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Chemical fingerprinting of Su-He-Xiang-Wan and attribution of major characteristic peaks for its quality control by GC-MS

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Journal of Central South University 2013年第8期20卷 2115-2123页

作者： WANG Wei-ping LIN Juan ZHANG liang-xiao ZHANG Ming-yue liang Yi-zeng Research Center of Modernization of Chinese Herbal Medicine College of Chemistry and Chemical Engineering Central South University Changsha 410083 China Xinjiang Uygur Autonomous Region Institute for Food and Drug Control Urumqi 830004 China Oilcrops Research Institute Chinese Academy of Agricultural Sciences Wuhan 430062 China

A simple and facile gas chromatography-mass spectrometer （GC-MS） fingerprint of Su-He-Xiang-Wan （SHXW） was developed, the similarity analysis was conducted, and attribution of the major characteristic peaks was identified for SHXW quality control. GC-MS analysis was performed on a QP2010 instrument （Shimadzu, Japan） equipped with a capillary column of RTX-5MS. The column temperature was initiated at 50℃, held for 5 min, increased at the rate of 3 ℃/min to 120 ℃, held for 2 min, and then increased at the rate of 4 ℃/min to 220℃, held for 10 min. Helium carrier gas was used at a constant flow rate of 1.3 mL/min. Mass conditions were ionization voltage, 70 eV; injector temperature, 250℃; ion source temperature, 250 ℃; splitting ratio, 30：1; full scan mode in the 40-500 Da mass ranges with rate of 0.2 s per scan. Attribution of the major characteristic peaks was identified for SHXW by comparing the chemical standards, references of Chinese herbal medicines and the negative controls of prescription samples （NC） of SHXW. With the help of the temperature-programmed retention indices （PTRIs） used together with mass spectra and chemical standards, 25 major characteristic peaks have been identified. Nine volatile medicinal materials were identified in the prescription of SHXW by attributing to the 27 major characteristic peaks. The results demonstrate that the proposed method is a powerful approach to quality control of complex herbal medicines.

关键词： chromatographic fingerprint attribution analysis quality control herbal medicines complex prescription

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Phylogenetic diversity and bioactivity of culturable deepsea-derived fungi from Okinawa Trough

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Journal of Oceanology and Limnology 2021年第3期39卷 892-902页

作者： xiaoyong ZHANG Yiyang LI Zonghe YU xiao liang Shuhua QI Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation College of Marine SciencesSouth China Agricultural UniversityGuangzhou 510642China Key Laboratory of Tropical Marine Bio-resources and Ecology/RNAM Center for Marine Microbiology/Guangdong Key Laboratory of Marine Material Medical South China sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China

Deep-sea sediments are now recognized as a home for rich and largely microbial ***,it has been believed in an increasing number of studies that bacteria could be abundant in deepsea sediments of many types;however,fungi in deep-sea sediments remain relatively *** phylogenetic diversity and bioactivity of culturable deep-sea-derived fungi from Okinawa Trough sediments were investigated in traditional method combined with fungal identification of molecular biology in this study.A total of 76 isolates belonged to 15 fungal taxa were recovered in a harsh condition of low nutrient and low temperature,indicating that the fungal communities in deep-sea sediments from Okinawa Trough were relatively abundant and ***,Cladosporium,and Penicillium were the dominant fungal genera,while Mycosphaerella,Purpureocillium,and Schizophyllum were relatively rare in the deep-sea sediments from Okinawa *** the six genera recovered,Mycosphaerella was firstly recovered from deep-sea sediments in this ***,about 75%of the extracts from the 15 fungal representative isolates displayed distinct bioactivity against at least one indicator bacterium or marine macrofouler,emphasizing the potentials of these deep-sea-derived fungi from Okinawa Trough as producers of bioactive ***,isolates Cladosporium oxysporum SCSIO z001 and Penicillium citrinum SCSIO z049 displayed a wide spectrum of bioactivities,isolates Cladosporium cladosporioides SCSIO z015,Cladosporium sphaerospermum SCSIO z030,and Penicillium verruculosum SCSIO z007 exhibited a strong anti-bacterial-growth activity,and isolate Penicillium chrysogenum SCSIO z062 displayed a strong anti-larval-settlement *** results suggest that these isolates deserved further study as potential sources of novel bioactive metabolites.

关键词： deep-sea-derived fungi phylogenetic diversity bioactivity Okinawa Trough hydrothermal vents

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Measuring aggregate trade costs and its empirical effects on manufacturing export composition in China

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China Finance and Economic Review 2016年第4期5卷 79-99页

作者： Xu Tongsheng liang xiao the Collaborative Innovation Center/International Economic Research Institute in Jiangxi University of Finance and Economics in China World Economics in Jiangxi University of Finance and Economics in China

On the basis of measuring the bilateral trade costs between China and 86 trade partners and the aggregate trade costs from 2000 to 2013,this paper takes China’s vertical specialization reality into account,to do an empirical study on the impact of China’s aggregate trade costs on comparative advantages and export share of 17 two-digit ISIC manufacturing industries,and to conduct these types of robust tests in order to eliminate endogeneity *** results show that China’s aggregate trade costs are declining,but it is still 1/3 higher than that of developed countries of 10 years ago;bilateral trade costs between China and some countries even rise instead;aggregate trade costs are the determinants,not only of‘global’and‘local’comparative advantages,but also of export share of China’s manufacturing products,and its effect is stronger in industries with higher trade cost ***,we should consider the product composition on trade cost intensity and domestic value-added value(DVAR),and reduce trade costs in order to promote the export of products with higher domestic value-added rate,and to realize the substantial transformation of foreign trade growth mode.

关键词： aggregate trade costs manufacturing export composition trade cost intensity domestic value added

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Reinforcement learning based energy efficient robot relay for unmanned aerial vehicles against smart jamming

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Science China(Information Sciences) 2022年第1期65卷 234-246页

作者： xiaozhen LU Jingfang JIE Zihan LIN liang xiao Jin LI Yanyong ZHANG Department of Information and Communication Engineering Xiamen University School of Computer Science and Technology University of Science and Technology of China School of Computer Science and Educational Software Guangzhou University

Unmanned aerial vehicles(UAVs) with limited energy resources, severe path loss, and shadowing to the ground base stations are vulnerable to smart jammers that aim to degrade the UAV communication performance and exhaust the UAV energy. The UAV anti-jamming communication performance, such as the outage probability, degrades if the robot relay is not aware of the jamming policies and the UAV network topology. In this paper, we propose a robot relay scheme for UAVs against smart jamming, which combines reinforcement learning with a function approximation approach named tile coding, to jointly optimize the robot moving distance and relay power with the unknown jamming channel states and locations. The robot mobility and relay policy are chosen based on the received jamming power, the robot received signal quality,location and energy consumption, and the bit error rate of the UAV messages. We also present a deep reinforcement learning version for the robot with sufficient computing resources. It uses three deep neural networks to choose the robot mobility and relay policy with reduced sample complexity, so as to avoid exploring dangerous policies that lead to the high outage probability of the UAV messages. The network architecture of the three networks is designed with fully connected layers instead of convolutional layers to reduce the computational complexity, which is analyzed by theoretical analyses. We provide the performance bound of the proposed schemes in terms of the bit error rate, robot energy consumption and utility based on a game-theoretic study. Simulation results show that the performance of our proposed relay schemes,including the bit error rate, the outage probability, and the robot energy consumption outperforms the existing schemes.

关键词： unmanned aerial vehicles relay jamming game theory reinforcement learning

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Towards reinforcement learning in UAV relay for anti-jamming maritime communications

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Digital Communications and Networks 2023年第6期9卷 1477-1485页

作者： Chuhuan Liu Yi Zhang Guohang Niu Luliang Jia liang xiao Jiangxia Luan Department of Information and Communication Engineering Xiamen UniversityXiamen361005China School of Space Information Space Engineering UniversityBeijing101400China Xiamen Meiya Pico Information Co. Ltd.Xiamen361005China

Maritime communications with sea surface reflections and sea wave occlusions are susceptible to jamming attacks due to the wide geographical area and intensive wireless communication *** Aerial Vehicles(UAVs)help relay messages to improve communication performance,but the relay policy that depends on the rapidly changing maritime environments is difficult to *** this paper,a reinforcement learning-based UAV relay policy for maritime communications is proposed to resist jamming *** on previous transmission performance,the relay location,the received power of the transmitted signal and the received jamming power,this scheme optimizes the UAV trajectory and relay power to save the energy consumption and decrease the Bit-Error-Rate(BER)of the maritime signals.A deep reinforcement learning-based scheme is also proposed,which designs a deep neural network with dueling architecture to further improve the communication performance and computational *** performance bounds regarding the signal to interference plus noise ratio,energy consumption and the communication utility are provided based on the Nash equilibrium of the game against jamming,and the computational complexity of the proposed schemes is *** results show that the proposed schemes improve the energy efficiency and decrease the BER compared with the benchmark.

关键词： Maritime communications Jamming Unmanned aerial vehicle Relay Reinforcement learning

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A Mooring System Deployment Design Methodology for Vessels at Varying Water Depths

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China Ocean Engineering 2020年第2期34卷 185-197页

作者： XU Sheng-wen liang Ming-xiao WANG Xue-feng DING Ai-bing State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration(CISSE) Shanghai 200240China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

In this paper,a methodology for designing mooring system deployment for vessels at varying water depths is *** Non-dominated Sorting Genetic Algorithm-II(NSGA-II)is combined with a self-dependently developed vessel-mooring coupled program to find the optimal mooring system deployment considering both station-keeping requirements and the safety of the mooring *** case studies are presented to demonstrate the methodology by designing the mooring system deployments for a very large floating structure(VLFS)module and a semi-submersible platform respectively at three different water *** can be concluded from the obtained results that the mooring system can achieve a better station-keeping ability with relatively shorter mooring line when deployed in the shallow *** safety factor of mooring line is mainly dominated by the maximum instantaneous tension increment in the shallow water,while the pre-tension has a decisive influence on the safety factor of the mooring line in the deep water.

关键词： mooring system deployment design methodology NSGA-II varying water depths

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Efficient stochastic successive cancellation list decoder for polar codes

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Science China(Information Sciences) 2020年第10期63卷 133-151页

作者： xiao liang Huizheng WANG Yifei SHEN Zaichen ZHANG xiaohu YOU Chuan ZHANG Laboratory of Efficient Architectures for Digital-communication and Signal-processing (LEADS) Southeast University National Mobile Communications Research Laboratory Southeast University Quantum Information Center of Southeast University

Polar codes are one of the most favorable capacity-achieving codes owing to their simple structures and low decoding complexity. Successive cancellation list(SCL) decoders with large list sizes achieve performances very close to those of maximum-likelihood(ML) decoders. However, hardware cost is a severe problem because an SCL decoder with list size L consists of L copies of a successive cancellation(SC)decoder. To address this issue, a stochastic SCL(SSCL) polar decoder is proposed. Although stochastic computing can achieve a good hardware reduction compared with the deterministic one, its straightforward application to an SCL decoder is not well-suited owing to the precision loss and severe latency. Therefore,a doubling probability approach and adaptive distributed sorting(DS) are introduced. A corresponding hardware architecture is also developed. Field programmable gate array(FPGA) results demonstrate that the proposed stochastic SCL polar decoder can achieve a good performance and complexity tradeoff.

关键词： SCL polar decoder stochastic computing 2-bit decoding distributed sorting hardware

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Prototype-based classifier learning for long-tailed visual recognition

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Science China(Information Sciences) 2022年第6期65卷 62-76页

作者： Xiu-Shen WEI Shu-Lin XU Hao CHEN liang xiao Yuxin PENG School of Computer Science and Engineering Nanjing University of Science and Technology Key Lab of Intelligent Perception and Systems for High-Dimensional Information of Ministry of Education and Jiangsu Key Lab of Image and Video Understanding for Social Security Wangxuan Institute of Computer Technology Peking University State Key Laboratory of Integrated Services Networks Xidian University

In this paper, we tackle the long-tailed visual recognition problem from the categorical prototype perspective by proposing a prototype-based classifier learning(PCL) method. Specifically, thanks to the generalization ability and robustness, categorical prototypes reveal their advantages of representing the category semantics. Coupled with their class-balance characteristic, categorical prototypes also show potential for handling data imbalance. In our PCL, we propose to generate the categorical classifiers based on the prototypes by performing a learnable mapping function. To further alleviate the impact of imbalance on classifier generation, two kinds of classifier calibration approaches are designed from both prototype-level and example-level aspects. Extensive experiments on five benchmark datasets, including the large-scale iNaturalist, Places-LT,and ImageNet-LT, justify that the proposed PCL can outperform state-of-the-arts. Furthermore, validation experiments can demonstrate the effectiveness of tailored designs in PCL for long-tailed problems.

关键词： long-tailed distribution categorical prototype classifier generation classifier calibration class imbalance

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Identification of a heat shock cognate protein 70 gene in Chinese soft-shell turtle (Pelodiscus sinensis) and its expression profiles under thermal stress

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2012年第6期13卷 465-477页

作者： xiao-liang LI Yue KANG xiao-yan ZHANG Bing-lin ZHU Wei-huan FANG Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine College of Animal SciencesZhejiang UniversityHangzhou 310058China

The heat shock cognate protein 70 (Hsc70) is a member of a 70-kDa heat shock protein (HSP70) family that functions as molecular *** this study,a novel Hsc70 gene from Chinese soft-shelled turtle (Pelodiscus sinensis) (tHsc70) was *** tHsc70 full-length complementary DNA (cDNA) is 2 272 bp long with a 1 941-bp open reading frame (ORF) encoding 646 amino *** characteristic signature regions of the HSP70 family,two major domains of an adenosine triphosphate (ATP)/guanosine triphosphate (GTP) binding domain (ABD),and a substrate-binding domain (SBD) were present in the predicted tHsc70 amino acid *** tHsc70 gene was expressed in Escherichia coli BL21 and the expression product reacted with the anti-Hsc70 mouse monoclonal antibody by Western *** analysis revealed that tHsc70 shared identity from 53.9% to 87.7% at the nucleotide level,and 49.1% to 99.5% at the amino acid level with the known *** analysis showed that tHsc70 was clustered together with the Hsc70 gene of another reptile species (Alligator mississippiensis).The tHsc70 was expressed in the liver,lung,heart,and skeletal *** expression patterns of tHsc70 messenger RNA (mRNA) differed among different tissues under different durations of heat stress at 40 °*** at 25 °C for 1 h after heat stress was also different among tissues and length of heat *** of different profiles of expression under heat stress,tHsc70 may play roles in protecting turtles from thermal stress.

关键词： Pelodiscus sinensis Heat shock cognate protein 70 (Hsc70) Phylogenetic analysis Heat stress

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Effects of pre-deformation on microstructure and properties of Al–Cu–Mg–Ag heat-resistant alloy

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Journal of Central South University 2017年第5期24卷 1027-1033页

作者： LIU xiao-yan WANG Zhao-peng LI Qing-shuai ZHANG Xi-liang CUI Hao-xuan ZHANG xiao-liang College of Materials Science and Engineering Hebei University of Engineering

The effects of the pre-deformation on the microstructure, mechanical properties and corrosion resistance of Al–Cu–Mg–Ag alloys were investigated by means of hardness tests, tensile tests, intergranullar corrosion (IGC) tests and transmission electron microscopy (TEM), respectively. The results show that with the increase of deformation amount, the aging hardening rate increases while the strength of the alloy decreases and then increases. The sample with a pre-deformation of 6% possesses the highest tensile strength due to the refinedly and homogeneously distributed precipitations. The pre-deformation aging accelerates the heterogeneous nucleation of Ω and θ′ phases at dislocations, and also refines the precipitations both in the grains and along the grain boundaries. The precipitation of Ω phase is restrained while that of θ′ phase is accelerated in pre-deformed Al–Cu–Mg–Ag alloy compared with the sample without pre-deformation. In addition, the width of the precipitate free zone decreases with increasing the pre-deformation amount, leading to a narrower IGC passageway. This results in an enhanced IGC resistance of Al–Cu–Mg–Ag alloy treated by pre-deformation aging. © 2017, Central South University Press and Springer-Verlag GmbH Germany.

关键词： Alloys Aluminum Corrosion Corrosion resistance Deformation Dislocations (crystals) Grain boundaries High resolution transmission electron microscopy Microstructure Nucleation Precipitation (chemical) Silver Tensile strength Tensile testing Transmission electron microscopy

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