148 research outputs found
Hard Rules and Soft Rules for XBRL
In January 2009, the SEC issued its final mandate for conversion to XBRL standards for financial statement reporting. However, the implementation has been painfully slow in the United States. In this article, I will investigate the factors impeding the XBRL conversion progress. I will recommend some available XBRL software for the “bolt-on,” “built-in,” and “deeply embedded” implementations. I will also try to help the readers understand all the major components of the XBRL taxonomy
Cash is King: An Easy Way to Understand Debits and Credits
In Accounting, it is a well-known problem that many students often have difficulty in deciding whether to debit or credit an account to increase its balance. After practicing and teaching Accounting for more than forty years, the authors have developed a simple, practical and fault-proof method of handling debits and credits--the Cash is King method. Ten representative examples are provided to demonstrate how to use the Cash is King Method to assist the students handle debits and credits and guide them in recording all accounting transactions correctly
Mechanical Properties of Epoxy and Its Carbon Fiber Composites Modified by Nanoparticles
Compressive properties are commonly weak parts in structural application of fiber composites. Matrix modification may provide an effective way to improve compressive performance of the composites. In this work, the compressive property of epoxies (usually as matrices of fiber composites) modified by different types of nanoparticles was firstly investigated for the following study on the compressive property of carbon fiber reinforced epoxy composites. Carbon fiber/epoxy composites were fabricated by vacuum assisted resin infusion molding (VARIM) technique using stitched unidirectional carbon fabrics, with the matrices modified with nanosilica, halloysite, and liquid rubber. Testing results showed that the effect of different particle contents on the compressive property of fiber/epoxy composites was more obvious than that in epoxies. Both the compressive and flexural results showed that rigid nanoparticles (nanosilica and halloysite) have evident strengthening effects on the compression and flexural responses of the carbon fiber composite laminates fabricated from fabrics
Reconstruction of a Long-term spatially Contiguous Solar-Induced Fluorescence (LCSIF) over 1982-2022
Satellite-observed solar-induced chlorophyll fluorescence (SIF) is a powerful
proxy for diagnosing the photosynthetic characteristics of terrestrial
ecosystems. Despite the increasing spatial and temporal resolutions of these
satellite retrievals, records of SIF are primarily limited to the recent
decade, impeding their application in detecting long-term dynamics of ecosystem
function and structure. In this study, we leverage the two surface reflectance
bands (red and near-infrared) available both from Advanced Very High-Resolution
Radiometer (AVHRR, 1982-2022) and MODerate-resolution Imaging Spectroradiometer
(MODIS, 2001-2022). Importantly, we calibrate and orbit-correct the AVHRR bands
against their MODIS counterparts during their overlapping period. Using the
long-term bias-corrected reflectance data, a neural network is then built to
reproduce the Orbiting Carbon Observatory-2 SIF using AVHRR and MODIS, and used
to map SIF globally over the entire 1982-2022 period. Compared with the
previous MODIS-based CSIF product relying on four reflectance bands, our
two-band-based product has similar skill but can be advantageously extended to
the bias-corrected AVHRR period. Further comparison with three widely used
vegetation indices (NDVI, kNDVI, NIRv; all based empirically on red and
near-infrared bands) shows a higher or comparable correlation of LCSIF with
satellite SIF and site-level GPP estimates across vegetation types, ensuring a
greater capacity of LCSIF for representing terrestrial photosynthesis.
Globally, LCSIF-AVHRR shows an accelerating upward trend since 1982, with an
average rate of 0.0025 mW m-2 nm-1 sr-1 per decade during 1982-2000 and 0.0038
mW m-2 nm-1 sr-1 per decade during 2001-2022. Our LCSIF data provide
opportunities to better understand the long-term dynamics of ecosystem
photosynthesis and their underlying driving processes
- …