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Revisiting the thermal ageing on the metallised polypropylene film capacitor:from device to dielectric film

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High Voltage 2023年第2期8卷 305-314页

作者： Yushuang he Feipeng Wang Guoqiang Du Lei Pan Kaizheng Wang Reimund Gerhard ronald Plath Pawel Rozga Pavel Trnka State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing UniversityChongqingChina Faculty of Electrical Engineering Kunming University of Science and TechnologyKunmingChina Soft Transducer Materials and Systems Universität PotsdamPotsdamGermany Faculty IV Electrical Engineering and Computer Science Technische Universität BerlinBerlinGermany Institute of Electrical Power Engineering Lodz University of TechnologyLodzPoland Faculty of Electrical Engineering University of West BohemiaPilsenCzech Republic

Metallised polypropylene film capacitors(MPPFCs)are widely used in power electronics and are generally degraded by elevated *** work aims to determine the relationships between the structural changes of MPPFC and the microstructural variations of the PP film during the thermal ageing of MPPFC at 100℃ for 38 *** capacitance of MPPFC has a slight decrease during thermal ***,the breakdown voltage of the MPPFC decreases by 39.4%by the *** partial discharge(PD)number of MPPFC increases linearly with ageing *** tear-down analysis of the MPPFC reveals that the molecular structure of the PP film has not been altered but has led to molecular chain scission and the generation of some polar fragments/***,the relative permittivity of the PP films rises as the ageing time ***,thermal ageing causes the conversion of aluminum to alumina in the metallised electrode,which is hydrophilic for polar groups and leads to an adhesion effect between the metallised electrodes and the PP *** angle measurements prove that the surface hydrophilicity of the PP sample increased after thermal ***,the PD/breakdown voltage in the MPPFC increases/decreases due to the uneven adhesion of the metallised PP film.

关键词： film thermal ageing

Release characteristic of different classes of sodium during combustion of Zhun-Dong coal investigated by laser-induced breakdown spectroscopy

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Science Bulletin 2015年第22期60卷 1927-1934页

作者： Yong he Kunzan Qiu ronald Whiddon Zhihua Wang Yanqun Zhu Yingzu Liu Zhongshan Li Kefa Cen State Key Laboratory of Clean Energy Utilization Zhejiang University Division of Combustion Physics Lund University

Serious fouling and slagging problems are associated with the combustion of Chinese Zhun-Dong coal due to its high content of sodium （Na）. Understanding the release characteristic of Na during the combustion is essential to viable utilization of this coal. In this work, coal samples were treated with a sequence of solvents： water （H2O）, ammonium acetate （NH4Ac）, hydrochloric acid （HC1）, and the release characteristics of various classes of Na during coal combustion were investigated using the technique of laser-induced breakdown spectroscopy. The relative contribution of various Na classes to the Na release during each combustion stage was found to be similar, in the order of H2O-soluble Na 〉 NHaAcsoluble Na 〉 HCl-soluble Na 〉 insoluble Na. Sodium released during the devolatilization stage can be attributed to each of the sodium classes. After the devolatilization stage, H2O-soluble Na and NHaAc-soluble Na dominated the Na release during both char and ash stages. Over 64 % of the total Na released during combustion comes from the H2O-soluble Na, which suggests that the Na release during the combustion of Zhun-Dong coal can be reduced effectively after treatment by H2O washing.

关键词： Zhun-Dong coal Laser-inducedbreakdown spectroscopy (LIBS) - Sodium releaseCombustion Online measurement

Beating the blues:engineering cryptochrome expression improves soybean yield

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Molecular Plant 2021年第2期14卷 202-204页

作者： ronald Pierik Plant Ecophysiology Department of BiologyUtrecht UniversityPadualaan 83584 CH Utrechtthe Netherlands

Phytochrome A overexpression can increase harvest index,as was shown 25 years ago in a breakthrough paper on tobacco(Robson et al.,1996).The impact of this important discovery has,however,not been fully *** at high densities often respond strongly to nearby competitors by strong elongation of their internodes and upward bending of their leaves,i.e.,shade *** is crucial for plants to ascertain access to sunlight,and this navigation through vegetation occurs through light cues that are sensed with various photoreceptors.A spectacular sensitivity is displayed by sun-loving plants that can already sense their nearby competitors even before mutual shading occurs and respond through a first acceleration of shoot *** anticipatory response is triggered through red(R):far-red(FR)light-sensitive phytochrome photoreceptors that detect FR light that is reflected by nearby *** the vegetation continues to grow and true shading occurs,there is also a significant depletion of red and blue light,since the latter two are absorbed for photosynthesis in the overhead leaves(reviewed in Pierik and Ballaré,2021).Plants can respond to blue light depletion,especially when integrating it with signaling of FR enrichment in Arabidopsis(de Wit et al.,2016).

关键词： depletion soybean breakthrough

Geometric morphometric analysis of the early Pleistocene hominin teeth from Jianshi,Hubei Province,China

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Science China Earth Sciences 2010年第8期53卷 1141-1152页

作者： ronald CLARKE University of the Witwatersrand JohannesburgSouth Africa

Although the early Pleistocene hominin fossils found in East Asia continent are widely recognized as the earliest hominins migrated from Africa, debates remain on the morphology and taxonomy of these fossils. In this study, dental crown shape of the three early Pleistocene hominin teeth (P3, M1, and M1) found in Jianshi, Hubei Province of China was analyzed by means of geometric morphometrics. The comparative samples of fossil hominins from Africa, Asia, and Europe as well as those of modern humans (N=257) were used. The results indicate that the contour, asymmetry, and cusp patterns of these three types of teeth differ obviously between the fossil hominins and modern humans. The crown shape of P3 in most fossil hominins including Australopithecus, African early Homo, and Asian Pleistocene hominins are asymmetric with their crown occlusal contours long and curving elliptic-shaped. The occlusal contour of the fossil hominin M1 is symmetric and rectangle-shaped with no marked cusp protrusion. The crown shape of fossil M1 is characterized by asymmetric contour with slightly projected metaconid and hypoconid. On the contrary, in modern Chinese and some European late Pleistocene hominins, the crowns of P3s show symmetric contours with buccal side wider than lingual side; the crown shape of M1 is asymmetric with lingual cusp distalplaced, especially for hypoconid; the M1 has symmetric and round crown contour. Our study reveals that Australopithecus has wide variations in its crown shape, whereas these dental morphospaces of Asian hominins are closely placed. The crown contour, symmetry, and cusp patterns of these three teeth of Jianshi hominin resemble those of Asian early and middle Pleistocene hominins. No marked difference in dental crown shape is shown between the Jianshi hominin and other Chinese Homo erectus, and there is also no evidence in support of the Jianshi hominin's closeness to Australopithecus and African early Homo members.

关键词： human evolution tooth shape geometric morphometric Jianshi Hubei China

Jurassic sedimentary evolution of southern Junggar Basin:Implication for palaeoclimate changes in northern Xinjiang Uygur Autonomous Region,China

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Journal of Palaeogeography 2014年第2期3卷 145-161页

作者： Shun-Li Li Xing-he Yu Cheng-Peng Tan ronald Steel School of Energy China University of Geosciences (Beijing) Jackson School of Geosciences University of Texas at Austin

Junggar Basin,located in northern Xinjiang,presents continuous and multikilometer-thick strata of the Jurassic *** Jurassic was entirely terrestrial fluvial and lacustrine deltaic *** outcrop sections across the Jurassic strata were measured at a resolution of meters in southern Junggar *** factors of sedimentary evolution and palaeoclimate changes in Junggar Basin during the Jurassic were discussed based on lithology,fossils and tectonic *** the Early to Middle Jurassic,the warm and wide Tethys Sea generated a strong monsoonal circulation over the central Asian continent,and provided adequate moisture for Junggar ***-bearing strata of the Badaowan,Sangonghe,and Xishanyao Formations were developed under warm and humid palaeoclimate in Junggar *** the late Middle Jurassic,Junggar Basin was in a semi-humid and semi-arid environment due to global warming *** in the upper part of the Middle Jurassic with less plant fossils became multicolor or reddish from dark color *** the Late Jurassic,collision of Lhasa and Qiangtang Block obstructed monsoon from the Tethys Sea.A major change in climate from semi-humid and semi-arid to arid conditions took place,and reddish strata of the Upper Jurassic were developed across Junggar Basin.

关键词： sedimentary evolution palaeoclimate change Jurassic Junggar Basin China

Chemokine signaling involving chemokine (C-C motif) ligand 2 plays a role in descending pain facilitation

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Neuroscience Bulletin 2012年第2期28卷 193-207页

作者： ronald Dubner Department of Neural and Pain Sciences School of Dentistry & Program in Neuroscience University of Maryland

Objective Despite accumulating evidence on a role of immune cells and their associated chemicals in mecha- nisms of pain, few studies have addressed the potential role of chemokines in the descending facilitation of persistent pain. The present study was undertaken to test the hypothesis that the chemokine （C-C motif） ligand 2 （CCL2）（commonly known as monocyte chemoattractant protein-1） signaling in the rostral ventromedial medulla （RVM）, a pivotal structure in brainstem pain modulatory circuitry, is involved in descending pain facilitation in rats. Methods An L5 spinal nerve ligation （SNL） was produced in rats under pentobarbital anesthesia. Western blot and immunohistochemistry were used to detect the expression levels of CCL2 and CCL2 receptor （CCR2）, and examine their distributions compared with the neuronal marker NeuN as well as glial markers glial fibrillary acidic protein （GFAP, astroglial） and CD 11 b （microglial）, respectively. Results SNL induced an increase in CCL2 expression in the RVM, and this returned to the control level at 4 weeks after injury. The induced CCL2 colocalized with NeuN, but not with GFAP and CD1 lb. CCR2 was also upregu- lated by SNL in the RVM, and this increase lasted for at least 4 weeks. CCR2 was colocalized with CD1 lb but not GFAP. Few RVM neurons also exhibited CCR2 staining. Neutralizing CCL2 with an anti-CCL2 antibody （0.2-20 ng） or injecting RS-102895 （0.1-10 pmol）, a CCR2b chemokine receptor antagonist, into the RVM on day 1 after SNL, significantly at- tenuated the established thermal and mechanical hypersensitivity. In addition, injection of recombinant rat CCL2 （0.03-3 pmol） into the RVM induced dose-dependent hyperalgesia, which was prevented by pretreatment with RS-102895 （10 pmol）. Interleukin-β （IL-1]3）, a potent inducer of neuronal CCL2, was also selectively upregulated in RVM reactive as- trocytes. Injection of IL-1 ]3 （120 fmol） into the RVM induced behavioral hyperalgesia, which was blocked by RS-102895 （10 pmol

关键词： monocyte chemoattractant protein-l chemokine (C-C motif) receptor 2 rostral ventromedial medulla neu-ron-glial interaction neuropathic pain rat

Artificial enzymes,cancer chemotherapy,conjugation and nanoelectronics,and prebiotic chemistry

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Science China Chemistry 2011年第12期54卷 1803-1814页

作者： BRESLOW ronald Department of Chemistry Columbia University

This is a summary,with extensive references,of several areas of chemistry in which the Breslow lab has been involved,leading to work still underway in several of *** principal conclusions are described,but it will be ... 详细信息

关键词： artificial enzymes cancer chemotherapy conjugation and nanoelectronics prebiotic chemistry

Influence of temperature and Ca(OH)2 on releasing tar and coal gas during lignite coal pyrolysis and char gasification

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Chinese Journal of Chemical Engineering 2019年第11期27卷 2788-2798页

作者： Sunel Kumar Zhihua Wang Zhang Kang Jun Xia ronald Whiddon Yong he Jaffri Gul-e-Rana Zain Ali Saleh Bairq Kefa Cen State Key Laboratory of Clean Energy Utilization Zhejiang UniversityHangzhou 310027China Department of Mechanical Aerospace and Civil EngineeringBrunel University LondonUxbridge UB83PHUK Fuel Research Centre PCSIRKarachi 75280Pakistan College of Chemistry and Chemical Engineering Hunan UniversityChangsha 410082China

The yield of tar and syngas has been investigated by catalytic pyrolysis of Pingzhuang lignite(PZL)over Ca(OH)2 catalyst in temperature range of 600℃-1000℃in a tube *** results show that the yield of volatile pyrolysis increases and char decreases with rising temperature for both raw and catalyzed Pingzhuang *** hydrogen fraction(H2)increased from 20%to 40%for the PZL sample;but,for the PZL-Ca(OH)2 sample,H2 fraction fluctuated randomly between 35%to 42%,with the maximum H2 fraction found at 1000℃.The Gaschromatography mass-spectroscopic(GC-MS)analysis revealed that the maximum tar yield at 800℃and 700℃was obtained for PZL and PZL-Ca(OH)2,*** surface morphology of PZL and PZL-Ca(OH)2 chars underwent different transformation in the presence of catalyst as illustrated by SEM/EDX,FTIR,and BET ***,char sample was investigated for the carbon conversion and reactivity index using TGA analysis under N2 and CO atmosphere.

关键词： Catalyzed coal pyrolysis Release volatiles of tar and coal gas Surface area Pore volume

Epidemiology of Sexual dysfunction in Asia compared to the rest of the world

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Asian Journal of Andrology 2011年第1期13卷 152-158页

作者： ronald W Lewis Section of Urology Medical College of Georgia Augusta GA 30912 USA

There have been a limited number of epidemiological studies published on sexual disorders in persons from Asia. This paper aims to assess the reports of sexual dysfunction epidemiological studies published in the English language that involved Asian countries. Key points are summarized in this paper from nine epidemiological papers on sexual dysfunction from Asia that were published in the English language. Seven met the criteria for evidence-based studies reaching a Prins score of at least 10 or more. Papers included in this report came from national and regional representative studies in peer review journals. These results for sexual dysfunction in the nine papers are summarized for various sexual dysfunctions in men and women in Asian countries. In three of these, worldwide data were presented in the same paper allowing comparisons with Asian data on prevalence rates. Detailed descriptions from each of these studies are presented in paragraph form. More detailed data on erectile dysfunction （ED） is presented in a tabular form. Collectively, there seems to be a need for country- and population-specific further descriptive and analytical epidemiological studies in all of the sexual disorders from Asia. This critical review paper should help guide these studies for reachinj[ evidence-based literature standards.

关键词： descriptive epidemiology male and female dysfunction male ED premature ejaculation