Absorption Peaks: α,?β,?γ and Their Covariance with Age and Hemoglobin in Human Blood Samples Using Photoacoustic Spectroscopy

This study reports the absorption peaks ??,???,??? in the Soret band of photoacoustic (PA) signals and their covariance with age and hemoglobin in human blood samples through PA spectroscopy. Samples were taken randomly from a masculine population grouped in three categories according to age: infants, young adults, and senior adults. Samples were prepared with two drops of blood from a 0.5?mL insulin syringe with a needle gauge 31G over 5?mm circles of filter paper. It was observed that the PA signal, the amplitude as a function of the wavelength, has a behavior as that reported for human blood for the three absorption peaks ??,???,???. In particular, the ratio ??/ ?? is due to electronic transitions associated with charge-transfer interactions of iron orbitals with the ligand states. Through an evaluation of optical absorption peaks in blood samples and their covariance with age and hemoglobin concentration, a relationship was found for the ratio peaks ??/ ?? and ??/ ?? with such parameters. Specifically, a negative covariance in the Soret band of the ratio peaks ??/ ?? and ??/ ?? with respect to both age and hemoglobin was found. This showed a tendency in their behavior. Further experiments of different populations may corroborate these conclusions.     

钨酸铅晶体的发光光谱及辐照诱导色心的研究

概要介绍了纯钨酸铅晶体和不同掺杂钨酸铅晶体发光光谱及辐照性能的研究结果．测量了晶体的光致发光和辐射激发发光光谱,比较了辐照诱导色心的密度和辐射发光光谱之间的关系．详细分析了钨酸铅晶体辐照诱导色心密度的分布,根据辐照诱导色心模型,计算了色心的能量及分布．     

AlSb多晶薄膜的制备及其潮解性研究

采用磁控溅射法制备了Al-Sb多层薄膜,通过调节Al和Sb亚层厚度及层数改变原子配比,并在真空中退火。用X射线衍射(XRD)、扫描电子显微镜(SEM)、金相显微镜、Hall测试及俄歇电子能谱仪研究了薄膜的结构和性能。结果表明,刚沉积的薄膜只有Sb的结晶相,经500℃退火后化合为P型AlSb多晶薄膜,且沿(111)择优取向,退火温度超过600℃薄膜产生局部损伤。通过台阶仪显微摄像探头及俄歇深度剖图观察和分析了薄膜的潮解现象,提出了几种保护措施。     

尼龙6/Kevlar纤维复合材料的非等温结晶行为及熔融特性

采用阴离子接枝法对K ev lar纤维(KF)进行表面改性,并用挤出方式分别制备尼龙6/未改性K ev lar纤维(PA 6/KF 0)及尼龙6/改性K ev lar纤维(PA 6/KF 1)复合材料。利用差示扫描量热仪(DSC)研究了KF 0和KF 1对PA 6/KF复合材料非等温结晶行为与熔融特性的影响,并与PA 6进行比较。结果表明,KF 0和KF 1起成核作用,提高了基体PA 6结晶的起始温度Tconset,减小其总结晶时间ttotal,同时提高了PA 6熔融时低温峰的相对强度,其中KF 1的效果更为明显;随着冷却速率β的加快,PA 6/KF 0和PA 6/KF 1复合材料中PA 6组分与纯PA 6一样,其Tocnset移向低温,且PA 6的熔融热谱由单重熔融峰向双重熔融行为转变。     

Infrared, Diffuse Reflectance and Dielectric Studies ofAntimony Trisulphide

Infrared absorption spectra of orange, black and transferred Sb2S3 samples have been Studied in the spectral range 200~4000cm-1. The pronounced difference between the different samples is the appearance of excess sulphur present in the orange and transferred samples except those of transferred at 543 K and the black Sb2S3. The change of sharpness of some IR peaks reveals the amorphous/crystalline change. The effect of the degree of crystallinity and stoichiometry on the energy gap values was investigated using optical method. The obtained dielectric parameters ε'and ε" of the different samples are thoroughly afFected by the degree of cryStallinity and smoothly affected by either the frequency or the temperature or both, except at lower frequencies.     

变质元素Sb对Al-Si共晶合金熔体结构的影响

用液态金属X射线衍射仪研究了合金Al＋12．5％Si和Al＋12．5％Si＋0．2Sb的液态结构,发现加Sb后合金熔体的结构因子曲线的第一峰高度比未加Sb时低,在小Q处出现了预峰,合金熔体的配位数在加Sb后有所下降;合金熔体径向分布函数Gauss分解后,0．39nm处的Si－Si峰加Sb后增强;DSC分析表明加Sb后的凝固过冷度减小．这些结果说明Sb增强了合金中Si原子的有序性．     

Internal friction in Se-Sb glasses

The internal friction,O ^–1, as a function of temperature has been investigated for Se_100–x Sb _x systems, wherex=7.5, 12.5 and 17.5 at%, using the magnetostrictive pulse-echo method in the range of vibrational frequencies 50–100 kHz. Two well-defined peaks appeared, characterizing this glass. The first peak covers the temperature range 320–330 K, where the peak position has been shifted to the higher temperature as Sb content increases. This peak indicates the glass transition temperature,T _g, of the tested glassy samples. The second peak was detected in the temperature range 360–378 K. The position of this peak has been shifted to a lower temperature as Sb content increases. This peak is attributed to the crystallization temperature,T _c, of each glassy sample tested. The peak height of both of the above peaks decreased as the Sb content increased. Also, the appearance of these two peaks was affected by annealing.     

Influence of Sb/As soak times on the structural and optical properties of GaAsSb/GaAs interfaces

The effects of Sb/As soak times, prior to growth of GaAsSb on GaAs were investigated by High Resolution X-Ray Diffraction (HRXRD) and photoluminescence (PL). Multiple quantum well samples with soak times of 0 s, 30 s and 60 s were grown at 500 °C with nominally identical Sb and As fluxes. HRXRD results show that a 30 s soak minimizes diffuse scattering seen around superlattice peaks in the reciprocal space maps, an effect attributed to corrugations in the GaAs-GaAsSb interface. An inferred band diagram calculated using a four band k.p model and modified taking into account the HRXRD results was used to explain PL spectra taken for each sample at 80 K. It is concluded that an optimum soak time exists for GaASb growth on GaAs, determined by the growth conditions.     

锑掺杂浓度对二氧化锡纳米微粉的影响

以无机盐为原料,采用共沉淀法制得了掺锑SnO₂纳米级微粉.运用X射线衍射(XRD)、透射电镜(TEM)和差热分析(DTA)等观测手段对微粉末进行了表征,比较系统地研究了掺锑浓度对物相、粉末颗粒度及电阻的影响规律.实验结果表明,低掺杂浓度样品(x≤0.462),Sb原子固溶于四方晶系SnO₂中,高掺杂浓度样品(x≥0.519),Sb原子将从固溶体中脱溶并被氧化为Sb₂O₄相;掺杂Sb可以减小SnO₂的晶粒度,在热处理时阻碍 SnO₂晶粒长大,掺杂浓度>0.181时,进一步掺杂对粉末粒度没有明显的影响;SnO₂粉末电导率随掺锑浓度的增大而提高,掺杂浓度为0.095时粉末电导率达到极大值,当掺杂浓度>0.245时,粉末电阻快速增大.兼顾掺杂浓度对粉末粒度和电阻的影响,合适的掺杂浓度x为0.181～0.230.     

Detection and discrimination of low concentration explosives using MOS nanoparticle sensors

In the present study, four explosives of NH(4)NO(3), mineral explosives (ME), picric acid (PA) and 2,6-dinitrotoluene (2,6-DNT) have been investigated by using ZnO-doped nanoparticle sensors with additives of Sb(2)O(3), TiO(2), V(2)O(5) and WO(3). Firstly, eighteen ZnO-doped nanoparticle sensors were optimized and selected six best sensors to compose a new optimized array. Then, the detection capability of the sensor array was studied by using static sampling method. The results showed that with the increase in concentration of samples, the sensitivities of the sensors also increased, and the lowest detection limit of the four samples were low to 3.34 microg/L. At last, for the sake of approaching closer practical application, these four explosives were also studied with full dynamic sampling method and the results demonstrated that all the samples could be well identified completely at the concentration of 15.4 microg/L when maximum values of slope were extracted as the feature parameters to DFA analysis.     

Observation of semiconductor to insulator transition in Sb/Sb2O3 clusters synthesized by low-energy cluster beam deposition with different conditions

Nanostructured thin films of Sb₂O₃ clusters having sizes in the range of 3-17 nm were synthesized by the low-energy cluster beam deposition technique. The crystallite size was found to decrease with increase in rate of flow of the carrier gas. The high-resolution transmission electron microscope image and the selected-area diffraction pattern show the formation of a core shell structure with Sb core and Sb₂O₃ shell at moderate oxygen flow pressure. Optical absorption spectra exhibit semiconductor characteristics for the samples prepared at intermediate oxygen flow pressure, and insulating features were observed in case of samples prepared at higher oxygen flow pressure. Room-temperature Raman spectra consist of a pair of broad peaks, red shifted with respect to the corresponding peaks of the bulk Sb₂O₃.     

AlSb多晶薄膜的制备及性质

用磁控溅射法制备了Al/Sb多层薄膜,通过X射线衍射(XRD)、X射线荧光(XRF)、Hall效应、暗电导率温度关系及透过谱的测试研究了退火前后薄膜的结构和性质。XRD测试结果表明,刚沉积的薄膜只有Sb的结晶相,而Al则以非晶态形式存在,500℃退火后化合为AlSb多晶,且沿(111)择优取向。Hall效应测试、电导激活能及光能隙的计算结果表明,所制备的AlSb多晶薄膜为P型材料,且载流子浓度为1019cm-3,光能隙为1.64eV,电导率随温度的变化可分为两个过程,在30℃到110℃,薄膜的电导率随温度的增加而缓慢增加,而在110℃到260℃间增加明显,升温电导激活能为0.11eV和0.01eV,这与AlSb多晶薄膜在升温过程中的结构变化有关。将制备的AlSb多晶薄膜应用于TCO/CdS/AlSb/ZnTe:Cu/Au结构的太阳电池器件中,已观察到明显的光伏效应,说明用这种方法制备的AlSb多晶薄膜适于作太阳电池的吸收层。     

Identification of Sb(V) complexes in biological and food matrixes and their stibine formation efficiency during hydride generation with ICPMS detection

Several studies have described the synthetic preparation of Sb(V) complexes with organic ligands, but only recently was such a complex identified to exist in beverages stored in PET containers. In the present study, we have investigated by using HPLC-ICPMS and HPLC-ES-MS(/MS), the formation of Sb(V) complexes in various biological (urine) and food matrixes (yoghurt and juice) spiked with noncomplexed inorganic Sb(V). Our results show that Sb(V) complex formation is matrix dependent and that several Sb(V) complexes form to a considerable extent in these matrixes. The results also suggest that the existence of Sb(V) complexes in natural samples may have previously been overlooked due to analytical method limitations, mainly chromatographic, but also detection limitations when hydride generation is used. To overcome some of these limitations, we have developed chromatographic methods suitable for preserving Sb-organic ligand complexes during their separation. When applying this mild nondestructive chromatographic method, we were able to identify novel Sb complexes in yoghurt spiked with inorganic Sb(V), i.e., 1:1 Sb(V)-citrate, 1:1 Sb(V)-lactate, 1:2 Sb(V)-lactate, and other Sb(V)-lactate complexes. This is the first characterization of Sb(V)-lactate complexes. Detailed studies on the hydride generation (HG) efficiency of Sb(V) complexes showed that Sb(V) complexes of high stability, such as Sb(V)-citrate, Sb(V)-(adenosine)n and Sb(V)-(lactate)n (n = 1 or 2), are nondetectable by HG-ICPMS. Furthermore, Sb(V) complexes formed in natural biological and food matrixes were only partly detectable by HG-ICPMS, confirming limitations of analytical methods based on HG volatilization and subsequent stibine detection in natural samples containing complexing ligands with affinity toward Sb(V).     

纳米ZrO2对热喷涂尼龙1010涂层非等温结晶与熔融行为的影响

利用火焰喷涂法制备了尼龙1010(PA1010)/n-ZrO2复合涂层,采用差示扫描量热法(DSC)对复合涂层的非等温结晶过程、熔融行为进行了分析.结果表明,纳米ZrO2粒子的加入不仅能提高复合涂层的结晶速率和结晶温度,而且使复合涂层的熔融峰肩峰的熔融温度高于纯PA1010涂层.结论:纳米ZrO2粒子具有成核剂的作用,诱导尼龙大分子结晶,使其结晶能力及结晶的完善程度提高.     

Dynamics of absorbed water in model composites of polyamide 6 and carbon fibre evaluated by differential scanning calorimetry

The crystallization and subsequent melting behaviour of absorbed water in the model composites of polyamide 6 (PA6) and carbon fibre were investigated by differential scanning calorimetry (DSC) in comparison with those in neat PA6, using the small rectangular specimens exposed to water at 90 °C. In the DSC curves of PA6 any exothermic peaks of crystallization and endothermic ones of melting were not observed, but a step corresponding to glass transition was observed at about −30 °C during the heating process. Thus water absorbed by neat PA6 was recognized as non-freezing bound water which does not crystallize, probably due to the strong interaction with the polyamide chains. On the other hand, for the model composite several exothermic peaks were clearly observed at temperatures ranging from −10 to −20 °C, and their intensity was increased with increasing the fibre content. The distinct endothermic peaks were detected around at 0 °C during the reversed heating process. The glass transition temperature was not affected by adding the carbon fibre. Comparing with the result of neat PA6 indicates that in the model composite water exists in a state near free water, besides the non-freezing bound water dispersed in the matrix polyamide. It is further implied that water is mainly accumulated in the matrix/fibre interfacial region with some microstructural heterogeneties or defects, in which the water molecules can easily move under much weaker interaction with the polyamide chains.     

Comparative analysis of oxide phase formation and its effects on electrical properties of SiO2/InSb metal-oxide-semiconductor structures

We report on the changes in the interfacial phases between SiO₂ and InSb caused by various deposition temperatures and heat treatments. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy were used to evaluate the relative amount of each phase present at the interface. The effect of interfacial phases on the electrical properties of SiO₂/InSb metal-oxide-semiconductor (MOS) structures was investigated by capacitance-voltage (C-V) measurements. The amount of both In and Sb oxides increased with the deposition temperature. The amount of interfacial In oxide was larger for all samples, regardless of the deposition and annealing temperatures and times. In particular, the annealed samples contained less than half the amount of Sb oxide compared with the as-deposited samples, indicating a strong interfacial reaction between Sb oxide and the InSb substrate during annealing. The interface trap density sharply increased for deposition temperatures above 240 °C. The C-V measurements and Raman spectroscopy indicated that elemental Sb accumulation due to the interfacial reaction of Sb oxide with InSb substrate was responsible for the increased interfacial trap densities in these SiO₂/InSb MOS structures.     

Helmholtz Resonances in Photoacoustic Experiment with Laser-Sintered Polyamide Including Thermal Memory of Samples

A minimum volume photoacoustic (PA) cell, employed as an acoustic resonator, is presented. A model of the PA cell transfer function, as a combination of two Helmholtz resonators, is derived. Frequency PA response is described as the product of theoretically derived pressure variation and the transfer function of the PA cell. The derived model is applied to the frequency PA measurements, performed on laser-sintered polyamide. It is shown that the derived model explains the occurrence of resonant peaks in the high-frequency domain (\({>}\)10 kHz), in both amplitude and phase measurements, obtained by a gas-microphone minimal volume PA cell. The implementation of the model in the growing possibilities of sample characterization using gas-microphone PA cell is discussed.     

Spectrophotometric determination of Sb(III) and Sb(V) in biological samples after micelle-mediated extraction

This work presents a micelle-mediated extraction method for simultaneous preconcentration and determination of Sb(III) and Sb(V) species in biological samples as a prior preconcentration step to their spectrophotometric determination. The analytical system is based on the selective reaction between Sb(III) and bromopyrogallol red (BPR) in the presence of cetyltrimethylammonium bromide (CTAB) and potassium iodide at pH 6.4. Total Sb concentration was determined after reduction of Sb(V) to Sb(III) in the presence of potassium iodide and ascorbic acid. The optimal extraction and reaction conditions were studied and the analytical characteristics of the method (e.g., limit of detection, linear range, preconcentration factor, and improvement factors) were obtained. Linearity for Sb(III) and Sb(V) were obeyed in the range of 0.2–20.0 ng mL⁻¹ and 0.4–25.0 ng mL⁻¹, respectively. The detection limit for the determination of Sb(III) and Sb(V) were 0.05 ng mL⁻¹ and 0.08 ng mL⁻¹, respectively. The interference effect of some anions and cations was also studied. The method was applied to the determination of Sb(III) in the presence of Sb(V) and total antimony in blood plasma and urine samples.     

Fabrication and characterization of microencapsulated PA with SiO<Subscript>2</Subscript> shell through sol–gel synthesis via sodium silicate precursor

In the present study, the microencapsulated phase change material with palmitic acid as core and inorganic SiO₂ shell was successfully fabricated by a sol–gel method in alkaline medium via sodium silicate precursor. The chemical compositions, crystalloid phase, microstructure and morphology of PA@SiO₂ microcapsule were studied by Fourier transform infrared spectroscopy, X-ray diffractometer, scanning electron microscopy and transmission electron microscopy. Differential scanning calorimetry and thermogravimetric analysis were used to determine the thermal properties and thermal stability of microcapsules, respectively. According to the XRD and FT-IR results, all the characteristic peaks of PA and SiO₂ were observed and there is no chemical reaction between them. Scanning electron microscopy images indicated that the microcapsule synthesized in pH 11 had a perfect spherical shape with smooth surfaces compared with other samples, and transmission electron microscopy images confirm that the PA have been well encapsulated by SiO₂. Differential scanning calorimetry analysis showed that the microcapsules indicated similar phase change behaviors as those of pristine PA, which melt at 67.2?°C with a latent heat of 111.2 J/g and freezing at 56.5?°C with a latent heat of 103.2 J/g. TGA analysis indicated that the thermal stability of the PA was also improved due to the protection of SiO₂ shell toward the encapsulated PA.     

Optical and structural characteristics of Sb-doped SnO2 thin films grown on Si (111) substrates by Sol–Gel technique

The optical and structural characteristics of Sb-doped SnO₂ films grown on Si (111) substrates by modified sol–gel technique have been investigated. The films are both polycrystalline and retain the SnO₂ peaks of the rutile phase corresponding to (110), (101), (211) and (310) without any other phases appearing. X-ray photoelectron spectroscopy shows the peaks corresponding to the Sn 3d _5/2, the O 1s, and the Sb 3d _5/2 states. Refractive indices n, and extinction coefficients k, as functions of the incident photon energy were obtained for the films by spectroscopic ellipsometry measurement, and the refractive indices were from 1.95 to 1.50 at 2.6 eV with increasing Sb content. The optical constants, n and k, of the films can be controlled by variable Sb content. These results are important for the applications in integrated optical devices.