Estimation of support pressure is extremely important to the support system design and the construction safety of tunnels.At present,there are many methods for the estimation of support pressure based on different roc...Estimation of support pressure is extremely important to the support system design and the construction safety of tunnels.At present,there are many methods for the estimation of support pressure based on different rock mass classification systems,such as Q system,GSI system and RMR system.However,various rock mass classification systems are based on different tunnel geologic conditions in various regions.Therefore,each rock mass classification system has a certain regionality.In China,the BQ-Inex(BQ system)has been widely used in the field of rock engineering ever since its development.Unfortunately,there is still no estimation method of support pressure with BQ-index as parameters.Based on the field test data from 54 tunnels in China,a new empirical method considering BQ-Inex,tunnel span and rock weight is proposed to estimate the support pressure using multiple nonlinear regression analysis methods.And then the significance and necessity of support pressure estimation method for the safety of tunnel construction in China is explained through the comparison and analysis with the existing internationally widely used support pressure estimation methods of RMR system,Q system and GSI system.Finally,the empirical method of estimating the support pressure based on BQ-index was applied to designing the support system in the China’s high-speed railway tunnel—Zhengwan high-speed railway and the rationality of this method has been verified through the data of field test.展开更多
In order to understand the influence of brittleness and confining stress on rock cuttability,the indentation tests were carried out by a conical pick on the four types of rocks.Then,the experimental results were utili...In order to understand the influence of brittleness and confining stress on rock cuttability,the indentation tests were carried out by a conical pick on the four types of rocks.Then,the experimental results were utilized to take regression analysis.The eight sets of normalized regression models were established for reflecting the relationships of peak indentation force(PIF)and specific energy(SE)with brittleness index and uniaxial confining stress.The regression analyses present that these regression models have good prediction performance.The regressive results indicate that brittleness indices and uniaxial confining stress conditions have non-linear effects on the rock cuttability that is determined by PIF and SE.Finally,the multilayer perceptual neural network was used to measure the importance weights of brittleness index and uniaxial confining stress upon the influence for rock cuttability.The results indicate that the uniaxial confining stress is more significant than brittleness index for influencing the rock cuttability.展开更多
Beginning from the first kind of integral equation, two kinds of methods, i. e. Singular Value Decomposition (SVD) and transform that are fit for the inversion calculation of NMR multi-relaxation data from rock, have ...Beginning from the first kind of integral equation, two kinds of methods, i. e. Singular Value Decomposition (SVD) and transform that are fit for the inversion calculation of NMR multi-relaxation data from rock, have been derived. The mathematical processing was discussed in detail. The advantage and disadvantage of the two methods have been compared in theory and application. From the view of the degree of freedom of the inversion solution, we discussed the resolution of the solution of NMR relaxation inversion and the selection of optimal inversion modeling. Results showed that SVD method is fit for the inversion of NMR relaxation data with a higher signal to noise ratio and transform inversion method is more flexible and can be used in NMR data with a lower signal to noise ratio. It is advisable that transform inversion method be selected for the multi-relaxation inversion of rock NMR data. SVD method can be used when the signal to noise ratio is better than 80. In order to ensure the accuracy, the number of T2 points should be varied from 30 to 50. The results of the research are useful for NMR core analysis and the interpretation of NMR logging data.展开更多
Macromolecular ligands with liver-targeting group (pyridoxamine, PM) PHEA-DTPA-PM and PAEA-DTPA-PM were prepared by the incorporation of different amount of diethylenetria-minepentaacetic acid monopyridoxamine group (...Macromolecular ligands with liver-targeting group (pyridoxamine, PM) PHEA-DTPA-PM and PAEA-DTPA-PM were prepared by the incorporation of different amount of diethylenetria-minepentaacetic acid monopyridoxamine group (DTPA-PM) into poly-α, β-[N-(2-hydroxyethyl)-L-aspartamide] (PHEA) and poly-α, β-[N-(2-aminoethyl)-L-aspartamide] (PAEA). The macromolecular ligands thus obtained were further complexed with gadolinium chloride to give macromolecular MRI contrast agents with different Gd(III) contents. These macromolecular ligands and their gadolinium complexes were characterized by1H NMR, IR, UV and elementary analysis. Relaxivity studies showed that these polyaspartamide gadolinium complexes possess higher relaxation effectiveness than that of the clinically used Gd-DTPA. Magnetic resonance imaging of the liver in rats and experimental data of biodistribution in mice indicate that these macromolecular MRI contrast agents containing pyridoxamine exhibit liver-targeting property.展开更多
In this paper we present a stochastic model for daily average temperature to calculate the temperature indices upon which temperature-based derivatives are written. We propose a seasonal mean and volatility model that...In this paper we present a stochastic model for daily average temperature to calculate the temperature indices upon which temperature-based derivatives are written. We propose a seasonal mean and volatility model that describes the daily average temperature behavior using the mean-reverting Ornstein-Uhlenbeck process. We also use higher order continuous-time autoregressive process with lag 3 for modeling the time evolution of the temperatures after removing trend and seasonality. Our model is fitted to 11 years of data recorded, in the period 1 January 2005 to 31 December 2015, Bahir Dar, Ethiopia, obtained from Ethiopia National Meteorological Services Agency. The analytical approximation formulas are used to price heating degree days(HDD) and cooling degree days(CDD) futures. The suggested model is analytically tractable for derivation of explicit prices for CDD and HDD futures and option. The price of the CDD future is calculated, using analytical approximation formulas. Numerical examples are presented to indicate the accuracy of the method. The results show that our model performs better to predict CDD indices.展开更多
Identifying code has been widely used in man-machine verification to maintain network security.The challenge in engaging man-machine verification involves the correct classification of man and machine tracks.In this s...Identifying code has been widely used in man-machine verification to maintain network security.The challenge in engaging man-machine verification involves the correct classification of man and machine tracks.In this study,we propose a random forest(RF)model for man-machine verification based on the mouse movement trajectory dataset.We also compare the RF model with the baseline models(logistic regression and support vector machine)based on performance metrics such as precision,recall,false positive rates,false negative rates,F-measure,and weighted accuracy.The performance metrics of the RF model exceed those of the baseline models.展开更多
A computable expression of the asymptotic expansion of the return map for a degenerate singular point of a class of planar differential system is given, and hence the stability and the type of the singular point can b...A computable expression of the asymptotic expansion of the return map for a degenerate singular point of a class of planar differential system is given, and hence the stability and the type of the singular point can be decided. These results generalize the corresponding results in [Nonlinearity, 13 (2000), p.709].展开更多
OBJECTIVE: To explore the relationship between Renying pulse (carotid) augmentation index (AI) and Cunkou pulse condition in different blood pres- sure groups, and the clinical significance of Reny- ing and Cunko...OBJECTIVE: To explore the relationship between Renying pulse (carotid) augmentation index (AI) and Cunkou pulse condition in different blood pres- sure groups, and the clinical significance of Reny- ing and Cunkou pulse parameters to reflect vascu- lar function. METHODS: Eighty-six patients with essential hyper- tension (EH) and 52 individuals with normal blood pressure (control group) between and January 2012 were included September 2010 this study. Reny- ing pulse AI was examined by a new diagnostic tool (ALOKA ProSound Alpha 10) --wave intensity (Wl) that is calculated as the product of the deriva- tives of the simultaneously recorded blood pres- sure changes (dP/dt) and blood-flow-velocity changes (dU/dt), while Cunkou pulse condition was detected by DDMX-100 Pulse Apparatus inboth EH and control groups. A multifactorial corre- lation analysis was performed for data analysis. RESULTS: After adjusting for potential confound- ing variables, in the EH group, AI was positively cor- related with ts, w2/t (rts=0.225, P〈0.05; rw2/t=0.230, P〈 0.05) and negatively correlated with hs, hs/hl and w2 (rhs=- 0.393,P〈0.01 ;rhs/l=- 0.444, P〈0.01 ;rw2=- 0.389, P〈0.01). In the control group, AI was positively cor- related with t3, t4, ts and w, (rt3=0.595, P〈0.01; r,4= 0.292, P〈0.05; rt5=0.318, P〈0.05; rw1=0.541, P〈0.01) and negatively correlated with h1, h2, h3, Ad and A (rh1= - 0.368, P〈0.05; rh2= - 0.330, P〈0.05; rh3= - 0.327, P〈 0.05; rAd=- 0.322, P〈0.05; rA=- 0.410, P〈0.01). In the total sample group (EH plus control group, n= 138), AI was positively correlated with t, ts, w1 and w, (rt=0.257, P〈0.01; rt5=0.266, P〈0.01; rw1=0.184, P〈 0.05; rw/t=0.210, P〈0.05) and negatively correlated with hs, hs/hl, w2 and Ad (rhs= - 0.230, P〈0.01; rh5/h1= - 0.218, P〈0.05; rw2= - 0.267, P〈0.01; rAd= - 0.246, P〈0.01). Multiple linear regression analysis was car- ried out to model the relationship (F=7.887, P〈 0.001).CONCLUSION: Renying pulse AI can effectively pre- dict arterial stiffness in synchrony with the manifes- tations of Cunkou pulse in elderly patients with hy- pertension. Cunkou pulse apparatus is a valuable tool for evaluating AI in clinical practice, The close correlations reported above reflect the holistic con- cept of Traditional Chinese Medicine.展开更多
基金Projects(51878567,51878568,51578458)supported by the National Natural Science Foundation of ChinaProjects(2017G007-F,2017G007-H)supported by China Railway Science and Technology Research and Development Plan。
文摘Estimation of support pressure is extremely important to the support system design and the construction safety of tunnels.At present,there are many methods for the estimation of support pressure based on different rock mass classification systems,such as Q system,GSI system and RMR system.However,various rock mass classification systems are based on different tunnel geologic conditions in various regions.Therefore,each rock mass classification system has a certain regionality.In China,the BQ-Inex(BQ system)has been widely used in the field of rock engineering ever since its development.Unfortunately,there is still no estimation method of support pressure with BQ-index as parameters.Based on the field test data from 54 tunnels in China,a new empirical method considering BQ-Inex,tunnel span and rock weight is proposed to estimate the support pressure using multiple nonlinear regression analysis methods.And then the significance and necessity of support pressure estimation method for the safety of tunnel construction in China is explained through the comparison and analysis with the existing internationally widely used support pressure estimation methods of RMR system,Q system and GSI system.Finally,the empirical method of estimating the support pressure based on BQ-index was applied to designing the support system in the China’s high-speed railway tunnel—Zhengwan high-speed railway and the rationality of this method has been verified through the data of field test.
基金Project(51904333) supported by the National Natural Science Foundation of China。
文摘In order to understand the influence of brittleness and confining stress on rock cuttability,the indentation tests were carried out by a conical pick on the four types of rocks.Then,the experimental results were utilized to take regression analysis.The eight sets of normalized regression models were established for reflecting the relationships of peak indentation force(PIF)and specific energy(SE)with brittleness index and uniaxial confining stress.The regression analyses present that these regression models have good prediction performance.The regressive results indicate that brittleness indices and uniaxial confining stress conditions have non-linear effects on the rock cuttability that is determined by PIF and SE.Finally,the multilayer perceptual neural network was used to measure the importance weights of brittleness index and uniaxial confining stress upon the influence for rock cuttability.The results indicate that the uniaxial confining stress is more significant than brittleness index for influencing the rock cuttability.
基金the National Natural Science Foundation of China (Grant No. 19705014) .
文摘Beginning from the first kind of integral equation, two kinds of methods, i. e. Singular Value Decomposition (SVD) and transform that are fit for the inversion calculation of NMR multi-relaxation data from rock, have been derived. The mathematical processing was discussed in detail. The advantage and disadvantage of the two methods have been compared in theory and application. From the view of the degree of freedom of the inversion solution, we discussed the resolution of the solution of NMR relaxation inversion and the selection of optimal inversion modeling. Results showed that SVD method is fit for the inversion of NMR relaxation data with a higher signal to noise ratio and transform inversion method is more flexible and can be used in NMR data with a lower signal to noise ratio. It is advisable that transform inversion method be selected for the multi-relaxation inversion of rock NMR data. SVD method can be used when the signal to noise ratio is better than 80. In order to ensure the accuracy, the number of T2 points should be varied from 30 to 50. The results of the research are useful for NMR core analysis and the interpretation of NMR logging data.
基金Acknowledgements The authors would like to thank Mr. Cao Guoqiang and Mr. Cao Wei (Department of Nuclear Medicine of Wuhan Union Hospital) for their assistance in the biodistribution experiment, Profs. Zheng Congyi and Mr. Qu Sanfu (College of Life Scien
文摘Macromolecular ligands with liver-targeting group (pyridoxamine, PM) PHEA-DTPA-PM and PAEA-DTPA-PM were prepared by the incorporation of different amount of diethylenetria-minepentaacetic acid monopyridoxamine group (DTPA-PM) into poly-α, β-[N-(2-hydroxyethyl)-L-aspartamide] (PHEA) and poly-α, β-[N-(2-aminoethyl)-L-aspartamide] (PAEA). The macromolecular ligands thus obtained were further complexed with gadolinium chloride to give macromolecular MRI contrast agents with different Gd(III) contents. These macromolecular ligands and their gadolinium complexes were characterized by1H NMR, IR, UV and elementary analysis. Relaxivity studies showed that these polyaspartamide gadolinium complexes possess higher relaxation effectiveness than that of the clinically used Gd-DTPA. Magnetic resonance imaging of the liver in rats and experimental data of biodistribution in mice indicate that these macromolecular MRI contrast agents containing pyridoxamine exhibit liver-targeting property.
文摘In this paper we present a stochastic model for daily average temperature to calculate the temperature indices upon which temperature-based derivatives are written. We propose a seasonal mean and volatility model that describes the daily average temperature behavior using the mean-reverting Ornstein-Uhlenbeck process. We also use higher order continuous-time autoregressive process with lag 3 for modeling the time evolution of the temperatures after removing trend and seasonality. Our model is fitted to 11 years of data recorded, in the period 1 January 2005 to 31 December 2015, Bahir Dar, Ethiopia, obtained from Ethiopia National Meteorological Services Agency. The analytical approximation formulas are used to price heating degree days(HDD) and cooling degree days(CDD) futures. The suggested model is analytically tractable for derivation of explicit prices for CDD and HDD futures and option. The price of the CDD future is calculated, using analytical approximation formulas. Numerical examples are presented to indicate the accuracy of the method. The results show that our model performs better to predict CDD indices.
基金Project supported by the National Natural Science Foundation of China(Nos.61673361 and 61422307)
文摘Identifying code has been widely used in man-machine verification to maintain network security.The challenge in engaging man-machine verification involves the correct classification of man and machine tracks.In this study,we propose a random forest(RF)model for man-machine verification based on the mouse movement trajectory dataset.We also compare the RF model with the baseline models(logistic regression and support vector machine)based on performance metrics such as precision,recall,false positive rates,false negative rates,F-measure,and weighted accuracy.The performance metrics of the RF model exceed those of the baseline models.
基金The work is supported by Zhejiang Provincial Natural Science Foundations(No.Y604359) National Natural Science Foundation of China (No.10371123,10471130).
文摘A computable expression of the asymptotic expansion of the return map for a degenerate singular point of a class of planar differential system is given, and hence the stability and the type of the singular point can be decided. These results generalize the corresponding results in [Nonlinearity, 13 (2000), p.709].
基金Supportedby the Science andTechnology Project of Fujian Province(No.2014Y0007)the Fujian Province Medical Innovation Foundation(No.2009-CXB-13)
文摘OBJECTIVE: To explore the relationship between Renying pulse (carotid) augmentation index (AI) and Cunkou pulse condition in different blood pres- sure groups, and the clinical significance of Reny- ing and Cunkou pulse parameters to reflect vascu- lar function. METHODS: Eighty-six patients with essential hyper- tension (EH) and 52 individuals with normal blood pressure (control group) between and January 2012 were included September 2010 this study. Reny- ing pulse AI was examined by a new diagnostic tool (ALOKA ProSound Alpha 10) --wave intensity (Wl) that is calculated as the product of the deriva- tives of the simultaneously recorded blood pres- sure changes (dP/dt) and blood-flow-velocity changes (dU/dt), while Cunkou pulse condition was detected by DDMX-100 Pulse Apparatus inboth EH and control groups. A multifactorial corre- lation analysis was performed for data analysis. RESULTS: After adjusting for potential confound- ing variables, in the EH group, AI was positively cor- related with ts, w2/t (rts=0.225, P〈0.05; rw2/t=0.230, P〈 0.05) and negatively correlated with hs, hs/hl and w2 (rhs=- 0.393,P〈0.01 ;rhs/l=- 0.444, P〈0.01 ;rw2=- 0.389, P〈0.01). In the control group, AI was positively cor- related with t3, t4, ts and w, (rt3=0.595, P〈0.01; r,4= 0.292, P〈0.05; rt5=0.318, P〈0.05; rw1=0.541, P〈0.01) and negatively correlated with h1, h2, h3, Ad and A (rh1= - 0.368, P〈0.05; rh2= - 0.330, P〈0.05; rh3= - 0.327, P〈 0.05; rAd=- 0.322, P〈0.05; rA=- 0.410, P〈0.01). In the total sample group (EH plus control group, n= 138), AI was positively correlated with t, ts, w1 and w, (rt=0.257, P〈0.01; rt5=0.266, P〈0.01; rw1=0.184, P〈 0.05; rw/t=0.210, P〈0.05) and negatively correlated with hs, hs/hl, w2 and Ad (rhs= - 0.230, P〈0.01; rh5/h1= - 0.218, P〈0.05; rw2= - 0.267, P〈0.01; rAd= - 0.246, P〈0.01). Multiple linear regression analysis was car- ried out to model the relationship (F=7.887, P〈 0.001).CONCLUSION: Renying pulse AI can effectively pre- dict arterial stiffness in synchrony with the manifes- tations of Cunkou pulse in elderly patients with hy- pertension. Cunkou pulse apparatus is a valuable tool for evaluating AI in clinical practice, The close correlations reported above reflect the holistic con- cept of Traditional Chinese Medicine.