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1. chinaXiv:201703.00918 [pdf]

Monadic NM-algebras

王军涛; 辛小龙; 贺鹏飞
Subjects: Mathematics >> Mathematics (General)

The main goal of this paper is to investigate (strong) monadic NM-algebras and to prove the (chain) completeness of the monadic NM-logic. In this paper, we introduce monadic NM-algebras: a variety of NM-algebras equipped with universal quanti#12;ers. Also, we study some properties of them and obtain some conditions under which a monadic NM-algebra becomes a monadic Boolean algebra. Besides, we show that the variety of NM-algebras are the equivalent algebraic semantics of the monadic fragment of NM predicate logic. Furthermore, we discuss relations between monadic NM-algebras and some related structures, likeness modal NMalgebras and rough approximation spaces. In addition, we introduce and investigate monadic #12;lters in monadic NM-algebras. In particular, by using monadic #12;lters on monadic NM-algebras, we characterize two kinds of monadic NM-algebras, which are simple and subdirectly irreducible. Moreover, we focus on a monadic analogous of representation theorem for NM-algebras and obtain that every strong monadic NM-algebra can be represented as subalgebras of products of linearly ordered ones. Then, we present monadic NM-logic, a system of many-valued logic capturing the tautologies of the predicate logics of nilpotent minimum t-norm and it's residua. As an application of (strong) monadic NM-algebras, we prove the (chain)completeness of monadic NM-logic. Our results constitute a crucial #12;rst step for providing a solid algebraic foundation for the one element fragment of NM predicate logic.

submitted time 2017-03-29 Hits7061Downloads1079 Comment 0

2. chinaXiv:201702.00130 [pdf]

黄土高原生态工程的生态成效

刘国彬,上官周平,姚文艺,杨勤科,赵敏娟,党小虎,郭明航,王国梁,王兵
Subjects: Other Disciplines >> Synthetic discipline

黄土高原是世界上水土流失最严重的地区,也是我国水土保持和生态建设的重点地区。20世纪80年代以后,国家在该地区先后开展了小流域治理工程、水土保持重点工程、退耕还林(草)工程、淤地坝建设和坡耕地整治等一系列生态工程,对土壤侵蚀控制、生态建设等均起到了良好作用。为全面评价该地区生态工程的生态成效,以野外站不同尺度监测及生态系统关键过程长期研究为基础,利用多种模型和统计分析方法,在地块-小流域-行政区和典型生态工程-典型样区-侵蚀和地貌区等不同尺度上,对土地利用和植被覆盖变化、土壤侵蚀动态变化、河流径流和输沙量动态变化以及社会经济结构动态变化进行了综合分析与评估。结果表明,黄土高原地区水土流失范围明显缩小、水土流失程度显著减轻,区域生态状况向良性发展、社会经济发展迅速。但局部地段(如陡坡耕地)水土流失仍然严重、生态环境仍然比较脆弱,治理形势依然严峻。据此,从该地区生态建设的内容、学科建设重点、监督和政策机制、产业结构调整等方面提出了该地区生态工程后期建设的方向和对策。

submitted time 2017-02-10 From cooperative journals:《中国科学院院刊》 Hits1290Downloads875 Comment 0

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