Low-power clock-deskew buffer for high-speed digital circuits

An IC containing four clock deskew buffers using the delay-locked-loop technology has been fabricated in a 0.6 μm single poly double metal CMOS process. The core chip area is 0.9×0.9 mm ². The maximum operating frequency is 80 MHz, and the total power dissipation of the four deskew buffers is 59 mW for a 3 V supply voltage. The maximum clock skew after deskewing is less than 300 ps, and the peak-to-peak clock jitter is less than 170 ps. The deskew range is 0.5-3.8 ns     

关于建设大型再生铝合金板带厂的设想

在有色金属结构材料中,废旧铝具有最高的可再生利用性,最大限度地回收废旧铝与充分有效地加以再生利用是建设节约型社会与环境友好型社会的重要一环,是又好又快建设可持续发展铝工业的必由之路.笔者首次提出中国有必要建设大型再生铝合金板带厂的意见,从各方面探讨了建厂的可行性,在长江三角洲或珠江三角洲地区建一个生产能力180 kt/a的再生铝合金板带厂,在资源、能源、技术、经济、环保、市场、政策、国际环境等方面都是可行的.产品种类为再生1XXX、3XXX、5XXX系合金民用板带.     

Adenocarcinoma combined with malignant peripheral nerve sheath tumor of the gallbladder

Adenocarcinoma of the gallbladder combined with a malignant peripheral nerve sheath tumor (MPNST) in the gallbladder in an 81-year-old woman is reported. The resected gallbladder showed two distinct tumor components, the epithelioid type of MPNST and adenocarcinoma with areas of mucin production. Although the immediate postoperative course was uneventful, a pathologic fracture of her right upper femur developed 4 months after the cholecystectomy. The pathology was determined to be a feature of metastatic MPNST rather than of adenocarcinoma. A whole body bone scan revealed multiple metastases, including the left parietal skull, left ninth rib, seventh thoracic vertebra, and right upper third of the femur. Despite cholecystectomy and postoperative irradiation therapy, she died 6 months after diagnosis of the tumor. Without an autopsy the primary site of the MPNST was unknown. We found that the prognosis was very poor in patients with distal metastatic MPNST, especially in older patients.     

Spectral amplitude-coding optical CDMA system using Mach-Zehnder Interferometers

In this paper, we propose a family of newly constructed codes to suppress the phase-induced intensity noise (PIIN) in spectral amplitude-coding (SAC) optical code division multiple access (OCDMA) systems. These new codes are derived from modified prime codes and their cross-correlation is not larger than one. We also present a novel SAC-OCDMA system employing the new codes together with Mach-Zehnder interferometers to eliminate the multi-user interference (MUI). Compared with the systems employing modified quadratic congruence codes (MQC codes), numerical results verify that our proposed system can more effectively suppress the PIIN and eliminate MUI. Hence, the number of simultaneously users and total transmission rate increases significantly.     

A stability analysis of turning a tailstock supported flexible work-piece

This paper proposes a new approach to analyze the stability of a cutting process. Previously, most studies have generally assumed the work-piece to be rigid and have, therefore, ignored work-piece deformation. In analyzing, the stability of the cutting process, these studies simply considered the dynamic equation of the tool. However, in practice, the work-piece undergoes deformation as a result of the application of an external force by the cutting tool. This deformation changes the chip thickness and has an effect on the critical chip thickness. Consequently, this study proposes a novel stability analysis method for the turning process in which deformation of the work-piece is considered. The cutting, which takes place in the turning process, is described using partial differential equations, and a set of dynamic equations is developed by considering the interaction between the tool and the work-piece. Having performed Laplace transformation, the stability of the cutting system can be analyzed in terms of the work-piece length, radius, natural frequency, deflection, slenderness ratio, cutting point, and material. The relationship between the critical chip width and the cutter spindle speed is investigated under a range of cutting and work-piece conditions. The analytical results for the current flexible work-piece are compared with those for a rigid work-piece. It is found that the critical chip width of the flexible work-piece is always greater than that of the rigid body.     

Rapid diagnosis of tuberculous meningitis by polymerase chain reaction assay of cerebrospinal fluid

A polymerase chain reaction (PCR) method for the rapid diagnosis of tuberculous meningitis (TBM) was used to study prospectively 47 cerebrospinal fluid (CSF) samples from 45 patients. Twenty CSF samples were from patients with clinically suspected TBM and another 27 samples came from patients without clinically suspected TBM. Mycobacterial DNA was detected in 15 CSF samples (14 from patients with clinically suspected TBM and 1 from a patient not suspected of having TBM). Of the PCR-positive samples, 4 were also positive for mycobacterial culture. However, 32 PCR-negative samples were all culture-negative. All samples were negative for the acid-fast bacillus by direct smear. The single PCR-positive patient in the clinically unsuspected TBM group was initially diagnosed as suffering from aseptic meningitis on the basis of his clinical features. The mycobacterial culture of his CSF specimen was also positive and a revised diagnosis of an aseptic type of TBM was made. The estimations of specificity and sensitivity in this study were 100% and 70% respectively. The results showed that using a PCR to detect mycobacterial DNA in CSF for the early diagnosis of TBM is not only a rapid but also an accurate method.     

The optimization of spectrum analysis for digital signals

This paper provides a complete method to solve the defects of spectrum analysis for discrete signals. Many researches had issued to deal with the defects of fast Fourier transform (FFT). Those methods may cause the characteristics of original signal altered, or solve this problem in part only. The defects of spectrum analysis cannot be solved efficiently and completely by those methods. These defects result from that those frequency scales cannot match with signal characteristics. This paper is based on the concept to establish a complete solution, divided into three steps: First, this paper analyzes the signal characteristics to be the basis of spectrum adjustment. A simple and accurate algorithm is used to find the frequency and amplitude of each component. Next, this paper finds optimum spectrum parameters to make the new spectrum match with signal characteristics. Finally, this paper takes the parameters to reanalyze the original signal. The method will make spectrum analysis reach optimization. Every procedure in this paper compares with traditional ones to prove its benefits. Moreover, the authors verify the theory feasible by analyzing actual signals.     

Theorem and application of adjustable spectrum

This paper affords the theorem, procedures, and evaluation of ability of adjustable spectrum for signals. By mean of adjusting frequency resolution and frequency shift, we can adjust frequency scale. The paper evaluates every process of computation to verify accurate computation and fast response of adjustable spectrum. Since frequency scale of this spectrum is adjustable, it makes the spectrum analysis of signal reach optimization. The method eliminates the picket-fence effect and the leakage effect by fast Fourier transform (FFT). Since the procedures remain as the characteristic of fast computation that this method can be used for real-time analysis.