检索结果-南通市图书馆

Limits on light emission from silicon

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Optics Letters 2009年第4期7卷 268-270页

作者： peter würfel Institut für Angewandte Physik Universitt KarlsruheD-76128 KarlsruheGermany

Although silicon is an indirect semiconductor, light emission from silicon is governed by the same gener- alized Planck＇s radiation law as the emission from direct semiconductors. The emission intensity is given by the absorptance of the volume in which there is a difference of the quasi Fermi energies. A difference of the Fermi energies may result h＇om the absorption of external light （photoluminescence） or from the injection of electrons and holes via selective contacts （electroluminescence）. The quantum efficiency may be larger than 0.5 for carrier densities below 10^15 cm^-3. At larger densities, non-radiative recombination, in particular Auger recombination dominates. At all carrier densities, the relation between emission intensity and difference of the quasi Fermi energies is maintained. Since this difference is equal to the voltage of a properly designed solar cell, luminescence is the key indicator of material quality for solar cells.

关键词： Carrier concentration Fermi level Light Light emission Photoluminescence Semiconducting silicon Silicon

Unfolded p53 in non-neuronal cells supports bacterial etiology of Alzheimer’s disease

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2022年第12期17卷 2619-2622页

作者： peter w.French Innlanz Limited SydneyNSWAustralia

Alzheimer’s disease has proven to be largely intractable to treatment,despite years of research,and numerous trials of therapies that target the hallmarks of the disease-amyloid plaques and neurofibrillary *** etiology of Alzheimer’s disease remains *** is a growing body of evidence for an infectious trigger of Alzheimer’s disease,and,in particular,the focus has been on the oral pathogen Porphyromonas gingivalis(***).Reports of the expression of a misfolded form of p53 in non-neuronal cells(fibroblasts,peripheral blood mononuclear cells,and B cells)and serum,which appears several years before clinical symptoms manifest,may provide further support for the role of bacteria in general,and *** in particular,in the initiation of the *** review presents a model of the pathway from initial oral infection with *** to amyloid plaque formation and neuronal degeneration,via the steps of chronic periodontitis;secretion of the inflammagens lipopolysaccharide and gingipains into the bloodstream;induction of an inflammatory response in both peripheral cells and tissues;disruption of the blood-brain barrier,and entry into the central nervous system of the inflammagens and the *** bacteria *** this model,the misfolded p53(or“unfolded p53”;up53)is induced in non-neuronal cells and upregulated in serum as a result of oxidative stress due to lipopolysaccharide from ***53 is therefore a potential biomarker for early diagnosis of the presence of a causative agent of Alzheimer’s *** dental hygiene and aggressive antibiotic treatment may prevent the patient progressing to clinical Alzheimer’s disease if serum up53 is detected at this pre-symptomatic stage.

关键词： Alzheimer’s disease gingipains lipopolysaccharide P.gingivalis periodontitis unfolded p53

Blind spots in climate finance for innovation peter wARREN

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2020年第1期11卷 60-64页

作者： peter wARREN School of Public Policy University College London(UCL)LondonWCIH 9QUUK

International climate finance is a sub-set of green finance and refers to investments specifically in climate change mitigation and adaptation activities,which primarily involve public finance and the leveraging of private finance in developing *** addition to continued international support for scaling low carbon solutions and facilitating replicability in developing countries,there remains an important need to increase the amount of climate finance provided to innovation,particularly demonstration(for technology innovation)and pilot implementation(for policy innovation),and to channel a greater proportion of Official Development Assistance(ODA)to‘hard-to-abate'areas,such as industrial decarbonisation,international transport and cross-sectoral issues like cooling and behavioural insights,to accelerate the commercialisation and implementation of technological,linancial and policy solutions to contribute to meeting the Paris Agreement's goal of limiting global warming to‘well-below'2℃ in these *** research,development and demonstration(RD&D)support with technical assistance is important in providing the route to obtain wider donor finance(concessional finance)and private finance to enable deployment through scalability and replicability.

关键词： Climate finance Climate policy Paris Agreement Official development assistance Industrial decarbonisation Sustainable cooling Behavioural insights International transport

Differential Kinematic Encoding of Saccades and Smooth-pursuit Eye Movements by Fastigial Neurons

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2022年第8期38卷 927-932页

作者： Zongpeng Sun peter w.Dicke peter Thier School of Psychology Shaanxi Normal UniversityXi’an710062China Department of Cognitive Neurology Hertie Institute for Clinical Brain Research72076TübingenGermany

Dear Editor,Saccades and smooth-pursuit eye movements(SPEMs)are two categories of eye movements with very different kinematics,in particular very different acceleration and velocity ranges,differences that have contributed to the notion of largely segregated underlying neuronal *** instance,it has been suggested that distinct wellsegregated pools of oculomotor vermis(OMV)Purkinje cells(PCs)are specialized for the fine-tuning of the relevant kinematic parameters characterizing each of them.

关键词： pursuit specialized instance

On the Range of the Common Cycle Time in a Road Network

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Harbin Institute of Technology(New Series) 2015年第6期22卷 31-36页

作者： Ting Lu Marko wlki peter wagner Institute of Transportation Systems German Aerospace Center (DLR) Faculty of Maritime and Transportation Ningbo University

In a coordinated road network,the optimal common cycle time is determined by evaluating the performance of the network in the given range of cycles. Normally,this range is determined by users 'experience. And a large range of common cycle time,e. g. [30,200] is chosen,which requires long computation time. This study considers that the optimal common cycle time ranges between the minimal and maximal value of intersections' individual optimal cycle time. It is proved mathematically from the convexity condition,that the delay of the network and each individual intersection are convex functions of the cycle time according to webster delay model. Finally,2 000 random cases for the network composed of two intersections and of eight intersections are created to underline the proposed conclusions. The results of all cases confirm the validity,and show up to 90% improvement in computation time to compare with experience range. The signal optimization tool,Synchro,is also used to validate the conclusion by 50 random cases. The results confirm reliability further.

关键词： common cycle traffic signal optimization convexity webster model

The Trans/national Cultural Economy of Latin American Film Musicals(1930s-50s)

在线全文

学校读者我要写书评

暂无评论

Journal of Foreign Languages and Cultures 2021年第2期5卷 127-142,156页

作者： peter w.Schulze University of Cologne

This essay traces the tensions between national imaginaries and transnational global media flows of tango,samba,and ranchera film musicals,taking into account their cross-media and intercultural configurations as well as interconnections between these three“transgenres.”From a comparative perspective and by means of a“histoire croisee,”or crisscrossing history,it touches upon developments in early Latin American sound film,Hollywood’s Spanish-language films and its Pan-Americanism,Spain’s cinematic Hispanoamericanismo,and PanLatin American film *** essay makes a case for the multifaceted trans/national cultural economy of the tango,samba,and ranchera film musical productions during their main phase,in the 1930s and 40s.

关键词： tango samba ranchera transgenre crisscrossing history globalization cinema

Human pluripotent stem cells:tools for regenerative medicine

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biomaterials Translational 2021年第4期2卷 294-300页

作者： peter w.Andrews The Centre for Stem Cell Biology The School of BioscienceThe University of SheffieldSheffieldUK

Human embryonic stem cells and induced pluripotent stem cells,together denoted as pluripotent stem cells have opened up unprecedented opportunities for developments in human healthcare over the past 20 *** much about the properties and behaviour of these cells required to underpin their applications has been discovered over this time,a number of issues *** brief review considers the history of these developments and some of the underlying biology,pointing out some of the problems still to be resolved,particularly in relation to their genetic stability and possible malignancy.

关键词： embryonic stem cell induced pluripotent stem cell human pluripotency differentiation

Geochronological constraints on 140-85 Ma thermal doming extension in the Dabie orogen, central China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2002年第9期45卷 801-817页

作者：许长海周祖翼马昌前 peter w. Reiners 1. MOU Laboratory of Marine Geology Tongji University 200092 Shanghai China 2. Faculty of Earth Sciences China University of Geosciences 430074 Wuhan China 3. Department of Geology Washington State University 99164-2812 Pullman WA USA

Regional architecture of geochronology and differential cooling pattern show that the Dabie orogen underwent a thermal doming extension during 140-85 Ma. This extension resulted in widespread re-melting of the Dabie basement, intense volcanic activities in North Huaiyang and the formation of fault-controlled depressions in the Hefei basin. This thermal doming extension can be further divided into two consecutive evolving stages, i.e. the intensifying stage (140-105 Ma) and the declining stage (105-85 Ma). In the first stage (140-105 Ma), the thermal doming mainly was concentrated in the Dabie block, and to a less degree, in the Hongan block. The thermal doming structure of the Dabie block is configured with Macheng-Yuexi thermal axis, Yuexi/Luotian thermal cores and their downslide flanks. The orientation of thermal axis is dominantly parallel to the strike of orogen, and UHP/HP units together with metamorphic rocks of North Huaiyang constitute the downslide flanks. The Yuexi core differs from the Luotian core in both the intensity and the shaping time. To some extent, the Hongan block can be regarded as part of downslide systems of the Dabie doming structure. The doming process is characterized by thermal-center's migration along the Macheng-Yuexi thermal axis; consequently, it is speculated to be attributed to the convective removal of thickened orogenic root, which is a process characterized by intermittance, migration, large-scale and differentiation. During the declining stage (105-85 Ma), the dome- shaped figure still structurally existed in the Dabie orogen, but orogenic units cooled remarkably slow and magmatic activities stagnated gradually. Study on the thermal doming of Dabieshan Mountains can thus provide detailed constraints on the major tectonic problems such as the UHP/HP exhumation model, the boundary between North Dabie and South Dabie, and the orogenesis mechanism.

关键词： Dabie orogen, geochronology, cooling pattern, thermal doming extension.

Effect of longwall-induced subsurface deformations on shale gas well casing stability under deep covers

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2019年第1期29卷 3-8页

作者： Daniel w.H.Su peter Zhang Mark Van Dyke Todd Minoski Center for Disease Control and Prevention(CDC) National Institute for Occupational Safety and Health(NIOSH)Pittsburgh Mining Research Division(PMRD)

This paper presents the results of a 2017 study conducted by the National Institute for Occupational Safety and Health(NIOSH), Pittsburgh Mining Research Division(PMRD), to evaluate the effects of longwall-induced subsurface deformations within a longwall abutment pillar under deep cover. The 2017 study was conducted in a southwestern Pennsylvania coal mine, which extracts 457 m-wide longwall panels under 361 m of cover. One 198 m-deep, in-place inclinometer monitoring well was drilled and installed over a 45 m by 84 m center abutment pillar. In addition to the monitoring well, surface subsidence measurements and underground coal pillar pressure measurements were conducted as the 457 m-wide longwall panel on the south side of the abutment pillar was being mined. Prior to the first longwall excavation, a number of simulations using FLAC3D^(TM) were conducted to estimate surface subsidence, increases in underground coal pillar pressure, and subsurface horizontal displacements in the monitoring well. Comparisons of the pre-mining FLAC3D simulation results and the surface, subsurface,and underground instrumentation results show that the measured in-place inclinometer casing deformations are in reasonable agreement with those predicted by the 3D finite difference models. The measured surface subsidence and pillar pressure are in excellent agreement with those predicted by the 3D *** from this 2017 research clearly indicate that, under deep cover, the measured horizontal displacements within the abutment pillar are approximately one order of magnitude smaller than those measured in a 2014 study under medium cover.

关键词： Longwall Deformations Shale gas wells Casing Safety and health