In the complicated and extreme hot-processing technology, the classical theories of dendrite growth based on the relative independency between thermodynamics and kinetics cannot be adapted to deal with the versatile mechanisms involved in complicated non-equilibrium solidifications, thus drastically limiting their industrial applications. This review summarized the development of dendrite growth theories assuming the thermo-kinetic independence, analyzed the inherent thermo-kinetic correlation, and described concisely the model for twin-roll casting technology and assuming the thermo-kinetic correlation. Applying above model, the correlation between thermodynamic driving force and kinetic energy barrier was quantitatively proved, and the alloy design and processing optimization in the twin-roll casting technology can be realized by selecting different thermo-kinetic combinations. Through declaring the shortcomings of the existing models, it is promising to generalize the further development of dendrite growth models and the application in realistic processing.

LaBr3∶Ce single crystal has excellent scintillation property, however, some micro-defects, such as inclusions, often appear in the crystal. The inclusions are harmful for the scintillation property of crystals. In this study, the LaBr3∶Ce crystals were grown with vertical Bridgman method. It was found that the inclusions mainly appear at the tail end of the crystal ingot. Polarization microscopy shows that there are two kinds of inclusions, one is bubble, and the other is solid inclusion. X-ray diffraction, differential thermal analysis and Raman spectroscopy were used to measure the samples with inclusion and without inclusions. However, no difference could be identified among the two types of samples. Therefore, it is conjectured that the solid inclusions are composed of substances which are similar to the matrix in composition and crystal structure. Based on these measurement results, the formation mechanism of the inclusions is explained with the constitutional supercooling theory.

A series of near-stoichiometric lithium niobate crystals doped with molybdenum (nSLN∶Mo) were grown, and their photorefractive properties were investigated. The experimental results show that the photorefractive sensitivity of nSLN∶Mo doping with 0.5mol% molybdenum reaches 0.25 cm/J and 0.21 cm/J with 488 nm and 532 nm laser, respectively. And the response time of nSLN∶Mo crystal at 488 nm can be further shortened by changing polarization condition. The results of infrared spectrum, ultraviolet-visible absorption spectrum and X-ray photoelectron spectroscopy reveal the reason for the change of photorefractive performance of nSLN∶Mo crystals.

The bandgap characteristics of two-dimensional phononic crystals in a triangular lattice with imperfect interface conditions were studied by using the boundary element method. Combined with Bloch theorem, the boundary element eigenvalue equations with imperfect interface conditions were derived for the two-component solid-solid phononic crystal in a triangular lattice. Based on the equation, the band structures of phononic crystals with different cross-section scatterers (circular, elliptical and square cross-section) were calculated, and the effects of the lattice symmetry on the band structures were discussed; additionally, the influences of the scatterer filling ratio on the position and width of the bandgaps were analyzed in the case of circular cross-section. Compared with other results calculated by other methods, it is shown that the boundary element method can effectively and accurately calculate the band structures of phononic crystals with different interface conditions and different shaped scatterers. Moreover, phononic crystals with imperfect interface conditions can open the complete band gap at low frequencies, especially for the phononic crystals with the circular cross-section.

A green-blue phosphors Sr5(PO4)3 F∶Eu2+ was prepared by high temperature solid-state method. The structure and spectral properties of the phosphor were characterized, and the effects of flux was studied. The results show that the doping of rare earth ions Eu2+ in Sr5(PO4)3F system does not change the structure; the excitation spectrum of phosphors Sr5(PO4)3F∶Eu2+ is the broadband with the main peak at 418 nm, and the emission spectrum is the broadband with the main peak at 524 nm; the optimum doping concentration of Eu2+ in phosphors Sr5(PO4)3F∶Eu2+ is 15mol%. Therefore, the phosphor Sr5(PO4)3F∶Eu2+ is a green-blue phosphor which can be effectively stimulated by near ultraviolet LED. The doping effects of flux have been studied, also. The results show that the doping concentration of flux H3BO3 is 5wt% in Sr5(PO4)3F∶Eu2+ system, which could reduce the reaction temperature from 1200 ℃ to 1100 ℃ and enhance the luminous intensity remarkably.

In recent years, with the rapid development of micro-electro-mechanical systems (MEMS), more urgent requirements have been put forward for the flexibility and electrical activity strength of ferroelectric materials. PVDF has attracted much attention as an excellent flexible ferroelectric material. In order to improve the ferroelectric properties of flexible PVDF films, three methods were used simultaneously in this paper. The three methods are (1)introducing TrFE into molecular chains, (2)doping low concentration BaTiO3 in solution system, (3)using thermal stretching method for thin films. The experimental results show that all three methods can effectively improve the ferroelectric properties of PVDF. The remnant polarization intensity of the films reached 19.8 μC/cm2. The low concentration of BaTiO3 doping will make the whole system unable to form a dense structure. High doping concentration will lead to the formation of clusters, resulting in the increase of defects in the film. Appropriate doping concentration can effectively improve the ferroelectric properties of thin films. In addition, the use of appropriate stretch temperature increases the molecular polarity and increases the ferroelectric phase content, the overall flexibility of the film greatly improves its application value.

The magnetoelectric effect of layered NFO/BTO composite films was studied based on the mechanical parameter model. It was found that the magnetoelectric coupling performance was best when the volume fraction of piezoelectric phase was about 0.47. The 2-2 NFO/BCZT films with different volume fraction ratios were grown by pulsed laser deposition with 0.7%Nb (001)-STO substrates. The results of XRD show that NFO/BCZT composite films are (00l) preferentially grown. The magnetoelectric coupling coefficient of the NFO/BCZT composite film was measured by a lock-in amplifier, the results show that the magnetoelectric performance is best when the volume of piezoelectric phase is slightly larger than that of piezoelectric phase.There are some differences between experimental results and theoretical results, which be mainly due to the difference between the actual parameters of the material and the parameters used in the calculation,the failure to obtain accurate k values due to the non-ideal coupling of the interface, and magnetoelectric effect is affected by microstructure and stress of thin films.

The TiO2 microspheres, ZnO microspheres and TiO2/ZnO composite microspheres were obtained by Sol-gel method and hydrothermal method with Carbon microspheres as a template. The samples were characterized by SEM and X-ray diffractometer. The result indicates that TiO2 microspheres, ZnO microspheres and TiO2/ZnO composite microspheres were obtained and the diameter of them were 5-10 μm. The photocatalytic properties of the obtained photocatalyst on methylene blue solution and lake water were studied under UV light and the sunlight. Photocatalytic experiments have shown that among the three microspheres, the TiO2 / ZnO composite microspheres have better photocatalytic activity.

Biomass graphene/LaFeO3 nanocomposites (graphene doping amount is 1%, 3%, 5% and 7% of LaFeO3) were prepared by two-step method. In order to obtain phase and microtopography, the biomass graphene/LaFeO3 nanocomposites were characterized by DTA-TG, XRD and SEM. Infrared analysis of samples was carried out by Fourier transform infrared spectrometer (FTIR). Effect of addition amount of the biomass graphene for the graphene/LaFeO3 nanocomposites on the photocatalytic activity in the methylene blue were studied. The results show that the biomass graphene/LaFeO3 nanophotocatalysts by two-step method have good stability and high efficiency photocatalytic activity. Addition of biomass graphene has improved photodegradation rate of LaFeO3 on the methylene blue. The optimal doping amount of the graphene is 7% and the photodegradation rate irradiated for 30 min reaches 56% under 175 W high pressure mercury lamp, which is 50% higher than LaFeO3 as the catalyst.

Using C16H36O4Ti, H2O, CH3COOH, C2H6O, La2O3 and CeO2 as raw materials.The nanostructure TiO2 and rare earth element (La, Ce) doped TiO2 composite were prepared by sol-gel method. The Performance and property of samples were studied by X-ray diffractometer, scanning electron microscope, ICP-OES, UV-Vis spectrometer and Medium diffusion. The result of experiment show that the experiment prepared to anatase crystal type of TiO2 powder and La/TiO2 powder, because cerium oxide slightly soluble in sour, doesn’t dissolve in solution.Ce is basically not mixed into titanium dioxide. The powder main of anatase type TiO2 and the compound of cerium oxides, no effect on the performance of TiO2.In the La/TiO powder has 8.24% La element. The 300 min La/TiO2 photocatalytic rhodamine B solution’s decolourization ratio increase to 91.2%, it has good inhibitory effect on staphylococcus aureus.

Bi4Ti3O12/BiOBr composite photocatalyst was prepared by one step solvothermal method. The composition, morphology and photocatalytic property of the sample were determined by X-ray diffraction, scanning electron microscopy, specific surface area aperture analyzer and ultraviolet-visible diffuse reflectance spectrometer. The influence of synthesis conditions on photocatalytic activity of sample was discussed. The active species and reaction mechanism in the process of photocatalytic reaction were explored. The results show that the as-prepared sample has high photocatalytic activity and good cycling stability while the ratio of Bi, Ti, Br is 10∶7∶5, ethylene glycol is used as solvent, polyvinylpyrrolidone is used as surfactant and its additive amount is 0.2 g. After 140 min of irradiation by 7 W LED lamp, the degradation rate of photocatalyst reaches 85.1%. ?O-2 and h+play a major role in the degradation process.

Firstly, Ni/CNTs precursor was synthesized using NiCl2?6H2O as nickel source and ethanol as solvent by solvothermal method. And then in hydrothermal reaction conditions, Ni/CNTs precursor was vulcanized by Na2S2O3?5H2O to successfully obtain NS/CNTs composites. The specific capacitance of NS/CNTs composites reach 533.33 F?g-1 at a current density of 1 A?g-1, and 42.50% of the specific capacitance is maintained after 1000 cycles. Compared with NS nanosheets (146.67 F?g-1 and 27.27%), the electrochemical properties of NS/CNTs composites have been greatly improved. The results indicate that the addition of CNTs can effectively enhance the electrochemical properties of nickel sulfides.

Cubic Co3O4 and CoO nanopowders were obtained by annealing Co(OH)2 precursor prepared from facile liquid phase precipitation method under air or hydrogen atmosphere. Compared with CoO, Co3O4 nanopowders possess larger size, bigger specific surface area, average pore size and pore volume. The electrochemical results show that Co3O4 delivers higher specific capacitances because of its high electrochemical activity, Co3O4 and CoO could achieve 618 F/g and 147 F/g at 0.5 A/g, respectively. However, CoO displays better rate performance, and the capacitance retention at 10 A/g compared with 0.5 A/g is 49.0% higher than 37.9% of Co3O4. After 2000 cycle tests, the capacitance of Co3O4 and CoO could achieve 100% and 137% of their initial capacitances, implying their excellent cycle performances.

By using first-principles calculations based on density-functional theory, the structure stability, magnetic properties and electronic structure of uniformly and nonuniformly alloyed Cu-Co monoatomic chains have been systematically investigated. The effect of elastic stretching/contraction deformations on the stability and electronic properties of alloyed Cu-Co atomic chains has also been studied. The cohesive energy per atom of Cu-Co atomic chain is lower than that for the corresponding ideal Cu atomic chain in the entire average interatomic distance. Thus, the alloyed Cu-Co atomic chain is more stable than the corresponding ideal Cu nanowire. It is established that Co dimers are easily formed in the nonuniformly alloyed Cu-Co atomic chain. The formation of Co2 dimers results in a nonuniformly distribution of the electron density and interatomic distances along the wire direction and leads to accelerated rupture of the wire between Cu atoms under stretching. While the uniformly alloyed Cu-Co atomic chain composed of regularly alternating Cu and Co atoms is stable under stretching up to large interatomic distances. The electronic structure reveale that strong hybridization between the Cu and Co states is responsible for the high stability of alloyed Cu-Co nanowire.

In recent years, the research on two-dimensional (2D) materials has become one of the most exciting areas of nanoscience. Among two-dimensional material preparation methods, liquid phase exfoliating of bulk materials with layered structure to prepare two-dimensional materials has become a hot topic. Compared to the bottom-up methods such as chemical vapor deposition (CVD), the industrially scalable method of preparing 2D materials and their dispersions by peeling off the bulk layered materials allows simple, versatile and low-cost techniques. Here we mainly study the preparation of water-based graphene, hexagonal boron nitride (h-BN) and transition metal chalcogenide (TMDs) solutions with a low-cost and environmental-friendly method. The composition and surface topography of the resulting layered nanosheets have been characterized by Raman, atomic force microscopy (AFM) as well as scanning electron microscopy (SEM). Estimation of concentrations at different centrifugal speeds has been performed by ultraviolet (UV) absorption spectroscopy. Finally, cyclic voltammetry measurements were carried out to measure the volumetric capacitance of the ionic liquid in the presence of MoS2 nanosheets. The average lateral size of the two-dimensional material nanosheets is around 400 nm, and the measured volumetric capacitance of the ionic liquid is 1.21 F/cm3, which is the key parameter for the study of the electronic devices. Our findings pave the way for the potential electronic applications of the water-soluble 2D material nanosheets.

The electronic structure and optical properties of Mn4Si7 and Mn4Si7 doped by Mo were calculated by the density functional theory (DFT) based first-principles method. The calculation results show that the bandgap width of Mn4Si7 Eg=0.804 eV, and the bandgap width of Mo doped Mn4Si7 Eg=0.636 eV. Doping changes the electronic structure near the Fermi surface of Mn4Si7. The bottom of conduction band by Γ transfer to Y points to low-energy, under the direction of migration to the top of valence band offset to high-energy direction, narrow band gap. The calculation also shows that Mo doping Mn4Si7 increases the dielectric function, refractive index, absorption coefficient, photoconductivity and other optical properties.

The investigation on the dipolar interactions and magnetization reversal in Ni three-Dimensional antidot arrays (3DAAs) using the first-order reversal curve (FORC) method. Ordered Ni 3DAAs were fabricated by electrochemical deposition into colloidal crystal templates of self-assembled polystyrene spheres. The samples have the same pore size of about 500 nm but different thicknesses, ranging from 0.3 μm to 1.2 μm. The FORC diagram analysis reveals a decrease in the magnetic dipolar interaction with the increasing sample thickness, as well as a decrease in the coercivity distribution. This results from the transition from the dipolar interaction to the exchange coupling as the thickness increases.

Carbon anode materials were extracted by one step pyrolysis carbonization of waste separator films, then the effects of the temperature and the time on the carbonization products were also investigat. The results suggest that the optimized temperature and time were 420 ℃ and 120 min during the pyrolysis carbonization of the waste separator films, respectively. As the anode in lithium ion battery, the reversible discharge specific capacity of carbon anode was as high as 543.8 mAh/g at low current density of 50 mA/g; even cycling at high current density of 2000 mA/g for 1000 cycles, the reversible discharge specific capacity could remain 125.0 mAh/g, indicating satisfactory electrochemical Li-storage performances. These results would not only facilitate to alleviate the harm of waste separator film to the environment but also make full use the utilization value of waste resource and reduce the preparation cost of the electrode materials.

Modification of polyacrylic acid carbonate precursor by self-template graft copolymerization of maleic anhydride and acrylic acid. The structure was stable and dense in the form of intersection network. LiNi0.5Mn1.5O4 cathode material for 5V lithium ion battery was prepared by high temperature sintering. XRD, SEM, galvanostatic charge discharge and electrochemical cyclic voltammetry show that the material has micro-nanostructure, regular crystal shape and uniform particle size. The working platform was 4.7 V, The first discharge capacity was 132 mAh/g at 0.5 C rate. The capacity retention rate of 50 cycles was 93%. The electrochemical performance is excellent.

Calcium carbonate whiskers were prepared from dolomite by gas-liquid contact method. The effect of calcination on the decomposition of dolomite was studied. At the same time, the preparation and mechanism of calcium carbonate whiskers were studied. The results showed that dolomite had the best decomposition effect at the calcination temperature of 850 ℃, the heating rate of 10 ℃/min and the calcination time of 4 h. The reaction temperature, aeration rate and stirring rate have significant effects on the formation of calcium carbonate whiskers.

In this paper, calcium carbide slag was used as raw material to prepare calcium sulfate whiskers in dilute sulfuric acid solution. On the basis of the optimal preparation conditions of the conventional hydrothermal method, the crystallization process of calcium sulfate whiskers was strengthened by using a microwave reactor without adding a surfactant. The effects of microwave reaction time and microwave radiation energy on the crystalline product were analyzed. The prepared product was characterized by X-ray diffractometry and scanning electron microscopy. The results show that the calcium carbide slag and dilute sulfuric acid solution react under microwave enhanced conditions for 10 min, and the microwave radiant energy was 400 W. The prepared calcium sulfate whiskers had uniform morphology, the average diameter of whiskers reaches 2.2 μm, and the average aspect ratio was 70. On this basis, the microwave effect and the growth mechanism of calcium sulfate whiskers were further analyzed.

Effect of hydroxyapatite (HAP) without graphene oxide (GO) and graphene oxide/hydroxyapatite composite (GO/HAP) containing 0.1% mass fraction of GO on in vitro remineralization of acid-etched bovine enamel was investigated. The surface and cross-section morphology, surface element, crystal structure and mechanical properties of the bovine enamel before and after remineralization were characterized by field emission scanning electron microscopy, EDX spectroscopy, X-ray diffractometer and Vickers microhardness tester. The results show that the GO/HAP composite form flower-like crystals with weak binding force on the surface of the acid-etched enamel. After ultrasonic stripping of these crystals, the demineralized enamel surface and the inter-rod gap are well repaired. The cross-section morphology shows that the GO/HAP composite can repair the deep enamel demineralization, promote the formation of a large number of tiny crystals between the enamel prisms, and the formation of order arranged crystals in the demineralized inter-rod gap. At the same time, the surface Ca/P molar ratio and crystal composition of the acid-etched enamel are well restored after the GO/HAP treatment.

The phase-separated droplet self-cleaning glaze was prepared with feldspar, kaolin and quartz as main raw materials. The properties of the samples were characterized by scanning electron microscopy, X-ray diffraction and contact angle measurement. The results show that when the content of titanium oxide is 5wt%, a large number of small solitary droplets are formed on the glaze surface, with a volume fraction of 58.48%, high surface hardness (869.10 kg/mm2) and good hydrophilic self-cleaning (surface wetting angle is 13.361°). Compared with the existing surface coated nano-coatings, the self-cleaning glaze has strong wear resistance and simple preparation method. It has good application prospects in the field of medium and high temperature architectural ceramics, and conforms to the concept of green environmental protection.

The WO3/TiO2 composite thin films have many special properties and become an excellent photoelectric functional material. Adopting advanced thin film deposition technology to obtain nanostructured WO3/TiO2 composite thin films with excellent properties is of great significance for improving the performance and application of photovoltaic devices. The sol-gel method, hydrothermal method, electrodeposition method and magnetron sputtering method were mainly introduced to prepare nanostructured WO3/TiO2composite thin films. The applications of nanostructured WO3/TiO2 composite thin films in electrochromic smart window, photocatalysis technology and humidity sensor were summarized. Finally, the future development tendency of nanostructured WO3/TiO2 composite thin films was proposed.

Preparation method and the important application background of ZnSe crystal were introduced. Various defects produced in the preparation of ZnSe by chemical vapor deposition (CVD), including haze, hole and microcrack, inclusion, layer and cellular, were summarized systematically. The defects were characterized by SEM, stereoscopic microscope, metallographic microscope and Fourier spectrometer. Based on domestic and foreign literatures and the analysis by our ourselves, the possible mechanism and inhibition methods of various defects were expounded and analyzed.

Multifunctional molecular-based magnetic materials can not only show the slow relaxation behavior of single-molecule magnets, but also exhibit other colorful physical or chemical properties such as fluorescence, chirality, ferroelectricity, adsorption, catalysis, etc. Various fields such as photoelectric and spintronic devices have potential application prospects. The design and development of new multifunctional molecular-based magnetic materials as an important research direction in the field of single-molecule magnets has attracted wide attention of researchers. In this review, based on the synthesis strategy and the relationship between structure and performance, the research progress of multi-functional molecular-based magnetic materials in recent years is reviewed, and the future development of related fields is prospected.

Graphene and its derivatives have been used in perovskite solar cells because of their excellent optical, electrical and flexible properties. The stability and photoelectric conversion efficiency of devices can be improved by adding graphene or graphene derivatives. This paper mainly introduces the application progress of graphene and its derivatives in perovskite solar cells. It may provide reference for the future to develop high performance and high stability devices by exploring the application of graphene and its derivatives in perovskite solar cells.

Ferroelectrics are a kind of functional materials with special properties and value. Among the recently reported ferroelectrics, the ferroelectrics constructed by organic heterocycles have excellent performance and have great application prospects. This paper reviews the nitrogen-containing organic heterocyclic ferroelectrics, which are more common and have outstanding properties, such as 1,4-diazabicyclo[2.2.2]-octane (dabco), quinuclidine. The principle of ferroelectric phase transition and related performance parameters are introduced, and the method of directional design of ferroelectrics is summarized. The aim is to provide reference for the synthesis of ferroelectric materials.