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Waveform Design for MIMO Radar with One-Bit DACs via Block-Sparse Semidefinite Relaxation

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Journal of Beijing Institute of Technology 2021年第4期30卷 323-339页

作者： Tong Wei bin liao the Interdisciplinary Centre for Security Reliability and Trust(SnT)University of LuxembourgL-1855Luxembourg the Guangdong Key Laboratory of Intelligent Information Processing Shenzhen UniversityShenzhen 518060China

Multiple-input multiple-output(MIMO)systems which deploy one-bit DACs are at-tractive in many fields,such as wireless communications and *** this paper,the problem of transmit waveform design in MIMO radar system with one-bit DACs is *** appropri-ately designing the transmitted QPSK signal waveforms,the majority of radiated energy can be fo-cused into the mainlobe region(s)by minimizing the integrated sidelobe to mainlobe ratio(ISMR)of beampattern,such that the intensity of backscattered signals from targets can be ***,the resulting optimization problem which consists of constrained fractional quadratic problem(CFQP)is *** tackle this problem,a block-sparse semidefinite relaxation meth-od is first utilized to reformulate the CFQP into a reduced convex semidefinite programming(SDP).Further,a customized interior point algorithm(IPA)is developed to solve the small-scale ***,the desirable one-bit transmit waveform sequence can be properly synthesized by us-ing Gaussian randomization *** simulation results demonstrate that the proposed method offer better performance than the state-of-the-art algorithms.

关键词： MIMO radar beampattern synthesis one-bit quantization waveform design

Tribological properties of CrN coating deposited on 20CrMo against tin bronze

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Science China(Technological Sciences) 2018年第11期61卷 1713-1722页

作者： LIU JiLiang liao RiDong XIE GuoXin XIANG JianHua LUO Jun liao bin LIU QingYi School of Mechanical Engineering Beijing Institute of TechnologyBeiiing 100081China Beijing Liang Xin Technology Co. Ltd.Beijing 100081China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China Beijing Radiation Center Beijing 100875China College of Nuclear Science and Technology Beijing Normal UniversityBeijing 100875China State Key Laboratory of Engine Reliability Weichai Power Co.Ltd.Weifang 261001China

A CrN coating was deposited on the piston pin material 20CrMo. The tribological properties of 20CrMo and CrN coating against tin bronze QSn7-0.2 were compared by pin-on-disk tests under dry friction and oil lubrication, respectively. The cross-sectional morphologies and structures of the coating were characterized through scanning electron microscopy and X-ray diffraction. The hardness, elastic modulus, and adhesion strength of the coating were tested through nano-hardness and scratch tests. The wear tracks were tested with an optical profilometer, and wear volume was calculated. Under dry friction conditions, the CrN coating exhibited a significantly stable friction coefficient and a relatively lower wear rate against QSn7-0.2 at various temperatures compared with 20CrMo. The wear rate decreased by 98.5% at 700°C. Under poly-alpha-olefine lubrication, the CrN coating reduced the load effect on the friction coefficient. Under engine oil 5 W40 lubrication, the CrN coating improved the tribological properties under high speed and heavy load conditions. Simultaneously, the CrN coating changed the friction and heat flow with increasing temperature.

关键词： CrN coating tribological properties piston pin friction coefficient wear rate

De novo production of 24-epi-ergosterol in bioengineered yeast

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Chinese Journal of Natural Medicines 2023年第5期21卷 321-322页

作者： XU Zi Fei DONG liao-bin State Key Laboratory of Natural Medicines School of Traditional Chinese PharmacyChina Pharmaceutical UniversityNanjing 211198China

Plant natural products(PNPs),a rich source of structurally unique and functionally diverse bioactive compounds,comprise a large variety of natural product families including alkaloids,terpenoids,and phenylpropanoids[1].PNPs possess a wide range of applications such as antibiotics,analgesics,and antiviral,antimalarial and antineoplastic agents[2,3].Classically,collection of PNPs relies on extraction and purification from natural ***,due to their low amounts in nature,the extraction process is often inefficient and *** synthesis,on the other hand,is difficult due to the stereochemical complexity of *** recent years,advances in synthetic biology have accelerated the process of producing complex PNPs in yeast cell *** cerevisiae(yeast)is charaterized by a wealth of well-established tools available for genetic manipulation,a well-characterized core metabolic network,low cultivation cost,and compatibility with high cell density fermentation[4-7].As a result,*** is increasingly used as a workhorse for enzyme characterization,biosynthetic pathway elucidation[8,9],and de novo production for various highvalue PNPs[10].

关键词： horse compatibility cultivation

Optimization of microstructure design for enhanced sensing performance in flexible piezoresistive sensors

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Journal of Advanced Ceramics 2024年第6期13卷 711-728页

作者： Xinghao Fan Hailong Hu bin liao Yaqi Zhang Fan Zhang School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China Research Institute of Aerospace Technology Central South UniversityChangsha 410083China

Flexible piezoresistive strain sensors have received significant attention due to their diverse applications in monitoring human activities and health,as well as in robotics,prosthetics,and human–computer interaction *** the various flexible sensor types,those with microstructure designs are considered promising for strain sensing due to their simple structure,high sensitivity,extensive operational range,rapid response time,and robust *** review provides a concise overview of recent advancements in flexible piezoresistive sensors based on microstructure design for enhanced strain sensing performance,including the impact of microstructure on sensing mechanisms,classification of microstructure designs,fabrication methods,and practical ***,this review delves into the analysis of piezoresistive sensor sensing mechanisms and performance parameters,exploring the relationship between microstructure design and performance ***,an in-depth discussion is presented,focusing on the primary themes of microstructure design classification,process selection,performance characteristics,and specific *** review employs mathematical modeling and hierarchical analysis to emphasize the directionality of different microstructures on performance enhancement and to highlight the performance advantages and applicable features of various microstructure *** conclusion,this review examines the multifunctionality of flexible piezoresistive sensors based on microstructure design and addresses the challenges that still need to be overcome and improved,such as achieving a wide range of stretchability,high sensitivity,and robust *** review summarizes the research directions for enhancing sensing performance through microstructure design,aiming to assist in the advancement of flexible piezoresistive sensors.

关键词： microstructure design sensing performance flexible piezoresistive strain sensors microsensing mechanism

Wideband Direction-of-Arrival Estimation Based on Deep Learning

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Journal of Beijing Institute of Technology 2021年第4期30卷 412-424页

作者： Liya Xu Yi Ma Jinfeng Zhang bin liao Shenzhen University Shenzhen 518060China

The performance of traditional high-resolution direction-of-arrival(DOA)estimation methods is sensitive to the inaccurate knowledge on prior information,including the position of ar-ray elements,array gain and phase,and the mutual coupling between the array ***-based methods are data-driven and are expected to perform better than their model-based counter-parts,since they are insensitive to the array *** paper presents a learning-based method for DOA estimation of multiple wideband far-field *** processing procedure mainly includes two ***,a beamspace preprocessing structure which has the property of fre-quency invariant is applied to the array outputs to perform focusing over a wide *** the second step,a hierarchical deep neural network is employed to achieve *** from neural networks which are trained through a huge data set containing different angle combinations,our deep neural network can achieve DOA estimation of multiple sources with a small data set,since the classifiers can be trained in different small *** results demonstrate that the proposed method performs well both in generalization and imperfections adaptation.

关键词： direction-of-arrival(DOA)estimation deep-neural network(DNN) wideband mul-tiple sources array imperfection

Application of Spatial Database in Quantitative Analysis of Litho-Paleogeography—A Case Study of a Middle Ordovician Sequence Interval in the Ordos Basin

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Geo-Spatial Information Science 2011年第1期14卷 27-38页

作者： LI bin liao Feiyan MENG Hao ZHONG Yanchun China University of Petroleum Beijing Campus (CUP) 18 Fuxue Road Beijing China 102249

Abstract In the study of sequence stratigraphy and litho-paleogeography, quantitative analysis, precise calculation and detailed comparison of tremendous geological data, such as field profiles, logging records and seismic curves from different areas, are the basic requirements. In order to obtain a more reliable and precise result, this paper presents a novel method that combines spatial database analysis with the single-factor mapping technology to establish sequence stratigraphical succession and to map the Ordovician litho-paleogeography of the Ordos Basin, one of the largest oil-gas bearing basins in North China Platform. By using this method, all of the related basic geological data can be quantitatively analyzed and effectively managed. Various attributes of the basic stratigraphic units and their characters, such as sequence thickness, penecontemporaneous dolostone content, shallow water parget content, and terrigenous material content, can be fully utilized statistically in facies analysis and in mapping. Based on this analysis, this paper has be exerted single-factor isopachous mapping quantitatively for each of the Ordovician sequences in the basin, and finally synthesized multiple factors to reconstruct the litho-paleogeography for each of the sequence intervals. The study shows that the proposed method is quite effective and has a much higher resolution in recognizing litho-paleogeographic subunits compared with traditional ways. For example, in one of the Middle Ordovician sequence intervals （SQ19 in the Lower Majiagou Formation） of the Ordos Basin, the authors have successfully developed a mathematical formula to divide the distribution of various facies units substantially, such as old lands, submarine uplifts, supratidal zones, intertidal zones and subtidal zones.

关键词： spatial database single-factor analysis Ordos Basin Ordovician sequence stratigraphy litho-paleogeography

Removal of metals by sorghum plants from contaminated land

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Journal of Environmental Sciences 2009年第10期21卷 1432-1437页

作者： ZHUANG Ping SHU Wensheng LI Zhian liao bin LI Jintian SHAO Jingsong Institute of Ecology South China Botanic Garden Chinese Academy of Sciences Guangzhou 510560 China. School of Life Sciences and State Key Laboratory of Biocontrol Sun Yat-sen University Guangzhou 510275 China

The growth of high biomass crops facilitated by optimal of agronomic practices has been considered as an alternative to phytoremediation of soils contaminated by heavy metals. A field trial was carded out to evaluate the phytoextraction efficiency of heavy metals by three varieties of sweet sorghum （Sorghum biocolor L.）, a high biomass energy plant. Ethylene diamine tetraacetate （EDTA）, ammonium nitrate （NH4NO3） and ammonium sulphate （（NH4）2SO4） were tested for their abilities to enhance the removal of heavy metals Pb, Cd, Zn, and Cu by sweet sorghum from a contaminated agricultural soil. Sorghum plants always achieved the greatest removal of Pb by leaves and the greatest removal of Cd, Zn and Cu by stems. There was no significant difference among the Keller, Rio and Mray varieties of sweet sorghums in accumulating heavy metals. EDTA treatment was more efficient than ammonium nitrate and ammonium sulphate in promoting Pb accumulation in sweet sorghum from the contaminated agricultural soil. The application of ammonium nitrate and ammonium sulphate increased the accumulation of both Zn and Cd in roots of sorghum plants. Results from this study suggest that cropping of sorghum plants facilitated by agronomic practices may be a sustainable technique for partial decontamination of heavy metal contaminated soils.

关键词： Sorghum biocolor field trial phytoextraction

Mechanical and Tribological Properties of CrN Coated Inconel X750

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Journal of Wuhan University of Technology(Materials Science) 2019年第4期34卷 804-810页

作者： LIU Jiliang liao Ridong School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Liang Xin Technology Co. Ltd.Beijing 100081China College of Nuclear Science and Technology Beijing Normal UniversityBeijing 100875China Beijing Radiation Center Beijing 100875China China North Vehicle Research Institute Beijing 100072China

Three CrN coatings were deposited on the Inconel X750 through the metal vapor vacuum arc ion implantation and the magnetic filtered cathodic vacuum arc deposition system(MEVVA-FCVA) with the N2 flow rates of 10,50,and 100sccm, *** surface morphologies and cross-section morphologies of the CrN coatings were obtained through scanning electron microscopy(SEM) and an optical *** microstructures of the coatings were characterized through X-ray diffraction(XRD).The hardness and the elastic modulus of the coatings were tested by a nano-hardness *** adhesion strength and friction coefficients were investigated through scratch tests and ball-on-disk tests and the wear tracks were tested by the optical profilometer. The experimental results indicate that the CrN coating deposited on the Inconel X750 substrate displays a uniform thickness and a smooth surface. The mechanical properties behaves well as the N2 flow rate *** CrN coating significantly reduces the friction coefficient fluctuation and improves the antiadhesion and anti-wear properties of the Inconel X750.

关键词： inconel X750 N2 flow rate CrN coating mechanical properties tribological properties

Experimental and computational study of visible light-induced photocatalytic ability of nitrogen ions-implanted TiO2 nanotubes

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Chinese Physics B 2020年第4期29卷 82-88页

作者： Ruijing Zhang Xiaoli Liu Xinggang Hou bin liao College of Physics and Materials Science Tianjin Normal UniversityTianjin 300387China Key Laboratory of Beam Technology and Material Modification of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China

Nitrogen-doped TiO2 nanotubes(TNTs)were prepared by ion implantation and anodic *** prepared samples were applied in photocatalytic(PC)oxidation of methyl blue,rhodamine B,and bisphenol A under light *** explore the influence of doped ions on the band and electronic structure of TiO2,computer simulations were performed using the VASP code implementing spin-polarized density functional theory(DFT).Both substitutional and interstitial nitrogen atoms were *** experimental and computational results propose that the electronic structure of TiO2 was modified because of the emergence of impurity states in the band gap by introducing nitrogen into the lattice,leading to the absorption of visible *** synergy effects of tubular structures and doped nitrogen ions were responsible for highly efficient and stable PC activities induced by visible and ultraviolet(UV)light.

关键词： photocatalytic activities nitrogen ion implantation TiO2 nanotube impurity energy level light irradiation