WCARS-ISPA火焰光谱特征选择的转炉炼钢终点预测

对转炉炼钢终点的实时精准控制能够有效提高钢铁产出的质量,炉口火焰光谱在炼钢不同时期的变化明显,对其进行分析处理并与机器学习方法相结合可有效用于炼钢终点的实时控制.针对炉口火焰光谱数据量大、现有方法对光谱特征提取在可信度和实时性上不足的缺陷,提出一种基于窗口竞争性自适应重加权采样(WCARS)结合迭代式连续投影算法(IS...     

一类一维在线单位聚类问题的随机近似算法

在给定的度量空间中, 单位聚类问题就是寻找最少的单位球来覆盖给定的所有点。这是一个众所周知的组合优化问题, 其在线版本为: 给定一个度量空间, 其中的n个点会一个接一个的到达任何可能的位置, 在点到达的时候必须给该点分配一个单位聚类, 而此时未来点的相关信息都是未知的, 问题的目标是最后使用的单位聚类数目最少。本文考虑的是带如下假设的一类一维在线单位聚类问题: 在相应离线问题的最优解中任意两个相邻聚类之间的距离都大于0.5。本文首先给出了两个在线算法和一些引理, 接着通过0.5的概率分别运行两个在线算法得到一个组合随机算法, 最后证明了这个组合随机算法的期望竞争比不超过1.5。     

脂肪酶催化乳酸与乙醇合成乳酸乙酯的反应动力学

对脂肪酶催化乳酸与乙醇合成乳酸乙酯反应的动力学进行了研究,根据乒乓机制和双底物抑制的特性建立了反应速率方程.反应时间常数(tR)和扩散时间常数(tD)的计算结果表明,酯化反应速率未受到明显的限制.反应速率方程可以很好地预测实验结果,由非线性拟合得到的动力学参数中,乳酸(A)和乙醇(B)的抑制常数分别为KiA=10.7mmol/L和KiB=275.0mmol/L.这说明乳酸作为短链极性脂肪酸,对酶的失活作用远大于乙醇.乳酸在微液层中聚集并产生了使酶失活的低pH值环境,同时在酯化反应中存在竞争性抑制作用.     

Analysis of erythritol in foods by polyclonal antibody-based indirect competitive ELISA

Sugar alcohols are widely used as food additives and drug excipients. Erythritol (INS 968) is an important four-carbon sugar alcohol in the food industry. Erythritol occurs naturally in certain fruits, vegetables, and fermented foods. Currently, HPLC and GC methods are in use for the quantification of erythritol in natural/processed foods. However, an immunoassay for erythritol has not been developed so far. We have utilized affinity-purified erythritol-specific antibodies generated earlier [9] to develop an indirect competitive ELISA. With erythritol–BSA conjugate (54 mol/mol; 100 ng/well) as the coating antigen, a calibration curve was prepared using known amounts of standard meso-erythritol (0.1–100,000 ng) in the immunoassay. Watermelon (Citrullus lanatus) and red wine were selected as the food sources containing meso-erythritol. The amount of meso-erythritol was calculated as 2.36 mg/100 g fresh weight of watermelon and 206.7 mg/L of red wine. The results obtained from the immunoassay are in close agreement with the reported values analyzed by HPLC and GC (22–24 mg/kg in watermelon and 130–300 mg/L in red wine). The recovery analyses showed that added amounts of meso-erythritol were recovered fairly accurately with recoveries of 86–105% (watermelon) and 85–93.3% (red wine). The method described here for erythritol is the first report of an immunoassay for a sugar alcohol. Figure Indirect competitive ELISA for quantitation of erythritol     

锂铝水滑石对水杨酸及其异构体的选择性插层研究

[LiAl_2(OH)_6]Cl·yH_2O was prepared by co-precipitation. The competitive intercalation of geometric isomers of hydroxybenzoic acid into the interlayer of layered double hydroxides (LDHs) was studied by the reaction of [LiAl_2(OH)_6]Cl·yH_2O with various mixtures of o-hydroxybenzoic acid, m-hydroxybenzoic acid and p-hydroxybenzoic acid. Powder X-ray diffraction (XRD) results confirmed the intercalation of the isomers, and high performance liquid chromatography (HPLC) was used for the quantitative study. The order of the preferential intercalation of the three isomers was found to be: o-hydroxybenzoic acid (1,2-C_7H_6O_3)》 p-hydroxybenzoic acid (1,4-C_7H_6O_3) > m-hydroxybenzoic acid (1,3-C_7H_6O_3).     

Multiple Reversals of Competitive Dominance in Ecological Reserves via External Habitat Degradation

In this article we continue an examination of the consequences of habitat degradation on species interactions begun by Cantrell, Cosner and Fagan in Cantrell et al., J. Math. Biol. 37, 491–533 (1998). In Cantrell et al., J. Math. Biol. 37, 491–533 (1998), two competing species were thought to inhabit a pristine patch of habitat surrounded by matrix habitat whose level of degradation is variable. The dynamics of the species interactions was modeled by diffusive Lotka–Volterra competition equations in the patch supplemented by Robin boundary conditions on the interface between the pristine patch and the matrix habitat. Habitat degradation was incorporated into the model via a tunable hostility parameter in the boundary conditions. Analysis of the model showed that it is possible for a species to be competitively dominant in the pristine patch when the surrounding environs are only mildly unfavorable but to lose this advantage and be competitively inferior in the patch when matrix hostility is severe. In this article we address the question of just how delicately competitive advantage within the pristine patch depends on the level of degradation in the environs surrounding the pristine patch. We show that it is indeed possible for competitive advantage to reverse more than once as the level of degradation in the matrix habitat increases and also examine the effects thereof on the number and nature of equilibria through a detailed bifurcation analysis.Dedicated to Professor Shui-Nee Chow on the occasion of his 60th birthday.     

Abstract competitive systems and orbital stability in

Competitive autonomous systems in have the remarkable property of verifying an analogue of the Poincaré-Bendixon theorem for planar equations. This fact allows us to prove the existence of orbitally stable closed orbits for those systems under easily checkable hypothesis. Our aim is to introduce, by changing the ordering in , a new class of autonomous systems for which the preceding results directly extend. As a consequence we shall reinterpret some of the results of R. A. Smith in terms of the theory of monotone systems.

     

具有前瞻区间的两个工件组单机在线排序问题

研究具有前瞻区间的两个不相容工件组单位工件单机无界平行分批在线排序问题.工件按时在线到达, 目标是最小化最大完工时间. 在无界平行分批排序中, 一台容量无限制机器可将多个工件形成一批同时加工, 每一批的加工时间等于该批中最长工件的加工时间. 具有前瞻区间是指在时刻t, 在线算法能预见到时间区间(t,t+beta]内到达的所有工件的信息.不可相容的工件组是指属于不同组的工件不能安排在同一批中加工.对该问题提供了一个竞争比为 1+alpha 的最好可能的在线算法,其中 alpha 是方程2alpha^{2}+(beta +1)alpha +beta -2=0的一个正根, 这里0leq beta <1.