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Seedling dynamics differ between canopy species and understory species in a tropical seasonal rainforest,SW China

Plant Diversity 2024年第5期46卷 671-677页

作者： Libing Pan Xiaoyang Song wenfu zhang Jie Yang Min Cao CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglunMengla 666303YunnanChina College of Life Sciences University of Chinese Academy of SciencesBeijing 100049China

We used 11 years of census data from 450 seedling quadrats established in a 20-ha forest dynamics plot to study seedling dynamics in tree species of a tropical seasonal rainforest in Xishuangbanna,southwestern *** found that overall seedling recruitment rate and relative growth rate were higher in the rainy season than in the dry *** the recruitment rate of seedlings from canopy tree species(two species)and the relative growth rate of seedlings from understory species(nine species)were higher in the rainy season than in the dry ***,in the rainy season,the recruitment rate of seedlings was higher for canopy tree species than for understory tree *** addition,relative growth rate of seedlings was higher in the canopy species than in understory seedlings in the dry *** also observed that,in both rainy and dry seasons,mortality rate of seedlings was higher for canopy species than for understory ***,canopy tree species appear to have evolved a flexible strategy to adapt to the seasonal changes of a monsoon *** contrast,understory tree species seem to have adopted a conservative ***,these species mainly release seedlings in the rainy season and maintain relatively stable populations with a lower mortality rate and recruitment rate in both dry and rainy *** study suggests that canopy and understory seedling populations growing in forest understory may respond to future climate change scenarios with distinct regeneration strategies.

关键词： Tropical forest Tree seedling Seasonality Recruitment Mortality Relative growth rate

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Design principles and parameters of rice ideal panicle type

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Chinese Science Bulletin 2005年第19期50卷 2253-2256页

作者： XU Zhengjin CHEN wenfu zhang Longbu YANG Shouren Rice Institute of Shenyang Agricultural University Key Laboratory ofCrop Physiology Ecology Genetics and Breeding Ministry of Agricul-ture Key Laboratory of Northern Japonica Rice Breeding of LiaoningShenyang 110161

On the basis of many years of research at the laboratory, and by making reference to the related literature published at home and abroad, in this paper the concept of rice ideal panicle type was introduced, and the principles of rice ideal panicle type design were elucidated. The parame-ters of rice ideal panicle type for Liaoning were preliminarily established as follows: Panicle length 2 mm, large vascular bundle and primary branch >15 pieces/panicle, primary branch grain >80 grains/panicle, secondary branch grains concentrating in the middle and upper parts of panicle axis, and panicle type index >0.5. In addition, the possibility of achieving unity of grain yield and quality at a still higher level by creating an ideal panicle type was explored.

关键词：水稻圆锥花序茎直径种植技术

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Advances in soliton microcomb generation

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Advanced Photonics 2020年第3期2卷 2-28页

作者： Weiqiang Wang Leiran Wang wenfu zhang Chinese Academy of Sciences Xi’an Institute of Optics and Precision MechanicsState Key Laboratory of Transient Optics and PhotonicsXi’anChina University of Chinese Academy of Sciences BeijingChina

Optical frequency combs,a revolutionary light source characterized by discrete and equally spaced frequencies,are usually regarded as a cornerstone for advanced frequency metrology,precision spectroscopy,high-speed communication,distance ranging,molecule detection,and many *** to the rapid development of micro/nanofabrication technology,breakthroughs in the quality factor of microresonators enable ultrahigh energy buildup inside cavities,which gives birth to microcavity-based frequency *** particular,the full coherent spectrum of the soliton microcomb(SMC)provides a route to low-noise ultrashort pulses with a repetition rate over two orders of magnitude higher than that of traditional mode-locking *** enables lower power consumption and cost for a wide range of *** review summarizes recent achievements in SMCs,including the basic theory and physical model,as well as experimental techniques for single-soliton generation and various extraordinary soliton states(soliton crystals,Stokes solitons,breathers,molecules,cavity solitons,and dark solitons),with a perspective on their potential applications and remaining challenges.

关键词： optical frequency comb soliton microcomb microcavity photonic integration Kerr effect four-wave mixing

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Scalable parallel ultrafast optical random bit generation based on a single chaotic microcomb

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Light(Science & Applications) 2024年第4期13卷 637-644页

作者： Pu Li Qizhi Li Wenye Tang Weiqiang Wang wenfu zhang Brent ELittle Sai Tek Chu KAlan Shore Yuwen Qin Yuncai Wang Institute of Advanced Photonics Technology School of Information EngineeringGuangdong University of TechnologyGuangzhou 51006China. Key Laboratory of Photonic Technology for Integrated Sensing and Communication Ministry of Education of ChinaGuangdong University of TechnologyGuangzhou 51006China. Guangdong Provincial Key Laboratory of Information Photonics Technology Guangdong University of TechnologyGuangzhou 51006China. Key Laboratory of Advanced Transducers andIntelligent Control System Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024China. State Key Laboratory of Transient Optics and Photonics Xi’an Institute of Optics and Precision MechanicsChinese Academy of SciencesXi’an 710119China. Department of Physics and Materials Science City University of Hong KongHong KongChina. School of Electronic Engineering Bangor UniversityBangorWales LL571UTUK

Random bit generators are critical for information security,cryptography,stochastic modeling,and *** and scalability are key challenges faced by current physical random bit ***,we propose a massively parallel scheme for ultrafast random bit generation towards rates of order 100 terabit per second based on a single micro-ring resonator.A modulation-instability-driven chaotic comb in a micro-ring resonator enables the simultaneous generation of hundreds of independent and unbiased random bit streams.A proof-of-concept experiment demonstrates that using our method,random bit streams beyond 2 terabit per second can be successfully generated with only 7 comb *** bit rate can be easily enhanced by further increasing the number of comb lines *** approach provides a chip-scale solution to random bit generation for secure communication and high-performance computation,and offers superhigh speed and large scalability.

关键词： resonator random chaotic

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Scanning dual-microcomb spectroscopy

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Science China(Physics,Mechanics & Astronomy) 2022年第9期65卷 65-71页

作者： Yang Wang Zhichuang Wang Xinyu Wang Wen Shao Long Huang Bo Liang Brent ELittle Sai TChu Wei Zhao Weiqiang Wang wenfu zhang State Key Laboratory of Transient Optics and Photonics Xi’an Institute of Optics and Precision MechanicsChinese Academy of SciencesXi’an 710119China University of Chinese Academy of Sciences Beijing 100049China Department of Physics and Materials Science City University of Hong KongHong Kong 999077China

Dual-comb spectroscopy(DCS) is a powerful tool in molecular spectroscopy benefiting from the advantages of high resolution and short measurement time. The recently developed soliton microcomb(SMC) can potentially transfer the dual-comb method to an on-chip platform. In this paper, we demonstrate DCS using two frequency scanning SMCs, termed scanning dual-microcomb spectroscopy(SDMCS). The two SMCs are generated by an auxiliary-assisted thermal balance scheme, and the pump laser frequency sweeps over one free spectral range of the microresonator(~49 GHz) using a feedback control system. The proposed SDMCS has a spectral resolution of 12.5 MHz, which is determined by the minimum sweeping step of the pump laser. Using this SDMCS system, we perform three types of gas molecule absorption spectroscopy recognition and gas concentration *** study paves the way for integrated DCS with a high signal-to-noise ratio, high spectral resolution, and fast acquisition rate.

关键词： microresonator soliton microcomb dual-comb spectroscopy molecular spectroscopy gas sensing

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Ultra-high-linearity integrated lithium niobate electro-optic modulators

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Photonics Research 2022年第10期10卷 2366-2373页

作者： HANKE FENG KE zhang WENZHAO SUN YANGMING REN YIWEN zhang wenfu zhang CHENG WANG Department of Electrical Engineering&State Key Laboratory of Terahertz and Millimeter Waves City University of Hong KongKowloonHong KongChina State Key Laboratory of Transient Optics and Photonics Xi’an Institute of Optics and Precision MechanicsChinese Academy of SciencesXi’an 710119China University of Chinese Academy of Sciences Beijing 100049China

Integrated lithium niobate(LN)photonics is a promising platform for future chip-scale microwave photonics systems owing to its unique electro-optic properties,low optical loss,and excellent scalability.A key enabler for such systems is a highly linear electro-optic modulator that could faithfully convert analog electrical signals into optical *** this work,we demonstrate a monolithic integrated LN modulator with an ultra-high spurious-free dynamic range(SFDR)of 120.04 dB·Hz^(4/5)at 1 GHz,using a ring-assisted Mach–Zehnder interferometer *** excellent synergy between the intrinsically linear electro-optic response of LN and an optimized linearization strategy allows us to fully suppress the cubic terms of third-order intermodulation distortions(IMD3)without active feedback controls,leading to∼20 dB improvement over previous results in the thin-film LN *** ultra-high-linearity LN modulators could become a core building block for future large-scale functional microwave photonic integrated circuits by further integration with other high-performance components like low-loss delay lines,tunable filters,and phase shifters available on the LN platform.

关键词： modulator interferometer lithium

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Overstory functional groups indicate the legacy of land use in a secondary tropical forest in southwestern China

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Journal of Forestry Research 2024年第5期35卷 91-105页

作者： Yun Deng wenfu zhang Min Cao Jinlong Dong Hui Chen Xiaobao Deng Jiajia Liu Xiaoyang Song Shangwen Xia Liqing Sha Shengdong Yuan Luxiang Lin CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303People’s Republic of China Center for Plant Ecology Core Botanical GardensChinese Academy of SciencesMengla 666303People’s Republic of China National Forest Ecosystem Research Station at Xishuangbanna Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303People’s Republic of China Department of Life Sciences Fudan UniversityShanghai 570228People’s Republic of China Department of Life Sciences University of Chinese Academy of SciencesBeijing 100049People’s Republic of China

Anthropogenic disturbances are widespread in tropical forests and influence the species composition in the ***,the impacts of historical disturbance on tropical forest overstory recovery are unclear due to a lack of disturbance data,and previous studies have focused on understory *** this study,the purpose was to deter-mine the influence of historical disturbance on the diver-sity,composition and regeneration of overstory species in present *** the 20-ha Xishuangbanna tropical sea-sonal rainforest dynamics plot in southwestern China,the historical disturbance boundaries were delineated based on panchromatic photographs from *** that drove species clustering in the overstory layer(DBH≥40 cm)were analyzed and the abundance,richness and composition of these species were compared among different tree groups based on multiple regression tree *** coefficient of variation of the brightness value in historical panchro-matic photographs from 1965 was the primary driver of spe-cies clustering in the overstory *** abundance and richness of overstory species throughout the regeneration process were similar,but species composition was always *** the proportion of large-seeded and vigorous-sprouting species showed no significant differ-ence between disturbed and undisturbed forests in the tree-let layer(DBH<20 cm),the difference became significant when DBH *** findings highlight that historical disturbances have strong legacy effects on functional group composition in the overstory and the recovery of overstory species was *** group composi-tion can better indicate the dynamics of overstory species replacement during secondary succession.

关键词： Historical disturbance Legacy effects Secondary forests Overstory species Functional groups

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Effects of Repetitive TranscranialMagnetic Stimulation on Upper Extremity Function in Acute Stroke:A Meta-analysis and Systematic Review

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Medicinal Plant 2024年第5期15卷 50-53页

作者： Chenyang ZHENG wenfu zhang Bao zhang Department of Hydrotherapy and Physiotherapy RehabilitationMedicine CenterTaihe HospitalHubei University of MedicineShiyan 434021China Department of Pediatric Rehabilitation Rehabilitation Medicine CenterTaihe HospitalHubei University of MedicineShiyan 434021China

[Objectives]To conduct a comprehensive examination of the evidence-based impact of repetitive transcranial magnetic stimulation(rTMS)on upper extremity functionality in patients with acute stroke.[Methods]A rigorous and systematic electronic search was conducted across the Medline,PubMed,and Web of Science databases,encompassing literature up to July 1,*** ensure the reliability of the in-cluded studies,an assessment of their risk of bias was conducted using RevMan 5.4 software,in accordance with the rigorous standards out-lined in the Cochrane Handbook for Systematic ***,we employed either the random-effects model or the fixed-effects model,depending on the heterogeneity of the data,to estimate the standardized mean difference(SMD)in outcomes,utilizing Stata 18.0 software for statistical analysis.[Results]Our review encompassed a total of five studies,involving 252 patients with acute *** pooled analysis of these studies revealed a statistically significant improvement in Fugl-Meyer Assessment of the Upper Extremity(FMA-UE)scores among pa-tients who received rTMS therapy(SMD=2.71,95%CI:0.85 to 4.56;P<0.0001),albeit with considerable heterogeneity(I^(2)=97.65%)across the trials.[Conclusions]The results of this systematic review and meta-analysis underscore the promising potential of rTMS in enhancing upper extremity function in patients who have experienced an acute *** findings provide compelling evidence for the therapeutic benefits of rTMS in this patient population.

关键词： Acute stroke rTMS Upper extremity function Meta-analysis

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Emerging material platforms for integrated microcavity photonics

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Science China(Physics,Mechanics & Astronomy) 2022年第10期65卷 10-28页

作者： Jin Liu Fang Bo Lin Chang Chun-Hua Dong Xin Ou Blake Regan Xiaoqin Shen Qinghai Song Baicheng Yao wenfu zhang Chang-Ling Zou Yun-Feng Xiao State Key Laboratory of Optoelectronic Materials and Technologies School of PhysicsSun Yat-sen UniversityGuangzhou 510000China MOE Key Laboratory of Weak-Light Nonlinear Photonics TEDA Institute of Applied Physics and School of PhysicsNankai UniversityTianjin 300071China State Key Laboratory of Advanced Optical Communications System and Networks School of ElectronicsPeking UniversityBeijing 100871China CAS Key Lab of Quantum Information University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Functional Material for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China School of Mathematical and Physical Sciences University of Technology SydneyUltimo 2007Australia School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information System Harbin Institute of TechnologyShenzhen 518055China Key Laboratory of Optical Fiber Sensing and Communications(Ministry of Education) University of Electronic Science and Technology of ChinaChengdu 611731China State Key Laboratory of Transient Optics and Photonics Xi’an Institute of Optics and Precision MechanicsChinese Academy of SciencesXi’an 710119China State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics School of PhysicsPeking UniversityBeijing 100871China

Many breakthroughs in technologies are closely associated with the deep understanding and development of new material *** the main material used in microelectronics,Si also plays a leading role in the development of integrated *** indirect bandgap,absence ofχ(2)nonlinearity and the parasitic nonlinear absorptions at the telecom band of Si imposed technological bottlenecks for further improving the performances and expanding the functionalities of Si microcavities in which the circulating light intensity is dramatically *** past two decades have witnessed the burgeoning of the novel material platforms that are compatible with the complementary metal-oxide-semiconductor(COMS)*** particular,the unprecedented optical properties of the emerging materials in the thin film form have resulted in revolutionary progress in microcavity *** this review article,we summarize the recently developed material platforms for integrated photonics with the focus on chip-scale microcavity *** material characteristics,fabrication processes and device applications have been thoroughly discussed for the most widely used new material *** also discuss open challenges and opportunities in microcavity photonics,such as heterogeneous integrated devices,and provide an outlook for the future development of integrated microcavities.

关键词： microcavity integrated optics nonlinear optics

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Generation of coexisting high-energy pulses in a mode-locked all-fiber laser with a nonlinear multimodal interference technique

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Photonics Research 2019年第2期7卷 187-192页

作者： GUANGWEI CHEN WENLEI LI GUOMEI WANG wenfu zhang CHAO ZENG WEI ZHAO State Key Laboratory of Transient Optics and Photonics Xi’an Institute of Optics and Precision MechanicsChinese Academy of Sciences University of Chinese Academy of Sciences (UCAS)

We demonstrate a passively mode-locked all-fiber laser incorporating a piece of graded-index multimode fiber as a mode-locking modulator based on a nonlinear multimodal interference technique, which generates two types of coexisting high-energy ultrashort pulses [i.e., the conventional soliton(CS) and the stretched pulse(SP)]. The CS with pulse energy as high as 0.38 n J is obtained at the pump level of 130 mW. When the pump increases to175 mW, the high-energy SP occurs at a suitable nonlinear phase bias and its pulse energy can reach 4 n J at a 610 mW pump. The pulse durations of the generated CS and SP are 2.3 ps and 387 fs, respectively. The theory of nonlinear fiber optics, single-shot spectral measurement by the dispersive Fourier-transform technique, and simulation methods based on the Ginzburg–Landau equation are provided to characterize the laser physics and reveal the underlying principles of the generated CS and SP. A rogue wave, observed between the CS and SP regions, mirrors the laser physics behind the dynamics of generating a high-energy SP from a CS. The proposed all-fiber laser is versatile, cost-effective and easy to integrate, which provides a promising solution for high-energy pulse generation.

关键词： Generation high-energy pulses

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