Distribution-free double-sampling precedence monitoring scheme to detect unknown shifts in the location parameter

In most applications, parametric monitoring schemes are used to monitor the majority of industrial and nonindustrial processes in order to improve the quality of the outputs or services. However, parametric monitoring schemes are known to underperform when the normality assumption is not met or when there is not enough information about the symmetry or asymmetry nature of the process underlying distribution. Hence, in this paper, a new nonparametric Phase II Shewhart-type double-sampling (DS) monitoring scheme based on the precedence statistic is proposed in order to efficiently monitor quality processes when the underlying process distribution departs from normality. The performance is investigated using the average run length (ARL), standard deviation of the run length (SDRL), expected ARL (EARL) and expected average number of observations to signal (EANOS), and the average sample sizes (ASS) metrics. The latter metrics are computed using Monte Carlo simulation and exact formulae. In general, it is shown that the new DS precedence scheme outperforms the existing basic Shewhart precedence scheme with and without supplementary runs rules in many situations. A real-life illustrative example based on a filling process of milk bottles is provided to demonstrate the application and implementation of the new DS precedence monitoring scheme.     

Bismuth oxycarbonate grafted NiFe-LDH supported on g-C3N4 as bifunctional catalyst for photoelectrochemical water splitting

In the present study, we report the synthesis of photoactive bismuth oxycarbonate (BOC, Bi₂O₂CO₃) grafted NiFe layered double hydroxide (LDH) supported on g-C₃N₄ (15 wt% of g-C₃N₄) by coprecipitation method. The band gap of this photoactive material is determined to be 1.7 eV. The Bi₂O₂CO₃ agglomerates are anchored on NiFe-LDH plates and g-C₃N₄ nanosheets intercalated between the LDH plates. This architecture helps in expediting electron transfer for hydrogen and oxygen evolution reactions. The pristine NiFe-LDH photoanode acquires bifunctional character because of Bi₂O₂CO₃ agglomerates and g-C₃N₄ embedded in the architecture of BOC/NiFe-LDH@g-C₃N₄. This is found to be an efficient photoanode for oxygen evolution and photocathode for hydrogen evolution reactions. The water splitting process occurs along the heterojunction formed between g-C₃N₄ nanosheets and Bi₂O₂CO₃ grafted NiFe-LDH. Further, an additional interfacial charge transfer aided by Bi₂O₂CO₃ results in S-scheme mechanism, which enhances the rate of photoelectrochemical hydrogen and oxygen evolution reactions.     

“双闪”铜冶炼工艺技术的发展

“双闪”铜冶炼工艺技术具有环境指标优越、综合能耗低、自动化程度高等优势，在中国得到广泛应用，目前中国已建成4个“双闪”铜冶炼厂，1个正在建设。通过对肯尼科特犹他冶炼厂、阳谷祥光铜业有限公司、铜陵有色金冠铜业分公司、广西金川有色金属有限公司、中铜东南铜业有限公司以及阳新弘盛铜业有限公司“双闪”铜冶炼工艺技术进行对比，研究了铜精矿干燥、铜精矿输送、闪速熔炼、冰铜粒化、冰铜制粉和输送、闪速吹炼、阳极精炼、残极处理以及烟气处理等工艺技术的发展情况，为“双闪”铜冶炼工艺技术的应用，以及未来的发展方向提供思路。     

Auto-thermal reforming of acetic acid for hydrogen production by ZnxNiyCrOm±δ catalysts: Effect of Cr promoted Ni-Zn intermetallic compound

A series of Zn_xNi_yCrO_m±δ catalysts were synthesized via a typical co-precipitation method, in which Zn-Cr layered double hydroxides (LDHs) were found and Ni-Zn intermetallic compound (IMC) was formed after reduction in hydrogen. During auto-thermal reforming (ATR) of acetic acid (HAc), the Ni-Zn IMC was transformed into Ni/(amorphous-ZnO)-ZnCr₂O₄ species with uniformed distribution and appropriate interaction within these Ni-Zn-Cr-O species; besides, the adsorbed oxygen promoted the activation and transfer of oxygen species; therefore, deactivation by oxidation, sintering and coking was inhibited. And the optimized Zn_2.37Ni_0.63CrO_4.5±δ catalyst presented high activity and stability in a 45-h ATR test with HAc conversion near 100% and hydrogen yield at 2.7 mol-H₂/mol-HAc, showing potential for hydrogen production via ATR of HAc.     

Boosting discharge capability of α-Ni(OH)2 by cobalt doping based on robust spherical structure

α-Ni(OH)₂ is a promising candidate of the currently commercialized β-Ni(OH)₂ due to its higher theoretical discharge capacity in alkaline solution; however, its instability and poor conductivity plague the practical application. Herein, we propose α-Ni(OH)₂ with Co doping and spherical structure to strengthen the stability and enhance the conductivity and use it as the cathode for nickel-metal hydride batteries. Studies show that proper Co doping promotes the electrochemical reaction between the active materials and the electrolyte due to the spherical α-Ni(OH)₂ with enlarged interlayer distance and abundant hole channels, as well as high conductivity of Co, therefore, the obtained spherical α-Ni(OH)₂ with 7 mol% Co doping delivers significantly improved discharge capability, which is 384.6 mAh g^?1 at 70 mA g^?1 (0.2 C), increased by 54.3 mAh g^?1 compared with pure α-Ni(OH)₂, and at a high current of 5 C, it still gives 269.4 mAh g^?1, in contrast 218.5 mA g^?1 for the pure α-Ni(OH)₂. Besides, the cycling stability of the α-Ni(OH)₂ with 7 mol% Co doping maintains 340 cycles at a capacity retention of 80% (1C), which is extended 110 cycles in contrast to the pure α-Ni(OH)₂. These results provide the underpinning platform of α-Ni(OH)₂ for battery applications with high discharge ability and cycle life.     

NiFe layered double hydroxide as an efficient bifunctional catalyst for electrosynthesis of hydrogen peroxide and oxygen

Two electron oxygen reduction reaction to produce hydrogen peroxide (H₂O₂) is a promising alternative technique to the multistep and high energy consumption anthraquinone process. Herein, Ni–Fe layered double hydroxide (NiFe-LDH) has been firstly demonstrated as an efficient bifunctional catalyst to prepare H₂O₂ by electrochemical oxygen reduction (2e^? ORR) and oxygen evolution reaction (OER). Significantly, the NiFe-LDH catalyst possesses a high faraday efficiency of 88.75% for H₂O₂ preparation in alkaline media. Moreover, the NiFe-LDH catalyst exhibits excellent OER electrocatalytic property with small overpotential of 210 mV at 10 mA cm^?2 and high stability in 1 M KOH solution. On this basis, a new reactor has been designed to electrolyze oxygen and generate hydrogen peroxide. Under the ultra-low cell voltage of 1 V, the H₂O₂ yield reaches to 47.62 mmol g_cat^?1 h^?1. In order to evaluate the application potential of the bifunctional NiFe-LDH catalyst for H₂O₂ preparation, a 1.5 V dry battery has been used as the power supply, and the output of H₂O₂ reaches to 83.90 mmol g_cat^?1 h^?1. The excellent electrocatalytic properties of 2e^? ORR and OER make NiFe-LDH a promising bifunctional electrocatalyst for future commercialization. Moreover, the well-designed 2e^? ORR-OER reactor provides a new strategy for portable production of H₂O₂.     

Double emulsion (W/O/W) gel stabilised by polyglycerol polyricinoleate and calcium caseinate as mangiferin carrier: insights on formulation and stability properties

Mangiferin (MGF) is a phenolic compound isolated from mango, but its poor solubility significantly limits its use. In this study, MGF was embedded into the inner aqueous phase of W₁/O/W₂ emulsions. Firstly, the dissolution method of MGF was determined. MGF remained stable in solution with pH 13 at 30 min, and its solubility reached 10 mg mL⁻¹. When the pH of MGF solutions was adjusted from pH 13 to pH 6, MGF did not immediately crystallise, providing sufficient time to construct the MGF-loaded W₁/O/W₂ emulsions. Subsequently, the MGF-loaded W₁/O/W₂ emulsions were constructed using polyglycerol polyricinoleate (PGPR) and calcium caseinate (CAS). The formation and stability of the W₁/O/W₂ emulsions were investigated. The MGF-loaded W₁/O/W₂ emulsions stabilised with 1% PGPR and 1% – 3% CAS exhibited a low viscosity, limited loading capacity, and poor stability. Conversely, the MGF-loaded W₁/O/W₂ emulsions stabilised by 3%PGPR–3%CAS exhibited optimal loading capacity (encapsulation efficiency = 95.31% and loading efficiency = 0.91%) and stability, which was attributed to the fact that high viscosity and gel state retarded the migration of inner aqueous phase. These results indicated that the W₁/O/W₂ emulsions stabilised by PGPR and CAS may be a potential alternative for encapsulating mangiferin.