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AWG-based large dynamic range fiber Bragg grating interrogation system

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Optoelectronics Letters 2024年第3期20卷 129-134页

作者： li shufeng YUAN Pei li Ke li Ting ZHU lianqing Key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument Beijing Information Science&Technology UniversityBeijing 100192China Beijing Laboratory of Optical Fiber Sensing and System Beijing Information Science&Technology UniversityBeijing 100016China

Arrayed waveguide gratings(AWGs) are extensively employed in fiber Bragg grating(FBG) interrogation systems due to their compact size, lightweight nature, and excellent interrogation performance. The resolution and total measurement range of AWG-based FBG interrogation systems are constrained by the output properties of AWG. We proposed an AWG-based large dynamic range interrogation system. The temperature dependence of AWG is exploited to achieve continuous interrogation. The test results show that the interrogation system has a dynamic range of 28.67 nm, an interrogation accuracy better than 25 pm, and a wavelength resolution of 6 pm.

关键词： fiber waveguide AWG

Glacial expansion of cold-tolerant species in low latitudes: megafossil evidence and species distribution modelling

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National Science Review 2023年第4期10卷 13-15页

作者： Luliang Huang shufeng li Weiye Huang Helanlin Xiang Jianhua Jin Alexei A.Oskolski State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources School of Life Sciences/School of Ecology Sun Yat-sen University State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences Department of Botany and Plant Biotechnology University of Johannesburg Botanical Museum Komarov Botanical Institute of the Russian Academy of Sciences

The Pleistocene was a time of repeated glaciations that severely affected the land biota over large areas of Eurasia and North America. Drastic climatic fluctuations during the Pleistocene drove largescale extinctions, migrations and diversification in plant and animal populations.These dramatic processes had a strong impact on the distribution of modern flora and fauna.

关键词： CliMATE PLEISTOCENE DIVERSITY RECORD CHINA

Research on encoding and decoding of non-binary polar codes over GF(2m)

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Digital Communications and Networks 2022年第3期8卷 359-372页

作者： shufeng li Mingyu Cai Robert Edwards Yao Sun libiao Jin The State Key Laboratory of Media Convergence and Communication School of Information and EngineeringCommunication University of ChinaBeijing100024China The Wolfson School of Mechanical Electrical and Manufacturing Engineering Loughborough UniversityLeicestershireLE113TEUK James Watt School of Engineering University of GlasgowG128QQScotlandUK

Binary Polar Codes (BPCs) have advantages of high-efficiency and capacity-achieving but suffer from large latency due to the Successive-Cancellation list (SCL) decoding. Non-Binary Polar Codes (NBPCs) have been investigated to obtain the performance gains and reduce latency under the implementation of parallel architectures for multi-bit decoding. However, most of the existing works only focus on the Reed-Solomon matrix-based NBPCs and the probability domain-based non-binary polar decoding, which lack flexible structure and have a large computation amount in the decoding process, while little attention has been paid to general non-binary kernel-based NBPCs and Log-likelihood Ratio (LLR) based decoding methods. In this paper, we consider a scheme of NBPCs with a general structure over GF(2m). Specifically, we pursue a detailed Monte-Carlo simulation implementation to determine the construction for proposed NBPCs. For non-binary polar decoding, an SCL decoding based on LLRs is proposed for NBPCs, which can be implemented with non-binary kernels of arbitrary size. Moreover, we propose a Perfect Polarization-Based SCL (PPB-SCL) algorithm based on LLRs to reduce decoding complexity by deriving a new update function of path metric for NBPCs and eliminating the path splitting process at perfect polarized (i.e., highly reliable) positions. Simulation results show that the bit error rate of the proposed NBPCs significantly outperforms that of BPCs. In addition, the proposed PPB-SCL decoding obtains about a 40% complexity reduction of SCL decoding for NBPCs.

关键词： Non-binary polar code Log-likelihood ratio Successive-cancellation list Perfect polarization based-SCL Decoding complexity

Interface regulation strategy of Al-CNTs composite induced by Al-Si eutectic reaction and its strengthening mechanism

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Journal of Materials Science & Technology 2023年第20期151卷 1-9页

作者： Xin Zhang Xin li Lei liu Bo li Xiaodong Hou Deng Pan lina Gao shufeng li School of Materials Science and Engineering Xi’an University of TechnologyXi’an 710048China Xi’an Key Laboratory of Advanced Powder Metallurgy Materials and New Technology Xi’an University of TechnologyXi’an 710048China Centre of Excellence for Advanced Materials Songshan LakeDongguan 523808China

Carbon nanotubes(CNTs)reinforced aluminum matrix composites(AMCs)show broad application prospects in the fields of aerospace and transportation because of their lightweight,high specific strength and specific modulus.A new alloying strategy in this study is proposed to regulate its weak intrinsic interface and uncontrollable interfacial reaction.Our results show that Si element could hinder the dissolution and diffusion of carbon atoms in Al matrix,inhibiting Al-CNTs interface reaction.Grain refinement and dislocation increment induced by the reinforcements promote the contributions to the strength of AMCs.The wettability and interface bonding of Al-CNTs could be effectively improved by Al/Si/CNTs composite interface,the formed discontinuous strong interface is advantageous to coordinate the plastic deformation of AMCs.Si particles can also firmly fix CNTs through pinning effect during deformation,which leads to a better load transfer.Therefore,the tensile strength of Al-5Si-0.5CNTs composite can be enhanced up to 391 MPa while maintaining an acceptable plasticity of 7.5%.It brings the strengthening effect of CNTs into full play in AMCs and achieves the strengthening effect of 1+1>2 under the comprehensive effect of grain refinement strengthening,dislocation strengthening,dispersion strengthening of Si particles and load transfer to CNTs。

关键词： Aluminum matrix composites Interface regulation Microstructure Strengthening effect Mechanical properties

Characteristics and Insights of Offshore Oil and Gas Exploration and Development Investment

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China Oil & Gas 2024年第1期31卷 27-35页

作者： liu Mingming li shufeng Zhao lin China University of Petroleum Beijing China National Oil and Gas Exploration and Development Company Ltd.

The oceans'vast expanse has given rise to copious oil and gas resources,with recent years witnessing a steady unlocking of offshore oil and gas potential,positioning them as a key successor in global energy reserves.Currently,offshore oil and gas extraction constitutes nearly a third of the world's oil and gas output.This segment has evolved into a mutually beneficial ecosystem where operators and service providers collaborate closely around exploration and development activities.Investment in offshore oil and gas typically follows a dual "one-third’"pattern,reflecting high upfront costs but promising returns.It also underscores the stark variations in project viability and regional economic efficiency,with monopolistic traits seen at both national and corporate levels.Collaboration has emerged as a key tactic for resource-rich countries and oil companies to advance their offshore ventures.Given the distinct nature of offshore oil and gas development,Chinese oil companies are advised to seize opportunities in marine exploration,emphasize the coordination and planning abilities of the global supply chain,focus on the reserves of offshore oil and gas development technologies,as well as the capabilities of commercial talents and other forms of support,courageously pursue significant offshore assets,and effectively utilize global technology,equipment,and expertise,and rapidly build a competitive edge in offshore oil and gas projects.

关键词： companies venture offshore

Macrophage-mediated tumor-targeted delivery of engineered Salmonella typhimurium VNP20009 in anti-PD1 therapy against melanoma

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Acta Pharmaceutica Sinica B 2022年第10期12卷 3952-3971页

作者： Leyang Wu lin li shufeng li lina liu Wenjie Xin Chenyang li Xingpeng Yin Xuebo Xu Feifei Bao Zichun Hua The State Key Laboratory of Pharmaceutical Biotechnology School of Life SciencesNanjing UniversityNanjing 210023China Changzhou High-Tech Research Institute of Nanjing University and Jiangsu TargetPharma Laboratories Inc. Changzhou 213164China School of Biopharmacy China Pharmaceutical UniversityNanjing 210023China Key Laboratory of Developmental Genes and Human Disease in Ministry of Education Department of Biochemistry and Molecular BiologyMedical School of Southeast UniversityNanjing 210009China

Bacterial antitumor therapy has great application potential given its unique characteristics,including genetic manipulation, tumor targeting specificity and immune system modulation. However,the nonnegligible side effects and limited efficacy of clinical treatment limit their biomedical applications. Engineered bacteria for therapeutic applications ideally need to avoid their accumulation in normal organs and possess potent antitumor activity. Here, we show that macrophage-mediated tumor-targeted delivery of Salmonella typhimurium VNP20009 can effectively reduce the toxicity caused by administrating VNP20009 alone in a melanoma mouse model. This benefits from tumor-induced chemotaxis for macrophages combined with their slow release of loaded strains. Inspired by changes in the tumor microenvironment, including a decrease in intratumoral dysfunctional CD8+T cells and an increase in PDL1 on the tumor cell surface, macrophages were loaded with the engineered strain VNP-PD1nb, which can express and secrete anti-PD1 nanoantibodies after they are released from macrophages. This novel triple-combined immunotherapy significantly inhibited melanoma tumors by reactivating the tumor microenvironment by increasing immune cell infiltration, inhibiting tumor cell proliferation, remodeling TAMs to an M1-like phenotype and prominently activating CD8+T cells. These data suggest that novel combination immunotherapy is expected to be a breakthrough relative to single immunotherapy.

关键词： Macrophage Salmonella typhimurium VNP20009 Anti-PD1 nanobody Tumor-targeted delivery Immune activation

The Paleogene to Neogene climate evolution and driving factors on the Qinghai-Tibetan Plateau

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Science China Earth Sciences 2022年第7期65卷 1339-1352页

作者： Jiagang ZHAO shufeng li Alexander FARNSWORTH Paul J.VALDES Tammo REICHGELT linlin CHEN Zhekun ZHOU Tao SU CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303China University of Chinese Academy of Sciences Beijing 100049China Center of Plant Ecology Core Botanical GardensChinese Academy of SciencesMengla 666303China School of Geographical Sciences University of BristolBristol BS8 ISSUK Department of Geosciences University of ConnecticutStorrs CT 06269USA CAS Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming 650204China State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

The growth of the Qinghai-Tibetan Plateau(QTP)during the Cenozoic drove dramatic climate and environmental change in this region.However,there has been limited comprehensive research into evolution of climate during this interval.Here we present a quantitative reconstruction using Bioclimatic Analysis(BA)and Joint Probability Density Functions(JPDFs)based on data available for 48 fossil floras,including macrofossils and palynological fossils collected in the QTP area from the Paleogene to Neogene(66–2.58 Ma).Both methods indicate that there was an overall decline in temperature and precipitation.Paleoclimatic simulations using Hadley Centre Coupled Model version3(HadCM3)show that the most prominent climate change was very likely driven by QTP orographic evolution from the late Eocene,which was accompanied by a shift in temperature from a latitudinal distribution to a topographically controlled pattern.In addition,with the growth of the QTP,temperature and precipitation decreased gradually in the northeastern part of the plateau.Different sources of evidence,including plant fossil records,climate simulations and other proxies,indicate that the topographic evolution of the QTP and other geological events,in conjunction with global cooling,may have been the main factors driving climate change in this region.This research can provide insights into Cenozoic environmental change and ecosystem evolution.

关键词： Qinghai-Tibetan Plateau Cenozoic Paleoclimate Plant fossil Climate modelling

Microstructure,Phase Transformation,Precipitation Behavior and Mechanical Properties of P/M Cu40Zn-1.0 wt%Ti Brass Alloy via Spark Plasma Sintering and Hot Extrusion

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Journal of Materials Science & Technology 2013年第11期29卷 1018-1024页

作者： shufeng li Hisashi Imai Katsuyoshi Kondoh Faculty of Materials Science and Engineering Xi'an University of Technology Joining and Welding Research Institute Osaka University

The effect of titanium addition on the microstructure and mechanical properties of brass Cu4OZn has been studied via the powder metallurgy （P/M） route. The water-atomized Cu4OZn-1.0 wt% Ti alloy powder was consolidated at different temperatures in the range of 400-600℃ using spark plasma sintering （SPS） and hot extrusion subsequently. Results show that the super-saturated solid solution titanium element in rapidly cooled brass Cu4OZn powder created high chemical potential for a precipitate reaction, showing significant grain refinement effects on the consolidated Cu4OZn matrix. Consequently, excellent mechanical properties were obtained by precipitation hardening and work hardening after sintering and extrusion, with yield strength of 390 MPa, ultimate tensile strength of 617 MPa, and Vickers micro-hardness of 192 HV, which are 28.7%, 23.4%, and 23.9% higher values than those of extruded Cu4OZn brass, respectively.

关键词： Brass Spark plasma sintering Extrusion Microstructure Mechanical property Precipitation Phase transformation

Late Eocene sclerophyllous oak from Markam Basin, Tibet, and its biogeographic implications

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Science China Earth Sciences 2021年第11期64卷 1969-1981页

作者： linlin CHEN Weiyudong DENG Tao SU shufeng li Zhekun ZHOU Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303China Key Laboratory of Biodiversity and Biogeography Kunming Institute of BotanyChinese Academy of SciencesKunming 650204China University of Chinese Academy of Sciences Beijing 100049China Center of Plant Ecology Core Botanical GardensChinese Academy of SciencesMengla 666303China

Sclerophyllous evergreen broad-leaved forests,mainly made up of sclerophyllous oak,Quercus section Heterobalanus(Øerst.)Menitsky,Fagaceae,represent the most typical forest type in the Hengduan Mountains.Their distribution pattern is closely related to the growth and formation of the Qinghai-Tibetan Plateau(QTP).The oldest fossil record of Quercus sect.Heterobalanus so far discovered is from the middle Miocene of the Gazhacun Formation in Namling County,southern Tibet.However,our recent discovery of leaf fossils from the upper Eocene of Lawula Formation in Markam Basin,southeastern Tibet,illustrates that their origin is nearly 20 Myr older than previously assumed.By integrating the results from geometric morphometrics,geographical range expansion,and ecological niche shifts of this section in what is now the QTP and the Hengduan Mountains,we infer that the leaves of Quercus sect.Heterobalanus were already adapted to cool and dry conditions in some local regions no later than in the late Eocene.Then,with the growth of the QTP and late Cenozoic global cooling,the expansion of cooler and drier habitats benefited the spread and development of this section and their leaves exhibited morphological stasis through stabilizing selection.Based on published fossil records and recent discoveries,we argue that Quercus sect.Heterobalanus appeared in the subtropical evergreen and deciduous broad-leaved mixed forests of the southeastern margin of what is now the QTP no later than in the late Eocene.Some taxa spread westwards along the Gangdese Mountains and later the Himalaya,and others spread eastwards and southeastwards,gradually becoming a dominant group of species in the Hengduan Mountains.This dispersal route is contrary to the previous“northwards hypothesis”of this section,and further supports the hypothesis of an East Asian origin for Quercus section Ilex Loudon.

关键词： Quercus section Heterobalanus Cenozoic Qinghai-Tibetan Plateau Geometric Morphometrics Morphological Evolutionary Stasis Biogeography