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。     

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.     

Realistic and effective interactions in the study of nuclear matter

The equation of state of symmetric nuclear matter is addressed starting both from a realistic interaction derived from nucleon-nucleon scattering processes and from a low-momentum effective potential. The approach is based on finite temperature Green’s functions. The internal energy per particle is estimated from the summation of diagrams and through the Galitskii-Koltun sum rule. The text was submitted by the author in English.     

用NAA研究清凉寺窑和张公巷窑青瓷胎的原料特征及来源

为研究清凉寺窑汝瓷胎和张公巷窑青瓷胎的原料特征及来源, 选取37个清凉寺窑汝瓷胎样品(32个汝官瓷胎和5个汝民瓷胎)、 32个张公巷窑青瓷胎样品以及14个岩石样品, 用中子活化分析 （NAA）方法测得每个样品中的23种元素含量; 使用散布分析及主成分分析方法处理NAA数据。 结果表明: 元素Fe, Ce, Ba, Ta, Th, La, Sm和Cr可作为区分汝官瓷胎和张公巷窑青瓷胎原料产地的指纹元素; 汝官瓷胎原料产地较集中, 来源相对稳定; 清凉寺窑汝民瓷胎料产地与汝官瓷基本相同, 均为就地取材; 张公巷窑青瓷胎原料产地较为分散, 与汝官瓷不同, 但二者距离相近。 关     

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.     

超短脉冲超强激光与固体靶相互作用中高能离子的产生

 用2D3V PIC粒子模拟方法得到了超短脉冲超强激光与固体靶相互作用中高能离子产生的图像，并对其机理进行了研究。在靶前后表面都观察到了高能离子的产生，并诊断了离子能谱。模拟结果表明，在靶前表面所产生的高能离子，角分布较大，在向靶内输运过程中会损失能量；在靶后表面产生的高能离子，定向性很好，能获得很高的能量。模拟得到的离子能量和实验观测结果在量级上相符。     

Transparencies of dielectric layers formed from size-controlled Bi-based glass powders obtained by spray pyrolysis

Submicron-size Bi-based glass powders were directly prepared by high-temperature spray pyrolysis. The mean sizes of the Bi-based glass powders were changed from 0.48 to 0.91 μm by changing the concentrations of spray solution. The dielectric layers formed from the Bi-based glass powders with fine size had higher transparencies than those of the dielectric layers formed from the Bi-based glass powders with large size. The transparencies of the dielectric layers formed from the glass powders obtained by spray pyrolysis from spray solution of 0.05 M decreased from 94 to 67% when the firing temperatures of the dielectric layers were changed from 580 to 500 °C. At the same firing temperatures, the transparencies of the dielectric layers formed from the glass powders obtained by spray pyrolysis from spray solution of 0.5 M decreased from 83 to 28%. The dielectric layers formed from the glass powders with fine size had dense and homogeneous structures even at low firing temperatures. PACS 42.70.Ce; 85.60.Pg; 71.55.Jv     

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。     

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。     

Electron energy loss spectroscopic investigation of palladium metal and palladium(II) oxide

Electron energy loss spectra (ELS) obtained from polycrystalline Pd metal and PdO powder using primary electron energies ranging from 100 to 1150 eV have been obtained and examined in an attempt to gain a better understanding of the origins of the loss features and to assess the utility of ELS in investigations of Pd catalysts. The two sets of ELS spectra differ significantly. The ELS spectra from Pd metal exhibit a predominant peak at 6.5 eV, shown to arise from a surface plasmon excitation, and two broad features at 25.1 and 31.9 eV, which originate from bulk loss processes. The broad features consist of several overlapping losses due mainly to interband transitions from the d-band, though a bulk plasmon excitation is believed to produce a feature near 24 eV. Two distinct peaks are present at 3.7 and 7.6 eV in the ELS spectra obtained from PdO, while a broad region of intensity appears over the range from 20 to 40 eV. The peak at 3.7 eV is attributed to a transition between the top of the valence band and the bottom of the conduction band. The feature at 7.6 eV is broad and arises from several overlapping features that are most likely caused by interband transitions rather than collective excitations. Furthermore, the ELS spectra obtained from PdO and oxidized Pd are also quite different indicating that ELS can provide useful information for determining the bonding states of oxygen on Pd-containing catalysts.     

新疆牛至挥发油化学成分的分析

气相色谱 -质谱技术对新疆牛至花和茎的挥发油化学成分进行分析研究。从牛至茎和花中分别鉴定了 4 2和 37种成分 ,占挥发油总量的 95 %以上 ,茎和花的挥发油化学成分相差很大     

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.     

Mechanism of light emission in low energy ion implanted silicon

A silicon wafer implanted with a single low energy (42 keV) silicon ion beam results in strong luminescence at room temperature. The implantation results in the formation of various luminescent defect centers within the crystalline and polymorphous regions of the wafer. The resulting luminescence centers (LC) are mapped using fluorescence lifetime imaging microscopy (FLIM). The emission from the ion-implanted wafer shows multiple PL peaks ranging from the UV to the visible; these emissions originate from bound excitonic states in crystal defects and interfacial states between crystalline/amorphous silicon and impurities within the wafer. The LCs are created from defects and impurities within the wafer and not from nanoparticles.     

Refinement of twinned crystal data

The refinement of structure from diffraction intensities measured from a twinned crystal involves the evaluation of intensity contributions from the various twin domains in the crystal and the corresponding structure factor derivatives. The modifications in the standard least-squares refinement program required for analysis of data from a twinned crystal sample are discussed. The procedure can be extended to cases involving more than two types of twin domains or to samples having mixed phases. The results and limitations of structure refinement using data obtained from a twinned LiKSO₄ crystal in various low-temperature phases are illustrated.     

The Study of α Emission Induced by 46.7MeV/u 12C on 58Ni、115In and 197Au

The energy spectra and angular distribution of α particles emitted from ¹²C induced reactions with ⁵⁸Ni,¹¹⁵In and ¹⁹⁷Au have been measured.Three moving sources of emitting α particle are clearly seen from invariant cross section distribution in velocity coordinates.The experimental data were analyzed by using three moving sources.Extracted parameters of the source with half-beam velocity are in agreement with the systematic values from Fermi Gas Model.The energy spectra and the extracted parameters for various targets are discussed.The low energy peak in energy spectra is possibly from the emitted α particle from equilibrium system after pre-equilibrium emission of target-like products.The energetic α particles are mainly from projectile fragmentation and projectile-like fragmentation.     

On the Theory of Brillouin Scattering in Piezoelectric Semiconductors with Acoustic Phonon-Conduction Electron Interaction

The theory of nonresonant Brillouin scattering in anisotropic piezoelectric semiconductors with deformation potential coupling and piezoelectric coupling between excited systems of acoustic phonons and conduction electrons is reviewed. The scattering efficiency is calculated using the appropriate dyadic electromagnetic GreeN′s function. The depletion of the scattered intensity arising from a non phase-matched scattering kinematics and from a spatial exponential decay of the sound amplitude is taken into account. The contributions to the Brillouin scattering from the free-carrier-screened indirect photoelastic effect and from the free-carrier density modulation are expressed in terms of the self-consistent electric field. This field is obtained from a Boltzmann-equation calculation of the effective ac conductivity tensor. The acoustic dispersion of the Brillouin-scattering efficiency is considered, and some possibilities of determining electronic transport properties by means of Brillouin scattering are outlined.     

Magnetic properties and electron spin resonance of Ecuadorian obsidians. Application to provenance research of archeological samples

Obsidians from major Ecuadorian sources were analyzed by SQUID magnetometry and electron spin resonance (ESR). The association of these two techniques permits to differentiate obsidians from the sources of Cotopaxi volcano and from the Quiscatola and Mullumica–Callejones sources of the Chacana caldera, taking into account various parameters arising from the M vs. H cycles and the X-band ESR spectra. The analysis of 27 archeological samples coming from the prehispanic site of La Maná allowed us to infer that most of them come from the Mullumica–Callejones source.     

FAAS法测定天然螺旋藻中微量元素

本文叙述了用火焰原子吸收法直接测定天然螺旋旋藻中的钾、钠、钙、镁、铜、铁、锰、锌等多种元素。方法简单便、快速、准确、可靠,具有良好的精密度和准确度,加收率为96%-103%,相对标准偏差为1.2%-5.2%。应用于国家标准物质甘蓝（GBW08504）的测定,获得了满意的结果。     

Relative transition probabilities of F(I) spectral lines in the visible

The relative transition probabilities of 36 neutral fluorine lines were determined by photoelectric measurements of the spectral lines emitted from a wall-stabilized arc operated in argon-fluorine mixtures. The arc current was varied from 50–70 A, the electron concentration from 1.25 to 1.55 x 10²³m^-3, and the temperature from 13,600 to 14,300 K. The assumption of LTE was used for optically thin spectral lines. The electron concentration was measured by introducing a small quantity of hydrogen, and the temperature was determined from the relative intensities of Ar lines. Close agreement was found with other experimental data obtained from arc sources.