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A transmitted optical fiber sensing system based on orthogonal demodulation algorithm is used for hydrogen detection in this paper. WO3/Pt fabricated by sol–gel method was used as sensing material. WO3 film reacts with hydrogen by the catalysis of Pt and refractive index of the sensing film changed, by measuring the transmitted optical power the concentration of hydrogen can be detected. Orthogonal demodulation algorithm was used to demodulate the weak transmitted optical intensity signals. Compared with the traditional ratio-type transmitted optical fiber hydrogen sensing system, the noise reduced by 28 times. The limit of detection is 495ppm and with good repeatability and stability. In order to improve the sensitivity of the system, three pieces of sensing film were used to increase the interaction length of the sensing material with hydrogen and the sensitivity increased by 2.592 times. With the orthogonal demodulated technique and multi pieces of sensing film, high sensitivity, fast response and low cost hydrogen sensing system was implemented and is very promising for the monitoring of hydrogen leakage in the field of hydrogen production, transportation, and storage.

Sulfur K-edge X-ray absorption near-edge structure (XANES) spectroscopy was employed to study the speciation of sulfur in raw coal, ash by-product and fine particulate matter from a small coal-burning boiler. By means of least square analysis of the XANES spectra, the major organic and inorganic sulfur forms were quantitatively determined. The results show that about 70% of the sulfur in raw coal is present as organic and a minor fraction of the sulfur occurs as other forms: 17% of pyrite and 13% of sulfate. While in bottom ash, fly ash, and PM(2.5), the dominant form of sulfur is sulfate, with the percentage of 80,79 and 94, respectively. Moreover, a number of other reduced sulfur including thiophenic sulfur, element sulfur and pyrrhotite are also present. During coal combustion, most of organic sulfur and pyrite were oxidized and released into the atmosphere as SO(2) gas, part of them was converted to sulfate existing in coal combustion by-products, and a small part of pyrite was probably reduced to elemental sulfur and pyrrhotite. The results may provide information for assessing the pollution caused by small boiler and developing new methods for the control of SO(2) pollution.

The impact of coal-burning emission on sulfur in camphor leaves was investigated using Proton Induced X-ray Emission (PIXE) and synchrotron radiation technique X-ray Absorption Near-Edge Structure (XANES) spectroscopy. The PIXE results show that the sulfur concentrations in the leaves collected at the polluted site are significantly higher than those in controls. The Sulfur XANES spectra show the presence of organic (disulfides, thiols, thioethers, sulfonates and sulfoxides) and inorganic sulfur (sulfates) in the leaves. The inorganic sulfur in the leaves of camphor tree polluted by coal combustion is 15% more than that of the control site. The results suggest that the long-term coal-burning pollution resulted in an enhanced content of the total sulfur and sulfate in the leaves, and the uptake of sulfur by leaves had exceeded the metabolic requirement of plants and the excess of sulfur was stored as SO(4)(2-). It can monitor the sulfur pollution in atmosphere.

In order to explore the interaction between the expression of ZnT3 (Zinc Transporter 3) mRNA (Messenger Ribonucleic Acid) and the concentration of elemental zinc in mouse brain, zinc distribution in brain was determined by synchrotron radiation X-ray fluorescence (SRXRF) technique and a ZnT3 mRNA expression in tissue was examined by the reverse-transcriptase polymerase chain reaction (RT-PCR) method.The results show that the zinc concentration is not evenly distributed in brain slices. Its concentrations in cerebral cortex and hippocampus are nearly 5-10 times higher than those in other positions. A corresponding relation is that ZnT3 mRNA in cerebral cortex, hippocampus and testis has higher abundant degree, but it is not examined out in other tissues. Furthermore, the results promote that ZnT3 facilitates the accumulation of zinc in synaptic vesicles and may play an important role in structuring of vesicular zinc pool.

This note deals with the scanning of femoral head slices from both normal and osteoporosis subjects using synchrotron radiation X-ray fluorescence (SRXRF) microprobe technique. The sample preparation and experimental apparatus are described in detail. The quantitative computerized tomography (QCT) of elemental distribution, such as Ca, P, K, Fe, Zn, Sr and Pb in bone slice tissue including cartilage, substantial compact and substantial spongy, is investigated. Combined with the correlation between P, K, Zn, Sr and Ca, the loss way of minerals and the physiological functions of some metal elements in bone are also discussed.

On account of the ease with which positron annihilation experiments may be made and the well-known manner in which positrons behave much in the way that hydrogen protons do, the positron technique is thus commonly used to study hydrogen-charging and hydrogen-absorbed metals and alloys. Indeed, the positron technique has been an indispensable and powerful tool to investigate the influence of hydrogen on microstructures and properties of materials, thus a lot of the related papers have been published. However, papers regarding the use of positrons to detect molecular hydrogen content are few in the literature. This is because hydrogen-charging of metallic materials is a quite complicated process. Generally speaking, when hydrogen-charging, the content of hydrogen increases but occasionally it becomes lower instead of higher with increasing charging time. In addition, positrons, after entering a material, are affected not only by the old defects and the newly generated defects, but by hydrogen proton screening as well. Therefore, the existence of certain relationships between the measured positron parameter and hydrogen content in the material has not been found. Among the curves of positron parameter as a function of charging time which appeared in publications, the one which has a wavelike characteristic was frequentlymore » seen. In this letter, the author found that the measured Doppler lineshape parameter happens to be roughly directly proportional to the molecular hydrogen content involved in a particular material.« less

This paper deals with the osteoporosis model of New Zealand rabbits in order to study the function of inorganic elements for women patients with osteoporosis. The thirty cases of iliac crest are collected and determined using neutron activation analysis (NAA). The results show that the fluorine concentrations in the experimental group are higher than those in control group and the magnesium concentrations are significantly lower (P

The speciation of iron in atmospheric particulate matter (APM) was investigated by EXAFS. APM samples with different particle sizes and from different sampling sites were collected in Shanghai, China. The chemical components of iron in the samples were calculated by the regression analysis of their EXAFS spectra. The results show that the iron in all samples mainly consists of Fe2O3, Fe3O4 and Fe2(SO4)3, however, their proportions are different in different samples.