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排序方式: 共有111条查询结果,搜索用时 31 毫秒
1.
通过对宁波港的交通环境,现有VTS系统及港口发展的趋势研究,提出了改善宁波港通航环境,建立和完善VTS系统的有效措施。 相似文献
2.
We study the vessel arrival process in bulk ports handling either cargo containers or minerals. Then we introduce the SHIP/G/1 queue to be able to study the queueing behavior at the port. We present approximations for the asymptotic probabilities of delay and the number of vessels at the port. Numerical examples show the accuracy of the approximations. In appendices, we provide details of the analysis of the number of vessels at the port and the correlation properties of the vessel arrival process. 相似文献
3.
近红外快速检测技术在全球范围内作为一项新兴的快速检测手段,已在农业、食品、饮料、石油、材料、制药、医学、动植物检疫及其工业化过程等领域得到了广泛应用。该文结合近红外光谱快速检测原理及其应用现状,针对口岸安全监管中的商品智能归类、材料成分快速鉴定、动植物产品快速检疫鉴定、商品装卸载过程的在线监测等需求,提出引入近红外光谱检测技术应用于口岸安全监管领域的设想,力求为实现口岸贸易安全与贸易便利化双重目标奠定科技基础,并给出了近红外在口岸安全监管研究方面的应用展望。 相似文献
4.
The influence of intake port design on the flow field in a dual-intake valve engine was investigated using computational fluid dynamics, in order to study the effect of inlet port design on the in-cylinder flow. A detailed 3D computational grid incorporating all the features of the Ford Zetec production engine inlet ports, valves and cylinder head was initially created and the flow structure modelled at 5 and 10 mm valve lifts under steady flow conditions. Comparisons of computational results with experimental data obtained by laser Doppler anemometry indicate that the flow characteristics have been predicted well in most regions. Flow generated by different intake port designs was also simulated by introducing air into the cylinder at different directions to the inlet valve axes and the effects of port deactivation, throttling and exhaust gas recirculation were examined. The implications of the results for intake port design are discussed. 相似文献
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6.
针对港口国监督(Port State Control, PSC)检查的复杂性和不确定性, 基于贝叶斯网络理论构建船舶PSC检查滞留风险分析模型. 以东京备忘录(Tokyo MOU)中2014~2017年船舶PSC检查样本数据为基础, 运用R语言bnlearn包进行贝叶斯网络的结构及参数学习. 同时分别执行贝叶斯网络的正向、逆向推理, 定量表示各风险因素与滞留结果之间的相互作用关系, 找出导致船舶滞留的高风险因素, 实现不确定环境下船舶PSC检查滞留风险的全面动态分析. 实证表明, 模型具有较高的精确度, 可为检查人员的滞留决策及航运公司的安全风险管理提供有效依据. 相似文献
7.
A simple and direct approach was developed for thermochemolytic analysis of a wide range of biomolecules present in plant materials using an injection port of a gas chromatograph/mass spectrometer (GC/MS) and a novel solids injector consisting of a coiled stainless steel wire placed inside a modified needle syringe. Optimum thermochemolysis (or Thermally Assisted Hydrolysis/Methylation) was achieved by using a suitable methanolic solution of trimethylsulfonium hydroxide (TMSH) or tetramethylammonium hydroxide (TMAH) with an injection port temperature of 350 °C. Intact, methylated flavonoids, saccharides, phenolic and fatty acids, lignin dimers and diterpene resin acids were identified. Samples include tea leaves, hemicelluloses, lignin isolates and herbal medicines. Unexpected chromatographic results using TMAH reagent revealed the presence of intact methylated trisaccharides (658 Da) and structurally informative dimer lignin markers. 相似文献
8.
将港口服务产品的网络外部性和服务质量水平引入到发货人的效用函数中,通过Hotelling价格竞争模型分析港口FDI企业与内资港口企业的博弈策略行为,分别研究在Nash和Stackelberg博弈条件下,港口服务价格、收益与网络外部性系数、服务质量水平之间的关系.理论研究的结论表明:港口FDI企业与内资港口企业在Stackelberg条件下的最优定价、均衡收益均大于Nash条件下的最优定价、均衡收益;企业最优定价随网络外部性强度线性递减,随服务水平线性递增;企业均衡收益受服务水平和网络外部性强度的影响,呈现出一定的区间变化规律,处于相同港口外部市场环境下,内资港口企业与港口FDI企业的服务策略选择和侧重点不相同. 相似文献
9.
Stephen F. Austin 《Journal of voice》1997,11(2):212-221
The present study addresses two questions: (a) Is the action and/orposture of the velopharyngeal valve conducive to allow significant resonance during Western tradition classical singing? (b) How do the actions of the velo-pharyngeal valve observed in this style of singing compare with normal speech? A photodetector system was used to observe the area function of the velopharyngeal port during speech and classical style singing. Identical speech samples were produced by each subject in a normal speaking voice and then in the low, medium, and high singing ranges. Results indicate that in these four singers the velopharyngeal port was closed significantly longer in singing than in speaking samples. The amount of time the velopharyngeal port was opened was greatest in speech and diminished as the singer ascended in pitch. In the high voice condition, little or no opening of the velopharyngeal port was measured. 相似文献
10.
船舶进出宁波港分道通航方案 总被引:1,自引:1,他引:0
近年来,宁波港吞吐量猛增,并有继续上升趋势,而大型船舶进出港口仅用虾峙门的单向航道,与宁波港口发展不相适应。提出二套船舶进出口方案,与现有的虾峙门航道构成分道通航制,供港口主管部门进行航道规划参考。 相似文献