高渗透乳化沥青技术的实践与认识

对国内应用高渗透乳化沥青技术进行简单分析,介绍了RPS-2型高渗透性乳化沥青的开发与应用,提出国内应用高渗透乳化沥青技术存在的一些值得探讨的问题.     

远红外定向加热器导电涂层的研制

从四个方面研究了远红外定向加热器的导电涂层，使加热器的节约能源、提高热效率方面获得了显著效果。     

浅谈津汕高速公路下封层施工

结合津汕高速下封层施工，对单层式层铺法沥青表面处治方法施．T_-X-艺进行了研究，介绍了智能型沥青撒布设备、石屑撒布设备使用情况，对同类道路工程具有一定指导意义。     

Effect of seed coat fragments on cotton yarn structure: impact of fragment size,attached fibres and position within yarn core

Seed coat fragments are a major source of cotton yarn imperfections. This article discusses the factors influencing the disruption caused by seed coat fragments in ring-spun yarn structure with a focus on three characteristics: the fragment's size, the amount of fibres attached to it and its position relative to the yarn core. The three characteristics were investigated through two experiments involving various types of yarn defects and a range of ring-spun yarn counts. Results presented in this article indicate that the three factors considered have a significant influence on the intensity of the disruption the seed coat fragment causes in the yarn structure, and are determinant of the type of defect that this disruption engenders (short/long defect).     

螺旋轴喷焊修复工艺和材料的研究

在造纸亚铵连蒸设备螺旋轴表面喷焊一层耐磨涂层,可使螺旋轴寿命提高10倍以上。本文研究了这种耐磨涂层的组成、喷焊工艺及其耐磨机理。     

浅谈粘结永磁材料

介绍了粘结永磁体的趋势和现状,着重讨论了其应用领域以及未来前景,阐明了粘结永磁材料以其特有的性能,将成为新一代永磁材料。     

Roasting effects on the distribution of tocopherols and phospholipids within each structural part and section of soybeans

To clarify the effects of microwave roasting on the distribution of tocopherols and FA of phospholipids within soybeans, whole soybeans (Glycine max) were treated by microwave and further evaluted as compared to a raw sample. Tocopherol homologs, measured using HPLC, and phospholipid profiles, quantified with GC, were determined in the seed coat, the embryonic axis, and selections of cotyledons separated from three cultivars. The tocopherols were predominantly detected in the axis, followed by the cotyledons, and then very little in the coat. As much as 25% of the individual tocopherols originally present in the coat were lost at 12 min of roasting, whereas <25% was lost in the cotyledons and the axis after 20 min of roasting. The greatest rate of phospholipid loss (P<0.05) was observed in PE, followed by PC and PI, and their changing patterns were more pronounced in the coat than in the cotyledons or the axis. Thus, tocopherol content and phospholipid profiles change with microwave roasting according to tissue.     

Managing value-at-risk for a bond using bond put options

This paper studies a strategy that minimizes the Value-at-Risk (VaR) of a position in a zero-coupon bond by buying a percentage of a put option, subject to a fixed budget available for hedging. We elaborate a formula for determining the optimal strike price for this put option in case of a Vasicek stochastic interest rate model. We demonstrate the relevance of searching the optimal strike price, since moving away from the optimum implies a loss, either due to an increased VaR or due to an increased hedging expenditure. In this way, we extend the results of [Ahn, Boudoukh, Richardson, and Whitelaw (1999). Journal of Finance, 54, 359–375] who minimize VaR for a position in a share. In addition, we look at the alternative risk measure Tail Value-at-Risk.     

Concrete Cracking in Tension Members and Application to Deck Slabs of Bridges

Currently, estimations of the crack width in the deck slab of bridges given by codes of practice are based on either theoretical or empirical approaches considering mainly the monotonic loading behavior. However, cracking in reinforced tensile members is highly influenced by the loading history (including both the loading and unloading processes) because of the irreversible nonlinear behavior of bond and of tensile response of concrete, resulting into residual cracks of non-negligible width. This paper investigates the influence of this phenomenon and presents a physical model describing it. An analytical model is developed and its results are compared to various tests with good agreement. Finally, a simple design formula is derived and recommendations for its application to practical cases are proposed.     

Nd2Fe14B/α-Fe纳米复合永磁的制备和性能

用超声化学法制备纳米Fe颗粒包覆的Nd2Fe14B复合粉体,将其在Ar气保护下经放电等离子烧结(SPS),得到Nd2Fe14B/α-Fe纳米晶复合磁体.Fe名义质量分数为5%的烧结磁体具有较高的磁性能:Br=0.86 T,Hci=683.8 kA/m,(BH)max=95.92 kJ/m3.烧结前对复合粉末进行适当的高能球磨,能促进显微组织进一步细化,增强软磁相与硬磁相之间的交换耦合,使相同Fe含量和烧结工艺的磁体Br和(BH)max分别提高到0.94 T和113.6 kJ/m3.