The environmental characteristics of hypothermia and hypoxia exert great selective pressure on the energy metabolism of high-altitude animals,especially the ectotherms.Current research on energy-limited adaptation of ...The environmental characteristics of hypothermia and hypoxia exert great selective pressure on the energy metabolism of high-altitude animals,especially the ectotherms.Current research on energy-limited adaptation of high-altitude ectotherms has focused on energy expenditures.However,the mechanisms of increasing energy intake in high-altitude ectotherms have been studied rarely.In order to investigate the adaptation mechanism of the small intestine,the key part of energy acquisition for animals,to energy limitation at high altitude in ectotherms,the gut proteins of Phrynocephalus vlangalii from high-and low-altitude populations were compared using label free proteomics.GO enrichment and KEGG pathway analysis showed that proteins associated with energy intake,such as those involved in oxidation-reduction processes,glutathione metabolism,oxidoreductase activity,cofactor binding,catalytic activity and metabolic pathways,were significantly up-regulated in high-altitude populations;while proteins associated with energy expenditure,such as immune responses and processes,membrane attack complexes,natural killer pathway and other immune-related processes,were significantly down-regulated in expression.展开更多
Existing explanations for several major phenomena in physics may need to be reconsidered in light of the description of a natural force termed KELEA (kinetic energy limiting electrostatic attraction). Three examples a...Existing explanations for several major phenomena in physics may need to be reconsidered in light of the description of a natural force termed KELEA (kinetic energy limiting electrostatic attraction). Three examples are selected for discussion in this paper: i) The proposed wave-particle duality of electrons;ii) cold fusion;and iii) superconductivity. The current interpretations of these enigmatic concepts are incomplete and not fully validated by scientific methods. The observations underlying these processes are seemingly consistent with KELEA acting as a repelling force between opposite electrical charges. Relatively simple experiments can be designed to either confirm or exclude KELEA in these and in various other currently perplexing physical phenomena.展开更多
To further reveal the failure mechanisms of thick ultra-high molecular weight polyethylene(UHMWPE)laminates,field firing tests were conducted for 10-,20-,and 30-mm thick laminates against 12.7-mm calibre wedge-shaped ...To further reveal the failure mechanisms of thick ultra-high molecular weight polyethylene(UHMWPE)laminates,field firing tests were conducted for 10-,20-,and 30-mm thick laminates against 12.7-mm calibre wedge-shaped fragment simulated projectiles at high velocities between 450 and 1200 m/s.The ballistic performance,deformation process,and staged failure characteristics of the laminates with different thicknesses were compared and analysed.The results demonstrate that the ballistic limits of the UHMWPE laminates increase almost linearly with laminate thickness.The 10-mm thick laminate generally experiences two-stage failure characteristics,whereas three-staged failure occurs in the 20-and 30-mm thick laminates and the progressive delamination is evident.The energy limit concept representing the maximum energy absorption efficiency and the idea of reuse of the thick UHMWPE laminates are proposed in this study.The findings of this research will be useful in the design of flexible and effective UHMWPE-based protective equipment.展开更多
This research aims to integrate Bekenstein’s bound and Landauer’s principle, providing a unified framework to understand the limits of information and energy in physical systems. By combining these principles, we ex...This research aims to integrate Bekenstein’s bound and Landauer’s principle, providing a unified framework to understand the limits of information and energy in physical systems. By combining these principles, we explore the implications for black hole thermodynamics, astrophysics, astronomy, information theory, and the search for new laws of nature. The result includes an estimation of the number of bits stored in a black hole (less than 1.4 × 10<sup>30</sup> bits/m<sup>3</sup>), enhancing our understanding of information storage in extreme gravitational environments. This integration offers valuable insights into the fundamental nature of information and energy, impacting scientific advancements in multiple disciplines.展开更多
We have studied the aggregation of particles on a hetero-substrate consisting of two different substrates A and B with finite surface barriers EAB and EBA between the AB and BA boundaries, respectively. With the diffu...We have studied the aggregation of particles on a hetero-substrate consisting of two different substrates A and B with finite surface barriers EAB and EBA between the AB and BA boundaries, respectively. With the diffusion energy limited aggregation (DELA) model, we find that the number of clusters and the mean radius of gyration of the clusters are dependent on the surface barriers EAB and EBA. For the case with a constant of EBA, a series of minima are summarized as EAB : (E0 - kBAEBA)/kAB with kAB and kBA being two integers, for main minima (kBA = kAB = 1) and two local minima (kBA = kAB and kBA = kAB + 1) between two neighbouring main minima.展开更多
In this article, two relaxation time limits, namely, the momentum relaxation time limit and the energy relaxation time limit are considered. By the compactness argument, it is obtained that the smooth solutions of the...In this article, two relaxation time limits, namely, the momentum relaxation time limit and the energy relaxation time limit are considered. By the compactness argument, it is obtained that the smooth solutions of the multidimensional nonisentropic Euler-Poisson problem converge to the solutions of an energy transport model or a drift diffusion model, respectively, with respect to different time scales.展开更多
To ascertain the function of signals,we have to first uncover the reasons behind signal variation.There are several potential driving forces,including background noise,predation cost,receiver perception,and energy lim...To ascertain the function of signals,we have to first uncover the reasons behind signal variation.There are several potential driving forces,including background noise,predation cost,receiver perception,and energy limitations.The energy limitation hypothesis assumes that individuals trade off signal intensity and energy expenditure according to resource condition,while variation of signal intensity likely associates with food availability.This hypothesis has been evidenced by a great number of researches on vocal signals,but no studies evaluated the influence of food availability on motion visual signal in lizards.Here we used an Asian agamid lizard Phr ynocephalus vlangalii and examined the effect of food availability on tail display intensity.We designed two food restriction treatments as well as a nature control treatment,and quantified individual tail display speed and display duration under different food availability conditions.Consistent with our prediction,our results showed that males significantly reduced their average tail display speed and maximum display speed in both food restriction treatments when compared to nature control condition.Therefore,our study provides direct evidence that lizards would trade off their display intensity according to the food condition,suggesting tail display is energetically costly and likely provides honest information on individual body condition and resource hold potential.展开更多
Geomaterials are known to be non-associated materials. Granular soils therefore exhibit a variety of failure modes, with diffuse or localized kinematical patterns. In fact, the notion of failure itself can be confusin...Geomaterials are known to be non-associated materials. Granular soils therefore exhibit a variety of failure modes, with diffuse or localized kinematical patterns. In fact, the notion of failure itself can be confusing with regard to granular soils, because it is not associated with an obvious phenomenology. In this study, we built a proper framework, using the second-order work theory, to describe some failure modes in geomaterials based on energy conservation. The occurrence of failure is defined by an abrupt increase in kinetic energy. The increase in kinetic energy from an equilibrium state, under incremental loading, is shown to be equal to the difference between the external second-order work,involving the external loading parameters, and the internal second-order work, involving the constitutive properties of the material. When a stress limit state is reached, a certain stress component passes through a maximum value and then may decrease. Under such a condition, if a certain additional external loading is applied, the system fails, sharply increasing the strain rate. The internal stress is no longer able to balance the external stress, leading to a dynamic response of the specimen. As an illustration, the theoretical framework was applied to the well-known undrained triaxial test for loose soils. The influence of the loading control mode was clearly highlighted. It is shown that the plastic limit theory appears to be a particular case of this more general second-order work theory. When the plastic limit condition is met, the internal second-order work is nil. A class of incremental external loadings causes the kinetic energy to increase dramatically, leading to the sudden collapse of the specimen, as observed in laboratory.展开更多
In order to explore the effect of loading rate on physical and mechanical properties of dihydrate gypsum,cyclic loading and unloading mechanical tests were carried out at different loading rates.Test results were anal...In order to explore the effect of loading rate on physical and mechanical properties of dihydrate gypsum,cyclic loading and unloading mechanical tests were carried out at different loading rates.Test results were analyzed from the aspects of stress-strain curve,energy distribution mode,damage law and failure mode of specimen.The main research results obtained in the thesis are as follows:with the increase of the loading rate,the peak value of specimen damage first increases rapidly,and then in-creases slowly,and there is a damage threshold.In the early stage of loading,the dissipated energy of the specimen accounts for about 70%of the total energy,most of the total energy input is converted into dissipated energy.The elastic energy density shows an increasing trend with the increase of the loading rate.The elastic energy density is the highest when the loading rate is 400 N/s,and more elastic energy can be stored.The ratio of elastic energy ue/u increases with the in-crease of loading rate and tends to be stable.The acoustic emission data show that the acoustic emission signals present a certain agglomeration phenomenon at the unloading point,and there is a“blank period”between the unloading point and the emergence of the next acoustic emission activity.In the early stage of specimen loading,friction-type acoustic emission is mainly generated.The cumulative ringing count when the load reaches the peak failure stress at low loading rate is more,indicating that low loading rate will produce more acoustic emission activities.With the increase of loading rate,the cumulative ringing number per unit time increases,indicating that the increase of loading rate accelerates the damage and failure of dihydrate gypsum near the peak value.The failure mode of gypsum specimens is shear failure,and the increase of loading rate of shear failure angle shows an increasing trend.The larger the loading rate is,the higher the strength of the specimen is.The more energy the press inputs during the loading process,the higher the energy absorbed by the unit volume specimen,which aggravates the development,expansion and penetration of the internal cracks of the specimen,resulting in the larger shear angle of the specimen.The test results provide a more comprehensive theoretical basis for the study of damage characteristics of dihydrate gypsum during cyclic loading and unloading.展开更多
基金supported by the National Natural Science Foundation of China(Nos.31471988 and 31200287)。
文摘The environmental characteristics of hypothermia and hypoxia exert great selective pressure on the energy metabolism of high-altitude animals,especially the ectotherms.Current research on energy-limited adaptation of high-altitude ectotherms has focused on energy expenditures.However,the mechanisms of increasing energy intake in high-altitude ectotherms have been studied rarely.In order to investigate the adaptation mechanism of the small intestine,the key part of energy acquisition for animals,to energy limitation at high altitude in ectotherms,the gut proteins of Phrynocephalus vlangalii from high-and low-altitude populations were compared using label free proteomics.GO enrichment and KEGG pathway analysis showed that proteins associated with energy intake,such as those involved in oxidation-reduction processes,glutathione metabolism,oxidoreductase activity,cofactor binding,catalytic activity and metabolic pathways,were significantly up-regulated in high-altitude populations;while proteins associated with energy expenditure,such as immune responses and processes,membrane attack complexes,natural killer pathway and other immune-related processes,were significantly down-regulated in expression.
文摘Existing explanations for several major phenomena in physics may need to be reconsidered in light of the description of a natural force termed KELEA (kinetic energy limiting electrostatic attraction). Three examples are selected for discussion in this paper: i) The proposed wave-particle duality of electrons;ii) cold fusion;and iii) superconductivity. The current interpretations of these enigmatic concepts are incomplete and not fully validated by scientific methods. The observations underlying these processes are seemingly consistent with KELEA acting as a repelling force between opposite electrical charges. Relatively simple experiments can be designed to either confirm or exclude KELEA in these and in various other currently perplexing physical phenomena.
基金the financial support from National Natural Science Foundation of China(Grant No.51978166)National Key Research and Development Program of China(Grant No.2019YFC0706105,2021YFC3100703)the Fundamental Research Funds for the Central Universities(Grant No.2242022R10124s)。
文摘To further reveal the failure mechanisms of thick ultra-high molecular weight polyethylene(UHMWPE)laminates,field firing tests were conducted for 10-,20-,and 30-mm thick laminates against 12.7-mm calibre wedge-shaped fragment simulated projectiles at high velocities between 450 and 1200 m/s.The ballistic performance,deformation process,and staged failure characteristics of the laminates with different thicknesses were compared and analysed.The results demonstrate that the ballistic limits of the UHMWPE laminates increase almost linearly with laminate thickness.The 10-mm thick laminate generally experiences two-stage failure characteristics,whereas three-staged failure occurs in the 20-and 30-mm thick laminates and the progressive delamination is evident.The energy limit concept representing the maximum energy absorption efficiency and the idea of reuse of the thick UHMWPE laminates are proposed in this study.The findings of this research will be useful in the design of flexible and effective UHMWPE-based protective equipment.
文摘This research aims to integrate Bekenstein’s bound and Landauer’s principle, providing a unified framework to understand the limits of information and energy in physical systems. By combining these principles, we explore the implications for black hole thermodynamics, astrophysics, astronomy, information theory, and the search for new laws of nature. The result includes an estimation of the number of bits stored in a black hole (less than 1.4 × 10<sup>30</sup> bits/m<sup>3</sup>), enhancing our understanding of information storage in extreme gravitational environments. This integration offers valuable insights into the fundamental nature of information and energy, impacting scientific advancements in multiple disciplines.
基金supported by the Natural Science Foundation of Zhejiang province,China(Grant No Y607142)by the National Natural Science Foundation of China(Grant No 20771092)
文摘We have studied the aggregation of particles on a hetero-substrate consisting of two different substrates A and B with finite surface barriers EAB and EBA between the AB and BA boundaries, respectively. With the diffusion energy limited aggregation (DELA) model, we find that the number of clusters and the mean radius of gyration of the clusters are dependent on the surface barriers EAB and EBA. For the case with a constant of EBA, a series of minima are summarized as EAB : (E0 - kBAEBA)/kAB with kAB and kBA being two integers, for main minima (kBA = kAB = 1) and two local minima (kBA = kAB and kBA = kAB + 1) between two neighbouring main minima.
基金Supported by the Chinese Postdoctoral Science Foundation, the Young Scientists Funds of NSF of China (10401019)the Tsinghua Basic Research Foundation.
文摘In this article, two relaxation time limits, namely, the momentum relaxation time limit and the energy relaxation time limit are considered. By the compactness argument, it is obtained that the smooth solutions of the multidimensional nonisentropic Euler-Poisson problem converge to the solutions of an energy transport model or a drift diffusion model, respectively, with respect to different time scales.
基金supported by the biodiversity survey and assessment project of the ministry of ecology and environment,China(grant number 2019HJ2096001006)from the National Na tural Science Founda tion of China to Y.QI(grant number 31872233)。
文摘To ascertain the function of signals,we have to first uncover the reasons behind signal variation.There are several potential driving forces,including background noise,predation cost,receiver perception,and energy limitations.The energy limitation hypothesis assumes that individuals trade off signal intensity and energy expenditure according to resource condition,while variation of signal intensity likely associates with food availability.This hypothesis has been evidenced by a great number of researches on vocal signals,but no studies evaluated the influence of food availability on motion visual signal in lizards.Here we used an Asian agamid lizard Phr ynocephalus vlangalii and examined the effect of food availability on tail display intensity.We designed two food restriction treatments as well as a nature control treatment,and quantified individual tail display speed and display duration under different food availability conditions.Consistent with our prediction,our results showed that males significantly reduced their average tail display speed and maximum display speed in both food restriction treatments when compared to nature control condition.Therefore,our study provides direct evidence that lizards would trade off their display intensity according to the food condition,suggesting tail display is energetically costly and likely provides honest information on individual body condition and resource hold potential.
基金the French Research Network Me Ge (Multiscale and Multiphysics Couplings in Geo-environmental Mechanics GDR CNRS 3176/2340, 2008e2015) for having supported this work
文摘Geomaterials are known to be non-associated materials. Granular soils therefore exhibit a variety of failure modes, with diffuse or localized kinematical patterns. In fact, the notion of failure itself can be confusing with regard to granular soils, because it is not associated with an obvious phenomenology. In this study, we built a proper framework, using the second-order work theory, to describe some failure modes in geomaterials based on energy conservation. The occurrence of failure is defined by an abrupt increase in kinetic energy. The increase in kinetic energy from an equilibrium state, under incremental loading, is shown to be equal to the difference between the external second-order work,involving the external loading parameters, and the internal second-order work, involving the constitutive properties of the material. When a stress limit state is reached, a certain stress component passes through a maximum value and then may decrease. Under such a condition, if a certain additional external loading is applied, the system fails, sharply increasing the strain rate. The internal stress is no longer able to balance the external stress, leading to a dynamic response of the specimen. As an illustration, the theoretical framework was applied to the well-known undrained triaxial test for loose soils. The influence of the loading control mode was clearly highlighted. It is shown that the plastic limit theory appears to be a particular case of this more general second-order work theory. When the plastic limit condition is met, the internal second-order work is nil. A class of incremental external loadings causes the kinetic energy to increase dramatically, leading to the sudden collapse of the specimen, as observed in laboratory.
基金support from the National Natural Science Foundation of China,grant number 52174087.
文摘In order to explore the effect of loading rate on physical and mechanical properties of dihydrate gypsum,cyclic loading and unloading mechanical tests were carried out at different loading rates.Test results were analyzed from the aspects of stress-strain curve,energy distribution mode,damage law and failure mode of specimen.The main research results obtained in the thesis are as follows:with the increase of the loading rate,the peak value of specimen damage first increases rapidly,and then in-creases slowly,and there is a damage threshold.In the early stage of loading,the dissipated energy of the specimen accounts for about 70%of the total energy,most of the total energy input is converted into dissipated energy.The elastic energy density shows an increasing trend with the increase of the loading rate.The elastic energy density is the highest when the loading rate is 400 N/s,and more elastic energy can be stored.The ratio of elastic energy ue/u increases with the in-crease of loading rate and tends to be stable.The acoustic emission data show that the acoustic emission signals present a certain agglomeration phenomenon at the unloading point,and there is a“blank period”between the unloading point and the emergence of the next acoustic emission activity.In the early stage of specimen loading,friction-type acoustic emission is mainly generated.The cumulative ringing count when the load reaches the peak failure stress at low loading rate is more,indicating that low loading rate will produce more acoustic emission activities.With the increase of loading rate,the cumulative ringing number per unit time increases,indicating that the increase of loading rate accelerates the damage and failure of dihydrate gypsum near the peak value.The failure mode of gypsum specimens is shear failure,and the increase of loading rate of shear failure angle shows an increasing trend.The larger the loading rate is,the higher the strength of the specimen is.The more energy the press inputs during the loading process,the higher the energy absorbed by the unit volume specimen,which aggravates the development,expansion and penetration of the internal cracks of the specimen,resulting in the larger shear angle of the specimen.The test results provide a more comprehensive theoretical basis for the study of damage characteristics of dihydrate gypsum during cyclic loading and unloading.