In this paper, to investigate the influence of soil inhomogeneity on the bending of circular thinplates on elastic foundations, the static problem of circular thin plates on Gibson elasticfoundation is solved using an...In this paper, to investigate the influence of soil inhomogeneity on the bending of circular thinplates on elastic foundations, the static problem of circular thin plates on Gibson elasticfoundation is solved using an iterative method based on the modified Vlasov model. On the basisof the principle of minimum potential energy, the governing differential equations and boundaryconditions for circular thin plates on modified Vlasov foundation considering the characteristics ofGibson soil are derived. The equations for the attenuation parameter in bending problem are alsoobtained, and the issue of unknown parameters being difficult to determine is solved using theiterative method. Numerical examples are analyzed and the results are in good agreement withthose form other literatures. It proves that the method is practical and accurate. Theinhomogeneity of modified Vlasov foundations has some influence on the deformation andinternal force behavior of circular thin plates. The effects of various parameters on the bending ofcircular plates and characteristic parameters of the foundation are discussed. The modified modelfurther enriches and develops the elastic foundations. Relevant conclusions that are meaningful toengineering practice are drawn.展开更多
An efficient computational framework for structural system reliability analysis and Updating based on Chain-Structure Bayesian networks(BNs)is present in the paper.The framework combines BNs and structural reliability...An efficient computational framework for structural system reliability analysis and Updating based on Chain-Structure Bayesian networks(BNs)is present in the paper.The framework combines BNs and structural reliability methods(SRMs)for reliability assessment and updating.BNs have advantages in evaluating complex probabilistic dependence structures and reliability updating,while SRMs are employed to assess the conditional probability table.The improved branch-and-bound(B&B)method is integrated with BNs to simplify the whole network.In order to further reduce computational demand,failure(or survival)path events are introduced to create chain-structure BNs.Considering the correlations between failure modes,the system reliability is obtained through the Probability Network Estimation Technology(PNET).Finally,the reliability updating is carried out through BNs inference.Results show that computational efficiency is improved by the Chain-Structure BNs.System reliability problems with both continuous and discrete random variables can be better resolved by combining BNs and SRMs.This approach is also able to update system reliability when new information available.展开更多
A new method for structural physical parameter identification is proposed for linear structure.Firstly,a linear structural identification model was obtained based on a series of transformation of the dynamic character...A new method for structural physical parameter identification is proposed for linear structure.Firstly,a linear structural identification model was obtained based on a series of transformation of the dynamic characteristic equation.Then the posterior distribution of the model is obtained by the Bayesian updating theory.Using the structural modal parameters and considering their randomness,the structural stiffness parameter is obtained from the conditional posterior distribution of the linear structural identification model.The Gibbs sampling based on the Markov Chain Monte Carlo(MCMC)method is employed during the process.In order to illustrate the proposed method,a 3-DOF linear shear building is used as an example to detect and quantify its damage based on model data measured before and after a severe loading event.The research shows that damage level and locations can be identified with little error by using proposed method.展开更多
Cobalt-free,nickel-rich LiNi_(1-x)Al_(x)O_(2)(x≤0.1)is an attractive cathode material because of high energy density and low cost but suffers from severe structural degradation and poor rate performance.In this study...Cobalt-free,nickel-rich LiNi_(1-x)Al_(x)O_(2)(x≤0.1)is an attractive cathode material because of high energy density and low cost but suffers from severe structural degradation and poor rate performance.In this study,we propose a molten salt-assisted synthesis in combination with a Li-refeeding induced aluminum segregation strategy to prepare Li_(5)AlO_(4)-coated single-crystalline slightly Li-rich Li_(1.04)Ni_(0.92)Al_(0.04)O_(2).The symbiotic formation of Li_(5)AlO_(4)from reaction between molten lithium hydroxide and doped aluminum in the bulk ensures a high lattice matching between the Ni-rich oxide and the homogenous conductive Li_(5)AlO_(4)that permits high Li^(+)conductivity.Benefiting from mitigated undesirable side reactions and phase evolution,the Li_(5)AlO_(4)-coated single-crystalline Li_(1.04)Ni_(0.92)Al_(0.04)O_(2)delivers a high specific capacity of220.2 mA h g^(-1)at 0.1 C and considerable rate capability(182.5 mA h g^(-1)at 10 C).Besides,superior capacity retention of 90.8%is obtained at 1/3 C after 100 cycles in a 498.1 mA h pouch full cell.Furthermore,the particulate morphology of Li_(1.04)Ni_(0.92)Al_(0.04)O_(2)remains intact after cycling at a cutoff voltage of 4.3 V,whereas slightly Li-deficient Li_(0.98)Ni_(0.97)Al_(0.05)O_(2)features intragranular cracks and irreversible lattice distortion.The results highlight the value of molten salt-assisted synthesis and Li-refeeding induced elemental segregation strategy to upgrade Ni-based layered oxide cathode materials for advanced Li-ion batteries.展开更多
Dear Editor,Attention deficit/hyperactivity disorder(ADHD),characterized by age-inappropriate symptoms of inattention,hyperactivity,and impulsivity,is a highly prevalent and heritable childhood-onset neurodevelopmenta...Dear Editor,Attention deficit/hyperactivity disorder(ADHD),characterized by age-inappropriate symptoms of inattention,hyperactivity,and impulsivity,is a highly prevalent and heritable childhood-onset neurodevelopmental disorder,with impairing symptoms that persist into adulthood in up to 65%of patients[1].Adults with persistent ADHD symptoms since childhood have been found to have neurocognitive impairments in multiple domains,especially in attention and cognitive control,which significantly contribute to an increased risk of social disability,educational and occupational failure,and other comorbid psychiatric disorders,resulting in significant economic burdens to the affected individuals, their families, andsociety [2, 3].展开更多
Silver-catalyzed decarboxylative C–H alkylation of cyclic aldimines with abundant aliphatic carboxylic acids has been realized under mild reaction conditions generating the corresponding products in moderate to good ...Silver-catalyzed decarboxylative C–H alkylation of cyclic aldimines with abundant aliphatic carboxylic acids has been realized under mild reaction conditions generating the corresponding products in moderate to good yields(32%–91%).In addition,a gram-scale reaction,late-stage modification of drug,synthetic transformation of the product,and further application of the catalytic strategy were also performed.Preliminary studies indicate that the reaction undergoes a radical process.展开更多
Genetic composition plays critical roles in the pathogenesis of autism spectrum disorder(ASD).Especially,inherited and de novo intronic variants are often seen in patients with ASD.However,the biological significance ...Genetic composition plays critical roles in the pathogenesis of autism spectrum disorder(ASD).Especially,inherited and de novo intronic variants are often seen in patients with ASD.However,the biological significance of intronic variants is difficult to address.Here,among a Chinese ASD cohort,we identified a recurrent inherited intronic variant in the CHD7 gene,which is specifically enriched in East Asian populations.CHD7 has been implicated in numerous developmental disorders including CHARGE syndrome and ASD.To investigate whether the ASD-associated CHD7 intronic variant affects neural development,we established human embryonic stem cells carrying this variant using CRISPR/Cas9 methods and found that the level of CHD7 mRNA significantly decreased compared to control.Upon differentiation towards the forebrain neuronal lineage,we found that neural cells carrying the CHD7 intronic variant exhibited developmental delay and maturity defects.Importantly,we found that TBR1,a gene also implicated in ASD,was significantly increased in neurons carrying the CHD7 intronic variant,suggesting the intrinsic relevance among ASD genes.Furthermore,the morphological defects found in neurons carrying CHD7 intronic mutations were rescued by knocking down TBR1,indicating that TBR1 may be responsible for the defects in CHD7-related disorders.Finally,the CHD7 intronic variant generated three abnormal forms of transcripts through alternative splicing,which all exhibited loss-of-function in functional assays.Our study provides crucial evidence supporting the notion that the intronic variant of CHD7 is potentially an autism susceptibility site,shedding new light on identifying the functions of intronic variants in genetic studies of autism.展开更多
This study proposed a damage identification method compared with the existing ones,based on relative curvature difference and frequency perturbation theory,showing sensitivity to local damage by changes in the curvatu...This study proposed a damage identification method compared with the existing ones,based on relative curvature difference and frequency perturbation theory,showing sensitivity to local damage by changes in the curvature mode and high recognition accuracy of frequencies.Considering the relative curvature difference as a damage index,numerical simulation is used for a simply supported beam under single and multiple damage conditions for different damage degrees.The damage is located according to the curvature mode curves,and the damage degree is qualitatively determined.Based on the perturbation theory,the damage equations are established by the changes between frequencies before and after damage,and the damage localization and degree are verified and determined.Effectiveness of the proposed method for identifying damage at different conditions is numerically investigated.This method potentially promotes the development of damage identification of beam structures.展开更多
We developed for the first time an unprecedented domino reaction of sulfonyl oximonitriles with secondary amines to streamline the synthesis of N-sulfonylformamidines in decent to high yields under mild reaction condi...We developed for the first time an unprecedented domino reaction of sulfonyl oximonitriles with secondary amines to streamline the synthesis of N-sulfonylformamidines in decent to high yields under mild reaction conditions.In addition,scale-up experiments and late-stage functionalization of drugs were also performed.Preliminary studies indicate that the loss of a cyano-/benzyloxy-group and a sulfonyl migration process are involved in this reaction.展开更多
基金financially supported by the National Natural Science Foundation of China (Grant 51278420)the Natural Science Foundation of Shaanxi Province (Grant 2017JM5021)
文摘In this paper, to investigate the influence of soil inhomogeneity on the bending of circular thinplates on elastic foundations, the static problem of circular thin plates on Gibson elasticfoundation is solved using an iterative method based on the modified Vlasov model. On the basisof the principle of minimum potential energy, the governing differential equations and boundaryconditions for circular thin plates on modified Vlasov foundation considering the characteristics ofGibson soil are derived. The equations for the attenuation parameter in bending problem are alsoobtained, and the issue of unknown parameters being difficult to determine is solved using theiterative method. Numerical examples are analyzed and the results are in good agreement withthose form other literatures. It proves that the method is practical and accurate. Theinhomogeneity of modified Vlasov foundations has some influence on the deformation andinternal force behavior of circular thin plates. The effects of various parameters on the bending ofcircular plates and characteristic parameters of the foundation are discussed. The modified modelfurther enriches and develops the elastic foundations. Relevant conclusions that are meaningful toengineering practice are drawn.
文摘An efficient computational framework for structural system reliability analysis and Updating based on Chain-Structure Bayesian networks(BNs)is present in the paper.The framework combines BNs and structural reliability methods(SRMs)for reliability assessment and updating.BNs have advantages in evaluating complex probabilistic dependence structures and reliability updating,while SRMs are employed to assess the conditional probability table.The improved branch-and-bound(B&B)method is integrated with BNs to simplify the whole network.In order to further reduce computational demand,failure(or survival)path events are introduced to create chain-structure BNs.Considering the correlations between failure modes,the system reliability is obtained through the Probability Network Estimation Technology(PNET).Finally,the reliability updating is carried out through BNs inference.Results show that computational efficiency is improved by the Chain-Structure BNs.System reliability problems with both continuous and discrete random variables can be better resolved by combining BNs and SRMs.This approach is also able to update system reliability when new information available.
文摘A new method for structural physical parameter identification is proposed for linear structure.Firstly,a linear structural identification model was obtained based on a series of transformation of the dynamic characteristic equation.Then the posterior distribution of the model is obtained by the Bayesian updating theory.Using the structural modal parameters and considering their randomness,the structural stiffness parameter is obtained from the conditional posterior distribution of the linear structural identification model.The Gibbs sampling based on the Markov Chain Monte Carlo(MCMC)method is employed during the process.In order to illustrate the proposed method,a 3-DOF linear shear building is used as an example to detect and quantify its damage based on model data measured before and after a severe loading event.The research shows that damage level and locations can be identified with little error by using proposed method.
基金supported by the China National Funds for Distinguished Young Scientists(21925503)the National Natural Science Foundation of China(21835004)the Jilin Scientific and Technological Development Program(20220301018GX)。
文摘Cobalt-free,nickel-rich LiNi_(1-x)Al_(x)O_(2)(x≤0.1)is an attractive cathode material because of high energy density and low cost but suffers from severe structural degradation and poor rate performance.In this study,we propose a molten salt-assisted synthesis in combination with a Li-refeeding induced aluminum segregation strategy to prepare Li_(5)AlO_(4)-coated single-crystalline slightly Li-rich Li_(1.04)Ni_(0.92)Al_(0.04)O_(2).The symbiotic formation of Li_(5)AlO_(4)from reaction between molten lithium hydroxide and doped aluminum in the bulk ensures a high lattice matching between the Ni-rich oxide and the homogenous conductive Li_(5)AlO_(4)that permits high Li^(+)conductivity.Benefiting from mitigated undesirable side reactions and phase evolution,the Li_(5)AlO_(4)-coated single-crystalline Li_(1.04)Ni_(0.92)Al_(0.04)O_(2)delivers a high specific capacity of220.2 mA h g^(-1)at 0.1 C and considerable rate capability(182.5 mA h g^(-1)at 10 C).Besides,superior capacity retention of 90.8%is obtained at 1/3 C after 100 cycles in a 498.1 mA h pouch full cell.Furthermore,the particulate morphology of Li_(1.04)Ni_(0.92)Al_(0.04)O_(2)remains intact after cycling at a cutoff voltage of 4.3 V,whereas slightly Li-deficient Li_(0.98)Ni_(0.97)Al_(0.05)O_(2)features intragranular cracks and irreversible lattice distortion.The results highlight the value of molten salt-assisted synthesis and Li-refeeding induced elemental segregation strategy to upgrade Ni-based layered oxide cathode materials for advanced Li-ion batteries.
基金supported by research grants from the New Jersey Commission on Brain Injury Research (CBIR17PIL012)the National Institutes of Mental Health (MH109791 and MH117368)+2 种基金the New Jersey Institute of Technology Start-up Award to Dr.Xiaobo Lithe National Natural Science Foundation of China (31771074)the Science and Technology Program of Guangzhou Province,China (201704020168 and 201807010064).
文摘Dear Editor,Attention deficit/hyperactivity disorder(ADHD),characterized by age-inappropriate symptoms of inattention,hyperactivity,and impulsivity,is a highly prevalent and heritable childhood-onset neurodevelopmental disorder,with impairing symptoms that persist into adulthood in up to 65%of patients[1].Adults with persistent ADHD symptoms since childhood have been found to have neurocognitive impairments in multiple domains,especially in attention and cognitive control,which significantly contribute to an increased risk of social disability,educational and occupational failure,and other comorbid psychiatric disorders,resulting in significant economic burdens to the affected individuals, their families, andsociety [2, 3].
基金financially supported by the National Natural Science Foundation of China(Nos.21402116,21502111,21572126)the Science and Technology Innovation Talents of Henan Province(No.2018JQ0011)the Key Science Research of Education Committee in Henan Province(No.21A150044)。
文摘Silver-catalyzed decarboxylative C–H alkylation of cyclic aldimines with abundant aliphatic carboxylic acids has been realized under mild reaction conditions generating the corresponding products in moderate to good yields(32%–91%).In addition,a gram-scale reaction,late-stage modification of drug,synthetic transformation of the product,and further application of the catalytic strategy were also performed.Preliminary studies indicate that the reaction undergoes a radical process.
基金the National Key R&D Program of China(2018YFA0108000)the National Natural Science Foundation of China(31625013,81941405,31771137,31722024,91732302,and 32000726)+4 种基金a Shanghai Brain-Intelligence Project from the Science and Technology Commission of Shanghai Municipality(16JC1420501)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDBS01060200 and XDA16010310)a Shanghai Municipal Science and Technology Major Project(2018SHZDZX05)the Shanghai Pujiang Program(17PJ1410200)the research was supported by the Open Large Infrastructure Research of the Chinese Academy of Sciences.
文摘Genetic composition plays critical roles in the pathogenesis of autism spectrum disorder(ASD).Especially,inherited and de novo intronic variants are often seen in patients with ASD.However,the biological significance of intronic variants is difficult to address.Here,among a Chinese ASD cohort,we identified a recurrent inherited intronic variant in the CHD7 gene,which is specifically enriched in East Asian populations.CHD7 has been implicated in numerous developmental disorders including CHARGE syndrome and ASD.To investigate whether the ASD-associated CHD7 intronic variant affects neural development,we established human embryonic stem cells carrying this variant using CRISPR/Cas9 methods and found that the level of CHD7 mRNA significantly decreased compared to control.Upon differentiation towards the forebrain neuronal lineage,we found that neural cells carrying the CHD7 intronic variant exhibited developmental delay and maturity defects.Importantly,we found that TBR1,a gene also implicated in ASD,was significantly increased in neurons carrying the CHD7 intronic variant,suggesting the intrinsic relevance among ASD genes.Furthermore,the morphological defects found in neurons carrying CHD7 intronic mutations were rescued by knocking down TBR1,indicating that TBR1 may be responsible for the defects in CHD7-related disorders.Finally,the CHD7 intronic variant generated three abnormal forms of transcripts through alternative splicing,which all exhibited loss-of-function in functional assays.Our study provides crucial evidence supporting the notion that the intronic variant of CHD7 is potentially an autism susceptibility site,shedding new light on identifying the functions of intronic variants in genetic studies of autism.
基金This study is supported by the National Natural Science Foundation of China under Grant No.51278420the Natural Science Foundation of Shaanxi Province under Grant No.2017JM5021.
文摘This study proposed a damage identification method compared with the existing ones,based on relative curvature difference and frequency perturbation theory,showing sensitivity to local damage by changes in the curvature mode and high recognition accuracy of frequencies.Considering the relative curvature difference as a damage index,numerical simulation is used for a simply supported beam under single and multiple damage conditions for different damage degrees.The damage is located according to the curvature mode curves,and the damage degree is qualitatively determined.Based on the perturbation theory,the damage equations are established by the changes between frequencies before and after damage,and the damage localization and degree are verified and determined.Effectiveness of the proposed method for identifying damage at different conditions is numerically investigated.This method potentially promotes the development of damage identification of beam structures.
基金This research was financially supported by the National Natural Science Foundation of China(No.21402116,21502111,21572126,22001161)the Key Science Research of Education Committee in Henan Province(no.21A150044,22A150051)Shangqiu Normal University(Program of Ecological Conservation and High-quality Development of the Old Course of Yellow River,no.2021KYFZ06).
文摘We developed for the first time an unprecedented domino reaction of sulfonyl oximonitriles with secondary amines to streamline the synthesis of N-sulfonylformamidines in decent to high yields under mild reaction conditions.In addition,scale-up experiments and late-stage functionalization of drugs were also performed.Preliminary studies indicate that the loss of a cyano-/benzyloxy-group and a sulfonyl migration process are involved in this reaction.