This paper studies the consensus control of multiagent systems with binary-valued observations.An algorithm alternating estimation and control is proposed.Each agent estimates the states of its neighbors based on a pr...This paper studies the consensus control of multiagent systems with binary-valued observations.An algorithm alternating estimation and control is proposed.Each agent estimates the states of its neighbors based on a projected empirical measure method for a holding time.Based on the estimates,each agent designs the consensus control with a constant gain at some skipping time.The states of the system are updated by the designed control,and the estimation and control design will be repeated.For the estimation,the projected empirical measure method is proposed for the binary-valued observations.The algorithm can ensure the uniform boundedness of the estimates and the mean square error of the estimation is proved to be at the order of the reciprocal of the holding time(the same order as that in the case of accurate outputs).For the consensus control,a constant gain is designed instead of the stochastic approximation based gain in the existing literature for binary-valued observations.And,there is no need to make modification for control since the uniform boundedness of the estimates ensures the uniform boundedness of the agents’states.Finally,the systems updated by the designed control are proved to achieve consensus and the consensus speed is faster than that in the existing literature.Simulations are given to demonstrate the theoretical results.展开更多
Uniaxial compressive strength tests were conducted on the saturated frozen Lanzhou silt (loess) at various constant strain rates and at various constant temperatures. It is concluded from the test results that: the co...Uniaxial compressive strength tests were conducted on the saturated frozen Lanzhou silt (loess) at various constant strain rates and at various constant temperatures. It is concluded from the test results that: the compressive strength (\%σ \% f) is very sensitive to temperature (\%θ\%) and increases with the temperature decreasing as a power law. Compressive strength is sensitive to strain rate (\%\%) and increases with strain rates increasing within a certain range of strain rates as a power law. Compressive strength decreases when time to failure (\%t\% f) increases, also following a power law. Finally, Compressive strength of frozen silt with higher dry density (\%γ\% d) is higher than that of frozen silt with lower dry density. The difference between them is mainly influenced by strain rate.展开更多
目的探讨基于前列腺影像报告和数据系统(prostate imaging reporting and data system,PI-RADS)V2.1版的动态对比增强磁共振成像(dynamic contrast enhanced magnetic resonance imaging,DCE-MRI)定量值对外周带前列腺癌(prostate cance...目的探讨基于前列腺影像报告和数据系统(prostate imaging reporting and data system,PI-RADS)V2.1版的动态对比增强磁共振成像(dynamic contrast enhanced magnetic resonance imaging,DCE-MRI)定量值对外周带前列腺癌(prostate cancer,PCa)和局灶性慢性前列腺炎(chronic prostatitis,CP)的鉴别价值。材料与方法回顾性分析2022年1月至2023年4月期间芜湖市第二人民医院收治的57例外周带PCa患者(研究组)和21例局灶性CP患者(对照组),所有患者接受T2WI、扩散加权成像(diffusion weighted imaging,DWI)、DCE-MRI检查,比较两组双参数(bi-parameter,bp)-MRI(T2WI+DWI)、多参数(multi-parameter,mp)-MRI(T2WI+DWI+DCE-MRI)扫描方案的PI-RADS V2.1评分、DCE-MRI扫描定量值,采用受试者工作特征(receiver operating characteristic,ROC)曲线评估各诊断方案对外周带PCa的诊断价值。结果研究组bp-MRI、mp-MRI扫描方案PI-RADS V2.1评分分别为(4.12±0.88)、(4.31±0.70)分,分别高于对照组的(2.42±1.14)、(2.52±1.22)分,P<0.05。研究组DCE-MRI定量值容积转运常数(volume transport constant,K^(trans))、速率常数(rate constant,K_(ep))均高于对照组(P<0.001),两组血管外细胞外间隙容积分数(extravascular extracellular volume fraction,V_(e))比较差异无统计学意义(P>0.05)。ROC分析显示,bp-MRI、mp-MRI、K^(trans)、K_(ep)诊断外周带PCa的ROC曲线下面积(area under the curve,AUC)[95%置信区间(confidenceinterval,CI)]分别为0.780(0.672~0.866)、0.857(0.759~0.926)、0.734(0.622~0.828)、0.818(0.716~0.896),mp-MRI诊断效能较bp-MRI稍高(P<0.05),其余各项比较差异无统计学意义(P>0.05)。采用logit(p)法建立ROC拟合诊断模型,结果显示K_(ep)+K^(trans)、mp-MRI+K^(trans)、mp-MRI+K_(ep)对外周带PCa诊断效能差异均无统计学意义(P>0.05);K_(ep)+K^(trans)的诊断效能与bp-MRI、mp-MRI、K^(trans)、K_(ep)比较差异均无统计学意义(P>0.05);mp-MRI+K^(trans)的诊断效能分别高于bp-MRI、mp-MRI、K_(ep)、K^(trans)(P<0.05);mp-展开更多
Objective： To evaluate the feasibility of dynamic contrast-enhanced magnetic resonance imaging（DCEMRI） for predicting tumor response to radiotherapy in patients with suspected primary central nervous system（CNS） ...Objective： To evaluate the feasibility of dynamic contrast-enhanced magnetic resonance imaging（DCEMRI） for predicting tumor response to radiotherapy in patients with suspected primary central nervous system（CNS） germ cell tumors（GCTs）.Methods： DCE-MRI parameters of 35 patients with suspected primary CNS GCTs were obtained prior to diagnostic radiation, using the Tofts and Kermode model. Radiosensitivity was determined in tumors diagnosed 2 weeks after radiation by observing changes in tumor size and markers as a response to MRI. Taking radiosensitivity as the gold standard, the cut-off value of DCE-MRI parameters was measured by receiver operating characteristic（ROC） curve. Diagnostic accuracy of DCE-MRI parameters for predicting radiosensitivity was evaluated by ROC curve.Results： A significant elevation in transfer constant（K^trans） and extravascular extracellular space（Ve）（P=0.000）, as well as a significant reduction in rate constant（Kep）（P=0.000） was observed in tumors. K^trans, relative K^trans, and relative Kep of the responsive group were significantly higher than non-responsive groups. No significant difference was found in Kep, Ve, and relative Ve between the two groups. Relative K^trans showed the best diagnostic value in predicting radiosensitivity with a sensitivity of 100%, specificity of 91.7%, positive predictive value（PPV） of 95.8%, and negative predictive value（NPV） of 100%.Conclusions： Relative K^trans appeared promising in predicting tumor response to radiation therapy（RT）. It is implied that DCE-MRI pre-treatment is a requisite step in diagnostic procedures and a novel and reliable approach to guide clinical choice of RT.展开更多
Using pulse radiolysis technique, the reaction between hydroxyl radical and 7 phenylpropanoidglycosides: echinacoside, verbascoside, leucosceptoside A, martynoside, pediculariosides A, M and N which were isolated from...Using pulse radiolysis technique, the reaction between hydroxyl radical and 7 phenylpropanoidglycosides: echinacoside, verbascoside, leucosceptoside A, martynoside, pediculariosides A, M and N which were isolated from Pedicularis were examined. The rate constants of these reactions were determined by transient absorption spectra. All 7 phenylpropanoid glycosides react with hydroxyl radical at high rate constants within (0.97-1.91)×1010L · mol-1 · s-1. suggesting that they are effective hydroxyl radical scavengers. The results demonstrate that the numbers of phenolic hydroxyl groups of phenylpropanoid glycosides are directly related to their scavenging activities. The scavenging activities are likely related to o-dihydroxy group of phenylpropanoid glycosides as well.展开更多
TIME-dependent （TD） quantum wave packet theory, with a relatively small amount of computational effort, has been widely used in quantum dynamics calculation of atom and molecule reaction scattering. Many computation...TIME-dependent （TD） quantum wave packet theory, with a relatively small amount of computational effort, has been widely used in quantum dynamics calculation of atom and molecule reaction scattering. Many computational scaling advantages of the TD method can be found apparently in polyatomic system. In this note, by using the TD quantum wave packet method with the potential-averaged 5D model （PA5D）, we give the calculated results of reaction probabilities, cross sections and rate constants for the H<sub>2</sub> + OD reaction. The energyprojection method is used to transform the TD wave function into the TI (energy-indepen-展开更多
Rate constants for the reactions of ozone with 1-octen-3-ol, 1-nonen-3-ol and 1-nonen-4-ol have been determined at 298 ±1 K and atmospheric pressure for the first time. The experiments were performed in a 100-L F...Rate constants for the reactions of ozone with 1-octen-3-ol, 1-nonen-3-ol and 1-nonen-4-ol have been determined at 298 ±1 K and atmospheric pressure for the first time. The experiments were performed in a 100-L FEP Teflon film bag using absolute rate method; the rate constants were （1.91 ± 0.19） ×10^-17, （1.89 ± 0.20） × 10^-17, and （0.83 ± 0.08） × 10^-17 cm^3/（molecule.sec） for 1-octen-3-ol, 1-nonen-3-ol, and 1-nonen-4-ol, respectively. The rate constants have been compared with those of unsaturated alcohols structural homologs, and used to estimate the reaction reactivity. The electronegativity of carbon-carbon double bond was calculated by atomic charges analysis. The calculated results show that the electronic effect of the lone pair electrons of hydroxyl oxygen is the main cause of the difference in rate coefficient. According to the obtained rate constants, the atmospheric lifetimes of studied unsaturated alcohols were also estimated, which indicates that the reaction with ozone is an important loss pathway in the atmosphere, especially in polluted areas.展开更多
Gas wiping is a decisive operation in hot-dip galvanizing process. In special, it has a crucial influence on the thickness and uniformity in coating film, but may be subsequently responsible for the problem of splashi...Gas wiping is a decisive operation in hot-dip galvanizing process. In special, it has a crucial influence on the thickness and uniformity in coating film, but may be subsequently responsible for the problem of splashing. The progress of industry demands continuously the reduction of production costs which may relate directly with the increase of coating speed, and the speed up of coating results in the increase of stagnation pressure in gas wiping system in final. It is known that the increase of stagnation pressure may accompany a harmful problem of splashing in general. Together with these, also, from the view point of energy consumption, it is necessary to design a nozzle optimally. And there is known that the downward tilting of nozzle using in air knife system is effective to prevent in somewhat the harmful problem of splashing. In these connections, first, we design a nozzle with constant expansion rate. Next, for the case of actual coating conditions in field, the effects of tilting of the constant expansion rate nozzle are investigated by numerical analysis. Under the present numerical conditions, it was turned out that the nozzle of constant expansion rate of p = having a downward jet angle of 5^0 is the most effective to diminish the onset of splashing, while the influence of small tilting of the nozzle on impinging wall pres- sure itself is not so large.展开更多
BACKGROUND Rectal carcinoma(RC),one of the most common malignancies globally,presents an increasing incidence and mortality year by year,especially among young people,which seriously affects the prognosis and quality ...BACKGROUND Rectal carcinoma(RC),one of the most common malignancies globally,presents an increasing incidence and mortality year by year,especially among young people,which seriously affects the prognosis and quality of life of patients.At present,dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)parameters and serum carbohydrate antigen 19-9(CA19-9)and CA125 Levels have been used in clinical practice to evaluate the T stage and differentiation of RC.However,the accuracy of these evaluation modalities still needs further research.This study explores the application and value of these methods in evaluating the T stage and differentiation degree of RC.AIM To analyze the diagnostic performance of DCE-MRI parameters combined with serum tumor markers(TMs)in assessing pathological processes and prognosis of RC patients.METHODS A retrospective analysis was performed on 104 RC patients treated at Yantai Yuhuangding Hospital from May 2018 to January 2022.Patients were categorized into stages T1,T2,T3,and T4,depending on their T stage and differentiation degree.In addition,they were assigned to low(L group)and moderate-high differentiation(M+H group)groups based on their differentiation degree.The levels of DCE-MRI parameters and serum CA19-9 and CA125 in different groups of patients were compared.In addition,the value of DCE-MRI parameters[volume transfer constant(Ktrans),rate constant(Kep),and extravascular extracellular volume fraction(Ve)in assessing the differentiation and T staging of RC patients was discussed.Furthermore,the usefulness of DCE-MRI parameters combined with serum CA19-9 and CA125 Levels in the evaluation of RC differentiation and T staging was analyzed.RESULTS Ktrans,Ve,CA19-9 and CA125 were higher in the high-stage group and L group than in the low-stage group and M+H Group,respectively(P<0.05).The areas under the curve(AUCs)of the Ktran and Ve parameters were 0.638 and 0.694 in the diagnosis of high and low stages,respectively,and 0.672 and 0.725 in diagnosing moderate-high and low differe展开更多
基金supported by the National Natural Science Foundation of China(61803370,61622309)the China Postdoctoral Science Foundation(2018M630216)the National Key Research and Development Program of China(2016YFB0901902)
文摘This paper studies the consensus control of multiagent systems with binary-valued observations.An algorithm alternating estimation and control is proposed.Each agent estimates the states of its neighbors based on a projected empirical measure method for a holding time.Based on the estimates,each agent designs the consensus control with a constant gain at some skipping time.The states of the system are updated by the designed control,and the estimation and control design will be repeated.For the estimation,the projected empirical measure method is proposed for the binary-valued observations.The algorithm can ensure the uniform boundedness of the estimates and the mean square error of the estimation is proved to be at the order of the reciprocal of the holding time(the same order as that in the case of accurate outputs).For the consensus control,a constant gain is designed instead of the stochastic approximation based gain in the existing literature for binary-valued observations.And,there is no need to make modification for control since the uniform boundedness of the estimates ensures the uniform boundedness of the agents’states.Finally,the systems updated by the designed control are proved to achieve consensus and the consensus speed is faster than that in the existing literature.Simulations are given to demonstrate the theoretical results.
文摘Uniaxial compressive strength tests were conducted on the saturated frozen Lanzhou silt (loess) at various constant strain rates and at various constant temperatures. It is concluded from the test results that: the compressive strength (\%σ \% f) is very sensitive to temperature (\%θ\%) and increases with the temperature decreasing as a power law. Compressive strength is sensitive to strain rate (\%\%) and increases with strain rates increasing within a certain range of strain rates as a power law. Compressive strength decreases when time to failure (\%t\% f) increases, also following a power law. Finally, Compressive strength of frozen silt with higher dry density (\%γ\% d) is higher than that of frozen silt with lower dry density. The difference between them is mainly influenced by strain rate.
文摘目的探讨基于前列腺影像报告和数据系统(prostate imaging reporting and data system,PI-RADS)V2.1版的动态对比增强磁共振成像(dynamic contrast enhanced magnetic resonance imaging,DCE-MRI)定量值对外周带前列腺癌(prostate cancer,PCa)和局灶性慢性前列腺炎(chronic prostatitis,CP)的鉴别价值。材料与方法回顾性分析2022年1月至2023年4月期间芜湖市第二人民医院收治的57例外周带PCa患者(研究组)和21例局灶性CP患者(对照组),所有患者接受T2WI、扩散加权成像(diffusion weighted imaging,DWI)、DCE-MRI检查,比较两组双参数(bi-parameter,bp)-MRI(T2WI+DWI)、多参数(multi-parameter,mp)-MRI(T2WI+DWI+DCE-MRI)扫描方案的PI-RADS V2.1评分、DCE-MRI扫描定量值,采用受试者工作特征(receiver operating characteristic,ROC)曲线评估各诊断方案对外周带PCa的诊断价值。结果研究组bp-MRI、mp-MRI扫描方案PI-RADS V2.1评分分别为(4.12±0.88)、(4.31±0.70)分,分别高于对照组的(2.42±1.14)、(2.52±1.22)分,P<0.05。研究组DCE-MRI定量值容积转运常数(volume transport constant,K^(trans))、速率常数(rate constant,K_(ep))均高于对照组(P<0.001),两组血管外细胞外间隙容积分数(extravascular extracellular volume fraction,V_(e))比较差异无统计学意义(P>0.05)。ROC分析显示,bp-MRI、mp-MRI、K^(trans)、K_(ep)诊断外周带PCa的ROC曲线下面积(area under the curve,AUC)[95%置信区间(confidenceinterval,CI)]分别为0.780(0.672~0.866)、0.857(0.759~0.926)、0.734(0.622~0.828)、0.818(0.716~0.896),mp-MRI诊断效能较bp-MRI稍高(P<0.05),其余各项比较差异无统计学意义(P>0.05)。采用logit(p)法建立ROC拟合诊断模型,结果显示K_(ep)+K^(trans)、mp-MRI+K^(trans)、mp-MRI+K_(ep)对外周带PCa诊断效能差异均无统计学意义(P>0.05);K_(ep)+K^(trans)的诊断效能与bp-MRI、mp-MRI、K^(trans)、K_(ep)比较差异均无统计学意义(P>0.05);mp-MRI+K^(trans)的诊断效能分别高于bp-MRI、mp-MRI、K_(ep)、K^(trans)(P<0.05);mp-
基金supported by Beijing Natural Science Foundation(No.7122029)
文摘Objective： To evaluate the feasibility of dynamic contrast-enhanced magnetic resonance imaging（DCEMRI） for predicting tumor response to radiotherapy in patients with suspected primary central nervous system（CNS） germ cell tumors（GCTs）.Methods： DCE-MRI parameters of 35 patients with suspected primary CNS GCTs were obtained prior to diagnostic radiation, using the Tofts and Kermode model. Radiosensitivity was determined in tumors diagnosed 2 weeks after radiation by observing changes in tumor size and markers as a response to MRI. Taking radiosensitivity as the gold standard, the cut-off value of DCE-MRI parameters was measured by receiver operating characteristic（ROC） curve. Diagnostic accuracy of DCE-MRI parameters for predicting radiosensitivity was evaluated by ROC curve.Results： A significant elevation in transfer constant（K^trans） and extravascular extracellular space（Ve）（P=0.000）, as well as a significant reduction in rate constant（Kep）（P=0.000） was observed in tumors. K^trans, relative K^trans, and relative Kep of the responsive group were significantly higher than non-responsive groups. No significant difference was found in Kep, Ve, and relative Ve between the two groups. Relative K^trans showed the best diagnostic value in predicting radiosensitivity with a sensitivity of 100%, specificity of 91.7%, positive predictive value（PPV） of 95.8%, and negative predictive value（NPV） of 100%.Conclusions： Relative K^trans appeared promising in predicting tumor response to radiation therapy（RT）. It is implied that DCE-MRI pre-treatment is a requisite step in diagnostic procedures and a novel and reliable approach to guide clinical choice of RT.
基金Project partly supported by the National Natural Science Foundation of China and partly by Open Laboratory of Radiation Chemistry, the Chinese Academy of Sciences.
文摘Using pulse radiolysis technique, the reaction between hydroxyl radical and 7 phenylpropanoidglycosides: echinacoside, verbascoside, leucosceptoside A, martynoside, pediculariosides A, M and N which were isolated from Pedicularis were examined. The rate constants of these reactions were determined by transient absorption spectra. All 7 phenylpropanoid glycosides react with hydroxyl radical at high rate constants within (0.97-1.91)×1010L · mol-1 · s-1. suggesting that they are effective hydroxyl radical scavengers. The results demonstrate that the numbers of phenolic hydroxyl groups of phenylpropanoid glycosides are directly related to their scavenging activities. The scavenging activities are likely related to o-dihydroxy group of phenylpropanoid glycosides as well.
文摘TIME-dependent （TD） quantum wave packet theory, with a relatively small amount of computational effort, has been widely used in quantum dynamics calculation of atom and molecule reaction scattering. Many computational scaling advantages of the TD method can be found apparently in polyatomic system. In this note, by using the TD quantum wave packet method with the potential-averaged 5D model （PA5D）, we give the calculated results of reaction probabilities, cross sections and rate constants for the H<sub>2</sub> + OD reaction. The energyprojection method is used to transform the TD wave function into the TI (energy-indepen-
基金supported by the National Natural Science Foundation of China (Nos. 41571130022, 91544223, 21473009)
文摘Rate constants for the reactions of ozone with 1-octen-3-ol, 1-nonen-3-ol and 1-nonen-4-ol have been determined at 298 ±1 K and atmospheric pressure for the first time. The experiments were performed in a 100-L FEP Teflon film bag using absolute rate method; the rate constants were （1.91 ± 0.19） ×10^-17, （1.89 ± 0.20） × 10^-17, and （0.83 ± 0.08） × 10^-17 cm^3/（molecule.sec） for 1-octen-3-ol, 1-nonen-3-ol, and 1-nonen-4-ol, respectively. The rate constants have been compared with those of unsaturated alcohols structural homologs, and used to estimate the reaction reactivity. The electronegativity of carbon-carbon double bond was calculated by atomic charges analysis. The calculated results show that the electronic effect of the lone pair electrons of hydroxyl oxygen is the main cause of the difference in rate coefficient. According to the obtained rate constants, the atmospheric lifetimes of studied unsaturated alcohols were also estimated, which indicates that the reaction with ozone is an important loss pathway in the atmosphere, especially in polluted areas.
文摘Gas wiping is a decisive operation in hot-dip galvanizing process. In special, it has a crucial influence on the thickness and uniformity in coating film, but may be subsequently responsible for the problem of splashing. The progress of industry demands continuously the reduction of production costs which may relate directly with the increase of coating speed, and the speed up of coating results in the increase of stagnation pressure in gas wiping system in final. It is known that the increase of stagnation pressure may accompany a harmful problem of splashing in general. Together with these, also, from the view point of energy consumption, it is necessary to design a nozzle optimally. And there is known that the downward tilting of nozzle using in air knife system is effective to prevent in somewhat the harmful problem of splashing. In these connections, first, we design a nozzle with constant expansion rate. Next, for the case of actual coating conditions in field, the effects of tilting of the constant expansion rate nozzle are investigated by numerical analysis. Under the present numerical conditions, it was turned out that the nozzle of constant expansion rate of p = having a downward jet angle of 5^0 is the most effective to diminish the onset of splashing, while the influence of small tilting of the nozzle on impinging wall pres- sure itself is not so large.
文摘BACKGROUND Rectal carcinoma(RC),one of the most common malignancies globally,presents an increasing incidence and mortality year by year,especially among young people,which seriously affects the prognosis and quality of life of patients.At present,dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)parameters and serum carbohydrate antigen 19-9(CA19-9)and CA125 Levels have been used in clinical practice to evaluate the T stage and differentiation of RC.However,the accuracy of these evaluation modalities still needs further research.This study explores the application and value of these methods in evaluating the T stage and differentiation degree of RC.AIM To analyze the diagnostic performance of DCE-MRI parameters combined with serum tumor markers(TMs)in assessing pathological processes and prognosis of RC patients.METHODS A retrospective analysis was performed on 104 RC patients treated at Yantai Yuhuangding Hospital from May 2018 to January 2022.Patients were categorized into stages T1,T2,T3,and T4,depending on their T stage and differentiation degree.In addition,they were assigned to low(L group)and moderate-high differentiation(M+H group)groups based on their differentiation degree.The levels of DCE-MRI parameters and serum CA19-9 and CA125 in different groups of patients were compared.In addition,the value of DCE-MRI parameters[volume transfer constant(Ktrans),rate constant(Kep),and extravascular extracellular volume fraction(Ve)in assessing the differentiation and T staging of RC patients was discussed.Furthermore,the usefulness of DCE-MRI parameters combined with serum CA19-9 and CA125 Levels in the evaluation of RC differentiation and T staging was analyzed.RESULTS Ktrans,Ve,CA19-9 and CA125 were higher in the high-stage group and L group than in the low-stage group and M+H Group,respectively(P<0.05).The areas under the curve(AUCs)of the Ktran and Ve parameters were 0.638 and 0.694 in the diagnosis of high and low stages,respectively,and 0.672 and 0.725 in diagnosing moderate-high and low differe
