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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

Comparative study of performance comparison of AlSi10Mg alloy prepared by selective laser melting and casting

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Journal of Materials Science & Technology 2020年第6期41卷 199-208页

作者： Qian yan bo Song Yusheng shi State Key Laboratory of Materials Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan430074China

The influence of the microstructure on mechanical properties of AlSi10Mg fabricated by casting and selective laser melting(SLM)were investigated and contrasted in this work,with an emphasis on understanding the forming *** microstructure,phase structure and mechanical properties were characterized by scanning electron microscopy/field-emission Transmission Electron Microscopy(SEM/TEM),X-Ray Diffraction(XRD),tensile and fatigue *** results indicated that the SLM AlSi10Mg exhibited a supersaturated Si network structure precipitated alongα-Al ***β-Al5FeSi andπ-Al8FeMg3Si6 phases were found in the as-cast and SLM AlSi10Mg respectively due to different thermal histories during *** SLM AlSi10Mg showed higher tensile strength but lower elongation than the casting,as the result of grain refinement and tortuous crack *** fatigue results revealed that unmelted powder,oxide inclusion and pores can considerably degrade the fatigue properties for the SLM *** SLM process offered a new method for material processing that would avoid harmful Fe-bearing intermetallic compounds and refine the microstructures for enhancing strength.

关键词： Selective laser melting Casting AlSi10Mg Intermetallic compound Mechanical properties

5-aza-2'-deoxycytidine in the regulation of antioxidant enzymes in retinal endothelial cells and rat diabetic retina

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International Journal of Ophthalmology(English edition) 2019年第1期12卷 1-7页

作者： Man-yun Xie yan yang Ping Liu yan Luo shi-bo Tang Department of Ophthalmology the Second Xiangya HospitalCentral South University Hunan Clinical Research Center of Ophthalmic Diseas The State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen University Aier School of Ophthalmology Central South University Aier Research Institute of Ophthalmology

AIM: To investigate the roles of a DNA methyltransferase(DNMT) inhibitor 5-aza-2'-deoxycytidine(5-aza-dC) in the regulation of antioxidant enzymes in diabetic retinopathy(DR) models. METHODS: DNMTs expressions and activity, and changes of two key antioxidant enzymes in DR, MnSOD(encoded by SOD2 gene) and glutathione S-transferase theta 1(GSTT1), were quantified in the isolated human retinal endothelial cells(HRECs) exposed to high glucose(HG) with or without 5-aza-dC treatment. The downstream exacerbating factors including vascular endothelial growth factor(VEGF), intercellular adhesion molecule 1(ICAM-1) and matrix metalloproteinase 2(MMP2), which are implicated in the pathogenesis of DR and closely related to oxidative stress were also analyzed. The key parameters were confirmed in the retina from streptozotocin(STZ) diabetic rats. RESULTS: DNMTs expression and DNMT activity was induced in HRECs exposed to HG. Hyperglycemia decreased MnSOD and GSTT1 expression. 5-aza-dC administration effectively suppressed DNMTs expression and activity and reversed the MnSOD and GSTT1 expression under HG condition. VEGF, ICAM-1 and MMP2 induced by HG were also suppressed by 5-aza-dC treatment. Similar results were observed in the retina from STZ diabetic rats. CONCLUSION: Our findings suggest that DNA methylation may serves as one of the mechanisms of antioxidant defense system disruption in DR progression. Modulation of DNA methylation using pharmaceutic means such as DNMT inhibitors could help maintain redox homeostasis and prevent further progression of DR.

关键词： DNA methylation diabetic model 5-aza-dC oxidative stress inflammation human retinal endothelial cells rat

Physical layer security strategies for downlink heterogeneous cloud radio access networks

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The Journal of China Universities of Posts and Telecommunications 2014年第5期21卷 47-54,60页

作者： yan shi WANG Wen-bo Key Laboratory of Universal Wireless Communication Beijing University of Posts and Telecommunications

Cloud radio access networks （C-RANs） were proposed as promising solutions to increase both spectrum and energy efficiency performance in next generation wireless communication systems. Much works discussed the concrete implementation technology to justify the huge development potential of C-RAN. However, only a few litterateurs focused on characterizing the physical layer security in the downlink. The authors studied the physical layer security in downlink heterogeneous C-RAN systems in the article. To characterize the random deployment of remote radio units （RRUs） with single antenna configuration, the stochastic geometry is based to evaluate the proposals＇ secrecy transmission capacity performances, where the closed-form expressions are derived. Furthermore, two security strategies based on eavesdropper neutralization region to protect the target RRU user against eavesdropping were presented and analyzed. Simulation illustrates the secrecy transmission capacity performance limits on different system parameters. The presented security strategies show a significant enhancement on the secrecy performance.

关键词： C-RAN Poisson point process (PPP) physical layer security heterogeneous

Model Potential Calculations of Oscillator Strength Spectra of Rydberg Li Atoms in External Fields

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Communications in Theoretical Physics 2009年第8期52卷 333-338页

作者： MENG Hui-yan shi Ting-yun School of Applied Science of Taiyuan University of Science and Technology Taiyuan 030024 China State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan 430071 China

By combining the B-spline basis set with model potential (B-spline + MP),we present oscillator strengthspectra of Rydberg Li atoms in external *** photoabsorption spectra are *** the narrow energyranges considered in this paper,the structure of the spectra can be independent of the initial state chosen for a *** results are in good agreement with previous high-precision experimental data and theoretical calculations,where the R-matrix approach together with multichannel quantum defect theory (R-matrix+MQDT) was *** issuggested that the present methods can be applied to deal with the oscillator strength spectra of Rydberg atoms incrossed electric and magnetic fields.

关键词： B-spline spectra

Fabrication and Statics Performance of Pyramidal Lattice Stitched Foam Sandwich Composites

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Computer Modeling in Engineering & Sciences 2021年第3期126卷 1251-1274页

作者： yun Zhao shi yan Jiale Jia Department of Engineering Mechanics Harbin University of Science and TechnologyHarbinChina

In this study,the pyramidal lattice stitched foam sandwich composite materials were manufactured by integrating top and bottom panels with pyramidal lattice core to overcome the weak interface between the core and the skins of the sandwich *** influence of the reinforcing core rods on the mechanical properties including compressive,shear,and three-point bending performances of the foam sandwich compositematerialswere revealed through theoretical analysis and comparative *** theoretical predictions were consistent with the experimental *** test,shear test and three-point bending test were *** experimental results show that the core rods can significantly improve the compressive performance and energy absorption efficiency of the pyramidal lattice stitched foam sandwich *** effect is related to the diameter of the core *** core rod with large diameter has better *** with the foamsandwich structure,the pyramidal lattice reinforcing foam composites have stronger shear and bending *** failure modes and failure mechanisms of the pyramidal lattice stitched foam sandwich structure under the shear load are *** failure modes and failure mechanisms of the pyramidal lattice stitched foam sandwich structure under the three-point bending load are also *** study concludes that compared with the foam sandwich structure,the overall mechanical properties of the lattice stitched foam sandwich structure composites are significantly improved.

关键词： Pyramidal lattice compressive performance shear three-point bending failure modes

Behaviors of Oxide Layer at Interface between Semi-solid Filler Metal and Aluminum Matrix Composites during Vibration

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Journal of Materials Science & Technology 2011年第8期27卷 746-752页

作者： Lei shi Jiuchun yan yanfei Han bo Peng State Key Laboratory of Advanced Welding and Joining School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

The joint interface between semi-solid Zn-Al filler metal and SiCp/Al composites with applying vibration for different time was examined. With increasing vibrating time, the oxide layer was disrupted prior at the centre to the periphery of the interface. And the solid grains near the centre of interface in semi-solid filler metal aggregated into two solid regions and compressed the composites during vibration; the solid grains near the periphery of interface moved toward the edge and scraped the composites during vibration. The models of disrupting oxide layer under the vibration condition were developed. At the centre of interface, the oxide layer was tore and stripped during the solid grains in the semi-solid filler metal depressing the composites with a very high compressive stress. At the periphery of interface, the oxide layer was cut and stripped into the filler metal during the solid grains scraping the interface.

关键词： SiCP/Al composites Brazing Oxide layer Semi-solid state

3-Methylcyclohexanone Processed n-Channel Organic Thin-Film Transistors Based on a Conjugated Polymer Synthesized by Direct Arylation Polycondensation

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Chinese Journal of Polymer Science 2023年第5期41卷 824-831,I0012页

作者： Dong-Sheng yan Xu-Wen Zhang zhon.-Li Wang Chen-Hui Xu Yi-bo shi yun-Feng Deng yang Han yan-Hou Geng School of Materials Science and Engineering and Tianjin Key Laboratory of Molecular Optoelectronic Science Tianjin Universityand Collaborative Innovation Center of Chemical Science and Engineering(Tianjin)Tianjin 300072China State Key Laboratory of Separation Membranes and Membrane Processes Tianjin Key Laboratory of Advanced Fibers and Energy StorageSchool of Material Science and EngineeringTiangong UniversityTianjin 300387China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350207China

The solubility of a direct arylation polycondensation(DArP)synthesized conjugated polymer,i.e.,poly(3,6-bis(furan-2-yl)-2,5-bis(4-tetradecyloctadecyl)-pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-alt-1,2-bis(3,4-d ifl uorothien-2-yl)ethene)(PFuD PP-4FTVT),in variou s organic solvents was *** polymer is soluble in 3-methylcyclohexanone(3-MC),a green solvent from peppermint oil,besides other solvents such as anisole,cyclopentyl methyl ether(CPME)and o-dichlorobenzene(o-DCB),*** on the Hansen solu bility parameters(HSP)analysis,3-MC is identified as a"marginal solvent"of *** morphology of the spin-coated films with 3-MC as the solvent strongly correlated with the solution preparation *** a 3-MC solution aged for 3 h at 70℃,n-channel organic thin-film transistors(OTFTs)with electron mobility(μe)above 1 cm^(2)·V^(-1)·s^(-1) and current on/off ratio(Ion/Ioff)higher than 105 were fabricated by *** is the first report on high mobility conjugated polymers for OTFTs processible with natu rally occurred green solvent.

关键词： Conjugated polymers Organic thin-film transistors Electron mobility Green solvent Direct arylation polycondensation

Interaction Between Cytochrome c and the Hapten 2,4-Dinitro- fluorobenzene by Electrospray Ionization Mass Spectrometry

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Chinese Journal of Chemical Physics 2008年第3期21卷 217-220页

作者： bo Wu yan-qiu Chu Zhao-yun Dai Chuan-fan Ding Physical Chemistry Institute Department of Chemistry Fudan University Shanghai 200433 China Infectious Disease Department Huadong Hospital Shanghai 200040 China

Allergic contact dermatitis is a delayed hypersensitivity reaction, which results from skin exposure to low molecular weight chemicals such as haptens. To clarify the pathogenic mechanism, electrospray ionization mass spectrometry （ESI-MS） and hydrogen/deuterium （H/D） exchange, as well as UV spectroscopy, were applied to determine the interaction between the model protein cytochrome c （cyt c） and the hapten 2,4- dinitro-fiuorobenzene （DNFB）. The ESI-MS results demonstrate that the conformation of cyt c can change from native folded state into partially unfolded state with the increase of DNFB. The equilibrium state H/D exchange followed by ESI-MS further confirms the above results. UV spectroscopy indicates that the strong- field coordination between iron of heme （prosthetic group） and His18 or Met80 of cyt c is not obviously affected by the hapten.

关键词： Interaction Cytochrome c 2 4-dinitro-fluorobenzene ESI-MS