排序方式: 共有73条查询结果,搜索用时 15 毫秒
31.
Saito M. Ono M. Fujimoto R. Tanimoto H. Ito N. Yoshitomi T. Ohguro T. Momose H.S. Iwai H. 《Electron Devices, IEEE Transactions on》1998,45(3):737-742
Radio Frequency (RF) CMOS is expected to replace bipolar and GaAs MESFETs in RF front-end ICs for mobile telecommunications devices in the near future. In order for the RF CMOS to be popularly used in this application, compatibility of its process for high-speed logic CMOS and low supply voltage operation are important for low fabrication cost and low power consumption. In this paper, a 0.15-μm RF CMOS technology compatible with logic CMOS for low-voltage operation is described. Because the fabrication process is the same as the high-speed logic CMOS, manufacturability of this technology is excellent. Some of the passive elements can be integrated without changing the process and others can be integrated with the addition of a few optional processes. Mixed RF and logic CMOS devices in a one-chip LSI can be realized with relatively low cost. Excellent high-frequency characteristics of small geometry silicon MOSFETs with low-power supply voltage are demonstrated. Cutoff frequency of 42 GHz of n-MOSFETs, which is almost the same level at that of general high-performance silicon bipolar transistors, was obtained. N-MOSFET's maintained enough high cutoff frequency of 32 GHz even at extremely low supply voltage of 0.5 V. Moreover, it was confirmed that degradation of minimum noise figure for deep submicron MOSFETs with 0.5 V operation is sufficiently small compared with 2.0 V operation. These excellent high-frequency characteristics of small geometry silicon MOSFETs under low-voltage operation are suitable for mobile telecommunications applications 相似文献
32.
Spontaneous amelanotic melanomas in the eyelids of F344 rats were found in one of 1/926 (0.11%) male and 5/925 (0.54%) female F344 rats that were used as control and treated animals in five different carcinogenicity studies conducted by the National Toxicology Program (Research Triangle Park, NC). These melanomas were grossly recognized as single, tan or white, well-circumscribed masses of the right or left eyelid. These melanomas primarily occurred in the dermis of the skin of the eyelids and consisted of poorly differentiated spindle cells characteristically arranged in interlacing fascicles. Rarely, epithelioid tumor cells were also observed, and these tumor cells showed a negative histochemical reaction for melanin. The epidermis and dermal-epidermal junction were usually uninvolved. The diagnosis of amelanotic melanoma could only be established by electron microscopic examination. The most striking ultrastructural feature of the tumor cells was a large number of intracytoplasmic premelanosomes (stage II melanosomes without melanin), which nearly filled the cytoplasm of most tumor cells. Giant premelanosomes and melanophagosomes were also seen. The tumor cells did not possess the ultrastructural features characteristics of Schwann cells (thin, long cell processes and pericytoplasmic basal laminae). The histologic and ultrastructural features of these palpebral tumors were similar to those of cutaneous amelanotic melanomas of the pinna in F344 rats. 相似文献
33.
1,3-Butadienylcyclopropanes activated by two electron-withdrawing groups ( 1 ) smoothly rearrange to vinylcyclopentene derivatives in the presence of a Pd(O) catalyst under mild conditions. For example, dimethyl 1,3-butadienylcyclopropane-1,1-dicarboxylate 1a reacts with 3 mol% Pd(PPh3)4 in DMSO at 25–60 °C for 30 min to provide dimethyl 2-ethenyl-3-cyclopentene-1,1-dicarboxylate 2a in 87% yield. Other data show that the new method is useful in the synthesis of cyclopentene derivatives including dolichodial and iridodiol. 相似文献
34.
Expressions of equivalent magnetic and electric currents for an aperture in an impedance surface is derived in a self-consistent manner. Each equivalent current consists of the combination of the tangential electric and magnetic fields in the aperture, and is placed in front of the original aperture where the surface is extended to close the aperture. The result is particularly useful for problems involving apertures in an impedance ground plane 相似文献
35.
36.
Nii H. Yoshino C. Yoshitomi S. Inoh K. Furuya H. Nakajima H. Sugaya H. Naruse H. Katsumata Y. Iwai H. 《Electron Devices, IEEE Transactions on》1999,46(4):712-721
In this paper, a 0.3-μm BiCMOS technology for mixed analog/digital application is presented. A typical emitter area of this technology is 0.3 μm×1.0 μm. This technology includes high f max of 37 GHz at the low collector current of 300 μA and high BVceo of 10 V NPN transistor, CMOS with Leff=0.3 μm, and passive elements. By using the shallow and deep trench isolation technology and nonselective epitaxial intrinsic base, the Cjc can be reduced to 1.6 fF, which is the lowest value reported so far. As a results, we have managed to obtain the high fmax at the low current region and high BV ceo concurrently. These features will contribute to the development of high-performance BiCMOS LSI's for various mixed analog/digital applications 相似文献
37.
Toru Yoshitomi Kazuhiro Kuramochi Long Binh Vong 《Science and Technology of Advanced Materials》2014,15(3)
We developed a nitroxide radicals–containing polymer (NRP), which is composed of poly(4-methylstyrene) possessing nitroxide radicals as a side chain via amine linkage, to scavenge reactive oxygen species (ROS) from cigarette smoke. In this study, the NRP was coated onto cigarette filters and its ROS-scavenging activity from streaming cigarette smoke was evaluated. The intensity of electron spin resonance signals of the NRP in the filter decreased after exposure to cigarette smoke, indicating consumption of nitroxide radicals. To evaluate the ROS-scavenging activity of the NRP-coated filter, the amount of peroxy radicals in an extract of cigarette smoke was measured using UV–visible spectrophotometry and 1,1-diphenyl-2-picrylhydrazyl (DPPH). The absorbance of DPPH at 517 nm decreased with exposure to cigarette smoke. When NRP-coated filters were used, the decrease in the absorbance of DPPH was prevented. In contrast, both poly[4-(cyclohexylamino)methylstyrene]- and poly(acrylic acid)-coated filters, which have no nitroxide radical, did not show any effect, indicating that the nitroxide radicals in the NRP scavenge the ROS in cigarette smoke. As a result, the extract of cigarette smoke passed through the NRP-coated filter has a lower cellular toxicity than smoke passed through poly[4-(cyclohexylamino)methylstyrene]- and poly(acrylic acid)-coated filters. Accordingly, NRP is a promising material for ROS scavenging from cigarette smoke. 相似文献
38.
S Ambiru M Miyazaki H Ito K Nakagawa H Shimizu Y Nukui S Nozawa A Okuno H Yoshitomi N Nakajima 《Canadian Metallurgical Quarterly》1997,42(8):1660-1665
The purpose of this prospective study was to evaluate the prognostic value of the type IV collagenase (IVase) activity in colorectal cancer tissue on disease-free and overall survival in 31 colorectal cancer patients. The clinicopathologic factors studied for prognostic value were age, tumor location, tumor differentiation, preoperative serum levels of carcinoembryonic antigen, Dukes' stage, and IVase activity in colorectal cancer tissue. IVase activities in colorectal cancer tissue were significantly higher in the group of patients with recurrences than in the group without recurrences (P = 0.019). Patients with high IVase activity in colorectal cancer tissue had a significantly shorter disease-free survival (P = 0.0016) and overall survival (P = 0.022) time than those with low IVase activity. Univariate and multivariate analysis showed that significant prognostic factors for disease-free survival were Dukes' stage (P = 0.029, P = 0.046, respectively) and IVase activity status (P = 0.0016, P = 0.0026, respectively). With respect to overall survival, only IVase activity status provided significant predictive value in multivariate analysis (P = 0.041). This prospective study suggests that IVase activity is a valuable prognostic factor in colorectal cancer patients. 相似文献
39.
A 40 nm gate length n-MOSFET 总被引:2,自引:0,他引:2
Ono M. Saito M. Yoshitomi T. Fiegna C. Ohguro T. Iwai H. 《Electron Devices, IEEE Transactions on》1995,42(10):1822-1830
Forty nm gate length n-MOSFETs with ultra-shallow source and drain junctions of around 10 nm are fabricated for the first time. In order to fabricate such small geometry MOSFETs, two special techniques have been adopted. One is a resist thinning technique using isotropic oxygen plasma ashing for the fabrication of 40 nm gate electrodes. The other is a solid phase diffusion technique from phosphorus doped silicated glass (PSG) for the fabrication of 10 nm source and drain junctions. The resulting 40 mm gate length n-MOSFETs operate quite normally at room temperature. Using these n-MOSFETs, we investigated short channel effects and current drivability in the 40 nm region at room temperature. We have also investigated hot-carrier related phenomena in the 40-nm region. Results indicate that the impact ionization rate increases slightly as the gate length is reduced to around 40 nm, and that both impact ionization rate and substrate current fall significantly as V/sub d/ falls below 1.5 V. This demonstrates that reliability as regards degradation due to hot carriers is not a serious problem even in the 40 mm region if V/sub d/ is less than or equal to 1.5 V.<> 相似文献
40.
Facial expression recognition of a speaker using front-view face judgment, vowel judgment, and thermal image processing 总被引:1,自引:1,他引:0
Tomoko Fujimura Yasunari Yoshitomi Taro Asada Masayoshi Tabuse 《Artificial Life and Robotics》2011,16(3):411-417
For facial expression recognition, we selected three images: (i) just before speaking, (ii) speaking the first vowel, and
(iii) speaking the last vowel in an utterance. In this study, as a pre-processing module, we added a judgment function to
distinguish a front-view face for facial expression recognition. A frame of the front-view face in a dynamic image is selected
by estimating the face direction. The judgment function measures four feature parameters using thermal image processing, and
selects the thermal images that have all the values of the feature parameters within limited ranges which were decided on
the basis of training thermal images of front-view faces. As an initial investigation, we adopted the utterance of the Japanese
name “Taro,” which is semantically neutral. The mean judgment accuracy of the front-view face was 99.5% for six subjects who
changed their face direction freely. Using the proposed method, the facial expressions of six subjects were distinguishable
with 84.0% accuracy when they exhibited one of the intentional facial expressions of “angry,” “happy,” “neutral,” “sad,” and
“surprised.” We expect the proposed method to be applicable for recognizing facial expressions in daily conversation. 相似文献