The mechanical properties, contact angle, thermomechanical and electrochemical properties of PE, PVDF, and ceramic separators were compared. The experimental results show that the PE separator has the largest porosity, the PVDF separator has the best mechanical properties, wettability, and heat resistance. Three kinds of separators were assembled into lithium-ion batteries for electrochemical tests. Among them, the PE separator has the best rate performance, and the ceramic separator has poor performance in charge-discharge cycles. At the same time, the PE and ceramic separators were tested with different amounts of electrolytes at room temperature and a high temperature, and it is found that the capacity of the PE separator is higher at room temperature, while the performance of the ceramic separator is better at a high temperature. The amount of electrolyte also has a certain influence on its electrochemical performance.

Cathode materials, nickel doped Cr₈O₂₁, were synthesized by a solid-state method. The effects of Ni doping on the electrochemical performances of Cr₈O₂₁ were investigated. The experimental results show that the discharge capacities of the samples depend on the nickel contents, which increases firstly and then decreases with increasing Ni contents. Optimized Ni_0.5Cr_7.5O₂₁ delivers a first capacity up to 392.6 mAh·g⁻¹ at 0.1 C. In addition, Ni doped sample also demonstrates enhanced cycling stability and rate capability compared with that of the bare Cr₈O₂₁. At 1 C, an initial discharge capacity of 348.7 mAh·g⁻¹ was achieved for Ni_0.5Cr_7.5O₂₁, much higher than 271.4 mAh·g⁻¹ of the un-doped sample, with an increase of more than 28%. Electrochemical impedance spectroscopy results confirm that Ni doping reduces the growth of interface resistance and charge transfer resistance, which is conducive to the electrochemical kinetic behaviors during charge-discharge.

Mo-5Ta targets were prepared by the spark plasma sintering (SPS) technology under the sintering temperatures of 1 400–1 600 °C, the holding times of 0–20 min, and the axial pressure of 30 MPa. The microstructure, performance, and grain growth kinetics of Mo-5Ta sputtering targets were studied. With the increase of sintering temperatures and times, Ta can more dissolve in Mo and form a Mo(Ta) solid solution. The grain sizes of Mo-5Ta targets remain unchanged at low temperatures (1 400–1 500 °C) while increasing significantly at high temperature (1 600 °C) with the extension of the holding time. In addition, the densities and Vickers hardness (HV_0.5) first ascend and then decrease with sintering proceeding. The thermal conductivity is positively correlated with the grain size and density, as a result of their joint action. Based on the comprehensive analysis, the grain growth is dominated by the combination of boundary diffusion and volume diffusion. When n=2, the activation energies of grain growth under holding times of 5, 10, 20 min are calculated as 762.70, 617.86, and 616.52 kJ/mol, respectively.

Catalysts consisting of Zeolite imidazolyl ester skeleton-67 (ZIF-67) and graphene oxide (GO) were fabricated through a solvothermal method, followed by etching ZIF-67 with oxygen-rich functional groups on GO in a reduction atmosphere at 400 °C. During this process, an open type of cobalt metal center was formed by the partial vaporization and oxidation of ZIF-67, further reducing to Co and partially combining with oxygen species to amorphous CoOx. Benefiting from the rich functional N, and metal/oxides active centers derived from the calcination process, the synthesized Co/CoOx@NSG-400 showed a low OER overpotential of 10 mA·cm⁻² at 298 mV, and an ORR half-wave potential of 0.8 V, which demonstrated its excellent bifunctional catalytic activity. Such a controllable calcination strategy with high yields could be expected to pave the way for synthesizing low-cost and efficient bifunctional electrocatalysts.

The composites were prepared by modifying silicon carbide fiber with particles of zirconium carbide (ZrC) and boron carbide (B₄C) and incorporating them into a phenolic resin matrix. The influence of ZrC and B₄C on the mechanical performance of SiC_f/phenolic composites after high-temperature pyrolysis was studied through flexural performance test. The results show that the composite material has good thermal stability and high-temperature mechanical properties. After static ablation at 1 400 °C for 15 minutes, the flexural strength of the composite material reaches 286 MPa, which is still 7.3% higher than at room temperature, indicating that the composite material still has good mechanical properties even after heat treatment at 1 400 °C.

SiC composite ceramics for solar absorber and storage integration are new concentrating solar power materials. SiC composite ceramics for solar absorber and storage integration were fabricated using SiC, black corundum and kaolin as the raw materials, Co₂O₃ as the additive via pressureless graphite-buried sintering method in this study. Influences of Co₂O₃ on the microstructure and properties of SiC composite ceramics for solar absorber and storage integration were studied. The results indicate that sample D2 (5wt% Co₂O₃) sintered at 1 480 °C exhibits optimal performances for 119.91 MPa bending strength, 93% solar absorption, 981.5 kJ/kg (25–800 °C) thermal storage density. The weight gain ratio is 12.58 mg/cm² after 100 h oxidation at 1 000 °C. The Co₂O₃ can decrease the liquid phase formation temperature and reduce the viscosity of liquid phase during sintering. The liquid with low viscosity not only promotes the elimination of pores to achieve densification, but also increases bending strength, solar absorption, thermal storage density and oxidation resistance. A dense SiO₂ layer was formed on the surface of SiC after 100 h oxidation at 1 000 °C, which protects the sample from further oxidation. However, excessive Co₂O₃ will make the microstructure loose, which is disadvantageous to the performances of samples.

The phosphors of KY_1−x(MoO₄)_2−y(WO₄) _y:xLn³⁺ (Ln³⁺ = Tm³⁺, Dy³⁺, Eu³⁺) were synthesized by using a sol-gel method. Then, the crystal structure, luminescence properties, energy transfer, and white emission of the prepared materials were researched. The molar ratio of the anion group on the photoluminescence(PL) emission and excitation intensity were investigated, revealing that the optimum intensity could be obtained by using = 3:1. The optimal Dy³⁺ doping concentration of KY(MoO₄)_1.5(WO₄)_0.5 was obtained. In addition, the color-tunable emissions of Dy³⁺/Eu³⁺-codoped KY(MoO₄)_1.5(WO₄)_0.5 phosphors were observed because of the effective energy transfer (ET) from Dy³⁺ to Eu³⁺ ions. Finally, by doping appropriate concentrations of Tm³⁺, Dy³⁺, and Eu³⁺ and different concentrations of (WO₄)²⁻, white light emitting phosphors KY_0.92(WO₄)₂:0.01Tm³⁺.0.06Dy³⁺, 0.01Eu³⁺ with excellent color-rending properties were obtained. The chromaticity coordinate was calculated as (x = 0.3238, y = 0.3173), closing to the artificial daylight (D65, x = 0.313, y = 0.329) illuminant, and which indicates the potential application of near ultraviolet White light-emitting diodes (WLEDs).

The sintering behavior and mechanical properties of zirconia doped with 2.0mol%–3.0mol% Y₂O₃ were studied by pressure-less sintering. The experimental results show that the densification temperature of zirconia ceramics increases gradually with the decrease of Y₂O₃ doping content by which decreases the sintering driving force due to the lower oxygen vacancy concentration of the systems. Furthermore, the bending strength and fracture toughness of the prepared zirconia ceramics increase with the decrease of Y₂O₃ doping content. It can be attributed to the fact that the phase stability of tetragonal zirconia decreases with the decrease of Y₂O₃ doping content, which is easier to induce “phase transformation toughening” and dissipate impact energy. The relative density, bending strength and fracture toughness of 2.0mol% Y₂O₃ doped zirconia ceramics (2.0Y-ZrO₂) sintered at 1 525 °C are 99.00%, 1 256.65±20.82 MPa and 9.85±0. 13 MPa·m^1/2, respectively.

A chiral low-molecular-weight gelator (LMWG) L-16Ala5PyPF6 was synthesized from L-alanine, which can cause physical gel in n-propanol, ethyl acetate, butylene oxide, water, benzene, 1,4-dioxane and chloroform. The sol-gel reactions were carried out in a mixture of stronger ammonia water and n-propanol at the volume ratio of 2:8. Single-handed twisted silica nanostructures with pore channels vertical to the wall surfaces were first prepared through a single-templating approach comparing with the reported double template method. The formation mechanism of radial pore structure was studied by transmission electron microscopy at different reaction time intervals, which indicated that the radial pore structure was formed via a structural transition in the sol-gel transcription process.

Biomineralization is a biological process of synthesizing inorganic minerals within organisms. It has been found that intracellular proteins are involved in the room temperature synthesis process of anatase TiO₂ in living mussels. Here, we used intracellular actin to synthesize hematite by biomineralization. Biomineralized hematite has a nano spindle structure with a particle size of approximately 150 nm. The microstructure indicates that the prepared hematite is a mesocrystals composed of ordered arrangement and assembly of primary nanoparticles. In addition, hematite mesocrystals exhibit good lithium storage performance as electrode materials for lithium batteries. The discharge specific capacity of the battery remained at 560.7 mAh·g⁻¹ after 130 cycles at a current density of 200 mA·g⁻¹. This work expands the synthesis methods of hematite by biomineralization, and provides a new strategy for preparing inorganic materials by intracellular proteins.

To explore ways to improve the accuracy of quantitative analysis of samples in the micrometer to nanometer range of magnitudes, we adopted analytical transmission electron microscopy (AEM/EDS) for qualitative and quantitative analysis of pyrite materials. Additionally, the k factor of pyrite is calculated experimentally. To develop an appropriate non-standard quantitative analysis model for pyrite materials, the experimentally calculated k factor is compared with that estimated from the non-standard quantitative analytical model of the instrument software. The experimental findings demonstrate that the EDS attached to a TEM can be employed for precise quantitative analysis of micro- and nanoscale regions of pyrite materials. Furthermore, it serves as a reference for improving the results of the EDS quantitative analysis of other sulfides.

A novel fiber optic sensor based on hydrogel-immobilized enzyme complex was developed for the simultaneous measurement of dual- parameter, the leap from a single parameter detecting fiber optic sensor to a fiber optic sensor that can continuously detect two kinds of parameters was achieved. By controlling the temperature from high to low, the function of fiber sulfide sensor and fiber DCP sensor can be realized, so as to realize the continuous detection of dual-parameter. The different variables affecting the sensor performance were evaluated and optimized. Under the optimal conditions, the response curves, linear detection ranges, detection limits and response times of the dual-parameter sensor for testing sulfide and DCP were obtained, respectively. The sensor displays high selectivity, good repeatability and stability, which have good potentials in analyzing sulfide and DCP concentration of practical water samples.

Tensile properties of fly ash based engineered geopolymer composites (FA-EGC) at different curing ages were studied by uniaxial tensile test and ultrasonic pulse velocity (UPV) methods, which included uniaxial tensile properties, the correlation between ultrasonic pulse velocity and tensile properties, and characteristic parameters of microcracks. The experimental results show that obvious strain hardening behavior can be found in FA-EGC at different curing ages. With the increase of curing age, the tensile strength increases, the tensile strain decreases and the toughness becomes worse. The UPV of FA-EGC increases with curing age, and a strong correlation can be found between tensile strength and UPV. With the increase of curing age, the average crack width of FA-EGC decreases and the total number of cracks increases. This is because the strength of geopolymer increases fast at early age, thus the later strength development of FA-EGC tend to be stable. At the same time, the bond strength between fiber and matrix, and the friction of fiber/matrix interface continue to increase with curing age, thus the bridging effect of fiber is gradually strengthened. In conclusion, the increase of curing age is beneficial to the development of tensile properties of FA-EGC.

Citric acid (CA) and chitosan (CS) were employed to modify magnesium oxychloride cement (MOC). Multiscale measurements were implemented to study the properties of the modified MOC pastes. Results show that the addition of CA/CS significantly changes the content of each phase and the microstructure of phase 5. The single addition of CA can effectively increase the compressive strength of MOC after 7 d curing, while CS exerts no obvious effect on the compressive strength. As to the simultaneous addition of CA and CS, the compressive strength of MOC gradually decreases with the increasing content of CS. Interestingly, mixing CA and CS significantly enhances the water resistance of MOC and decreases the degradation rate of MOC in phosphate buffered solution, which can be ascribed to the low specific surface area of the plate-like crystals in the modified MOC and the reduction of pores in the structure.

To investigate the assumptions proposed in this paper, the evolution law governing the strength and expansion performance of MgO and nano-MgO micro-expansive concrete in the environment of mineral powder was firstly observed in this study. Secondly, SEM, XRD, and TG-DSC microscopic tests were conducted to reveal the effects of the active mineral-powder admixture on the hydration degree and expansion performance of MgO and nano-MgO in HPC. Our experimental results successfully verified our hypothesis, which indicated that the expansion performance of macro-MgO and nano-MgO was indeed depressed by the addition of active mineral power admixtures, even though the mechanical property of concrete composites was effectively improved. Furthermore, the hydration test also demonstrated the negative interference on the mineral powders, which was induced by the expansion agents. It is found the amounts of hydrates tend to decrease because the mineral powder ratio reaches and exceeds 40%. Moreover, it is also concluded the effect of expansion agents is governed by the alkalinity cement paste, especially for the nano-MgO. In other words, the expansion performance of nano-MgO will vary more obviously with the hydration process, than MgO. The results of this study provide that effective experimental and theoretical data support the hydration-inhibition mechanism of magnesium expansive agents.

Cement, phosphorous slag (PS), and steel slag (SS) were used to prepare low-carbon cementitious materials, and triisopropanolamine (TIPA) was used to improve the mechanical properties by controlling the hydration process. The experimental results show that, by using 0.06% TIPA, the compressive strength of cement containing 60% PS or 60% SS could be enhanced by 12% or 18% at 28 d. The presence of TIPA significantly affected the hydration process of PS and SS in cement. In the early stage, TIPA accelerated the dissolution of Al in PS, and the formation of carboaluminate hydrate was facilitated, which could induce the hydration; TIPA promoted the dissolution of Fe in SS, and the formation of Fe-monocarbonate, which was precipitated on the surface of SS, resulting in the postponement of hydration, especially for the high SS content. In the later stage, under the continuous solubilization effect of TIPA, the hydration of PS and SS could refine the pore structure. It was noted that compared with portland cement, the carbon emissions of cement-PS-TIPA and cement-SS-TIPA was reduced by 52% and 49%, respectively.

To improve the efficiency and stability of chloride immobilization of portland cement paste, hydrated calcium aluminate cement (HCAC) prepared by wet grinding of CAC was added into portland cement paste as an additive. The immobilized chloride ratio (ICR) was evaluated, and the mechanism of chloride immobilization was researched by XRD, DTG, NMR, and MIP tests. The analysis results demonstrated that HCAC could improve the chloride immobilization capacity of portland cement paste. The mechanism was attributed to the following aspects: chemical binding capacity was enhanced via producing more Kuzel’s salt; physical adsorption capacity was reduced by decreasing the C-S-H gel; migration resistance was enhanced through refining the pore structure.

To improve the pozzolanic reactivity, waste glass (WG) needs to be micronized to fine particles so as to expedite the leaching of active constituent. The key feature of this work is to examine the effect of wet-grinded WG on the mechanical and structural properties of cement based materials. The experimental results show that wet-grinding can improve the ions leaching behavior of WGP and decrease the stability of silicon oxide bond. The pozzolanic reactivity of WGP was dramatically enhanced after wet-grinding, as high as 144.1% at 1 d and 110.9% at 28 d when the mean grain size of WGP reached 0.90 µm. The ground WGP can promote the transformation of capillary pores to gel pores to improve the compactness of microstructure regardless of the reaction time.

By the addition of superplasticizer and air entraining agent, manufactured sand self-compacting concrete (MS SCC) with slump flow varying from 500 to 700 mm and air content varying from 2.0% to 9.0% were prepared and the pumpability of MS SCC was studied by a sliding pipe rheometer (Sliper). According to the Kaplan’s model, the initial pump pressure and the pump resistance of MS SCC were obtained. Meanwhile, rheological properties including the yield stress and the plastic viscosity of MS SCC were measured by a rheometer. The experimental results show that the increase of slump flow contributes to a higher pumpability and a proper air content, i e, 6% is beneficial for the pumpability of MS SCC. Due to the existence of stone powder and stronger angularity of MS, the initial pump pressure of MS SCC is only about 60%–88% that of river sand (RS) SCC with the same slump flow and air content, indicating that MS SCC possesses a higher pumpability than RS SCC.

The coal gangue as the only source of silicon and aluminum was employed to synthesize sodalite and faujasite using hydrothermal method, which directly treated the mixture of pre-treated coal gangue and NaOH solution under hydrothermal environment. X-ray powder diffraction analysis (XRD), thermogravimetry analysis (TG) and differential thermogravimetry analysis (DTG), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), N₂ adsorption-desorption technique, X-ray photoelectron spectroscopy (XPS), etc. were used to characterize the samples. Cd²⁺ ion was used to evaluate the heavy metal ions removal performance of the samples. The experimental results show that the coal gangue, which consists of quartz, calcium feldspar, potassium feldspar and kaolinite, can transform to sodalite and faujasite under alkali-hydrothermal condition at 150 and 180 °C, respectively. The as-prepared sodalite and faujasite can effectively remove the simulated Cd²⁺ ion wastewater and actual industrial wastewater containing As³⁺, Cd²⁺, and Cr³⁺ ions, and the good heavy metal ion removal performance of the zeolites is mainly attributed to their low Si/Al ratio and high Na⁺ content. This alkali-hydrothermal method appears to be a simple and efficient method for transformation of coal gangue to high purity zeolites.

A bidirectional ribbed concrete beam slab structure was widly adopted for the upper space of industrial buildings. To maintain ample space and minimize the presence of conventional columns, a bidirectional prestressed concrete beam is often employed. The intersection node of the prestressed concrete frame beam column was characterized by a high density of steel reinforcement, significant structural loads, and complex construction requirements. To ensure the quality, safety, and progress of prestressed frame beam-column intersection nodes during construction, this article proposed a new technology for constructing such nodes, which includes setting the tensioning and haunching ends of nodes at different positions, using ABAQUS finite element software to optimize the design of cross-sectional dimensions, conducting stress analysis simulations.

The polyacrylamide which is directly added into concrete shows strong water absorption property. Thus the construction of underwater constructure would demand high amount of water, resulting in poor workability of concrete and strength shrinkage after hardening. Herein, a kind of anionic polyacrylamide (APAM) grafted with water reducing functional group (-COOH) was synthesized at low temperatures by partial factor design and response surface design. The structure and morphology of APAM were characterized by UV, FTIR and SEM methods. The experimental results show that the molecular weight of the synthesized APAM could reach 11 million, under the condition that the temperature was 35 °C, the pH value was 8, the monomer concentration was 27wt%, the initiator dosage was 0.6wt%, and the monomer ratio (n(AM): n(AA)) was 3. When the APAM was applied into the underwater slurry, it presented good flocculation and low water demand. When the dosage was 1% of the mass of the cement, the water demand increased by 12%, which could meet the self-leveling and anti-dispersity of the underwater slurry at the same time. This technology provides technical guidance for the large-scale industrial production of polyacrylamide for underwater concrete construction while achieving environmental protection during production.

During the modernization or rehabilitation activity, the demolished structural waste causes large soil pollution and unavailability of natural aggregate is the big concern for the construction industry. Therefore, this manuscript deals with the Composite Steel Circular Column (CSCC) with Recycled Aggregate concrete (RAC) as infill is partly used, with the replacement of 25% and 50% in M30 grade of Concrete. And internal reinforcement steel is fully replaced by rolled steel tubes (circular and square) with varied thickness, ISA-unequal angle. Around 14 specimens are cast and examined under axial load for analysis of the deflection characteristics, the load-bearing capacity along with its buckling behavior. The experimental values are estimated through LVDT (linear variable differential transducer) at 3-phase. The curve of load-deflection is drawn with the load pattern. From the date interpretation, it is found column made of 50%-RAC has more than 25%-RAC.

An accurate flow stress model was established by considering the parameters of strain rate, strain and temperature as well as β → α+β phase transformation in order to develop the plastic forming theory of TC18 titanium alloy. Firstly, the phase transition kinetics of TC18 titanium alloy during isothermal and continuous cooling at 1 073 and 1 273 K was studied by thermodynamic calculation, meanwhile, the relationship of volume fraction of phase transition with temperature and time was obtained. Constitutive models were calculated by investigating flow behaviors under hot compression tests with the strain rates of 0.001–1 s⁻¹ and temperatures of 973–1 223 K in the single β and α+β regions in TC18 titanium alloy, respectively. By combining the phase transformation dynamic kinetics with constitutive models, an accurate flow stress model was established, providing theoretical basis and data support for the hot forging of TC18 titanium alloy.

The impact-abrasive wear behavior of ZTA (zirconia toughened alumina) particle(ZTAp) and NbC particle (NbCp) reinforced Fe60 matrix composites (ZTAp-NbCp/Fe60) were investigated. Specimens of pure Fe60 matrix material, NbCp reinforced Fe60 composite (NbCp/Fe60) and ZTAp-NbCp/Fe60 with different contents of ZTAp were prepared through vacuum sintering and tested on an MLD-10B Impact Wear Rig. As revealed by the results, NbCp could strengthen Fe60 matrix, and had fine grain strengthening effect on Fe60 matrix. When the mass fraction of ZTAp was 5%–15%, the impact-abrasive wear performance of ZTAp-NbCp/Fe60 composites was better than that of Fe60 and NbCp/Fe60. When the mass fraction was 15%, the ZTAp-NbCp/Fe60 had the best performance. ZTAp could weaken the impact and wear effect of abrasive particles on the composite and protect the matrix. Cracks occured at the interface and at defects in the ZTAp. The former leaded to ZTAp shedding, while the latter leaded to ZTAp fracturing. In both cases, the performance of the composite material would decrease.

The hollow strontium carbonate pompons was synthesized for the first time by a controlled reaction precipitation method with sodium dodecyl benzene sulfonate (SDBS) and polyvinyl pyrrolidone (PVP) work together as template. The sampled particles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption-desorption measurement, X-ray diffraction (XRD), Energy dispersive X-Ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis and differential scanning calorimetry (TGA-DSC), etc. It is shown that the assynthesized hollow strontium carbonate pompons with the size of about 2 µm consist of flake-like particles under the optimal reaction conditions. The formation mechanism of hollow strontium carbonate pompons was preliminarily explored.

The metastable β titanium alloy TB8 (Ti-12.76Mo-2.13Nb-2.73A1-0.16Si) was used as the original material, and the secondary processing method combining equal channel angular pressing (ECAP) and heat treatment was adopted. With the help of optical microscope (OM), scanning electron microscope (SEM) and X-ray diffractometer (XRD), the corrosion behavior of TB8 titanium alloy after different secondary processing (800 °C/850 °C solid solution-520°C aging, ECAP-800 °C/850 °C solid solution-520 °C aging, and 800 °C/850 °C solid solution-ECAP-520 °C aging) was studied. The experimental results show that the hot corrosion products of the six samples are similar, mainly Na₂Si₂O₅, MoS₂, TiCl₂, Ti(SO₄)₂, and TiS. Due to the grains of the TB8 titanium alloy treated by 850 °C solid solution-ECAP-520 °C aging are obviously refined, the surface structure is the most smooth and dense, forming a continuous Al₂O₃ protective film, and the surface defects are the least after corrosion. Its corrosion layer thickness is the lowest (102.3 µm), only 36.5%–81.4% of that of other secondary processing titanium alloys. In addition, the corrosion kinetics curves of the six materials all follow parabolic laws, and the minimum corrosion weight gain of the samples after 850 °C solution-ECAP-520 °C aging treatment is 0.7507 mg·mm⁻², showing better hot corrosion resistance.

The failure process was characterized by complex diffusion of elements in the bonding layer, TGO growth and growth stress inside the coating. We studied the aluminum migration phenomenon of NiCoCrAlY and NiCoCrAlYHf coatings under high temperature oxidation, TGO growth characteristics, the microstructure and composition of the bonding layer, and integrates them into the description of the surface strain under coating tension. The experimental results show that the TGO growth rate of NiCoCrAIYHf coating is lower than that of NiCoCrAIY coating, and the formed TGO is thinner. After high temperature oxidation, the cracking time of NiCoCrAIY coating is advanced, while the cracking time of rare earth doped coating is delayed. The addition of rare earth elements can effectively inhibit the generation of spinel phase, improve the fracture toughness of TGO, refine the grains in the bonding layer, and increase the grain boundary strengthening by 29.1 MPa which is consistent with the experimental value. Therefore, the yield strength of the doped coating is improved and the crack time of the coating is delayed.

We presented a strategy to prepare spherical tungsten powder by the combination of hydrothermal method and H₂ reduction process. In hydrothermal process, the micelle of tetraethylammonium bromide (TEAB) act as spherical templates for the deposition of tungsten oxide, whereas the excessive TEAB inhibit the formation of spherical tungsten oxide due to the dense molecular layer of TEAB on the tungsten oxide particles. Citric acid (CA) can control the formation rate and structure of the tungsten oxide when its concentration is more than 0.2 mol/L, because of its ability to coordinate with tungsten atoms. The synergistic effect of TEAB and CA facilitates the formation of spherical tungsten oxide with nanorod crown. After being treated by H₂ at 600 and 650 °C, the tungsten oxide particles are reduced to tungsten particles, which maintain the spherical structure of tungsten oxide and have porous structure.

TRIP980 high-strength steel plate/SPCC low-carbon steel plate were welded by RPW. The key factors such as size and material of filler were studied, and the structure, fusion ratio and mechanical properties of the RPW joint were analyzed. The experimental results show that the calculation formulas of the length and diameter of the filler were designed reasonably. Q235 as a filler for RPW of TRIP980 high -strength steel plate/SPCC low-carbon steel plate is suitable according to schaeffler organization chart. The deposited metal of RPW joint is in the shape of “spool”, and the base metal and cap of deposited metal are alternately combined. The deposited metal has the characteristics of “locking” as rivets, which is beneficial to the improvement of mechanical properties of RPW joint. The nugget of RPW joint is uniform without deviates. TRIP980 high-strength steel plate, SPCC low-carbon steel plate, and filler were metallurgically bonded in the RPW joint.

Both Cu60Ni38Co2 and Cu60Ni40 alloy were naturally cooled after rapid solidification from the liquid phase. The transformation law of the microstructure characteristics of the rapidly solidified alloy with the change of undercooling (ΔT) was systematically studied. It is found that the two alloys experience the same transformation process. The refinement structures under different undercoolings were characterized by electron backscatter diffraction (EBSD). The results show that the characteristics of the refinement structure of the two alloys with low undercooling are the same, but the characteristics of the refinement structure with high undercooling are opposite. The transmission electron microscopy (TEM) results of Cu60Ni38Co2 alloy show that the dislocation network density of low undercooled microstructure is lower than that of high undercooled microstructure. By combining EBSD and TEM, it could be confirmed that the dendrite remelting fracture is the reason for the refinement of the low undercooled structure, while the high undercooled structure is refined due to recrystallization. On this basis, in the processing of copper base alloys, there will be serious work hardening phenomenon and machining hard problem of consciousness problems caused by excessive cutting force. A two-dimensional orthogonal turning finite element model was established using ABAQUS software to analyze the changes in cutting speed and tool trajectory in copper based alloy ultrasonic elliptical vibration turning. The results show that in copper based alloy ultrasonic elliptical vibration turning, cutting process parameters have a significant impact on cutting force. Choosing reasonable process parameters can effectively reduce cutting force and improve machining quality.

A series of π-conjugated compounds ending with 9,9-diethyl-1-phenyl-1,9-dihydrofluoreno[2,3-d]imidazole were conveniently synthesized by condensation of the key intermediate 9,9-diethyl-N²-phenyl-9H-fluorene-2,3-diamine with the corresponding symmetric aryl phthalaldehydes under very mild conditions. The structures of these compounds were confirmed by ¹H NMR, ¹³C NMR, and HRMS. Their UV-Vis spectroscopy data, fluorescent spectroscopy data, and further details of the electronic properties from cyclic voltammetry measurements and theoretical calculations were studied. Most compounds possess good fluorescence-emitting ability with quantum yield of fluorescence values in the region of 0.36–0.92 and display emission within 449–513 nm depending on the molecular nature.

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