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排序方式: 共有239条查询结果,搜索用时 31 毫秒
231.
Susa N. Nakagome H. Mikami O. Ando H. Kanbe H. 《Quantum Electronics, IEEE Journal of》1980,16(8):864-870
Low dark current and low multiplication noise properties for an In0.53 Ga0.47 As/InP avalanche photodiode are described. The diode is prepared with an In0.53 Ga0.47 As light absorption layer and an InP avalanche multiplication region. The lowest dark current density of5.2 times 10^{-4} A/cm2is obtained at 90 percent of a breakdown voltage. Multiplication noise power is proportional to the 2.7th power of the current multiplication factor. Impact ionization coefficient by holes is larger by 2-3 times than that by electrons in 相似文献
232.
Nakajima Y Tashiro T Sugano N Yonenobu K Koyama T Maeda Y Tamura Y Saito M Tamura S Mitsuishi M Sugita N Sakuma I Ochi T Matsumoto Y 《IEEE transactions on bio-medical engineering》2007,54(9):1703-1706
A new method for fluoroscopic tracking of a proximal bone fragment in femoral fracture reduction is presented. The proposed method combines 2-D and 3-D image registration from single-view fluoroscopy with tracking of the head center position of the proximal femoral fragment to improve the accuracy of fluoroscopic registration without the need for repeated manual adjustment of the C-arm as required in stereo-view registrations. Kinematic knowledge of the hip joint, which has a positional correspondence with the femoral head center and the pelvis acetabular center, allows the position of the femoral fragment to be determined from pelvis tracking. The stability of the proposed method with respect to fluoroscopic image noise and the desired continuity of the fracture reduction operation is demonstrated, and the accuracy of tracking is shown to be superior to that achievable by single-view image registration, particularly in depth translation. 相似文献
233.
Ono K Ban N Ojima M Yoshinaga S Akahane K Fujii K Toyota M Hamada F Kouriyama C Akiba S Kunugita N Shimada Y Kai M 《Radiation protection dosimetry》2011,146(1-3):260-262
A nationwide survey was conducted in Japan on paediatric CT among children of public health and school nurses to examine a possibility for a follow-up study on radiation effects. A survey questionnaire was sent out to 3173 public primary and junior high schools and 317 public health centres during October to December in 2009. According to the collected responses, 410 (16.2 %) children received the CT scans and the total number of CT scans was 585. Most of respondents expressed a high interest in radiation health effects and an intent to participate in the epidemiological study that will follow-up the health conditions of children. This study provides information to discuss the feasibility of the epidemiological study on health effects in children who received CT scans. 相似文献
234.
Okada H Nomura N Nakahara T Maruhashi K 《Journal of Bioscience and Bioengineering》2002,93(2):228-233
The substrate specificity of Mycobacterium sp. G3 with desulfurization activity against dibenzothiophene (DBT) was investigated. Desulfurization reactions were carried out using a concentrated cell suspension of G3. The conversion from 4,6-dipropyl DBT, one of the sulfur-containing compounds that is difficult to desulfurize in diesel oil, to 2-hydroxy-3,3'-dipropylbiphenyl as an end -product of the desulfurization reaction was found in the water reaction system and in the oil/water two-phase reaction system. 4,6-Dibutyl DBT and 4,6-dipentyl DBT were metabolized to the hydroxybiphenyl form via the sulfone form in the water reaction system. These results indicate that G3 has high membrane permeability and superior substrate specificity for high molecular weight alkyl DBTs, which are represented by 4,6-dipentyl DBT as C10-DBT. Furthermore, G3 could desulfurize diesel oil, and the sulfur concentration was decreased from 116 mg l(-1) to 48 mg l(-1) within 24 h. 相似文献
235.
The rotational frequency noise (also known as the pulsation noise) due to the mistuning of impeller blade rows introduced at the manufacturing stage of the impellers is observed in the small-sized centrifugal compressor for automobile turbochargers. The present paper addresses the elucidation of the generating mechanism and parame- ter dependency such as the kind and degree of mistuning. In order to analyze numerically the rotational frequency noise due to mistuning, the unsteady computational fluid dynamics (CFD) of the whole compressor including vo- lute is executed, and the resultant time history of the pressure is fed into the spectral analysis. 相似文献
236.
Hemmi A Tabata M Homma T Ohno N Terada N Fujii Y Ohno S Nemoto N 《Journal of electron microscopy》2006,55(2):89-95
A case of elastofibroma in a middle-aged Japanese woman was examined by the quick-freezing and deep-etching (QF-DE) method, as well as by immunohistochemistry and conventional electron microscopy. The slowly growing tumor developed at the right scapular region and was composed of fibrous connective tissue with unique elastic materials called elastofibroma fibers. A normal elastic fiber consists of a central core and peripheral zone, in which the latter has small aggregates of 10 nm microfibrils. By the QF-DE method, globular structures consisting of numerous fibrils (5-20 nm in width) were observed between the collagen bundles. We could confirm that they were microfibril-rich peripheral zones of elastofibroma fibers by comparing the replica membrane and conventional electron microscopy. One of the characteristics of elastofibroma fibers is that they are assumed to contain numerous microfibrils. Immunohistochemically, spindle tumor cells showed positive immunoreaction for vimentin, whereas alpha-smooth muscle actin, desmin, S-100 protein and CD34 showed negative immunoreaction. By conventional electron microscopy, the tumor cell had thin cytoplasmic processes, pinocytotic vesicles and prominent rough endoplasmic reticulum. Abundant intracytoplasmic filaments were observed in some tumor cells. Thick lamina-like structures along with their inner nuclear membrane were often observed in the tumor cell nuclei. The whole image of the tumor cell was considered to be a periosteal-derived cell, which would produce numerous microfibrils in the peripheral zone of elastofibroma fibers. This study indicated that the QF-DE method could be applied to the pathological diagnosis and analysis of pathomechanism, even for surgical specimens obtained from a patient. 相似文献
237.
238.
Hisashi Kambe Nobuhiko Yamasaki Myeong Won Lee 《Computer Animation and Virtual Worlds》1994,5(4):265-279
This paper presents an interactive tool for designing and simulating textile images. It comprises a yarn editor, a textile editor and a texture mapper. These subsystems share a colour editor that can modify the colours of yarn and textile images interactively. We describe how yarn and textile images are generated, and how they are mapped to a target picture read from an image scanner. The user interface in the tool has many useful functions so that users can design textile images without knowledge of computer graphics and programming languages. Several examples of texture mapping are included. 相似文献
239.
Yeoh Wen Liang Miyata Ryosuke Fukuda Osamu Yamaguchi Nobuhiko Okumura Hiroshi 《Artificial Life and Robotics》2023,28(3):553-559
Artificial Life and Robotics - To help ease the caregiving burden that comes with population aging, we proposed a bistable control system for walking-assist robots in which the transition between... 相似文献