串联电解池的创新实验

城市地下输电线路断开后,会与潮湿土壤中处于地上或地下的铁轨(管线)形成回路,加快铁轨(管线)腐蚀。该原理相当于将串联电解池的电解质溶液合并,两池中非连接电源的两电极合为一导体平放于连接电源的两极之间,形成一个特殊的串联电解池。基于以上内容,创新了实验。     

A hybrid multi-objective imperialist competitive algorithm and Monte Carlo method for robust safety design of a rail vehicle

This paper deals with the robust safety design optimization of a rail vehicle system moving in short radius curved tracks. A combined multi-objective imperialist competitive algorithm and Monte Carlo method is developed and used for the robust multi-objective optimization of the rail vehicle system. This robust optimization of rail vehicle safety considers simultaneously the derailment angle and its standard deviation where the design parameters uncertainties are considered. The obtained results showed that the robust design reduces significantly the sensitivity of the rail vehicle safety to the design parameters uncertainties compared to the determinist one and to the literature results.     

Characterization of heavy ion tracks in polymers by transmission electron microscopy

Ultrathin sections of two polymers—poly(ethylene terephthalate) and polyimide—were irradiated with heavy ions of 11.1 MeV per nucleon. The size and morphology of the latent tracks were examined with transmission electron microscopy. Polymers readily decomposed under the imaging electron beam. Samples were therefore stained with either osmium tetroxide or ruthenium tetroxide before and/or after ion irradiation. This treatment significantly reduced the radiolytic sensitivity. In addition, however, with dynamic video electron imaging, quasi‐instantaneous damage processes were observed within seconds of observation, modifying in particular both tracks in the bulk and to a lesser extent those on the two confining surfaces. The staining agent was embedded into amorphous regions of the matrix as metallic nanoparticles. Prestained tracks appeared as bright cylindrical regions with diameters of ～6–10 nm. In ultrathin samples, the central track region showed a significant loss of material and even an open hole. Following poststaining, tracks exhibited a dark contrast because of preferential diffusion of the staining agent into the tracks. Poststained tracks were larger than prestained tracks. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2892–2901, 2003     

Study of spatial structure and energy spectrum of ion beams by means of LR 115A and PM-355 nuclear track detectors

The paper reports on measurements of pulsed plasma-ion streams, as performed with the selected solid-state nuclear track detectors (SSNTD). The ion-beams were produced by an experimental device (RPI-IBIS) equipped with coaxial electrodes (each made of molybdenum rods) and a fast-acting gas valve. The device was operated at 30 kV/44 kJ, with puffing of pure hydrogen or deuterium. The spatial structure of the ion beams was studied with pinhole cameras equipped with replaceable detectors, and ion mass- and energy-spectra were measured with a Thomson spectrometer. To analyse low-energy ions (below the energy thresholds of LR 115A and PM-355 SSNTD) an additional accelerating system was applied. It was observed that ions of energy are emitted in bunches, and the ion flux amounts to at a distance of 30 cm from the electrodes outlet. Energy spectra of protons and deuterons ranged from about 30 keV to about 400 keV. The ion distributions, as recorded by means of the PM-355 and LR 115A detectors, are similar.     

Solar wind and cosmogenic rare gases in Luna 16 and 20 soils and their correlation with cosmic ray produced fossil tracks in lunar samples

The elemental and isotopic composition of Ne, Ar, Kr and Xe were measured in the bulk soil samples obtained from Luna 16 and 20 missions. The average cosmic ray exposure ages for the Luna 16 soils is higher than that of Luna 20 soils. The trapped solar wind composition is deduced by correcting for the cosmogenic component and is found to be in good agreement with the values published by others. The correlation between the solar wind gases and cosmic ray tracks in lunar samples is quantitatively studied and some systematic features regarding lunar regolith dynamics are tentatively established.     

Tagungen

By means of the fission-track method age determinations were performed with five naturallyrhyodacitic glasses (volcanic glasses). Although there are partly relatively great differences between fission-track ages and hitherto existing geological classification, a correspondence relating to the order of magnitude can be found at least for three samples. K/Ar-ages which were determined with the same material are in a higher contradiction to the geological assumptions than the fission-track ages.     

Originalarbeiten: Study of Boron Transport in Plants with a Microradiographic Method

The process of passive transport of borate and tetraborate ions was studied in the root of carrot and in the tuber of potato with a quantitative microradiographic method. The boron concentration profiles developing within the plants were determined after various diffusion times, by utilization of the ¹⁰B(n, α) ⁷Li nuclear reaction. A polycarbonate nuclear track detector registered the ⁷Li nuclei and the alpha-particles. The differential equation of linear diffusion combined with convection was used to describe the concentration profiles within the plants. The diffusion coefficients were determined by means of a computer programme.     

模糊线性规划在列车运行调整中的应用

利用模糊集理论来处理列车运行调整过程中涉及的不确定因素,通过合理的权重系数来表示不同约束条件和目标函数的相对重要程度,在Werners方法的基础上提出一种基于加法算子带权重系数的对称型模糊线性规划.将该模型用于沪宁段列车运行晚点调整的优化问题,计算得到了优于Werners方法的结果.     

An improved local branching approach for train formation planning

The train formation plan (TFP) determines routing and frequency of trains, and assigns the demands to trains. In this paper, an improved local branching algorithm is proposed for the TFP model in Iranian railway. This solution strategy is exact in nature, although it is designed to improve the heuristic behavior of the mixed integer programming (MIP) solver at hand. In the local branching algorithm, additional constraints are built in the model for the binary variables, but in the improved local branching algorithm, the additional constraints are built in the model for integer variables. A state-of-the-art method is applied for parameter tuning using design of experiments approach. To evaluate the proposed solution method, we have simulated and solved twenty test problems. The results show the efficiency and effectiveness of the proposed approach. The proposed algorithm is implemented for Iranian Railway network as a case study.     

A disjunctive graph model and framework for constructing new train schedules

Train scheduling is a complex and time consuming task of vital importance in many countries. To create completely new train schedules that are more accurate and efficient than permitted by current techniques, a novel “hybrid” job shop approach is proposed and implemented in this paper. Unique characteristics of train scheduling are firstly incorporated into a disjunctive graph representation of the solution. Dedicated “stand-alone” constructive algorithms that utilise this representation are then developed. The modelling approach and the constructive algorithms are essential as they provide the basis for which meta-heuristics and other iterative refinement algorithms can be applied. A numerical investigation and case study is provided and demonstrates the viability of the modelling approach. Furthermore it is demonstrated that good quality solutions are provided with reasonable computational effort.