船舶重量分布载荷强度计算方法研究

为解决船舶重量分布载荷强度计算过程中重量缺失或失真等问题,提出一种重量分布载荷强度计算方法。在分析船舶重量分布载荷强度分布原则和基本计算模型的基础上,该方法将船首、船尾分别视为一个完整的理论站距,将20个理论站距扩充到22个,分别计算设备在各理论站距内的重量分布载荷强度,再将船首、船尾2个理论站距载荷强度折算到相邻的2个理论站距,得到20个理论站距的船舶重量分布载荷强度。最后,通过VBA对Excel进行计算程序开发,并结合实例进行应用。该计算方法能更真实地反映船舶的重量分布,也为船舶行业提供一种快速、规范的重量分布载荷强度计算方法。

An environment-friendly control method for congestion flow ahead of expressway toll stations

To alleviate the resulting increase in energy consumption and emissions and other issues caused by the traffic congestion ahead of the expressway toll station, a novel traffic flowcontrol method is put forward based on the environment-friendly conception. The technical thinking of inducing the slowly moving traffic into a batch pass is determined based on the conclusion of the research, traffic flowtheory and traffic sensing detection technology. The model of stop times is established and the parameters of the system are optimized in accordance with the principle of minimizing the fuel consumption. The optimal location selection of traffic control lights and Detector 2 for queue of different lengths at toll stations are calculated based on the model. Finally, the effect of the congestion flowcontrol system is verified via the Paramics simulation system. The result shows that the control system is capable of reducing90% of fuel consumption for vehicles going through toll stations.

利用计算软件进行稳性复核需要注意的几个问题

文中从实际出发,总结了多年来计算软件进行稳性复核的经验,针对理论站距、重量重心、剖面底线等问题,结合计算软件应用中的困难,提出了稳性复核的解决办法和建议,切实提高图纸审核的质量和效率。

Capacity models on expressway near a bus bay stop with an access

To determinate the expressway capacity near a bus bay stop with an access, capacity models on the expressway near a bus stop with an access were developed on the basis of gap acceptance theory and queuing theory. Depending on a bus stop position to an entrance or an exit ramp, the capacity models were developed for four cases. Bus bay stops with overflow and bus bay stops without overflow were considered. A comparison of simulation experiment and model calculation was carried out. Results show that the suggested models have high accuracy and reliability, at bus arrival rate below 60 vehicles per hour(veh/h) or vehicle volumes at the entrance and the exit below 200 passenger cars units per hour(pcu/h), and there are no significant difference in the capacities for four cases. When bus arrival rate is above 240 veh/h, the capacities of all four cases will decline rapidly. With berth number increasing, the increasing of the capacities is no obvious for four cases. As the bus arrival rate and vehicle volumes at the entrance and the exit increase, bus stops located downstream of an entrance and upstream of an exit have a remarkably effect on the capacities. The latter case is much heavier than the former. Those results can be used to traffic design and optimization on urban expressway near a bus stop with an access.

Theoretical Investigation on the Absence of Spore Photoproduct Analogue at Cytosine-Thymine Site

As a well known DNA photolesion product, the special UV induced pyrimidine dimmer called spore photoproduct （SP）, has aroused strong research interests. The SP formation was reported solely between two adjacent thymidine residues. It remains unclear in pervious experimental observations why there is an absence of the cytosine-derived SP-like photoprod- uct formation at the cytosine containing DNA strand, although the cytosine residue holds great similarity to thymine in terms of molecular structure. From a theoretical perspec- tive, we have explored this issue in this work by means of density functional theory at the B3LYP/6-311＋＋G（d,p） //B3LYP/6-31G（d,p） level for the DNA dinucleotide fragment, cy- tosine phosphate thymine （CpT）. Key factors blocking the formation of the SP-like product between two adjacent cytosine and thymidine residues are revealed. Instead of undergoing photochemical SP reaction, a photophysical deactivation pathway back to the ground state turns out to be favorable for the CpT dinucleotide fragment.

Survival analysis of car travel time near a bus stop in developing countries

This paper presents an important investigation into car travel time affected by mixed traffic flow near a bus stop on the basis of survival analysis theory.Travel time data associated with mixed traffic characteristics near a bus stop were collected by video cameras.A hazard-based duration model was introduced to analyze the effects of mixed traffic flow on car travel time.The results indicate that mixed traffic flow impacts car travel time significantly.And the presence of bus berthing violation would delay car travel time.The proposed model can be used to forecast temporal shifts in car travel time due to changes in mixed traffic flow.The influential factors related to mixed traffic flow should be given full consideration in the planning and designing of bus stops in developing countries.