The equivalence between multilayered barriers regarding diffusion and adsorption was studied.The bottom boundary of the liner system is defined by assuming concentration continuous and flux continuous conditions of th...The equivalence between multilayered barriers regarding diffusion and adsorption was studied.The bottom boundary of the liner system is defined by assuming concentration continuous and flux continuous conditions of the contaminant between the bottom liner layer and the underlying soil.Five different liner systems were compared in terms of solute breakthrough time.The results of the analysis showed that breakthrough time of the hydrophobic organic compounds for a 2-meter-thick compacted clay liner(CCL)could be 3-4 orders of magnitude is greater than the breakthrough time for a geosynthetic clay liner(GCL)composite liner.The GM/GCL and GM/CCL composite liner systems provide a better diffusion barrier for the hydrophilic organic compounds than that for the hydrophobic compounds due to their different Henry's coefficient.The calculated breakthrough times of the organic contaminants for the Chinese standard liner systems were found to be generally greater than those for the GCL alternatives,for the specific conditions examined.If the distribution coefficient increases to 2.8 for the hydrophobic compounds or 1.0 for the hydrophilic compounds,the thickness of the attenuation layer needed to achieve the same breakthrough time as the standard liner systems can be reduced by a factor of about 1.9-2.4.As far as diffusive and adsorption contaminant transport are concerned,GM or GCL is less effective than CCL.展开更多
In order to deeply research the structure discrepancy and modeling mechanism among different grey prediction models, the equivalence and unbiasedness of grey prediction models are analyzed and verified. The results sh...In order to deeply research the structure discrepancy and modeling mechanism among different grey prediction models, the equivalence and unbiasedness of grey prediction models are analyzed and verified. The results show that all the grey prediction models that are strictly derived from x^（0）（k） ＋az^（1）（k） = b have the identical model structure and simulation precision. Moreover, the unbiased simulation for the homogeneous exponential sequence can be accomplished. However, the models derived from dx^（1）/dt ＋ ax^（1）= b are only close to those derived from x^（0）（k） ＋ az^（1）（k） = b provided that ｜a｜ has to satisfy｜a｜ 0.1; neither could the unbiased simulation for the homogeneous exponential sequence be achieved. The above conclusions are proved and verified through some theorems and examples.展开更多
With the growth of capacity of high voltage direct current(HVDC) transmission lines,the ratings of thyristor valves,which are one of the most critical equipments,are getting higher and higher.Verification of performan...With the growth of capacity of high voltage direct current(HVDC) transmission lines,the ratings of thyristor valves,which are one of the most critical equipments,are getting higher and higher.Verification of performance of thyristor valves particularly designed for HVDC project plays an important role in the handover of products between the manufacturer and the client.Conventional test facilities based on philosophy of direct test cannot meet the requirements for modern thyristor valves.New test facilities with high ratings are necessarily built based on philosophy of synthetic test.Over the conventional direct test circuit,the later is an economical and feasible solution with less financial investment and higher test capability.However,the equivalency between the synthetic test and the direct test should be analyzed technically in order to make sure that the condition of verification test in a synthetic test circuit should satisfy the actual operation condition of thyristor valves existing in a real HVDC project,just as in a direct test circuit.Equivalency analysis is focused in this paper,covering the scope of thyristor valves' steady state,and transient state.On the basis of the results achieved,a synthetic test circuit of 6 500 A/50 kV for operational tests of thyristor valves used for up to UHVDC project has newly been set up and already put into service in Xi'an High Voltage Apparatus Research Institute Co.,Ltd.(XIHARI),China.Some of the results have been adopted also by a new national standard of China.展开更多
This paper is concerned with the general study in the existence,uniqueness and error estimationof finite element solutions for a larger class of 'saddle-point' schemes. The established theory inthe form of Lax...This paper is concerned with the general study in the existence,uniqueness and error estimationof finite element solutions for a larger class of 'saddle-point' schemes. The established theory inthe form of Lax-like equivalency theorem includes Brezzi’s theory that has been treated as a specialcase.Two criteria are presented so as to help the practical verification of S-Babuska condition.展开更多
This study explores the possibility of opening a policy window for the adoption of the FAIR Guidelines—that data be Findable, Accessible, Interoperable, and Reusable(FAIR)—in Uganda’s e Health sector. Although the ...This study explores the possibility of opening a policy window for the adoption of the FAIR Guidelines—that data be Findable, Accessible, Interoperable, and Reusable(FAIR)—in Uganda’s e Health sector. Although the FAIR Guidelines were not mentioned in any of the policy documents relevant to Uganda’s e Health sector, the study found that 83% of the documents mentioned FAIR Equivalent efforts, such as the adoption of the National Identification Number(NIN) as a unique identifier in Uganda’s national Electronic Health Management Information System(e HMIS)(findability), the planned/ongoing integration of various information systems(interoperability), and the alignment of various projects with international best practices/standards(reusability). A FAIR Equivalency Score(FE-Score), devised in this study as an aggregate score of the mention of the equivalent of FAIR facets in the policy documents, showed that the documents at the core of Uganda’s digital health/e Health policy have the highest score of all the documents analysed, indicating that there is a degree of alignment between Uganda’s National e Health Vision and the FAIR Guidelines. Therefore, it can be concluded that favourable conditions exist for the adoption and implementation of the FAIR Guidelines in Uganda’s e Health sector. Hence, it is recommended that the FAIR community adopt a capacity building strategy through organisations with a worldwide mandate, such as the World Health Organization, to promote the adoption of the FAIR Guidelines as part of international best practices.展开更多
This study explored the regulatory framework in Kenya that may facilitate the implementation of the FAIR Guidelines in health research, as well as the possibility of adopting the FAIR Guidelines at the national level....This study explored the regulatory framework in Kenya that may facilitate the implementation of the FAIR Guidelines in health research, as well as the possibility of adopting the FAIR Guidelines at the national level. Fourteen key documents pivotal to the emerging digital health sector in Kenya were identified and analysed using a comprehensive coding and labelling approach based on a binary system for whether or not they mention the FAIR Guidelines or terms and vocabulary related to the FAIR Guidelines. The analysis revealed gaps in data stewardship that could be filled by the implementation of the FAIR Guidelines and, although the documents analysed do not explicitly mention the FAIR Guidelines, FAIR Equivalent terminology and practices are mentioned in varying detail. However, our analysis shows that there are still no provisions for the introduction and implementation of the FAIR Guidelines in health research in Kenya. Therefore, we recommend that the leadership be provided with a comprehensive introduction to the FAIR Guidelines, success stories about the FAIRification of data and research infrastructure in other parts of the world, and a demonstration of the steps needed for the FAIRification of health data in Kenya.展开更多
This paper investigates whether or not there is a policy window for making health data ‘Findable’, ‘Accessible’(under well-defined conditions), ‘Interoperable’ and ‘Reusable’(FAIR) in Ethiopia. The question is...This paper investigates whether or not there is a policy window for making health data ‘Findable’, ‘Accessible’(under well-defined conditions), ‘Interoperable’ and ‘Reusable’(FAIR) in Ethiopia. The question is answered by studying the alignment of policies for health data in Ethiopia with the FAIR Guidelines or their ‘FAIR Equivalency’. Policy documents relating to the digitalisation of health systems in Ethiopia were examined to determine their FAIR Equivalency. Although the documents are fragmented and have no overarching governing framework, it was found that they aim to make the disparate health data systems in Ethiopia interoperable and boost the discoverability and(re)usability of data for research and better decision making. Hence, the FAIR Guidelines appear to be aligned with the regulatory frameworks for ICT and digital health in Ethiopia and, under the right conditions, a policy window could open for their adoption and implementation.展开更多
Let A be a Grothendieck category.Theλ-pure singularity category D_(λ-sg)^(b)(A)of A is a Verdier quotient of the boundedλ-pure derived category D_(λ)^(b)(A)by a thick subcategory K^(b)(PPλ),i.e.,D_(λ-sg)^(b)(A):...Let A be a Grothendieck category.Theλ-pure singularity category D_(λ-sg)^(b)(A)of A is a Verdier quotient of the boundedλ-pure derived category D_(λ)^(b)(A)by a thick subcategory K^(b)(PPλ),i.e.,D_(λ-sg)^(b)(A):=D_(λ)^(b)(A)/K b(PPλ).We mainly verify that D_(λ-sg)^(b)(A)is triangle equivalent to another quotient category under a special condition.And we also prove that a triangle equivalence between special homotopy categories induces aλ-pure derived equivalence,and it induces aλ-pure singular equivalence too.展开更多
In this paper,an equivalency condition of nonsingularity in nonlinear semidefinite programming,which can be viewed as a generalization of the equivalency condition of nonsingularity for linearsemidefinite programming,...In this paper,an equivalency condition of nonsingularity in nonlinear semidefinite programming,which can be viewed as a generalization of the equivalency condition of nonsingularity for linearsemidefinite programming,is established under certain conditions of convexity.展开更多
equivalency n. a level of achievement equivalent to completion of an educational or trainingprogram。同等学历(相当于完成某一教育或训练计划的学业成绩水平):a highschool equivalency certificate中学同等学历证书。注意不能...equivalency n. a level of achievement equivalent to completion of an educational or trainingprogram。同等学历(相当于完成某一教育或训练计划的学业成绩水平):a highschool equivalency certificate中学同等学历证书。注意不能用equivalence。majorly[’meid??li]adv.[1956]展开更多
The subject matter of this paper is the thesis on the underdetermination of theory by experience,in the local account due to Duhem and in the global version due to Quine.This thesis has significant implications concer...The subject matter of this paper is the thesis on the underdetermination of theory by experience,in the local account due to Duhem and in the global version due to Quine.This thesis has significant implications concerning some epistemic uncertainty about the accuracy of the tested predictions of theories.We find this thesis plausible,though more feasible,limited to physical theories,as in Duhem’s approach.We examine the thesis of the impossibility of crucial experiments that Duhem finds implied by his thesis on empirical indeterminacy,as well as the thesis of the possibility of empirically equivalent theories that are logically incompatible,which Quine also finds linked to his thesis on empirical indeterminacy.From a conceptualist approach that acknowledges the abstract character of physical concepts and the idealized nature of physical laws,and assuming Hanson’s thesis on the theory laden of scientific observation,we conclude that the anterior Duhem’s thesis is sound,although the preceding Quine’s thesis does not seem viable.展开更多
Maintaining the structural integrity of parallel natural gas pipelines during leakage-induced jet fires remains a critical engineering challenge.Existing methods often fail to account for the complex interactions amon...Maintaining the structural integrity of parallel natural gas pipelines during leakage-induced jet fires remains a critical engineering challenge.Existing methods often fail to account for the complex interactions among heat transfer,material behavior,and pipeline geometry,which can lead to overly simplified and potentially unsafe assessments.To address these limitations,this study develops a multiphysics approach that integrates small-orifice leakage theory with detailed thermo-fluid-structural simulations.The proposed framework contributes to a more accurate failure analysis through three main components:(1)coupled modeling that tracks transient heat flow and stress development as fire conditions evolve;(2)risk assessment incorporating spatial layout,material property changes with temperature,and operational limits;and(3)sensitivity analysis to identify key design factors that influence structural performance under high thermal loads.Simulation results demonstrate that thermal radiation from neighboring jet fires significantly accelerates material degradation,with inter-pipeline spacing emerging as a critical determinant of structural response.Notably,increasing the spacing between pipelines reduces thermal interaction and mechanical stress transfer.As a result,systems with optimized spacing exhibit markedly lower deformation than conventional configurations.These findings provide a foundation for re-evaluating pipeline layout strategies and strengthening safety protocols,particularly in high-risk environments where fire exposure can severely compromise structural reliability.The proposed approach offers actionable guidance for engineers and policymakers seeking to enhance the resilience of pipeline infrastructure under extreme thermal conditions.展开更多
A shaking table test was performed to investigate the different responses of piles with and without cement-soil reinforcement,considering both inertial and kinematic interactions.A comparison of the dynamic shear stre...A shaking table test was performed to investigate the different responses of piles with and without cement-soil reinforcement,considering both inertial and kinematic interactions.A comparison of the dynamic shear stress−strain hysteresis curves of soil profiles on the pile side with and without cement-soil reinforced piles indicates that cement-soil reinforced piles not only bear more tremendous shear stress but also have smaller strains under the action of cyclic shear stress.Furthermore,the cement-soil on the pile side not only shares part of the shear stress and modifies the bending moment distribution but also significantly enhances the resistance of the pile-side soil,reducing the lateral displacement of the superstructure.Cement-soil reinforcement reduced shear strains,inhibited sand liquefaction,and reduced superstructure displacements by 27%−47%(instantaneous)and 40%−65%(permanent).The proportion of horizontal load sharing between cement-soil reinforcement and saturated sand is considered,along with the change pattern of the subgrade reaction after sand liquefaction.An equivalent subgrade reaction calculation method is proposed,which accounts for the horizontal load-sharing ratios of soils with two different strengths.The test results indicate that the pile stress and displacement,estimated using the equivalent subgrade reaction,are in good agreement with the observed results.展开更多
In fatigue damage tolerance verification tests of aircraft structures,the simulation and loading of flight-byflight spectra require considerable time and resources.To improve the efficiency of load spectrum design and...In fatigue damage tolerance verification tests of aircraft structures,the simulation and loading of flight-byflight spectra require considerable time and resources.To improve the efficiency of load spectrum design and testing,an equivalent constant-amplitude spectrum design method for flight-by-flight spectra is proposed based on the equivalence of crack growth behavior.By combining the Paris crack growth model with the Walker stress ratio correction,the equivalent stress amplitude is directly calculated using structural parameters and load spectrum characteristics,enabling a rapid transformation from variable-amplitude spectra to constant-amplitude spectra.The original spectrum is discretized based on the load-exceedance curve,and the equivalence relationship between multilevel block spectra and constant-amplitude spectra is established.Taking a typical lower wing skin structure of a transport aircraft as an example,two equivalent spectra are designed and validated through fatigue crack growth tests on 2024-T351 center-hole plate specimens.The experimental results show that the fatigue life deviation between the equivalent spectra and the original flight-by-flight spectrum is within 10%,demonstrating the effectiveness of the proposed method.Moreover,the equivalent spectrum constructed under the condition of invariant mean flight stress exhibits higher equivalence accuracy.The influence of spectral shape on the equivalent stress amplitude is further analyzed,revealing that the equivalent stress amplitude increases with the spectrum shape coefficient.The proposed method provides a useful reference for load spectrum design in aircraft structural damage tolerance verification tests.展开更多
Tajikistan,a mountainous country and a vital water tower for Central Asia,is becoming increasingly vulnerable to snow drought under climate change,threatening its snow-and glacier-fed streamflow.Yet,the impacts of sno...Tajikistan,a mountainous country and a vital water tower for Central Asia,is becoming increasingly vulnerable to snow drought under climate change,threatening its snow-and glacier-fed streamflow.Yet,the impacts of snow drought on the regional hydrology remain insufficiently understood.In this study,we integrated multisource data,including the Fifth Generation European Centre for Medium-Range Weather Forecasts Atmospheric Reanalysis for Land Applications(ERA5-Land)data and hydrological station data,to systematically assess the snow drought patterns and their impacts on streamflow during 1950–2023.We identified snow drought events based on precipitation and snow fraction anomalies relative to climatological means and classified them into warm snow drought,dry snow drought,and warm&dry snow drought.The results revealed that snow drought was a recurrent phenomenon,occurring in 51.70%of the years during the study period,with warm&dry snow drought accounting for 21.90%of the total events.Both the frequency and severity exhibited pronounced spatial variability,largely governed by the elevation and snowfall fraction.Specifically,the frequency of warm snow drought was negatively correlated with the snowfall fraction,decreasing on average by 0.20 per unit increase in snowfall fraction,whereas the frequency of dry snow drought was positively correlated,increasing by 0.07 per unit increase.The streamflow analysis results demonstrated that snow drought typically reduced the warm-season discharge by 5.00%–18.00%in certain rivers,thereby exacerbating the water stress during the dry season.The results of this study advance our understanding by explicitly linking the types of snow drought to hydrological responses in Central Asia’s high mountains,providing a scientific basis for climate adaptation and sustainable water resource management in Tajikistan.展开更多
The Good Wife is an American TV series that focuses on women’s independence,politics,and law.The drama has been remade in China,Japan,and South Korea.This research aims to use Nida’s Functional Equivalence Theory to...The Good Wife is an American TV series that focuses on women’s independence,politics,and law.The drama has been remade in China,Japan,and South Korea.This research aims to use Nida’s Functional Equivalence Theory to analyze the methods of its English-to-Chinese subtitle translation by considering social,cultural,and historic backgrounds between China and America.After data collection and case analysis,the study found that:(1)Five major translation methods are adopted in the subtitle translation of The Good Wife.They are free translation,variation,literal translation,addition,and omission.Among them,free translation is the most frequently used,while omission is used least.(2)The subtitle translation of films and TV series is limited by time and space restrictions,social-cultural differences,and other factors.When translating,translators should try to use humorous words,euphemism,intonation,and other ways,and combine different methods such as literal translation,free translation,variation,addition,omission,and other methods to seek equivalence both in the meaning and function of subtitles under the guidance of Functional Equivalence Theory.展开更多
We show that in Schwarzschild equivalent mediums,the massless spin particles obey the same dynamical equation,from which we obtain remarkably simple formulae for the frequencies of the quasibound states.We find that t...We show that in Schwarzschild equivalent mediums,the massless spin particles obey the same dynamical equation,from which we obtain remarkably simple formulae for the frequencies of the quasibound states.We find that the quasibound frequencies of different bosons can be identical at the same quantum number l,and the same is true of different fermions,but a quasibound frequency for bosons can never equal a quasibound frequency for fermions.These results mean that in Schwarzschild equivalent mediums with the quasibound-state boundary conditions,characteristics of electromagnetic waves are the same as those for all the massless bosonic waves,thereby allowing electromagnetic waves to simulate gravitational waves.Our predictions can be tested in future experiments,building upon the successful preparation of Schwarzschild equivalent mediums.展开更多
As binary geological media,soil-rock mixtures(SRMs)exhibit a distinct gradational composition,leading to their unique mechanical behaviors.To appraise the stability of SRM slopes,it is essential to determine equivalen...As binary geological media,soil-rock mixtures(SRMs)exhibit a distinct gradational composition,leading to their unique mechanical behaviors.To appraise the stability of SRM slopes,it is essential to determine equivalent parameters of SRMs,which are typically obtained through experimental and numerical methods.In contrasted to other numerical methods,the numerical manifold method(NMM)is more effective in addressing SRM problems.This is because the high-precision regular mathematical meshes in NMM can be used without aligning with the soil-rock interfaces and boundaries of SRMs.In the current research,the equivalent strength parameters of SRMs,i.e.the equivalent cohesion ce and internal friction angleϕ_(e),are determined using NMM.Initially,an NMM triaxial numerical model is established and validated based on triaxial experiments.Subsequently,the soil and rock parameters are derived through parameter inversion.Moreover,the impacts of rock content,size,shape and rock blocks'major-axis orientation on ce andϕ_(e) of SRMs are thoroughly examined using the NMM triaxial numerical model.Additionally,a fitting function is proposed to linkϕ_(e) to the rock content and size of SRMs.When other influencing factors are fixed,the above fitting model leads to the following conclusions:(1)the predictedϕ_(e) of SRMs increase with the increase of rock content;and(2)SRM samples with smaller rocks display a higher predictedϕ_(e).展开更多
For the ultra HVDC(UHVDC)with the hierarchical connection mode at the inverter side,considering the change of the Thevenin equivalent parameters(TEP)of post-fault AC grid,a coordinated control strategy to the subseque...For the ultra HVDC(UHVDC)with the hierarchical connection mode at the inverter side,considering the change of the Thevenin equivalent parameters(TEP)of post-fault AC grid,a coordinated control strategy to the subsequent commutation failure(SCF)at both layers is newly proposed.The originality of this work is manifested in three aspects.1)The mechanism of the SCF at the fault layer is newly found by deriving the analytical expression of the extinction angle with the TEP,and that at the non-fault layer is newly found by the voltage-time area theory with the DC current coupling.2)An estimation model for the TEPs of two AC grids at the inverter side is proposed with the post-fault quantities.To address the random noise and inaccurate measurement data,an adaptive robust least squares method based on the median principle is proposed to solve the TEP model.3)A coordinated control strategy with the estimated TEP is proposed to compensate for the extinction angle at the fault layer and limit the DC current at the non-fault layer,thus suppressing the SCF.The simulation results verify the suppression effect of the proposed control on the SCF under different fault conditions.展开更多
Generalised reduced masses with a set of equations governing the three relative motions between two of 3-bodies in their gravitational field are established,of which the dynamic characteristics of 3-body dynamics,fund...Generalised reduced masses with a set of equations governing the three relative motions between two of 3-bodies in their gravitational field are established,of which the dynamic characteristics of 3-body dynamics,fundamental bases of this paper,are revealed.Based on these findings,an equivalent system is developed,which is a 2-body system with its total mass,constant angular momentum,kinetic and potential energies same as the total ones of three relative motions,so that it can be solved using the well-known theory of the 2-body system.From the solution of an equivalent system with the revealed characteristics of three relative motions,the general theoretical solutions of the 3-body system are obtained in the curve-integration forms along the orbits in the imaged radial motion space.The possible periodical orbits with generalised Kepler’s law are presented.Following the description and mathematical demonstrations of the proposed methods,the examples including Euler’s/Lagrange’s problems,and a reported numerical one are solved to validate the proposed methods.The methods derived from the 3-body system are extended to N-body problems.展开更多
基金supported by the National Science Fundfor Distinguished Young Scholars(No.50425825)the National Natural Science Foundation of China(No.50538080)
文摘The equivalence between multilayered barriers regarding diffusion and adsorption was studied.The bottom boundary of the liner system is defined by assuming concentration continuous and flux continuous conditions of the contaminant between the bottom liner layer and the underlying soil.Five different liner systems were compared in terms of solute breakthrough time.The results of the analysis showed that breakthrough time of the hydrophobic organic compounds for a 2-meter-thick compacted clay liner(CCL)could be 3-4 orders of magnitude is greater than the breakthrough time for a geosynthetic clay liner(GCL)composite liner.The GM/GCL and GM/CCL composite liner systems provide a better diffusion barrier for the hydrophilic organic compounds than that for the hydrophobic compounds due to their different Henry's coefficient.The calculated breakthrough times of the organic contaminants for the Chinese standard liner systems were found to be generally greater than those for the GCL alternatives,for the specific conditions examined.If the distribution coefficient increases to 2.8 for the hydrophobic compounds or 1.0 for the hydrophilic compounds,the thickness of the attenuation layer needed to achieve the same breakthrough time as the standard liner systems can be reduced by a factor of about 1.9-2.4.As far as diffusive and adsorption contaminant transport are concerned,GM or GCL is less effective than CCL.
基金supported by the National Natural Science Foundation of China(1147105951375517+5 种基金71271226)the China Postdoctoral Science Foundation Funded Project(2014M560712)Chongqing Frontier and Applied Basic Research Project(cstc2014jcyj A00024)the Ministry of Education of Humanities and Social Sciences Youth Foundation(14YJAZH033)the Chongqing Municipal Education Scientific Planning Project(2012-GX-142)the Higher School Teaching Reform Research Project in Chongqing(1202010)
文摘In order to deeply research the structure discrepancy and modeling mechanism among different grey prediction models, the equivalence and unbiasedness of grey prediction models are analyzed and verified. The results show that all the grey prediction models that are strictly derived from x^（0）（k） ＋az^（1）（k） = b have the identical model structure and simulation precision. Moreover, the unbiased simulation for the homogeneous exponential sequence can be accomplished. However, the models derived from dx^（1）/dt ＋ ax^（1）= b are only close to those derived from x^（0）（k） ＋ az^（1）（k） = b provided that ｜a｜ has to satisfy｜a｜ 0.1; neither could the unbiased simulation for the homogeneous exponential sequence be achieved. The above conclusions are proved and verified through some theorems and examples.
基金Project Supported by National Development and Reform Commission(No.[2006]2709)
文摘With the growth of capacity of high voltage direct current(HVDC) transmission lines,the ratings of thyristor valves,which are one of the most critical equipments,are getting higher and higher.Verification of performance of thyristor valves particularly designed for HVDC project plays an important role in the handover of products between the manufacturer and the client.Conventional test facilities based on philosophy of direct test cannot meet the requirements for modern thyristor valves.New test facilities with high ratings are necessarily built based on philosophy of synthetic test.Over the conventional direct test circuit,the later is an economical and feasible solution with less financial investment and higher test capability.However,the equivalency between the synthetic test and the direct test should be analyzed technically in order to make sure that the condition of verification test in a synthetic test circuit should satisfy the actual operation condition of thyristor valves existing in a real HVDC project,just as in a direct test circuit.Equivalency analysis is focused in this paper,covering the scope of thyristor valves' steady state,and transient state.On the basis of the results achieved,a synthetic test circuit of 6 500 A/50 kV for operational tests of thyristor valves used for up to UHVDC project has newly been set up and already put into service in Xi'an High Voltage Apparatus Research Institute Co.,Ltd.(XIHARI),China.Some of the results have been adopted also by a new national standard of China.
文摘This paper is concerned with the general study in the existence,uniqueness and error estimationof finite element solutions for a larger class of 'saddle-point' schemes. The established theory inthe form of Lax-like equivalency theorem includes Brezzi’s theory that has been treated as a specialcase.Two criteria are presented so as to help the practical verification of S-Babuska condition.
基金VODAN-Africathe Philips Foundation+2 种基金the Dutch Development Bank FMOCORDAIDthe GO FAIR Foundation for supporting this research
文摘This study explores the possibility of opening a policy window for the adoption of the FAIR Guidelines—that data be Findable, Accessible, Interoperable, and Reusable(FAIR)—in Uganda’s e Health sector. Although the FAIR Guidelines were not mentioned in any of the policy documents relevant to Uganda’s e Health sector, the study found that 83% of the documents mentioned FAIR Equivalent efforts, such as the adoption of the National Identification Number(NIN) as a unique identifier in Uganda’s national Electronic Health Management Information System(e HMIS)(findability), the planned/ongoing integration of various information systems(interoperability), and the alignment of various projects with international best practices/standards(reusability). A FAIR Equivalency Score(FE-Score), devised in this study as an aggregate score of the mention of the equivalent of FAIR facets in the policy documents, showed that the documents at the core of Uganda’s digital health/e Health policy have the highest score of all the documents analysed, indicating that there is a degree of alignment between Uganda’s National e Health Vision and the FAIR Guidelines. Therefore, it can be concluded that favourable conditions exist for the adoption and implementation of the FAIR Guidelines in Uganda’s e Health sector. Hence, it is recommended that the FAIR community adopt a capacity building strategy through organisations with a worldwide mandate, such as the World Health Organization, to promote the adoption of the FAIR Guidelines as part of international best practices.
基金VODAN-Africathe Philips Foundation+2 种基金the Dutch Development Bank FMOCORDAIDthe GO FAIR Foundation for supporting this research
文摘This study explored the regulatory framework in Kenya that may facilitate the implementation of the FAIR Guidelines in health research, as well as the possibility of adopting the FAIR Guidelines at the national level. Fourteen key documents pivotal to the emerging digital health sector in Kenya were identified and analysed using a comprehensive coding and labelling approach based on a binary system for whether or not they mention the FAIR Guidelines or terms and vocabulary related to the FAIR Guidelines. The analysis revealed gaps in data stewardship that could be filled by the implementation of the FAIR Guidelines and, although the documents analysed do not explicitly mention the FAIR Guidelines, FAIR Equivalent terminology and practices are mentioned in varying detail. However, our analysis shows that there are still no provisions for the introduction and implementation of the FAIR Guidelines in health research in Kenya. Therefore, we recommend that the leadership be provided with a comprehensive introduction to the FAIR Guidelines, success stories about the FAIRification of data and research infrastructure in other parts of the world, and a demonstration of the steps needed for the FAIRification of health data in Kenya.
基金VODAN-Africathe Philips Foundation+2 种基金the Dutch Development Bank FMOCORDAIDthe GO FAIR Foundation for supporting this research
文摘This paper investigates whether or not there is a policy window for making health data ‘Findable’, ‘Accessible’(under well-defined conditions), ‘Interoperable’ and ‘Reusable’(FAIR) in Ethiopia. The question is answered by studying the alignment of policies for health data in Ethiopia with the FAIR Guidelines or their ‘FAIR Equivalency’. Policy documents relating to the digitalisation of health systems in Ethiopia were examined to determine their FAIR Equivalency. Although the documents are fragmented and have no overarching governing framework, it was found that they aim to make the disparate health data systems in Ethiopia interoperable and boost the discoverability and(re)usability of data for research and better decision making. Hence, the FAIR Guidelines appear to be aligned with the regulatory frameworks for ICT and digital health in Ethiopia and, under the right conditions, a policy window could open for their adoption and implementation.
文摘Let A be a Grothendieck category.Theλ-pure singularity category D_(λ-sg)^(b)(A)of A is a Verdier quotient of the boundedλ-pure derived category D_(λ)^(b)(A)by a thick subcategory K^(b)(PPλ),i.e.,D_(λ-sg)^(b)(A):=D_(λ)^(b)(A)/K b(PPλ).We mainly verify that D_(λ-sg)^(b)(A)is triangle equivalent to another quotient category under a special condition.And we also prove that a triangle equivalence between special homotopy categories induces aλ-pure derived equivalence,and it induces aλ-pure singular equivalence too.
基金supported by the National Natural Science Foundation of China under Grant No. 10871098the Natural Science Fund of Jiangsu Province under Grant No. BK2009397the Innovation Fund of Youth of Fujian Province under Grant No. 2009J05003 and CNPq Brazil
文摘In this paper,an equivalency condition of nonsingularity in nonlinear semidefinite programming,which can be viewed as a generalization of the equivalency condition of nonsingularity for linearsemidefinite programming,is established under certain conditions of convexity.
文摘equivalency n. a level of achievement equivalent to completion of an educational or trainingprogram。同等学历(相当于完成某一教育或训练计划的学业成绩水平):a highschool equivalency certificate中学同等学历证书。注意不能用equivalence。majorly[’meid??li]adv.[1956]
文摘The subject matter of this paper is the thesis on the underdetermination of theory by experience,in the local account due to Duhem and in the global version due to Quine.This thesis has significant implications concerning some epistemic uncertainty about the accuracy of the tested predictions of theories.We find this thesis plausible,though more feasible,limited to physical theories,as in Duhem’s approach.We examine the thesis of the impossibility of crucial experiments that Duhem finds implied by his thesis on empirical indeterminacy,as well as the thesis of the possibility of empirically equivalent theories that are logically incompatible,which Quine also finds linked to his thesis on empirical indeterminacy.From a conceptualist approach that acknowledges the abstract character of physical concepts and the idealized nature of physical laws,and assuming Hanson’s thesis on the theory laden of scientific observation,we conclude that the anterior Duhem’s thesis is sound,although the preceding Quine’s thesis does not seem viable.
文摘Maintaining the structural integrity of parallel natural gas pipelines during leakage-induced jet fires remains a critical engineering challenge.Existing methods often fail to account for the complex interactions among heat transfer,material behavior,and pipeline geometry,which can lead to overly simplified and potentially unsafe assessments.To address these limitations,this study develops a multiphysics approach that integrates small-orifice leakage theory with detailed thermo-fluid-structural simulations.The proposed framework contributes to a more accurate failure analysis through three main components:(1)coupled modeling that tracks transient heat flow and stress development as fire conditions evolve;(2)risk assessment incorporating spatial layout,material property changes with temperature,and operational limits;and(3)sensitivity analysis to identify key design factors that influence structural performance under high thermal loads.Simulation results demonstrate that thermal radiation from neighboring jet fires significantly accelerates material degradation,with inter-pipeline spacing emerging as a critical determinant of structural response.Notably,increasing the spacing between pipelines reduces thermal interaction and mechanical stress transfer.As a result,systems with optimized spacing exhibit markedly lower deformation than conventional configurations.These findings provide a foundation for re-evaluating pipeline layout strategies and strengthening safety protocols,particularly in high-risk environments where fire exposure can severely compromise structural reliability.The proposed approach offers actionable guidance for engineers and policymakers seeking to enhance the resilience of pipeline infrastructure under extreme thermal conditions.
基金Project(52078129)supported by the National Natural Science Foundation of ChinaProject(MTF2023009)supported by the Open Project of Key Laboratory of Transport Industry of Comprehensive Transportation Theory(Nanjing Modern Multimodal Transportation Laboratory),ChinaProject(2242024K40037)supported by the Fundamental Research Funds for the Central Universities,China。
文摘A shaking table test was performed to investigate the different responses of piles with and without cement-soil reinforcement,considering both inertial and kinematic interactions.A comparison of the dynamic shear stress−strain hysteresis curves of soil profiles on the pile side with and without cement-soil reinforced piles indicates that cement-soil reinforced piles not only bear more tremendous shear stress but also have smaller strains under the action of cyclic shear stress.Furthermore,the cement-soil on the pile side not only shares part of the shear stress and modifies the bending moment distribution but also significantly enhances the resistance of the pile-side soil,reducing the lateral displacement of the superstructure.Cement-soil reinforcement reduced shear strains,inhibited sand liquefaction,and reduced superstructure displacements by 27%−47%(instantaneous)and 40%−65%(permanent).The proportion of horizontal load sharing between cement-soil reinforcement and saturated sand is considered,along with the change pattern of the subgrade reaction after sand liquefaction.An equivalent subgrade reaction calculation method is proposed,which accounts for the horizontal load-sharing ratios of soils with two different strengths.The test results indicate that the pile stress and displacement,estimated using the equivalent subgrade reaction,are in good agreement with the observed results.
基金supported by the National Natural Science Foundation of China(No.52075244).
文摘In fatigue damage tolerance verification tests of aircraft structures,the simulation and loading of flight-byflight spectra require considerable time and resources.To improve the efficiency of load spectrum design and testing,an equivalent constant-amplitude spectrum design method for flight-by-flight spectra is proposed based on the equivalence of crack growth behavior.By combining the Paris crack growth model with the Walker stress ratio correction,the equivalent stress amplitude is directly calculated using structural parameters and load spectrum characteristics,enabling a rapid transformation from variable-amplitude spectra to constant-amplitude spectra.The original spectrum is discretized based on the load-exceedance curve,and the equivalence relationship between multilevel block spectra and constant-amplitude spectra is established.Taking a typical lower wing skin structure of a transport aircraft as an example,two equivalent spectra are designed and validated through fatigue crack growth tests on 2024-T351 center-hole plate specimens.The experimental results show that the fatigue life deviation between the equivalent spectra and the original flight-by-flight spectrum is within 10%,demonstrating the effectiveness of the proposed method.Moreover,the equivalent spectrum constructed under the condition of invariant mean flight stress exhibits higher equivalence accuracy.The influence of spectral shape on the equivalent stress amplitude is further analyzed,revealing that the equivalent stress amplitude increases with the spectrum shape coefficient.The proposed method provides a useful reference for load spectrum design in aircraft structural damage tolerance verification tests.
基金supported by the National Key Research and Development Project of China(2025YFE0103300)the National Natural Science Foundation of China(W2412135)+2 种基金the Natural Science Foundation of Xinjiang Uygur Autonomous Region(2024D01A143,2025D01B165)the China Postdoctoral Science Foundation(GZC20250226)the S&T Innovation and Development Project of Information Institution of Ministry of Emergency Management,China(2024506).
文摘Tajikistan,a mountainous country and a vital water tower for Central Asia,is becoming increasingly vulnerable to snow drought under climate change,threatening its snow-and glacier-fed streamflow.Yet,the impacts of snow drought on the regional hydrology remain insufficiently understood.In this study,we integrated multisource data,including the Fifth Generation European Centre for Medium-Range Weather Forecasts Atmospheric Reanalysis for Land Applications(ERA5-Land)data and hydrological station data,to systematically assess the snow drought patterns and their impacts on streamflow during 1950–2023.We identified snow drought events based on precipitation and snow fraction anomalies relative to climatological means and classified them into warm snow drought,dry snow drought,and warm&dry snow drought.The results revealed that snow drought was a recurrent phenomenon,occurring in 51.70%of the years during the study period,with warm&dry snow drought accounting for 21.90%of the total events.Both the frequency and severity exhibited pronounced spatial variability,largely governed by the elevation and snowfall fraction.Specifically,the frequency of warm snow drought was negatively correlated with the snowfall fraction,decreasing on average by 0.20 per unit increase in snowfall fraction,whereas the frequency of dry snow drought was positively correlated,increasing by 0.07 per unit increase.The streamflow analysis results demonstrated that snow drought typically reduced the warm-season discharge by 5.00%–18.00%in certain rivers,thereby exacerbating the water stress during the dry season.The results of this study advance our understanding by explicitly linking the types of snow drought to hydrological responses in Central Asia’s high mountains,providing a scientific basis for climate adaptation and sustainable water resource management in Tajikistan.
文摘The Good Wife is an American TV series that focuses on women’s independence,politics,and law.The drama has been remade in China,Japan,and South Korea.This research aims to use Nida’s Functional Equivalence Theory to analyze the methods of its English-to-Chinese subtitle translation by considering social,cultural,and historic backgrounds between China and America.After data collection and case analysis,the study found that:(1)Five major translation methods are adopted in the subtitle translation of The Good Wife.They are free translation,variation,literal translation,addition,and omission.Among them,free translation is the most frequently used,while omission is used least.(2)The subtitle translation of films and TV series is limited by time and space restrictions,social-cultural differences,and other factors.When translating,translators should try to use humorous words,euphemism,intonation,and other ways,and combine different methods such as literal translation,free translation,variation,addition,omission,and other methods to seek equivalence both in the meaning and function of subtitles under the guidance of Functional Equivalence Theory.
基金supported by the National Natural Science Foundation of China under Grant No.12175198。
文摘We show that in Schwarzschild equivalent mediums,the massless spin particles obey the same dynamical equation,from which we obtain remarkably simple formulae for the frequencies of the quasibound states.We find that the quasibound frequencies of different bosons can be identical at the same quantum number l,and the same is true of different fermions,but a quasibound frequency for bosons can never equal a quasibound frequency for fermions.These results mean that in Schwarzschild equivalent mediums with the quasibound-state boundary conditions,characteristics of electromagnetic waves are the same as those for all the massless bosonic waves,thereby allowing electromagnetic waves to simulate gravitational waves.Our predictions can be tested in future experiments,building upon the successful preparation of Schwarzschild equivalent mediums.
基金supported by the National Natural Science Foundation of China(Grant Nos.12272393 and 52130905).
文摘As binary geological media,soil-rock mixtures(SRMs)exhibit a distinct gradational composition,leading to their unique mechanical behaviors.To appraise the stability of SRM slopes,it is essential to determine equivalent parameters of SRMs,which are typically obtained through experimental and numerical methods.In contrasted to other numerical methods,the numerical manifold method(NMM)is more effective in addressing SRM problems.This is because the high-precision regular mathematical meshes in NMM can be used without aligning with the soil-rock interfaces and boundaries of SRMs.In the current research,the equivalent strength parameters of SRMs,i.e.the equivalent cohesion ce and internal friction angleϕ_(e),are determined using NMM.Initially,an NMM triaxial numerical model is established and validated based on triaxial experiments.Subsequently,the soil and rock parameters are derived through parameter inversion.Moreover,the impacts of rock content,size,shape and rock blocks'major-axis orientation on ce andϕ_(e) of SRMs are thoroughly examined using the NMM triaxial numerical model.Additionally,a fitting function is proposed to linkϕ_(e) to the rock content and size of SRMs.When other influencing factors are fixed,the above fitting model leads to the following conclusions:(1)the predictedϕ_(e) of SRMs increase with the increase of rock content;and(2)SRM samples with smaller rocks display a higher predictedϕ_(e).
基金supported in part by the National Natural Science Foundation of China under Grant 51877061.
文摘For the ultra HVDC(UHVDC)with the hierarchical connection mode at the inverter side,considering the change of the Thevenin equivalent parameters(TEP)of post-fault AC grid,a coordinated control strategy to the subsequent commutation failure(SCF)at both layers is newly proposed.The originality of this work is manifested in three aspects.1)The mechanism of the SCF at the fault layer is newly found by deriving the analytical expression of the extinction angle with the TEP,and that at the non-fault layer is newly found by the voltage-time area theory with the DC current coupling.2)An estimation model for the TEPs of two AC grids at the inverter side is proposed with the post-fault quantities.To address the random noise and inaccurate measurement data,an adaptive robust least squares method based on the median principle is proposed to solve the TEP model.3)A coordinated control strategy with the estimated TEP is proposed to compensate for the extinction angle at the fault layer and limit the DC current at the non-fault layer,thus suppressing the SCF.The simulation results verify the suppression effect of the proposed control on the SCF under different fault conditions.
文摘Generalised reduced masses with a set of equations governing the three relative motions between two of 3-bodies in their gravitational field are established,of which the dynamic characteristics of 3-body dynamics,fundamental bases of this paper,are revealed.Based on these findings,an equivalent system is developed,which is a 2-body system with its total mass,constant angular momentum,kinetic and potential energies same as the total ones of three relative motions,so that it can be solved using the well-known theory of the 2-body system.From the solution of an equivalent system with the revealed characteristics of three relative motions,the general theoretical solutions of the 3-body system are obtained in the curve-integration forms along the orbits in the imaged radial motion space.The possible periodical orbits with generalised Kepler’s law are presented.Following the description and mathematical demonstrations of the proposed methods,the examples including Euler’s/Lagrange’s problems,and a reported numerical one are solved to validate the proposed methods.The methods derived from the 3-body system are extended to N-body problems.
