239 research outputs found
Vertical profiles of Doppler spectra of hydrometeors from a Micro Rain Radar recorded during the austral summer of 2016/2017 in the Southern Ocean on the Antarctic Circumnavigation Expedition (ACE).
No full text<p>***** Dataset abstract *****</p>
<p>This dataset includes vertical profiles of the Doppler spectra and derived quantities of hydrometeors using a Micro Rain Radar (MRR-2) during the Antarctic Circumnavigation Expedition in 2016/2017. The MRR is a frequency-modulated-continuous-wave (FMCW) Doppler radar working at 24 GHz (K band). It measures the Doppler spectrum at vertical incidence with 31 range gates of 100 m. The data is processed to calculate rainfall and snowfall rates. For rainfall, the drop size distribution and the rainfall rate are derived using the method by Peters et al. (2005). For snowfall, the particle size distribution is estimated from the Doppler spectrum to compute the snowfall rate as described in Maahn & Kollias (2012).</p>
<p>**** Dataset contents *****</p>
<p>- RawSpectra/{month}/MRR_ACE_{month}{day}_RAW.nc: raw data of Doppler spectra for rainfall events. Null values are denoted as -99900.<br>
- ProcessedData/{year}{month}/MRR_ACE_{year}{day}_PRO.nc: 10-second averages (highest resolution) for specific precipitation events, using the standard products from Metek (MRR physical basics, 2009).<br>
- AveData/{month}/MRR_ACE_{month}{day}_AVE.nc: one-minute averages for specific precipitation events, using the standard products from Metek (MRR physical basics, 2009).<br>
- Processed_IMProToo/{year}{month}/mrr_improtoo_0.101_ACE_{year}{day}.nc: processed data for snowfall events using IMProToo (Maahn & Kollias 2012) in one-minute averages.<br>
- RR_timeline/{month}/RR_MRR_ACE_{month}{day}.csv: 10-minute running mean with one-minute resolution of rain rate for [100-200]m and [200-300]m range gate. Null values are denoted as ‘nan’.<br>
- RR_timeline/{year}{month}/RR_MRR_ACE_{year}{day}.png: daily plots of rain rates.<br>
- PrecipitationEvents.txt: text file classifying the precipitation events according to hydrometeors (rain, snow or hail).<br>
- Graphs_Metek/{month}/moments_MRR_ACE_{month}{day}_AVEnc.png: daily plots of Radar reflectivity and Doppler velocity for rainfall events.<br>
- Graphs_IMProToo/{year}{month}/moments_mrr_improtoo_0101_ACE_{year}{day}.png: daily plots of Radar reflectivity and Doppler velocity for snowfall events.<br>
- RawSpectra_data_file_header.txt, metadata, text format<br>
- Metek_ProcessedData_data_file_header.txt, metadata, text format<br>
- IMProToo_ProcessedData_data_file_header.txt, metadata, text format<br>
- AveData_data_file_header.txt, metadata, text format<br>
- README.txt, metadata, text format</p>
<p>***** Dataset license *****</p>
<p>This vertical Doppler spectra profile dataset is made available under the Creative Commons Attribution 4.0 International License (CC BY 4.0) whose full text can be found at https://creativecommons.org/licenses/by/4.0/</p>The Antarctic Circumnavigation Expedition was made possible by funding from the Swiss Polar Institute and Ferring Pharmaceuticals
A fractional Gehring lemma, with applications to nonlocal equations
No full textTo Carlo Sbordone on his 65th birthday.This paper reports the content of a talk given by the second-named author at the Accademia dei Lincei on November 26, 2013.International audienceWe describe a fractional version of the classical Gehring lemma. As a consequence, new self-improving regularity properties of solutions to integrodifferential equations emerge
[[alternative]]An Analogy of a Theorem of Gehring and Pommerenke under Nehari's
No full text[[abstract]]我們定義一個局部單葉的亞純函數 f 其 Schwarz 導數在 f'(z)≠0
的點為S_f=(f'')(f')'-1/2(f''/f')^2, 而在單極處則訂為 S_f=S_(1/
f). 我們早就知道S_f=0 若且唯若 f 是一個 Mobius 變換. 直接從定義
可得知 S_f 是一個可析函數.相反地, 如果 φ 是一個可析函數, 則存在
一個亞純函數 f 使得 S_f=φ. 早在1949年, Z. Nehari 就證明了 ∣
S_f(z)∣≦ 2/(1-∣z∣^2)^2) 及∣S_f(z)∣≦(π^2)/2 可導出 f 在單
位圓盤上的單葉性.F. W. Gehring 及 C.Pommerenke 更針對第一種條件
作深入的研究, 得到可同胚及可擬保角延拓的充分條件.而我們將注意力
集中在滿足Nehari第二種條件的函數和這些函數的延拓性.而這篇論文主
要是在單位圓盤D中就∣S_f(z)∣≦(π^2)/2 的條件作一檢視. 整個論文
的架構平行於Gehring 及 Pommerenke 的架構. 其中部份的技巧則模仿自
M. Chuaqui 及 B. Osgood 的研究工作.首先, 我們討論了 f 的解析性,
並且對 ∣f'∣及 ∣f∣ 的範圍作一估計.其次, 我們討論了 f 的單葉
性. 接著證明了 f 可連續延拓到 D 的邊界上. 再就此延拓是否一對一分
別討論. 如果是一對一, 則 f 可以擬保角延拓到整個複數平面; 若不是
一對一, f 則與 2/π tan πz/2 Mobius 共軛. 最後, 我們知道如果 f
不是與 2/ π tan πz/2 Mobius 共軛, 則 f 在 D 上滿足 Lipcshitz
條件.
We define the Schwarzian derivative of a function f which is
meromorphic andlocally univalent as S_f=(f''/f')'-(1/2)(f''/f')
^2 at the points where f'(0) is not equal to 0. And we define
S_f(z)=S_(1/f)(z) at the points which are simple poles. It's
shown in early age that S_f = 0 if and only if f is a Mobius
transformation. Directly from the definition, we know that S_f
is analytic. Conversely, suppose that φ is analytic
function, there exists a meromorphic function f such that S_f=
φ. Early in 1949, Z.
Nehari showed that conditions∣S_f(z)∣≦2/(1-∣z∣^2 )^2 and ∣
S_f(z)∣≦(π^2)/2 both imply that f is univalent in the unit
disk D. F. W. Gehring and C. Pommerenke focused their research
on the first condition that Nehari's deduced, and they had the
sufficient conditions that thefunction f can be extended to a
homeomorphic function and a quasiconformalfunction on the plane.
This paper mainly makes an investgation on which properties f
possessesunder the condition ∣S_f∣≦(π^2)/2 in the unit disc
D. The structure of this paper is parallel with the one of
Gehring and Pommerenke. And there are some skills imitated from
the research of M. Chuaqui and B. Osgood. First, we discuss the
analytic property of f under∣S_f∣≦(π^2)/2. We also estimate
the bound of ∣f'∣and ∣f∣. Next, we discuss the univalence of
fand prove that f has a continuous extension to the boundary of
D. Whether this extension is univalent or not give us two
directions. If the extension isone-to-one, f possess a
quasiconformal extension to the whole complex plane.If not, f is
a Mobius conjugate to 2/π tan πz/2. Finally, we prove that if
f is not a Mobius conjugate to f, then f satisfies Lipschitz
condition,which is the special case of Holder's continuity.
We define the Schwarzian derivative of a function f which is
Single-molecule quantum-transport phenomena in break junctions
No full textSingle-molecule junctions — devices in which a single molecule is electrically connected by two electrodes — enable the study of a broad range of quantum-transport phenomena even at room temperature. These quantum features are related to molecular orbital and spin degrees of freedom and are characterized by various energy scales that can be chemically and physically tuned: level spacings, charging energies, tunnel couplings, exchange energies, vibrational energies and Kondo correlation energies. The competition between these different energy scales leads to a rich variety of processes, which researchers are now starting to be able to control and tune experimentally. In this Technical Review, we present the status of the molecular electronics field from this quantum-transport perspective with a focus on recent experimental results obtained using break-junction devices, including scanning probe and mechanically controlled break junctions, as well as electromigrated gold and graphene break junctions.Accepted Author ManuscriptQN/van der Zant LabQN/Thijssen Grou
Evidence for intrinsic magnetic scatterers in the topological semimetal (Bi2)5(Bi2Se3)7
No full textWe report the synthesis and characterization of high-quality thin films of the topological semimetal (Bi2)5(Bi2Se3)7. Cryogenic magneto-transport experiments reveal strong metallic character and spin–orbit coupling in the films. By studying the temperature dependence of the electrical resistance of the topological semimetal, we observe a pronounced Kondo effect, which points toward the presence of magnetic scatterers. With the aid of density functional theory calculations, we identify Bi vacancies as intrinsic magnetic scatterers in this topological semimetal
Implementation of SNS thermometers into molecular devices for cryogenic thermoelectric experiments
No full textThermocurrent flowing through a single-molecule device contains valuable information about the quantum properties of the molecular structure and, in particular, on its electronic and phononic excitation spectra and entropy. Furthermore, accessing the thermoelectric heat-to-charge conversion efficiency experimentally can help to select suitable molecules for future energy conversion devices, which - predicted by theoretical studies - could reach unprecedented efficiencies. However, one of the major challenges in quantifying thermocurrents in nanoscale devices is to determine the exact temperature bias applied to the junction. In this work, we have incorporated a superconductor-normal metal-superconductor Josephson junction thermometer into a single-molecule device. The critical current of the Josephson junction depends accurately on minute changes in the electronic temperature in a wide temperature range from 100 mK to 1.6 K. Thus, we present a device architecture which can enable thermoelectric experiments on single molecules down to millikelvin temperatures with high precision. Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.QN/van der Zant La
House church and mission: the importance of household structures in early Christianity
No full textTitle: House church and mission: the importance of household structures in early Christianity. Author: Gehring, Roger W House church and mission xvi, 408 p. Publisher: Peabody, Mass : Hendrickson, 2004
Thermoelectric Effects in Nanoscale Devices
No full textBottom-up synthesized atomically precise graphene nanoribbons (GNRs) are Designer Quantum Materials, materials in which the properties can be designed and adjusted on-demand. GNRs offer a variety of properties: tunable bandgap, in-situ pn-junction formation, quantum dot behavior, and even exhibit topologically non-trivial phases. This shows that graphene nanoribbons are a versatile platform for novel electronic devices. However, many challenges remain in the device integration of these materials, especially regarding contacting and gating strategies. These two challenges directly enter the thermoelectric figure of merit zT via the electrical conductivity. This thesis covers various aspects of the GNR device integration for thermoelectric characterization. This involves the development of contacting and gating strategies for assessing the electrical conductivity of GNRs. Further, the Seebeck coefficient of GNR based devices is determined using an advanced measurement platform and scheme. Finally, a novel Raman-based method is established to map thermal conductivity. Although the working principle of this method is demonstrated on defect-engineered graphene membranes, it is extendable to films of GNRs
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