犹豫模糊集的截集及其性质

通过引入犹豫模糊集的截集概念并研究截集的性质,建立了沟通犹豫模糊集合与经典集合之间的桥梁.进一步,讨论了犹豫模糊关系的截关系及其性质.     

基于灰色关联理论的新疆生产建设兵团城镇化水平评价

从社会发展指标、经济建设指标、社会稳定指标和生态环境指标四个方面选取19个指标作为评价新疆生产建设兵团城镇化水平指标,运用灰色关联理论法,计算各指标之间的关联度,得到新疆生产建设兵团13个师城镇化发展水平的排名,从而验证了模型的科学性和实用性.     

Managing inventory and service levels in a safety stock‐based inventory routing system with stochastic retailer demands

The inherent uncertainty in supply chain systems compels managers to be more perceptive to the stochastic nature of the systems' major parameters, such as suppliers' reliability, retailers' demands, and facility production capacities. To deal with the uncertainty inherent to the parameters of the stochastic supply chain optimization problems and to determine optimal or close to optimal policies, many approximate deterministic equivalent models are proposed. In this paper, we consider the stochastic periodic inventory routing problem modeled as chance‐constrained optimization problem. We then propose a safety stock‐based deterministic optimization model to determine near‐optimal solutions to this chance‐constrained optimization problem. We investigate the issue of adequately setting safety stocks at the supplier's warehouse and at the retailers so that the promised service levels to the retailers are guaranteed, while distribution costs as well as inventory throughout the system are optimized. The proposed deterministic models strive to optimize the safety stock levels in line with the planned service levels at the retailers. Different safety stock models are investigated and analyzed, and the results are illustrated on two comprehensively worked out cases. We conclude this analysis with some insights on how safety stocks are to be determined, allocated, and coordinated in stochastic periodic inventory routing problem. Copyright © 2017 John Wiley & Sons, Ltd.     

城市蔬菜品种污染状态空间的定性识别分析

本研究提出“两线一点实时监测预警”的一套方法来完善已经建立的城市蔬菜品种污染监控系统,即在由多元统计法建立的城市蔬菜品种污染监控系统研究基础上,利用分步聚类法对蔬菜品种污染空间进行分步聚类,同时采用非参数判别法对儿污染状态进行识别分析。该套方法的提出确保了城市蔬菜品种污染监控系统的正确性、准确性和科学性,为污染监控系统提供了“双保险”。     

Level algebras with bad properties

This paper can be seen as a continuation of the works contained in the recent article (J. Alg., 305 (2006), 949-956) of the second author, and those of Juan Migliore (math. AC/0508067). Our results are:

1). There exist codimension three artinian level algebras of type two which do not enjoy the Weak Lefschetz Property (WLP). In fact, for , we will construct a codimension three, type two -vector of socle degree such that all the level algebras with that -vector do not have the WLP. We will also describe the family of those algebras and compute its dimension, for each .

2). There exist reduced level sets of points in of type two whose artinian reductions all fail to have the WLP. Indeed, the examples constructed here have the same -vectors we mentioned in 1).

3). For any integer , there exist non-unimodal monomial artinian level algebras of codimension . As an immediate consequence of this result, we obtain another proof of the fact (first shown by Migliore in the above-mentioned preprint, Theorem 4.3) that, for any , there exist reduced level sets of points in whose artinian reductions are non-unimodal.

     

阴离子掺杂TiO2的芯位移和热力学性质的第一性原理研究

采用第一性原理计算考察了阴离子(硼、碳、氮、氟、磷、硫)掺杂的二氧化钛(包括锐钛矿相和金红石相)。芯位移计算结果表明,在氮掺杂的TiO2中,间隙掺杂类型的N的1s能级在XPS能谱上峰的位置要比替代掺杂的能级高,类似的结果也在硼、碳、磷和硫掺杂的TiO2上发现。然而对于F掺杂的TiO2,替代掺杂的峰位置比间隙掺杂的高,且与TiO2的晶相无关。还对阴离子掺杂的TiO2进行了热力学研究。结果表明,替换掺杂的形成焓高于间隙掺杂的,因此替代掺杂的TiO2的制备需要苛刻的条件,而间隙掺杂TiO2的制备只需温和的湿化学条件。     

The Electronic Structure of the Al3− Anion: Is it Aromatic?

Multiconfigurational high‐level electronic structure calculations show that the ${{\rm Al}{{- \hfill \atop 3\hfill}}}$ ring‐like cluster anion has three close low‐lying electronic states of different spin, all of them having strong multiconfigurational character. The aromaticity of the cluster has, therefore, been studied by means of total electron delocalization and normalized multicenter electron delocalization indices evaluated from the multiconfigurational wave functions of each state. The lowest‐lying singlet and triplet states are found to be highly aromatic, whereas the next lowest‐lying state, the quintet state, has much less, though non‐negligible, aromatic character.     

Advanced data analysis and process monitoring across manufacturing plants using multilevel methods

Three‐level versions of Multilevel Simultaneous Component Analysis (MLSCA) and Multilevel Partial Least Squares (MLPLS) were developed, which are capable of separating between‐plant, between‐run and within‐run process variation, and modeling these three levels in a multivariate way. In comparison to the two‐level versions they allow to discriminate between overall differences between plants and the variation between runs within a plant. It was shown that the three‐level version of MLSCA has clear added value for the analysis of process runs from different plants. In MLPLS other projections of the multivariate data onto latent variables and different views of the data are obtained when relevant Y information is available. This has clear added value for obtaining insight into the relation between process data and Y. A special use of MLPLS is to diagnose aberrations in first principles models. In batch process monitoring MLSCA at three levels allows simultaneous multivariate modelling of batch data from different manufacturing plants. By filtering out the between‐plant and between‐run sources of variation, and using only within‐run variation, monitoring models can be improved. Using within‐run data, it is possible to build monitoring models across manufacturing units and reduce the number of nuisance alarms, while improving abnormal situation detection and diagnosis. Model transfer is only possible if static between‐plant differences exist, but not if there are dynamic differences.     

Explaining Level Inversion of the La and Lb States of Indole and Indole Derivatives in Polar Solvents

Quantum chemical methods are used to study the solvent effects on the spectra of indole and a series of methyl‐substituted indoles. We focus on the low‐lying L_a and L_b states and study their interplay. We find that the solvent mainly affects emission from the L_a state, by stabilizing its energy in its excited‐state geometry. The stabilization of the L_a state increases with increasing solvent polarity, which accounts for the large fluorescence shift observed in indoles and leads to an inversion in the nature of the lowest emitting state, from L_b in vacuum to L_a in water. To the best of our knowledge, this is the first theoretical evidence for level inversion done for a series of indoles. The underlying mechanism of level inversion is analyzed in detail. The usual interpretation of level inversion in terms of their static dipole moment is criticized and an improved predictive measurement is suggested.