电喷汽油机循环变动的测量分析

本文在EQ491汽油机上测取了电喷改装前后的示功图，经过对比分析认为：随负荷及转速增加，燃烧循环变动降低；在空燃比一致时，电喷汽油机与化油器式汽油机的燃烧循环变动一致。论文还对在怠速工况燃烧循环变动进行了统计分析。     

The influence of travel time variability on the value of time

Current benefits from travel time savings have only been related to the benefits from reducing mean travel time. Some previous attempts of including variability in the generalised cost function have mainly assumed commuters with fixed arrival time. This paper presents a comprehensive framework for valuing travel time variability that allows for any journey purpose and arrival time constraint. The proposed model is based on the expected utility approach and the mean-standard deviation approach. Stated Preference methods are considered the best technique for providing the data for calibrating the models. The values of time derived from the models are highly influenced by the value of travel time variability and it strongly depends on the probability distribution function travellers are faced with.     

Resilience of Touristic Island Beaches Under Sea Level Rise: A Methodological Framework

This contribution addresses the need for a simple model for managers to employ when planning strategies for the management of touristic beaches under sea level rise. A methodological framework was developed and tested in two Aegean archipelago islands (Lesvos and Rhodes, Greece). The scheme can represent the status of touristic island beaches, based on easily obtained variables/indicators and projections of beach erosion/retreat under different scenarios of mean sea level rise (MSLR) and extreme events. Information on beach geomorphological characteristics, environmental setting, water quality, management, and services (such as those used in the “Blue Flag” classification) was collated/collected and beach erosion/retreat due to CV & C was estimated through suitable ensembles of cross-shore (1-D) morphodynamic models. A Strength-Weaknesses-Opportunities-Threats (SWOT) framework was employed to assist in the selection of indicators and multicriteria analysis used to optimize indicator weights and rank beaches according to their sustainability under sea level rise. Implementation of the framework at the two islands has shown that: the majority of Lesvos and Rhodes beaches (82% of a total of 217 beaches and 58% of a total of 97 beaches, respectively) can be classified as beaches with no, or minimal, human interference, suggesting that under environmentally sound coastal management further touristic development might be afforded; there could be very significant effects of the sea level rise on the carrying and buffering capacities of the most developed (“Blue Flag”) beaches, with some expected even under conservative projections to be completely eroded by 2100, unless technical adaptation measures are taken; and using the proposed framework, touristic beaches can be rapidly ranked in terms of their resilience to sea level rise and their development potential, allowing prioritization of effective management responses.     

Review on the seasonal variation of the surface circulation in the Japan/East Sea

The seasonal variation of the surface circulation in the Japan/East Sea (JES) and the Tsushima/Korea Straits (TKS) is reviewed and discussed, focusing on mesoscale and submesoscale variabilities.The monsoon modified by coastal geographical features near Vladivostok generates a dipole of vortex off Vladivostok which induces dramatic changes in the surface circulation in the northwest JES, splitting the Subpolar Gyre into two smaller gyres by generating the Vladivostok Dome. Between these two smaller gyres, the Northwest Thermal Front is formed and current reversal is induced along the North Korean coast. The winter monsoon also induces a current reversal along the Sakhalin coast. The volume transport of the surface Subpolar Gyre has two maxima in January and August. The maximum in August is induced by the summer intensification of the Liman-North Korean Cold Current and the shallow and narrow surface coastal jet generated by the sea ice and snow melting. The maximum in January is induced by the northwest monsoon and associated cooling.Salient features in the TKS are the submesoscale variabilities. In the western channel, submesoscale eddies with length scale of about 80 km and time scale of 5–6 days develop in the cold period. On the lee side of the Tsushima Islands, Karman-like vortex pairs are generated in the warm period. Anticyclonic vortices generated at the northern tip of the Tsushima Islands have a time scale of 5 to 8 days, length scale of 35 to 60 km, and propagate toward the JES with a phase speed of 8 cm/s. Cyclonic vortices south of the anticyclonic counter part of the vortex pairs are rather stationary with intermittent occasional propagation toward the east. The development of stratification seems to be necessary for the development of Karman-like vortex pairs.Summarizing the results above, a schematic surface circulation with seasonal change is proposed.     

自发性夜间胃碱化形成机制探讨

目的　探讨自发性夜间胃碱化的形成是否与十二指肠胃反流 (DGR)及迷走神经功能有关。方法　 2 0例功能性消化不良 (FD)患者采用胃内 pH和胆红素同步监测法 ,比较夜间自发性碱化与胆汁反流的关系 ;另外 2 0例无心血管疾病的FD患者采用胃内 pH和心电Holter同步监测 ,进行心率变异性 (HRV)时域分析 ,以SDNN、rMSSD、PNN5 0为指标 ,观察夜间自发性碱化与迷走神经功能的关系。结果　 2 0例FD患者中出现夜间自发性碱化者 1 2例 ,其中 8例 (占66.7% )同时有胆红素吸光值升高 ;2 0例无心血管疾病的FD患者中 1 3例有夜间自发性碱化 ,7例无自发性碱化 ,二者比较SDNN、rMSSD均在正常范围 ,差异无显著性 (P >0 .0 5 ) ;2 4h胃 pH与PNN5 0对照观察表明 ,夜间时段与白天相比PNN5 0明显升高 ,有自发性碱波组与无自发性碱化组二者相比 ,PNN5 0无显著差别。结论　自发性夜间胃碱化的形成与DGR有关 ,并不是迷走神经张力降低导致胃酸分泌减少所致。     

脑电双频谱指数和心率变异指数联合用于监测腹腔镜胆囊切除术患者麻醉深度的临床观察

目的采用脑电双频谱指数(BIS)和心率变异指数(HRVI)联合监测腹腔镜胆囊切除术患者的麻醉深度,观察手术患者中枢神经系统的抑制程度及植物神经系统对外科手术等伤害刺激的反应性,更加合理地评价腹腔镜胆囊切除术患者的麻醉深度。方法选择ASAⅠ~Ⅱ级,全麻下择期腹腔镜胆囊切除手术患者80例,依麻醉深度检测手段的不同随机分为4组:对照组(组Ⅰ)、BIS监测组(组Ⅱ)、HRVI监测组(组Ⅲ)、BIS和HRVI联合监测组(组Ⅳ),维持BIS值40~50,HRVI值30~40。结果麻醉期间组Ⅳ丙泊酚的使用量显著低于组Ⅰ、组Ⅱ和组Ⅲ;组Ⅲ、组Ⅳ瑞芬太尼的使用量显著高于组Ⅰ和组Ⅱ;组Ⅳ苏醒时间显著短于组Ⅰ、组Ⅱ和组Ⅲ;拔管后患者烦躁例数组Ⅲ、组Ⅳ显著低于组Ⅰ和组Ⅱ。4组患者术后均未发生术中知晓。结论采用BIS和HRVI联合监测腹腔镜胆囊切除手术患者的麻醉深度,可以较为准确地反映手术患者中枢神经系统的抑制程度及植物神经系统对外科手术等伤害刺激的反应性,可更加合理地评价麻醉深度。     

基于自动删除算法的广义变化性指标恒虚警检测器

针对自动删除均值检测器存在的排序时间过长的问题,先提出了一种修正自动删除均值检测器.计算机仿真显示,与自动删除均值检测器相比,该检测器的性能或与其相同,或稍有改善,但排序时间却减少了一半.推导了该检测器的平均虚警概率、平均检测概率的解析表达式.比较了该检测器与基于自动删除算法的最小选择恒虚警检测器的性能,分析了这2种检测器各自适用的场合.为了得到稳定的检测性能,提出了一种广义变化性指标恒虚警检测器,该检测器根据变化性指标可以自动在修正自动删除均值检测器和基于自动删除算法的最小选择恒虚警检测器之间转换.最后通过计算机仿真验证了该检测器的有效性.     

Investigating the effect of travel time variability on drivers' route choice decisions in Shanghai,China

Abstract

This paper investigates the effect of travel time variability on drivers' route choice behavior in the context of Shanghai, China. A stated preference survey is conducted to collect drivers' hypothetical choice between two alternative routes with designated unequal travel time and travel time variability. A binary choice model is developed to quantify trade-offs between travel time and travel time variability across various types of drivers. In the model, travel time and travel time variability are, respectively, measured by expectation and standard deviation of random travel time. The model shows that travel time and travel time variability on a route exert similarly negative effects on drivers' route choice behavior. In particular, it is found that middle-age drivers are more sensitive to travel time variability and less likely to choose a route with travel time uncertainty than younger and elder drivers. In addition, it is shown that taxi drivers are more sensitive to travel time and more inclined to choose a route with less travel time. Drivers with rich driving experience are less likely to choose a route with travel time uncertainty.     

RAP级配变异性对温拌再生沥青混合料水稳性能影响

温拌再生沥青混合料（Warm Mix Asphalt,WMA）是一种节能、环保、废料二次利用的新型路用材料,但其水稳性能不良是该材料推广、应用的技术瓶颈。研究从RAP级配变异性角度分析其对WMA水稳性能的影响。首先依托渝长高速大修工程、成渝高速大修工程,进行回收沥青混合料（Recycled Asphalt Pavement,RAP）级配变异性分析;其次分析RAP级配变异对温拌再生沥青混合料（Warm Mix Asphalt,WMA）水稳性能的影响。结果表明：RAP级配变异性对WMA水稳性评价指标TSR影响较为明显,且对试件空隙率、冻后强度影响较大,而对试件冻前强度影响不明显;与直接回收RAP的级配变异性相比,采用破碎、分档工艺对回收RAP进行处理,可较好控制RAP级配变异性,进一步保证WMA水稳性能。