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Metal thiophosphates have wide potential critical applications in various fields, such as nonlinear optical materials, magnetic materials, photoluminescence materials and solid electrolytes. However, a detailed review of the relationship among structure, performance and application in thiophosphates has not been reported so far. In this work, we have undertaken integrated generalization for the structural features and application prospects of 312 known metal thiophosphates (117 ternary and 195 quaternary). A survey of their crystal structures shows that they have various link modes used to form the [P x S y ] n − ligands through the [PS4]3− building unit, for example, the ethane-like [P2S6]4− dimer, edge-sharing [P2S6]2−, corner-sharing [P2S7]4−, cyclic [P3S9]3− cluster, corner-sharing [P3S10]5− cluster, corner-sharing [P4S13]6− cluster and corner-sharing [P4S12]4− ring. Interestingly, various (P-S) ligands can also link other motifs to compose different structural features including zero-dimensional (0D) clusters, 1D chains, 2D layers and 3D networks. A detailed survey provides clear recognition of the inherent structure–performance relationship for thiophosphates and this result also illustrates that thiophosphates have huge potential as superior multifunctional materials.

Theoretical relations between load factors and distribution transformer noise are analysed. A 10kV/400kVA three-phase oil-immersed distribution transformer is used for sound pressure level test in various load conditions including various load ratios, unbalanced loads and power factors. The sound pressure levels of distribution transformer in different load conditions are compared and analysed. The results can be referenced for the field noise and vibration control of distribution power transformers.

A preprocessing method based on wavelet packet decomposition and spectral subtraction algorithm is proposed in this paper. The tested original noise signal is decomposed with the wavelet packet analysis. It is divided into several bands with different frequency range. In these bands, the noisy signals are further processed by spectral subtraction method. The theoretical analysis result shows that the proposed method is effective in restraining the influence of surrounding noises on the result of transformer noise measurement. The proposed method can be referenced for the noise measurement of power transmission and transformation projects.

In order to investigate the winding vibration characteristics of UHV shunt reactors, a scale model of UHV reactor is designed and manufactured with rated voltage 29.27 kV and rated current 669.9 A. The magnetic-structure coupled finite element model is proposed to analyze the winding vibration of the reactor. With this model, the distribution and time variation magnetic flux density (MFD) of the reactor is calculated. The Lorentz force in the winding is used as load input for structure analysis. The vibration displacement and acceleration distribution and variation process of the reactor winding is obtained.

Partial discharge fault detection based audible noise is a kind of new method. This paper set up a needle-plate discharge system, and investigates the feasibility of measuring the audible noise of partial discharge in transformer oil. A needle-plate discharge system is built, and audio noise of partial discharge inside and outside of transformer oil is measured by a microphone and a specially designed hydrophone. According to signal processing, it’s found that the characteristics of internal and external noise have good consistency on time domain wave, spectrum distribution, and time-frequency distribution, except that the former is much larger than the latter in amplitude. The experiment results show that it’s feasible to measure the noise of partial discharge in the transformer oil and have significant advantage in signal to noise ratio.

Low frequency noise has the characteristics of slow attenuation, strong penetration and long propagation distance. Compared with other types of environmental noise with the same equivalent sound level, the subjective annoyance of low frequency noise in substation is higher, which easily leads to the problem of public complaints. In order to quantify people’s subjective and objective feelings of noise, researchers established the relationship between subjective perception and objective parameters through human perception test. In this paper, the development history of low frequency noise human perception test method and the present situation are investigated, and a feasible human perception test method suitable for substation low frequency noise is put forward.

When the load current flows through the main row of the switch cabinet, the induction current is generated on both sides of the cabinet, and the electric power of the interaction between the bus and the panel appears. Because of the thin switch cabinet panel and double-layer plate structure, when the load current is large, the double-layer panel vibrates violently and collides with each other under the action of electric power, and then resulting in abnormal noise. It may lead to hidden danger of equipment safety for long time. In this paper, acoustic imaging technology is used to accurately locate the sound source, and then the vibration acceleration amplitude is measured by the vibration sensors. Based on its spectrum characteristics analyse result, the causes of abnormal noise are discussed and solutions are put forward.

In this paper, based on the acoustic impedance tube model established by COMSOL, we studied the influence of the boundary conditions on the frequency characteristics of the damping acoustic plate, the effect of the thickness of the damping layer on the single-layer and double-layer sandwich structure damping acoustic plate. Based on the simulation results, two conclusions can be obtained: (1) the damping layer can effectively increase the sound insulation of the sound insulation plate, and when the thickness of the damping layer is 2∼3 times of the bottom plate thickness, the performance-price ratio is the highest; (2) the sound insulation characteristics of the damping sound insulation plate follow the law of mass, and the sound insulation increases with the increase of frequency under the free boundary condition, while under the fixed support boundary condition, the low frequency sound insulation is larger.

The noise of substation is generally generated by the main transformer, reactor, capacitor and other electrical equipment, in which the transformer is the main sound source equipment. Its spectrum characteristics are mainly low frequency noise, medium and high frequency noise as auxiliary. The noise band is wide, the wave grow is long, the attenuation is slow, and the penetration ability to the building structure is strong, which seriously affects the daily life of the residents. In this paper, the noise source of a 500kV substation with noise exceeding the standard is tested and analyzed first, then the noise reduction scheme design and sound field simulation calculation are carried out to verify the feasibility of the scheme.

This paper presented the dynamic characteristics of transformer housing under rigid/flexible foundation conditions based on finite element method. The deformation and stress distribution were analyzed due to interior excitations. The dynamic response for different stiffness coefficients was also investigated. Results show the maximum deformation of the housing occurs at the top of high pressure bushing with the value of 132.6μm. And the maximum equivalent stress occurs at the junction between the steel bar and the supporting steel frame with the value of 18.5 MPa. The velocity, stress and deformation at the measuring point show a periodic response, besides the response frequency is consistent with the exciting force. Foundation stiffness has a great influence on the dynamic response of the transformer housing. The amplitude of equivalent stress decreases with the decreasing foundation stiffness, while the amplitude of deformation shows an opposite trend.

MgO-C refractories were prepared by using fused magnesia and flake graphite as main raw materials, adding metal aluminium powder as antioxidant, and using sucrose solution instead of phenolic resin as binder. The mechanical properties of MgO-C refractories obtained under different temperature conditions were studied and compared with those of phenolic resin bonded MgO-C refractories. The results show that CO2 and water vapor were mainly released from the solidified sucrose solution during the heating process, which can effectively solve the problem of harmful gases such as formaldehyde and phenol when the phenolic resin is heated. The MgO-C refractory material prepared by the sucrose solution as a binder has a good bonding strength after curing at 180 °C. The flexural strength and compressive strength of MgO-C refractories obtained by adding 6wt% sucrose solution are 4.90 MPa and 41 MPa. At high temperature, sucrose carbonization forms a strong carbon bonding, and the flexural strength of MgO-C refractories is 5.16 MPa and the compressive strength is 34 MPa, which is similar to the performance of the phenolic resin bonded MgO-C refractories.

In this study, novel MgO-C refractories using environmentally friendly sucrose as binder were prepared. To solve the harmful effects of formaldehyde and phenolic compounds that cause serious harm to the environment and human health released during the development, production and use of phenolic resin binders for MgO-C refractories, MgO-C refractories using environmentally friendly sucrose instead of phenolic resins as binders were prepared. The phase, microstructure, oxidation resistance and the antioxidant mechanism of MgO-C refractories prepared by adding sucrose as binder at different temperatures were analyzed. The formula between the weight loss of the material and the temperature is y=1.6225x+0.215 (600°C ∼ 1200°C). The addition of aluminium resulted in the formation of Al2O3 inside the refractories. Meanwhile, MgAl2O4 crystals were synthesized by Al2O3 and MgO at high temperature. The formation of Al2O3 and MgAl2O4 played an important role in improving the oxidation resistance property of MgO-C refractories using sucrose as binder.

The harmful components such as formaldehyde and phenolic compounds released during the development, production and use of MgO-C refractories prepared by using phenolic resin as a binder can cause serious harm to the environment and human health. In this paper, MgO-C refractory material with sucrose as binder and metal aluminium powder as antioxidant is prepared. Different slag temperature and time factors have a largely influence on the slag corrosion resistance of as-prepared samples. By analyzing the microstructure and composition of the samples, it is found that under the condition of constant time, the higher the temperature, the more obvious the slag corrosion phenomenon; under isothermal conditions, the longer the time, the more obvious the slag corrosion phenomenon. At the same time, it is revealed that the main corrosion process of MgO-C refractories prepared by adding sucrose as a binder is carbon oxidation and slag corrosion, which provides a theoretical basis for optimizing the slag resistance of MgO-C refractories.

In this paper, the big data analysis method is applied to the analysis of the factors affecting the DC magnetic bias of the transformer. The improved k-means clustering algorithm is used to identify the different magnetic reasons. The weighted relevance analysis is used to evaluate the influence of different factors on the magnetic current. Finally, the correctness of the method is verified by an example analysis, thus providing an effective basis for “one-button sequence control” DC magnetic bias treatment.

Transformer DC magnetic bias is difficult to accurately analyze and predict because it is caused by complex factors and has a wide influence. This paper combines big data with DC bias magnetic analysis method, making a breakthrough in the DC bias prediction model that only considers a single factor. From the perspective of multi-system coupling, this paper analyzes the modeling of DC magnetic bias based on multi-dimensional big data, and extracts the key influencing factors of transformer DC bias through multi-system big data cleaning and dimensionality reduction technology, thus providing an effective basis for "one-button sequence control" bias magnetic treatment.

Nanostructure reinforced nitride ceramics play an important role in the family of structural ceramics. In this study, large scale of one-dimensional (1D) β-sialon nanostructures and β-sialon-β-Si3N4 composite powders were synthesized simultaneously via a reduction nitridation process by using powders of silicon, aluminum, and silica as raw materials. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM/HRTEM), Fourier-transform infrared spectroscopy (FT-IR) and energy dispersive x-ray spectroscopy (EDS) were used to characterize the phase composition, morphology, and microstructure of the as-obtained products. As a result, large scale of 1D β-sialon nanostructures can be prepared at 1600 °C. The diameter of the as-prepared nanowires in the range of 80 to 170 nm can be tailored by the addition of aluminum. The growth of 1D β-sialon nanostructures is achieved by a vapor-solid (VS) mechanism. Photoluminescence (PL) of the 1D β-sialon nanostructures was characterized which exhibit violet/blue emission peaks, making it have the potential to be applied in optoelectronic nanodevices. Besides, nitride ceramic composite powders including β-Si3N4 and β-sialon with in situ formed β-sialon nanowires were also achieved. The phase transformation behavior and the thermodynamical analysis of the ceramic composite powders were also studied by characterizing the phase composition of the products synthesized at different temperature. The as-grown β-sialon nanowires and the composite powders have great potential to be applied in nanostructure reinforced structural ceramics.

Phase change materials (PCMs) have been widely investigated for thermal energy storage due to their excellent heat storage densities and narrow operating temperature. However, their poor thermal conductivity and shape stability during utilization always restrict their further application. In this paper, polyethylene glycol/expanded perlite phase change materials with Cu powder phase-change materials (PEG-Cu/EP PCMs) are prepared by vacuum impregnation to overcome these problems. The results indicated that Cu particles are well dispersed in PEG and uniformly enwrapped inside the pores and surfaces of EP due to their excellent physical interactions by capillary force and surface tension. Thus the as-prepared composites exhibit superior shape stability around the working temperature around 253 °C. Furthermore, when 9.35% Cu powders are added into PEG, its thermal conductivity of corresponding composite is significantly enhanced by 129.9%, with a nearly invariable phase change enthalpy at the same time. Therefore, the PEG-Cu/EP PCMs are confirmed to be promising energy storage materials for applications in solar energy generation, building energy conservation, and industrial waste heat utilization.

Expanded graphite/β-SiC nanowires composites (ESNC) were prepared through chemical vapor deposition, and paraffin/expanded graphite/β-SiC nanowires composites (PESNC) were made through vacuum impregnation to overcome liquid leakage during phase transition and enhance the thermal conductivity of paraffin. Fourier transform infrared spectroscopy showed no chemical interactions between the paraffin and ESNC. Differential scanning calorimetry estimated the temperature and latent heat of PESNC during melting to 45.73 °C and 124.31 J g−1, respectively. The respective values of these quantities during freezing were recorded as 48.93 °C and 124.14 J g−1. The thermal conductivity of PESNC was estimated to 0.75 W mK−1, which was 3.26-folds that of pure paraffin (0.23 W mK−1). PESNC perfectly maintained its phase transition after 200 melting–freezing cycles. The resulting ideal thermal conductivity, good chemical stability, thermal properties and thermal reliability of PESNC are promising for use in energy efficient buildings and solar energy systems.

This paper mainly researched the hydrothermal synthesis of Natrolite, using amorphous silicon source from the purified attapulgite. The effects of silicon source, silicon aluminum ratio, crystallization time and crystallization temperature on the synthesis of natrolite were investigated. The results showed that the optimal synthesis condition of natrolite was: Hydrothermal activated ATP with NaOH was silicon source, silicon aluminum ratio was 10:1, crystallization time lasted to 72h and crystallization temperature was 150°C, the template was removed by calcining 8 hours at 550°C. The structural formula of obtained natrolite is Na2Al2Si3O10•2H2O.

In this research, ordered silver nanowires (NWs) were transferred to flexible, freestanding nanofibrillated cellulose (NFC) thin film. Silver NWs were synthesized via a solution chemistry method and arranged by a novel assemble method at the oil–water–air, three phase interface. The transparent nanopaper was made of NFC through vacuum suction filtrated method. Then the arranged Ag NWs were transferred to the surface of the nanopaper using a relatively simple method to form a compound, nanopaper/Ag NWs. X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, atomic force microscopy, and transmission electron microscope were taken to characterize the phase and the morphology of the as-prepared products. Characterization of the as-synthesized nanopaper/Ag NWs indicated that they were compounded physically and the Ag NWs were well crystalline. The as-synthesized nanopaper showed well translucency. The nanopaper/Ag NWs showed excellent flexibility and conductivity. The as-synthesized products have the potential application in flexible conductor. This study may provide an effective strategy to design and construct nano-metallic materials with multitudinous features and potential applications in electric devices sensors, flexible devices and conductive materials.

Herein, ultralong silicon nitride nanowires were synthesized via a chemical vapor deposition method by using the low-cost quartz and silicon powder as raw materials. Simple processes were used for the fabrication of disordered and ordered nanowire membranes of pure silicon nitride nanowires. The nanowires in the disordered nanopapers are intertwined with each other to form a paper-like structure which exhibit excellent flame retardancy and mechanical properties. Fourier-transform infrared spectroscopy and thermal gravity analysis were employed to characterize the refractory performance of the disordered nanopapers. Highly ordered nanowire membranes were also assembled through a three-phase assembly approach which make the Si3N4 nanowires have potential use in textured ceramics and semiconductor field. Moreover, the surface nanowires can also be modified to be hydrophobic; this characteristic make the as-prepared nanowires have the potential to be assembled by the more effective Langmuir–Blodgett method and also make the disordered nanopapers possess a super-hydrophobic surface.