Search

The continuous process for the production of insoluble sulfur (IS) has been developed to overcome the disadvantages associated with the traditional batch process, such as low automation, discontinuous production, and high consumption of sulfur and CS2. The consumption of CS2 in the continuous process is lower than that in the batch process. The recovery of solvent facilitates the recycling of CS2 and N2 in addition to the closed circulation of the entire system. The key process and recovery parameters of the IS synthesis were simulated using Aspen Plus. Sulfur was completely recovered after high-temperature pyrolysis, and the utilization ratio of sulfur atoms was increased from approximately 50% to more than 95%. Tail gas was comprehensively utilized through compression and cryogenic green treatment. Based on the developed green synthesis process and simulated process parameters, the continuous production of IS was evaluated on an industrial scale of 10,000 metric tonnes. Owing to the continuous characteristics of the production process, the air tightness of the production process was significantly improved, and the quality of the product was more stable than that of the product obtained by the current domestic batch process. The unconverted sulfur could be recycled after recovery, without low-grade sulfur as a by-product. The amount of sulfur used as raw material per unit product was reduced; the comprehensive conversion rate of sulfur to IS exceeded 95%, which significantly improved the utilization rate of sulfur atoms. Through the compression and condensation of the tail gas, the recovery efficiency of CS2 was considerably improved at the same temperature, and compressed N2 could be simultaneously obtained. The liquefaction rate of CS2 approached 91.78%, which was characterized by obvious greening.

The W-4.9Ni-2.1Fe alloy with different addition of Y2O3 was prepared by high energy ball milling and spark plasma sintering techniques, the microstructure, mechanical property, friction and wear behavior of the high density alloy were investigated by the Rockwell hardness tester, X-ray diffractometer, reciprocating friction and wear tester, 3D profiler, etc. The results show that adequate doping of the trace Y2O3 can effectively inhibit the grain size, promote the γ-(Ni,Fe) bonding phase and tungsten particles uniformly distribute, increase the relative density, hardness, friction and wear properties. But the excessive Y2O3 addition can easily aggregate at grain boundary, weaken the inhibition effect, and decrease the mechanical and wear properties of the alloy. So the addition of Y2O3 should be appropriate. When the adding mass fraction of Y2O3 particles is 0.4%, the comprehensive performance of the alloy is the best.

Laser Ablation (LA) combined with Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) avoids cumbersome analysis of solution and time-consuming pre process, thus reducing possible pollution during sample preparation. Moreover, LA-ICP-MS has the advantages of low cost, rapid determination, and high precision of analysis data. The lower fractionation effect of elements is discussed by combing laser energy density and denudation frequency. Meanwhile, the main working parameters such as RF power, sampling depth, carrier gas and He gas flow rate are matched to obtain high sensitivity and stability of the signal. Based on these, the optimal parameters of the instrument are obtained and reliable zircon U-Pb dating method is established. By mutual determination of zircon age standard substance 91500, GJ-1, and Plešovic, the respective weighted average ages of 206Pb/238U were 1063.9±6.0 Ma (2σ, n=20), 600.3±2.6 Ma (2σ, n=27), and 337.6±1.7 Ma (2σ, n=20). The accuracy and precision are within 1%, consistent with previous studies. Using the optimized parameters of the instrument, the quartz-orthoclase diorite porphyrite from the Tonglushan Orefield in Southeast Hubei has the 206Pb/238U age of zircon, basically consistent with the previous results, indicating that this method can be used for zircon U-Pb dating.

Accurate and quantifiable detection of the specific wavelength is vital in different application scenarios. Herein, a novel self‐driven narrowband photodetector (NB‐PD) based on CH(NH2)2PbBr2.5I0.5 crystal film is employed for building a yellow light intensity meter. By taking advantage of the carrier collection narrowing mechanism, a sensitive NB‐PD with peak response at 580 nm and the full‐width at half‐maximum of 23 nm are successfully achieved. The asymmetric contact electrodes of Ag/Pt allow the device to work without bias. The optoelectronic analysis demonstrates that the NB‐PD achieves a maximum responsivity of 59.89 mA W−1, a fast response speed of 202/331 µs, and a high on/off ratio of 636 at zero bias. Then, through introducing the back‐end circuit, a yellow light intensity meter is constructed with the NB‐PD. The absolute error and relative error of the light meter are estimated to be lower than 0.08 mW cm−2 and 4.22%, respectively, indicating the good capability for the yellow light monitoring. Given the simple device geometry and good performance, the achieved yellow light intensity meter can also be extended to other narrowband light detection system. [ABSTRACT FROM AUTHOR]

A narrowband photodetection system that can specifically distinguish green, yellow and red light has potential application in intelligent transportation systems. In this work, a series of MAPbBr3−nXn (X = Cl, I) single-crystal films with controllable thickness have been grown through space-limited inverse temperature crystallization. Filter-free narrowband photodetectors with peak responses at 505, 590 and 620 nm, corresponding to the green, yellow and red of traffic lights, are successfully achieved through the charge collection narrowing mechanism. The as-fabricated narrowband photodetectors demonstrate superior performance, with full width at half-maximum all less than 35 nm, a maximum responsivity of 182 mA W−1, and specific detectivity of 9.68 × 1010 Jones. Finally, a traffic light recognition assembly based on the three narrowband photodetectors is constructed. The photocurrent of the photodetector is approximately five to ten times that of the interference from other light sources, indicating good color recognition capability for traffic lights. [ABSTRACT FROM AUTHOR]

Free-standing Pt–Ni nanowires were fabricated by a one-pot solvothermal method. Nanowires with an optimal Pt/Ni ratio of 1.86 exhibited a high activity and a 100% H2 selectivity for hydrous hydrazine decomposition at mild temperatures, which are comparable to the levels of supported catalysts. Our study reveals for the first time that basic support is not a prerequisite for achieving favorable catalytic performance and provides a renewed perspective for the design of advanced catalysts for on-demand H2 generation from hydrous hydrazine. [ABSTRACT FROM AUTHOR]

Two kinds of 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene (BODIPY) dyads BDP‐OH containing 4‐hydroxystyrene groups and BDP‐PY bearing pyridinyl units were prepared. In addition, a naphthalene derivative NAP‐PY modified by pyridinyl moieties substituent was made. The above three dyads could be used to construct white‐light emission (WLE) material by a supramolecular engineering strategy due to their three primary colors of blue, green and red. The supramolecular correlations between the hydroxyl group of BDP‐OH and the pyridinyl groups of NAP‐PY and BDP‐PY were confirmed by 1H NMR titration, 2D NOESY and FTIR. A fluorescence monitor application was carried out based on the realization of WLE. This work might be useful for designing other WLE supramolecular systems and image display. [ABSTRACT FROM AUTHOR]

The W–4.9Ni–2.1Fe–xDy2O3 heavy alloy was fabricated by high-energy ball milling and spark plasma sintering (SPS) technique, and the microstructure, mechanical and friction behavior and anti-corrosion ability were investigated by scanning electron microscope (SEM), Rockwell hardness tester, X-ray diffraction (XRD), reciprocating friction and wear tester, electrochemical station, etc. The results show that the trace Dy2O3 particles, which mainly distributes in the W–M (tungsten-matrix) interface and the tungsten matrix phase, can dramatically decrease the tungsten grain size and the amount of O and P impurities aggregating in the interface, promote the γ-(Ni, Fe) bonding phase and tungsten particles uniform distribution, and increase the relative density, hardness, and wear and corrosion resistance properties. But the excessive Dy2O3 addition can make the inhibition effect weaken, resulting in the decrease in the comprehensive performances of the alloy. So, the amount of Dy2O3 should be appropriate. When the adding amount of Dy2O3 particles is 0.7 wt%, the comprehensive performances of the heavy alloy are the best. [ABSTRACT FROM AUTHOR]

Free-standing Pt-Ni nanowires were fabricated by a one-pot solvothermal method. Nanowires with an optimal Pt/Ni ratio of 1.86 exhibited a high activity and a 100% H2 selectivity for hydrous hydrazine decomposition at mild temperatures, which are comparable to the levels of supported catalysts. Our study reveals for the first time that basic support is not a prerequisite for achieving favorable catalytic performance and provides a renewed perspective for the design of advanced catalysts for on-demand H2 generation from hydrous hydrazine.