The insufficient damping capabilities of aluminum alloy under low temperatures(<120℃)were addressed by developing high-damping laminated composites of NiTip/5052Al.This is achieved through the incorporation of var...The insufficient damping capabilities of aluminum alloy under low temperatures(<120℃)were addressed by developing high-damping laminated composites of NiTip/5052Al.This is achieved through the incorporation of varied pre-aging states of NiTi particles into the 5052Al matrix using a rolling composite technique.The aim is to enhance the application scope of aluminum alloy for vibration and noise reduction.The results demonstrated a distinct and integrated interface between the particle layer and the 5052Al alloy,with numerous interparticle interfaces within the particle layer.Increasing the aging temperature of the NiTi particles from 450 to 550℃ shifted the phase transition peaks of the composites to lower temperatures.The damping capacity of the laminated NiTip/5052Al composites notably surpasses that of the 5052Al alloy.At 28 and 66℃,the phase transformation damping peaks of the pre-aged NiTi particle layer reinforced 5052Al matrix composites are 1.93 and 2 times those of the 5052Al alloy at the corresponding temperatures,respectively.The collaborative impact of interparticle interface damping mechanism and the phase transformation damping mechanism of NiTi-reinforced particles significantly amplify the low-temperature damping performance of the laminated NiTip/5052Al composites.展开更多
The general use of aluminium as an indentation standard for the iteration of contact heights for the determination of ISO-14577 hardness and elastic modulus is challenged because of as yet not appreciated phase-change...The general use of aluminium as an indentation standard for the iteration of contact heights for the determination of ISO-14577 hardness and elastic modulus is challenged because of as yet not appreciated phase-changes in the physical force-depth standard curve that seemed to be secured by claims from 1992. The physical and mathematical analyses with closed formulas avoid the still world-wide standardized energy-law violation by not reserving 33.33% (h2 belief) (or 20% h3/2 physical law) of the loading force and thus energy for all not depth producing events but using 100% for the depth formation is a severe violation of the energy law. The not depth producing part of the indentation work cannot be done with zero energy! Both twinning and structural phase-transition onsets and normalized phase-transition energies are now calculated without iterations but with physically correct closed arithmetic equations. These are reported for Berkovich and cubecorner indentations, including their comparison on geometric grounds and an indentation standard without mechanical twinning is proposed. Characteristic data are reported. This is the first detection of the indentation twinning of aluminium at room temperature and the mechanical twinning of fused quartz is also new. Their disqualification as indentation standards is established. Also, the again found higher load phase-transitions disqualify aluminium and fused quartz as ISO-ASTM 14577 (International Standardization Organization and American Society for Testing and Materials) standards for the contact depth “hc” iterations. The incorrect and still world-wide used black-box values for H- and Er-values (the latter are still falsely called “Young’s moduli” even though they are not directional) and all mechanical properties that depend on them. They lack relation to bulk moduli from compression experiments. Experimentally obtained and so published force vs depth parabolas always follow the linear FN = kh3/2 + Fa equation, where Fa is the axis-cut before and after the phase-transition branches (never “h2” as falsely enforced and used for H, Er and giving incorrectly calculated parameters). The regression slopes k are the precise physical hardness values, which for the first time allow for precise calculation of the mechanical qualities by indentation in relation to the geometry of the indenter tip. Exactly 20% of the applied force and thus energy is not available for the indentation depth. Only these scientific k-values must be used for AI-advises at the expense of falsely iterated indentation hardness H-values. Any incorrect H-ISO-ASTM and also the iterated Er-ISO-ASTM modulus values of technical materials in artificial intelligence will be a disaster for the daily safety. The AI must be told that these are unscientific and must therefore be replaced by physical data. Iterated data (3 and 8 free parameters!) cannot be transformed into physical data. One has to start with real experimental loading curves and an absolute ZerodurR standard that must be calibrated with standard force and standard length to create absolute indentation results. .展开更多
The thermal flux curve of phase-transition fluid(PF)was tested using differential scanning calorimetry,based on which a reaction kinetics model was established to reflect the relationship between phase transition conv...The thermal flux curve of phase-transition fluid(PF)was tested using differential scanning calorimetry,based on which a reaction kinetics model was established to reflect the relationship between phase transition conversion rate,temperature and time.A temperature field model for fractures and rock matrix considering phase transition heat was then constructed,and its reliability was verified using previously established temperature field models.Additionally,the new model was used to study the effects of different injection parameters and phase-transition fracturing performance parameters on the temperature variations in fractures and matrix.The study indicates that,at different positions and times,the cooling effect of the injected cold fluid and the exothermic effect during the phase transition alternately dominate the temperature within the fracture.At the initial stage of fracturing fluid injection,the temperature within the fracture is high,and the phase transition rate is rapid,resulting in a significant impact of exothermic phase transition on the reservoir rock temperature.In the later stage of injection,the fracture temperature decreases,the phase transition exothermic rate slows,and the cooling effect of the fracturing fluid on the reservoir rock intensifies.Phase transition heat significantly affects the temperature of the fracture.Compared to cases where phase transition heat is not considered,when it is taken into account,the temperature within the fracture increases to varying degrees at the end of fluid injection.As the phase transition heat increases from 20 J/g to 60 J/g,the maximum temperature rise in the fracture increases from 2.1℃ to 6.2℃.The phase transition heat and PF volume fraction are positively correlated with fracture temperature changes,while specific heat capacity is negatively correlated with temperature changes.With increasing injection time,the temperature and phase transition rate at the fracture opening gradually decrease,and the location of the maximum phase transition rate and temperature difference gradually shifts from the fracture opening to about 10 m from the opening.展开更多
Bacterial cellulose(BC)is one of the most versatile natural biopolymers with unique physical,chemical,and biological features.However,the lack of intrinsic antibacterial property of native BC limits its broad biomedic...Bacterial cellulose(BC)is one of the most versatile natural biopolymers with unique physical,chemical,and biological features.However,the lack of intrinsic antibacterial property of native BC limits its broad biomedical applications where such property is highly required to prevent contamination or infection caused by attached bacteria.In this work,we developed a simple and facile method to fabricate a dualfunctional BC membrane by physical incorporation of gold nanorods(GNRs)followed by deposition of a phase-transitioned bovine serum albumin(PTB)film.Due to the broad-spectrum antifouling property of the PTB film,the resulting membrane could prevent the adhesion and accumulation of bacteria.A few bacteria that broke through the protection of the PTB film could be eradicated under short-term irradiation of a near-infrared laser due to the excellent photothermal property of incorporated GNRs.The whole fabrication was conducted in a simple and environmentally friendly manner,avoiding complicated processes and toxic organic solvents.Moreover,because all the components were biocompatible,the resulting membrane showed negligible cytotoxicity in vitro and good histocompatibility in vivo.This work thus provided a reliable way to endow BC with antibacterial property,being beneficial for diverse biomedical applications.展开更多
-The ISO standard 14577 is challenged for its violation of the energy law, its wrong relation of normal force FN with impression depth h, and for its iterative treatments. The solution of this dilemma is the use of sa...-The ISO standard 14577 is challenged for its violation of the energy law, its wrong relation of normal force FN with impression depth h, and for its iterative treatments. The solution of this dilemma is the use of sacrosanct simplest calculation rules for the loading parabola (now FN = kh3/2) giving straight lines for cones, pyramids and wedges. They provide the physical penetration resistance hardness k with dimension [Nm-3/2] and allow for non-iterative calculations with closed formulas, using simple undeniable calculation rules. The physically correct FN versus h3/2 plot is universally valid. It separates out the most common surface effects and reveals gradients. It provides unmatched precision, including reliability checks of experimental data. Regression analysis of FN versus h3/2 plots reveals eventual unsteadiness kink phase-transition onset with the transition-energy. This is shown for all kinds of solid materials, including salts, silicon, organics, polymers, composites, and superalloys. Exothermic and endothermic single and consecutive multiple phase-transitions with their surface dependence are distinguished and the results compared in 5 Tables. The sharp phase-transition onsets and the transition energies provide unprecedented most important materials’ characteristics that are indispensable for safety reasons. ISO ASTM is thus urged to thoroughly revise ISO 14577 and to work out new standards for the mechanically (also thermally) stressed materials. For example, the constancy of the first phase-transition parameters must be controlled, and materials must only be admitted for maximal forces well below the first phase-transition onset. Such onset loads can now be easily calculated. The nevertheless repeated oppositions against the physical analysis of indentations rest on incredibly poor knowledge of basic mathematics, errors that are uncovered. The safety aspects caused by the present unphysical materials’ parameters are discussed.展开更多
A moist plume forms when the flue gas emitted from wet desulfurization equipment exits into the ambi- ent air, resulting in a waste of water resources and visual pollution. In addition, sulfur trioxide （SO3）, water ...A moist plume forms when the flue gas emitted from wet desulfurization equipment exits into the ambi- ent air, resulting in a waste of water resources and visual pollution. In addition, sulfur trioxide （SO3）, water with dissolved salts, and particles in the wet flue gas form secondary pollution in the surrounding atmosphere. In this study, a deep purification technology for flue gas involving phase-transition agglom- eration and dehumidification （PAD） is proposed. This deep purification technology includes two technical routes： the integrated technology of phase-transition agglomeration and a wet electrostatic precipitator （PAW）; and the integrated technology of phase-transition agglomeration and a mist eliminator （PAM）. Industrial applications of PAW and PAM were carried out on 630 and 1000 MW coal-fired units, respectively. The results show that the average amount of recycled water obtained from wet flue gas by means of PAD is more than 4 g.（kg.℃）-1 Decreasing the wet flue gas temperature by 1.5-5.3 ℃ allows 5%-20% of the moisture in the flue gas to be recycled; therefore, this process could effectively save water resources and significantly reduce water vapor emissions. In addition, the moist plume is effectively elim- inated. With the use of this process, the ion concentration in droplets of flue gas is decreased by more than 65%, the SO3 removal efficiency from flue gas is greater than 75%, and the removal efficiency of par- ticulate matter is 92.53%.展开更多
The structures,grain sizes and magnetism were analyzed and computed for three typical samples:the stock of polycrystalline metal Gd(sample 1),the bulk nanocrystalline Gd prepared by spark plasma sintering(SPS) techniq...The structures,grain sizes and magnetism were analyzed and computed for three typical samples:the stock of polycrystalline metal Gd(sample 1),the bulk nanocrystalline Gd prepared by spark plasma sintering(SPS) technique and subjected to the annealing process of 623 K for 0.5 h(sample 2) and the bulk nanocrystalline Gd prepared by the SPS technique at 573 K(sample 3).The computation results indicated that the sample 3 had the efficiency of space filling up to 99.38%.The computation results of magnetization i...展开更多
Electrochemistry with antifouling sensing interfaces that effectively resist the adsorption of nonspecific biomolecules provides a powerful mean for the accurate and sensitive detection of disease biomarkers tive dete...Electrochemistry with antifouling sensing interfaces that effectively resist the adsorption of nonspecific biomolecules provides a powerful mean for the accurate and sensitive detection of disease biomarkers tive dete in complex biofluids.However.there are few strategies to acquire a stable and solid antifouling coat-ing on any substrate by a simple way.Herein,a simple one-step assembly methød has been adopted to construct phase-transited bovine serum albumin(PTB)antifouling Layers.Prior to construction of the an-tifouling layers.the poly(3,4-ethylenedioxythiophene)(PEDOT)doped with 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide(ionic liquid,IL)were firstly electrodeposited on bare electrodes,en-dowing good conductiviry and catalytic capability for the developed sensor.Subsequently.with the assist of tris(2-carboxyethyl)phosphine(TCEP)the disulfide bonds of bovine serum albumin(BSA)were re-Im alb duced to form PTB,which can be coated on the PEDOT-It modified electrode to construct an antifouling electrochemical senor(PTB/PEDOT-ILCCE)for the detection of uric acid(UA)in human serum.The UA sensor demonstrated a good linear range from 1.11 umol/L to 798.9 umol/L with a high sensltivity of0,556 jA umolL^(-1)cm^(-2).The combination of conducting polymers with one-step assembly of PTB offers a universal and rellable method før the modification of various electrodes to determine target molecules in complex human body fluids.展开更多
The QCD deconfinement phase transition in pure SU（3） gauge theory is studied on an anlsotropic lattice. The critical temperature is determined to be Tc ≈ 285 MeV. The relation between the deconfinement phase transi...The QCD deconfinement phase transition in pure SU（3） gauge theory is studied on an anlsotropic lattice. The critical temperature is determined to be Tc ≈ 285 MeV. The relation between the deconfinement phase transition and the breakdown of Z（3） center symmetry is also discussed.展开更多
The non-Hermitian PT-symmetric system can live in either unbroken or broken PT-symmetric phase. The separation point of the unbroken and broken PT-symmetric phases is called the PT-phase-transition point.Conventionall...The non-Hermitian PT-symmetric system can live in either unbroken or broken PT-symmetric phase. The separation point of the unbroken and broken PT-symmetric phases is called the PT-phase-transition point.Conventionally, given an arbitrary non-Hermitian PT-symmetric Hamiltonian, one has to solve the corresponding Schrodinger equation explicitly in order to determine which phase it is actually in. Here, we propose to use artificial neural network(ANN) to determine the PT-phase-transition points for non-Hermitian PT-symmetric systems with short-range potentials. The numerical results given by ANN agree well with the literature, which shows the reliability of our new method.展开更多
The grand canonical Monte Carlo (GCMC), the canonical Monte Carlo by using equal probability perturbation, and the molecular dynamics (MD) methods were used to study the capillary phase-transition (capillary condensat...The grand canonical Monte Carlo (GCMC), the canonical Monte Carlo by using equal probability perturbation, and the molecular dynamics (MD) methods were used to study the capillary phase-transition (capillary condensation and evaporation) and self-diffusion for a simple Lennard-Jones model of ethylene confined in slit carbon pores of 2.109 nm at temperatures between 141.26 K and 201.80 K. The critical point of capillary phase-transition was extrapolated by the critical power law and the law of rectilinear diameter from the capillary phase-transition data in the near critical region. The effects of temperature and fluid density on the parallel self-diffusion coefficients of ethylene molecules confined in the slit carbon pores were examined. The results showed that the parallel selfdiffusion coefficients in the capillary phase transition area strongly depended on the fluids local densities in the slit carbon pores.展开更多
The transformation of Li_(2)S_(2)-Li_(2)S is indubitably the most crucial and labored rate-limiting step among the sophisticated reactions for the lithium-sulfur batteries(LSBs),the adjustment of which is anticipated ...The transformation of Li_(2)S_(2)-Li_(2)S is indubitably the most crucial and labored rate-limiting step among the sophisticated reactions for the lithium-sulfur batteries(LSBs),the adjustment of which is anticipated to impede the shuttle effect.Herein,a N,Se dual-doped carbon nanocages embedded by Co-CoSe_(2)nanoparticles(Co-CoSe_(2)@NSeC)is employed as a functional coating layer on commercial separator to improve the performance of LSBs.The well-designed N,Se co-doped nanostructures endow the modified layer with a satisfactory capacity for blocking polysulfides.Both calculations and experiments jointly disclose that the Li_(2)S_(2)to Li_(2)S reaction,including the liquid-solid conversion,was prominently expedited both thermodynamically and electrodynamically.Consequently,the batteries fabricated with Co-CoSe_(2)@NSeC modified separator can deliver a favorable 764.2 mAh g^(−1)with 8.0 C,accompanied by a salient long cycling lifespan(only 0.066%at 1 C and 0.061%under 2 C after 1000 and 2000 cycles),and a desired anode protection.In addition,despite a raised areal loading of 7.53 mg cm^(−2)was introduced,the cells assembled by Co-CoSe_(2)@NSeC@PP are allowed to produce an outstanding initial behavior of 8.71 mAh cm^(−2)under 0.2 C.This work may reinforce further explorations and serve with valuable insights into N,Se dual-doping materials for high-performance LSBs.展开更多
The water gas shift （WGS） reaction is reacts with water on a catalytic surface a process of industrial importance to form CO2 and H2. We study this In this reaction carbon monoxide reaction with thermal （Langmuir- ...The water gas shift （WGS） reaction is reacts with water on a catalytic surface a process of industrial importance to form CO2 and H2. We study this In this reaction carbon monoxide reaction with thermal （Langmuir- Hinshelwood） and non-thermal （precursor and Eley-Rideal） reaction mechanisms using the techniques of Monte Carlo computer simulation. The details of surface coverages and production rates are given as a function of CO partial pressure. The diffusion of species on the surface as well as their desorption from the surface is also introduced to include temperature effects. The phase diagrams of the system have been drawn to observe the behaviour of reacting species on the surface. The study reveals that the production rates are higher for non-thermal precursor mechanism and are in agreement with the experimental finding.展开更多
Moessbauer studies on the effect of substitution with 3% Al, Co, Mn atoms in the intermetallic compound of Hf0.8Ta0.2Fe2 are reported. The Al substitution leads to increase of the FM-AFM transition temperature and to ...Moessbauer studies on the effect of substitution with 3% Al, Co, Mn atoms in the intermetallic compound of Hf0.8Ta0.2Fe2 are reported. The Al substitution leads to increase of the FM-AFM transition temperature and to decrease of the AFM-PM transition temperature. The Co substitution leads to disappearance of the FM state, only showing some FM impurity component, while Mn substituted compound indicates coexistence of FM and AFM states at low temperature. The phenomena imply complex itinerant electron properties in these magnetic systems.展开更多
In situ resistivity measurement has been performed to investigate the electron transport property of powered CdTe under high pressure and moderate temperature in a designed diamond anvil cell. Several abnormal resisti...In situ resistivity measurement has been performed to investigate the electron transport property of powered CdTe under high pressure and moderate temperature in a designed diamond anvil cell. Several abnormal resistivity changes can be found at room temperature when the pressure increases from ambient to 33 GPa. The abnormal resistivity changes at about 3.8 GPa and 10 GPa are caused by the structural phase transitions to the rock-salt phase and to the Cmcm phase, respectively. The other abnormal resistivity changes at about 6.5 GPa, 15.5 GPa, 22.2 GPa and about 30 GPa never observed before are due to the electronic phase transitions of CdTe. The origin of the abnormal change occurred at about 6.5 GPa is discussed. The temperature dependence of the resistivity of CdTe shows its semiconducting behaviour at least before 11.3 GPa.展开更多
The Nanoindentation is a precise technique for the elucidation of mechanical properties. But such elucidation requires physically based interpretation of the loading curves that is widely still not practiced. The use ...The Nanoindentation is a precise technique for the elucidation of mechanical properties. But such elucidation requires physically based interpretation of the loading curves that is widely still not practiced. The use of indentation hardness <em>H</em> and indentation modulus <em>E<sub>r</sub></em> is unphysical and cannot detect the most important phase-transitions under load that very often occur. The claim that <em>H </em>versus<em> E </em>plots relate linearly for all different materials is neither empirically found nor correctly deduced. It is most dangerous by producing incorrect materials properties and misleading. The use of <em>H/E</em> (that is also called “elasticity index”) in complicated formulas for brittle parameter, yield strength, toughness, and so-called “true hardness” is also in error. The use of<em> H/E </em>cannot reveal the true qualities of materials without considering phase-transitions under load that require the correct exponent 3/2 on <em>h</em> for the loading curves (instead of disproved 2). This is exemplified with the physical data of different mollusk shells that experience phase-transitions, a new bionics model, and different contributions for their strengthening. The data are compared to the ones of aragonite and calcite and vaterite.展开更多
We perform the in-situ conductivity measurement on BaF2 at high pressure using a microcircuit fabricated on a diamond anvil cell. The results show that BaF2 initially exhibits the electrical property of an insulator a...We perform the in-situ conductivity measurement on BaF2 at high pressure using a microcircuit fabricated on a diamond anvil cell. The results show that BaF2 initially exhibits the electrical property of an insulator at pressure below 25 GPa, it transforms to a wide energy gap semiconductor at pressure from 25 to 30 GPa, and the conductivity increases gradually with increasing pressure from 30 GPa. However, the metallization predicted by theoretical calculation at 30-33 GPa cannot be observed. In addition, we measure the temperature dependence of the conductivity at several pressures and obtain the relationship between the energy gap and pressure. Based on the experimental data, it is predicted that BaF2 would transform to a metal at about 87 GPa and ambient temperature. The conductivity of BaF2 reaches the order of 10^-3Ω^-1 cm^-1 at 37 GPa and 2400 K, the superionic conduction is not observed during the experiments, indicating the application of pressure elevates greatly the transition temperature of the superionic conduction.展开更多
A new kind of multifractal is constructed by fractional Fourier transform of Cantor sets. The wavelet transform modulus maxima method is applied to calculate the singularity spectrum under an operational definition of...A new kind of multifractal is constructed by fractional Fourier transform of Cantor sets. The wavelet transform modulus maxima method is applied to calculate the singularity spectrum under an operational definition of multifractal. In particular, an analysing procedure to determine the spectrum is suggested for practice. Nonanalyticities of singularity spectra or phase transitions are discovered, which are interpreted as some indications on the range of Boltzmann temperature q, on which the scaling relation of partition function holds.展开更多
The CO-NO reaction on a catalytic surface is studied by using Langmuir-Hinshclwood thermal mechanism with Monte Carlo computer simulation. In this model, a novel concept of CO CO repulsion is introduced, which has exp...The CO-NO reaction on a catalytic surface is studied by using Langmuir-Hinshclwood thermal mechanism with Monte Carlo computer simulation. In this model, a novel concept of CO CO repulsion is introduced, which has experimental evidence due to the formation of dipoles when these molecules are chemisorbed on the surface. The system is investigated by applying two approaches of NO dissociation. In the first ca.se, NO always decomposes into N and O before adsorption on the surface, In the second case, NO adsorbs on the surface molecularly and then dissociates into N and O if a vacancy is present in its adjacent neighbourhood. The steady state reactive window （i.e. the continuous production of CO2 and N2） is obtained only with the diffusion of N-atoms on the surface, which extends with CO-CO repulsion in the first, case. Itowever, in the second case, reactive window is obtained with CO-CO repulsion alone, The reactive window width in this case is reasonably large. The first-order phase transition is eliminated in both the cases with CO-CO repulsion.展开更多
The CO-NO catalytic reaction on body-centred cubic （bcc） lattice is studied by Monte Carlo simulation. The simple Langmuir-Hinshelwood （LH） mechanism yields a steady reactive window, which is separated by continuo...The CO-NO catalytic reaction on body-centred cubic （bcc） lattice is studied by Monte Carlo simulation. The simple Langmuir-Hinshelwood （LH） mechanism yields a steady reactive window, which is separated by continuous and discontinuous irreversible phase transitions. The effect of precursor mechanism on the phase diagram of the system is also studied. According to this mechanism, the precursor motion of CO molecules is considered only on the surface of bcc lattice. Some interesting observations are reported.展开更多
基金National Natural Science Foundation of China (No. 52061011)Guangxi Natural Science Foundation,China (No. 2022GXNSFAA035574)Innovation Project of Guangxi Graduate Education,China (No. YCSW2023361)。
文摘The insufficient damping capabilities of aluminum alloy under low temperatures(<120℃)were addressed by developing high-damping laminated composites of NiTip/5052Al.This is achieved through the incorporation of varied pre-aging states of NiTi particles into the 5052Al matrix using a rolling composite technique.The aim is to enhance the application scope of aluminum alloy for vibration and noise reduction.The results demonstrated a distinct and integrated interface between the particle layer and the 5052Al alloy,with numerous interparticle interfaces within the particle layer.Increasing the aging temperature of the NiTi particles from 450 to 550℃ shifted the phase transition peaks of the composites to lower temperatures.The damping capacity of the laminated NiTip/5052Al composites notably surpasses that of the 5052Al alloy.At 28 and 66℃,the phase transformation damping peaks of the pre-aged NiTi particle layer reinforced 5052Al matrix composites are 1.93 and 2 times those of the 5052Al alloy at the corresponding temperatures,respectively.The collaborative impact of interparticle interface damping mechanism and the phase transformation damping mechanism of NiTi-reinforced particles significantly amplify the low-temperature damping performance of the laminated NiTip/5052Al composites.
文摘The general use of aluminium as an indentation standard for the iteration of contact heights for the determination of ISO-14577 hardness and elastic modulus is challenged because of as yet not appreciated phase-changes in the physical force-depth standard curve that seemed to be secured by claims from 1992. The physical and mathematical analyses with closed formulas avoid the still world-wide standardized energy-law violation by not reserving 33.33% (h2 belief) (or 20% h3/2 physical law) of the loading force and thus energy for all not depth producing events but using 100% for the depth formation is a severe violation of the energy law. The not depth producing part of the indentation work cannot be done with zero energy! Both twinning and structural phase-transition onsets and normalized phase-transition energies are now calculated without iterations but with physically correct closed arithmetic equations. These are reported for Berkovich and cubecorner indentations, including their comparison on geometric grounds and an indentation standard without mechanical twinning is proposed. Characteristic data are reported. This is the first detection of the indentation twinning of aluminium at room temperature and the mechanical twinning of fused quartz is also new. Their disqualification as indentation standards is established. Also, the again found higher load phase-transitions disqualify aluminium and fused quartz as ISO-ASTM 14577 (International Standardization Organization and American Society for Testing and Materials) standards for the contact depth “hc” iterations. The incorrect and still world-wide used black-box values for H- and Er-values (the latter are still falsely called “Young’s moduli” even though they are not directional) and all mechanical properties that depend on them. They lack relation to bulk moduli from compression experiments. Experimentally obtained and so published force vs depth parabolas always follow the linear FN = kh3/2 + Fa equation, where Fa is the axis-cut before and after the phase-transition branches (never “h2” as falsely enforced and used for H, Er and giving incorrectly calculated parameters). The regression slopes k are the precise physical hardness values, which for the first time allow for precise calculation of the mechanical qualities by indentation in relation to the geometry of the indenter tip. Exactly 20% of the applied force and thus energy is not available for the indentation depth. Only these scientific k-values must be used for AI-advises at the expense of falsely iterated indentation hardness H-values. Any incorrect H-ISO-ASTM and also the iterated Er-ISO-ASTM modulus values of technical materials in artificial intelligence will be a disaster for the daily safety. The AI must be told that these are unscientific and must therefore be replaced by physical data. Iterated data (3 and 8 free parameters!) cannot be transformed into physical data. One has to start with real experimental loading curves and an absolute ZerodurR standard that must be calibrated with standard force and standard length to create absolute indentation results. .
基金Supported by the China Postdoctoral Science Foundation(2024M752803)the Open Fund of Key Laboratory of Deep Geothermal Resources of Ministry of Natural Resources(KLDGR2024B01)+1 种基金the National Natural Science Foundation of China(52179112)the Open Fund of National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University)(PLN2023-02)。
文摘The thermal flux curve of phase-transition fluid(PF)was tested using differential scanning calorimetry,based on which a reaction kinetics model was established to reflect the relationship between phase transition conversion rate,temperature and time.A temperature field model for fractures and rock matrix considering phase transition heat was then constructed,and its reliability was verified using previously established temperature field models.Additionally,the new model was used to study the effects of different injection parameters and phase-transition fracturing performance parameters on the temperature variations in fractures and matrix.The study indicates that,at different positions and times,the cooling effect of the injected cold fluid and the exothermic effect during the phase transition alternately dominate the temperature within the fracture.At the initial stage of fracturing fluid injection,the temperature within the fracture is high,and the phase transition rate is rapid,resulting in a significant impact of exothermic phase transition on the reservoir rock temperature.In the later stage of injection,the fracture temperature decreases,the phase transition exothermic rate slows,and the cooling effect of the fracturing fluid on the reservoir rock intensifies.Phase transition heat significantly affects the temperature of the fracture.Compared to cases where phase transition heat is not considered,when it is taken into account,the temperature within the fracture increases to varying degrees at the end of fluid injection.As the phase transition heat increases from 20 J/g to 60 J/g,the maximum temperature rise in the fracture increases from 2.1℃ to 6.2℃.The phase transition heat and PF volume fraction are positively correlated with fracture temperature changes,while specific heat capacity is negatively correlated with temperature changes.With increasing injection time,the temperature and phase transition rate at the fracture opening gradually decrease,and the location of the maximum phase transition rate and temperature difference gradually shifts from the fracture opening to about 10 m from the opening.
基金financially supported by the National Natural Science Foundation of China(Nos.21774086 and 22175125)the Natural Science Foundation of Jiangsu Province(No.BK20180093)+1 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.21KJA150008)the Suzhou Municipal Science and Technology Foundation(No.SYS2018026)。
文摘Bacterial cellulose(BC)is one of the most versatile natural biopolymers with unique physical,chemical,and biological features.However,the lack of intrinsic antibacterial property of native BC limits its broad biomedical applications where such property is highly required to prevent contamination or infection caused by attached bacteria.In this work,we developed a simple and facile method to fabricate a dualfunctional BC membrane by physical incorporation of gold nanorods(GNRs)followed by deposition of a phase-transitioned bovine serum albumin(PTB)film.Due to the broad-spectrum antifouling property of the PTB film,the resulting membrane could prevent the adhesion and accumulation of bacteria.A few bacteria that broke through the protection of the PTB film could be eradicated under short-term irradiation of a near-infrared laser due to the excellent photothermal property of incorporated GNRs.The whole fabrication was conducted in a simple and environmentally friendly manner,avoiding complicated processes and toxic organic solvents.Moreover,because all the components were biocompatible,the resulting membrane showed negligible cytotoxicity in vitro and good histocompatibility in vivo.This work thus provided a reliable way to endow BC with antibacterial property,being beneficial for diverse biomedical applications.
文摘-The ISO standard 14577 is challenged for its violation of the energy law, its wrong relation of normal force FN with impression depth h, and for its iterative treatments. The solution of this dilemma is the use of sacrosanct simplest calculation rules for the loading parabola (now FN = kh3/2) giving straight lines for cones, pyramids and wedges. They provide the physical penetration resistance hardness k with dimension [Nm-3/2] and allow for non-iterative calculations with closed formulas, using simple undeniable calculation rules. The physically correct FN versus h3/2 plot is universally valid. It separates out the most common surface effects and reveals gradients. It provides unmatched precision, including reliability checks of experimental data. Regression analysis of FN versus h3/2 plots reveals eventual unsteadiness kink phase-transition onset with the transition-energy. This is shown for all kinds of solid materials, including salts, silicon, organics, polymers, composites, and superalloys. Exothermic and endothermic single and consecutive multiple phase-transitions with their surface dependence are distinguished and the results compared in 5 Tables. The sharp phase-transition onsets and the transition energies provide unprecedented most important materials’ characteristics that are indispensable for safety reasons. ISO ASTM is thus urged to thoroughly revise ISO 14577 and to work out new standards for the mechanically (also thermally) stressed materials. For example, the constancy of the first phase-transition parameters must be controlled, and materials must only be admitted for maximal forces well below the first phase-transition onset. Such onset loads can now be easily calculated. The nevertheless repeated oppositions against the physical analysis of indentations rest on incredibly poor knowledge of basic mathematics, errors that are uncovered. The safety aspects caused by the present unphysical materials’ parameters are discussed.
文摘A moist plume forms when the flue gas emitted from wet desulfurization equipment exits into the ambi- ent air, resulting in a waste of water resources and visual pollution. In addition, sulfur trioxide （SO3）, water with dissolved salts, and particles in the wet flue gas form secondary pollution in the surrounding atmosphere. In this study, a deep purification technology for flue gas involving phase-transition agglom- eration and dehumidification （PAD） is proposed. This deep purification technology includes two technical routes： the integrated technology of phase-transition agglomeration and a wet electrostatic precipitator （PAW）; and the integrated technology of phase-transition agglomeration and a mist eliminator （PAM）. Industrial applications of PAW and PAM were carried out on 630 and 1000 MW coal-fired units, respectively. The results show that the average amount of recycled water obtained from wet flue gas by means of PAD is more than 4 g.（kg.℃）-1 Decreasing the wet flue gas temperature by 1.5-5.3 ℃ allows 5%-20% of the moisture in the flue gas to be recycled; therefore, this process could effectively save water resources and significantly reduce water vapor emissions. In addition, the moist plume is effectively elim- inated. With the use of this process, the ion concentration in droplets of flue gas is decreased by more than 65%, the SO3 removal efficiency from flue gas is greater than 75%, and the removal efficiency of par- ticulate matter is 92.53%.
基金supported by the National Basic Research Program of China (2006CB705601)the National Natural Science Foundation of China (50771002)
文摘The structures,grain sizes and magnetism were analyzed and computed for three typical samples:the stock of polycrystalline metal Gd(sample 1),the bulk nanocrystalline Gd prepared by spark plasma sintering(SPS) technique and subjected to the annealing process of 623 K for 0.5 h(sample 2) and the bulk nanocrystalline Gd prepared by the SPS technique at 573 K(sample 3).The computation results indicated that the sample 3 had the efficiency of space filling up to 99.38%.The computation results of magnetization i...
基金supported by the China Postdoctoral Science Foundation(No.2022M711745)the Science and Technology Benefiting the People Project of Qingdao(No.20-3-4-53-nsh)the Taishan Scholar Program of Shandong Province of China(No.ts20110829).
文摘Electrochemistry with antifouling sensing interfaces that effectively resist the adsorption of nonspecific biomolecules provides a powerful mean for the accurate and sensitive detection of disease biomarkers tive dete in complex biofluids.However.there are few strategies to acquire a stable and solid antifouling coat-ing on any substrate by a simple way.Herein,a simple one-step assembly methød has been adopted to construct phase-transited bovine serum albumin(PTB)antifouling Layers.Prior to construction of the an-tifouling layers.the poly(3,4-ethylenedioxythiophene)(PEDOT)doped with 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide(ionic liquid,IL)were firstly electrodeposited on bare electrodes,en-dowing good conductiviry and catalytic capability for the developed sensor.Subsequently.with the assist of tris(2-carboxyethyl)phosphine(TCEP)the disulfide bonds of bovine serum albumin(BSA)were re-Im alb duced to form PTB,which can be coated on the PEDOT-It modified electrode to construct an antifouling electrochemical senor(PTB/PEDOT-ILCCE)for the detection of uric acid(UA)in human serum.The UA sensor demonstrated a good linear range from 1.11 umol/L to 798.9 umol/L with a high sensltivity of0,556 jA umolL^(-1)cm^(-2).The combination of conducting polymers with one-step assembly of PTB offers a universal and rellable method før the modification of various electrodes to determine target molecules in complex human body fluids.
基金Supported by NSFC under Grant Nos.10347110,10575107,10421003,10835002CAS under Grant No.KJCX3-SYW-N2the Numerical Calculations were Performed on DeepComp 6800 Supercomputer of the Supercomputing Center of Chinese Academy of Sciences,Dawning 4000A Supercomputer of Shanghai Supercomputing Center,and NKstar 2 Supercomputer of Nankai University
文摘The QCD deconfinement phase transition in pure SU（3） gauge theory is studied on an anlsotropic lattice. The critical temperature is determined to be Tc ≈ 285 MeV. The relation between the deconfinement phase transition and the breakdown of Z（3） center symmetry is also discussed.
基金Supported by the National Natural Science Foundation of China (Grant Nos.11535004,11975167,11761161001,11375086,11565010,11881240623 and 11961141003)the National Key R&D Program of China (Grant Nos.2018YFA0404403 and 2016YFE0129300)+1 种基金the Science and Technology Development Fund of Macao (Grant No.008/2017/AFJ)the Fundamental Research Funds for the Central Universities (Grant Nos.22120210138 and 22120200101)。
文摘The non-Hermitian PT-symmetric system can live in either unbroken or broken PT-symmetric phase. The separation point of the unbroken and broken PT-symmetric phases is called the PT-phase-transition point.Conventionally, given an arbitrary non-Hermitian PT-symmetric Hamiltonian, one has to solve the corresponding Schrodinger equation explicitly in order to determine which phase it is actually in. Here, we propose to use artificial neural network(ANN) to determine the PT-phase-transition points for non-Hermitian PT-symmetric systems with short-range potentials. The numerical results given by ANN agree well with the literature, which shows the reliability of our new method.
基金the National Science Foundation of China (NSFC) the China Petrochemical Corporation (SINOPEC) (No. 29792077).
文摘The grand canonical Monte Carlo (GCMC), the canonical Monte Carlo by using equal probability perturbation, and the molecular dynamics (MD) methods were used to study the capillary phase-transition (capillary condensation and evaporation) and self-diffusion for a simple Lennard-Jones model of ethylene confined in slit carbon pores of 2.109 nm at temperatures between 141.26 K and 201.80 K. The critical point of capillary phase-transition was extrapolated by the critical power law and the law of rectilinear diameter from the capillary phase-transition data in the near critical region. The effects of temperature and fluid density on the parallel self-diffusion coefficients of ethylene molecules confined in the slit carbon pores were examined. The results showed that the parallel selfdiffusion coefficients in the capillary phase transition area strongly depended on the fluids local densities in the slit carbon pores.
基金supported by the National Natural Science Foundation of China(No.21875039)the Project on the Integration of Industry-Education-Research of Fujian Province(No.2021H6020).
文摘The transformation of Li_(2)S_(2)-Li_(2)S is indubitably the most crucial and labored rate-limiting step among the sophisticated reactions for the lithium-sulfur batteries(LSBs),the adjustment of which is anticipated to impede the shuttle effect.Herein,a N,Se dual-doped carbon nanocages embedded by Co-CoSe_(2)nanoparticles(Co-CoSe_(2)@NSeC)is employed as a functional coating layer on commercial separator to improve the performance of LSBs.The well-designed N,Se co-doped nanostructures endow the modified layer with a satisfactory capacity for blocking polysulfides.Both calculations and experiments jointly disclose that the Li_(2)S_(2)to Li_(2)S reaction,including the liquid-solid conversion,was prominently expedited both thermodynamically and electrodynamically.Consequently,the batteries fabricated with Co-CoSe_(2)@NSeC modified separator can deliver a favorable 764.2 mAh g^(−1)with 8.0 C,accompanied by a salient long cycling lifespan(only 0.066%at 1 C and 0.061%under 2 C after 1000 and 2000 cycles),and a desired anode protection.In addition,despite a raised areal loading of 7.53 mg cm^(−2)was introduced,the cells assembled by Co-CoSe_(2)@NSeC@PP are allowed to produce an outstanding initial behavior of 8.71 mAh cm^(−2)under 0.2 C.This work may reinforce further explorations and serve with valuable insights into N,Se dual-doping materials for high-performance LSBs.
文摘The water gas shift （WGS） reaction is reacts with water on a catalytic surface a process of industrial importance to form CO2 and H2. We study this In this reaction carbon monoxide reaction with thermal （Langmuir- Hinshelwood） and non-thermal （precursor and Eley-Rideal） reaction mechanisms using the techniques of Monte Carlo computer simulation. The details of surface coverages and production rates are given as a function of CO partial pressure. The diffusion of species on the surface as well as their desorption from the surface is also introduced to include temperature effects. The phase diagrams of the system have been drawn to observe the behaviour of reacting species on the surface. The study reveals that the production rates are higher for non-thermal precursor mechanism and are in agreement with the experimental finding.
基金Supported by the National Natural Science Foundation of China under Grant No 20050284003.
文摘Moessbauer studies on the effect of substitution with 3% Al, Co, Mn atoms in the intermetallic compound of Hf0.8Ta0.2Fe2 are reported. The Al substitution leads to increase of the FM-AFM transition temperature and to decrease of the AFM-PM transition temperature. The Co substitution leads to disappearance of the FM state, only showing some FM impurity component, while Mn substituted compound indicates coexistence of FM and AFM states at low temperature. The phenomena imply complex itinerant electron properties in these magnetic systems.
基金Supported by the National Natural Science Foundation of China under Grant Nos 40473034, 40404007, 10574055, and 50532020, and the National Basic Research Programme of China under Grant No 2005CB724404. To whom correspondence should be addressed.
文摘In situ resistivity measurement has been performed to investigate the electron transport property of powered CdTe under high pressure and moderate temperature in a designed diamond anvil cell. Several abnormal resistivity changes can be found at room temperature when the pressure increases from ambient to 33 GPa. The abnormal resistivity changes at about 3.8 GPa and 10 GPa are caused by the structural phase transitions to the rock-salt phase and to the Cmcm phase, respectively. The other abnormal resistivity changes at about 6.5 GPa, 15.5 GPa, 22.2 GPa and about 30 GPa never observed before are due to the electronic phase transitions of CdTe. The origin of the abnormal change occurred at about 6.5 GPa is discussed. The temperature dependence of the resistivity of CdTe shows its semiconducting behaviour at least before 11.3 GPa.
文摘The Nanoindentation is a precise technique for the elucidation of mechanical properties. But such elucidation requires physically based interpretation of the loading curves that is widely still not practiced. The use of indentation hardness <em>H</em> and indentation modulus <em>E<sub>r</sub></em> is unphysical and cannot detect the most important phase-transitions under load that very often occur. The claim that <em>H </em>versus<em> E </em>plots relate linearly for all different materials is neither empirically found nor correctly deduced. It is most dangerous by producing incorrect materials properties and misleading. The use of <em>H/E</em> (that is also called “elasticity index”) in complicated formulas for brittle parameter, yield strength, toughness, and so-called “true hardness” is also in error. The use of<em> H/E </em>cannot reveal the true qualities of materials without considering phase-transitions under load that require the correct exponent 3/2 on <em>h</em> for the loading curves (instead of disproved 2). This is exemplified with the physical data of different mollusk shells that experience phase-transitions, a new bionics model, and different contributions for their strengthening. The data are compared to the ones of aragonite and calcite and vaterite.
基金Supported by the National Natural Science Foundation of China under Grant Nos 40473034, 40404007, 10574055, and 50532020, and the National Basic research Program of China under Grant No 2005CB724404.
文摘We perform the in-situ conductivity measurement on BaF2 at high pressure using a microcircuit fabricated on a diamond anvil cell. The results show that BaF2 initially exhibits the electrical property of an insulator at pressure below 25 GPa, it transforms to a wide energy gap semiconductor at pressure from 25 to 30 GPa, and the conductivity increases gradually with increasing pressure from 30 GPa. However, the metallization predicted by theoretical calculation at 30-33 GPa cannot be observed. In addition, we measure the temperature dependence of the conductivity at several pressures and obtain the relationship between the energy gap and pressure. Based on the experimental data, it is predicted that BaF2 would transform to a metal at about 87 GPa and ambient temperature. The conductivity of BaF2 reaches the order of 10^-3Ω^-1 cm^-1 at 37 GPa and 2400 K, the superionic conduction is not observed during the experiments, indicating the application of pressure elevates greatly the transition temperature of the superionic conduction.
文摘A new kind of multifractal is constructed by fractional Fourier transform of Cantor sets. The wavelet transform modulus maxima method is applied to calculate the singularity spectrum under an operational definition of multifractal. In particular, an analysing procedure to determine the spectrum is suggested for practice. Nonanalyticities of singularity spectra or phase transitions are discovered, which are interpreted as some indications on the range of Boltzmann temperature q, on which the scaling relation of partition function holds.
文摘The CO-NO reaction on a catalytic surface is studied by using Langmuir-Hinshclwood thermal mechanism with Monte Carlo computer simulation. In this model, a novel concept of CO CO repulsion is introduced, which has experimental evidence due to the formation of dipoles when these molecules are chemisorbed on the surface. The system is investigated by applying two approaches of NO dissociation. In the first ca.se, NO always decomposes into N and O before adsorption on the surface, In the second case, NO adsorbs on the surface molecularly and then dissociates into N and O if a vacancy is present in its adjacent neighbourhood. The steady state reactive window （i.e. the continuous production of CO2 and N2） is obtained only with the diffusion of N-atoms on the surface, which extends with CO-CO repulsion in the first, case. Itowever, in the second case, reactive window is obtained with CO-CO repulsion alone, The reactive window width in this case is reasonably large. The first-order phase transition is eliminated in both the cases with CO-CO repulsion.
文摘The CO-NO catalytic reaction on body-centred cubic （bcc） lattice is studied by Monte Carlo simulation. The simple Langmuir-Hinshelwood （LH） mechanism yields a steady reactive window, which is separated by continuous and discontinuous irreversible phase transitions. The effect of precursor mechanism on the phase diagram of the system is also studied. According to this mechanism, the precursor motion of CO molecules is considered only on the surface of bcc lattice. Some interesting observations are reported.
