Biological invasions are a major driver of global biodiversity loss,impacting endemic species,ecosystems,and economies.Although the influence of life history traits on invasive success is well-established,the role of ...Biological invasions are a major driver of global biodiversity loss,impacting endemic species,ecosystems,and economies.Although the influence of life history traits on invasive success is well-established,the role of behavior in the invasive potential of animals is less studied.The common coqui frog,Eleutherodactylus coqui,is a highly successful invader in Hawai'i.We build on previous research characterizing changes in physiology and morphology to explore behavioral variation across the invasive range of coqui in Hawai'i.Coqui have expanded both outward and upward from their initial introduction site,andby comparing frogs from different densities and elevations-we specifically asked how the physiological challenges of high-elevation living interact with the competitive challenge of high-densities at population centers.To investigate whether differences in the field represent local adaptation or behavioral plasticity,we additionally evaluated behavior following acclimation to a shared laboratory environment.Although we identified only subtle behavioral variation among populations in the field,we found that individuals from all populations became less bold,active,and exploratory in the laboratory,converging on a similar behavioral phenotype.Alongside previous work,our results suggest that coqui adjust their behavior to local environmental conditions across their invasive range and that behavioral flexibility may contribute to invasive success.展开更多
Paternal predation risk can program offspring phenotypes via maternal responses and epigenetic marks of spermatozoa.However,the processes and consequences of this experience in biparental species are unknown.Here,we e...Paternal predation risk can program offspring phenotypes via maternal responses and epigenetic marks of spermatozoa.However,the processes and consequences of this experience in biparental species are unknown.Here,we examined how preconception and postconception paternal cat odor(CO)exposure affects anxiety-like behavior and antipredator response in Brandt’s voles(Lasiopodomys brandtii).We found that preconception paternal CO exposure inhibited maternal investment when offspring were raised by mothers alone,while postconception exposure increased paternal investment towards the offspring raised by both parents.The increased paternal behavior may be associated with an increasing grooming behavior received from their mates,which alleviated the anxiety-like behavior in CO-exposed males.Both paternal experiences increased the levels of anxiety-like behavior in adolescent offspring but differentially altered adult phenotypes.Specifcally,adult females from preconception CO-exposed fathers spent less time in defensive concealing,whereas the offspring of postconception CO-exposed fathers showed more in response to acute cat urine exposure.Correspondingly,baseline corticosterone levels were decreased and increased in these offspring,respectively.Our results indicate that in biparental species,paternal predation risk exposure affects offspring phenotypes in pathway-dependent and age-specifc manners and that only the presence of both parents can elicit adaptive responses to a high predation-risk environment.展开更多
The serrated flow behavior,known as the Portevin-Le Chatelier(PLC)effect,is commonly observed during high-temperature deformation.In this study,we report a serrated flow behavior in FeCoCrNiMo0.2 high-entropy alloy(HE...The serrated flow behavior,known as the Portevin-Le Chatelier(PLC)effect,is commonly observed during high-temperature deformation.In this study,we report a serrated flow behavior in FeCoCrNiMo0.2 high-entropy alloy(HEA),which is mediated by nano-twinning and phase transformation at cryogenic temperatures.During uniaxial tensile deformation at 77 K,the alloy exhibited the formation of high-density deformation nano-twinning,cross-twinning,stacking faults(SFs)and Lomer-Cottrell locks(L-C locks).Additionally,the lower stacking fault energy(SFE)at low temperatures promotes the formation of the 9R phase.The high-density twin boundaries effectively hinder dislocation movement,leading to the instability of plastic deformation and promoting the serrated flow behavior.Furthermore,the rapid and unstable transformation of the 9R phase contributes to the pronounced serrated flow behavior.Nano-twinning,SFs,cross-twinning,L-C locks and 9R phase collectively induce a dynamic Hall-Petch effect,enhancing the strength-ductility synergy and strain-hardening ability of deformed alloy at 77 K.Our work provides valuable insights into the mechanism of tensile deformation at cryogenic temperatures in single-phase FCC HEA.展开更多
Shape memory alloys(SMAs)and shape memory ceramics(SMCs)exhibit high recovery ability due to the martensitic transformation,which complicates the fracture mechanism of SMAs and SMCs.The phase field method,as a powerfu...Shape memory alloys(SMAs)and shape memory ceramics(SMCs)exhibit high recovery ability due to the martensitic transformation,which complicates the fracture mechanism of SMAs and SMCs.The phase field method,as a powerful numerical simulation tool,can efficiently resolve the microstructural evolution,multi-field coupling effects,and fracture behavior of SMAs and SMCs.This review begins by presenting the fundamental theoretical framework of the fracture phase field method as applied to SMAs and SMCs,covering key aspects such as the phase field modeling of martensitic transformation and brittle fracture.Subsequently,it systematically examines the phase field simulations of fracture behaviors in SMAs and SMCs,with particular emphasis on how crystallographic orientation,grain size,and grain boundary properties influence the crack propagation.Additionally,the interplay between martensite transformation and fracture mechanisms is analyzed to provide deeper insights into the material responses under mechanical loading.Finally,the review explores future prospects and emerging trends in phase field simulations of SMA and SMC fracture behavior,along with potential advancements in the fracture phase field method itself,including multi-physics coupling and enhanced computational efficiency for large-scale simulations.展开更多
Shale reservoirs have abundant bedding structures,which deeply alter the mechanical properties of rocks,and thus affect the reservoir stimulation performance.Previous research mostly focuses on the effects of parallel...Shale reservoirs have abundant bedding structures,which deeply alter the mechanical properties of rocks,and thus affect the reservoir stimulation performance.Previous research mostly focuses on the effects of parallel bedding on fracture propagation,while the mechanical properties and mechanisms of fracture propagation remain unclear for rocks with complex wavy bedding(e.g.China’s continentalorigin Gulong shale).Herein,a mixed phase-field fracture model of the wavy-bedding shale was applied,based on the local tension-compression decomposition phase field method(PFM)and geometric structure generation algorithm for the bedding with controllable morphological features.The parametric analysis of fracture propagation behaviors in the case of abundant complex bedding structures showed that with wavy bedding,the vertical fracture propagation rate is far higher than the horizontal propagation rate.Moreover,the development of branch fractures is suppressed during the fracturing process of the wavy-bedding sample,and the stimulated volume is limited,which is different from the characteristic of parallel bedding that promotes horizontal fracture initiation and propagation.The results showed that larger amplitudes,higher frequencies,higher inclination angles,and larger strengths of wavy bedding all promote the formation of vertical penetrating fractures and suppress the growth of branch fractures.Under such circumstances,it is hard to create a well-connected fracture network after fracturing.This research may provide a theoretical basis for understanding fracture behaviors in rocks with such complex wavy bedding.展开更多
Ti750s titanium alloy,a novel high-temperature titanium alloy designed for short-term service at elevated temperatures(700–750℃),has previously lacked comprehensive understanding of its hot processing behavior.In th...Ti750s titanium alloy,a novel high-temperature titanium alloy designed for short-term service at elevated temperatures(700–750℃),has previously lacked comprehensive understanding of its hot processing behavior.In this study,the high-temperature deformation behavior and microstructural evolution of the Ti750s alloy were systematically investigated through thermal simulation compression tests conducted at temperatures ranging from 900 to 1070℃and strain rates between 0.1 and 10 s⁻1.A hot processing map was constructed using the dynamic material model to optimize the hot processing parameters.The results indicated that the optimal processing window was between 1040 and 1070℃with a strain rate of 0.1 s⁻1.Processing within the instability region resulted in localized plastic deformation,manifesting as pronounced shear bands and a highly heterogeneous strain distribution;this region should be avoided during hot deformation.Within theα+βphase safety zone characterized by low power dissipation rates between 0.32 and 0.4,the primary deformation mechanism in this region was dynamic recovery(DRV),where the lamellarαgrains underwent deformation and rotation.Conversely,in theα+βphase safety zone with high-power dissipation rates between 0.45 and 0.52,dynamic spheroidization of theαphase and dynamic recrystallization(DRX)of theβphase occurred concurrently.In theβphase safety zone with low power dissipation rates between 0.32 and 0.51,the primary deformation mechanism consisted of DRV ofβgrains,accompanied by limited DRX.However,in theβphase safety zone with high-power dissipation rates exceeding 0.56,both DRV and DRX ofβgrains took place,resulted in a significant increase in the size and number of recrystallized grains compared to those observed under low power dissipation conditions.展开更多
Background:Prosocial behavior plays a crucial role in improving interpersonal relationships and social well-being,especially in times of crisis.The COVID-19 pandemic caused a severe humanitarian crisis,prompting gover...Background:Prosocial behavior plays a crucial role in improving interpersonal relationships and social well-being,especially in times of crisis.The COVID-19 pandemic caused a severe humanitarian crisis,prompting governments to implement measures such as social confinement.The main objective of the study was to analyze the psychological and sociodemographic variables that may predict prosocial behavior during quarantine.Methods:The sample consisted of 172 participants from Spain,divided into two groups based on whether they reported an increase in prosocial behaviors during quarantine.An online survey was administered to analyze the psychological and sociodemographic variables.Results:Overall,results demonstrate that emotional regulation,morality and age may predict prosocial behavior.Conclusions:Understanding the predictors of prosocial behavior during social crises is crucial for devising effective policies aimed at fostering community resilience and support networks,with particular attention to factors such as the capacity to regulate emotions,morality,and age.展开更多
Based on the microstructure characterization,electrochemical impedance spectroscopy,potentiodynamic polarization,and immersion corrosion,this work comparatively analyzed the differences in the electrochemical corrosio...Based on the microstructure characterization,electrochemical impedance spectroscopy,potentiodynamic polarization,and immersion corrosion,this work comparatively analyzed the differences in the electrochemical corrosion morphology and post-foil formation surface morphology of laser beam welded(LBW)sample and spin-formed sample,and compared the corrosion resistance and Cu foil formation ability of two samples in H_(2)SO_(4)/NaCl solution and CuSO_(4) reducing electrolyte.Results show that in H_(2)SO_(4) and NaCl solutions,LBW sample and spin-formed sample exhibit excellent passivation ability and corrosion resistance.Both samples show uniform corrosion morphologies and similar corrosion resistance in the strong acidic solution containing Cl^(-).Meanwhile,the Cu foil formation ability of the welded joint is similar to that of the spin-formed sample,and both samples obtain intact Cu foils with high-quality surfaces and small differences in properties.展开更多
Social working memory(SWM)—the ability to maintain and manipulate social information in the brain—plays a crucial role in social interactions.However,research on SWM is still in its infancy and is often treated as a...Social working memory(SWM)—the ability to maintain and manipulate social information in the brain—plays a crucial role in social interactions.However,research on SWM is still in its infancy and is often treated as a unitary construct.In the present study,we propose that SWM can be conceptualized as having two relatively independent components:"externally oriented SWM"(e-SWM)and"internally oriented SWM"(i-SWM).To test this external–internal hypothesis,participants were tasked with memorizing and ranking either facial expressions(e-SWM)or personality traits(i-SWM)associated with images of faces.We then examined the neural correlates of these two SWM components and their functional roles in empathy.The results showed distinct activations as the e-SWM task activated the postcentral and precentral gyri while the i-SWM task activated the precuneus/posterior cingulate cortex and superior frontal gyrus.Distinct multivariate activation patterns were also found within the dorsal medial prefrontal cortex in the two tasks.Moreover,partial least squares analyses combining brain activation and individual differences in empathy showed that e-SWM and i-SWM brain activities were mainly correlated with affective empathy and cognitive empathy,respectively.These findings implicate distinct brain processes as well as functional roles of the two types of SWM,providing support for the internal–external hypothesis of SWM.展开更多
Captive environments often fail to resemble the wild environment in respects of limited space, unchanging habitat, lack of stimulus and contingency. Common animal welfare problems which occur in captive animals includ...Captive environments often fail to resemble the wild environment in respects of limited space, unchanging habitat, lack of stimulus and contingency. Common animal welfare problems which occur in captive animals include low behavioral diversity, abnormal behavior and excessive inactivity. Environmental enrichment, as an effective strategy to tackle these problems and promote mental health of captive animals, has been recognized as an important principal for captive animal management. Among all the enriehment techniques, olfactory enrichment is a simple and effective method for improving the well-being of the olfactory sensitive felids. Behavioral problems were observed in six Amur leopards Panthera pardus orientalis at Beijing Zoological Garden. These were held in the older type exhibits which have now been rebuilt. These behaviors include stereotypic behavior and excessive inactivity caused by the spatially limited enclosures with low levels of stimuli. To determine the effects of predator, prey, and herb odors as potential enrichment materials for captive leopards, we conducted olfactory enrichment experiments for the leopards and tested the effects of nutmeg Myristica fragrans, feces of roe deer Capreolus capreolus and urine of Amur tiger Panthera tigris altaica to test for an increase in behavioral repertoire and activity. Odors provided in this study were also believed to improve the psychological and physiological health of individuals. To standardize the method of presentation the odors were introduced to the enclosures by rubbing or spraying onto a clean towel. Our results show that the selected three odors effectively increased the behavioral diversity. Ten new behavior types were observed in the nutmeg experiment, eight in the feces of roe deer experiment and six in the tiger urine experiment. Among the three odors, cats responded to nutmeg for the longest duration, followed by tiger urine and feces of roe deer. Leopards showed more play behavior in presence of nutmeg while more investigatory behavior in presences of feces of roe deer and tiger urine. Providing novel odors increased the spatial use of the exhibit and the animal＇ s increased use of the logs, sleeping platforms and bars in the cages. Novel odors also significantly increased the overall activity of the leopards, but the effects were diminished in about three hours.展开更多
The fields of behavioral ecology, conservation science, and environmental toxicology individually aim to protect and manage the conservation of wildlife in response to anthropogenic stressors, including widespread ant...The fields of behavioral ecology, conservation science, and environmental toxicology individually aim to protect and manage the conservation of wildlife in response to anthropogenic stressors, including widespread anthropogenic pollution. Although great emphasis in the field of toxicology has been placed on understanding how single pollutants affect survival, a comprehensive, interdis- ciplinary approach that includes behavioral ecology is essential to address how anthropogenic compounds are a risk for the survival of species and populations in an increasingly polluted world. We provide an integrative framework for behavioral ecotoxicology using Tinbergen＇s four postu- lates （causation and mechanism, development and ontogeny, function and fitness, and evolution- ary history and phylogenetic patterns）. The aims of this review are： 1） to promote an integrative view and re-define the field of integrative behavioral ecotoxicology; 2） to demonstrate how study- ing ecotoxicology can promote behavior research; and 3） to identify areas of behavioral ecotoxicol- ogy that require further attention to promote the integration and growth of the field.展开更多
Behavior affects an individual's life in all aspects,e.g.,enhancing fitness,leveraging predation risk,and reducing competition with conspecifics.However,the sequential distribution of behaviors received less atten...Behavior affects an individual's life in all aspects,e.g.,enhancing fitness,leveraging predation risk,and reducing competition with conspecifics.However,the sequential distribution of behaviors received less attention and is unclear what the function of displacement behavior is.Displacement activities can be found in vertebrate species but there is no formal method to determine whether a behavior is expressed as a displaced or normal activity.Analyzing the sequential distributions of behaviors in a natural setting may allow researchers to identify unexpected distributions as a possible signature of displacement activities.In this study,we used a behavior random permutation model to detect the presence of a displacement activity in the Tibetan antelope Pantholops hodgsonii and the Tibetan gazelle Procapra picticaudata.The results showed that grooming in both ungulates tended to be accompanied with vigilance,and the frequency of grooming after vigilance was significantly higher than before vigilance.A significant positive correlation between the scan rate and grooming rate in the 2 ungulates was obtained.We suggest that grooming could sometimes be expressed as a displacement activity in ungulates.In addition to providing a general method for further research on displacement activities in a variety of animal species,this study sheds light on the importance of a spectral analysis of sequential distribution of animal behaviors.Behavior random permutation models can be used to explore the relevance between any 2 behaviors in a specific sequence,especially to identify a myriad of unexpected behaviors relative to their normal context of occurrence.展开更多
β titanium alloys with bi-modal structure which exhibit improved strength-ductility combination and fatigue property are widely used in aviation and aerospace industry.However,owing to the small size of primary α(α...β titanium alloys with bi-modal structure which exhibit improved strength-ductility combination and fatigue property are widely used in aviation and aerospace industry.However,owing to the small size of primary α(αp) and nano-scaled multi variant distribution of secondary α platelets(αs),investigating the deformation behavior is really a challenging work.In this work,by applying transmission electron microscopy(TEM),the slip behavior in αp and transformed β matrix with different tensile strain was studied.After α/β solution treatment,the initial dislocation slips on {110} plane with <1 1 1> direction in β matrix.During furtherdeformation,(110),(101) and(1 1 2) multi slip is generated which shows a long straight cro s sing configuration.Dislocation cell is exhibited in β matrix at tensile strain above 20 %.Diffe rent from the solid solution treated sample,high density wavy dislocations are generated in transformedβ matrix.High fraction fine as hinders dislocation motion in β matrix effectively which in turn dominates the strength of the alloy.In primary α phase(αp),a core-shell structure is formed during deformation.Both pyramidal a+c slip and prismatic/basal a slip are generated in the shell layer.In core region,plastic deformation is governed by prismatic/basal a slip.Formation of the core-shell structure is the physical origin of the improved ductility.On one hand,the work hardening layer(shell) improves the strength of αp,which could deform compatibly with the hard transformed β matrix.Meanwhile,the center area(core) deforms homogeneously which will sustain plastic strain effectively and increase the ductility.This paper studies the slip behavior and reveals the origin of the improved strength-ductility combination in Bi-modal structure on a microscopic way,which will give theoretical advises for developing the next generation high strength β titanium alloys.展开更多
A water-quenching technique has been adopted to evaluate thermal shock fracture and fatigue behaviors of porous Si3N4 ceramics in an air atmosphere. The high-porosity Si3N4 ceramics exhibit a higher strength retention...A water-quenching technique has been adopted to evaluate thermal shock fracture and fatigue behaviors of porous Si3N4 ceramics in an air atmosphere. The high-porosity Si3N4 ceramics exhibit a higher strength retention and a better resistance to thermal shock fatigue because of its role of the pores as crack arresters.A dense and coherent surface oxide layer leads to a significant benefit in residual strength during thermal fatigue, however, an increased fatigue number to 30 th cycle cannot cause a further influence although a thicker oxide layer presents, which is attributed to holes defect and disappearance of part intergranular phase.展开更多
The authors regret to inform that(i)a wrong Table 1 was uploaded,and a corrected one was show below;(ii)a reference label is missing in caption of Fig.8(A),and it should be:Fig.8.Interfacial evolution between nanozone...The authors regret to inform that(i)a wrong Table 1 was uploaded,and a corrected one was show below;(ii)a reference label is missing in caption of Fig.8(A),and it should be:Fig.8.Interfacial evolution between nanozones and lamellar zones during thermal exposure:(A)as-deposited state[45];(B)20 h;(C)500 h;(iii)a wrong figure was uploaded in Fig.2(A,0 h),and a revised one is shown below.展开更多
Plasma spray-physical vapor deposition(PS-PVD)has exhibited the potential ability to prepare columnar structures for advanced thermal barrier coatings(TBCs).The coating structure is nominally affected by operating par...Plasma spray-physical vapor deposition(PS-PVD)has exhibited the potential ability to prepare columnar structures for advanced thermal barrier coatings(TBCs).The coating structure is nominally affected by operating parameters,but it is controlled by the type of deposition unit actually and essentially.In order to realize the columnar structure deposited by gaseous phase units,the transition behavior of gaseous phase units to clusters must be fundamentally understood.This work investigated the transport process of gaseous phase units in the PS-PVD near-substrate boundary layer along with the condensation behavior.The Monte Carlo method was used to examine the transport process and condensation behavior of gaseous phase units under different scale boundary layers.Simulation results show that it is easier to form more numerous larger clusters at the edge of the plasma jet than at the center.Based on the understanding of the changes in deposition unit caused by the condensation of gaseous phase in the near-substrate boundary layer of PS-PVD,an outlook towards TBCs with different structures is presented.And it is in good agreement with the experimental data.展开更多
The mechanical behavior of nanoscale metallic multilayers （NMMs） has attracted much attention from both scientific and practical views. Compared with their monolithic counterparts, the large number of interfaces exi...The mechanical behavior of nanoscale metallic multilayers （NMMs） has attracted much attention from both scientific and practical views. Compared with their monolithic counterparts, the large number of interfaces existing in the NMMs dictates the unique behavior of this special class of structural composite materials. While there have been a number of reviews on the mechanical mechanism of micro- laminates, the rapid development of nanotechnology brought a pressing need for an overview focusing exclusively on a property-based definition of the NMMs, especially their size- dependent microstructure and mechanical performance. This article attempts to provide a comprehensive and up-to-date review on the microstructure, mechanical property and plas- tic deformation physics of NMMs. We hope this review could accomplish two purposes： （1） introducing the basic concepts of scaling and dimensional analysis to scientists and engi- neers working on NMM systems, and （2） providing a better understanding of interface behavior and the exceptional qual- ities the interfaces in NMMs display at atomic scale.展开更多
The TiSiN-Cu nanocomposite coating was deposited on F690 steel substrate by arc ion plating.The structure and composition,tribocorrosion behavior and anti-microbiologically influenced corrosion(MIC)properties of TiSiN...The TiSiN-Cu nanocomposite coating was deposited on F690 steel substrate by arc ion plating.The structure and composition,tribocorrosion behavior and anti-microbiologically influenced corrosion(MIC)properties of TiSiN-Cu coating were investigated.The results show that the TiSiN-Cu coating has unique nanocomposite structures.The results of tribocorrosion show that the potential and current change of F690 steel and TiSiN-Cu coatings tend to be opposite.The reason is that the F690 steel is non-passivated metal and the TiSiN-Cu coating has passivation phenomenon.The TiSiN-Cu coating possesses excellent tribocorrosion resistance.Cu ion released from TiSiN-Cu coating can effectively inhibit the corrosion caused by SRB.展开更多
The three-parameter Petal-Teja equation of state coupled with a characterization proceduref0r C<sub>7+</sub>-fraction based on gamma distribution function was employed to predict the phase behaviorof eight...The three-parameter Petal-Teja equation of state coupled with a characterization proceduref0r C<sub>7+</sub>-fraction based on gamma distribution function was employed to predict the phase behaviorof eight gas condensates.The lumping of the subdivided single carbon number（SCN）hydrocarbons inthe plus-fraction and the choice of empirical correlations for calculating the critical properties andacentric factor of SCN hydrocarbons were discussed.展开更多
Objective To realize AIDS related knowledge, attitude and behavior among floating people in China and discuss its influencial factors, and to provide the evidence for how to prevent AIDS in floating population. Method...Objective To realize AIDS related knowledge, attitude and behavior among floating people in China and discuss its influencial factors, and to provide the evidence for how to prevent AIDS in floating population. Methods The data were collected from the ＂Sex and Reproductive Health Baseline Survey among Floating People in China＂ conducted in March 2004. The standard questionnaires were used to interview altogether 4 900 floating people from 6 provinces. Results Nearly 95.4 % of them had heard about AIDS, but only 0.5% can judge all the transmitted ways and no-transmitted ways correctly, 45.9 % believed that we need to isolate the HIV positive people. Only 65.7% knew that using condom can preventive HIV infection, 43. 7% showed their understanding about the man who has long time no sexual life has sex with a sexual worker. About 13.6% floating people chose condom as FP method and among them only 34. 6% used condom every time. Conclusion Chinese floating people are lack of AIDS knowledge. Most of them do not practise Safe Sex Activity. We need to give more intervention to the floating population.展开更多
基金supported by the United States Department of Agriculture National Institute of Food and Agriculture Hatch project 1026333(ILLU-875-984 to K.M.S)a University of Ilinois Graduate College Master's Fellowship(to K.M.S)+2 种基金a University of Illinois Graduate College Travel Award(to K.M.S)Ilinois State Toll Highway Authority funding(to D.E and A.L.C)University of Illinois Laboratory Start-up funds(to E.K.F).
文摘Biological invasions are a major driver of global biodiversity loss,impacting endemic species,ecosystems,and economies.Although the influence of life history traits on invasive success is well-established,the role of behavior in the invasive potential of animals is less studied.The common coqui frog,Eleutherodactylus coqui,is a highly successful invader in Hawai'i.We build on previous research characterizing changes in physiology and morphology to explore behavioral variation across the invasive range of coqui in Hawai'i.Coqui have expanded both outward and upward from their initial introduction site,andby comparing frogs from different densities and elevations-we specifically asked how the physiological challenges of high-elevation living interact with the competitive challenge of high-densities at population centers.To investigate whether differences in the field represent local adaptation or behavioral plasticity,we additionally evaluated behavior following acclimation to a shared laboratory environment.Although we identified only subtle behavioral variation among populations in the field,we found that individuals from all populations became less bold,active,and exploratory in the laboratory,converging on a similar behavioral phenotype.Alongside previous work,our results suggest that coqui adjust their behavior to local environmental conditions across their invasive range and that behavioral flexibility may contribute to invasive success.
基金supported by grants from the National Natural Science Foundation of China(31770422 and 31900334)Natural Science Foundation of Jiangsu Province(BK20190910)+2 种基金Postdoctoral Science Foundation of China(2018M630610 and 2019T120468)Students’Project for Innovation and Entrepreneurship Training Program of Yangzhou University(XCX20230796)Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Paternal predation risk can program offspring phenotypes via maternal responses and epigenetic marks of spermatozoa.However,the processes and consequences of this experience in biparental species are unknown.Here,we examined how preconception and postconception paternal cat odor(CO)exposure affects anxiety-like behavior and antipredator response in Brandt’s voles(Lasiopodomys brandtii).We found that preconception paternal CO exposure inhibited maternal investment when offspring were raised by mothers alone,while postconception exposure increased paternal investment towards the offspring raised by both parents.The increased paternal behavior may be associated with an increasing grooming behavior received from their mates,which alleviated the anxiety-like behavior in CO-exposed males.Both paternal experiences increased the levels of anxiety-like behavior in adolescent offspring but differentially altered adult phenotypes.Specifcally,adult females from preconception CO-exposed fathers spent less time in defensive concealing,whereas the offspring of postconception CO-exposed fathers showed more in response to acute cat urine exposure.Correspondingly,baseline corticosterone levels were decreased and increased in these offspring,respectively.Our results indicate that in biparental species,paternal predation risk exposure affects offspring phenotypes in pathway-dependent and age-specifc manners and that only the presence of both parents can elicit adaptive responses to a high predation-risk environment.
基金supported by the National Natural Science Foundation of China(Nos.52474403,52364050 and 52301137)Guizhou Provincial Program on Commercialization of Scientific and Technological Achievements(No.[2023]001)+2 种基金Guizhou Province Science and Technology Project(No.[2022]050)Guiyang city Science and Technology Project(No.[2023]48-16)the Central Government in Guidance of Local Science and Technology Development Funds(No.[2024]032).
文摘The serrated flow behavior,known as the Portevin-Le Chatelier(PLC)effect,is commonly observed during high-temperature deformation.In this study,we report a serrated flow behavior in FeCoCrNiMo0.2 high-entropy alloy(HEA),which is mediated by nano-twinning and phase transformation at cryogenic temperatures.During uniaxial tensile deformation at 77 K,the alloy exhibited the formation of high-density deformation nano-twinning,cross-twinning,stacking faults(SFs)and Lomer-Cottrell locks(L-C locks).Additionally,the lower stacking fault energy(SFE)at low temperatures promotes the formation of the 9R phase.The high-density twin boundaries effectively hinder dislocation movement,leading to the instability of plastic deformation and promoting the serrated flow behavior.Furthermore,the rapid and unstable transformation of the 9R phase contributes to the pronounced serrated flow behavior.Nano-twinning,SFs,cross-twinning,L-C locks and 9R phase collectively induce a dynamic Hall-Petch effect,enhancing the strength-ductility synergy and strain-hardening ability of deformed alloy at 77 K.Our work provides valuable insights into the mechanism of tensile deformation at cryogenic temperatures in single-phase FCC HEA.
基金supported by the National Natural Science Foundation of China(12202294)the Sichuan Science and Technology Program(2024NSFSC1346).
文摘Shape memory alloys(SMAs)and shape memory ceramics(SMCs)exhibit high recovery ability due to the martensitic transformation,which complicates the fracture mechanism of SMAs and SMCs.The phase field method,as a powerful numerical simulation tool,can efficiently resolve the microstructural evolution,multi-field coupling effects,and fracture behavior of SMAs and SMCs.This review begins by presenting the fundamental theoretical framework of the fracture phase field method as applied to SMAs and SMCs,covering key aspects such as the phase field modeling of martensitic transformation and brittle fracture.Subsequently,it systematically examines the phase field simulations of fracture behaviors in SMAs and SMCs,with particular emphasis on how crystallographic orientation,grain size,and grain boundary properties influence the crack propagation.Additionally,the interplay between martensite transformation and fracture mechanisms is analyzed to provide deeper insights into the material responses under mechanical loading.Finally,the review explores future prospects and emerging trends in phase field simulations of SMA and SMC fracture behavior,along with potential advancements in the fracture phase field method itself,including multi-physics coupling and enhanced computational efficiency for large-scale simulations.
基金supported by the Technology Project of CNPC(Grant No.2023ZZ08)the National Natural Science Foundation of China(Grant No.52274058)the USTC Research Funds of the Double First-Class Initiative(Grant No.YD2090002025).
文摘Shale reservoirs have abundant bedding structures,which deeply alter the mechanical properties of rocks,and thus affect the reservoir stimulation performance.Previous research mostly focuses on the effects of parallel bedding on fracture propagation,while the mechanical properties and mechanisms of fracture propagation remain unclear for rocks with complex wavy bedding(e.g.China’s continentalorigin Gulong shale).Herein,a mixed phase-field fracture model of the wavy-bedding shale was applied,based on the local tension-compression decomposition phase field method(PFM)and geometric structure generation algorithm for the bedding with controllable morphological features.The parametric analysis of fracture propagation behaviors in the case of abundant complex bedding structures showed that with wavy bedding,the vertical fracture propagation rate is far higher than the horizontal propagation rate.Moreover,the development of branch fractures is suppressed during the fracturing process of the wavy-bedding sample,and the stimulated volume is limited,which is different from the characteristic of parallel bedding that promotes horizontal fracture initiation and propagation.The results showed that larger amplitudes,higher frequencies,higher inclination angles,and larger strengths of wavy bedding all promote the formation of vertical penetrating fractures and suppress the growth of branch fractures.Under such circumstances,it is hard to create a well-connected fracture network after fracturing.This research may provide a theoretical basis for understanding fracture behaviors in rocks with such complex wavy bedding.
基金supported by the National basic scientific research projects(JCKY2021204A004)the National Ministries and Commissions Projects(2019-112hbz)the National Natural Science Foundation of China(No.52271113).
文摘Ti750s titanium alloy,a novel high-temperature titanium alloy designed for short-term service at elevated temperatures(700–750℃),has previously lacked comprehensive understanding of its hot processing behavior.In this study,the high-temperature deformation behavior and microstructural evolution of the Ti750s alloy were systematically investigated through thermal simulation compression tests conducted at temperatures ranging from 900 to 1070℃and strain rates between 0.1 and 10 s⁻1.A hot processing map was constructed using the dynamic material model to optimize the hot processing parameters.The results indicated that the optimal processing window was between 1040 and 1070℃with a strain rate of 0.1 s⁻1.Processing within the instability region resulted in localized plastic deformation,manifesting as pronounced shear bands and a highly heterogeneous strain distribution;this region should be avoided during hot deformation.Within theα+βphase safety zone characterized by low power dissipation rates between 0.32 and 0.4,the primary deformation mechanism in this region was dynamic recovery(DRV),where the lamellarαgrains underwent deformation and rotation.Conversely,in theα+βphase safety zone with high-power dissipation rates between 0.45 and 0.52,dynamic spheroidization of theαphase and dynamic recrystallization(DRX)of theβphase occurred concurrently.In theβphase safety zone with low power dissipation rates between 0.32 and 0.51,the primary deformation mechanism consisted of DRV ofβgrains,accompanied by limited DRX.However,in theβphase safety zone with high-power dissipation rates exceeding 0.56,both DRV and DRX ofβgrains took place,resulted in a significant increase in the size and number of recrystallized grains compared to those observed under low power dissipation conditions.
基金supported by the Ministry of Education,Culture and Sport(Predoctoral Contract University Faculty Training Program:FPU15/04335)later by the Spanish Public Administration“Ministerio de Universidades”and the European Union through the“NextGeneration EU”(Postdoctoral contract Margarita Salas).
文摘Background:Prosocial behavior plays a crucial role in improving interpersonal relationships and social well-being,especially in times of crisis.The COVID-19 pandemic caused a severe humanitarian crisis,prompting governments to implement measures such as social confinement.The main objective of the study was to analyze the psychological and sociodemographic variables that may predict prosocial behavior during quarantine.Methods:The sample consisted of 172 participants from Spain,divided into two groups based on whether they reported an increase in prosocial behaviors during quarantine.An online survey was administered to analyze the psychological and sociodemographic variables.Results:Overall,results demonstrate that emotional regulation,morality and age may predict prosocial behavior.Conclusions:Understanding the predictors of prosocial behavior during social crises is crucial for devising effective policies aimed at fostering community resilience and support networks,with particular attention to factors such as the capacity to regulate emotions,morality,and age.
基金Key Research and Development Program of Shaanxi Province(2022GY-410)Funding of Western Titanium Technologies Co.,Ltd(WX2210)。
文摘Based on the microstructure characterization,electrochemical impedance spectroscopy,potentiodynamic polarization,and immersion corrosion,this work comparatively analyzed the differences in the electrochemical corrosion morphology and post-foil formation surface morphology of laser beam welded(LBW)sample and spin-formed sample,and compared the corrosion resistance and Cu foil formation ability of two samples in H_(2)SO_(4)/NaCl solution and CuSO_(4) reducing electrolyte.Results show that in H_(2)SO_(4) and NaCl solutions,LBW sample and spin-formed sample exhibit excellent passivation ability and corrosion resistance.Both samples show uniform corrosion morphologies and similar corrosion resistance in the strong acidic solution containing Cl^(-).Meanwhile,the Cu foil formation ability of the welded joint is similar to that of the spin-formed sample,and both samples obtain intact Cu foils with high-quality surfaces and small differences in properties.
基金supported by the Key Program of Natural Science Foundation of Zhejiang Province(LZ20C090001)the National Natural Science Foundation of China(32271090,32171031,and 32071044)the China Brain Project(2021ZD0200409).
文摘Social working memory(SWM)—the ability to maintain and manipulate social information in the brain—plays a crucial role in social interactions.However,research on SWM is still in its infancy and is often treated as a unitary construct.In the present study,we propose that SWM can be conceptualized as having two relatively independent components:"externally oriented SWM"(e-SWM)and"internally oriented SWM"(i-SWM).To test this external–internal hypothesis,participants were tasked with memorizing and ranking either facial expressions(e-SWM)or personality traits(i-SWM)associated with images of faces.We then examined the neural correlates of these two SWM components and their functional roles in empathy.The results showed distinct activations as the e-SWM task activated the postcentral and precentral gyri while the i-SWM task activated the precuneus/posterior cingulate cortex and superior frontal gyrus.Distinct multivariate activation patterns were also found within the dorsal medial prefrontal cortex in the two tasks.Moreover,partial least squares analyses combining brain activation and individual differences in empathy showed that e-SWM and i-SWM brain activities were mainly correlated with affective empathy and cognitive empathy,respectively.These findings implicate distinct brain processes as well as functional roles of the two types of SWM,providing support for the internal–external hypothesis of SWM.
基金founded by the Knowledge Innovation Project of the Chinese Academy of Sciences (CXTDS2005-4)the Natural Scientific Foundation of China (No.30230080,No.30670267)
文摘Captive environments often fail to resemble the wild environment in respects of limited space, unchanging habitat, lack of stimulus and contingency. Common animal welfare problems which occur in captive animals include low behavioral diversity, abnormal behavior and excessive inactivity. Environmental enrichment, as an effective strategy to tackle these problems and promote mental health of captive animals, has been recognized as an important principal for captive animal management. Among all the enriehment techniques, olfactory enrichment is a simple and effective method for improving the well-being of the olfactory sensitive felids. Behavioral problems were observed in six Amur leopards Panthera pardus orientalis at Beijing Zoological Garden. These were held in the older type exhibits which have now been rebuilt. These behaviors include stereotypic behavior and excessive inactivity caused by the spatially limited enclosures with low levels of stimuli. To determine the effects of predator, prey, and herb odors as potential enrichment materials for captive leopards, we conducted olfactory enrichment experiments for the leopards and tested the effects of nutmeg Myristica fragrans, feces of roe deer Capreolus capreolus and urine of Amur tiger Panthera tigris altaica to test for an increase in behavioral repertoire and activity. Odors provided in this study were also believed to improve the psychological and physiological health of individuals. To standardize the method of presentation the odors were introduced to the enclosures by rubbing or spraying onto a clean towel. Our results show that the selected three odors effectively increased the behavioral diversity. Ten new behavior types were observed in the nutmeg experiment, eight in the feces of roe deer experiment and six in the tiger urine experiment. Among the three odors, cats responded to nutmeg for the longest duration, followed by tiger urine and feces of roe deer. Leopards showed more play behavior in presence of nutmeg while more investigatory behavior in presences of feces of roe deer and tiger urine. Providing novel odors increased the spatial use of the exhibit and the animal＇ s increased use of the logs, sleeping platforms and bars in the cages. Novel odors also significantly increased the overall activity of the leopards, but the effects were diminished in about three hours.
基金JPS was funded by the National Science Foundation （IOS1257590）. The sym- posium from which this paper emerged was funded by the Animal Behavior Society.
文摘The fields of behavioral ecology, conservation science, and environmental toxicology individually aim to protect and manage the conservation of wildlife in response to anthropogenic stressors, including widespread anthropogenic pollution. Although great emphasis in the field of toxicology has been placed on understanding how single pollutants affect survival, a comprehensive, interdis- ciplinary approach that includes behavioral ecology is essential to address how anthropogenic compounds are a risk for the survival of species and populations in an increasingly polluted world. We provide an integrative framework for behavioral ecotoxicology using Tinbergen＇s four postu- lates （causation and mechanism, development and ontogeny, function and fitness, and evolution- ary history and phylogenetic patterns）. The aims of this review are： 1） to promote an integrative view and re-define the field of integrative behavioral ecotoxicology; 2） to demonstrate how study- ing ecotoxicology can promote behavior research; and 3） to identify areas of behavioral ecotoxicol- ogy that require further attention to promote the integration and growth of the field.
基金Authors thank the Tibet Major Science and Technology Project(XZ201901-GA-06)National Natural Science Foundation of China(grant nos.31360141 and 31772470)West Light Foundation of Chinese Academy of Sciences(2015)in supporting the study financially.
文摘Behavior affects an individual's life in all aspects,e.g.,enhancing fitness,leveraging predation risk,and reducing competition with conspecifics.However,the sequential distribution of behaviors received less attention and is unclear what the function of displacement behavior is.Displacement activities can be found in vertebrate species but there is no formal method to determine whether a behavior is expressed as a displaced or normal activity.Analyzing the sequential distributions of behaviors in a natural setting may allow researchers to identify unexpected distributions as a possible signature of displacement activities.In this study,we used a behavior random permutation model to detect the presence of a displacement activity in the Tibetan antelope Pantholops hodgsonii and the Tibetan gazelle Procapra picticaudata.The results showed that grooming in both ungulates tended to be accompanied with vigilance,and the frequency of grooming after vigilance was significantly higher than before vigilance.A significant positive correlation between the scan rate and grooming rate in the 2 ungulates was obtained.We suggest that grooming could sometimes be expressed as a displacement activity in ungulates.In addition to providing a general method for further research on displacement activities in a variety of animal species,this study sheds light on the importance of a spectral analysis of sequential distribution of animal behaviors.Behavior random permutation models can be used to explore the relevance between any 2 behaviors in a specific sequence,especially to identify a myriad of unexpected behaviors relative to their normal context of occurrence.
基金supported financially by the National Natural Science Foundation of China (Nos. 51671158 and 51621063)the National Program on Key Basic Research Project (No. 2014CB644003)the Programme of Introducing Talents of Discipline to Universities (No. PB2018008)。
文摘β titanium alloys with bi-modal structure which exhibit improved strength-ductility combination and fatigue property are widely used in aviation and aerospace industry.However,owing to the small size of primary α(αp) and nano-scaled multi variant distribution of secondary α platelets(αs),investigating the deformation behavior is really a challenging work.In this work,by applying transmission electron microscopy(TEM),the slip behavior in αp and transformed β matrix with different tensile strain was studied.After α/β solution treatment,the initial dislocation slips on {110} plane with <1 1 1> direction in β matrix.During furtherdeformation,(110),(101) and(1 1 2) multi slip is generated which shows a long straight cro s sing configuration.Dislocation cell is exhibited in β matrix at tensile strain above 20 %.Diffe rent from the solid solution treated sample,high density wavy dislocations are generated in transformedβ matrix.High fraction fine as hinders dislocation motion in β matrix effectively which in turn dominates the strength of the alloy.In primary α phase(αp),a core-shell structure is formed during deformation.Both pyramidal a+c slip and prismatic/basal a slip are generated in the shell layer.In core region,plastic deformation is governed by prismatic/basal a slip.Formation of the core-shell structure is the physical origin of the improved ductility.On one hand,the work hardening layer(shell) improves the strength of αp,which could deform compatibly with the hard transformed β matrix.Meanwhile,the center area(core) deforms homogeneously which will sustain plastic strain effectively and increase the ductility.This paper studies the slip behavior and reveals the origin of the improved strength-ductility combination in Bi-modal structure on a microscopic way,which will give theoretical advises for developing the next generation high strength β titanium alloys.
基金financial support of the project from the National Natural Science Foundation of China (Nos. 51272206 and 51472198)the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT1280)+2 种基金the National Key Laboratory Functional Composite (No. 9140C560109130C56201)the Fundamental Research Funds for the Central University (No. xkjc2014009)the State Key Laboratory for Mechanical Behavior of Materials (No. 20121207)
文摘A water-quenching technique has been adopted to evaluate thermal shock fracture and fatigue behaviors of porous Si3N4 ceramics in an air atmosphere. The high-porosity Si3N4 ceramics exhibit a higher strength retention and a better resistance to thermal shock fatigue because of its role of the pores as crack arresters.A dense and coherent surface oxide layer leads to a significant benefit in residual strength during thermal fatigue, however, an increased fatigue number to 30 th cycle cannot cause a further influence although a thicker oxide layer presents, which is attributed to holes defect and disappearance of part intergranular phase.
文摘The authors regret to inform that(i)a wrong Table 1 was uploaded,and a corrected one was show below;(ii)a reference label is missing in caption of Fig.8(A),and it should be:Fig.8.Interfacial evolution between nanozones and lamellar zones during thermal exposure:(A)as-deposited state[45];(B)20 h;(C)500 h;(iii)a wrong figure was uploaded in Fig.2(A,0 h),and a revised one is shown below.
基金supported by the National Key Research and Development Program of China(No.2017YFB0306103)R&D Program in Key Fields of Guangdong Province(No.2019B010936001)+2 种基金the National Natural Science Foundation of China(Grant No.51901175)the China Postdoctoral Science Foundation funded project(No.2019M653602)the National Program for Support of Top-notch Young Professionals。
文摘Plasma spray-physical vapor deposition(PS-PVD)has exhibited the potential ability to prepare columnar structures for advanced thermal barrier coatings(TBCs).The coating structure is nominally affected by operating parameters,but it is controlled by the type of deposition unit actually and essentially.In order to realize the columnar structure deposited by gaseous phase units,the transition behavior of gaseous phase units to clusters must be fundamentally understood.This work investigated the transport process of gaseous phase units in the PS-PVD near-substrate boundary layer along with the condensation behavior.The Monte Carlo method was used to examine the transport process and condensation behavior of gaseous phase units under different scale boundary layers.Simulation results show that it is easier to form more numerous larger clusters at the edge of the plasma jet than at the center.Based on the understanding of the changes in deposition unit caused by the condensation of gaseous phase in the near-substrate boundary layer of PS-PVD,an outlook towards TBCs with different structures is presented.And it is in good agreement with the experimental data.
基金supported by the National Natural Science Foundation of China (Grants 51171141, 51271141, and 51471131)the Program for New Century Excellent Talents in University (Grant NCET-11-0431)
文摘The mechanical behavior of nanoscale metallic multilayers （NMMs） has attracted much attention from both scientific and practical views. Compared with their monolithic counterparts, the large number of interfaces existing in the NMMs dictates the unique behavior of this special class of structural composite materials. While there have been a number of reviews on the mechanical mechanism of micro- laminates, the rapid development of nanotechnology brought a pressing need for an overview focusing exclusively on a property-based definition of the NMMs, especially their size- dependent microstructure and mechanical performance. This article attempts to provide a comprehensive and up-to-date review on the microstructure, mechanical property and plas- tic deformation physics of NMMs. We hope this review could accomplish two purposes： （1） introducing the basic concepts of scaling and dimensional analysis to scientists and engi- neers working on NMM systems, and （2） providing a better understanding of interface behavior and the exceptional qual- ities the interfaces in NMMs display at atomic scale.
基金supported financially by the National Key R&D Program of China(No.2016YFB0300604)the National Natural Science Foundation of China(Nos.51575510 and 51771221)
文摘The TiSiN-Cu nanocomposite coating was deposited on F690 steel substrate by arc ion plating.The structure and composition,tribocorrosion behavior and anti-microbiologically influenced corrosion(MIC)properties of TiSiN-Cu coating were investigated.The results show that the TiSiN-Cu coating has unique nanocomposite structures.The results of tribocorrosion show that the potential and current change of F690 steel and TiSiN-Cu coatings tend to be opposite.The reason is that the F690 steel is non-passivated metal and the TiSiN-Cu coating has passivation phenomenon.The TiSiN-Cu coating possesses excellent tribocorrosion resistance.Cu ion released from TiSiN-Cu coating can effectively inhibit the corrosion caused by SRB.
文摘The three-parameter Petal-Teja equation of state coupled with a characterization proceduref0r C<sub>7+</sub>-fraction based on gamma distribution function was employed to predict the phase behaviorof eight gas condensates.The lumping of the subdivided single carbon number（SCN）hydrocarbons inthe plus-fraction and the choice of empirical correlations for calculating the critical properties andacentric factor of SCN hydrocarbons were discussed.
基金This study was funded by the Japanese International Cooperation Agency
文摘Objective To realize AIDS related knowledge, attitude and behavior among floating people in China and discuss its influencial factors, and to provide the evidence for how to prevent AIDS in floating population. Methods The data were collected from the ＂Sex and Reproductive Health Baseline Survey among Floating People in China＂ conducted in March 2004. The standard questionnaires were used to interview altogether 4 900 floating people from 6 provinces. Results Nearly 95.4 % of them had heard about AIDS, but only 0.5% can judge all the transmitted ways and no-transmitted ways correctly, 45.9 % believed that we need to isolate the HIV positive people. Only 65.7% knew that using condom can preventive HIV infection, 43. 7% showed their understanding about the man who has long time no sexual life has sex with a sexual worker. About 13.6% floating people chose condom as FP method and among them only 34. 6% used condom every time. Conclusion Chinese floating people are lack of AIDS knowledge. Most of them do not practise Safe Sex Activity. We need to give more intervention to the floating population.
