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The effect of the density difference between supercritical CO_(2) and supercritical CH_(4) on their adsorption capacities: An experimental study on anthracite in the Qinshui Basin

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Petroleum Science 2022年第4期19卷 1516-1526页

作者： Si-Jie Han Shu-Xun Sang Piao-Piao Duan jin-chao zhang Wen-Xin Xiang Ang Xu Jiangsu Key Laboratory of Coal-based Greenhouse Gas Control and Utilization China University of Mining and TechnologyXuzhouJiangsu221008China Carbon Neutrality Institute China University of Mining and Technology XuzhouJiangsu221008China School of Resources and Geosciences China University of Mining and TechnologyXuzhouJiangsu221116China

Deep unmineable coals are considered as economic and effective geological media for CO_(2) storage and CO_(2) enhanced coalbed methane(CO_(2)-ECBM) recovery is the key technology to realize CO_(2) geological sequestration in coals. Anthracite samples were collected from the Qinshui Basin and subjected to mercury intrusion porosimetry, low-pressure CO_(2) adsorption, and high-pressure CH_(4)/CO_(2) isothermal adsorption experiments. The average number of layers of adsorbed molecules(ANLAM) and the CH_(4)/CO_(2) absolute adsorption amounts and their ratio at experimental temperatures and pressures were calculated. Based on a comparison of the density of supercritical CO_(2) and supercritical CH_(4), it is proposed that the higher adsorption capacity of supercritical CO_(2) over supercritical CH_(4) is the result of their density differences at the same temperature. Lastly, the optimal depth for CO_(2)-ECBM in the Qinshui Basin is recommended. The results show that:(1) the adsorption capacity and the ANLAM of CO_(2) are about twice that of CH_(4) on SH-3 anthracite. The effect of pressure on the CO_(2)/CH_(4) absolute adsorption ratio decreases with the increase of pressure and tends to be consistent.(2) A parameter(the density ratio between gas free and adsorbed phase(DRFA)) is proposed to assess the absolute adsorption amount according to the supercritical CO_(2)/CH_(4) attributes. The DRFA of CO_(2) and CH_(4) both show a highly positive correlation with their absolute adsorption amounts, and therefore, the higher DRFA of CO_(2) is the significant cause of its higher adsorption capacity over CH_(4) under the same temperature and pressure.(3) CO_(2) adsorption on coal shows micropore filling with multilayer adsorption in the macro-mesopore, while methane exhibits monolayer surface coverage.(4) Based on the ideal CO_(2)/CH_(4) competitive adsorption ratio, CO_(2) storage capacity, and permeability variation with depth, it is recommended that the optimal depth for CO_(

关键词： CO_(2)geological storage Competitive adsorption Deep unmineable coal Average number of layers of adsorbed molecules Density ratio between free phase and adsorbed phase Micropore filling

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Three-dimensional coupled-mode model and characteristics of low-frequency sound propagation in ocean waveguide with seamount topography

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Chinese Physics B 2022年第8期31卷 453-462页

作者： Ya-Xiao Mo chao-jin zhang Li-Cheng Lu Sheng-Ming Guo Key Laboratory of Underwater Acoustic Environment Institute of AcousticsChinese Academy of SciencesBeijing 100190China China State Shipbuilding Corporation Systems Engineering Research Institute Beijing 100094China

Large-scale topography, such as a seamount, substantially impacts low-frequency sound propagation in an ocean waveguide, limiting the application of low-frequency acoustic detecting techniques. A three-dimensional(3D) coupledmode model is developed to calculate the acoustic field in an ocean waveguide with seamount topography and analyze the3D effect. In this model, a correction is introduced in the bottom boundary, theoretically making the acoustic field satisfy the energy conservation. Furthermore, a large azimuth angle calculation range is obtained by using the operator theory and higher-order Pade approximation. Additionally, the model has advantages related to the coupling mode and parabolic equation theory. The couplings corresponding to the effects of range-dependent environment are fully considered, and the numerical implementation is kept feasible. After verifying the accuracy and reliability of the model, low-frequency sound propagation characteristics in the seamount environment are analyzed. The results indicate lateral variability in bathymetry can lead to out-of-plane effects such as the horizontal refraction phenomenon, while the coupling effect tends to restore the abnormal sound field and produces acoustic field diffraction behind the seamount. This model effectively considers the effects of the horizontal refraction and coupling, which are proportional to the scale of the seamount.

关键词： coupled-mode model three-dimensional sound propagation seamount topography horizontal interference structure

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Two Nonmonotone Proximal Gradient Methods for Nonsmooth Optimization over the Stiefel Manifold

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Acta Mathematicae Applicatae Sinica 2024年

作者： jin-chao zhang Juan GAO Ya-kui HUANG Xin-wei LIU Institute of Mathematics Hebei University of Technology School of Artificial Intelligence Hebei University of Technology

We propose two nonmonotone retraction-based proximal gradient methods for solving a class of nonconvex nonsmooth optimization problems over the Stiefel manifold. The proposed methods are equipped with the descent direction obtained by a proximal mapping restricted in tangent space of the manifold and the BarzilaiBorwein stepsizes determined by two recent iteration points and the corresponding descent directions. By employing, respectively, the Grippo-Lampariello-Lucidi nonmonotone line search strategy and the Dai-Fletcher nonmonotone line search strategy, our proposed methods are proved to be globally convergent. Analysis on the iteration complexity of NPGL for obtaining an?-stationary solution is provided. Numerical results on the sparse principle component analysis problems demonstrate the efficiency of our methods.

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High-order Bragg forward scattering and frequency shift of low-frequency underwater acoustic field by moving rough sea surface

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Chinese Physics B 2024年第3期33卷 459-470页

作者：莫亚枭张朝金鹿力成孙启航马力 Key Laboratory of Underwater Acoustic Environment Institute of AcousticsChinese Academy of Sciences (CAS)Beijing 100190China China State Shipbuilding Corporation Systems Engineering Research Institute Beijing 100094China Little Bird Co. LtdBeijing 100089China

Acoustic scattering modulation caused by an undulating sea surface on the space-time dimension seriously affects underwater detection and target ***,underwater acoustic scattering modulation from a moving rough sea surface is studied based on integral equation and parabolic *** with the principles of grating and constructive interference,the mechanism of this acoustic scattering modulation is *** periodicity of the interference of moving rough sea surface will lead to the interference of the scattering field at a series of discrete angles,which will form comb-like and frequency-shift characteristics on the intensity and the frequency spectrum of the acoustic scattering field,respectively,which is a high-order Bragg scattering *** the conventional Doppler effect,the frequency shifts of the Bragg scattering phenomenon are multiples of the undulating sea surface frequency and are independent of the incident sound wave ***,even if a low-frequency underwater acoustic field is incident,it will produce obvious frequency ***,under the action of ideal sinusoidal waves,swells,fully grown wind waves,unsteady wind waves,or mixed waves,different moving rough sea surfaces create different acoustic scattering processes and possess different frequency shift *** the swell wave,which tends to be a single harmonic wave,the moving rough sea surface produces more obvious high-order scattering and frequency *** same phenomena are observed on the sea surface under fully grown wind waves,however,the frequency shift slightly offsets the multiple peak frequencies of the wind wave *** with the swell and fully-grown wind waves,the acoustic scattering and frequency shift are not obvious for the sea surface under unsteady wind waves.

关键词： high-order Bragg scattering frequency shift low-frequency acoustic field moving rough sea surface

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Grid-Connected/Islanded Switching Control Strategy for Photovoltaic Storage Hybrid Inverters Based on Modified Chimpanzee Optimization Algorithm

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Energy Engineering 2025年第1期122卷 265-284页

作者： chao Zhou NarisuWang Fuyin Ni Wenchao zhang School of Electrical and Information Engineering Jiangsu University of TechnologyChangzhou213001China Jiangsu Key Laboratory of Power Transmission&Distribution Equipment Technology Jiangsu University of TechnologyChangzhou213001China

Uneven power distribution,transient voltage,and frequency deviations are observed in the photovoltaic storage hybrid inverter during the switching between grid-connected and island *** response to these issues,this paper proposes a grid-connected/island switching control strategy for photovoltaic storage hybrid inverters based on the modified chimpanzee optimization *** proposed strategy incorporates coupling compensation and power differentiation elements based on the traditional droop ***,it combines the angular frequency and voltage amplitude adjustments provided by the phase-locked loop-free pre-synchronization control *** pre-synchronization is achieved by regulating the virtual current to zero and aligning the photovoltaic storage hybrid inverter with the grid ***,two novel operators,learning and emotional behaviors are introduced to enhance the optimization precision of the chimpanzee *** operators ensure high-precision and high-reliability optimization of the droop control parameters for photovoltaic storage hybrid inverters.A Simulink model was constructed for simulation analysis,which validated the optimized control strategy’s ability to evenly distribute power under load *** strategy effectively mitigated transient voltage and current surges during mode ***,seamless and efficient switching between gridconnected and island modes was achieved for the photovoltaic storage hybrid *** enhanced energy utilization efficiency,in turn,offers robust technical support for grid stability.

关键词： Photovoltaic storage hybrid inverters modified chimpanzee optimization algorithm droop control seamless switching

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Asymmetric Total Synthesis of a Diastereisomer A of Tuxpanolide

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有机化学 2004年第Z1期24卷 149-页

作者： WANG,jin-Xin zhang,chao-Xin LI,Ying State Key Laboratory of Applied Organic Chemistry Lanzhou University Lanzho 730000 Department of Medicinal Chemistry China Pharmaceutical University Nanjing 210009 State Key Laboratory of Applied Organic Chemistry Lanzhou University Lanzho 730000 State Key Laboratory of Applied Organic Chemistry Lanzhou University Lanzho 730000

　　α-Alkylidene-β-hydroxy butyrolactones have been attractive and challenging targets for organic synthesis in various laboratories because that not only they are rich in skeletal diversity and stereochemistry complexity but also many of them possess quite intriguing and wide biological activities.[1] A novel class of the phytane-type diterpenoid named Tuxpanolide, bearing α-alkylidene-β-hydroxy-γ-butyrolactone skeleton, was isolated from Perymenium hintonii in Central Mexico by Maldonado and co-wokers in 1998.[2] Now we firstly report the efficient strategy of the stereocontrolled total synthesis of a diastereisomer A of Tuxpanolide.……

关键词： biological activities organic synthesis total synthesis

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Asymmetric Synthesis of β, γ-β-Hydroxyl-γ-butyrolactones

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有机化学 2003年第Z1期23卷 461-461页

作者： WANG jin-Xin zhang chao-Xin LI Ying National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000 National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000 National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000

　　Chiral β-hydroxyl-γ-butyrolactones have attracted substantial interest in recent years due to their presence inmany strongly active natural products having antitumor, fungicidal, anti-inflammatory activity, and their use as important precursors in natural product synthesis. [1] In the course of the total synthesis of the natural product Tuxpano lide ,[2] we found a concise and efficient strategy on the stereocontrolled synthesis of β-hydroxyl-γ-butyrolactonederivatives from cheap and achiral starting material.……

关键词： natural products total synthesis

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Flexible Graphene Field‑Effect Transistors and Their Application in Flexible Biomedical Sensing

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Nano-Micro Letters 2025年第2期17卷 252-313页

作者： Mingyuan Sun Shuai Wang Yanbo Liang chao Wang Yunhong zhang Hong Liu Yu zhang Lin Han Institute of Marine Science and Technology Shandong UniversityQingdao 266237ShandongPeople’s Republic of China State Key Laboratory of Crystal Materials Shandong UniversityJinan 250100ShandongPeople’s Republic of China School of Integrated Circuits Shandong UniversityJinan 250100ShandongPeople’s Republic of China Shandong Engineering Research Center of Biomarker and Artificial Intelligence Application Jinan250100ShandongPeople’s Republic of China

Flexible electronics are transforming our lives by making daily activities more *** to this innovation are field-effect transistors(FETs),valued for their efficient signal processing,nanoscale fabrication,low-power consumption,fast response times,and ***,known for its exceptional mechanical properties,high electron mobility,and biocompatibility,is an ideal material for FET channels and *** combination of graphene and FETs has given rise to flexible graphene field-effect transistors(FGFETs),driving significant advances in flexible electronics and sparked a strong interest in flexible biomedical ***,we first provide a brief overview of the basic structure,operating mechanism,and evaluation parameters of FGFETs,and delve into their material selection and patterning *** ability of FGFETs to sense strains and biomolecular charges opens up diverse application *** specifically analyze the latest strategies for integrating FGFETs into wearable and implantable flexible biomedical sensors,focusing on the key aspects of constructing high-quality flexible biomedical ***,we discuss the current challenges and prospects of FGFETs and their applications in biomedical *** review will provide valuable insights and inspiration for ongoing research to improve the quality of FGFETs and broaden their application prospects in flexible biomedical sensing.

关键词： Flexible Graphene Field-effect transistor Wearable Implantable Biosensor

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Force and impulse multi-sensor based on flexible gate dielectric field effect transistor

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 214-220页

作者： chao Tan Junling Lü Chunchi zhang Dong Liang Lei Yang Zegao Wang College of Materials Science and Engineering Sichuan UniversityChengdu 610065China The 54th Research Institute of China Electronics Technology Group Corporation Shijiazhuang 050081China

Nowadays,force sensors play an important role in industrial production,electronic information,medical health,and many other ***-dimensional material-based filed effect transistor(2D-FET)sensors are competitive with nano-level size,lower power consumption,and accurate ***,few of them has the capability of impulse detection which is a path function,expressing the cumulative effect of the force on the particle over a period of *** we fabricated the flexible polymethyl methacrylate(PMMA)gate dielectric MoS_(2)-FET for force and impulse sensor *** systematically investigated the responses of the sensor to constant force and varying forces,and achieved the conversion factors of the drain current signals(I_(ds))to the detected impulse(I).The applied force was detected and recorded by I_(ds)with a low power consumption of~30 *** sensitivity of the device can reach~8000%and the 4×1 sensor array is able to detect and locate the normal force applied on ***,there was almost no performance loss for the device as left in the air for two months.

关键词： flexible gate dielectric transistor force sensor impulse sensor force sensor array

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Structural Modal Parameter Recognition and Related Damage Identification Methods under Environmental Excitations: A Review

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Structural Durability & Health Monitoring 2025年第1期19卷 25-54页

作者： chao zhang Shang-Xi Lai Hua-Ping Wang School of Civil Engineering and Mechanics Lanzhou UniversityLanzhou730000China Key Laboratory of Special Functional Materials and Structural Design Ministry of EducationLanzhou UniversityLanzhou730000China

Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the ***,it is particularly signiﬁcant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientiﬁc basis for structural damage identiﬁcation and dynamic model modiﬁ*** view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and brieﬂy describes how to identify structural damages based on the derived modal *** paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),brieﬂy describes damage identiﬁcation methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artiﬁcial intelligence(AI)methods in the direction of modal parameter recognition and damage identiﬁcation is further *** on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identiﬁcation methods are given to provide scientiﬁc references for the optimized design and functional upgrading of SHM systems.

关键词： Structural health monitoring data information modal parameters damage identiﬁcation AI method

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