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Eulerian and Bipartite Binary Delta-matroids

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Acta Mathematicae Applicatae Sinica 2022年第4期38卷 813-821页

作者： Qi yan Xian-an jin School of Mathematics China University of Mining and TechnologyXuzhou 221116China School of Mathematical Sciences Xiamen UniversityXiamen 361005China

Delta-matroid theory is often thought of as a generalization of topological graph *** is well-known that an orientable embedded graph is bipartite if and only if its Petrie dual is *** this paper,we first introduce the concepts of Eulerian and bipartite delta-matroids and then extend the result from embedded graphs to arbitrary binary *** dual of any bipartite embedded graph is *** also extend the result from embedded graphs to the class of delta-matroids that arise as twists of binary *** related results are also obtained.

关键词： matroid delta-matroid binary bipartite Eulerian

Checkerboard Colourable Twuals

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Acta Mathematica Sinica,English Series 2022年第3期38卷 612-622页

作者： Qi yan Xian An jin School of Mathematics China University of Mining and TechnologyXuzhou221116P.R.China School of Mathematical Sciences Xiamen UniversityXiamen361005P.R.China

In this article we show that any embedded graph has a checkerboard colourable twual,which is equivalent to having a bipartite *** also obtain that any Eulerian embedded graph has a checkerboard colourable partial Petr... 详细信息

关键词： Embedded graphs twuals twisted dual partial duality petrie dual medial graphs direction checkerboard colourable

湿地表层底泥溶解性有机质荧光组分特征及与真菌群落相关性

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光谱学与光谱分析 2025年第1期45卷 191-196页

作者：史传奇李艳孟令波胡钰金梁哈尔滨学院黑龙江省寒区湿地生态与环境研究重点实验室黑龙江哈尔滨150086 北京市农林科学院植物营养与资源环境研究所北京100097 东北农业大学资源与环境学院黑龙江哈尔滨150038

溶解性有机质(DOM)和微生物群落间具有紧密联系,DOM为微生物提供营养,微生物代谢可转化DOM,两者间相互作用共同影响着生态系统的物质循环与能量流动。采集北方寒区天然湿地(河流湿地,HL;湖泊湿地,HP)和人工湿地(水田,ST;鱼塘,YT)表层(0~... 详细信息

溶解性有机质(DOM)和微生物群落间具有紧密联系,DOM为微生物提供营养,微生物代谢可转化DOM,两者间相互作用共同影响着生态系统的物质循环与能量流动。采集北方寒区天然湿地(河流湿地,HL;湖泊湿地,HP)和人工湿地(水田,ST;鱼塘,YT)表层(0~15 cm)底泥样品,采用三维荧光光谱法和高通量测序技术,揭示不同类型湿地表层底泥DOM荧光光谱及真菌群落特征,并进一步分析其相关性。结果表明:表层底泥DOM荧光光谱共识别出4种荧光组分,包括类富里酸(C1)、类胡敏酸(C2)和类蛋白质(类色氨酸C3和类酪氨酸C4)。C1和C2成显著正相关,而与类蛋白质间相关性不显著。C1的相对浓度高于C2,C3和C4的相对浓度接近。YT中DOM浓度相对高于其余样品,HL和HP中C2和类蛋白质相对浓度具有显著差异,ST和YT中C1、C2和C3的相对浓度均具有显著差异。湿地表层底泥真菌群落优势门(除未分类类群)为子囊菌门(Ascomycota)、担子菌门(Basidiomycota)、罗兹菌门(Rozellomycota)。YT中真菌群落Chao1丰富度指数、Shannon多样性指数显著较低,而Simpson优势度指数显著较高,HP中Shannon多样性指数显著高于其余样品。C1、C2与真菌群落多样性显著相关,C2与真菌群落组成显著相关,而类蛋白质与真菌群落无显著相关性。C1、C2与子囊菌门均成显著正相关,C1与壶菌门(Chytridiomycota)和单毛壶菌门(Monoblepharomycota)成显著负相关,C2与担子菌门、罗兹菌门、壶菌门、单毛壶菌门均成显著负相关。因此,真菌群落对DOM相对大分子量荧光组分的相对浓度具有显著影响。针对北方寒区典型湿地表层底泥DOM荧光光谱特征及与真菌群落相关性进行分析,为湿地环境监测与评价提供基础数据,并为湿地合理利用提供理论参考。

关键词：三维荧光光谱溶解性有机质荧光组分真菌

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藻类爆发成因及处理技术探讨

水利技术监督 2025年第1期 231-236页

作者：金敬慈严爱兰浙江水利水电学院浙江杭州310018

藻类爆发引起的“水华”仍然是我国自然水域污染治理中亟待解决的问题之一。通过梳理和分析相关文献,探讨并综述藻类大量繁殖的成因及藻类处理前沿技术动态和发展趋势,结果显示,藻类生长呈现明显的季节性变化,常见的藻类处理技术包括物... 详细信息

藻类爆发引起的“水华”仍然是我国自然水域污染治理中亟待解决的问题之一。通过梳理和分析相关文献,探讨并综述藻类大量繁殖的成因及藻类处理前沿技术动态和发展趋势,结果显示,藻类生长呈现明显的季节性变化,常见的藻类处理技术包括物理、化学、生物技术,藻类监控技术等方面。研究结果为藻类相关领域提供有益的参考和启示,为藻类水华的处理、研究和发展提供一定的理论支撑。

关键词：藻类水华水环境藻类监控藻类处理

A Reverse Auction Framework for Hybrid Access in Femtocell Network

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Journal of Computer Science & Technology 2017年第6期32卷 1250-1264页

作者： yan-Jiao Chen Xiao-yan Yin jin Zhang State Key Laboratory of Software Engineering School of Computer Wuhan University Wuhan 430072 China School of Information Science and Technology Northwest University Xi'an 710127 China Department of Computer Science and Engineering Southern University of Science and Technology Shenzhen 518055 China

In the two-tier macro-femto heterogeneous network, hybrid access is regarded as the most ideal access con- trol approach to mitigating macro-femto cross-tier interference and enhancing overall network performance. However, the implementation of hybrid access is hindered by a lack of incentive market mechanism to motivate private femtocell owners to offer access permissions to macro users. In this paper, we propose a reverse auction framework for access permission transaction between a macrocell operator and multiple femtocell owners to promote hybrid access. Our goal is to maximize social welfare while guaranteeing the truthfulness of the auction. Since the coverage of multiple femtocells may overlap, we partition each cell to adjust the granularity of access permission availability. We first propose a Vickery-Clarke-Grove （VCG）-based mechanism, which costs the least among all auction mechanisms that produce maximum social welfare. As the VCG mechanism is too time-consuming, we propose two alternative truthful mechanisms, namely, generalized second- price and suboptimal mechanism. We further extend the auction framework to the scenario where femtocell owners have heterogeneous valuations for access permissions in different locations.

关键词： femtocell hybrid access reverse auction

Priority effects of forbs arriving early:the role of root interaction and asymmetric competition

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Ecological Processes 2024年第1期13卷 53-65页

作者： Xiaohong yan Xiliang Li Ke jin Institute of Grassland Research Chinese Academy of Agricultural Sciences

Background The priority effect of plant arrival is a key driver of community assembly and ecosystem succession during the restoration of degraded plant communities. However, the significance of the arrival order of different plant functional groups and their interactions with community assemblies remains unclear. Using a phytotron experiment with three fully crossed factors, we investigated the underlying mechanisms of priority effects and their relationships with the biomass and biodiversity effects in mixed plant communities by manipulating the order of arrival of species, isolation of roots, and removal of specific *** The results showed that the strength and direction of priority effects were influenced by arrival order, root interactions, asymmetric competition among species, and their interactions. The identities of early and late-sown species also determined the magnitude of priority effects. The priority effects were stronger in grass-first(24.76%) and legume-first communities(24.48%) than in forb-first communities. The pot biomass of the different priority treatments was highest in grass-first(5.85 g), followed by legume-first(3.94 g) and forb-first(2.48 g). The order of arrival in the mixture significantly affected the net biodiversity effects(P < 0.001), which were driven by dominance effects. The community had lower overall biomass when forbs were sown first, whereas the species grown later had fewer costs with an increased overall net benefit for the resulting *** Our results emphasize that root interactions and asymmetric competition are vital determinants of order-specific priority effects in community assemblies. In addition, the importance of the priority effect of forbs sown first is related to community assembly, which may be a key determinant in successfully establishing a highly diverse community in the early stages of restoration. Species with weak competition should be considered in the early stage of community ass

关键词： Community assembly Order of arrival Overyielding Plant functional group Root isolation

Simple preparation of C(CS)/g-C_(3)N_(4)/Co carbon aerogel and its catalytic performance for ammonium perchlorate

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Defence Technology（防务技术） 2024年第3期33卷 186-196页

作者： Yujie yan Bo jin Rufang Peng State Key Laboratory of Environment-friendly Energy Materials School of Materials Science and EngineeringSouthwest University of Science and TechnologyMianyang621010China

Biomass chitosan(CS)was used as a template,graphitic phase carbon nitride(g-C_(3)N_(4))with high nitrogen content and certain catalytic activity was used as a dopant,and nano-transition metal cobalt(Co)was used as a catalytic center *** carbon aerogel(C(CS)/g-C_(3)N_(4)/Co)with a three-dimensional network-like structure was prepared by assembling the three materials through experimental operations such as freeze-drying and high-temperature *** was demonstrated by scanning and transmission characterization that the CS in the carbon aerogel could provide more active sites for the cobalt nanoparticles,and the doping of graphite-phase carbon nitride as a template dispersed the cobalt nanoparticles and changed the conductivity of the *** investigate the catalytic effect of carbon aerogel on ammonium perchlorate(AP),it was investigated by differential thermal analyzer and TG thermal *** carbon aerogel was very effective in catalyzing AP,and the 10 wt% content of the catalyst reduced the AP pyrolysis peak from 703.9 to 595.5 *** to further investigate the synergistic effect of the three materials,further carbon aerogels such as C(CS)/Co,g-C_(3)N_(4)/Co were prepared and applied to catalyze AP,and the same ratio reduced the AP pyrolysis peak by 98.1℃ and 97.7℃.This result indicates a synergistic effect of the assembly of the three materials.

关键词： g-C_(3)N_(4) Chitosan Co Ammonium perchlorate Pyrolysis kinetics

On the Martensitic Transformation Temperatures and Mechanical Properties of NiTi Alloy Manufactured by Selective Laser Melting: Effect of Remelting

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Acta Metallurgica Sinica(English Letters) 2021年第9期34卷 1223-1233页

作者： Jian-Bin Zhan yan-jin Lu jin-Xin Lin College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350007China Key Laboratory of Optoelectronic Materials Chemistry and Physics Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China

In this study, the infl uence of laser remelting on the relative density, martensitic transformation temperatures(MTTs), and mechanical properties of a NiTi alloy fabricated by selective laser melting(SLM) at a laser power between 15 and 75 W were investigated. A relative alloy density of approximately 99% was achieved in the power range of 45–60 W corresponding to the forming energy density range of 65.45–87.27 J/mm3. The MTTs increased with the increase in the energy density;thus, the initial contents of the B2 and B19′ phases of the SLM-produced NiTi alloy can be tailored by the utilized technique. However, the number of defects such as metallurgical pores and microcracks considerably increased at higher energy densities(> 87.27 J/mm3). Interestingly, the concentration of these defects was reduced by remelting in the energy density range of 21.82–65.45 J/mm3, while the alloy relative density increased to 99.7% ± 0.1% at a remelting energy density of 65.45 J/mm3. The results of tensile testing revealed that when the remelting energy was 75% or 100% of the forming energy input, the ultimate tensile strength and elongation of the alloy significantly increased. Therefore, the remelting strategy represents a promising route for manufacturing NiTi alloys with desired MTT ranges and mechanical properties.

关键词： Selective laser melting NiTi alloy Laser remelting Martensitic transformation temperature

Lower Bounds of Distance Laplacian Spectral Radii of n-Vertex Graphs in Terms of Fractional Matching Number

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Journal of the Operations Research Society of China 2023年第1期11卷 189-196页

作者： jin yan yan Liu Xue-Li Su School of Mathematical Sciences South China Normal UniversityGuangzhou510631GuangdongChina

A fractional matching of a graph G is a function f: E(G)→[0,1] such that for each vertex v, ∑eϵΓG(v)f(e)≤1.. The fractional matching number of G is the maximum value of ∑e∈E(G)f(e) over all fractional matchings f. Tian et al. (Linear Algebra Appl 506:579–587, 2016) determined the extremal graphs with minimum distance Laplacian spectral radius among n-vertex graphs with given matching number. However, a natural problem is left open: among all n-vertex graphs with given fractional matching number, how about the lower bound of their distance Laplacian spectral radii and which graphs minimize the distance Laplacian spectral radii? In this paper, we solve these problems completely.

关键词： Distance Laplacian Spectral radius Fractional matching number