An integrated machine learning model for accurate and robust prediction of superconducting critical temperature

Discovering new superconductors via traditional trial-and-error experimental approaches is apparently a time-consuming process,and the correlations between the critical temperature(Tc) and material features are still obscure.The rise of machine learning(ML) technology provides new opportunities to speed up inefficient exploration processes,and could potentially uncover new hints on the unclear correlations.In this work,we utilize open-source materials data,ML models,and data mining methods to explore the correlation between the chemical features and Tcvalues of superconducting materials.To further improve the prediction accuracy,a new model is created by integrating three basic algorithms,showing an enhanced accuracy with the coefficient of determination(R2) score of 95.9 % and root mean square error(RMSE) of 6.3 K.The average marginal contributions of material features towards Tcvalues are estimated to determine the importance of various features during prediction processes.The results suggest that the range thermal conductivity plays a critical role in Tcprediction among all element features.Furthermore,the integrated ML model is utilized to screen out potential twenty superconducting materials with Tcvalues beyond 50.0 K.This study provides insights towards Tcprediction to accelerate the exploration of potential high-Tcsuperconductors.

Size Effects of the Critical Temperature in Ferroelectric Thin Films

The size effects of the critical behaviors for the systems of interacting spins are discussed extensively inliterature.In this paper,the finite-size dependence of the critical temperature and susceptibility of the ferroelectric thinfilm are investigated numerically based on the four-state Potts model with the nearest-neighbor interactions between thedipole moments.The four orientations of the domains exist in the ferroelectric film and the movement of the domainwalls determines the polarization switching process besides the boundary conditions of the film.The critical exponentsare obtained and our investigations show that the boundary conditions play the important roles for the ferroelectricproperties of the thin films and the critical behavior of the thin films strongly depends on the feature of the surface.

Uncertainties of critical temperatures based on higher-order fluctuations of the largest fragment charge

The new signature of liquid-gas phase transition has been well indicated by the higher-order fluctuations of the largest fragment charge,but the uncertainties of critical temperatures based on this signature have not been revealed.This study extracts the critical temperatures of liquid-gas phase transition in nuclear reactions and investigates their uncertainties.Utilizing the isospin-dependent quantum molecular dynamics model in conjunction with the statistical model GEMINI enables us to describe the dynamical path from the initial to the final state.An isotope thermometer and a quantum fluctuation thermometer are employed to extract the nuclear temperature.The higher-order fluctuations of the largest fragment charge and critical temperatures are studied in^(124)Sn+^(120)Sn collisions ranging from 400 to 1000 MeV/nucleon and^(124)Sn+AZ collisions at 600 MeV/nucleon.Observations revealed that the pseudo-critical point is robustly indicated by the higher-order fluctuations of the largest fragment charge.The critical temperatures extracted by the isotope thermometer are relatively consistent,with an uncertainty of 15%,while those obtained by the quantum fluctuation thermometer are heavily influenced by the incident energy and mass number of target nuclei.The excitation energy E∗and bound charge Zbound are used for event-sorting.These two ensembles represent the statistical properties of the initial and final states of the system,respectively.The initial-final correlations of statistical properties might lead to two phenomena.First,the size distribution of the largest fragment at the pseudo-critical point based on the Zbound ensemble is wide,while that based on E∗ensemble exhibits bimodality,which is a typical characteristic in the liquid-gas coexistence of a finite system.Second,the temperature at the pseudo-critical point based on the Zbound ensemble is higher than that based on the E∗ensemble.Furthermore,the projectile-like system exhibits a significant dynamical effect in its evolution path from the initial to final state,closely associated with the fluctuation of critical temperature.

Predictive modeling of critical temperatures in magnesium compounds using transfer learning

This study presents a transfer learning approach for discovering potential Mg-based superconductors utilizing a comprehensive target dataset.Initially,a large source dataset(Bandgap dataset)comprising approximately∼75k compounds is utilized for pretraining,followed by fine-tuning with a smaller Critical Temperature(T_(c))dataset containing∼300 compounds.Comparatively,there is a significant improvement in the performance of the transfer learning model over the traditional deep learning(DL)model in predicting Tc.Subsequently,the transfer learning model is applied to predict the properties of approximately 150k compounds.Predictions are validated computationally using density functional theory(DFT)calculations based on lattice dynamics-related theory.Moreover,to demonstrate the extended predictive capability of the transfer learning model for new materials,a pool of virtual compounds derived from prototype crystal structures from the Materials Project(MP)database is generated.T_(c) predictions are obtained for∼3600 virtual compounds,which underwent screening for electroneutrality and thermodynamic stability.An Extra Trees-based model is trained to utilize E_(hull)values to obtain thermodynamically stable materials,employing a dataset containing Ehull values for approximately 150k materials for training.Materials with Ehull values exceeding 5 meV/atom were filtered out,resulting in a refined list of potential Mg-based superconductors.This study showcases the effectiveness of transfer learning in predicting superconducting properties and highlights its potential for accelerating the discovery of Mg-based materials in the field of superconductivity.

Holographic energy loss near critical temperature in an anisotropic background

We study the energy loss of a quark moving in a strongly coupled quark gluon plasma under the influence of anisotropy.The heavy quark drag force,diffusion coefficient,and jet quenching parameter are calculated using the Einstein–Maxwell-dilaton model,where the anisotropic background is characterized by an arbitrary dynamical parameter A.Our findings indicate that as the anisotropic factor A increases,the drag force and jet quenching parameter both increase,while the diffusion coefficient decreases.Additionally,we observe that the energy loss becomes more significant when the quark moves perpendicular to the anisotropy direction in the transverse plane.The enhancement of the rescaled jet quenching parameters near critical temperature Tc,as well as drag forces for a fast-moving heavy quark is observed,which presents one of the typical features of quantum chromodynamics phase transition.

A New Method Based on the Non-isothermal Kinetic Equation to Estimate the Critical Temperature of Thermal Explosion for Energetic Materials Using Non-isothermal DSC

A method for estimating the critical temperature of thermal explosion for energetic materials using differential scanning calorimetry (DSC) measurement is derived from the Semenov's thermal explosion theory and the non-isothermal kinetic equation based on Harcourt-Esson's kinetic equation.The result obtained from this method coincides completely with that of the Hu-Yang-Liang-Wu method.

Critical temperature below the Curie temperature of ferroelectric ceramics PZT

The article presents the results of research the pre-transitional features of the behavior of solid solutions based on lead zirconate-titanate.The presence of a“special”critical temperature T_(d)on the temperature dependences of the permittivityε(T)and the remanent polarization P_(r)(T),preceding the temperature of the paraelectric phase transition at the Curie temperature T_(C),is noted.In the temperature range T<T_(d),the P_(r)(T)dependence obeys a power law.In the temperature range T_(d)<T<T_(C),this law is not fulfilled.The results of X-ray experiments make it possible to associate this behavior with reversible disordering at T<T_(d)of an ordered domain structure formed during the polarization of piezoelectric ceramics and with its irreversible disordering in the temperature range T_(d)<T<T_(C).This is due to the appearance of internal mechanical stresses in a polycrystalline ferroelectric due to irreversible depolarization of the samples at temperatures T_(d)<T<T_(C).

Dislocation Vibration, Morse Potential Function and Temperature Dependence of Critical Resolved Shear Stress of Some Single Crystals

By using Morse potential model,we calculate the temperature dependence of critical resolved shear stress (CRSS) of some single crystals. Dislocation-phonon interaction is considered in this paper. Theoretical calculations fit experimental law well. Investigations show: interatomic force is the physical intrinsic that controls the plastic deformation processing of materials, and thetemperature dependence of CRSS mainly comes from the temperature dependence of dislocationvibration.

The E3 ubiquitin ligase CSIT1 regulates critical sterility-inducing temperature by ribosome-associated quality control to safeguard two-line hybrid breeding in rice

Two-line hybrid breeding can fully utilize heterosis in crops.In thermo-sensitive genic male sterile(TGMS)lines,low critical sterility-inducing temperature(CSIT)is vital to safeguard the production of two-line hybrid seeds in rice(Oryza sativa),but the molecular mechanism determining CSIT is unclear.Here,we report the cloning of CSIT1,which encodes an E3 ubiquitin ligase,and show that CSIT1 modulates the CSIT of thermo-sensitive genic male sterility 5(tms5)-based TGMS lines through ribosome-associated quality control(RQC).Biochemical assays demonstrated that CSIT1 binds to the 80S ribosomes and ubiquitinates abnormal nascent polypeptides for degradation in the RQC process.Loss of CSIT1 function inhibits the possible damage of tms5 to the ubiquitination system and protein translation,resulting in enhanced accumulation of anther-related proteins such as catalase to suppress abnormal accumulation of reactive oxygen species and premature programmed cell death in the tapetum,thereby leading to a much higher CSIT in the tms5-based TGMS lines.Taken together,our findings reveal a regulatory mechanism of CSIT,providing new insights into RQC and potential targets for future two-line hybrid breeding.

Manipulating the Phase Transition Behavior of Dual Temperature-Responsive Block Copolymers by Adjusting Composition and Sequence

Temperature-responsive polymers have garnered significant attention due to their ability to respond to external stimuli.In this work,dual temperature-responsive block copolymers are synthesized via reversible addition-fragmentation chain transfer polymerization(RAFT)polymerization utilizing zwitterionic monomer methacryloyl ethyl sulfobetaine(SBMA) and N-isopropyl acrylamide(NIPAAm) as monomers.The thermal responsive behaviors can be easily modulated by incorporating additional hydrophobic monomer benzyl acrylate(BN) or hydrophilic monomer acrylic acid(AA),adjusting concentration or pH,or varying the degree of polymerization of the block chain segments.The cloud points of the copolymers are determined by UV-Vis spectrophotometry,and these copolymers exhibit both controlled upper and lower critical solu bility temperatures(LCST and UCST) in aqueous solution.This study analyzes and summarizes the influencing factors of dual temperature responsive block copolymers by exploring the effects of various conditions on the phase transition temperature of temperature-sensitive polymers to explore the relationship between their properties and environment and structure to make them more selective in terms of temperature application range and regulation laws.It is very interesting that the introduction of poly-acrylic acid(PAA) segments in the middle of di-block copolymer PSBMA_(55)-b-PNIPAAm_(80) to form PSBMA_(55)-b-PAA_(x)-b-PNIPAAm_(80) results in a reversal of temperature-responsive behaviors from 'U'(LCST UCST) type,while the copolymer PSBMA_(55)-b-P(NIPAAm_(80)-co-AA_(x)) not.This work provides a clue for tuning the phase transition behavior of polymers for manufacture of extreme smart materials.

Magnetic properties of La2CuMnO6 double perovskite ceramic investigated by Monte Carlo simulations

We present a theoretical study of the magnetic properties of the lanthanum copper manganate double perovskite La2CuMnO6 ceramic,using Monte Carlo simulations.We analyze and discuss the ground state phase diagrams in different planes to show the effect of every physical parameter.Based on the Monte Carlo simulations,which combine Metropolis algorithm and Ising model,we explore the thermal behavior of the total magnetization and susceptibility.We also present and discuss the influence of physical parameters such as the external magnetic field,the exchange coupling interactions between magnetic atoms,and the exchange magnetic field on the magnetization of the system.Moreover,the critical temperature of the system is about Tc=70 K,in agreement with the experimental value.Finally,the hysteresis loops of La2CuMnO6 are discussed.

Calculation of Pairwise Thermal Entanglement for Odd Qubit XX Chain

Using Jordan-Winger transformation and finite Fourier transformation,the Hamiltonian of XX chain canbe transformed to the diagonal form.If the total qubits number N = odd,the internal energy U,and correlation functionG_(zz) in thermal equilibrium can be calculated.Then the pairwise concurrence and the critical value β_(cr) can be calculated.For N≥5 XX chains,there are pairwise concurrences in thermal equilibrium for antiferromagnetic and ferromagneticeases when β>β_(cr).

Effect of exchange interaction in ferromagnetic superlattices:A Monte Carlo study

The Monte Carlo simulation is used to investigate the magnetic properties of ferromagnetic superlattices through the Ising model. The reduced critical temperatures of the ferromagnetic superlattices are studied each as a function of layer thickness for different values of exchange interaction. The exchange interaction in each layer within the interface and the crystal field in the unit cell are studied. The magnetic coercive fields and magnetization remnants are obtained for different values of exchange interaction, different values of temperature and crystal field with fixed values of physical parameters.

Erratum to“Fabrication of Tl_(2)Ba_(2)CaCu_(2)O_(8) superconducting films without thallium pellets

The rocking curve of Tl-2212 thin films in Fig.2 of our original paper[1]should be replaced with the following new one.Accordingly,in the fifth paragraph of Section 3 of the original paper,the statement“The full width at half maximum(FWHM)of the(0012)peak of the Tl-2212 phase is about 0.24°”should be“The full width at half maximum(FWHM)of the(0012)peak of the Tl-2212 phase is about 0.42°”.

Electron Auto-Localization Tailored by Its Thermal Energy: Dynamic Matrix Approach (DMA)

This paper investigates the thermal energy effect on electron auto-localization. The polaron characteristics (self-action potential and effective mass) are observed to be expressed via the renormalized electron-phonon coupling constant tailored by the thermal energy. Low temperatures are observed to favour auto-localization of the carrier while high temperatures favour polaron undressing and subsequent quenching of the quantum behaviour thereby rendering the system classical. The critical (transition) temperature τc expressed via the critical coupling constant ϒC is found to be the separating boundary between the quantum and the classical phases. Therefore, the polaron undergoes phase transition (from self-tapped to quasi free states) when the temperature of the medium is enhanced.

Implementation of a Semi-Classical Theory for Superconductors

When the temperature of certain materials is lowered to exceed a certain value called the critical temperature, a state transition occurs: the system passes from the normal state to the superconducting state. A superconductor has two fundamental physical properties: a zero electrical resistance to direct current and a Meissner effect (the material repels any external magnetic flux). Lacking a suitable theory, physicists have attempted to explain the existence of this exotic low-temperature state using phenomenological approaches. In this work, we introduce a semi-classical (non-phenomenological) theory of superconductors. We demonstrate then that only the behavior of the gas of free electrons following the variation of the temperature in the metal explains not only the physical properties of the superconductors but also the existence of superconductors at high critical temperature. The critical temperature then plays the same role as the liquefaction temperature in a gaseous state-liquid state transition and the same role as the Curie temperature in a paramagnetic state-ferromagnetic state transition.

Peierls Structural Transition in Q1D Organic Crystals of TTT<SUB>2</SUB>I<SUB>3</SUB>for Different Values of Carrier Concentration

The Peierls structural transition in the TTT2I3 (tetrathiotetracene-iodide) crystal, for different values of carrier concentration is studied in 3D approximation. A crystal physical model is applied that considers two of the most important hole-phonon interactions. The first interaction describes the deformation potential and the second one is of polaron type. In the presented physical model, the interaction of carriers with the structural defects is taken into account. This is crucial for the explanation of the transition. The renormalized phonon spectrum is calculated in the random phase approximation for different temperatures applying the method of Green functions. The renormalized phonon frequencies for different temperatures are presented in two cases. In the first case the interaction between TTT chains is neglected. In the second one, this interaction is taken into account. Computer simulations for the 3D physical model of the TTT2I3 crystal are performed for different values of dimensionless Fermi momentum kF, that is determined by variation of carrier concentration. It is shown that the transition is of Peierls type and strongly depends on iodine concentration. Finally, the Peierls critical temperature was determined.

Polymer Vesicles with Upper Critical Solution Temperature for Near-infrared Light-triggered Transdermal Delivery of Metformin in Diabetic Rats

Near-infrared light(NIR)triggered transdermal drug delivery systems are of great interest due to their on-demand drug release,which enable to enhance drug treatment efficiency as well as reduce side effect.Herein,a NIR-triggered microneedle(MN)patch array has been fabricated through depositing the photothermal conversion agent and anti-diabetic drug-loaded polymer vesicles with upper critical solution temperature(UCST)into dissolvable polymer matrix.The UCST-type polymer has a clearing point temperature of 41℃ and the drug-loaded polymer vesicles present excellent NIR-triggered and temperature responsive drug release behavior in vitro due to the disassociation of polymer vesicles upon NIR irradiation.After applying MNs to diabetic rats,significant hypoglycemic effect is achieved upon interval NIR irradiation and the blood glucose concentration can decrease to normal state for several hours,which enables to achieve the goal of on-demand drug release.This work suggests that the NIR-triggered MN drug release device has a potential application in the treatment of diabetes,especially for those requiring an active drug release manner.

Visualizing phase transition of upper critical solution temperature (UCST) polymers with AIE

The stimuli-responsive polymers with upper critical solution temperatures(UCST) are highly attractive for drug delivery applications. However, the phase transition process of UCST polymer is usually characterized by turbidity measurement and electron microscopy, which are significantly restricted by low sensitivity and static observation. In contrary, the fluorescence technique has significant advantages in terms of high sensitivity, easy operation, and dynamic observation. However, the conventional fluorophores suffer from the drawbacks of aggregation-caused quenching(ACQ) after being encapsulated by UCST polymers, which are not suitable for direct visualization of the phase transition process. To tackle this challenge, we herein developed a series of UCST polymers based on polyacrylamides decorated with bile acid and aggregation-induced emission(AIE)-active tetraphenylethene(TPE) groups, which can be used for direct fluorescence monitoring of the phase transition process. Moreover, the AIE-active UCST polymers can serve as drug carriers, which can not only monitor the drug release process under thermal stimuli, but also verify the drug release by fluorescence recovery after thermal stimuli. It is expected that the AIE-active UCST polymers with self-monitoring ability are promising for biomedical applications.

Research Progress on Fertility of Two-line Male Sterile Rice Lines

Great achievements have been made in the exploration of male sterile resources, gene mapping and cloning and molecular mechanism revealing, as well as in breeding and application of two-line rice in China. This paper briefly reviewed the discovery, types and cloning of sterile genes in rice and molecular breeding of two-line rice, and summarized the research progress of critical sterility inducing temperature, so as to provide new ideas for the research and breeding of two-line hybrid rice.