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High Voltage 2024年第1期9卷 56-65页

作者： Hao hu Zhidong Jia Xilin Wang Ruiyang Guan Weinan Fan simin Luo Tsinghua Shenzhen International Graduate School Tsinghua UniversityShenzhenChina Guangzhou Power Supply China Southern Power Grid Company Ltd.GuangzhouChina

Silicone rubber(SR)is widely used for cable insulation and operates in multi-stress coupling conditions.Its dielectric properties and ageing performance are the essential factors affecting cable operation.In this study,the frequency domain spectroscopy of unaged SR and SR aged under various conditions is measured.The dielectric responses before and after ageing are analysed in depth by the conjoint analysis via multiple complex planes(permittivity,conductivity,and modulus).Typical conductivity and interfacial polarisation properties,as well as property changes resulting from thermal and tensile ageing,are examined.Experimental results show that tensile ageing promotes conductance and interfacial polarisation,while thermal ageing shows the opposite effects.Based on the multi-core model and charge carrier hopping transport model,thermal and tensile ageing mechanisms on the conductance and interfacial polarisation behaviours of SR are demonstrated.Both behaviours exhibit positively correlated changing characteristics,suggesting that the two behaviours may originate from a common process.The carrier transport process,promoted by the tensile effect and slightly suppressed by the thermal effect,is the primary factor and considered an important indicator to evaluate the dielectric properties of SR insulation.

关键词： interfacial rubber insulation

Temporal changes in mixing effects on litter decay and nitrogen release in a boreal riparian forest in northeastern China

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Journal of Forestry Research 2024年第2期35卷 33-41页

作者： simin Wang Bo Liu Rui Li Xiaoxin Sun Rong Mao Key Laboratory of National Forestry and Grassland Administration on Forest Ecosystem Protection and Restoration of Poyang Lake Watershed College of ForestryJiangxi Agricultural UniversityNanchang 330045People’s Republic of China Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102People’s Republic of China Key Laboratory of Sustainable Forest Ecosystem Management of Ministry of Education School of ForestryNortheast Forestry UniversityHarbin 150040People’s Republic of China Heilongjiang Sanjiang Plain Wetland Ecosystem Research Station Fuyuan 156500People’s Republic of China

In riparian forests,litter decay provides essential energy and nutrients for both terrestrial and fluvial ecosystems.Litter mixing effects(LMEs)are crucial in regulating litter decay and nutrient dynamics,yet how LMEs change over time is unclear in riparian forests.In this study,leaf litter of three common species(Alnus sibirica Fisch.ex Turcz,Betula platyphylla Sukaczev,and Betula fruticosa Pall.)were mixed in an equal mass ratio and LMEs were measured for mass and nitrogen(N)remaining in whole litter mixtures over a 3-year period in a boreal riparian forest,northeastern China.LMEs were also assessed for component litter mass and N remaining by separating litter mixtures by species.During the decay of litter mixtures,antagonistic effects on mass and N remaining were dominant after one and two years of decay,whereas only additive effects were observed after three years.LMEs correlated negatively with functional diversity after the first and two years of decay but disappeared after three years.When sorting litter mixtures by species,non-additive LMEs on mass and N remaining decreased over incubation time.Moreover,non-additive LMEs were more frequent for litter of both B.platyphylla and B.fruticosa with lower N concentration than for A.sibirica litter with higher N concentration.These results indicate that incubation time is a key determinant of litter mixing effects during decay and highlight that late-stage litter mixture decay may be predicted from single litter decay dynamics in boreal riparian forests.

关键词： Biodiversity Litter quality Litter mixtures Synergistic effects Functional diversity

Copper-catalyzed C(sp)-H aryl amination enables modular synthesis of quinolines and 2-quinolinones

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Science China Chemistry 2024年第2期67卷 595-603页

作者： Yang Gao Haixia Li simin Yang Yanping huo Qian Chen Xianwei Li Zhe Wang Xiao-Qiang hu School of Chemical Engineering and Light Industry Guangdong University of TechnologyGuangzhou510006China Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory Jieyang515200China Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education&hubei Key Laboratory of Catalysis and Materials Science School of Chemistry and Materials ScienceSouth-Central University for NationalitiesWuhan430074China

Herein,we disclose a novel copper-catalyzed C(sp)-H aryl amination of terminal alkynes with anthranils,enabling the rapid generation of highly reactive secondary N-aryl ynamines for the modular synthesis of structurally diverse C2-substituted quinolines and 2-quinolinones.The in-situ formed carbonyl-ynamines are prone to tautomerize to carbonyl-ketenimines,which can efficiently react with a series of nucleophiles,including amines,alcohols,phenols,thiols,thiophenols,active-methylene compounds,and even water to produce various quinoline derivatives with the generation of H_(2)O as a sole and green byproduct.This method also unlocks a practical route to create various quinoline-fused heterocycles and can be successfully applied to the late-stage modification of complex molecules and the concise synthesis of bioactive targets.Mechanistic studies reveal a coppercatalyzed inner-sphere nitrene transfer process by using anthranils as novel aryl nitrene precursors.

关键词： copper catalysis anthranils C(sp)-H aryl amination carbonyl-ketenimines quinolines

Molecular quantification of copepod Acartia erythraea feeding on different algae preys

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Acta Oceanologica Sinica 2023年第9期42卷 125-131页

作者： simin hu Tao Li hui huang Sheng Liu Key Laboratory of Tropical Marine Bio-resources and Ecology Chinese Academy of SciencesGuangzhou 510301China Guangdong Provincial Key Laboratory of Applied Marine Biology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China CAS-HKUST Sanya Joint Laboratory of Marine Science Research/Key Laboratory of Tropical Marine Biotechnology of Hainan Province Sanya Institute of Ocean Eco-Environmental EngineeringSouth China Sea Institute of OceanologySanya 572000China Sanya National Marine Ecosystem Research Station Tropical Marine Biological Research Station in HainanChinese Academy of SciencesSanya 572000China

Quantitative evaluation of the copepod feeding process is critical for understanding the functioning of marine food webs, as this provides a major link between primary producers and higher trophic levels. In this study, a molecular protocol based on quantitative polymerase chain reaction(qPCR) targeting 18S rDNA was developed and used to investigate the feeding and digestion rates of the copepod Acartia erythraea in a laboratory experiment using microalgae Thalassiosira weissflogii, Prorocentrum shikokuense, and Alexandrium catenella as prey. Although offered an equal encounter rate based on biovolume, prey uptake varied substantially among the three algal species, with the ingestion rate(IR) and digestion rate(DR) of A. erythraea differing significantly(P <0.001) based on both cell counting and qPCR detection. Acartia erythraea showed the highest IR(2.79×10~4 cells/(ind.·h)) and DR(2.43×10~4 cells/(ind.·h)) on T. weissflogii, and the lowest amounts of ingested P. shikokuense were detected. The highest assimilation rate(~90.64%, IR/DR) was observed in copepods fed with P. shikokuense. The qPCR method used here can help determine the digestion rate and assimilation rate of copepods by detecting cells remaining in the gut hence providing the possibility to examine trophic links involving key species in the marine ecosystem. Our results indicate that A. erythraea has diet-specific feeding performance in different processes, and a quantitative assessment of copepod feeding is needed to accurately determine its functional role in the energy and matter uptake from marine food webs.

关键词： copepod ingestion rate digestion rate 18S rDNA real-time PCR

Significant strain-rate dependence of sensing behavior in TiO2@carbon fibre/PDMS composites for flexible strain sensors

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Journal of Advanced Ceramics 2021年第6期10卷 1350-1359页

作者： Fan ZHANG Hailong hu simin hu Jianling YUE School of Minerals Processing and Bioengineering Central South University School of Aeronautics & Astronautics Central South University Research Center in Intelligent Thermal Structures for Aerospace Central South University

Carbon fibre(CF) embedded into elastomeric media has been attracting incredible interest as flexible strain sensors in the application of skin electronics owing to their high sensitivity in a very small strain gauge. To further improve the sensitivity of CF/PDMS composite strain sensor, the relatively low temperature prepared TiO2nanowire via hydrothermal route was employed herein to functionalize CF.The results showed a significant increase in the sensitivity of the TiO2@CF/PDMS composite strain sensors which was reflected by the calculated gauge factor. As the prepared TiO2nanowire vertically embraced the surroundings of the CF, the introduced TiO2nanowire contributed to a highly porous structure which played a predominant role in improving the sensitivity of strain sensors. Moreover,the significant strain rate dependent behavior of TiO2@CF/PDMS strain sensor was revealed when performing monotonic tests at varied strain rate. Therefore, introducing TiO2nanowire on CF offers a new technique for fabricating flexible strain sensors with improved sensitivity for the application of flexible electronics.

关键词： composites dependence of strain rate sensitivity flexible strain sensors

Detection of composition of functional component theabrownins in Pu-erh tea by degradation method

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Food Science and human Wellness 2022年第3期11卷 643-647页

作者： simin hu Xiaolei Li Chuangchuang Gao Xianyu Meng Mingchao Li Yuqian Li Tianrui Xu Qian Hao Faculty of Life Science and Technology Kunming University of Science and TechnologyKunming 650500China Research Center for Analysis and Measurement Kunming University of Science and TechnologyKunming 650093China

Habitual tea consumption can reduce the risk of ASCVD morbidity and mortality and all-cause mortality in China,and long-term adherence to this habit can provide greater protection.Pu-erh tea is one of the representatives of post-fermented teas,and the polymers in Pu-erh tea have anti-cancer and anti-hyperlipidemic activities,but their chemical composition is still unknown.In this study,the chemical composition of Pu-erh tea was investigated in detail and eight(1–8)known compounds were isolated.The polymers in Pu-erh tea were also degraded by thiol degradation,and the fragments of quercetin and(–)-epicatechin-3-O-gallate were found in the thiol degradation products of Pu-erh tea polymers by UPLC observation and separation and purification.This is the first time that this fragment was obtained in Pu-erh tea polymer.

关键词： Pu-erh tea Polymer Theabrownin Thiol degradation

Genome-wide identification and characterization of the lateral organ boundaries domain gene family in Brassica rapa var.rapa

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Plant Diversity 2020年第1期42卷 52-60页

作者： Qin Yu simin hu Jiancan Du Yongping Yang Xudong Sun Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of Botany.Chinese Academy of ScienceKunming 650201China Plant Germplasm and Genomics Center The Cermplasm Bank of Wild SpeciesKunming Institute of BotanyChinese Academy of SciencesKunming 650201 China Institute of Tibetan Plateau Research at Kunming.Kunming Institute of Botany Chinese Academy of Sciences.Kunming 650201China University of the Chinese Academy of Sciences Beijing 100049China

The Lateral Organ Boundaries Domain(LBD)genes encode highly conserved plant-specific LOB domain proteins which regulate growth and development in various species.However,members of the LBD gene family have yet to be identified in Brassica rapa var.rapa.In the present study,fifty-nine LBD genes were identified and distributed on 10 chromosomes.The BrrLBD proteins are predicted to encode hydrophobic polypeptides between 118 and 394 amino acids in length and with molecular weights ranging from 13.31 to 44.24 kDa;the theoretical pi for these proteins varies from 4.83 to 9.68.There were 17 paralogous gene pairs in the BrrLBD family,suggesting that the amplification of the BrrLBD gene family involved largescale gene duplication events.Members of the BrrLBD family were divided into 7 subclades(class I a to e,class II a and b).Analysis of gene structure and conserved domains revealed that most BrrLBD genes of the same subclade had similar gene structures and protein motifs.The expression profiles of 59 BrrLBD genes were determined through Quantitative Real-time fluorescent PCR(qRT-PCR).Most BrrLBD genes in the same subclade had similar gene expression profiles.However,the expression patterns of 7 genes differed from their duplicates,indicating that although the gene function of most BrrLBD genes has been conserved,some BrrLBD genes may have undergone evolutionary change.

关键词： LBD Transcription factors LBD gene sequence analysis Expression profiles Brassica rapa var.rapa

Dietary separation between co-occurring copepods in a food-limited tropical coral reef of the Sanya Bay

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Acta Oceanologica Sinica 2020年第4期39卷 65-72页

作者： simin hu Tao Li Sheng Liu hui huang Key Laboratory of Tropical Marine Bio-Resources and Ecology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Guangdong Provincial Key Laboratory of Applied Marine Biology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Tropical Marine Biological Research Station in Hainan Chinese Academy of SciencesSanya 572000China

Food differentiation among coexistent species in the field is important strategy for copepods to acquire materials and maintain population stabilization.In situ diet analysis of co-occurring six copepod species in coral waters of the Sanya Bay was conducted using a PCR protocol based on 18 S ribosomal gene.Various prey organisms were uncovered,including dinoflagellate,diatom,green algae and plant,protozoa and metazoan.All these spatially coexisting six species showed different dietary diversity,with the food niche breadth(B)ranging from 1.00(Temora turbinate in morning)to 10.68(Calanopia elliptica in night).While food overlap between all these copepods were low,with the average value of the diet niche overlap index being approximately 0.09.Even temporally co-existing species sampled from the same time point fed on different groups of prey items with the food overlap index of 0.04 to 0.07 in midday and night but 0 in morning.As the most important dominant copepod in the Sanya Bay,Subeucalanus subcrassus seems to be capable to regulate its feeding,by exhibiting a rhythm of herbivorous feeding in midday and carnivorous feeding in morning and night,to better coordinate with other competitors for utilization of food resources.For most copepods,none of the prey items belonged to the dominant phytoplankton in the ambient water,indicating that copepod can better their survival by widening the choice of potential food resources in food limited environment.The dietary separation observed here might be important strategy for copepod to maintain population stabilization and thriving in the Sanya coastal waters.

关键词： copepod food partitioning Sanya Bay coral reef ecosystem

玉米秸秆复合高吸水树脂的制备及对Pb^(2+)的吸附研究

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化工新型材料 2024年第4期52卷 223-227,232页

作者：胡鹏贺龙强李艳梅汤思敏焦作大学化工与环境工程学院焦作454000 焦作市源波环保科技有限公司焦作454000

以来源丰富的玉米秸秆、高岭土为原料,以丙烯酸、丙烯酰胺为聚合单体,通过水溶液聚合法制备了复合高吸水树脂,并用红外光谱(FT-IR)和扫描电镜(SEM)对其结构进行了表征分析。利用合成的复合高吸水树脂对含Pb^(2+)模拟废水进行了吸附研究... 详细信息

以来源丰富的玉米秸秆、高岭土为原料,以丙烯酸、丙烯酰胺为聚合单体,通过水溶液聚合法制备了复合高吸水树脂,并用红外光谱(FT-IR)和扫描电镜(SEM)对其结构进行了表征分析。利用合成的复合高吸水树脂对含Pb^(2+)模拟废水进行了吸附研究,考察了复合高吸水树脂用量、Pb^(2+)初始浓度、吸附时间和溶液pH及对Pb^(2+)去除率的影响,最优条件下复合高吸水树脂对Pb^(2+)的去除率达88.57%,吸附Pb^(2+)后的复合高吸水树脂经处理后可循环使用。

关键词：玉米秸秆复合高吸水性树脂吸附 Pb^(2+)

Flexible feeding patterns of copepod Centropages tenuiremis in fluctuating conditions: a possible survival strategy to cope with disturbance

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Acta Oceanologica Sinica 2020年第2期39卷 59-68页

作者： Cuilian Xu simin hu Zhiling Guo Tao Li hui huang Leo Lai Chan Sheng Liu Key Laboratory of Tropical Marine Bio-resources and Ecology/Guangdong Provincial Key Laboratory of Applied Marine Biology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Tropical Marine Biological Research Station in Hainan Chinese Academy of SciencesSanya 572000China Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity Research Centre for the Oceans and Human HealthCity University of Hong Kong Shenzhen Research InstituteShenzhen 518057China State Key Laboratory in Marine Pollution City University of Hong KongHong Kong 999077China

Centropages tenuiremis is a species with a wide distribution range in disturbed coastal waters.However,due to a lack of dietary information,it remains unclear as to how they maintain such dominance in fluctuating conditions.In this study,C.tenuiremis was collected from the Daya Bay Nuclear Power Plant both in inlet and outfall regions at 06:00,12:00 and 18:00 on April 27,2011 and their in situ diet was analyzed using a PCR protocol targeting 18S ribosomal genes.Thirty-four species of prey organisms were identified totally,including Dinophyta,Baciliariophyta,Viridiplantae,Rhizaria,Apicomplexa,Chordata,Mollusca,Arthropoda and Fungi,indicating an obvious omnivorous feeding habit of C.tenuiremis.Centropages tenuiremis obviously exhibited spatial and temporal variations in diet composition.More plant prey(land plants and phytoplankton)were consumed in the morning(~50%),while more animal prey(metazoans and protozoans)were ingested at midday and night(60%–70%).Furthermore,a more diverse diet was detected in the outfall region(10–11 taxa),where the temperatures were relatively higher and more fluctuating,than in the control region(5–10 taxa).This finding indicated that C.tenuiremis could potentially expand its food spectrum under stressful condition.Specifically,C.tenuiremis exhibited phytoplankton preference(58.62%–67.64%)in the outfall region with a lower omnivory index(0.27–0.35)than in the control region(0.51–0.95).However,phytoplankton density was lower than that in the control region,suggesting a possible herbivorous tendency of C.tenuiremis under elevated temperatures to balance the energy acquirement and feeding effort.The flexible food choices of C.tenuiremis observed here could effectively buffer environmental fluctuations and might be an important survival strategy in coastal ecosystems.

关键词： Centropages feeding response feeding strategy coastal ecosystem Daya Bay