反渗透抗污染膜在污水回用上的工艺研究

利用城市污水处理厂达标排放水为源水,经过生化塔-两级过滤-反渗透系统处理后,产水水质达到了电厂循环冷却水的水质标准,成功的取代了自来水.VONTRON公司的抗污染反渗透膜FR11-8040在系统中经过两年的运行表现出很好的稳定性,系统的回收率总体保持在70%左右,系统脱盐率在99%左右.     

上市公司财务预警的正则化逻辑回归模型

基于统计学习理论的正则化技术构建L1(一范数约束惩罚)正则化的逻辑回归(Logistic Regression)模型,同比建立了logistic回归模型和L2(二范数约束惩罚)正则化的logistic回归模型,结合沪深股市ST公司和正常公司的T-3年和T-2年财务数据进行仿真实验用于上市公司财务预警实证分析.实验结果表...     

����L�ռ�Ľ��ij��п��ٹ������������о�

城市快速公交网络性质研究对其规划建设、运营管理具有重要意义.本文将复杂网络理论研究领域由传统的轨道交通扩展到整个城市快速公交,并针对L空间度值物理意义模糊、路径选择实际意义匮乏等缺陷,提出了新型S空间模型构建方法.以常州BRT系统为例,采用新型建模方法,用计算度值、聚类系数、路径长度等特征指标分析了城市快速公交网络整体性能.继而采用效益费用比指标,比较其各支线优化方案效用,为资源限制条件下支线优化方案的选择提供建议;最后通过比较城市快速公交骨架网络及常规公交衔接下的快速公交网络的鲁棒性,验证了城市快速公交与常规公交一体化衔接规划的重要性.     

2 500 TEU集装箱船的总体设计

随着人们对环境保护的日益重视,越来越多的法规对船舶设计提出更高的环保要求.通过2 500 TEU集装箱船的总体设计,对装载和破舱稳性等总体性能等进行了设计计算,使该船布置合理紧凑,各项指标达到国际先进水平.但燃油舱划分和分布要满足有关新规划,还需作适当调整.     

Operator changes through competitive tendering: Empirical evidence from German local bus transport

In this paper, we empirically investigate operator changes and the structural conditions in competitive tendering of bus services in Germany. We show that the focus has been on regional services, which has led to a loss in market share for the incumbent DB Stadtverkehr companies and gains for private companies, whereas municipal services have rarely been tendered out. The high average number of bidders (5.1) and the high probability of an operator change (58.2%) are positively influenced by tendering in larger volumes and longer contractual lengths. Tenders in early years have been more likely subject to an operator change. By contrast, complexity drivers such as the number of lines and mixed urban and regional transports exhibit a negative influence on competition.     

UR-S11A对大型集装箱船结构设计的影响研究

国际船级社协会针对集装箱船的新标准UR-S11A已于2016年7月1日正式生效,其对大型集装箱船结构设计的具体影响值得研究。以一艘13 500 TEU集装箱船为例,首先分析了UR-S11A相比UR-S11和劳氏船级社(LR)规范在强度校核上的差异,然后通过对总纵屈服强度、屈曲强度和极限强度的研究分析了新标准对船体结构的影响。结果表明,UR-S11A对在0.3~0.4船长处船体梁的总纵弯曲和极限强度的要求更高,部分纵舱壁板与外板的剪切和屈曲强度以及双层底桁材纵骨的屈曲强度受新规范影响较大。     

女性外阴病变及其与HPV16/18、HPV6的相关性

目的研究外阴病变及其与HPV16/18、HPV6的关系。方法收集西安交通大学医学院第二附属医院手术治疗的44例女性外阴病变患者的临床病理资料,包括鳞癌11例,鳞状上皮内瘤变(VIN)10例,尖锐湿疣9例及白色病变14例。采用免疫组化SP方法检测HPV16/18E6蛋白、HPV6L1蛋白的表达。结果①4组外阴病变患者年龄中位数依次为:外阴鳞癌61岁、VIN 45.5岁、尖锐湿疣24岁、外阴白色病44岁,尖锐湿疣组中位年龄低于外阴鳞癌组及白色病变组(P<0.05),其余各组间中位年龄无统计学差异。②HPV16/18E6蛋白在外阴白色病变组、尖锐湿疣组、VIN组及外阴鳞癌组的阳性率分别为2/14、3/9、3/10、8/11,外阴鳞癌组高于白色病变组(P<0.05),其余各组间无统计学差异;HPV6L1蛋白在外阴白色病变组、尖锐湿疣组、VIN组、外阴鳞癌组的阳性率分别为1/14、8/9、4/10、3/11,尖锐湿疣组高于其他各外阴病变组(P<0.05),其余各组间比较差异无统计学意义。③HPV16/18E6蛋白、HPV6L1蛋白在早期外阴鳞癌的阳性率均高于中晚期(P<0.05);HPV16/18E6蛋白、HPV6L1蛋白表达均与外阴鳞癌的组织学分级、年龄分组、绝经情况、产次不相关(P>0.05);HPV16/18E6蛋白与HPV6L1蛋白在外阴鳞癌中的表达不相关(P>0.05)。结论外阴病变的发病与年龄及HPV16/18、HPV6感染有关;外阴鳞癌中HPV16/18、HPV6的感染率与FIGO分期有关,HPV16/18感染率与HPV6的感染率无关。     

基于车致桥梁响应和L1正则化的损伤识别研究

桥梁损伤识别是典型的反问题,通常需采用正则化手段求解.基于L1正则化的损伤识别方法能很好地利用损伤所具有的稀疏性,在桥梁监测领域得到了广泛的应用.此类方法通常利用频率和振型的变化作为判断损伤的依据,然而实际测试中可获得的频率阶数有限、振型测试精度低,严重影响其效果.采用移动荷载激励下的桥梁动力响应,提出一种基于有限元模...     

Cruise activity and pollution: The case of Barcelona

One of the main causes of mortality worldwide is air pollution. To tackle this problem, local, regional and national governments have implemented policies to reduce emissions from industrial and on-road sources. However, when these policies are being designed, shipping emissions are often overlooked. There has been a drastic increase in the demand for cruises and its economic relevance is also growing in port-cities. Barcelona is Europe’s leading cruise port, and it is located near the centre of the city. In this context, this paper analyses the impact of cruise ships in the air quality of the entire city of Barcelona using a dataset with information about pollutants and the number of cruises arriving to the port. We show that there is a direct impact between cruises staying at the port and city pollution. Additionally, the size and age of the cruise also affect air quality. The larger (or newer) the cruise is, the higher the emission generated. Moreover, our simulations show that the whole city is affected by these emissions.     

Does the increase of public transit fares deteriorate air quality in Beijing?

Since 2006, Beijing lowered its public transit fares as a way to improve air quality. However, Beijing increased public transportation fare prices from December 28, 2014, and commuters pay for the distance they traveled rather than a flat fare. This paper explores the effect of Beijing public transit fares increase on air quality. We collect daily data of air pollution and weather variables and use synthetic control method of Abadie and Gardeazabal (2003) to select control units. We then estimate a difference-in-differences model and assess the effect of the policy on air quality index (AQI). We find a 16.28% increase in air pollution in short run. However, we find no longer-run effect on air quality.