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Belowground Bud Bank Is Insensitive to Short-Term Nutrient Addition in the Meadow Steppe of Inner Mongolia

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Phyton-International Journal of Experimental Botany 2024年第6期93卷 1129-1141页

作者： Jin Tao Jiatai Tian Dongmei Li Jinlei zhu Qun Ma Zhiming Zhang Jungang Chen Yipeng Liu jianqiang Qian College of Forestry Henan Agricultural UniversityZhengzhou450002China Institute of Ecological Conservation and Restoration Chinese Academy of ForestryBeijing100093China Institute of Applied Ecology Chinese Academy of SciencesShenyang110164China Institute of Botany Chinese Academy of SciencesBeijing100093China Liaoning Metallurgical Geological Exploration Research Institute Co. Anshan114038China

Human activities and industrialization have signiﬁcantly increased soil nutrients,such as nitrogen(N)and phos-phorus(P),profoundly impacting the composition and structure of plant community,as well as the ecosystem functions,especially in nutrient-limited ***,as the key propagule pool of perennial grasslands,how belowground bud bank and its relationship with aboveground vegetation respond to short-term changes in soil nutrients was still *** this study,we conducted a short-term(2021–2022)soil fertilization experiment with N addition(10 g N m^(-2) yr^(-1))and P addition(5 g N m^(-2) yr^(-1))in the meadow steppe of Inner Mongolia,China,to explore the responses of belowground bud bank,aboveground shoot population and their relationships(represented by the ratio of bud to shoot density-meristem limitation index(MLI))for the whole community and three plant functional groups(perennial rhizomatous grasses-PR,perennial bunchgrasses-PB,and perennial forbs-PF)to nutrient *** short-term nutrient addition had no signiﬁcant inﬂuences on belowground bud density,aboveground shoot density,and MLI of the whole plant *** functional groups showed different responses to soil ***ﬁcally,N addition signiﬁcantly increased the bud density and shoot density of PR,especially in combination with P addition.N addition reduced the shoot density of PF but had no inﬂuence on its bud density and *** addition had signiﬁcant effects on the three indicators of *** study indicates that the belowground bud bank and its relationship with aboveground vegetation in temperate meadow steppe are insensitive to short-term soil fertilization,but plant functional groups exhibit speciﬁc responses in terms of population regeneration,which implies that plant community composition and ecosystem functions will be changed under the ongoing global change.

关键词： Clonal trait population regeneration community dynamics soil resource availability nitrogen addition

Transmittance and phase measurement via self-calibrated balanced heterodyne detection

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Chinese Optics Letters 2018年第6期16卷 44-49页

作者： Jie Miao Xuejie Zhang Zhan Li Zijian Cui Yanjia Zhang Dean Liu jianqiang zhu Key Laboratory of High Power Laser and Physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800 China University of Chinese Academy of Sciences Beijing 100049 China

It is rare for a conventional direct detection method to measure the transmittance uniformity of mirrors with rigorous standards, especially to meet the requirement of transmittance/reflectance and phase detection simultaneously. In this study, a new method of self-calibrated balanced heterodyne detection（SCBHD） is proposed. It can be self-calibrated by a two-channel structure to overcome the environmental effects in large optics scanning detection by employing highly accurate heterodyne interference. A typical transmittance measurement experiment was performed at 1053 nm wavelength via SCBHD. A standard deviation（SD） of 0.038% was achieved in the preliminary experiment. The experimental results prove to reduce the SD by approximately two orders of magnitude compared with the conventional direct detection method in the same condition. The proposed method was verified as being promising not only for its wider dynamic measurement range and its higher accuracy but also for its simultaneous transmittance and phase detection ability.

关键词： Heterodyne detection High power lasers Phase measurement Phase modulation Phase shift Transmittance

An investigation of the L-shell x-ray conversion efficiency for laser-irradiated tin foils

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Plasma Science and Technology 2020年第4期22卷 48-54页

作者： David BAILIE Cormac HYLAND Raj L SINGH Steven WHITE Gianluca SARRI Francis P KEENAN David RILEY Steven J ROSE Edward G HILL Feilu WANG Dawei YUAN Gang ZHAO Huigang WEI Bo HAN Baoqiang zhu jianqiang zhu Pengqian YANG Centre for Plasma Physics School of Mathematics and PhysicsQueen's University BelfastBelfastBT7 INNUnited Kingdom Astrophysics Research Centre School of Mathematics and PhysicsQueen's University BelfastBelfastBT7 INNUnited Kingdom Plasma Physics Group Blackett LaboratoryPrince Consort RoadLondonSW72AZUnited Kingdom Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100012People's Republic of China Department of Astronomy Beijing Normal UniversityBeijing 100875People's Republic of China Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences.Shanghai 201800People's Republic of China

We have used the ShenguangⅡlaser in third harmonic(351 nm)to investigate the emission of L-shell radiation in the 3.3–4.4 ke V range generated using thin foils of Sn coated onto a parylene substrate with irradiation of order 1015 W cm-2 and nanosecond pulse *** our experiment,we have concentrated on assessing the emission on the non-laser irradiated side as this allows an experimental geometry relevant to experiments on photo-ionised plasmas where a secondary target must be placed close to the source,to achieve x-ray fluxes appropriate to astrophysical *** L-shell conversion efficiencies are estimated to be of order 1%,with little dependence on Sn thickness between 400 and 800 nm.

关键词： conversion efficiency laser plasma x-ray sources laboratory astrophysics

根茎克隆植物芦苇应对风沙活动过程的生长和生殖的权衡关系

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Journal of Plant Ecology 2024年第1期17卷 68-77页

作者： Chaoqun Ba Shanshan Zhai jianqiang Qian Bo Liu Jinlei zhu Zhimin Liu Institute of Applied Ecology Chinese Academy of SciencesShenyang 110016China University of Chinese Academy of Sciences Beijing 100049China College of Forestry Henan Agricultural UniversityZhengzhou 450002China College of Life Science Qufu Normal UniversityQufu 273165China Institute of Ecological Conservation and Restoration Chinese Academy of ForestryBeijing 100093China

生长和繁殖之间的权衡是克隆植物适应性策略的重要组成部分。根茎型沙生植物通过权衡策略应对风沙过程(埋沙和风蚀)对它们在流动沙丘上的定居尤为重要。尽管根茎型物种对风沙过程的响应已经有了部分研究,但这些克隆物种如何通过生长和... 详细信息

生长和繁殖之间的权衡是克隆植物适应性策略的重要组成部分。根茎型沙生植物通过权衡策略应对风沙过程(埋沙和风蚀)对它们在流动沙丘上的定居尤为重要。尽管根茎型物种对风沙过程的响应已经有了部分研究,但这些克隆物种如何通过生长和繁殖中的潜在权衡关系来应对风沙过程仍不清楚。在本研究中,我们采用了野外调查和生物量建模的手段,评估了芦苇(Phragmites communis)在沙埋和风蚀条件下,营养生长和生殖生长以及分株数量和大小之间的权衡关系。研究结果表明,沙埋促进了种子生物量和生殖努力(RE)的增加;风蚀减少了RE,但对种子生物量没有显著影响。沙埋增加了分株的生物量,而风蚀增加了分株种群密度并加速了分株的成熟。这些研究表明,根茎型沙地植物通过调整其生长策略来应对风沙过程,即在沙埋条件下,增加生殖生长和分株大小,而在风蚀条件下,增加营养生长和分株数量。

关键词：适应策略沙埋风蚀芦苇(Phragmites communis) 有性生长无性生长根茎

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热容型板条激光器的感应折射率计算

中国激光 2008年第2期35卷 225-230页

作者：尹宪华朱健强祖继锋范滇元中国科学院上海光学精密机械研究所高功率激光物理实验室上海201800

高平均功率固体激光器的增益介质由于受热而容易发生畸变,如常用材料YAG,波前畸变和去偏振现象会同时发生,高热负载固体激光介质的热效应已成为制约激光器输出功率进一步提高的严重障碍。给出一种计算热容型板条激光器热感生折射率的方... 详细信息

高平均功率固体激光器的增益介质由于受热而容易发生畸变,如常用材料YAG,波前畸变和去偏振现象会同时发生,高热负载固体激光介质的热效应已成为制约激光器输出功率进一步提高的严重障碍。给出一种计算热容型板条激光器热感生折射率的方法。把YAG晶体的四阶压光张量从晶胞坐标系转换到实验室坐标系,采用经过坐标转换后的新的张量,可以分析在YAG激光器中任意应力分布引起的热感应双折射。进一步的计算表明,在zigzag板条激光器中,应力双折射率与板条从晶体毛胚上切割成材的角度有关。同时也对热容板条激光器的热效应和应力特性进行了二维的理论性概述。

关键词：激光器固体激光器应力双折射压光张量

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基于虚拟光阑调制的刀口法自动定量检测技术

光学学报 2023年第21期43卷 150-163页

作者：华翔焦兆阳朱健强中国科学院上海光学精密机械研究所高功率激光物理重点实验室上海201800 中国科学院中国工程物理研究院高功率激光物理联合实验室上海201800 中国科学院大学北京100049

依靠算法提高光学测量精度的方法和应用越来越广泛,由于刀口法在光学非球面检测中的应用有其独特性,本文提出了在非焦点处采样,对应CCD像面上辅以虚拟光阑调制的刀口法环带,实现定量检测。以检测一个凹球面为例,将其与干涉仪标准方法的... 详细信息

依靠算法提高光学测量精度的方法和应用越来越广泛,由于刀口法在光学非球面检测中的应用有其独特性,本文提出了在非焦点处采样,对应CCD像面上辅以虚拟光阑调制的刀口法环带,实现定量检测。以检测一个凹球面为例,将其与干涉仪标准方法的检测结果进行对比,其中主要环带位置偏差不超过1%,峰谷(PV)值和均方根(RMS)值误差均在7%左右,可以实现至少λ/15左右的检测灵敏度。该研究为光学车间检测提供了一种定量化检测的新思路,优化了光学加工与检测的效率,为自动化刀口仪的研制奠定了基础。

关键词：光学检测刀口仪自动化光学仪器

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基于刀口仪轴向移动的自动化非球面检测技术

光学学报 2022年第23期42卷 79-86页

为了解决自动化刀口仪面临的如何搜索并收敛到特征点的核心问题,提出一种基于刀口仪轴向移动的非球面检测技术,实现了在搜索过程中提取环带误差信息,一方面在搜索过程中动态获得波前特性,另一方面可以加速收敛找到特征点。利用所提方法... 详细信息

为了解决自动化刀口仪面临的如何搜索并收敛到特征点的核心问题,提出一种基于刀口仪轴向移动的非球面检测技术,实现了在搜索过程中提取环带误差信息,一方面在搜索过程中动态获得波前特性,另一方面可以加速收敛找到特征点。利用所提方法对不同参数的镜面环带误差进行检测,所得带差位置与干涉仪检测结果的相对误差小于3.3%,验证了所提方法的有效性。所提方法为刀口仪的自动化测量提供了一个便捷的解决方案,为进一步提高非球面加工效率提供了技术支撑。

关键词：测量刀口仪自动化光学检测光学仪器

大口径超短脉冲聚焦系统波前误差对时间信噪比的影响

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光学学报 2014年第10期34卷 322-328页

作者：朱坪谢兴龙焦兆阳朱健强中国科学院上海光学精密机械研究所高功率激光物理国家实验室上海201800 中国科学院大学北京100049

理解大口径光学系统离轴抛物面镜聚焦后超短脉冲时间信噪比(SNR)在焦斑处空间分布的特性有助于更准确地认识超快激光物理实验中的脉冲时空特性。利用空间上菲涅耳近似下的分两步聚焦的坐标变换快速傅里叶变换(FFT)算法,结合时间域的傅... 详细信息

理解大口径光学系统离轴抛物面镜聚焦后超短脉冲时间信噪比(SNR)在焦斑处空间分布的特性有助于更准确地认识超快激光物理实验中的脉冲时空特性。利用空间上菲涅耳近似下的分两步聚焦的坐标变换快速傅里叶变换(FFT)算法,结合时间域的傅里叶积分变换方法,引入了光学系统波前误差,对聚焦过程进行时空仿真。解释了大口径光学系统波前误差造成时间信噪比退化的原因,计算分析随机波前误差参数(误差大小、空间尺度)对聚焦时间信噪比的影响,并针对不同频段的光学系统波前误差控制提出要求。明确大口径光学系统中随机波前误差与时间信噪比之间的关系,为大口径超短脉冲系统的设计指标分配与波前误差控制提供了理论基础。

关键词：超快光学时间信噪比波前误差傅里叶变换坐标变换

抛光粉颗粒度对高功率激光玻璃材料抛光效率和粗糙度的影响

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光学学报 2009年第7期29卷 1905-1911页

作者：张宝安包蕾朱健强中国科学院上海光学精密机械研究所上海201800

磷酸盐钕玻璃、熔石英和BK7是3类用于激光惯性约束聚变(ICF)装置主要光学元件材料。实验中采用不同平均粒径的氧化铈抛光粉对上述3类材料分别进行抛光,对特定材料抛光去除量和抛光粉平均粒径的关系进行了研究。实验表明:由于材料的物理... 详细信息

磷酸盐钕玻璃、熔石英和BK7是3类用于激光惯性约束聚变(ICF)装置主要光学元件材料。实验中采用不同平均粒径的氧化铈抛光粉对上述3类材料分别进行抛光,对特定材料抛光去除量和抛光粉平均粒径的关系进行了研究。实验表明:由于材料的物理和化学特性不同,特定的材料需选用相应平均粒径大小的抛光粉才能达到最佳的抛光效率。实验还就上述3类高功率激光玻璃材料抛光中各个阶段的抛光粗糙度与抛光粉平均粒径的关系进行了研究,结果表明:某一规格抛光粉的粒径对不同特性材料抛光后的表面粗糙度影响表征情况不同。

关键词：高功率激光玻璃光学加工抛光粉