Learning physical states of bulk crystalline materials from atomic trajectories in molecular dynamics simulation

Melting of crystalline material is a common physical phenomenon,yet it remains elusive owing to the diversity in physical pictures.In this work,we proposed a deep learning architecture to learn the physical states(solid-or liquidphase)from the atomic trajectories of the bulk crystalline materials with four typical lattice types.The method has ultrahigh accuracy(higher than 95%)for the classification of solid-liquid atoms during the phase transition process and is almost insensitive to temperature.The atomic physical states are identified from atomic behaviors without considering any characteristic threshold parameter,which yet is necessary for the classical methods.The phase transition of bulk crystalline materials can be correctly predicted by learning from the atomic behaviors of different materials,which confirms the close correlation between atomic behaviors and atomic physical states.These evidences forecast that there should be a more general undiscovered physical quantity implicated in the atomic behaviors and elucidate the nature of bulk crystalline melting.

Contactless Raman Spectroscopy-Based Monitoring of Physical States of Silyl-Modified Polymers during Cross-Linking

Cross-linking of silyl-modified polymers occurs at the alkoxysilane groups attached to the ends of polymer chains by hydrolysis and polycondensation mechanisms in the presence of moisture. During these reactions, three different physical states can be identified (viscous, skin effect and cross-linked state). Knowledge of the evolution of these states at each reaction time is essential to determine the open time for the adhe-sive industry and is generally obtained by a manual method. Automation of this moni-toring could avoid operator error and could be used for very long cross linking reac-tions or to screen a large number of catalysts. Thus, a contactless micro process tech-nology was developed to correlate these physical states with an optical technology, Raman spectroscopy, by monitoring the decrease in intensity of the Si-OCH3 groups during chemical reactions. This online characterization method can also be used to compare the efficiencies of several catalysts for the cross-linking of silyl-modified polymers, using a minimum amount of chemical materials.

Orthogonal Collision of Particles Produces New Physical State

Collider is a machine or device that usually causes two beams of high-speed particles moving to collide in a straight line. The fundamental purpose of a collision is to obtain an abnormal mass-energy density and attempt to discover new physics and new substances namely new physical states. However, linear collisions are not easy to achieve the above purpose. Through the comparable experiment of rear-end collision, head-on collision and orthogonal collision of two low-velocity particles, this paper theoretically proposes a new idea that the orthogonal collision between two-beam high-velocity particles can really produce an abnormal mass-energy density. This machine based on the new idea of orthogonal collision can not only greatly reduce the construction cost of colliders, but also is the most effective way to achieve the purpose of collision.

Functional Optical Fiber Sensors Detecting Imperceptible Physical/Chemical Changes for Smart Batteries

The battery technology progress has been a contradictory process in which performance improvement and hidden risks coexist.Now the battery is still a“black box”,thus requiring a deep understanding of its internal state.The battery should“sense its internal physical/chemical conditions”,which puts strict requirements on embedded sensing parts.This paper summarizes the application of advanced optical fiber sensors in lithium-ion batteries and energy storage technologies that may be mass deployed,focuses on the insights of advanced optical fiber sensors into the processes of one-dimensional nano-micro-level battery material structural phase transition,electrolyte degradation,electrode-electrolyte interface dynamics to three-dimensional macro-safety evolution.The paper contributes to understanding how to use optical fiber sensors to achieve“real”and“embedded”monitoring.Through the inherent advantages of the advanced optical fiber sensor,it helps clarify the battery internal state and reaction mechanism,aiding in the establishment of more detailed models.These advancements can promote the development of smart batteries,with significant importance lying in essentially promoting the improvement of system consistency.Furthermore,with the help of smart batteries in the future,the importance of consistency can be weakened or even eliminated.The application of advanced optical fiber sensors helps comprehensively improve the battery quality,reliability,and life.

Physical dispersion state and fluorescent property of Eu-complex in the Eu-complex/silicon rubber composites

The fluorescent complex Eu（TTA）2（Phen）（MA） （HTTA=2-Thenoyltrifluoroacetone, Phen=1,10-phenanthroline, MA=Maleic an- hydrider） was synthesized and characterized with elemental analysis, infrared spectrum （IR）, scanning electron microscope （SEM）, X-ray Diffraction（XRD）, differential scanning calorimetry（DSC）, and fluorescent measurement. To explore the effect of different physical dispersion state of Eu-complex on the fluorescent property of the Eu-complex/silicon rubber composites, various quantifies of Eu（TTA）2（phen） （MA） were mixed with silicon rubber （SIR） and peroxide to form uncured composites. These composites were vulcanized to obtain cured Eu-complex/SiR composites at 250 ℃, which was higher than the melting-point of Eu-complex. The SEM, XRD, DSC, and the fluorescent measurement of these composites showed that both the complex molecules dispersed in the silicon rubber during the melting process and the parent Eu-complex particles had positive effects on fluorescent property, whereas the re-crystallized Eu-complex particles and the aggregating complexes formed during the melting-process had negative effects on fluorescent property. For the uncured composites, their fluorescent intensities almost did not change with the increasing amount of Eu-complex. Furthermore, for the composites with small content of Eu-complex, their fluorescent intensities decreased significantly after curing, and this difference in fluorescent intensity became smaller as the content of Eu-complex increases.

Studies on Some Basic Physical Problems in Macromolecular Condensed State

Macromolecular condensed state involves crystalline state and non-crystalline state of long-chain synthetic and naturally occurring molecules. The noncrystalline state may be a polymeric fluid, a rubbery elastic semi-solid or a rigid glass.

Ultrafast photoemission electron microscopy:A multidimensional probe of nonequilibrium physics

Exploring the realms of physics that extend beyond thermal equilibrium has emerged as a crucial branch of condensed matter physics research.It aims to unravel the intricate processes involving the excitations,interactions,and annihilations of quasi-and many-body particles,and ultimately to achieve the manipulation and engineering of exotic non-equilibrium quantum phases on the ultrasmall and ultrafast spatiotemporal scales.Given the inherent complexities arising from many-body dynamics,it therefore seeks a technique that has efficient and diverse detection degrees of freedom to study the underlying physics.By combining high-power femtosecond lasers with real-or momentum-space photoemission electron microscopy(PEEM),imaging excited state phenomena from multiple perspectives,including time,real space,energy,momentum,and spin,can be conveniently achieved,making it a unique technique in studying physics out of equilibrium.In this context,we overview the working principle and technical advances of the PEEM apparatus and the related laser systems,and survey key excited-state phenomena probed through this surface-sensitive methodology,including the ultrafast dynamics of electrons,excitons,plasmons,spins,etc.,in materials ranging from bulk and nano-structured metals and semiconductors to low-dimensional quantum materials.Through this review,one can further envision that time-resolved PEEM will open new avenues for investigating a variety of classical and quantum phenomena in a multidimensional parameter space,offering unprecedented and comprehensive insights into important questions in the field of condensed matter physics.

Physical Parameter Identification Method Based on Modal Analysis for Two-axis On-road Vehicles:Theory and Simulation

Physical parameters are very important for vehicle dynamic modeling and analysis.However,most of physical parameter identification methods are assuming some physical parameters of vehicle are known,and the other unknown parameters can be identified.In order to identify physical parameters of vehicle in the case that all physical parameters are unknown,a methodology based on the State Variable Method（SVM） for physical parameter identification of two-axis on-road vehicle is presented.The modal parameters of the vehicle are identified by the SVM,furthermore,the physical parameters of the vehicle are estimated by least squares method.In numerical simulations,physical parameters of Ford Granada are chosen as parameters of vehicle model,and half-sine bump function is chosen to simulate tire stimulated by impulse excitation.The first numerical simulation shows that the present method can identify all of the physical parameters and the largest absolute value of percentage error of the identified physical parameter is 0.205%;and the effect of the errors of additional mass,structural parameter and measurement noise are discussed in the following simulations,the results shows that when signal contains 30 d B noise,the largest absolute value of percentage error of the identification is 3.78%.These simulations verify that the presented method is effective and accurate for physical parameter identification of two-axis on-road vehicles.The proposed methodology can identify all physical parameters of 7-DOF vehicle model by using free-decay responses of vehicle without need to assume some physical parameters are known.

MECHANICAL BEHAVIORS OF SATURATED SAND UNDER COMPLICATED LOADING

The different physical states of saturated sand, including shear elasticity, positive dilatancy, and negative dilatancy (preliminary negative dilatancy, secondary negative dilatancy and reversal negative dilatancy) are revealed based on the pore water pressure response of saturated sand in undrained dynamic torsional tests of thin cylinder samples and also checked by the drained cyclic triaxial tests under a given mean effective normal stress. According to the effective stress path of different physical states under the undrained cyclic torsional tests the physical state transformation surface, stress history boundary and yield surface are determined, and the state boundary surface is also determined by the range of effective frictional stress state movement. Based on the moving yield surface without rotation, and the expanding stress history boundary surface relevant to the stress path variations under different physical states in 3D stress space, a physical state model is proposed to provide a new approach to calculating the transient pore water pressure under the undrained condition, and the volume strain of dilatation under drained condition in this paper.

Concrete Physics Method for Solving NP hard Problem

With a NP hard problem given, we may find a equivalent physical world. The rule of the changing of the physical states is simply the algorithm for solving the original NP hard problem .It is the most natural algorithm for solving NP hard problems. In this paper we deal with a famous example , the well known NP hard problem——Circles Packing. It shows that our algorithm is dramatically very efficient. We are inspired that, the concrete physics algorithm will always be very efficient for NP hard problem.

Thermodynamical Evaluation on Magnetocaloric Effect of Magnetic Refrigerating Materials Near Room Temperature

The relationship between isothermal magnetic entropy change DELTA S andadiabatic temperature change DELTA T_(ad) was deduced according to the principles of thermodynamics.The MCE and the engineering application were discussed for Gd and several new kinds of magneticrefrigerating materials near room temperature, Gd_5Si_2Ge_2, MnFeP_(0.45)As_(0.55) and LaFe_(11.2)Co_(0.7)Si_(1.1). Isothermal entropy change is proportional to adiabatic temperature change with afactor of T/C (T is temperature, C is heat capacity). When the comparison of magnetacoloric effectis made for two different materials, we should consider isothermal entropy change as well asadiabatic temperature change.

Neutron star mass-radius relation with gravitational field shielding by a scalar field

The currently well-developed models for equations of state （EoSs） have been severely impacted by recent measurements of neutron stars with a small radius and/or large mass. To explain these measurements, the theory of gravitational field shielding by a scalar field is applied. This theory was recently developed in accor- dance with the five-dimensional （5D） fully covariant Kaluza-Klein （KK） theory that has successfully unified Einstein＇s general relativity and Maxwell＇s electromagnetic theory. It is shown that a massive, compact neutron star can generate a strong scalar field, which can significantly shield or reduce its gravitational field, thus making it more massive and more compact. The mass-radius relation developed under this type of modified gravity can be consistent with these recent measurements of neutron stars. In addition, the effect of gravitational field shielding helps explain why the supernova explosions of some very massive stars （e.g.9 40 MQ as measured recently） actually formed neutron stars rather than black holes as expected. The EoS models, ruled out by measurements of small radius and/or large mass neutron stars according to the the- ory of general relativity, can still work well in terms of the 5D fully covariant KK theory with a scalar field.

Solid State Physics View of Liquid State Chemistry—Electrical conduction in pure water

Engineering characterization of water has produced huge varieties of materials with special properties to meet human needs. Equilibrium properties of water-based liquids are well understood via localized atomic and molecular orbital theories. However, the mechanism of electrical conductivity of pure water has proven elusive. We show here it is trapping limited drift of positive and negative quasi-protons （or protons and proton-vacancies） on the extended water lattice, which is accounted for by the long-range correlation inherent in the Fermion （electrons and protons） and Boson （phonons） energy band theory of quasi-particles in solids, with vigorous adherence to equilibrium and nonequilibrium states.

Solid State Physics View of Liquid State Chemistry Ⅱ. Electrical Capacitance of Pure and Impure Water

More than 80 years of theories and experiments on water suggested to us, described in our first water-physics report, that pure water＇s ＂abnormally＂ high electrical conductivity is due to transport of positive and negative quasi-protons, p＋ and p-, between the neutral proton traps V （H20） in the extended water, [（H20）N]＋, converting it respectively to positively and negatively charged proton traps, V＋ = （H30）1＋ and V- = （HO）1-. In this second report, we present the theoretical charge control capacitances of pure and impure water as a function of the DC electric potential applied to water.

Solid State Physics View of Liquid State Chemistry Ⅲ. Electrical Conductance of Pure and Impure Water

The ＇abnormally＇ high electrical conductivity ofpure water was recently studied by us using our protonic bond, trap and energy band model, with five host particles： the positive and negative protons, and the amphoteric protonic trap in three charge states, positive, neutral and negative. Our second report described the electrical charge storage capacitance of pure and impure water. This third report presents the theory of particle density and electrical conductance of pure and impure water, including the impuritons, which consist of an impurity ion bonded to a proton, proton-hole or proton trap and which significantly affect impure waters＇ properties.