Optimum Optical Length of the Gas Cell Used for Monitoring Gas-In-Oil with FTIR

Dedicated experiments are designed to collect the infrared spectra of dissolved gas-in-oil of power transformers. Spectra of diagnostic gases are collected by 3 different laboratorial FTIR spectrometers using 3 different gas cells with various sets of equipment parameters. A formula is deduced to calculate the shortest optical length to detect a specific concentration according to measurements on gases with known concentrations near to the minimum detection limit. Collected spectra and calculated results suggested that the optimum optical length of the gas cell should be 150 mm to realize on-line monitoring of diagnostic gases within the required concentration range. At the end, an economic novel design of the gas cell is proposed based on the optimum length.

Differentiations of 5-HT and GAS cells in the digestive canals of Rana chensinensis tadpoles

In the current study, 5-nydroxytryptamine （5-HT） and gastrin （GAS） cells in the digestive canals of Rana chensinensis tadpoles at different developmental stages were investigated by immunohistochemistry. Results showed that the 5-HT cells were only detected in the duodenum before metamorphosis began, and were extensively distributed in the stomach, duodenum, small intestine, and rectum thereafter, with the highest counts found in the duodenum and rectum when metamorphosis was completed. The GAS cells were only distributed in the stomach and duodenum, and only rarely detected in the duodenum before metamorphosis began, but increased in the stomach during metamorphosis and showed zonal distribution in the gastric mucosa when metamorphosis was completed. Metamorphosis is a critical period for amphibians, during which structural and functional physiological adaptations are required to transition from aquatic to terrestrial environments. During metamorphosis, the differentiations of 5-HT cells in the gastrointestinal canals of tadpoles could facilitate mucus secretion regulation, improve digestive canal lubrication, and help water- shortage food digestion in terrestrial environments. Conversely, GAS cell differentiations during metamorphosis might contribute to the digestive and absorptive function transition from herbivore to omnivore.

Study of a Distributed Feedback Diode Laser Based Hygrometer Combined Herriot-Gas Cell and Waterless Optical Components

A distributed feedback diode laser （DFB-DL） based hygrometer combined with a long-path-length Herriot gas cell and waterless optical components was proposed and investigated. The main function of this sensor was to simultaneously improve the measurement reliability and resolution. A comparison test between a 10-cm normal transmission-type gas cell and a 3-m Herriot gas cell was carried out to demonstrate the improvement. Reliability improvement was achieved by influence suppression of water vapor inside optical components （WVOC） through combined action of the Herriot gas cell and waterless optical components. The influence of WVOC was suppressed from 726ppmv to 25ppmv using the Herriot gas cell. Moreover, combined with waterless optical components, the influence of WVOC was further suppressed to no more than 4ppmv. Resolution improvement from l l.7ppmv to 0.32ppmv was achieved mainly due to the application of the long-path-length Herriot gas cell. The results show that the proposed sensor has a good performance and considerable potential application in gas sensing, especially when probed gas possibly permeates into optical components.

Gas6-Tyro3 signaling is required for Schwann cell myelination and possible remyelination

Myelin plays important roles in vertebrates,ensuring the rapid propagation of action potentials and the long-term integrity of axons,but the molecular mechanisms of myelin formation remain poorly understood.Recent studies have demonstrated that myelination is regulated by the TYRO3,AXL（also known as UFO）and MERTK.

Atomic layer deposition of ultrathin layered TiO_2 on Pt/C cathode catalyst for extended durability in polymer electrolyte fuel cells

This study shows the preparation of a TiO2 coated Pt/C（TiO2/Pt/C） by atomic layer deposition（ALD）,and the examination of the possibility for TiO2/Pt/C to be used as a durable cathode catalyst in polymer electrolyte fuel cells（PEFCs）. Cyclic voltammetry results revealed that TiO2/Pt/C catalyst which has 2 nm protective layer showed similar activity for the oxygen reduction reaction compared to Pt/C catalysts and they also had good durability. TiO2/Pt/C prepared by 10 ALD cycles degraded 70% after 2000 Accelerated degradation test, while Pt/C corroded 92% in the same conditions. TiO2 ultrathin layer by ALD is able to achieve a good balance between the durability and activity, leading to TiO2/Pt/C as a promising cathode catalyst for PEFCs. The mechanism of the TiO2 protective layer used to prevent the degradation of Pt/C is discussed.

Study on Preparation and Electrical Properties of Ba_(1.03)Ce_(0.8)Eu_(0.2)O_(3-α) Solid Electrolyte

Ba_(1.03)Ce_(0.8)Eu_(0.2)O_(3-α) solid electrolyte with nonstoichiometric composition was prepared by high temperature solid-state reaction. Phase composition, surface and fracture morphologies of the specimen were characterized by using XRD and SEM, respectively. Ionic conduction was researched by gas concentration cell, the performance of hydrogen-air fuel cell was measured in the temperature range of 600～1000 ℃, and compared them with those of BaCe_(0.8)Eu_(0.2)O_(3-α) and Ba_(0.98)Ce_(0.8)Eu_(0.2)O_(3-α). The results indicate that Ba_(1.03)Ce_(0.8)Eu_(0.2)O_(3-α) is a single-phase perovskite-type orthorhombic system. It is a pure proton conductor in the temperature range of 600～1000 ℃ in hydrogen atmosphere, and its proton conduction is superior to that of BaCe_(0.8)Eu_(0.2)O_(3-α) and Ba_(0.98)Ce_(0.8)Eu_(0.2)O_(3-α). It is a mixed conductor of oxide ion and electron hole in oxygen atmosphere. At 1000 ℃, the performance of the fuel cell in which Ba_(1.03)Ce_(0.8)Eu_(0.2)O_(3-α) as electrolyte is higher than that of BaCe_(0.8)Eu_(0.2)O_(3-α) or Ba_(0.98)Ce_(0.8)Eu_(0.2)O_(3-α).

Electrical Conductivity of SrCe_(0.9)Ho_ (0.1)O_ (3-α) Ceramics

Proton-conducting SrCe0.9Ho0.1O3-α ceramics was prepared by high-temperature solid state reaction. X-ray powder diffraction patterns show that the ceramics is of a single orthorhombic phase of perovskite-type SrCe03. Using the ceramics as solid electrolyte and porous platinum as electrodes, the protonic conduction in the ceramics was investigated by using ac impedance spectroscopy and gas concentration cell methods in the temperature range of 600 ~ 1000 ℃.

Ionic conduction in Ba_xCe_(0.8)Pr_(0.2)O_(3–α)

BaxCe0.8Pr0.2O3-α (x=0.98-1.03) ceramics were prepared by high temperature solid-state reaction. X-ray diffraction (XRD) patterns showed that the materials were perovskite-type orthorhombic single phase. By using gas concentration cell and AC impedance spectroscopy methods, the electrical conduction behavior of the materials was investigated in different gases at 500-900 °C. The influence of non-stoichiometry in the materials with x≠1 on conduction properties was studied and compared with that in the material with x=1. The results indicated that Ba1.03Ce0.8Pr0.2O3-α was a pure protonic conductor, and Ba0.98Ce0.8Pr0.2O3-α was a mixed conductor of protons and electrons in wet hydrogen at 500-900 °C. BaCe0.8Pr0.2O3-α was a pure protonic conductor in 500-600 °C, and a mixed conductor of protons and electrons above 600 °C in wet hydrogen. In 500-900 °C, they were all mixed conductors of oxide ions and electronic holes in dry air, and mixed conductors of protons, oxide ions and electronic holes in wet air. Both the protonic and oxide ionic conductivities increased with increasing barium content in the materials in wet hydrogen, dry air and wet air, respectively.

Two-phase flow distributors for fuel cell flow channels

All existing proton exchange membrane （PEM） fuel cell gas flow fields have been designed on the basis of single-phase gas flow distribution. The presence of liquid water in the flow causes non-uniform gas distribution, leading to poor cell performance. This paper demonstrates that a gas flow restrictor/distributor, as is commonly used in two-phase flow to stabilize multiphase transport lines and multiphase reactors, can improve the gas flow distribution by significantly reducing gas real-distribution caused by either non-uniform water formation in parallel flow channels or flow instability associated with negative-slope pressure drop characteristic of two-phase horizontal flow systems.

Ionic Conduction in In3＋-doped ZrP2O7 at Intermediate Temperatures

A new series of Zr1-xInxP2O7 （x=0.03, 0.06, 0.09, 0.12） samples were prepared by a solid state reaction method. XRD patterns indicated that the samples of x=0.03–0.09 exhibited a single cubic phase structure, and the doping limit of In3＋ in ZrP2O7 was x=0.09. The conduction behavior was investigated in wet hydrogen using various electrochemical methods including AC impedance spectroscopy, isotope effect, gas concentration cells at intermediate temperatures （373–573 K）. The conductivities were affected by the doping levels, and increased in the order： σ （x=0.03）〈σ （x=0.12）〈σ （x=0.06）〈σ （x=0.09）. The highest conductivity was observed for the sample Zr0.91In0.09P2O7 to be 1.59×10-2 S·cm-1 in wet hydrogen at 573 K. The isotope effect also confirmed the proton conduction of the sample under water vapor-containing atmosphere. It was found that in wet hydrogen atmosphere Zr0.91In0.09P2O7 was almost pure ionic conductor, the ionic conduction was contributed mainly to proton and partially to oxide ionic. The H2/air fuel cell using x=0.09 sample as electrolyte （thickness： 1.73 mm） generated a maximum power density of 13.5 mW·cm？2 at 423 K and 16.9 mW·cm？2 at 448 K, respectively.

Ionic Conduction and Application of Ba1.03Ce0.8Tm0.2O3-a Ceramic

BaBa1.03Ce0.8Tm0.2O3-aceramic with orthorhombic perovskite structure was prepared by conventional solid-state reaction. The conductivity and ionic transport number of BaBa1.03Ce0.8Tm0.2O3-a a were measured by ac impedance spectroscopy and gas concentration cell methods in the temperature range of 500-900 ℃ in wet hydrogen and wet air. Using the ceramic as solid electrolyte and porous platinum as electrodes, the hydrogen-air fuel cell was constructed, and the cell performance was examined at 500-900℃. The results indicate that the specimen is a pure ionic conductor with the ionic transport number of 1 at 500-900 ℃ in wet hydrogen. In wet air, the specimen is a mixed conductor of proton, oxide ion and electron hole. The protonic transport numbers are 0.071-0.018, and the oxide ionic transport numbers are 0.273-0.365. The conductivities of Bal.03Ceo.sTmo.203 a under wet hydrogen, wet air or fuel cell atmosphere are higher than those of BaBa1.03Ce0.8Tm0.2O3-a a （RE=Y, Eu, Ho） reported previously by us. The fuel cell can work stably. At 900℃ the maximum power output density is 122.7 mWocm 2, which is higher than that of our previous cell using BaBa1.03Ce0.8Tm0.2O3-a（RE=Y, Eu, Ho） as electrolyte.