TM1型机车齿轮箱铸件工艺特点分析

通过对TM1型机车转向架齿轮箱铸件结构及其特性的分析,确定了齿轮箱铸造生产过程中,从材料选择到造型、熔炼、浇注等工序的一系列铸造工艺参数,达到成功生产出口铸件的质量要求。     

病毒性肝炎患者血浆前列腺素和血栓素的检测

本文对我院1988年～1990年100例各型病毒性肝炎患者以放免法检测血浆6-keto-PGF_(10)和TXB_2。其结果显示血浆中PGF_(10)、TXB_2在肝炎患者中均升高,PGF_(10)/TXB_2比值降低,与正常人有明显差异。对两者变化原因与黄疸并发症的相关性进行了分析。并提出两者在肝炎的发病机理中的作用。     

发展中的滴状冷凝强化换热研究

根据"八*五"、"九*五"滴状冷凝课题研究情况,介绍BFe30-1-1管表面实现滴状冷凝换热的工艺及其换热试验结果,并简介BFe30-1-1管表面滴状冷凝换热实现机理.     

电力电子器件在电动汽车上的应用与选择准则

电力电子器件的特性对电动汽车的性能有很大的影响,分析了电动汽车电气驱动系统对电力电子器件的要求,给出了不同器件的比较结果,介绍了器件选择的准则。     

高血压盐敏感者血管性血友病因子与尿内皮素-1及动态血压的关系

目的　探讨盐敏感性高血压患者血浆血管性血友病因子 (vWF)水平与尿内皮素 1(ET 1 )及动态血压的关系。方法　 32例原发性高血压患者和 2 1例血压正常自愿者用急性静脉盐水负荷试验确定盐敏感者 ,并检测血浆vWF水平、尿ET 1排泄量、尿钠排泄量及血压。结果　盐敏感性高血压患者血浆vWF水平显著高于盐不敏感者 ,盐水负荷后 4h盐敏感性高血压患者血浆vWF水平较盐负荷前显著增加 ,尿ET 1排泄量在盐敏感性高血压患者显著低于盐不敏感者 (P <0 .0 1 )。盐敏感性高血压患者盐负荷后尿钠排泄明显减少 ,血浆vWF与尿ET 1呈负相关 ,与动态血压水平呈正相关。结论　盐敏感性高血压患者存在明显内皮功能障碍 ,并与尿ET 1排泄减少及较高血压水平有关。     

纤溶酶原激活物抑制物1与神经母细胞瘤

目的　研究纤溶酶原激活物抑制物 1 (PAI 1 )在神经母细胞瘤中的表达情况 ,评估其在肿瘤浸润转移中的作用。方法　应用免疫组化ABC法检测 42例神经母细胞瘤中PAI 1的表达 ;用RT PCR方法检测患儿骨髓和外周血中的神经蛋白基因产物 9 5 (PGP9 5 )mRNA ,确定瘤细胞的转移程度。结果　PAI 1阳性染色定位于肿瘤细胞和少许血管内皮细胞膜以及部分肿瘤细胞胞浆。PAI 1在神经母细胞瘤中的阳性表达率为 71 4% (3 0 /42 ) ,在进展期肿瘤阳性表达率是 85 7% (2 4 /2 8) ,局灶期肿瘤是 42 9% (6 /1 4) ,两者相比差异有显著性 (P <0 0 1 ) ;在预后不良组织型 (UH)病例中 ,PAI 1阳性率是 91 7% (2 2 /2 4 ) ,与预后良好型 (FH)病例的 44 4%(8/1 8)相比 ,有显著性差异 (P <0 0 1 )。在PAI 1阳性病例组 ,PGP9 5阳性检出率为 6 0 % (1 8/3 0 ) ,PAI 1阴性病例组为 8 3 % (1 /1 2 ) ,两者相比差异亦有显著性 (P <0 0 1 )。结论　PAI 1在神经母细胞瘤的浸润转移过程中发挥重要的作用。     

DK-1型机车电空制动机的制动控制的改进

针对DK-1型机车电空制动机使用20多年来存在的一些问题,从DK-1型电空制动机的操纵方式、均衡风缸压力控制及制动缸压力控制等制动的控制方面提出了改进建议,同时提出了微机控制技术及信息化技术在DK-1型机车电空制动机中的应用要点。     

Road traffic conditions in Kenya: Exploring the policies and traffic cultures from unstructured user-generated data using NLP

Road traffic accidents (RTA) are a prevalent cause of fatality with African countries having the highest fatality index (25–34 per quota). The World Health Organization estimates Kenya's fatality rate due to RTA at 28 per quota. From literature, the country's fatality and injuries have increased by 26% and 46.5%, respectively, since the year 2015. The country is faced with incomplete RTA data capturing, hindering effective planning and policy adjustments to curb the menace. In this paper, we scrapped user-generated data (Twitter) and national transport and safety authority's (NTSA) reports to shed light on traffic safety, practices, and cultures in the country. To this end, we gathered 1,000,000 tweets and 8000 speeding entries between 2015 and 2021 and performed natural language processing (NLP) and quantitative study of the data. We applied NLP and n-gram search of keywords to categorize data into 8 topics: traffic, public service vehicle (PSVs), policing, accident, infrastructure, recklessness, robbery, and corruption. From the data, policing, which touches on all police and law-enforcement-related activity was found to be highly correlated with PSVs, recklessness, accidents, traffic congestion, robbery, infrastructure, and corruption with indices of r(76) = 0.92, 0. 91, 0.87, 0.82, 0.81, 0.76, and 0.70, respectively with p < 0.001. The topic modeling confirmed the identified topics to be the latent discussion issues affecting the public. From the study, PSVs, policing and traffic flow were isolated as key issues that ought to be addressed immediately. The research recommended the integration of driver monitoring systems to strengthen policing. The research, which utilized unstructured data, points to the utility of data mining which would greatly benefit traffic research, particularly African-based studies, that suffer from data inadequacy.     

Optimization of traffic demand management policy in China: towards a sustainable mode split

The rapid increase in private car use in large metropolitan areas has led to irrational travel mode splits and severe traffic problems. Traffic demand management (TDM) is an effective policy to achieve a more sustainable development of traffic systems. This study analyzes the relationships between TDM policy, mode split, and travel mode choice using Stackelberg game theory. Then, using 0–1 programming, it establishes a combination of TDM policy instruments that can achieve a more sustainable mode split in a city and provides a case study in China. The method presented in this research has strong theoretical implications for TDM policymakers.     

Electric vehicle park-charge-ride programs: A planning framework and case study in Chicago

In suburban areas, combining the use of electric vehicles (EV) and transit systems in an EV Park-Charge-Ride (PCR) approach can potentially help improve transit accessibility, facilitate EV charging and adoption, and reduce the need for long-distance driving and ensuing impacts. Despite the anticipated growth of EV adoption and charging demand, PCR programs are limited. With a focus on multi-modal trips, this study proposes a generic planning process that integrates EV infrastructure development with transit systems, develops a systematic assessment approach to fostering the PCR adoption, and illustrates a case implementation in Chicago. Specifically, this study develops a Suitability Index (SI) for EV charging locations at parking spots that are suitable for both EV charging and transit connections. SI can be customized for short-term and long-term planning scenarios. SI values are derived in Chicago as an example for (1) commuter rail stations (for work trips), and (2) shopping centers near transit stops as potential opportunities for additional weekday parking and EV charging (for multi-purpose trips/MPT). Furthermore, carbon emissions and vehicle miles travelled (VMT) across various travel modes and trip scenarios (i.e., work trips and MPT) are calculated. Compared to the baseline of driving a conventional vehicle, this study found that an EV PCR commuter can reduce up to 87% of personal VMT and 52% of carbon emissions. A more active role of the public sector in the PCR program development is recommended.