梯田式人工湿地出水致突变性研究

应用蚕豆根尖细胞微核技术对梯田式人工湿地出水进行致突变性研究，测定了生活污水、梯田式人工湿地出水、常规垂直流人工湿地出水及自来水的蚕豆根尖细胞微核千分率（MCN‰）及污染指数（PI），并对各水样的MCN‰进行了舱验．结果表明：梯田式人工湿地出水的致突变性（MCN％。为1.8‰）与生活污水（MCN‰为10．2‰）有显著差异，低于常规垂直流人工湿地（MCN‰为3．2‰），与自来水无明显差异（MCN‰为1．6‰），出水无致突变性，具有安全性．     

weyl群的定义关系及其应用

首 先深化 Ｒ． Ｓｔｅｉｎｂｅｒｇ 关于 Ｗ ｅｙｌ 群定义 关系的一个定 理，作为应 用，对 Ｂｌ ， Ｃｌ 型 Ｗ ｅｙｌ群分别构造了一 个指数为２的正 规子群     

线性自治NDDE与CDDE解空间为有限维的充要条件

本文把文［２］中关于 Ｒ Ｄ Ｄ Ｅ 解空间为有限维的结果完整地推广到 Ｎ Ｄ Ｄ Ｅ 和 Ｃ Ｄ Ｄ Ｅ 上去，给出了相应的充要条件     

一种改进的单位根检验程序

原假设的合理设定是单位根检验的首要问题,至今尚无学者对此进行深入研究。通过剖析以往单位根检验原假设设定存在的缺陷,在同时考虑原假设的可信度和检验可靠性的前提下,本文提出了单位根检验原假设的一种合理的设定策略及改进的检验程序。     

Root continuity theorems in valued fields. II

The continuity estimates of Theorem 6 of the first part are improved, using Theorem 2 of the author’s article on the norms of roots and coefficients.     

Zero-free regions for multivariate Tutte polynomials (alias Potts-model partition functions) of graphs and matroids

The chromatic polynomial P_G(q) of a loopless graph G is known to be non-zero (with explicitly known sign) on the intervals (−∞,0), (0,1) and (1,32/27]. Analogous theorems hold for the flow polynomial of bridgeless graphs and for the characteristic polynomial of loopless matroids. Here we exhibit all these results as special cases of more general theorems on real zero-free regions of the multivariate Tutte polynomial Z_G(q,v). The proofs are quite simple, and employ deletion–contraction together with parallel and series reduction. In particular, they shed light on the origin of the curious number 32/27.     

矩阵特征值Ky Fan定理的另一个推广

任给A∈Mn(n≥2),且A具有如下循环式分块形式     

Testing for cointegration using induced-order statistics

In this paper we explore the usefulness of induced-order statistics in the characterization of integrated series and of cointegration relationships. We propose a non-parametric test statistic for testing the null hypothesis of two independent random walks against wide cointegrating alternatives including monotonic nonlinearities and certain types of level shifts in the cointegration relationship. We call our testing device the induced-order Kolmogorov–Smirnov cointegration test (KS), since it is constructed from the induced-order statistics of the series, and we derive its limiting distribution. This non-parametric statistic endows the test with a number of desirable properties: invariance to monotonic transformations of the series, and robustness for the presence of important parameter shifts. By Monte Carlo simulations we analyze the small sample properties of this test. Our simulation results show the robustness of the induced order cointegration test against departures from linear and constant parameter models. This paper is an extension of the work of Aparicio and Granger (1995) and Aparicio and Escribano (1998).     

Generalized cluster complexes via quiver representations

We give a quiver representation theoretic interpretation of generalized cluster complexes defined by Fomin and Reading. Using d-cluster categories defined by Keller as triangulated orbit categories of (bounded) derived categories of representations of valued quivers, we define a d-compatibility degree (−∥−) on any pair of “colored” almost positive real Schur roots which generalizes previous definitions on the noncolored case and call two such roots compatible, provided that their d-compatibility degree is zero. Associated to the root system Φ corresponding to the valued quiver, using this compatibility relation, we define a simplicial complex which has colored almost positive real Schur roots as vertices and d-compatible subsets as simplices. If the valued quiver is an alternating quiver of a Dynkin diagram, then this complex is the generalized cluster complex defined by Fomin and Reading. Supported by the NSF of China (Grants 10471071) and by the Leverhulme Trust through the network ‘Algebras, Representations and Applications’.