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长江经济带新型城镇化与空气污染的脱钩分析

生态经济 2025年第1期41卷 140-148,194页

作者：詹成郭明晶周文潇陈嘉浩中国地质大学(武汉)经济管理学院湖北武汉430074

城市的快速发展带来了污染物的集中。为了协调经济发展与环境污染之间的关系,中国制定并实施了新型城镇化战略。但是,对新型城镇化与空气污染的具体关系的研究尚不充足,仍不清楚空气污染是否与新型城镇化脱钩。因此,基于2009—2021年长... 详细信息

城市的快速发展带来了污染物的集中。为了协调经济发展与环境污染之间的关系,中国制定并实施了新型城镇化战略。但是,对新型城镇化与空气污染的具体关系的研究尚不充足,仍不清楚空气污染是否与新型城镇化脱钩。因此,基于2009—2021年长江经济带108个城市的面板数据,构建了人口、经济、空间、社会和生态五个维度的新型城镇化评价指标体系。利用Tapio脱钩模型和追赶脱钩模型探讨了新型城镇化与PM_(2.5)浓度之间的脱钩关系和区域异质性。结果表明:(1)长江经济带PM_(2.5)浓度在2013年后持续减少。(2)新型城镇化的驱动力主要来自经济城镇化和社会城镇化。(3)PM_(2.5)浓度与新型城镇化之间长期保持脱钩状态,但在短期尺度内存在脱钩和负脱钩的交替现象。(4)大部分追赶城市对模范城市的追赶并不理想,地区间的不平衡现象还将长期持续。

关键词：新型城镇化空气质量 PM2.5 Tapio模型

毛叶芋兰不同组织qRT-PCR内参基因选择与验证

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热带作物学报 2025年第1期46卷 35-43页

作者：池珈仪刘舒璇向思诗詹若挺何瑞广州中医药大学中药资源科学与工程研究中心/广州中医药大学岭南中药资源教育部重点实验室/广州中医药大学中药学院广东广州510006

毛叶芋兰(Nervilia plicata)是一种珍稀南药,目前对其有效成分及其分子调控机理鲜有报道。实时荧光定量PCR(real-time quantitative PCR,qRT-PCR)在植物基因表达分析中得到了广泛应用,但在毛叶芋兰中缺少研究,限制了相关工作的开展。在... 详细信息

毛叶芋兰(Nervilia plicata)是一种珍稀南药,目前对其有效成分及其分子调控机理鲜有报道。实时荧光定量PCR(real-time quantitative PCR,qRT-PCR)在植物基因表达分析中得到了广泛应用,但在毛叶芋兰中缺少研究,限制了相关工作的开展。在前期工作基础上,本研究从毛叶芋兰转录组数据库中筛选出Actin、GAPDH、TUA、UBC、UBQ、EF-1α、EF-1β、CYP、RPL共9个常见管家基因,以毛叶芋兰叶片、叶柄和球茎3个组织部位为材料,开展qRT-PCR内参基因的筛选工作。经过9个基因在不同组织的表达水平、稳定性和综合分析,筛选出最适合的内参基因,并选择毛叶芋兰花青素合成途径关键基因NpDFR、Np3GT进行验证。结果发现:EF-1α和CYP的表达稳定性相近,整体稳定性最好。2个内参基因单独或共同使用时,NpDFR、Np3GT在不同组织的表达情况与转录组测序结果基本一致,表明其均可用作qRT-PCR的内参基因。本研究结果为进一步开展毛叶芋兰药效相关基因的分子作用机理研究提供依据。

关键词：毛叶芋兰内参基因实时荧光定量PCR 表达稳定性

Preparation of Polyimide/BaTiO_3/Ag Nanocomposite Films via in situ Technique and Study of Their Dielectric Behavior

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Chinese Journal of Polymer Science 2014年第4期32卷 424-431页

作者： Jia-yu zhan Guo-feng Tian zhan-peng Wu Sheng-li Qi 武德珍 State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Beijing Building Materials Academy of Science Research/State Key Laboratory of Solid Waste Reuse for Building Materials

Triphase polyimide nanocomposite films were fabricated using barium titanate （BaTiO3） with high dielectric constant and silver （Ag） with high conductivity as fillers. In situ method was utilized to obtain the homogeneous dispersion of nanoparticles. The in situ polymerization of polyimide precursor-poly（amic acid） was performed in the presence of BaTiO3 particles. Silver compound 1,1,1-trifluoro-2,4-pentadionato silver（I） was added into the BaTiO3 containing poly（amic acid） solution to achieve silver nanoparticles via in situ self metallization technique. The thermally induced reduction converted silver （I） to metallic silver with concomitant imidization of poly（amic acid） to polyimide. Both BaTiO3 and silver nanoparticles were uniformly dispersed in the polyimide substrate. The dependence of dielectric behavior on the BaTiO3 and Ag contents was studied. The incorporation of small amount of silver nanoparticles greatly increased dielectric constant of composite films.

关键词： Polyimide Silver Barium titanate Nanocomposites Dielectrics.

WD+RG systems as the progenitors of type Ia supernovae

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Research in Astronomy and Astrophysics 2010年第3期10卷 235-243页

作者： Bo Wang zhan-Wen Han National Astronomical Observatories/Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

Type Ia supernovae （SNe Ia） play an important role in the study of cosmic evolution, especially in cosmology. There are several progenitor models for SNe Ia proposed in the past years. By considering the effect of accretion disk instability on the evolution of white dwarf （WD） binaries, we performed detailed binary evolution calculations for the WD ＋ red-giant （RG） channel of SNe Ia, in which a carbon--oxygen WD accretes material from a RG star to increase its mass to the Chandrasekhar mass limit. According to these calculations, we mapped out the initial and final parameters for SNe Ia in the orbital period-secondary mass （log Pi_ M2^i） plane for various WD masses for this channel. We discussed the influence of the variation of the duty cycle value on the regions for producing SNe Ia. Similar to previous studies, this work also indicates that the long-period dwarf novae offer possible ways for producing SNe Ia. Meanwhile, we find that the surviving companion stars from this channel have a low mass after the SN explosion, which may provide a means for the formation of the population of single low-mass WDs （〈0.45 M⊙）.

关键词： stars: evolution -- supernovae: general -- binaries: close -- white dwarfs

Graded Hochschild Cohomology of a Path Algebra with Oriented Cycles

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Acta Mathematica Sinica,English Series 2014年第9期30卷 1495-1512页

作者： Fang LI De zhan TAN Department of Mathematics Zhejiang University

The aim of this paper is to characterize the first graded Hochschild cohomology of a hereditary algebra whose Gabriel quiver is admitted to have oriented cycles. The interesting conclusion we have obtained shows that the standard basis of the first graded Hochschild cohomology depends on the genus of a quiver as a topological object. In this paper, we overcome the limitation of the classical Hochschild cohomology for hereditary algebra where the Gabriel quiver is assumed to be acyclic. As preparation, we first investigate the graded differential operators on a path algebra and the associated graded Lie algebra.

关键词： Quiver. genus graded Hochschild cohomology graded Lie algebras oriented cycle

Radical-Mediated Selective Functionalization of Unactivated Primary C-H Bonds

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Chinese Journal of Chemistry 2022年第14期40卷 1751-1753页

作者： zhan-Lin Wang Fei Wang State Key Laboratory of Elemento-Organic Chemistry College of ChemistryNankai UniversityTianjin 300071China

Radical-mediated sp^(3)C—H functionalization has found broad applications in synthesis and late-stage derivatization of complex *** site-selectivity of a given reaction is mainly dictated by the bond strength,polarity and steric accessibility of diverse C—H bonds as well as the characters of hydrogen atom *** sp^(3)C—H bonds usually follow the relative reactivity sequence of tertiary>secondary>primary,which is even recognized as the innate preferences of certain *** development of innovative methods capable of overriding the“inherent”site-selectivity is exceedingly *** it has been demonstrated that secondary C—H bonds could be selectively converted in the presence of weaker tertiary C—H bonds by tuning the steric and electronic properties of hydrogen atom acceptors,the selective activation of primary C—H bonds remains a daunting ***,we highlight the recently emerging attempts towards this goal by interrogating the steric effect of hydrogen atom acceptors.

关键词： C-H activation Hydrogen atom transfer Radical reactions Regioselectivity Steric hindrance

A likely candidate of type Ia supernova progenitors: the X-ray pulsating companion of the hot subdwarf HD 49798

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Research in Astronomy and Astrophysics 2010年第7期10卷 681-688页

作者： Bo Wang zhan-Wen Han National Astronomical Observatories / Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650011 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

HD 49798 is a hydrogen depleted subdwarf 06 star and has an X-ray pulsating companion （RX J0648.0-4418）. The X-ray pulsating companion is a massive white dwarf. Employing Eggleton＇s stellar evolution code with the optically thick wind assumption, we find that the hot subdwarf HD 49798 and its X-ray pulsating companion could produce a type Ia supernova （SN Ia） in future evolution. This implies that the binary system is a likely candidate of an SN Ia progenitor. We also discuss the possibilities of some other WD ＋ He star systems （e.g. V445 Pup and KPD 1930＋2752） for producing SNe Ia.

关键词： binaries close -- stars individual (HD 49798) -- stars evolution -- supernovae general -- white dwarfs

Gelfand–Kirillov Dimension and Reducibility of Scalar Generalized Verma Modules

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Acta Mathematica Sinica,English Series 2019年第11期35卷 1854-1860页

作者： zhan Qiang BAI Wei XIAO School of Mathematical Sciences Soochow UniversitySuzhou 215006P.R.China College of Mathematics and statistics Shenzhen Key Laboratory of Advanced Machine Learning Applications Shenzhen UniversityShenzhen 518060P.R.China

The Gelfand–Kirillov dimension is an invariant which can measure the size of infinitedimensional algebraic structures. In this article, we show that it can also measure the reducibility of scalar generalized Verma modules. In particular, we use it to determine the reducibility of scalar generalized Verma modules associated with maximal parabolic subalgebras in the Hermitian symmetric case.

关键词： Gelfand–Kirillov dimension generalized Verma module reducibility

Intelligent Mining Technology for an Underground Metal Mine Based on Unmanned Equipment

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Engineering 2018年第3期4卷 381-391页

作者： Jian-guo Li Kai zhan BGRIMM Technology Group Beijing 100160 China

This article analyzes the current research status and development trend of intelligent technologies for underground metal mines in China, where such technologies are under development for use to develop mineral resources in a safe, efficient, and environmentally friendly manner. We analyze and summarize the research status of underground metal mining technology at home and abroad, including some specific examples of equipment, technology, and applications. We introduce the latest equipment and technolo- gies with independent intellectual property rights for unmanned mining, including intelligent and unmanned control technologies for rock-drilling jumbos, down-the-hole （DTH） drills, underground scrapers, underground mining trucks, and underground charging vehicles. Three basic platforms are used for intelligent and unmanned mining： the positioning and navigation platform, information-acquisition and communication platform, and scheduling and control platform. Unmanned equipment was tested in the Fankou Lead-Zinc Mine in China, and industrial tests on the basic platforms of intelligent and unmanned mining were carried out in the mine. The experiment focused on the intelligent scraper, which can achieve autonomous intelligent driving by relying on a wireless communication system, location and navigation system, and data-acquisition system. These industrial experiments indicate that the technol- ogy is feasible. The results show that unmanned mining can promote mining technology in China to an intelligent level and can enhance the core competitive ability of China＇s mining industry.

关键词： Underground Autonomous Communication Navigation Intelligent