甲烷磺酸电镀Sn-Pb合金添加剂研究

介绍了国内外磺酸型Sn-Pb合金电镀添加剂近十年的研究历程现况并根据各组分的化学结构及其在电镀中所体现出的性质将添加剂分为Sn^2 离子稳定剂、光亮剂及分散剂三类。最后列出了新研制的甲烷磺酸Sn-Pb合金电镀添加剂的主要性能及具体工艺配方。     

基于Pro／E的VERICUT虚拟机床模型开发

虚拟机床建模是VERICUT中数控加工仿真的基础,以一个带升降台的3轴立式铣床为例,介绍VERICUT中虚拟机床模型在Pro／E系统中的创建、装配及输出过程,借以探讨二者的结合应用．该方法具有良好的通用性,可作为其它机床建模的参考．     

黄骅坳陷白水头断裂系统生长模式及其成因分析

在系统分析白水头断裂系统的断层组合、构造样式、主干断层及次级断层生长模式的基础之上,结合区域构造背景、伸展边界条件及断层间的相互作用,探讨了该断裂系统的形成机制.分析结果表明,区域构造背景下存在的伸展边界控制了整个白水头断裂系统总的构造格局.进一步证实了区内右旋走滑作用与伸展作用的相互耦合,致使次级断层沿走滑构造带出现转向或中断.断裂系统及系统内部断层间的运动学关系表明白水头断裂系统在古近纪是受两个构造动力控制,其一是地幔热作用引起岩石圈北西-南东向引张作用,其二是北北东向深断裂带的右旋剪切作用.     

基于网络消费者购买过程的网络营销策略分析

网络消费者是新的消费群体,与传统市场消费群体有着截然不同的特性。企业要想卓有成效地开展网络营销活动,获得来自虚拟世界的利益,就必须了解、分析和把握住网络消费者的消费过程,尽可能地为营销活动提供可靠的数据分析和营销依据。本文从网络消费者购买行为形成和实现的过程入手,对网络消费者购买过程的环节进行策略分析。     

大学生树立理性婚恋观的几点思考

于2005年9月1日正式实施的《普通高等学校学生管理规定》对于在校大学生能否结婚给出了明确、肯定的答案。详尽分析了在校大学生不宜结婚的主客观原因,提出应大力开展“爱情教育”和营造良好精神氛围以帮助大学生树立理性婚恋观。     

物探方法在隧道勘查中的应用探讨

通过对若干隧道的物探勘查表明,合理的运用高密度电法、地震折射波法和瞬态瑞雷波法以及声波测井法,可以有效的查明隧址区第四系覆盖层厚度、基岩垂向分带情况,推定断裂等构造破碎带的位置和产状,计算岩体波速、划分围岩级别,为隧址区的工程评价和隧址的合理选择提供科学依据。指出目前折射波法勘探存在的局限性,强调综合物探的合理性。提出采用高密度电阻率法、声波测井法和瞬态瑞雷波法的综合勘查方法进行隧道工程物探勘查,期望能为今后的隧道物探勘查提供指导。     

胶粉改性聚苯乙烯材料的制备与性能

以聚苯乙烯(PS)为基体材料,制备废旧胶粉(WRP)改性聚苯乙烯材料;并探讨了胶粉增韧剂SBS和偶联剂用量对胶粉改性聚苯乙烯材料的综合物理性能的影响.     

Key techniques for predicting the uncertain trajectories of moving objects with dynamic environment awareness

Railway Engineering Science - Emerging technologies of wireless and mobile communication enable people to accumulate a large volume of time-stamped locations, which appear in the form of a...     

利用水厂生产废水促进UASB工艺处理低温城市污水启动

为缩短UASB工艺处理低温城市污水的启动周期,开展在原水中添加水厂生产废水强化UASB系统污泥颗粒化可行性研究,并以常规启动方式做为比较,对启动过程中系统运行特性和形成的颗粒污泥特性进行探讨。试验结果表明,在水温为15℃,初始有机负荷为0.25kgCOD/（m3.d）的条件下,采用逐步提高负荷的传统启动方式和添加生产废水的强化启动方式都能实现UASB工艺的低温启动,相应的启动周期分别为120d和95d左右。在整个启动过程中,添加生产废水启动方式对有机负荷提高适应性较强,达到4kgCOD/（m3.d）时较常规方式缩短30d,而且具有较高的COD去除效率和微生物增长速率（分别为0.029g VSS/d和0.043g VSS/d）。与常规启动方式相比,强化启动方式颗粒粒径较大,在第95d内可形成2mm粒径颗粒污泥。采用添加生产废水的启动方式能够缩短UASB工艺的启动周期并强化污泥颗粒化,提高低温城市污水的处理效率和运行稳定性。     

Graft copolymerization studies. III. Methyl methacrylate onto polypropylene and polyethylene terephthalate

The tert‐butoxy radical‐facilitated grafting of methyl methacrylate (MMA) onto commercial polypropylene (PP) pellets and fiber was investigated in heterogeneous conditions similar to practical systems. Free‐radical grafting of several other monomers onto PP fiber was also investigated. Also, preliminary data from the grafting of MMA onto poly(ethylene terephthalate) pellets is presented. The PP‐graft‐PMMA residues were detected by solid‐state ¹³C‐NMR and photoacoustic IR spectroscopy. There was a good correlation between the degree of grafting (DG) determined from these spectroscopic techniques and the results from gravimetric methods. A maximum grafting efficiency of over 50% was found, whereas DG (20%) remained constant at various PP pellet, initiator, and monomer concentrations. However, at relatively low PP fiber concentrations, the DG was 27%; the increase was most likely due to the greater surface area of the fiber. There was also a reduction in DG (14%) at relatively low initiator concentrations. The reaction conditions were altered to favor grafting by the addition of more polymer substrate. When the ratio of tert‐butoxy radicals to PP was decreased, more of the substrate remained unmodified, and empirical calculations showed the formation of grafts with up to 40 monomer units. At high initiator concentrations, calculations showed that the graft residues were 1–2 units long. Therefore, variation of the polymer, initiator, and monomer concentrations was shown to have a significant effect on grafting. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 898–915, 2002