Analysis of Dopant distributions in LEC-InP

It is often important to be able to estimate the concentration of dopant atoms incorporated into InP crystals grown from InP melt of given composition. In this paper we present a simple parameter (G) to revise the commonly used effective distribution coefficient (k(eff)) and the Scheil equation. The results obtained for various dopants and different initial concentrations in LEC-grown InP ingots are discussed. It is shown that the revised dopant concentration curves tally with the real distributions.

热退火γ-Al_2O_3/Si异质结构薄膜质量改进

采用高真空MOCVD外延技术，利用TMA（Al(CH_3)_3）和O_2作为反应源，在Si(100)衬底上外延生长γ－Al_2O_3绝缘膜形成γ-Al_2O_3/Si异质结构材料。同时，引入外延后退火工艺以便改善γ-Al_2O_3薄膜的晶体质量及电学性能。测试结果表明，通过在O_2常压下的退火工艺可以有效地消除γ－Al_2O_3外延层的残余热应力及孪晶缺陷，改善外延层的晶体质量，同时可以提高MOS电容的抗击穿能力，降低漏电电流。

磷酸三丁脂萃取Pa(Ⅴ)的研究

以TBP(磷酸三丁脂)为萃取剂,苯为稀释剂,以233Pa为示踪剂,研究盐酸溶液中Pa(Ⅴ)的萃取行为。讨论了盐酸浓度、萃取剂浓度对Pa(Ⅴ)萃取的影响。同时萃取时间对萃取的影响也进行了讨论。

A high-resolution, absolute-dated Holocene and deglacial Asian monsoon record from Dongge Cave, China

IEECAS SKLLQG

BGO高能γ探测器性能测定与效率模拟

实验测定了两套新制作的75× 1 0 0BGO高能γ探测器的能量分辨与时间分辨 ,根据BGO晶体中Ge的热中子俘获所释放的 2条高能γ射线对γ能谱作能量刻度 .模拟计算了 4— 3 0MeV能量区间BGOγ探测器的全能峰效率、单逃逸率与双逃逸率 ,计算了入射γ光子在 0— 3 0MeV区间均匀分布时BGO探测器的实际计数响应与计数效率随γ光子能量的变化 ,分析了γ光子在探测介质中的能损向下延展造成的能谱扭曲

SFC轴向注入系统和中心区的研究和设计

介绍了在ＨＩＲＦＬ注入器ＳＦＣ上进行的中心区、聚束器系统和轴向注入 束运线的设计、加工和调试结果．中心区的设计采用了两种注入半径及相应的 两套螺旋式静电偏转镜，解决了高频电压在某些工作区域偏低及三次谐波加速 时轴向注入线上空间电荷效应较为严重的问题．新的锯齿波聚束器系统不仅可 以提高聚束效率，而且还提出了采用半频聚束模式以提高ＳＦＣ与主加速器ＳＳＣ 的纵向匹配效率．新设计的轴向注入束运线配备了两台在线 ＥＣＲ离子源，提高 了电荷态分辨能力和注入相空间匹配能力，在提高注入效率的同时还改善了离 子源及束运线的工作环境和调束手段．

大气CO_2浓度升高对稻田土壤线虫群落的影响

本试验利用无锡稻 麦轮作FACE系统研究平台 ,开展了稻田土壤线虫群落对大气CO2 浓度升高响应的研究。实验中共观测到线虫 2 7科 4 0属 ,其中短腔属 (Brevibucca)、茎属(Ditylenchus)和垫刃属 (Tylenchus)为优势属。拔节期稻田土壤线虫总数、食细菌线虫和捕食 /杂食线虫对大气CO2 浓度升高表现出正响应。食真菌线虫在拔节期和抽穗期对CO2 浓度升高表现出负响应 ,成熟期捕食 /杂食线虫对CO2 浓度升高表现出负响应。在FACE条件下 ,植物寄生线虫的潜根属 (Hirschmanniella)和散香属 (Boleodorus)线虫数量显著增加 ,对CO2 浓度升高敏感

辽宁省昌图烟区植烟土壤养分肥力状况及评价

通过田间采样室内分析的方法,对辽宁省昌图烟区145个土壤样品的肥力指标进行分析测定。根据昌图地区植烟土壤养分状况和作物生长特性提出肥力分级标准,并利用测定数据对昌图地区植烟土壤肥力状况进行评价。结果表明:昌图烟区宝力、金家子、付家、长发、古榆树、七家子等6个乡镇中分别有75%、90%、95%、100%、100%、100%的植烟土壤的有机质含量低于当地的适宜值范围;七家子、古榆树、付家、金家子、长发等5个乡镇中分别有80%、100%、90%、90%、80%的植烟土壤处于缺氮状态;有效磷含量都处于适宜值范围之内;昌图地区植烟土壤的有效钾含量普遍处于缺乏状态。

土壤侵蚀稀土元素示踪法实验研究

作为研究土壤侵蚀垂直分布的新方法 ,较详细地描述了稳定性稀土元素 (REE)示踪法的原理与操作技术 ;通过实例说明了诸如示踪元素的选择原则、施放量的计算、施放方法及其注意事项等实际应用中可能遇到的各种问题的解决办法 ;给出了该方法的精度计算公式。

NDVI spatial pattern and its differentiation on the Mongolian Plateau

GIMMS NDVI database and geo-statistics were used to depict the spatial distribution and temporal stability of NDVI on the Mongolian Plateau. The results demonstrated that: (1) Regions of interest with high NDVI indices were distributed primarily in forested mountainous regions of the east and the north, areas with low NDVI indices were primarily distributed in the Gobi desert regions of the west and the southwest, and areas with moderate NDVI values were mainly distributed in a middle steppe strap from northwest to southeast. (2) The maximum NDVI values maintained for the past 22 years showed little variation. The average NDVI variance coefficient for the 22-year period was 15.2%. (3) NDVI distribution and vegetation cover showed spatial autocorrelations on a global scale. NDVI patterns from the vegetation cover also demonstrated anisotropy; a higher positive spatial correlation was indicated in a NW-SE direction, which suggested that vegetation cover in a NW-SE direction maintained increased integrity, and vegetation assemblage was mainly distributed in the same specific direction. (4) The NDVI spatial distribution was mainly controlled by structural factors, 88.7% of the total spatial variation was influenced by structural and 11.3% by random factors. And the global autocorrelation distance was 1178 km, and the average vegetation patch length (NW-SE) to width (NE-SW) ratio was approximately 2.4:1.0.