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Highly efficient acousto-optic modulation using nonsuspended thin-fil1m lithium niobate-chalcogenide hybrid waveguides

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Light(Science & Applications) 2022年第6期11卷 1285-1295页

作者： Lei Wan Zhiqiang Yang Wenfeng Zhou Meixun Wen Tianhua Feng Siqing Zeng Dong liu Huan Li Jingshun Ppan Ning Zhu weiping liu Zhaohui Li Department of Electronic Engineering College of Information Science and TechnologyJinan University510632 GuangzhouChina Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems Sun Yat-sen University510275 GuangzhouChina State Key Laboratory for Modern Optical Instrumentation College of Optical Science and EngineeringInternational Research Center for Advanced PhotonicsZhejiang UniversityZijingang Campus310058 HangzhouChina Institute of Semiconductor Science and Technology Guangdong Engineering Technology Research Center of Low Carbon and New Energy MaterialsSouth China Normal University510631 GuangzhouChina Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) 519000 ZhuhaiChina

A highly efficient on-chip acousto-optic modulator is as a key component and occupies an exceptional position in microwave-to-optical *** thin-film lithium niobate is preferentially employed to build the suspended configuration for the acoustic resonant cavity,with the aim of improving the modulation efficiency of the ***,the limited cavity length and complex fabrication recipe of the suspended prototype restrain further breakthroughs in modulation efficiency and impose challenges for waveguide *** this work,based on a nonsuspended thin-film lithium niobate-chalcogenide glass hybrid Mach-Zehnder interferometer waveguide platform,we propose and demonstrate a built-in push-pull acousto-optic modulator with a half-wave-voltage-length product VnL as low as 0.03 V cm that presents a modulation efficiency comparable to that of a state-of-the-art suspended counterpart.A microwave modulation link is demonstrated using our developed built-in push-pull acousto-optic modulator,which has the advantage of low power *** nontrivial acousto-optic modulation performance benefits from the superior photoelastic property of the chalcogenide membrane and the completely bidirectional participation of the antisymmetric Rayleigh surface acoustic wave mode excited by the impedance-matched interdigital transducer,overcoming the issue of low modulation efficiency induced by the incoordinate energy attenuation of acoustic waves applied to the Mach-Zehnder interferometer with two arms in traditional push-pull acousto-optic modulators.

关键词： modulator waveguide interferometer

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The Incidence of Lymphoma in Beijing:Comparing Results from MIS-CASS(2019)and Beijing Cancer Registry(2017)

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China CDC weekly 2021年第52期3卷 1118-1125,I0001页

作者： Hongrui Tian weiping liu Yuqin Song Lan Mi Zhen liu Mengfei liu Chuanhai Guo Fangfang liu Ying liu Yaqi Pan Jun Zhu Zhonghu He Yang Ke Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education/Beijing) Laboratory of GeneticsPeking University Cancer Hospital&InstituteBeijingChina Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education/Beijing) Department of LymphomaPeking University Cancer Hospital&InstituteBeijingChina.

Introduction:This study aimed to evaluate the performance of the Medical-Insurance-System-based Cancer Surveillance System(MIS-CASS)in estimating cancer incidence by comparing the results with the Beijing Cancer Registry(BCR),which is one of the highest-quality population-based cancer registries in ***:Using lymphoma as an example,we extracted relevant claims data from the administrative systems of medical insurance in Beijing(2012–2020)and estimated the most current lymphoma incidence in Beijing(2019)using a standard data processing *** absolute number of new cases,crude incidence rate,and age-standardized incidence rate of lymphoma were compared with the latest data reported by the BCR(2017).Results:Both lymphoma incidence rates and age distribution of new cases estimated based on MISCASS were similar to the BCR data(crude incidence rate:9.8/100,000 vs.10.6/100,000).However,because MIS-CASS included more designated hospitals and covered a larger local stationary population irrespective of household registration(hukou),the absolute number of incident lymphoma cases identified by MIS-CASS was 39.1%higher than that reported by the BCR(2,002 vs.1,439).Conclusions:The MIS-CASS approach reflected the actual cancer burden in a more complete and timely manner as compared with the current BCR,providing new insights for improving cancer surveillance strategies in China.

关键词： CASS Registry absolute

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Microstructure and tensile behavior of hot extruded AZ91 alloys at room temperature

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Journal of University of Science and Technology Beijing 2002年第5期9卷 352-355页

作者： Yuanyuan Li, Datong Zhang, Ying liu, Yan Long, and weiping ChenCollege of Mechanical Engineering, South China University of Technology Guangzhou 510640, China College of Mechanical Engineering South China University of Technology Guangzhou 510640 China

AZ91 alloys were prepared by hot extrusion and its microstructure and tensile behavior at room temperature were investigated. Compared to as-cast ingot, the grain size of hot-extruded material is more refined, the intermetallic phase MgnAl12 is broken and dispersed discontinuously. Both strength and elongation of AZ91 are improved by hot extrusion. Tensile behavior and fracture surface of the experimental material were studied. Due to the change in microstructure, the fracture mechanism of extruded material is different from that of as-cast ingot, the latter is mainly a brittle fracture. Ductile fracture plays a role in hot-extruded AZ91 failure at room temperature.

关键词： magnesium alloy hot extrusion microstructure tensile behavior

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Pt-Ru Catalysts Prepared by a Modified Polyol Process for Direct Methanol Fuel Cells

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贵金属 2012年第A01期33卷 222-226页

作者： ZHANG Junmin ZHU Fangfang ZHANG Kunhua liu weiping GUAN Weiming State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals Kunming Institute of Precious MetalsKunming 650106China

Supported PtRu/C catalysts used in direct methanol fuel cells (DMFCs) were prepared by a new modified polyol method. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and cyclic voltammograms (CVs) were carried out to characterize the morphology, composition and the electrochemical properties of the PtRu/C catalyst. The results revealed that the PtRu nanoparticles with small average particle size (≈2.5 nm), and highly dispersed on the carbon support. The PtRu/C catalyst exhibited high catalytic activity and anti poisoned performance than that of the JM PtRu/C. It is imply that the modified polyol method is efficient for PtRu/C catalyst preparation.

关键词： PtRu/C catalysts modified polyol method direct methanol fuel cells(DMFCs) electrochemical performance

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Heterogeneous optomechanical crystal cavity coupled by a wavelength-scale mechanical waveguide

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Photonics Research 2023年第9期11卷 1509-1516页

作者： YANG LUO HONGYI HUANG LEI WAN weiping liu ZHAOHUI LI Department of Electronic Engineering College of Information Science and TechnologyJinan UniversityGuangzhou 510632China International Institute for Innovative Design and Intelligent Manufacturing Tianjin UniversityShaoxing 312000China Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems Sun Yat-sen UniversityGuangzhou 510275China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519000China

Integrated optomechanical crystal(OMC)cavities provide a vital device prototype for highly efficient microwave to optical conversion in quantum information *** this work,we propose a novel heterogeneous OMC cavity consisting of a thin-film lithium niobate(TFLN)slab and chalcogenide(ChG)photonic crystal nanobeam coupled by a wavelength-scale mechanical *** optomechanical coupling rate of the heterogeneous OMC cavity is optimized up to 340 kHz at 1.1197 *** with phononic band and power decomposition,17.38%energy from the loaded RF power is converted into dominant fundamental horizontal shear mode(SH0)in the narrow LN mechanical *** on this fraction,as a result,3.51%power relative to the loaded RF energy is scattered into the fundamental longitudinal mode(L0)facing the TFLN-ChG heterogeneous *** acoustic breathing mode of the heterogeneous OMC is successfully excited under the driving of the propagating L0 mode in the heterogeneous waveguide,demonstrating the great potentials of the heterogeneous piezo-optomechanical transducer in high-performance photon–phonon interaction fields.

关键词： waveguide cavity crystal

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Behavior　of　the　herbicide　dimepiperate　with　homoionic　clays　in　aqueous　solution

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Journal of Environmental Sciences 1996年第4期8卷 454-459页

作者： liu weiping Wang Qiquan Shao Ying Ji Jing(Department of Chemistry,Zhejiang University, Hangzhou 310027,China) Department of Chemistry Zhejiang University Hangzhou 310027 China

The adsorption of the herbicide dimepiperate with homoionic Fe￣(3+) ,Al￣(3+),Cu￣(2+) ,Ca￣(2+) ,K￣+ and Na￣+ saturated montmorillonite in aqueous solution was investigated. The adsorption to six homoionic clays was described well by the Freundlicb equation. The adsorption capacity decreases in order to Cu￣(2+) >Fe￣(3+) >Al￣(3+) >Ca￣(2+) >K￣+ >Na￣+ clay and the same order of their acidities except for Cu￣(2+),because Cu￣(2+) has great catalytical ability. The kinetic of its hydrolysis was also studied. Among the six metal ions,Cu￣(2+) clay exhibited a particular affect of catalysis. The IR results suggest that only findirig the adsorption of the hydrolytic product on Cu￣(2+)clay and dimepiperate on K￣+,Na￣+ clays, there being two compounds (dimepiperate and its hyrolytic product) adsorptions on Fe￣(3+) and Al￣(3+) clays.

关键词： dimepiperate montmorillonite adsorption isotherm adsorption mechanisms.

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Genetic abnormalities assist in pathological diagnosis and EBVpositive cell density impact survival in Chinese angioimmunoblastic T-cell lymphoma patients

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Chinese Journal of Cancer Research 2023年第5期35卷 536-549页

作者： Yunfei Shi Haojie Wang Yanfei liu Mengping Long Ning Ding Lan Mi Yumei Lai Lixin Zhou Xinting Diao Xianghong Li weiping liu Jun Zhu Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education/Beijing) Department of PathologyPeking University Cancer Hospital&InstituteBeijing 100142China Institute of Genetics and Developmental Biology Chinese Academy of SciencesBeijing 100101China Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education/Beijing) Department of LymphomaPeking University Cancer Hospital&InstituteBeijing 100142China

Objective:To explore the application of genetic abnormalities in the diagnosis of angioimmunoblastic T-cell lymphoma(AITL)and the reliable pathological prognostic ***:This study included 53 AITL cases,which were reviewed for morphological patterns,immunophenotypes,presence of Hodgkin and Reed-Sternberg(HRS)-like cells,and co-occurrence of B cell *** Epstein-Barr virus(EBV)-positive cells in tissues were counted,and cases were classified into“EBV encoded RNA(EBER)high-density”group if>50/*** exome sequencing was ***:Mutation data can assist AITL diagnosis:1)with considerable HRS-like cells(20 cases):RHOA mutated in 14 cases(IDH2 co-mutated in 3 cases,4 cases with rare RHOA mutation),TET2 was mutated in 5 cases(1 case comutated with DNMT3A),and DNMT3A mutated in 1 case;2)accompanied with B cell lymphoma(7 cases):RHOA mutated in 4 cases(1 case had IDH2 mutation),TET2 mutated in 2 cases and DNMT3A mutated in 1 case;3)mimic peripheral T cell lymphoma,not otherwise specified(5 cases):RHOA mutated in 2 cases(IDH2 co-mutated in 1 case),TET2 mutated in 3 cases,and DNMT3A mutated in 1 case;4)pattern 1(1 case),RHOA and TET2 *** RHOAG17V(30/35),rare variant included RHOAK18N,RHOAR68H,RHOAC83Y,RHOAD120G and RHOAG17del,IDH2R172 co-mutated with IDH2M397V in one *** were recurrent mutations of FAT3,PCLO and PIEZO1 and genes of epigenetic remodeling,T-cell activation,APC and PI3K/AKT *** high-density independently indicated adverse overall survival and progression-free survival(P=0.046 and P=0.008,KaplanMeier/log-rank).Conclusions:Over half AITL cases might be confused in diagnosis for certain conditions without mutation *** exome sequencing with a comprehensive panel is crucial to detect both hot-spot and rare mutation variants for RHOA and IDH2 and other recurrent mutated genes in addition to TET2 and *** highdensity independently indicated adverse survival.

关键词： T cell lymphoma mutation pathology prognosis

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Clipping discrete multi-tone for peak-power-constraint IM/DD optical systems

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Science China(Information Sciences) 2023年第5期66卷 227-237页

作者： Ji ZHOU Liangchuan LI Jiale HE Xiaofeng LU Yu BO Guanyu WANG Yuanda HUANG Gengchen liu Yanzhao LU Shecheng GAO Yuanhua FENG Shancheng ZHAO weiping liu Changyuan YU Zhaohui LI Department of Electronic Engineering College of Information Science and Technology Jinan University Optical Research Department Huawei Technologies Co. Ltd. Department of Electronic and Information Engineering The Hong Kong Polytechnic University Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems Sun Yat-sen University Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai)

High peak-to-average power ratio(PAPR) is a major drawback of discrete multi-tone(DMT) in peak-power-constraint(PPC) intensity-modulation/direct-detection(IM/DD) optical systems. Symmetric clipping operation is a frequently-used and practical method for mitigating the PAPR of the DMT ***, clipping noise is inevitably induced by the symmetric clipping operation, thereby deteriorating the system’s performance. In this paper, we study the statistical characteristics of the clipping noise in *** on the statistical characteristics, clipping-noise-cancellation(CNC) algorithms are proposed to mitigate the clipping noise in the clipping DMT systems. Theoretically, the clipping noise can be completely removed using the low-density-parity-check-assisted CNC algorithm(LDPC-assisted CNC algorithm). To verify the superiority of the clipping DMT with the CNC algorithm, we conduct an experiment with a50 Gb/s DMT system using 10G-class commercial devices for the scenario of PPC passive optical *** receiver sensitivity of the clipping DMT system with the CNC algorithm can reach-24 d Bm at a 20%soft-decision forward-error-correction limit, which is 2.5 d B higher than that of the DMT system without clipping operation. The clipping operation and the CNC algorithm are added after the original digital signal processing, thereby demonstrating the potential to efectively overcome the drawback in DMT signals and other high-PAPR signals.

关键词： discrete multi-tone peak-to-average power ratio peak-power constraint clipping-noise cancellation intensity-modulation/direct-detection optical systems

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High Resolution Differential Capacitance Detection Scheme for Micro Levitated Rotor Gyroscope

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Chinese Journal of Aeronautics 2007年第6期20卷 546-551页

作者： Huang Xiaogang Chen Wenyuan liu Wu Zhang weiping Wu Xiaosheng Key Laboratory for Thin Film and Microfabrication Technology of Ministry of Education National Key Laboratory of Nano/Micro Fabrication Technology Institute of Micro and Nano Science and Technology Shanghai Jiao Tong University Shanghai 200030 China

A differential capacitance detection circuit aiming at detection of rotating angle in a novel levitation structure is presented. To ensure the low non-linearity and high resolution, noise analysis and non-linearity simulation are conducted. In the capacitance interface, an integral charge amplifier is adopted as a front end amplifier to reduce the parasitic capacitance caused by connecting wire. For the novel differential capacitance bridge with a coupling capacitor, the noise floor and non-linearity of the detection circuit are analyzed, and the results show that the detecting circuit is capable of realizing angle detection with high angular resolution and relative low non-linearity. With a specially designed printed circuit board, the circuit is simulated by PSpice. The practical experiment shows that the detection board can achieve angular resolution as high as 0.04° with a non-linearity error 2.3%.

关键词： MEMS micro gyroscope capacitance sensing inertial sensor angle detection

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A new interpolation method based on satellite physical character in using IGS precise ephemeris

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Geodesy and Geodynamics 2014年第3期5卷 29-33页

作者： liu weiping Hao Jinming School of Navigation and Aerospace Engineering Information Engineering University

Due to the deficiency of sliding Lagrange polynomial interpolation, the author proposes a new interpolation method, which considers the physical character of satellite movement in coordinate transformation and reasonable selection of interpolation function. Precision of the two methods is compared by a numerical example. The result shows that the new method is superior to the sliding Lagrange polynomial interpolation in interpolation and extrapolation, especially in extrapolation that is over short time spans.

关键词： precise ephemeris interpolation trigonometric interpolation coordinate transformation physical character

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