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Effect of thinning intensity on understory herbaceous diversity and biomass in mixed coniferous and broad-leaved forests of Changbai Mountain

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Forest Ecosystems 2021年第4期8卷 713-725页

作者： Gerong Wang Yue Sun Mo Zhou naiqian guan Yuwen Wang Runhua Jiang Zhiyu Liu Mengjia Wu Fucai Xia Key Laboratory of State Forestry Administration on Conservation and Efficient Utilization of Precious and Rare Forest Resource in Changbai Mountain Forestry CollegeBeihua University132013 JilinChina West Campus of Hebei Agricultural University 2596 Lekai South StreetLianchi District071000 BaodingChina

Background:Herbs are an important part of the forest ecosystem,and their diversity and biomass can reflect the restoration of vegetation after forest thinning *** on the near-mature secondary coniferous and broad-leaved mixed forest in Jilin Province Forestry Experimental Zone,this study analyzed seasonal changes of species diversity and biomass of the understory herb layer after different intensities of ***:The results showed that although the composition of herbaceous species and the ranking of importance values were affected by thinning intensity,they were mainly determined by seasonal *** the entire growing season,the species with the highest importance values in thinning treatments included Carex pilosa,Aegopodium alpestre,Meehania urticifolia,and Filipendula palmata,which dominated the herb layer of the coniferous and broad-leaved mixed *** number of species,Margalef index,Shannon-Wiener index and Simpson index all had their highest values in May,and gradually decreased with *** index was roughly inverted“N”throughout the growing *** did not increase the species *** can promote the total biomass,above-and below-ground *** number of plants per unit area and coverage were related to the total biomass,above-and below-ground *** average height had a significantly positive correlation with herb biomass in May but not in ***,it exerted a significantly negative correlation with herb biomass in *** biomass in the same month increased with increasing thinning *** herb biomass,above-and below-ground biomass showed positive correlations with Shannon-Winner index,Simpson index and Pielou evenness index in ***:Thinning mainly changed the light environment in the forest,which would improve the plant diversity and biomass of herb layer in a short *** different thinning intensity had different effects on the diversity of understory

关键词： Selective thinning Mixed coniferous and broad-leaved forests Herbaceous plants Diversity Biomass

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The stress-thermal equivalence“memory effect”in glass materials

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Science China(Physics,Mechanics & Astronomy) 2024年第10期67卷 175-176页

作者： Pengfei guan Beijing Computational Science Research Center Beijing 100193China

Glass materials,including metallic,organic,and silicate glasses,are crucial in various engineering applications due to their unique disordered atomic packing ***,these materials suffer from stress decay under constant... 详细信息

关键词： glasses glass stress

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A low-frequency and broadband wave-insulating vibration isolator based on plate-shaped metastructures

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1171-1188页

作者： Wei WEI Feng guan Xin FANG College of Intelligent Science National University of Defense TechnologyChangsha410073China Naval Research Academy Beijing100161China

A metamaterial vibration isolator,termed as wave-insulating isolator,is proposed,which preserves enough load-bearing capability and offers ultra-low and broad bandgaps for greatly enhanced wave *** consists of plate-shaped metacells,whose symmetric and antisymmetric local resonant modes offer several low and broad mode bandgaps although the complete bandgap remains high and *** bandgap mechanisms,vibration isolation properties,effects of key parameters,and robustness to complex conditions are *** experimentally demonstrated,the wave-insulating isolator can improve the vibration insulation in the ranges of[50 Hz,180 Hz]and[260 Hz,400 Hz]by 15 dB and 25 dB,respectively,in contrast to the conventional isolator with the same first resonant frequency.

关键词： metamaterial and metastructure vibration isolation bandgap wave insulation plate

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Brain Mechanisms Underlying Panic Attack and Panic Disorder

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Neuroscience Bulletin 2024年第6期40卷 795-814页

作者： Xuyan guan Peng Cao Tsinghua Institute of Multidisciplinary Biomedical Research Tsinghua UniversityBeijing102206China National Institute of Biological Sciences(NIBS) Beijing102206China

Panic disorder is a psychiatric disorder characterized by recurrent panic attacks,with a prevalence of~4%in the general population,causing heavy personal and socioeconomic *** similarities of animal defense responses to clinical panic attack symptoms in humans make it possible to translate neuroanatomical pathways identified in animal studies to panic disorder in ***,in this review we first present a basic overview of panic disorder in humans including the main subtypes,models commonly used to trigger panic attacks,related hypotheses,the neurotransmitter systems that may be involved,and the current clinical treatments to give the reader a comprehensive understanding of panic *** animal section introduces the models that trigger panic-like behavior in animals and the brain regions that may be involved,providing insights for future elucidation of the neural circuit mechanisms behind panic attacks.

关键词： Panic disorder Panic attack Defense responses Animal studies Humans

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3D Localization for Multiple AUVs in Anchor-Free Environments by Exploring the Use of Depth Information

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 1051-1053页

作者： Yichen Li Wenbin Yu Xinping guan the Department of Automation Shanghai Jiao Tong UniversityShanghai 200240 the Key Laboratory of System Control and Information Processing Ministry of Education of ChinaShanghai Jiao Tong UniversityShanghai 200240China

Dear Editor,This letter investigates the cooperative localization problem for multiple autonomous underwater vehicles(AUVs)in underwater anchor-free environments,where AUV localization errors grow without bound due to the accumulated errors in inertial measurements(termed accumulated errors hereafter)and the lack of anchors(with known positions).

关键词： AUVs underwater hereafter

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Proactive Resilience Enhancement of Power Systems with Link Transmission Model-based Dynamic Traffic Assignment Among Electric Vehicles

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1320-1330页

作者： Haoyuan Yan Tianyang Zhao Zhanglei guan Energy Electricity Research Center Jinan UniversityGuangzhou 510632China Energy Research Institute Nanyang Technological UniversitySingapore IEEE

The rapid development of electric vehicles(EVs)is strengthening the bi-directional interactions between electric power networks(EPNs)and transportation networks(TNs)while providing opportunities to enhance the resilience of power systems towards extreme *** quantify the temporal and spatial flexibility of EVs for charging and discharging,a novel dynamic traffic assignment(DTA)problem is *** DTA problem is based on a link transmission model(LTM)with extended charging links,depicting the interaction between EVs and power *** models the charging rates as continuous variables by an energy boundary *** consider the evacuation requirements of TNs and the uncertainties of traffic conditions,the DTA problem is extended to a two-stage distributionally robust *** is further incorporated into a two-stage distributionally robust unit commitment problem to balance the enhancement of EPNs and the performance of *** problem is reformulated into a mixed-integer linear programming problem and solved by off-the-shelf commercial *** studies are performed on two test *** effectiveness is verified by the numerical results,e.g.,reducing the load shedding amount without increasing the unmet traffic demand.

关键词： Coupled transportation and power network link transmission model resilience enhancement

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Reduced magma generation and its implications for the Pulang giant porphyry Cu-polymetallic deposit in Northwest Yunnan,China

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Acta Geochimica 2024年第4期43卷 802-813页

作者： Jingwei guan Tao Ren Lei Wang Shenjin guan Lianrong Wu Baosheng Shi Faculty of Land Resources Engineering Kunming University of Science and TechnologyKunming 650093People’s Republic of China Diqing Nonferrous Metals Co. LtdShangri-La 674400People’s Republic of China

The Pulang giant porphyry Cu-Mo polymetallic deposit is located in the Zhongdian area in the center of the Sanjiang Tethys tectonic domain,which was formed by the westward subduction of the Garze-Litang oceanic slab beneath the Zhongza ***-pyrrhotite-pyritemolybdenite occurs as disseminations,veins,veinlets,and stockworks distributed in the K-silicate alteration zone in the monzonite porphyry,which is superimposed by *** chemical compositions of biotite and amphibole analyzed by electron probe microanalysis(EPMA)indicate that the ore-forming magma and exsolved fluids experienced a continuous decrease in the oxygen fugacity(fO_(2)).Primary amphibolite and biotite(type I)crystallized at relatively high temperatures(744-827°C)and low fO_(2)(log fO_(2)=−12.26 to−11.91)during the magmatic *** fluids exsolved from the magma have a relatively lower temperature(621-711°C)and fO_(2)(log fO_(2)=−14.36 to−13.32)than the original *** addition,the presence of a high abundance of pyrrhotite and an insufficiency of primary magnetite and sulfate in the ore(i.e.,anhydrite and gypsum)indicate that the deposit may be a reduced porphyry *** and fluid fO_(2)results,combined with previous research on magmatic fO_(2)at the Pulang deposit,indicate that the magma associated with the reduced Pulang ore assemblages was initially generated as a highly oxidized magma that was subsequently reduced by sedimentary rocks of the Tumugou Formation.

关键词： Porphyry deposit Oxygen fugacity(fO_(2)) Contamination of surrounding rock Pulang Zhongdian arc

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Automatic Requirement Dependency Extraction Based on Integrated Active Learning Strategies

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Machine Intelligence Research 2024年第5期21卷 993-1010页

作者： Hui guan Guorong Cai Hang Xu Department of Computer Science and Technology Shenyang University of Chemical TechnologyShenyang110142China Key Laboratory of Industrial Intelligence Technology on Chemical Process Shenyang110142China

Since requirement dependency extraction is a cognitively challenging and error-prone task,this paper proposes an automatic requirement dependency extraction method based on integrated active learning *** this paper,the coefficient of variation method was used to determine the corresponding weight of the impact factors from three different angles:uncertainty probability,text similarity difference degree and active learning variant prediction divergence *** combining the three factors with the proposed calculation formula to measure the information value of dependency pairs,the top K dependency pairs with the highest comprehensive evaluation value are selected as the optimal *** the optimal samples are continuously added into the initial training set,the performance of the active learning model using different dependency features for requirement dependency extraction is rapidly ***,compared with other active learning strategies,a higher evaluation measure of requirement dependency extraction can be achieved by using the same number of ***,the proposed method using the PV-DM dependency feature improves the weight-F1 by 2.71%,the weight-recall by 2.45%,and the weight-precision by 2.64%in comparison with other strategies,saving approximately 46%of the labelled data compared with the machine learning approach.

关键词： Requirement dependency dependency extraction dependency features integrated active learning strategies coefficient of variation

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W-band millimeter wave vialess microstrip-to-microstrip vertical transition in multilayer LCP substrate

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The Journal of China Universities of Posts and Telecommunications 2024年第3期31卷 87-94页

作者： Liu Weihong Zhang Xu guan Dongyang School of Electronic Engineering Xian University of Posts and TelecommunicationsXi'an 710121China

In this paper,a W-band broadband vialess microstrip(MS)-to-MS vertical transition in multilayer liquid crystal polymer(LCP)substrate is presented,which consists of two MS lines in the top layer,a common ground plane and slotline resonators in the second layer,and a close-loop transmission-line in the third *** increase the passband of the vialess vertical transition,an H-shaped slotline resonator is introduced,which greatly improves the impedance performance of the slotline resonator,and the full-wave simulated results indicate that insertion loss(IL)is less than 2 dB and return loss(RL)is better than 10 dB at *** verify this design,the broadband vertical transition is fabricated and *** measured results indicate that a broadband vertical transition with RL better than 10 dB and IL less than 5.67 dB can be obtained in the frequency range from 70.00 GHz to 104.09 *** to the fabrication error in the preparation process,the measured results are deteriorated compared to the simulated results,and the investigation indicates that the deviation is caused by the thickness error of the LCP substrate.

关键词： W-band broadband microstrip(MS)-to-MS vialess vertical transition liquid crystal polymer(LCP)

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Review on synergistic damage effect of irradiation and corrosion on reactor structural alloys

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Nuclear Science and Techniques 2024年第3期35卷 109-141页

作者： Hui Liu guan-Hong Lei He-Fei Huang Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

The synergistic damage effect of irradiation and corrosion of reactor structural materials has been a prominent research *** paper provides a comprehensive review of the synergistic effects on the third-and fourth-generation fission nuclear energy structural materials used in pressurized water reactors and molten salt *** competitive mechanisms of multiple influencing factors,such as the irradiation dose,corrosion type,and environmental temperature,are summarized in this *** approaches are proposed to alleviate the synergistic damage caused by irradiation and corrosion,thereby promoting in-depth research in the future and solving this key challenge for the structural materials used in reactors.

关键词： Irradiation and corrosion Synergistic effect Austenitic stainless steels Nickel-based alloys Reactors

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