p-MOS controlled lateral thyristor: A MOS controllable thyristor suitable for integration

A novel CMOS compatible lateral thyristor is proposed in this paper. Its thyristor conduction is fully controlled by a p-MOS gate. Loss of MOS control due to parasitic latch-up has been eliminated and triggering of the main thyristor at lower forward current achieved. The device operation has been verified by 2-D numerical simulations and experimental fabrication.

Shifts in the estuarine demersal fish community after a fishery closure in Puget Sound, Washington

Puget Sound is one of the largest and most ecologically significant estuaries in the United States, but the status and trends of many of its biological components are not well known. We analyzed a 21-year time series of data from standardized bottom trawl sampling at a single study area to provide the first assessment of population trends of Puget Sound groundfishes after the closure of bottom trawl fisheries. The expected increase in abundance was observed for only 3 of 14 species after this closure, and catch rates of most (10) of the abundant species declined through time. Many of these changes were stepwise (abrupt) rather than gradual, and many stocks exhibited changes in catch rate during the 3-year period from 1997 through 2000. No detectable change was recorded for either temperature or surface salinity over the entire sampling period. The abrupt density reductions that were observed likely do not reflect changes in demographic rates but may instead represent distributional shifts within Puget Sound.

芹菜人工种子的初步研究

本研究建立了芹菜的悬浮培养系统。包括愈伤组织的诱导培养物的过滤及胚胎发生的诱导。此外还进行了胚状体的包裹以制造人工种子的实验。主要结果如下:①诱导芹菜的愈伤组织建立无性系以下胚轴为外植体效果最好，并且激素只用1m g/L的2.4-P即可。②对悬浮培养物用筛网过滤后继续培养可大幅度提高分生细胞(团)在总细胞中的比例，并使胚胎发生同步性提高③继代时间长短和温度对于球形胚的继续发育起重要作用。④用藻酸钙包裹胚状体或得的人工种子在培养基上以75%的频率长成植株。⑥碳源对于胚状体的萌发起重要作用。