To enhance the accuracy of 2πα and 2πβ particle surface emission rate measurements and address the identification issues of nuclides in conventional methods, this study introduces two artificial neural network(ANN...To enhance the accuracy of 2πα and 2πβ particle surface emission rate measurements and address the identification issues of nuclides in conventional methods, this study introduces two artificial neural network(ANN) algorithms: back-propagation(BP) and genetic algorithm-based back-propagation(GA-BP). These algorithms classify pulse signals from distinct α and β particles. Their discrimination efficacy is assessed by simulating standard pulse signals and those produced by contaminated sources, mixing α and β particles within the detector. This study initially showcases energy spectrum measurement outcomes, subsequently tests the ANNs on the measurement and validation datasets, and contrasts the pulse shape discrimination efficacy of both algorithms. Experimental findings reveal that the proportional counter's energy resolution is not ideal, thus rendering energy analysis insufficient for distinguishing between 2πα and 2πβ particles. The BP neural network realizes approximately 99% accuracy for 2πα particles and approximately 95% for 2πβ particles, thus surpassing the GA-BP's performance. Additionally, the results suggest enhancing β particle discrimination accuracy by increasing the digital acquisition card's threshold lower limit. This study offers an advanced solution for the 2πα and 2πβ surface emission rate measurement method, presenting superior adaptability and scalability over conventional techniques.展开更多
Using the Global Energy and Water Cycle Experiment-Asian Monsoon-Tibet Plateau Experiment (GAME-Tibet) observa-tional data-from October 2002 through September 2003-of Gaize in the western Qinghai-Xizang Plateau (QXP),...Using the Global Energy and Water Cycle Experiment-Asian Monsoon-Tibet Plateau Experiment (GAME-Tibet) observa-tional data-from October 2002 through September 2003-of Gaize in the western Qinghai-Xizang Plateau (QXP),the land-surface characteristics of the Qinghai-Xizang Plateau are simulated by the improved land-surface model Common Land Model (CoLM).The results show that CoLM can reproduce the land-surface characteristics of plateau areas well.In the sur-face-energy balance of the western QXP in the winter half year,the sensible heat (SH) flux constituted the dominant energy,and the latent heat (LH,here and after) flux is very small.Although the LH flux nearly equals zero in freezing season,it cannot be ig-nored during the period of freezing-thawing in QXP.In the transition season from midto late-May,the frequent phase change of soil water that is caused by the freezing-thawing process leads to the increase of LH flux and decrease of the Bowen ratio.The simulation results also indicate that the changes of surface effective heat fluxes (SH and LH flux) are associated with precipitation and the frequent change between freezing and thawing processes in soil surface.展开更多
With the help of several discriminants about the zero points of a quartic polynomial, the sufficient and necessary conditions for the positivity and nonnegativity of the quartic polynomial over an interval I(-∞,+...With the help of several discriminants about the zero points of a quartic polynomial, the sufficient and necessary conditions for the positivity and nonnegativity of the quartic polynomial over an interval I(-∞,+∞) was derived. Based on these conclusions, the sufficient and necessary conditions for the positivity and convexity of the 2×2 Bézier surface over a rectangle were obtained. A simple sufficient condition was deduced also and finally several examples were given.展开更多
In this study, the crust and upper mantle structure of Anatolia have been investigated by measuring the group velocity dispersion data of discriminated seismic surface waves. In the scope of the study, it has selected...In this study, the crust and upper mantle structure of Anatolia have been investigated by measuring the group velocity dispersion data of discriminated seismic surface waves. In the scope of the study, it has selected the profiles between six stations located in western Anatolia of Bogazici University Kandilli Observatory Earthquake Research Institute, national network of Turkey, and records of an earthquake (having about 10°epicentral distance) occurred in the eastern of Anatolia have been used. Firstly, surface wave discrimination filter based on the polarization properties has been applied tothree-component recordsand emphasized to surface waves. Then the group velocities have been calculated by multiple filter technique. A five-layered crustal model having total thickness of 38 - 40 km and Pn-wave velocity of 8.00 km/sec in the upper-mantle has been determined through inversion of surface wave group velocity dispersion data in the period range of 10 sec to 60 sec.展开更多
为提高液熏腊肉风味品质及生产效率,以液熏腊肉为研究对象,改进烟熏液的传统使用方式,探究烟熏液辅助腌制液熏腊肉的加工工艺。以烟熏液体积分数、烟熏液添加量、腌制时间和烘烤时间为单因素影响因子,感官评分为响应值,进行响应面优化分...为提高液熏腊肉风味品质及生产效率,以液熏腊肉为研究对象,改进烟熏液的传统使用方式,探究烟熏液辅助腌制液熏腊肉的加工工艺。以烟熏液体积分数、烟熏液添加量、腌制时间和烘烤时间为单因素影响因子,感官评分为响应值,进行响应面优化分析,与传统湘西腊肉品质进行对比,并采用偏最小二乘判别分析(partial least squares-discriminant analysis,PLS-DA)对液熏腊肉烘烤过程中滋味物质的变化进行综合评价。结果表明:液熏腊肉最佳工艺条件为烟熏液体积分数70%、烟熏液添加量2%(m/m)、腌制时间4d、烘烤时间8d;相比市售湘西腊肉,液熏腊肉具有较高水分含量和亮度值,且食盐和亚硝酸盐含量更低,分别为3.8%和1.20mg/kg;液熏腊肉感官评分为84.56±1.10;通过滋味活度值分析可得,肌苷酸、鸟苷酸(guanosine monophosphate,GMP)、丙氨酸、谷氨酸、赖氨酸、精氨酸、缬氨酸、组氨酸及腺苷酸是液熏腊肉的主要滋味物质;PLS-DA表明,不同烘烤时间下液熏腊肉滋味物质含量存在差异,瓜氨酸、色氨酸、半胱氨酸、次黄嘌呤、GMP、谷氨酰胺、甘氨酸、异亮氨酸及亮氨酸是影响不同烘烤时间液熏腊肉滋味差异的关键指标。展开更多
文摘To enhance the accuracy of 2πα and 2πβ particle surface emission rate measurements and address the identification issues of nuclides in conventional methods, this study introduces two artificial neural network(ANN) algorithms: back-propagation(BP) and genetic algorithm-based back-propagation(GA-BP). These algorithms classify pulse signals from distinct α and β particles. Their discrimination efficacy is assessed by simulating standard pulse signals and those produced by contaminated sources, mixing α and β particles within the detector. This study initially showcases energy spectrum measurement outcomes, subsequently tests the ANNs on the measurement and validation datasets, and contrasts the pulse shape discrimination efficacy of both algorithms. Experimental findings reveal that the proportional counter's energy resolution is not ideal, thus rendering energy analysis insufficient for distinguishing between 2πα and 2πβ particles. The BP neural network realizes approximately 99% accuracy for 2πα particles and approximately 95% for 2πβ particles, thus surpassing the GA-BP's performance. Additionally, the results suggest enhancing β particle discrimination accuracy by increasing the digital acquisition card's threshold lower limit. This study offers an advanced solution for the 2πα and 2πβ surface emission rate measurement method, presenting superior adaptability and scalability over conventional techniques.
基金supported by the China National Science Foundation (NSFC) (NO.40875050,40575037)the National Basic Research Program "973" (2007CB411506)
文摘Using the Global Energy and Water Cycle Experiment-Asian Monsoon-Tibet Plateau Experiment (GAME-Tibet) observa-tional data-from October 2002 through September 2003-of Gaize in the western Qinghai-Xizang Plateau (QXP),the land-surface characteristics of the Qinghai-Xizang Plateau are simulated by the improved land-surface model Common Land Model (CoLM).The results show that CoLM can reproduce the land-surface characteristics of plateau areas well.In the sur-face-energy balance of the western QXP in the winter half year,the sensible heat (SH) flux constituted the dominant energy,and the latent heat (LH,here and after) flux is very small.Although the LH flux nearly equals zero in freezing season,it cannot be ig-nored during the period of freezing-thawing in QXP.In the transition season from midto late-May,the frequent phase change of soil water that is caused by the freezing-thawing process leads to the increase of LH flux and decrease of the Bowen ratio.The simulation results also indicate that the changes of surface effective heat fluxes (SH and LH flux) are associated with precipitation and the frequent change between freezing and thawing processes in soil surface.
文摘With the help of several discriminants about the zero points of a quartic polynomial, the sufficient and necessary conditions for the positivity and nonnegativity of the quartic polynomial over an interval I(-∞,+∞) was derived. Based on these conclusions, the sufficient and necessary conditions for the positivity and convexity of the 2×2 Bézier surface over a rectangle were obtained. A simple sufficient condition was deduced also and finally several examples were given.
文摘In this study, the crust and upper mantle structure of Anatolia have been investigated by measuring the group velocity dispersion data of discriminated seismic surface waves. In the scope of the study, it has selected the profiles between six stations located in western Anatolia of Bogazici University Kandilli Observatory Earthquake Research Institute, national network of Turkey, and records of an earthquake (having about 10°epicentral distance) occurred in the eastern of Anatolia have been used. Firstly, surface wave discrimination filter based on the polarization properties has been applied tothree-component recordsand emphasized to surface waves. Then the group velocities have been calculated by multiple filter technique. A five-layered crustal model having total thickness of 38 - 40 km and Pn-wave velocity of 8.00 km/sec in the upper-mantle has been determined through inversion of surface wave group velocity dispersion data in the period range of 10 sec to 60 sec.
文摘为提高液熏腊肉风味品质及生产效率,以液熏腊肉为研究对象,改进烟熏液的传统使用方式,探究烟熏液辅助腌制液熏腊肉的加工工艺。以烟熏液体积分数、烟熏液添加量、腌制时间和烘烤时间为单因素影响因子,感官评分为响应值,进行响应面优化分析,与传统湘西腊肉品质进行对比,并采用偏最小二乘判别分析(partial least squares-discriminant analysis,PLS-DA)对液熏腊肉烘烤过程中滋味物质的变化进行综合评价。结果表明:液熏腊肉最佳工艺条件为烟熏液体积分数70%、烟熏液添加量2%(m/m)、腌制时间4d、烘烤时间8d;相比市售湘西腊肉,液熏腊肉具有较高水分含量和亮度值,且食盐和亚硝酸盐含量更低,分别为3.8%和1.20mg/kg;液熏腊肉感官评分为84.56±1.10;通过滋味活度值分析可得,肌苷酸、鸟苷酸(guanosine monophosphate,GMP)、丙氨酸、谷氨酸、赖氨酸、精氨酸、缬氨酸、组氨酸及腺苷酸是液熏腊肉的主要滋味物质;PLS-DA表明,不同烘烤时间下液熏腊肉滋味物质含量存在差异,瓜氨酸、色氨酸、半胱氨酸、次黄嘌呤、GMP、谷氨酰胺、甘氨酸、异亮氨酸及亮氨酸是影响不同烘烤时间液熏腊肉滋味差异的关键指标。
