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Journal of Harbin Institute of Technology(New Series) 2013年第1期20卷 23-27页

作者： Xiu-Hua Li Lin Ma xue-zhi tan Xin Liu Communication Research Center Harbin Institute of Technology Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory

A novel pilot-aided ridge regression (RR) channel estimation for SC-FDE system on time-varying frequency selective fading channel is derived. Previous least square (LS) channel estimation, which does not consider and utilize the influence of noise, has poor performance when the observed signal is corrupted abnormally by noise. In order to overcome the inherent disadvantage of LS estimation, the proposed RR estimation uses the influence of noise to get better performance. The performance of this new estimator is examined. The numerical results are presented to show that the new estimation improves the accuracy of estimation especially in low channel signal-to-noise ratio (CSNR) level and outperforms LS estimation. In addition, the proposed RR estimation can get the gains of about 1dB compared with LS estimation.

关键词： SC-FDE channel estimation least square ridge regression

A Static Spectrum Aggregation Algorithm in Cognitive Radio System

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Journal of Harbin Institute of Technology(New Series) 2013年第2期20卷 40-44页

作者： Cong Yin xue-zhi tan Lin Ma Xiu-Hua Li Communication Research Center Harbin Institute of Technology Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory

Cognitive radio ( CR) is known as an intelligent technology allowing a secondary user ( SU) to occupy a primary user's ( PU's) band when it is idle. Appearance of the idle band may be contiguous or non-contiguous. In other words,the PU's band and the idle band are distributed alternately over the spectrum. Apparently the non-contiguous idle band cannot be fully utilized in this context. This paper proposes an algorithm to solve the problem of low utilization of the non-contiguous idle band and to increase the number of the SU who needs access to the spectrum by a static spectrum aggregation ( SSA) method combined with non-contiguous orthogonal frequency division multiplexing ( NC-OFDM) . The simulation results show that the SSA algorithm realizes at least 70% utilization of the idle band which provides access to the spectrum for as many as 30 SUs as expected.

关键词： cognitive radio static spectrum aggregation non-contiguous OFDM

Multi-slots Wideband Cooperative Spectrum Sensing Based on Weighed Data Fusion in Cognitive Radio

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Journal of Harbin Institute of Technology(New Series) 2013年第1期20卷 1-7页

作者： Xin Liu Xiu-Hua Li Rong-Fei Fan xue-zhi tan Communication Research Centre Harbin Institute of Technology School of Electrical and Electronic Engineering Nanyang Technological University Dept. of Electrical and Computer Engineering University of Alberta

In order to avoid the interference to the primary user(PU), in this paper Cognitive Radio (CR) periodically senses the presence of PU, and during one period, CR can sense all the sub-channels based on weighed data fusion and then use all the idle channels decided by the coordinator. The local sensing time of CR is divided into multi-slots in which CR can sense any sub-channel. Through reasonably allocating the sensing slots and users by mathematic optimization, the proposed algorithm can improve the total throughput of CR. The optimization problem of the proposed scheme which seeks to maximize the throughput subject to the constraint of the detected performance of each sub-channel is proposed in order to choose the optimum local sense time and the number of the cooperative CRs. The simulation results indicate that the proposed scheme can obtain higher throughput than the conventional single-channel sense, and there are the optimum local sense time and the number of cooperative CRs to make the throughput reach maximum.

关键词： cognitive radio energy detection cooperative detection weighed data fusion thoughput

A Joint Rate Control and AMC Algorithm for Adaptive Transmission Systems

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Journal of Harbin Institute of Technology(New Series) 2013年第2期20卷 12-16页

作者： Yang Yu xue-zhi tan Yong-Gang Chi Lin Ma Yao Wang Communication Research Center Harbin Institute of Technology

The traditional communication system is effectively designed for the worst-case channel state and it can not use the spectral efficiently over the time-varying multipath channel. In order to improve the spectral efficiency and ensure robust and spectrally-efficient transmission over the time-varying multipath channel,a joint rate control and adaptive modulation and coding ( AMC) algorithm for adaptive transmission systems is proposed in this paper. Firstly,the proposed algorithm can formulate a modulation and coding scheme ( MCS) switching table according to the offline simulation results and the target bit error rate ( BER) . Then,the optimal MCS is selected in MCS switching table according to the channel state information ( CSI) and then passes to the transmitter and receiver to implement. So the adaptive system which always uses the optimal MCS to transmit signals uses the spectral efficiently. The simulation results validate the proposed algorithm and show that under the premise of meeting the target BER,the adaptive system performing the proposed algorithm has a higher average spectral efficiency ( ASE) than that of the non-adaptive system.

关键词： adaptive modulation and coding average spectral efficiency adaptive transmission system modulation and coding scheme switching table

Identification of homogeneous regions in the Pearl River Delta using a physically-based approach

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Identification of homogeneous regions in the Pearl River Del...

Real-world evidence on the efficacy and safety of vonoprazanamoxicillin dual therapy for Helicobacter pylori treatment in elderly patients

中国水利学会2021学术年会

作者：唐亦汉 xue-zhi tan Pei-yi Li Cheng-jia Su Xiao-hong Chen Guangdong Research Institute of Water Resources and Hydropower School of Civil Engineering Sun Yat-sen University Guangdong Hydropower Planning and Design Institute

The increasing risk of flood in deltas calls for more reliable estimates of design flood levels. Applying a unified probability density function（PDF） for a whole delta area ignores the hydrodynamic diversity, and flood zones, where the flood level distributions in different spots are identical, need to be defined. A methodology to define flood zones, which considers the physical features of flood, has been proposed and applied in the Pearl River Delta（PRD）, Southern China. Results show that the flood zones defined solely according to the statistical characteristics are inapplicable for the spots that share similar statistical features but different driving forces of flood generation, es-pecially in spots where the river network density is high and unevenly distributed. The methodology proposed can solve this problem. Three flood zones are detected in the PRD area: Zone A is over 60 km away from the delta out-lets;Zone B is between 25 km and 60 km and Zone C is within 25 km towards the delta outlets. If one unified PDF is applied in the whole PRD, the overestimation of a 100-year design flood level Zone A can reach up to 0. 77 m. This research presents a sample to identify flood zones in a delta where the river network density is high, and the floods are induced by the interaction of river floods and tides.

关键词： Flood zone physical features design flood level estimation dense river network Pearl River Delta

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World Journal of Gastroenterology 2025年第1期31卷 68-78页

作者： Wen Gao Jing-Wen Li Hui Ye xue-zhi Zhang Jian-Xiang Liu Hong Cheng Department of Gastroenterology Peking University First HospitalBeijing 100034China School of Medicine Tsinghua MedicineTsinghua UniversityBeijing 100034China Department of Traditional Chinese Medicine and Integrative Medicine Peking University First HospitalBeijing 100034China

BACKGROUND A dual therapy regimen containing amoxicillin is a common treatment option for the eradication of Helicobacter pylori(***).While substantial research supports the efficacy and safety of vonoprazan and amoxicillin(VA)dual therapy in the general population,there is still a lack of studies specifically focusing on its safety in elderly *** To evaluate efficacy and safety of VA dual therapy as first-line or rescue treatment for *** in elderly *** As a real-world retrospective study,data were collected from elderly patients aged 60 years and above who accepted VA dual therapy(vonoprazan 20 mg twice daily+amoxicillin 1000 mg thrice daily for 14 days)for *** eradication in the Department of Gastroenterology at Peking University First Hospital between June 2020 and January *** status was evaluated by^(13)C-urease breath test 6 weeks after *** adverse events(AEs)during treatment were *** In total,401 cases were ***-one cases were excluded due to loss to follow-up,lack of re-examination,or unwillingness to take *** total of 380 included cases comprised 250 who received VA dual therapy as first-line treatment and 130 who received VA dual therapy as rescue *** was successfully eradicated in 239 cases(95.6%)in the first-line treatment group and 116 cases(89.2%)in the rescue treatment *** overall incidence of AEs was 9.5%for both ***,9.2%of patients experienced an AE in the first-line treatment group and 10.0%in the rescue treatment *** patients discontinued treatment due to AE,with a discontinuation rate of 1.3%.No serious AE *** The VA dual therapy regimen as a first-line treatment and a rescue therapy was effective and safe for elderly patients aged 60 and older.

关键词： Helicobacter pylori Vonoprazan Amoxicillin Dual therapy Elderly

Laser cladding of Ni-based alloy on stainless steel

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中国有色金属学会会刊：英文版 2004年第Z1期14卷 296-300页

作者： xue Chun-fang TIAN Xin-li tan Yong-sheng WU zhi-yuan Department of Mechanical Engineering Academy of Armored Force Engineering Beijing 100072 China Department of Mechanical Engineering Academy of Armored Force Engineering Beijing 100072 China Key Laboratory for High Energy Density Beam Processing TechnologyGeneral Company of Aeronautics Industry Beijing 100024 China Department of Mechanical Engineering Academy of Armored Force Engineering Beijing 100072 China

The coatings on a stainless steel substrate were conducted by laser cladding of Ni-based alloy, using a 5 kW continuous wave CO2 flow transverse laser. SEM, EDX and X-ray diffraction were used to analyze the microstructure and constituent phases of the obtained coatings by laser cladding with direct injection of the powder into the melt pool. Solidification planar, cellular and dendrite structures were observed in Ni-based alloy coating. There exists an optimum metallurgical bond between Ni-based laser cladding layer and the base material. The high hardness of the Ni-based alloy coating is attributed to the presence of M7C3-type carbides (essentially chromium-riched carbide) dispersed in the γ(Ni,Fe) phase matrix.

关键词： laser cladding Ni-based alloy microstructure

Foreign residency rights and companies’ auditor choice

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China Journal of Accounting Research 2019年第1期12卷 93-112页

作者： xue Yang zhi Jin Jinsong tan Business School Chengdu University of Technology School of Accounting Southwestern University of Finance and Economics Center for Accounting Finanace and InstitutionsSun Yat-sen University

Recently, with the migration of wealthy Chinese elites becoming increasingly prevalent, the market has come to believe that firms with controlling persons with foreign residency rights have serious agency problems. We study the impact of controlling persons with foreign residency rights on corporate audit perspective. We find that firms whose controlling persons have foreign residency rights are more likely to use high-quality auditing services, and that this behavior is more obvious in regions with lower marketization and in firms with higher separation of ownership and control. We further study the effect of firms whose controlling persons have foreign residency rights that use high-quality Big 4 auditors and find that such firms have better corporate governance and accounting performance.

关键词： Foreign residency rights Audit Corporate governance Signal transmission

Heat Capacities and Thermodynamic Properties of 3-(2,2-Dichloroethenyl)-2,2-dimethylcyclopropanecarboxylic Acid

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Chemical Research in Chinese Universities 2007年第4期23卷 460-464页

作者： xue Bin WANG Jian-ya tan zhi-cheng WU Tong-hao School of Petrochemical Engineering Shenyang University of Technology Liaoyang 111003 P. R. China College of Chemistry Jilin University Changchun 130021 P. R. China Thermochemistry Laboratory Dalian Institute of Chemical Physics Chinese Academy of Science Dalian 116023 P. R. China

The heat capacities of 3-（ 2,2-dichloroethenyl）-2,2-dimethylcyclopropanecarboxylic acid （a racemic mixture, molar ratio of cis-/trans-structure is 35/65） in a temperature range from 78 to 389 K were measured with a precise automatic adiabatic calorimeter. The sample was prepared with a purity of 98.75% （ molar fraction）. A solid-liquid fusion phase transition was observed in the experimental temperature range. The melting point, Tm, enthalpy and en- tropy of fusion, △fusHm, △fusSm, of the acid were determined to be （331.48±0.03 ） K, （16.321±0.031） kJ/mol, and （49.24±0.19） J/（ K·mol）, respectively. The thermodynamic functions of the sample, Ht-H298.15, Sr-S298.15 and Gr-G298.15, were reported at a temperature intervals of 5 K. The thermal decomposition of the sample was studied using thermogravimetric（TG） analytic technique, the thermal decomposition starts at ca. 418 K and ends at ca. 544 K, the maximum decomposition rate was obtained at 510 K. The order of reaction, preexponential factor and activation energy are n =0.23, A =7.3 ×10^7 min^-1 , E =70.64 kJ/mol, respectively.

关键词： 3-(2,2-Dichloroethenyl)-2,2-dimethylcyclopropanecarboxylic acid Adiabatic calorimetry Heat capacity Thermodynamic function Thermal decomposition

Determination of Chlorine in Human Urine by Detecting Backscattering Signals with a New Optical Assembly

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Chinese Chemical Letters 2006年第5期17卷 679-682页

作者： Ke Jun tan Yuan Fang LI Cheng zhi HUANG xue Lian LIU College of Chemistry and Chemical Engineering Southwest University Chongqing 400715

Detection of backscattering signals （BSS） generally suffers from the interference of reflected light, and it is hard to apply these signals for analytical purpose. Herein we provided an optical assembly, which effectively eliminated the interference of reflected light so that the scattering signals of analyte could be measured distinctly. With this assembly, chlorine in human urine could be detected with the limit of detection （LOD） of 2.0 ng/mL by measuring the enhanced BSS signals produced between the interactions of chlorine with silver nitrate.

关键词： Chlorine urine backscattering signals.