9,632 research outputs found

    Current Chinese bryological literature (4)

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    According to our collections of literature, about 400 scientific papers dealing with Chinese bryophytes have been published in China and abroad during 1990’s. Among these, more than 50 % were published in different scientific journals in China and often written in Chinese with English abstract, which are not well known and assessable for foreign bryologists. Therefore, in addition to previous Chinese literature I-III (Cao et al. 1990, Li et Zhang 1993, 1994), we present the fourth part of Chinese literature herewith. It is hoped that this up-dated list will provide useful information for all people who are interested in bryological research

    Does Trade Globalization Induce or Inhibit Corporate Transparency? Unbundling the Growth Potential and Product Market Competition Channels

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    How does increasing globalization affect corporate transparency? Freer trade represents different facets and in theory has ambiguous effects on corporate transparency. On the one hand, by exposing firms to more product market competition, it could discourage discretionary disclosure. On the other hand, by opening up foreign markets and enhancing firms’ growth opportunities, it may promote more transparency. Rather than simply estimating a net effect, this paper pursues an approach that allows separate estimation of the two potentially opposing channels. We employ three different measures of corporate transparency and track their evolutions for 4061 firms in 49 countries during 1992-2005. By using detailed product-level tariff schedules for these countries, we construct a measure of growth opportunities enabled by foreign tariff liberalizations at the sector-country-year level, and a second measure of globalization-induced product market competition based on a country’s own tariff liberalization (again at the sector–country-year level). We find strong evidence that higher growth opportunities engendered by globalization promotes corporate transparency, especially in industries that depend heavily on external financing. At the same time, we find somewhat weaker evidence that greater product market competition engendered by globalization discourages corporate transparency. The results demonstrate the importance of disentangling the multiple and potentially conflicting effects of globalization.

    Underwater Particle Image Velocimetry (PIV) Measurement of Turbulence Over Mussel Bed in a Deepsite of Lake Michigan

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    The influence of the benthic filter feeders, such as bivalves, on ecosystem plankton, and nutrient dynamics is considered significant in shallow marine and freshwater systems. Recent indirect evidence showed that the profundal quagga mussels (Dreissena rostriformis bugensis) have fundamentally altered energy flow and dynamics of nutrients and phytoplankton in Lake Michigan and other Great Lakes. To investigate the phytoplankton grazing rate of the quagga mussel and the mussel siphon currents induced bio-mixing, a self-contained in situ Underwater Particle Image Velocimetry was developed to measure the turbulence structure and the turbulent diffusion coefficient immediately above the profundal quagga mussel covered substrate in the deep-water site located in Lake Michigan. The system was deployed from July to October 2018, and 500 sets of datasets were acquired with 400 snaps of 2D velocity and particle concentration maps for each set. The diffusion coefficients were estimated and compared from multiple methods with measurements of turbulence and particle density. Field data analysis suggested that in the low energetic deep lake benthic boundary, mussels’ siphon currents are the major source of turbulence. Turbulent diffusivity/viscosity varied between 10-6 to 10-5 (m2 s-1), which seemed to correlate with the ambient particle concentration. Collective pumping rates of mussels were also estimated from measured near-bed turbulent flux of particles. Data also showed that near-bed turbulent diffusivity increases linearly with mussels’ pumping rate. This empirical linear relation was applied to a one-D numerical model. Simulation results proved the hypothesis that profundal mussels can maximize their grazing efficiently by the enhanced near-bed turbulence due to siphon currents. Modeling simulation also suggested that an optimal collective pumping rate may exist, which varied between about 1 to 5 liters per day per individual, depending on the ambient mixing condition

    Homo- and Mixed-valence [2 Ă— 2] Grid Complexes

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