上下文无关语言分析树的一种表示形式

介绍了上下文无关语言 (CFL)的句子的一种分析树表示 ,它适合用于一类与以往不同的 CFL 的应用 ,即对分析树空间效率要求较高且不需标记分析树的应用 ,典型的就是把 CFL的句子用作算法加工对象 .这种表示比传统分析树不仅空间较小 ,而且进行结构匹配的速度快 .还介绍了这种分析树表示的实现技术 .

光谱选择性涂层的传热分析

对光谱选择性涂层与太阳、大气、环境的传热进行了分析，并对灰色光谱选择性涂层作了传热计算，表明光谱选择性涂层具有明显的降温效果，得出了理想光谱选择性涂料应具有的反射光谱曲线。

电子束的绝热展开

考虑空间电荷效应，用数值方法模拟计算了电子束绝热展开过程．当初始磁感应强度与最终磁感应强度之比为Ｋ时，电子束横向温度由初始值Ｔｉ降低 Ｔｉ／Ｋ．研究了不同能量、不同流强的电子束达到预期的绝热展开倍数所需的最低磁感应强度．

陕北新修梯田地膜小麦优化施肥栽培模式研究

采用田间正交旋转试验设计 ,于 1999年在延安市燕沟进行了小麦产量与氮肥 (N)、磷肥 (P2 O5)和有机肥 (M) 3因子 5水平的新修梯田地膜小麦试验。通过对试验结果数学建模及模型分析得出 ,本区影响产量的因子效应为 N >P≈ M,N肥产量效应约为磷肥、有机肥的 3倍 ,有机肥增产趋势在低肥力时最低 ,随着肥力水平提高 ,其增施肥料的增产能力增加 ,而氮肥、磷肥肥效均呈递减趋势 ,即肥效随施肥量增加而减小。还分析了本区小麦单位面积产量≥ 2 5 0 0 kg/ hm2 的优化施肥组合 ,筛选的施肥方案为 N 2 5 1.8～ 2 72 .5 kg/ hm2 ,P2 O510 8.9～136 .5 kg/ hm2 ,有机肥 12 80 0～ 16 40 0 kg/ hm2。均值依次为 2 6 1.1,12 5 .1和 146 0 0 kg/ hm2。

Extending electrochemical activity of polyaniline to alkaline media via electrostatic interaction and sol-gel route

The electroactivity of polyaniline was extended to pH = 14 alkaline media by preparation of a novel electrostatic interaction conductive hybrid from water-borne conductive polyaniline and silica network containing carboxyl groups via sol-gel process. In addition, the obtained conductive polyaniline hybrid film displayed very low conductivity threshold percolation and demonstrated excellent stability upon cycling.

Paleoenvironment evolution of the East Philippine Sea recorded in the new-type ferromanganese crust since the terminal Late Miocene

From systemic research of microstructure, geochemistry, uranium-series and Be-10 isotope dating on a new-type deepwater ferromanganese crust from the East Philippine Sea, the paleoenvironment evolution of the target area since the terminal Late Miocene was recovered. The vertical section changes of microstructure and chemical composition are consistent in the studied crust, which indicate three major accretion periods and corresponding paleoenvironment evolution of the crust. The bottom crust zone was formed in the terminal Late Miocene (5.6 Ma) with loose microstructure, high detritus content and high growth rate. Reductions of mineral element content, accretion rate and positive Ce-anomaly degree at 4.6 Ma indicate temporal warming, which went against the crust accretion and finally formed an accretion gap in the terminal Middle Pliocene (2.8-2.7 Ma). The more active Antarctic bottom seawaters in the Late Pliocene (2.7 Ma) facilitated the fast transfer to the top pure crust zone. Hereafter, with the further apart of volcanic source and the keeping increase of eolian material (1.0 Ma), although surrounding conditions were still favorable, mineral element content still shows an obvious reducing trend. It thereby offers new carrier and data for the unclear paleoceanographic research of the target area since the terminal Late Miocene.

小型啮齿动物种群系统调节复合因子理论的野外实验研究:食物可利用性和捕食对根田鼠种群动态作用的分析

本研究在野外围栏条件下采用析因实验设计，测定营养、捕食及空间行为对根田鼠（Ｍｉ－ｃｒｏｔｕｓｏｅｃｏｎｏｍｕｓ）种群统计特征的影响。本文旨在检验下述特定假设：高质量食物可利用性和捕食对限制小型啮齿动物种群密度具有独立的和累加的效应。３年期间，４种野外实验处理６个重复的研究结果表明，附加食物并预防捕食者处理的种群具有最高密度；未附加食物及不预防捕食者处理（对照）的种群密度最低；而单一处理的种群，其密度居中。不同处理条件下，新生个体在种群的补充模式以及种群瞬时增长率的变化均与种群密度的变动相应一致。双因素ＡＮＯＶＡ的结果证明，附加高质量食物能明显地提高根田鼠的种群密度，而对种群补充量的作用则较弱，仅接近显著水平；预防捕食者不仅能显著地作用于种群密度，更能强烈地影响种群补充量。高质量食物和捕食者的作用具有累加的性质，两者的交互作用对种群密度和补充量均无显著影响。