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Global patterns in above-ground net primary production and precipitation-use efficiency in grasslands

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Journal of Mountain Science 2018年第8期15卷 1682-1692页

作者： QIN Xiao-jing HONG Jiang-tao ma xing-xing WANG Xiao-dan Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of ScienceChengdu 610041China University of Chinese Academy of Sciences Beijing 100049China College of Urban and Environment Sciences Shanxi Normal UniversityLinfen 041000China

The above-ground net primary production(ANPP) and the precipitation-use efficiency(PUE) regulate the carbon and water cycles in grassland ecosystems, but the relationships among the ANPP, PUE and precipitation are still controversial. We selected 717 grassland sites with ANPP and mean annual precipitation(maP) data from 40 publications to characterize the relationships ANPP–maP and PUE–maP across different grassland types. The maP and ANPP showed large variations across all grassland types, ranging from 69 to 2335 mm and 4.3 to 1706 g m^(-2), respectively. The global maximum PUE ranged from 0.19 to 1.49 g m^(-2) mm^(-1) with a unimodal pattern. Analysis using the sigmoid function explained the ANPP–maP relationship best at the global scale. The gradient of the ANPP–maP graph was small for arid and semi-arid sites(maP maP across dry grassland ecosystems. It provides new perspectives on the prediction and modeling of variations in the ANPP for different grassland types along precipitation gradients.

关键词： Litter decomposition Alpine communities Tea bag index Carbon cycle Above-ground net primary production Precipitation-use efficiency Sigmoid function Precipitation gradients

Impacts of warming on root biomass allocation in alpine steppe on the north Tibetan Plateau

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Journal of Mountain Science 2017年第8期14卷 1615-1623页

作者： ma xing-xing YAN Yan HONG Jiang-tao LU Xu-yang WANG Xiao-dan Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of Sciences University of Chinese Academy of Sciences

Biomass is an important component of global carbon cycling and is vulnerable to climate change. Previous studies have mainly focused on the responses of aboveground biomass and phenology to warming, while studies of root architecture and of root biomass allocation between coarse and fine roots have been scarcely reported in grassland ecosystems. We conducted an open-top-chamber warming experiment to investigate the effect of potential warming on root biomass and root allocation in alpine steppe on the north Tibetan Plateau. The results showed that Stipa purpurea had significantly higher total root length, root surface area and tips than Carex moocroftii. However,there were no differences in total root volume, mean diameter and forks for the two species. Warming significantly increased total root biomass(27.60%), root biomass at 0–10 cm depth(27.84%) and coarse root biomass(diameter > 0.20 mm, 57.68%) in the growing season(August). However, warming had no significant influence on root biomass in the non-growing season(April). Root biomass showed clear seasonalvariations: total root biomass, root biomass at 0–10 cm depth and coarse root biomass significantly increased in the growing season. The increase in total root biomass was due to the enhancement of root biomass at 0–10 cm depth, to which the increase of coarse root biomass made a great contribution. This research is of significance for understanding biomass allocation, carbon cycling and biological adaptability in alpine grassland ecosystems under future climate change.

关键词： Coarse root Fine root Root architecture Warming Climate change Open-top chambers

Optimal investment, retirement, and life insurance with consumption ratcheting and time-inhomogeneous utility

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Science China mathematics 2025年

作者： Jie xing Jingtang ma School of Big Data Application and Economics Guizhou University of Finance and Economics School of mathematics Southwestern University of Finance and Economics

In this paper, we study a portfolio selection problem of an investor with a retirement option, who has possibility to buy life insurance and does not tolerate any decline in consumption. The agent's optimization problem can be viewed as a mixed singular control and optimal stopping problem with time-inhomogeneous utility functions. The closed-form optimal solution is not available in general. We use the dual control method to convert the original problem into two classes of optimal stopping problems in finite and infinite *** show that the optimal consumption strategy and the best retirement time depend on the free-boundary functions which satisfy Fredholm and Volterra integral equations. We derive the closed-form formulas for these two free boundaries for some special cases and develop numerical methods to solve the integral equations of the free boundaries for general cases.

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Solution‑Processed Thin Film Transparent Photovoltaics:Present Challenges and Future Development

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Nano-Micro Letters 2025年第2期17卷 566-600页

作者： Tianle Liu Munerah M.S.Almutairi Jie ma Aisling Stewart Zhaohui xing Mengxia Liu Bo Hou Yuljae Cho UM-SJTU Joint Institute Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China School of Physics and Astronomy Cardiff UniversityCardiff CF243AAWalesUK Department of Electrical and Computer Engineering Yale UniversityNew HavenCT 06511USA Energy Sciences Institute Yale UniversityWest HavenCT 06516USA Future Photovoltaics Research Center Global Institute of Future TechnologyShanghai Jiao Tong UniversityShanghai 200240People’s Republic of China

Electrical energy is essential for modern society to sustain economic *** soaring demand for the electrical energy,together with an awareness of the environmental impact of fossil fuels,has been driving a shift towards the utilization of solar ***,traditional solar energy solutions often require extensive spaces for a panel installation,limiting their practicality in a dense urban *** overcome the spatial constraint,researchers have developed transparent photovoltaics(TPV),enabling windows and facades in vehicles and buildings to generate electric *** TPV advancements are focused on improving both transparency and power output to rival commercially available silicon solar *** this review,we first briefly introduce wavelength-and non-wavelengthselective strategies to achieve *** of merit and theoretical limits of TPVs are discussed to comprehensively understand the status of current TPV *** we highlight recent progress in different types of TPVs,with a particular focus on solution-processed thin-film photovoltaics(PVs),including colloidal quantum dot PVs,metal halide perovskite PVs and organic *** applications of TPVs are also reviewed,with emphasis on agrivoltaics,smart windows and ***,current challenges and future opportunities in TPV research are pointed out.

关键词： Transparent semiconductors Solution-processable transparent solar cell Emerging solar cell materials Buildingintegrated photovoltaics

De novo synthesis of atropisomeric benzofurans via Cu/SPDO complex catalyzed asymmetric formal [3 + 2] annulation

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Science China Chemistry 2025年第1期68卷 174-180页

作者： Fan-Xiao Meng xing-Yu Wang Ka Lu Ju-Song Yang Fu-Min Zhang Ai-Jun ma Bao Du Yong-Qiang Tu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering Lanzhou University School of Chemistry and Chemical Engineering Shanghai Jiao Tong University School of Biotechnology and Health Sciences Wuyi University

Herein, the de novo synthesis of atropisomeric benzofurans through the Cu/spirocyclic-pyrrolidine-oxazoline(SPDO) complex catalyze asymmetric formal [3 + 2] cycloaddition between quinones and ynamides is explored, producing a range of structurally diverse axially chiral benzofurans in satisfactory yields with good to excellent enantioselectivities. Furthermore, density functional theory calculations were applied to explain the possible reaction mechanism.

关键词： benzofuran atropisomers novel de novo synthetic strategy asymmetric formal [3 + 2] cycladdition Cu/SPDO complex DFT calculations

Small extracellular vesicles derived from human induced pluripotent stem cell-differentiated neural progenitor cells mitigate retinal ganglion cell degeneration in a mouse model of optic nerve injury

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Neural Regeneration Research 2025年第2期20卷 587-597页

作者： Tong Li Hui-Min xing Hai-Dong Qian Qiao Gao Sheng-Lan Xu Hua ma Zai-Long Chi State Key Laboratory of Ophthalmology Optometry and Visual ScienceEye HospitalWenzhou Medical UniversityWenzhouZhejiang ProvinceChina National Clinical Research Center for Ocular Diseases Eye HospitalWenzhou Medical UniversityWenzhouZhejiang ProvinceChina

Several studies have found that transplantation of neural progenitor cells(NPCs)promotes the survival of injured ***,a poor integration rate and high risk of tumorigenicity after cell transplantation limits their clinical *** extracellular vesicles(sEVs)contain bioactive molecules for neuronal protection and *** studies have shown that stem/progenitor cell-derived sEVs can promote neuronal survival and recovery of neurological function in neurodegenerative eye diseases and other eye *** this study,we intravitreally transplanted sEVs derived from human induced pluripotent stem cells(hiPSCs)and hiPSCs-differentiated NPCs(hiPSC-NPC)in a mouse model of optic nerve *** results show that these intravitreally injected sEVs were ingested by retinal cells,especially those localized in the ganglion cell *** with hiPSC-NPC-derived sEVs mitigated optic nerve crush-induced retinal ganglion cell degeneration,and regulated the retinal microenvironment by inhibiting excessive activation of *** analysis further revealed that hiPSC-NPC derived sEVs transported neuroprotective and anti-inflammatory miRNA cargos to target cells,which had protective effects on RGCs after optic nerve *** findings suggest that sEVs derived from hiPSC-NPC are a promising cell-free therapeutic strategy for optic neuropathy.

关键词： exosome miRNA neural progenitor cell neurodegeneration neuroinflammation neuroprotection optic nerve crush optic neuropathy retinal ganglion cell small extracellular vesicles

中学生青春期性教育现状调查报告——以潮汕地区为例

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中国青年政治学院学报 2007年第6期26卷 1-5页

作者：任苇苏昕马星星中国青年政治学院青少年工作系北京100089

对潮汕地区两所中学的调查发现,现行的中学生性教育存在几个突出的问题:一是学校和家庭在青春期性教育中的作用缺失,二是学校性教育的定位偏低,三是学校性教育的内容狭窄,四是学生得不到正确的指导。因此,应当开展同伴教育,将学校的老... 详细信息

对潮汕地区两所中学的调查发现,现行的中学生性教育存在几个突出的问题:一是学校和家庭在青春期性教育中的作用缺失,二是学校性教育的定位偏低,三是学校性教育的内容狭窄,四是学生得不到正确的指导。因此,应当开展同伴教育,将学校的老师培养成同伴教育者。同时,还要积极开展小组活动,设立小组负责人等,以此达到中学生青春期性教育的目的。

关键词：中学生青春期性与生殖健康教育

晋南煤矿复垦区博落回根系形态特征对氮添加的响应

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草地学报 2023年第9期31卷 2769-2776页

作者：郝嘉湉马嘉丽李泽斌张永清马星星山西师范大学地理科学学院山西太原030031

为研究氮添加对晋南煤矿复垦区博落回(macleaya cordata)根系形态的影响,揭示博落回根系在不同施氮量下的生长适应策略。本研究在2020—2021年开展了0(CK),75(N1),150(N2),225(N3)和300 kg·hm^(-2)(N4)5个氮水平的控制实验,测定根系形... 详细信息

为研究氮添加对晋南煤矿复垦区博落回(macleaya cordata)根系形态的影响,揭示博落回根系在不同施氮量下的生长适应策略。本研究在2020—2021年开展了0(CK),75(N1),150(N2),225(N3)和300 kg·hm^(-2)(N4)5个氮水平的控制实验,测定根系形态参数和株高等数据。结果表明:2020年3次采样的博落回根系指标,除平均直径和比根长外,均在N3,N4处理下最大;2021年CK,N3和N4处理的博落回根体积、根表面积均随采样月份表现出“V”型变化,最低值出现在8月;2020年N3,N4处理可以快速促进植物根系生长,到2021年N3,N4处理对植物根系生长的促进作用减弱。本研究认为氮添加于土壤,再反馈于博落回根系需要较长时间,建议在该复垦区开展长期控制实验,得出最优施氮方案。

关键词：氮添加根系形态特征煤矿复垦区博落回

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英语专业新生语言学习观念差异的影响因素分析

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成都师范学院学报 2014年第9期30卷 56-61页

作者：马星星重庆大学城市科技学院重庆402167

通过对某大学英语专业新生语言学习观念的问卷调查,采用定量分析方法分析了新生语言学习观念差异背后的原因。分析结果表明,当今大学生对语言学习本质的理解更全面,他们意识到语言学习不仅要学语法、词汇而且要提高综合技能,尤其是交际... 详细信息

通过对某大学英语专业新生语言学习观念的问卷调查,采用定量分析方法分析了新生语言学习观念差异背后的原因。分析结果表明,当今大学生对语言学习本质的理解更全面,他们意识到语言学习不仅要学语法、词汇而且要提高综合技能,尤其是交际能力的培养;他们的工具型动机较弱而融入型动机较强;不同外语水平的学生只在语言学习本质、语言学习动机观念上存在显著性差异。

关键词：英语专业新生语言学习观念