In order to investigate the damage tolerance of a metastable Ti-5Al-3V-3Mo-2Cr-2Zr-1Nb-1Fe(Ti5321)alloy with bimodal microstructure using void growth quantification and micromechanical modeling,in situ tensile testing...In order to investigate the damage tolerance of a metastable Ti-5Al-3V-3Mo-2Cr-2Zr-1Nb-1Fe(Ti5321)alloy with bimodal microstructure using void growth quantification and micromechanical modeling,in situ tensile testing was performed during X-ray microtomography experiments.Compared with investigations of surface voids by traditional two-dimensional(2D)methods involving post-mortem characterization,three-dimensional(3D)information on void evolution inside optically opaque samples obtained through X-ray microtomography is essential.The Rice and Tracey model and Huang model were applied to predict void growth and show good agreement with experimental data using calibration of the damage parameterα.The void growth kinetics of Ti5321 with bimodal microstructure was analyzed by comparing theαvalue with that of Ti64 for different microstructure morphologies.The damage mechanism of ductile fracture of Ti5321 with bimodal microstructure is discussed.It was found that the size of the voids apparently increases with the triaxiality of stress.Post-mortem scanning electron microscopy(SEM)was also used to demonstrate this damage mechanism of ductile fracture of Ti5321.展开更多
This study reviews light-responsive polymers in various applications,including drug delivery,information storage,sensor,self-healing material,antibacterial or anti-fouling,and environmental applications.Light-responsi...This study reviews light-responsive polymers in various applications,including drug delivery,information storage,sensor,self-healing material,antibacterial or anti-fouling,and environmental applications.Light-responsive polymers are a new material type being developed for various medical,electronics,engineering,and environmental applications.The working principle of light-responsive materials is based on metalligand interactions or non-covalent interactions between polymer functional groups,metal ions,and other filler functional groups.Light irradiation causes physical and mechanical changes in drug delivery and antibacterial systems,which results in the materials releasing more drugs or antibacterial substances.When materials in information storage devices and sensors are exposed to light,they can change color or glow.This has been applied for data storage to reveal QR codes under UV light.Additionally,this review discusses the thermodynamic aspects and computer modeling of light-responsive materials to emphasize the importance and development of these materials.Finally,light-responsive polymer development for various applications is presented.展开更多
The specification of germ cells in zebrafish mostly relies on an inherited mechanism by which localized maternal determinants,called germ plasm,confer germline fate in the early embryo.Extensive studies have partially...The specification of germ cells in zebrafish mostly relies on an inherited mechanism by which localized maternal determinants,called germ plasm,confer germline fate in the early embryo.Extensive studies have partially allowed the identification of key regulators governing germ plasm formation and subsequent germ cell development.RNA-binding proteins,acting in concert with other germ plasm components,play essential roles in the organization of the germ plasm and the specification,migration,maintenance,and differentiation of primordial germ cells.The loss of their functions impairs germ cell formation and causes sterility or sexual conversion.Evidence is emerging that they instruct germline development through differential regulation of mRNA fates in somatic and germ cells.However,the challenge remains to decipher the complex interplay of maternal germ plasm components in germ plasm compartmentalization and germ cell specification.Because failure to control the developmental outcome of germ cells disrupts the formation of gametes,it is important to gain a complete picture of regulatory mechanisms operating in the germ cell lineage.This review sheds light on the contributions of RNA-binding proteins to germ cell development in zebrafish and highlights intriguing questions that remain open for future investigation.展开更多
Plate subduction leads to complex exhumation processes on continents.The Huangling Massif lies at the northern margin of the South China Block.Whether the Huangling Massif was exhumed as a watershed of the middle reac...Plate subduction leads to complex exhumation processes on continents.The Huangling Massif lies at the northern margin of the South China Block.Whether the Huangling Massif was exhumed as a watershed of the middle reaches of the Paleo-Yangtze River during the Mesozoic remains under debate.We examined the exhumation history of the Huangling Massif based on six granite bedrock samples,using apatite fission track(AFT)and apatite and zircon(U-Th)/He(AHe and ZHe)thermochronology.These samples yielded ages of 157–132 Ma(ZHe),119–106 Ma(AFT),and 114–72 Ma(AHe),respectively.Thermal modeling revealed that three phases of rapid cooling occurred during the Late Jurassic–Early Cretaceous,late Early Cretaceous,and Late Cretaceous.These exhumation processes led to the high topographic relief responsible for the emergence of the Huangling Massif.The integrated of our new data with published sedimentological records suggests that the Huangling Massif might have been the watershed of the middle reaches of the Paleo-Yangtze River since the Cretaceous.At that time,the rivers flowed westward into the Sichuan Basin and eastward into the Jianghan Basin.The subduction of the Pacific Plate beneath the Asian continent in the Mesozoic deeply influenced the geomorphic evolution of the South China Block.展开更多
This study proposes a novel strategy for the design of a new family of metastable Zr alloys.These al-loys offer improved mechanical properties for implants,particularly in applications where conventional stainless ste...This study proposes a novel strategy for the design of a new family of metastable Zr alloys.These al-loys offer improved mechanical properties for implants,particularly in applications where conventional stainless steels and Co-Cr alloys are currently used but lack suitability.The design approach is based on the controlled twinning-induced plasticity(TWIP)effect,significantly enhancing the ductility and strain-hardenability of the Zr alloys.In order to draw a“blueprint”for the compositional design of biomedical T WIP(Bio-T WIP)Zr alloys-using only non-toxic elements,the study combines D-electron phase stability calculations(specifically bond order(Bo)and mean d-orbital energy(Md))with a systematic experimental screening of active deformation mechanisms within the Zr-Nb-Sn alloy system.This research aids in ac-curately identifying the TWIP line,which signifies the mechanism shift between TWIP and classic slip as the primary deformation mechanism.To demonstrate the efficacy of the TWIP mechanism in enhancing mechanical properties,Zr-12Nb-2Sn,Zr-13Nb-1Sn,and Zr-14Nb-3Sn alloys are selected.Results indicate that the TWIP mechanism leads to a significant improvement of strain-hardening rate and a uniform elongation of∼20%in Zr-12Nb-2Sn,which displays both{332}<113>mechanical twinning and disloca-tion slip as the primary deformation mechanisms.Conversely,Zr-14Nb-3Sn exhibits the typical mechan-ical properties found in stable body-centered cubic(BCC)alloys,characterized by the sole occurrence of dislocation slip.Cell viability tests confirm the superior biocompatibility of Zr-Nb-based alloys with deformation twins on the surface,in line with existing literature.Based on the whole set of results,a comprehensive design diagram is proposed.展开更多
The enhanced coalbed methane recovery using CO_(2) injection(CO_(2)-ECBM)is widely proposed as a way of achieving the energy transition and reducing atmospheric CO_(2),in areas such as the Lorrain basin in France,wher...The enhanced coalbed methane recovery using CO_(2) injection(CO_(2)-ECBM)is widely proposed as a way of achieving the energy transition and reducing atmospheric CO_(2),in areas such as the Lorrain basin in France,where heavy industry is responsible for huge CO_(2) emissions and coal mines have been closed for more than a decade.This paper deals with the feasibility of extracting methane from the Lorraine basin using CO_(2)-ECBM by comparing data from sorption isotherms,thermogravimetric analyses and breakthrough curves for two coal samples.One is bituminous(Box 18),from Folschviller(France)and is compared with another sub-bituminous(THO1)from La Houve(France),which is used as a reference because it was identified as a good candidate for CO_(2)-ECBM in a previous research program.The quantities of adsorbed gases(CO_(2)/CH_(4))obtained by sorption isotherms,thermogravimetry and CO,breakthrough curves showed that Box 18 adsorbs more CO_(2) and CH_(4) than THO1 due to its higher porosity and good affinity for gases(CO_(2)/CH_(4)).Toth model fits the experimental CH_(4) and CO_(2) adsorption isotherms better,reflecting the fact that the adsorption surface of the coals studied is heterogeneous.Adsorption enthalpies obtained by calorimetry indicated physisorption for gas-coal interactions,with higher values for CO_(2) than for CH_(4).Thermogravimetric analyses and breakthrough curves carried out at up to 50%relative humidity showed that the adsorption capacity of CO_(2) decreases with increasing temperature and the presence of water,respectively.The compilation of these experimental data explained the adsorption process of the studied coals and revealed their advantages for CO_(2)-ECBM.展开更多
Models for when and how the continental crust was formed are constrained by estimates in the rates o crustal growth. The record of events preserved in the continental crust is heterogeneous in time with distinctive pe...Models for when and how the continental crust was formed are constrained by estimates in the rates o crustal growth. The record of events preserved in the continental crust is heterogeneous in time with distinctive peaks and troughs of ages for igneous crystallisation, metamorphism, continental margin and mineralisation. For the most part these are global signatures, and the peaks of ages tend to b associated with periods of increased reworking of pre-existing crust, reflected in the Hf isotope ratios o zircons and their elevated oxygen isotope ratios. Increased crustal reworking is attributed to periods o crustal thickening associated with compressional tectonics and the development of supercontinents Magma types similar to those from recent within-plate and subduction related settings appear to hav been generated in different areas at broadly similar times before ~3.0 Ga. It can be difficult to put th results of such detailed case studies into a more global context, but one approach is to consider when plate tectonics became the dominant mechanism involved in the generation of juvenile continental crust The development of crustal growth models for the continental crust are discussed, and a number o models based on different data sets indicate that 65%-70% of the present volume of the continental crus was generated by 3 Ga. Such estimates may represent minimum values, but since ~3 Ga there has been reduction in the rates of growth of the continental crust. This reduction is linked to an increase in th rates at which continental crust is recycled back into the mantle, and not to a reduction in the rates a which continental crust was generated. Plate tectonics results in both the generation of new crust and it destruction along destructive plate margins. Thus, the reduction in the rate of continental crustal growth at ~3 Ga is taken to reflect the period in which plate tectonics became the dominant mechanism b which new continental crust was generated.展开更多
Among cervids,maternal investment,estimated as the amount of resources and care allocated to the offspring,was expected to be related to species body size. Therefore,maternal investment in a herd of captive Chinese wa...Among cervids,maternal investment,estimated as the amount of resources and care allocated to the offspring,was expected to be related to species body size. Therefore,maternal investment in a herd of captive Chinese water deer Hydropotes inermis,a relatively small species of cervid,was investigated over 3 years. Except during the lactation period,reproductive females spent about 2-fold more time resting than feeding. During lactation,the amount of time spent feeding increased highly (25.3 min/h during lactation vs 17.3 min/h during the gestation period). Females spent less than 30% of time in communal behaviours with offspring. They did not reject alien fawns during this care period. Frequency and duration of suckling events decreased exponentially from the second week onwards. More than 10% of suckling bouts were non-filial. Prenatal investment leads to a mean litter mass (about 12% of maternal mass) higher than in most cervid species. Postnatal investment in fawns represents a daily mass gain of ca. 85 g/d during the first 2 weeks,without any sexual difference. Female production,timing and synchrony of births and survival of fawns characterized reproductive success. Seventy percent of mature females gave birth,with a mean of 1.9 offspring per female. The sex ratio was even. Births were synchronous,80% of births occurring in 25 days. In this herd,0.74 fawn per female was successfully weaned and 0.56 fawn per female survived through their first year. Based on these results we conclude that reproductive strategy of Chinese water deer was efficient and characterized by mother-offspring relationships typical of hiders and high levels of pre-and postnatal investments. This strategy seems typical of small species of cervids without marked sexual dimorphism.展开更多
This paper reports on a study of active vibration control of functionally graded beams with upper and lower surface-bonded piezoelectric layers. The model is based on higher-order shear deformation theory and implemen...This paper reports on a study of active vibration control of functionally graded beams with upper and lower surface-bonded piezoelectric layers. The model is based on higher-order shear deformation theory and implemented using the finite element method （FEM）. The proprieties of the functionally graded beam （FGB） are graded along the thickness direction. The piezoelectric actuator provides a damping effect on the FGB by means of a velocity feedback control algorithm. A Matlab program has been developed for the FGB model and compared with ANSYS APDL. Using Newmark＇s method numerical solutions are obtained for the dynamic equations of FGB with piezoelectric layers. Numerical results show the effects of the constituent volume fraction and the influence the feedback control gain on the frequency and dynamic response of FGBs.展开更多
The effects of an external DC(direct current)electric field on recrystallization texture evolution in the cold-rolled aluminum sheets with 99.99%purity were investigated by means of X-ray diffraction techniques.The co...The effects of an external DC(direct current)electric field on recrystallization texture evolution in the cold-rolled aluminum sheets with 99.99%purity were investigated by means of X-ray diffraction techniques.The cold-rolled high-purity aluminum sheets were annealed for 60 min at 200,300 and 400℃,respectively with and without an external DC electric field of 800 V/mm.The results show that with DC electric field,the recrystallization cube texture is strengthened at the stage of grain growth. Possible reason for the strengthening of the recrystallization cube texture with the applied electric field may be attributed to both selected nucleation and selected growth of cube oriented crystal nuclei.展开更多
This paper reviews the common mechanical features of the metallic cellular material under impact loading as well as the characterization methods of such behaviours. The main focus is on the innovations of various test...This paper reviews the common mechanical features of the metallic cellular material under impact loading as well as the characterization methods of such behaviours. The main focus is on the innovations of various testing methods at impact loading rates.Following aspects were discussed in details.（1） The use of soft nylon Hopkinson/Kolsky bar for an enhanced measuring accuracy in order to assess if there is a strength enhancement or not for this class of cellular materials under moderate impact loading;（2） The use of digital image correlations to determine the strain fields during the tests to confirm the existence of a pseudo-shock wave propagation inside the cellular material under high speed impact： （3） The use of new combined shear compression device to determine the loading envelop of cellular materials under impact multiaxial loadings.展开更多
Gold nanoparticles dispersed Y2O3 films were prepared through a sol-gel method by using yttrium acetate and Au nanoparticles colloid as precursors. The films were characterized by X-ray diffraction （XRD）, transmissi...Gold nanoparticles dispersed Y2O3 films were prepared through a sol-gel method by using yttrium acetate and Au nanoparticles colloid as precursors. The films were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM） and UV-VIS absorption spectra. XRD patterns and TEM images of Y2O3 ＋ Au films give the same resuits on structure and particle size as that of pure Y2O3 films. The surface plasma resonance （SPR） of Au nanoparticles in Y2O3 ＋ Au film was observed around 550 nm in the absorption spectrum and its position shifts to red with increasing annealing temperature is caused by the increase of dielectric constant of Y2O3 matrix and the size of Au nanoparticles. The second and third order nonlinear optical effects of Y2O3 ＋ Au films were also observed. The photoluminescent properties of Y2O3 ： Eu ＋ Au films were investigated and results indicate that there exist an energy transfer from Eu^3 ＋ to Au nanoparticles and this energy transfer decreases the emission of Eu^3 ＋ in Y2O3 ： Eu ＋ Au film.展开更多
The commercially pure copper with dimension of 80 mm×20 mm×4 mm was used for equal channel angular pressing (ECAP), of which their outward appearance coordinate is corresponded with that of rolling deformati...The commercially pure copper with dimension of 80 mm×20 mm×4 mm was used for equal channel angular pressing (ECAP), of which their outward appearance coordinate is corresponded with that of rolling deformation modes. Cold-deformed texture was investigated. The results show that the texture character in pure copper processed by ECAP is related with intersection angle (Φ) of the die channel. When Φ is 90° and the sample is extruded for one pass, its texture consists of α and β orientation lines including mainly C, B, S and Goss components, moreover a little rotated cube is found. When Φ is 135°, as extrusion pass increases, the weak texture forms on the scope of deviation from rotated cube (ψ=0°, θ=0°,φ=450°±150°) and develops to the ψ=45° fiber mainly including rotated cube. When Φ is 120°, the texture is ψ=45° fiber mainly including rotated cube that is maintained constant as extrusion pass increases.展开更多
The phenomenon of planar cell polarity is critically required for a myriad of morphogenetic processes in metazoan and is accurately controlled by several conserved modules.Six“core”proteins,including Friz zled,Flami...The phenomenon of planar cell polarity is critically required for a myriad of morphogenetic processes in metazoan and is accurately controlled by several conserved modules.Six“core”proteins,including Friz zled,Flamingo(Celsr),Van Gogh(Vangl),Dishevelled,Prickle,and Diego(Ankrd6),are major components of the Wnt/planar cell polarity pathway.The Fat/Dchs protocadherins and the Scrib polarity complex also function to instruct cellular polarization.In vertebrates,all these pathways are essential for tissue and organ morphogenesis,such as neural tube closure,left-right symmetry breaking,heart and gut morphogenesis,lung and kidney branching,stereociliary bundle orientation,and proximal-distal limb elongation.Mutations in planar polarity genes are closely linked to various congenital diseases.Striking advances have been made in deciphering their contribution to the establishment of spatially oriented pattern in developing or gans and the maintenance of tissue homeostasis.The challenge remains to clarify the complex interplay of different polarity pathways in organogenesis and the link of cell polarity to cell fate specification.Inter disciplinary approaches are also important to understand the roles of mechanical forces in coupling cellular polarization and differentiation.This review outlines current advances on planar polarity regulators in asymmetric organ formation,with the aim to identify questions that deserve further investigation.展开更多
基金supported by the China Postdoctoral Science Foundation(No.2022M720399).
文摘In order to investigate the damage tolerance of a metastable Ti-5Al-3V-3Mo-2Cr-2Zr-1Nb-1Fe(Ti5321)alloy with bimodal microstructure using void growth quantification and micromechanical modeling,in situ tensile testing was performed during X-ray microtomography experiments.Compared with investigations of surface voids by traditional two-dimensional(2D)methods involving post-mortem characterization,three-dimensional(3D)information on void evolution inside optically opaque samples obtained through X-ray microtomography is essential.The Rice and Tracey model and Huang model were applied to predict void growth and show good agreement with experimental data using calibration of the damage parameterα.The void growth kinetics of Ti5321 with bimodal microstructure was analyzed by comparing theαvalue with that of Ti64 for different microstructure morphologies.The damage mechanism of ductile fracture of Ti5321 with bimodal microstructure is discussed.It was found that the size of the voids apparently increases with the triaxiality of stress.Post-mortem scanning electron microscopy(SEM)was also used to demonstrate this damage mechanism of ductile fracture of Ti5321.
基金the Franco-Thai Cooperation Programme in Higher Education and Research(Franco-Thai Mobility Programme/PHC SIAM)Year 2024-2025。
文摘This study reviews light-responsive polymers in various applications,including drug delivery,information storage,sensor,self-healing material,antibacterial or anti-fouling,and environmental applications.Light-responsive polymers are a new material type being developed for various medical,electronics,engineering,and environmental applications.The working principle of light-responsive materials is based on metalligand interactions or non-covalent interactions between polymer functional groups,metal ions,and other filler functional groups.Light irradiation causes physical and mechanical changes in drug delivery and antibacterial systems,which results in the materials releasing more drugs or antibacterial substances.When materials in information storage devices and sensors are exposed to light,they can change color or glow.This has been applied for data storage to reveal QR codes under UV light.Additionally,this review discusses the thermodynamic aspects and computer modeling of light-responsive materials to emphasize the importance and development of these materials.Finally,light-responsive polymer development for various applications is presented.
文摘The specification of germ cells in zebrafish mostly relies on an inherited mechanism by which localized maternal determinants,called germ plasm,confer germline fate in the early embryo.Extensive studies have partially allowed the identification of key regulators governing germ plasm formation and subsequent germ cell development.RNA-binding proteins,acting in concert with other germ plasm components,play essential roles in the organization of the germ plasm and the specification,migration,maintenance,and differentiation of primordial germ cells.The loss of their functions impairs germ cell formation and causes sterility or sexual conversion.Evidence is emerging that they instruct germline development through differential regulation of mRNA fates in somatic and germ cells.However,the challenge remains to decipher the complex interplay of maternal germ plasm components in germ plasm compartmentalization and germ cell specification.Because failure to control the developmental outcome of germ cells disrupts the formation of gametes,it is important to gain a complete picture of regulatory mechanisms operating in the germ cell lineage.This review sheds light on the contributions of RNA-binding proteins to germ cell development in zebrafish and highlights intriguing questions that remain open for future investigation.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.41671011,41871019,41877292,41972212)Research Foundation of Chutian Scholars Program of Hubei Province(Grant No.8210403)Shanxi Key Research and Development program:Feng Cheng(Grant No.2021SF2-03).
文摘Plate subduction leads to complex exhumation processes on continents.The Huangling Massif lies at the northern margin of the South China Block.Whether the Huangling Massif was exhumed as a watershed of the middle reaches of the Paleo-Yangtze River during the Mesozoic remains under debate.We examined the exhumation history of the Huangling Massif based on six granite bedrock samples,using apatite fission track(AFT)and apatite and zircon(U-Th)/He(AHe and ZHe)thermochronology.These samples yielded ages of 157–132 Ma(ZHe),119–106 Ma(AFT),and 114–72 Ma(AHe),respectively.Thermal modeling revealed that three phases of rapid cooling occurred during the Late Jurassic–Early Cretaceous,late Early Cretaceous,and Late Cretaceous.These exhumation processes led to the high topographic relief responsible for the emergence of the Huangling Massif.The integrated of our new data with published sedimentological records suggests that the Huangling Massif might have been the watershed of the middle reaches of the Paleo-Yangtze River since the Cretaceous.At that time,the rivers flowed westward into the Sichuan Basin and eastward into the Jianghan Basin.The subduction of the Pacific Plate beneath the Asian continent in the Mesozoic deeply influenced the geomorphic evolution of the South China Block.
基金the support of the French Agence Nationale de la Recherche(ANR),under grant ANR-21-CE08-0022(project ISANAMI)Junhui TANG is sponsored by the China Scholarship Council.
文摘This study proposes a novel strategy for the design of a new family of metastable Zr alloys.These al-loys offer improved mechanical properties for implants,particularly in applications where conventional stainless steels and Co-Cr alloys are currently used but lack suitability.The design approach is based on the controlled twinning-induced plasticity(TWIP)effect,significantly enhancing the ductility and strain-hardenability of the Zr alloys.In order to draw a“blueprint”for the compositional design of biomedical T WIP(Bio-T WIP)Zr alloys-using only non-toxic elements,the study combines D-electron phase stability calculations(specifically bond order(Bo)and mean d-orbital energy(Md))with a systematic experimental screening of active deformation mechanisms within the Zr-Nb-Sn alloy system.This research aids in ac-curately identifying the TWIP line,which signifies the mechanism shift between TWIP and classic slip as the primary deformation mechanism.To demonstrate the efficacy of the TWIP mechanism in enhancing mechanical properties,Zr-12Nb-2Sn,Zr-13Nb-1Sn,and Zr-14Nb-3Sn alloys are selected.Results indicate that the TWIP mechanism leads to a significant improvement of strain-hardening rate and a uniform elongation of∼20%in Zr-12Nb-2Sn,which displays both{332}<113>mechanical twinning and disloca-tion slip as the primary deformation mechanisms.Conversely,Zr-14Nb-3Sn exhibits the typical mechan-ical properties found in stable body-centered cubic(BCC)alloys,characterized by the sole occurrence of dislocation slip.Cell viability tests confirm the superior biocompatibility of Zr-Nb-based alloys with deformation twins on the surface,in line with existing literature.Based on the whole set of results,a comprehensive design diagram is proposed.
基金financed by the REGALOR project(Ressources Gazieres de Lorraine).
文摘The enhanced coalbed methane recovery using CO_(2) injection(CO_(2)-ECBM)is widely proposed as a way of achieving the energy transition and reducing atmospheric CO_(2),in areas such as the Lorrain basin in France,where heavy industry is responsible for huge CO_(2) emissions and coal mines have been closed for more than a decade.This paper deals with the feasibility of extracting methane from the Lorraine basin using CO_(2)-ECBM by comparing data from sorption isotherms,thermogravimetric analyses and breakthrough curves for two coal samples.One is bituminous(Box 18),from Folschviller(France)and is compared with another sub-bituminous(THO1)from La Houve(France),which is used as a reference because it was identified as a good candidate for CO_(2)-ECBM in a previous research program.The quantities of adsorbed gases(CO_(2)/CH_(4))obtained by sorption isotherms,thermogravimetry and CO,breakthrough curves showed that Box 18 adsorbs more CO_(2) and CH_(4) than THO1 due to its higher porosity and good affinity for gases(CO_(2)/CH_(4)).Toth model fits the experimental CH_(4) and CO_(2) adsorption isotherms better,reflecting the fact that the adsorption surface of the coals studied is heterogeneous.Adsorption enthalpies obtained by calorimetry indicated physisorption for gas-coal interactions,with higher values for CO_(2) than for CH_(4).Thermogravimetric analyses and breakthrough curves carried out at up to 50%relative humidity showed that the adsorption capacity of CO_(2) decreases with increasing temperature and the presence of water,respectively.The compilation of these experimental data explained the adsorption process of the studied coals and revealed their advantages for CO_(2)-ECBM.
基金supported by grants from the LeverhulmeTrust RPG-2015-422 and EM-2017-047\4 to Chris HawkesworthNERC NE/K008862/1 to Bruno Dhuimefrom AustralianResearch Council FL160100168 to Peter A. Cawood
文摘Models for when and how the continental crust was formed are constrained by estimates in the rates o crustal growth. The record of events preserved in the continental crust is heterogeneous in time with distinctive peaks and troughs of ages for igneous crystallisation, metamorphism, continental margin and mineralisation. For the most part these are global signatures, and the peaks of ages tend to b associated with periods of increased reworking of pre-existing crust, reflected in the Hf isotope ratios o zircons and their elevated oxygen isotope ratios. Increased crustal reworking is attributed to periods o crustal thickening associated with compressional tectonics and the development of supercontinents Magma types similar to those from recent within-plate and subduction related settings appear to hav been generated in different areas at broadly similar times before ~3.0 Ga. It can be difficult to put th results of such detailed case studies into a more global context, but one approach is to consider when plate tectonics became the dominant mechanism involved in the generation of juvenile continental crust The development of crustal growth models for the continental crust are discussed, and a number o models based on different data sets indicate that 65%-70% of the present volume of the continental crus was generated by 3 Ga. Such estimates may represent minimum values, but since ~3 Ga there has been reduction in the rates of growth of the continental crust. This reduction is linked to an increase in th rates at which continental crust is recycled back into the mantle, and not to a reduction in the rates a which continental crust was generated. Plate tectonics results in both the generation of new crust and it destruction along destructive plate margins. Thus, the reduction in the rate of continental crustal growth at ~3 Ga is taken to reflect the period in which plate tectonics became the dominant mechanism b which new continental crust was generated.
文摘Among cervids,maternal investment,estimated as the amount of resources and care allocated to the offspring,was expected to be related to species body size. Therefore,maternal investment in a herd of captive Chinese water deer Hydropotes inermis,a relatively small species of cervid,was investigated over 3 years. Except during the lactation period,reproductive females spent about 2-fold more time resting than feeding. During lactation,the amount of time spent feeding increased highly (25.3 min/h during lactation vs 17.3 min/h during the gestation period). Females spent less than 30% of time in communal behaviours with offspring. They did not reject alien fawns during this care period. Frequency and duration of suckling events decreased exponentially from the second week onwards. More than 10% of suckling bouts were non-filial. Prenatal investment leads to a mean litter mass (about 12% of maternal mass) higher than in most cervid species. Postnatal investment in fawns represents a daily mass gain of ca. 85 g/d during the first 2 weeks,without any sexual difference. Female production,timing and synchrony of births and survival of fawns characterized reproductive success. Seventy percent of mature females gave birth,with a mean of 1.9 offspring per female. The sex ratio was even. Births were synchronous,80% of births occurring in 25 days. In this herd,0.74 fawn per female was successfully weaned and 0.56 fawn per female survived through their first year. Based on these results we conclude that reproductive strategy of Chinese water deer was efficient and characterized by mother-offspring relationships typical of hiders and high levels of pre-and postnatal investments. This strategy seems typical of small species of cervids without marked sexual dimorphism.
文摘This paper reports on a study of active vibration control of functionally graded beams with upper and lower surface-bonded piezoelectric layers. The model is based on higher-order shear deformation theory and implemented using the finite element method （FEM）. The proprieties of the functionally graded beam （FGB） are graded along the thickness direction. The piezoelectric actuator provides a damping effect on the FGB by means of a velocity feedback control algorithm. A Matlab program has been developed for the FGB model and compared with ANSYS APDL. Using Newmark＇s method numerical solutions are obtained for the dynamic equations of FGB with piezoelectric layers. Numerical results show the effects of the constituent volume fraction and the influence the feedback control gain on the frequency and dynamic response of FGBs.
基金Project(50374028)supported by the National Natural Science Foundation of China and Shanghai Bao Steel Group of ChinaProject(PRAMX04-02)supported by Sino-French Cooperation Program
文摘The effects of an external DC(direct current)electric field on recrystallization texture evolution in the cold-rolled aluminum sheets with 99.99%purity were investigated by means of X-ray diffraction techniques.The cold-rolled high-purity aluminum sheets were annealed for 60 min at 200,300 and 400℃,respectively with and without an external DC electric field of 800 V/mm.The results show that with DC electric field,the recrystallization cube texture is strengthened at the stage of grain growth. Possible reason for the strengthening of the recrystallization cube texture with the applied electric field may be attributed to both selected nucleation and selected growth of cube oriented crystal nuclei.
文摘This paper reviews the common mechanical features of the metallic cellular material under impact loading as well as the characterization methods of such behaviours. The main focus is on the innovations of various testing methods at impact loading rates.Following aspects were discussed in details.（1） The use of soft nylon Hopkinson/Kolsky bar for an enhanced measuring accuracy in order to assess if there is a strength enhancement or not for this class of cellular materials under moderate impact loading;（2） The use of digital image correlations to determine the strain fields during the tests to confirm the existence of a pseudo-shock wave propagation inside the cellular material under high speed impact： （3） The use of new combined shear compression device to determine the loading envelop of cellular materials under impact multiaxial loadings.
文摘Gold nanoparticles dispersed Y2O3 films were prepared through a sol-gel method by using yttrium acetate and Au nanoparticles colloid as precursors. The films were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM） and UV-VIS absorption spectra. XRD patterns and TEM images of Y2O3 ＋ Au films give the same resuits on structure and particle size as that of pure Y2O3 films. The surface plasma resonance （SPR） of Au nanoparticles in Y2O3 ＋ Au film was observed around 550 nm in the absorption spectrum and its position shifts to red with increasing annealing temperature is caused by the increase of dielectric constant of Y2O3 matrix and the size of Au nanoparticles. The second and third order nonlinear optical effects of Y2O3 ＋ Au films were also observed. The photoluminescent properties of Y2O3 ： Eu ＋ Au films were investigated and results indicate that there exist an energy transfer from Eu^3 ＋ to Au nanoparticles and this energy transfer decreases the emission of Eu^3 ＋ in Y2O3 ： Eu ＋ Au film.
基金Project(Lnzr0201) supported by the Foundation of Science and Technology Committee of Liaoning Province of China
文摘The commercially pure copper with dimension of 80 mm×20 mm×4 mm was used for equal channel angular pressing (ECAP), of which their outward appearance coordinate is corresponded with that of rolling deformation modes. Cold-deformed texture was investigated. The results show that the texture character in pure copper processed by ECAP is related with intersection angle (Φ) of the die channel. When Φ is 90° and the sample is extruded for one pass, its texture consists of α and β orientation lines including mainly C, B, S and Goss components, moreover a little rotated cube is found. When Φ is 135°, as extrusion pass increases, the weak texture forms on the scope of deviation from rotated cube (ψ=0°, θ=0°,φ=450°±150°) and develops to the ψ=45° fiber mainly including rotated cube. When Φ is 120°, the texture is ψ=45° fiber mainly including rotated cube that is maintained constant as extrusion pass increases.
基金supported by grants from the National Natural Science Foundation of China(grant number 32070813)the French Muscular Dystrophy Association (AFM-Telethon grant number 23545)+1 种基金the Centre National de la Recherche Scientifiquethe Sorbonne University
文摘The phenomenon of planar cell polarity is critically required for a myriad of morphogenetic processes in metazoan and is accurately controlled by several conserved modules.Six“core”proteins,including Friz zled,Flamingo(Celsr),Van Gogh(Vangl),Dishevelled,Prickle,and Diego(Ankrd6),are major components of the Wnt/planar cell polarity pathway.The Fat/Dchs protocadherins and the Scrib polarity complex also function to instruct cellular polarization.In vertebrates,all these pathways are essential for tissue and organ morphogenesis,such as neural tube closure,left-right symmetry breaking,heart and gut morphogenesis,lung and kidney branching,stereociliary bundle orientation,and proximal-distal limb elongation.Mutations in planar polarity genes are closely linked to various congenital diseases.Striking advances have been made in deciphering their contribution to the establishment of spatially oriented pattern in developing or gans and the maintenance of tissue homeostasis.The challenge remains to clarify the complex interplay of different polarity pathways in organogenesis and the link of cell polarity to cell fate specification.Inter disciplinary approaches are also important to understand the roles of mechanical forces in coupling cellular polarization and differentiation.This review outlines current advances on planar polarity regulators in asymmetric organ formation,with the aim to identify questions that deserve further investigation.
