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Hyperspectral imaging technology can obtain the spatial information and spectral information of the simulated operational background and its camouflage materials at the same time and identify and classify them according to their differences. In this paper, we collected the hyperspectral images (400–1000 nm) of the desert background, jungle background, desert camouflage netting, jungle camouflage netting, and jungle camouflage clothing through the hyperspectral imaging system, and the samples were preprocessed by denoising and black-and-white correction. Then, we analysed the region of interest (ROI) of the training samples by principal component analysis (PCA). After the pixels in the region of interest and their surrounding areas were averaged, 60% of the data was used as the training samples, and the remaining 40% was used as the test samples. According to their similarities and differences between them and referenced spectrum, the models of classification were established by combining the Naive Bayes (NB) algorithm, K-nearest neighbour (KNN) algorithm, random forest (RF) algorithm, and support vector machine (SVM) algorithm. The results show that among the four models, SVM model has the highest accuracy of classification and the recognition rate of jungle camouflage clothing is the highest. This study verifies the scientific and feasibility of hyperspectral imaging technology for camouflage identification and classification in a simulated operational environment, which has some practical significance.

According to the principle of phase-shifting interferometry and spiral phase characteristics of the vortex beam, this article proposes a method for detecting the surface profile of a transparent object, in which the +1 order vortex beam is generated by a spatial light modulator and is taken as the reference light. The influence of the nonlinear phase modulation characteristics of the spatial light modulator on the measurement precision is studied. The results show that nonlinear phase modulation has a great impact on the measurement. Then, the vortex lights with initial phases of 0, π/2, π, and 3π/2 are used to measure the H-type thin film sample based on the Twyman-Green interference system after correcting the nonlinear phase modulation characteristics. The experimental results show that the measurement error of the surface profile to an object with the theoretical value of 20 nm is 1.146 nm, and the feasibility of the optical vortex phase-shifting technique used to measure the surface profile of an object is verified.

The rapid development of sustainable energy has led to the production of a large number of spent lithium-ion batteries (LIBs), and the toxic metals in spent LIBs will have an adverse impact on the environment and human health. An environmentally friendly and economical recycling method is essential for resource recycling and environmental management. In this work, “treating waste with waste” is innovatively proposed to realize the high-value utilization of different types of solid waste based on the reduction conversion between antibiotic bacteria residues (ABRs) and spent cathode powder (SCP). The reaction products are primarily transformed into Ni, Co, C, MnO, Li2CO3 and CaO under the optimum conditions of ABRs thermal reduction. Then, the valuable metals can be efficiently recovered by low acid leaching without reducing agent. The recovery of Ni, Co, Mn, and Li are 99.4%, 99.5%, 99.9% and 99.9% respectively under the optimum leaching condition of 1.0 mol L−1 H2SO4, L/S ratio of 20:1, reaction temperature of 333 K and reaction time of 60 min. In addition, the acid leaching residue can be directly reutilized as LIBs anode materials, which exhibit excellent electrochemical performance. Comparing with the traditional thermal reduction method, this method has advantages of realizing synergistic treatment of two kinds of wastes simultaneously through one-step heat treatment, efficient recovery of valuable metals with low acid and high value utilization of ABRs. The process of treating waste with waste provides a new direction for the recovery of spent LIBs and the treatment of carbonaceous solid wastes.

In this study, a promising process has been developed for selective recovery of valuable metals from spent lithium ion batteries (LIBs). First, reduction roasting which used spent anode powder as reduction agent and water immersion are applied to preferentially recover lithium. Subsequently, an ammonia leaching method is adopted to eff ;ectively separate nickel and cobalt from water immersion residue. Results indicate that Li2CO3, (NiO)m·(MnO)n, Ni, Co are the ultimate reduction products at 650 °C for 1 h with 5% anode powder. 82.2 % Li is preferentially leached via water immersion after reduction roasting and Li2CO3 products are obtained by evaporation crystallization. Thermodynamics shows that reducing ammonia leaching is feasible for water immersion residue. Amounts of 97.7 % Ni and 99.1 % Co can be selectively leached by NH3·H2O and (NH4)2SO3 while Mn remain in the residue as (NH4)2Mn(SO3)2·H2O, (NH4)2Mn(SO4)2·6H2O and (NH4)2Mn2(SO3)3 under the optimized conditions. Ammonia leaching kinetic show the activation energy of Ni and Co is 84.44 kJ/mol and 91.73 kJ/mol, which indicate the controlling steps are the chemical reaction. Summarily, the whole process achieves the maximum degree of selective recovery and reduces the environmental pollution caused by the multistep purification.

An efficient and environmentally friendly closed loop process combing low-temperature chlorination pyrolysis with water leaching is proposed for one-step selective recovery and cyclic utilization of valuable metals from spent lithium-ion batteries (LIBs). First, the spent LiNixCoyMnzO2 (s-NCM) cathode materials are pyrolyzed with NH4Cl as a chlorination agent and the valuable metals (Ni, Co, Mn, Li) can be converted into readily soluble chloride which attribute to the release of HCl and NH3 from NH4Cl. After the s-NCM cathode materials treated via low-temperature chlorination pyrolysis at 300 °C for 30 min with NH4Cl/s-NCM mass ratio of 3:1, more than 99.9% of the valuable metals can be recovered by simple water leaching. Moreover, thermodynamic analysis show that the valuable metals can be converted to chloride while the impurity metals (Fe, Al) do not participate in the reaction at this temperature, which can achieve the one-step selective recovery of valuable metals. Therefore, the water leaching solution can be directly used to synthesize regenerated pristine NCM (r-NCM) cathode materials which exhibit excellent cycle and rate performance. In summary, one-step selective leaching and regeneration of valuable metals can be accomplished by low-temperature chlorination pyrolysis. The whole process reduces the energy consumption and the environmental pollution caused by alleviating the introduction of acidic or alkaline chemicals and realize the high-value utilization of waste resources.

Fiber reinforced plastic has the characteristics of light weight, high strength, good aging performance and strong insulation performance, so the composite overhead transmission line tower may become a substitute for the traditional iron tower in the future. At present, the researches on the composite transmission tower mainly focused on the electrical properties, few on the aging performance, which is an unknown influence on the transmission line with composite transmission towers. In this paper, a 5000 h multi-factor accelerated aging test was used to investigate the aging performance of modified polyurethane (PU) composites for composite transmission towers. The test periodically simulated the environment of high voltage, rainfall, humidity, alternating high and low temperatures, ultraviolet and salt fog. The results show that pultrusion process PU composites are more suitable to be used as the materials of composite towers because of its higher bending modulus. Then, a research on PU composites aging performance improvement scheme was carried out by another multi-factor accelerated aging test. The results show that the mixture of ultraviolet absorber and ultraviolet stabilizer is helpful to improve the aging performance of PU composites, and the addition of 0.275wt% of the total amount with a ratio of 1:1 is a viable scheme.