Orange Zinc Germanate with Metallic Ge-Ge Bonds as a Chromophore-Like Center for Visible-Light-Driven Water Splitting

The efficiency of solar-energy-conversion devices depends on the absorption region and intensity of the photon collectors. Organic chromophores, which have been widely stabilized on inorganic semiconductors for light trapping, are limited by the interface between the chromophore and semiconductor. Herein we report a novel orange zinc germanate (Zn-Ge-O) with a chromophore-like structure, by which the absorption region can be dramatically expanded. Structural characterizations and theoretical calculations together reveal that the origin of visible-light response can be attributed to the unusual metallic Ge-Ge bonds which act in a similar way to organic chromophores. Benefiting from the enhanced light harvest, the orange Zn-Ge-O demonstrates superior capacity for solar-driven hydrogen production.

Civic engagement and the arts and humanities: a UK perspective

Higher education in the UK is in a state of flux and this is having particular impact on the humanities. On the one hand the pressure to support a STEM agenda is seen by some as forcing higher education down a narrow economic agenda, while government requirements for assessing the social and economic impact of research has raised concerns about excessive utilitarianism and a downgrading of ‘disinterested enquiry’. This paper argues that these concerns may be misplaced. The research impact agenda has the potential to promote more socially engaged research and more democratic engagement in the creation and dissemination of knowledge. In the US concerns about the democratic role of higher education more often seem to focus on the student experience. By contrast, in the UK concerns about citizenship education and democratic participation more often focus on high school students, perhaps because university students are more likely to have a formal role in institutional governance. The paper concludes that the papers in this forum have a very American feel, but the issues they address resonate on a much wider scale.

Civic engagement in a divided society: the role of Queen’s University Belfast in Northern Ireland

The purpose of this paper is to examine the role of a university in a society emerging from decades of political violence and to show ways in which public engagement can help promote democratic practice and contribute to the strengthening of peace. Our understanding of the concept of public engagement follows the UK National Coordinating Centre for Public Engagement definition:

'Public engagement describes the myriad of ways in which the activity and benefits of higher education and research can be shared with the public. Engagement is by definition a two-way process, involving interaction and listening, with the goal of generating mutual benefit .'

The case study is provided by the example of Queen's University Belfast. We will begin by examining some of the history and context of the university, then discuss the political and social context of Northern Ireland, before going on to examine some of the publicly engaged work being carried out by Queen's and consider how this might be taken forward.

Modeling the Rossiter-McLaughlin Effect: Impact of the Convective Center-to-limb Variations in the Stellar Photosphere

bservations of the Rossiter–McLaughlin (RM) effect provide information on star–planet alignments, which can inform planetary migration and evolution theories. Here, we go beyond the classical RM modeling and explore the impact of a convective blueshift that varies across the stellar disk and non-Gaussian stellar photospheric profiles. We simulated an aligned hot Jupiter with a four-day orbit about a Sun-like star and injected center-to-limb velocity (and profile shape) variations based on radiative 3D magnetohydrodynamic simulations of solar surface convection. The residuals between our modeling and classical RM modeling were dependent on the intrinsic profile width and v sin i; the amplitude of the residuals increased with increasing v sin i and with decreasing intrinsic profile width. For slowly rotating stars the center-to-limb convective variation dominated the residuals (with amplitudes of 10 s of cm s−1 to ~1 m s−1); however, for faster rotating stars the dominant residual signature was due a non-Gaussian intrinsic profile (with amplitudes from 0.5 to 9 m s−1). When the impact factor was 0, neglecting to account for the convective center-to-limb variation led to an uncertainty in the obliquity of ~10°–20°, even though the true v sin i was known. Additionally, neglecting to properly model an asymmetric intrinsic profile had a greater impact for more rapidly rotating stars (e.g., v sin i = 6 km s−1) and caused systematic errors on the order of ~20° in the measured obliquities. Hence, neglecting the impact of stellar surface convection may bias star–planet alignment measurements and consequently theories on planetary migration and evolution.