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High-performance distributed feedback quantum dot lasers with laterally coupled dielectric gratings

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Photonics Research 2022年第5期10卷 1271-1279页

作者： ZHUOHUI YANG ZHENGQING DING LIN LIU HANCHENG ZHONG SHENG CAO xinzhong zhang SHIZHE LIN XIAOYING HUANG HUADI DENG YING YU SIYUAN YU State Key Laboratory of Optoelectronic Materials and Technologies School of Electronics and Information TechnologySun Yat-sen UniversityGuangzhou 510275China

The combination of grating-based frequency-selective optical feedback mechanisms,such as distributed feedback(DFB)or distributed Bragg reflector(DBR)structures,with quantum dot(QD)gain materials is a main approach towards ultrahigh-performance semiconductor lasers for many key novel applications,as either stand-alone sources or on-chip sources in photonic integrated circuits.However,the fabrication of conventional buried Bragg grating structures on GaAs,GaAs/Si,GaSb,and other material platforms has been met with major material regrowth difficulties.We report a novel and universal approach of introducing laterally coupled dielectric Bragg gratings to semiconductor lasers that allows highly controllable,reliable,and strong coupling between the grating and the optical mode.We implement such a grating structure in a low-loss amorphous silicon material alongside GaAs lasers with InAs/GaAs QD gain layers.The resulting DFB laser arrays emit at pre-designed 0.8 THz local area network wavelength division multiplexing frequency intervals in the 1300 nm band with record performance parameters,including sidemode suppression ratios as high as 52.7 dB,continuous-wave output power of 26.6 mW(room temperature)and 6 mW(at 55℃),and ultralow relative intensity noise(RIN)of<-165 dB/Hz(2.5-20 GHz).The devices are also capable of isolator-free operating under very high external reflection levels of up to-12.3 dB while maintaining high spectral purity and ultralow RIN qualities.These results validate the novel laterally coupled dielectric grating as a technologically superior and potentially cost-effective approach for fabricating DFB and DBR lasers free of their semiconductor material constraints,which are thus universally applicable across different material platforms and wavelength bands.

关键词： dielectric performance quantum

Niche differentiation shapes the bacterial diversity and composition of apple

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Horticultural Plant Journal 2023年第1期9卷 35-44页

作者： Yimei Huang Xiaofen Chai Xiaona Wang Beibei Gao Hui Li Zhenhai Han Xuefeng Xu xinzhong zhang Ting Wu Yi Wang College of Horticulture China Agricultural UniversityBeijing100193China

Microorganisms play an important role in plant growth,health and ecological function.It is necessary to explore the microbial community because of the significant ecological and economic value of apples(Malus x domestica).However,the related bacterial communities in different ecological habitats are not clear in the unique scion/rootstock combinations of apples.In this study,the Illumina Miseq platform was used to analyze the bacterial communities in different niches(bulk soil,rhizosphere soil and roots)of two scion/rootstock combinations[Fuji/Malus xiaojinensis Cheng et Jiang(Mx)and Fuji/Malus baccata(L.)Borkh.(Mb)].The relationship between the microbial community,soil properties,and plant characters was explored.The results showed that the diversity of the bacterial community decreased from bulk soil to rhizosphere soil and then to roots.In addition,at the phylum level,Proteobacteria,Actinobacteria and Acitinobacteria were dominant and had notable divergence in different ecological niches.Distinct niches had remarkable effects on the diversity and composition of the bacterial community according to PCoA.The rootstock genotype had an effect on the bacterial composition but no effect on the diversity.pH,soil organic matter(SOM),alkaline hydrolyzable nitrogen(AN)were the main factor affecting the structure of bacterial community in rhizosphere soil,as shown by Pearson analysis.Bacteria taxa in the roots were affected by starch,fructose,sucrose and sorbitol.This study showed the microbial community structure in different ecological niches of different scion/rootstock combinations and provided some evidence for understanding the microbial-plant interaction of apple rootstocks.

关键词： Apple Microbial community Rootstock genotype Ecology niche

ERF4 affects fruit ripening by acting as a JAZ interactor between ethylene and jasmonic acid hormone signaling pathways

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Horticultural Plant Journal 2022年第6期8卷 689-699页

作者： Yanan Hu Hualin Sun Zhenyun Han Shuai Wang Ting Wang Qiqi Li Ji Tian Yi Wang xinzhong zhang Xuefeng Xu Zhenhai Han Ting Wu State Key Laboratory of Agrobiotechnology College of HorticultureChina Agricultural UniversityBeijing 100193China Plant Science and Technology College Beijing University of AgricultureBeijing 102206China

The regulation of apple(Malus domestica)fruit texture during ripening is complex and a fundamental determinant of its commercial quality.In climacteric fruit,ripening-related processes are regulated by ethylene(ET),and jasmonate(JA)is also involved in the ethylene biosynthesis pathway,mainly through the transcription factor MYC2.However,the molecular genetic mechanism for fruit ripening processes between the JA and ET signaling pathways still needs to be elucidated.In order to explore how JA regulates apple fruit ripening through ERF4,we used’Gala’and’Ralls Janet’fruit at different developmental stages as experimental materials to determine the fruit firmness and related gene expression analysis.Meanwhile,we carried out different hormone treatments on’Gala’fruit at ripening stage.Here,we show that ERF4 is a core JA signaling hub protein JASMONATE ZIM-DOMAIN(JAZ)interactor that affects ethylene signaling pathways.During fruit development,ERF4 represses the expression of ACS1 and ACO1 by interacting with JAZ,as well as with the JA-activated transcription factor MYC2.Ripening is promoted in JAZ-suppressed apples.Thus,ERF4 acts as a molecular link between ethylene and JA hormone signals,and the natural variation of the ERF4Ethylene-responsive binding factor-associated amphiphilic repression(EAR)motif decreases repression of ethylene biosynthesis genes.

关键词： Apple ERF4 Ethylene Fruit ripening JAZ

Genome-wide identification and characterization of the IPT family members in nine Rosaceae species and a functional analysis of MdIPT5b in cold resistance

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Horticultural Plant Journal 2023年第4期9卷 616-630页

作者： Yi Feng Jiahong Lv Mengqun Peng Jie Li Yue Wu Min Gao Xinyi Wu Yi Wang Ting Wu xinzhong zhang Xuefeng Xu Zhenhai Han College of Horticulture China Agricultural UniversityBeijing100193China State Key Laboratory of Plant Physiology and Biochemistry College of Biological SciencesChina Agricultural UniversityBeijing100193China

Cytokinins are members of a group of phytohormones involved in various growth and developmental processes in plants.Isopentenyl transferase(IPT)is the rate-limiting enzyme in catalyzing the biosynthesis of cytokinins.In this study,to understand the role of IPT family in cold resistance,78 IPT candidates were identified and characterized in nine Rosaceae genomes.The expansion of IPT families in the Rosaceae primarily occurred through segmental duplication rather than tandem duplication.In general,purifying selection controlled the evolution of IPT families in the Rosaceae,with IPT3 and IPT5 homologs as the primary drivers of evolution.Cis-elements,which are involved in the responses to many environmental stresses or phytohormone signals,were identified in the promoters of MdIPT members.This was consistent with the trends of expression of the MdIPT genes in apple(Malus domestica)calli.MdIPT5b was also found to exhibit multiple responses to phytohormones and stress signals.The ectopic expression of MdIPT5b resulted in an increase in cold resistance in transformed apple calli and tomato(Solanum lycopersicum)plantlets.The redox balance was partially stabilized through the accumulation of proline under cold stress.However,the ascorbate–glutathione cycle cannot be stabilized in the cold.All physiological and biochemical assays are preformed in spectrophotometer.These results showed that regulating the expression of IPT genes for moderate cytokinin improvement could enhance the accumulation of proline to stabilize the osmotic and redox balances to improve resistance to cold stress.

关键词： Rosaceae Apple Isopentenyl transferase Cytokinin Cold stress Bioinformatics

A paleo-hydrological simulation experiment and its verification in an inland basin

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Research in Cold and Arid Regions 2019年第4期11卷 267-282页

作者： YuXin zhang Yu Li xinzhong zhang ChengQi zhang WangTing Ye Yuan Liu Key Laboratory of Western China's Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesCenter for Hydrologic Cycle and Water Resources in Arid RegionLanzhou UniversityLanzhouGansu 730000China Key Laboratory of Ecohydrology of Inland River Basin/Gansu Hydrology and Water Resources Engineering Research Center Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhouGansu 730000China

Hydrological circulation,as the most basic material cycle and active natural phenomenon on earth,exerts a significant in fluence on climate change.The mid-Holocene is an important period to better understand modern environmental change;however,little research has focused on its quantitative simulation of paleo-hydrological process.In this research,we first collected chronological evidence and sediment records from six Holocene sedimentary sections in the Shiyang River Ba sin to reconstruct the mid-Holocene environment and terminal paleo-lake area.Secondly,we comprehensively analyzed modern pollen combinations and their propagation characteristics in surface soil,air,river and lacustrine sediments in the Shiyang River Basin,and combined the pollen records,as well as quantitatively reconstructed the millennial-scale vegeta tion zones.Finally,based on the land-cover adjustment results during the mid-Holocene,we successfully used the Soil and Water Assessment Tool(SWAT)model,a modern distributed hydrological watershed model,to simulate mid-Holocene runoff in the basin.Results show that the reconstructed climate in the basin was warmer and moister than that in recent times.Vegetation types in the mid-Holocene mainly consisted of sub-alpine shrub distributed between 2,550 m and 2,750 m,forest at an elevation of 2,550 2,750 m,steppe at an elevation of 1,550 2,150 m and desert steppe below 1,550 m.The up stream,midstream,downstream and average annual runoff of the mid-Holocene in the basin were 16.76×10^8 m^3,22.86×10^8 m^3,9.00×10^8 m^3 and 16.20×10^8 m^3 respectively,compared to 15.61×10^8 m^3 of modern annual runoff.Also,the area of terminal paleo-lake in the mid-Holocene was 628 km^2.Thus,this study provides a new quantitative method for paleo-hy drological simulation.

关键词： SWAT model inland basin vegetation reconstruction runoff simulation mid-Holocene

Reprogramming of phytopathogen transcriptome by a non-bactericidal pesticide residue alleviates its virulence in rice

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Fundamental Research 2022年第2期2卷 198-207页

作者： Haruna Matsumoto Yuan Qian Xiaoyan Fan Sunlu Chen Yanxia Nie Kun Qiao Dandan Xiang xinzhong zhang Meng Li Bo Guo Peilin Shen Qiangwei Wang Yunlong Yu Tomislav Cemava Mengcen Wang State Key Laboratory of Rice Biology&Ministry of Agricultural and Rural Affairs Laboratory of Molecular Biology of Crop Pathogens and Insects Institute of Pesticide and Environmental ToxicologyZhejiang UniversityHangzhou 310058China Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province College of Agriculture and BiotechnologyZhejiang UniversityHangzhou 310058China Institute of Environmental Biotechnology Graz University of TechnologyPetersgasse 128010 GrazAustria Global Education Program for AgriScience Frontiers Graduate School of AgricultureHokkaido UniversitySapporo 0608589Japan State Key Laboratory of Crop Genetics and Germplasm Enhancement Nanjing Agricultural UniversityNanjing 210095China Ecology and Environmental Sciences Center South China Botanical GardenChinese Academy of SciencesGuangzhou 510650China Key laboratory of South Subtropical Fruit Biology and Genetic Resource Uilization(MOA) Instiute of Fruit Tree ResearchGuangdong Acadermy of Agricultural SciencesGuangzhou 510640China Tea Research Instiute Chinese Academy of Agriculural SciencesHangzhou 310008China Shanghai Intermnational Studies University Shanghai 200083China Xiaoshan Agricultural Comprehensive Development Zone&Management Committee Hangzhou 311200China

Bacteria equipped with virulence systems based on highly bioactive small molecules can circumvent their host's defense mechanisms.Pathogens employing this strategy are currently threatening global rice production.In the present study,variations in the virulence of the highly destructive Barkholderiaplantarii were observed in different rice-producing regions.The environment-linked variation was not attributable to any known host-related or external factors.Co-occurrence analyses indicated a connection between reduced virulence and 5-Amino-l,3,4-thiadiazole-2-thiol(ATT),a non-bactericidal organic compound.ATT,which accumulates in rice plants during metabolization of specific agrochemicals,was found to reduce virulence factor secretion by B.plantarii up to 88.8%and inhibit pathogen virulence by hijacking an upstream signaling cascade.Detailed assessment of the newly discovered virulence inhibitor resulted in mechanistic insights into positive effects of ATT accumulation in plant tissues.Mechanisms of virulence alleviation were deciphered by integrating high-throughput data,gene knockout mutants,and molecular interaction assays.TroK,a histidine protein kinase in a two-component system that regulates virulence factor secretion,is likely the molecular target antagonized by ATT.Our findings provide novel insights into virulence modulation in an important plant-pathogen system that relies on the host's metabolic activity and subsequent signaling interference.

关键词： Phytopathogen Virulence factor Transcriptome reprogramming Agrochemical Pesticide Rice

Holocene lake carbon sequestration, hydrological status and vegetation change, China

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Research in Cold and Arid Regions 2019年第4期11卷 295-326页

作者： LingMei Xu Yu Li WangTing Ye xinzhong zhang YiChan Li YuXin zhang Key Laboratory of Western China’s Environmental Systems (Ministry of Education) College of Earth and Environmental Sciences Center for Hydrologic Cycle and Water Resources in Arid Region Lanzhou University

Lakes have received considerable attention as long-term sinks for organic carbon(C)at regional and global scales.Previ ous studies have focused on assessment and quantification of carbon sinks,and few have worked on the relationship be tween millennial-scale lake C sequestration,hydrological status and vegetation,which has important scientific signifi cance in improving our understanding of lake C stocks and storage mechanisms.Here,we present a comprehensive study of pollen records,organic geochemical proxies,lake-level records,sediment accumulation rate(SAR)and organic C accu mulation rate(CAR)in China since the Holocene.We also include numerical climate classification and lake-level simula tions,to investigate variations of lake C sequestration,hydrological status and vegetation during the Holocene.Results in dicate that the evolution of lake C accumulation showed an out-of-phase relationship with hydrological status and vegeta tion in China.Lake C accumulation exhibited an overall trend of increasing from the early to late Holocene in response to gradually increasing terrestrial organic matter input.However,China as a whole experienced the densest vegetation cover in the middle Holocene,corresponding to the mid-Holocene optimum of a milder and wetter climate.Optimal hydrologi cal conditions were asynchronous in China;for example,early Holocene in Asian monsoon dominated areas,and middle Holocene in westerlies controlled regions.Our synthesis indicated that climate change was the main factor controlling the long-term variability in lake C accumulation,hydrologic conditions,as well as vegetation,and human influences were usu ally superimposed on the natural trends.

关键词： lake sediment millennial-scale organic carbon accumulation lake hydrological status vegetation climate change

A continuous simulation of Holocene effective moisture change represented by variability of virtual lake level in East and Central Asia

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Science China Earth Sciences 2020年第8期63卷 1161-1175页

作者： Yu LI Yuxin zhang xinzhong zhang Wangting YE Lingmei XU Qin HAN Yichan LI Hebin LIU Simin PENG Key Laboratory of Western China s Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesCenter for Hydrologic Cycle and Water Resources in Arid RegionLanzhou UniversityLanzhou 730000China

The fluctuation of a single lake level is a comprehensive reflection of water balance within the basin, while the regional consistent fluctuations of lake level can indicate the change of regional effective moisture. Previous researches were mainly focused on reconstructing effective moisture by multiproxy analyses of lake sediments. We carried out a series of experiments, including a transient climate evolution model, a lake energy balance model and a lake water balance model to simulate continuous Holocene effective moisture change represented by variability of virtual lake level in East and Central Asia.The virtual lake level, area, water depth and salinity are not equivalent to actual values, but we estimated relative changes of the regional effective moisture. We also explored the driving mechanisms of effective moisture change in different geographical regions. Our results indicated that gradually falling effective moisture during the Holocene in northern China was due to the combined effects of high lake evaporation caused by longwave and shortwave radiation, and low precipitation caused by reductions of summer solar insolation. A decline in effective moisture through the Holocene in the Tibetan Plateau and southern Central Asia resulted from decreased precipitation because of the weakening of the Asian summer monsoon. Increased precipitation induced by the strengthening of the westerly circulation contributed to the effective moisture rise during the Holocene in northern Central Asia.

关键词： Effective moisture Virtual lake level Continuous simulation Holocene Solar radiation

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茶叶中手性农药残留分析与风险评估研究进展

茶叶科学 2024年第3期44卷 363-385页

作者：胡月宁亚婷黎洪霞罗逢健尹荣秀张新忠中国农业科学院茶叶研究所浙江杭州310008 中国农业科学院研究生院北京100081 贵州省农业科学院茶叶研究所贵州贵阳550006

手性农药存在一个或多个对映体,其对映体在生物活性、毒性、环境行为、降解代谢等方面可能存在差异。茶叶作为三大无酒精饮品之一,其质量安全问题备受关注。虽然目前更关注手性农药外消旋体残留总量,但随着分析技术的发展,同时为了更好... 详细信息

手性农药存在一个或多个对映体,其对映体在生物活性、毒性、环境行为、降解代谢等方面可能存在差异。茶叶作为三大无酒精饮品之一,其质量安全问题备受关注。虽然目前更关注手性农药外消旋体残留总量,但随着分析技术的发展,同时为了更好地发挥药效、减少残留及对非靶标物危害,充分了解茶叶中手性农药对映体的立体选择性行为,分析在茶叶中的残留降解规律,建立对映体的残留限量标准显得尤为重要。综述了茶叶中手性农药对映体残留检测技术现状,如液相色谱法、气相色谱法和超临界流体色谱法等方法,并对手性农药对映体在茶叶中的残留降解行为和风险评估进行归纳和展望,为后续深入开展茶叶中手性农药对映体的相关研究提供借鉴。

关键词：茶叶手性农药对映体残留分析风险评估

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