Response surface methodology（RSM） is introduced into corrosion research as a tool to assess the effects of environmental factors and their interactions on corrosion behavior and establish a model for corrosion predi...Response surface methodology（RSM） is introduced into corrosion research as a tool to assess the effects of environmental factors and their interactions on corrosion behavior and establish a model for corrosion prediction in complex coupled environment（CCE）. In this study, a typical CCE, that is, the corrosion environment of pipelines in gas field is taken as an example. The effects of environmental factors such as chloride concentration, pH value and pressure as well as their interactions on critical pitting temperature（CPT） were evaluated, and a quadratic polynomial model was developed for corrosion prediction by RSM. The results showed that the model was excellent in corrosion prediction with R2= 0.9949. CPT was mostly affected by single environmental factor rather than interaction, and among the whole factors, chloride concentration was the most influential factor of CPT.展开更多
Betavoltaic cells(BCs)are promising self-generating power cells with long life and high power density.However,the low energy conversion efficiency(ECE)has limitations in practical engineering applications.Widebandgap ...Betavoltaic cells(BCs)are promising self-generating power cells with long life and high power density.However,the low energy conversion efficiency(ECE)has limitations in practical engineering applications.Widebandgap semiconductors(WBGSs)with three-dimensional(3-D)nanostructures are ideal candidates for increasing the ECE of BCs.This paper proposes hydrothermally grown ZnO nanorod arrays(ZNRAs)for ^(63)Ni-powered BCs.A quantitative model was established for simulation using the parameter values of the dark characteristics,which were obtained from the experimental measurements for a simulated BC based on a Ni-incorporated ZNRAs structure.Monte Carlo(MC)modeling and simulation were conducted to obtain the values of the β energy deposited in ZNRAs with different nanorod spacings and heights.Through the simulation and optimization of the 3-D ZNRAs and 2-D ZnO bulk structures,the performance of the ^(63)Ni-powered BCs based on both structures was evaluated using a quantitative model.The BCs based on the 3-D ZNRAs structure and 2-D ZnO bulk structure achieved a maximum ECE of 10.1%and 4.69%,respectively,which indicates the significant superiority of 3-D nanostructured WBGSs in increasing the ECE of BCs.展开更多
Charge transfer mechanisms of contact electrification(CE)are essential for widening applications of the triboelectric nanogenerator,and thus are widely studied by scientists around the world.However,the quantitative m...Charge transfer mechanisms of contact electrification(CE)are essential for widening applications of the triboelectric nanogenerator,and thus are widely studied by scientists around the world.However,the quantitative modeling of CE,especially that between polymers,is still lacking.Herein,a model was proposed to describe the contributions from different mechanisms,including electron transfer and mass transfer in polymer/polymer CE through the fieldassisted thermionic emission,where three groups of charge transfer mechanisms were distinguished by the polarity of the charge transfer and the corresponding electric field.The results indicated that the total generated charge in CE is actually much larger than the measured net surface charge,confirming the bidirectional material-dependent charge transfer mechanisms between two surfaces,which is meaningful for understanding the millennium puzzle in triboelectrification and provides a new perspective for promoting the applications to tailor surface charge generation.展开更多
Metal magnetic memory（MMM） testing has been widely used to detect welded joints. However, load levels, environmental magnetic field, and measurement noises make the MMM data dispersive and bring difficulty to quanti...Metal magnetic memory（MMM） testing has been widely used to detect welded joints. However, load levels, environmental magnetic field, and measurement noises make the MMM data dispersive and bring difficulty to quantitative evaluation. In order to promote the development of quantitative MMM reliability assessment, a new MMM model is presented for welded joints. Steel Q235 welded specimens are tested along the longitudinal and horizontal lines by TSC-2M-8 instrument in the tensile fatigue experiments. The X-ray testing is carried out synchronously to verify the MMM results. It is found that MMM testing can detect the hidden crack earlier than X-ray testing. Moreover, the MMM gradient vector sum K_（vs） is sensitive to the damage degree, especially at early and hidden damage stages. Considering the dispersion of MMM data, the K_（vs） statistical law is investigated, which shows that K_（vs） obeys Gaussian distribution. So K_（vs） is the suitable MMM parameter to establish reliability model of welded joints. At last, the original quantitative MMM reliability model is first presented based on the improved stress strength interference theory. It is shown that the reliability degree R gradually decreases with the decreasing of the residual life ratio T, and the maximal error between prediction reliability degree R_1 and verification reliability degree R_2 is 9.15%. This presented method provides a novel tool of reliability testing and evaluating in practical engineering for welded joints.展开更多
Grain boundary segregation(GBS)of solutes influences the grain size,texture,and strength of Mg wrought alloys.So far,solutes'GBS in Mg has mostly been investigated by qualitative experimental observations.In this ...Grain boundary segregation(GBS)of solutes influences the grain size,texture,and strength of Mg wrought alloys.So far,solutes'GBS in Mg has mostly been investigated by qualitative experimental observations.In this work,we develop a quantitative model to compute the grain boundary segregation energy(ΔE_(seg))in binary Mg based alloys that takes the relative atomic density of GB into account.The model is utilized to computeΔE_(seg)of Al,Zn,Ca,Sn,Y,Gd,and Nd solutes in Mg.The result suggests that rare earth elements and Ca are more prone to GBS than Al,Zn,and Sn.Segregation of Gd solutes can explain the smaller grain size and slower grain growth in Mg-Gd extruded alloys than Mg-Al and Mg-Zn counterparts.It also provides an explanation for the weak extrusion texture in Mg-Gd.展开更多
This paper reviews the history and lessons of global oil crises while exploring the establishment of a quantitative evaluation model for oil security with Chinese characteristics.Using principal component analysis,it ...This paper reviews the history and lessons of global oil crises while exploring the establishment of a quantitative evaluation model for oil security with Chinese characteristics.Using principal component analysis,it constructs an oil security evaluation indicator system for China with two main-level indicators:foreign oil dependency and its impacts,and market intervention and security assurance.展开更多
This paper deeply explores the autonomous collision avoidance algorithm for intelligent ships,aiming to enhance the intelligence level and safety of ship collision avoidance by integrating navigation experience.An aut...This paper deeply explores the autonomous collision avoidance algorithm for intelligent ships,aiming to enhance the intelligence level and safety of ship collision avoidance by integrating navigation experience.An autonomous collision avoidance algorithm based on navigation experience is designed,a collision avoidance experience database is constructed,a quantitative model is established,and specific algorithm steps are implemented.The algorithm is verified and analyzed through simulation tests.The results show that the algorithm can effectively achieve autonomous ship collision avoidance in different scenarios,providing new ideas and methods for the development of intelligent ship collision avoidance technology.展开更多
Branch angles are an important plant morphological trait affecting light interception within forest canopies.However,studies on branch angles have been limited due to the time-consuming nature of manual measurements u...Branch angles are an important plant morphological trait affecting light interception within forest canopies.However,studies on branch angles have been limited due to the time-consuming nature of manual measurements using a protractor.Terrestrial laser scanning(TLS),however,provides new opportunities to measure branch angles more efficiently.Despite this potential,studies validating branch angle measurements from TLS have been limited.Here,our aim is to evaluate both manual and automatic branch angle measurements of European beech from TLS data using traditional field-measurements with a protractor as a reference.We evaluated the accuracy of branch angle measurements based on four automated algorithms(aRchiQSM,TreeQSM,Laplacian,SemanticLaplacian)from TLS data.Additionally,we assessed different ways of manual branch angle measurements in the field.Our study was based on a dataset comprising 124 branch angles measured from six European beech in a European deciduous forest.Our results show that manual branch angle measurements from TLS data are in high agreement with the reference(root-mean-squared error,RMSE:[3.57°-4.18°],concordance correlation coefficient,CCC:[0.950.97])across different branch length positions.Automated algorithms also are in high agreement with the reference although RMSE is approximately twice as large compared to manual branch angle measurements from TLS(RMSE:[9.29°-10.55°],CCC:[0.830.86])with manual leaf points removal.When applying the automatic wood-leaf separation algorithm,the performance of the four methods declined significantly,with only approximately 20 branch angles successfully identified.Moreover,it is important to note that there is no influence of the measurement position(branch surface versus center)for branch angle measurements.However,for curved branches,the selection of branch measurement length significantly impacts the branch angle measurement.This study provides a comprehensive understanding of branch angle measurements in forests.We show that automated measurement methods based on TLS data of branch angles are a valuable tool to quantify branch angles at larger scales.展开更多
The stretching process of some Tertiary rift basins in eastern China is characterized by multiphase rifting. A multiple instantaneous uniform stretching model is proposed in this paper to simulate the formation of the...The stretching process of some Tertiary rift basins in eastern China is characterized by multiphase rifting. A multiple instantaneous uniform stretching model is proposed in this paper to simulate the formation of the basins as the rifting process cannot be accurately described by a simple (one episode) stretching model. The study shows that the multiphase stretching model, combined with the back-stripping technique, can be used to reconstruct the subsidence history and the stretching process of the lithosphere, and to evaluate the depth to the top of the asthenosphere and the deep thermal evolution of the basins. The calculated results obtained by applying the quantitative model to the episodic rifting process of the Tertiary Qiongdongnan and Yinggehai basins in the South China Sea are in agreement with geophysical data and geological observations. This provides a new method for quantitative evaluation of the geodynamic process of multiphase rifting occurring during the Tertiary in eastern China.展开更多
The quantitative evaluation of multi-process collaborative operation is of great significance for the improvement of production planning and scheduling in steelmaking–continuous casting sections(SCCSs). However, this...The quantitative evaluation of multi-process collaborative operation is of great significance for the improvement of production planning and scheduling in steelmaking–continuous casting sections(SCCSs). However, this evaluation is difficult since it relies on an in-depth understanding of the operating mechanism of SCCSs, and few existing methods can be used to conduct the evaluation, due to the lack of full-scale consideration of the multiple factors related to the production operation. In this study, three quantitative models were developed, and the multiprocess collaborative operation level was evaluated through the laminar-flow operation degree, the process matching degree, and the scheduling strategy availability degree. Based on the evaluation models for the laminar-flow operation and process matching levels, this study investigated the production status of two steelmaking plants, plants A and B, based on actual production data. The average laminar-flow operation(process matching) degrees of SCCSs were obtained as 0.638(0.610) and 1.000(0.759) for plants A and B, respectively, for the period of April to July 2019. Then, a scheduling strategy based on the optimization of the furnace-caster coordinating mode was suggested for plant A. Simulation experiments showed higher availability than the greedy-based and manual strategies. After the proposed scheduling strategy was applied,the average process matching degree of the SCCS of plant A increased by 4.6% for the period of September to November 2019. The multi-process collaborative operation level was improved with fewer adjustments and interruptions in casting.展开更多
A multi-objective intelligent coordinating optimization strategy based on qualitative and quantitative synthetic model for Pb-Zn sintering blending process was proposed to obtain optimal mixture ratio. The mechanism a...A multi-objective intelligent coordinating optimization strategy based on qualitative and quantitative synthetic model for Pb-Zn sintering blending process was proposed to obtain optimal mixture ratio. The mechanism and neural network quantitative models for predicting compositions and rule models for expert reasoning were constructed based on statistical data and empirical knowledge. An expert reasoning method based on these models were proposed to solve blending optimization problem, including multi-objective optimization for the first blending process and area optimization for the second blending process, and to determine optimal mixture ratio which will meet the requirement of intelligent coordination. The results show that the qualified rates of agglomerate Pb, Zn and S compositions are increased by 7.1%, 6.5% and 6.9%, respectively, and the fluctuation of sintering permeability is reduced by 7.0%, which effectively stabilizes the agglomerate compositions and the permeability.展开更多
The relationships of cooling rate with microstructure and thermal conductivity of vermicular graphite cast iron(VGI) cylinder block were studied, which are important for design and optimization of the casting process ...The relationships of cooling rate with microstructure and thermal conductivity of vermicular graphite cast iron(VGI) cylinder block were studied, which are important for design and optimization of the casting process of VGI cylinder blocks. Cooling rates at different positions in the cylinder block were calculated based on the cooling curves recorded with a solidification simulation software. The metallographic structure and thermal conductivity were observed and measured using optical microscopy(OM), scanning electrical microscopy(SEM) and laser flash diffusivity apparatus, respectively. The effects of the cooling rate on the vermicularity, total and average areas of all graphite particles, and the pearlite fraction in the VGI cylinder block were investigated. It is found that the vermicularity changes in parabola trend with the increase of cooling rate. The total area of graphite particles and the cooling rate at eutectoid stage can be used to predict pearlite fraction well. Moreover, it is found that the thermal conductivity at room temperature is determined by the average area of graphite particles and pearlite fraction when the range of vermicularity is from 80% to 93%. Finally, the quantitative models are established to calculate the vermicularity, pearlite fraction, and thermal conductivity of the VGI cylinder block.展开更多
The influence of surface S^2- dangling bonds and surface doped ions（Se^2-, Cu^2＋, and Hg^2＋） on the photoluminescence of Cd^2＋-rich CdS QDs was investigated. A quantitative model was proposed to understand the co...The influence of surface S^2- dangling bonds and surface doped ions（Se^2-, Cu^2＋, and Hg^2＋） on the photoluminescence of Cd^2＋-rich CdS QDs was investigated. A quantitative model was proposed to understand the complex transfer processes of excited electrons in CdS QDs. The transfer of excited electrons from either the conduction band or the Cd^2＋-related trap-state to the surface S^2-related shallow hole trap-state is effective. However, the trap of excited electrons by surface doped ion trap-states from the Cd^2＋-related trap-state is more effective than that from the conduction band. The efficiency of trapping electrons from both the conduction band and the Cd^2＋-related trap-state can be quantitatively understood with the help of the proposed model. The results show that the transfer efficiency of excited electrons is dependent on the location of the energy-level of the relevant surface-related trap-state. The trap of excited electrons by the surface trap-state with energy-level closer to that of the conduction band is more effective, especially for the trap of excited electrons from Cd^2＋-related trap-state.展开更多
AIM: To set up a mathematic model for gastric cancer screening and to evaluate its function in mass screening for gastric cancer.METHODS: A case control study was carried on in 66patients and 198 normal people, then t...AIM: To set up a mathematic model for gastric cancer screening and to evaluate its function in mass screening for gastric cancer.METHODS: A case control study was carried on in 66patients and 198 normal people, then the risk and protective factors of gastric cancer were determined, including heavy manual work, foods such as small yellow-fin tuna, dried small shrimps, squills, crabs, mothers suffering from gastric diseases, spouse alive, use of refrigerators and hot food,etc. According to some principles and methods of probability and fuzzy mathematics, a quantitative assessment model was established as follows: first, we selected some factors significant in statistics, and calculated weight coefficient for each one by two different methods; second, population space was divided into gastric cancer fuzzy subset and non gastric cancer fuzzy subset, then a mathematic model for each subset was established, we got a mathematic expression of attribute degree (AD).RESULTS: Based on the data of 63 patients and 693 normal people, AD of each subject was calculated. Considering the sensitivity and specificity, the thresholds of AD values calculated were configured with 0.20 and 0.17, respectively.According to these thresholds, the sensitivity and specificity of the quantitative model were about 69% and 63%.Moreover, statistical test showed that the identification outcomes of these two different calculation methods were identical (P＞0.05).CONCLUSION: The validity of this method is satisfactory.It is convenient, feasible, economic and can be used to determine individual and population risks of gastric cancer.展开更多
Breast cancer is presently one of the most common malignancies worldwide,with a higher fatality rate.In this study,a quantitative structure-activity relationship(QSAR)model of compound biological activity and ADMET(Ab...Breast cancer is presently one of the most common malignancies worldwide,with a higher fatality rate.In this study,a quantitative structure-activity relationship(QSAR)model of compound biological activity and ADMET(Absorption,Distribution,Metabolism,Excretion,Toxicity)properties prediction model were performed using estrogen receptor alpha(ERα)antagonist information collected from compound samples.We first utilized grey relation analysis(GRA)in conjunction with the random forest(RF)algorithm to identify the top 20 molecular descriptor variables that have the greatest influence on biological activity,and then we used Spearman correlation analysis to identify 16 independent variables.Second,a QSAR model of the compound were developed based on BP neural network(BPNN),genetic algorithm optimized BP neural network(GA-BPNN),and support vector regression(SVR).The BPNN,the SVR,and the logistic regression(LR)models were then used to identify and predict the ADMET properties of substances,with the prediction impacts of each model compared and assessed.The results reveal that a SVR model was used in QSAR quantitative prediction,and in the classification prediction of ADMET properties:the SVR model predicts the Caco-2 and hERG(human Ether-a-go-go Related Gene)properties,the LR model predicts the cytochrome P450 enzyme 3A4 subtype(CYP3A4)and Micronucleus(MN)properties,and the BPNN model predicts the Human Oral Bioavailability(HOB)properties.Finally,information entropy theory is used to validate the rationality of variable screening,and sensitivity analysis of the model demonstrates that the constructed model has high accuracy and stability,which can be used as a reference for screening probable active compounds and drug discovery.展开更多
In this paper, decision making in complex environment is considered and an approach integrating quantitative decision model with qualitative judgment is proposed. The concept of belief degree for quantitative decision...In this paper, decision making in complex environment is considered and an approach integrating quantitative decision model with qualitative judgment is proposed. The concept of belief degree for quantitative decision model in a complex environment is presented. The integration in formulation and reasoning of quantitative model with qualitative judgment is studied. The combination of various belief degree generated by quantitative model and qualitative judgment is discussed. A decision rule of tradeoff between optimality and belief degree of optimality is proposed.展开更多
We calibrate the macroscopic vortex high-order harmonic generation(HHG)obtained by the quantitative rescattering(QRS)model to compute single-atom induced dipoles against that by solving the time-dependent Schr?dinger ...We calibrate the macroscopic vortex high-order harmonic generation(HHG)obtained by the quantitative rescattering(QRS)model to compute single-atom induced dipoles against that by solving the time-dependent Schr?dinger equation(TDSE).We show that the QRS perfectly agrees with the TDSE under the favorable phase-matching condition,and the QRS can accurately predict the main features in the spatial profiles of vortex HHG if the phase-matching condition is not good.We uncover that harmonic emissions from short and long trajectories are adjusted by the phase-matching condition through the time-frequency analysis and the QRS can simulate the vortex HHG accurately only when the interference between two trajectories is absent.This work confirms that it is an efficient way to employ the QRS model in the single-atom response for precisely simulating the macroscopic vortex HHG.展开更多
We review the recently improved quantitative rescattering theory for nonsequential double ionization, in which the lowering of threshold due to the presence of electric field at the time of recollision has been taken ...We review the recently improved quantitative rescattering theory for nonsequential double ionization, in which the lowering of threshold due to the presence of electric field at the time of recollision has been taken into account. First,we present the basic theoretical tools which are used in the numerical simulations, especially the quantum theories for elastic scattering of electron as well as the processes of electron impact excitation and electron impact ionization. Then,after a brief discussion about the properties of the returning electron wave packet, we provide the numerical procedures for the simulations of the total double ionization yield, the double-to-single ionization ratio, and the correlated two-electron momentum distribution.展开更多
The inclusions of Al in steels have great influence on the properties and the quality of steels.But there are some difficulties on the content determination of Al inclusions with accuracy and rapidity.Conventional qua...The inclusions of Al in steels have great influence on the properties and the quality of steels.But there are some difficulties on the content determination of Al inclusions with accuracy and rapidity.Conventional quantity analysis of stable inclusions is electrolysis method with the disadvantages of long analytical period,trivial operation and a little loss of some fine and instable oxides.The content of insoluble aluminum can be obtained by the subtraction between the content of total Al and acid soluble Al determined by chemical methods with the disadvantage of complicate procedure.Original position statistic distribution analysis(OPA) can be used for the determination of inclusions by collecting and discriminating the signals produced by single spark discharge in the way of no pre-sparking,scanning and emitting continuously.In this study the element of Al in some spectrum certified reference materials of carbon and medium or low-alloyed steels was analyzed by original opposition statistic distribution technique.Two quantitative mathematical models used by original position distribution analysis technology for the analysis of the content of Al inclusions have been investigated and been applied to the analysis of the content of Al inclusions in many kinds of spectrum certified reference materials and some medium and low-alloyed steel samples.The scope of application of the models and their limited conditions were discussed.It was found that the results calculated by OPA had great difference with the value by chemical method for some samples with the total content of Al above 0.2%.The reason is that some intensity of abnormal sparks have gone beyond the range of the largest intensity that can be determined by the instrument so that there is a certain deviation on the identification of abnormal sparks and the calculation of threshold value.It was found that the size distribution of Al inclusions had a great influence on the application of the two models.For most of certified reference materials for spectrum analysis and real steel samples the results of the content of Al in inclusions calculated by model 1 was satisfied and had good coincidence with the value of insoluble Al by chemical method. But for the samples with so many large inclusions of Al existed,the influence of intensity should be considered because the signal increase did not vary in the form of simple function.So model 2 was more suitable for the content calculation of Al in inclusions in this case.In order to choose suitable model to be used it is suggested that the size distribution of inclusions should be determined by OPA before content determination of Al in inclusions. The results of the content of Al inclusions calculated by the selected mathematical model were satisfied and had good coincidence with the value of insoluble Al obtained by the subtraction between the content of total Al and soluble Al determined by chemical methods when the content of total aluminum was below 0.2%.展开更多
Since the 1990s, with the in-depth study and understanding of sustainable development, quantitative study of regional sustainable development (RSD) was increasingly hot in China. Based on quantitative study of RSD fro...Since the 1990s, with the in-depth study and understanding of sustainable development, quantitative study of regional sustainable development (RSD) was increasingly hot in China. Based on quantitative study of RSD from Core Periodical in China National Knowledge Infrastructure (1992–2008), statistical analysis on the annual distribution, periodicals distribution and changes of the distribution were made. And from perspectives of social–economic, ecological, systematic and emerging methods, the course, problems and trends of the quantitative study methods on RSD were examined and analyzed to get a clear summary. By the review, the context on the quantitative study of RSD was to be clarified. The study also showed that, primarily, fields involving quantitative study are expanding; second, big progresses and constant development have been made on the systematic method gradually sophisticated, the flourishing ecological method and emerging new methods in the context of cross and integration which has made complex integrated systems a more satisfactory solution; third, the method system has been more multi-angled, and the clues of independent innovation have been observed despite the fact that the introduction of imported method is the main trend. Although many problems exist, multi-scale study, dynamic timeseries study and inter-regional comparative study will be further exploited and increasingly carried out with the progress of spatial information technology, which would boost the development and application of new methods in RSD study.展开更多
基金financially supported by the Hundred Talents Program of Chinese Academy of Sciencesthe National Natural Science Foundation of China (No. U1460202)the Key Laboratory of Superlight Material and Surface Technology (Harbin Engineering University), Ministry of Education
文摘Response surface methodology（RSM） is introduced into corrosion research as a tool to assess the effects of environmental factors and their interactions on corrosion behavior and establish a model for corrosion prediction in complex coupled environment（CCE）. In this study, a typical CCE, that is, the corrosion environment of pipelines in gas field is taken as an example. The effects of environmental factors such as chloride concentration, pH value and pressure as well as their interactions on critical pitting temperature（CPT） were evaluated, and a quadratic polynomial model was developed for corrosion prediction by RSM. The results showed that the model was excellent in corrosion prediction with R2= 0.9949. CPT was mostly affected by single environmental factor rather than interaction, and among the whole factors, chloride concentration was the most influential factor of CPT.
基金supported by the National Natural Science Foundation of China(Nos.12175190 and U2241284)the National Key R&D Program of China(Nos.SQ2022YFB190165)+1 种基金the Natural Science Foundation of Fujian Province,China(No.2022J02006)the Special Funds for Central Government Guiding Shenzhen Development in Science and Technology,China(No.2021Szvup066).
文摘Betavoltaic cells(BCs)are promising self-generating power cells with long life and high power density.However,the low energy conversion efficiency(ECE)has limitations in practical engineering applications.Widebandgap semiconductors(WBGSs)with three-dimensional(3-D)nanostructures are ideal candidates for increasing the ECE of BCs.This paper proposes hydrothermally grown ZnO nanorod arrays(ZNRAs)for ^(63)Ni-powered BCs.A quantitative model was established for simulation using the parameter values of the dark characteristics,which were obtained from the experimental measurements for a simulated BC based on a Ni-incorporated ZNRAs structure.Monte Carlo(MC)modeling and simulation were conducted to obtain the values of the β energy deposited in ZNRAs with different nanorod spacings and heights.Through the simulation and optimization of the 3-D ZNRAs and 2-D ZnO bulk structures,the performance of the ^(63)Ni-powered BCs based on both structures was evaluated using a quantitative model.The BCs based on the 3-D ZNRAs structure and 2-D ZnO bulk structure achieved a maximum ECE of 10.1%and 4.69%,respectively,which indicates the significant superiority of 3-D nanostructured WBGSs in increasing the ECE of BCs.
文摘Charge transfer mechanisms of contact electrification(CE)are essential for widening applications of the triboelectric nanogenerator,and thus are widely studied by scientists around the world.However,the quantitative modeling of CE,especially that between polymers,is still lacking.Herein,a model was proposed to describe the contributions from different mechanisms,including electron transfer and mass transfer in polymer/polymer CE through the fieldassisted thermionic emission,where three groups of charge transfer mechanisms were distinguished by the polarity of the charge transfer and the corresponding electric field.The results indicated that the total generated charge in CE is actually much larger than the measured net surface charge,confirming the bidirectional material-dependent charge transfer mechanisms between two surfaces,which is meaningful for understanding the millennium puzzle in triboelectrification and provides a new perspective for promoting the applications to tailor surface charge generation.
基金Supported by National Natural Science Foundation of China(Grant Nos.11272084,11472076)PetroChina Innovation Foundation(Grant No.2015D-5006-0602)Postdoctoral Science Research Developmental Foundation of Chinese Heilongjiang Province(Grant No.LBH-Q13035)
文摘Metal magnetic memory（MMM） testing has been widely used to detect welded joints. However, load levels, environmental magnetic field, and measurement noises make the MMM data dispersive and bring difficulty to quantitative evaluation. In order to promote the development of quantitative MMM reliability assessment, a new MMM model is presented for welded joints. Steel Q235 welded specimens are tested along the longitudinal and horizontal lines by TSC-2M-8 instrument in the tensile fatigue experiments. The X-ray testing is carried out synchronously to verify the MMM results. It is found that MMM testing can detect the hidden crack earlier than X-ray testing. Moreover, the MMM gradient vector sum K_（vs） is sensitive to the damage degree, especially at early and hidden damage stages. Considering the dispersion of MMM data, the K_（vs） statistical law is investigated, which shows that K_（vs） obeys Gaussian distribution. So K_（vs） is the suitable MMM parameter to establish reliability model of welded joints. At last, the original quantitative MMM reliability model is first presented based on the improved stress strength interference theory. It is shown that the reliability degree R gradually decreases with the decreasing of the residual life ratio T, and the maximal error between prediction reliability degree R_1 and verification reliability degree R_2 is 9.15%. This presented method provides a novel tool of reliability testing and evaluating in practical engineering for welded joints.
基金supported by the National Key Research and Development Program of China(No.2021YFB3702602)the National Natural Science Foundation of China(Nos.51825101,52425101)。
文摘Grain boundary segregation(GBS)of solutes influences the grain size,texture,and strength of Mg wrought alloys.So far,solutes'GBS in Mg has mostly been investigated by qualitative experimental observations.In this work,we develop a quantitative model to compute the grain boundary segregation energy(ΔE_(seg))in binary Mg based alloys that takes the relative atomic density of GB into account.The model is utilized to computeΔE_(seg)of Al,Zn,Ca,Sn,Y,Gd,and Nd solutes in Mg.The result suggests that rare earth elements and Ca are more prone to GBS than Al,Zn,and Sn.Segregation of Gd solutes can explain the smaller grain size and slower grain growth in Mg-Gd extruded alloys than Mg-Al and Mg-Zn counterparts.It also provides an explanation for the weak extrusion texture in Mg-Gd.
文摘This paper reviews the history and lessons of global oil crises while exploring the establishment of a quantitative evaluation model for oil security with Chinese characteristics.Using principal component analysis,it constructs an oil security evaluation indicator system for China with two main-level indicators:foreign oil dependency and its impacts,and market intervention and security assurance.
基金Research and Development of Unmanned Vessel System Based on Intelligent Ship-Shore Collaborative Technology,Hainan University of Science and Technology Science Research(HKKY2024-79)。
文摘This paper deeply explores the autonomous collision avoidance algorithm for intelligent ships,aiming to enhance the intelligence level and safety of ship collision avoidance by integrating navigation experience.An autonomous collision avoidance algorithm based on navigation experience is designed,a collision avoidance experience database is constructed,a quantitative model is established,and specific algorithm steps are implemented.The algorithm is verified and analyzed through simulation tests.The results show that the algorithm can effectively achieve autonomous ship collision avoidance in different scenarios,providing new ideas and methods for the development of intelligent ship collision avoidance technology.
基金supported by the Chinese Scholarship Council under Grant 202106910006.
文摘Branch angles are an important plant morphological trait affecting light interception within forest canopies.However,studies on branch angles have been limited due to the time-consuming nature of manual measurements using a protractor.Terrestrial laser scanning(TLS),however,provides new opportunities to measure branch angles more efficiently.Despite this potential,studies validating branch angle measurements from TLS have been limited.Here,our aim is to evaluate both manual and automatic branch angle measurements of European beech from TLS data using traditional field-measurements with a protractor as a reference.We evaluated the accuracy of branch angle measurements based on four automated algorithms(aRchiQSM,TreeQSM,Laplacian,SemanticLaplacian)from TLS data.Additionally,we assessed different ways of manual branch angle measurements in the field.Our study was based on a dataset comprising 124 branch angles measured from six European beech in a European deciduous forest.Our results show that manual branch angle measurements from TLS data are in high agreement with the reference(root-mean-squared error,RMSE:[3.57°-4.18°],concordance correlation coefficient,CCC:[0.950.97])across different branch length positions.Automated algorithms also are in high agreement with the reference although RMSE is approximately twice as large compared to manual branch angle measurements from TLS(RMSE:[9.29°-10.55°],CCC:[0.830.86])with manual leaf points removal.When applying the automatic wood-leaf separation algorithm,the performance of the four methods declined significantly,with only approximately 20 branch angles successfully identified.Moreover,it is important to note that there is no influence of the measurement position(branch surface versus center)for branch angle measurements.However,for curved branches,the selection of branch measurement length significantly impacts the branch angle measurement.This study provides a comprehensive understanding of branch angle measurements in forests.We show that automated measurement methods based on TLS data of branch angles are a valuable tool to quantify branch angles at larger scales.
文摘The stretching process of some Tertiary rift basins in eastern China is characterized by multiphase rifting. A multiple instantaneous uniform stretching model is proposed in this paper to simulate the formation of the basins as the rifting process cannot be accurately described by a simple (one episode) stretching model. The study shows that the multiphase stretching model, combined with the back-stripping technique, can be used to reconstruct the subsidence history and the stretching process of the lithosphere, and to evaluate the depth to the top of the asthenosphere and the deep thermal evolution of the basins. The calculated results obtained by applying the quantitative model to the episodic rifting process of the Tertiary Qiongdongnan and Yinggehai basins in the South China Sea are in agreement with geophysical data and geological observations. This provides a new method for quantitative evaluation of the geodynamic process of multiphase rifting occurring during the Tertiary in eastern China.
基金financially supported by the National Natural Science Foundation of China (Nos.50874014 and 51974023)the Fundamental Research Funds for Central Universities (No.FRF-BR-17-029A)。
文摘The quantitative evaluation of multi-process collaborative operation is of great significance for the improvement of production planning and scheduling in steelmaking–continuous casting sections(SCCSs). However, this evaluation is difficult since it relies on an in-depth understanding of the operating mechanism of SCCSs, and few existing methods can be used to conduct the evaluation, due to the lack of full-scale consideration of the multiple factors related to the production operation. In this study, three quantitative models were developed, and the multiprocess collaborative operation level was evaluated through the laminar-flow operation degree, the process matching degree, and the scheduling strategy availability degree. Based on the evaluation models for the laminar-flow operation and process matching levels, this study investigated the production status of two steelmaking plants, plants A and B, based on actual production data. The average laminar-flow operation(process matching) degrees of SCCSs were obtained as 0.638(0.610) and 1.000(0.759) for plants A and B, respectively, for the period of April to July 2019. Then, a scheduling strategy based on the optimization of the furnace-caster coordinating mode was suggested for plant A. Simulation experiments showed higher availability than the greedy-based and manual strategies. After the proposed scheduling strategy was applied,the average process matching degree of the SCCS of plant A increased by 4.6% for the period of September to November 2019. The multi-process collaborative operation level was improved with fewer adjustments and interruptions in casting.
基金Project(2002CB312203) supported by the National Key Fundamental Research and Development Programof China pro-ject(60574030) supported bythe National Natural Science Foundation of China project(06FD026) supported bythe Natural Science Foun-dation of Hunan Province , China
文摘A multi-objective intelligent coordinating optimization strategy based on qualitative and quantitative synthetic model for Pb-Zn sintering blending process was proposed to obtain optimal mixture ratio. The mechanism and neural network quantitative models for predicting compositions and rule models for expert reasoning were constructed based on statistical data and empirical knowledge. An expert reasoning method based on these models were proposed to solve blending optimization problem, including multi-objective optimization for the first blending process and area optimization for the second blending process, and to determine optimal mixture ratio which will meet the requirement of intelligent coordination. The results show that the qualified rates of agglomerate Pb, Zn and S compositions are increased by 7.1%, 6.5% and 6.9%, respectively, and the fluctuation of sintering permeability is reduced by 7.0%, which effectively stabilizes the agglomerate compositions and the permeability.
文摘The relationships of cooling rate with microstructure and thermal conductivity of vermicular graphite cast iron(VGI) cylinder block were studied, which are important for design and optimization of the casting process of VGI cylinder blocks. Cooling rates at different positions in the cylinder block were calculated based on the cooling curves recorded with a solidification simulation software. The metallographic structure and thermal conductivity were observed and measured using optical microscopy(OM), scanning electrical microscopy(SEM) and laser flash diffusivity apparatus, respectively. The effects of the cooling rate on the vermicularity, total and average areas of all graphite particles, and the pearlite fraction in the VGI cylinder block were investigated. It is found that the vermicularity changes in parabola trend with the increase of cooling rate. The total area of graphite particles and the cooling rate at eutectoid stage can be used to predict pearlite fraction well. Moreover, it is found that the thermal conductivity at room temperature is determined by the average area of graphite particles and pearlite fraction when the range of vermicularity is from 80% to 93%. Finally, the quantitative models are established to calculate the vermicularity, pearlite fraction, and thermal conductivity of the VGI cylinder block.
基金Supported by the Measurement and Testing Center of Zhejiang Province, China(No.02079).
文摘The influence of surface S^2- dangling bonds and surface doped ions（Se^2-, Cu^2＋, and Hg^2＋） on the photoluminescence of Cd^2＋-rich CdS QDs was investigated. A quantitative model was proposed to understand the complex transfer processes of excited electrons in CdS QDs. The transfer of excited electrons from either the conduction band or the Cd^2＋-related trap-state to the surface S^2-related shallow hole trap-state is effective. However, the trap of excited electrons by surface doped ion trap-states from the Cd^2＋-related trap-state is more effective than that from the conduction band. The efficiency of trapping electrons from both the conduction band and the Cd^2＋-related trap-state can be quantitatively understood with the help of the proposed model. The results show that the transfer efficiency of excited electrons is dependent on the location of the energy-level of the relevant surface-related trap-state. The trap of excited electrons by the surface trap-state with energy-level closer to that of the conduction band is more effective, especially for the trap of excited electrons from Cd^2＋-related trap-state.
基金Supported by National Nature Science Foundation of China, No.30170828
文摘AIM: To set up a mathematic model for gastric cancer screening and to evaluate its function in mass screening for gastric cancer.METHODS: A case control study was carried on in 66patients and 198 normal people, then the risk and protective factors of gastric cancer were determined, including heavy manual work, foods such as small yellow-fin tuna, dried small shrimps, squills, crabs, mothers suffering from gastric diseases, spouse alive, use of refrigerators and hot food,etc. According to some principles and methods of probability and fuzzy mathematics, a quantitative assessment model was established as follows: first, we selected some factors significant in statistics, and calculated weight coefficient for each one by two different methods; second, population space was divided into gastric cancer fuzzy subset and non gastric cancer fuzzy subset, then a mathematic model for each subset was established, we got a mathematic expression of attribute degree (AD).RESULTS: Based on the data of 63 patients and 693 normal people, AD of each subject was calculated. Considering the sensitivity and specificity, the thresholds of AD values calculated were configured with 0.20 and 0.17, respectively.According to these thresholds, the sensitivity and specificity of the quantitative model were about 69% and 63%.Moreover, statistical test showed that the identification outcomes of these two different calculation methods were identical (P＞0.05).CONCLUSION: The validity of this method is satisfactory.It is convenient, feasible, economic and can be used to determine individual and population risks of gastric cancer.
基金Supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX23_0082)
文摘Breast cancer is presently one of the most common malignancies worldwide,with a higher fatality rate.In this study,a quantitative structure-activity relationship(QSAR)model of compound biological activity and ADMET(Absorption,Distribution,Metabolism,Excretion,Toxicity)properties prediction model were performed using estrogen receptor alpha(ERα)antagonist information collected from compound samples.We first utilized grey relation analysis(GRA)in conjunction with the random forest(RF)algorithm to identify the top 20 molecular descriptor variables that have the greatest influence on biological activity,and then we used Spearman correlation analysis to identify 16 independent variables.Second,a QSAR model of the compound were developed based on BP neural network(BPNN),genetic algorithm optimized BP neural network(GA-BPNN),and support vector regression(SVR).The BPNN,the SVR,and the logistic regression(LR)models were then used to identify and predict the ADMET properties of substances,with the prediction impacts of each model compared and assessed.The results reveal that a SVR model was used in QSAR quantitative prediction,and in the classification prediction of ADMET properties:the SVR model predicts the Caco-2 and hERG(human Ether-a-go-go Related Gene)properties,the LR model predicts the cytochrome P450 enzyme 3A4 subtype(CYP3A4)and Micronucleus(MN)properties,and the BPNN model predicts the Human Oral Bioavailability(HOB)properties.Finally,information entropy theory is used to validate the rationality of variable screening,and sensitivity analysis of the model demonstrates that the constructed model has high accuracy and stability,which can be used as a reference for screening probable active compounds and drug discovery.
文摘In this paper, decision making in complex environment is considered and an approach integrating quantitative decision model with qualitative judgment is proposed. The concept of belief degree for quantitative decision model in a complex environment is presented. The integration in formulation and reasoning of quantitative model with qualitative judgment is studied. The combination of various belief degree generated by quantitative model and qualitative judgment is discussed. A decision rule of tradeoff between optimality and belief degree of optimality is proposed.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12274230,91950102,and 11834004)the Funding of Nanjing University of Science and Technology (Grant No.TSXK2022D005)the Postgraduate Research&Practice Innovation Program of Jiangsu Province of China (Grant No.KYCX230443)。
文摘We calibrate the macroscopic vortex high-order harmonic generation(HHG)obtained by the quantitative rescattering(QRS)model to compute single-atom induced dipoles against that by solving the time-dependent Schr?dinger equation(TDSE).We show that the QRS perfectly agrees with the TDSE under the favorable phase-matching condition,and the QRS can accurately predict the main features in the spatial profiles of vortex HHG if the phase-matching condition is not good.We uncover that harmonic emissions from short and long trajectories are adjusted by the phase-matching condition through the time-frequency analysis and the QRS can simulate the vortex HHG accurately only when the interference between two trajectories is absent.This work confirms that it is an efficient way to employ the QRS model in the single-atom response for precisely simulating the macroscopic vortex HHG.
基金Project supported by the National Natural Science Foundation of China(Grant No.11274219)the Science and Technology Planning Project of Guangdong Province of China(Grant No.180917124960522)the Program for Promotion of Science at Universities in Guangdong Province of China(Grant No.2018KTSCX062)
文摘We review the recently improved quantitative rescattering theory for nonsequential double ionization, in which the lowering of threshold due to the presence of electric field at the time of recollision has been taken into account. First,we present the basic theoretical tools which are used in the numerical simulations, especially the quantum theories for elastic scattering of electron as well as the processes of electron impact excitation and electron impact ionization. Then,after a brief discussion about the properties of the returning electron wave packet, we provide the numerical procedures for the simulations of the total double ionization yield, the double-to-single ionization ratio, and the correlated two-electron momentum distribution.
文摘The inclusions of Al in steels have great influence on the properties and the quality of steels.But there are some difficulties on the content determination of Al inclusions with accuracy and rapidity.Conventional quantity analysis of stable inclusions is electrolysis method with the disadvantages of long analytical period,trivial operation and a little loss of some fine and instable oxides.The content of insoluble aluminum can be obtained by the subtraction between the content of total Al and acid soluble Al determined by chemical methods with the disadvantage of complicate procedure.Original position statistic distribution analysis(OPA) can be used for the determination of inclusions by collecting and discriminating the signals produced by single spark discharge in the way of no pre-sparking,scanning and emitting continuously.In this study the element of Al in some spectrum certified reference materials of carbon and medium or low-alloyed steels was analyzed by original opposition statistic distribution technique.Two quantitative mathematical models used by original position distribution analysis technology for the analysis of the content of Al inclusions have been investigated and been applied to the analysis of the content of Al inclusions in many kinds of spectrum certified reference materials and some medium and low-alloyed steel samples.The scope of application of the models and their limited conditions were discussed.It was found that the results calculated by OPA had great difference with the value by chemical method for some samples with the total content of Al above 0.2%.The reason is that some intensity of abnormal sparks have gone beyond the range of the largest intensity that can be determined by the instrument so that there is a certain deviation on the identification of abnormal sparks and the calculation of threshold value.It was found that the size distribution of Al inclusions had a great influence on the application of the two models.For most of certified reference materials for spectrum analysis and real steel samples the results of the content of Al in inclusions calculated by model 1 was satisfied and had good coincidence with the value of insoluble Al by chemical method. But for the samples with so many large inclusions of Al existed,the influence of intensity should be considered because the signal increase did not vary in the form of simple function.So model 2 was more suitable for the content calculation of Al in inclusions in this case.In order to choose suitable model to be used it is suggested that the size distribution of inclusions should be determined by OPA before content determination of Al in inclusions. The results of the content of Al inclusions calculated by the selected mathematical model were satisfied and had good coincidence with the value of insoluble Al obtained by the subtraction between the content of total Al and soluble Al determined by chemical methods when the content of total aluminum was below 0.2%.
基金supported by Research Projects of Province-ministry Co-constructing Henan University (Grant no. SBGJ090111)Research Projects of Social Science Plan in Shandong Province (Grant no. 08DJGJ16)Humanities and Social Science Research Projects Authorized by Education Department of Shandong Province (Grant no. J08WE14)
文摘Since the 1990s, with the in-depth study and understanding of sustainable development, quantitative study of regional sustainable development (RSD) was increasingly hot in China. Based on quantitative study of RSD from Core Periodical in China National Knowledge Infrastructure (1992–2008), statistical analysis on the annual distribution, periodicals distribution and changes of the distribution were made. And from perspectives of social–economic, ecological, systematic and emerging methods, the course, problems and trends of the quantitative study methods on RSD were examined and analyzed to get a clear summary. By the review, the context on the quantitative study of RSD was to be clarified. The study also showed that, primarily, fields involving quantitative study are expanding; second, big progresses and constant development have been made on the systematic method gradually sophisticated, the flourishing ecological method and emerging new methods in the context of cross and integration which has made complex integrated systems a more satisfactory solution; third, the method system has been more multi-angled, and the clues of independent innovation have been observed despite the fact that the introduction of imported method is the main trend. Although many problems exist, multi-scale study, dynamic timeseries study and inter-regional comparative study will be further exploited and increasingly carried out with the progress of spatial information technology, which would boost the development and application of new methods in RSD study.
