Nutrient cycling in two traditional Central American agroforestry systems

A preliminary nutrient cycling study quantified total and temporal nutrient inputs via litterfall and pruning residues in two agroforestry systems: (1) Coffea arabica (perennial crop)-Erythrina poeppigiana (leguminous shade tree); and (2) C. arabica-E. poeppigiana-Cordia alliodora with emphasis on the effect of the timber tree C. alliodora. The total annual input of litterfall plus pruning residues was similar in both associations. Total annual input from E. poeppigiana was less than half in the association with C. alliodora than without, but the litterfall from this latter species compensated for the loss. Large differences in the total annual nutrient input of K, Ca and Mg was found between associations, but not for N or P. The amount of nutrients recycled by the associated trees reached the recommended level of fertilizer required for coffee production. The inclusion of C. alliodora within the C. arabica-E. poeppigiana association resulted in a more evenly distributed annual nutrient input.     

The Storage of Tree Data Structure by Gradation and Classification and Application in CAD for Engineering Structure

The traditional storage of tree data structure is according to the relation of the elements' frant-and-back. Since it is difficult to define the frant-and-back relation of graphics units in CAD for Engineering structure, the application of the tree structure becomes inconvenient. The authors change the storing method for the tree structure into gradation and classification. And a graded equivalence relation of graphics units is brought forward, which grade the graphics units with the equivalence relation. By using this storing method, we can easily accomplish some operations, such as picking up the subtree with a certain character, deleting a node, insert a graded and classified node, etc. The example provided indicates that the storage by gradation and classification can speed up searching and process the data of the subtree by gradation and classification expediently. This kind of storing method for the tree structure is applicable for data which contain the graded equivalence relation.     

高维Mobius群的初等子群

研究了４ 种高维 Ｍｏｂｉｕｓ 群的初等子群定义之间的关系⒚得到了高维 Ｍｏｂｉｕｓ 群是初等群的充要条件；在离散的条件下，给出了这种初等子群的结构性定理⒚     

《天净沙·秋思》英译本之我见——与黄国文、金春笙先生商榷

《中国翻译》上刊登了黄国文和金春笙先生对《天净沙.秋思》英译本的分析和研究。针对金先生和黄先生相驳的两种观点,文章首先从语言学角度审视了“形式对等”的真正内涵、实用性以及可接受性;然后从文学角度——音律、情感逻辑、意象虚实等来探讨《天净沙.秋思》的Schlepp和翁显良两种英译本孰优孰劣;最后建议运用语言学的分析方法来理性思考,结合文学的印象式、感悟式和经验式的翻译批评可以使得译文更富艺术魅力。     

具非整数滞后的不确定性线性定常离散控制系统的鲁棒镇定

应用频率等价法研究了一类非整数滞后不确定性线性定常离散控制系统的鲁棒镇定问题，给出了该系统鲁棒镇定的估计公式．     

关于极限八个等价定理的循环证明

使用分析的常用技巧对极限的八个等价定理给出了循环证明,体现了分析方法的技巧性,并且提出了以“基本列必收敛”为公理的公理化体系。     

基于生态绿当量的乌海市土地利用结构研究

基于生态绿当量的理论,构建土地利用结构模型,利用乌海市2005年和2010年土地利用现状数据,测算出乌海市各种用地类型的绿当量和区域总绿当量,用以分析生态环境现状。分析结果表明：①2005年、2010年乌海市生态绿当量都小于1,生态环境较差;②优化方案需要通过林地、园地、城市绿地及绿化带的增加来提高土地利用生态效益。     

文体翻译对等的量化评估

文体对等是翻译过程中所要求达到对等的一个层面。本文通过统计正负文体成分在语篇中的比值,来量化评估译文与原文在文体上是否对等,通过实例评估取得了较为满意的结果,为量化评估译文质量开辟了一条道路。     

二元Hamming码Ham(r,2)及其对偶码的性质研究

Hamming码Ham(r,q)作为一种完备的线形分组码,具有许多良好的性质,并且其译码方法非常简洁有效。在此基础上,对二元Hamming码Ham(r,2)及对偶码进行了进一步的研究,讨论了其对偶码所具有的几个性质。     

几类图簇匹配等价图的结构性质

利用匹配多项式的代数性质,证明了几类图簇的匹配多项式因式分解理论,进而得到了这几类图簇匹配等价图的结构性质.