Common due date assignment scheduling for a no-wait flowshop with convex resource allocation and learning effect

This article addresses the no-wait flowshop scheduling problem with simultaneous consideration of common due date assignment, convex resource allocation and learning effect in a two machine setting. The processing time of each job can be controlled by its position in a sequence and also by allocating extra resource, which is a convex function of the amount of a common continuously divisible resource allocated to the job. The objective is to determine the optimal common due date, the resource allocation and the schedule of jobs such that the total earliness, tardiness and common due date cost (the total resource consumption cost) are minimized under the constraint condition that the total resource consumption cost (the total earliness, tardiness and common due date cost) is limited. Polynomial time algorithms are developed for two versions of the problem.     

再生细骨料质量标准及检验方法的研究

我国目前尚无再生细骨料的技术标准，制定再生细骨料的技术标准，对于推动再生混凝土产业化具有重要意义．再生细骨料的质量要求，除了JGJ52-92要求的细度模数、级配、泥块含量、有害物质含量（包括云母、轻物质、有机物、硫化物及硫酸盐、氯离子含量等）外，还应增加再生胶砂需水量比（简称需水量比）、再生胶砂强度比（简称强度比）和坚固性．胶砂需水量比和胶砂强度比是笔者首次提出的两项指标，它们很好地反映了再生细骨料与普通细骨料之间的性能差异．依据胶砂需水量比、胶砂强度比和坚固性指标，提出了对再生细骨料进行分类的建议．     

Metal-doped carbon aerogels as catalysts during ozonation processes in aqueous solutions

The efficiency of Co(II)-, Mn(II)-, and Ti(IV)-doped carbon aerogels for the transformation of ozone into (*)OH radicals was investigated. The carbon aerogels had a markedly acid surface character (pH(PZC approximately equal) congruent with 3-4) with very high surface oxygen concentrations (O approximately equal with 20%). X-ray photoelectron spectroscopy (XPS) analyses of the samples showed the oxidation state of the metals was +2 for Co and Mn and +4 for Ti. The presence of Mn(II)-doped carbon aerogel enhanced ozone transformation into (*)OH radicals, whereas the presence of Co(II) and Ti(IV) carbon aerogels presented no activity in this process. Moreover, it was observed that an increase in the concentration of Mn in the surface of the aerogel increases its efficiency to transform ozone into (*)OH radicals, with an Rct value ([OH]/[O(3)]) of 5.36 x 10(-8) for the aerogel doped with 16% of surface Mn(II) compared to an R(ct) of 2.68 x 10(-9) for conventional ozonation. Regardless of the aerogel used, XPS analysis of the ozonated aerogel samples showed an increase in the concentration of surface oxygen when the exposure to ozone was longer. However, presence of oxidized metal species after ozone treatment was only detected in the case of the Mn-doped aerogel, (Mn(III) and Mn(IV)). CO(2) activation of carbon aerogel produced a marked increase in its efficiency to transform ozone into (*)OH radicals compared with non-activated sample. The efficiency of Mn activated carbon aerogel to transform ozone into (*)OH radicals was greater than that of Witco commercial activated carbon or H(2)O(2) in the ozonation of water from Lake Zurich (Zurich, Switzerland).     

当前公路监理工作的几点思考

就当前我国公路监理行业的现状与监理队伍的现状,谈如何在当前的公路监理环境下提高监理人员的业务水平和做好监理工作,以有效推动监理行业的发展。     

预应力抗拔锚杆在体育馆工程中的应用

某体育馆工程地下室有严格的抗浮要求,管桩基础抗拔力承担不了地下水浮力与大斜柱的拉力,在传递拉力的大斜柱下部承台部位,设计了预应力抗拔锚杆。整个工程共设计160根,长度14.5cm～30cm,使工程达到抗浮要求。     

浅析我国房地产价格的影响因素

从土地价格上涨和建安成本上涨两方面对影响房地产价格的成本因素进行了分析,并从居民收入增长和流动性过剩两方面对其需求因素进行了探讨,最后针对我国房地产业的未来发展趋势提出了相关的建议,以加快建立和完善房地产市场,引导各类真实有效需求。     

Efficiency of activated carbon to transform ozone into *OH radicals: influence of operational parameters

Based on previous findings (Jans, U., Hoigné, J., 1998. Ozone Sci. Eng. 20, 67-87), the activity of activated carbon for the transformation of ozone into *OH radicals including the influence of operational parameters (carbon dose, ozone dose, carbon-type and carbon treatment time) was quantified. The ozone decomposition constant (k(D)) was increased by the presence of activated carbon in the system and depending on the type of activated carbon added, the ratio of the concentrations of *OH radicals and ozone, the R(ct) value ([*OH]/[O3]), was increased by a factor 3-5. The results obtained show that the surface chemical and textural characteristics of the activated carbon determines its activity for the transformation of ozone into *OH radicals. The most efficient carbons in this process are those with high basicity and large surface area. The obtained results show that the interaction between ozone and pyrrol groups present on the surface of activated carbon increase the concentration of O2*- radicals in the system, enhancing ozone transformation into *OH radicals. The activity of activated carbon decreases for extended ozone exposures. This may indicate that activated carbon does not really act as a catalyst but rather as a conventional initiator or promoter for the ozone transformation into *OH radicals. Ozonation of Lake Zurich water ([O3] = 1 mg/L) in presence of activated carbon (0.5 g/L) lead to an increase in the k(D) and R(ct) value by a factor of 10 and 39, respectively, thereby favouring the removal of ozone-resistant contaminants. Moreover, the presence of activated carbon during ozonation of Lake Zurich water led to a 40% reduction in the content of dissolved organic carbon during the first 60 min of treatment. The adsorption of low concentrations of dissolved organic matter (DOM) on activated carbon surfaces did not modify its capacity to initiate/promote ozone transformation into *OH radicals.     

《电镀与涂饰》杂志网店开业

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《电镀与涂饰》杂志网店开业

随着网络的飞速发展,应广大读者要求,《电镀与涂饰》杂志开通网店。读者通过网店购买杂志、图书、光盘、资料等,可享受邮费折扣、礼品赠送等优惠。欢迎广大读者访问购买。网店网址:http://www.plating.org/wsdy.htm。     

《电镀与涂饰》杂志网店开业

正随着网络的飞速发展,应广大读者要求,《电镀与涂饰》杂志开通网店。读者通过网店购买杂志、图书、光盘、资料等,可享受邮费折扣、礼品赠送等优惠。欢迎广大读者访问购买。网店网址:http://www.plating.org/wsdy.htm。