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A Low-Complexity PTS Based on Greedy and Genetic Algorithm for OFDM Systems

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Chinese Journal of Electronics 2015年第4期24卷 857-861页

作者： LUO Renze ZHANG Chengsen NIU Na LI Rui State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University university of Electronic Science and Technology of China

Partial transmit sequence(PTS) is one of effective technique to reduce high Peak-to-average power ratio(PAPR) in Orthogonal frequency division multiplexing(OFDM) system. However, the complexity of Original PTS(O-PTS) increases exponentially with the number of sub-blocks. To reduce the computational complexity while still offering a lower PAPR, a new PTS method is proposed to search for suboptimal rotating vectors in this paper. In the proposed method, the candidate rotation vectors are generated based on greedy and genetic *** also combine the proposed method and the superimposed training sequence method to get a further PAPR reduction. The theory and simulations results show that the proposed method can achieve better PAPR reduction and significantly reduce the computational complexity.

关键词： PTS PAPR reduction OFDM Suboptimal rotating vectors

Electrical, mechanical and damage self-sensing properties of basalt fiber reinforced polymer composites modified by electrophoretic deposition

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Progress in Natural Science:Materials International 2023年第5期33卷 593-600页

作者： Haoming Sun Dong Xiang Jie Zhang Wei Tan Eileen Harkin-Jones Junjie Wang Menghan Wang Bin Wang Chunxia Zhao Hui Li Zhenyu Li Yuntao Li Yuanpeng Wu School of New Energy and Materials Southwest Petroleum University The Center of Functional Materials for Working Fluids of Oil and Gas Field Sichuan Engineering Technology Research Center of Basalt Fiber Composites Development and Application Southwest Petroleum University Collaborative Scientific Innovation Platform of Universities in Sichuan for Basalt Fiber Southwest Petroleum University School of Mechanical Engineering Southwest Petroleum University School of Engineering and Materials Science Queen Mary University of London School of Engineering Ulster University Department of Civil Engineering Tsinghua University College of Materials Science and Engineering Chongqing University

In this work, basalt fiber reinforced polymer(BFRP) with enhanced electrical, mechanical properties and in-situ damage self-sensing capability was prepared using carboxylic carbon nanotubes(COOH-CNTs) modified BF fabrics via electrophoretic deposition(EPD) at different voltages. The BFRP with BF fabrics modified at a deposition voltage of 20 V(EPD20-BFRP) showed the lowest electrical resistivity. Compared with unmodified BFRP, the tensile and flexual moduli of EPD20-BFRP increased by 37.5 % and 14.9 %, respectively. Single-layer EPD20-BFRP exhibited a high gauge factor(GF) of 44.3 during tensile damage self-sensing. The acoustic emission(AE) signals during tensile and flexual damage process agreed well with the relative resistance changes(RRC),which confirmed different damage stages within loading process, such as elastic deformation, damage evolution,crack coalescence, and complete fracture. In addition, the multi-layer BFRP containing a single-layer EPD20-BFRP on the upper or lower surface of laminate exhibited distinct electrical signal responses subjected to the flexural loading.

关键词： Carbon nanotubes and nanofibers Natural fibers Polymer-matrix composites (PMCs) Non-destructive testing

A multi-band and polarization-independent perfect absorber based on Dirac semimetals circles and semi-ellipses array

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Chinese Physics B 2021年第9期30卷 574-578页

作者： Zhiyou Li Yingting Yi Danyang Xu Hua Yang Zao Yi Xifang Chen Yougen Yi Jianguo Zhang Pinghui Wu Joint Laboratory for Extreme Conditions Matter Properties Southwest University of Science and TechnologyMianyang 621010China State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals Lanzhou University of TechnologyLanzhou 730050China College of Physics and Electronics Central South UniversityChangsha 410083China College of Science Zhejiang University of TechnologyHangzhou 310023China Department of Physics and Electronic Engineering Jinzhong UniversityJinzhong 030619China research Center for Photonic Technology Key Laboratory of Information Functional Material for Fujian Higher EducationQuanzhou Normal UniversityQuanzhou 362000China

We design a four-band terahertz metamaterial absorber that relied on the block Dirac semi-metal(BDS).It is composed of a Dirac material layer,a gold reflecting layer,and a photonic crystal slab(PCS)medium *** structure achieved perfect absorption of over 97%at 4.06 THz,6.15 THz,and 8.16 *** high absorption can be explained by the localized surface plasmon resonance(LSPR).And this conclusion can be proved by the detailed design of the surface ***,the resonant frequency of the device can be dynamically tuned by changing the Fermi energy of the *** to the advantages such as high absorption,adjustable resonance,and anti-interference of incident angle and polarization mode,the Dirac semi-metal perfect absorber(DSPA)has great potential value in fields such as biochemical sensing,information communication,and nondestructive detection.

关键词： metamaterials terahertz block Dirac semi-metal localized surface plasmon resonance

Arsenic species in electronic cigarettes:Determination and potential health risk

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Journal of Environmental Sciences 2020年第5期32卷 168-176页

作者： Qingqing Liu Chengzhi Huang XChris Le Chongqing Key Laboratory of Biomedical Analysis(southwest university) Chongqing Science&Technology CommissionCollege of Chemistry and Chemical EngineeringSouthwest UniversityChongqing 400715China College of Resources and Environment Southwest UniversityChongqing400715China Key Laboratory of Luminescent and Real-Time Analytical System Chongqing Science and Technology BureauCollege of Pharmaceutical SciencesSouthwest UniversityChongqing 400715China Department of Laboratory Medicine and Pathology Faculty of Medicine and DentistryUniversity of Alberta10102 Clinical Sciences BuildingEdmontonAlberta T6G 2G3Canada

Human exposure to contaminants from electronic cigarettes(e-cigarettes)and the associated health effects are poorly *** has been no report on the speciation of arsenic in e-liquid(solution used for e-cigarettes)and *** report here determination of arsenic species in e-liquids and aerosols generated from vaping the *** e-liquid samples of major brands,purchased from local and online stores in Canada and China,were analyzed for arsenic species using high-performance liquid chromatography and inductively coupled plasma mass *** condensed from vaping the eliquids were also analyzed and compared for arsenic *** arsenic species were detected,including inorganic arsenate(iAsⅤ),arsenite(iAsⅢ),monomethylarsonic acid(MMA),and three new arsenic species not reported *** e-liquids,iAsⅢwas detected in 59%,iAsⅤin 94%,and MMA in 47%of the *** the condensate of aerosols from vaping the e-liquids,iAsⅢwas detected in 100%,iAsv in 88%,and MMA in 13%of the *** arsenic species were predominant in e-liquids and aerosols of *** concentration of iAsⅢin the condensate of aerosols(median 3.27μg/kg)was significantly higher than that in the e-liquid(median 1.08μg/kg)*** concentration of inorganic arsenic in the vaping air was approximately 3.4μg/m3,which approaches to the permissible exposure limit(10μg/m3)set by the United States Occupational Safety and Health Administration(OSHA).According to the Environmental Protection Agency’s unit risk factor(4.3×10-3 perμg/m3)for inhalation exposure to inorganic arsenic in the air,the estimated excess lung cancer risk from lifetime exposure to inorganic arsenic in the ecigarette vaping air(3.4μg/m3),assuming e-cigarette vaping at 1%of the time,is as high as1.5×*** results raise health concerns over the exposure to arsenic from electronic cigarettes.

关键词： Electronic cigarettes E-liquid E-cigarette aerosol Arsenic speciation Inhalation exposure Metals Lung cancer risk

Study on the subgrade deformation under high-speed train loading and water–soil interaction

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Acta Mechanica Sinica 2016年第2期32卷 233-243页

作者： Jian Han Guo-Tang Zhao Xiao-Zhen Sheng Xue-Song Jin State Key Laboratory of Traction Power Southwest Jiaotong University Chengdu 610031 China China Railway Corporation Beijing 100844 China

It is important to study the subgrade characteristics of high-speed railways in consideration of the water–soil coupling dynamic problem,especially when high-speed trains operate in rainy *** study develops a nonlinear water–soil interaction dynamic model of slab track coupling with subgrade under high-speed train loading based on vehicle–track coupling *** using this model,the basic dynamic characteristics,including water–soil interaction and without water induced by the high-speed train loading,are *** main factors-the permeability coefficien and the porosity-influencin the subgrade deformation are *** developed model can characterize the soil dynamic behaviour more realistically,especially when considering the influenc of water-rich soil.

关键词： Water–soil interaction High-speed train loading Finite difference method Subgrade deformation Permeability coefficien Porosity

Position Control Optimization of Aerodynamic Brake Device for High-speed Trains

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Chinese Journal of Mechanical Engineering 2014年第2期27卷 287-295页

作者： ZUO Jianyong LUO Zhuojun CHEN Zhongkai Institute of Railway and Urban Mass Transit Tongji University

The aerodynamic braking is a clean and non-adhesion braking, and can be used to provide extra braking force during high-speed emergency braking. The research of aerodynamic braking has attracted more and more attentions in recent years. However, most researchers in this field focus on aerodynamic effects and seldom on issues of position control of the aerodynamic braking board. The purpose of this paper is to explore position control optimization of the braking board in an aerodynamic braking prototype. The mathematical models of the hydraulic drive unit in the aerodynamic braking system are analyzed in detail, and the simulation models are established. Three control functions--constant, linear, and quadratic--are explored. Two kinds of criteria, including the position steady-state error and the acceleration of the piston rod, are used to evaluate system performance. Simulation results show that the position steady state-error is reduced from around 12-2 mm by applying a linear instead of a constant function, while the acceleration is reduced from 25,71-3.70 m/s2 with a quadratic control function. Use of the quadratic control function is shown to improve system performance. Experimental results obtained by measuring the position response of the piston rod on a test-bench also suggest a reduced position error and smooth movement of the piston rod. This implies that the acceleration is smaller when using the quadratic function, thus verifying the effectiveness of control schemes to improve to system performance. This paper proposes an effective and easily implemented control scheme that improves the position response of hydraulic cylinders during position control.

关键词： high-speed train aerodynamic brake hydraulic position control optimization.

Meropenem as an Alternative Antibiotic Agent for Suppression of Agrobacterium in Genetic Transformation of Orchid

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Agricultural Sciences in China 2006年第11期5卷 839-846页

作者： CAO Ying Niimi Yoshiyuki HU Shang-lian School of Life Science and Engineering Southwest University of Science and Technology Mianyang 621000 P.R. China Department of Plant Resources Hiroshima Prefectural University Hiroshima 727-0027 Japan

A case of Meropenem as a novel antibacterial agent to suppress and eliminate Agrobacterium tumefaciens in the Agrobacterium-mediated transformation of orchid protocorm-like bodies （PLBs） has been reported in this article. The in vitro activities of meropenem and four comparator antibacterial agents against three Agrobacterium tumefaciens strains, LBA4404, EHA101, and GV3101, were assessed. In addition, the effect of meropenem on the growth of Dendrobium phalaenopsis PLBs was determined. Compared with other commonly used antibiotics （including ampicillin, carbenicillin, cefotaxime, and cefoperazone）, meropenem showed the highest activity in suppressing all tested A. tumefaciens strains （minimum inhibitory concentration [MIC] 〈 0.5 mg L^-1, which is equal to minimum bactericidal concentration [MBC]）. Meropenem, at all tested concentrations, except for 10 mg L^-1 concentration, had little negative effect on the growth of orchid tissues. The A. tumefaciens strain EHA101 in genetic transformation with vector plG121Hm in infected PLBs of the orchid was visually undetectable after a two-month subculture in 1/2 MS medium with 50 mg L^-1 meropenem and 25 mg L^-1 hygromacin. The expression and incorporation of the transgenes were confirmed by GUS histochemical assay and PCR analysis. Meropenem may be an alternative antibiotic for the effective suppression of A. tumefaciens in genetic transformation.

关键词： antibiotics meropenem Agrobacterium tumefaciens antibacterial activity genetic transformation protocormlike bodies (PLBs)

Development and application of hyaluronic acid in tumor targeting drug delivery

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Acta Pharmaceutica Sinica B 2019年第6期9卷 1099-1112页

作者： Zhijian Luo Yan Dai Huile Gao Ultrasound Diagnosis Department of the Affiliated Hospital of southwest Medical university Southwest Medical UniversityLuzhou 646000China Department of Pharmacy of the Affiliated Hospital of southwest Medical university Southwest Medical UniversityLuzhou 646000China Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial TechnologyWest China School of PharmacySichuan UniversityChengdu 610041China

Hyaluronic acid(HA)is a natural polysaccharide that has gained much attention due to its biocompatibility,enzyme degradation capacity and active tumor targeting *** receptor,CD44,is overexpressed in many kinds of cancers and is associated with tumor progress,infiltration and ***,many researchers have developed various HA-based drug delivery systems for CD44-mediated tumor *** this review,we systemically overview the basic theory of HA,its receptor and hyaluronidase,then we categorize the studies in HA-based drug delivery systems according to the functions of HA,including tumor-targeting materials,enzyme-sensitive biodegradable modality,pHsensitive component,reduction-sensitive component,and the gel ***,the perspective is discussed.

关键词： Hyaluronic acid Tumor-active targeting CD44 Tumor microenvironment Reduction-sensitive Enzyme-sensitive Nanoparticles

Theoretical study on phase conjugation in weakly injected vertical-cavity surface-emitting lasers

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Chinese Physics B 2008年第5期17卷 1821-1825页

作者：张伟利潘炜罗斌李孝峰邹喜华王梦遥 School of Information Science & Technology Southwest Jiaotong University

This paper gives a detailed theoretical investigation on phase conjugation induced by nearly degenerate fourwave mixing in single mode vertical-cavity surface-emitting lasers （VCSELs） with weak optical injection. Considering VCSELs that can work in linearly polarized or elliptically polarized states, it derives the theoretical expression of the conjugated field by small signal analysis based on the vectoral rate equations-the spin-flip model. For linearly polarized state, VCSELs show similar conjugate spectra to edge-emitting semiconductor lasers. For the elliptically polarized state, dichroism and birefringence parameters as well as the spin-flip rate can change the conjugate spectra. Especially, when frequency detuning of the probe and pump waves is between the positive and negative relaxation oscillation frequency, changes are evident. For specific values of parameters, conjugate efficiency between 20 dB to 40 dB are obtained.

关键词： phase conjugate VCSELs polarization four-wave mixing