Graphic Sequences with an A-Connected Realization

A non-increasing sequence \({\pi = (d_1, d_2, \ldots, d_n)}\) of non-negative integers is said to be graphic if it is the degree sequence of a simple graph G on n vertices. Let A be an (additive) abelian group. An extremal problem for a graphic sequence to have an A-connected realization is considered as follows: determine the smallest even integer \({\sigma (A, n)}\) such that each graphic sequence \({\pi = (d_1, d_2, \ldots, d_n)}\) with d _n ≥ 2 and \({\sigma (\pi) = d_1 + d_2 + \cdots +d_n \ge \sigma (A, n)}\) has an A-connected realization. In this paper, we determine \({\sigma (A, n)}\) for |A| ≥ 5 and n ≥ 3.     

Bernstein Polynomial Estimation in the Partially Linear Model under Monotonicity Constraints

In this paper, a Bernstein-polynomial-based likelihood method is proposed for the partially linear model under monotonicity constraints. Monotone Bernstein polynomials are employed to approximate the monotone nonparametric function in the model. The estimator of the regression parameter is shown to be asymptotically normal and efficient, and the rate of convergence of the estimator of the nonparametric component is established, which could be the optimal under the smooth assumptions. A simulation study and a real data analysis are conducted to evaluate the finite sample performance of the proposed method.     

长吻鮠肝脏线粒体DNA的研究

采用密度梯度离心法及ＤＮａｓｅⅠ、ＲＮａｓｅ消化法制备并纯化了长吻鮠　（ＬｅｉｏｃａｓｓｉｓＬｏｎｇｉｒｏｓｔｒｉｓ）肝脏线粒体ＤＮＡ（ｍｔＤＮＡ）．用９种限制性内切酶对ｍｔＤＮＡ进行了分析．ＸｈｏⅠ、ＢｇｌⅡ、ＥｃｏＲⅠ、ＰｓｔⅠ、ＢｇｌⅠ、ＢａｍＨⅠ、ＸｂａⅠ、ＨｉｎｄⅢ、ＳａｌⅠ在长吻　ｍｔＤＮＡ分子上分别具１、３、３、２、１、２、４、７、０个切点．ｍｔＤＮＡ分子量约１０．３１×１０５道尔顿，大小为１６．６９ｋｂ．根据单酶和双酶解片段的数目和分子量，建立了长吻　ｍｔＤＮＡ的限制性酶切图谱．     

Permanence of a logistic type impulsive equation with infinite delay

In this paper, a non-autonomous logistic type impulsive equation with infinite delay is investigated. For the general non-autonomous case, some sufficient conditions which guarantee the permanence of solutions are obtained. Our results extend a known result of Seifert.     

基于ERP的(s,S)策略下库存优化控制决策支持系统

针对当前ERP软件系统无法动态地给出优化订购策略并对历史数据进行有效的分析等不足,以最小化库存费用为目标建立起折扣准则下库存优化数学模型,对ERP软件中导出的各类历史数据进行模型化分析,动态地得出各类产品(s,S)结构形式的优化订购策略.基于该模型设计并开发了库存优化控制决策支持系统,为用户提供决策支持,很大程度降低了企业库存费用.     

Turing structures and stability for the 1-D Lengyel–Epstein system

This paper continues the analysis on the Lengyel–Epstein reaction- diffusion system of the chlorite-iodide-malonic acid-starch (CIMA) reaction for the rich Turing structures. The steady state structures, especially the double bifurcation one, and their stability and multiplicity are studied by the use of Lyapunov–Schmidt reduction technique and singularity theory. Numerical simulations are presented to support our theoretical studies. The results show that the richer stationary Turing patterns heavily rely both on the size of the reactor and on the effective diffusion rate in the CIMA reaction.     

Robust cellulose-carbon nanotube conductive fibers for electrical heating and humidity sensing

Multifunctional fibers have attracted widespread attention due to applications in flexible smart wearable devices. However, simultaneously obtaining a strong and functional woven fiber is still a great challenge owing to the conflict between the properties mentioned above. Herein, mechanically strong and highly conductive cellulose/carbon nanotube (CNT) composite fibers were spun using an aqueous alkaline/urea solution. The microstructure as well as physical properties of the resulting fibers were characterized via scanning electron microscopy, infrared spectroscopy, mechanical and electrical measurement. We demonstrated that carboxylic CNTs can be well dispersed in alkali/urea aqueous systems which also dissolved cellulose well. The subsequent wet spinning process aligned the CNTs and cellulose molecules inside the regenerated composite fiber well, enhancing the interaction between these two components and endowing the composite fiber having a 20% CNT loading with an excellent mechanical strength of 185 MPa. Benefiting from the formation of conductive paths, the composite fiber with the diameter of about 50 μm possessed an electrical conductivity value in the range of 64–1274 S/m for 5–20 wt% CNT loading. This excellent mechanical strength and high electrical conductivity enable the composite fiber to exhibit a great potential in joule heating; the heating temperature of cellulose/CNT-20 fiber reached more than 55 °C within 15 s at 9 V. In addition, the multifunctional filaments are further manufactured as a water sensor to measure humidity. This work provides a potential material that can be applied in the fields of wearable electronics and smart flexible fabrics.

Graphic abstract

     

Synthetic Studies on Selectin Ligands/Inhibitors: One-Pot Synthesis of the Mono- and Oligo-Sulfated 2-(Tetradecyl)Hexadecyl β-D-Galacto- and Lactopyranosides as the Sulfatide Mimetics 1

Abstract

The ¹³C NMR spectra of inulin oligomers in D₂O with degree of polymerization (DP) of 3 through 9, along with two other inulin oligomer mixtures of average DP = 17 and DP = 31 were recorded. Significant variations in the chemical shift of some fructofuranose carbon signals indicates that unlike glucans, simple helical structures are not the predominant conformation for inulin oligomers—at least up to DP = 9. Models of the DP = 5 oligomer show that it should prefer a single helical conformation which however, would not be accessible to longer DP oligomers due to severe steric interactions.