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181.
我国物流企业市场营销问题与策略 总被引:1,自引:0,他引:1
随着社会经济的发展,人们对物流市场营销的认识也不断深化。我国加入WTO后,融入世界经济体系的进程不断加快,面临着这些机遇与挑战,我国的物流企业必须运用现代的营销策略将企业做大做好。文中分析目前我国物流企业在营销过程中存在的问题,阐述物流企业应该运用的市场营销策略。 相似文献
182.
60N钢轨18号无砟道岔在京沈客运专线喀左站进行了试铺,通过预打磨试验、联调联试道岔动力学性能测试及开通后服役性能分析,验证其在高速条件下的适应性。结果表明:60N钢轨道岔可实现与区间60N钢轨的匹配,与60 kg/m钢轨18号无砟道岔预打磨相比减少打磨工作量60%以上,打磨质量更容易保证;综合检测列车以不同速度通过60N钢轨18号无砟道岔时,安全性、平稳性、舒适性和道岔结构动力学等指标均满足列车运行要求。与60 kg/m钢轨18号无砟道岔列车动力学性能测试结果对比表明,构架脱轨系数和轮轨横向力峰值有所降低,其他动力学指标基本相当;60N钢轨18号无砟道岔服役性能试验结果表明,钢轨服役性能良好,无明显磨耗及伤损情况产生。 相似文献
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为解决选取隧道照明光源时未考虑光谱能量分布和相关色温因素造成光源选用不当的问题,结合中间视觉模型,对道路隧道常用光源的光谱能量分布和相关色温进行测试研究,分析不同隧道常用光源的光谱能量分布与相关色温关系; 通过引入光谱S/P值的计算方法,从人眼感知角度分析不同隧道常用光源S/P值与相关色温关系。研究表明: 1)LED光源的相关色温随着蓝光比例的增加而增加; 2)不同类型光源的S/P值与光源的相关色温不是一一对应的关系,但LED光源的S/P值随着相关色温的增加而增大; 3)金属卤化物灯、白色荧光灯和LED光源适合应用于隧道照明,但从长远来看,隧道照明选用相关色温较高的LED光源更为合理。 相似文献
186.
Gongquan Tao Xiren Liang Dexiang Ren Xuesong Jin 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2019,57(1):1-16
This paper presents an investigation into the mechanism of polygonal wear of metro train wheels through experiments conducted at field sites. The experiments comprise dynamic behaviour test of vehicle and track system, the wheel transverse wear and polygonal wear measurements, rail corrugation and rail weld joint irregularities’ measurements. Moreover, the numerical modal analysis of the wheelset is also performed. The wheel measurement results show that most wheels exhibit obvious eccentricity and polygonal wear with 5–8 harmonics. The investigation results indicate that the wavelength-fixing mechanism of the wheel out-of-roundness with 5–8 harmonics is the P2 resonance. Four measures have been proposed to mitigate the formation of wheel polygonal wear based on the field measurement results. 相似文献
187.
To ensure hull structural strength of container ships in association with their increase in size, it is very important to grasp the hull stress histories all over the hull structure in actual sea state. However, ordinary hull stress monitoring systems are insufficient for this purpose because of the small number of stress sensors actually practicable. Therefore, in this paper, we discuss an approach to reproduce the hull stress responses which are not measured based on the estimated wave spectrum from the limited measurement data. To achieve this, we introduce a new model to estimate directional wave spectra based on measured ship stress responses and ship response functions, and further we estimate other ship responses using the model. To model an arbitrarily shaped directional wave distribution, the 360° direction is discretized into 36 directions of 10-degree intervals instead of using a directional distribution function, and in each direction, the wave spectrum is represented using the Ochi (3P) spectrum with three parameters (average wave period, significant wave height, and kurtosis). The authors discuss the evaluation results based on two stress response combinations, and a comparison is made between the sea state estimates made by the proposed method and the ocean wave hindcast database (JWA). Furthermore, by comparing the significant values and the spectra of the measured response of the ship with the estimated response based on both the estimated sea state by the proposed method and the hindcast sea state, the accuracies of the proposed method and the hindcast method are discussed in terms of ship stress estimation at non-instrumented locations. 相似文献
188.
介绍了哈尔滨大连电气化铁道所引进德国的S.P.I.D.E.R.远动系统用于对供电系统的控制、监督、采集和分析数据,并提供一个建立网络控制应用的操作平台。系统的引进为我国电气化铁道远动控制提供了可借鉴的经验。 相似文献
189.
Organically complexed and total dissolved copper and nickel were measured in the Thermaikos Gulf waters during winter 1998. Total concentrations ranged from 1.13 nmol/L to 7.02 nmol/L for copper and from 3.04 nmol/L to 9.50 nmol/L for nickel. The C18 Sep-Pak solid phase extraction technique was used in order to determine the amount of copper and nickel complexed with the hydrophobic component of the dissolved organic matter (DOM). Up to 32.4% of total copper and 4.57% of total nickel were complexed with the DOM extracted by C18. By applying HPLC analysis it was shown that the majority of the organic compounds retained by C18 had intermediate to low polarity. Using the absorbance ratio a254/a436 it was possible to unravel that humic substances of both terrestrial and marine origin were present in the Thermaikos Gulf and their distribution followed the dilution of riverine waters. Moreover our results indicated that organic binding of both Cu and Ni was stronger with the hydrophobic compounds of terrestrial origin than with those of marine origin. 相似文献
190.
运三高速公路自通车以来,部分路段出现严重的车辙等病害,根据路况调查结果,提出病害路段技术处治措施及维修施工质量控制要点。 相似文献