Remarkable room‐temperature magnetoresistance in silicon strip devices

In this paper, we report remarkable room‐temperature magnetoresistance (MR) in silicon strip devices. Saturating and non‐saturating MRs can be realized based on the measuring configurations with one top contact and ten top contacts, respectively. Using the one‐top‐contact measurement, a saturating MR ratio of ～400% is obtained at an applied voltage of only 1.0 V when the magnetic field is larger than 0.8 T. While the non‐saturating MR is achieved in the ten‐top‐contact measurement and the MR ratio is only ～155% for the 1.0 V applied voltage even under the magnetic field of 1.2 T. The differences for MR ratio values and change trends in these two measuring configurations are attributed to the enhanced Hall electric field with the increase of the top contact number.     

Determination of velum opening for french nasal vowels by magnetic resonance imaging

MRI techniques have been used to describe velum opening of French vowels. Data based on 18 joined axial slices of 4 mm thickness were recorded with four subjects. Differences in velum opening are calculated from areas measured in the tract between the lowered velum and the back pharynx wall. Results show that for all subjects, the back vowel / / has the smallest opening, while some variations are observed for the other vowels.     

Just noticeable differences of open quotient and asymmetry coefficient in singing voice

This study aims to explore the perceptual relevance of the variations of glottal flow parameters and to what extent a small variation can be detected. Just Noticeable Differences (JNDs) have been measured for three values of open quotient (0.4, 0.6, and 0.8) and two values of asymmetry coefficient (2/3 and 0.8), and the effect of changes of vowel, pitch, vibrato, and amplitude parameters has been tested. Two main groups of subjects have been analyzed: a group of 20 untrained subjects and a group of 10 trained subjects. The results show that the JND for open quotient is highly dependent on the target value: an increase of the JND is noticed when the open quotient target value is increased. The relative JND is constant: ΔO_q/O_q = 14% for the untrained and 10% for the trained. In the same way, the JND for asymmetry coefficient is also slightly dependent on the target value–an increase of the asymmetry coefficient value leads to a decrease of the JND. The results show that there is no effect from the selected vowel or frequency (two values have been tested), but that the addition of a vibrato has a small effect on the JND of open quotient. The choice of an amplitude parameter also has a great effect on the JND of open quotient.     

Early results of transcutaneous injection laryngoplasty with micronized acellular dermis versus type-I thyroplasty for glottic incompetence dysphonia due to unilateral vocal fold paralysis

Medialization thyroplasty (type I) has become the gold standard to improve glottic closure due to unilateral vocal fold paralysis. A newer injection method utilizing homologous collagen from cadaveric human tissue has been described as an attractive alternative as no donor site is required, there is a very low risk of hypersensitivity, and the intact, acellular collagen fibers may suffer a reduced long-term reabsorption rate. Preliminary results on eight patients comparing presurgical and postsurgical parameters (perceptual, stroboscopic, acoustic, and aerodynamic) revealed comparable results when compared with a control group of individuals, age- and sex-matched, that had undergone standard medialization thyroplasty (type I). Further study is needed to assess the long-term results with this minimally invasive method of vocal fold medialization.     

Magnetorheological suspension electromagnetic brake

The magnetorheological suspension (MRS) brake is of the monoblock type. The main part of the electromagnetic brake is an electromagnet, between whose poles two MRS disks are placed. For distances between disks of 0.65×10⁻³ m±10%, revolutions of the electric motor, coupled to the electromagnetic brake, ranging between 200 and 1600 rev/min and braking powers of up to 85 W, there are no differences in revolutions between the disks of the electromagnetic brake. For fixed revolutions of the electric motor, the revolution of the parallel disk can be modified continuously by means of the intensity of the magnetic field. In all cases, the quantity of MRS is of 0.35×10⁻³ kg.     

Radiosterilization of sulfonamides: I: determination of the effects of gamma irradiation on solid sulfonamides

Three antibiotics sulfafurazole (SFZ), sulfamethoxazole (SMZ) and sulfacetamide sodium (SSA-Na) belonging to sulfonamides were irradiated and changes in physico-chemical properties, pH, melting points, UV, IR, NMR, TLC, GC-MS, ESR characteristics, antimicrobial activities of active components were studied at normal and accelerated stability test conditions. Two radiolytic intermediates for both SFZ and SMZ and four radiolytic intermediates for SSA-Na were found in the irradiated solid samples after the GC-MS analysis. The results obtained under normal and accelerated stability test conditions were observed to be consistent with the unirradiated values.     

Clustering of rare earths in GeAs sulfide glass

Clustering of rare-earth dopants in GeAs sulfide glasses was studied by fluorescence spectroscopy of Pr-doped glasses and by EPR measurements of Gd-doped samples. The linewidth of the g  2 resonance of Gd³⁺, as well as the relative intensity of emission from the ¹D₂ level of Pr³⁺, was used as a relative measure of rare-earth clustering. Rare earths were found to have low solubility in uncodoped GeAs sulfide glasses, which also displayed poor fluorescence efficiency due to severe clustering. Codoping such glasses with Ga greatly enhanced rare-earth solubility and dispersal, particularly for Ga:rare earth ratios ≥ 10:1, as evidenced by the narrower EPR resonances and more intense luminescence of Gd- and Pr-doped glasses, respectively. In, P and Sn were also observed to ‘decluster’ rare earths, although less efficiently than Ga, whereas codoping with I was found to have no effect on clustering. These phenomena are explained by a structural model in which (1) rare-earth dopants and codopants are spatially associated and (2) rare-earth dispersal is accomplished by a statistical distribution of codopants in tetrahedral network sites.     

Microwave Assisted-extraction of Flavonols from Acanthopanax Senticosus Harms and High-performance Liquid Chromatography Analysis

Flavonols were extracted from Acanthopanax Senticosus Harms by Soxhlet extraction(SE),atmospheric pressure microwave-assisted extraction(AMAE) and pressurized microwave-assisted extraction(PMAE).The influences of experimental conditions,such as concentration of ethanol in the eluent,microwave irradiation time,etc.on the extraction yield were studied.Four flavonols(hyperin,rutin,quercitrin and quercetin) in the extracts were determined quantitatively by HPLC method.The experimental results demonstrate the ad...     

电子水平仪

采用双环光放大反射镜和二维位置传感器（PSD）制作了电子水平仪,利用该仪器可以测出待测平面与水平面之间的夹角,并且能自动控制其角度的变化。     

MCM‐41 Supported Aminopropylsiloxane Palladium Acetate Complex: A Highly Active and Stereoselective Catalyst for Heck Reaction

A new MCM‐41 supported aminopropylsiloxane palladium acetate was prepared and characterized. This catalyst is highly active and stereoselective for Heck reaction at 70°C.