9,380 research outputs found

    EXPERIMENTAL STUDY ON THE MECHANICAL AND DEFORMATION PROPERTIES OF PIPE AND SOIL IN RECTANGULAR PIPE JACKING CONSTRUCTION WITH CONTROLLABLE CEMENT GROUTING TECHNOLOGY

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    Based on the utility tunnel project of Chengbei Road in Suzhou, the experimental study on the mechanical and deformation properties of pipe and soil in rectangular pipe jacking construction with controllable cement grouting drag reduction technology is carried out. Based on the monitoring and analysis of pipe and soil stress and deformation of pipe joints during pipe jacking, the relevant theoretical model is established and the finite element simulation is carried out to experimentally study and compare the stress and deformation of pipe and soil in rectangular pipe jacking construction with controllable cement grouting drag reduction technology. The results show that the controllable cement grouting drag reduction technology has a significant effect on the pipe and soil stress in rectangular pipe jacking, which reduces pipe-soil interaction forces effectively, and improves the overall safety of pipe jacking construction

    Effects of Rashba spin-orbit coupling and a magnetic field on a polygonal quantum ring

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    Using standard quantum network method, we analytically investigate the effect of Rashba spin-orbit coupling (RSOC) and a magnetic field on the spin transport properties of a polygonal quantum ring. Using Landauer-Buttiker formula, we have found that the polarization direction and phase of transmitted electrons can be controlled by both the magnetic field and RSOC. A device to generate a spin-polarized conductance in a polygon with an arbitrary number of sides is discussed. This device would permit precise control of spin and selectively provide spin filtering for either spin up or spin down simply by interchanging the source and drain

    Involvement of the JNK/FOXO3a/Bim Pathway in Neuronal Apoptosis after Hypoxic-Ischemic Brain Damage in Neonatal Rats.

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    c-Jun N-terminal kinase (JNK) plays a key role in the regulation of neuronal apoptosis. Previous studies have revealed that forkhead transcription factor (FOXO3a) is a critical effector of JNK-mediated tumor suppression. However, it is not clear whether the JNK/FOXO3a pathway is involved in neuronal apoptosis in the developing rat brain after hypoxia-ischemia (HI). In this study, we generated an HI model using postnatal day 7 rats. Fluorescence immunolabeling and Western blot assays were used to detect the distribution and expression of total and phosphorylated JNK and FOXO3a and the pro-apoptotic proteins Bim and CC3. We found that JNK phosphorylation was accompanied by FOXO3a dephosphorylation, which induced FOXO3a translocation into the nucleus, resulting in the upregulation of levels of Bim and CC3 proteins. Furthermore, we found that JNK inhibition by AS601245, a specific JNK inhibitor, significantly increased FOXO3a phosphorylation, which attenuated FOXO3a translocation into the nucleus after HI. Moreover, JNK inhibition downregulated levels of Bim and CC3 proteins, attenuated neuronal apoptosis and reduced brain infarct volume in the developing rat brain. Our findings suggest that the JNK/FOXO3a/Bim pathway is involved in neuronal apoptosis in the developing rat brain after HI. Agents targeting JNK may offer promise for rescuing neurons from HI-induced damage

    Physical properties of CO-dark molecular gas traced by C+^+

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    Neither HI nor CO emission can reveal a significant quantity of so-called dark gas in the interstellar medium (ISM). It is considered that CO-dark molecular gas (DMG), the molecular gas with no or weak CO emission, dominates dark gas. We identified 36 DMG clouds with C+^+ emission (data from Galactic Observations of Terahertz C+ (GOT C+) project) and HINSA features. Based on uncertainty analysis, optical depth of HI τHI\tau\rm_{HI} of 1 is a reasonable value for most clouds. With the assumption of τHI=1\tau\rm_{HI}=1, these clouds were characterized by excitation temperatures in a range of 20 K to 92 K with a median value of 55 K and volume densities in the range of 6.2×1016.2\times10^1 cm3^{-3} to 1.2×1031.2\times 10^3 cm3^{-3} with a median value of 2.3×1022.3\times 10^2 cm3^{-3}. The fraction of DMG column density in the cloud (fDMGf\rm_{DMG}) decreases with increasing excitation temperature following an empirical relation fDMG=2.1×103T(ex,τHI=1)f\rm_{DMG}=-2.1\times 10^{-3}T_(ex,\tau_{HI}=1)+1.0. The relation between fDMGf\rm_{DMG} and total hydrogen column density NHN_H is given by fDMGf\rm_{DMG}=1.03.7×1020/NH1.0-3.7\times 10^{20}/N_H. The values of fDMGf\rm_{DMG} in the clouds of low extinction group (AV2.7A\rm_V \le 2.7 mag) are consistent with the results of the time-dependent, chemical evolutionary model at the age of ~ 10 Myr. Our empirical relation cannot be explained by the chemical evolutionary model for clouds in the high extinction group (AV>2.7A\rm_V > 2.7 mag). Compared to clouds in the low extinction group (AV2.7A\rm_V \le 2.7 mag), clouds in the high extinction group (AV>2.7A\rm_V > 2.7 mag) have comparable volume densities but excitation temperatures that are 1.5 times lower. Moreover, CO abundances in clouds of the high extinction group (AV>2.7A\rm_V > 2.7 mag) are 6.6×1026.6\times 10^2 times smaller than the canonical value in the Milky Way. #[Full version of abstract is shown in the text.]#Comment: Accepted for publishing in Astronomy & Astrophysics. 13 pages, 8 figure

    Concurrence-Aware Long Short-Term Sub-Memories for Person-Person Action Recognition

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    Recently, Long Short-Term Memory (LSTM) has become a popular choice to model individual dynamics for single-person action recognition due to its ability of modeling the temporal information in various ranges of dynamic contexts. However, existing RNN models only focus on capturing the temporal dynamics of the person-person interactions by naively combining the activity dynamics of individuals or modeling them as a whole. This neglects the inter-related dynamics of how person-person interactions change over time. To this end, we propose a novel Concurrence-Aware Long Short-Term Sub-Memories (Co-LSTSM) to model the long-term inter-related dynamics between two interacting people on the bounding boxes covering people. Specifically, for each frame, two sub-memory units store individual motion information, while a concurrent LSTM unit selectively integrates and stores inter-related motion information between interacting people from these two sub-memory units via a new co-memory cell. Experimental results on the BIT and UT datasets show the superiority of Co-LSTSM compared with the state-of-the-art methods

    Growth and Development of Sapphire Crystal for LED Applications

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