重物高空坠落撞击多层钢筋混凝土楼板的仿真计算分析

本文针对重物高空坠落高速撞击钢筋混凝土楼（屋）盖时的结构损伤分析，根据弹塑性靶板理论以及动能守恒定理提出了一种计算板及周边梁中内力的简化手算算法。计算结果和现场实测资料吻合，说明该算法可以用于实际工程。     

粗合成纤维增强混凝土的冲击动载特性

为了研究将掺量为6-13kg／m^3的粗合成纤维和掺量40-60kg／m^3的钢纤维掺入水泥混凝土后，对硬化混凝土动载特性的效用，试验研究了国产异型聚丙烯、日本Barchip、美国Forta粗合成纤维和钢纤维增强混凝土的抗弯冲击性能，探讨了纤维掺量对冲击动载特性的影响。研究表明：纤维掺量增加，纤维混凝土梁的初裂冲击次数先增加后减少，破坏冲击次数一直增加：粗合成纤维对混凝土冲击性能有显著的增韧效果，混凝土由脆性破坏变为有良好的延展性。     

Indoor air pollution and its impact on children under five years old in Bangladesh

Indoor air concentrations of volatile organic compounds (VOCs), carbon monoxide (CO), carbon dioxide (CO2), nitrogen dioxide (NO2), and dust particles were measured for 49 biomass and 46 fossil fuel users in urban slums of Dhaka, Bangladesh. The health impacts of these pollutants were assessed on 65 and 51 children under five years old from families who use biomass and fossil fuel as main source of energy, respectively. Mean concentrations of CO were found to be significantly higher in biomass fuel users (P = 0.010), while geometric mean concentrations of benzene, xylene, toluene, hexane, total VOCs, and NO2 were significantly higher (P < 0.01) in the fossil fuel users. Symptoms such as redness of eyes, itching of skin, nasal discharge, cough, shortness of breath, chest tightness, wheezing, or whistling chest were found to be associated with the choice of biomass fuel, with the odds ratio ranging from 4.0 to 6.3. No significant association of use of biomass fuel with respiratory diseases, eczema, diarrhea, or viral fever was observed after adjustment for potential confounders. These results suggest a significant association between the biomass fuel-using population and respiratory symptoms. These symptoms may not be due to the pollutants only, as some other underlying causes may be present. PRACTICAL IMPLICATIONS: The health of children under five years old in Bangladesh, especially those living in poor socioeconomic conditions, is considered to be worsening because of indoor air pollution. It is commonly suggested that biomass fuel should be replaced by fossil fuel, as pollution levels are believed to be higher with biomass fuel. Our findings, however, suggest that pollution can be higher with fossil fuels, and indicate that a switch in fuel from biomass to fossil does not necessarily improve the children's health. Awareness programs should therefore be undertaken to avoid the unnecessary use of gas. Clean fuels and clean stoves should also be ensured to reduce emissions of indoor air pollutants.     

公共机构既有建筑绿色改造技术适宜性研究

在对600家国家机关和学校两类典型公共机构既有建筑改造项目调研基础上,分析公共机构典型既有建筑绿色改造的不同需求和绿色特征及其与绿色建筑的差距,确定适宜技术筛选范围和原则,建立公共机构既有建筑绿色改造技术体系和技术适宜性分析方法,按照绿色改造通用技术和非通用技术进行适宜性分析,确定公共机构绿色改造技术适宜性清单及适宜性等级。研究结果适合于区域绿色改造技术规划、技术初步筛选,为公共机构选择绿色改造技术提供技术指引。     

PVC—U塑料门窗型材抗冲改性剂应用

通过对氯化聚乙烯（CPE）和聚丙烯酸酯（ACR）抗冲改性剂的性能及其抗冲机理的分析，对目前国内塑料门窗使用的抗冲改性剂提出了一些建议。     

岩石冲击破坏的数值流形方法模拟(英文)

岩石冲击破坏是一种典型的动力学问题。为了更好地利用数值流形方法对动力学问题进行分析,本文在对原数值流形方法中的动力学问题求解思想进行分析的基础上,采用动力有限元方法中的Newmark法对该算法进行了改进。改进后的数值流形方法与原来相比具有3个明显的优势:①当选择合适的参数后,该方法能够保证解的无条件收敛;②可以采用比原算法大的多的时间步长;③充分地考虑了动力学问题中的阻尼效应。最后通过一个算例说明了改进后的数值流形方法能够很好地模拟岩石在冲击载荷作用下破坏的全过程,克服了有限元法不能模拟岩石破坏后块体运动情况的不足。     

浅谈光纤偏振模色散对宽带光网络的影响

主要阐述了光纤偏振模色散PMD产生的机理、原因和测试方法,及光纤偏振模色散PMD指标对宽带光网络的影响和限制作用,光纤质量的好坏决定着宽带光网络PMD的好坏。     

聚丙烯纤维和丁苯乳液对水泥砂浆性能的影响

研究了掺量为0~0.3%(体积分数)的聚丙烯纤维,掺量为0~12%(质量分数)的丁苯乳液在单掺、复掺情况下对水泥砂浆3,28,90 d抗压、抗折强度,以及28 d龄期时磨损、冲击性能等的影响.研究结果表明,纤维的掺入大幅度提高了丁苯乳液砂浆的抗冲击和抗磨损性能,提高丁苯乳液砂浆抗磨损性能的最佳纤维掺量为0.1%;纤维掺量越大,对提高丁苯乳液砂浆的抗冲击性能越有利.丁苯乳液的掺入改善了聚丙烯纤维与基体之间的界面粘结,增强了掺纤维砂浆的长期力学性能.丁苯乳液、聚丙烯纤维的复掺效果优于这两者单掺的情况,复掺对水泥砂浆起到了双重改性的效果.     

冲击荷载作用下圆环的动态响应

本文用动光弹性方法研究冲击载荷下不同支承条件的圆环的动态响应；开口圆环模型内部应力波的传播、动应力分布；在圆环开口处镶嵌不同材料介质后，动应力分布状况的变化。文中还对内边界受冲击力作用的镶嵌圆环进行了实验研究。     

谈基础回填土的质量控制

介绍了回填土质量监控方法，提出了施工中常见问题，并针对性地阐述了解决办法，实践证明，此地既能保证回填土的施工质量，又可加快工程进度。