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The Impact of Nano CaCO3 Modified in situ with Methacrylic Acid on the Structure and Properties of Natural Rubber

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Journal of Wuhan University of Technology(Materials Science) 2020年第6期35卷 1169-1176页

作者： ZENG Zongqiang LI Yongzhen WANG Chao zhao pengfei Chinese Agricultural Ministry Key Laboratory of Tropical Crops Processing Agricultural Products Processing Research InstituteChinese Academy of Tropical Agricultural SciencesZhanjiang 524001China Rubber Research Institute Chinese Academy of Tropical Agricultural SciencesHaikou 571101China

Natural rubber (NR) was reinforced in situ with nano CaCO3 that had been modified with methacrylic acid (MAA)(M-CaCO3).The structures and properties of the resulting composites were studied using attenuated total reflection Fourier transform infrared spectroscopy(ATR-FTIR),scanning electron microscopy(SEM),and Mooney viscometer and mechanical *** results show that when NR is physically blended with CaCO3 and MAA,(Ca2+)-(–OOC) is formed in *** dicumyl peroxide (DCP) is added,the (Ca^2+)-(–OOC) self-homopolymerizes,and during the curing process poly-(Ca^2+)-(–OOC) is formed and grafts to the molecular chains of the NR via carbon-carbon double *** NR/M-CaCO3 composites formed have close interfacial interaction and are well *** with the NR composites reinforced with unmodified nano CaCO3,the NR/M-CaCO3 composites have very different cure characteristics,rheological behavior,and mechanical properties,and these characteristics and properties show a significant relationship with the loading of M-CaCO3.

关键词： natural rubber nano CaCO3 nano composites in situ modification

Effects of fracture evolution and non-Darcy flow on the thermal performance of enhanced geothermal system in 3D complex fractured rock

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International Journal of Mining Science and Technology 2024年第4期34卷 443-459页

作者： Yachen Xie Jianxing Liao pengfei zhao Kaiwen Xia Cunbao Li Department of Civil and Mineral Engineering University of TorontoToronto M5S1A4Canada College of Water Resources and Hydropower Sichuan UniversityChengdu 610225China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsWuhan 430071China College of Civil Engineering Guizhou UniversityGuiyang 550025China Institute of Geosafety School of Engineering and TechnologyChina University of GeosciencesBeijing 100083China State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering Shenzhen UniversityShenzhen 518060China

In fractured geothermal reservoirs,the fracture networks and internal fluid flow behaviors can significantly impact the thermal *** this study,we proposed a non-Darcy rough discrete fracture network(NR-DFN)model that can simultaneously consider the fracture evolution and non-Darcy flow dynamics in studying the thermo-hydro-mechanical(THM)coupling processes for heat extraction in geothermal *** further employed the model on the Habanero enhanced geothermal systems(EGS)project located in ***,our findings illustrate a clear spatial-temporal variation in the thermal stress and pressure perturbations,as well as uneven spatial distribution of shear failure in 3D fracture *** shear failure is mainly concentrated in the first fracture ***,channeling flow have also been observed in DFNs during heat extraction and are further intensified by the expansion of fractures driven by thermal ***,the combined effect of non-Darcy flow and fracture evolution triggers a rapid decline in the resulting heat rate and *** NR-DFN model framework and the Habanero EGS's results illustrate the importance of both fracture evolution and non-Darcy flow on the efficiency of EGS production and have the potential to promote the development of more sustainable and efficient EGS operations for stakeholders.

关键词： Coupled THM model Non-Darcy flow Deformable DFN Enhanced geothermal systems

Differential study of DCE-MRI parameters in spinal metastatic tumors, brucellar spondylitis and spinal tuberculosis

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Chinese Journal of Cancer Research 2018年第4期30卷 425-431页

作者： pengfei Qiao pengfei zhao Yang Gao Yuzhen Bai Guangming Niu Department of Magnetic Resonance Imaging the Affiliated Hospital of Inner Mongolia Medical University

Objective： In the present study, spinal metastatic tumors, brucellar spondylitis and spinal tuberculosis werequantitatively analyzed using dynamic contrast-enhanced magnetic resonance imaging （DCE-MRI） to assess thevalue of DCE-MRI in the differential diagnosis of these ***： Patients with brucellar spondylitis, spinal tuberculosis or a spinal metastatic tumor （30 cases of each）received conventional MRI and DCE-MRI examination. The volume transfer constant （Ktrans）, rate constant （Kep）,extravascular extracellular volume fraction （Ve） and plasma volume fraction （Vp） of the diseased vertebral bodieswere measured on the perfusion parameter map, and the differences in these parameters between the patients ***： For pathological vertebrae in cases of spinal metastatic tumor, brucellar spondylitis and spinaltuberculosis, respectively, the Ktrans values （median ＋ quartile pitch） were 0.989±0.014, 0.720±0.011 and0.317±0.005 min-1; the Kep values were 2.898±0.055, 1.327±0.017 and 0.748±0.006 min-1; the Ve values were0.339±0.008, 0.542±0.013 and 0.428±0.018; the Vp values were 0.048±0.008, 0.035±0.004 and 0.028±0.009; thecorresponding H values were 50.25 （for Ktrans）, 52.47 （for Kep）, 48.33 （for Ve） and 46.56 （for Vp）, and all differenceswere statistically significant （two-sided P〈0.05）.Conclusions： The quantitative analysis of DCE-MRI has a certain value in the differential diagnosis of spinalmetastatic tumor, brucellar spondylitis and spinal tuberculosis.

关键词： Differential diagnosis dynamic contrast enhanced MRI spinal tuberculosis spinal metastatic tumor brucellar spondylitis

Fabrication of Rice Husk Ash/Natural Rubber Composites by the Latex Process

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Journal of Wuhan University of Technology(Materials Science) 2020年第1期35卷 42-46页

作者：曾宗强 LI Yongzhen zhao pengfei 余和平 Key Laboratory of Tropical Crop Product Processing Ministry of Agriculture and Rural Affairs of the People’s Republic of ChinaAgricultural Product Processing Research InstituteChinese Academy of Tropical Agricultural SciencesZhanjiang 524001China Rubber Research Institute Chinese Academy Of Tropical Agricultural Sciences Danzhou 571731China

Rice husk ash/natural rubber composites were fabricated by modifying rice husk ash with the rare earth coupling agent DN-8102. The structure of the rice husk ash and the morphological dispersion of the rice husk ash in a rubber matrix were charactered by scanning and transmission electron microscopy, *** mechanical properties of the composites were experimentally studied. The surface energy and the interaction between rice husk ash particles can be reduced by surface modification of rice husk ash with a rare earth coupling agent, which reduces the agglomeration of rice husk ash in both liquid and rubber matrices and enhances the interactions between rice husk ash and the rubber phase, and thus results in improved mechanical properties for the resulting rice husk ash/natural rubber composite. The modulus of the composites will increase as the loading level of modified rice husk ash increases. A maximum tensile strength of 25.96 MPa for the composites can be obtained when the modified rice husk ash loading level is 4%.

关键词： natural rubber rice husk ash composite

Decision Aid Model for Private-owned Electric Vehicles Participating in Frequency Regulation Ancillary Service Market

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 621-629页

作者： Liwei Wang Yingyun Sun Haotian Wang pengfei zhao Muhammad Safwan Jaffar School of Electrical and Electronic Engineering North China Electric Power UniversityBeijing 102206China

To reduce the difficulty and enhance the enthusiasm of private-owned electric vehicles(EVs) in participating in frequency regulation ancillary service market(FRASM), a decision aid model(DAM) is proposed. This paper presents three options for EV participating in FRASM, i. e., the base mode(BM), unidirectional charging mode(UCM), and bidirectional charging/discharging mode(BCDM), based on a reasonable simplification of users' participating willingness. In BM, individual EVs will not be involved in FRASM, and DAM will assist users to set the optimal charging schemes based on travel plans under the time-of-use(TOU) price. UCM and BCDM are two modes in which EVs can take part in FRASM. DAM can assist EV users to create their quotation plan, which includes hourly upper and lower reserve capabilities and regulation market mileage prices. In UCM and BCDM, the difference is that only the charging rate can be adjusted in the UCM, and the EVs in BCDM can not only charge but also discharge if necessary. DAM can estimate the expected revenue of all three modes, and EV users can make the final decision based on their preferences. Simulation results indicate that all the three modes of DAM can reduce the cost, while BCDM can get the maximum expected revenue.

关键词： Electric vehicle(EV) frequency regulation decision aid model(DAM) utility maximization battery wear cost

Multi-Core Conformal Lenses

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Chinese Physics Letters 2020年第8期37卷 48-52页

作者： Xinghong Zhu pengfei zhao Huanyang Chen Institute of Electromagnetics and Acoustics and Key Laboratory of Electromagnetic Wave Science and Detection Technology Xiamen UniversityXiamen 361005China

We propose multi-core conformal lenses by combining conformal transformation optics with absolute *** on the cores and incident angles,the conformal lenses have tunable functionalities like focusing,reflection,and tra... 详细信息

关键词： conformal thereby absolute

Preparation of superhydrophobic CdS cotton using visible light response and its application for the control of water pollution

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Science China(Technological Sciences) 2019年第12期62卷 2236-2242页

作者： GE Bo REN GuiNa zhao pengfei JIN ChuanYu LI WenZhi ZHANG zhaoZhu School of Materials Science and Engineering Liaocheng UniversityLiaocheng 252000China School of Environmental and Material Engineering Yantai UniversityYantai 264405China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

Sewage discharge produced by homes and industries contains both oil and water-soluble components. In order to remove oil from water, materials with specific wettability can be used;however, these materials cannot remove dissolved contaminants from water. In this research, we prepared a superhydrophobic Cd S cotton for water purification. This material has the ability to adsorb different types of oil due to its non-wettability(WCA = 152°). Moreover, its response behavior towards visible light enables it to remove water-soluble pollutants as well. The highest oil absorption rate of superhydrophobic Cd S cotton is nearly 30 times, and it can absorb light below 564 nm and produce ·OH to degrade water soluble pollutants. Finally, based on Mott-Schottky curve,the position of Fermi energy level was determined(–0.55 e V). Also, the positions of valence and conduction bands were calculated based on the analysis of band gap which helps in proving photoelectric response characteristics.

关键词： superhydrophobic cotton CdS photocatalytic

PERFORMANCE OF ULTRA-LOW FREQUENCY PASSIVE VERTICAL VIBRATION ISOLATION SYSTEM WITH REVERSE PENDULUM

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Acta Mechanica Solida Sinica 2002年第1期15卷 45-48页

作者： zhao pengfei Huang Yuying Tang Mengxi Sun Shijun Department of Mechanics Huazhong University of Science and TechnologyWuhan 430074China Department of Physics Zhanjiang Normal CollegeZhanjiang 524048China Department of Physics Zhongshan UniversityGuangzhou 510275China

A novel long period passive vertical vibration isolatorconstructed by mounting reverse pendu- lums on two pairs of torsionsprings is presented. By theoretical analysis and numericalcalculation, it is shown that the isolator can achieve much longerresonant period due to gravitational positive feedback and is smallerin size than the current torsion spring isolators with the samegeometric parameters.

关键词： vertical vibration isolation torsion spring reverse pendulum resonantperiod

Preparation of porous sea-urchin-like CuO/ZnO composite nanostructure consisting of numerous nanowires with improved gas-sensing performance

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Frontiers of Materials Science 2022年第1期16卷 71-85页

作者： Haibo REN Huaipeng WENG pengfei zhao Ruzhong ZUO Xiaojing LU Jiarui HUANG School of Materials Science and Engineering Anhui Polytechnic UniversityWuhu 241000China Key Laboratory of Functional Molecular Solids(Ministry of Education) College of Chemistry and Materials ScienceAnhui Normal UniversityWuhu 241002China Modern Technology Center Anhui Polytechnic UniversityWuhu 241000China

A sea-urchin-like CuO/ZnO porous nanostructure is obtained via a simple solution method followed by a calcination *** are abundant pores among the resulting nanowires due to the thermal decomposition of copper-zinc hydroxide *** specific surface area of the as-prepared CuO/ZnO sample is determined as 31.3 m^(2)·g^(-1).The gas-sensing performance of the sea-urchin-like CuO/ZnO sensor is studied by exposure to volatile organic compound(VOC)*** contrast to a pure porous sea-urchin-like ZnO sensor,the sea-urchin-like CuO/ZnO sensor shows superior gas-sensing behavior for acetone,formaldehyde,methanol,toluene,isopropanol and *** exhibits a high response of 52.6-100 ppm acetone vapor,with short response/recovery *** superior sensing behavior is mainly ascribed to the porous nanowireassembled structure with abundant p-n heterojunctions.

关键词： copper oxide zinc oxide copper-zinc hydroxide carbonate volatile organic compound gas sensor