分数阶Fourier域多通道采样的滤波器组高效实现

研究了分数阶Fourier域周期非均匀采样以及多通道采样的滤波器组高效插值和重建方法．首先，根据分数阶Fourier变换的性质，得到了分数阶Fourier域插值和采样的恒等结构；然后根据该恒等结构，得到了从分数阶Fourier域多通道采样和周期非均匀采样中重建原始信号的滤波器组高效实现方法；最后建立了分数阶Fourier域多通道采样和分数阶Fourier域滤波器组的关系，并进一步说明可以通过分数阶Fourier域准确重建滤波器组，导出分数阶Fourier域新的采样和重建策略．     

Investigations of ZnO thin films deposited by a reactive pulsed laser ablation

Highly transparent ZnO thin films were deposited at different substrate temperatures by pulsed laser deposition in an oxygen atmosphere.The thin films were characterized by various techniques including X-ray diffraction,scanning electron microscopy,optical absorption,and photoluminescence.We demonstrated that oriented wurtzite ZnO thin films could be deposited at room temperature using a high purity zinc target.Variable temperature photoluminescence revealed new characteristics in the band edge emission.The...     

Novel Elastomeric Fabrics for the Treatment of Hypertrophic Burn Scars Using Polyhexamethylene Biguanide Antimicrobial Agents

In burn treatments,microorganisms on pressure garments during pressure therapy can prevent rehabilitation by causing functional,hygienic,and aesthetic difficulties. As bacterium is one of the most trouble-causing organisms,they can threaten patients causing infection during the long period of use of these garments.Novel burn pressure garments having durable antimicrobial property were developed using polyhexamethylene biguanide( PHMB)antimicrobial agent procedure on highly elastic nylon 66 /spandex fabrics in powernet,flat warp and weft knitted structures using paddry-cure method. Commercial wireless pressure sensors were used to control pressures at an acceptable medical range. Antimicrobial activity,wash durability,Fourier transform infrared spectroscopy(FTIR) and Scanning electron microscopy(SEM) analyses were conducted for the treated samples. Antimicrobial test results following AATCC 100 Test Method showed 99% reduction of bacteria for the fabric samples treated with PHMB. A small but significant decrease in antimicrobial activity was observed even after50 launderings. These treatments also yield good results to prevent odor,decrease infection by preventing and /or blocking microbial growth according to the antimicrobial mechanism and support reducing of scarring by providing a hygienic environment around the scar.     

A family study of endophenotypes for psychosis within an early intervention programme in Hong Kong: Rationale and preliminary findings

The study of endophenotypes may be a viable strategy to tackle the genetic complexity and phenotypic heterogeneity of psychosis, but this research direction is relatively under-developed in China as compared to Western countries. We have recently initiated one of the first family studies of endophenotypes for psychosis in China. Patients entering an established early psychosis intervention service are recruited into this research project for phenotyping, endophenotyping and genotyping. At the endophenotypic...     

A hybrid-stress solid-shell element for non-linear analysis of piezoelectric structures

This paper presents eight-node solid-shell elements for geometric non-linear analyze of piezoelectric structures.To subdue shear,trapezoidal and thickness locking,the assumed natural strain method and an ad hoc modified generalized laminate stiffness matrix are employed.With the generalized stresses arising from the modified generalized laminate stiffness matrix assumed to be independent from the ones obtained from the displacement,an extended Hellinger-Reissner functional can be derived.By choosing the ass...     

On fractional control method for four-wheel-steering vehicle

Four-wheel-steering (4WS) system can enhance vehicle cornering ability by steering the rear wheels in accordance with the front wheels steering and vehicle status.With such steering control system,it becomes possible to improve the lateral stability and handling performance.In this paper,a new control method for 4WS vehicle is proposed,its rear wheels steering angle is in accordance with the angle of front wheels steering and vehicle yaw rate,and the effects of front wheels steering angle velocity are consi...     

c-Myc regulates mammalian body size by controlling cell number but not cell size.

Overexpression of the proto-oncogene c-myc has been implicated in the genesis of diverse human tumours. c-Myc seems to regulate diverse biological processes, but its role in tumorigenesis and normal physiology remains enigmatic. Here we report the generation of an allelic series of mice in which c-myc expression is incrementally reduced to zero. Fibroblasts from these mice show reduced proliferation and after complete loss of c-Myc function they exit the cell cycle. We show that Myc activity is not needed for cellular growth but does determine the percentage of activated T cells that re-enter the cell cycle. In vivo, reduction of c-Myc levels results in reduced body mass owing to multiorgan hypoplasia, in contrast to Drosophila c-myc mutants, which are smaller as a result of hypotrophy. We find that c-myc substitutes for c-myc in fibroblasts, indicating they have similar biological activities. This suggests there may be fundamental differences in the mechanisms by which mammals and insects control body size. We propose that in mammals c-Myc controls the decision to divide or not to divide and thereby functions as a crucial mediator of signals that determine organ and body size.