By deriving the stress concentration factor of theestimation approach for residual fatigue life’ an estimationapproach for structure crack propagation based on multiplefactors correction is proposed. Then’ the quant...By deriving the stress concentration factor of theestimation approach for residual fatigue life’ an estimationapproach for structure crack propagation based on multiplefactors correction is proposed. Then’ the quantitativeexpression among the structure factor’ stress ratio’ loadingtype’ the manufacture processing factor and the crackpropagation is achieved. The proposed approach iimplemented in a case study for an instance structure’ and theinfluences of correction factors on the crack propagation areanalyzed. Meanwhile’ the probabilistic method based onWeibull distribution probability density function is selected toevaluate the precision of the corrected estimation approach’and the probability density of results is calculated by theprobability density function. It is shown that the resultsestimated by the corrected approach is more precise than thoseestimated by the fracture mechanics, and they are closer to thetest data.展开更多
To solve the problem that the standard Kalman filter cannot give the optimal solution when the system model and stochastic information are unknown accurately, single fading factor Kalman filter is suitable for simple ...To solve the problem that the standard Kalman filter cannot give the optimal solution when the system model and stochastic information are unknown accurately, single fading factor Kalman filter is suitable for simple systems. But for complex systems with multi-variable, it may not be sufficient to use single fading factor as a multiplier for the covariance matrices. In this paper, a new multiple fading factors Kalman filtering algorithm is presented. By calculating the unbiased estimate of the innovation sequence covariance using fenestration, the fading factor matrix is obtained. Adjusting the covariance matrix of prediction error Pk｜k-1 using fading factor matrix, the algorithm provides different rates of fading for different filter channels. The proposed algorithm is applied to strapdown inertial navigation system （SINS） initial alignment, and simulation and experimental results demonstrate that, the alignment accuracy can be upgraded dramatically when the actual system noise characteristics are different from the pre-set values. The new algorithm is less sensitive to uncertainty noise and has better estimation effect of the parameters. Therefore, it is of significant value in practical applications.展开更多
Objective To evaluate whether the clustering of risk factors, both environmental and genetic, increases the risk of essential hypertension （EH） and the accumulation of risk factors influences the blood pressure leve...Objective To evaluate whether the clustering of risk factors, both environmental and genetic, increases the risk of essential hypertension （EH） and the accumulation of risk factors influences the blood pressure level in normotensives. Methods On the basis of a prevalence survey, 501 subjects of Mongolian ethnicity （243 hypertensives and 258 normotensives） who were not related to each other were selected to conduct a case-control study. All subjects were interviewed with questionnaires and their blood specimens were collected. Renin gene insertion/deletion （I/D） polymorphism, a new genetic marker, was genotyped with PCR and polyacrylamide gel electrophoresis. Results Overweight, alcohol consumption, and renin gene I/D polymorphism were significant risk factors of EH （P〈0.05）. The odds ratios （OR） for the number of risk factors were 2.39 （95%CI： 0.98-6.74） for one risk factor, 5.03 （95%CI： 2.06-14.18） for two, and 6.09 （95%CI： 1.85-22.38） for three respectively after adjusting for age and sex. In normotensives, age- and sex-adjusted mean blood pressures increased with more accumulation of risk factors. However, there were no significant differences among the different blood pressure levels according to the number of risk factors （P〉0.05）. Conclusion Overweight, alcohol consumption, and renin gene I/D polymorphism are risk factors of EH in the Mongolian ethnic population of China. The accumulation of the risk factors causes a sharp increase of the risk of EH.展开更多
The oxygen evolution reaction(OER) plays a crucial role in many electrochemical energy technologies,and creating multiple beneficial factors for OER catalysis is desirable for achieving high catalytic efficiency.Here,...The oxygen evolution reaction(OER) plays a crucial role in many electrochemical energy technologies,and creating multiple beneficial factors for OER catalysis is desirable for achieving high catalytic efficiency.Here,we highlight a new halogen-chlorine(Cl)-anion doping strategy to boost the OER activity of perovskite oxides.As a proof-of-concept,proper Cl doping at the oxygen site of LaFeO3(LFO) perovskite can induce multiple favorable characteristics for catalyzing the OER,including rich oxygen vacancies,increased electrical conductivity and enhanced Fe-O covalency.Benefiting from these factors,the LaFeO2.9-δCl0.1(LFOCl) perovskite displays significant intrinsic activity enhancement by a factor of around three relative to its parent LFO.This work uncovers the effect of Cl-anion doping in perovskites on promoting OER performance and paves a new way to design highly efficient electrocatalysts.展开更多
The effects of various contaminants in the electrolytic refinement of indium were investigated using a glow discharge mass spectrometer(GDMS).The effects of several factors such as the indium ion(In3+)concentration,th...The effects of various contaminants in the electrolytic refinement of indium were investigated using a glow discharge mass spectrometer(GDMS).The effects of several factors such as the indium ion(In3+)concentration,the sodium chloride(NaCl)concentration,the current density,the gelatin concentration,the pH,and the electrode distance,were examined.Significant variations in impurity levels concerning gelatin concentration were observed.Both the gelatin and In3+concentration were moderately positively correlated with the Pb content.The Sb concentration was associated positively with the NaCl concentration,while the Ti concentration had an adverse correlation with the NaCl concentration.The Bi element content was positively linked to the electrode distance.As the current density increased,Cu,Pb,and Bi impurities initially rose and then eventually declined.Notably,a critical current density of 45 A·m^(-2) was identified in this behavior.展开更多
Objective： To investigate potential prognostic factors affecting patient outcomes and to evaluate the optimal methods and effects of radiotherapy（RT） in the management of extramedullary plasmacytoma（EMP）.Methods...Objective： To investigate potential prognostic factors affecting patient outcomes and to evaluate the optimal methods and effects of radiotherapy（RT） in the management of extramedullary plasmacytoma（EMP）.Methods： Data from 55 patients with EMP between November 1999 and August 2015 were collected. The median age was 51（range, 22–77） years. The median tumor size was 3.5（range, 1.0–15.0） cm. The median applied dose was 50.0（range, 30.0–70.0） Gy. Thirty-nine patients（70.9%） presented with disease in the head or neck region. Twelve patients received RT alone, 9 received surgery（S） alone, 3 received chemotherapy（CT） alone, and 3 patients did not receive any treatment. Combination therapies were applied in 28 patients.Results：The median follow-up duration was 56 months.The 5-year local recurrence-free survival（LRFS）,multiple myeloma-free survival（MMFS）,progression-free survival（PFS）and overall survival（OS）rates were 79.8%,78.6%,65.2% and 76.0%,respectively.Univariate analysis revealed that RT was a favourable factor for all examined endpoints.Furthermore,head and neck EMPs were associated with superior LRFS,MMFS and PFS.Tumor size〈4 cm was associated with superior MMFS,PFS and OS;serum M protein negativity was associated with superior MMFS and PFS;age≥50 years and local recurrence were associated with poor MMFS.The dose≥45 Gy group exhibited superior 5-year LRFS,MMFS and PFS rates（94.7%,94.4%,90.0%,respectively）,while the corresponding values for the dose〈45 Gy group were 62.5%（P=0.008）,53.3%（P=0.036）and 41.7%（P〈0.001）.Conclusions：Involved-site RT of at least 45 Gy should be considered for EMP.Furthermore,patients with head and neck EMP,tumor size〈4 cm,age〈50 years and serum M protein negativity had better outcomes.展开更多
This article aims to address the clustering effect caused by unorganized charging of electric vehicles by adopting a two-tier recommendation method.The electric vehicles(EVs)are classified into high-level alerts and g...This article aims to address the clustering effect caused by unorganized charging of electric vehicles by adopting a two-tier recommendation method.The electric vehicles(EVs)are classified into high-level alerts and general alerts based on their state of charge(SOC).EVs with high-level alerts have the most urgent charging needs,so the distance to charging stations is set as the highest priority for recommendations.For users with general alerts,a comprehensive EV charging station recommendation model is proposed,taking into account factors such as charging price,charging time,charging station preference,and distance to the charging station.Using real data from EV charging stations and ride-hailing vehicles in Xiamen City,Fujian Province,simulation analyses are conducted using Python for different periods of the day.The research results show that the stability of the multi-factor recommendation model in terms of service density variance,coverage rate,price cost,and distance cost outperform single-factor models.This indicates that our composite multi-factor recommendation model has significant practical value in resolving the clustering phenomenon caused by unorganized EV charging,optimizing the EV charging service system,and improving user satisfaction.展开更多
In this paper, we present the first order perturbation bounds for the SR factorization with respect to left multiplicative perturbation, and the first order and rigorous perturbation bounds for this factorization with...In this paper, we present the first order perturbation bounds for the SR factorization with respect to left multiplicative perturbation, and the first order and rigorous perturbation bounds for this factorization with respect to right multiplicative perturbation.Moreover, taking the properties of SR factors into consideration, we also provide some refined perturbation bounds.展开更多
To describe the empirical data of collaboration networks, several evolving mechanisms have been proposed, which usually introduce different dynamics factors controlling the network growth. These models can reasonably ...To describe the empirical data of collaboration networks, several evolving mechanisms have been proposed, which usually introduce different dynamics factors controlling the network growth. These models can reasonably reproduce the empirical degree distributions for a number of we11-studied real-world collaboration networks. On the basis of the previous studies, in this work we propose a collaboration network model in which the network growth is simultaneously controlled by three factors, including partial preferential attachment, partial random attachment and network growth speed. By using a rate equation method, we obtain an analytical formula for the act degree distribution. We discuss the dependence of the act degree distribution on these different dynamics factors. By fitting to the empirical data of two typical collaboration networks, we can extract the respective contributions of these dynamics factors to the evolution of each networks.展开更多
Elastic anisotropy of shales is critical to accurate constraints for rock physical models,quantitative interpretation and hydraulic fracturing.However,the causes of elastic anisotropy of shales are very complicated,an...Elastic anisotropy of shales is critical to accurate constraints for rock physical models,quantitative interpretation and hydraulic fracturing.However,the causes of elastic anisotropy of shales are very complicated,and the understanding of how multiple influence factors affect the elastic anisotropy of shales is still not clear.Hence,the orthogonal experiment,as an effective multiple factors experimental method,is adopted in this study to analyze the effect of multiple factors for shale elastic anisotropy.Three factors,clay content,organic matter(OM)content and compaction stress are selected as independent variables,the orthogonal test table L_(16)(4^(3))with four levels for each factor is adopted.According to the designed orthogonal table,sixteen artificial shales are constructed based on the cold-pressing method,and all the dry artificial shales are measured by the ultrasonic measurements.The influence of each factor on the elastic anisotropy and the sensitivity orders of three factors are obtained using the range analysis.The orders of sensitivity for selected factors follow the sequence clay content>compaction stress>OM content for velocity anisotropy parameters.The compaction mechanism of artificial shales is also discussed by the compaction factor,which are positively correlated with the velocity anisotropy parameters.The clay platelets orientation distribution function(ODF)of samples is evaluated by a theoretical model,the ODF coefficients are significantly affected by the clay content and compaction stress,and W200 are much more sensitive to these factors than W400.The results can provide a critical rock physics basis for quantitative interpretation and reservoir prediction of the low-maturity or maturity shale reservoir.展开更多
The effects of intensive versus regular therapy on incidence and progress of microalbuminuria in type 2 diabetes were compared. During a follow-up of 3 years, 96 cases of diabetes mellitus were randomized to intensive...The effects of intensive versus regular therapy on incidence and progress of microalbuminuria in type 2 diabetes were compared. During a follow-up of 3 years, 96 cases of diabetes mellitus were randomized to intensive and regular therapy groups. HbA 1c goal was same in the two groups, but the goal of blood pressure (Bp) and lipid was more strict in the intensive therapy group than in the regular therapy group. There was statistically significant difference in the incidence and progression of vascular complications between the two groups. Logistic stepwise-regression analysis (odds ration, OR) showed that there was significant difference in the progression of nephropathy (OR 0.24, 95 % CI 0.12-0.76), retinopathy (OR 0.38, 95 % CI 0.16-0.88), peripheral neuropathy (OR 0.42, 95 % CI 0.22-0.86) and autonomic neuropathy (OR 0.29, 95 % CI 0.12-0.86) between the two groups (P<0.01). It was concluded that intensive blood glucose controlling could retard diabetic vascular complications. Intensive therapy of multiple factors interventions (controlling Bp, regulating blood lipid, improving microcirculation) could decrease various risk factors for diabetic vascular complications.展开更多
In this work,heat treatment experiments at 1050 and 1100℃were carried out on single-crystal su-peralloy specimens coated with the electron beam physical vapor deposition(EB-PVD)thermal barrier coating(TBC)system.Furt...In this work,heat treatment experiments at 1050 and 1100℃were carried out on single-crystal su-peralloy specimens coated with the electron beam physical vapor deposition(EB-PVD)thermal barrier coating(TBC)system.Furthermore,the evolution of microstructural characteristics and sintering-induced mechanical properties were separately obtained by the field emission scanning electron microscope(FE-SEM)and nanoindenter,providing inputs for damage modeling.Meanwhile,the critical compressive strain of TBCs at room temperature was acquired using 3D digital image correlation(3D-DIC)technology to characterize the interfacial damage combined with the experimentally observed buckling modes.The re-sults demonstrate that not only does oxidative damage exist in the TBCs system due to thermally grown oxide(TGO)growth,but additional damage is generated by thermal cycling and sintering behavior,re-spectively.Then,a nonlinear cumulative interfacial damage model considering multiple failure factors is developed to predict TBCs’life.The error between the measured damage and calculated damage is less than 15%,showing good prediction accuracy.展开更多
Dominant early heading(DEH)in rice(Oryza sativa L.)is of interest in both breeding and genetics.The genetic mechanisms underlying DEH have remained largely unclear.We have developed a near-isogenic DEH line without yi...Dominant early heading(DEH)in rice(Oryza sativa L.)is of interest in both breeding and genetics.The genetic mechanisms underlying DEH have remained largely unclear.We have developed a near-isogenic DEH line without yield drag named DEH_229 by sister-line backcross(BC)breeding with MH63,a restorer,as the genetic background.We conducted a pilot genetic investigation under both short-day(SD)and long-day(LD)conditions.The DEH line harbored only 1.06%variation in the genome sequence relative to MH63.The variants were distributed throughout the genome.Using QTL mapping by sequencing(QTL-seq)on an F_(2) population derived from a cross of MH63×DEH_229,57 loci were detected under the SD condition.Joint mapping employing a genome-wide association study with accessions from the 3000 rice genome sequencing project(3K-RG),reduced the number of QTL by 43.9%.Using Rice Functional Genomics&Breeding(RFGB)database,the number of SNP cluster regions within the QTL regions reduced by 27.3%.Further comparison of the genome variation between DEH_229 and MH63 in addition to gene annotation information revealed a new DEH allele of DTH3 with multiple variable sites as a possible major factor underlying the early-heading phenotype of DEH_229.An InDel marker,ZMEH_1,was designed based on the variation between DEH_229 and MH63 within this region.It accounted for 86.0%of heading date variation under both SD and LD conditions in 109 randomly chosen progeny derived from extreme lines of the MH63×DEH_229 population.This study reveals the genetic complexity of DEH in the near-isogenic line and may provide useful material and marker information for plant molecular breeding.展开更多
Background Patients with acute type A aortic dissection have a high incidence of postoperative cerebral complication. Better understanding of the risk factors could help to optimize prevention and treatment strategies...Background Patients with acute type A aortic dissection have a high incidence of postoperative cerebral complication. Better understanding of the risk factors could help to optimize prevention and treatment strategies. Method A total of 298 patients of acute type A aortic dissection operated in Guangdong Cardiac Institution from 2010.10 to 2014.12 were included, 253 of them were male and the other 45 were female. Their average age was 45.8__. 12.2y. All the patients were divided into cerebral complication and no cerebral complication groups. Data collectedfrom both groups were analyzed by univariate and multivariate analyses to identify the indepen- dent risk factors of postoperative cerebral complication. Result The incidence of postoperative cerebral compli- cation was 37.9% （113/298）. Among 113 patients, temporary nerve damage （TND） group and permanent nerve damage （PND） accounted for 93 cases（31.2%） and 20 cases （6.7%） respectively. Logistic Regress multivariate analysis showed that history of hypertension （OR=2.560, 95%CI, 1.397-4.692, P〈0.01）, total arch replacement （OR=2.315, 95%CI, 1.386-3.869, P〈0.01）, time of aortic arrest （OR=1.008, 95%CI, 1.004-1.012, P〈0.01） and postoperative hypoxemia （OR=1.858, 95%CI, 1.122-3.078, P〈0.05） were the independent risk factors of the post- operative cerebral complication in patients with acute type A aortic dissection. Conclusion Incidence of postop- erative cerebral complication is high in the acute type A aortic dissection patients itsmajor risk factors are hypertension history, total arch replacement, and long duration of aortic arrest or hypoxemia.展开更多
In the last few years, interest in burnup calculations using Monte Carlo methods has increased. Previous burnup codes have used diffusion theory for the neutronic portion of the codes. Diffusion theory works well for ...In the last few years, interest in burnup calculations using Monte Carlo methods has increased. Previous burnup codes have used diffusion theory for the neutronic portion of the codes. Diffusion theory works well for most reactors. However, diffusion theory does not produce accurate results in burnup problems that include strong absorbers or large voids. MCNPX code based on Mont Carlo Method, is used to design a three dimensional model for a BWR fuel assembly in a typical operating temperature and pressure conditions. A test case was compared with a benchmark problem and good agreement was found. The model is used to calculate the distribution of pin by pin power and flux inside the assembly. The effect of axial variation of water （coolant） density, and of control rods motion on the neutron flux and power distribution is analyzed. The effect of addition of Gd2O3 to natural uranium （0.711%） on both the thermal neutron flux and normalized power are analyzed. The concentration of U^235, U^238, Pu^239, and its isotopes is also calculated at burn-up 50 GWD/T.展开更多
This paper is concerned with the adaptive robust cubature Kalman filtering problem for the case that the dynamics model error and the measurement model error exist simultaneously in the satellite attitude estimation s...This paper is concerned with the adaptive robust cubature Kalman filtering problem for the case that the dynamics model error and the measurement model error exist simultaneously in the satellite attitude estimation system. By using Hubel-based robust filtering methodology to correct the measurement covariance formulation of cubature Kalman filter, the proposed filtering algorithm could effectively suppress the measurement model error. To further enhance this effect and reduce the impact of the dynamics model error, two different adaptively robust filtering algorithms,one with the optimal adaptive factor based on the estimated covariance matrix of the predicted residuals and the other with multiple fading factors based on strong tracking algorithm, are developed and applied for the satellite attitude estimation. The quaternion is employed to represent the global attitude parameter, and three-dimensional generalized Rodrigues parameters are introduced to define the local attitude error. A multiplicative quaternion error is derived from the local attitude error to maintain quaternion normalization constraint in the filter. Simulation results indicate that the proposed novel algorithm could exhibit higher accuracy and faster convergence compared with the multiplicative extended Kalman filter, the unscented quaternion estimator, and the adaptive robust unscented Kalman filter.展开更多
Nonlinear initial alignment is a significant research topic for strapdown inertial navigation system(SINS).Cubature Kalman filter(CKF)is a popular tool for nonlinear initial alignment.Standard CKF assumes that the sta...Nonlinear initial alignment is a significant research topic for strapdown inertial navigation system(SINS).Cubature Kalman filter(CKF)is a popular tool for nonlinear initial alignment.Standard CKF assumes that the statics of the observation noise are pre-given before the filtering process.Therefore,any unpredicted outliers in observation noise will decrease the stability of the filter.In view of this problem,improved CKF method with robustness is proposed.Multiple fading factors are introduced to rescale the observation noise covariance.Then the update stage of the filter can be autonomously tuned,and if there are outliers exist in the observations,the update should be less weighted.Under the Gaussian assumption of KF,the Mahalanobis distance of the innovation vector is supposed to be Chi-square distributed.Therefore a judging index based on Chi-square test is designed to detect the noise outliers,determining whether the fading tune are required.The proposed method is applied in the nonlinear alignment of SINS,and vehicle experiment proves the effective of the proposed method.展开更多
Previously,troughs in continental faulted depressions were usually considered as a zone of hydrocarbon generation and expulsion rather than a zone for hydrocarbon accumulation.If they were confirmed to be the source k...Previously,troughs in continental faulted depressions were usually considered as a zone of hydrocarbon generation and expulsion rather than a zone for hydrocarbon accumulation.If they were confirmed to be the source kitchen,the possibility that they could constitute potential plays would be overlooked in the subsequent exploration program.Based on the hydrocarbon exploration practice of the Jizhong Depression and the Erlian Basin in the past several years,this paper discusses a new understanding that reservoir distribution is controlled by multiple factors and lithological accumulations are more likely to form in trough areas.It further documents the three main factors controlling the formation of large lithological hydrocarbon accumulations in trough areas.The paper also discusses the new concept that structural and lithological accumulations not only co-exist but also complement each other.We propose that fan-delta fronts on inverted steep slopes in troughs,delta fronts and sublacustrine fans on gentle slopes,channel sands along toes of fault scarps are favorable locations for discovery of new oil accumulations.The application of this concept has led to the discovery of several hundreds of million tonnes of oil in place in trough areas in the Jizhong Depression and the Erlian Basin.展开更多
The narrowing deformation of reservoir valley during the initial operation period threatens the long-term safety of the dam,and an accurate prediction of valley deformation(VD)remains a challenging part of risk mitiga...The narrowing deformation of reservoir valley during the initial operation period threatens the long-term safety of the dam,and an accurate prediction of valley deformation(VD)remains a challenging part of risk mitigation.In order to enhance the accuracy of VD prediction,a novel hybrid model combining Ensemble empirical mode decomposition based interval threshold denoising(EEMD-ITD),Differential evolutions—Shuffled frog leaping algorithm(DE-SFLA)and Least squares support vector machine(LSSVM)is proposed.The non-stationary VD series is firstly decomposed into several stationary subseries by EEMD;then,ITD is applied for redundant information denoising on special sub-series,and the denoised deformation is divided into the trend and periodic deformation components.Meanwhile,several relevant triggering factors affecting the VD are considered,from which the input features are extracted by Grey relational analysis(GRA).After that,DE-SFLA-LSSVM is separately performed to predict the trend and periodic deformation with the optimal inputs.Ultimately,the two individual forecast components are reconstructed to obtain the final predicted values.Two VD series monitored in Xiluodu reservoir region are utilized to verify the proposed model.The results demonstrate that:(1)Compared with Discrete wavelet transform(DWT),better denoising performance can be achieved by EEMD-ITD;(2)Using GRA to screen the optimal input features can effectively quantify the deformation response relationship to the triggering factors,and reduce the model complexity;(3)The proposed hybrid model in this study displays superior performance on some compared models(e.g.,LSSVM,Backward Propagation neural network(BPNN),and DE-SFLA-BPNN)in terms of forecast accuracy.展开更多
基金The National Natural Science Foundation of China(No.51675098)Chinese Specialized Research Foundation for Doctoral Program of Higher Education(No.20130092110003)Graduate Student Research Innovation Foundation of Jiangsu Province(No.KYLX15_0059)
文摘By deriving the stress concentration factor of theestimation approach for residual fatigue life’ an estimationapproach for structure crack propagation based on multiplefactors correction is proposed. Then’ the quantitativeexpression among the structure factor’ stress ratio’ loadingtype’ the manufacture processing factor and the crackpropagation is achieved. The proposed approach iimplemented in a case study for an instance structure’ and theinfluences of correction factors on the crack propagation areanalyzed. Meanwhile’ the probabilistic method based onWeibull distribution probability density function is selected toevaluate the precision of the corrected estimation approach’and the probability density of results is calculated by theprobability density function. It is shown that the resultsestimated by the corrected approach is more precise than thoseestimated by the fracture mechanics, and they are closer to thetest data.
基金Pre-research Foundation of PLA General Armaments Department （51309010602） National Natural Science Foundation of China （60774002）
文摘To solve the problem that the standard Kalman filter cannot give the optimal solution when the system model and stochastic information are unknown accurately, single fading factor Kalman filter is suitable for simple systems. But for complex systems with multi-variable, it may not be sufficient to use single fading factor as a multiplier for the covariance matrices. In this paper, a new multiple fading factors Kalman filtering algorithm is presented. By calculating the unbiased estimate of the innovation sequence covariance using fenestration, the fading factor matrix is obtained. Adjusting the covariance matrix of prediction error Pk｜k-1 using fading factor matrix, the algorithm provides different rates of fading for different filter channels. The proposed algorithm is applied to strapdown inertial navigation system （SINS） initial alignment, and simulation and experimental results demonstrate that, the alignment accuracy can be upgraded dramatically when the actual system noise characteristics are different from the pre-set values. The new algorithm is less sensitive to uncertainty noise and has better estimation effect of the parameters. Therefore, it is of significant value in practical applications.
基金This study was supported by the National Natural Sciences Foundation of China (Grant No. 30271149)Beijing Municipal NaturalSciences Foundation (No. 7001004)China Medical Board in New York (No. 96-657).
文摘Objective To evaluate whether the clustering of risk factors, both environmental and genetic, increases the risk of essential hypertension （EH） and the accumulation of risk factors influences the blood pressure level in normotensives. Methods On the basis of a prevalence survey, 501 subjects of Mongolian ethnicity （243 hypertensives and 258 normotensives） who were not related to each other were selected to conduct a case-control study. All subjects were interviewed with questionnaires and their blood specimens were collected. Renin gene insertion/deletion （I/D） polymorphism, a new genetic marker, was genotyped with PCR and polyacrylamide gel electrophoresis. Results Overweight, alcohol consumption, and renin gene I/D polymorphism were significant risk factors of EH （P〈0.05）. The odds ratios （OR） for the number of risk factors were 2.39 （95%CI： 0.98-6.74） for one risk factor, 5.03 （95%CI： 2.06-14.18） for two, and 6.09 （95%CI： 1.85-22.38） for three respectively after adjusting for age and sex. In normotensives, age- and sex-adjusted mean blood pressures increased with more accumulation of risk factors. However, there were no significant differences among the different blood pressure levels according to the number of risk factors （P〉0.05）. Conclusion Overweight, alcohol consumption, and renin gene I/D polymorphism are risk factors of EH in the Mongolian ethnic population of China. The accumulation of the risk factors causes a sharp increase of the risk of EH.
基金financially supported by the Australian Research Council (Discovery Early Career Researcher Award No. DE190100005)the support of the Australian Research Council (Grant No. FT160100207)the ontinued support from the Queensland University of Technology (QUT) through the centre for Materials Science。
文摘The oxygen evolution reaction(OER) plays a crucial role in many electrochemical energy technologies,and creating multiple beneficial factors for OER catalysis is desirable for achieving high catalytic efficiency.Here,we highlight a new halogen-chlorine(Cl)-anion doping strategy to boost the OER activity of perovskite oxides.As a proof-of-concept,proper Cl doping at the oxygen site of LaFeO3(LFO) perovskite can induce multiple favorable characteristics for catalyzing the OER,including rich oxygen vacancies,increased electrical conductivity and enhanced Fe-O covalency.Benefiting from these factors,the LaFeO2.9-δCl0.1(LFOCl) perovskite displays significant intrinsic activity enhancement by a factor of around three relative to its parent LFO.This work uncovers the effect of Cl-anion doping in perovskites on promoting OER performance and paves a new way to design highly efficient electrocatalysts.
基金supported by the National Natural Science Foundation of China(52074180)the Science and Technology Major Project of Yunnan Province(202302AB080020)+2 种基金the Independent Research Project of State Key Laboratory of Advanced Special Steel,Shanghai Key Laboratory of Advanced Ferrometallurgy,Shanghai University(SKLASS 2023-Z07)the Science and Technology Commission of Shanghai Municipality(19DZ2270200)the Program for Professor of Special Appointment(Eastern Scholar)at SIHL,Shanghai Sailing Program(19YF1416500).
文摘The effects of various contaminants in the electrolytic refinement of indium were investigated using a glow discharge mass spectrometer(GDMS).The effects of several factors such as the indium ion(In3+)concentration,the sodium chloride(NaCl)concentration,the current density,the gelatin concentration,the pH,and the electrode distance,were examined.Significant variations in impurity levels concerning gelatin concentration were observed.Both the gelatin and In3+concentration were moderately positively correlated with the Pb content.The Sb concentration was associated positively with the NaCl concentration,while the Ti concentration had an adverse correlation with the NaCl concentration.The Bi element content was positively linked to the electrode distance.As the current density increased,Cu,Pb,and Bi impurities initially rose and then eventually declined.Notably,a critical current density of 45 A·m^(-2) was identified in this behavior.
文摘Objective： To investigate potential prognostic factors affecting patient outcomes and to evaluate the optimal methods and effects of radiotherapy（RT） in the management of extramedullary plasmacytoma（EMP）.Methods： Data from 55 patients with EMP between November 1999 and August 2015 were collected. The median age was 51（range, 22–77） years. The median tumor size was 3.5（range, 1.0–15.0） cm. The median applied dose was 50.0（range, 30.0–70.0） Gy. Thirty-nine patients（70.9%） presented with disease in the head or neck region. Twelve patients received RT alone, 9 received surgery（S） alone, 3 received chemotherapy（CT） alone, and 3 patients did not receive any treatment. Combination therapies were applied in 28 patients.Results：The median follow-up duration was 56 months.The 5-year local recurrence-free survival（LRFS）,multiple myeloma-free survival（MMFS）,progression-free survival（PFS）and overall survival（OS）rates were 79.8%,78.6%,65.2% and 76.0%,respectively.Univariate analysis revealed that RT was a favourable factor for all examined endpoints.Furthermore,head and neck EMPs were associated with superior LRFS,MMFS and PFS.Tumor size〈4 cm was associated with superior MMFS,PFS and OS;serum M protein negativity was associated with superior MMFS and PFS;age≥50 years and local recurrence were associated with poor MMFS.The dose≥45 Gy group exhibited superior 5-year LRFS,MMFS and PFS rates（94.7%,94.4%,90.0%,respectively）,while the corresponding values for the dose〈45 Gy group were 62.5%（P=0.008）,53.3%（P=0.036）and 41.7%（P〈0.001）.Conclusions：Involved-site RT of at least 45 Gy should be considered for EMP.Furthermore,patients with head and neck EMP,tumor size〈4 cm,age〈50 years and serum M protein negativity had better outcomes.
基金the Jiangsu Provincial College Students Innovation and Entrepreneurship Training Plan Project(Grant Number 202311276097Y).
文摘This article aims to address the clustering effect caused by unorganized charging of electric vehicles by adopting a two-tier recommendation method.The electric vehicles(EVs)are classified into high-level alerts and general alerts based on their state of charge(SOC).EVs with high-level alerts have the most urgent charging needs,so the distance to charging stations is set as the highest priority for recommendations.For users with general alerts,a comprehensive EV charging station recommendation model is proposed,taking into account factors such as charging price,charging time,charging station preference,and distance to the charging station.Using real data from EV charging stations and ride-hailing vehicles in Xiamen City,Fujian Province,simulation analyses are conducted using Python for different periods of the day.The research results show that the stability of the multi-factor recommendation model in terms of service density variance,coverage rate,price cost,and distance cost outperform single-factor models.This indicates that our composite multi-factor recommendation model has significant practical value in resolving the clustering phenomenon caused by unorganized EV charging,optimizing the EV charging service system,and improving user satisfaction.
基金Supported by the National Natural Science Foundation of China(Grant No.11201507)
文摘In this paper, we present the first order perturbation bounds for the SR factorization with respect to left multiplicative perturbation, and the first order and rigorous perturbation bounds for this factorization with respect to right multiplicative perturbation.Moreover, taking the properties of SR factors into consideration, we also provide some refined perturbation bounds.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11305139 and 11147178
文摘To describe the empirical data of collaboration networks, several evolving mechanisms have been proposed, which usually introduce different dynamics factors controlling the network growth. These models can reasonably reproduce the empirical degree distributions for a number of we11-studied real-world collaboration networks. On the basis of the previous studies, in this work we propose a collaboration network model in which the network growth is simultaneously controlled by three factors, including partial preferential attachment, partial random attachment and network growth speed. By using a rate equation method, we obtain an analytical formula for the act degree distribution. We discuss the dependence of the act degree distribution on these different dynamics factors. By fitting to the empirical data of two typical collaboration networks, we can extract the respective contributions of these dynamics factors to the evolution of each networks.
基金supported by the National Natural Science Fund Projects(42104107)the Fundamental Research Funds for the Central Universities(2022XJDC06).
文摘Elastic anisotropy of shales is critical to accurate constraints for rock physical models,quantitative interpretation and hydraulic fracturing.However,the causes of elastic anisotropy of shales are very complicated,and the understanding of how multiple influence factors affect the elastic anisotropy of shales is still not clear.Hence,the orthogonal experiment,as an effective multiple factors experimental method,is adopted in this study to analyze the effect of multiple factors for shale elastic anisotropy.Three factors,clay content,organic matter(OM)content and compaction stress are selected as independent variables,the orthogonal test table L_(16)(4^(3))with four levels for each factor is adopted.According to the designed orthogonal table,sixteen artificial shales are constructed based on the cold-pressing method,and all the dry artificial shales are measured by the ultrasonic measurements.The influence of each factor on the elastic anisotropy and the sensitivity orders of three factors are obtained using the range analysis.The orders of sensitivity for selected factors follow the sequence clay content>compaction stress>OM content for velocity anisotropy parameters.The compaction mechanism of artificial shales is also discussed by the compaction factor,which are positively correlated with the velocity anisotropy parameters.The clay platelets orientation distribution function(ODF)of samples is evaluated by a theoretical model,the ODF coefficients are significantly affected by the clay content and compaction stress,and W200 are much more sensitive to these factors than W400.The results can provide a critical rock physics basis for quantitative interpretation and reservoir prediction of the low-maturity or maturity shale reservoir.
基金This project was supported by grants from Science and Re-search Founction of the Ministry of Health ( No.96- 2 - 10 2 )and Hubei Provincial Natural SciencesFoundation ( No.96J0 77)
文摘The effects of intensive versus regular therapy on incidence and progress of microalbuminuria in type 2 diabetes were compared. During a follow-up of 3 years, 96 cases of diabetes mellitus were randomized to intensive and regular therapy groups. HbA 1c goal was same in the two groups, but the goal of blood pressure (Bp) and lipid was more strict in the intensive therapy group than in the regular therapy group. There was statistically significant difference in the incidence and progression of vascular complications between the two groups. Logistic stepwise-regression analysis (odds ration, OR) showed that there was significant difference in the progression of nephropathy (OR 0.24, 95 % CI 0.12-0.76), retinopathy (OR 0.38, 95 % CI 0.16-0.88), peripheral neuropathy (OR 0.42, 95 % CI 0.22-0.86) and autonomic neuropathy (OR 0.29, 95 % CI 0.12-0.86) between the two groups (P<0.01). It was concluded that intensive blood glucose controlling could retard diabetic vascular complications. Intensive therapy of multiple factors interventions (controlling Bp, regulating blood lipid, improving microcirculation) could decrease various risk factors for diabetic vascular complications.
基金supported by the National Natural Science Foundation of China(Grant Nos.12202028,52022007,51905510)the National Science and Technology Major Project(Grant Nos.J2019-IV-0009-0077,J2019-IV-0006-0074,J2019-IV-0016-0084).
文摘In this work,heat treatment experiments at 1050 and 1100℃were carried out on single-crystal su-peralloy specimens coated with the electron beam physical vapor deposition(EB-PVD)thermal barrier coating(TBC)system.Furthermore,the evolution of microstructural characteristics and sintering-induced mechanical properties were separately obtained by the field emission scanning electron microscope(FE-SEM)and nanoindenter,providing inputs for damage modeling.Meanwhile,the critical compressive strain of TBCs at room temperature was acquired using 3D digital image correlation(3D-DIC)technology to characterize the interfacial damage combined with the experimentally observed buckling modes.The re-sults demonstrate that not only does oxidative damage exist in the TBCs system due to thermally grown oxide(TGO)growth,but additional damage is generated by thermal cycling and sintering behavior,re-spectively.Then,a nonlinear cumulative interfacial damage model considering multiple failure factors is developed to predict TBCs’life.The error between the measured damage and calculated damage is less than 15%,showing good prediction accuracy.
基金We appreciate supports from the National Key Research and Development Program of China(2016YFD0101801)the National Natural Science Foundation of China(31871715)+2 种基金the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(ICS2020YJ07BX,1610092015003-10,and Y2020PT24)the Open Program from the Guangxi Key Laboratory of Rice Genetics and Breeding(2018-05-Z06-KF01)the“Green Super Rice”Project from Bill&Melinda Gates’Foundation(OPP1130530).
文摘Dominant early heading(DEH)in rice(Oryza sativa L.)is of interest in both breeding and genetics.The genetic mechanisms underlying DEH have remained largely unclear.We have developed a near-isogenic DEH line without yield drag named DEH_229 by sister-line backcross(BC)breeding with MH63,a restorer,as the genetic background.We conducted a pilot genetic investigation under both short-day(SD)and long-day(LD)conditions.The DEH line harbored only 1.06%variation in the genome sequence relative to MH63.The variants were distributed throughout the genome.Using QTL mapping by sequencing(QTL-seq)on an F_(2) population derived from a cross of MH63×DEH_229,57 loci were detected under the SD condition.Joint mapping employing a genome-wide association study with accessions from the 3000 rice genome sequencing project(3K-RG),reduced the number of QTL by 43.9%.Using Rice Functional Genomics&Breeding(RFGB)database,the number of SNP cluster regions within the QTL regions reduced by 27.3%.Further comparison of the genome variation between DEH_229 and MH63 in addition to gene annotation information revealed a new DEH allele of DTH3 with multiple variable sites as a possible major factor underlying the early-heading phenotype of DEH_229.An InDel marker,ZMEH_1,was designed based on the variation between DEH_229 and MH63 within this region.It accounted for 86.0%of heading date variation under both SD and LD conditions in 109 randomly chosen progeny derived from extreme lines of the MH63×DEH_229 population.This study reveals the genetic complexity of DEH in the near-isogenic line and may provide useful material and marker information for plant molecular breeding.
基金supported by Science and Technology Program of Guangzhou(No.2014y2-00052)Guangdong medical science and Technology Research Fund(No.201512513201245)
文摘Background Patients with acute type A aortic dissection have a high incidence of postoperative cerebral complication. Better understanding of the risk factors could help to optimize prevention and treatment strategies. Method A total of 298 patients of acute type A aortic dissection operated in Guangdong Cardiac Institution from 2010.10 to 2014.12 were included, 253 of them were male and the other 45 were female. Their average age was 45.8__. 12.2y. All the patients were divided into cerebral complication and no cerebral complication groups. Data collectedfrom both groups were analyzed by univariate and multivariate analyses to identify the indepen- dent risk factors of postoperative cerebral complication. Result The incidence of postoperative cerebral compli- cation was 37.9% （113/298）. Among 113 patients, temporary nerve damage （TND） group and permanent nerve damage （PND） accounted for 93 cases（31.2%） and 20 cases （6.7%） respectively. Logistic Regress multivariate analysis showed that history of hypertension （OR=2.560, 95%CI, 1.397-4.692, P〈0.01）, total arch replacement （OR=2.315, 95%CI, 1.386-3.869, P〈0.01）, time of aortic arrest （OR=1.008, 95%CI, 1.004-1.012, P〈0.01） and postoperative hypoxemia （OR=1.858, 95%CI, 1.122-3.078, P〈0.05） were the independent risk factors of the post- operative cerebral complication in patients with acute type A aortic dissection. Conclusion Incidence of postop- erative cerebral complication is high in the acute type A aortic dissection patients itsmajor risk factors are hypertension history, total arch replacement, and long duration of aortic arrest or hypoxemia.
文摘In the last few years, interest in burnup calculations using Monte Carlo methods has increased. Previous burnup codes have used diffusion theory for the neutronic portion of the codes. Diffusion theory works well for most reactors. However, diffusion theory does not produce accurate results in burnup problems that include strong absorbers or large voids. MCNPX code based on Mont Carlo Method, is used to design a three dimensional model for a BWR fuel assembly in a typical operating temperature and pressure conditions. A test case was compared with a benchmark problem and good agreement was found. The model is used to calculate the distribution of pin by pin power and flux inside the assembly. The effect of axial variation of water （coolant） density, and of control rods motion on the neutron flux and power distribution is analyzed. The effect of addition of Gd2O3 to natural uranium （0.711%） on both the thermal neutron flux and normalized power are analyzed. The concentration of U^235, U^238, Pu^239, and its isotopes is also calculated at burn-up 50 GWD/T.
基金co-supported by the National Natural Science Foundation of China (No. 61573113)the Harbin Research Foundation for Leaders of Outstanding Disciplines, China (No. 2014RFXXJ074)
文摘This paper is concerned with the adaptive robust cubature Kalman filtering problem for the case that the dynamics model error and the measurement model error exist simultaneously in the satellite attitude estimation system. By using Hubel-based robust filtering methodology to correct the measurement covariance formulation of cubature Kalman filter, the proposed filtering algorithm could effectively suppress the measurement model error. To further enhance this effect and reduce the impact of the dynamics model error, two different adaptively robust filtering algorithms,one with the optimal adaptive factor based on the estimated covariance matrix of the predicted residuals and the other with multiple fading factors based on strong tracking algorithm, are developed and applied for the satellite attitude estimation. The quaternion is employed to represent the global attitude parameter, and three-dimensional generalized Rodrigues parameters are introduced to define the local attitude error. A multiplicative quaternion error is derived from the local attitude error to maintain quaternion normalization constraint in the filter. Simulation results indicate that the proposed novel algorithm could exhibit higher accuracy and faster convergence compared with the multiplicative extended Kalman filter, the unscented quaternion estimator, and the adaptive robust unscented Kalman filter.
基金This work is supported by National Natural Science Foundation of China under Grant No.41574069The Major National Projects of China under Grant No.GFZX0301040303.
文摘Nonlinear initial alignment is a significant research topic for strapdown inertial navigation system(SINS).Cubature Kalman filter(CKF)is a popular tool for nonlinear initial alignment.Standard CKF assumes that the statics of the observation noise are pre-given before the filtering process.Therefore,any unpredicted outliers in observation noise will decrease the stability of the filter.In view of this problem,improved CKF method with robustness is proposed.Multiple fading factors are introduced to rescale the observation noise covariance.Then the update stage of the filter can be autonomously tuned,and if there are outliers exist in the observations,the update should be less weighted.Under the Gaussian assumption of KF,the Mahalanobis distance of the innovation vector is supposed to be Chi-square distributed.Therefore a judging index based on Chi-square test is designed to detect the noise outliers,determining whether the fading tune are required.The proposed method is applied in the nonlinear alignment of SINS,and vehicle experiment proves the effective of the proposed method.
文摘Previously,troughs in continental faulted depressions were usually considered as a zone of hydrocarbon generation and expulsion rather than a zone for hydrocarbon accumulation.If they were confirmed to be the source kitchen,the possibility that they could constitute potential plays would be overlooked in the subsequent exploration program.Based on the hydrocarbon exploration practice of the Jizhong Depression and the Erlian Basin in the past several years,this paper discusses a new understanding that reservoir distribution is controlled by multiple factors and lithological accumulations are more likely to form in trough areas.It further documents the three main factors controlling the formation of large lithological hydrocarbon accumulations in trough areas.The paper also discusses the new concept that structural and lithological accumulations not only co-exist but also complement each other.We propose that fan-delta fronts on inverted steep slopes in troughs,delta fronts and sublacustrine fans on gentle slopes,channel sands along toes of fault scarps are favorable locations for discovery of new oil accumulations.The application of this concept has led to the discovery of several hundreds of million tonnes of oil in place in trough areas in the Jizhong Depression and the Erlian Basin.
基金the National Key R&D Program of China(No.2018YFC0407004)the National Natural Science Foundation Project of China(No.11772118).
文摘The narrowing deformation of reservoir valley during the initial operation period threatens the long-term safety of the dam,and an accurate prediction of valley deformation(VD)remains a challenging part of risk mitigation.In order to enhance the accuracy of VD prediction,a novel hybrid model combining Ensemble empirical mode decomposition based interval threshold denoising(EEMD-ITD),Differential evolutions—Shuffled frog leaping algorithm(DE-SFLA)and Least squares support vector machine(LSSVM)is proposed.The non-stationary VD series is firstly decomposed into several stationary subseries by EEMD;then,ITD is applied for redundant information denoising on special sub-series,and the denoised deformation is divided into the trend and periodic deformation components.Meanwhile,several relevant triggering factors affecting the VD are considered,from which the input features are extracted by Grey relational analysis(GRA).After that,DE-SFLA-LSSVM is separately performed to predict the trend and periodic deformation with the optimal inputs.Ultimately,the two individual forecast components are reconstructed to obtain the final predicted values.Two VD series monitored in Xiluodu reservoir region are utilized to verify the proposed model.The results demonstrate that:(1)Compared with Discrete wavelet transform(DWT),better denoising performance can be achieved by EEMD-ITD;(2)Using GRA to screen the optimal input features can effectively quantify the deformation response relationship to the triggering factors,and reduce the model complexity;(3)The proposed hybrid model in this study displays superior performance on some compared models(e.g.,LSSVM,Backward Propagation neural network(BPNN),and DE-SFLA-BPNN)in terms of forecast accuracy.
