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排序方式: 共有668条查询结果,搜索用时 15 毫秒
71.
K Yoshiura Y Higuchi K Araki M Shinohara T Kawazu K Yuasa O Tabata S Kanda 《Canadian Metallurgical Quarterly》1997,83(6):712-718
PURPOSE: The purpose of this study was to analyze the effects of lesion site and epithelial keratinization on the morphologic characteristics of odontogenic cysts and clarify determinate factors for cyst morphology. MATERIAL AND METHODS: Computed tomographic images of 92 odontogenic cysts were analyzed: 31 primordial, 31 dentigerous and 30 radicular. Thirty-four cysts were located in the maxilla (6 primordial, 10 dentigerous, and 18 radicular) and 58 in the mandible (25 primordial, 21 dentigerous, and 12 radicular). Histologically, 31 cysts showed epithelial keratinization (18 primordial and 13 dentigerous). No keratinization was seen in radicular cysts. The morphologic features of cysts were assessed by measuring long length parallel to dental arch and short length vertical to it and calculating the long/short ratio. In addition, the computed tomography pattern of the cyst was classified into unilocular, lobulated, and multilocular patterns. Appearance of the sclerotic rim and surrounding cortex were classified into three and four patterns respectively to evaluate the developmental features of the cyst. RESULTS: As a whole, the long length of the primordial cysts was statistically larger than the other two cyst groups and resulted in a larger long/short ratio. Statistical differences of CT pattern were also seen among cyst groups. There was no preference in any cyst group for the appearance of the sclerotic rim and cortex. There were statistical differences between maxilla and mandible in short axis and long/short ratio. The maxillary cysts generally showed round shapes irrespective of their histologic characteristics. A multilocular pattern was more frequent in the keratinized group of mandibular primordial cysts. In dentigerous cysts, a multilocular pattern was seen only in the keratinized group and the long/short ratio was statistically larger; cyst shape was elliptical along the long axis. CONCLUSION: Our results demonstrated morphologic differences of odontogenic cysts caused by lesion site and keratinization. The dentigerous cyst with predominant keratinization should be included in the primordial cyst (odontogenic keratocyst) group. 相似文献
72.
Haruo Arashi 《Journal of the American Ceramic Society》1992,75(4):844-847
The pressure dependence of the Raman spectra of HfO2 was measured by a micro-Raman technique using a singlecrystal specimen in the pressure range from 0 to 10 GPa at room temperature. The symmetry assignment of Raman bands of the monoclinic phase was experimentally accomplished from the polarization measurements for the single crystal. With increased pressure, a phase transformation for the monoclinic phase took place at 4.3 ± 0.3 GPa. Nineteen Raman bands were observed for the high-pressure phase. The spectral structure of the Raman bands for the high-pressure phase was similar with those reported previously for ZrO2 . The space group for the high-pressure phase of HfO2 was determined as Pbcm , which was the same as that of the high-pressure phase for ZrO2 on the basis of the number and the spectral structure of the Raman bands. 相似文献
73.
Osamu Nakagawa Haruo Shimamoto Tetsuya Ueda Kou Shimomura Tsutomu Hata Toru Tachikawa Jiro Fukushima Toshinobu Banjo Isamu Yamamoto 《Journal of Electronic Materials》1989,18(5):633-643
As electronic devices become more highly integrated, the demand for small, high pin count packages has been increasing. We
have developed two new types of IC packages in response to this demand. One is an ultra thin small outline package (TSOP)
which has been reduced in size from the standard SOP and the other, which uses Tape Automated Bonding (TAB) technology, is
a super thin, high pin count TAB in cap (T.I.C.) package. In this paper, we present these packages and their features along
with the technologies used to improve package reliability and TAB. Thin packages are vulnerable to high humidity exposure,
especially after heat shock.1 The following items were therefore investigated in order to improve humidity resistance: (1)
The molding compound thermal stress, (2) Water absorption into the molding compound and its effect on package cracking during
solder dipping, (3) Chip attach pad area and its affect on package cracking, (4) Adhesion between molding resin and chip attach
pad and its affect on humidity resistance. With the improvements made as a result of these investigations, the reliability
of the new thin packages is similar to that of the standard thicker plastic packages. 相似文献
74.
When a benzene/cyclohexane mixture was permeated through poly(dimethyl acrylamide-random-methyl methacrylate) (DMAA-r-MMA)
and poly(dimethyl acrylamide)-graft-poly(methyl methacrylate) (DMAA-g-MMA) membranes by pervaporation, the benzene-permselectivity
of the DMAA-r-MMA membrane changed from the diffusivity selectivity to the solubility selectivity with increasing DMAA content
but DMAA-g-MMA membranes with a high DMAA content had the higher apparent diffusivity selectivity than the apparent solubility
selectivity. Furthermore, the apparent solubility selectivity for a benzene/cyclohexane mixture between the DMAA-r-MMA membrane
and the DMAA-g-MMA membrane with a high DMAA content was remarkably different. These results were attributed to the difference
of structure between the copolymers.
Received: 27 August 1997/Revised version: 22 October 1997/Accepted: 30 October 1997 相似文献
75.
Akira Miyazaki Takayuki Yamazaki Taikan Suehara Toshio Namba Shoji Asai Tomio Kobayashi Haruo Saito Toshitaka Idehara Isamu Ogawa Yoshinori Tatematsu 《Journal of Infrared, Millimeter and Terahertz Waves》2014,35(1):91-100
Positronium is an ideal system for research on Quantum Electrodynamics (QED), especially in a bound state. A discrepancy of 3.9 standard deviations has been found between the measured hyperfine structure (Ps-HFS) and the QED predictions. This may be due to the contribution of unknown new physics or common systematic effects in previous measurements, in all of which the Zeeman effect was used. We propose a new method to directly measure the Ps-HFS using a high power gyrotron. We compare two resonators which have been developed to supply sufficient power to drive the direct transition, a Fabry-Pérot resonator and a ring resonator with a diffraction grating. We plan to perform first direct measurement of Ps-HFS within the next six months. 相似文献
76.
77.
Tomiji Wakida Huishun Li Yukihiro Sato Haruo Kawamura Mitsuo Ueda Haruo Mizushima Shoji Takekoshi 《Coloration Technology》1993,109(9):292-296
Polyester fabrics and films treated with two fluorocarbon resins were washed and heat treated. Water repellency, surface tension and ESCA measurements were carried out. Changes in the water repellency of the resin-treated polyester fabric caused by washing and heat treatment are related to modification of the chemical composition of the polyester surface. 相似文献
78.
79.
80.
T Kinjo D Tabata K Arikawa R Ishibe K Tanaka A Taira 《Canadian Metallurgical Quarterly》1994,47(7):588-591
A case of anastomotic recurrence after a radical operation for thoracic esophageal carcinoma is presented. A 68-year-old male was treated by subtotal esophagectomy and esophagogastrostomy through retrosternal route. One year after the operation he experienced dysphagia and anastomotic recurrence was detected by an upper gastrointestinal series and fiberscopy. He was admitted to our hospital for radiation therapy. The response was poor and dysphagia wasn't disappeared after radiation therapy at a dose of 10,200 rad. He was consulted to our surgical department for operative therapy. Cervical esophagectomy, partial resection of gastric tube and free jejunal transplantation for the reconstruction were performed. He had been eating anything of food after the operation. 相似文献