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Modulating the degree of O vacancy defects to achieve selective control of electrochemical CO_(2) reduction products

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Chinese Chemical Letters 2024年第5期35卷 482-486页

作者： Tianbo Jia Lili Wang Zhouhao Zhu Baikang Zhu Yingtang Zhou Guoxing Zhu Mingshan Zhu Hengcong Tao School of Petrochemical Engineering&Environment Zhejiang Ocean UniversityZhoushan 316022China department of General Practice First Medical CenterChinese PLA General HospitalBeijing 100853China National&Local Joint Engineering Research Center of Harbor Oil&Gas storage and transportation Technology Zhoushan 316022China School of Chemistry and Chemical Engineering Jiangsu UniversityZhenjiang 212013China Guangdong Key Laboratory of Environmental Pollution and Health School of EnvironmentJinan UniversityGuangzhou 511443China

Conversion of CO_(2) into high-value products using electrochemical CO_(2) reduction(ECR)technology is an effective way to alleviate global warming and reach carbon *** oxygen vacancies in heterogenous catalysis are generally considered as a powerful method to enhance the performance of ECR by promoting CO_(2) adsorption and ***,the extent of defects in oxygen vacancies-activity relation has rarely been ***,we prepared Cu-Cd bimetallic catalysts with adjustable oxygen defect degree by controlling the amount of cadmium *** transform infrared spectroscopy characterization results reveal that the formation of oxygen vacancies is attributed to the asymmetric stretching of Cu-O by the addition of *** results show that the oxygen defect degree can modulate the selectivity of ECR products.A low degree of oxygen defects(CuO)is generally associated with lower product Faraday efficiency(FE_(C2)/FE_(C1)≈114%),but overabundant oxygen vacancies(CuO_(2.625)-CdO_(0.375))are not entirely favorable to improving ECR activity(FE_(C2)/FE_(C1)≈125%)and single selectivity,while an appropriate degree of oxygen vacancies(CuO_(2.75)-CdO_(0.25))can facilitate the ECR process toward single product selective production(FE_(C2)/FE_(C1)≈296%).The theoretical calculation showed that the O vacancy formed on CuO and the interface between CdO and CuO were conducive to enhancing the formation of ^(*)COOH intermediate and promoting the generation of ethylene *** study provides a new approach and insight into the selective production of single products for future industrial applications of ECR.

关键词： CO_(2) O-vacancies Bimetallic catalysts Copper oxide Cadmium oxide Selective

Enabling Efficient Data Transmission in Wireless Sensor Networks-Based IoT Application

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Computers, Materials & Continua 2024年第6期79卷 4197-4218页

作者： Ibraheem Al-Hejri Farag Azzedin Sultan Almuhammadi Naeem Firdous Syed Information and Computer Science department King Fahd University of Petroleum andMineralsDhahran31261Saudi Arabia Center for Cyber Resilience and Trust(CREST) Deakin UniversityGeelong3220Australia

The use of the Internet of Things(IoT)is expanding at an unprecedented scale in many critical applications due to the ability to interconnect and utilize a plethora of wide range of *** critical infrastructure domains like oil and gas supply,intelligent transportation,power grids,and autonomous agriculture,it is essential to guarantee the confidentiality,integrity,and authenticity of data collected and ***,the limited resources coupled with the heterogeneity of IoT devices make it inefficient or sometimes infeasible to achieve secure data transmission using traditional cryptographic ***,designing a lightweight secure data transmission scheme is becoming *** this article,we propose lightweight secure data transmission(LSDT)scheme for IoT *** consists of three phases and utilizes an effective combination of symmetric keys and the Elliptic Curve Menezes-Qu-Vanstone asymmetric key agreement *** design the simulation environment and experiments to evaluate the performance of the LSDT scheme in terms of communication and computation *** and performance analysis indicates that the LSDT scheme is secure,suitable for IoT applications,and performs better in comparison to other related security schemes.

关键词： IoT lightweight computation complexity communication overhead cybersecurity threats threat prevention secure data transmission Wireless Sensor Networks(WSNs) elliptic curve cryptography

Secure Transmission of Compressed Medical Image Sequences on Communication Networks Using Motion Vector Watermarking

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Computers, Materials & Continua 2024年第3期78卷 3283-3301页

作者： Rafi Ullah Mohd Hilmi bin Hasan Sultan Daud Khan Mussadiq Abdul Rahim Computer and Information Sciences department Universiti Teknologi PETRONASBandar Seri Iskandar Perak32610Malaysia department of Computer Science National University of TechnologyIslamabad46000Pakistan Interdisciplinary Research Center for Intelligent Secure Systems King Fahd University of Petroleum and MineralsDammam31261Saudi Arabia

Medical imaging plays a key role within modern hospital management systems for diagnostic *** methodologies are extensively employed to mitigate storage demands and enhance transmission speed,all while upholding image ***,an increasing number of hospitals are embracing cloud computing for patient data storage,necessitating meticulous scrutiny of server security and privacy ***,considering the widespread availability of multimedia tools,the preservation of digital data integrity surpasses the significance of compression *** response to this concern,we propose a secure storage and transmission solution for compressed medical image sequences,such as ultrasound images,utilizing a motion vector watermarking *** watermark is generated employing an error-correcting code known as Bose-Chaudhuri-Hocquenghem(BCH)and is subsequently embedded into the compressed sequence via block-based motion *** the process of watermark embedding,motion vectors are selected based on their magnitude and phase *** embedding watermarks,no specific spatial area,such as a region of interest(ROI),is used in the *** embedding of watermark bits is dependent on motion *** reversible watermarking allows the restoration of the original image sequences,we use the irreversible watermarking *** reason for this is that the use of reversible watermarks may impede the claims of ownership and legal *** restoration of original data or images may call into question ownership or other legal *** peak signal-to-noise ratio(PSNR)and structural similarity index(SSIM)serve as metrics for evaluating the watermarked image *** all images,the PSNR value exceeds 46 dB,and the SSIM value exceeds *** results substantiate the efficacy of the proposed technique in preserving data integrity.

关键词： Block matching algorithm(BMA) compression full-search algorithm motion vectors ultrasound image sequence watermarking

Apically guiding electron/mass transfer reaction induced by Ag/FeN_(x)Mott-Schottky effect within a hollow star reactor toward high performance zinc-air batteries

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Journal of Energy Chemistry 2024年第8期95卷 106-116,I0004页

作者： Kaixiang Shi Kaixin Wang Tong Li Junhao Li Jie Ren Xu Li Yonggang Min Zhouguang Lu Wei Tan Quanbing Liu Guangdong Provincial Laboratory of Chemistry and Fine Chemical Engineering Jieyang Center(Rongjiang Laboratory) Guangdong University of TechnologyJieyang 515200GuangdongChina Guangzhou Key Laboratory of Clean transportation Energy Chemistry Guangdong Provincial Key Laboratory of Plant Resources BiorefinerySchool of Chemical Engineering and Light IndustryGuangdong University of TechnologyGuangzhou 510006GuangdongChina Key Laboratory of Electrochemical Energy storage and Energy Conversion of Hainan Province School of Chemistry and Chemical EngineeringHainan Normal UniversityHaikou 571158HainanChina School of Materials and Energy Guangdong University of TechnologyGuangzhou 510006GuangdongChina department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055GuangdongChina

The disparity in the transfer of carriers(electrons/mass)during the reaction in zinc-air batteries(ZABs)results in sluggish kinetics of the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),along with elevated overpotentials,thereby imposing additional constraints on its ***,the pre-design and target-development of inexpensive,high-performance,and long-term stable bifunctional catalysts are urgently *** this work,an apically guiding dual-functional electrocatalyst(Ag-FeN_(x)-N-C)was prepared,in which a hierarchical porous nitrogen-doped carbon with three-dimensional(3D)hollow star-shaped structure is used as a substrate and high-conductivity Ag nanoparticles are coupled with iron nitride(FeN_(x))*** calculations indicate that the Mott-Schottky heterojunction as an inherent electric field comes from the two-phase bound of Ag and FeN_(x),of which electron accumulation in the FeN_(x)phase region and electron depletion in the Ag phase region promote orientated-guiding charge *** effective modulation of local electronic structures felicitously reforms the d-band electron-group distribution,and intellectually tunes the masstransfer reaction energy barriers for both ORR/***,the hollow star-s haped hierarchical porous structure provides an apical region for fast mass *** results show that the halfwave potential for ORR is 0.914 V,and the overpotential for OER is only 327 mV at 10 mA cm^(-2).A rechargeable ZAB with Ag-FeN_(x)-N-C as the air cathode demonstrates long-term cycling performance exceeding 1500 cycles(500 h),with a power density of 180 mW cm^(-2).Moreover,when employing AgFeN_(x)-N-C as the air cathode,flexible ZABs demonstrate a notable open-circuit voltage of 1.42 V and achieve a maximum power density of 65.6 mW cm^(-2).Ag-FeN_(x)-N-C shows guiding electron/mass transfer route and apical reaction microenvironment for the electrocatalyst architecture in the explo

关键词： Hollow star structure Mott-Schottky effect Apically guiding effect Bifunctional catalysis Zinc-air batteries

Performance analysis of a photovoltaic/thermal system with lunar regolith-based thermal storage for the lunar base

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Science China(Technological Sciences) 2024年第4期67卷 1113-1123页

作者： SUN WenGan ZHAO Bin PEI Yu SHI LingFeng HU MaoBin LI MuJun REN Xiao PEI Gang Deep Space Exploration Laboratory Hefei 230026China department of Thermal Science and Energy Engineering University of Science and Technology of ChinaHefei 230026China department of Mechanical and Aerospace Engineering University of California San DiegoLa JollaCA 92093USA department of Precision Machinery and Precision Instrumentation University of Science and Technology of ChinaHefei 230026China College of New Energy China University of Petroleum(East China)Qingdao 266000China

Powering a moon base,especially keeping it warm during the long lunar night,is a big *** paper introduces a photovoltaic/thermal(PV/T)system incorporating regolith thermal storage to solve the challenge of power and heat provision for the lunar base *** vacuum of space around the moon helps this system by reducing heat *** the moon's daytime,the system not only generates electricity but also captures *** stored heat in the regolith is then used at night,reducing the amount of equipment we need to send from *** spectrally selective PV/T panels are designed to absorb a wide range of sunlight(0.3–2.5μm)while minimizing heat loss in the infrared range(3–30μm).Simulation results of the hybrid solar energy system indicate the average value of the overall efficiency is 45.9%,which relatively elevates 56.1%compared to the PV *** launch mass of the proposed PV/T system is only 8.4%of a traditional photovoltaic-lithium battery system with the same amount of energy *** the total specific energy of the proposed system is 7.3 kWh kg^(-1),while that of the photovoltaic-lithium battery system is about 0.3 kWh kg^(-1).In summary,this study proposes an alternative combined heat and electricity supply system for the lunar base,which can greatly reduce the launch mass and free up load for other scientific research equipment.

关键词： in-situ resource utilization(IRSU) regolith thermal storage photovoltaic/thermal(PV/T) spectral selectivity

Experimental Study on Thermal Performance of FLNG Spiral Wound Heat Exchanger under Sloshing Conditions

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Journal of Thermal Science 2019年第5期28卷 1042-1053页

作者： YAN Yan SUN Chongzheng HAN Hui LI Yuxing College of Pipeline and Civil Engineering/Shandong Provincial Key Laboratory of Oil & Gas storage and transportation Safety/Qingdao Key Laboratory of Circle Sea Oil & Gas storage and transportation Technology China University of Petroleum

The FLNG spiral wound heat exchanger(SWHE) is affected by the sea conditions, which leads to more complex flow process and decrease the heat transfer performance of the heat exchanger. In order to study the thermal performance of FLNG SWHE under heaving and swaying conditions, the experimental devices of FLNG SWHE and six-DOF(degree of freedom) sloshing platform were built. The effects of heaving and swaying motions on the pressure drop and heat transfer characteristics were analyzed at different sloshing amplitudes. The results showed that the heaving and swaying motions can cause the temperature rise and pressure fluctuation of SWHE, especially for swaying. The effect of sloshing on the heat transfer performance at the top of SWHE was greater than bottom. The pressure fluctuation percentage was within 7% and the amount of temperature change was less than 2℃, under the sloshing displacement among 120–255 mm.

关键词： spiral wound heat exchanger FLNG experimental sloshing

Enhanced gas production and CO_(2) storage in hydrate-bearing sediments via pre-depressurization and rapid CO_(2) injection

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Chinese Journal of Chemical Engineering 2024年第3期67卷 126-134页

作者： Hongnan Chen Yifei Sun Bojian Cao Minglong Wang Ming Wang Jinrong Zhong Changyu Sun Guangjin Chen State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China School of Chemistry and Chemical Engineering Changsha University of Science&TechnologyChangsha 410114China

Carbon emission reduction and clean energy development are urgent demands for mankind in the coming *** an efficient CO_(2) storage method can significantly reduce CO_(2) emissions in the short *** this study,we attempted to construct sediment samples with different residual CH_(4) hydrate amounts and reservoir conditions,and then investigate the potentials of both CO_(2) storage and enhanced CH_(4) recovery in depleted gas hydrate deposits in the permafrost and ocean zones,*** results demonstrate that CO_(2) hydrate formation rate can be significantly improved due to the presence of residual hydrate seeds;However,excessive residual hydrates in turn lead to the decrease in CO_(2) storage *** by the T-P conditions of the reservoir,the storage amount of liquid CO_(2) can reach 8 times that of gaseous CO_(2),and CO_(2) stored in hydrate form reaches 2-4 ***,we noticed two other advantages of this *** is that CO_(2) injection can enhance CH_(4) recovery rate and increases CH_(4) recovery by 10%-20%.The second is that hydrate saturation in the reservoir can be restored to 20%-40%,which means that the solid volume of the reservoir avoids serious ***,this is crucial for protecting the goaf *** summary,this approach is greatly promising for high-efficient CO_(2) storage and safe exploitation of gas hydrate.

关键词： Hydrate Depressurization CO_(2) storage CH_(4) production Reservoir remediation

An Integrated Optimization Method for CO_(2) Pre-Injection during Hydraulic Fracturing in Heavy Oil Reservoirs

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Fluid Dynamics & Materials Processing 2024年第9期20卷 1971-1991页

作者： Hong Dong Xiding Gao Xinqi Zhang Qian Wang Haipeng Xu Binrui Wang Chengguo Gao Kaiwen Luo Hengyi Jiang PetroChina Xinjiang Oilfield Company Karamay834000China National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500China department of Modern Mechanics University of Science and Technology of ChinaHefei230026China

CO_(2) pre-injection during hydraulic fracturing is an important method for the development of medium to deep heavy oil *** reduces the interfacial tension and viscosity of crude oil,enhances its flowability,maintains reservoir pressure,and increases reservoir drainage *** the Badaowan Formation as an example,in this study a detailed three-dimensional geomechanical model based on static data from well logging interpretations is elaborated,which can take into account both vertical and horizontal geological variations and mechanical characteristics.A comprehensive analysis of the impact of key construction parameters on Pre-CO_(2) based fracturing(such as cluster spacing and injection volume),is therefore ***,using optimized construction parameters,a non-structured grid for dynamic development prediction is introduced,and the capacity variations of different production scenarios are *** the basis of the simulation results,reasonable fracturing parameters are finally determined,including cluster spacing,fracturing fluid volume,proppant concentration,and well spacing.

关键词： Heavy oil reservoir pre-storage CO_(2)energy fracturing horizontal well fracturing parameters numerical simulation

Hydrate formation in oil–water systems: Investigations of the influences of water cut and anti-agglomerant

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Chinese Journal of Chemical Engineering 2020年第2期28卷 369-377页

作者： Guangchun Song Yuxing Li Wuchang Wang Kai Jiang Zhengzhuo Shi Shupeng Yao Shandong Province Key Laboratory of Oil-Gas storage and transportation Safety China University of PetroleumQingdao 266580China

To investigate the characteristics of hydrate formation in oil–water systems, a high-pressure cell equipped with visual windows was used where a series of hydrate formation experiments were performed from natural gas + diesel oil + water systems at different water cuts and anti-agglomerant concentrations. According to the temperature and pressure profiles in test experiments, the processes of hydrate formation under two kinds of experimental procedures were analyzed first. Then, based on the experimental phenomena observed through the visual windows, the influences of water cut and anti-agglomerant on the places of hydrate formation and distribution, hydrate morphologies and hydrate morphological evolvements were investigated. Hydrate agglomeration, hydrate deposition and hydrate film growth on the wall were observed in experiments. Furthermore, three different mechanisms for hydrate film growth on the wall were identified. In addition, the influences of water cut and anti-agglomerant on the induction time of hydrate formation were also studied.

关键词： Hydrates Formation Oil–water system Water cut Anti-agglomerant