The strategies involve defect-mediated trap states,multi-electron redox processes,radical-dependent stabilization,and an interfacial charge pool in Faradaic junctions to work together,leading to extended hydrogen evolution reaction(HER)in the dark.Long afterglow phosphorescent materials(e.g.,Sr_(2)MgSi_(2)O_(7):Eu^(2+),Dy^(3+))incorporated in heterojunction architectures with type II or Z-scheme band alignments can also promote fast charge separation for energy storage and subsequently enable controlled release after light quenching by the phosphorescent emis-sion.Advances in band-structure engineering,plasmonic coupling,and redox-active interfacial design result in systems with extraordinary stability and catalytic activity under natural day-night cycles.These stable photocatalytic systems off er a fundamentally new strategy for effi cient and environmentally benign sunlight-driven fuel production,meeting both per-formance and sustainability challenges to renewable energy technologies.
基金The paper presented at the 28th Seminar on Recent Advances inAnimal Health and Production, University Putra Malaysia, KualaLumpur, Malaysia, March 28th, 2005
文摘A review of the systemic acute phase reaction with major cytokines involved, and the hepatic metabolic changes, negative and positive acute phase proteins (APPs) with function and associated pathology is given. It appears that APPs represent appropriate analytes for assessment of animal health. Whereas they represent non-specific markers as biological effect reactants, they can be used for assessing nutritional deficits and reactive processes, especially when positive and negative acute phase variables are combined in an index. When such acute phase index is applied to separate healthy animals from animals with some disease, much better results are obtained than with single analytes and statistically acceptable results for culling individual animals may be reached. Unfortunately at present no cheap, comprehensive and easy to use system is available for assessing various acute phase proteins in serum or blood samples at the same time. Protein microarray or fluid phase microchip technology may satisfy this need; and permit simultaneous analysis of numerous analytes in the same small volume sample and enable integration of information derived from systemic reactivity and nutrition with disease specific variables. Applying such technology may help to solve health problems in various countries not only in animal husbandry but also in human populations.
文摘In many second-rotation Pinus radiata forest planta-tions, there has been a steady trend towards wider tree spacing and an increased rate of application of P fertiliser. Under these regimes, the potential for understory growth is expected to in-crease through increased light and greater nutrient resources. Therefore, understory vegetation could become a more signifi-cant component of P cycling in P. radiata forests than under closely-spaced stands. Studies have shown that growth rates and survival of trees is reduced in the presence of understory vegeta-tion due to the competition of understory vegetation with trees. Other studies have suggested that understory vegetation might have beneficial effects on nutrient cycling and conservation within forest stands. This review discusses the significance of understory vegetation in radiata pine forest stands, especially their role in enhancing or reducing P availability to forest trees.
文摘Potassium （K^＋） is an essential macronutrient for all living organisms and large amounts are required for plant growth and development. In many regions of Asia K＋-fertilization has been neglected and soils have become K＋-depleted. K＋- deficiency in the field diminishes not only crop production but also leads to environmental problems due to inefficient usage and leaching of nitrate. Consequences of K^＋-deficiency on crop production range from decreased biomass, nutritional quality and taste of the crops to inferior harvest and storage properties, as well as increased susceptibility to disease. Effects of K^＋-deficiency on plant physiology include decreased photosynthetic rate, impaired tissue allocation of sugars and amino acids, decreased protein synthesis.
基金Supported by National Natural Science Foundation of China under Grant Nos. 70431002, 10647001, and 60874087
文摘A large unified hybrid network model with a variable speed growth （LUHNM-VSG） is proposed as third model of the unified hybrid network theoretical framework （UHNTF）. A hybrid growth ratio vg of deterministic linking number to random linking number and variable speed growth index a are introduced in it. The main effects of vg and a on topological transition features of the LUHNM-VSC are revealed. For comparison with the other models, we construct a type of the network complexity pyramid with seven levels, in which from the bottom level-1 to the top level-7 of the pyramid simplicity-universality is increasing but complexity-diversity is decreasing. The transition relations between them depend on matching of four hybrid ratios （dr, fd, gr, vg）. Thus the most of network models can be investigated in the unification way via four hybrid ratios （dr, fd, gr, vg）. The LUHNM-VSG as the level-1 of the pyramid is much better and closer to description of real-world networks as well as has potential application.
