Optical magnetic field probe with a loop antenna element doubly loaded with electrooptic crystals

We propose a new type of optical probe designed to detect magnetic near-fields with high accuracy up to the gigahertz range. Its probe head consists of a loop antenna element doubly loaded with electrooptic crystals. Using optical technology, it realizes hybrid operation of a conventional double-loaded loop probe and requires no metallic cables or electrical hybrid junction. We examined probe characteristics for magnetic field detection up to 10 GHz. We confirmed that the probe can measure magnetic fields near a microstrip line with high accuracy in the gigahertz range and can suppress influence of electric fields.     

Off-axis notched strength of fiber–metal laminates and a formula for predicting anisotropic size effect

Experimental and theoretical studies of the effects of notch size and fiber orientation on the off-axis notched strength of the fiber–metal laminate GLARE-3 have been conducted. The notched strength decreased with increasing notch size, regardless of the fiber orientation. The notch sensitivity in GLARE-3 was highest in the fiber direction, and it decreased with increasing fiber orientation angle to the lowest in the 45° direction. A new multiaxial criterion for the tensile failure of notched orthotropic fiber composites was developed from a phenomenological point of view. From the proposed multiaxial failure criterion, an anisotropic size effect law for predicting the off-axis notched strength of orthotropic composite laminates was derived. By comparison with the experimental results on GLARE-3, it was demonstrated that the anisotropic size effect law can accurately and efficiently predict the off-axis notched strength of GLARE-3, regardless of the notch size and fiber orientation.     

任意形状位移边界条件下薄板受角位错作用的应力分析

推导并得到了任意形状的位移边界条件下在集中角位错作用下的薄板弯曲问题的封闭形式的应力函数解。在求解过程中利用了复变函数及有理型的保角映射的方法。并针对相应的边界条件采取了解析接续的技术以直接得到应力函数的解。为不失一般性,提供了在固定的边界条件下针对一个菱形孔的一些计算结果。得到的应力函数可作为格林函数模拟裂纹等情况下的外界作用。     

8.5 m/spl Omega/ /spl middot/ cm/sub 2/ 600-V double-epitaxial MOSFETs in 4H-SiC

The most important issue in realizing a 4H-SiC vertical MOSFET is to improve the poor channel mobility at the MOS interface, which is related to high on-resistance. This letter focuses on a novel 4H-SiC vertical MOSFET device structure where a low acceptor concentration epitaxial layer is used as a channel. We call this structure a double-epitaxial MOSFET (DEMOSFET). In the structure, the p-well is composed of two p-type epitaxial layers, while an n-type region between the p-wells is formed by low-dose n-type ion implantation. A buried channel is formed at the surface of the upper p/sup $/epitaxial layer. A fabricated DEMOSFET showed an on-resistance of 8.5 m/spl Omega//spl middot/cm/sup 2/ at a gate voltage of 15 V and a blocking voltage of 600 V. This on-resistance is the lowest so far reported for a vertical MOSFET with a blocking voltage of 600 V.     

Hydrothermal Synthesis of Novel Smectite-Like Mesoporous Materials

Hydrothermal reaction of slurries made from Si-Mg hydrous oxide and water yielded trioctahedral smectite-like mesoporous materials (SMMs). The OH anion had a marked effect on the properties of SMMs under hydrothermal condition whereas Na cation did not influence SMMs properties. With the increase in synthesis pH at 200°C, pore volume, specific surface area and average pore diameter decreased whereas methylene blue adsorption increased in the pH range of 8.5 to 11.4. Therefore, the SMMs having different layer charges could be synthesized. Both micropore and macropore formation rates decreased with increasing synthesis temperature in the range of 125–200°C and the formation of latter increased over 200°C. As a result, the SMMs synthesized at 200°C from slurries of pH 9.0–9.3 revealed the maximum mesopore formation rate: 0.98 and gave a narrow pore size distribution curve of 3–5 nm. The SMMs were characterized by specific surface areas of 243–679 m² g^-1, pore volumes of 0.20–0.48 cm³ g^-1, average pore diameters of 2.2–5.4 nm and methylene blue adsorption values of 0.16–0.96 meq · g^-1.     

Thermal expansion of TRU nitride solid solutions as fuel materials for transmutation of minor actinides

The lattice thermal expansion of the transuranium nitride solid solutions was measured to investigate the composition dependence. The single-phase solid solution samples of (Np_0.55Am_0.45)N, (Pu_0.59Am_0.41)N, (Np_0.21Pu_0.52Am_0.22Cm_0.05)N and (Pu_0.21Am_0.18Zr_0.61)N were prepared by carbothermic nitridation of the respective transuranium dioxides and nitridation of Zr metal through hydride. The lattice parameters were measured by the high temperature X-ray diffraction method from room temperature up to 1478 K. The linear thermal expansion of each sample was determined as a function of temperature. The average thermal expansion coefficients over the temperature range of 293-1273 K for the solid solution samples were 10.1, 11.5, 10.8 and 8.8 × 10⁻⁶ K⁻¹, respectively. Comparison of these values with those for the constituent nitrides showed that the average thermal expansion coefficients of the solid solution samples could be approximated by the linear mixture rule within the error of 2-3%.     

One-stage repair of interrupted aortic arch with selective cerebral perfusion

To minimize the neurological compromise after the circulatory arrest, the selective cerebral perfusion could be beneficial. We underwent one-stage repair of the interrupted aortic arch (IAA) with various intracardiac anomalies for the six patients, age ranging from 12 days to 4 months, by using the selective cerebral perfusion. Cardiopulmonary bypass was established by using two-way arterial cannulation supported by the two respective pump systems, one of which utilized the EPTFE graft anastmosed to either the bracheocephalic artery or the right subclavian artery and second of which enrouted through the arterial ductus to the descending aorta. The cerebral perfusion during the circulatory arrest for the aortic arch repair was maintained by the selective perfusion via EPTFE graft with 10 ml/kg/min blood flow. After the completion of the arch repair, the total system perfusion was restarted through the graft and the repair of the intracardiac anomalies was followed. Of six, no operative death or neurological complications related to the operation were found. The clinical neurological evaluation after operation also demonstrated the normal for the age. In conclusion, the selective cerebral perfusion by using the EPTFE graft during the circulatory arrest might decrease the risk of brain damage.