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Universal paradigm of ternary metacomposites with tunable epsilon-negative and epsilon-near-zero response for perfect electromagnetic shielding

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Rare Metals 2024年第2期43卷 796-809页

作者： Yun-Peng Qu Yun-Lei Zhou yang Luo Yao liu Jun-Fei Ding yan-li chen Xiu Gong Jing-liang yang Qiong Peng Xiao-Si Qi College of Physics Guizhou UniversityGuiyang550025China Hangzhou Institute of Technology Xidian UniversityHangzhou311231China Department of Materials ETH Zurich8093ZurichSwitzerland Key Laboratory for liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJinan250061China

CaCu_(3)Ti_(4)O_(12)(CCTO)ceramic nanocomposites incorporating graphene–carbon black(GRCB)fillers were fabricated by spark plasma sintering *** percolative effects of conductive GRCB fillers on dielectric response of GRCB/CCTO ternary metacomposites were systematically *** weakly real permittivity(ε′)-negative response(ε′~−1×10^(2))was achieved which originated from weakly low-frequency plasmonic state of free carriers within constructed GRCB *** enhancing three-dimensional GRCB network,the plasma frequency of metacomposites increased while the damping factor ***,theε′-negative values of metacomposites were tuned from−10^(2) to−10^(4) orders of magnitude andε′-near-zero(ENZ)frequencies from~142 to~340 MHz which substantially benefited from the moderate carrier concentration of GRCB dual *** Drude model and equivalent circuit models were adopted to demonstrate dielectric and electrical *** obtained metacomposites show strong EM shielding effect along with enhanced plasmonic oscillation and even better achieving perfect EM shielding effect in ENZ *** work achieves the tunableε′-negative andε′-near-zero response and more importantly clarifies its regulation mechanism in ceramic-based ternary metacomposites,which opens up the possibility of designing high-performance EM shielding materials based on metacomposites.

关键词： Metacomposites Ceramic matrix composites Negative permittivity Epsilon-near-zero Electromagnetic shielding

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Clinical effects of detailed nursing management interventions on medication adherence and disease perception in patients with drugresistant tuberculosis

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World Journal of Clinical Cases 2024年第20期12卷 4191-4198页

作者： yan-li chen Ya-Qin Xie Ming-Yue Wei Dong-Mei Xu Nursing Department The First People’s Hospital of Tianmen in Hubei ProvinceTianmen 431700Hubei ProvinceChina Infectious Disease Department The First People’s Hospital of Tianmen in Hubei ProvinceTianmen 431700Hubei ProvinceChina

BACKGROUND Tuberculosis(TB)is a chronic respiratory infectious disease that considerably jeopardizes human health,and there is no effective vaccine suitable for its prevention in the entire *** To investigate the promotion of medication adherence and disease cognition in patients with drug-resistant(DR-)TB using detailed nursing *** In total,114 patients with DR-TB who were diagnosed and treated at our hospital between January 2019 and January 2023 were included in this *** in the control group(n=57)were managed with conventional nursing care,while those in the observation group(n=57)were managed with detailed nursing *** adherence,disease awareness scores,medication safety,and nursing satisfaction were compared between the two groups after the *** The post-intervention medication compliance rate was 91.23%in the observation group and 75.44%in the control group,with the former being 15.79%higher than the latter(Pling and pain,hearing loss,electrolyte disorders,and liver and kidney function abnormalities were lower in the observation group than those in the control *** total nursing satisfaction of the observation group was higher than that of the control group(P<0.05).CONCLUSION Implementation of detailed nursing management for patients with DR-TB can effectively improve medication adherence,enhance awareness of the disease,ensure safety of medication,and improve satisfaction with nursing care.

关键词： Medication adherence Detailed nursing management Drug-resistant tuberculosis Disease perception Tuberculosis

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Synthesis and Crystal Structure of a Dinuclear Complex:Bis[aqua(phen)(4-aba)copper(Ⅱ)nitrate(4-abaH)dihydrate]

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Chinese Journal of Structural Chemistry 2007年第3期26卷 263-266页

作者： li yan-Guo chen Hong-Ji Department of Material Science and Engineering Jinan University Guangzhou 510632 China

The title complex has been obtained by the reaction of copper nitrate trihydrate with 4-abaH （4-abaH = 4-aminobenzonic acid） and phenanthroline in ethanol solution, and its structure was determined by X-ray crystallography with the following data： monoclinic, space group C2/c, M, = 1266.13, Cu2C52H54N10O20, a = 25.884（5）, b = 10.205（2）, c = 20.849（4） A, β= 106.34（3）°, Z= 4, V= 5284.7（18） A^3, F（000） = 2616, Dc = 1.591 g/cm^3, μ = 0.896 mm ^-1, the final R = 0.0441 and wR = 0.1148 for 4200 observed reflections （Ⅰ 〉 2σ（Ⅰ））. In the molecule of the title complex, the asymmetric unit contains one half molecule, The Cu（Ⅱ） atom is five-coordinated by a tenninal water molecule, a bidentate phcnanthroline and two monodentate 4-ammobenzoate ligands forming a square pyramidal coordination environment. The two bridging 4-aminobenzoate ligands result in a dinuclear copper（Ⅱ） cluster with a short Cu-Cu distance （3.048 A） and a π-π rstacking between the adjacent phenanthroline rings （2.96 A）.

关键词： dinuclear copper(Ⅱ) phenanthroline 4-aminobenzonic acid crystal structure

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Generalized Latin Matrix and Construction of Orthogonal Arrays

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Acta Mathematicae Applicatae Sinica 2017年第4期33卷 1083-1092页

作者： Shan-qi PANG li-yan chen College of Mathematics and Information Science Henan Engineering Laboratory for Big Data Statistical Analysis and Optimal Control Henan Normal University Xinxiang 453007 China Anyang Preschool Education College Anyang 456150 China

In this paper, generalized Latin matrix and orthogonal generalized Latin matrices are proposed. By using the property of orthogonal array, some methods for checking orthogonal generalized Latin matrices are presented. We study the relation between orthogonal array and orthogonal generalized Latin matrices and obtain some useful theorems for their construction. An example is given to illustrate applications of main theorems and a new class of mixed orthogonal arrays are obtained.

关键词： orthogonal array generalized Latin matrix orthogonal generalized Latin matrices matrix image generalized permutation difference matrix

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Aeroelastic modeling of wind loading on a cable-net supported glass wall

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Acta Mechanica Sinica 2010年第3期26卷 409-415页

作者： Zhifu Gu Letian yang yan li Bin chen LTCS and College of Engineering Peking University 100871 Beijing China

Wind loading study on a cable-net supported glass wall is conducted by means of wind tunnel tests. An equiva- lent aeroelastic model is designed and constructed. Response of displacements of the wall is measured and analyzed. In order to design a glass wall under wind loading, the ＂wind- vibration factor＂ is estimated and discussed. In fact, the mech- anism of wind acting on the wall is commonly known not only as positive pressure, but also as negative pressure caused by the flow separation on the corners of the building. Due to the diffidence in the mechanism of wind acting, two typi- cal response cases are classified. The results show that the dynamic response of the structure caused by the negative pressure is stronger than that of the positive pressure case. To determine the aerodynamic wind loading on a flexible part of structure on a building, wind tunnel study may be useful and play an important role.

关键词： Wind tunnel study Cable-net supported glasswall - Wind-vibration factor Aeroelastic model

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Theoretical Studies on the Iodine-catalyzed Nucleophilic Addition of Acetone with Five-membered Heterocycles

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Chemical Research in Chinese Universities 2008年第4期24卷 520-524页

作者： WANG yan-hua li li chen Xue-song College of Biology and Environment Engineering Zhejiang Shuren University Hangzhou 310015 P. R. China

The iodine-catalyzed nucleophilic addition reactions of pyrrole, furan, or thiophene with acetone were studied in gas and solvent by the density functional theory at the level of Lanl2DZ^＊. It was seen that the halogen bond between iodine and carbonyl oxygen appeared to have an important catalytic effect on such reactions, and the first iodine molecule maximally diminished the barrier height by 41 kJ/mol, while the second iodine molecule could not improve such reactions largely. It was concluded that the C2-addition was generally more favorable than the C3-addition for the three heterocycles; however, iodine considerably more effectively catalyzed the C3-addition than the C2-addition for pyrrole. It was also revealed by PCM calculation that the iodine-catalyzed nucleophilic additions occurred more easily in solvent than in gas, which explained the experiment performed by Bandgar et al..

关键词： Halogen bond, Catalytic effect Nucleophilic addition Density functional theory

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Synthesis and antitumor activity of heterocyclic acid ester derivatives of 20S-camptothecins

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Chinese Chemical Letters 2007年第11期18卷 1335-1338页

作者： Di Zao li yan li Xiao Guang chen chen Gen Zhu Jing yang Hong yan liu Xian Dao Pan Institute of Materia Medica Chinese Academy of Medical Sciences ＆ Peking Union Medical College Beijing 100050 China

A series of heterocyclic acid esters of camptothecins as new compounds had been synthesized by acylation method, their in vitro and in vivo antitumor activities were evaluated. The cytotoxic results showed that 6 possessed the best efficacy on six human cancer cell lines in the six classes of CPTs＇ derivatives. In vivo testing results indicated that 9 had better antitumor activity against mouse liver carcinoma H22 than topotecan.

关键词： Camptothecin Synthesis Heterocyclic acid Antitumor activity

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H_∞ controller design for a 4-meter direct-drive azimuth axis

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Research in Astronomy and Astrophysics 2015年第11期15卷 1931-1944页

作者： li-yan chen Zhen-Chao Zhang Xiao-li Song Da-Xing Wang National Astronomical Observatories Nanjing Institute of Astronomical Optics & TechnologyChinese Academy of Sciences Key Laboratory of Astronomical Optics & Technology Nanjing Institute of Astronomical Optics & Technology Chinese Academy of Sciences University of Chinese Academy of Sciences

To pursue a higher imaging resolution for exploring more details in the information conveyed by the Universe, the next generation of optical telescopes based on a direct drive widely employ the extremely large aperture structure, which also introduces more disturbances and uncertain factors to the control system. Facing this new challenge, the PID control method in main-axis control systems of traditional astronomical telescopes cannot suffice for the requirement of the tracking precision and disturbance sensitivity in angular velocity. To overcome this shortcoming, we establish a dynamic model and propose an H∞ controller for a 4-meter azimuth direct drive control system that consists of a revolving platform（azimuth axis）, a three-phase torque motor, a motor drive, an encoder, a data acquisition card and a small computers. Simulations are carried out to analyze the model and guide the real *** results show that the proposed H∞ controller reduces the tracking error by a maximum of 80.69%（average 57.8%） and the disturbance sensitivity by a maximum of 82.3%（average 50.96%） compared with the traditional tuned PI controller;furthermore, the order of the model describing the proposed controller can be reduced to three, thus its feasibility in real systems is guaranteed.

关键词： disturbance azimuth uncertain guaranteed torque details encoder aperture conveyed pursue

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Coarsening and Age Hardening Behaviors of γ' Particles in GH742 During High Temperature Treatment

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Journal of Iron and Steel Research International 2009年第5期16卷 81-86页

作者： li Hong-yu SONG Xi-ping WANG yan-li chen Guo-liang State Key Lab for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China

The coarsening and ageing hardening behaviors of γ′ particles in superalloy GH742 have been investigated by field emission scanning electron microscopy （FESEM）, coarsening kinetics calculation and microhardness testing when ageing at 1 050, 950 and 900 ℃ for different time. The cube of γ′ particle size and ageing time follows a linear law as predicted by LSW theory. The particle size distributions give better fit to the LSW theoretical distribution. The activation energy for γ′ coarsening is accurately determined to have 245. 06±14.42 kJ/mol when considering the effect of temperature on the solution concentrations in matrix. Based on the activation energy, the coarsening kinetics of γ′ particle is predicted as r^-t^3=7.35×10^15 Ce/T exp -（245060±14420）/RT *** microhardness studies indicate that microhardness decreases rapidly with increasing the ageing temperature and it has a maximum value corresponding to a critical particle size beyond which the microhardness increase stalls with increasing the ageing time.

关键词： superalloy γ′ particle coarsening kinetics activation energy microhardness

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Fully Nonlinear Equations of Krylov Type on Riemannian Manifolds with Totally Geodesic Boundary

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Acta Mathematica Sinica,English Series 2024年第5期40卷 1293-1307页

作者： li chen yan HE Faculty of Mathematics and Statistics Hubei Key Laboratory of Applied MathematicsHubei UniversityWuhan 430000P.R.China

In this paper,we study fully nonlinear equations of Krylov type in conformal geometry on compact smooth Riemannian manifolds with totally geodesic *** prove the a priori estimates for solutions to these equations and ... 详细信息

关键词： The modified Schouten tensor k-convex Hessian type equation

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