利用Arnol'd的Legendrian理论,对三维Anti de Sitter空间中Lorentzian曲面进行了研究.引入光维高度函数概念研究了三维Anti de Sitter空间Lorentzian曲面的S1t×S1s-值、光锥Gauss映射的奇点,进行了奇点分类,揭示了类光Causs-kr...利用Arnol'd的Legendrian理论,对三维Anti de Sitter空间中Lorentzian曲面进行了研究.引入光维高度函数概念研究了三维Anti de Sitter空间Lorentzian曲面的S1t×S1s-值、光锥Gauss映射的奇点,进行了奇点分类,揭示了类光Causs-kronecker曲率之间的关系;并研究了Lorentzian曲面的一些基本几何性质.展开更多
In this study, fresh pork tenderness, drip-loss, pH value and color parameters （ CIE, a ＊ , b ＊ and L ＊ values） were simultaneously predicted using hyperspectral scattering imaging （HSI） technique. The hyperspe...In this study, fresh pork tenderness, drip-loss, pH value and color parameters （ CIE, a ＊ , b ＊ and L ＊ values） were simultaneously predicted using hyperspectral scattering imaging （HSI） technique. The hyperspectral scattering images of dO fresh pork samples were collected at the wavelength of 400 -I 100 nm, and the scattering profiles were fitted via Lorontzian distribution （ LD ） function to give three parameters a （ asymptotic value ）, b （peak value ） and c （ full width at b/2）. Stepwise discrimination was performed to determine the optimal wavelengths combinations. The LD parameters combinations （a, b and c） of optimal wavelengths were used to establish multi-linear regression （MLR） models to predict the pork attributes. The models were able to predict pork with high correlation coefficients of 0.92 for drip-loss, 0.94, 0.92 and 0.98 respectively for color parameters （ a ＊ , b＊ and L ＊ ）, and for tenderness and pH value the models gave the correlation coefficients of 0.69 and 0.76, respectively. These results showed that the hyperspectral scattering technique was capable of predicting quality parameters of perk. The study provides an efficient means for rapid and nondestructive determination of pork quality simultaneously.展开更多
This study aimed to investigate the capabilities of hyperspectral scattering imaging in tandem with Gaussian function,Exponential function and Lorentzian function for rapid and nondestructive determination of total vi...This study aimed to investigate the capabilities of hyperspectral scattering imaging in tandem with Gaussian function,Exponential function and Lorentzian function for rapid and nondestructive determination of total viable count(TVC)in pork meat.Two batches of fresh pork meat was purchased from a local market and stored at 10°C for 1-9 d.Totally 60 samples were used,and several samples were taken out randomly for hyperspectral scattering imaging and conventional microbiological tests on each day of the experiments.The functions of Gaussian,Exponential and Lorentzian were employed to model the hyperspectral scattering profiles of pork meat,and good fitting results were obtained by all three functions between 455 nm and 1000 nm.The Lorentzian function performed best for fitting the hyperspectral scattering profiles of pork meat compared with other functions.Both principal component regression(PCR)and partial least squares regression(PLSR)methods were performed to establish the prediction models.Among all the developed models,the models developed using parameters CE(scattering width parameter of Exponential function)and CL(scattering width parameter of Lorentzian function)by PLSR method gave superior results for predicting pork meat TVC,with RV and RMSEV of 0.92,0.59 log CFU/g,and 0.91,0.61 log CFU/g,respectively.In addition,based on the improved hyperspectral scattering system,parameter c which represented the scattering widths in all three functions gave more accurate prediction results,regardless of the modeling methods(PCR or PLSR).The obtained results demonstrated that hyperspectral scattering imaging combined with the presented data analysis algorithm can be a powerful tool for evaluating the microbial safety of meat in the future.展开更多
In this paper, we present a micro-displacement sensor formed by the fixed and movable photonic crystal slabs. In this sensor, a waveguide was created by changing the radius of holes rather than removing them. At a pro...In this paper, we present a micro-displacement sensor formed by the fixed and movable photonic crystal slabs. In this sensor, a waveguide was created by changing the radius of holes rather than removing them. At a proper operating wavelength, the structure could be used as the micro-displacement sensor. The results revealed that the micro-displacement sensor had a sensitivity of 3.6 gm-1, the Q-factor was nearly 180, and the sensing range was 0.0 ~tm - 0.5 p.m. The properties of the micro-displacement sensor are also analyzed theoretically and verified using the finite-difference time-domain （FDTD） method carried out using the software （Rsoft）.展开更多
Anti de Sitter space is a maximally symmetric, vacuum solution of Einstein's field equation with an attractive cosmological constant, and is the hyperquadric of semi-Euclidean space with index 2. So it is meaningf...Anti de Sitter space is a maximally symmetric, vacuum solution of Einstein's field equation with an attractive cosmological constant, and is the hyperquadric of semi-Euclidean space with index 2. So it is meaningful to study the submanifold in semi-Euclidean 4-space with index 2. However, the research on the submanifold in semi-Euclidean 4-space with index 2 has not been found from theory of singularity until now. In this paper, as a generalization of the study on lightlike hypersurface in Minkowski space and a preparation for the further study on anti de Sitter space, the singularities of lightlike hypersurface and Lorentzian surface in semi- Euclidean 4-space with index 2 will be studied. To do this, we reveal the relationships between the singularity of distance-squared function and that of lightlike hypersurface. In addition some geometric properties of lightlike hypersurface and Lorentzian surface are studied from geometrical point of view.展开更多
文摘利用Arnol'd的Legendrian理论,对三维Anti de Sitter空间中Lorentzian曲面进行了研究.引入光维高度函数概念研究了三维Anti de Sitter空间Lorentzian曲面的S1t×S1s-值、光锥Gauss映射的奇点,进行了奇点分类,揭示了类光Causs-kronecker曲率之间的关系;并研究了Lorentzian曲面的一些基本几何性质.
基金Supported by Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi Province(2013123)
文摘In this study, fresh pork tenderness, drip-loss, pH value and color parameters （ CIE, a ＊ , b ＊ and L ＊ values） were simultaneously predicted using hyperspectral scattering imaging （HSI） technique. The hyperspectral scattering images of dO fresh pork samples were collected at the wavelength of 400 -I 100 nm, and the scattering profiles were fitted via Lorontzian distribution （ LD ） function to give three parameters a （ asymptotic value ）, b （peak value ） and c （ full width at b/2）. Stepwise discrimination was performed to determine the optimal wavelengths combinations. The LD parameters combinations （a, b and c） of optimal wavelengths were used to establish multi-linear regression （MLR） models to predict the pork attributes. The models were able to predict pork with high correlation coefficients of 0.92 for drip-loss, 0.94, 0.92 and 0.98 respectively for color parameters （ a ＊ , b＊ and L ＊ ）, and for tenderness and pH value the models gave the correlation coefficients of 0.69 and 0.76, respectively. These results showed that the hyperspectral scattering technique was capable of predicting quality parameters of perk. The study provides an efficient means for rapid and nondestructive determination of pork quality simultaneously.
基金The authors gratefully acknowledge the China Postdoctoral Science Foundation(Project No.2014M561096)the Special Fund for Agro-scientific Research in the Public Interest Program(Project No.201003008)the National Science and Technology Support Program(Project No.2012BAH04B00)for supporting this research.
文摘This study aimed to investigate the capabilities of hyperspectral scattering imaging in tandem with Gaussian function,Exponential function and Lorentzian function for rapid and nondestructive determination of total viable count(TVC)in pork meat.Two batches of fresh pork meat was purchased from a local market and stored at 10°C for 1-9 d.Totally 60 samples were used,and several samples were taken out randomly for hyperspectral scattering imaging and conventional microbiological tests on each day of the experiments.The functions of Gaussian,Exponential and Lorentzian were employed to model the hyperspectral scattering profiles of pork meat,and good fitting results were obtained by all three functions between 455 nm and 1000 nm.The Lorentzian function performed best for fitting the hyperspectral scattering profiles of pork meat compared with other functions.Both principal component regression(PCR)and partial least squares regression(PLSR)methods were performed to establish the prediction models.Among all the developed models,the models developed using parameters CE(scattering width parameter of Exponential function)and CL(scattering width parameter of Lorentzian function)by PLSR method gave superior results for predicting pork meat TVC,with RV and RMSEV of 0.92,0.59 log CFU/g,and 0.91,0.61 log CFU/g,respectively.In addition,based on the improved hyperspectral scattering system,parameter c which represented the scattering widths in all three functions gave more accurate prediction results,regardless of the modeling methods(PCR or PLSR).The obtained results demonstrated that hyperspectral scattering imaging combined with the presented data analysis algorithm can be a powerful tool for evaluating the microbial safety of meat in the future.
文摘In this paper, we present a micro-displacement sensor formed by the fixed and movable photonic crystal slabs. In this sensor, a waveguide was created by changing the radius of holes rather than removing them. At a proper operating wavelength, the structure could be used as the micro-displacement sensor. The results revealed that the micro-displacement sensor had a sensitivity of 3.6 gm-1, the Q-factor was nearly 180, and the sensing range was 0.0 ~tm - 0.5 p.m. The properties of the micro-displacement sensor are also analyzed theoretically and verified using the finite-difference time-domain （FDTD） method carried out using the software （Rsoft）.
基金supported by National Natural Science Foundation of China (Grant No.10871035)the New Century Excellent Talents in University of China (Grant No. 05-0319)
文摘Anti de Sitter space is a maximally symmetric, vacuum solution of Einstein's field equation with an attractive cosmological constant, and is the hyperquadric of semi-Euclidean space with index 2. So it is meaningful to study the submanifold in semi-Euclidean 4-space with index 2. However, the research on the submanifold in semi-Euclidean 4-space with index 2 has not been found from theory of singularity until now. In this paper, as a generalization of the study on lightlike hypersurface in Minkowski space and a preparation for the further study on anti de Sitter space, the singularities of lightlike hypersurface and Lorentzian surface in semi- Euclidean 4-space with index 2 will be studied. To do this, we reveal the relationships between the singularity of distance-squared function and that of lightlike hypersurface. In addition some geometric properties of lightlike hypersurface and Lorentzian surface are studied from geometrical point of view.
