Community responses to road traffic noise in Hanoi and Ho Chi Minh City

Vietnam is a developing country in southeast Asia, and its environment has been seriously affected by industrialization and urbanization. In large cities like Hanoi (northern Vietnam) and Ho Chi Minh City (southern Vietnam), noise emission from road traffic has been found to be a serious concern among general public. In 2005 and 2007, two large-scale socio-acoustic surveys of community response to road traffic noise were conducted to investigate human reactions to road traffic noise in these cities; the sample sizes were 1503 people in Hanoi and 1471 in Ho Chi Minh City. The noise exposure levels (L_den) were 70–83 dB in Hanoi and 75–83 dB in Ho Chi Minh City. Noise annoyance was estimated using standardized annoyance scales. For both cities, dose–response relationships were established between L_den and the percentage of highly annoyed respondents. Compared to annoyance responses of European people, Vietnamese were less annoyed by road traffic noise by about 5 dB. Hanoi respondents seemed to be more annoyed by noise than Ho Chi Minh City respondents. Conversation and sleep disturbances were not as serious as expected in either city. Furthermore, window orientation in the home was found to affect activity disturbances.     

超宽带减反射膜的设计和制备

设计了400～900 nm波段上的超宽带减反射膜,在410～850 nm范围内的平均残余反射率设计值约为0.2%,在设计的全波段上约为0.24%.讨论了初始膜系结构的选择原则,分析了带宽、膜层折射率差、最外层折射率和膜层总厚度等因素对宽带减反射特性的影响.对特定的带宽.增加两种薄膜材料的折射率差和选择尽可能低的最外层折射率对获得优良的减反射特性是非常重要的.实验制备了K9玻璃上TiO2/MgF2两种材料组成的8层结构的超宽带减反射膜,实测结果表明,在带宽520 nm范围内的平均残余反射率约为0.44%,说明用二种材料设计超宽带减反射膜是成功的,对垂直入射的减反射膜.多种材料的膜系并不比两种材料更具优越性.     

Current reversals in an inhomogeneous system with asymmetric unbiased fluctuations

We present a study of the transport of a Brownian particle moving in a periodic symmetric potential in the presence of asymmetric unbiased fluctuations. The particle is considered to move in a medium with periodic space dependent friction. By tuning the parameters of the system, the direction of the current exhibits reversals, both as a function of temperature as well as the amplitude of rocking force. We found that the mutual interplay between the opposite driving factors is the necessary term for current reversals.Received: 11 October 2003, Published online: 9 April 2004PACS: 05.40.-a Fluctuation phenomena, random processes, noise, and Brownian motion - 02.50.Ey Stochastic processes - 87.10. + e General theory and mathematical aspects     

Observation and analysis ofE mesons in\bar p p annihilation at rest in H2 gas

Antiproton-proton annihilation at rest in a gaseous H₂ target at NTP into the final state π⁺ π^? K ^± π^? (K ⁰) with an undetectedK ⁰ or \(\bar K^0 \) has been investigated. We observe theE(1420) resonance in the invariant mass spectrum (K ⁰)_miss K ^± π^? with massM _E =1413±8 MeV/c² and widthГ ^E =62 ± 16MeV/c² and find evidence for the production of thef ₁(1285). The absolute branching ratio of \(\bar p\) p → π⁺ π^? E ⁰,E ⁰ →K ₀ ^L K ^± π ^? at (61±6)%P wave annihilation is (3.0±0.9)·10^?4 of all annihilations. The observed suppression of theE production fromP wave with respect to theS wave together with some simple selection rules suggest that the quantum numbers of theE(1420) areJ ^pc=0^?+ and not I⁺⁺.     

Optical and atomic force microscopic study on step bunching in BaB2O4 crystal growth

The formation of macrostep during high-temperature phase of barium meta-borate (α-BaB 2 O 4) single crystal growth has been investigated by both optical in-situ observation system and atomic force microscopy (AFM).The insitu observation results demonstrate that the critical linear size of growing facet exceeding the size that the macrostep generates is significantly anisotropic.The critical linear sizes are around 280 μm and 620 μm for {1010} and {1010} planes,respectively.AFM study illustrates that macrostep train with a height of 150 nm～200 nm is one typical morphological feature of the as-grown crystal surface.The riser of each macrostep consists of several straight and parallel sub-steps,indicating the occurrence of step bunching.Additionally,triangular sub-steps with heights of several nanometers on the treads of the macrosteps are found to be another typical feature of surface morphology,which implies a microscopically competitive bunching of sub-steps between various crystallographic orientations.     

肾脏热物性测量及低温下细胞形态分析

肾脏热物性参数获取和微观结构的观察,对研究冰温延时保存器官的机理非常重要。采用差示扫描量热仪测量了离体肾脏导热系数、冰点和器官保存液冰点;利用低温显微系统对肾脏组织不同保存温度及不同降温速率等状态条件,做了细胞形态的观察与分析。研究结果认为,鲜活肾脏导热系数值对肾脏冷却速率影响较大,同时发现在实验条件范围内较小的降温速率对细胞的损伤较轻。     

Structures of rotating traditional neutron stars and hyperon stars in the relativistic $\sigma-\omega$ model

The influence of rotation on the total masses and radii of neutron stars is calculated by Hartles slow-rotation formalism, while the equation of state is considered in a relativistic - model. As the changes of the mass and radius of a real neutron star caused by rotation are very small in comparison with the total mass and radius, one can see that Hartles approximate method is rational to deal with the rotating neutron stars. If three property values, mass, radius and period, are observed for the same neutron star, then the EOS of this neutron star could be decided entirely.Received: 7 November 2003, Revised: 17 February 2004, Published online: 31 August 2004PACS: 04.40.Dg Relativistic stars: structure, stability, and oscillations - 95.30.Sf Relativity and gravitation - 97.10.Kc Stellar rotation - 97.60.Jd Neutron stars     

Growth behavior of high k LaAlO3 films on Si by metalorganic chemical vapor deposition for alternative gate dielectric application

LaAlO₃ (LAO) is explored in this work to replace SiO₂ as the gate dielectric material in metal–oxide–semiconductor field effect transistor. Amorphous LAO gate dielectric films were deposited on Si (0 0 1) substrates by low pressure metalorganic chemical vapor deposition using La(dpm)₃ and Al(acac)₃ sources. The effect of processing parameters such as deposition temperature and precursor vapor flux on growth, structure, morphology, and composition of LAO films has been investigated by various analytical methods deeply. The film growth mechanism on Si is reaction limiting instead of mass transport control. The reaction is thermally activated with activation energy of 37 kJ/mol. In the initial growth stage, Al element is deficient due to higher nucleation barrier on Si. The LAO films show a smooth surface and good thermal stability and remain amorphous up to a high temperature of 850 °C. The electrical properties of amorphous LAO ultrathin films on Si have also been evaluated, indicating LAO is suitable for high k gate dielectric applications.     

Interfacial structure and electrical properties of LaAlO3 gate dielectric films on Si by metalorganic chemical vapor deposition

LaAlO₃ (LAO) gate dielectric films were deposited on Si substrates by low-pressure metalorganic chemical vapor deposition. The interfacial structure and composition distribution were investigated by high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), secondary-ion mass spectroscopy (SIMS), and Auger-electron spectroscopy (AES). HRTEM confirms that there exists an interfacial layer between LAO and Si in most samples. AES, SIMS, and XPS analyses indicate that the interfacial layer is compositionally graded La–Al silicate and the Al element is severely deficient close to the Si surface. Electrical properties of LAO films were evaluated. No evident difference in electrical properties between samples with and without native SiO₂ layers was observed. The electrical properties are discussed in terms of LAO growth mechanisms, in relation to the interfacial structure. PACS 73.40.Qv; 81.15.Gh; 77.55.+f; 68.35.-p     

Separable Skyrme interactions and quasiparticle RPA

A finite rank separable approximation for the quasiparticle random phase approximation with Skyrme interactions is applied to study the low-lying quadrupole and octupole states in some S isotopes and giant resonances in some spherical nuclei. It is shown that characteristics calculated within the suggested approach are in good agreement with available experimental data.