中直机关大有庄100号专家住宅楼地下工程防水施工工艺

介绍了中直机关大有庄100号专家住宅楼地下工程采用钢筋混凝土结构自防水和外包双层"4+3"SBS改性沥青防水卷材的防水设计,对钢筋混凝土结构自防水和底板、外墙及其节点的防水施工工艺均进行了详细阐述.     

改性聚丙烯纤维混凝土氯离子扩散试验研究

聚丙烯纤维通过提高混凝土的早期抗裂能力增强了混凝土的抗渗性能。将掺入改性聚丙烯纤维的混凝土试件浸泡于3.5%NaCl溶液和青岛海域海水溶液中,测试混凝土不同深度的氯离子浓度,并计算不同腐蚀龄期混凝土的氯离子扩散系数,通过对比分析,研究掺入改性聚丙烯粗纤维或粗细混杂纤维后的混凝土的抗氯离子腐蚀性能。研究结果表明,掺加改性聚丙烯纤维能提高混凝土抗氯离子腐蚀性能,降低氯离子在混凝土中的扩散速率,且掺粗、细混杂纤维的效果要好于单掺纤维。     

基于改进欧拉法的反馈分析

借鉴重锤拉紧装置的实体模型,建立数学模型,并且进行简化,利用改进欧拉法对拉紧装置的反馈展开分析,确定弹性刚度和黏性阻尼系数后得出一系列数据,进而预测整个系统的动态趋势,为实际生产的可控性提供保证。     

一种临近空间高超声速目标航迹起始算法

提出一种三维空间中基于多普勒的改进修正霍夫变换快速航迹起始算法。利用传统航迹起始算法起始高超声速目标将导致目标容易丢失和虚假航迹增多,这不利于对高超声速目标的跟踪。文中提出的方法在三维空间中首先利用条件约束和多普勒信息辅助剔除部分虚假点,再利用修正霍夫变换法进行航迹起始。该算法不仅能有效起始航迹,而且极大地抑制虚假航迹。通过蒙特卡洛仿真实验表明,该算法能快速高效地起始航迹,是一种可行的临近空间高超声速目标的航迹起始算法。     

社交媒体中转基因食品的媒介框架研究——基于美国YouTube视频网站的案例分析

社交媒体在科学传播中扮演的角色日益重要,在促进争议科学题材的传播中发挥的作用尤为显著。本文以世界上最大的社交视频网站You Tube中的转基因食品短片为案例,从传播主体、媒介框架和传播技巧三方面来分析社交媒体的框架建构过程。研究发现,在You Tube网站上美国的各种社会组织抢占了绝对的话语主导权,媒体也有积极参与,而政府和科研机构基本处于失语状态。在媒介框架上,最多的一类是关于食品安全、经济和科技的话题,且大部分都具有负面属性。在塑造技巧上,最受欢迎的短片大部分具有刺激性标题、诉诸于情感和特定价值、制造矛盾吸引受众三个显著特点。     

植酸改性淀粉性质的研究

本文对植酸改性淀粉的糊性质进行研究，为其应用提供依据。用X-衍射、电镜、红外光谱等手段对植酸改性淀粉进行研究，表明用植酸钠对淀粉改性时，反应发生在颗粒的表面；脱水葡萄糖的C6伯醇羟基易与植酸钠反应；由淀粉碘复合物的可见光谱图推测支链淀粉最先起反应。     

Study of long-term skid and wear resistance of waterborne epoxy resin-SBR compound modified emulsified asphalt microsurfacing

As an eco-friendly technology for pavement preventive maintenance, microsurfacing (MS) has the potential properties of cost-saving and excellent performance benefits in repairing distress. MS also improves the surface function, especially skid resistance, of old pavements that have gradually decayed under the coupled effects of long-term environment and loads. Reasonable assessments of the long-term skid and wear resistance of the MS can provide support for accurate decision-making on preventive maintenance, which in turn reduces maintenance costs and saves maintenance costs, and ensures traffic safety. To evaluate the long-term skid and wear resistance of MS in different natural and traffic environments, this paper investigated the change of British pendulum number (BPN), rutting depth, and mass loss rate of waterborne epoxy resin-SBR compound emulsified asphalt micro-surfacing (WER-SBR MEAMS) under different environmental factors and traffic conditions based on the self-developed accelerated loading abrasion instrument. The factors considered in the experiment include temperature, rainfall, UV radiation, speed, and load. The results showed that temperature and vehicle speed had a detrimental effect on the durability of WER-SBR MEAMS, which was more pronounced after 10,000 wear loading cycles. Reducing immersion time and slowing down the aging rate can improve the durability of WER-SBR MEAMS. Further, the influence degrees of different factors on the skid and wear resistance of MS were evaluated using the gray correlation method. From the results of the gray correlation analysis, the correlation coefficients between external variables and BPN, rutting depth, and mass loss rate are all greater than 0.8, which indicate that all the variables involved have relatively obvious and regular effects on the skid and wear resistance of WER-SBR MEAMS.     

转基因食品的安全性评价

转基因食品的安全性一直受到各国政府、科学工作者及广大消费者的重视如何科学地评价该类食品的安全性,FAO/WHO等国际组织提出了一些政策性建议本文就转基因食品安全性评价的发展、评价原则、安全性要求、评价方法等作综述     

Modified Atmosphere and Modified Humidity Packaging of Fresh Mushrooms

Sorbitol and sodium chloride were used to modify the in-package relative humidity (IPRH) of fresh mushrooms (water irrigated and CaCl₂ irrigated) stored in a modified atmosphere package (MAP) at 12°C. No differences were observed for maturity index and microbial population between mushrooms stored in modified atmosphere package (MAP) with or without moisture absorbers. Lower IPRH was observed in packages containing water irrigated (normally grown) mushrooms with sodium chloride, but resulted in over-drying of mushrooms and did not improve color. Normally grown mushrooms with 10 and 15g sorbitol had the best color. IPRH of 87–90%, within 9 days storage was considered optimum. No improvements in quality were found with moisture absorbers with normally grown mushrooms. However, a small amount of sorbitol helped to avoid condensation with CaCl₂ irrigated mushrooms.     

改性铵油连续混合用双轴扇形叶片混合机

介绍了一种适用于改性铵油炸药连续化生产的双轴扇形叶片混合机，对该设备的结构特征、工作原理及使用安全措施进行了说明。认为该设备可用于硝酸铵改性、木粉干燥、物料的连续混合等工序，对发展工业炸药连续化自动化生产具有一定意义。