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Significantly Enhanced Electromagnetic Interference Shielding Performances of Epoxy Nanocomposites with Long-Range Aligned Lamellar Structures

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Nano-Micro Letters 2022年第12期14卷 617-629页

作者： Lei Wang Zhonglei Ma hua qiu Yali Zhang Ze Yu Junwei Gu Shaanxi Key Laboratory of Catalysis School of Chemistry&Environment ScienceShaanxi University of TechnologyHanzhong 723001People’s Republic of China Shaanxi Key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072People’s Republic of China

High-efficiency electromagnetic interference(EMI)shielding materials are of great importance for electronic equipment reliability,information security and human *** this work,bidirectional aligned Ti_(3)C_(2)T_(x)@Fe_(3)O_(4)/CNF aerogels(BTFCA)were firstly assembled by bidirectional freezing and freeze-drying technique,and the BTFCA/epoxy nanocomposites with long-range aligned lamellar structures were then prepared by vacuum-assisted impregnation of epoxy *** from the successful construction of bidirectional aligned three-dimensional conductive networks and electromagnetic synergistic effect,when the mass fraction of Ti_(3)C_(2)T_(x) and Fe_(3)O_(4) are 2.96 and 1.48 wt%,BTFCA/epoxy nanocomposites show outstanding EMI shield-ing effectiveness of 79 dB,about 10 times of that of blended Ti_(3)C_(2)T_(x)@Fe_(3)O_(4)/epoxy(8 dB)nanocomposites with the same loadings of Ti_(3)C_(2)T_(x) and Fe_(3)O_(4).Meantime,the corresponding BTFCA/epoxy nanocomposites also present excellent thermal stability(T_(heat-resistance index) of 198.7℃)and mechanical properties(storage modulus of 9902.1 MPa,Young’s modulus of 4.51 GPa and hardness of 0.34 GPa).Our fabricated BTFCA/epoxy nanocomposites would greatly expand the applications of MXene and epoxy resins in the fields of information security,aerospace and weapon manufacturing,etc.

关键词： Electromagnetic interference shielding Epoxy nanocomposites Ti_(3)C_(2)Tx Fe_(3)O_(4) Bidirectional aligned three-dimensional conductive networks

A mini-review of MXene porous films:Preparation,mechanism and application

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Journal of Materials Science & Technology 2022年第8期103卷 42-49页

作者： Yali Zhang Yi Yan hua qiu Zhonglei Ma Kunpeng Ruan Junwei Gu Shaanxi Key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China

MXene presents excellent electrical conductivity,abundant surface functional groups and wonderful filmforming performance,but the lamellar layers are prone to self-stacking during film formation,which will reduce the loss of electromagnetic waves,hinder ion transmission,and limit the effective load of other functional *** construction of the porous structure can effectively solve the self-stacking problem of MXene *** article reviews the research progress of MXene porous films for electromagnetic interference(EMI)shielding,lithium/sodium ion batteries,pseudocapacitors,and biomedical science *** focuses on the preparation methods of MXene porous films,and discusses the pore-forming mechanism of the porous structure formed by different preparation methods and the internal relationship between the“microstructure-macroscopic performance”of the MXene porous films,points out the key scientific and technical bottlenecks that need to be solved urgently in the preparation and application of the MXene porous *** is hoped to provide certain guidance for the design,preparation,optimization,industrial application,and development of MXene porous films.

关键词： MXene porous films Preparation method Pore formation mechanism Application fields

Structural Design Strategies of Polymer Matrix Composites for Electromagnetic Interference Shielding:A Review

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Nano-Micro Letters 2021年第11期13卷 322-350页

作者： Chaobo Liang Zhoujie Gu Yali Zhang Zhonglei Ma hua qiu Junwei Gu Key Laboratory of Functional Nanocomposites of Shanxi Province College of Materials Science and EngineeringNorth University of ChinaTaiyuan 030051China Shaanxi Key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXian 710072China Research and Development Center Guangdong Suqun New Materials Co.LtdDongguan 523000China

With the widespread application of electronic communication technology,the resulting electromagnetic radiation pollution has been significantly *** matrix electromagnetic interference(EMI)shielding materials have disadvantages such as high density,easy corrosion,difficult processing and high price,*** matrix EMI shielding composites possess light weight,corrosion resistance and easy ***,the current polymer matrix composites present relatively low electrical conductivity and poor EMI shielding *** review firstly discusses the key concept,loss mechanism and test method of EMI *** the current development status of EMI shielding materials is summarized,and the research progress of polymer matrix EMI shielding composites with different structures is illustrated,especially for their preparation methods and ***,the corresponding key scientific and technical problems are proposed,and their development trend is also prospected.

关键词： Polymer matrix composites Electromagnetic interference shielding Structural design

GLOBAL STABILITY OF LARGE SOLUTIONS TO THE 3D MAGNETIC BéNARD PROBLEM

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Acta Mathematica Scientia 2022年第2期42卷 588-610页

作者： Xulong QIN hua qiu Zheng-an YAO School of Mathematics Sun Yat-sen UniversityGuangzhou 510275China Department of Mathematics South China Agricultural UniversityGuangzhou 510642China

In this paper,we consider the 3D magnetic Bénard *** precisely,we prove that the large solutions are stable under certain *** we obtain the equivalent condition with respect to this stability ***,we also establish th... 详细信息

关键词： Magnetic Bénard problem large solutions global stability perturbations

Algebraic attacks on two kinds of special nonlinear filter generators

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High Technology Letters 2012年第2期18卷 151-154页

作者：杨文峰 Hu Yupu qiu hua Key Laboratory of Computer Networks&Information Security Ministry of EducationXidian UniversityXi'an 710071P.R.China Navy Submarine Academy Qingdao 266071P.R.China

This letter proposes algebraic attacks on two kinds of nonlinear filter generators with symmetric Boolean functions as the filter fimctions. Different fxom the classical algebraic attacks, the proposed attacks take the advantage of the combinational property of a linear feedback shift register （LFSR） and the symmetric Boolean function to obtain a tow-degree algebraic relation, and hence the complexities of the proposed attacks are independent of the algebraic immunity （AI） of the filter functions. It is shown that improper combining of the LFSR with the filter function can make the filter generator suffer from algebraic attacks. As a result, the bits of the LFSR must be selected properly to input the filter function with large AI in order to withstand the proposed algebraic attacks.

关键词： stream cipher linear feedback shift register (LFSR) Boolean function algebraic attack cryptanalysis

Different roles of capsule endoscopy and double-balloon enteroscopy in obscure small intestinal diseases

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World Journal of Gastroenterology 2015年第23期21卷 7297-7304页

作者： Zhi-Hong Zhang Chun-hua qiu Yi Li Department of Gastroenterology Sichuan Provincial People’s Hospital Sichuan Provincial Academy of Medical Sciences

AIM: To compare the roles of capsule endoscopy(CE)and double-balloon enteroscopy(DBE) in the diagnosis of obscure small bowel ***: From June 2009 to December 2014, 88 patients were included in this study; the patients had undergone gastroscopy, colonoscopy, radiological small intestinal barium meal, abdominal computed tomography or magnetic resonance imaging scan and mesenteric angiography, but their diagnoses were still unclear. The patients with gastrointestinal obstructions,fistulas, strictures, or cardiac pacemakers, as well as pregnant women, and individuals who could not accept the capsule-retention or capsule-removal surgery were excluded. Patients with heart, lung and other vital organ failure diseases were also excluded. Everyone involved in this study had undergone CE and DBE. The results were divided into:(1) the definite diagnosis(the diagnosis was confirmed at least by one of the biopsy,surgery, pathology or the drug treatment effects with follow-up for at least 3 mo);(2) the possible diagnosis(a possible diagnosis was suggested by CE or DBE,but not confirmed by the biopsy, surgery or follow-up drug treatment effects); and(3) the unclear diagnosis(no exact causes were provided by CE and DBE for the disease). The detection rate and the diagnostic yield of the two methods were compared. The differencein the etiologies between CE and DBE was estimated,and the different possible etiologies caused by the age groups were also ***: CE exhibited a better trend than DBE for diagnosing scattered small ulcers(P = 0.242, Fisher's test), and small vascular malformations(χ 2 = 1.810,P = 0.179, Pearson χ 2 test), but with no significant differences, possible due to few cases. However,DBE was better than CE for larger tumors(P =0.018, Fisher's test) and for diverticular lesions with bleeding ulcers(P = 0.005, Fisher's test). All three hemangioma cases diagnosed by DBE in this study(including sponge hemangioma, venous hemangioma,and hemangi

关键词： Capsule endoscopy Double-balloon enteroscopy Obscure small intestinal diseases

A new monoterpenoid indole alkaloid from Rauvolfia yunnanensis

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Chinese Chemical Letters 2009年第10期20卷 1221-1223页

作者： Bao Hui Cheng Jian Chao Chen Ming hua qiu a State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of Botany Chinese Academy of Sciences Kunming 650204 China Graduate School of Chinese Academy of Sciences Beijing 100039 China

One new monoterpenoid indole alkaloid, l l-methoxyburnamine-17-O-3′,4′,5′-trimethoxybenzoate （1）, was isolated from Rauvolfia yunnanensis Tsiang. Its structure was identified by speclroscopic evidences.

关键词： Rauvolfia yunnanensis Monoterpenoid indole alkaloid Akuammiline-type rnonoterpenoid indole alkaloid

A facile approach to asymmetrical biaryls via coupling reaction of aryl halides with sodium tetraphenylborate catalyzed by MCM-41-supported sulfur palladium(0) complex

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Chinese Chemical Letters 2007年第4期18卷 387-389页

作者： qiu hua Xu Ping Ping Wang Ming Zhong Cai Department of Chemistry Jiangxi Normal University 330027 Nanchang China Department of Chemistry Jiujiang University 332000 Jiujiang China

Various functionalized asymmetrical biaryls can be synthesized in high to excellent yields via coupling reaction of aryl iodides or bromides with NaBPh4 catalyzed by MCM-41-supported sulfur palladium（0） complex. Thi... 详细信息

关键词： Asymmetrical biaryl NaBPh4 Aryl halide Palladium Coupling reaction

One pot synthesis of bis-silicon-bridged stilbene derivatives

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Chinese Chemical Letters 2007年第12期18卷 1436-1438页

作者： Chen Hui Li hua Yu qiu Cai Hong Xu Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education Hangzhou Teachers College Hangzhou 310012 China Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

Bis-silicon-bridged stilbene derivatives were synthesized in a modified procedure that combined the preparation of bis[2- （silyl）phenyl]acetylene and its intramolecular reductive cyclization in one pot. The results indicated that the one pot approach produced target products in a comparable yield to that of the two-step method reported previously.

关键词： Bis-silicon-bridged stilbene Reductive cyclization One pot synthesis