AnoOnly: Semi-Supervised Anomaly Detection without Loss on Normal Data

Semi-supervised anomaly detection (SSAD) methods have demonstrated their effectiveness in enhancing unsupervised anomaly detection (UAD) by leveraging few-shot but instructive abnormal instances. However, the dominance of homogeneous normal data over anomalies biases the SSAD models against effectively perceiving anomalies. To address this issue and achieve balanced supervision between heavily imbalanced normal and abnormal data, we develop a novel framework called AnoOnly (Anomaly Only). Unlike existing SSAD methods that resort to strict loss supervision, AnoOnly suspends it and introduces a form of weak supervision for normal data. This weak supervision is instantiated through the utilization of batch normalization, which implicitly performs cluster learning on normal data. When integrated into existing SSAD methods, the proposed AnoOnly demonstrates remarkable performance enhancements across various models and datasets, achieving new state-of-the-art performance. Additionally, our AnoOnly is natively robust to label noise when suffering from data contamination. Our code is publicly available at https://github.com/cool-xuan/AnoOnly.Comment: Under review for NeurIPS202

Allelopathic effects of Ulva pertusa, Corallina pilulifera and Sargassum thunbergii on the growth of the dinoflagellates Heterosigma akashiwo and Alexandrium tamarense

The allelopathic effects of fresh tissue, dry powder and aqueous extracts of three macroalgae, Ulva pertusa, Corallina pilulifera and Sargassum thunbergii, on the growth of the dinoflagellates Heterosigma akashiwo and Alexandrium tamarense were evaluated using coexistence culture systems in which concentrations of the three macroalga were varied. The results of the coexistence assay showed that the growth of the two microalgae was strongly inhibited by using fresh tissue, dry powder and aqueous extracts of the three macroalga; the allelochemicals were lethal to H. akashiwo at relatively higher concentrations of the three macroalga. The macroalgae showing the most allelopathic effect on H. akashiwo and A. tamarense using fresh tissue were U. pertusa and S. thunbergii, using dry powder were S. thunbergii and U. pertusa, and using aqueous extracts were U. pertusa and C. pilulifera. We also examined the potential allelopathic effect on the two microalgae of culture filtrate of the three macroalga; culture medium filtrate initially exhibited no inhibitory effects when first added but inhibitory effects became apparent under semi-continuous addition, which suggested that continuous release of small quantities of rapidly degradable allelochemicals from the fresh macroalgal tissue were essential to effectively inhibit the growth of the two microalgae

Impact of Tourists’ Perceived Value and Sense of Social Responsibility on the Low-Carbon Consumption Behavior Intention: A Case Study of Zhangjiajie National Forest Park

People’s increasing attention towards environmental issues and carbon emission level per capita of consumption has made the influencing factors of low-carbon consumption behavior a research hotspot. In this study, a random sample of tourists in Zhangjiajie National Forest Park in China were surveyed by questionnaire to examine the impact of tourists’ perceived value and sense of social responsibility on the low-carbon consumption behavior intention. Results suggest that tourists’ perceived value has a direct and significant positive effect on the sense of social responsibility and low-carbon consumption behavior intention. Tourists’ sense of social responsibility demonstrates a significant positive impact on consumption attitude, with the latter having a positive impact on tourists’ low-carbon consumption behavior intention. A sense of social responsibility and the consumption attitude are found to play an important intermediary role between perceived value and tourists’ low-carbon consumption behavior intention. Some suggestions for managing and promoting tourists’ low-carbon consumption behavior intention are also put forward in this paper

Impact of Tourists’ Perceived Value and Sense of Social Responsibility on the Low-Carbon Consumption Behavior Intention: A Case Study of Zhangjiajie National Forest Park

People’s increasing attention towards environmental issues and carbon emission level per capita of consumption has made the influencing factors of low-carbon consumption behavior a research hotspot. In this study, a random sample of tourists in Zhangjiajie National Forest Park in China were surveyed by questionnaire to examine the impact of tourists’ perceived value and sense of social responsibility on the low-carbon consumption behavior intention. Results suggest that tourists’ perceived value has a direct and significant positive effect on the sense of social responsibility and low-carbon consumption behavior intention. Tourists’ sense of social responsibility demonstrates a significant positive impact on consumption attitude, with the latter having a positive impact on tourists’ low-carbon consumption behavior intention. A sense of social responsibility and the consumption attitude are found to play an important intermediary role between perceived value and tourists’ low-carbon consumption behavior intention. Some suggestions for managing and promoting tourists’ low-carbon consumption behavior intention are also put forward in this paper

Leaching Ni and Co from Saprolitic Laterite Ore by Employing Atmospheric Acid Leaching Solution with High Concentration of FeCl3 at Mild Conditions

Limonitic and saprolitic laterite ores are used to produce Ni by employing different kinds of processes. Acid leaching is an energy-saving process for pure Ni metal production. The high concentration of Fe in atmospheric acid leaching solution caused difficulties in metal-ions separation. In this work, saprolitic laterite ore was leached by atmospheric acid leaching solution of limonitic laterite ore at moderate temperatures. Conditions affecting the leaching of valuable metals and the conversion ratio of Fe were investigated. The results showed that optimal output was obtained after 1.5 h of leaching at 150 degrees C with 1.0 liquid/solid ratio (volume/weight). X-ray diffraction analysis and mineral liberation analysis indicate that some nickel was adsorbed by leached residues, resulting in the loss of nickel. The physiochemical properties of leached residues could be changed due to the presence of Al and Cr. The decrease in zeta potential and the increase in specific surface area resulted in the increase of Ni adsorption

Crystallization of gibbsite from synthetic chromate leaching solution in sub-molten salt process

For the clean and economical production of chromium compounds, it is crucial to remove aluminates from chromate alkali solutions and utilize aluminum-containing compounds. In this work, carbonization was used to remove aluminates from a synthetic chromate leaching solution containing a high K_2O/Al_2O_3 mole ratio. The influence of reaction temperature, carbonization time, flow rate of carbon dioxide, and seed ratio on the precipitation of Al was investigated. The optimal output was obtained under the following experimental conditions: a reaction temperature of 50 °C, a carbonization time of 100 min, a carbon dioxide flow rate of 0.1 L/min, and a seed ratio of 1.0. Gibbsite was obtained following carbonization. The structure and morphology of the gibbsite were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and laser particle size analyzer. The particle size distribution and morphology of the gibbsite were significantly influenced by the experimental conditions. The gibbsite had a mean particle size (d_(50)) of 16.72 μm. The thermal decomposition of the gibbsite was analyzed by XRD and the decomposition path was determined. The obtained coarse α-Al_2O_3 precipitate, which contains 0.08% Cr_2O_3 and 0.10% K_2O, was suitable for subsequent utilization

Characterization and atmospheric hydrochloric acid leaching of a limonitic laterite from Indonesia

The characterization and atmospheric hydrochloric acid leaching of a limonitic laterite from Indonesia were investigated in the current paper. The mineral and chemical compositions of the laterite were studied by X-ray diffraction (XRD) analysis, optical microscopy, scanning electron microscopy/X-ray energy dispersive spectroscopy (SEM/EDS), carbon/sulfur (C-S) analysis, and Fe(II) content titration. The laterite mainly contained goethite, siderite (similar to 16.6 wt.%), chrysotile, and magnetite (similar to 14.6 wt.%); Ni was incorporated in all major minerals. Complete leaching of the host minerals in hydrochloric acid was investigated, given that economical regeneration of the acid by hydrolysis was possible. Atmospheric leaching experiments were carried out to investigate the effect of acid-ore ratio (a/o), liquid-solid ratio (l/s), leaching temperature and time on the leach recovery of Ni (95.1%), Co (99.0%), and Fe (94.6%). Siderite and chrysotile in the ore were highly leachable; goethite dissolved in a wide range of a/o; magnetite and maghemite were moderately active. (C) 2012 Published by Elsevier B.V

Precipitation of alpha-Fe2O3 and recovery of Ni and Co from synthetic laterite-leaching solutions

Atmospheric hydrochloric-acid leaching of nickel laterite can produce a leaching solution containing a large amount of Fe. To recover Ni and Co, Fe should be separated from the laterite-leaching solutions. In this study, hydrolytic distillation was used to remove Fe from the synthetic laterite-leaching solutions; Ni and Co remained as soluble chlorides in the solutions, while most Fe was removed as Fe2O3. The conversion of Fe, recovery of Ni and Co, recovery of HCI, and the concentration of HCI, were investigated under various conditions. The results showed that the optimal output was obtained under the following process conditions: the hydrolysis temperature was 170 degrees C, the pressure was 0.03 MPa, the water flow rate was 1.67 mL/min, and the hydrolysis duration was 2 h. The effects of impurities under the optimized conditions were also studied, showing that as the amount of metal chlorides increased, the conversion of Fe decreased. The residues were characterized by X-ray diffraction analysis and scanning electron microscopy with X-ray energy-dispersive spectroscopy. Using the results, a growth model of alpha-Fe2O3 (hematite) spheres from the synthetic laterite-leaching solutions was constructed. (C) 2015 Elsevier B.V. All rights reserved

Extraction of metals from saprolitic laterite ore through pressure hydrochloric-acid selective leaching

In this study, pressure hydrochloric-add selective leaching was used to leach Ni and Co from saprolitic laterite ore on the basis of potential-pH diagrams constructed for Fe-Si-Cl-H2O and Ni-Si-Cl-H2O systems. The leaching of Ni, Co, Mg, Mn, and Fe was investigated under various conditions. The results showed that the optimal output was obtained under the following conditions: leaching temperature of 150 degrees C, HCl concentration of 350 g/L, liquid to solid ratio (I/s) of 1.0, and leaching time of 90 min. The saprolitic laterite and leached residue were characterized via X-ray diffraction analysis, infrared spectrometry, and mineral liberation analysis. The related acid leaching mechanism was analyzed based on the results, and the kinetics of the leaching process was discussed. The results of this study suggest that pressure hydrochloric-acid selective leaching is a viable method for efficiently leaching Ni from laterite ores. (C) 2015 Elsevier B.V. All rights reserved.</p

Leaching metals from saprolitic laterite ore using a ferric chloride solution

In this work, FeCl3 solution was used as a lixiviant to leach Ni, Co, Mg, and Mn from saprolitic laterite ore. Investigation into the leaching of these metals and the precipitation of Fe in the lixiviant, found the optimal leaching conditions to be a temperature of 150 degrees C, a Fe concentration in the lixiviant of 178.9 g/L, a liquid to solid ratio (L/S) of 1.0, and a leaching time of 90 min. The kinetics of the leaching process was also discussed. Saprolitic ore with and without goethite seeds was leached using FeCl3 solution under identical conditions. X-ray diffraction (XRD) analysis, infrared spectrometry (IR), and mineral liberation analysis (MLA) were used to characterize the leached residues. The leaching mechanism was analyzed based on these results. (C) 2015 Elsevier Ltd. All rights reserved