Platinum-based(Pt)catalysts are notoriously susceptible to deactivation in industrial chemical processes due to carbon monoxide(CO)poisoning.Overcoming this poisoning deactivation of Pt-based catalysts while enhancing...Platinum-based(Pt)catalysts are notoriously susceptible to deactivation in industrial chemical processes due to carbon monoxide(CO)poisoning.Overcoming this poisoning deactivation of Pt-based catalysts while enhancing their catalytic activity,selectivity,and durability remains a major challenge.Herein,we propose a strategy to enhance the CO tolerance of Pt clusters(Pt_n)by introducing neighboring functionalized vip single atoms(such as Fe,Co,Ni,Cu,Sb,and Bi).Among them,antimony(Sb)single atoms(SAs)exhibit significant performance enhancement,achieving 99%CO selectivity and 33.6%CO_(2)conversion at 450℃,Experimental results and density functional theory(DFT)calculations indicate the optimization arises from the electronic interaction between neighboring functionalized Sb SAs and Pt clusters,leading to optimal 5d electron redistribution in Pt clusters compared to other functionalized vip single atoms.The redistribution of 5d electrons weaken both theσdonation andπbackdonation interactions,resulting in a weakened bond strength with CO and enhancing catalyst activity and selectivity.In situ environmental transmission electron microscopy(ETEM)further demonstrates the exception thermal stability of the catalyst,even under H_(2)at 700℃.Notably,the functionalized Sb SAs also improve CO tolerance in various heterogenous catalysts,including Co/CeO_(2),Ni/CeO_(2),Pt/Al_(2)O_(3),and Pt/CeO_(2)-C.This finding provides an effective approach to overcome the primary challenge of CO poisoning in Pt-based catalysts,making their broader applications in various industrial catalysts.展开更多
Baculoviruses are insect-specific viruses with a circular double-stranded DNA genome ranging in size from 80-180 kb （Lu et al., 2012）. Two distinct types of viri- ons have been identified during the infectious cycle...Baculoviruses are insect-specific viruses with a circular double-stranded DNA genome ranging in size from 80-180 kb （Lu et al., 2012）. Two distinct types of viri- ons have been identified during the infectious cycle of baculoviruses, namely budded virions （BVs） and occlu- sion-derived virions （ODVs）. BVs mediate infection from cell to cell, while ODVs initiate oral infection in the insect midgut （Braunagel and Summers, 2007）.展开更多
Many studies exist in the literature of scale and scope economies in institutions of higher education employing multi-product cost functions of quadratic, constant elasticity substitution （CES）, or hybrid translog f...Many studies exist in the literature of scale and scope economies in institutions of higher education employing multi-product cost functions of quadratic, constant elasticity substitution （CES）, or hybrid translog form. A single product cost function is normally considered inadequate and yield distorted results. Both quadratic and single product cost functions have been applied to university data from China＇s Ministry of Education （MOE）. This study compares those two methods and their statistical results and finds that ray economies of scale from these two cost functions are quite similar though the single product cost function which can not be used to calculate product-specific economies of scale or economies of scope.展开更多
Background The surgical outcomes have been greatly improved over the past four decades for functional single ventricle(FSV). However,the repair for coexistence of FSV and total anomalous pulmonary venous connection(TA...Background The surgical outcomes have been greatly improved over the past four decades for functional single ventricle(FSV). However,the repair for coexistence of FSV and total anomalous pulmonary venous connection(TAPVC),especially obstructed TAPVC,has remained a clinical challenge. Little is known about the results of surgical treatment for patients with FSV-TAPVC in China. Methods Forty consecutive patients with FSV-TAPVC undergoing initial surgical palliation(median age:16.8 months;body weight:8.25 kg)were retrospectively enrolled from 2006 to 2016 in a specialized cardiovascular institute. TAPVC was repaired in 30 patients. The mean follow-up period was 49 months. Results All of the 7 patients with preoperative pulmonary vein obstruction(PVO)underwent repair of TAPVC at the first operation and survived. When a systemic to pulmonary(S-P)shunt or pulmonary artery banding(PAB)was necessary,patients with concomitant TAPVC repair had lower mortality(30.0%)and higher total cavopulmonary connection completion rate(20.0%)than those without TAPVC repair[75.0% and 0%,respectively],although with no statistical significance(Fisher test,P=0.505 and P=0.245). The overall survival rates for the cohort at 1,3 and 5 years after the initial surgical intervention were 80.0%,77.1% and 77.1%,respectively. Multivariate COX regression analysis detected that SP shunt(adjusted odds ratio:6.51;95%CI:1.26-33.71,P=0.030)is the only risk factor for survival. The reintervention rate for postoperative PVO was higher in patients with preoperative PVO than those without(57.1%vs. 4.3%,Log Rank:P=0.006). Conclusion The mid-term results of surgical repair of FSV-TAPVC are still challenging. When PVO exists,surgical repair for TAPVC is suggested as soon as possible. Repair for TAPVC should also be considered when S-P shunt or PAB is necessary. Further study with larger population are warranted to support our finding.展开更多
Fibroblast growth factor(FGF) is found throughout multicellular organisms; however, fgf homologs(vfgf) have only been identified among viruses in lepidopteran baculoviruses. The function of v FGFs from Group I alphaba...Fibroblast growth factor(FGF) is found throughout multicellular organisms; however, fgf homologs(vfgf) have only been identified among viruses in lepidopteran baculoviruses. The function of v FGFs from Group I alphabaculoviruses, including Autographa californica multiple nucleopolyhedrovirus(Ac MNPV) and Bombyx mori nucleopolyhedrovirus(Bm NPV), involves accelerated killing of infected larvae by both viruses. The v FGF of Group II alphabaculovirus is structurally different from that of Group I alphabaculovirus, with a larger C-terminal region and additional N-linked glycosylation sites. In this study, we characterized the Group II alphabaculovirus v FGF of Helicoverpa armigera single nucleopolyhedrovirus(Hear NPV). The transcription and expression of vfgf was detected at 3 h and 16 h post-infection in Hear NPV-infected cells. To further study v FGF function, we constructed vfgf-knockout and-repaired Hear NPV bacmids and investigated their affect in both cultured cells and insects. Deletion of vfgf had no effect on budded-virus production or viral DNA replication in cultured Hz AM1 cells. However, bioassays showed that Hear NPV vfgf deletion significantly increased the median lethal dose and delayed the median lethal time by ~12 h in the host insect when the virus was delivered orally. These results suggested that v FGF is an important virulent factor for HearN PV infection and propagation in vivo.展开更多
This paper deals with the conditional density estimator of a real response variable given a functional random variable(i.e.,takes values in an infinite-dimensional space).Specifically,we focus on the functional index ...This paper deals with the conditional density estimator of a real response variable given a functional random variable(i.e.,takes values in an infinite-dimensional space).Specifically,we focus on the functional index model,and this approach represents a good compromise between nonparametric and parametric models.Then we give under general conditions and when the variables are independent,the quadratic error and asymptotic normality of estimator by local linear method,based on the single-index structure.Finally,wecomplete these theoretical advances by some simulation studies showing both the practical result of the local linear method and the good behaviour for finite sample sizes of the estimator and of the Monte Carlo methods to create functional pseudo-confidence area.展开更多
This paper is concerned with the problem of safety stabilization for switched systems where the solvability of the problem under study for individual subsystems is not assumed.A new state-dependent switching strategy ...This paper is concerned with the problem of safety stabilization for switched systems where the solvability of the problem under study for individual subsystems is not assumed.A new state-dependent switching strategy with guaranteed dwell-time for switched systems is constructed,and a sufficient condition for absence of Zeno behavior is derived.Also,a novel switched control design method is proposed to simultaneously guarantee the safety of the switched closed-loop system and stabilize the system based on the union of a common barrier function and a single Lyapunov function,which effectively handles the conflict between safety and stability objectives.Finally,two examples are presented to demonstrate the effectiveness of the proposed design approach.展开更多
In this article, we consider analytical solutions of the time fractional derivative Gardner equation by using the new version of F-expansion method. With this proposed method multiple Jacobi elliptic functions are sit...In this article, we consider analytical solutions of the time fractional derivative Gardner equation by using the new version of F-expansion method. With this proposed method multiple Jacobi elliptic functions are situated in the solution function. As a result, various exact analytical solutions consisting of single and combined Jacobi elliptic functions solutions are obtained.展开更多
The stability analysis and anti-windup design problem is investigated for two linear switched systems with saturating actuators by using the single Lyapunov function approach. Our purpose is to design a switching law ...The stability analysis and anti-windup design problem is investigated for two linear switched systems with saturating actuators by using the single Lyapunov function approach. Our purpose is to design a switching law and the anti-windup compensation gains such that the maximizing estimation of the domain of attraction is obtained for the closed-loop system in the presence of saturation. Firstly, some sufficient conditions of asymptotic stability are obtained under given anti-windup compensation gains based on the single Lyapunov function method. Then, the anti-windup compensation gains as design variables are presented by solving a convex optimization problem with linear matrix inequality （LMI） constraints. Two numerical examples are given to show the effectiveness of the proposed method.展开更多
The problem of non-fragile dynamic output feedback H∞control for a class of uncertain switched systems with time-varying delay is discussed.Firstly,the form of non-fragile dynamic output feedback H∞controller is giv...The problem of non-fragile dynamic output feedback H∞control for a class of uncertain switched systems with time-varying delay is discussed.Firstly,the form of non-fragile dynamic output feedback H∞controller is given.Under the condition that the upper bound of time delay and the upper bound of delay derivative are limited simultaneously,Lyapunov functional and its corresponding switching rules are constructed by using single Lyapunov function method and convex combination technique;Secondly,we use the inequality lemma to scale the derived Lyapunov functional in order to eliminate the time-varying delay term in the inequality,and then introduce the J-function to obtain a nonlinear matrix inequality that satisfies the H∞performance indexγ,we also employ Schur complement lemma to transform the nonlinear matrix inequality into set of linear matrix inequalities consisting of two linear matrix inequalities,a sufficient condition for the existence of a non-fragile dynamic output feedback H∞controller and satisfying the H∞performance indexγis concluded for a class of uncertain switching systems with variable time delay;Finally,a switched system composed of two subsystems is considered and the effectiveness and practicability of the theorem are illustrated by numerical simulation with LMI toolbox.展开更多
This paper is concerned with the H-infinity control problem for a class of cascade switched nonlinear systems. Each switched system in this class is composed of a zero-mput asymptotically stable nonlinear part, which ...This paper is concerned with the H-infinity control problem for a class of cascade switched nonlinear systems. Each switched system in this class is composed of a zero-mput asymptotically stable nonlinear part, which is also a switched system, and a linearizable part which is controllable. Conditions under which the H-infinity control problem is solvable under arbitrary switching law and under some designed switching law are derived respectively. The nonlinear state feedback and switching law are designed. We exploit the structural characteristics of the switched nonlinear systems to construct common Lyapunov functions for arbitrary switching and to find a single Lyapunov function for designed switching law. The proposed methods do not rely on the solutions of Hamilton-Jacobi inequalities.展开更多
Motivated by the autopilot of an unmanned aerial vehicle（UAV） with a wide flight envelope span experiencing large parametric variations in the presence of uncertainties, a fuzzy adaptive tracking controller（FATC） ...Motivated by the autopilot of an unmanned aerial vehicle（UAV） with a wide flight envelope span experiencing large parametric variations in the presence of uncertainties, a fuzzy adaptive tracking controller（FATC） is proposed. The controller consists of a fuzzy baseline controller and an adaptive increment, and the main highlight is that the fuzzy baseline controller and adaptation laws are both based on the fuzzy multiple Lyapunov function approach, which helps to reduce the conservatism for the large envelope and guarantees satisfactory tracking performances with strong robustness simultaneously within the whole envelope. The constraint condition of the fuzzy baseline controller is provided in the form of linear matrix inequality（LMI）, and it specifies the satisfactory tracking performances in the absence of uncertainties. The adaptive increment ensures the uniformly ultimately bounded（UUB） predication errors to recover satisfactory responses in the presence of uncertainties. Simulation results show that the proposed controller helps to achieve high-accuracy tracking of airspeed and altitude desirable commands with strong robustness to uncertainties throughout the entire flight envelope.展开更多
An analytical surface potential model for the single material double work function gate （SMDWG） MOSFET is developed based on the exact resultant solution of the two-dimensional Poisson equation. The model includes t...An analytical surface potential model for the single material double work function gate （SMDWG） MOSFET is developed based on the exact resultant solution of the two-dimensional Poisson equation. The model includes the effects of drain biases, gate oxide thickness, different combinations of S-gate and D-gate length and values of substrate doping concentration. More attention has been paid to seeking to explain the attributes of the SMDWG MOSFET, such as suppressing drain-induced barrier lowering （DIBL）, accelerating carrier drift velocity and device speed. The model is verified by comparison to the simulated results using the device simulator MEDICI. The accuracy of the results obtained using our analytical model is verified using numerical simulations. The model not only offers the physical insight into device physics but also provides the basic designing guideline for the device.展开更多
Innovations in genomics have enabled the development of low-cost,high-resolution,single nucleotide polymorphism(SNP)genotyping arrays that accelerate breeding progress and support basic research in crop science.Here,w...Innovations in genomics have enabled the development of low-cost,high-resolution,single nucleotide polymorphism(SNP)genotyping arrays that accelerate breeding progress and support basic research in crop science.Here,we developed and validated the Soy SNP618 K array(618,888 SNPs)for the important crop soybean.The SNPs were selected from whole-genome resequencing data containing 2,214 diverse soybean accessions;29.34%of the SNPs mapped to genic regions representing 86.85%of the 56,044annotated high-confidence genes.Identity-by-state analyses of 318 soybeans revealed 17 redundant accessions,highlighting the potential of the Soy SNP618 K array in supporting gene bank management.The patterns of population stratification and genomic regions enriched through domestication were highly consistent with previous findings based on resequencing data,suggesting that the ascertainment bias in the Soy SNP618 K array was largely compensated for.Genome-wide association mapping in combination with reported quantitative trait loci enabled fine-mapping of genes known to influence flowering time,E2 and Gm PRR3 b,and of a new candidate gene,Gm VIP5.Moreover,genomic prediction of flowering and maturity time in 502 recombinant inbred lines was highly accurate(>0.65).Thus,the Soy SNP618 K array is a valuable genomic tool that can be used to address many questions in applied breeding,germplasm management,and basic crop research.展开更多
In this paper the definition of order-sorted algebra is generalized by introducing transforma-tion functions between subtypes and supertypes. According to our definition, a type needn'tbe a subset of its supertype...In this paper the definition of order-sorted algebra is generalized by introducing transforma-tion functions between subtypes and supertypes. According to our definition, a type needn'tbe a subset of its supertype and a record model may form an order-sorted algebra. A newdefinition of equation is given. It has also been proved that equational theories and describingsingle inheritance have the initial model.展开更多
基金financially supported by the Shanghai RisingStar Program(No.23QA1403700)the National Natural Science Foundation of China(NSFC,Grant No.U2230102)+1 种基金the sponsored by National Key Research and Development Program of China(No.2021YFB3502200)the Shanghai Technical Service Center of Science and Engineering Computing,Shanghai University.
文摘Platinum-based(Pt)catalysts are notoriously susceptible to deactivation in industrial chemical processes due to carbon monoxide(CO)poisoning.Overcoming this poisoning deactivation of Pt-based catalysts while enhancing their catalytic activity,selectivity,and durability remains a major challenge.Herein,we propose a strategy to enhance the CO tolerance of Pt clusters(Pt_n)by introducing neighboring functionalized vip single atoms(such as Fe,Co,Ni,Cu,Sb,and Bi).Among them,antimony(Sb)single atoms(SAs)exhibit significant performance enhancement,achieving 99%CO selectivity and 33.6%CO_(2)conversion at 450℃,Experimental results and density functional theory(DFT)calculations indicate the optimization arises from the electronic interaction between neighboring functionalized Sb SAs and Pt clusters,leading to optimal 5d electron redistribution in Pt clusters compared to other functionalized vip single atoms.The redistribution of 5d electrons weaken both theσdonation andπbackdonation interactions,resulting in a weakened bond strength with CO and enhancing catalyst activity and selectivity.In situ environmental transmission electron microscopy(ETEM)further demonstrates the exception thermal stability of the catalyst,even under H_(2)at 700℃.Notably,the functionalized Sb SAs also improve CO tolerance in various heterogenous catalysts,including Co/CeO_(2),Ni/CeO_(2),Pt/Al_(2)O_(3),and Pt/CeO_(2)-C.This finding provides an effective approach to overcome the primary challenge of CO poisoning in Pt-based catalysts,making their broader applications in various industrial catalysts.
基金supported by the grants from the National Science Foundation of China(No.31570153,31130058,31321001 and 31400142)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB11030400)the Core Facility and Technical Support of Wuhan Institute of Virology for technical assistance
文摘Baculoviruses are insect-specific viruses with a circular double-stranded DNA genome ranging in size from 80-180 kb （Lu et al., 2012）. Two distinct types of viri- ons have been identified during the infectious cycle of baculoviruses, namely budded virions （BVs） and occlu- sion-derived virions （ODVs）. BVs mediate infection from cell to cell, while ODVs initiate oral infection in the insect midgut （Braunagel and Summers, 2007）.
文摘Many studies exist in the literature of scale and scope economies in institutions of higher education employing multi-product cost functions of quadratic, constant elasticity substitution （CES）, or hybrid translog form. A single product cost function is normally considered inadequate and yield distorted results. Both quadratic and single product cost functions have been applied to university data from China＇s Ministry of Education （MOE）. This study compares those two methods and their statistical results and finds that ray economies of scale from these two cost functions are quite similar though the single product cost function which can not be used to calculate product-specific economies of scale or economies of scope.
基金the National Key R&D Program of China(No.2018YFC1002600)National Natural Science Foundation of China(No.81903287)+4 种基金Natural Science Foundation of Guangdong Province(No.2018A030313329)the Science and Technology Planning Project of Guangdong Province(No.2017A070701013)the Science and Technological Program of Guangzhou,China(No.201704020126)Guangdong Medical Research Foundation(No.A2017328)Guangdong Provincial Administration of Traditional Chinese Medicine(No.20181004).
文摘Background The surgical outcomes have been greatly improved over the past four decades for functional single ventricle(FSV). However,the repair for coexistence of FSV and total anomalous pulmonary venous connection(TAPVC),especially obstructed TAPVC,has remained a clinical challenge. Little is known about the results of surgical treatment for patients with FSV-TAPVC in China. Methods Forty consecutive patients with FSV-TAPVC undergoing initial surgical palliation(median age:16.8 months;body weight:8.25 kg)were retrospectively enrolled from 2006 to 2016 in a specialized cardiovascular institute. TAPVC was repaired in 30 patients. The mean follow-up period was 49 months. Results All of the 7 patients with preoperative pulmonary vein obstruction(PVO)underwent repair of TAPVC at the first operation and survived. When a systemic to pulmonary(S-P)shunt or pulmonary artery banding(PAB)was necessary,patients with concomitant TAPVC repair had lower mortality(30.0%)and higher total cavopulmonary connection completion rate(20.0%)than those without TAPVC repair[75.0% and 0%,respectively],although with no statistical significance(Fisher test,P=0.505 and P=0.245). The overall survival rates for the cohort at 1,3 and 5 years after the initial surgical intervention were 80.0%,77.1% and 77.1%,respectively. Multivariate COX regression analysis detected that SP shunt(adjusted odds ratio:6.51;95%CI:1.26-33.71,P=0.030)is the only risk factor for survival. The reintervention rate for postoperative PVO was higher in patients with preoperative PVO than those without(57.1%vs. 4.3%,Log Rank:P=0.006). Conclusion The mid-term results of surgical repair of FSV-TAPVC are still challenging. When PVO exists,surgical repair for TAPVC is suggested as soon as possible. Repair for TAPVC should also be considered when S-P shunt or PAB is necessary. Further study with larger population are warranted to support our finding.
基金supported by grants from the National Science Foundation of China (No.31200124 and 31321001)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No.XDB11030400)
文摘Fibroblast growth factor(FGF) is found throughout multicellular organisms; however, fgf homologs(vfgf) have only been identified among viruses in lepidopteran baculoviruses. The function of v FGFs from Group I alphabaculoviruses, including Autographa californica multiple nucleopolyhedrovirus(Ac MNPV) and Bombyx mori nucleopolyhedrovirus(Bm NPV), involves accelerated killing of infected larvae by both viruses. The v FGF of Group II alphabaculovirus is structurally different from that of Group I alphabaculovirus, with a larger C-terminal region and additional N-linked glycosylation sites. In this study, we characterized the Group II alphabaculovirus v FGF of Helicoverpa armigera single nucleopolyhedrovirus(Hear NPV). The transcription and expression of vfgf was detected at 3 h and 16 h post-infection in Hear NPV-infected cells. To further study v FGF function, we constructed vfgf-knockout and-repaired Hear NPV bacmids and investigated their affect in both cultured cells and insects. Deletion of vfgf had no effect on budded-virus production or viral DNA replication in cultured Hz AM1 cells. However, bioassays showed that Hear NPV vfgf deletion significantly increased the median lethal dose and delayed the median lethal time by ~12 h in the host insect when the virus was delivered orally. These results suggested that v FGF is an important virulent factor for HearN PV infection and propagation in vivo.
文摘This paper deals with the conditional density estimator of a real response variable given a functional random variable(i.e.,takes values in an infinite-dimensional space).Specifically,we focus on the functional index model,and this approach represents a good compromise between nonparametric and parametric models.Then we give under general conditions and when the variables are independent,the quadratic error and asymptotic normality of estimator by local linear method,based on the single-index structure.Finally,wecomplete these theoretical advances by some simulation studies showing both the practical result of the local linear method and the good behaviour for finite sample sizes of the estimator and of the Monte Carlo methods to create functional pseudo-confidence area.
基金the National Natural Science Foundation of China(Nos.62173075,61773100,61733018)the 111 Project(No.B16009)+1 种基金the Liaoning Revitalization Talents Program(No.XLYC1907043)the Fundamental Research Funds for the Central Universities(No.N2004015).
文摘This paper is concerned with the problem of safety stabilization for switched systems where the solvability of the problem under study for individual subsystems is not assumed.A new state-dependent switching strategy with guaranteed dwell-time for switched systems is constructed,and a sufficient condition for absence of Zeno behavior is derived.Also,a novel switched control design method is proposed to simultaneously guarantee the safety of the switched closed-loop system and stabilize the system based on the union of a common barrier function and a single Lyapunov function,which effectively handles the conflict between safety and stability objectives.Finally,two examples are presented to demonstrate the effectiveness of the proposed design approach.
文摘In this article, we consider analytical solutions of the time fractional derivative Gardner equation by using the new version of F-expansion method. With this proposed method multiple Jacobi elliptic functions are situated in the solution function. As a result, various exact analytical solutions consisting of single and combined Jacobi elliptic functions solutions are obtained.
基金supported by Scientific Research Fund of Education Department of Liaoning Province(No.L2014159)
文摘The stability analysis and anti-windup design problem is investigated for two linear switched systems with saturating actuators by using the single Lyapunov function approach. Our purpose is to design a switching law and the anti-windup compensation gains such that the maximizing estimation of the domain of attraction is obtained for the closed-loop system in the presence of saturation. Firstly, some sufficient conditions of asymptotic stability are obtained under given anti-windup compensation gains based on the single Lyapunov function method. Then, the anti-windup compensation gains as design variables are presented by solving a convex optimization problem with linear matrix inequality （LMI） constraints. Two numerical examples are given to show the effectiveness of the proposed method.
基金science basic research program of the education department of Liaoning Province(No.LJC202002).
文摘The problem of non-fragile dynamic output feedback H∞control for a class of uncertain switched systems with time-varying delay is discussed.Firstly,the form of non-fragile dynamic output feedback H∞controller is given.Under the condition that the upper bound of time delay and the upper bound of delay derivative are limited simultaneously,Lyapunov functional and its corresponding switching rules are constructed by using single Lyapunov function method and convex combination technique;Secondly,we use the inequality lemma to scale the derived Lyapunov functional in order to eliminate the time-varying delay term in the inequality,and then introduce the J-function to obtain a nonlinear matrix inequality that satisfies the H∞performance indexγ,we also employ Schur complement lemma to transform the nonlinear matrix inequality into set of linear matrix inequalities consisting of two linear matrix inequalities,a sufficient condition for the existence of a non-fragile dynamic output feedback H∞controller and satisfying the H∞performance indexγis concluded for a class of uncertain switching systems with variable time delay;Finally,a switched system composed of two subsystems is considered and the effectiveness and practicability of the theorem are illustrated by numerical simulation with LMI toolbox.
文摘This paper is concerned with the H-infinity control problem for a class of cascade switched nonlinear systems. Each switched system in this class is composed of a zero-mput asymptotically stable nonlinear part, which is also a switched system, and a linearizable part which is controllable. Conditions under which the H-infinity control problem is solvable under arbitrary switching law and under some designed switching law are derived respectively. The nonlinear state feedback and switching law are designed. We exploit the structural characteristics of the switched nonlinear systems to construct common Lyapunov functions for arbitrary switching and to find a single Lyapunov function for designed switching law. The proposed methods do not rely on the solutions of Hamilton-Jacobi inequalities.
文摘Motivated by the autopilot of an unmanned aerial vehicle（UAV） with a wide flight envelope span experiencing large parametric variations in the presence of uncertainties, a fuzzy adaptive tracking controller（FATC） is proposed. The controller consists of a fuzzy baseline controller and an adaptive increment, and the main highlight is that the fuzzy baseline controller and adaptation laws are both based on the fuzzy multiple Lyapunov function approach, which helps to reduce the conservatism for the large envelope and guarantees satisfactory tracking performances with strong robustness simultaneously within the whole envelope. The constraint condition of the fuzzy baseline controller is provided in the form of linear matrix inequality（LMI）, and it specifies the satisfactory tracking performances in the absence of uncertainties. The adaptive increment ensures the uniformly ultimately bounded（UUB） predication errors to recover satisfactory responses in the presence of uncertainties. Simulation results show that the proposed controller helps to achieve high-accuracy tracking of airspeed and altitude desirable commands with strong robustness to uncertainties throughout the entire flight envelope.
基金supported by the National Youth Science Foundation of China(No.61006064)the Natural Science Foundation of Education Office,Anhui Province(No.KJ2013A071)
文摘An analytical surface potential model for the single material double work function gate （SMDWG） MOSFET is developed based on the exact resultant solution of the two-dimensional Poisson equation. The model includes the effects of drain biases, gate oxide thickness, different combinations of S-gate and D-gate length and values of substrate doping concentration. More attention has been paid to seeking to explain the attributes of the SMDWG MOSFET, such as suppressing drain-induced barrier lowering （DIBL）, accelerating carrier drift velocity and device speed. The model is verified by comparison to the simulated results using the device simulator MEDICI. The accuracy of the results obtained using our analytical model is verified using numerical simulations. The model not only offers the physical insight into device physics but also provides the basic designing guideline for the device.
基金supported by the Agricultural Science and Technology Innovation Program(ASTIP)of Chinese Academy of Agricultural Sciences(CAAS-ZDRW20210)the National Key Research and Development Program of China(nos.2020YFE0202300 and 2021YFD1201600)the Platform of National Crop Germplasm Resources of China(nos.2016-004 and 2017-004)。
文摘Innovations in genomics have enabled the development of low-cost,high-resolution,single nucleotide polymorphism(SNP)genotyping arrays that accelerate breeding progress and support basic research in crop science.Here,we developed and validated the Soy SNP618 K array(618,888 SNPs)for the important crop soybean.The SNPs were selected from whole-genome resequencing data containing 2,214 diverse soybean accessions;29.34%of the SNPs mapped to genic regions representing 86.85%of the 56,044annotated high-confidence genes.Identity-by-state analyses of 318 soybeans revealed 17 redundant accessions,highlighting the potential of the Soy SNP618 K array in supporting gene bank management.The patterns of population stratification and genomic regions enriched through domestication were highly consistent with previous findings based on resequencing data,suggesting that the ascertainment bias in the Soy SNP618 K array was largely compensated for.Genome-wide association mapping in combination with reported quantitative trait loci enabled fine-mapping of genes known to influence flowering time,E2 and Gm PRR3 b,and of a new candidate gene,Gm VIP5.Moreover,genomic prediction of flowering and maturity time in 502 recombinant inbred lines was highly accurate(>0.65).Thus,the Soy SNP618 K array is a valuable genomic tool that can be used to address many questions in applied breeding,germplasm management,and basic crop research.
文摘In this paper the definition of order-sorted algebra is generalized by introducing transforma-tion functions between subtypes and supertypes. According to our definition, a type needn'tbe a subset of its supertype and a record model may form an order-sorted algebra. A newdefinition of equation is given. It has also been proved that equational theories and describingsingle inheritance have the initial model.
