Self-Consistent Learning: Cooperation between Generators and Discriminators

Using generated data to improve the performance of downstream discriminative models has recently gained popularity due to the great development of pre-trained language models. In most previous studies, generative models and discriminative models are trained separately and thus could not adapt to any changes in each other. As a result, the generated samples can easily deviate from the real data distribution, while the improvement of the discriminative model quickly reaches saturation. Generative adversarial networks (GANs) train generative models via an adversarial process with discriminative models to achieve joint training. However, the training of standard GANs is notoriously unstable and often falls short of convergence. In this paper, to address these issues, we propose a $\textit{self-consistent learning}$ framework, in which a discriminator and a generator are cooperatively trained in a closed-loop form. The discriminator and the generator enhance each other during multiple rounds of alternating training until a scoring consensus is reached. This framework proves to be easy to train and free from instabilities such as mode collapse and non-convergence. Extensive experiments on sentence semantic matching demonstrate the effectiveness of the proposed framework: the discriminator achieves 10+ AP of improvement on the zero-shot setting and new state-of-the-art performance on the full-data setting

Low-temperature direct dehydrogenation of propane over binary oxide catalysts: insights into geometric effects and active sites

Binary ZnZrxOy catalysts were prepared and employed to catalyze propane dehydrogenation at relatively low temperatures. The evaluation of these materials for propane dehydrogenation was supplemented by material characterization and density functional theory calculations, to provide molecular insights into the nature of the catalytic active sites. Combined, these experiments suggested that coordinatively unsaturated Zn cations (Zncus) in Zncus–O–Zrcus were the active sites for the first step of propane dehydrogenation, and coordinatively unsaturated Zr cations (Zrcus) in Zncus–O–Zrcus were active sites for the second step. This synergistic effect, derived from both these components, led to significant enhancements in activity. Furthermore, the combination of Zn and Zr species resulted in notable changes to the structure of the catalysts, leading to both the formation of the Zrcus active site and improved oxygen mobility. ZnZr2 exhibited relatively high activity

Thermoresponsive hydrogels for atmospheric water vapor harvesting

Currently, freshwater scarcity is a global challenge that is threatening four billion people across the world. To satisfy people’s increasing freshwater demand, harvesting atmospheric water from the air could be an alternative way. This work developed copolymer P(NIPAM-co-15%BzDMA) hydrogels to harvest atmospheric water vapor. Two methods were investigated to improve its adsorption performance: decreasing synthesis temperature below the LCST and copolymerizing with the optimum amount of quaternary ammonium salt (QAS). We found these two methods can effectively improve the water vapor uptake. After copolymerizing NIPAM with 15% QAS at 20°C, the water vapor uptake could be increased by almost 20% to 232 mg/g at 20°C and P/P0 of 0.75 compared with pure PNIPAM prepared at 60°C (194 mg/g). The significant increase can be attributed to the more uniform porous structure and the hygroscopicity of QAS. After coating PNIPAM onto the PESPU sponge skeleton, the PESPU-PNIPAM_60 could adsorb 180 mg/g gas water at 20°C and P/P0 of 0.75, and the modified sponges inherit the switchable wettability from PNIPAM. This research provides polymer processing parameters and their character for harvesting water vapor from the air with hydrogels

Energy Saving Characteristics of a Winch System Driven by a Four-Quadrant Hydraulic Pump

In this study, an integrated system of winch driving and potential energy recovery using a four-quadrant pump was proposed, aimed at the large amount of recoverable gravitational potential energy in a winch system. The proposed system changed the original open system into a closed-structure part, using a four-quadrant pump to drive the winch, and an open-structure part, using an open hydraulic pump to balance torque. The closed-structure and open-structure parts were coaxial, and connected with the engine through the transfer case, which was able to make full use of the four-quadrant pump characteristics. It was able to achieve flow regeneration when the weight was lowered, and to achieve direct use of gravitational potential energy. The AMESim model of the original and proposed systems was further established according to a working characteristics analysis of the energy consumption of the winch-driving system. The simulation results verified that the proposed system kept good controllability while recovering potential energy. An experimental prototype was built; the test results showed that, compared with the original winch system, the proposed system increased lifting speed and reduced fuel consumption significantly. Additionally, diesel consumption was reduced by 87% in the descending process

Critical role of small micropores in high CO2 uptake

Microporous carbon materials with extremely small pore size are prepared by employing polyaniline as a carbon precursor and KOH as an activating agent. CO2 sorption performance of the materials is systematically investigated at the temperatures of 0, 25 and 75 degrees C. The prepared carbons show very high CO2 uptake of up to 1.86 and 1.39 mmol g(-1) under 1 bar, 75 degrees C and 0.15 bar, 25 degrees C, respectively. These values are amongst the highest CO2 capture amounts of the known carbon materials. The relation between CO2 uptake and pore size at different temperatures is studied. An interesting and innovative point that the micropores with pore size smaller than a critical value play a crucial role in CO2 adsorption at different temperatures is demonstrated. It is found that the higher the sorption temperature is, the smaller this critical value of pore size is. Pores smaller than 0.54 nm are manifested to determine CO2 capture capacity at high sorption temperature, e.g. 75 degrees C. This research proposes a basic principle for designing highly efficient CO2 carbon adsorbents; that is, the adsorbents should be primarily rich in extremely small micropores

Dietary Sodium Butyrate Changed Intestinal Histology and Microbiota of Rainbow Trout (Oncorhynchus mykiss), but Did Not Promote Growth and Nutrient Utilization

The study investigated the effects of dietary sodium butyrate (SB) on the growth performance, nutrient utilization, intestinal histology, and microbiota of rainbow trout (Oncorhynchus mykiss). A high fishmeal diet and a low fishmeal diet were formulated to contain 200 g/kg or 100 g/kg fishmeal, respectively. Coated SB (50%) was supplemented to each of the diets at levels of 0, 1.0, and 2.0 g/kg to create 6 diets. The diets were fed to rainbow trout with initial body weight of 29.9±0.2 g for 8 weeks. Compared to the high fishmeal group, the low fishmeal group showed significantly lower weight gain (WG), intestine muscle thickness, and significantly higher feed conversion ratio (FCR) and amylase activity (P0.05). The supplementation of 2.0 g/kg SB in low fishmeal diet significantly increased the villus height, villus width, and muscular thickness, while the supplementation of 2.0 g/kg SB in high fishmeal diet also significantly increased the intestinal villus height (P0.05). In conclusion, the addition of SB in diets containing 100 or 200 g/kg fishmeal did not enhance the growth performance and nutrient utilization of rainbow trout, but improved intestinal morphology and changed intestinal microbial flora

A Back Propagation Neural Network Model for Postharvest Blueberry Shelf-Life Prediction Based on Feature Selection and Dung Beetle Optimizer

(1) Background: Traditional kinetic-based shelf-life prediction models have low fitting accuracy and inaccurate prediction results for blueberries. Therefore, this study aimed to develop a blueberry shelf-life prediction method based on a back propagation neural network (BPNN) optimized by the dung beetle optimizer using an elite pool strategy and a Gaussian distribution estimation strategy (GDEDBO); (2) Methods: The “Liberty” blueberry cultivar was used as the research object, and 23 quality indicators, including color parameters, weight loss rate, decay rate, and texture parameters, were measured under storage temperatures of 0, 4, and 25 °C. Based on the maximum relevance minimum redundancy (MRMR) algorithm, seven key influencing factors of shelf life were selected as the input parameters of the model, and then the MRMR-GDEDBO-BPNN prediction model was established; (3) Results: the results showed that the model outperformed the baseline model at all three temperatures, with strong generalization ability, high prediction accuracy, and reliability; and (4) Conclusions: this study provided a theoretical basis for the shelf-life determination of blueberries under different storage temperatures and offered technical support for the prediction of remaining shelf life

Visible Light Accelerates Cr(III) Release and Oxidation in Cr–Fe Chromite Residues: An Overlooked Risk of Cr(VI) Reoccurrence

The reduced chromite ore processing residue (rCOPR) deposited in environments is susceptible to surrounding factors and causes reoccurrence of Cr(VI). However, the impact of natural sunlight on the stability of rCOPR is still unexplored. Herein, we investigated the dissolution and transformation behaviors of Cr(III)–Fe(III) hydroxide, a typical Cr(III)-containing component in rCOPR, under visible light. At acidic conditions, the release rate of Cr(III) under illumination markedly increased, up to 7 times higher than that in the dark, yet no Cr(VI) was produced. While at basic conditions, only Cr(VI) was obtained by photo-oxidation, with an oxidation rate of ∼7 times higher than that by δ-MnO2 under dark conditions at pH 10, but no reactive oxygen species was generated. X-ray absorption near-edge structure and density functional theory analyses reveal that coexisting Fe in the solid plays a critical role in the pH-dependent release and transformation of Cr(III), where photogenerated Fe(II) accelerates Cr(III) produced at acidic conditions. Meanwhile, at basic conditions, the production of intermediate Cr(III)–Fe(III) clusters by light leads to the oxidation of Cr(III) into Cr(VI) through the nonradical “metal-to-metal charge transfer” mechanism. Our study provides a new insight into Cr(VI) reoccurrence in rCOPR and helps in predicting its environmental risk in nature

Mechanical Properties and Reaction Characteristics of Al-ZrH₂-PTFE Composites under Quasi-Static Compression

To analyze the mechanical properties and reaction characteristics of Al-ZrH2-PTFE (aluminum-zirconium hydride-polytetrafluoroethylene) composites under quasi-static compression, five types of specimens with different ZrH2 contents (0%, 5%, 10%, 20% and 30%) were prepared by molding-vacuum sintering. The true stress-strain curves and reaction rates of the different specimens were measured using quasi-static compression. The specific reaction processes were recorded by a high-speed camera. The corresponding reaction products were characterized by the XRD phase analysis, the calorific value was tested by a Calorimeter, and the reaction mechanism was analyzed. According to the results, the strength of the composites increased first and then decreased with the increase in the content of ZrH2. It reached a maximum of 101.01 MPa at 5%. Violent reaction occurred, and special flames were observed during the reaction of the specimens with 5% ZrH2. With the increase in the content of ZrH2, the chemical reaction was hard to induce due to the reduction in strength and toughness of composites. The reaction mechanism of Al/ZrH2/PTFE reveals that high temperatures at crack tip induced the reaction of Al and PTFE. Subsequently, ZrH2 decomposed to release hydrogen and generate ZrC. Calorimetric experiment shows that the calorific value of Al/ZrH2/PTFE with 20% ZrH2 is higher than that of Al/PTFE. The findings verify the potential of ZrH2 as an energetic additive for the enhancement of strength and release of the energy of the composites

Automatic Walking Method of Construction Machinery Based on Binocular Camera Environment Perception

In this paper, we propose an end-to-end automatic walking system for construction machinery, which uses binocular cameras to capture images of construction machinery for environmental perception, detects target information in binocular images, estimates the relative distance between the current target and cameras, and predicts the real-time control signal of construction machinery. This system consists of two parts: the binocular recognition ranging model and the control model. Objects within 5 m can be quickly detected by the recognition ranging model, and at the same time, the distance of the object can be accurately ranged to ensure the full perception of the surrounding environment of the construction machinery. The distance information of the object, the feature information of the binocular image, and the control signal of the previous stage are sent to the control model; then, the prediction of the control signal of the construction machinery can be output in the next stage. In this way, the automatic walking experiment of the construction machinery in a specific scenario is completed, which proves that the model can control the machinery to complete the walking task smoothly and safely