We reported an inexpensive and high-efficiency hydrogen generation method from NaBH₄ hydrolysis promoted by oxalic acid. NaBH₄ and H₂C₂O₄ were premixed and hydrogen generation was initiated by adding water into the solid mixture. H₂C₂O₄ was selected as the acid promotor due to its solid state and low mass per proton. The effect of reactant ratio on the hydrogen yield and hydrogen storage density was investigated. With optimized reactant ratio, high gravimetric hydrogen storage up to 4.4wt% based on all the reactants can be achieved with excellent hydrogen generation kinetics.

The molecular dynamics simulation method was adopted to study the transient characteristics of Li⁺, CO₃ ²⁻, and SO₄ ²⁻ in Na⁺, K⁺, Li⁺, Cl⁻, and SO₄ ²⁻/H₂O system. The composition of Na⁺, K⁺, Li⁺, Cl⁻, SO₄ and CO₃ was selected to optimize the initial structural model and conduct dynamic simulation. The mean azimuth shift and diffusion coefficient of Li⁺, CO₃ ²⁻, and SO₄ ²⁻ in the system, the radial distribution function and potential energy between Li⁺ and −OW, SO₄ ^{2 −} and −OW as well as CO₃ ^{2 −} and −OW, and the dielectric constant of hydrogen bond were expounded and analyzed. At the same time, the Li enrichment behavior in the evaporation process of salt lake brine was analyzed based on the simulated data. The results show that the simulation results are in good agreement with the experimental values, which verifies that, compared with other ions, the crystallization of Li⁺ and SO₄ ²⁻ occurs earlier after reaching saturation.

Artificial zeolite was modified by nano-Fe₃O₄ for development of functional adsorbents. Subsequently, adsorbents such as calcium cross-linked nano-Fe₃O₄ microspheres (Ca-MS), calcium cross-linked nano-Fe₃O₄ modified zeolite microspheres (Ca-MZS) and iron cross-linked nano-Fe₃O₄ modified zeolite microspheres (Fe-MZS) were prepared and compared for their adsorption performance. The effects of adsorbent dosage, solution pH, initial concentration and ion content on the removal of Cu²⁺ from wastewater are investigated, and the adsorption kinetics and isotherms for the adsorbent materials were analyzed. The experimental results indicate that for the initial concentration of Cu²⁺ of 30 mg/L, the adsorption is noted to be most stable. The optimal initial pH for adsorbing Cu²⁺ is observed to be 5.5. At an optimal dosage of Ca-MZS of 900 mg/L, the adsorption capacity is measured to be 28.25 mg/g, along with the removal rate of 72.49%. The addition of Na⁺ and K⁺ affects the adsorption of Cu²⁺. For the Na⁺ and K⁺ concentration of 0.2 mmol/L, the Cu²⁺ removal rate by Ca-MZS drops to 11.94% and 22.12%, respectively. As compared with the adsorbents such as Natural Zeolite (NZ), Ca-MS and Fe-MZS, Ca-MZS demonstrates the best removal effect in solution, where the removal rate reaches 84.27%, with the maximum adsorption capacity of 28.09 mg/g. The Cu²⁺ adsorption kinetics of Ca-MZS is observed to follow the Elovich kinetic model, with the adsorption isotherm data fitting the Freundlich isotherm model by using the non-linear method.

B₄C-TiB₂-SiC composites with excellent properties were prepared by reactive hot-pressing using B₄C, TiC, and Si powders as the raw materials. The phase transition process was investigated by heating the powder mixture to different temperatures and combined with XRD tests. TiB₂ and SiC phases were synthesized through an in situ reaction, and the mechanical and thermal properties were improved simultaneously. Microstructure and mechanical properties were also studied, and the 60wt% B₄C-21.6wt% TiB₂-18.4wt% SiC composite showed a relative density of 99.1%, Vickers hardness of 34.6 GPa, flexural strength of 582 MPa, and fracture toughness of 5.08 MPa·m^1/2. In addition, the values of thermal conductivity and thermal expansion coefficient were investigated, respectively.

In view of the special requirements of transducers for power ultrasonic processing, the piezoelectric ceramic material Pb(Zr,Ti)O₃ was modified by adding other effective elements. The piezoelectric ceramic piece has a good crystal phase structure, a stable piezoelectric constant, a higher dielectric constant, and a lower dielectric loss by adding a small amount of Sr²⁺, Ba²⁺, Ga²⁺, Sn⁴⁺, Nb⁵⁺, etc. These properties are well suited to requirements of power ultrasonic transducer more than 1 000 W. The crystal phase structure and surface morphology of the modified piezoelectric ceramic chips were analyzed by X-ray and scanning electron microscopy (SEM) to prove that the piezoelectric ceramic chips have good crystal structure and density. The dielectric constant of the polarized piezoelectric ceramic chips was measured using an LCR meter. Finally, the piezoelectric ceramic chips were used to design the ultrasonic transducer, and the transducer was analyzed and measured by the impedance analyzer. The measurement results show that the performance of the piezoelectric ceramic chips is reasonable and feasible.

The demand for alternative cementitious materials is on the rise, as the cement causes huge energy consumption and produces greenhouse gas emission. Additionally, there is economic potential for the construction industry to reuse wastes as supplementary building materials. The purpose of this study is to evaluate the potential of utilizing ferrochrome slag wastes in mortar as supplementary cementitious materials (SCMs), thereby achieving this double-sided goal. Thus, the mechanical and physical properties of ferrochrome slag wastes were investigated to be used as admixtures in concrete production. Three different cement mortar specimens were prepared by replacing cement with ferrochrome slag in ratios of 0, 30%, and 60% by mass and flexural and compressive strengths of the specimens were determined at the ages of 7, 28, 56, 90, and 180 days. Also, the effects of the ferrochrome slag replacement ratio on workability, setting time and volume expansion were revealed. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were also investigated to study the microstructural properties of the specimens containing ferrochrome slag. Based on the results, it is concluded that ferrochrome slag wastes have pozzolanic activity, therefore reusing them as SCMs in the cement and concrete industry is convenient.

Low calcium β-C₂S and γ-C₂S minerals with low hydration activity was activated by accelerated carbonation curing to be used as new binding materials. Synthetic β-C₂S and γ-C₂S were synthetized and compacted to prepare cube samples and then subjected to CO₂ chamber for accelerated carbonation curing. The CO₂ uptake, mechanical strength, and microstructure changes of β-C₂S and γ-C₂S were analyzed by TG, XRD, MAS-NMR, and MIP. The experimental results indicate the CO₂ uptake of γ-C₂S is much higher than that of β-C₂S, but the compressive strength of γ-C₂S samples is lower than that of β-C₂S. Calcium carbonate and other carbonation products stack in the pore structure and the porosity is reduced from about 42% to 30.1% and 22.0% for β-C₂S and γ-C₂S samples after 2 h carbonation curing, respectively. The difference in compressive strength development is caused by the different properties of carbonation products. Except for calcium carbonate, there also exists obvious difference in properties of amorphous phases: γ-C₂S formed silica gel in the whole carbonation progress; however, β-C₂S can react to produce silica gel and C-S-H gel with high Van der Waals forces, and C-S-H gel will continue to react with CO₂ to form calcium carbonate and silica gel in later carbonation reaction; In addition the microhardness of carbonated β-C₂S was more higher than that of γ-C₂S.

The nanostructure and chloride binding capacity evolution of C-A-S-H gel exposed to aggressive solutions were investigated, utilizing ²⁹Si NMR, ²⁷Al NMR, SEM-EDS, and XRD techniques. The experimental results show that while Cl⁻ ions show a smaller effect on the microstructure of C-A-S-H sample, and SO₄ ²⁻ ions can react with C-A-S-H, resulting in decreasing Ca/Si and Al[4]/Si for the C-A-S-H gel (i e, decalcification and dealuminization). The presence of Mg²⁺ ions can aggravate the decalcifying and dealuminizing effects of SO₄ ²⁻ ions on the C-A-S-H. With decreasing Ca/Si ratio and aluminum substitution for the original C-A-S-H gel, the depolymerization degree of silicate tetrahedra increases and the calcium aluminosilicate skeleton strengthens. C-A-S-H gel with lower Ca/Si ratio and higher Al[4]/Si ratio shows gentler nanostructure evolution under chemical attack, i e, improving thermodynamic stability under chemical attack. Furthermore, the chloride binding capacity of C-A-S-H gel is decreased after the sulfate attack. Aluminum substitution can also help C-A-S-H gel resist the degraded chloride binding capacity induced by sulfate attack.

This work aimed to use oyster shell powder (OSP) as the partial replacement of Ag/TiO₂ particle to obtain multifunctional β-hemihydrate gypsum. Thus, the β-hemihydrate gypsum was mixed with different contents of OSP and Ag/TiO₂ particle. Antibacterial and MB removal experiments were conducted to assess the antibacterial characteristic and photocatalytic activity of β-hemihydrate gypsum with Ag/TiO₂ particle and OSP. Besides, the formaldehyde degradation test was carried out to evaluate its formaldehyde removal ratio. Moreover, their setting times, compressive and flexural strengths at 1, 3, and 28 days were comparatively analyzed. The experimental results prove that the composite use of OSP and Ag/TiO₂ particle provide feasible multifunction for the β-hemihydrate gypsum. They can further improve the bactericidal rates and exhibit extra MB removal ratios compared with the gypsum plasters with single Ag/TiO₂ particle. Besides, they can increase the formaldehyde degradation ratios, and this promotion is related to the introduction of Ag/TiO₂ particle. However, OSP delays the initial setting time but promotes the final setting time of β-hemihydrate gypsum, and Ag/TiO₂ particle hardly affects the setting times. Furthermore, OSP reduces the strengths of plasters at 1, 3, and 28 days. But in general, the composite addition of OSP and Ag/TiO₂ particle increase the compressive and flexural strengths of gypsum plasters at 1, 3, and 28 days. These results provide theoretical guidance for the recycling of OSP and the preparation of gypsum-based products with antibacterial and formaldehyde degradation capabilities.

Effects of organosilane-modified PCE (OS-PCE) on the fluidity and the hydration properties of cement-fly ash (FA) composite binder were systematically analyzed. The experimental results show that OS-PCE possesses respectively 36.98% and 36.67% higher saturated adsorption amount on cement and FA, in comparison with ordinary PCE, and can contribute to higher fluidity of cement-FA composite binder. The addition of OS-PCE retards hydration process of cement-FA composite binder proportionally with the dosage of OS-PCE, but promotes the hydration kinetics of the composite binder. The reactivity enhancement is attributed to the well-dispersed FA by OS-PCE, which provides more nucleation sites for the reaction of heterogeneous C-S-H and enhances the contact with water to react with CH forming pozzolanic C-S-H. Well-distributed hydration products are exhibited in the hardened binder added with OS-PCE, with a large number of hydrated gels uniformly fill in the pores and gaps, which improves the compaction of the hardened structure.

Based on the investigated microstructure of different zones in the annealed automatic gas tungsten arc weld joint of TA16 and TC4 titanium alloys, the mechanical property of them was assessed under fatigue crack growth rate tests. For evaluation of fatigue crack growth rate, three points bending specimens were used. The correlation between the range of stress intensity factor and crack growth rate was determined in different zones of the annealed weld joint. Fatigue crack growth rates were obviously different in different zones of weld joint of dissimilar titanium alloys, due to their different microstructures. Scanning electron microscope examinations were conducted on the fracture surface in order to determine the relevant fracture mechanisms and crack growth mechanisms with respect to the details of microstructure.

The effect of particle size on the density and resistivity of ITO green bodies and targets was systematically investigated. The experimental results show that the relative density of ITO green bodies decreases with the increase of ITO particle size. When the particle size is 10.7 nm, the relative density of ITO green bodies rises to the maximum value of 56.6%. The resistivity declines exponentially with the increase of particle size, which satisfies the exponential equation of R = exp(−41.823 × d). When the particle size is 41.6 nm, the resistivity reaches the minimum value of 0.8 Ω·cm. The relative density of ITO target decreases with the increase of particle size. Fine particles can increase the driving force of densification in initial stage. Electron mobility, caused by grain boundary scattering, will increase due to the increase of particle size or the decrease of grain boundary potential. When the particle size is 10.7 nm, the target with compact grain stacking and low porosity shows a maximum relative density of 99.25%, and the resistivity reaches the minimum value of 0.34×10⁻³ Ω·cm.

The isothermal compression tests of C71500 copper-nickel alloy at different temperatures (1 073–1 273 K) and strain rates (0.01–10 s⁻¹) were carried out on Gleeble-3500 thermo-mechanical simulator. The real stress-strain data were obtained. On the basis of dynamic material model, the power dissipation was established. The peak efficiency of the power dissipation is 57%. At the same time, Prasad’s, Murty’s and Babu’s instability criteria based on Ziegler’s expectant rheology theory, and Gegel’s and Malas’s instability criteria based on Lyaponov’s function theory, were used to predict the unstable regions in the processing map. The maximum entropy generation rate and large plastic deformation principle are more in line with the hot deformation process of C71500 alloy, so the accuracy of Prasad’s instability criterion is much better. According to the obtained macro-crack and micro-metallographic structure morphologies, the temperature range of 1 098–1 156 K and the strain rate range of 2.91–10 s⁻¹, and the temperature range of 1 171–1 273 K and the strain rate range of 0.01–0.33 s⁻¹ are more suitable for the processing area of C71500 alloy. The accuracy of the above conclusions were verified by the forging of materials and the analysis of hot piercing tubes. The significance of this paper is to provide theoretical basis and technological conditions for hot-press processing of C71500 alloy.

The high-temperature tensile behavior of laser welded Ti-22Al-25Nb (at%) joints was investigated at 500, 650, 800, and 1 000 °C. The temperatures for tensile tests were selected according to the phase transformation sequence of Ti₂AlNb-based alloys. At temperatures lower than the B2+O phase field (500 °C) and higher than the B2+O phase field (1 000 °C), the joints fracture in the base metal in ductile fracture mode. By contrast, the joints exhibit obvious high-temperature brittleness in the B2+O phase field (650 °C and 800 °C). Heat treatments were conducted with respect to the thermal history of tensile specimens. Intergranular microcracks along the grain boundary of B2 phase are found in the fusion zone after the heat treatments at 650 °C and 800 °C. The high-temperature brittleness at 650 °C and 800 °C is attributed to the B2→O transformation along the grain boundary. The stress concentration caused by the volume change of B2→O transformation also contributes to the high-temperature brittleness of laser welded Ti-22Al-25Nb joints.

To improve the removal efficiency of such submicron inclusions, we designed an argon blowing method for an RH facility based on mathematical simulations. The effect of the argon blowing on the liquid steel flow and the movement of submicron inclusions was studied using the k-ε flow model coupled with the DPM model for inclusion movement based on fluid computational dynamics in FLUENT. It was found that a more uniform argon flow can be achieved in the up-leg snorkel with a new nozzle position and inner diameter, which resulted in a favorable up-lifting and mixing movement. The new design also increased the circulation rate of molten steel in the RH chamber. The increased turbulent kinetic energy and turbulent dispersing rate enhanced the collision probability of submicron inclusions, which results in an improved removal for 0.5–1 µm inclusions. The proposed RH facility could increase the removal rate of submicron inclusions from the original 57.1% to 66.4%, which improves the magnetic properties of non-oriented silicon steel.

The effects of kerosene flow rate on the microstructure and wearing properties were investigated for Fe-based amorphous coatings sprayed by High Velocity Oxygen Fuel (HVOF). The microstructures and wearing properties of the Fe-based amorphous coatings were analyzed with scanning electron microscope (SEM), X-ray diffraction analyzer (XRD), and ball-on-disc tribometer (CFT-1), respectively. The experimental results show that the well interfacial bonding can be observed between the amorphous coating layer and the substrate, and the porosity in amorphous coating layer is less to 1%. Only some crystalline α-Fe and FeO phases can be detected by XRD in the amorphous coatings, while the amorphous content is up to 99.4%. The wearing coefficient is near to 0.15, which is superior to SUS316 of 0.28. As the increasing of wearing loads, the failure mode is changed from oxidation wear to the composite of oxidation and abrasive wear.

The roles of hot isostatic pressing (HIP) temperatures (490 °C/100 MPa/2 h, 510 °C/100 MPa/2 h, 530 C/100 MPa/2 h) in the microstructure and properties of AlSi7Cu2Mg alloy step castings with three types wall thicknesses were studied. The experimental results show that HIP at 490 C could effectively eliminate the internal closed porosity of the castings with a wall thickness of ≼40 mm, but for heavy castings (70 mm), even HIP at 530 C, a few loose defects remained inside the castings. Two types of incipient eutectics containing Al5Mg8Si6Cu2 and Al2Cu were observed in the samples that HIP at 530 C, which was responsible for the decrease of the tensile strength of the castings within the medium wall thickness (40 mm) compared with that HIP at 490 C. HIP could greatly reduce the difference of the tensile strength values of castings with wall thicknesses 17 mm and 70 mm from 117.93 MPa (without HIP) to 25.7 MPa (with HIP at 530 C).

The mechanical properties of dual-phase steel (DP1000) over the strain rate range of 10⁻³-10³ s⁻¹ were studied using an electronic universal testing machine and a high-speed tensile testing machine. The plastic deformation mechanism was investigated from the perspectives of the strain rate sensitivity index, activation volume and dynamic factors. The results show that the tensile strength and yield strength of DP1000 increase as the strain rate increases. The elongation increases without any change after fracture, and then decreased rapidly when the strain rate reaches 10³ s⁻¹. The true strain curves of DP1000 show three stages: the point of instability decreases in the strain range of 10⁻³-10⁻¹ s⁻¹; the instability point increases between 10⁰-5×10² s⁻¹; above 5×10² s⁻¹, and the instability strain becomes smaller again. The plastic deformation mechanism of the DP was determined by the competitive contributions of work hardening (strain hardening, strain rate hardening) and softening effects due to the adiabatic temperature rise.

A novel conductive drug-loading system was prepared by using an improved emulsion electrostatic spinning method which contained polylactic acid (PLA), graphene oxide (GO), and nerve growth factor (NGF) coated with bovine serum albumin (BSA) nanoparticles. Firstly, the structure, mechanical properties, morphology and electrical conductivity of PLA/GO electro spun fiber membranes with different GO ratios were characterized. PLA/GO scaffolds can exhibit superior porosity, hydrophilic and biomechanical properties when the GO incorporation rate is 0.5%. The addition of GO in the PLA/GO electro spun fiber membranes can also create appropriate pH environment for the repair of injured nerve when the GO incorporation rate is above 0.5%. Secondly, PLA/GO/BSA/Genipin/NGF particles (with a ratio of BSA/NGF = 3:1) prepared by modified emulsion electro spinning method will release more NGF than PLA/GO/NGF particles. In addition, PLA/0.5%GO/NGF scaffold can maintain its structure stability for at least 8 weeks observed by scanning electron microscope (SEM). Moreover, the degradation of PLA/0.5%GO/NGF scaffold is consistent with its weight loss. Finally, in vitro assay confirmes that PLA/GO composite scaffold exhibits low cytotoxicity to RSC96 cells. Cellular results have demonstrated that PLA/0.5%GO/NGF sustained-release drug sustained-release system with appropriate electrical stimulation (ES) can promote PC12 cell proliferation, and it can maintain its differentiation capability for at least 3 weeks. In conclusion, PLA/0.5%GO/NGF sustained-release drug sustained-release system can maintain its biological activity for at least 3 weeks and promote cell proliferation with appropriate ES.

This paper provides a new treatment for gastric cancer with a new OMT delivery system. We synthesized MPEG-PCL, an amphiphilic polymer, to construct a nanoparticle encapsulated OMT by pH gradient method, and then examined the nanodrug’s therapeutic efficacy. An integral analytical method was used to characterize the structure of MPEG-PCL. The single factor method and orthogonal test were utilized to investigate the optimum preparation process. The morphology and average size of the OMT-NPs were analyzed by transmission electron microscopy and Zetasizer. CCK-8 assay and confocal fluorescent microscope were used to study the inhibitory effect on SGC-7901 gastric cancer cells. The average size of nanoparticles was 95.86±1.54 nm. The maximum encapsulation efficiency of OMT was 46.84±4.37%, while the drug loading content was 8.89±1.09%. The cumulative release of nanoparticles was 73.07±1.5%, inspected through dynamic dialysis in vitro. Compared with free OMT, OMT-NPs showed enhanced cytotoxic effects in SGC-7901 cells. The nanoparticles could efficiently deliver the OMT into the cancer cells and release it. The OMT delivery system prepared in this paper provides a potential platform for the treatment of gastric cancer.

Natural rubber (NR) was reinforced in situ with nano CaCO₃ that had been modified with methacrylic acid (MAA)(M-CaCO₃). The structures and properties of the resulting composites were studied using attenuated total reflection Fourier transform infrared spectroscopy(ATR-FTIR), scanning electron microscopy(SEM), and Mooney viscometer and mechanical tests. The results show that when NR is physically blended with CaCO₃ and MAA, (Ca2+)-(⁻OOC) is formed in situ. When dicumyl peroxide (DCP) is added, the (Ca²⁺)-(⁻OOC) self-homopolymerizes, and during the curing process poly-(Ca²+)-(⁻OOC) is formed and grafts to the molecular chains of the NR via carbon-carbon double bonds. The NR/M-CaCO₃ composites formed have close interfacial interaction and are well dispersed. Compared with the NR composites reinforced with unmodified nano CaCO₃, the NR/M-CaCO₃ composites have very different cure characteristics, rheological behavior, and mechanical properties, and these characteristics and properties show a significant relationship with the loading of M-CaCO₃.