Abstract:Through long-term compression creep tests on two kinds of rubber waterproof gasket for the shield tunnel of Section A and Section B under the constant pressure, it is found that the relationship between creep deformation of gasket and logarithm of time is almost linear and a predictor formula was put forward. The param- eters in the predictor formula fitted by the first creep test data were used to forecast the second test data and the rationality of the predictor formula was validated. Through the comparison among the prediction formula, Kelvin model, and the three parameters model, it was found that the predictor formula can effectively reflect the com- pression creep behavior of rubber gasket under constant pressure and is the best one to reflect the creep behav- ior among the three models. The research results show that the temperature has less impact on the compression creep behavior of the rubber gasket, which indicates that creep tests can better reflect the durability of the wa- terproof pad than that of stress relaxation tests. Besides, the results may be of practical value for the study and prediction of long-time mechanical behavior and service life of rubber materials.

Abstract:The natural geography and economy in Ningdong mining area were analyzed and experience concern- ing the survey and design of special lines in Ningdong mining area in recent years was concluded. In view of the unfavorable geological phenomena such as sandstorm and goaf, as well as the typical engineering geological problems such as overlaid minerals and design of protective coal pillars, etc. in the engineering geological route selection of railway special lines, combined with project examples, this paper adopted the method of combining theoretical analysis with practical calculation, explained in detail the rationality of the engineering setting and presented some line selection principles in terms of these unfavorable geological phenomena and engineering ge- ological problems.

Abstract:Aiming at the short distance overlapped tunnel in silt reclamation stratum, this paper explored the ef- fects of the construction of the new shield tunnel on the surrounding environment by the 3D finite element soft- ware PLAXIS. The construction generated 14mm moving up for the existing tunnel, resulting in 69mm of surface settlement, which can not meet the deformation control of shield construction. In order to effectively control the impact of shield construction on the surrounding environment, the silt reclamation stratum must be reinforced. Then, the effects of different reinforcement range on the additional deformation of the tunnel were analyzed by 2D finite element method. A specific reinforcement scheme for the silt reclamation stratum was proposed. The silt reclamation stratum within 3m on both sides of the tunnel was reinforced with high-pressure rotary jet grout- ing pile in full depth. It was found that under the condition of reinforcement, the existing tunnel move-up defor- mation and surface settlement can be reduced by 44% and 86% compared with those without reinforcement. The research results show that in the silt reclamation stratum, the reinforcement scheme proposed can effectively control the environmental deformation caused by the tunnel construction and reduce the construction impact.

Abstract:In order to study the influence of the pre-stressing tension on the bridge force under complex climatic conditions in mountain areas and monitor in real time the concrete stress of long-span bridge in the process of pre-stressing tension, by taking the construction of Wanlongshan Bridge as an example, plastered fiber grating sensor with high-accuracy was adopted to monitor the whole process of pre-stressing tension in Block 12 of Pier 2. The research results show that when the prestressing tension is carried out by using the asymmetrical tension method, the phenomenon of alternating tension-compression strains occurs in the box girder section. When the tension occurs in the roof, the bottom board and web produced obvious tension stress, and the web of the other side without tension also produced obvious tension stress; the prestressed steel beam of the roof produced more obvious prestressing force than that of the bottom board. After the prestressing of 12 # block was completed, a compressive strain of -120με was produced at the top of box girder section, and tensile strain of 40με and 80με were produced respectively at web and bottom board, which directly reflected the effect of stress tension.

Abstract:Through coagulation beaker test, research on coagulation effect of sedimentation tank slduge reflux was carried out, and the effects of PAC dosage, sludge turbidity and reflux ratio parameters on sludge reflux coagula- tion was analyzed in this study. The research results show that when the dosage of PAC was less than 30 mg/L, muddy water turbidity was from 16 to 40 NTU, and reflux ratio was from 2% to 10%, the sedimentation tank sludge water can promote the process of colloid flocculation, strengthen the coagulation effect, and improve the water quality. Besides, by way of the orthogonal test, it obtained the optimal reflux conditions: sludge water reflux ratio = 6%, PAC dosage=25 mg/L, sludge water turbidity= 30 NTU, and dosage can be saved 28.6% compared with the sludge water without reflux.

Abstract:The vertical concrete retaining walls are widely used in bank revetment projects, having detrimental impacts on landscape environment and ecology to varying degrees. High-strength plastic sheet pile has the ad- vantages of light weight, good durability, low maintenance cost, economical cost and quick construction. In this study, the field test has been thoroughly carried out. It designed and implemented plastic sheet pile revetment deformation monitoring test, and demonstrated the feasibility and innovation of the application of high strength plastic steel interlocking composite sheet pile ecological revetment in waterway engineering.

Abstract:The arch axis combination method of approximate analytical solution for rational arch axis under muti- type loads was proposed in this paper as there was no general method solving this problem. Based on the analy- sis of multi-type loads， the multi-type loads were firstly divided into a series of single type loads， and then the analytical solution for rational arch axis and horizontal thrust was deduced in every single type load; according to the contributions to total horizontal thrust， a linear combination of these rational arch axes was the approximate analytical solution for muti-type loads. Based on the basic principles of mathematics and mechanics， the pro- posed method was verified through the deduction of three aspects for single type load mathematical function. By taking several typical deduction work of rational arch axis under muti-type loads as examples， the universality and accuracy of proposed method were tested from the aspects of pressure line coordinates， main arch bending moment and horizontal thrust. The research results show that approximate analytical solution of rational arch axis can be easily deduced by the proposed method， which is of great universality; axis deviation between approxi- mate analytical solution and actually rational arch axis is very small， and the bending moment of main arch ring is close to zero; the horizontal thrust is a precise solution under continuous loads， and the continuous transfor- mation of discrete concentrated force will bring some small errors in horizontal thrust of the proposed method.

Abstract:“The Belt and Road” initiative, a national strategy proposed by our country, has profound and far- reaching impacts on all-round development of China. The connectivity of transport infrastructure represents the priority area in pushing forward “the Belt and Road” initiative, while civil aviation transportation plays an im- portant part in this process which necessitates the analysis and recognition for civil aviation transportation mar- ket. In this paper, the indicator system to evaluate importance of civil aviation transportation market was built and the present situation was analyzed based on this indicator. Then, the factor analysis method was adopted to obtain overall scores of market importance. Finally, important civil aviation transportation markets under “the Belt and Road” initiative were identified. The research results show that Indonesia and India play the most sig- nificant role in advancing “the Belt and Road” initiative, followed by Turkey, Singapore, Thailand, Saudi Arabia, Malaysia, the Philippines, United Arab Emirates, Iran, and then South Africa, Vietnam, Poland, Pakistan, Bangladesh, Egypt and Kazakhstan.

Abstract:To accurately estimate road section travel time in small mountainous cities, the travel time modifica- tion model was proposed based on traffic property analysis, traditional BPR model analysis, as well as the accu- mulative traffic flow analysis of mixed traffic road sections. In this paper, the manual recording method was adopted to collect field data under non-congestion state, and VISSIM software was simulated to acquire experi- mental data under congestion state. Then, the traditional BPR model was modified based on a large amount of traffic flow data, and an error comparison between the traditional and modified BPR models was made. The re- search results show that the traditional and modified BPR models respectively produce the average errors of 35.021% and 4.597% in travel time for arterial roads, and of 46.737% and 3.120% in travel time for access roads. It can be concluded that the estimation performance of the modified BPR model is better than that of the traditional BPR model, and the effects of non-motor vehicle interference on access road travel time is more sig- nificant.

Abstract:The tunnel lighting system not only affects the safety of tunnel traffic, but also is the key to reducing the construction and operation cost of highway tunnel. Under the premise of ensuring the safety of the tunnel traffic, it is necessary to effectively reduce the power consumption of lighting system. Energy -saving studies based on energy-saving tunnel lighting lamps, parameters optimization of tunnel lighting system, and intelligent control were summarized and analyzed. A more energy-saving and efficient scheme was proposed, i.e. optimizing the installation parameters of LED luminaires of all sections of tunnel with the purpose of saving energy, under the condition of tunnel lighting meeting the traffic requirements, then, stepless dimming control was carried out through the installation-parameter-optimized lighting system. Finally, CAN bus was used to control and manage the power of every LED luminaire, so as to maximize the energy saving of the tunnel lighting system.

Abstract:The current approach to optimizing the urban intersections is to set waiting-areas for left-turning and waiting-areas for direct movement. But the two methods have their own setting conditions, and have some re- quirements for geometric characteristics of the intersections and traffic. The integrated area is a new method for the improvement of the intersections in recent years, which can increase the queuing capacity, shorten the queu- ing length indirectly, and reduce the vehicle delay on the basis of making full use of the road space. In order to optimize the traffic situation, the site survey and analysis of the intersection of Changnan Road and Yingbin North Road in Nanchang city were carried out. The integrated waiting area was set to optimize the intersection, and the road modeling and simulation were carried out. The research results show that the setting of the integrat- ed waiting area can improve the traffic capacity and efficiency of the intersection as well as reduce the delay.

Abstract:Through classification and summarization, this paper studied the edge control set partition for some graphs concerning fan graph, and optimized the conclusion and proof process of set edge control number for the fan graph F_n from existing papers. This paper also put forward generalized fan graphF_m,n，and obtained the set edge control number with higher accuracy.

Abstract:The content of lead in soil was detected by spectrophotometry with dithizone as color reagent. The soil was digested to make lead in soil and the dithizone a color complex. The absorbance was measured at the maxi- mum wavelength of 517 nm and the effects of the coloration time, and the amount of the color reagent on the measurement were investigated. The concentration of lead complied with the Lambert-Beers Law when it was in the range of 0 ~ 1 μg/mL. Then the linear regression equation, and the linear regression coefficientwith good correlation were obtained. The research results show that only slight pollution exits as the lead content in the soil of the green belt is 42.17 mg/kg, and the lead content in soil along a major road is 77.73 mg/kg. This method is applicable to the detection of lead in soil.

Abstract:Solidification process and phase transformation behavior of DZ22B superalloys were analyzed by dif- ferential scanning calorimetry methods. After comparison of solidification microstructure with different cooling rates, the transition regularity of secondary dendrite spacing and carbidesphase were explored. Obvious dendrite refinement occurred with the increase of cooling rate, and the average secondary dendrite spacing decreased from 125 μm at the cooling rate of 5 K/min to 37 μm at the cooling rate of 80 K/min. The refinement of dendrite morphology was advantageous for the reduction of solute micro-segregation at later solidification stage, which generated the morphology change of carbides from continuous net shape to dispersive strips or blocks. Moreover, the skin effect of Hf element can be suppressed for higher cooling rate because of the thinner flowing channel and shorter solidification period, which can facilitate the formation of rich-Hf carbides.

Abstract:This paper proposed a new interleaved three -level converter with dual transformers, which was realized by paralleling an auxiliary bridge arm to the main bridge arm and series connecting the secondary side of the auxiliary transformer series to the primary side of the main transformer.The advantages of traditional three-level converter were maintained, and wide range output voltage was obtained through the on/off of auxiliary arm. It analyzed the working principle of dual transformer three level converter, compared the efficiency of the converter and the traditional converter in different output range. Finally, a prototype of 1500W was built to verify the correctness of the theoretical analysis and the feasibility of the new converter.

Abstract:The energy of the sensor network nodes is limited, and in order to save the energy consumption of the sensor nodes, an improved compressed sensing algorithm combining the LEACH model with the CS theory based on the spatial-temporal correlation of nodes was proposed. The LEACH algorithm was used to cluster the net- work nodes and select the cluster head. Then, the cluster head node was sampled by the compressed sensing theory. The sampled data was passed to the remote sink node through multi-hop routing. Finally, a small amount of data from the cluster head used a reconstruction algorithm to accurately recover the original signal. The simu- lation results show that this method can effectively reduce the amount of data transmission, save the energy con- sumption of nodes and prolong the lifetime of the wireless sensor network.

Abstract:Tensor decomposition is a significant method to deal with large-scale data, which can reduce the data effectively. The high-order tensor is widely used in neuroscience, signal processing, image analysis, computer vi- sion and other fields as it has such advantages as uniqueness, robustness to noises and zero impact on the origi- nal data of the spatial structure and internal potential information. In this paper, the traditional dimensionality reduction methods were introduced firstly, and their problems and shortcomings were also discussed. Secondly, general analysis of three classical algorithms of tensor decomposition was carried out from the aspects of algo- rithm, basic ideas, algorithm framework and algorithm applications of CP decomposition, Tucker decomposition and non-negative tensor decomposition. Then, The CP decomposition algorithm and the Tucker decomposition algorithm were compared and analyzed from different angles. Finally, the present situation, practical application and future research trends of tensor decomposition were summarized and analyzed.

Abstract:Currently, the photovoltaic power generation system lacks professional operation and maintenance, and the problems can not be solved in time, which will affect the power generation efficiency and economic benefits. This paper proposed a self-service operation and maintenance system based on mobile APP client through pho- tovoltaic power generation. This system has real-time monitoring module, fault warning module, fault reporting module and manual control module, together with the establishment of event database, which can be able to pro- vide data support for the system. The owner can view the real time monitoring of the photovoltaic power genera- tion system, the equipment warning and the equipment failure through the APP, so as to find the problems in time. The owner can carry out the self-service maintenance of the photovoltaic equipment after obtaining the corresponding solutions through APP. Finally, by taking 1.8kW's household type photovoltaic power generation system as an example, this paper evaluated the maintenance benefit of the proposed system. The research results show that the system can effectively reduce the cost of photovoltaic operation and maintenance, and improve the efficiency of power generation.

Abstract:The electric locomotive obtains the electric energy through the electrical contact between pantograph and catenary. And the arc fault between the pantograph and catenary is a common phenomenon when the electric locomotive is running. The arc fault in pantograph-catenary system will not only damage the catenary and the pantograph, but also disturb the operation of the electric equipment in electric locomotive. The arc fault has the characteristic of randomness and irregularity, so it is difficult to diagnose the fault timely and accurately. Ac- cording to the existing problems in arc fault diagnosis, this paper introduced a new diagnosis method based on the support vector machine(SVM). After obtaining the raw data of the current in pantograph-catenary system, the power spectrum entropy was adopted to extract the feature vectors needed by arc fault diagnosis and the SVM was used to classify these feature vectors. Then, the normal current from arc fault can be recognized. The re- search results show that the diagnosis model established in this paper has a high accuracy in classifying the fault state and normal state, which provides an useful method and research approach for arc fault diagnosis.

Abstract:Effective control of peak carbon emissions plays a crucial role in the development of one region. Ac- cording to the statistical data of Hunan province during 2006-2015, different growth rates of per capita GDP and energy efficiency in Hunan province were simulated. Then, nine scenarios were designed to forecast the peak value of energy carbon emissions in Hunan province in the next 30 years. The research results show that the slower the energy efficiency grows and the earlier the peak value appears, the smaller the peak value is; the slower the growth rate of per capita GDP is, the earlier the peak value appears and the smaller the peak value is; when population is stable, the improvement of energy efficiency is one of the important factors leading to the peak value of the rapid growth of per capita GDP; in the high-high mode and medium-high mode, it cannot reach the peak value of carbon emissions before 2030 in Hunan province, and the per capita GDP growth exerts an great impact on carbon emissions. Compared with the impacts of 0.2% change for high, medium and low modes of per capita GDP, the 0.2% change for the three modes of energy efficiency have greater impacts on the prediction results. Therefore, to design the carbon emission reduction policies of carbon peak value, it is neces- sary to take carbon emissions space in Hunan province to prevent sharp economic fluctuation