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Polymetallic Te-rich melts contribute to efficient enrichment and precipitation of Au in hydrothermal ore deposits

Geochimica et Cosmochimica Acta 2025年 397卷 176-187页

作者： Fan, Gao-Hua Li, Jian-Wei Zhong, Ri-Chen Gleeson, Sarah A. Yao, Zhuo-Sen Harlov, Daniel E. Deng, Xiao-Dong Cui, Hao Yu, Chang Gao, Wen-Sheng State Key Laboratory of Geological Process and Mineral Resources China University of Geosciences Wuhan 430074 China School of Earth Resources China University of Geosciences Wuhan 430074 China School of Civil and Resource Engineering University of Science and Technology Beijing Beijing 100083 China Deutsches GeoForschungsZentrum GFZ Potsdam 14473 Germany Institute of Geological Sciences Freie Universität Berlin Malteserstrasse 74-100 Berlin 12249 Germany

Tellurides are abundant in a large variety of hydrothermal Au deposits. Previous studies have proposed that these phases crystallize from polymetallic Te-rich melts that may act as scavengers for Au to form high grade deposits. However, the conditions under which Te-rich melts form and whether such melts can act as agents to concentrate Au have not been directly assessed. Here, we present an experimental study using natural ore samples from a giant Te-rich Au deposit (Dongping, China) to show that tellurides in Au ores crystallized from polymetallic melts and these melts behaved as a critical agent for Au enrichment and precipitation. The samples investigated contain abundant polymetallic inclusions, which consist of various telluride-gold mineral assemblages as well as minor chalcopyrite. Individual inclusions typically comprise one micron-sized gold grain. Annealing experiments of these inclusions were carried out at 300, 350, 400, and 450 °C. The polymetallic inclusions had relatively subtle changes in morphology and texture at 300 and 350 °C, but changed markedly at 400 and 450 °C, accompanying with the formation of abundant droplet-like and/or vermiculate gold grains randomly dispersed in the telluride matrix. Three in-situ scanning electron microscopy heating–cooling experiments with different heating rates and durations revealed a eutectic temperature of 243 to 270 °C for polymetallic tellurides, at which native gold began to dissolve into molten tellurides. During the heating processes of the three experimental runs, changes in topographic contrast occurred, with the formation of transient holes in the tellurides and the appearance of tellurides on the surface of chalcopyrite. These observations are indicative of localized migration of the molten tellurides. Upon cooling in run #1 and #2, native gold recrystallized at ∼ 340 °C from the molten tellurides and subsequently regrew in a gradual manner. After these two runs, many newly-formed telluride-gold globul

关键词： Agents for gold accumulation Gold deposit Melting behavior Polymetallic Te-rich melt

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Cobalt-modified MCM-41 catalysts with multiple acidic sites for energy-efficient CO₂ desorption of functionalized ionic liquid absorbents

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Separation and Purification Technology 2025年 373卷

作者： Chu, Haozhan Zeng, Shaojuan Zhang, Xiangping Zhan, Guoxiong Wang, Bo Zhang, Hongyu Zhong, Sheng Liu, Wei Beijing Key Laboratory of Solid State Battery and Energy Storage Process State Key Laboratory of Mesoscience and Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China School of Future Technology University of Chinese Academy of Sciences Beijing 101408 China School of Chemical Engineering University of Chinese Academy of Sciences Beijing 101408 China National Key Laboratory of Heavy Oil China University of Petroleum Beijing 102249 China

Ionic liquids (ILs) show great application potentials in CO2 capture due to extremely low vapor pressures, tunable structures, and strong CO2 affinity. Up to date, many efforts have been focused on the design and abso... 详细信息

Ionic liquids (ILs) show great application potentials in CO₂ capture due to extremely low vapor pressures, tunable structures, and strong CO₂ affinity. Up to date, many efforts have been focused on the design and absorption performance of novel functionalized ILs, rather than desorption performance. In our previous work, the IL solvent [Cho][Triz]/TMS exhibited exceptional CO₂ absorption performance. As a successive study on decreasing regeneration energy consumption, this work focused on the design and synthesis of novel metal-modified MCM-41 catalysts with multiple acidic sites to enhance CO₂ catalytic desorption in the nonaqueous [Cho][Triz]/TMS (80 wt%/20 wt%) absorbent under lower temperatures. Among all the composite MCM-41 catalysts, the CoM-1/4 catalyst exhibits superior catalytic performance because of the increase of Brønsted acid sites by 232.3 % and Lewis acid sites by 56.2 % compared with pristine MCM-41, which promote CO₂ desorption by accelerating C-N bond breaking. The CO₂ desorption rate and amount increased by 180.2 % and 95.7 %, and the activation energy reduced by 46.7 % compared to the non-catalysis. Therefore, the theoretical regeneration energy consumption of the catalyst-added system was 0.88 GJ/t CO₂, representing a 76.7 % reduction compared with the 30 wt% MEA solution. Furthermore, the CoM-1/4 catalyst maintained high catalytic activity after 20 cycles. This work indicated that the CoM-1/4 catalyst effectively enhanced the regeneration performance of IL absorbent, facilitating the development of an energy-efficient CO₂ capture process for industrial applications. © 2025 Elsevier B.V.

关键词： Catalytic desorption CO2 capture Ionic liquids Low energy consumption

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The role of temperature in mechanical degradation of catalyst coated membrane in fuel cell: A 4D in-situ investigation based on X-ray computed tomography

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Applied Energy 2025年 393卷

作者： Shi, Shouwen Xie, Gaoyuan Huang, Wei Lin, Qiang Sun, Zhihao Zhao, Tiankuo Chen, Xu School of Chemical Engineering and Technology Tianjin University Tianjin300072 China Tianjin Key Laboratory of Chemical Process Safety and Equipment Technology Tianjin300350 China State Key Laboratory of Chemical Engineering and Low-Carbon Technology Tianjin300350 China Zhejiang Institute of Tianjin University Zhejiang Ningbo315201 China

The application of polymer-electrolyte fuel cells for heavy-duty vehicles requires higher temperature and longer lifetime. However, the effect of temperature on the mechanical degradation mechanisms remains unclear, especially at higher temperature. In this study, the in-situ mechanical degradation behavior of catalyst coated membrane (CCM) is investigated at 70 °C, 80 °C and 90 °C using 4D X-ray computed tomography to track the evolution of mechanical damage throughout the lifetime, with the aim of clarifying the mechanical degradation mechanisms at different temperature to elucidate the role of temperature. Buckling in catalyst layer (CL) is observed at 70 °C, 80 °C and 90 °C, which is thought to be the key factor for mechanical degradation, and the degree of buckling at 90 °C is more severe. The path of buckling in CL is in alignment with cracks in microporous layer (MPL), occurring only in wider MPL crack regions. The deteriorated mechanical properties and increased plastic flow of CCM at higher temperature make CL more vulnerable to buckling, leading to the premature failure and reduced lifetime at 90 °C. In addition, the distribution of cracks at different temperatures is also different. While multiple cracks form due to buckling in the channel area at 90 °C, cracks are observed only at the edge of flow field plate at 70 °C and 80 °C without associated CL buckling progressing into cracks, which is ascribed to the competition between stress in channels and the loading conditions at edges. Finally, mechanisms of mechanical degradation at different temperatures as well as strategies for optimization of fuel cells are proposed. © 2025 Elsevier Ltd

关键词： Cracks

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The potential of ionic liquids in biopharmaceutical engineering

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Chinese Journal of Chemical engineering 2021年第2期34卷 236-243页

作者： Xuan Lin Zhiguo Su Yanli Yang Songping Zhang State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China

Biopharmaceuticals,such as proteins,peptides,nucleic acids and vaccines,bring about great hopes for the prevention and treatment of various diseases,but the industrialization of these products still faces challenges such as structural instability,inefficient bioactivity and low *** liquids(ILs),the marvelous solvent media with inimitable and tunable properties,may provide alternative solutions to overcome the above problems of biopharmaceutical *** has gradually been made through studies by combination of ILs with *** applications involved the stabilization,protection,and delivery of *** trends are being forwarded to using ILs in vaccines and nucleic acid ***,challenges remain on the toxicity and safety ***,the cost of adding ILs to the benefits of biopharmaceuticals need to be considered.

关键词： Ionic liquids Biopharmaceutical engineering Biomacromolecules Stabilization Vaccine Delivery

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Zero-Sum Optimal Control for a Cyber-Physical System in Unreliable Communications via Secure Decentralized Policy Iteration

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IEEE Internet of Things Journal 2025年

作者： Zhang, Kun Dong, Xiwang Zhang, Huaguang Su, Rong Beihang University School of Astronautics Beijing100191 China Beihang University Institute of Unmanned System Institute of Artificial Intelligence School of Automation Science and Electrical Engineering Beijing100191 China Northeastern University School of Information Science and Engineering State Key Laboratory of Synthetical Automation for Process Industries Shenyang110819 China School of Electrical and Electronic Engineering Singapore639798 Singapore

This paper investigates the robust consensus scheme for a specific type of leader-follower multi-agent systems (MASs) in the context of a human-cyber-physical interactive system. The system encounters frequent communication challenges characterized by packet loss and data leakage. To address these challenges, the paper proposes a secure decentralized scheme that leverages game theory to determine optimal policies in a zero-sum game. The scheme utilizes the adaptive dynamic programming (ADP) method, which involves a decentralized iterative process. The paper demonstrates that the generated sequence exhibits exponential convergence and provides the maximum iteration number based on the convergence error. To mitigate data leakage among players, the scheme incorporates a secure operation that involves encrypted data. This integration seamlessly combines data conversion and encryption-decryption into decentralized computation. Finally, the paper presents a simulation example to validate the efficacy of the consensus scheme. © 2014 IEEE.

关键词： Information leakage

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Enhancement of aromatics selectivity in waste LLDPE with HZSM-5@MCM-41 Core-Shell catalysts synthesized by One-Step hydrothermal method

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Fuel 2025年 397卷

作者： Lin, Huaping Zhan, Yuejin Vladimirovich, Vasilevich Sergey Oboirien, Bilainu Xie, Fanghua Xiong, Qingang Zhou, Yefeng National & Local United Engineering Research Centre for Chemical Process Simulation and Intensification College of Chemical Engineering Xiangtan University Xiangtan411105 China Institute of Power Engineering National Academy of Sciences of Belarus Minsk220072 Belarus Department of Chemical Engineering University of Johannesburg Johannesburg17011 South Africa State Key Laboratory of Pulp and Paper Engineering South China University of Technology Guangzhou510640 China

In order to alleviate the pressure on environmental governance caused by waste plastics and to promote the development of a circular economy, this study proposed a HZSM-5@MCM-41 catalyst prepared by a simple one-step hydrothermal method to convert plastics into aromatic hydrocarbons, especially monocyclic aromatic hydrocarbons. HZSM-5, known for its outstanding shape-selective catalytic properties, is widely used in plastic pyrolysis. However, its microporous structure inherently restricts the diffusion of large-molecule compounds. The study revealed that by introducing the mesoporous MCM-41 layer, the specific surface area and pore volume increased by more than 50% compared to HZSM-5. Additionally, by adjusting the Si/Al ratio, the catalyst exhibited a high density of weak acid sites and a low density of strong acid sites. These improvements effectively optimized the pore structure and acid site distribution of the catalyst, ultimately enhancing the catalytic activity HZSM-5@MCM-41. Consequently, the optimized catalyst achieved the highest AHs and MAHs selectivity to 89.45% and 72.03%, respectively, for the pyrolysis of LLDPE. Furthermore, the performance tests of regenerated catalyst showed that the selectivity to MAHs remained at 90% of the initial value after five regenerations of HZSM-5@MCM-41. Finally, based on the "structure–activity relationship" between the microstructure of the core–shell catalyst and its catalytic performance, a diffusion–reaction mechanism for plastic degradation was presented, providing valuable insights into the sustainable transformation of waste plastics into high-value chemical products. © 2025 Elsevier Ltd

关键词： Mesopores

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Mechanistic insights into the preparation and electrodeposition characteristics of Cu–Fe powder employing magnetic field fluidized bed electrode

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Chemical engineering Journal 2025年 512卷

作者： Li, Hongtao Yang, Haitao Cheng, Jiaxin Wang, Xin Fu, Guohui Xu, Liansheng Chai, Qingping State Key Laboratory of Mesoscience and Engineering Institute of Process Engineering Chinese Academy of Sciences P. O. Box353 Beijing100190 China School of Chemical Engineering University of Chinese Academy of Sciences Beijing100049 China Ansteel Beijing Research Institute Beijing102200 China Ansteel Group Mining Corporation Limited Anshan114001 China

Metal-coated powders are widely applied in numerous fields like communications, electronic information, and aerospace. Nevertheless, traditional approaches for the preparation of metal-coated powders are confronted with challenges and limitations regarding environmental protection, economic benefits, and powder functionality, which makes it an urgent necessity to develop novel, further efficient, and further environmentally friendly preparation methods. In this study, a preparation strategy for fabricating metal-coated powders through magnetic fluidized bed electrodeposition is innovatively put forward, and the feasibility of strengthening powder electrodeposition by means of magnetic fluidized bed is investigated. The synergistic effect of high gas velocity and strong magnetic field can effectively enhance the electrodeposition process of powders, resolving issues for the poor electrical contact effect of the cathode, the difficulty in regulating coatings, and the easy adhesion of powders. In the course of the electrodeposition process, the introduction of the magnetic field and Fe powder furnishes more favorable kinetic conditions for the growth of copper within the coatings, allowing copper ions to be uniformly and densely coated on the surface of Fe powder via a continuous growth mechanism. Eventually, under the synergistic effect of high gas velocity and strong magnetic field, Cu–Fe powders with excellent coating quality are successfully and efficiently fabricated through parameter optimization. This novel magnetic fluidized bed electrodeposition technology offers new perspectives for the field of metal-coated powder preparation. © 2025 Elsevier B.V.

关键词： Metal ions

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Three-dimensional CFD simulation of alkaline electrolyzers: flow pattern and electric field

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Chemical engineering Journal 2025年 515卷

作者： Bai, Jinhao Guan, Xiaoping Yang, Ning State Key Laboratory of Mesoscience and Engineering Institute of Process Engineering Chinese Academy of Sciences P. O. Box 353 Beijing 100190 China School of Chemical Engineering University of Chinese Academy of Sciences Beijing 100049 China

Electrolysis for hydrogen production is a key driver for the future of green energy. The pressure-filtered alkaline electrolyzer is widely used in industrial hydrogen production. A 3D Euler-Euler CFD model, coupled with electric field and electro-chemical model, was established to simulate the two-phase flow and the performance of a pilot-scale mastoid plate electrolyzer. The fully-coupled model predicts higher overall gas holdup than the model without considering multi-physics. This discrepancy arises from the non-uniform distribution of current density and gas production rate. Moreover, the gas distribution pattern within the electrolyzer changes from a layered distribution to a tree-like distribution due to the increase in liquid flowrate, which, to our knowledge, has not been reported previously. Additionally, the effects of operating voltage and liquid flowrate on the components of overpotential were analyzed. The findings are beneficial for process intensification and optimization for industrial electrolyzers. © 2025 Elsevier B.V.

关键词： Alkaline electrolyzer Convex-concave structure Flow pattern Green hydrogen Overpotential Two-phase flow

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Quaternary ammonium COF-based proton exchange membranes for enhanced electrochemical hydrogen compression

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Chemical engineering Journal 2025年 515卷

作者： Pang, Xiao Liu, Ziwen Xu, Shuting Lv, Kexin Shi, Benbing Dong, Xu Xing, Na Gao, Zhong Zhu, Shiyi Zhang, Leilang Yao, Zengguang Cheng, Lijuan Wang, Hui Xu, Kai Liu, Yawei Wu, Hong Jiang, Zhongyi Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and Technology Tianjin University Tianjin300072 China Ningbo Key Laboratory of Green Petrochemical Carbon Emission Reduction Technology and Equipment Zhejiang Institute of Tianjin University Zhejiang Ningbo315201 China State Key Laboratory of Synthetic Biology Tianjin University Tianjin300072 China Beijing Key Laboratory of Ionic LiquidsClean Process CAS Key Laboratory of Green Process and Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing100190 China MOE Key Laboratory of Bioorganic NST Phosphorous Chemistry and Chemical Biology Department of Chemistry Tsinghua University Beijing100084 China

Proton exchange membranes (PEMs) with high proton conductivity, excellent mechanical strength, and minimal hydrogen crossover are crucial for the practical implementation of electrochemical hydrogen energy conversion devices, including electrochemical hydrogen compression (EHC). Herein, hydrazone-linked ionic covalent organic frameworks (iCOF) bearing quaternary ammonium (QA) groups were synthesized and introduced into the sulfonated poly (ether ether ketone) (SPEEK) matrix to fabricate hybrid PEMs. Among them, the orderly arrangement of QA and –NH- groups on iCOF not only rearranged the distribution of −SO3H groups in the SPEEK polymer matrix, increasing the continuity and connectivity of the proton conduction pathways but also formed acid-base pairs with −SO3H groups to facilitate proton dissociation. Additionally, the electrostatic and hydrogen bonding interactions formed between iCOF and SPEEK matrix optimized the microphase separation structure and enhanced the mechanical stability of membranes. As a result, the hybrid PEMs exhibited an enhanced proton conductivity of 469.0 mS cm−1 (80 °C, 100 % RH) with only 2 wt% iCOF content, high mechanical strength of 91.3 MPa, and superior EHC performance with a high outlet pressure of 3.31 MPa (30 °C, 100 % RH) and high-purity hydrogen (>99.9 %) from a 40 % hydrogen–nitrogen mixture. © 2025 Elsevier B.V.

关键词： Compressive strength

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EM-DETR: Efficient Multi-scale DETR for Gas Leak Detection Based on Infrared Imaging

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IEEE Sensors Journal 2025年第11期25卷 20538-20546页

作者： Wang, Qi Zhu, Shilin Lu, Zhenlin Sun, Yunlong Qian, Yizhuo Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology Qinhuangdao066004 China Northeastern University State Key Laboratory of Synthetical Automation for Process Industries Shenyang110819 China Northeastern University College of Information Science and Engineering Shenyang110819 China Beijing Institute of Microelectronics Technology Beijin100076 China

Industrial gases play a crucial role in modern industrial production. However, many industrial gases are only visible in the infrared spectrum. Therefore, using infrared camera for gas leak detection is essential for the normal operation of production lines and the safety of personnel. Existing automatic leak detection algorithms based on convolutional neural networks often involve numerous handcrafted feature components, resulting in complex model architectures, with hyperparameter selection significantly impacting model performance. To address these issues, we propose an efficient and high-performance end-to-end object detection network, the Efficient Multi-scale Detection Transformer (EM-DETR), for automatic gas leak detection. To reduce model computational overhead, we design a new efficient encoder. Additionally, to handle leaks of varying ranges due to gas dispersion, we implement bidirectional fusion of multi-scale features to capture granularity information of gases at different scales. Finally, based on the similar unified distribution of gas leak images, we introduce a pre-auxiliary loss to adjust the learnable object queries initialized. Experimental results demonstrate that the EM-DETR R50/R101 outperforms previous methods, achieving 40.7%/43.2% AP on gas leak infrared image datasets with minimal parameters and computational resources, providing a superior solution for automatic gas leak detection using infrared camera. © 2001-2012 IEEE.

关键词： Convolutional neural networks

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