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Vegetation pattern of Northeast China during the special periods since the Last Glacial Maximum

Science China Earth Sciences 2019年第8期62卷 1224-1240页

作者： Xiaoqiang LI chao ZHAO Xinying zhou Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences Institute of Vertebrate Paleontology and PalaeoanthropologyChinese Academy of SciencesBeijing100044China University of Chinese Academy of Sciences Beijing100039China Center for Excellence in Life and Paleoenvironment Chinese Academy of SciencesBeijing100044China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing100101China

Since the Last Glacial Maximum(LGM), the global climate has experienced several stages, such as cold and warming events, which provide an ideal model for evaluating climate change in the future. Based on the pollen records in Northeast(NE) China, the vegetation pattern during special periods since the LGM was reconstructed in this work. During the LGM(approximately 18,000 cal yr BP), the steppes expanded rapidly in NE China, and a cold-dry meadow-steppe developed on the Songnen Plain. The Liaohe Plain and the Hulun Buir Plateau were occupied by a steppe-desert, with forest-steppe vegetation grown in the central and southern plains;there were cold-dry coniferous forests and mixed conifer-broadleaf forests in mountainous areas. In the early Holocene(10,000–9,000 cal yr BP), Changbai mountain(CBM) forests thrived in the eastern hilly area and the Sanjiang Plain, while the central region was dominated by steppes, and warm-temperate broadleaf forests developed northward. During the Holocene warm period(approximately 6,000 cal yr BP), CBM forests and cold-temperate coniferous forests developed in the north, while spruce-fir forests developed in the eastern Xiao Hinggan Mountains and the Sanjiang Plain. The distribution centre of deciduous broadleaf forests migrated to the south of the Changbai Mountains and the Liaodong Peninsula. The isolated woodlands increased on the Songnen Plain and the meadow-steppes expanded to the Liaohe Plain. Therefore, the increase in temperature leads to the increase of monsoon precipitation in NE China, which is beneficial to the development of warm-temperate forest vegetation. The increase of summer monsoons and precipitation caused by climate warming may be the main reason for the improved plant load.

关键词： Last Glacial Maximum Holocene warm period Vegetation pattern Northeast China

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Comparison of aerodynamic characteristics between a novel highly loaded injected blade with curvature induced pressure-recovery concept and one with conventional design

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Chinese Journal of Aeronautics 2017年第3期30卷 939-950页

作者： Zhiyuan CAO chao zhou Zhili SUN Stute Key Laboratory fot Turbulenee and Complex Systems College of Engineering Peking University Beijing 100871 China BIC-ESA T Peking University Beijing 100871 China Collabarative Innovation Center of Advaneed Aero-Engine Beijing 100083 China

This paper introduces a novel design method of highly loaded compressor blades with air *** methods were firstly validated with existing data and then used to develop and investigate the new method based on a compressor cascade.A compressor blade is designed with a curvature induced pressure-recovery concept.A rapid drop of the local curvature on the blade suction surface results in a sudden increase in the local pressure,which is referred to as a curvature induced ‘Shock＇.An injection slot downstream from the ‘Shock＇ is used to prevent ‘Shock＇ induced separation,thus reducing the *** a result,the compressor blade achieves high loading with acceptable ***,the design concept based on a 2D compressor blade profile is ***,a 3D cascade model is investigated with uniform air injection along the *** effects of the incidence are also investigated on emphasis in the current *** mid-span flow field of the 3D injected cascade shows excellent agreement with the 2D designed flow *** the highly loaded cascade without injection,the flow separates immediately downstream from the ‘Shock＇;the initial location of separation shows little change in a large incidence *** air injection with the same injection configuration effectively removes the flow separation downstream from the curvature induced ‘Shock＇ and reduces the size of the separation zone at different *** the endwall,the flow within the incoming passage vortex mixes with the injected *** a result,the size of the passage vortex reduces significantly downstream from the injection *** air injection,the loss coefficient along spanwise reduces significantly and the flow turning angle increases.

关键词： Axial compressor Air injection Curvature induced ‘Shock’ Flow control Separation

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Fractal Surface Synthesis Based on Two Dimensional Discrete Fourier Transform

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Chinese Journal of Mechanical Engineering 2013年第6期26卷 1101-1108页

作者： zhou chao GAO Chenghui HUANG Jianmeng School of Mechanical Engineering and Automation Fuzhou University Fujian Provincial Research Center of Digital Design for Manufacturing

The discrete Fourier transform（DFT） is used for fractional Brownian motion（FBM） surface synthesis in tribology（i.e., contact, sliding, and sealing, etc）. However, the relationship between fractal parameters（fractal dimension and scale factor） and traditional parameters, the influence of fractal parameters on surface appearance, have not been deeply discussed yet. These lead to some kind of difficulty to ensure the synthesized surfaces with ideal fractal characteristic, required traditional parameters and geometric appearance. A quantitative relationship between fractal parameters and the root mean square deviation of surface （Sq） is derived based on the energy conservation property between the space and frequency domain of DFT. Under the stability assumption, the power spectrum of a FBM surface is composed of concentric circles strictly, a series of FBM surfaces with prescribed Sq could be synthesized with given fractal dimension, scale factor, and sampling numbers, but the ten-point height（Sz）, the skewness（Ssk） and the kurtosis（Sku） are still in random, where the probability distributions of Sz and Ssk are approximately normal distribution. Furthermore, by iterative searching, a surface with desired Abbott-Firestone curve could be obtained among those surfaces. An intuitive explanation for the influence of fractal dimension and scale factor on surface appearance is obtained by discussing the effects on the ratio of energy between high and low frequency components. Based on the relationship between Sq and surface energy, a filtering method of surface with controllable Sq is proposed. The proposed research ensures the synthesized surfaces possess ideal FBM properties with prescribed Sq, offers a method for selecting desired Abbott-Firestone curve of synthesized fractal surfaces, and makes it possible to control the Sq of surfaces after filtering.

关键词： fractional Brownian motion discrete Fourier transform fractal surface power spectrum

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Unsteady Aerodynamic Forces and Power Consumption of a Micro Flapping Rotary Wing in Hovering Flight

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Journal of Bionic Engineering 2018年第2期15卷 298-312页

作者： chao zhou Yanlai Zhang Jianghao Wu School of Transportation Science and Engineering Beihang University Beijing 100191 China

The micro Flapping Rotary Wing （FRW） concept inspired by insects was proposed recently. Its aerodynamic performance is highly related to wing pitching and rotational motions. Therefore, the effect of wing pitching kinematics and rotational speed on unsteady aerodynamic forces and power consumption of a FRW in hovering flight is further studied in this paper using computational fluid dy- namics method. Considering a fixed pitching amplitude （i.e., 80°）, the vertical force of FRW increases with the downstroke angle of attack and is enhanced by high wing rotational speed. However, a high downstroke angle of attack is not beneficial for acquiring high rotational speed, in which peak vertical force at balance status （i.e., average rotational moment equals zero.） is only acquired at a comparatively small negative downstroke angle of attack. The releasing constraint of pitching amplitude, high rotational speed and enhanced balanced vertical force can be acquired by selecting small pitching amplitude despite high power consumption. To confirm which wing layout is more power efficient for a certain vertical force requirement, the power consumed by FRW is compared with the Rotary Wing （RW） and the Flapping Wing （FW） while considering two angle of attack strategies without the Reynolds number （Re） constraint. FRW and RW are the most power efficient layouts when the target vertical force is produced at an angle of attack that corresponds to the maximum vertical force coefficient and power efficiency, respectively. However, RW is the most power efficient layout overall despite its insufficient vertical force production capability under a certain Re.

关键词： micro air vehicle flapping rotary wing aerodynamic forces power consumption computational fluid dynamics

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Non-coding RNAs in acute ischemic stroke:from brain to periphery

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Neural Regeneration Research 2025年第1期20卷 116-129页

作者： Shuo Li Zhaohan Xu Shiyao Zhang Huiling Sun Xiaodan Qin Lin Zhu Teng Jiang Junshan zhou Fuling Yan Qiwen Deng Department of Neurology Nanjing First HospitalNanjing Medical UniversityNanjingJiangsu ProvinceChina Department of Neurology Zhongda HospitalSchool of MedicineSoutheast UniversityNanjingJiangsu ProvinceChina General Clinical Research Center Nanjing First HospitalNanjing Medical UniversityNanjingJiangsu ProvinceChina

Acute ischemic stroke is a clinical emergency and a condition with high morbidity,mortality,and *** predictive,diagnostic,and prognostic biomarkers and effective therapeutic targets for acute ischemic stroke remain *** innovations in high-throughput gene sequencing analysis,many aberrantly expressed non-coding RNAs(ncRNAs)in the brain and peripheral blood after acute ischemic stroke have been found in clinical samples and experimental *** expressed ncRNAs in the post-stroke brain were demonstrated to play vital roles in pathological processes,leading to neuroprotection or deterioration,thus ncRNAs can serve as therapeutic targets in acute ischemic ***,distinctly expressed ncRNAs in the peripheral blood can be used as biomarkers for acute ischemic stroke prediction,diagnosis,and *** particular,ncRNAs in peripheral immune cells were recently shown to be involved in the peripheral and brain immune response after acute ischemic *** this review,we consolidate the latest progress of research into the roles of ncRNAs(microRNAs,long ncRNAs,and circular RNAs)in the pathological processes of acute ischemic stroke–induced brain damage,as well as the potential of these ncRNAs to act as biomarkers for acute ischemic stroke prediction,diagnosis,and *** from this review will provide novel ideas for the clinical application of ncRNAs in acute ischemic stroke.

关键词： acute ischemic stroke apoptosis blood–brain barrier damage circular RNAs excitatory toxicity long non-coding RNAs microRNAs neuroinflammation non-coding RNAs oxidative stress

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Productivity Growth in China's Agriculture During 1985-2010

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Journal of Integrative Agriculture 2013年第10期12卷 1896-1904页

作者： LI zhou ZHANG hai-peng Rural Development Institute Chinese Academy of Social Sciences Collaborative Innovation Center for Rural Reform and Development

This paper made an empirical analysis of China＇s agricultural growth path and influential factors using the province-level panel data of agricultural inputs and outputs during *** findings indicate that the increase in agricultural inputs and TFP contributed 40.6 and 55.2% to the agricultural output growth,respectively;China＇s agriculture had jumped out of the pattern which output growth was mainly driven by increasing *** the total inputs,chemical fertilizer had the most important contribution to the output growth,followed by mechanical *** contribution of land and labor was ***＇s agricultural output growth belonged to the type of induced technology ***＇s agricultural TFP growth had characteristics of fluctuations over time and unbalanced between regions,but the gap between the eastern,the middle,and the western regions has been narrowed.

关键词： agricultural output growth input total factor productivity(TFP)

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Impacts of Climate Change on Rice Yield in China From 1961 to 2010 Based on Provincial Data

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Journal of Integrative Agriculture 2014年第7期13卷 1555-1564页

作者： CHEN chao zhou Guang-sheng zhou Li Chinese Academy of Meteorological Sciences Sichuan Provincial Climate Center

The impacts of climate change on rice yield in China from 1961 to 2010 were studied in this paper, based on the provincial data, in order to develop scientiifc countermeasures. The results indicated that increase of average temperature improved single cropping rice production on national level by up to 11%relative to the average over the study period, however, it resulted in an overall loss of double cropping rice by up to 1.9%. The decrease of diurnal temperature range （DTR） in the major producing regions caused the decrease by up to 3.0%for single cropping rice production and 2.0%for double cropping rice production. Moreover, the contribution of precipitation change reached about 6.2%for single cropping rice production, but no signiifcant effect for double cropping rice production in recent 50 years.

关键词： impact climate change warming precipitation rice yield provincial level China

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Distribution of Equilibrium Free Energies in a Thermodynamic System with Broken Ergodicity

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Communications in Theoretical Physics 2008年第3期49卷 659-664页

作者： zhou hai-Jun LI Kang Institute of Theoretical Physics the Chinese Academy of Sciences Beijing 100080 China

At low temperatures the configurational phase space of a macroscopic complex system （e.g., a spin-glass） of N - 10^23 interacting particles may split into an exponential number Ωs - exp（const × N） of ergodic sub-spaces （thermodynamic states）. It is usually assumed that the equilibrium collective behavior of such a system is determined by its ground thermodynamic states of the minimal free-energy density, and that the equilibrium free energies follow the distribution of exponentied decay. But actually for some complex systems, the equilibrium free-energy values may follow a Gaussian distribution within an intermediate temperature range, and consequently their equilibrium properties are contributed by excited thermodynamic states. Based on this analysis, the re-weighting parameter y in the cavity approach of spin-glasses is easily understood. Depending on the free-energy distribution, the optimal y can either be equal to or be strictly less than the inverse temperature β.

关键词： free-energy distribution spin-glass thermodynamic state cavity approach broken ergodicity

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Sufcient Conditions for Error Bounds and Linear Regularity in Banach Spaces

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Acta Mathematica Sinica,English Series 2014年第3期30卷 423-436页

作者： zhou WEI Qing hai HE Department of Mathematics Yunnan University

In this paper, we study error bounds for lower semicontinuous functions defined on Banach space and linear regularity for finitely many closed subset in Banach spaces. By using Clarke＇s subd- ifferentials and Ekeland variational principle, we establish several sufficient conditions ensuring error bounds and linear regularity in Banach spaces.

关键词： Error bound linear regularity normal cone Clarke subdifferential Ekeland variationalprinciple

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All-electrical switching of a topological non-collinear antiferromagnet at room temperature

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National Science Review 2023年第2期10卷 123-130页

作者： Yongcheng Deng Xionghua Liu Yiyuan Chen Zongzheng Du Nai Jiang chao Shen Enze Zhang Houzhi Zheng hai-zhou Lu Kaiyou Wang State Key Laboratory for Superlattices and Microstructures Institute of SemiconductorsChinese Academy of Sciences Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and Technology (SUSTech) International Quantum Academy Beijing Academy of Quantum Information Sciences Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences

Non-collinear antiferromagnetic Weyl semimetals,combining the advantages of a zero stray field and ultrafast spin dynamics,as well as a large anomalous Hall effect and the chiral anomaly of Weyl fermions,have attracted extensive ***,the all-electrical control of such systems at room temperature,a crucial step toward practical application,has not been ***,using a small writing current density of around 5 × 106A·cm-2,we realize the all-electrical current-induced deterministic switching of the non-collinear antiferromagnet Mn3Sn,with a strong readout signal at room temperature in the Si/SiO2/Mn3Sn/AlOxstructure,and without external magnetic field or injected spin *** simulations reveal that the switching originates from the current-induced intrinsic non-collinear spin-orbit torques in Mn3Sn *** findings pave the way for the development of topological antiferromagnetic spintronics.

关键词： spintronics non-collinear antiferromagnetic Weyl semimetals all-electrical switching spin-orbit torques

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