郑州西南绕城高速公路不同时期生态系统服务价值研究

根据黄土沟壑地带高速公路建设不同时期生态系统特征和生态服务功能的内涵,选择了水土保持、固定CO2、释放O2、滞尘、吸收有害气体、营养元素循环等指标,采用物质量和价值量相结合的评价方法,使用市场价值法、影子工程法、生产成本法、机会成本法研究了郑州西南绕城高速公路不同时期生态系统服务功能经济价值.结果表明: 研究区建设前农业生态系统服务功能价值平均每年为424.2万元,建设中期间为197.5万元,生态防护后为484.6万元.生态防护前后生态服务价值的差异极为显著,防护后生态服务价值超过原农业生态系统价值.     

白坭水道航道整治工程环境影响研究

白坭水道航道整治工程拟通过疏浚、炸礁等航道整治工程措施来达到航道建设目的。通过数值模拟计算的方法,对施工环节的环境影响进行预测。结果表明:在充分落实各项环境保护对策与措施的前提下,整治工程疏浚、炸礁产生的水体中悬浮物浓度增加对白坭水道沿线水厂取水口取水安全不会产生不利影响,对水道沿线鱼类洄游通道、产卵场等生态环境影响可以接受。     

加工精密支架类零件的数控工艺创新

数控机床是现代化制造技术的重要工具,本文以某型号产品精密支架类零件的数控加工关键工艺为例,从加工工序、工装、刀具、坐标系建立等研究方向入手,对基于数控机床加工精密支架类零件的数控工艺设计进行了初步探讨。     

质量缺陷的避免和处理措施

根据施工现场的具体情况，从施工方案，加强试验和控制施工关键部位等方面提出了避免质量缺陷及发生质量缺陷后的处理方法。     

通用信息系统开发平台研究

给出了一种通用信息系统开发平台（CISDS）的设计思想和实现方式，采用集成化开发思想对信息系统进行抽象描述和概括分析，并对通用信息系统核心数据库的结构及数据字典进行了描述，重点讨论了其使用自动化软件开发技术和软件重用技术的工作方式，阐述了各功能模块及其实现方式。     

Multimode trip information detection using personal trajectory data

Handheld global positioning system (GPS) devices can serve as a new tool to collect an individual's trip information with advantages of low cost, accurate data, and intensive spatial coverage. Various machine learning algorithms have been explored to detected trip train information in previous studies; however, few of them focused on the evaluation and comparison of the performance and applicability of different models. Meanwhile, according to previous studies, car and bus mode detection is a thorny issue due to their similar travel characteristics, and algorithms still need to be well explored and improved to solve this problem. In this article, an innovative method is proposed to detect trip information, including trip modes, mode-changing time and location, and other attributes, from personal trajectory data. The method is a two-step process. A machine learning algorith-based module (including artificial neural network, support vector machine, random forests, and Bayesian network) is firstly used to identify walk, bicycle, and motorized trip modes (bus or car); we thoroughly compared the performance of these four algorithms. Then a second module, using critical points on the GPS trajectories, is further developed to distinguish car and bus mode, incorporated with GIS map information. Field test results show that the proposed machine learning models can all be applied for walk, bicycle, and motorized mode detection with high detection rates exceeding 90%; however, the algorithms work relatively poorly for bus and car mode detection, with results mostly below 75%. The proposed two-step method can greatly improve bus and car mode detection accuracy by 14–30%. As a result, the average mode detection rates for all the four modes are above 90%. Compared with mode detection results by using only the machine learning algorithm, the proposed two-step method has much better performance in both accuracy and consistency.     

双馈变频供电的电力推进系统研究

文章提出了一种由双馈发电机提供变频电源,驱动变频电机的电力推进系统。该系统通过对双馈发电机转子励磁,产生变压变频电源驱动电机调速运行。由于双馈发电机转子侧只需提供转差功率,使得变频器的容量较小,可以在一定程度上缓解电力推进对变频器容量需求较高的问题。文章给出了电力推进系统的结构框架,建立了系统的数学模型,并根据所建立的数学模型,利用MATLAB对其进行了仿真分析,验证了此电力推进系统变频调速的可行性。     

地震作用下松散斜坡崩塌拟静力离心模型试验

根据拟静力法思想,通过改变沙堆模型底坡不同角度值的方式来模拟不同地震烈度大小对斜坡崩塌的影响。对试验技术进行分析表明,改变不同的沙堆模型底坡角度值会引起不同的水平峰值加速度,从而模拟不同地震烈度大小对松散体斜坡崩塌的影响。     

冷再生柔性基层试验路的技术研究

介绍了冷再生做为柔性基层在营大线的实施情况,就原路面的路况调查、室内试验研究、试验路方案的确定及试验路的完成情况做了全面的阐述。     

209HS型转向架下旁承蠕变现象分析

对提速客车209HS型转向架超高分子量聚乙烯下旁承蠕变问题进行了分析,提出了选用改性聚酰胺材料作为下旁承磨耗板材料的方案,并对下旁承结构进行了调整,经装车试用,磨耗板状态良好,解决了209HS型转向架原超高分子量聚乙烯下旁承蠕变问题。