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The O + O2 isotope exchange reactions play an important role in determining the oxygen isotopic composition of a number of trace gases in the atmosphere, and their temperature dependence and kinetic isotope effects (KIEs) provide important constraints on our understanding of the origin and mechanism of these and other unusual oxygen KIEs important in the atmosphere. This work reports a quantum dynamics study of the title reactions on the newly constructed Dawes-Lolur-Li-Jiang-Guo (DLLJG) potential energy surface (PES). The thermal reaction rate coefficients of both the 18O + 32O2 and 16O + 36O2 reactions obtained using the DLLJG PES exhibit a clear negative temperature dependence, in sharp contrast with the positive temperature dependence obtained using the earlier modified Siebert-Schinke-Bittererova (mSSB) PES. In addition, the calculated KIE shows an improved agreement with the experiment. These results strongly support the absence of the "reef" structure in the entrance/exit channels of the DLLJG PES, which is present in the mSSB PES. The quantum dynamics results on both PESs attribute the marked KIE to strong near-threshold reactive resonances, presumably stemming from the mass differences and/or zero point energy difference between the diatomic reactant and product. The accurate characterization of the reactivity for these near-thermoneutral reactions immediately above the reaction threshold is important for correct characterization of the thermal reaction rate coefficients. [ABSTRACT FROM AUTHOR]

The FH2- anion has a stable structure that resembles a configuration in the vicinity of the transition state for neutral reaction F + H2 → HF + H. Electron photodetachment spectra of the FH2- anion reveal the neutral reaction dynamics in the critical transition-state region. Accurate quantum dynamics simulations of the photodetachment spectra using highly accurate new ab initio potential energy surfaces for both anionic and neutral FH2 are performed and compared with all available experimental results. The results provide reliable interpretations for the experimental observations of FH2- photoelectron detachment and reveal a detailed picture of the molecular dynamics around the transition state of the F + H2 reaction. The latest high-resolution photoelectron detachment spectra [Kim et al. Science, 2015, 349, 510-513] confirm the high accuracy of our new potential energy surface for describing the resonance-enhanced reactivity of the neutral F + H2 reaction. [ABSTRACT FROM AUTHOR]

Digital television middleware is a new research field of digital television. It is a software platform in the receiver of digital television broadcasting. It allows various set-top boxes to be used in digital television broadcasting network. This paper addresses the structure of digital television middleware system. The security sub-system is investigated and analyzed. The fundamental principles of construction and operation of the security sub-system accord with Chinese digital television middleware standards are presented. The security sub-system is designed and implemented by using encryption techniques. It has been used in real environment of interactive DTV system [ABSTRACT FROM AUTHOR]

This paper addresses an end-to-end operation system for digital television (DTV) applications. It is designed to develop, broadcast, download and execute interactive DTV applications. The system is composed of three subsystems. They are application execution system (AES), data broadcast system (DBS) and application development environment (ADE). AES, generally called DTV middleware system, is the software system running in DTV Se-top Box (STB) to execute and control interactive DTV applications. It isolates DTV applications from STB hardware. DBS is used to multiplex, transmit and broadcast DTV data, as well as manage DTV applications. ADE is a special integrative toolkit designed for developing interactive DTV applications. Application developers can edit, compile, debug and test a DTV application in ADE. Then DBS broadcasts the application through DTV channel. After being downloaded into STB, the application is executed by AES in the STB. Design and implementation of these three subsystems are presented in this paper. The proposed system has been used in real environment of interactive DTV operation. [ABSTRACT FROM AUTHOR]

This paper gives a brief introduction to establishing a knowledge-based system for intelligent stamping process planning. Studies on the system’s framework, knowledge model and reasoning mode are introduced. Some key technologies such as the feasibility of the stamping process, an optimal algorithm for blank layout, intelligent strip layout and force calculation are researched. The efficiency of stamping process planning can be improved by the system. [ABSTRACT FROM AUTHOR]

Background: Increasing evidence indicates that radioresistance remains a major problem in the treatment of patients with esophageal squamous cell carcinoma (ESCC). This study was designed to investigate the expression of microRNA-381 (miR-381) and its function in the radioresistance of ESCC. Methods: In this study, miR-381 expression was first detected in ESCC cell lines and tissue samples by quantitative real-time polymerase chain reaction (qRT-PCR). Then, the effects of miR-381 expression on growth, apoptosis, and radiosensitivity of ESCC cells were analyzed by MTT, colony formation, and flow cytometry, respectively. Dual-luciferase reporter assays were performed to validate the regulation of a putative target of miR-381, in corroboration with qRT-PCR and Western blotting assays. Results: ESCC cell lines or tissues were found to express significantly lower miR-381 than normal esophageal epithelial cells or adjacent normal tissues, respectively. Ectopic expression of miR-381 in ESCC cell lines blocked proliferation, reduced colony formation, enhanced apoptosis, and increased radiosensitivity by enhancing irradiation-induced apoptosis. In addition, dual-luciferase reporter assays showed that miR-381 binds to the 3'-untranslated region of X-linked inhibitor of apoptosis protein (XIAP), suggesting that XIAP should be a direct target of miR-381. Re-expression of miR-381 suppressed XIAP protein expression in ESCC cells, and the effects of miR-381 upregulation on ESCC cells were found to be similar with silencing of XIAP. In addition, XIAP mRNA expression significantly increased in ESCC tissues and was inversely correlated with miR-381 expression. Conclusion: The results of this study suggest that miR-381/XIAP pathway contributed to the growth inhibition, increase in apoptosis, and enhancement of radiosensitivity in ESCC cells Therefore, miR-381 may be a potential therapeutic target in human ESCC. [ABSTRACT FROM AUTHOR]