This study employs a new SATES(Self-Adaptive Turbulence Eddy Simulation)-FGM(Flamelet Generated Manifold)-CRN(Chemical Reactor Network)coupling method to numerically predict the combustion pollutions of CO and NO_(x)t...This study employs a new SATES(Self-Adaptive Turbulence Eddy Simulation)-FGM(Flamelet Generated Manifold)-CRN(Chemical Reactor Network)coupling method to numerically predict the combustion pollutions of CO and NO_(x)together in a methane/air turbulent diffusion flame(Sandia Flame D).Two SATES models are developed based on the underlying realizable k-εand BSL k-ωturbulence models.The prediction accuracy of the combustion field and the CO pollutant distribution are compared and analyzed by coupling two SATES models and two RANS(Reynolds-Averaged Navier-Stokes)models with FGM combustion model.Furthermore,CRN is utilized to construct the NO_(x)distribution characteristics for different scales and rules using the unsteady high-fidelity combustion field results obtained from SATES-FGM.The results demonstrate that SATES-FGM can accurately predict the turbulent diffusion flame and improve the sensitivity of different RANS models to flow patterns in the framework of the SATES method.However,the results show a large deviation in predicting the main combustion zone.The SATES-FGM method can efficiently and accurately simulate flow fields of the free-jet turbulent flame.Additionally,it performs well in predicting the pollution products associated with combustion process,such as CO,while the SATES-CRN coupling method can accurately predict the post-combustion pollutants like NO_(x).The number of CRN zones can be adjusted to fit the combustor.Excessive reaction zones not only reduce the efficiency but also result in a deviation in the NO_(x)prediction.The unsteady SATES-CRN coupling method is better suited for complex partitioning rules.The developed SATES-FGM-CRN method can offer a new and efficient approach to simultaneously predict the distributions of CO and NO_(x)pollutions.展开更多
Two traditional methods for compensating function model errors, the method of adding systematic parameters and the least-squares collection method, are introduced. A proposed method based on a BP neural network （call...Two traditional methods for compensating function model errors, the method of adding systematic parameters and the least-squares collection method, are introduced. A proposed method based on a BP neural network （called the H-BP algorithm） for compensating function model errors is put forward. The function model is assumed as y =f（x1, x2,… ,xn）, and the special structure of the H-BP algorithm is determined as （ n ＋ 1） ×p × 1, where （n ＋ 1） is the element number of the input layer, and the elements are xl, x2,…, xn and y＇ （ y＇ is the value calculated by the function model）; p is the element number of the hidden layer, and it is usually determined after many tests; 1 is the dement number of the output layer, and the element is △y = y0-y＇（y0 is the known value of the sample）. The calculation steps of the H-BP algorithm are introduced in detail. And then, the results of three methods for compensating function model errors from one engineering project are compared with each other. After being compensated, the accuracy of the traditional methods is about ± 19 mm, and the accuracy of the H-BP algorithm is ± 4. 3 mm. It shows that the proposed method based on a neural network is more effective than traditional methods for compensating function model errors.展开更多
In this editorial preface, I briefly r eview cancer bioinformatics and introduce the four articles in this special issue highlighting important applications of the field: detection of chromatin states; detection of SN...In this editorial preface, I briefly r eview cancer bioinformatics and introduce the four articles in this special issue highlighting important applications of the field: detection of chromatin states; detection of SNP- containing motifs and association with transcription factor-binding sites; improvements in functional enrichment modules; and gene association studies on aging and cancer. We expect this issue to provide bioinformatics scientists, cancer biologists, and clinical doctors with a better understanding of how cancer bioinformatics can be used to identify candidate biomarkers and targets and to conduct functional analysis.展开更多
The vibration of thermodynamic machinery will affect its cooling system.In this research,a high-resolution simulation of jet impingement was performed to quantify the unsteady turbulent convection under vibration cond...The vibration of thermodynamic machinery will affect its cooling system.In this research,a high-resolution simulation of jet impingement was performed to quantify the unsteady turbulent convection under vibration conditions.A newly developed Self-Adaptive Turbulence Eddy Simulation(SATES)method was used.The Reynolds number was Re=23000,the jet-towall distance was fixed at H/D=2,and the vibrating frequency of the impinging wall f varied from 0 to 200 Hz.Compared with the static wall case,the maximum enhancement of the stagnation point and area averaged Nusselt number within r/D=1 could reach up to 5%due to the larger primary vortices,whereas it could reduce the heat transfer by 10%beyond r/D=3 due to the suppression of the wall vortices development.Based on the unsteady analysis and Proper Orthogonal Decomposition(POD)pattern,the modes controlled by vibration were recognized and their contributions to the heat transfer performance were also evaluated.The introduction of the vibration promoted the development of the primary vortices and changed the radial alternating motion to a vertical alternating motion at the wall jet region.The former was beneficial for the heat transfer,while the latter was unfavorable.展开更多
The development of cadmium-free CIGS solar cells with high conversion efficiency is crucial due to the toxicity of cadmium. Zinc-based buffer layers seem to be the most promising. In this paper, a numerical analysis u...The development of cadmium-free CIGS solar cells with high conversion efficiency is crucial due to the toxicity of cadmium. Zinc-based buffer layers seem to be the most promising. In this paper, a numerical analysis using SCAPS-1D software was used to explore the Zn(Mg,O) layer as an alternative to the toxic CdS layer. The effect of several properties such as thickness, doping, Mg concentration of the Zn(Mg,O) layer on the current-voltage parameters was explored and their optimal values were proposed. The simulation results reveal that the optimal value of the ZMO layer thickness is approximately 40 nm, the doping at 10<sup>17</sup> cm<sup>-3</sup> and an Mg composition between 0.15 and 0.2. In addition, the effect of Gallium (Ga) content in the absorber as well as the Zn(Mg,O)/CIGS interface properties on the solar cell’s performance was examined. The results show that contrary to the CdS buffer layer, the best electrical characteristics of the ZMO/CIGS heterojunction are obtained using a Ga-content equal to 0.4 and high interface defect density or unfavorable band alignment may be the causes of poor performances of Zn(Mg,O)/CIGS solar cells in the case of low and high Mg-contents.展开更多
It is known that exp [iA （Q] P1 - i/2）] is a unitary single-mode squeezing operator, where Q1, P1 are the coordinate and momentum operators, respectively. In this paper we employ Dirac＇s coordinate representation t...It is known that exp [iA （Q] P1 - i/2）] is a unitary single-mode squeezing operator, where Q1, P1 are the coordinate and momentum operators, respectively. In this paper we employ Dirac＇s coordinate representation to prove that the exponential operator Sn ≡exp[iλi=1∑n（QiPi＋1＋Qi＋1Pi））],（Qn＋1=Q1,Pn＋1=P1）,is an n-mode squeezing operator which enhances the standard squeezing. By virtue of the technique of integration within an ordered product of operators we derive Sn＇s normally ordered expansion and obtain new n-mode squeezed vacuum states, its Wigner function is calculated by using the Weyl ordering invariance under similar transformations.展开更多
The work deals with analysis of geographical factor as one of the main factor determining the historical change of a border on the example of Georgia. The research was conducted in two main directions： the evaluation...The work deals with analysis of geographical factor as one of the main factor determining the historical change of a border on the example of Georgia. The research was conducted in two main directions： the evaluation of historical transformations of state borders of Georgia throughout of XIX-XX centuries and identification the leading geographical factors. Special emphasis has been made on geographical and cartometric analysis of modern state border of Georgia. In order to identify the historical transformations of state border that have used different methods as well as GIS-technologies, the research is based on the historical, cartographical and statistical data. On the base of a lot of cartographic sources, it is concluded that the borderline in modem topographic maps is often plotted by ignoring the international practice related to plotting the state borders across the physical-geographical objects. This is why the geographical factor seems important in the historical transformations of the state border creating similarly a negative perspective in the future. The main results of research are： （1） classification of geographical factors causing the transformations of the state borders; （2） Evaluation of sensitivity of state border; and （3） creation of DB of the state border of Georgia, allowing continuing the studies in the future.展开更多
During the restoration of degraded ecosystems,different shrub species often segregate along environmental water gradients.However,the physiological mechanisms driving this segregation remain unclear.To address this ga...During the restoration of degraded ecosystems,different shrub species often segregate along environmental water gradients.However,the physiological mechanisms driving this segregation remain unclear.To address this gap,we conducted a drought stress experiment(70%-80%field water holding capacity,CK;40%-50%field water holding capacity,MD;20%-30%field water holding capacity,SD)to explore the physiological mechanisms driving the dominance of different shrub species at various stages of ecosystem restoration.Salix gordejevii,a species dominant in the early stages of restoration with high water availability,and Caragana microphylla,a species dominant in the later stages under low water availability,were studied.The results showed that the living state index(LSI)of S.gordejevii was significantly lower than that of C.microphylla under drought stress(P<0.05).Differences in plant hydraulics and water-use strategies explained how these species adapt to varying soil moisture conditions.Salix gordejevii employed a proactive water-use strategy with lower water-use efficiency(WUE)and reduced resistance to xylem embolism(xylem water potentials corresponding to 50%loss of conductivity,P50),making it better suited to environments with more abundant water.In contrast,C.microphylla adopted a conservative water-use strategy.This strategy was characterized by increased WUE and enhanced resistance to drought-induced xylem embolism,which allowed it to thrive under more drought-prone conditions.Importantly,hydraulic efficiency(Kleaf,Ks and K1)emerged as the primary determinant of living state in both S.gordejevii(47.30%)and C.microphylla(62.20%).The lower embolism resistance of S.gordejevii(P50=1.3 MPa)made it more susceptible to xylem cavitation,leading to a decline in hydraulic efficiency under SD.In contrast,C.microphylla’s higher embolism resistance(P50=2.3 MPa)enabled it to maintain stable hydraulic conductance across all drought treatments.These differences in hydraulic efficiency,driven by xylem embolism resistance,were key factors influencing shifts in shrub dominance during ecosystem restoration.These findings provide a physiological explanation for the replacement of shrub species during ecosystem restoration,where soil moisture is the main limiting factor.展开更多
We present an analysis of the newly observed pentaquark P(4312)+to shed light on its quantum num-bers.To do that,the QCD sum rules approach is used.The measured mass of this particle is close to the∑++cD-threshold an...We present an analysis of the newly observed pentaquark P(4312)+to shed light on its quantum num-bers.To do that,the QCD sum rules approach is used.The measured mass of this particle is close to the∑++cD-threshold and has a small width,which supports the possibility of its being a molecular state.We consider an inter-polating current in a molecular form and analyze both the positive and negative parity states with spin-1/2.We also consider the bottom counterpart of the state with similar molecular form.Our mass result for the charm pentaquark state supports that the quantum numbers of the observed state are consistent with J^(P)=1/2^(-).展开更多
基金financially supported by the National Natural Science Foundation of China(No.52376114 and No.92041001)the Jiangsu Provincial Natural Science Foundation(BK20200069)the National Science and Technology Major Project(J2019-III-0015-0059)。
文摘This study employs a new SATES(Self-Adaptive Turbulence Eddy Simulation)-FGM(Flamelet Generated Manifold)-CRN(Chemical Reactor Network)coupling method to numerically predict the combustion pollutions of CO and NO_(x)together in a methane/air turbulent diffusion flame(Sandia Flame D).Two SATES models are developed based on the underlying realizable k-εand BSL k-ωturbulence models.The prediction accuracy of the combustion field and the CO pollutant distribution are compared and analyzed by coupling two SATES models and two RANS(Reynolds-Averaged Navier-Stokes)models with FGM combustion model.Furthermore,CRN is utilized to construct the NO_(x)distribution characteristics for different scales and rules using the unsteady high-fidelity combustion field results obtained from SATES-FGM.The results demonstrate that SATES-FGM can accurately predict the turbulent diffusion flame and improve the sensitivity of different RANS models to flow patterns in the framework of the SATES method.However,the results show a large deviation in predicting the main combustion zone.The SATES-FGM method can efficiently and accurately simulate flow fields of the free-jet turbulent flame.Additionally,it performs well in predicting the pollution products associated with combustion process,such as CO,while the SATES-CRN coupling method can accurately predict the post-combustion pollutants like NO_(x).The number of CRN zones can be adjusted to fit the combustor.Excessive reaction zones not only reduce the efficiency but also result in a deviation in the NO_(x)prediction.The unsteady SATES-CRN coupling method is better suited for complex partitioning rules.The developed SATES-FGM-CRN method can offer a new and efficient approach to simultaneously predict the distributions of CO and NO_(x)pollutions.
基金The National Basic Research Program of China(973 Program)(No.2006CB705501)the National High Technology Research and Development Program of China (863 Program)(No.2007AA12Z228)
文摘Two traditional methods for compensating function model errors, the method of adding systematic parameters and the least-squares collection method, are introduced. A proposed method based on a BP neural network （called the H-BP algorithm） for compensating function model errors is put forward. The function model is assumed as y =f（x1, x2,… ,xn）, and the special structure of the H-BP algorithm is determined as （ n ＋ 1） ×p × 1, where （n ＋ 1） is the element number of the input layer, and the elements are xl, x2,…, xn and y＇ （ y＇ is the value calculated by the function model）; p is the element number of the hidden layer, and it is usually determined after many tests; 1 is the dement number of the output layer, and the element is △y = y0-y＇（y0 is the known value of the sample）. The calculation steps of the H-BP algorithm are introduced in detail. And then, the results of three methods for compensating function model errors from one engineering project are compared with each other. After being compensated, the accuracy of the traditional methods is about ± 19 mm, and the accuracy of the H-BP algorithm is ± 4. 3 mm. It shows that the proposed method based on a neural network is more effective than traditional methods for compensating function model errors.
文摘In this editorial preface, I briefly r eview cancer bioinformatics and introduce the four articles in this special issue highlighting important applications of the field: detection of chromatin states; detection of SNP- containing motifs and association with transcription factor-binding sites; improvements in functional enrichment modules; and gene association studies on aging and cancer. We expect this issue to provide bioinformatics scientists, cancer biologists, and clinical doctors with a better understanding of how cancer bioinformatics can be used to identify candidate biomarkers and targets and to conduct functional analysis.
基金the financial supports for the project from the National Major Science and Technology Projects of China(2017-Ⅲ-0010-0036)the support of the Jiangsu Specially Appointed Professor Program of China。
文摘The vibration of thermodynamic machinery will affect its cooling system.In this research,a high-resolution simulation of jet impingement was performed to quantify the unsteady turbulent convection under vibration conditions.A newly developed Self-Adaptive Turbulence Eddy Simulation(SATES)method was used.The Reynolds number was Re=23000,the jet-towall distance was fixed at H/D=2,and the vibrating frequency of the impinging wall f varied from 0 to 200 Hz.Compared with the static wall case,the maximum enhancement of the stagnation point and area averaged Nusselt number within r/D=1 could reach up to 5%due to the larger primary vortices,whereas it could reduce the heat transfer by 10%beyond r/D=3 due to the suppression of the wall vortices development.Based on the unsteady analysis and Proper Orthogonal Decomposition(POD)pattern,the modes controlled by vibration were recognized and their contributions to the heat transfer performance were also evaluated.The introduction of the vibration promoted the development of the primary vortices and changed the radial alternating motion to a vertical alternating motion at the wall jet region.The former was beneficial for the heat transfer,while the latter was unfavorable.
文摘The development of cadmium-free CIGS solar cells with high conversion efficiency is crucial due to the toxicity of cadmium. Zinc-based buffer layers seem to be the most promising. In this paper, a numerical analysis using SCAPS-1D software was used to explore the Zn(Mg,O) layer as an alternative to the toxic CdS layer. The effect of several properties such as thickness, doping, Mg concentration of the Zn(Mg,O) layer on the current-voltage parameters was explored and their optimal values were proposed. The simulation results reveal that the optimal value of the ZMO layer thickness is approximately 40 nm, the doping at 10<sup>17</sup> cm<sup>-3</sup> and an Mg composition between 0.15 and 0.2. In addition, the effect of Gallium (Ga) content in the absorber as well as the Zn(Mg,O)/CIGS interface properties on the solar cell’s performance was examined. The results show that contrary to the CdS buffer layer, the best electrical characteristics of the ZMO/CIGS heterojunction are obtained using a Ga-content equal to 0.4 and high interface defect density or unfavorable band alignment may be the causes of poor performances of Zn(Mg,O)/CIGS solar cells in the case of low and high Mg-contents.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 10775097 and 10874174)the Research Foundation of the Education Department of Jiangxi Province of China
文摘It is known that exp [iA （Q] P1 - i/2）] is a unitary single-mode squeezing operator, where Q1, P1 are the coordinate and momentum operators, respectively. In this paper we employ Dirac＇s coordinate representation to prove that the exponential operator Sn ≡exp[iλi=1∑n（QiPi＋1＋Qi＋1Pi））],（Qn＋1=Q1,Pn＋1=P1）,is an n-mode squeezing operator which enhances the standard squeezing. By virtue of the technique of integration within an ordered product of operators we derive Sn＇s normally ordered expansion and obtain new n-mode squeezed vacuum states, its Wigner function is calculated by using the Weyl ordering invariance under similar transformations.
文摘The work deals with analysis of geographical factor as one of the main factor determining the historical change of a border on the example of Georgia. The research was conducted in two main directions： the evaluation of historical transformations of state borders of Georgia throughout of XIX-XX centuries and identification the leading geographical factors. Special emphasis has been made on geographical and cartometric analysis of modern state border of Georgia. In order to identify the historical transformations of state border that have used different methods as well as GIS-technologies, the research is based on the historical, cartographical and statistical data. On the base of a lot of cartographic sources, it is concluded that the borderline in modem topographic maps is often plotted by ignoring the international practice related to plotting the state borders across the physical-geographical objects. This is why the geographical factor seems important in the historical transformations of the state border creating similarly a negative perspective in the future. The main results of research are： （1） classification of geographical factors causing the transformations of the state borders; （2） Evaluation of sensitivity of state border; and （3） creation of DB of the state border of Georgia, allowing continuing the studies in the future.
基金supported by Inner Mongolia Autonomous Region Major Scientific and Technological Innovation Demonstration Project for Desertification Control and Sand Stabilization under the“Open Competition(Merit-Based Selection)”Mechanism(2024JBGS0005)the National Natural Science Foundation of China(32071845,32201289,32471968,32201329)+2 种基金the Key Science and Technology Project of Inner Mongolia Autonomous Region(2021ZD001505)the Science and Technology Programs of Gansu Province(23JRRA572)Gansu Provincial Young Talents Individual Project(2024QNGR03).
文摘During the restoration of degraded ecosystems,different shrub species often segregate along environmental water gradients.However,the physiological mechanisms driving this segregation remain unclear.To address this gap,we conducted a drought stress experiment(70%-80%field water holding capacity,CK;40%-50%field water holding capacity,MD;20%-30%field water holding capacity,SD)to explore the physiological mechanisms driving the dominance of different shrub species at various stages of ecosystem restoration.Salix gordejevii,a species dominant in the early stages of restoration with high water availability,and Caragana microphylla,a species dominant in the later stages under low water availability,were studied.The results showed that the living state index(LSI)of S.gordejevii was significantly lower than that of C.microphylla under drought stress(P<0.05).Differences in plant hydraulics and water-use strategies explained how these species adapt to varying soil moisture conditions.Salix gordejevii employed a proactive water-use strategy with lower water-use efficiency(WUE)and reduced resistance to xylem embolism(xylem water potentials corresponding to 50%loss of conductivity,P50),making it better suited to environments with more abundant water.In contrast,C.microphylla adopted a conservative water-use strategy.This strategy was characterized by increased WUE and enhanced resistance to drought-induced xylem embolism,which allowed it to thrive under more drought-prone conditions.Importantly,hydraulic efficiency(Kleaf,Ks and K1)emerged as the primary determinant of living state in both S.gordejevii(47.30%)and C.microphylla(62.20%).The lower embolism resistance of S.gordejevii(P50=1.3 MPa)made it more susceptible to xylem cavitation,leading to a decline in hydraulic efficiency under SD.In contrast,C.microphylla’s higher embolism resistance(P50=2.3 MPa)enabled it to maintain stable hydraulic conductance across all drought treatments.These differences in hydraulic efficiency,driven by xylem embolism resistance,were key factors influencing shifts in shrub dominance during ecosystem restoration.These findings provide a physiological explanation for the replacement of shrub species during ecosystem restoration,where soil moisture is the main limiting factor.
文摘We present an analysis of the newly observed pentaquark P(4312)+to shed light on its quantum num-bers.To do that,the QCD sum rules approach is used.The measured mass of this particle is close to the∑++cD-threshold and has a small width,which supports the possibility of its being a molecular state.We consider an inter-polating current in a molecular form and analyze both the positive and negative parity states with spin-1/2.We also consider the bottom counterpart of the state with similar molecular form.Our mass result for the charm pentaquark state supports that the quantum numbers of the observed state are consistent with J^(P)=1/2^(-).
