Effect of chain architecture on the compression behavior of nanoscale polyethylene particles

Polymeric particles with controlled internal molecular architectures play an important role as constituents in many composite materials for a number of emerging applications. In this study, classical molecular dynamics techniques are employed to predict the effect of chain architecture on the compression behavior of nanoscale polyethylene particles subjected to simulated flat-punch testing. Cross-linked, branched, and linear polyethylene chain architectures are each studied in the simulations. Results indicate that chain architecture has a significant influence on the mechanical properties of polyethylene nanoparticles, with the network configuration exhibiting higher compressive strengths than the branched and linear architectures. These findings are verified with simulations of bulk polyethylene. The compressive stress versus strain profiles of particles show four distinct regimes, differing with that of experimental micron-sized particles. The results of this study indicate that the mechanical response of polyethylene nanoparticles can be custom-tailored for specific applications by changing the molecular architecture.     

面向应用加速的两阶段数据压缩流程

在应用加速技术中,为进一步提高数据压缩率和网络传输性能,提出基于低粒度自适应的两阶段数据压缩流程。该流程基于Zipf和Heaps分布定律和字节粒度,首先检测传输数据是否属已发送内容,若是,则先对传输数据进行减缩,然后根据适应性压缩策略作进一步压缩。实验结果表明,两阶段的数据压缩流程可以有效地减小传输数据量,从而为保障企业关键业务流高速地通过广域网传输提供一种解决方案。     

大孔洞率混凝土多孔砖砌体抗压性能试验研究

以某实际工程为背景,介绍了大孔洞率混凝土多孔砖砌体的抗压试验,为结构设计计算提供技术依据.     

Effect of micronisation and electromagnetic radiation on physical and mechanical properties of Canadian barley

The effect of micronisation (high‐intensity infrared heating) and microwave radiation of normal barley (NB), high‐amylose barley (HAB) and waxy barley (WB) on the physical and mechanical properties was studied. Samples were tempered to 42–45% moisture content and then subjected to infrared or microwave radiation to reduce the moisture content to approximately 10%. The grain surface temperature during radiation was maintained at 100 °C. The changes in physical and mechanical properties were compared with unprocessed samples. Thermal radiation increased slightly the volume of the kernels because of the diffusion of water vapour from inside to the outer surface. These changes resulted in a decrease in particle and bulk densities. Thermal radiation affected the Hunter colour values, as well. The mechanical properties including bio‐yield point, modulus of elasticity and breakage susceptibility were affected by micronisation and microwave heating.     

数字化电视设备浅析

由于各电视台现有设备及经济状况各不相同,向数字化过渡的途径又有多种,针对部分数字化电视设备,对数字接口、数据压缩标准、节目的采集和编辑等几个方面作一些探讨。     

软煤岩巷道受压破坏及维修支护的应用研究

针对大雁二矿的生产实际,阐述了褐煤软煤岩巷道受压破坏的基本规律,探讨了控制褐煤软煤岩巷道受压破坏、减少翻修量及维修支护的基本途径,论述了喷砼的作用原理,通过试验分析了可行性,提出了施工方法和要求,得出了肯定性的结论。     

镇安隧道千枚岩变形特征及施工方法

简要分析了千枚岩地质变形特征，介绍了千枚岩隧道现场监控量测方法，并对量测结果进行了分析，在此基础上选取科学合理的施工方法，从而有效地控制围岩大变形的发生。     

Deceived and distorted: Game outcome retrospectively determines the reported time of action.

Previous work suggested the association between intentionality and the reported time of action was exclusive, with intentionality as the primary facilitator to the mental time compression between the reported time of action and its effect (Haggard, Clark, & Kalogeras, 2002). In three experiments, we examined whether mental time compression could also be observed in an unintended action. Participants performed an externally cued key press task that elicited one of two possible tones. The reported time of action shifted closer to the tone when the tone was used to indicate the winner of a race (Exp.2) compared to when the tone was meaningless and did not indicate winning (Exp.1). This suggests that reported time of an unintended action could shift toward the effect in some contexts. Furthermore, the results from Exp.2 and Exp.3 (tones were substituted with verbal feedback) showed that a presumed winning action was judged to occur earlier whereas a presumed losing action was judged to be later. These findings therefore support the view that the reported time of action is reconstructed from known temporal information rather than determined by intentionality. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

山西体育中心自行车馆静压桩施工质量控制

以山西体育中心自行车馆地基处理工程为例，结合自身工作实践，详细介绍了静压桩施工流程和施工工艺，并分别阐述了各工序施工过程中的质量控制措施及注意事项，总结了静压管桩的优点，以促进其推广。     

焦炭抗压强度简便检验方法研究

关于焦炭成分的组成,对焦炭抗压强度的影响因素进行了系统性的理论分析,得到焦炭在高炉冶炼过程中的高温抗压强度受温度和失碳率的双重影响。同时试验验证了这一分析结果,并且进一步研究得到检验焦炭高温抗压强度的简便计算方法。