安徽枞阳出土西周至战国时期青铜器的矿料来源研究

采用激光剥蚀电感耦合等离子体质谱(LA-ICP-MS),对枞阳境内出土西周至战国时期青铜器和汤家墩遗址出土炼渣中的铜颗粒进行微量元素原位无损分析,以探讨枞阳县境内出土青铜器的铜矿来源。结果表明,枞阳汤家墩遗址冶炼铜金属颗粒中的Co,As,Sb,Ag和Bi等元素含量较高,其微量元素特征不同于铜陵和铜绿山的冶炼金属铜;从西周至战国时期,枞阳青铜器所用铜矿来源比较稳定,主要来自汤家墩遗址周边的枞阳县境内,有少量器物的铜矿可能来自长江以南的铜陵地区;LA-ICP-MS可用于青铜器和古铜矿冶遗址炼渣中所夹杂铜颗粒的微量元素原位无损分析,从而为利用炼渣探讨古矿冶遗址冶炼金属产品的微量元素特征奠定了基础,对探讨三代青铜器的矿料来源研究具有重要的应用价值。     

激光诱导Co等离子体电子温度的时间空间演化特性研究

本文在380～500 nm波长范围内测定了激光烧蚀Co等离子体中Co原子的时间和空间分辨发射光谱.由发射光谱线的强度和Stark展宽分别计算了等离子体电子温度和电子密度,并由实验结果讨论了激光等离子体中电子温度的时间和空间演化特性.实验结果表明,当延时在100～1000 ns范围内变化时,相应的电子温度Te范围为8000～25000 K;当距离靶表面0～1.8 mm范围内变化时,相应的电子温度Te范围为13000～25000 K,电子温度在激光束方向上的分布具有很好的对称性.     

激光诱导Al等离子体电子温度的时间空间演化特性研究

实验测定了激光烧蚀Al等离子体中Al原子在380-500nm 波长范围内的时间和空间分辨发射光谱。由Al原子390.068nm、394.4nm、396.152nm、466.3056nm、451.25nm、352 .95nm发射光谱线的强度计算了等离子体电子温度,并由实验结果讨论了激光等离子体中电子温度的时间和空间演化特性。实验结果表明,当延时在100-1500ns范围内变化时,相应的电子温度Te范围为6200K -32700K;当距离靶表面0-1.8mm范围内变化时,相应的电子温度Te范围为9800K- 32700K, 电子温度在沿激光束方向上的分布具有很好的对称性。     

ICF靶丸内燃料的气液两相组分组成分析

 在质量守恒的基础上,运用拉乌尔定律和道尔顿分压定律,对以摩尔分数比为3∶3∶4比例充入到ICF靶丸内的氘气、氚气和氘化氚三元系的热核燃料,在工作温度为22,24,26,28和30 K下处于相平衡时气液两相的组分组成进行了分析讨论。结果显示:工作温度为22 K时,随着充气压强从1 MPa增大到5 MPa,液层中氘气的摩尔分数从0.251增大到0.290,氚气的摩尔分数从0.350减小到0.310;气泡中氘气的摩尔分数从0.322增大到0.365,氚气的摩尔分数从0.278减小到0.241。充气压强为5 MPa时,随着工作温度从22 K提高到30 K,液层中氘气摩尔分数从0.290减小到0.261,氚气的摩尔分数从0.309增大到0.341;气泡中氘气的摩尔分数从0.365减小到0.302,氚气的摩尔分数从0.241增大到0.298。     

煤中矿物质对其半焦反应活性的影响

本工作考察了大同煤、神木煤、蔚县煤镜质组酸洗前后半焦反应活性的变化。煤酸洗后灰分的失去导致了半焦反应活性的降低。煤种不同,制焦条件不同,矿物质在半焦中的分布形式及存在状态不同,对半焦反应的催化能力也不同。煤种不同,煤中矿物质对半焦活化能的影响彼此不同。在整个反应历程中,具有催化作用的矿物质对半焦活化能的影响并不是恒定的。煤酸洗后半焦反应活性的降低是活化能和指前因子共同变化的结果。     

新疆两处遗址出土绿松石文物的成分分析和产源判别

绿松石是一种产地有限,却在世界范围内被广泛使用的珍稀宝石资源,研究绿松石文物的矿料来源可为了解古代不同地区间珍稀资源的获取与交流模式、文化传播途径、早期贸易网络等学术问题提供帮助。新疆绿松石文物的矿料来源是近年来科技考古关注的热点问题之一,目前存在中原说、波斯说、新疆说和多元说等观点。研究新疆绿松石文物的产源,其难点在于既要保证文物的安全,又要确保分析数据的准确性,同时要避免样品表面污染对数据结果带来的干扰。鉴于此,采用等离子体原子发射光谱LA-ICP-AES对新疆加依、西沟两处墓地出土的绿松石进行化学成分分析,并结合秦岭东部五处产地的绿松石成分数据,经主成分分析绘制散点图——建立产地区分模型。主成分分析结果显示加依墓地样品中有五枚是罕见的锌绿松石,其余同西沟墓地绿松石的成分相近,均含有相对较高比例的Fe和Sr。结合中原地区的绿松石成分数据对比分析,发现新疆两遗址绿松石的微量元素特征相近,以高B2O低BaO为特征区别于中原地区的绿松石样品。在产地区分模型中,代表加依墓地和西沟墓地出土绿松石的散点聚集成团,且明显区分于白河、郧县、洛南、竹山、淅川五地的散点分布区域。综上结果表明新疆东部两处遗址的绿松石制品与中原东秦岭五处绿松石矿区所产矿料的成分差异较大,鉴于近年来新疆哈密发现与两处遗址同时代的绿松石采矿遗址,推测加依墓地、西沟墓地的绿松石制品其矿料来自中原地区的可能性较小。     

Unifying effectors of circadian rhythm: Protein N-acetylation,phosphorylation, sulfation and other electrical effects

The vast literature concerning circadian rhythm is devoted mostly to forces that influence operation and harmful effects resulting from disturbances to the clock. The present review presents a novel, unifying theme for influences from protein N-acetylation, phosphorylation and sulfation based on electrochemistry. The unifying theme entails formation of electrostatic fields in the various processes, namely from formation of amide from protein amine in acetylation, presence of phosphate anions from phosphorylation and sulfate anions from sulfation. The electrostatic fields may operate as bridges in communication or in energetics derived from phosphorylation. Other electrochemical and magnetic effects are presented.     

进口锆英砂放射性γ能谱分析

利用γ能谱分析技术对2个产地共17个进口锆英砂样品中的放射性核素226Ra、232Th和40K进行了定量分析,并提出了一种新的样品自吸收修正方法。结果:产地1样品中226Ra的比活度均值为2399.75Bq/kg,232Th的比活度均值为422.72Bq/kg;产地2样品中226Ra的比活度均值为1852.91Bq/kg,232Th的比活度均值为455.45Bq/kg;2个产地样品中40K的比活度均很低。研究表明,锆英砂样品中放射性主要来源是226Ra、232Th。两产地样品中232Th的放射性比活度相差较小,而226Ra的放射性比活度差别明显。同一产地样品中放射性核素比活度也存在较大差异。样品自吸收对分析结果的影响可达10%—30%,须进行自吸收修正。     

Using the OSL single-aliquot regenerative-dose protocol with quartz extracted from building materials in retrospective dosimetry

We report on the application of the single-aliquot regenerative-dose (SAR) protocol to the optically stimulated luminescence signal from quartz extracted from fired bricks and unfired mortar in retrospective dosimetry. The samples came from a radioactive materials storage facility, with ambient dose rates of about 0.1 mGy/h. A detailed dose-depth profile was analysed from one brick, and compared with dose records from area TL dosemeters. Small-aliquot dose-distributions were analysed from the mortar samples; one associated with the exposed brick, and one from a remote site exposed only to background radiation. We conclude that unfired materials have considerable potential in retrospective dosimetry.     

Mott criterion application to analysis of electrical conductivity in Na-β-aluminates doped by yttrium

The mechanism of electrical conductivity in yttrium-doped Na-β-aluminate has been investigated in terms of the Mott criterion in the range from room temperature to 1073 K. The activation energies for electrical conduction and thermoelectromotive force are determined from high-temperature measurements. The results obtained and the data derived from optical measurements are in satisfactory agreement. It is shown that electrical conductivity is determined by nonlocalized states in the temperature range from 973 to 1073 K and by localized states in the range from room temperature to 973 K.     

The effects of deviations from Lorentz–Berthelot rules on the properties of a simple mixture

Generally, the parameters in the interaction potential between like molecules in a mixture can be determined in a relatively straightforward manner from the properties of the pure components. However, the determination of the parameters in the interaction potential between the unlike pairs in the mixtures is more difficult. As a result, these parameters are usually estimated from averages of the like parameters. The most common recipes are the Lorentz–Berthelot mixing rules, where the energy and molecular size parameters are presumed to be geometric and arithmetic averages, respectively. There have been some studies of the consequences of deviations from the energy rule but almost no studies of the consequences of deviations from the size rule. Here, we study the effects of deviations from both rules on the radial distribution functions of a simple mixture. We find from simulations that, for this mixture, the effect of deviations from the energy rule on the radial distribution function are rather small but that the effect of deviations from the size rule can be significant and are interesting.     

The effect of nearby bubbles on array gain

The coherent processing of signals from multiple hydrophones in an array offers improvements in angular resolution and signal-to-noise ratio. When the array is steered in a particular direction, the signals arriving from that direction are added in phase, and any signals arriving from other directions are not. Array gain (AG) is a measure of how much the signal arriving from the steering direction is amplified relative to signals arriving from all other directions. The subject of this paper is the manner in which the AG of an acoustic array operating in water that contains air bubbles is affected by scattering from nearby bubbles. The effects of bubbles on acoustic attenuation and dispersion are considered separately from their effects on AG. Acoustic measurements made in bubbly water using the AB Wood tank at the Institute of Sound and Vibration Research, University of Southampton, in June 2008 show that as bubble density increases, relative phase shifts in individual hydrophone signals increase and signal correlation among the hydrophones is reduced. A theory and numerical simulation linking bubble density at the hydrophone to the AG is in good agreement with the measurements up to the point where multiple scattering becomes important.     

Forensic analysis of automotive paints by Raman spectroscopy

In this work, the possible contribution of Raman spectroscopy in forensic science is evaluated, more specifically for the analysis of automotive paint samples. Spectra from paint flakes as well as from cross sections were examined, in order to identify not only the pigments but also binders and extenders in all paint layers. Moreover, the possibility of distinguishing paint samples from different cars was evaluated to assess the use of vibrational spectroscopic techniques in the investigation of a hit-and-run accident. The presence of rutile and extenders, such as calcite and barium sulphate, could be demonstrated by their characteristic Raman bands. However, the identification of the binder by Raman spectroscopy was hampered: only with additional information from IR analysis could most of the bands in the spectrum be assigned to molecular vibrations of the binders. In contrast, organic pigments, having very distinctive and well-resolved characteristic bands, could easily be identified by comparing the spectra from the basecoat of the sample with spectra from a reference database. Because of these characteristic bands, the basecoat seems to provide the best spectra to distinguish paint samples. Moreover, some paints can also be distinguished by the absence or presence of the bands from calcium carbonate and barium sulphate in the primer surfacer. When recording spectra from paint flakes, Raman bands from the spectra of the clearcoat as well as from the basecoat are obtained. Copyright © 2005 John Wiley & Sons, Ltd.     

Three Dimensional Monitoring of Stack Plume Dynamics by a Scanning Mie Lidar System as a Plume Watchdog Station

A scanning lidar system was developed to watch the nighttime diffusion process of plume from a smokestack of a large incinerator located around 3 km from the system. Observed data sets were visualized as three dimensional images in which could be seen the diffusion pattern from any direction, and this made it easy to investigate the exhaust dynamics. Observation results showed that the original plume extended at least 1.6 km, where there was a residential area, from the smokestack increasing in diameter to about 500 m. High density aerosols originating from the smokestack were measured in that area even at midnight. The lidar system performance as a plume watchdog station was discussed from the standpoint of publichealth-related plume monitoring.     

On ionization energy losses of high-energy electron–positron pair in thin targets

The present Letter deals with consideration of high-energy electron–positron pair ionization losses in thin dielectric plate which it traverses after being emitted from substance where it is created. It is shown that in this case the Chudakov effect of reduction of pair energy losses takes place on much larger distance from its creation point than in the case of the pair motion in homogeneous infinite medium. It is demonstrated that due to transition radiation which appears during the pair emission from the substance the ratio of the pair energy losses in two plates situated on different distances from it is noticeably different from the case when the radiation is neglected.     

Characteristics of indirect laser-induced plasma from a thin film of oil on a metallic substrate

Optical emissions from the major and trace elements embodied in a transparent gel prepared from cooking oil were detected after the gel was spread in a thin film on a metallic substrate. Such emissions are due to the indirect breakdown of the coating layer. The generated plasma, a mixture of substances from the substrate, the layer, and the ambient gas, was characterized using emission spectroscopy. The characteristics of the plasma formed on the metal with and without the coating layer were investigated. The results showed that Al emission induced from the aluminum substrates coated with oil films extends away from the target surface to ablate the oil film. This finally formed a bifurcating circulation of aluminum vapor against a spherical confinement wall in the front of the plume, which differed from the evolution of the plasma induced from the uncoated aluminum target. The strongest emissions of elements from the oil films can be observed at 2 mm above the target after a detection delay of 1.0 μs. A high temperature zone has been observed in the plasma after the delay of 1.0 μs for the plasma induced from the coated metal. This higher temperature determined in the plasma allows the consideration of the sensitive detection of trace elements in liquids, gels, biological samples, or thin films.     

Spectral and temporal characteristics of metallic nanoparticles produced by femtosecond laser pulses

We study the time of flight optical emission from titanium and tungsten nanosized particles, generated through femtosecond laser-matter interaction in vacuum, in the wavelength spectral range from 300 to 900 nm. Typical spectra consist of broadband structureless signals similar to black body emission from a macroscopic object. Nanoparticles temperature, deduced from their emission spectra, decreases drastically as a function of their time of arrival at a given distance from the target. This behaviour is seen to be independent of individual particle velocities.     

提高双参量光纤传感器精度的一种方法

分析了光纤传感器进行双参量测量时，系数矩阵的态性对待测量精度的影响，提出采用对系数矩阵进行预处理的方法，使得处理后的矩阵由病态变成良态。用方法对文献「４」和文献「５」给出的系数矩阵分别进行了处理。处理后，文献「４」系数矩阵的条件数从３４２降低到４，文献「５」系数矩阵的条件数从１６１降低到３，传感器输出不确定主降低了两个数量级。     

Analysis of blood plasma at terahertz frequencies

Terahertz time-domain spectroscopy in the 0.05-2.5 THz frequency range was employed to analyze blood plasma samples obtained from laboratory animals with experimental diabetes and from healthy controls. It was found that transmission and reflection coefficients of samples from rats with diabetes differed significantly from control values in both amplitude and phase. The cause of the detected differences is discussed with respect to variation in the terahertz response of water.     

Calculation of vibrational structure in the core and valence esca spectra of CO and N2

The vibrational excitations in the core and valence ESCA bands of CO and N₂ have been investigated by means of Franck—Condon (FC) analysis. FC factors obtained from optimized geometries and from the force constants of the neutral ground and ionized states are compared with those obtained from calculated ionized-state energy gradients. Geometries, force constants, and energy gradients are calculated both from frozen-orbital energies and from OS RHF wavefunctions. The differences between the results of the methods employed are discussed in the light of experimental data.