Proposed design and experimental performance of short two-dimensional curved wall diffusers utilizing suction slots

Design, characteristics, and performance tests of short two dimensional curved wall diffusers using suction slot

Deconvolution of directly precipitating and trap-precipitating electrons in solar flare hard x-rays. III.Yohkoh hard x-ray telescope data analysis

We analyze the footpoint separation d and flux asymmetry A of magnetically conjugate double footpoint sources in hard X-ray images from the Yohkoh Hard X-Ray Telescope (HXT). The data set of 54 solar flares includes all events simultaneously observed with the Compton Gamma Ray Observatory (CGRO) in high time resolution mode. From the CGRO data we deconvolved the direct-precipitation and trap-precipitation components previously (in Paper II). Using the combined measurements from CGRO and HXT, we develop an asymmetric trap model that allows us to quantify the relative fractions of four different electron components, i.e., the ratios of direct-precipitating (q_P1, q_P2) and trap-precipitating electrons (q_T1, q_T2) at both magnetically conjugate footpoints. We find mean ratios of q_P1=0.14+/-0.06, q_P2=0.26+/-0.10, and q_T=q_T1+q_T2=0.60+/-0.13. We assume an isotropic pitch-angle distribution at the acceleration site and double-sided trap precipitation (q_T2/q_T1=q_P2/q_P1) to determine the conjugate loss-cone angles (alpha_1=42^deg+/-11^deg and alpha_2=52^deg+/-10^deg) and magnetic mirror ratiosat both footpoints (R_1=1.6,...,4.0 and R_2=1.3,...,2.5). From the relative displacement of footpoint sources we also measure altitude differences of hard X-ray emission at different energies, which are found to decrease systematically with higher energies, with a statistical height difference of h_Lo-h_M1=980+/-250 km and h_M1-h_M2=310+/-300 km between the three lower HXT energy channels (Lo, M1, M2

Millet agriculture dispersed from Northeast China to the Russian Far East: integrating archaeology, genetics, and linguistics

Broomcorn and foxtail millets were being cultivated in the West Liao River basin in Northeast China by at least the sixth millennium BCE. However, when and how millet agriculture spread from there to the north and east remains poorly understood. Here, we trace the dispersal of millet agriculture from Northeast China to the Russian Far East and weigh demic against cultural diffusion as mechanisms for that dispersal. We compare two routes for the spread of millet into the Russian Far East discussed in previous research—an inland route across Manchuria, and a coastal/inland route initially following the Liaodong Peninsula and Yalu River—using an archaeological dataset including millet remains, pottery, stone tools, spindle whorls, jade and figurines. We then integrate the archaeological evidence with linguistic and genetic findings in an approach we term ‘triangulation’. We conclude that an expansion of agricultural societies in Northeast China during the Middle to Late Hongshan (4000–3000 BCE) coincided with the arrival of millet cultivation in eastern Heilongjiang and the Primorye province of the Russian Far East. Our findings support the inland, Manchuria route for the dispersal of millet to the Primorye and suggest that, as well as long-distance cultural exchange, demic diffusion was also involved. Our results are broadly compatible with the farming/language dispersal hypothesis and consistent with a link between the spread of millet farming and proto-Tungusic, the language ancestral to the contemporary Tungusic languages, in late Neolithic Northeast Asia. © 2020 The Author

Role of cerium in lithium niobate for holographic recording

Cerium-doped lithium niobate crystals are tested for holographic recording. A photochromic effect is observed in crystals doped with cerium and manganese. But two-center recording in the sample is not as effective as in iron and manganese doubly doped crystals. Photocurrent measurements in cerium and iron singly doped crystals indicate that the photovoltaic constant in the cerium-doped crystal is only one third of that of the iron-doped one. This is the main reason accounting for the low sensitivity of cerium-doped lithium niobate crystals. However, in the diffusion dominated case, i.e., for reflection geometry, cerium-doped lithium niobate may give a strong effect

Shock Therapy\u27 for Aktiengesellschaften: Can the Sarbanes-Oxley Certification Requirements Transform German Corporate Culture, Practice and Prospects?

The Sarbanes-Oxley Act (Act) of 20021 was the U.S. Congress\u27s hasty response to the wave of corporate scandals that had begun to devastate U.S. investor confidence during the previous year. Its sixty-six pages contain a wide range of measures designed to enhance the quality and independence of corporate audits and disclosure under the U.S. securities-regulation regime. The Act applies to public corporations-corporations that are required to file regular financial reports under the Securities Exchange Act of 1934 (Exchange Act). Objections from German corporations and observers were particularly vigorous. At least one German foreign private issuer registered with the SEC has since deregistered and left the U.S. regulatory regime. The implications and effects of the Act\u27s certification requirements for German foreign private issuers are in controversy

Shock Therapy\u27 for Aktiengesellschaften: Can the Sarbanes-Oxley Certification Requirements Transform German Corporate Culture, Practice and Prospects?

The Sarbanes-Oxley Act (Act) of 20021 was the U.S. Congress\u27s hasty response to the wave of corporate scandals that had begun to devastate U.S. investor confidence during the previous year. Its sixty-six pages contain a wide range of measures designed to enhance the quality and independence of corporate audits and disclosure under the U.S. securities-regulation regime. The Act applies to public corporations-corporations that are required to file regular financial reports under the Securities Exchange Act of 1934 (Exchange Act). Objections from German corporations and observers were particularly vigorous. At least one German foreign private issuer registered with the SEC has since deregistered and left the U.S. regulatory regime. The implications and effects of the Act\u27s certification requirements for German foreign private issuers are in controversy