The assertion that a climate crisis is rapidly approaching due to excess carbon dioxide (CO2) in the atmosphere is said to be based on science. This science is summarized in the statements of the major scientific soci...The assertion that a climate crisis is rapidly approaching due to excess carbon dioxide (CO2) in the atmosphere is said to be based on science. This science is summarized in the statements of the major scientific societies. These statements, have motivated, governments, the media, and much of the public to commit to abandoning fossil, i.e. going to “net zero” at some time in the not-so-distant future, perhaps by 2050, 26 years from now. The claims of these scientific societies clearly have a profound impact on the government, the media and the public, and therefore the scientific basis for these claims needs to be frequently and rigorously reexamined by the societies, and scrutinized by the public. This paper illustrates some serious concerns regarding the claims of these societies. It is not difficult to question these claims by comparing them with actual data from well-established organizations such as NOAA and NASA. Furthermore, the claims seem to go against such well-established scientific laws as the Stefan Boltzman radiation law, and le Chatelier’s principle. If the statements of the societies overstate the danger, or are even incorrect, they may be motivating the United States, the western world, or even the whole world to make an enormously expensive and unnecessary transition to an energy infrastructure that is more expensive, less reliable, and more environmentally damaging than the one we have today. This article suggests that these scientific societies reexamine their climate statements with the goal of making them more moderate and more scientifically correct.展开更多
This article mainly investigates the fuzzy optimization robust control issue for nonlinear networked systems characterized by the interval type-2(IT2)fuzzy technique under a differential evolution algorithm.To provide...This article mainly investigates the fuzzy optimization robust control issue for nonlinear networked systems characterized by the interval type-2(IT2)fuzzy technique under a differential evolution algorithm.To provide a more reasonable utilization of the constrained communication channel,a novel adaptive memory event-triggered(AMET)mechanism is developed,where two event-triggered thresholds can be dynamically adjusted in the light of the current system information and the transmitted historical data.Sufficient conditions with less conservative design of the fuzzy imperfect premise matching(IPM)controller are presented by introducing the Wirtinger-based integral inequality,the information of membership functions(MFs)and slack matrices.Subsequently,under the IPM policy,a new MFs intelligent optimization technique that takes advantage of the differential evolution algorithm is first provided for IT2 TakagiSugeno(T-S)fuzzy systems to update the fuzzy controller MFs in real-time and achieve a better system control effect.Finally,simulation results demonstrate that the proposed control scheme can obtain better system performance in the case of using fewer communication resources.展开更多
Layered backfill is commonly used in mining operations,and its mechanical behavior is strongly influenced by delamination parameters.In this study,13 specimens with different numbers of delamination and delamination a...Layered backfill is commonly used in mining operations,and its mechanical behavior is strongly influenced by delamination parameters.In this study,13 specimens with different numbers of delamination and delamination angle were prepared to investigate the anisotropic mechanical behavior,energy dissipation characteristics and crack development of backfill.P-wave velocity,uniaxial compression,scanning electron microscope(SEM),and acoustic emission(AE)experiments were conducted.The results indicate that:(1)The P-wave velocity has linear and elliptical relationships with the number of delamination surface and delamination angle,respectively;the strength,delamination parameters and P-wave velocity show a high degree of coincidence in terms of their function relationship,which can realize the rapid prediction of strength.(2)The microstructure of the delaminated surface is looser than that of the matrix,leading to a decrease in strength and an increase at the pore-fissure compaction stage.The number and angle of delamination increase linearly with the anisotropy coefficient.(3)The energy evolution in angle-cut backfill can be divided into four stages,with a decrease in the proportion of elastic energy at the initiation stress and peak stress with increasing number of delamination planes and delamination angle.(4)Crack development increases with the number of delamination surface and delamination angle,resulting in a decrease in energy dissipation coefficient and peak AE energy.These findings provide valuable insights for the design of filling materials and processes in mining operations.展开更多
Reaction of copper powder, dibenzoyl peroxide and 2-amino-4methyl-5-ethoxycarbonyl thiazole (amet) by refluxing in acetone yielded the dinuclearcopper(Ⅱ) complex Cu2 (μ-PhCOO)4 (amet)2- 2CH3COCH3. Crystal structure ...Reaction of copper powder, dibenzoyl peroxide and 2-amino-4methyl-5-ethoxycarbonyl thiazole (amet) by refluxing in acetone yielded the dinuclearcopper(Ⅱ) complex Cu2 (μ-PhCOO)4 (amet)2- 2CH3COCH3. Crystal structure determination showed that each copper atom is coordinated by four bridged benzoxy and oneamet molecule with an M-M bond (Cu-Cu (A) = 2.6899 (7 ) ), therefore the coor-dination environment around the copper center is a distorted square pyramid with N(1)at the apical position. Blocks of Cu2 (μ-PhCOO)4 (amet)2·2CH3COCH3 crystallize inthe triclinic space group Ph, with Mr= 1100.14, a= 9. 631 (1), b=10. 446 (2), c=12. 758(2) ; a=91. 31 (1), β=95. 50(1),γ= 94. 87(1)°, V=1272. 4(3), Z=1, Dc= 1. 436 g/cm3, F(000) = 570, μ=0. 986 mm-1 and R=0.033, Rw=0.049.The IR spectra, which are of great interest since the molecule has ketone, ester andcarboxylate group simultaneously, are also discussed.展开更多
文摘The assertion that a climate crisis is rapidly approaching due to excess carbon dioxide (CO2) in the atmosphere is said to be based on science. This science is summarized in the statements of the major scientific societies. These statements, have motivated, governments, the media, and much of the public to commit to abandoning fossil, i.e. going to “net zero” at some time in the not-so-distant future, perhaps by 2050, 26 years from now. The claims of these scientific societies clearly have a profound impact on the government, the media and the public, and therefore the scientific basis for these claims needs to be frequently and rigorously reexamined by the societies, and scrutinized by the public. This paper illustrates some serious concerns regarding the claims of these societies. It is not difficult to question these claims by comparing them with actual data from well-established organizations such as NOAA and NASA. Furthermore, the claims seem to go against such well-established scientific laws as the Stefan Boltzman radiation law, and le Chatelier’s principle. If the statements of the societies overstate the danger, or are even incorrect, they may be motivating the United States, the western world, or even the whole world to make an enormously expensive and unnecessary transition to an energy infrastructure that is more expensive, less reliable, and more environmentally damaging than the one we have today. This article suggests that these scientific societies reexamine their climate statements with the goal of making them more moderate and more scientifically correct.
基金supported by the National Natural Science Foundation of China(61973105,62373137)。
文摘This article mainly investigates the fuzzy optimization robust control issue for nonlinear networked systems characterized by the interval type-2(IT2)fuzzy technique under a differential evolution algorithm.To provide a more reasonable utilization of the constrained communication channel,a novel adaptive memory event-triggered(AMET)mechanism is developed,where two event-triggered thresholds can be dynamically adjusted in the light of the current system information and the transmitted historical data.Sufficient conditions with less conservative design of the fuzzy imperfect premise matching(IPM)controller are presented by introducing the Wirtinger-based integral inequality,the information of membership functions(MFs)and slack matrices.Subsequently,under the IPM policy,a new MFs intelligent optimization technique that takes advantage of the differential evolution algorithm is first provided for IT2 TakagiSugeno(T-S)fuzzy systems to update the fuzzy controller MFs in real-time and achieve a better system control effect.Finally,simulation results demonstrate that the proposed control scheme can obtain better system performance in the case of using fewer communication resources.
文摘Layered backfill is commonly used in mining operations,and its mechanical behavior is strongly influenced by delamination parameters.In this study,13 specimens with different numbers of delamination and delamination angle were prepared to investigate the anisotropic mechanical behavior,energy dissipation characteristics and crack development of backfill.P-wave velocity,uniaxial compression,scanning electron microscope(SEM),and acoustic emission(AE)experiments were conducted.The results indicate that:(1)The P-wave velocity has linear and elliptical relationships with the number of delamination surface and delamination angle,respectively;the strength,delamination parameters and P-wave velocity show a high degree of coincidence in terms of their function relationship,which can realize the rapid prediction of strength.(2)The microstructure of the delaminated surface is looser than that of the matrix,leading to a decrease in strength and an increase at the pore-fissure compaction stage.The number and angle of delamination increase linearly with the anisotropy coefficient.(3)The energy evolution in angle-cut backfill can be divided into four stages,with a decrease in the proportion of elastic energy at the initiation stress and peak stress with increasing number of delamination planes and delamination angle.(4)Crack development increases with the number of delamination surface and delamination angle,resulting in a decrease in energy dissipation coefficient and peak AE energy.These findings provide valuable insights for the design of filling materials and processes in mining operations.
文摘Reaction of copper powder, dibenzoyl peroxide and 2-amino-4methyl-5-ethoxycarbonyl thiazole (amet) by refluxing in acetone yielded the dinuclearcopper(Ⅱ) complex Cu2 (μ-PhCOO)4 (amet)2- 2CH3COCH3. Crystal structure determination showed that each copper atom is coordinated by four bridged benzoxy and oneamet molecule with an M-M bond (Cu-Cu (A) = 2.6899 (7 ) ), therefore the coor-dination environment around the copper center is a distorted square pyramid with N(1)at the apical position. Blocks of Cu2 (μ-PhCOO)4 (amet)2·2CH3COCH3 crystallize inthe triclinic space group Ph, with Mr= 1100.14, a= 9. 631 (1), b=10. 446 (2), c=12. 758(2) ; a=91. 31 (1), β=95. 50(1),γ= 94. 87(1)°, V=1272. 4(3), Z=1, Dc= 1. 436 g/cm3, F(000) = 570, μ=0. 986 mm-1 and R=0.033, Rw=0.049.The IR spectra, which are of great interest since the molecule has ketone, ester andcarboxylate group simultaneously, are also discussed.
