Waiting time distribution for electron transport in a molecular junction with electron-vibration interaction

On the elementary level, electronic current consists of individual electron tunnelling events that are separated by random time intervals. The waiting time distribution is a probability to observe the electron transfer in the detector electrode at time $t+\tau$ given that an electron was detected in the same electrode at earlier time $t$. We study waiting time distribution for quantum transport in a vibrating molecular junction. By treating the electron-vibration interaction exactly and molecule-electrode coupling perturbatively, we obtain master equation and compute the distribution of waiting times for electron transport. The details of waiting time distributions are used to elucidate microscopic mechanism of electron transport and the role of electron-vibration interactions. We find that as nonequilibrium develops in molecular junction, the skewness and dispersion of the waiting time distribution experience stepwise drops with the increase of the electric current. These steps are associated with the excitations of vibrational states by tunnelling electrons. In the strong electron-vibration coupling regime, the dispersion decrease dominates over all other changes in the waiting time distribution as the molecular junction departs far away from the equilibrium

Lessons Learned from Two Case Studies in Higher Education

As places where future citizens are educated, knowledge is (co-)produced and societal developments are critically reflected, higher education institutions (HEIs) can play a key role in addressing sustainability challenges. In order to accelerate mutual learning, shared problem understanding, and joint development of sustainable solutions, interinstitutional exchange and collaboration between HEIs is crucial. However, little research to date has focused on institutional HEI networks in the field of sustainability. More specifically, we still understand little about the concrete development, implementation, and adaptation of such networks. This article explores early-stage HEI networks for sustainability from a conceptual and empirical stance in order to develop a framework that facilitates structured descriptions of these networks, as well as to foster cross-HEI learning on their effective performance. It therefore combines insights from an explorative literature review, two case studies and an interactive workshop at the ISCN Conference 2018. As results, we first suggest an analytical framework to facilitate a systematic characterization of HEI networks. Second, by applying the framework to the two case studies, we present and discuss lessons learned on how a single HEI can contribute to establishing a network and how it can utilize its network membership effectively to strengthen its efforts for sustainability

Sustainable digitalization ‐ fostering the twin transformation in a transdisciplinary way

Can digitalization be designed in such a way that it does not harm the environment or promote unsustainable lifestyles? Can it even promote a green transformation? The authors of this GAIA special issue discuss how stakeholder engagement and transdisciplinary approaches can help address digitalization and sustainability in an integrated way. The special issue deepens insights into the state of knowledge on sustainable digitalization in both scientific and political discourses

MARDELS: A full-sky X-ray selected galaxy cluster catalog

We present the MARDELS catalog of 8,471 X-ray selected galaxy clusters over 25,000 deg^2 of extragalactic sky. The accumulation of deep, multiband optical imaging data, the development of the optical counterpart classification algorithm MCMF, and the release of the DESI Legacy Survey DR10 catalog covering the extragalactic sky makes it possible -- for the first time, more than 30 years after the launch of the ROSAT X-ray satellite -- to identify the majority of the galaxy clusters detected in the ROSAT All-Sky-Survey source catalog (2RXS). The resulting 90% pure MARDELS catalog is the largest ICM-selected cluster sample to date. MARDELS probes a large dynamic range in cluster mass spanning from galaxy groups to the most massive clusters in the Universe. The cluster redshift distribution peaks at z~0.1 and extends to redshifts z~1. Out to z~0.4, the MARDELS sample contains more clusters per redshift interval (dN/dz) than any other ICM-selected sample. In addition to the main sample, we present two subsamples with 6,930 and 5,522 clusters, exhibiting 95% and 99% purity, respectively. We forecast the utility of the sample for a cluster cosmological study, using realistic mock catalogs that incorporate most observational effects, including the X-ray exposure time and background variations, the existence likelihood selection adopted in 2RXS and the impact of the optical cleaning with MCMF. Using realistic priors on the observable--mass relation parameters from a DES-based weak lensing analysis, we estimate the constraining power of the MARDELSxDES sample to be of 0.026, 0.033 and 0.15 ($1\sigma$) on the parameters $\Omega_\mathrm{m}$, $\sigma_8$ and $w$, respectively.Comment: 20 pages, 11 figures, submitted to MNRA

Cross-case knowledge transfer in transformative research: enabling learning in and across sustainability-oriented labs through case reporting

The field of transdisciplinary sustainability research has brought forward a number of approaches aimed at fostering sustainability transformations and generating knowledge through collaborative experimentation in real-world settings. These cases are strongly embedded in their local context and thus the transfer of knowledge remains a key challenge. In this paper, we propose a case reporting approach that supports the structured and coherent reporting of such cases. This scheme is aimed at sustainability-oriented labs, where sustainability solutions are collaboratively developed through experimentation. The scheme focuses the reporting on local contexts, lab processes, and experiments. It is accompanied by a logic model and a set of four principles guiding the reporting procedure. The approach is designed to be general, in that it is applicable to diverse contexts and project designs, while its modularity allows the scheme to be adapted to the needs and specifics of each cases. The scheme was jointly developed and tested by a group of seven Urban Living Labs, each in their own unique context. With our approach we aim to contribute to knowledge transfer from and across cases of sustainability-oriented labs as emerging approaches in action-oriented research bridging the divide of case-based research and (meta) comparison