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基于局部密度聚类的WSN多Sink节点部署研究 被引量:1
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作者 李翠然 吕安琪 +1 位作者 谢健骊 孙振刚 《传感技术学报》 CAS CSCD 北大核心 2024年第2期326-331,共6页
针对无线传感器网络中传感器节点能量受限,网络生命周期短的问题,在考虑网络成本的情况下,提出一种基于节点局部密度聚类的多Sink节点优化部署算法。首先,基于多属性因子构建聚类决策函数确定Sink节点部署位置,完成传感器节点聚类;然后... 针对无线传感器网络中传感器节点能量受限,网络生命周期短的问题,在考虑网络成本的情况下,提出一种基于节点局部密度聚类的多Sink节点优化部署算法。首先,基于多属性因子构建聚类决策函数确定Sink节点部署位置,完成传感器节点聚类;然后,根据下一跳节点与Sink节点间距离最短准则搜索并形成数据传输路径;最后,以网络生命周期成本比最大化为依据确定最优的Sink节点数目,实现多Sink节点优化部署。仿真结果表明:与已有算法相比,所提算法能够有效延长网络生命周期,具有较高的网络生命周期能效比。 展开更多
关键词 无线传感器网络 sink节点部署 局部密度聚类 网络生命周期
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跳数受限下的传感云网络多Sink节点重选址方法
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作者 钟林 刘利 《传感技术学报》 CAS CSCD 北大核心 2024年第3期533-538,共6页
当传感云网络中的Sink节点处于静止状态时,分布在其周围的邻居节点极易出现“能量空洞”,导致能量消耗不均,节点出现不同的网络生存期,影响节点间数据正常传输。为此,在限制节点跳数的前提下,提出一种多Sink节点重选址方法。基于Sink节... 当传感云网络中的Sink节点处于静止状态时,分布在其周围的邻居节点极易出现“能量空洞”,导致能量消耗不均,节点出现不同的网络生存期,影响节点间数据正常传输。为此,在限制节点跳数的前提下,提出一种多Sink节点重选址方法。基于Sink节点寿命和传感云网络代价函数引入质心理论,建立质点系并确定质心位置;将Sink节点向流量大的节点移动,并与其他Sink节点相互协作、避免发生冲突,直至到达质心位置,实现多Sink节点重选址。结果表明,所提方法重选址的节点生存时间最高为1 000 s为,数据包交付率为98%,节点平均剩余能量值高于0.6 J。 展开更多
关键词 传感云网络 sink节点 节点重选址 质点系 网络生存期
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Dynamics and vibration reduction performance of asymmetric tristable nonlinear energy sink 被引量:3
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作者 Hongyan CHEN Youcheng ZENG +2 位作者 Hu DING Siukai LAI Liqun CHEN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第3期389-406,共18页
With its complex nonlinear dynamic behavior,the tristable system has shown excellent performance in areas such as energy harvesting and vibration suppression,and has attracted a lot of attention.In this paper,an asymm... With its complex nonlinear dynamic behavior,the tristable system has shown excellent performance in areas such as energy harvesting and vibration suppression,and has attracted a lot of attention.In this paper,an asymmetric tristable design is proposed to improve the vibration suppression efficiency of nonlinear energy sinks(NESs)for the first time.The proposed asymmetric tristable NES(ATNES)is composed of a pair of oblique springs and a vertical spring.Then,the three stable states,symmetric and asymmetric,can be achieved by the adjustment of the distance and stiffness asymmetry of the oblique springs.The governing equations of a linear oscillator(LO)coupled with the ATNES are derived.The approximate analytical solution to the coupled system is obtained by the harmonic balance method(HBM)and verified numerically.The vibration suppression efficiency of three types of ATNES is compared.The results show that the asymmetric design can improve the efficiency of vibration reduction through comparing the chaotic motion of the NES oscillator between asymmetric steady states.In addition,compared with the symmetrical tristable NES(TNES),the ATNES can effectively control smaller structural vibrations.In other words,the ATNES can effectively solve the threshold problem of TNES failure to weak excitation.Therefore,this paper reveals the vibration reduction mechanism of the ATNES,and provides a pathway to expand the effective excitation amplitude range of the NES. 展开更多
关键词 ASYMMETRIC nonlinear energy sink(NES) tristable vibration control po-tential barrier
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海洋牧场WSN中移动Sink节点的路径规划
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作者 林海伦 王骥 《电子测量与仪器学报》 CSCD 北大核心 2024年第8期208-217,共10页
针对静态部署的海洋牧场无线传感网络在数据多跳传输过程中近Sink节点区域易出现能量空洞的问题,提出一种基于改进蚁群算法的移动Sink节点可靠通信路径规划方法。首先,对于传统蚁群算法,采用非均匀分配初始信息素浓度,解决算法初期盲目... 针对静态部署的海洋牧场无线传感网络在数据多跳传输过程中近Sink节点区域易出现能量空洞的问题,提出一种基于改进蚁群算法的移动Sink节点可靠通信路径规划方法。首先,对于传统蚁群算法,采用非均匀分配初始信息素浓度,解决算法初期盲目搜索的问题;修改状态转移概率函数,增加拥挤度因子,避免死锁现象的同时加快收敛速度;采用改进的信息素更新规则,保证算法后期的收敛能力。其次,利用LEACH协议对网络进行分簇,根据簇头节点的位置和通信覆盖区情况,构建移动Sink遍历节点集。最后,将移动Sink节点路径规划问题看成旅行商问题,并通过改进蚁群算法和构建的骨干节点集求出移动Sink节点的最优路径。仿真实验结果表明,在275个网络节点规模内,该方法与其他算法相比,在路径长度方面依次减少了41.9%、20.3%、30.4%,数据传输时延依次降低了42%、38.5%、46.7%,网络吞吐量依次提高了10%、10.6%、16.4%,验证了该方法的优越性。文章所提出的方法通过引入移动Sink节点并利用其移动路径的合理性可以有效优化海洋牧场无线传感网络数据接收的可靠性、网络的能耗特性与生命周期。 展开更多
关键词 无线传感网络 路径规划 蚁群算法 移动sink节点 节点集 海洋牧场
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Dynamic performance and parameter optimization of a half-vehicle system coupled with an inerter-based X-structure nonlinear energy sink
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作者 Yong WANG Peili WANG +1 位作者 Haodong MENG Liqun CHEN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第1期85-110,共26页
Inspired by the demand of improving the riding comfort and meeting the lightweight design of the vehicle, an inerter-based X-structure nonlinear energy sink(IXNES) is proposed and applied in the half-vehicle system to... Inspired by the demand of improving the riding comfort and meeting the lightweight design of the vehicle, an inerter-based X-structure nonlinear energy sink(IXNES) is proposed and applied in the half-vehicle system to enhance the dynamic performance. The X-structure is used as a mechanism to realize the nonlinear stiffness characteristic of the NES, which can realize the flexibility, adjustability, high efficiency, and easy operation of nonlinear stiffness, and is convenient to apply in the vehicle suspension, and the inerter is applied to replacing the mass of the NES based on the mass amplification characteristic. The dynamic model of the half-vehicle system coupled with the IX-NES is established with the Lagrange theory, and the harmonic balance method(HBM) and the pseudo-arc-length method(PALM) are used to obtain the dynamic response under road harmonic excitation. The corresponding dynamic performance under road harmonic and random excitation is evaluated by six performance indices, and compared with that of the original half-vehicle system to show the benefits of the IX-NES. Furthermore, the structural parameters of the IX-NES are optimized with the genetic algorithm. The results show that for road harmonic and random excitation, using the IX-NES can greatly reduce the resonance peaks and root mean square(RMS) values of the front and rear suspension deflections and the front and rear dynamic tire loads, while the resonance peaks and RMS values of the vehicle body vertical and pitching accelerations are slightly larger.When the structural parameters of the IX-NES are optimized, the vehicle body vertical and pitching accelerations of the half-vehicle system could reduce by 2.41% and 1.16%,respectively, and the other dynamic performance indices are within the reasonable ranges.Thus, the IX-NES combines the advantages of the inerter, X-structure, and NES, which improves the dynamic performance of the half-vehicle system and provides an effective option for vibration attenuation in the vehicle engineering. 展开更多
关键词 inerter X-structure nonlinear energy sink(NES) half-vehicle system dynamic performance
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A viscoelastic nonlinear energy sink with an electromagnetic energy harvester:Narrow-band random response
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作者 廖志晶 孙亚辉 刘洋 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期147-156,共10页
Nonlinear energy sink is a passive energy absorption device that surpasses linear dampers, and has gained significant attention in various fields of vibration suppression. This is owing to its capacity to offer high v... Nonlinear energy sink is a passive energy absorption device that surpasses linear dampers, and has gained significant attention in various fields of vibration suppression. This is owing to its capacity to offer high vibration attenuation and robustness across a wide frequency spectrum. Energy harvester is a device employed to convert kinetic energy into usable electric energy. In this paper, we propose an electromagnetic energy harvester enhanced viscoelastic nonlinear energy sink(VNES) to achieve passive vibration suppression and energy harvesting simultaneously. A critical departure from prior studies is the investigation of the stochastic P-bifurcation of the electromechanically coupled VNES system under narrowband random excitation. Initially, approximate analytical solutions are derived using a combination of a multiple-scale method and a perturbation approach. The substantial agreement between theoretical analysis solutions and numerical solutions obtained from Monte Carlo simulation underscores the method's high degree of validity. Furthermore, the effects of system parameters on system responses are carefully examined. Additionally, we demonstrate that stochastic P-bifurcation can be induced by system parameters, which is further verified by the steady-state density functions of displacement. Lastly,we analyze the impacts of various parameters on the mean square current and the mean output power, which are crucial for selecting suitable parameters to enhance the energy harvesting performance. 展开更多
关键词 nonlinear energy sink fractional-order damping multiple-scale method energy harvester
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Effects of urbanization and forest type on species composition and diversity,forest characteristics,biomass carbon sink,and their associations in Changchun,Northeast China:implications for urban carbon stock improvement
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作者 Yuanyuan Wang Xinzhu Dai +5 位作者 Xingling Chen Dan Zhang Guiqing Lin Yuanhang Zhou Tianyi Wang Yulong Cui 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第2期146-162,共17页
Differences in forest attributes and carbon sequestration of each organ and layer between broadleaved and conifer forests of central and outer urban areas are not well-defined,hindering the precise management of urban... Differences in forest attributes and carbon sequestration of each organ and layer between broadleaved and conifer forests of central and outer urban areas are not well-defined,hindering the precise management of urban forests and improvement of function.To clarify the effect of two forest types with different urbanization intensities,we determined differences in vegetation composition and diversity,structural traits,and carbon stocks of 152 plots(20 m×20 m)in urban park forests in Changchun,which had the largest green quantity and carbon density effectiveness.We found that 1.1-fold thicker and healthier trees,and 1.6-to 2.0-fold higher,healthier,denser,and more various shrubs but with sparser trees and herbs occurred in the central urban forests(p<0.05)than in the outer forests.The conifer forests exhibited 30–70%obviously higher tree aboveground carbon sequestration(including stem and leaf)and 20%bigger trees,especially in the outer forests(p<0.05).In contrast,1.1-to 1.5-fold higher branch stocks,healthier and more diverse trees were found in broadleaved forests of both the inner and outer forests(p<0.05).Plant size and dominant species had similarly important roles in carbon stock improvement,especially big-sized woody plants and Pinus tabuliformis.In addition,a higher number of deciduous or needle species positively affected the broadleaved forest of the central urban area and conifer forest of the outer urban area,respectively.These findings can be used to guide precise management and accelerate the improvement of urban carbon function in Northeast China in the future. 展开更多
关键词 Species diversity Forest characteristics Biomass carbon sink Forest-type effect Urbanization effect Urban forests
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Effects of phosphorus limitation on sinking velocities of phytoplankton during summer in the Changjiang River Estuary
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作者 Xinchi You Qiang Hao +6 位作者 Jie Zhu Wei Zhang Haiyan Jin Dewang Li Huanhong Ji Yu Ke Feng Zhou 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第6期131-141,共11页
The sinking of phytoplankton is critical to organic matter transportation in the ocean and it is an essential process for the formation of coastal hypoxic zones.This study was based on a field investigation conducted ... The sinking of phytoplankton is critical to organic matter transportation in the ocean and it is an essential process for the formation of coastal hypoxic zones.This study was based on a field investigation conducted during the summer of 2022 in the Changjiang River(Yangtze River) Estuary(CJE) and its adjacent waters.The settling column method was employed to measure the sinking velocity(SV) of different size fractions of phytoplankton at the surface of the sea and to analyze their environmental control mechanisms.The findings reveal significant spatial variation in phytoplankton SV(-0.55-2.41 m/d) within the CJE.High-speed sinking was predominantly observed in phosphate-depleted regions beyond the CJE front.At the same time,an upward trend was more commonly observed in the phosphate-rich regions near the CJE mouth.The SV ranges for different sizefractionated phytoplankton,including micro-(>20 μm),nano-(2-20 μm),and picophytoplankton(0.7-2 μm),were-0.50-4.74 m/d,-1.04-1.59 m/d,and-1.24-1.65 m/d,respectively.Correlation analysis revealed a significant negative correlation between SV and dissolved inorganic phosphorus(DIP),implying that the influence of DIP contributes to SV.The variations in phytoplankton alkaline phosphatase activity suggested a significant increase in SV across all size fractions in the event of phosphorus limitation.Phytoplankton communities with limited photo synthetic capacity(maximum photochemical efficience,Fv/Fm <0.3) were found to have higher SV than that of communities with strong capacity,suggesting a link between sinking and alterations in physiological conditions due to phosphate depletion.The findings from the in situ phosphate enrichment experiments confirmed a marked decrease in SV following phosphate supplementation.These findings suggest that phosphorus limitation is the primary driver of elevated SV in the CJE.This study enhances the comprehension of the potential mechanisms underlying hypoxic zone formation in the CJE,providing novel insights into how nearshore eutrophication influences organic carbon migration. 展开更多
关键词 PHYTOPLANKTON sinking velocity Changjiang River Estuary phosphorus limitation alkaline phosphatase
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Effects of nutrient limitations on the sinking velocity of Thalassiosira weissflogii
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作者 Jie Zhu Qiang Hao +2 位作者 Wei Zhang Yingying Ma Jiangning Zeng 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第6期163-172,共10页
The sinking of diatoms is critic al to the formation of oceanic biological pumps and coastal hypoxic zones.However,little is known about the effects of different nutrient restrictions on diatom sinking.In this study,w... The sinking of diatoms is critic al to the formation of oceanic biological pumps and coastal hypoxic zones.However,little is known about the effects of different nutrient restrictions on diatom sinking.In this study,we measured the sinking velocity(SV) of Thalassiosira weissflogii using a new phytoplankton video observation instrument and analyzed major biochemical components under varying nutrient conditions.Our results showed that the SV of T.weissflogii under different nutrient limitation conditions varied substantially.The highest SV of(1.77±0.02) m/d was obtained under nitrate limitation,signific antly surpassing that under phosphate limitation at(0.98±0.13) m/d.As the nutrient limitation was released,the SV steadily decreased to(0.32±0.03) m/d and(0.15±0.05) m/d,respectively.Notably;under conditions with limited nitrate and phosphate concentrations,the SV values of T.weissflogii significantly positively correlated with the lipid content(P <0.001),with R^(2) values of 0.86 and 0.69,respectively.The change of the phytoplankton SV was primarily related to the intracellular compo sition,which is controlled by nutrient conditions but did not significantly correlate with transparent extracellular polymer and biosilica contents.The results of this study help to understand the regulation of the vertical sinking process of diatoms by nutrient restriction and provide new insights into phytoplankton dynamics and their relationship with the marine nutrient structure. 展开更多
关键词 nutrient limitation Thalassiosira weissflogii sinking velocity biochemical component lipid content
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A comprehensive review on microchannel heat sinks for electronics cooling
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作者 Zhi-Qiang Yu Mo-Tong Li Bing-Yang Cao 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第2期133-162,共30页
The heat generation of electronic devices is increasing dramatically,which causes a serious bottleneck in the thermal management of electronics,and overheating will result in performance deterioration and even device ... The heat generation of electronic devices is increasing dramatically,which causes a serious bottleneck in the thermal management of electronics,and overheating will result in performance deterioration and even device damage.With the development of micro-machining technologies,the microchannel heat sink(MCHS)has become one of the best ways to remove the considerable amount of heat generated by high-power electronics.It has the advantages of large specific surface area,small size,coolant saving and high heat transfer coefficient.This paper comprehensively takes an overview of the research progress in MCHSs and generalizes the hotspots and bottlenecks of this area.The heat transfer mechanisms and performances of different channel structures,coolants,channel materials and some other influencing factors are reviewed.Additionally,this paper classifies the heat transfer enhancement technology and reviews the related studies on both the single-phase and phase-change flow and heat transfer.The comprehensive review is expected to provide a theoretical reference and technical guidance for further research and application of MCHSs in the future. 展开更多
关键词 microchannel heat sink thermal management of electronics microscale heat transfer heat transfer enhancement
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A vertical track nonlinear energy sink
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作者 Meng LI Hu DING 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第6期931-946,共16页
Eliminating the effects of gravity and designing nonlinear energy sinks(NESs)that suppress vibration in the vertical direction is a challenging task with numerous damping requirements.In this paper,the dynamic design ... Eliminating the effects of gravity and designing nonlinear energy sinks(NESs)that suppress vibration in the vertical direction is a challenging task with numerous damping requirements.In this paper,the dynamic design of a vertical track nonlinear energy sink(VTNES)with zero linear stiffness in the vertical direction is proposed and realized for the first time.The motion differential equations of the VTNES coupled with a linear oscillator(LO)are established.With the strong nonlinearity considered of the VTNES,the steady-state response of the system is analyzed with the harmonic balance method(HBM),and the accuracy of the HBM is verified numerically.On this basis,the VTNES prototype is manufactured,and its nonlinear stiffness is identified.The damping effect and dynamic characteristics of the VTNES are studied theoretically and experimentally.The results show that the VTNES has better damping effects when strong modulation responses(SMRs)occur.Moreover,even for small-amplitude vibration,the VTNES also has a good vibration suppression effect.To sum up,in order to suppress the vertical vibration,an NES is designed and developed,which can suppress the vertical vibration within certain ranges of the resonance frequency and the vibration intensity. 展开更多
关键词 track nonlinear energy sink(TNES) vertical direction GRAVITY nonlinear stiffness harmonic balance method(HBM) vibration control
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Heat dissipation enhancement method for finned heat sink for AGV motor driver's IGBT module
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作者 刘璇 ZHANG Mingchao +2 位作者 LIU Chengwen ZHOU Chuanan LV Xiaoling 《High Technology Letters》 EI CAS 2024年第2期170-178,共9页
With the widespread use of high-power and highly integrated insulated gate bipolar transistor(IGBT),their cooling methods have become challenging.This paper proposes a liquid cooling scheme for heavy-duty automated gu... With the widespread use of high-power and highly integrated insulated gate bipolar transistor(IGBT),their cooling methods have become challenging.This paper proposes a liquid cooling scheme for heavy-duty automated guided vehicle(AGV)motor driver in port environment,and improves heat dissipation by analyzing and optimizing the core component of finned heat sink.Firstly,the temperature distribution of the initial scheme is studied by using Fluent software,and the heat transfer characteristics of the finned heat sink are obtained through numerical analysis.Secondly,an orthogonal test is designed and combined with the response surface methodology to optimize the structural parameters of the finned heat sink,resulting in a 14.57%increase in the heat dissipation effect.Finally,the effectiveness of heat dissipation enhancement is verified.This work provides valuable insights into improving the heat dissipation of IGBT modules and heat sinks,and provides guidance for their future applications. 展开更多
关键词 finned heat sink insulated gate bipolar transistor(IGBT)module heat dissipation orthogonal test response surface methodology
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Carbon emission risk of construction industry in Hebei Province of China based on carbon sink thresholds
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作者 NIU Jian-guang ZHANG Yu-ke +1 位作者 XIN Bo-xiong WANG Ming-qi 《Ecological Economy》 2024年第3期265-277,共13页
In order to assess the environmental risks caused by carbon emissions from the construction industry in Hebei Province of China,an environmental risk assessment model based on forest carbon sink threshold was construc... In order to assess the environmental risks caused by carbon emissions from the construction industry in Hebei Province of China,an environmental risk assessment model based on forest carbon sink threshold was constructed to evaluate the carbon emission risks of the construction industry in Hebei Province,China from 2005 to 2020.The results are shown as follows:(1)The overall carbon emissions of the construction industry in Hebei Province of China showed an inverted"V"-shaped evolution trend during the past 16 years.Tangshan and Shijiazhuang maintained high carbon emissions,while Langfang,Hengshui and Baoding saw rapid increases in carbon emissions.(2)The environmental safety threshold of carbon emission from the construction industry in Hebei Province,China,has been continuously improved,and the provincial environmental safety threshold is between 9475080-23144760 tons;The environmental safety threshold was the highest in Baoding and Langfang,and the lowest in Xingtai.(3)In the past 16 years,the carbon emission risk of the construction industry in Hebei Province of China has been in a state of extremely serious risk,and the risk index generally presents an inverted"V"type trend.(4)The carbon emission risk of Hebei city in China presents a spatial pattern of"high in the south and low in the north",which goes through two stages:risk increase period and risk reduction period. 展开更多
关键词 carbon emission in construction industry forest carbon sink environmental risk safety threshold
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Coupling and Long-term Change Characteristics of Forest Carbon Sink and Forestry Economic Development in China
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作者 Ying ZHANG Na MENG Keren ZHANG 《Asian Agricultural Research》 2024年第7期1-11,共11页
[Objectives]To analyze the changes in of forest carbon sink and forestry economic development,provide reference for relevant management decisions,ecological governance and resource and environment management,and promo... [Objectives]To analyze the changes in of forest carbon sink and forestry economic development,provide reference for relevant management decisions,ecological governance and resource and environment management,and promote the development of green low-carbon economy in China.[Methods]Based on the data of six forest resource inventories from 1989 to 2018 and related studies,the comprehensive evaluation model of forest carbon sink and forestry economic development,the coupling degree model of forest carbon sink and forestry economic development,and the coupling coordination degree model of forest carbon sink and forestry economic development were adopted.The coupling degree of forest carbon sink and forestry economic development from 1992 to 2018 was analyzed.Stepwise regression and ARIMA model were used to analyze the influencing factors and lagging characteristics of forest carbon sink.The coupling degree between forest carbon sink and forestry economic development in China from 2019 to 2030 was predicted by autoregression and ADF test.The coupling between forest carbon sink and forestry economic development in China and its long-term change characteristics were also discussed in this study.[Results](i)The investment of ecological construction and protection,the actual investment of forestry key ecological projects,GDP and the import of forest products had a significant impact on forest resources carbon stock.The total output value of forestry industry,the actually completed investment of forestry key ecological projects and the export volume of forest products had a significant impact on the forest carbon sink,and the actually completed investment of forestry key ecological projects has the greatest impact on the two.(ii)The impact of actually completed investment of forestry key ecological projects had a lag of 2 years on the forest resources carbon stock and a lag of 1 year on the forest carbon sink.When investing in forest carbon sink,it is necessary to make a good plan in advance,and do a good job in forest resources management and time optimization.(iii)From 1992 to 2018,the coupling degree of forest resources carbon stock,forest carbon sink and long-term development of forestry economy in China was gradually increasing.Although there were some fluctuations in the middle time,the coupling degree of forest resources carbon stock and the long-term development of forestry economy increased by 9.24%annually,and the degree of coupling coordination increased from"serious imbalance"in 1992 to"high-quality coordination"in 2018.From 1993 to 2018,the coupling degree of forest carbon sink and long-term development of forestry economy increased by 9.63%annually,slightly faster than the coupling coordination degree of forest resources carbon stock and long-term development of forestry economy.The coordination level also rose from level 2 in 1993 to level 10 in 2018.(iv)The prediction shows that the coupling coordination degree of forest resources carbon stock,forest carbon sink and the long-term development of forestry economy would increase from 2019 to 2030.The coupling coordination degree(D)values of both were close to 1,the coordination level was also 10 for a long time,and the degree of coupling coordination was also maintained at the"high-quality coordination"level for a long time.[Conclusions]Forest has multiple benefits of society,economy and ecology,and forest carbon sink is only a benefit output.The long-term coupling analysis of forest carbon sink and forestry economic development is a key point to multiple benefit analysis.The analysis shows that the spillover effect and co-evolution effect of forest carbon sink in China are significant.From 1992 to 2018,the coupling coordination degree of forest carbon sink and forestry economic development was gradually rising.The prediction analysis also indicate that the coupling coordination degree between the forest carbon sink and the long-term development of forestry economy will remain at the level of"high-quality coordination"for a long time from 2019 to 2030.Therefore,improving the level of forest management and maintaining the current trend of increasing forest resources are the key to achieving the goal of carbon peaking and carbon neutrality in China. 展开更多
关键词 Forest resources carbon stock Forest carbon sink Coupling coordination degree Forestry economic development Long-term trend
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基于元胞自动机的移动sink路径规划算法
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作者 吕安琪 李翠然 谢健骊 《兰州交通大学学报》 CAS 2023年第6期44-49,共6页
为降低无线传感器网络中移动sink数据收集时延,提出一种基于元胞自动机的移动sink路径规划算法。首先,利用网格划分获得移动sink备选驻留点;然后,基于元胞自动机搜索获得移动sink驻留点集合,采用Von Neumann元胞邻居模型计算备选驻留点... 为降低无线传感器网络中移动sink数据收集时延,提出一种基于元胞自动机的移动sink路径规划算法。首先,利用网格划分获得移动sink备选驻留点;然后,基于元胞自动机搜索获得移动sink驻留点集合,采用Von Neumann元胞邻居模型计算备选驻留点预估密度,根据备选驻留点预估密度与备选驻留点至移动sink间距离选择驻留点;最后,使用蚁群算法优化经过所有驻留点的移动sink路径。仿真结果表明:所提算法可以减少驻留点数目,缩短移动sink路径长度,从而降低数据收集时延。 展开更多
关键词 无线传感器网络 移动sink 元胞自动机 蚁群算法 时延
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Multi-scenario Simulation for 2060 and Driving Factors of the Eco-spatial Carbon Sink in the Beibu Gulf Urban Agglomeration, China 被引量:6
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作者 QIN Menglin ZHAO Yincheng +3 位作者 LIU Yuting JIANG Hongbo LI Hang ZHU Ziming 《Chinese Geographical Science》 SCIE CSCD 2023年第1期85-101,共17页
Since China announced its goal of becoming carbon-neutral by 2060, carbon neutrality has become a major target in the development of China's urban agglomerations. This study applied the Future Land Use Simulation(... Since China announced its goal of becoming carbon-neutral by 2060, carbon neutrality has become a major target in the development of China's urban agglomerations. This study applied the Future Land Use Simulation(FLUS) model to predict the land use pattern of the ecological space of the Beibu Gulf urban agglomeration, in 2060 under ecological priority, agricultural priority and urbanized priority scenarios. The Integrated Valuation of Ecosystem Services and Trade-offs(In VEST) model was employed to analyse the spatial changes in ecological space carbon storage in each scenario from 2020 to 2060. Then, this study used a Geographically Weighted Regression(GWR) model to determine the main driving factors that influence the changes in land carbon sinking capacity. The results of the study can be summarised as follows: firstly, the agricultural and ecological priority scenarios will achieve balanced urban expansion and environmental protection of resources in an ecological space. The urbanized priority scenario will reduce the carbon sinking capacity. Among the simulation scenarios for 2060, carbon storage in the urbanized priority scenario will decrease by 112.26 × 10^(6) t compared with that for 2020 and the average carbon density will decrease by 0.96 kg/m^(2) compared with that for 2020. Carbon storage in the agricultural priority scenario will increase by 84.11 × 10^(6) t, and the average carbon density will decrease by 0.72 kg/m^(2). Carbon storage in the ecological priority scenario will increase by 3.03 × 10^(6) t, and the average carbon density will increase by 0.03 kg/m^(2). Under the premise that the population of the town will increases continuously, the ecological priority development approach may be a wise choice.Secondly, slope, distance to river and elevation are the most important factors that influence the carbon sink pattern of the ecological space in the Beibu Gulf urban agglomeration, followed by GDP, population density, slope direction and distance to traffic infrastructure.At the same time, urban space expansion is the main cause of the changes of this natural factors. Thirdly, the decreasing trend of ecological space is difficult to reverse, so reasonable land use policy to curb the spatial expansion of cities need to be made. 展开更多
关键词 Integrated Valuation of Ecosystem Services and Trade-offs(InVEST)model carbon sink multi-scenario simulation ecological space driving factor Beibu Gulf urban agglomeration
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一种广域无线传感网络移动Sink节点路径规划方法
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作者 何栋 桂志国 《传感技术学报》 CAS CSCD 北大核心 2023年第3期475-480,共6页
在广域无线传感网络中,大量Sink节点处在移动状态,路径规划过程易受其他节点特征的干扰,导致规划效果较差,提出一种针对广域无线传感网络的移动Sink节点路径规划方法。利用Sink数据采集协议确定节点的最佳位置,通过计算最大网络寿命成... 在广域无线传感网络中,大量Sink节点处在移动状态,路径规划过程易受其他节点特征的干扰,导致规划效果较差,提出一种针对广域无线传感网络的移动Sink节点路径规划方法。利用Sink数据采集协议确定节点的最佳位置,通过计算最大网络寿命成本比确定节点的最佳数量后,根据节点的最佳位置和数量规划出最大容量路径。依据最大容量路径计算出Sink节点在四个方向上的权值系数,并沿着最大权值系数的方向移动,完成广域无线传感网络移动Sink节点路径规划。仿真结果表明,所提方法的运行时间低于6 s、路径长度最长为53 cm、拐点数量少于9个、迭代次数高达69次。 展开更多
关键词 广域无线传感网络 数据采集协议 sink节点路径规划 最大网络寿命 最佳节点个数 网络能耗模型 传输路径
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Effects of viscoelasticity on the stability and bifurcations of nonlinear energy sinks 被引量:1
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作者 A.MOSLEMI M.R.HOMAEINEZHAD 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第1期141-158,共18页
Due to the increasing use of passive absorbers to control unwanted vibrations,many studies have been done on energy absorbers ideally,but the lack of studies of real environmental conditions on these absorbers is felt... Due to the increasing use of passive absorbers to control unwanted vibrations,many studies have been done on energy absorbers ideally,but the lack of studies of real environmental conditions on these absorbers is felt.The present work investigates the effect of viscoelasticity on the stability and bifurcations of a system attached to a nonlinear energy sink(NES).In this paper,the Burgers model is assumed for the viscoelasticity in an NES,and a linear oscillator system is considered for investigating the instabilities and bifurcations.The equations of motion of the coupled system are solved by using the harmonic balance and pseudo-arc-length continuation methods.The results show that the viscoelasticity affects the frequency intervals of the Hopf and saddle-node branches,and by increasing the stiffness parameters of the viscoelasticity,the conditions of these branches occur in larger ranges of the external force amplitudes,and also reduce the frequency range of the branches.In addition,increasing the viscoelastic damping parameter has the potential to completely eliminate the instability of the system and gradually reduce the amplitude of the jump phenomenon. 展开更多
关键词 VISCOELASTICITY Burgers model nonlinear energy sink(NES) saddle-node bifurcation Hopf bifurcation
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Vertical vibration control using nonlinear energy sink with inertial amplifier
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作者 Weixing ZHANG Wei ZHANG Xiangying GUO 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第10期1721-1738,共18页
To reduce additional mass, this work proposes a nonlinear energy sink(NES)with an inertial amplifier(NES-IA) to control the vertical vibration of the objects under harmonic and shock excitations. Moreover, this paper ... To reduce additional mass, this work proposes a nonlinear energy sink(NES)with an inertial amplifier(NES-IA) to control the vertical vibration of the objects under harmonic and shock excitations. Moreover, this paper constructs pure nonlinear stiffness without neglecting the gravity effect of the oscillator. Both analytical and numerical methods are used to evaluate the performance of the NES-IA. The research findings indicate that even if the actual mass is 1% of the main oscillator, the NES-IA with proper inertia angles and mass distribution ratios can still effectively attenuate the steady-state and transient responses of the main oscillator. Nonlinear stiffness and damping also have important effects. Due to strongly nonlinear factors, the coupled system may exhibit higher branch responses under harmonic excitation. In shock excitation environment, the NES-IA with a large dynamic mass can trigger energy capture of both main resonance and high-frequency resonance. Furthermore, the comparison with the traditional NES also confirms the advantages of the NES-IA in overcoming mass dependence. 展开更多
关键词 nonlinear energy sink(NES) vibration reduction inertial amplifier(IA) higher branch response high-frequency resonance
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Computer simulation of Cu:AlOOH/water in a microchannel heat sink using a porous media technique and solved by numerical analysis AGM and FEM
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作者 S.A.Abdollahi P.Jalili +4 位作者 B.Jalili H.Nourozpour Y.Safari P.Pasha D.D.Ganji 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2023年第3期177-187,共11页
Extensive improvements in small-scale thermal systems in electronic circuits,automotive industries,and microcomputers conduct the study of microsystems as essential.Flow and thermic field characteristics of the cohere... Extensive improvements in small-scale thermal systems in electronic circuits,automotive industries,and microcomputers conduct the study of microsystems as essential.Flow and thermic field characteristics of the coherent nanofluid-guided microchannel heat sink are described in this perusal.The porous media approximate was used to search the heat distribution in the expanded sheet and Cu:γ-AlOOH/water.A hybrid blend of Boehme copper and aluminum nanoparticles is evaluated to have a cooling effect on the microchannel heat sink.By using Akbari Ganji and finite element methods,linear and non-linear differential equations as well as simple dimensionless equations have been analyzed.The purpose of this study is to investigate the fluid and thermal parameters of copper hybrid solution added to water,such as Nusselt number and Darcy number so that we can reach the best cooling of the fluid.Also,by installing a piece of fin on the wall of the heat sink,the coefficient of conductive heat transfer and displacement heat transfer with the surrounding air fluid increases,and the efficiency of the system increases.The overall results show that expanding values on the NP(series heat transfer fluid system maximizes performance with temperatures)volume division of copper,as well as boehmite alumina particles,lead to a decrease within the stream velocity of the Cu:AlOOH/water.Increasing the volume fraction of nanoparticles in the hybrid mixture decreases the temperature of the solid surface and the hybrid nanofluid.The Brownian movement improves as the volume percentage of nanoparticles in the hybrid mixture grows,spreading the heat across the environment.As a result,heat transmission rates rise.As the Darcy number increases,the thermal field for solid sections and Cu:AlOOH/water improves. 展开更多
关键词 Finite element method AGM method MICROCHANNEL Heat sink Porous media Cu:γ-AlOOH/water
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