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In this study, we measured the liquid–liquid equilibrium (LLE) data of the ternary system {water + 2,2-difluoroethanol + solvent (1-hexanol, 1-heptanol, 1-octanol, and 1-nonanol)} at 303.2 K and 101.3 kPa. The distribution coefficient (D) and separation factor (S) of the solvent were calculated from the experimental data to examine the extraction performance of the solvent, and the results showed that the solvent extraction capacity increased with the increase in the number of carbon atoms. The NRTL and UNIQUAC activity coefficient models were applied to correlate the experimental values and optimize the binary interaction parameters. The reliability of the binary interaction parameters was verified by a hybrid surface analysis on the basis of the Gibbs energy topology. The root-mean-square error (RMSD) values of both models were below 0.01%, which implies that both models are suitable for correlating the LLE experimental data of this study. In addition, the interaction forces between the solvent and {water + 2,2-difluoroethanol} were also analyzed by σ-profile.

To explore the performance of n-alkanes with different alkyl chain lengths to extract ethyl acrylate from aqueous solutions, LLE data for the ternary system [water + ethyl acrylate + n-alkanes (C5, C6, C7, and C12)] were measured at 303.2 K, 101.25 kPa. Partition coefficients and separation factors were calculated as parameters for the evaluation of extractant extraction performance, where n-dodecane had the highest Sand Dvalues, indicating that it is a suitable extractant. The NRTL and UNIQUAC models were used to correlate the systems involved in this work, and the optimal binary interaction parameters were obtained. The smaller rmsd values indicate the good applicability of these two models for this ternary system, with values less than 0.88 and 0.78%, respectively. The mixed surface analysis of the Gibbs energy topology was used to test the obtained parameters, and the results showed that the parameters were reliable. In addition, the molecular force between the extractant and ethyl acrylate was determined to be van der Waals force by σ-Profile analysis and increased with the number of carbon atoms of n-alkanes.

Industrial wastewater usually contains large amounts of butanols which form azeotropic mixtures with water. Efficiently and cleanly separating these azeotropes while saving energy is an urgent problem to solve. This study used two types of solvents to measure the ternary liquid-liquid equilibrium (LLE) data for extracting n-butanol, sec-butanol, and tert-butanol from water at 298.2 K and 101.3 kPa. The obtained data was correlated with NRTL and UNIQUAC models to obtain relevant binary interaction parameters. The reliability of the binary interaction parameters was verified using a Gibbs energy topology-based mixture surface analysis method. The root mean square deviations of the two models were less than 0.0061 and 0.0072, respectively, indicating that both the NRTL and UNIQUAC models could correlate the experimental data well. The extraction performance was evaluated using the distribution coefficient (D) and the separation factor (S). Isopentyl acetate showed better extraction performance, and the differences in the molecular structures of butanols also showed regularity during the extraction process. Combined with quantum chemistry calculations, the hydrogen bond donors and acceptors between six ternary systems were analyzed using the COSMO-SAC method. The intermolecular interaction energies were calculated using the Dmol3module. Finally, through IGMH and AIM analysis, it was proved that the difference in hydrogen bond strength between isopentyl acetate/ethyl acetate and butanols with different molecular structures is the reason for this difference. This study provides basic data and parameters for the design of butanols extraction processes through a combination of experiments and quantum chemistry calculations.

Nonlinear optical materials, especially two-dimensional materials, are anticipated to reveal broadband optical nonlinearity for future miniaturized photonic applications. Herein, we report a physical vapor deposition method to produce β-In2Se3thin film and investigate the broadband nonlinear absorption (β) and refraction (n2) characteristics. The β-In2Se3semiconductor shows an excellent optical nonlinearity with large βin 102cm GW−1scale and n2in 10−12cm2W−1scale from visible to NIR wavelengths, which are superior to those of metal carbides and nitrides (MXenes) and metal-organic frameworks. This excellent optical nonlinearity makes β-In2Se3a promising candidate for advanced nanophotonic devices and beyond.

All-optical modulators based on a MXene-Ti_3C_2T_x have recently garnered much attention due to their broadband light–matter interactions and ultrafast carrier dynamics. To investigate the modulation characteristics of pump intensity and pump light modulation frequency, we establish an all-optical modulator with a sandwich structure based on MXene-Ti_3C_2T_x/PVA (polyvinyl alcohol) film. The result shows that this modulator can achieve a high modulation depth of 12.55 dB and a modulation frequency of 50 kHz corresponding to a response time at the microsecond scale. The successful preparation of the modulator is attributed to the saturable absorption characteristics of the MXene-Ti_3C_2T_x. This modulator has great potential in all-optical communications and ultrafast optical signal processing.

Wastewater from coking and pharmaceutical processes often contain a significant amount of 2-methylpyridine, which forms an azeotropic mixture with water. Effectively and cleanly separating 2-methylpyridine from wastewater while conserving energy and obtaining high purity products is an urgent challenge. In this study, ternary liquid-liquid equilibrium (LLE) data for the extraction of 2-methylpyridine from wastewater were measured using three distinct solvents at temperatures of 303.2 K, 313.2 K, and 323.2 K. The obtained ternary data were subsequently correlated with thermodynamic models (NRTL and UNIQUAC) to get relevant binary interaction parameters, bridging a gap in Aspen Plus simulations of 2-methylpyridine separation by octanol solvents. Furthermore, the GUI tool was used to validate these parameters and the results confirmed the reliability of the obtained parameters. It was observed that as the temperature increased, the extraction performance of all systems decreased, indicating that elevated temperature are not conducive to the extraction process. Among the various components, iso-octanol showed the highest separation factor indicating better extraction efficiency of 2-methylpyridine. Additionally, this study integrated quantum chemical calculations to reveal the interaction mechanisms between different solvents, 2-methylpyridine, and water at the microscopic level. The computational results indicated that iso-octanol exhibited the most robust binding affinity with 2-methylpyridine, suggesting that iso-octanol has more excellent extraction properties.

Ultrafast charge transfer in van der Waals heterostructures can effectively engineer the optical and electrical properties of two-dimensional semiconductors for designing photonic and optoelectronic devices. However, the nonlinear absorption conversion dynamics with the pump intensity and the underlying physical mechanisms in a type-II heterostructure remain largely unexplored, yet hold considerable potential for all-optical logic gates. Herein, two-dimensional ReSe2/ReS2heterostructure is designed to realize an unusual transition from reverse saturable absorption to saturable absorption (SA) with a conversion pump intensity threshold of approximately 170 GW/cm2. Such an intriguing phenomenon is attributed to the decrease of two-photon absorption (TPA) of ReS2and the increase of SA of ReSe2with the pump intensity. Based on the characterization results of X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, femtosecond transient absorption spectrum, Kelvin probe force microscopy, and density functional theory calculation, a type-II charge-transfer-energy level model is proposed combined with the TPA of ReS2and SA of ReSe2processes. The results reveal the critical role of ultrafast interfacial charge transfer in tuning the unusual nonlinear absorption and improving the SA of ReSe2/ReS2under different excitation wavelengths. Our finding deepens the understanding of nonlinear absorption physical mechanisms in two-dimensional heterostructure materials, which may further diversify the nonlinear optical materials and photonic devices.

In order to recover 3-methoxybutyl acetate from an aqueous solution containing 3-methoxybutyl acetate, four n-alkanols (C5–C8) with different carbon chain lengths were selected as solvents for the liquid–liquid equilibrium (LLE) experiment of water + 3-methoxybutyl acetate + n-alkanols and the LLE data were measured at 303.2 K, 101.3 kPa. And by calculating the distribution coefficient (D) and separation factor (S), the separation effect of different extractants was compared and discussed. The obtained LLE data were correlated by NRTL and UNIQUAC models, and the binary interaction parameters of each system were determined. The model data for each system passed the hybrid surface analysis test of the Gibbs energy topology, indicating that the obtained model data are reliable. The root-mean-square deviation (RMSD) of the two models was less than 0.72 and 0.58%, respectively. The σ-profiles and interaction energy analysis were used to investigate the effect of alkyl chain length on separation efficiency. The analysis showed that the longer the alkyl chain length of n-alkanols, the higher the extraction efficiency of n-alkanols.

Liquid–liquid equilibrium (LLE) measurements were conducted at a temperature of 298.2 K and a pressure of 101.3 kPa for the ternary system consisting of 1,3-propanediol, 2-propyl-1-heptanol, and various extractants (n-hexane, vinyl acetate, ethyl benzene, and water). By calculating the distribution constant (D) and selectivity (S) in each system, the ability of four extractants to separate the mixture of 1,3-propanediol and 2-propyl-1-heptanol was compared. Furthermore, the LLE data underwent regression using thermodynamic models NRTL and UNIQUAC. The degree of deviation between the experimental data and regression data was assessed using the root mean square deviation (RMSD) and the average absolute deviation (AAD). The RMSD values for the NRTL and UNIQUAC models were below 0.74 and 0.76%, respectively, with corresponding AAD values below 0.39 and 0.60%. These results indicate a robust concurrence between the experimental data and the outcomes of the regression analysis. Finally, the GUI-MATLAB tool was employed to validate the coherence of the experimental data with the regression parameters. σ-Profiles are used to discuss the interactions of substances in this work. The results showed that the Dand Sof all four systems were greater than 1, indicating that all four extractants were effective in separating 1,3-propanediol and 2-propyl-1-heptanol. The order of their extraction capacity was water ≥ hexane ≥ ethyl benzene ≥ vinyl acetate.

Inspired by recent advancements of graphene-based ultrafast photonic devices, Ti3C2Tx-MXene, as a graphene-like two-dimensional layer-structure material, has gained extensive interest in nonlinear optical applications, especially in all-optical intensity modulation. Herein, we successfully fabricated an all-optical modulator based on Ti3C2Tx-Mxene/polyvinyl-alcohol film with nanosecond-scale response time, modulation speed of 100 kHz, and modulation depth of 10%. Furthermore, the variation of fall edges of modulated signal pulse caused by thermo-optic effect under different pump power was also observed. Considering the ease of fabrication, low cost, and ease of integration, the proposed modulator may open the door for high-speed all-optical communications and signal processing.

We demonstrate an all fiber high-repetition-rate erbium-doped ultrashort laser based on the Ti3C2Tx-Mxene saturable absorber (SA), and the 56th harmonic mode-locking with a repetition rate of 622.2 MHz, a central wavelength of 1590.7 nm, and a pulse duration of 1.31 ps is achieved. Meanwhile, dual-wavelength mode-locking pulses are also realized, with the central wavelengths of 1575.6, 1587.5 nm. The results of the work indicate that Ti3C2Tx-Mxene is an outstanding SA for generating ultrashort pulse or modulating the light and the diversity Mxene family can bring new vigor and vitality into advanced photonic devices.

This paper designs a novel retractable suspension structure for amphibious equipment, combined with the principle and characteristics of the retractable suspension mechanism, and uses ADAMS/Insight to develop a set of optimization strategies that meet the characteristics of its dual-function process. Then based on this optimization strategy, the retractable index and the wheel alignment parameters of the retractable suspension are optimized respectively, and significant results are obtained, which verifies the feasibility of the optimization strategy.

An integrated container performance parameter testing device is developed for the packaging container with metal as material. It is suitable for the comprehensive performance test of the metal packaging container, and can realize the rapid and accurate measurement of the volume, sealing, vacuum degree and pressure strength of the metal packing container. This paper introduces the working principle, hardware structure, software system and testing function of the device. The hardware system is composed of differential pressure sensor, absolute pressure sensor, temperature sensor, mass flow controller and USB-2611 high speed acquisition card. The application program of data acquisition and processing based on LabVIEW is designed. This system can realize the function of collecting, storing, real-time displaying and processing analysis. The experimental results show that the device can measure the volume, sealing, vacuum and compressive strength of metal packaging container quickly and accurately.