FIR filters with field-programmable gate arrays

Distributed arithmetic techniques are the key to efficient implementation of DSP algorithms in FPGAs. The distributed arithmetic process is briefly described. A representative DSP design application in the form of an 8 tap FIR filter is offered for the Xilinx XC3042 field programmable logic array (FPGA). The design is presented in sufficient detail—from filter specifications via filter design software through detailed logic of salient data and control functions to obtain a realistic placing and routing of configurable logic block (CLBs) and in/out block (IOBs) components for simulation verification and performance evaluation vis-a-vis commercially available dedicated 8 tap FIR filter chips.     

Family economic stress and adjustment of early adolescent girls.

Proposes a family process model that links economic stress in family life to prosocial and problematic adolescent adjustment. With a sample of 220 7th-grade girls living in intact families in the rural Midwest, the theoretical constructs in the model were measured using both trained observer and family member reports. In general, results were consistent with the proposed model. Economic pressures led to depression and demoralization for both parents, the result of which was greater marital conflict and disruptions in skillful parenting. The emotions and behaviors of both mothers and fathers were almost equally affected by financial difficulties, and disruptions in each parent's childrearing behaviors had adverse consequences for adolescent development. Parents' depressed mood and disrupted childrearing practices both directly affected girls' adjustment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review

Rural Planning and Development in the United States by Mark B. Lapping, Thomas L. Daniels & John W. Keller, New York & London, Guilford Press, 1989, ISBN 0-89862-384-7, 342pp., £32.00 HB.

Conflict and Change in the Countryside by Guy M. Robinson, London, Belhaven Press, 1990, ISBN 1-85293-044-6, 482pp., £40.00 HB, £14.95 PB.

Monitoring Environmental Change with Color Slides by Arthur W. Magill, 1989, Gen. Tech. Rep. PSW-117, Berkeley CA, 55pp. From Pacific Southwest Forest and Range Experiment Station, PO Box. 245, Berkeley, California94071,

Time Exposure: the Peak National Park — Past and Present, by Ray Manley, 1991, Peak Park Joint Planning Board, ISBN 0-907543-48-0, 88pp. Reviewed by Peter Howard, Department of Design, University of Plymouth

ISBN 0-89381-447-4, 80pp, $14.50.

Beyond Wilderness, Aperture, No.120, Late Summer 1990,

From Aperture, 20 East 23 Street, New York, NY 10010-4463.

Britain's Changing Environment from the Air edited by Tim Bayliss Smith & Susan Owens, Cambridge U P, 1990, ISBN 0-521-37121, 256pp.

Use of vegetation in civil engineeringedited by N.J. Coppin & I.G. Richards, London, Butterworths, 1990, ISBN 0408-03849-7, 292pp. £50. (£40 for members through CIRIA)

Nature Areas for City People by Jacklyn Johnston for the London Ecology Unit, Ecology Handbook 14, 1990, ISBN 187104510X, 116pp., £6.00.     

人造板树脂技术创新--中国人造板企业面临的挑战和机遇

近10年来中国的中纤板产量增长迅速。1995年的产量约为53．7万m^，而2005年已经超过1500万m^3。尽管如此，据测算未来两、三年内中纤板的新增产量将非常有限。根据《国际人造板叛WBPI）资料，2006年新增的生产线只有14条，生产能力为92万m^3。该行业的快速增长以及随之而来的增长放缓将导致竞争加剧，最后使生产规模趋于合理化。最先淘汰的很可能是原有的旧厂，     

Studies of the fracture surface of rice grains using environmental scanning electron microscopy

Raw and processed grains of rice (Oryza sativa) were examined using the environmental scanning electron microscope (ESEM), which allows specimens to be imaged at high resolution with minimal preparation. Images were obtained for milled rice grains that were fractured along natural transverse fracture planes. The images showed two distinct features: a smooth surface, where the fracture plane is suggested to be between endosperm cells, and a rough, more disorganised surface, which is likely to correspond to the fracture plane passing through an endosperm cell. Individual starch granules exposed in the fractured surface ranged from 3 to 11 µm in diameter. The ESEM revealed morphological differences between grains of different varieties. Parboiled rice showed a glassy fracture surface in which features of endosperm cells and starch granules were clearly recognisable but smaller than those of uncooked rice grains. Rice grains that had been heated and puffed showed a complete loss of organisational structure. The ESEM was able to capture the effect of processing treatments on the organisational structure of the grains. Copyright © 2004 Society of Chemical Industry