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Characterization of alpine meadow surface crack and its correlation with root-soil properties

Journal of Arid Land 2024年第6期16卷 834-851页

作者： WU Yuechen ZHU Haili ZHANG Yu ZHANG Hailong liu guosong liu Yabin LI Guorong HU Xiasong School of Geological Engineering Qinghai UniversityXining 810016China Key Laboratory of the Cenozoic Resources and Environment on the North Rim of the Qinghai-Tibet Plateau Xining 810016China Qinghai Provincial Transportation Planning and Design Research Institute Co.Ltd. Xining 810002China

Quantifying surface cracks in alpine meadows is a prerequisite and a key aspect in the study of grassland crack *** characterization indices are crucial for the quantitative characterization of complex cracks,serving as vital factors in assessing the degree of cracking and the development *** far,research on evaluating the degree of grassland degradation through crack characterization indices is rare,especially the quantitative analysis of the development of surface cracks in alpine meadows is relatively ***,based on the phenomenon of surface cracking during the degradation of alpine meadows in some regions of the Qinghai-Tibet Plateau,we selected the alpine meadow in the Huangcheng Mongolian Township,Menyuan Hui Autonomous County,Qinghai Province,China as the study area,used unmanned aerial vehicle(UAV)sensing technology to acquire low-altitude images of alpine meadow surface cracks at different degrees of degradation(light,medium,and heavy degradation),and analyzed the representative metrics characterizing the degree of crack development by interpreting the crack length,length density,branch angle,and burrow(rat hole)distribution density and combining them with in situ crack width and depth ***,the correlations between the crack characterization indices and the soil and root parameters of sample plots at different degrees of degradation in the study area were analyzed using the grey relation *** results revealed that with the increase of degradation,the physical and chemical properties of soil and the mechanical properties of root-soil composite changed significantly,the vegetation coverage reduced,and the root system aggregated in the surface layer of alpine *** the degree of degradation increased,the fracture morphology developed from"linear"to"dendritic",and eventually to a complex and irregular"polygonal"*** crack length,width,depth,and length density were identified as the crack char

关键词： alpine meadow grassland degradation grassland cracks crack characterization index crack morphology root length density grey relation analysis

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Bioinspired nanotransducers for neuromodulation

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Nano Research 2024年第2期17卷 618-632页

作者： Fan Yang Xiang Wu Sa Cai guosong Hong Department of Materials Science and Engineering Stanford UniversityStanfordCA 94305USA Wu Tsai Neurosciences Institute Stanford UniversityStanfordCA 94305USA School of Science Shenzhen Campus of Sun Yat-sen UniversityShenzhen 518107China

The field of neuromodulation has experienced significant advancements in the past decade,owing to breakthroughs in disciplines such as materials science,genetics,bioengineering,photonics,and *** convergence of these fields has resulted in the development of nanotransducers,devices that harness the synergies of these diverse *** nanotransducers,essential for neuromodulation,often draw inspiration from energy conversion processes found in nature for their unique *** this review,we will delve into the latest advancements in wireless neuromodulation facilitated by optical,magnetic,and mechanical *** will examine their working principles,properties,advantages,and limitations in comparison to current methods for deep brain neuromodulation,highlighting the impact of natural systems on their design and ***,we will underscore potential future directions,emphasizing how continued progress in materials science,neuroscience,and bioengineering might expand the horizons of what is achievable with nanotransducer-enabled neuromodulation.

关键词： bioinspired synthesis neuromodulation mechanoluminescence focused ultrasound nanotransducers sono-optogenetics

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Metallogenesis of the Baidi Au-Sb deposit, southwest Guizhou Province, China: mineralogical and geochemical evidence from sulfur-bearing minerals

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Acta Geochimica 2024年第2期43卷 199-213页

作者： Jun Yan Yong Xia Qinping Tan Zhuojun Xie guosong Ji State KeyLaboratory of Ore Deposit Geochemistry Institute of GeochemistryChineseAcademy of SciencesGuiyang 550081China Guizhou InstituteofTechnology Guiyang550003China No.102 GeologicalTeam Guizhou Bureau of Geologyand Mineral Exploration&DevelopmentZunyi563003China

The Baidi Au-Sb deposit, which contains 8 t of Au and 10,979 Mt of Sb, is a typical and rare paragenetic deposit located in southwestern Guizhou Province, *** studies have focused on individual ores, but have not combined them to identify their paragenetic mechanism or metallogenic regularity. Therefore, we used field investigations, microscopic observations, and in situ analyses to identify the spatial distribution, mineral paragenesis, compositional evolution, and metallogenic material sources of the ore bodies. We also determined the Au and Sb paragenetic characteristics and the metallogenesis of the deposit. The main Au-bearing minerals in the deposit were early(Apy1–2) and late(Apy3) stage arsenopyrites, as well as pre-mineralization(Py1), mineralization(Py2–5), and late mineralization(Py6–7) stage pyrites. The main Sb-bearing minerals were stibnite(Snt), skinnerite, bournonite,and valentinite. The minerals formed in the order of Py1,Py2–3 + Apy1, Py4–5 + Apy2, Snt, and Py6–7 + *** δ34S values of the arsenopyrites and pyrites ranged from-5 to 5‰, while those of stibnite were mostly less than-5‰ in the later mineralization stages. Sulfur was provided by deep magmatic hydrothermal fluids, but sedimentary sulfur was added in the later stages. Moreover,the trace elemental contents fluctuated and eventually became similar to those of the sedimentary strata. By comprehensively considering the ores along with the geological characteristics of the deposit, we determined that deep magma provided the Au during ore formation. Later tectonic changes provided Sb from the sedimentary strata,which precipitated along fault expansion areas and produced Au and Sb paragenesis.

关键词： Au-Sb mineralization Arsenopyrite Pyrite Stibnite Metallogenetic process

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The Experimental Vibration Analysis of Small-scale Unmanned Helicopter for Control Design

The Experimental Vibration Analysis of Small-scale Unmanned ...

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第37届中国控制会议

作者： Shuai TANG guosong liu Li ZHANG Bin ZHOU Army Logistics University of PLA National University of Defense Technology

This paper focuses on the experimental vibration analysis of the small-scale unmanned helicopter and the methods to weaken the influence for control design. The vibration source of the small-scale helicopter and the evaluation criteria are introduced. The influence of the main blades dynamic balance on vibration is analyzed and the way to decrease is presented;based on frequency domain analysis technology, the influence of the main rotor speed is well-analyzed and the method to optimize the rotor speed is proposed. The experimental results show that the analysis and the methods are effective and suitable for vibration reduction.

关键词： Small-scale helicopter Vibration Intensity Natural frequency Frequency spectrum

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Elevation of brain magnesium enhances pattern separation and prevents fear generalization

Elevation of brain magnesium enhances pattern separation and...

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中国神经科学学会第十届全国学术会议

作者： Nashat ABUMARIA Lin LUO Matae AHN guosong liu Department of Basic Medical Research School of MedicineTsinghua University Center for Learning and Memory School of MedicineUniversity of Texas at Austin

Enhancement of pattern separation could be helpful in improving the quality of normal daily learning and in treating individuals with cognitive impairment and/or certain psychiatric *** example,pattern separation declines during normal ***-traumatic stress disorder（PTSD） patients re-experience symptoms in response to novel contexts that are reminiscent of the original one associated with the ***,depressed patients often negatively overgeneralize autobiographical memories in response to emotion-related ***,we have shown that elevating brain magnesium,by a novel magnesium compound（magnesium-L-threonate;MgT）,enhances extinction of fear memory without enhancing amygdala dependent fear ***,we investigated the effects of MgT treatment on contextual-fear memory and subsequent pattern separation;a higher cognitive function that is impaired in PTSD ***-Dawley male rats were treated with MgT for 4 weeks and memory was evaluated using contextual fear conditioning *** pattern separation ability of MgT-treated rats was assessed using a spatial-context-discrimination *** treatment did not enhance the retention of contextual fear ***,the ability to discriminate between two,more or less distinct,contexts was enhanced in MgT-treated *** results suggest that elevation of brain magnesium might be helpful in enhancing pattern separation besides preventing aversive-event-induced fear *** with our previous study,the data support the potential use of MgT in treating the cognitive impairments associated with psychiatric disorders such as depression,phobias and PTSD.

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Reconfiguration of Synaptic Network and Enhancement of Memory by Magnesium Ion

Reconfiguration of Synaptic Network and Enhancement of Memor...

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中国神经科学学会第四次会员代表大会暨第七届全国学术会议

作者： guosong liu Center for Learning and Memory,School of Medicine,Tsinghua University

＜正＞The human brain has roughly 10 billion neurons that communicate with one another through synaptic connections. Each neuron is capable of making 5,000-10,000 synapses its targets,leading to 50-100 trillion synaptic connections in the *** connections between neurons give rise to functional neural networks that provide the cellular substrate for higher cognitive functions such as learning,memory and,ultimately,*** these complex connections are established during the early phases of nervous system development and optimized in lifespan remains largely unknown. Continuing our inquiries into the regulation of the relationships among neurons and among synapses within a single neuron,we are increasing our understanding of the conditions necessary to maximize the efficacy of these relationships, and thus to optimize the performance of neural ***,we explored the molecular profiles,synaptic function, and network configuration necessary for circuitry plasticity and identified several endogenous factors,which serve as key regulators of synaptic plasticity and *** of molecules is *** the way;we also demonstrated that the memory capacity of synaptic network is controlled not only by the proteins critical for synaptic plasticity,but also by the functional organization of synapses on *** intact animal,increase in Magnesium intake is effective to enhance the memory function of young animal,prevent age-associated memory decline in aging animal,and alleviate the cognitive impairment of the transgenic mice with Alzheimer *** clinical trials based our discovery are undergoing to translate the knowledge from our research to the new therapy for the treatment of neurological disease with decline of memory function.

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Quasi-CW Diode Laser End-pumped Yb3+: Glass Microchip Laser

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Chinese Journal of Lasers 2002年第2期11卷 6-8页

作者： DAI Shixun HU Lili liu Zhuping HUANG guosong JIANG Zhonghong( Shanghai Institute of Optics and Fine Mechanics, The Chinese Academyof Sciences, Shanghai 201800, China)YASUKAZU Izawa(Institute of Laser Engineering, Oska University, Osaka 565-0871, Japan ) Shanghai Institute of Optics and Fine Mechanics The Chinese Academy of Sciences 上海 Shanghai Institute of Optics and Fine Mechanics The Chinese Academy of Sciences 上海 201800 Institute of Laser Engineering Oska University 日本 Osaka 565-0871

Quasi-CW diode-pumped Yb3+: borate glass and Yb3+: phosphate glass microchip lasers have been reported. From Yb3+: phosphate glass laser, the maximum average output power was 31 mW and the optical-optical conversion efficiency was 5% . The maximum average output power was 18 mW, and optical-optical conversion efficiency was 3% for Yb3+ :borate glass laser.

关键词： LD pumping ytterbium doped borate glasses ytterbium doped phosphate glasses Quasi-CW lasers

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Electrolyte Effect on Photoetching of Gallium Nitride

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Nanomanufacturing and Metrology 2024年第1期7卷 61-74页

作者： Huiqiang Liang Zhenghao Wei Jiongchong Fang Yanming Li Changli Li Zhirun Xie Yun Hau Ng guosong Zeng Shenzhen Key Laboratory of Intelligent Robotics and Flexible Manufacturing Systems Southern University of Science and TechnologyShenzhen 518055People’s Republic of China Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen 518055People’s Republic of China School of Materials Sun Yat-Sen UniversityGuangzhou 510275People’s Republic of China School of Energy and Environment City University of Hong KongKowloon 999077Hong Kong SARPeople’s Republic of China City University of Hong Kong Shenzhen Research Institute Shenzhen Hi-Tech Industrial ParkNanshan DistrictShenzhen 518000People’s Republic of China SUSTech Energy Institute for Carbon Neutrality Southern University of Science and TechnologyShenzhen 518055People’s Republic of China

The limited material removal rate of conventional chemical mechanical polishing(CMP)significantly hinders the fabrica-tion efficiency and surface quality,thereby preventing the development of gallium nitride(GaN)-based ***,the incorporation of photoelectrochemistry in CMP has garnered increasing attention because of its potential to enhance the quality and efficiency of the GaN ***,a considerable gap still exists in the comprehensive understanding of the specific photoelectrochemical(PEC)behavior of ***,we report the influence of the electrolyte on the PEC etching of *** acids and bases were tested,with their pH being carefully *** concentrations of the cations and anions were also *** results showed that photocorrosion/photoetching was more pronounced in sulfuric acid,phosphoric acid,and nitric acid environments than in alkaline environments,but it was less pronounced in hydrochloric ***,the effects of pH and anion concentration on photoetching were investigated,and the results revealed that pho-toetching in acidic environments weakened with increasing pH levels and diminished with increasing sulfate *** underlying reasons contributing to this observation were *** findings provide ideas for improving the pho-toetching efficiency of GaN,thereby enriching the photoelectrochemical mechanical polishing(PECMP)technology of GaN.

关键词： GaN Photoelectrochemistry Photoetching pH

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国有林场的功能优势与创新管理策略探讨

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林业勘查设计 2022年第3期51卷 21-23,38页

作者：刘国松辽宁省海城市上英林场辽宁海城114200

国有林场是林业生态文明建设的核心力量。在林业发展中,国有林场功能优势十分显著,使其优势得到充分发挥,关键因素在于林场的科学管理,同时还要不断创新。由于国有林场在过去长期受传统经济体制的制约,在经营管理上较为粗放和落后,研究... 详细信息

国有林场是林业生态文明建设的核心力量。在林业发展中,国有林场功能优势十分显著,使其优势得到充分发挥,关键因素在于林场的科学管理,同时还要不断创新。由于国有林场在过去长期受传统经济体制的制约,在经营管理上较为粗放和落后,研究和摸索更加适合国有林场发展的管理思路,创建和完善国有林场的管理体系。在分析国有林场功能优势的基础上,提出国有林场的管理方略和创新路径,促进国有林场管理水平的进一步提升。

关键词：国有林场功能优势创新管理策略

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内箝位型压电精密步进旋转驱动器

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机械工程学报 2006年第11期42卷 103-108页

作者：刘建芳杨志刚赵宏伟程光明刘国嵩吉林大学机械科学与工程学院长春130022

提出一种新型的压电精密步进旋转驱动器。该驱动器以仿生运动的原理,以压电陶瓷叠堆为动力源,采用定子内侧箝位的方式和薄壁柔性铰链微变形结构,提高该驱动器箝位的稳定性和步进旋转的稳定性。通过静力学有限元分析和动力学分析,较深入... 详细信息

提出一种新型的压电精密步进旋转驱动器。该驱动器以仿生运动的原理,以压电陶瓷叠堆为动力源,采用定子内侧箝位的方式和薄壁柔性铰链微变形结构,提高该驱动器箝位的稳定性和步进旋转的稳定性。通过静力学有限元分析和动力学分析,较深入地研究了该驱动器的运动特性,并对驱动器旋转分辨率、旋转速度、驱动转矩等方面进行试验研究。研制的内箝位型压电精密步进旋转驱动器能够实现高频率(40 Hz),较高速度(325μrad/s),大行程(大于360°),高分辨率(1μrad),较大驱动力矩(30N·cm)等特点,有效提高了压电精密步进旋转驱动器的驱动性能。该驱动器在精密运动、微操作、光学工程以及精密定位等精密工程中具有广阔的应用前景。

关键词：压电陶瓷叠堆定子内侧箝位薄壁柔性铰链有限元分析分辨率

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