Fluctuations on metal surfaces and molecule/metal interfaces

We combine the tools of statistical mechanics with direct imaging at the atomic scale, using scanning tunneling microscopy (STM) to observe and characterize intrinsic fluctuation properties on surfaces and interfaces, and further explore how these properties are affected by current, the electromigration problem. Fluctuation properties of steps and islands on metal surfaces, twin boundaries on metal nanowires, are investigated and the underneath mass transport mechanisms are determined. Then we has studied how mass transport properties are affected by undesirable impurity on surfaces or deposited molecules, especially we focus on island shape change and fluctuations of molecule/metal interfaces. For the organic-metal system, we further investigate related electromigration properties, and find island migration and step bend due to wind force. Finally, organic thin films are also investigated, including the novel 2D chiral structure, and phase boundary fluctuations in an organic thin film. All these studies not only are important in the fundamental physics, but also provide basic and useful information for designing and building future organic electronic devices

The impacts of extreme marine weather and marine scientific and technological innovation on marine economic development: Evidence form China’s coastal regions

The extreme marine weather is a very vital factor and has important implications for of marine economic development. However, there is a lack of systematic and quantitative analyses of its impact on the marine economic development. Here, we study the impacts of extreme marine weather on marine economic development of 11 coastal regions in China, using the dynamic panel model. We found that extreme marine weather exerts a significant negative impact on the marine economic development. The marine scientific and technological innovation promotes marine economic development in a prominent manner. The marine scientific and technological innovation slows down the unfavorable impact of extreme marine weather on the marine economy. After considering different industries for marine economic development and heterogeneity, we found that extreme marine weather and marine scientific and technological innovation have a great impact on marine economic development in the tertiary industry and the areas with high development concerning marine economy level, while deliver a small impact on the marine economic development in the primary industry and the areas low development level. This paper empirically studies the relationship between the two variables of marine extreme weather and marine science and technology innovation and its impact on marine economic development, enriches the research perspective of extreme weather on marine economic development, and provides new method evidence for improving the level of marine scientific and technological innovation and promoting the development of marine economy

Black holes regulate cold gas accretion in massive galaxies

Nearly every massive galaxy contains a supermassive black hole (BH) at its center. For decades, both theory and numerical simulations have indicated that BHs play a central role in regulating the growth and quenching of galaxies. Specifically, BH feedback by heating or blowing out the interstellar medium (ISM) serves as the groundwork for current models of massive galaxy formation. However, direct evidence for such an impact on the galaxy-wide ISM from BHs has only been found in some extreme objects. For general galaxy populations, it remains unclear whether and how BHs impact the ISM. Here based on a large sample of nearby galaxies with measurements of masses of both black holes and atomic hydrogen, the major component of cold ISM, we reveal that the atomic hydrogen content ($f_{\rm HI} = M_{\rm HI}/M_{\star}$) is tightly and anti-correlated with black hole mass ($M_{\rm BH}$) with $f_{\rm HI} \propto M^{-\alpha}_{\rm BH}$ ($\alpha \sim 0.5-0.6$). This correlation is valid across five orders of magnitude in $M_{\rm BH}$. Once this correlation is taken into account, $f_{\rm HI}$ loses dependence on other galactic parameters, demonstrating that $M_{\rm BH}$ serves as the primary driver of $f_{\rm HI}$. These findings provide critical evidence for how the accumulated energy from BH accretion impacts galaxy-wide ISM, representing a crucial step forward in our understanding on the role of BHs in regulating the growth and quenching of massive galaxies.Comment: 24 pages, 7 figures. Submitted to Natur