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Theoretical study on thermal decomposition of azoisobutyronitrile in ground state

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Science china {1. 2004年第5期47卷 373-380页

作者： SUN chengke1,2. zhao hongmei1 & li {2. 1. department of chemistry, beijing normal university, beijing 100875, china 2. department of chemistry, Qujing normal College, Qujing 655000, china 1. department of {1. Beijing Normal University 100875 Beijing China 2. {1. of chemistry Qujing Normal College 655000 Qujing China

The thermal decomposition mechanisms of azoisobutyronitrile (AIBN) in the ground state have been investigated systematically. Based on the potential energy surfaces (PES) of various possible dissociation paths obtained using the semiempirical AM1 method with partial optimization, the density function theory B3LYP/6-311G* method was employed to optimize the geometric parameters of the reactants, the intermediates, the products and the transition states, which were further confirmed by the vibrational analysis. The obtained results show that the re- action process of the two-bond (three-body) simultaneous cleavage Me2.CN)C─ N=N─ C(CN)Me2. 2.e2.CN)C?+N2.is much more favorable than the reaction process of the two one- bond asynchronous cleavage Me2.CN)CN=N─C(CN)Me2.? Me2.CN)CN=N?+ Me2.CN)C?? Me2.CN)C?+ N2. It was suggested that the electron shrinking effect of double bond (─N=N─) in AIBN and the stabilities of the Me2.CN)C?radical as well as N2.molecule are main factors of leading to the reaction proceeding in the former pathway. The calculation results were consistent with all the experimental facts.

关键词： azoisobutyronitrile, radicals, thermal decomposition, density function theory (DFT).

Theoretical study on the reaction mechanism of(CH_3)_3CO+CO

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Science china {1. 2005年第1期48卷 18-24页

作者： zhao hongmei1,2.3, SUN chengke1,4, ZHANG Rongchang3, XI Hongmin3 & li {2. 1. department of chemistry, beijing normal university, beijing 100875, china 2. The Laboratory of Molecular Reaction Dynamics, Institute of chemistry, Chinese Academy of Sciences, beijing 100080, china 3. department of chemistry, Beihua university, Jilin 132.13, china 4. department of chemistry, Qujing normal university, Yunnan 655000, china 1. department of {1. Beijing Normal University 100875 Beijing China 2. The Laboratory of Molecular Reaction Dynamics Institute of Chemistry Chinese Academy of Sciences 100080 Beijing China 3. department of {1. Beihua University 132013 Jilin China 4. department of {1. Qujing Normal University 655000 Yunnan China

The reaction mechanism of (CH3)3CO with CO has been theoretically investigated using density-functional theory (DFT) calculations at B3LYP/6-31.* level. In order to get more reliable energy values the single-point energy is evaluated at CCSD (T)/6-31.+G** level. The results show that the reaction is multi-channel and the reaction of (CH3)3CO radical with CO mostly produces (CH3)3C + CO{1. The reaction could play a role in eliminating air pollution.

关键词： DFT, B3LYP, (CH3)3CO, radical.

Proton induced X-ray emission (PIXE) analysis of sources of porcelain body of Ru Guan and Jun Guan porcelains

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Science china(Physics,Mechanics & Astronomy) 2006年第4期49卷 411-420页

作者： li Guoxia1, zhao Weijuan1, li Rongwu2. SUN Hongwei1, GUO Min1, WANG Yanfang1, liu Hui1, zhao Qingyun3, SUN Xinmin3, zhao Wenjun3 & CHENG Huansheng4 1. Faculty of Physical Engineering, Zhengzhou university, Zhengzhou 450052. china 2. department of Physics, beijing normal university, beijing 100875, china 3. Institute of Cultural Relic and Archaeology of Henan Province, Zhengzhou 450000, china 4. Institute of Modern Physics, Fudan university, Shanghai 2.0433, china Faculty of Physical Engineering Zhengzhou University Zhengzhou 450052 China department of Physics Beijing Normal University Beijing 100875 China Institute of Cultural Relic Archaeology of Henan Province Zhengzhou 450000 China Institute of Modern Physics Fudan University Shanghai 200433 China

34 samples of Ru Guan porcelain body and 50 samples of Jun Guan porcelain body (both kinds being in different body colors) were selected with the purpose of finding out the source of raw materials and their classification relationship so as to search for ways of non-destructive discrimination. Proton induced X-ray emission (PIXE) has been applied to these samples to determine their chemical elements. The data of seven major chemical elements collected from these samples were further studied through fuzzy cluster analysis. Results indicate that the origin of raw materials of Jun Guan porcelain body samples is comparatively more concentrated in certain places, while that of Ru Guan porcelain body samples is scattered about. The places of origin of raw materials of the majority of Ru Guan and Jun Guan porcelain body samples have something in common, but some differences still exist. It might be an important way for non-destructive discrimination among Ru Guan and Jun Guan porcelains by combining PIXE with fuzzy cluster analysis.

关键词： Ru Guan and Jun Guan porcelain, source of porcelain body, PIXE, fuzzy cluster analysis, non-destructive discrimination.

RETINOBLASTOMA RELATED 1.switches mitosis to meiosis in rice

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Plant Communications 2024年第6期5卷 193-212页

作者： Yongjie Miao Hanli You Huixin {1. Yangzi zhao Jiangzhe zhao Yafei li Yi Shen Ding Tang Baohui {1. Kewei Zhang Zhukuan Cheng Guangdong Provincial Key Laboratory of Plant Adaptation and Molecular Design Innovative Center of Molecular Genetics and EvolutionSchool of Life SciencesGuangzhou UniversityGuangzhou 510006China Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Zhongshan Biological Breeding Laboratory/Key Laboratory of Plant Functional Genomics of the Ministry of Education Agricultural College of Yangzhou UniversityYangzhou 225009China State Key Laboratory of Plant Genomics Institute of Genetics and Developmental BiologyInnovation Academy for Seed DesignChinese Academy of SciencesBeijing 100101China Zhejiang Provincial Key Laboratory of Biotechnology on Specialty Economic Plants Department of BiologyCollege of Life SciencesZhejiang Normal UniversityJinhua 321004China Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops/Jiangsu Key Laboratory of Crop Genetics and Physiology Yangzhou UniversityYangzhou 225009China

The transition from mitosis to meiosis is a critical event in the reproductive development of all sexually reproducing ***,the mechanisms that regulate this process in plants remain largely ***,we find that the rice(Oryza sativa L.)protein RETINOBLASTOMA RELATED 1.RBR1.is essential to the transition from mitosis to *** of RBR1.function results in hyper-proliferative sporogenous-celllike cells(SCLs)in the anther locules during early stages of reproductive *** hyperproliferative SCLs are unable to initiate meiosis,eventually stagnating and degrading at late developmental stages to form pollen-free *** results suggest that RBR1.acts as a gatekeeper of entry into ***,cytokinin content is significantly increased in rbr1.mutants,whereas the expression of type-B response factors,particularly LEPTO1.is significantly *** the known close association of cytokinins with cell proliferation,these findings imply that hyper-proliferative germ cells in the anther locules may be attributed to elevated cytokinin concentrations and disruptions in the cytokinin *** a genetic strategy,the association between germ cell hyper-proliferation and disturbed cytokinin signaling in rbr1.has been *** summary,we reveal a unique role of RBR1.in the initiation of meiosis;our results clearly demonstrate that the RBR1.regulatory module is connected to the cytokinin signaling pathway and switches mitosis to meiosis in rice.

关键词： RETINOBLASTOMA RELATED1 meiosis initiation cytokinin rice

Proteomic analysis of mitochondria reveals a metabolic switch from fatty acid oxidation to glycolysis in the failing heart

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Science china({1.fe Sciences) 2009年第11期52卷 1003-1010页

作者： WANG Jun1,2. BAI ling1,2. li Jing3, SUN ChaoFeng1,2. zhao Jin1, CUI ChangCong1,2. HAN Ke1,2. liu Yu1,2. ZHUO XiaoZhen1,2. WANG TingZhong1,2. liu Ping1,2. FAN Fenling1,2. GUAN YouFei3 & MA AiQun1,2.1 department of Cardiology, First affiliated hospital of medical college of Xi’an Jiaotong university, Xi’an 710061, china 2.Ion Channel Disease Laboratory, Key Laboratory of Environment and Genes Related to Diseases of Education Ministry, Xi’an 710061, china 3 department of Physiology and Pathophysiology Key Laboratory of Molecular Cardiovascular Sciences of the Ministry of Education, Peking university Health Science Center, beijing 100083, china 1. department of Cardiology First affiliated hospital of medical college of Xi’an Jiaotong University Xi’an 710061 China 2. Ion Channel Disease Laboratory Key Laboratory of Environment and Genes Related to Diseases of Education Ministry Xi’an 710061 China 3. department of Physiology and Pathophysiology Key Laboratory of Molecular Cardiovascular Sciences of the Ministry of Education Peking University Health Science Center Beijing 100083 China

This work characterizes the mitochondrial proteomic profile in the failing heart and elucidates the molecular basis of mitochondria in heart failure. Heart failure was induced in rats by myocardial infarction, and mitochondria were isolated from hearts by differential centrifugation. Using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization-time of flight mass spectrometry, a system biology approach was employed to investigate differences in mitochondrial proteins between normal and failing hearts. Mass spectrometry identified 2. proteins differentially expressed that involved in energy metabolism. Among those, the up-regulated proteins included tricarboxylic acid cycle enzymes and pyruvate dehydrogenase complex subunits while the down-regulated proteins were involved in fatty acid oxidation and the OXPHOS complex. These results suggest a substantial metabolic switch from free fatty acid oxidation to glycolysis in heart failure and provide molecular evidence for alterations in the structural and functional parameters of mitochondria that may contribute to cardiac dysfunction during ischemic injury.

关键词： mitochondria heart failure proteome two-dimensional electrophoresis energy metabolism

Advantageous properties of halide perovskite quantum dots towards energy-efficient sustainable applications

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Green Energy & Environment 2024年第6期9卷 949-965页

作者： Qian zhao Shuo Wang Young-Hoon Kim Shekhar Mondal Qingqing Miao Simiao {1. Danya liu Miao Wang Yaxin Zhai Jianbo Gao Abhijit Hazarika Guo-Ran {1. School of Materials Science and Engineering Nankai UniversityTianjin300350China department of Energy Engineering Hanyang UniversitySeoul04763Republic of Korea Polymers and Functional Materials Division CSIR-Indian Institute of Chemical TechnologyUppal RoadTarnakHyderabad500007India Institute of Process Engineering Chinese Academy of SciencesBeijing100190China Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Department of PhysicsHunan Normal UniversityChangshHunan410081China department of {1. Brock University1812 Sir Isaac WaySt CatharinesOntarioCanada

As lead halide perovskite(LHP)semiconductors have shown tremendous promise in many application fields,and particularly made strong impact in the solar photovoltaic area,low dimensional quantum dot forms of these perovskites are showing the potential to make distinct marks in the fields of electronics,optoelectronics and *** so-called perovskite quantum dots(PQDs)not only possess the most important features of LHP materials,i.e.,the unusual high defect tolerance,but also demonstrate clear quantum size effects,along with exhibiting desirable optoelectronic properties such as near perfect photoluminescent quantum yield,multiple exciton generation and slow hot-carrier ***,we review the advantageous properties of these nanoscale perovskites and survey the prospects for diverse applications which include lightemitting devices,solar cells,photocatalysts,lasers,detectors and memristors,emphasizing the distinct superiorities as well as the challenges.

关键词： Perovskite quantum dot light-emitting Detector Laser Solar cell

Giant panda(Ailuropoda melanoleuca)neonates use broadband calls to communicate with their mothers

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Integrative Zoology 2024年第2期19卷 277-287页

作者： lin {1. Jianbin CHENG Wen ZENG Bo YANG Guiquan ZHANG Desheng li Hemin ZHANG Christina DBUESCHING Dingzhen liu Ministry of Education Key Laboratory of Biodiversity Science and Ecological EngineeringCollege of Life SciencesBeijing Normal UniversityBeijingChina Key Laboratory of State Forestry and Grassland Administration on Conservation Biology of Rare Animals in The Giant Panda National Park China Conservation and Research Center for the Giant PandaDujiangyanSichuan611830China department of Biology Irving K.Barber Faculty of ScienceUniversity of British ColumbiaOkanaganKelownaBritish ColumbiaCanada

Infant call structure should have evolved to elicit maximum maternal attention and *** of giant pandas produce three types of vocalizations reported to be vitally important in the context of mother–infant ***,how cubs,0–1. days old,communicate with their mothers to elicit maternal care remains *** analyzed 1.3}different call parameters of 3475 squawks,1.55 squalls,and 491.croaks from 1. captive giant panda(Ailuropoda melanoleuca)neonates from age 0 to 1. *** playback experiments,we also tested whether mothers could detect *** results show that neonates use broadband calls with ultrasonic frequencies up to 65 kHz to convey information about their physiological needs and to attract maternal *** playback experiments,we tested if mothers reacted differently to broadband calls(BBC)than to artificially altered calls that included only frequencies2. kHz(AUDC)or calls that included only frequencies>2. kHz(USC).Playback confirmed that,although adult females responded significantly less often to USC,BBC than to or AUDC,they could detect USC,BBC and generally made appropriate behavioral responses,indicating a potential benefit for neonates to utilize ultrasonic and broadband *** findings provide a new insight into mother–infant communication in giant pandas and will be helpful for reducing the mortality of cubs,younger than 1.month old,in captivity.

关键词： acoustic communication broadband calls maternal care neonates ultrasonic frequencies

Friend or foe? Using eye-tracking technology to investigate the visual discrimination ability of giant pandas

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Current Zoology 2024年第4期70卷 430-439页

作者： Xinrui Huang Guo li Guiquan Zhang Zixiang li lin zhao Mengdie Zhu Qinghua Xiang Xuefeng liu Mei Tian Hemin Zhang Christina D.Buesching Dingzhen liu Ministry of Education Key Laboratory of Biodiversity Science and Ecological EngineeringDepartment of EcologyCollege of Life SciencesBeijing Normal UniversityBeijing 100875China Key Laboratory of State Forestry and Grassland Administration on Conservation Biology of Rare Animals in the Giant Panda National Park China Conservation and Research Center for the Giant PandaSichuan 623004China School of Computer and Information Technology Beijing Jiaotong UniversityBeijing 100044China beijing Key Laboratoryof CaptiveWild{1.fe Technology Beijing ZooBeijing100044China department of Biology Irving K.Barber Faculty of ScienceThe University of British ColumbiaOkanagan CampusKelownaBCCanada

The role that visual discriminative ability plays among giant pandas in social communication and individual discrimination has received less attention than olfactory and auditory ***,we used an eye-tracker technology to investigate pupil fixation patterns for 8 captive male giant pandas Ailuropoda *** paired images(N={1.)of conspecifics against:1.sympatric predators(gray wolves and tigers),and non-threatening sympatric species(golden pheasant,golden snub-nosed monkey,takin,and red panda),{1.conspecifics with atypical fur colora-tion(albino and brown),and 3)zookeepers/non-zookeepers wearing either work uniform or plain *** each session,we tracked the pan-da's pupil movements and measured pupil first fixation point(FFP),fixation latency,total fixation count(TFC),and duration(TFD)of attention to each ***,pandas exhibited similar attention(FFPs and TFCs)to images of predators and non-threatening sympatric *** of golden pheasant,snub-nosed monkey,and tiger received less attention(TFD)than images of conspecifics,whereas images of takin and red panda received more attention,suggesting a greater alertness to habitat or food competitors than to potential ***'TFCs were greater for images of black-white conspecifics than for albino or brown phenotypes,implying that familiar color elicited more *** reacted differently to images of men versus *** images of women only,pandas gave more attention(TFC)to familiar combinations(uniformed zookeepers and plain-clothed non-zookeepers),consistent with the familiarity *** pandas can use visual perception to discriminate intra-specifically and inter-specifically,including details of human appearance,has applications for panda conservation and captive husbandry.

关键词： eye movement tracker giant panda images total fixation duration total pupil fixation count visual discrimination.

非相干辐照对liNbO_3:Fe晶体光折变非线性的影响与控制作用

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物理学报 2003年第2期52卷 395-400页

作者：汪大云刘思敏陈晓虎赵红娥郭儒杨立森高垣梅黄春福陆猗南开大学物理学院天津300071 内蒙古师范大学物理系呼和浩特010022 天津理工学院自动化系天津300191

研究了非相干辐照对liNbO3:Fe晶体中从自散焦到自聚焦的动态转换过程的影响和控制作用 .无论是从前向还是从背向加入非相干辐照 ,都能加快自散焦、自聚焦过程以及从自散焦到自聚焦的转换过程 ,增大折射率的变化值 .当非相干辐照以一定... 详细信息

研究了非相干辐照对liNbO3:Fe晶体中从自散焦到自聚焦的动态转换过程的影响和控制作用 .无论是从前向还是从背向加入非相干辐照 ,都能加快自散焦、自聚焦过程以及从自散焦到自聚焦的转换过程 ,增大折射率的变化值 .当非相干辐照以一定的时间间隔重复辐照在晶体上时 ,透射功率能迅速地上升和下降 ,具有明显的开关效应 .这种在非相干辐照控制下折射率的迅速改变有望应用于全光学开关器件 .

关键词： liNbO3:Fe晶体光折变非线性控制作用非相干辐照光伏效应自散焦自聚焦铌酸锂晶体铁掺杂