Multi‐bit storage in reset process of Phase Change Access Memory (PRAM)

A Phase Change Access Memory (PRAM) cell with stacked phase‐change layers and heater layers is prepared. Multi‐bit storage in the reset process of the PRAM is realized by this stacked structure including phase‐change layers with uniform thickness and heater layers with different thickness. The thermal simulation results show three phase‐change layers in three temperature zones, and they will transform from polycrystalline to amorphous state layer by layer. There are four levels of resistance appearing in the R –V characteristics, and 2‐bit storage is realized. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

内陆地区近地面大气消光系数统计特征及气象要素影响分析

使用能见度仪测量了合肥地区2005年6月到2007年7月期间近地面的大气消光系数.给出了大气消光系数的时间变化特征和频数分布特征以及大气消光系数与相应时间段的水汽、温度、气压、风速的相关性.结果表明：局地大气消光系数具有明显的日变化、月变化、季节变化和频数特征|不同季节的消光系数与气象要素的相关性有所不同|其中水汽、温度是两个较为重要的影响消光系数特征分布的因素.分析结果可以作为局地大气消光系数模型建立的基础.     

Method for estimating the influence of an external electric field on the probability of photochemical transformations

We propose an approach to estimating the influence of a strong external electric field on the probability of photochemical transformations. The approach is based on an analysis of the appearance or disappearance of the resonance levels of interacting subsystems that are necessary for the chemical transformation and the change of overlap integral of the corresponding wave functions. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 4, pp. 543–545, July–August, 2007.     

Investigation of the matrix effect in determining microimpurities in boron and its compounds by atomic-emission spectrometry

We carried out a systematic study of the influence of the main component on the change of analytical signal during atomic-emission analysis of boron compounds. Changes in the intensity of spectral lines of microimpurities as functions of their concentrations in the analytical system based on graphite powder with a variable content of boric acid and boron oxide are presented. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 4, pp. 537–540, July–August, 2007.     

The effect of aluminum alloying on strength properties and deformation mechanisms of the 〈123〉 Hadfield steel single crystals

The role of aluminum alloying on strength properties and deformation mechanisms (slip, twinning) of 〈123〉 single crystals of Hadfield steel under tensile loading at T = 300 K is demonstrated. It is found out that aluminum alloying suppresses twinning deformation in the 〈123〉 single crystals and, during slip, results in a dislocation structure change from a uniform dislocation distribution to a planar dislocation structure. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 3–7, October, 2007.     

Stability of a solid solution under irradiation and mechanoactivation

Irradiation or severe mechanical deformation can change the stability conditions of solid solutions. This is manifested through changes of the stratification temperature. In the present work, it is demonstrated that mechanoactivation, as well as irradiation, results in the occurrence of elastic tensile stresses and increased concentration of excessive vacancies. The excessive vacancies change the energy of interatomic interactions and the entropy of the system. These changes directly affect the stability of the solid solution. Conditions of solid solution stratification are obtained as functions of the concentration of excessive vacancies generated under irradiation or created by severe plastic deformation. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 79–84, September, 2007.     

Magnetorotational instability in a nonuniform magnetic field

It is shown that the characteristics of the magnetorotational instability noticeably change in the presence of the inhomogeneity of a magnetic field in which rotation occurs. A decrease in the magnetic field with an increase in the distance from the rotation center, which is typical for astrophysical objects, can lead to a significant decrease in the threshold velocity of the object medium rotation, as well as to mitigation of the requirements on a rotation velocity profile that are necessary for the development of instability. Other examples that demonstrate the indicated effects are given. Original Russian Text ? V.I. Ilgisonis, I.V. Khalzov, 2007, published in Pis’ma v Zhurnal éksperimental’noĭ i Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 11, pp. 815–818.     

High temperature experiments: a way to observe Raman scattering in luminescent samples

Two methods to decrease the luminescence of a sample and to observe the Raman scattering are described: the change of the wavelength of excitation or the change of the temperature of the sample. The evolution of the luminescence intensity with temperature is explained by the use of an energy model with a metastable state and radiationless processes whose activation energy can be calculated. This method is applied with success to a Roman silicate glass: the Raman scattering initially hidden by the luminescence is then observed. Copyright © 2007 John Wiley & Sons, Ltd.     

Effect of the size of nanoparticles on the properties of a capacitive high-frequency discharge

The properties of a capacitive HF discharge with growing nanoparticles are studied with the use of kinetic PIC-MCC simulation. At the initial stage of growth, the nanoparticles are shown to be localized at the interface between the near-electrode layer and quasi-neutral plasma, where the rate of ionization by electron impact has the maximum value. At the beginning of formation of particles, plasma parameters change rapidly and a transition between the capacitive and spatial discharge burning modes is observed for a certain critical size of the particles. If the growth of the dust particles continues, their distribution over the discharge becomes more uniform and the steady-state parameters of the gas-discharge plasma hardly change. Original Russian Text ? I.V. Shveigert, F.M. Peeters, 2007, published in Pis’ma v Zhurnal éksperimental’noĭ i Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 9, pp. 657–661.     

Study of the state of Ag and Pd in silver-palladium catalysts on a titanium dioxide substrate by IR spectroscopy of adsorbed CO

We have used IR spectroscopy of adsorbed CO to study the effect of the method for preparation of silver-palladium catalysts on a TiO₂ substrate and exposure to an oxidizing or reducing gaseous atmosphere on the state of Ag and Pd centers. We have shown that as a result of the metal-support interaction, the reducibility of the Ag and Pd particles is increased, which leads to a change in their adsorption and catalytic properties. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 1, pp. 16–20, January–February, 2007.     

Effect of magnetic pulsed field on luminescence of zinc sulfide doped with CuCl,In, and MnS

The effect of a magnetic pulsed field (MPF) of induction B = 1 T on photoluminescence, electroluminescence, and luminescence excitation spectra of powdered ZnS doped with CuCl, In, and MnS is investigated. It is shown that MPF treatment of these materials changes the photoluminescence spectra only in the case of luminophor ZnS:In whereas only the luminescence excitation spectra change for ZnS:CuCl and ZnS:Mn. __________ Translated from Zhurnal Prikladnoi Spektroskopii Vol. 74, No. 3, pp. 367–372, May–June, 2007.     

基于SPOT-VGT NDVI的西藏羊卓雍错流域地表覆被变化研究

利用1998年—2007年SPOT-VGT NDVI植被指数,分析了羊卓雍错流域NDVI时空变化特征及其与主要气候因子(气温,降水)的相关关系。结果表明：时间上,流域平均NDVI年内季节变化明显,变化幅度在0.12～0.31之间,5月份开始较快上升,最高值出现在9月份。1998—2007年10年间,羊卓雍错流域NDVI的多年平均值为0.19,总体上呈缓慢上升的趋势,表明流域的生态环境有改善的趋势。从空间分布看,NDVI高值区与水源、海拔高度和植被类型有很大关系,在水源附近区域NDVI值相对较高,草甸型草场NDVI值最高。气温和降水是影响流域植被的重要气候因子,在植被生长季节月平均NDVI与上月平均气温和降水的线性相关系数分别为0.7和0.71,近年来流域的暖湿化气候变化趋势有利于流域生态环境的改善。     

Synchronization and bistability of a qubit coupled to a driven dissipative oscillator

We study numerically the behavior of a qubit coupled to a quantum dissipative driven oscillator (resonator). Above a critical coupling strength the qubit rotations become synchronized with the oscillator phase. In the synchronized regime, at certain parameters, the qubit exhibits tunneling between two orientations with a macroscopic change of the number of photons in the resonator. The lifetimes in these metastable states can be enormously large. The synchronization leads to a drastic change of qubit radiation spectrum with the appearance of narrow lines corresponding to recently observed single artificial-atom lasing [O. Astafiev, Nature (London) 449, 588 (2007)].     

Absolute intensity and phase of the resonant X-ray scattering from a germanium crystal

The 222 and 600 reflections near the germanium absorption K edge were studied on the Kurchatov synchrotron radiation source. The energy spectrum of the 222 reflection is caused by the interference of the weak nonresonant and purely resonant contributions to the tensor atomic factor, whereas the 600 reflection is purely resonant. The energy dependence of the magnitude and phase of the resonant contribution to the scattering amplitude was determined from a change in the interference pattern. The numerical simulation of the energy spectra of reflections with the inclusion of the dipole-quadrupole and thermally induced contributions shows that the latter is dominant at room temperature. Original Russian Text ? E.Kh. Mukhamedzhanov, M.M. Borisov, A.N. Morkovin, A.A. Antonenko, A.P. Oreshko, E.N. Ovchinnikova, V.E. Dmitrienko, 2007, published in Pis’ma v Zhurnal éksperimental’noĭ i Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 12, pp. 896–900.     

基于卫星高光谱遥感的2007年-2017年新疆地区大气NO2时空变化趋势分析

自2013年国务院颁布《大气污染防治行动计划》等大气综合治理政策以来,我国东部地区大气颗粒物等重要污染物得到了有效控制。伴随着我国能源政策的变化,西北地区在加大能源开发力度的同时,大气污染亦呈现加剧趋势,但在之前的研究中未得到重视。卫星遥感的监测手段较地面观测具有不受地域限制,观测时间长,观测污染物种类多等优势。其中,星载紫外-可见高光谱仪OMI自2005年在轨运行,在大气污染的时空变化趋势探测、排放源估计以及模式的同化和验证等科学应用中得到广泛应用。中国科学技术大学的卫星对流层NO₂柱浓度产品,通过对OMI原始测量光谱的二次标定和气体反演算法的关键优化,在与地基观测的结果对比验证中呈现良好的相关性,适合用于我国高气溶胶背景下的大气污染分析。结合中国科学技术大学OMI NO₂数据产品,我国新疆地区大气NO₂污染的时空分布特征得以表征。在2007年-2017年期间,新疆地区的NO₂污染集中分布于北疆,其中“乌鲁木齐-昌吉-石河子”城市群（乌昌石地区）与新疆总体NO₂水平月变化相关性很强（相关性系数r=0.942,p-value<0.01）。新疆NO₂年际变化存在明显阶段性特征,与相关政策以及能源行业排放变化相符：2007年-2010年变化趋势不明显,2014年较2010年总体年平均浓度增长18.5％,其中乌昌石地区增长41.3％;2017年较2014年总体平均浓度下降26.4%,乌昌石地区下降42.8%。乌昌石地区由于石油化工企业,经济开发区等分布密集,成为NO₂污染的聚集区,与乌鲁木齐市,昌吉市NO₂变化具有强相关性（r=0.982,p-value<0.01;r=0.951,p-value<0.01）。受采暖时期排放以及特殊气象条件控制,乌昌石地区NO₂污染峰值为12月,冬季污染尤其显著;在2007年-2016年采暖期间（每年10月-次年4月初）,乌昌石地区NO₂水平有显著上升趋势（显著性水平α=0.01）,在未来大气治理中需要格外关注。     

Prism design for image orientation changes by the screw triangle method

We apply the screw triangle method (STM), which was conventionally used in the field of mechanism design, to design a prism to produce a specified image orientation change (IOC). Compared to existing methods [Tsai and Lin, Appl. Opt.45, 3951 (2006); Appl. Opt.46, 3087 (2007)], the proposed method is both simpler and more efficient, since its derivations are essentially vector-based calculations. The validity of the proposed approach is demonstrated via an illustrative example.     

Optical properties of multilayer heterostructures based on zinc chalcogenides upon strong laser excitation

We have carried out an experimental study of the nonlinear optical properties of multilayer heterostructures based on zinc chalcogenides when excited by ultrashort laser pulses. We have observed a strong change in the optical properties of the samples over a broad spectral region for two-photon and one-photon excitation of the ZnSe sublattice. The fast relaxation time of the nonlinearity is ∼2–5 psec in both cases. We propose a physical model qualitatively explaining the observed effects. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 6, pp. 805–809, November–December, 2007.     

DNA tertiary structure and changes in DNA supercoiling upon interaction with ethidium bromide and gyrase monitored by UV resonance Raman spectroscopy

The tertiary structure of DNA is important for many of its biological functions. In this work supercoiled and relaxed forms of purified plasmid DNA pBR322 in dilute aqueous solutions are investigated by means of UVRR spectroscopy to assess changes in B‐DNA conformation. Spectral variation in the CO and exocyclic NH₂ vibration above 1600 cm⁻¹ indicate changes in hydrogen bonding. A minor shift of the CN stretching mode of adenosine and guanosine at 1487 cm⁻¹ supports these findings. Changes in ribose conformation are visible in the spectral region 1320–1360 cm⁻¹ by vibrational coupling of the ribose pucker to the vibrations of the purine and pyrimidine bases. The intercalating phenanthridinium drug ethidium bromide is known to reduce the negative supercoiling of DNA. This change in DNA topology is reflected in variations of the UVRR marker bands of DNA identified above. Principal component analysis helped to extract the features of interest from the complex spectra of the intercalation complex. Within the bacterial cells the change in DNA topology is achieved by the action of topoisomerases. In this work, the DNA‐binding subunit GyrA of the enzyme gyrase was extracted from E. coli and applied to relaxed and supercoiled pBR322. The observed changes in the vibrational signature of the relaxed DNA in the presence of GyrA indicate a change of topology towards the supercoiled form. With already supercoiled DNA no further change in DNA topology is observed. Copyright © 2007 John Wiley & Sons, Ltd.