Grain size and texture of Cu2ZnSnS4 thin films synthesized by co-sputtering binary sulfides and annealing: effects of processing conditions and sodium

ManuscriptWe investigate the synthesis of kesterite Cu2ZnSnS4 (CZTS) polycrystalline thin films using cosputtering from binary sulfide targets followed by annealing in sulfur vapor at 500 ?C to 650 ?C. The films are the kesterite CZTS phase as indicated by x-ray diffraction, Raman scattering, and optical absorption measurements. The films exhibit (112) fiber texture and preferred low-angle and ?3 grain boundary populations which have been demonstrated to reduce recombination in Cu(In,Ga)Se2 and CdTe films. The grain growth kinetics are investigated as functions of temperature and the addition of Na. Significantly, lateral grain sizes above 1 ?m are demonstrated for samples grown on Na-free glass, demonstrating the feasibility for CZTS growth on substrates other than soda lime glass

Ferromagnetism in Ga1-xMnxP: evidence for inter-Mn exchange mediated by localized holes within a detached impurity band

We demonstrate that in ferromagnetic Ga1-xMnxP exchange is mediated by holes localized in a Mn-derived band. For x<0.06, infrared absorption and photoconductivity spectra indicate the presence of a Mn impurity band which is not merged with the valence band. At temperatures above TC (<65 K) electrical transport is dominated by excitation across this energy gap while nearest neighbor hopping dominates below TC. Magnetization measurements reveal a moment of 3.5 Bohr magnetons per substitutional Mn, while the large anomalous Hall signal unambiguously demonstrates that the ferromagnetism is carrier-mediated.Comment: Equation 1 correcte

Political transition and emergent forest-conservation issues in Myanmar.

Political and economic transitions have had substantial impacts on forest conservation. Where transitions are underway or anticipated, historical precedent and methods for systematically assessing future trends should be used to anticipate likely threats to forest conservation and design appropriate and prescient policy measures to counteract them. Myanmar is transitioning from an authoritarian, centralized state with a highly regulated economy to a more decentralized and economically liberal democracy and is working to end a long-running civil war. With these transitions in mind, we used a horizon-scanning approach to assess the 40 emerging issues most affecting Myanmar's forests, including internal conflict, land-tenure insecurity, large-scale agricultural development, demise of state timber enterprises, shortfalls in government revenue and capacity, and opening of new deforestation frontiers with new roads, mines, and hydroelectric dams. Averting these threats will require, for example, overhauling governance models, building capacity, improving infrastructure- and energy-project planning, and reforming land-tenure and environmental-protection laws. Although challenges to conservation in Myanmar are daunting, the political transition offers an opportunity for conservationists and researchers to help shape a future that enhances Myanmar's social, economic, and environmental potential while learning and applying lessons from other countries. Our approach and results are relevant to other countries undergoing similar transitions

Political transition and emergent forest-conservation issues in Myanmar.

Political and economic transitions have had substantial impacts on forest conservation. Where transitions are underway or anticipated, historical precedent and methods for systematically assessing future trends should be used to anticipate likely threats to forest conservation and design appropriate and prescient policy measures to counteract them. Myanmar is transitioning from an authoritarian, centralized state with a highly regulated economy to a more decentralized and economically liberal democracy and is working to end a long-running civil war. With these transitions in mind, we used a horizon-scanning approach to assess the 40 emerging issues most affecting Myanmar's forests, including internal conflict, land-tenure insecurity, large-scale agricultural development, demise of state timber enterprises, shortfalls in government revenue and capacity, and opening of new deforestation frontiers with new roads, mines, and hydroelectric dams. Averting these threats will require, for example, overhauling governance models, building capacity, improving infrastructure- and energy-project planning, and reforming land-tenure and environmental-protection laws. Although challenges to conservation in Myanmar are daunting, the political transition offers an opportunity for conservationists and researchers to help shape a future that enhances Myanmar's social, economic, and environmental potential while learning and applying lessons from other countries. Our approach and results are relevant to other countries undergoing similar transitions

Investigation and analysis of knowledge and perceptions on tuberculosis prevention and control among university students in Chengdu, China

To explore Tuberculosis (TB) health promotion&nbsp;and&nbsp;education in universities, and to provide a feasible reference method and specific implementation measures for improving health education among university students. We collected a total of 811 respondents, using a uniform questionnaire online survey questionnaire network.&nbsp;The completed questionnaires were double-entered using EpiData3.1, the database was established, and the&nbsp;analysis was performed&nbsp;by Excel2016 and SPSS&nbsp;22&nbsp;software.&nbsp;The total awareness rate of the&nbsp;8&nbsp;core information on&nbsp;tuberculosis prevention and control&nbsp;was&nbsp;74.2&nbsp;%.&nbsp;Among them, “the state provides free anti-tuberculosis drugs and major tests for infectious tuberculosis patients” with the lowest awareness rate of&nbsp;49.2&nbsp;%; followed by the awareness rate of “should care about tuberculosis patients and should not discriminate against tuberculosis patients”, for&nbsp;63.8&nbsp;%.&nbsp;The channels for college students to acquire knowledge about tuberculosis prevention were “newspapers and magazines”, accounted for&nbsp;50.3&nbsp;percent; “broadcasting, television and video” accounted for&nbsp;52.4&nbsp;%; “wall advertising, bulletin boards, slogans” accounted for&nbsp;44.6&nbsp;%; “School Health Education” accounted for&nbsp;38.5&nbsp;% of “school propaganda columns or publicity panels” accounted for&nbsp;34.9&nbsp;%.&nbsp;The favourite way for college students to promote was “watching TV”&nbsp;40.3&nbsp;%

Hydrogen bonds in Al2O3 as dissipative two-level systems in superconducting qubits

Dissipative two-level systems (TLS) have been a long-standing problem in glassy solids over the last fifty years, and have recently gained new relevance as sources of decoherence in quantum computing. Resonant absorption by TLSs in the dielectric poses a serious limitation to the performance of superconducting qubits; however, the microscopic nature of these systems has yet to be established. Based on first-principles calculations, we propose that hydrogen impurities in Al(2)O(3) are the main source of TLS resonant absorption. Hydrogen is an ubiquitous impurity and can easily incorporate in Al(2)O(3). We find that interstitial H in Al(2)O(3) forms a hydrogen bond (O-H…O). At specific O-O distances, consistent with bond lengths found in amorphous Al(2)O(3) or near Al(2)O(3) surfaces or interfaces, the H atom feels a double well. Tunneling between two symmetric positions gives rise to resonant absorption in the range of 10 GHz, explaining the experimental observations. We also calculate the expected qubit-TLS coupling and find it to lie between 16 and 20 MHz, consistent with experimental measurements