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macroscopic model and statistical model to characterize electromagnetic information of a digital coding metasurface

National Science Review 2024年第03期11卷 159-171页

作者： Rui wen Shao Jun Wei Wu Zheng Xing Wang Hui Xu Han qing Yang Qiang Cheng Tie Jun Cui Institute of Electromagnetic Space Southeast University State Key Laboratory of Millimeter Waves Southeast University Peng Cheng Laboratory Pazhou Laboratory(Huangpu)

A digital coding metasurface is a platform connecting the digital space and electromagnetic wave space, and has therefore gained much attention due to its intriguing value in reshaping wireless channels and realizing new communication architectures. Correspondingly, there is an urgent need for electromagnetic information theory that reveals the upper limit of communication capacity and supports the accurate design of metasurface-based communication systems. To this end, we propose a macroscopic model and a statistical model of the digital coding metasurface. The macroscopic model uniformly accommodates both digital and electromagnetic aspects of the meta-atoms and predicts all possible scattered fields of the digital coding metasurface based on a small number of simulations or measurements. Full-wave simulations and experimental results show that the macroscopic model is feasible and accurate. A statistical model is further proposed to correlate the mutual coupling between meta-atoms with covariance and to calculate the entropy of the equivalent currents of digital coding metasurface. These two models can help reconfigurable intelligent surfaces achieve more accurate beamforming and channel estimation, and thus improve signal power and coverage. Moreover, the models will encourage the creation of a precoding codebook in metasurface-based direct digital modulation systems, with the aim of approaching the upper limit of channel capacity. With these two models, the concepts of current space and current entropy, as well as the analysis of information loss from the coding space to wave space, is established for the first time, helping to bridge the gap between the digital world and the physical world, and advancing developments of electromagnetic information theory and new-architecture wireless systems.

关键词： electromagnetic information theory current entropy current space digital coding metasurface macroscopic model statistical model

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machine learning for carbonate formation drilling: Mud loss prediction using seismic attributes and mud loss records

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Petroleum Science 2024年第2期21卷 1241-1256页

作者： Hui-wen Pang Han-qing Wang Yi-Tian Xiao Yan Jin Yun-Hu Lu Yong-Dong Fan Zhen Nie National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China College of Science China University of Petroleum-BeijingBeijing102249China Petroleum Exploration and Production Research Institute SINOPECBeijing102206China College of Petroleum Engineering China University of Petroleum-BeijingBeijing102249China Research Institute of Petroleum Exploration and Development CNPCBeijing100083China

Due to the complexity and variability of carbonate formation leakage zones, lost circulation prediction and control is one of the major challenges of carbonate drilling. It raises well-control risks and production expenses. This research utilizes the H oilfield as an example, employs seismic features to analyze mud loss prediction, and produces a complete set of pre-drilling mud loss prediction solutions. Firstly, 16seismic attributes are calculated based on the post-stack seismic data, and the mud loss rate per unit footage is specified. The sample set is constructed by extracting each attribute from the seismic trace surrounding 15 typical wells, with a ratio of 8:2 between the training set and the test set. With the calibration results for mud loss rate per unit footage, the nonlinear mapping relationship between seismic attributes and mud loss rate per unit size is established using the mixed density network ***, the influence of the number of sub-Gausses and the uncertainty coefficient on the model's prediction is evaluated. Finally, the model is used in conjunction with downhole drilling conditions to assess the risk of mud loss in various layers and along the wellbore trajectory. The study demonstrates that the mean relative errors of the model for training data and test data are 6.9% and 7.5%, respectively, and that R2is 90% and 88%, respectively, for training data and test data. The accuracy and efficacy of mud loss prediction may be greatly enhanced by combining 16 seismic attributes with the mud loss rate per unit footage and applying machine learning methods. The mud loss prediction model based on the MDN model can not only predict the mud loss rate but also objectively evaluate the prediction based on the quality of the data and the model.

关键词： Lost circulation Risk prediction machine learning Seismic attributes Mud loss records

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The Crystallization Behavior of L-Poly(lactic acid)/Polypropylene Blends:The Acceleration for Both L-Poly(lactic acid)and Polypropylene

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Chinese Journal of Polymer Science 2024年第6期42卷 775-786页

作者： Shuang-Cheng Li Wei-Jia Zhou wen-Jie Wu Jun Shao Shui-Liang Chen Hao-qing Hou Sheng Xiang College of Chemistry&Chemical Engineering and Nanofiber Engineering Center of Jiangxi Province Jiangxi Normal UniversityNanchang330022China National Engineering Research Center for Carbohydrate Synthesis/Key Lab of Fluorine and Silicon for Energy materials and Chemistry of Ministry of Education Jiangxi Normal UniversityNanchang330022China wenzhou Institute University of Chinese Academy of SciencesWenzhou325001China

For a polymer/polymer dismissible blend with two crystallizable components,the crystallization behavior of different components and the reciprocal influences between different crystals are interesting and important,but did not investigate in *** this study,the L-poly(lactic acid)/polypropylene(PLLA/PP)blends with different weight ratios were prepared by melt mixing and the crystallization behavior of the blends were *** showed that the crystalline structures of PLLA and PP were not altered by the *** the crystallization of PLLA,both the diffusion of chain segments and crystallization rate were enhanced under the existence of PP *** the crystallization of PP,its crystallization rate was depressed under the existence of amorphous PLLA molecular *** the PP crystallized from the existence of PLLA crystals,although the diffusion rate of PP was reduced by PLLA crystals,the nucleation positions were obviously enhanced,which accelerated the formation of PP *** investigation would supply more basic data for the application of PLLA/PP blend.

关键词： L-poly(lactic acid) Polypropylene Blends Crystalization behavior Crystallization acceleration

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Ultrasound diagnosis of congenital Morgagni hernias: Ten years of experience at two Chinese centers

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World Journal of Clinical Cases 2024年第3期12卷 495-502页

作者： Hui-qing Shi wen-Juan Chen Qiang Yin Xue-Hua Zhang Department of Ultrasound Fujian Children’s Hospital(Fujian Branch of Shanghai Children’s Medical Center)College of Clinical Medicine for Obstetrics&Gynecology and PediatricsFujian Medical UniversityFuzhou 350011Fujian ProvinceChina Department of Ultrasound Hunan Children’s HospitalUniversity of South ChinaChangsha 410007Hunan ProvinceChina Department of Pediatric Surgery Hunan Children’s HospitalUniversity of South ChinaChangsha 410007Hunan ProvinceChina

BACKGROUND Morgagni hernias are rare anomalies that are easily misdiagnosed or *** To summarize the ultrasound(US)imaging characteristics of Morgagni hernias through a comparison of imaging and surgical *** The records of children with Morgagni hernias who were hospitalized at two hospitals between January 2013 and November 2023 were retrospectively re-viewed in terms of clinical findings,US features,and operative *** Between 2013 and 2023,we observed nine(five male and four female)children with Morgagni *** abdominal scanning revealed a widening of the prehepatic space,with an abnormal channel extending from the xiphoid process to the right or left side of the thoracic *** channel had intestinal duct and intestinal gas *** contents were found in the transverse colon(n=6),the colon and small intestine(n=2),and the colon and stomach(n=1).Among the patients,seven had a right-sided lesion,two had a left-sided lesion,and all of them had hernial *** US imaging can accurately determine the location,extent,and content of Morgagni *** suspected Mor-gagni hernias,we recommend performing sonographic screening first.

关键词： Children Congenital diaphragmatic hernias Morgagni hernia Operation Ultrasound Gastrointestinal imaging

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Brønsted-acid sites induced photocatalytic cracking of low-polarity polyethylene plastics

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Journal of Energy Chemistry 2024年第9期96卷 509-515页

作者： Qianyou wen Quan Zhang Zhengzheng Liu Huining Wang Shuya Hao Fan Zhang Lijuan Zhang qing Han Gengfeng Zheng Laboratory of Advanced materials Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsFudan UniversityShanghai 200438China

Polyolefins such as polyethylene(PE)are one of the largest-scale synthetic plastics and play a key role in modern ***,polyethylene is extremely inert to chemical recycling owing to its lack of chemical functionality and low polarity,making it one of the most challenging environmental hazards ***,we developed a phosphorylated CeO_(2)catalyst by an organophosphate precursor and featured efficient photocatalysis of low-density polyethylene(LDPE)without the acid or alkaline *** to pristine CeO_(2),the surface phosphorylation allows to introduce Brønsted acid sites,which facilitate to form carbonium ions on LDPE via *** addition,the suitable band structure of the phosphorylated CeO_(2)catalyst enables efficient photoabsorption and generates reactive oxygen species,leading to the C–C bond cleavage of *** a result,the phosphorylated CeO_(2)catalyst exhibited an outstanding carbon conversion rate of>94%after 48 h of photocatalysis under 50 mW/cm^(2)of simulated sunlight,with a high CO_(2)product selectivity of>99%.Furthermore,the PE microparticles with sizes larger than 10μm released from LDPE plastic wrap were directly and completely degraded by photocatalysis within 12 h,suggesting an attractive and environmentally benign strategy of utilizing solar energy-based photocatalysis for reducing potential hazards of LDPE plastic trashes.

关键词： Photocatalytic cracking Polyethylene Surface phosphorylation Bronsted-acid site Carbon conversion

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Cross-linked Electrospun Gel Polymer Electrolytes for Lithium-Ion Batteries

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Chinese Journal of Polymer Science 2024年第8期42卷 1021-1028页

作者： Xue Gong Qin Xiao qing-Yin Li wen-Cui Liang Feng Chen Long-Yu Li Shi-Jie Ren College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China

Lithium-ion batteries(LIBs)benefit from an effective electrolyte system design in both terms of their safety and energy storage ***,a series of precursor membranes with high porosity were produced using electrospinning technology by mixing PVDF and triblock copolymer(PS-PEO-PS),resulting in a porous structure with good interconnections,which facilitates the absorbency of a large amount of electrolyte and further increases the ionic conductivity of gel polymer electrolytes(GPEs).It has been demonstrated that post-cross-linking of the precursor membranes increa ses the rigidity of the nanofibers,which allows the polymer film to be dimensionally sta ble up to 260℃while maintaining superior electrochemical *** obtained cross-linked GPEs(CGPEs)showed high ionic conductivity up to 4.53×10^(-3)S·cm^(-1).With the CGPE-25,the assembled Li/LiFeP04 half cells exhibited good rate capability and maintained a capacity of 99.4%and a coulombic efficiency of99.3%at 0.1 *** results suggest that the combination of electrospinning technique and post-cross-linking is an effective method to construct polymer electrolytes with high thermal stability and steadily decent electrochemical performance,particularly useful for Lithium-ion battery applications that require high-temperature usage.

关键词： Electrospinning Cross-linked Gel polymer electrolytes Lithium-ion batteries

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Tunable Phase Structure of Side-chain Liquid Crystalline Polymers Enabled by Molecular Engineering of Dual Mesogenic Cores

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Chinese Journal of Polymer Science 2024年第10期42卷 1459-1469,I0009页

作者： wen-Huan Yao Lan-Sheng Liu Jie Zhao Yan-Xia Wang An-Zhi ma Zheng-Rui ma Lan-Ying Zhang Ruo-Chen Lan College of Chemistry and Chemical Engineering Hunan UniversityChangsha410082China Key Laboratory of Eco-Functional Polymer materials of the Ministry of Education Key Laboratory of Eco-Environmental Polymer Materials of Gansu ProvinceCollege of Chemistry and Chemical EngineeringNorthwest Normal UniversityLanzhou730070China Department of materials Science and Engineering College of EngineeringPeking UniversityBeijing100871China Institute of Advanced materials&Key Lab of Fluorine and Silicon for Energy materials and Chemistry of Ministry of Education College of Chemistry and Chemical EngineeringJiangxi Normal UniversityNanchang330022China

A series of novel side-chain liquid crystalline(SCLC)copolymers were synthesized by attaching two distinct mesogenic units,namely a chiral cholesteryl-based monomer(M1)and an achiral biphenyl-based monomer(M2),to a poly(3-mercaptopropylmethylsiloxane)(PMMS)backbone via thiol-ene click *** influence of side chain composition on the self-assembly behavior and phase structures of these SCLC copolymers was systematically investigated using different *** indicate that three distinct liquid crystalline phases and four unique molecular configurations were identified within the polymer series,with the emergence of the liquid crystalline phase being a synergistic outcome of the two distinct side *** study underscores the critical influence of side chain dimensions,rigidity,and spatial volume on the self-assembly structures and phase characteristics of liquid crystalline polymers,providing valuable insights for the rational design and development of advanced functional materials with tailored properties.

关键词： Liquid crystalline copolymers Self-assembly Phase structure Chiral molar ratio

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Role of Multi-scale Hierarchical Structures in Regulating Wetting State and Wetting Properties of Structured Surfaces

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Journal of Bionic Engineering 2024年第3期21卷 1347-1359页

作者： Yue Jiang Xinyi Li Zhichao ma Zhihui Zhang Cuie wen Zhonghao Jiang Nan Lin Luquan Ren Key Laboratory of Bionic Engineering of Ministry of Education College of Biological and Agricultural EngineeringJilin UniversityChangchun130022China Hubei Provincial Engineering Technology Research Center for Microgrid College of Electrical Engineering and New EnergyChina Three Gorges UniversityYichang443002China School of Mechanical and Aerospace Engineering Jilin UniversityChangchun130025China Centre for Additive manufacturing School of EngineeringRMIT UniversityMelbourneVictoria3001Australia Key Laboratory of Automobile materials of Ministry of Education College of Materials Science and EngineeringJilin UniversityChangchun130025China State Key Laboratory of Inorganic Synthesis and Preparative Chemistry Jilin UniversityChangchun130012China

Amplifying the intrinsic wettability of substrate material by changing the solid/liquid contact area is considered to be the main mechanism for controlling the wettability of rough or structured *** theoretical analysis and experimental exploration,we have found that in addition to this wettability structure amplification effect,the surface structure also simultaneously controls surface wettability by regulating the wetting state via changing the threshold Young angles of the Cassie-Baxter and wenzel wetting *** wetting state regulation effect provides us with an alternative strategy to overcome the inherent limitation in surface chemistry by tailoring surface *** wetting state regulation effect created by multi-scale hierarchical structures is quite significant and plays is a crucial role in promoting the superhydrophobicity,superhydrophilicity and the transition between these two extreme wetting properties,as well as stabilizing the Cassie-Baxter superhydrophobic state on the fabricated lotus-like hierarchically structured Cu surface and the natural lotus leaf.

关键词： Hierarchical structure Wetting state regulation Wetting transition Superhydrophobicity Superhydrophilicity

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A mixed-coordination electron trapping-enabled high-precision touch-sensitive screen for wearable devices

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Bio-Design and manufacturing 2024年第4期7卷 413-427页

作者： Xi Zhang Junchi ma Hualin Deng Jinming Zhong Kaichen Xu Qiang Wu Bo wen Dongfeng Diao Guangdong Provincial Key Laboratory of Micro/Nano Optomechatronics Engineering College of Mechatronics and Control EngineeringShenzhen UniversityShenzhen 518060China State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou 310058China Shenzhen University General Hospital Shenzhen 518055China Research Center of Medical Plasma Technology Shenzhen UniversityShenzhen 518060China

Touch-sensitive screens are crucial components of wearable *** such as reduced graphene oxide(rGO),carbon nanotubes(CNTs),and graphene offer promising solutions for flexible touch-sensitive ***,when stacked with flexible substrates to form multilayered capacitive touching sensors,these materials often suffer from substrate delamination in response to deformation;this is due to the materials having different Young’s modulus *** results in failure to offer accurate touch screen *** this work,we demonstrate an induced charge-based mutual capacitive touching sensor capable of high-precision touch *** is enabled by electron trapping and polarization effects related to mixed-coordinated bonding between copper nanoparticles and vertically grown graphene ***,we used an electron cyclotron resonance system to directly fabricate graphene-metal nanofilms(GMNFs)using carbon and copper,which are firmly adhered to flexible *** being subjected to 3000 bending actions,we observed almost no change in touch *** screen interaction system,which has a signal-to-noise ratio of 41.16 dB and resolution of 650 dpi,was tested using a handwritten Chinese character recognition trial and achieved an accuracy of 94.82%.Taken together,these results show the promise of touch-sensitive screens that use directly fabricated GMNFs for wearable devices.

关键词： Flexible touch-sensitive screen Graphene-metal nanofilms Mixed coordination Wearable device

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Green carbonization of waste coffee grounds into porous C/Fe hybrids for broadband and high-efficiency microwave absorption

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Journal of materials Science & Technology 2024年第3期170卷 1-10页

作者： Xin wen Cui Li Hui Liu Guohua Fan Yanan Tang Chuncheng Hao Lili ma Pingan Song Institute of Advanced Electrical materials College of Materials Science and EngineeringQingdao University of Science and TechnologyQingdao 266042China Center for Future materials University of Southern QueenslandSpringfieldQLD 4300Australia School of Agriculture and Environmental Science University of Southern QueenslandSpringfieldQLD 4300Australia

Recently great effort s have been focused on designing high-performance microwave absorbers using sustainable biomass resources,but there remains a lack of green and efficient fabrication ***,inspired by natural porous character of biomass waste,we demonstrated a green one-step route to convert waste coffee grounds into porous C/Fe hybrids,and further explored their potential applications for broadband and high-efficiency microwave *** this design,the WCG-20-750(incorporated 20 wt%Fe(C_(5)H_(7)O_(2))_(3)catalyst and carbonized at 750℃)exhibited porous microstructure with the highest char yield of 55.45 wt%.Furthermore,the as-prepared C/Fe hybrids from WCG-20-750 displayed excellent microwave absorption ***,the minimum reflection loss(RL_(min))reached to-52.86 dB and the widest effective absorption bandwidth(EAB)was 6.40 GHz at the thickness of 3.0 *** work provides an economically viable and environmentally friendly strategy to convert biomass wastes into value-added microwave absorbers,ultimately making contributions to the upcycling of renewable biomass resources and the fostering of sustainable environment.

关键词： Waste recycling Microwave absorption Green carbonization Porous carbon Biomass

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