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Preparation of Polyurea Elastomer with Flame Retardant, Insulation and Thermal Conductivity Properties

Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 781-789页

作者：方今 DONG Yang LU Shangkai LIU Junbang AI Lianghui 刘平 State Key Laboratory of Luminescent Materials and Devices Research Institute of Materials ScienceSouth China University of TechnologyGuangzhou 510640China

By using 6,6-((sulfonylbis(4,1-phenylene)bis(azanediyl))bis(thiophen-2-ylm-ethylene))bis6H-di-benzo[c,e][1,2]oxaphosphinine 6-oxide(DOPO-N)as phosphorus-nitrogen flame retardant,the polyurea(PUA)with flame retardant properties(PUA/DOPO-N)was *** addition,organically modified montmorillonite(OMMT)and magnesium hydroxide(MH)were used as co-effectors respectively,and the flame retardant PUA(PUA/DOPO-N/OMMT and PUA/DOPO-N/MH)were also *** properties,flame retardant properties,flame retardant mechanism and mechanical properties of PUA/DOPO-N,PUA/DOPO-N/OMMT and PUA/DOPO-N/MH were investigated by thermogravimetric(TG)analysis,limiting oxygen index(LOI),UL 94,cone calorimeter test,scanning electron microscopy(SEM),and tensile *** results show that the LOI value of PUA/20%DOPO-N,PUA/18%DOPO-N/2%OMMT and PUA/15%DOPO-N/5%MH are 27.1%,27.7%,and 28.3%,respectively,and UL 94 V-0 rating is *** with PUA,the peak heat release rate(pk-HRR),total heat release(THR)and average effective heat combustion(av-EHC)of PUA/20%DOPO-N,PUA/18%DOPO-N/2%OMMT and PUA/15%DOPO-N/5%MH decrease *** results indicate that the residual chars of PUA/20%DOPO-N,PUA/18%DOPO-N/2%OMMT and PUA/15%DOPO-N/5%MH are completer and more *** complex of DOPO-N/OMMT and DOPO-N/MH have synergistic flame *** mechanical properties of PUA can be improved by the addition of DOPO-N,DOPO-N/OMMT and DOPO-N/MH,*** insulation performance test shows that the volume resistivity of PUA/20%DOPO-N is 6.25×10^(16)Ω.***,by using modified boron nitride(mbn)as heat dissipating material,the complex of PUA/mbn was prepared,and the thermal conductivity of PUA/mbn was *** thermal conductivity of PUA/8%mbn complex coating at room temperature is 0.166 W/(M·K),which is a 163%improvement over pure PUA.

关键词： polyurea organic flame retardant inorganic flame retardant synergistic flame retardancy insulation thermal conductivity

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Warming intensified the effects of nitrogen addition on N_(2)O emissions from alpine meadow in the northern Qinghai-Tibet Plateau

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Advances in Climate Change research 2024年第1期15卷 101-112页

作者： Ming-Jie LI Yi-Qing GE Hasbagan GANJURJAV Guo-Zheng HU Hong-Bao WU Jun YAN Shi-Cheng HE Qing-Zhu GAO Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural SciencesBeijing 100081China National Agricultural Experimental Station for Agricultural Environment Nagqu 852100China Ecology and Nature Conservation Institute Chinese Academy of ForestryBeijing 100091China College of Resource and Environment Anhui Science and Technology UniversityFengyang 233100China Nagqu Agriculture Animal Husbandryand Prataculture Science and Technology Research and Extension CenterNagqu 852100China Tongliao Experimental Middle School Tongliao 028000China

Warming and nitrogen(N)addition may impact soil nitrous oxide(N_(2)O)emissions,but the relationship between plant community composition and soil microbial activities remains *** a two-year field study in the Qinghai-Tibet Plateau,open-top chambers were used to quantify the effects of warming,N-addition,and their interactions on N_(2)O *** found that the N-addition greatly increased N_(2)O emissions by 77.4%in 2018 when compared to the control *** contrast,warming showed little effect on N_(2)0 emissions but did increase the activity of enzymes associated with soil nitrification and denitrification.A combined effect of warming and N-addition of resulted in 208.6%(2018)and 90.8%(2019)increase in N_(2)0 emissions,respectively,compared to the individual treatments of warming or *** warming in alpine meadows is causally linked to increased legume biomass which is further intensified with the *** legume biomass(pmbn)(p<0.05)correlated with reduced N_(2)O *** results indicated that N-addition has a positive effect on N_(2)O emissions,and the addition of warming further intensifies this *** increased dominance of legumes and microbial N content contributes to this *** outcomes suggest that warming and atmospheric N deposition can stimulate N_(2)O emissions of alpine meadows inthefuture.

关键词： Alpine meadow Community composition Nitrogen addition Nitrous oxide flux Qinghai-Tibet Plateau Warming

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Neuromorphic nanocluster networks:Critical role of the substrate in nano-link formation

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Nano research 2023年第7期16卷 10500-10506页

作者： Wenkai Wu Alexey V.Verkhovtsev Theodoros Pavloudis Andrey V.Solov’yov Richard E.Palmer Nanomaterials Lab Faculty of Science and EngineeringSwansea UniversityBay CampusFabian WaySA18ENSwanseaUK mbn research center Altenhöferallee 360438 Frankfurt am MainGermany School of Physics Faculty of SciencesAristotle University of ThessalonikiGR-54124 ThessalonikiGreece

Atomic cluster-based networks represent a promising architecture for the realization of neuromorphic computing systems,which may overcome some of the limitations of the current computing *** formation and breakage of links between the clusters are of utmost importance for the functioning of these computing *** paper reports the results of molecular dynamics simulations of synapse(bridge)formation at elevated temperature and thermal breaking processes between 2.8 nmsized Au1415 clusters deposited on a carbon substrate,a model ***,we find that the bridge formation process is driven by the diffusion of gold atoms along the substrate,no matter how small the gap between the clusters *** complementary simulations of the bridge breaking process reveal the existence of a threshold bias voltage to activate bridge rupture via Joule *** results provide an atomistic-level understanding of the fundamental dynamical processes occurring in neuromorphic cluster arrays.

关键词： atomic-switch network nanoclusters nanoparticles(NPs) clusters on surfaces synapse neuromorphics molecular dynamics(MD)

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Caution to Apply Magnetic Barkhausen Noise Method to Nondestructive Evaluation of Plastic Deformation in Some Ferromagnetic Materials

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Chinese Journal of Mechanical Engineering 2019年第6期32卷 85-91页

作者： Manru He Takanori Matsumoto Tetsuya Uchimoto Toshiyuki Takagi Hongen Chen Shejuan Xie Zhenmao Chen Shannxi Engineering research center for NDT and Structural Integrity Evaluation State Key Laboratory for Strength and Vibration of Mechanical StructuresSchool of AerospaceXi’an Jiaotong UniversityXi’an 710049China Institute of Fluid Science Tohoku UniversitySendai 980‑8577Japan

Magnetic Barkhausen Noise(mbn) method is known as an effective nondestructive evaluation(NDE) method for evaluation of residual stress in ferromagnetic materials. Some studies on the feasibility of the mbn method for NDE of residual strains were also conducted and found applicable. However, these studies are mainly focused on the state of residual strains which were introduced through a one-cycle-loading process. In practice, however, structures may suffer from an unpredictable and complicated loading history, i.e., the final state of plastic strain may be induced by several times of large loads. Whether the loading history has influences on mbn signals or not is of great importance for the practical application of the mbn method. In this paper, several ferromagnetic specimens with the same final state of residual strain but of different loading history were fabricated and inspected by using a mbn testing system. The experimental results reveal that the loading history has a significant influence on the detected mbn signals especially for a residual strain in range less than 1%, which doubts the feasibility to apply the mbn method simply in the practical environment. In addition, micro-observations on the magnetic domain structures of the plastic damaged specimens were also carried out to clarify the influence mechanism of loading history on the mbn signals.

关键词： Plastic damage Deformation history mbn method Ferromagnetic materials

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浅析我国便利店赢利模式

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科技资讯 2010年第12期8卷 181-182页

作者：张文达哈尔滨商业大学mbn教育中心黑龙江哈尔滨150001

本文通过分析便利店的业态优势,我国现状及成因,提出从差异化、成本领先(规模化)角度探索便利店的赢利模式。然后从立地策略、商品差异化策略、业态创新策略、电子商务结合策略四个方面探索对便利店发展和赢利的影响。将便利店与网络经... 详细信息

本文通过分析便利店的业态优势,我国现状及成因,提出从差异化、成本领先(规模化)角度探索便利店的赢利模式。然后从立地策略、商品差异化策略、业态创新策略、电子商务结合策略四个方面探索对便利店发展和赢利的影响。将便利店与网络经营相结合,提升企业竞争力和赢利能力的。

关键词：便利店赢利模式特许经营电子商务

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Soil Organic Matter Fractions under Different Vegetation Types in Permafrost Regions along the Qinghai-Tibet Highway, North of Kunlun Mountains, China

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Journal of Mountain Science 2015年第4期12卷 1010-1024页

作者： SHANG Wen ZHAO Lin WU Xiao-dong LI Yu-qiang YUE Guang-yang ZHAO Yong-hua QIAO Yong-ping Cryosphere research Station on Qinghai-Tibet Plateau State Key laboratory of Cryospheric Sciences Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences University of Chinese Academy of Sciences Naiman Desertification research Station Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences

As a key attribute of soil quality, soil organic matter(SOM) and its different fractions play an important role in regulating soil nutrient cycling and soil *** study evaluated the soil carbon(C) and nitrogen(N) concentrations in different SOM fractions(light– and heavy fractions,microbial biomass) under different vegetation types and analyzed their influencing factors in continuous permafrost regions along the Qinghai-Tibet Highway in the North of Kunlun Mountains, *** samples were collected in pits under four vegetation types — Alpine swamp meadow(ASM), Alpine meadow(AM), Alpine steppe(AS) and Alpine desert(AD) — at the depth of 0-50 *** vegetation coverage was the highest at ASM and AM, followed byAS and *** results indicated that the concentrations of light fraction carbon(LFC) and nitrogen(LFN), and microbial biomass carbon(MBC)and nitrogen(mbn) decreased as follows: ASM > AM >AS > AD, with the relatively stronger decrease of LFC,whereas the heavy fraction carbon(HFC) and nitrogen(HFN) concentrations were lower in AS soils than in the AD *** relatively higher proportions of LFC/SOC and MBC/SOC in the 0-10 cm depth under the ASM soils are mainly resulted from its higher substrate input and soil moisture *** analysis demonstrated that aboveground biomass, soil moisture content, soil organic carbon(SOC) and total nitrogen(TN) positively correlated to LFC, LFN, HFC, HFN, MBC and mbn, while p H negatively correlated to LFC, LFN, HFC, HFN, MBC and *** was no relationship between active layer thickness and SOM fractions, except for the *** suggested that vegetation cover, soil moisture content, and SOC and TN concentrations were significantly correlated with the amount and availability of SOM fractions, while permafrost had less impact on SOM fractions in permafrost regions of the central Qinghai–Tibet Plateau.

关键词： Soil organic matter Light fraction Heavy fraction Microbial biomass Vegetation types Tibetan permafrost soil

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Impact of Land Degradation on Soil Microbial Biomass and Activity in Northeast Brazil

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Pedosphere 2012年第1期22卷 88-95页

作者： J.S.NUNES A.S.F.ARAUJO L.A.P.L.NUNES L.M.LIMA R.F.V.CARNEIRO A.A.C.SALVIANO S.M.TSAI Soil Quality Lab. Agricultural Science CenterFederal University of PiauíTeresinaPI(Brazil) center of Nuclear Energy in Agriculture University of Sao PauloPiracicabaSP(Brazil)

Land degradation causes great changes in the soil biological *** process of degradation may decrease soil microbial biomass and consequently decrease soil microbial *** study was conducted out during 2009 and 2010 at the four sites of land under native vegetation(NV),moderately degraded land(LDL),highly degraded land(HDL) and land under restoration for four years(RL) to evaluate changes in soil microbial biomass and activity in lands with different degradation levels in comparison with both land under native vegetation and land under restoration in Northeast *** samples were collected at 0-10 cm *** organic carbon(SOC),soil microbial biomass C(MBC) and N(mbn),soil respiration(SR),and hydrolysis of fluorescein diacetate(FDA) and dehydrogenase(DHA) activities were *** two years of evaluation,soil MBC,mbn,FDA and DHA had higher values in the NV,followed by the *** decreases of soil microbial biomass and enzyme activities in the degraded lands were approximately 8-10 times as large as those found in the ***,after land restoration,the MBC and mbn increased approximately 5-fold and 2-fold,respectively,compared with the *** results showed that land degradation produced a strong decrease in soil microbial ***,land restoration may promote short-and long-term increases in soil microbial biomass.

关键词： land restoration microorganisms soil quality soil respiration

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Leaf litter and crop residue decomposition in ginkgo agroforestry systems in eastern China: Soil fauna diversity and abundance,microbial biomass and nutrient release

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Journal of Forestry research 2019年第5期30卷 1895-1902页

作者： Jing Guo Guibin Wang Yaqiong Wu Quanzheng Geng Fuliang Cao Co-Innovation center for Sustainable Forestry in Southern China Nanjing Forestry University

The response of soil fauna to the litter decomposition process has received considerable attention,but this effect has not been fully examined in agroforestry systems.A 1-year in situ decomposition experiment was carried out in a pure ginkgo plantation and two ginkgo agroforestry systems using a litterbag method(11 different treatments were tested in three systems).We found that the application of different organic materials(crop residues)produced positive effects on the number of soil fauna in the ginkgo planting systems;the mixture of ginkgo leaves and corn leaves was the best performing *** and Acarina were the predominant groups in the litter bags and were mainly responsible for the differences among the *** mixing promoted the abundance,richness,and diversity of soil fauna,and significant differences regarding the Shannon–Wiener index of the soil fauna were observed among the 11 treatments in *** higher soil MBC(microbial biomass carbon)and mbn(microbial biomass nitrogen)were observed in agroforestry systems than in pure ginkgo *** results suggest that the practice of intercrop residue application plays an important role in enhancing soil ecosystem function in ginkgo agroforestry systems and may ultimately contribute to sustainable intercrop production,soil fertility,and local economic diversity.

关键词： Ginkgo agroforestry Litter decomposition Soil fauna Microbial biomass Nutrient release

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Seasonal variation in soil microbial biomass carbon and nitrogen in an artificial sand-binding vegetation area in Shapotou, northern China

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research in Cold and Arid Regions 2013年第6期5卷 733-738页

作者： YuYan Zhou XuanMing Zhang XiaoHong Jia JinQin Ma YanHong Gao Gansu Productivity Promotion center Shapotou Desert research and Experiment Station Cold and Arid Regions Environment and Engineering InstituteChinese Academy of Sciences Institute of Desertification Studies Chinese Academy of Forestry

In this study, seasonal variation characteristics of surface soil microbial biomass carbon （MBC） and soil microbial biomass nitrogen （mbn） of an artificial vegetation area located in Shapotou for different time periods were studied using the chloroform fumigation method, and the results were compared with those of near-natural vegetation areas and mobile dunes. Results showed that the MBC and mbn levels in the 0-5 cm soil layer were higher in autumn than in summer and spring. As the prolongation of vegetation restoration raised the MBC and mbn levels in summer and autumn, no clear variation was found in spring. However, the MBC and mbn in 5-20 cm had no obvious seasonal variation. During summer and autumn, the variation trend of MBC and mbn in the vertical direction was shown to be 0-5 〉 5-10 〉 10-20 cm in the vegetation area, while for mobile dunes, the MBC and mbn levels increased as the depth increased. The natural vegetation area was shown to possess the highest MBC and mbn levels, and yet mobile dunes have the lowest MBC and mbn levels. MBC and mbn levels in artificial sand-binding vegetation increased with the prolongation of vegetation restoration, indicating that the succession of sand-binding vegetation will result in the ac- cumulation of soil carbon and nitrogen, as well as the restoration of soil fertility.

关键词： re-vegetation area soil microbial biomass carbon soil microbial biomass nitrogen

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Synthesis and Crystal Structure of a Three-dimensional Manganese(II) Complex (tataH)_2[Mn(pydc)_2]·4H_2O (tata = 2,4,6-Triamino-1,3,5-triazine, pydcH_2 = Pyridine-2,6-dicarboxylic Acid)

引用

Chinese Journal of Structural Chemistry 2008年第6期27卷 712-716页

作者：孙一峰李季坤崔一平 Advanced Photonics center School of Electronic Science and EngineeringSoutheast University Department of Chemistry Taishan University

A manganese（Ⅱ） complex （tataH）2[Mn（pydc）2]·4H2O （C20H28mbn14O12, Mr = 711.50, tata = 2,4,6-triamino-1,3,5-triazine, pydcH2 = pyridine-2,6-dicarboxylic acid） has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P1^-, with a = 9.9847（3）, b = 10.9813（3）, c = 15.2616（5）A, a = 101.5310（10）, β = 90.2610（10）, γ = 116.4600（ 10）% V = 1459.44（8）A^3, Z = 2, Dc = 1.619 g/cm^3,μ = 0.539 mm^-1, F（000） = 734, the final R = 0.0292 and wR = 0.0745. In the crystal the Mnn atom is six-coordinated by four carbonyl oxygen atoms and two pyridine nitrogen atoms from two tridentate pydc ligands to furnish a distorted octahedral geometry. The complex shows the A…D…D＇…A＇ H-bonded tetramer. The molecules are packed in a three-dimensional framework structure by the combination of O-H…O, N-H…O and N-H…N hydrogen bonds between （tataH）^＋, [Mn（pydc）2]^2- and crystal water.

关键词： manganese(Ⅱ) complex 2,6-pyridinedicarboxylic acid hydrogen-bonding interaction crystal structure

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