The deformation in sedimentary rock induced by train loads has potential threat to the safe operation of tunnels. This study investigated the influence of stratification structure on the infrared radiation and tempora...The deformation in sedimentary rock induced by train loads has potential threat to the safe operation of tunnels. This study investigated the influence of stratification structure on the infrared radiation and temporal damage mechanism of hard siltstone. The uniaxial compression tests, coupled with acoustic emission(AE) and infrared radiation temperature(IRT) were conducted on siltstones with different stratification effects. The results revealed that the stratigraphic structure significantly affects the stress-strain response and strength degradation characteristics. The mechanical parameters exhibit anisotropy characteristics, and the stratification effect exhibits a negative correlation with the cracking stress and peak stress. The failure modes caused by the stratification effect show remarkable anisotropic features, including splitting failure(Ⅰ: 0°-22.50°, Ⅱ: 90°), composite failure(45°), and shearing failure(67.50°). The AE temporal sequences demonstrate a stepwise response characteristic to the loading stress level. The AE intensity indicates that the stress sensitivity of shearing failure and composite failure is generally greater than that of splitting failure. The IRT field has spatiotemporal migration and progressive dissimilation with stress loading and its dissimilation degree increases under higher stress levels. The stronger the stratification effect, the greater the dissimilation degree of the IRT field. The abnormal characteristic points of average infrared radiation temperature(AIRT) variance at local stress drop and peak stress can be used as early and late precursors to identify fracture instability. Theoretical analysis shows that the competitive relationship between compaction strengthening and fracturing damage intensifies the dissimilation of the infrared thermal field for an increasing stress level. The present study provides a theoretical reference for disaster warnings in hard sedimentary rock mass.展开更多
An iterative optimization strategy is proposed and applied to the steady state optimizing control of the bio-dissimilation process of glycerol to 1,3-propanediol in the presence of model-plant mismatch and input con- ...An iterative optimization strategy is proposed and applied to the steady state optimizing control of the bio-dissimilation process of glycerol to 1,3-propanediol in the presence of model-plant mismatch and input con- straints. The scheme is based on the Augmented Integrated System Optimization and Parameter Estimation (AI- SOPE) technique, but a linearization of some performance function in the modified model-based optimization problem of AISOPE is introduced to overcome the difficulty of determining an appropriate penalty parameter. When carrying out the iterative optimization, the penalty coefficient is set to a larger value at the current iteration than at the previous iteration, which can promote the evolution rate of the iterative optimization. Simulation studies illustrate the potential of the approach presented for the optimizing control of the bio-dissimilation process of glyc- erol to 1,3-propanediol. The effects of measurement noise, measured and unmeasured disturbances on the proposed algorithm are also investigated.展开更多
The cognition and attitudes of resources environment affect environmental behavior of behavior subject,the changes of attitude and behavior become one of the key factors of influencing harmonious and healthy developme...The cognition and attitudes of resources environment affect environmental behavior of behavior subject,the changes of attitude and behavior become one of the key factors of influencing harmonious and healthy development of ecological environment. With PRA survey method for obtaining questionnaire data and based on behavior geography and social psychology theory,farming-pastoral,dry grassland,desert grassland, typical project village alpine grassland of returning fazing land to grasslands as an example,with main body cognitive perspective of the aid of resources,the article analyzed space dissimilation of stakeholders environmental cognitive and behavior preference response in the area of returning grazing land to grasslands from ecological environment from policy environment,ecological environment and family economic environment aspects. The results showed that： stakeholders judgment of Grassland degradation in different ecological function area had obvious regularity,the cognitive proportion of Grassland degradation gradually increase from farming-pastora to alpine savanes. The satisfaction from returning grazing land to grasslands showed a changing tendency of reversed U. stakeholders had more strongly negative cognition in the area of dry steppe and desertsteppe. From farming-pastoral to alpine savanes,the economic environment tend to worse situation. Negative environmental behaviors tend to increase,Positive behavior on the contrary.展开更多
基金National Natural Science Foundation of China(No.52178393)2023 High-level Talent Research Project from Yancheng Institute of Technology(No.xjr2023019)+1 种基金Open Fund Project of Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering(Grant No.YT202302)Science and Technology Innovation Team of Shaanxi Innovation Capability Support Plan(No.2020TD005).
文摘The deformation in sedimentary rock induced by train loads has potential threat to the safe operation of tunnels. This study investigated the influence of stratification structure on the infrared radiation and temporal damage mechanism of hard siltstone. The uniaxial compression tests, coupled with acoustic emission(AE) and infrared radiation temperature(IRT) were conducted on siltstones with different stratification effects. The results revealed that the stratigraphic structure significantly affects the stress-strain response and strength degradation characteristics. The mechanical parameters exhibit anisotropy characteristics, and the stratification effect exhibits a negative correlation with the cracking stress and peak stress. The failure modes caused by the stratification effect show remarkable anisotropic features, including splitting failure(Ⅰ: 0°-22.50°, Ⅱ: 90°), composite failure(45°), and shearing failure(67.50°). The AE temporal sequences demonstrate a stepwise response characteristic to the loading stress level. The AE intensity indicates that the stress sensitivity of shearing failure and composite failure is generally greater than that of splitting failure. The IRT field has spatiotemporal migration and progressive dissimilation with stress loading and its dissimilation degree increases under higher stress levels. The stronger the stratification effect, the greater the dissimilation degree of the IRT field. The abnormal characteristic points of average infrared radiation temperature(AIRT) variance at local stress drop and peak stress can be used as early and late precursors to identify fracture instability. Theoretical analysis shows that the competitive relationship between compaction strengthening and fracturing damage intensifies the dissimilation of the infrared thermal field for an increasing stress level. The present study provides a theoretical reference for disaster warnings in hard sedimentary rock mass.
基金the State Science and Technology Project of China (No.2001BA204B01).
文摘An iterative optimization strategy is proposed and applied to the steady state optimizing control of the bio-dissimilation process of glycerol to 1,3-propanediol in the presence of model-plant mismatch and input con- straints. The scheme is based on the Augmented Integrated System Optimization and Parameter Estimation (AI- SOPE) technique, but a linearization of some performance function in the modified model-based optimization problem of AISOPE is introduced to overcome the difficulty of determining an appropriate penalty parameter. When carrying out the iterative optimization, the penalty coefficient is set to a larger value at the current iteration than at the previous iteration, which can promote the evolution rate of the iterative optimization. Simulation studies illustrate the potential of the approach presented for the optimizing control of the bio-dissimilation process of glyc- erol to 1,3-propanediol. The effects of measurement noise, measured and unmeasured disturbances on the proposed algorithm are also investigated.
基金Supported by the National Natural Science Fund(40971039)Gansu Province Science and Technology Support Program(1011FKCA157)the Fundamental Research Funds Project of Colleges and Universities in Gansu Province
文摘The cognition and attitudes of resources environment affect environmental behavior of behavior subject,the changes of attitude and behavior become one of the key factors of influencing harmonious and healthy development of ecological environment. With PRA survey method for obtaining questionnaire data and based on behavior geography and social psychology theory,farming-pastoral,dry grassland,desert grassland, typical project village alpine grassland of returning fazing land to grasslands as an example,with main body cognitive perspective of the aid of resources,the article analyzed space dissimilation of stakeholders environmental cognitive and behavior preference response in the area of returning grazing land to grasslands from ecological environment from policy environment,ecological environment and family economic environment aspects. The results showed that： stakeholders judgment of Grassland degradation in different ecological function area had obvious regularity,the cognitive proportion of Grassland degradation gradually increase from farming-pastora to alpine savanes. The satisfaction from returning grazing land to grasslands showed a changing tendency of reversed U. stakeholders had more strongly negative cognition in the area of dry steppe and desertsteppe. From farming-pastoral to alpine savanes,the economic environment tend to worse situation. Negative environmental behaviors tend to increase,Positive behavior on the contrary.
