Results 1 - 10 of 84
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[en] O(1D) + HCl(v = 0; j = 0) → ClO + H and its isotope exchange reaction O(1D) + DCl(v = 0; j = 0) → ClO + D are studied in the collision energy range 14.0-20.0 kcal/mol based on the potential energy surface 1A′ state. Reaction probabilities, integral cross sections, the two angular distribution functions (concerning the initial/final velocity vector, and the product rotational momentum vector), and the product rotational alignment parameters are calculated as a function of the collision energy for the two reactions. The four generalized polarization dependent differential cross sections are presented to manifest the polarization characters. Also, the effect of the collision energy and the kinetic isotope effect are studied. (author)
[en] Rising concerns about pro-environment and energy conservation bring about the escalating interests in adsorption cooling systems using renewable energy. Adsorption chillers with common refrigerants (water, ethanol, methanol, etc.) face the problem that advanced technologies and intricate design considerations are required to maintain high vacuum. This paper aims at the parameters optimization of adsorption system being operated with the novel working pair, MIL-101-isobutane, under typical conditions of ice making and air-condition. Adsorption isotherms and dynamic of isobutane on MIL-101 are discussed simultaneously. When the hot water inlet temperature, cooling water temperature and desorption time are 95 °C, 30 °C and 30 min, respectively, the cooling capacity is 45.7 kJ/kg, which is 1.7 times as much as that of activated carbon–isobutane pair. Structural stability of MIL-101 subjected to 500 times adsorption/desorption cycles has been successfully verified by XRD (X-ray diffraction). - Highlights: • Adsorption isotherms and kinetic of isobutane on MIL-101 were studied. • A single bed adsorption chiller with MIL-101-isobutane pair was built. • System performed better than that using activated carbon–isobutane pair. • Stability of MIL-101 subjected to 500 ad/desorption cycles has been verified.
[en] The European X-ray free-electron laser (EXFEL) project is a big science project which is developed by more than 10 countries, including China. Large cryogenic thermostat is one of the core components in EXFEL device. The role of the cryostat for the superconducting device is to provide necessary and stable cryogenic environment for working. The static thermal load is an important value for evaluating the design of the cryostat. Therefore, thermal load analysis can be the reference for the design and operating of the cryostat. In this paper, finite element analysis method is used for the thermal simulation of the EXFEL cryostat, and the results of the static thermal load are obtained. (authors)
[en] We investigated whether the high mobility group B 1 (HMGB1), an abundant nuclear protein in all mammalian cells, affects HIV-1 transcription. Intracellular expression of human HMGB1 repressed HIV-1 gene expression in epithelial cells. This inhibitory effect of HMGB1 was caused by repression of long terminal repeat (LTR)-mediated transcription. Other viral promoters/enhancers, including simian virus 40 or cytomegalovirus, were not inhibited by HMGB1. In addition, HMGB1 inhibition of HIV-1 subtype C expression was dependent on the number of NFκB sites in the LTR region. The inhibitory effect of HMGB1 on viral gene expression observed in HeLa cells was confirmed by an upregulation of viral replication in the presence of antisense HMGB1 in monocytic cells. In contrast to what was found in HeLa cells and monocytic cells, endogenous HMGB1 expression did not affect HIV-1 replication in unstimulated Jurkat cells. Thus, intracellular HMGB1 affects HIV-1 LTR-directed transcription in a promoter- and cell-specific manner
[en] Objective: To detect the changes of soluble αB-crystallin in X-ray irradiated rat lens, and to explore the potential role of αB-crystallin in the pathogenesis of radiation-induced cataract. Methods: The radiation cataract model was established with the accelerator linear in male Sprague-Dawley (SD) rats. The rats were divided into normal control group, experimental control group and X-irradiated group (the doses were 5, 15, and 25 Gy, respectively). The rats were killed at 3 morlths post-irradiation, and the lenses were carefully isolated and homogenized. The protein changes of αB-crystallin in lens supernatant were measured by Western blotting. Results: Typical radiation-induced cataract was observed in 15 and 25 Gy groups, while the lenses of the normal control group, experimental control group and the 5 Gy irradiation group remained transparent. The αB-crystallin protein level was significandy decreased in a dose-dependent manner (5 Gy group: 0.871 ± 0.085; 15 Gy group: 0.643 ± 0.096; 25 Gy group: 0.338 ± 0.160; F=40.764, P<0.05). Conclusions: The decreased expression of the molecular chaperone αB-crystallin in X-irradiated rat lens indicates its important role in the pathogenesis of irradiation cataract. (authors)
[en] FRB 180916.J0158+65 has been found to repeatedly emit fast radio bursts with a period of roughly 16 days. We propose that such periodicity comes from the orbit-induced spin precession of the emitter, which we assume to be a neutron star. Depending on the mass of the companion, the binary period ranges from several hundreds to thousands of seconds. Such tight binaries have relatively short lifetimes, and they are not likely to be products of gravitational decay from wide binaries. We comment on the relation of such binaries to GW190425 and the possibility of detecting them with LISA and LIGO.
[en] The quasi-classical trajectory (QCT) method is used to study the H+HS reaction on a newly built potential energy surface (PES) of the triplet state of H2S (3A″) in a collision energy range of 0–60 kcal/mol. Both scalar properties, such as the reaction probability and the integral cross section (ICS), and the vector properties, such as the angular distribution between the relative velocity vector of the reactant and that of the product, etc., are investigated using the QCT method. It is found that the ICSs obtained by the QCT method and the quantum mechanical (QM) method accord well with each other. In addition, the distribution for the product vibrational states is cold, while that for the product rotational states is hot for both reaction channels in the whole energy range studied here. (atomic and molecular physics)
[en] Objective: To explore the applicable value of hyaluronic acid (HA), collagen type IV(C-IV), N-terminal procollagen III(P III NP), laminin (LN), NAG and the PGA ratio (PT/GCT/Apo- A1) in the detection of diagnosis of liver fibrosis. Methods: Serum markers were studied in 217 patients (contain 82 pathologies) with viral hepatitis:(1)HA,C-IV, P III NP, LN were determined by radio-immunoassay. (2)NAG and PGA ratio were determined by biochemical auto-analyzer. Results: (1)Serum HA, NAG and PGA ratio elevated significantly with the progress of inflammation and fibrosis(P<0.05). (2)Serum P III NP, C-IV increased with the progress of inflammatory severity but no significant change was observed between S2-S3 fibrotic grades. (3) Serum LN remained unchanged in different histological grades, therefore it was not able to reflect the progress of inflammation and liver fibrosis. Conclusions: (1)Co-detection of serum HA, NAG and PGA ratio provides accurate and reliable indexes for the clinical diagnosis. Dynamic observation of their changes may be used to know the progress of disease and be used as reliable indexes to judge the therapeutic effect of antifibrotic drugs. (2) To some extent it is important to differentiate middle hepatitis from mild hepatitis of serum P III NP and C-IV, therefore these serum markers may be taken as indexes to reflect levels of hepatitis severity. (authors)
[en] This paper obtains the multi-component Harry–Dym (H–D) hierarchy and its integrable couplings by using two kinds of vector loop algebras G-tilde 3 and G-tilde 6. The Hamiltonian structures of the above system are given by the quadratic-form identity. The method can be used to produce the Hamiltonian structures of the other integrable couplings or multi-component hierarchies. (general)