神农架的植被及其1：200，200植被图的编制

神农架位于湖北省西部，长江以北、汉水以南的广阔地带，属北亚热带向暖温带的过渡区域。本文依据该地区所处地理位置的植被分布规律等资料，绘制了1：20万的植被复原图。并在此基础上，运用ERDAS imagine 8.4和Maplnfoprofessional 6.0软件，分别对神农架地区的TM影像（5、4、3波段）进行监督分类及目视解译，同时结合野外的样方调查，绘制了神农架地区1：20万的植被类型图，并建立了相应的属性数据库。最后，根据野外的GPS定位点对制图精度进行了Kappa检验。 制图结果表明，制图区总面积3476.67 km2，共计504个斑块。据统计，林地面积2607.45 km2，森林覆盖率75%;山地灌丛及亚高山灌丛总面积358.62 km2，占总面积的10.3%：草甸面积156.84 km2，占4.51%。自然植被划分为10个植被型，46个群系，以及农田（包括居民点）和茶园两种农业土地利用类型。其中针叶、落叶阔叶混交林面积最大（6个群系），约908 km2，占总面积的26.12%;其它依次为落叶阔叶林（1 1个群系），针叶林（4个群系），常绿阔叶林（3个群系），山地灌丛（5个群系），常绿阔叶、落叶阔叶混交林（3个群系），亚高山灌丛(6个群系)，草甸（4个群系）以及亚高山针叶林（3个群系）等。另外，两种农业土地利用类型面积共计430 kn12，占总面积的12.37%。 植被类型图与复原图叠加分析表明：①常绿阔叶林的理论分布区域，由常绿阔叶林，常绿、落叶阔叶混交林等7种植被型以及农田（含居民点）等土地利用类型共同组成。因处低海拔区域，人口集中，所以农田（含居民点）分布最广，所占面积最大，占到该区域面积的35.28%;加上长期的人为干扰，常绿阔叶林面积缩小至48.76 krr12，占到该区域面积的13.93%;②常绿、落叶阔叶混交林的理论分布区域内，因干扰后落叶阔叶林恢复较快，逐渐占据优势。另外，该区域海拔较低，人类活动也较频繁，农田（含居民点）面积仍有相当的比例;③针阔混交林理论分布区海拔位置高，人为活动影响少，原地带性植被保存较好，分布面积最大;其余部分为落阔林等7种植被型共同组成。④针叶林理论分布区域应是以巴山冷杉林为单优种的亚高山针叶林带，但因历史上的皆伐及火烧等原因，现面积仅有17 kfr12，占该区域的19.8%，其余则为亚高山灌丛及亚高山草甸所替代。

200 mile Exclusive Economic Zone and fishery development in Sri Lanka

Following details of the marine fishery resources of Sri Lanka, prospects for fishery development with respect to the 200-mile Economic Zone are examined, outlining also the 5-year fisheries development plan (1979-83).

200-V lateral superjunction LIGBT on partial SOI

This letter presents a novel lateral superjunction lateral insulated-gate bipolar transistor (LIGBT) in partial silicon-on-insulator (SOI) technology in 0.18-μm partial-SOI (PSOI) high-voltage (HV) process. For an n-type superjunction LIGBT, the p-layer in the superjunction drift region not only helps in achieving uniform electric field distribution but also contributes to the on-state current. The superjunction LIGBT successfully achieves a breakdown voltage (BV) of 210 V with an R dson of 765 mΩ ̇ mm 2. It exhibits half the value of specific on-state resistance R dson and three times higher saturation current (I dsat) for the same BV, compared to a comparable lateral superjunction laterally diffused metal-oxide-semiconductor fabricated in the same technology. It also performs well in higher temperature dc operation with 38.8% increase in R dson at 175°C, compared to the room temperature without any degradation in latch-up performance. To realize this device, it only requires one additional mask layer into X-FAB 0.18-μm PSOI HV process. © 2012 IEEE.

200 v superjunction N-type lateral insulated-gate bipolar transistor with improved latch-up characteristics

This paper evaluates the technique used to improve the latching characteristics of the 200 V n-type superjunction (SJ) lateral insulated-gate bipolar transistor (LIGBT) on a partial silicon-on-insulator. SJ IGBT devices are more prone to latch-up than standard IGBTs due to the presence of a strong pnp transistor with the p layer serving as an effective collector of holes. The initial SJ LIGBT design latches at about 23 V with a gate voltage of 5 V with a forward voltage drop (VON) of 2 V at 300 Acm2. The latch-up current density is 1100 Acm2. The latest SJ LIGBT design shows an increase in latch-up voltage close to 100 V without a significant penalty in VON. The latest design shows a latch-up current density of 1195 A cm2. The enhanced robustness against static latch-up leads to a better forward bias safe operating area. © 1963-2012 IEEE.

Yb3+-doped 200 mu m diameter core, gain guided index-antiguided fiber

The lasing in an end-pumped gain guided index-antiguided (GG-IAG) Yb3+-doped silicate glass fiber with a 200 mu m diameter core is demonstrated. Laser beams with similar beam propagation factors M (2) and mode field diameters W (0) (> 160 mu m) were observed at the output end of the GG-IAG fibers under different pump powers, which indicated that single mode behavior and excellent beam quality were achieved during propagation. Furthermore, the laser amplifier characteristics in the present Yb3+-doped GG-IAG fiber were also evaluated.

~(40)Ar~(10+)轰击Al和Si固体表面形成的200～1000nm光谱

报道了利用兰州重离子加速器国家实验室ECR离子源提供的高电荷态离子~(40)Ar~(10+)入射到Al和p型Si表面所产生的Al,Si,Ar原子的200～1000nm特征光谱的实验测量结果。结果表明,低速高电荷态离子与团体表面原子相互作用可有效地激发靶原子和靶离子的特征谱线,而且由于发射二次电子的无辐射退激与辐射光子退激过程的竞争,使得在p型Si表面上Ar原子的光谱强度总体大于在Al表面上的光谱强度。