Study on phase behavior–impact strength relationship of unsaturated polyester/polyurethane hybrid polymer network

The phase behavior of a hybrid polymer network (HPN) composed of poly[(propylene glycol maleate)-co-(propylene glycol phthalate)] crosslinked with styrene and polyester–urethane crosslinked with methylene-bis-ortho-chloroaniline was examined. The correlation between phase separation and impact strength of the HPNs is discussed. The composition of HPNs has an effect on their properties.     

一种制做三维牙——颌骨光弹性模型的新方法

本文提出一种用“整体浇注法”制做三维牙——颌骨光弹性模型的新方法,即用价格便宜的石膏做阴模,先制出与真实牙几何相似的牙光弹性模型和模拟牙周膜的乳胶套,将它们粘接好,然后将其放入颌骨石膏阴模的适当位置,浇入环氧树脂混合液,用“二次固化法”进行固化,即可制成三维牙——颌骨整体光弹性模型。此法能保证模型与实物的严格几何相似和牙周的边界条件相似,使实验精度大大提高且工艺简单、成本低。     

锻压机械打击力测量误差的加速度补偿

提出了锻压机械打击力测量中存在的问题，介绍了常用的补偿法，并通过实验验证了加速度补偿法是消除锻压机械打击力测量误差的有效途径。     

十二烷基苯磺酸钠水溶液聚集性质的研究

用滴体积法测出十二烷基苯磺酸钠（ＳＤＢＳ）稀水溶液的表面张力；然后求出其临界胶束浓度（ＣＭＣ）。同时通过溶液的电导率、吸收光谱以及荧光光谱测定求出其ＣＭＣ。这样测出的ＣＭＣ值为１．２～１．６×１０－３ｍｏｌ／Ｌ，与文献值相符。也研究了部分水解的聚丙烯酰胺（ＰＨＰＡＭ）对ＳＤＢＳ聚集性质的影响；发现ＳＤＢＳ的ＣＭＣ值随ＰＨＰＡＭ的加人而减少并且ＰＨＰＡＭ水溶液的粘度随ＳＤＢＳ的存在而急剧降低（类似盐效应）。这些方法与性质对强化采油（ＥＯＲ）是重要的。     

Nanocrystalline CeO2 in SBA-15: Performance of Pt/CeO2/SBA-15 Catalyst for Water-gas-shift Reaction

CeO₂ particles confined within the pores of an SBA-15 mesoporous silica host were prepared by incipient wetness impregnation (IMP) and deposition precipitation (DP) methods. The materials were characterized by XRD, N₂-adsorption and temperature programmed reduction (TPR) to evaluate the structure, texture, and redox properties. The preparation procedure had significant impact on the assembling mode of CeO₂ inside the SBA-15 mesopores. A high dispersion of CeO₂ particles was achieved via DP, whereas the dispersion of CeO₂ prepared by IMP was found to be inhomogeneous and CeO₂ partially blocked the pores. The CO conversion in the water-gas-shift reaction was enhanced over 1 wt% Pt supported on CeO₂-modified SBA-15 obtained by DP.     

顶部定常吸气对高层建筑模型气动力的影响

为减少高层建筑受到的风荷载,提高高层建筑抗风性能,提出一种顶部吸气的主动控制方法。在一高宽比为H/d=5的正方形截面柱体的高层建筑模型上,通过在其顶部前边缘开设狭缝进行吸气来实现流动控制。通过风洞试验研究了顶部吸气对气动力与顶部分离流的影响.利用流动可视化与流场测试结果揭示了顶部狭缝吸气的控制机理.实验对比了不同吸气系数Q(=U/U_∞,U为狭缝吸气速度)对气动力控制效果的影响,并对Q=0,1和3的三种工况下风压分布与顶部剪切流进行了详细对比.研究发现狭缝吸气改变了顶部分离流特性,并对模型所有高度上的气动力均有显著影响.Q=1时控制效果最佳,脉动阻力与脉动升力分别减小17.8%和45.5%.此时顶面分离流被削弱并伴随有再附现象且湍流强度较大,最有利于顶部剪切流与尾流间的动量交换,从而削弱柱体展向涡脱落与脉动气动力.     

A Stochastic Vehicle Routing Problem with Travel Time Uncertainty: Trade-Off Between Cost and Customer Service

On-time shipment delivery is critical for just-in-time production and quick response logistics. Due to uncertainties in travel and service times, on-time arrival probability of vehicles at customer locations can not be ensured. Therefore, on-time shipment delivery is a challenging job for carriers in congested road networks. In this paper, such on-time shipment delivery problems are formulated as a stochastic vehicle routing problem with soft time windows under travel and service time uncertainties. A new stochastic programming model is proposed to minimize carrier’s total cost, while guaranteeing a minimum on-time arrival probability at each customer location. The aim of this model is to find a good trade-off between carrier’s total cost and customer service level. To solve the proposed model, an iterated tabu search heuristic algorithm was developed, incorporating a route reduction mechanism. A discrete approximation method is proposed for generating arrival time distributions of vehicles in the presence of time windows. Several numerical examples were conducted to demonstrate the applicability of the proposed model and solution algorithm.     

网络攻击的防范策略

近年来计算机网络受到攻击及瘫痪的现象频频发生,给企业和社会造成极大的经济损失,在社会上影响极坏。因此,除了传统的预防方法之外,为改变这种被动受攻击的局面,本文对网络攻击的防范策略进行了探讨。     

An improved Henry gas solubility optimization for optimization tasks

Applied Intelligence - The henry gas solubility optimization (HGSO) is a new nature-inspired algorithm that mimics Henry Gas Solubility to solve global optimization problems. The main changes of...