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121.
An implementation of the IF section of WCDMA mobile transceivers with a set of two chips fabricated in an inexpensive 0.35-/spl mu/m two-poly three-metal CMOS process is presented. The transmit/receive chip set integrates quadrature modulators and demodulators, wide dynamic range automatic gain control (AGC) amplifiers, with linear-in-decibel gain control, and associated circuitry. This paper describes the problems encountered and the solutions envisaged to meet stringent specifications, with process and temperature variations, thus overcoming the limitations of CMOS devices, while operating at frequencies in the range of 100 MHz-1 GHz. Detailed measurement results corroborating successful application of the new techniques are reported. A receive AGC dynamic range of 73 dB with linearity error of less than /spl plusmn/2 dB and spread of less than 5 dB for a temperature range of -30/spl deg/C to +85/spl deg/C in the gain control characteristic has been measured. The modulator measurement shows a carrier suppression of 35 dB and sideband/third harmonic suppression of over 46 dB. The core die area of each chip is 1.5 mm/sup 2/.  相似文献   
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Reconfigurable computing is consolidating itself as a real alternative to ASICs (Application Specific Integrated Circuits) and general-purpose processors. The main advantage of reconfigurable computing derives from its unique combination of broad applicability, provided by the reconfiguration capability, and achievable performance, through the potential parallelism exploitation. The key aspects of the scheduling problem in a reconfigurable architecture are discussed, focusing on a task scheduling methodology for DSP and multimedia applications, as well as the context management and scheduling optimizations.  相似文献   
125.
Forty paediatric cases of A.R.F. (Acute Renal Failure) of various aetiology were included in the study. 60% of patients were less than 4 years of age with male predominance. 80% cases reported to us very late with oligoanuria of more than 24 hours (2-7 days). Diarrhoea, vomiting and fever were other dominant symptoms. Maximum cases were severely anaemic (87.5%) with mean Hb 7.73 +/- 1.9 gm%. 40% cases were of underweight while only one case (2.5%) was of over weight, inspite of volume excess in 40% cases. All 24 cases, who were estimated for serum albumin, found to have marked hypoalbuminemia. Mortality was found to be as high as 65% inspite of effective peritoneal dialysis in all cases. High mortality seems to be due to profound anuria of many days (because of marked delay in reaching the hospital), fever and malnutrition besides other factors as aetiology.  相似文献   
126.
Three models of cancerogenesis were used to test the anti-cancerogenic effects of pentoxiphylline. In female rats, breast adenocarcinoma was induced by intramammary injections of N-methyl-N-nitrosourea (MNU) or colonic and rectal adenocarcinomas by intrarectal instillations of MNU. In female mice, squamous cell carcinomas of the cervix uteri and vagina were induced by intravaginal applications of 7,12-dimethyl-benz(a) anthracene (DMBA). Pentoxifylline was given with drinking water at a concentration of 500 mg/l long at the stage of carcinogenesis promotion/progression. Pentoxifylline exerted a strong inhibitory effect on the development of mammary tumors and a moderate inhibitory effect on the development of colonic and rectal tumors induced by MNU in rats. However, the drug did not affect the development of cervical and vaginal tumors caused by DMBA in mice.  相似文献   
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Nine female patients with a urethral diverticulum were admitted to our center over a six period: The clinical symptomatology was not specific. The diagnosis has been performed by voiding and retrograde cysto-uretrogram. The surgical treatment consisted in the excision of the diverticula, with the patient in the supine position. No perioperative morbidity was observed.  相似文献   
129.
Electron emission from insulator-semiconductor interface in ZnS:Mn ac thin film electroluminescent (ACTFEL) display devices was investigated by studying the current and field waveforms. A new technique for measuring the interface electron energy distribution at insulator-semiconductor interfaces was developed. The technique involves the measurement of tunnel current transients and can be used to study the interface electron energy distribution between any insulator-semiconductor pair with which an ac thin film test structure can be fabricated. It was applied to a ZnS:Mn display device at two temperatures of 10 K and 300 K and to a metal interface device structure  相似文献   
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