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Nano Research 2024年第3期17卷 2070-2078页

作者： Wenhao Liang Juntao Wu Shan Zhang pei-yan zhao Yi Cong Yongqiang Guo Guang-Sheng Wang Key Laboratory of Bioinspired Smart Interfacial Science and Technology of Ministry of Education School of ChemistryBeihang UniversityBeijing 100191China

With the rapid development of wireless communication technology and electronic devices,the issue of electromagnetic interference(EMI)is becoming increasingly *** a new and flexible electromagnetic interference shielding material has become a challenging ***,a sandwich-structured EMI shielding composite film was prepared using electrospinning and vacuum filtration *** this process,a porous MXene was synthesized through a reaction with cobalt acetate and served as the intermediate layer in the composite film to shield electromagnetic *** electrospun polyimide(PI)fibers were used as the top and bottom layers of the composite film,which can protect the porous MXene from *** lightweight and flexible composite film integrates electromagnetic interference shielding and thermal insulation capabilities,showing excellent comprehensive *** composite film achieves an EMI shielding effectiveness of 48.8 dB in X-band(8.2–12.4 GHz),and absolute shielding effectiveness of the composite film reached a satisfying 4142.43(dB·cm^(2))/*** to the design of a multi-layer porous structure,the density of the composite film is 0.65 g/***,the thermal conductivity of the film is 0.042 W/(m·K)due to the clamping of electrospun PI fibers,showing excellent thermal insulation ***,the composite film exhibits excellent high and low-temperature *** summary,this work provides a feasible strategy for preparing a lightweight polymer-based EMI shielding film.

关键词： porous MXene polyimide electromagnetic interference shielding thermal insulation

3D Ultralight Hollow NiCo Compound@MXene Composites for Tunable and High-E cient Microwave Absorption

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Nano-Micro Letters 2021年第12期13卷 322-336页

作者： Hui-Ya Wang Xiao-Bo Sun Shu-Hao yang pei-yan zhao Xiao-Juan Zhang Guang-Sheng Wang Yi Huang School of Chemistry Beihang UniversityBeijing 100191People’s Republic of China College of Chemistry and Materials Engineering Beijing Technology and Business UniversityBeijing 100048People’s Republic of China School of Materials Science and Engineering Nankai UniversityTianjin 300350People’s Republic of China

The 3D hollow hierarchi-cal architectures tend to be designed for inhibiting stack of MXene flakes to obtain satisfactory lightweight,high-e cient and broadband ***,the hollow NiCo compound@MXene networks were prepared by etching the ZIF 67 template and subsequently anchoring the Ti_(3)C_(2)Tx nanosheets through electrostatic *** electromagnetic parameters and microwave absorption property can be distinctly or slightly regulated by adjusting the filler loading and decoration of Ti_(3)C_(2)Tx *** on the synergistic e ectsof multi-components and special well-constructed structure,NiCo layered double hydroxides@Ti_(3)C_(2)Tx(LDHT-9)absorber remarkably achieves unexpected e ective absorption bandwidth(EAB)of 6.72 GHz with a thickness of 2.10 mm,covering the entire *** calcination,transition metal oxide@Ti_(3)C_(2)Tx(TMOT-21)absorber near the percolation threshold possesses minimum reflection loss(RLmin)value of-67.22 dB at 1.70 mm within a filler loading of only 5 wt%.This work enlightens a simple strategy for constructing MXene-based composites to achieve high-e cient microwave absorbents with lightweight and tunable EAB.

关键词： 3D hollow hierarchical architecture Tunable EAB High-performance microwave absorption Ultralight

Electrospinning fabrication and ultra-wideband electromagnetic wave absorption properties of CeO_(2)/N-doped carbon nanofibers

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Nano Research 2022年第9期15卷 7788-7796页

作者： pei-yan zhao Hui-Ya Wang Bo Cai Xiao-Bo Sun Zhi-Ling Hou Jun-Tao Wu Ming Bai Guang-Sheng Wang School of Chemistry Beihang UniversityBeijing 100191China School of Electronics and Information Engineering Beihang UniversityBeijing 100191China College of Mathematics and Physics&Beijing Key Laboratory of Environmentally Harmful Chemical Analysis Beijing University of Chemical TechnologyBeijing 100029China

The impedance mismatch of carbon materials is a key factor limiting their widespread use in electromagnetic(EM)wave *** this work,the novel CeO_(2)/nitrogen-doped carbon(CeO_(2)/N-C)nanofiber was prepared to solve the problem by electrospinning and sintering.X-ray diffraction(XRD),Raman,X-ray photoelectron spectroscopy(XPS),and transmission electron microscopy(TEM)analyses demonstrated CeO_(2)was successfully loaded onto the surface of partially graphitized carbon *** sintering temperatures change the graphitization degree of material,and the oxygen vacancy structure of CeO_(2)and defects from N doping optimize the impedance matching of the *** the sintering temperature reaches 950℃,CeO_(2)/N-C fiber possesses the minimum reflection loss(RLmin)value of−42.59 dB at 2.5 mm with a filler loading of only 3 wt.%in polyvinylidene difluoride(PVDF).Meanwhile,the CeO_(2)/N-C fiber achieves a surprising wideband(8.48 GHz)at a thickness of 2.5 mm,covering the whole Ku-band as well as 63%of the X-band at the sintering temperature of 650℃.This work provides the research basis for widely commercial applications of carbon-based nanofiber absorbers.

关键词： electrospinning electromagnetic wave absorption CeO_(2)/N-doped carbon nanofiber wideband

Metasurface-assisted low-frequency performance enhancement of ultra-broadband honeycomb absorber based on carbon nanotubes

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Nano Research 2024年第9期17卷 8542-8551页

作者： Cai-Liang Wang Shuang Bai pei-yan zhao Tao Zhou Hui-Ya Wang Jun-Peng Wang Luo-Xin Wang Guang-Sheng Wang School of Chemistry Beihang UniversityBeijing 100191China Aerospace Science and Industry Corporation of Wuhan Magnetoelectricity Co. Ltd.Wuhan 430070China College of Materials Science and Engineering Key Laboratory for New Textile Materials and Applications of Hubei ProvinceWuhan Textile UniversityWuhan 430200China School of Chemistry and Chemical Engineering Lingnan Normal UniversityZhanjiang 524048China School of Materials Science and Engineering Zhejiang Sci-Tech UniversityHangzhou 310018China

Here,we present a unique method to enhance the low-frequency absorption performance of a honeycomb absorber by integrating a *** geometrical dimensions of the proposed metasurface have been numerically *** introduction of the metasurface allows exploitation of its robust resonance and superior impedance matching in low-frequency bands,thereby improving microwave absorption *** incorporation of the metasurface does not impact the wave transmission performance of the honeycomb core absorber at high-frequency band,thus preserving its high-frequency *** broadens the absorption range,leading to an expanded *** results reveal that the composite absorber(CA)exhibits strong absorption performance with an incident angle stability up to 45°for both transverse electric(TE)and transverse magnetic(TM)*** absorption mechanism of the CA has been investigated by using an equivalent circuit model and electromagnetic field analysis.A prototype was designed,fabricated,and tested to validate the proposed *** simulation and measurement results demonstrate that the prototype can achieve an average absorption rate exceeding 90%across a 1.0-18.0 GHz *** study introduces an innovative technique for creating microwave absorbers for low-frequency wideband applications.

关键词： low frequency metasurface radar absorption impedance matching

Establishing a new testing protocol of the electrochemical stability window for electric double-layer capacitors

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Science China Chemistry 2025年第1期68卷 217-225页

作者： Ruilin Hou Xiaoxi zhao Tingting Liang Qingyun Dou Shan Xu Xingbin yan School of Materials Science and Engineering Sun Yat-sen University Laboratory of Clean Energy Chemistry and Materials Lanzhou Institute of Chemical Physics Chinese Academy of Sciences College of Engineering and Applied Sciences Nanjing University Center of Industrial Analysis and Testing Guangdong Academy of Science

The electrochemical stability window(ESW) is crucial for determining the energy density of electric double-layer capacitors(EDLCs). However, current ESW testing protocols of EDLCs are strongly affected by artificial factors, thereby leading to unreliable result. To solve this problem, we first identify the key shortcomings of the traditional protocols by analyzing their test principles. Subsequently, taking an aqueous carbon-based EDLC as an example, we design a side reaction descriptor to represent the response difference in the charging capacitance to side reactions between the cyclic voltammetry and galvanostatic chargedischarge methods. With the aid of this descriptor, we propose a new ESW testing protocol, which is not only able to completely avoid the adverse influence of subjective factors but also fully consider the operating condition limitations. The protocol can be extended from the single electrode to the full device. This work proposes a more rigorous definition of ESW and provides a reliable protocol for evaluating the ESW of EDLCs.

关键词： electric double-layer capacitors electrochemical stability window testing protocol side reaction descriptor operating limitation

Channel pruning on frequency response

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Science China(Information Sciences) 2025年第1期68卷 159-170页

作者： Hang LIN Yifan PENG Lin BIE Chenggang yan Xibin zhao Yue GAO School of Software Tsinghua University School of Automation Hangzhou Dianzi University

Network pruning has a significant role in reducing network parameters and accelerating the inference time of the network. Some existing methods prune the network based on the frequency of the data, and finally obtain a sub-network with high accuracy. However, according to our experimental analysis, different frequencies of information in the data contribute differently to the accuracy of the model, and using this information directly for pruning without making a selection will lead to incorrect results. We believe that pruning should retain the convolutional kernels in the network that process important information, while those kernels that process unimportant information should be removed. In this paper, we first investigate the meaning of each frequency band information in the spectrum and their contribution to the prediction accuracy of the network,and according to these results, we propose a new pruning method based on frequency response(PFR). Our PFR finds and removes the convolutional kernels in the network that specialize in processing unimportant information, resulting in a compact neural network model. PFR obtains significant experimental results on different datasets, for example, a 56.0% raduction of float points operations(FLOPs) on Res Net-50 and only 0.37% of Top-1 accuracy degradation on the Image Net dataset.

关键词： deep learning model compression filter pruning channel pruning frequency response

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“Zero‑Strain” NiNb_(2)O_(6) Fibers for All‑Climate Lithium Storage

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Nano-Micro Letters 2025年第1期17卷 348-360页

作者： yan zhao Qiang Yuan Liting yang Guisheng Liang Yifeng Cheng Limin Wu Chunfu Lin Renchao Che College of Physics Donghua UniversityShanghai 201620People’s Republic of China School of Materials Science and Engineering Institute of Materials for Energy and EnvironmentQingdao UniversityQingdao 266071People’s Republic of China Laboratory of Advanced Materials Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsAcademy for Engineering&TechnologyFudan UniversityShanghai 200438People’s Republic of China Zhejiang Laboratory Hangzhou 311100People’s Republic of China Inner Mongolia University Hohhot 010021People’s Republic of China

Niobates are promising all-climate Li^(+)-storage anode material due to their fast charge transport,large specific capacities,and resistance to electrolyte ***,their moderate unit-cellvolume expansion(generally 5%–10%)during Li^(+)storage causes unsatisfactory long-term ***,“zero-strain”NiNb_(2)O_(6) fibers are explored as a new anode material with comprehensively good electrochemical *** Li^(+)storage,the expansion of electrochemical inactive NiO_(6) octahedra almost fully offsets the shrinkage of active NbO_(6) octahedra through reversible O *** superior volume-accommodation capability of the NiO_(6) layers guarantees the“zero-strain”behavior of NiNb_(2)O_(6) in a broad temperature range(0.53%//0.51%//0.74%at 25//−10//60℃),leading to the excellent cyclability of the NiNb_(2)O_(6) fibers(92.8%//99.2%//91.1%capacity retention after 1000//2000//1000 cycles at 10C and 25//−10//60℃).This NiNb_(2)O_(6) material further exhibits a large reversible capacity(300//184//318 mAh g−1 at 0.1C and 25//−10//60℃)and outstanding rate performance(10 to 0.5C capacity percentage of 64.3%//50.0%//65.4%at 25//−10//60℃).Therefore,the NiNb_(2)O_(6) fibers are especially suitable for large-capacity,fast-charging,long-life,and all-climate lithium-ion batteries.

关键词： NiNb_(2)O_(6)porous fiber “Zero-strain”mechanism Electrochemical property Harsh-temperature operation Operando characterization

Screening the stage-specific expression gene from different germ cells of rat

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生殖医学杂志 2002年第Z1期11卷 29-37页

作者： Jia Mengchun(贾孟春) Lou Lixia(娄利霞) pei Kaiyan(裴开颜) zhao Longmei(赵龙梅) Shi Xinquan(石心泉) National Research Institute for Family Planning Beijing 100081 National Research Institute for Family Planning Beijing 100081 National Research Institute for Family Planning Beijing 100081 National Research Institute for Family Planning Beijing 100081 National Research Institute for Family Planning Beijing 100081

Objective: To screen the stage-specific expression genes from rat spermatogonia, pachytene spermatocytes and round spermatids. Methods: Highly purified spermatogonia were isolated from 9-day-old rats, pachytene spermatocytes and round spermatids from adult rats by sedimentation velocity at unit gravity, using 2%-4% BSA gradient in DMEM/F12 medium. A mRNA differential display method was used for screening the stage-specific expression gene. Results: Nineteen differentially expressed cDNA fragments were obtained. After excluding the false positive cDNA fragments by dot blot, 13 cDNAs were selected to clone and sequence. To obtain longer cDNAs, six ESTs were used to screen the rat testis λ-zap II cDNA library. Two longer cDNA fragments, designated as LY21 and LM66, were obtained. The analysis with DNAMAN software indicated that LY21 had a long open reading frame coding 372 amino acids while LM66 had no long open reading frame. LY21 were highly homologous with hnRNP H1. To observe the expression patterns of LY21 gene in the testicular cells, we performed in situ hybridization on testis sections from adult rats. The LY21 gene expression was found in the spermatogonia and primary ***: This study indicated that LY21 gene was associated with spermatogenesis. Further studies will be needed to explore the function of LY21.

关键词： Spermatogenesis Differential display method Express sequence tag (EST) Gene

Modular assembly of Co4-thiacalix[4]arene units and Keggin-type SiW12O40 for visible-light photothermal conversion

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Tungsten 2025年第1期7卷 112-119页

作者： Jia-Hui Li Qing zhao Dong-Ao Mao Kun Zhou Bao-Kuan Chen yan-Feng Bi School of Petrochemical Engineering Liaoning Petrochemical University

The construction of metal-organic coordination clusters（MCCs） using modular secondary building units is an important method for preparing functional *** this study,two new MCCs modularly assembled from Keggin-type {SiW12O40}H4TC4A=p-tert-Butylthiacalix[4]arene(SiW12) units and thiacalixarene-supported Co4-thiacalix[4]arene(Co4-TC4A polynuclear second-building units（PSBUs,H4TC4A=p-tert-Butylthiacalix[4]arene） are *** two MCCs,abbreviated as Co4-SiW12and Co8-SiW12,were structurally characterized by single-crystal X-ray *** Co4-SiW12is a supramolecular structure involving cation-anion interactions between Co4-TC4A PSBUs and ***8-SiW12features "barbell-like" shapes with two Co4-TC4A coordinatively linked to a Keggin-type SiW12unit on opposite via W-O_t-Co *** coordination of Co4-TC4A to SiW12in Co8-SiW12resulted in significantly improved photothermal conversion performances compared with Co4-SiW12and pure SiW12or ***-gap determination and photophysical analysis combined with density functional theory calculations indicated the binding mode between Co4-TC4A PSBUs and SiW12,which considerably influences the way of electron transport and the conversion ability of visible light to heat.

关键词： Modular construction Photothermal conversion Polyoxometalate Thiacalixarene

Low‑Temperature Fabrication of Stable Black‑Phase CsPbI_(3)Perovskite Flexible Photodetectors Toward Wearable Health Monitoring

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Nano-Micro Letters 2025年第3期17卷 232-245页

作者： Yingjie zhao Yicheng Sun Chaoxin pei Xing Yin Xinyi Li Yi Hao Mengru Zhang Meng Yuan Jinglin Zhou Yu Chen yanlin Song College of Chemistry and Pingyuan Laboratory Zhengzhou UniversityZhengzhou 450001People’s Republic of China Key Laboratory of Green Printing Institute of ChemistryChinese Academy of SciencesBeijing 100190People’s Republic of China Key Laboratory of Bio‑Inspired Materials and Interfacial Science Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190People’s Republic of China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049People’s Republic of China

Flexible wearable optoelectronic devices fabricated fromorganic–inorganic hybrid perovskites significantly accelerate the developmentof portable energy,biomedicine,and sensing fields,but their poor thermal stabilityhinders further ***,all-inorganic perovskites possessexcellent thermal stability,but black-phase all-inorganic perovskite filmusually requires high-temperature annealing steps,which increases energy consumptionand is not conducive to the fabrication of flexible wearable *** this work,an unprecedented low-temperature fabrication of stable blackphaseCsPbI3perovskite films is demonstrated by the in situ hydrolysis reactionof diphenylphosphinic chloride *** released diphenyl phosphateand chloride ions during the hydrolysis reaction significantly lower the phasetransition temperature and effectively passivate the defects in the perovskitefilms,yielding high-performance photodetectors with a responsivity of 42.1 AW−1 and a detectivity of 1.3×10^(14)***,high-fidelity imageand photoplethysmography sensors are demonstrated based on the fabricated flexible wearable *** work provides a newperspective for the low-temperature fabrication of large-area all-inorganic perovskite flexible optoelectronic devices.

关键词： In situ hydrolyzation Low-temperature processing All-inorganic perovskite Flexible photodetectors Health monitoring