Abstract:The lifting efficiency of traditional air-lift system is low，therefore a jet air-lift of annular jet pump structure is designed in this article，and an experimental device of air-lift system is established.In the experiment，riversand is chosen as the lifting object，and the influence laws of jet air-lift lifting water and solid capacity by air flow rate on submergence ration are researched.The flow pattern inside the riser is analyzed，and the lifting solid capacity of traditional air-lift and jet air-lift is compared.The efficiency model of air-lift is established by energy conservation law，and the lifting solid efficiency of traditional air-lift and jet air-lift is compared.The result show that there is a best air flow rate making the highest of water and solid flow rate.The water and solid flow rate increase as the submergence ration increases，and the system can lift water and solid effectively when the flow pattern is churn flow.The lifting solid efficiency of jet air-lift is higher than that of traditional one，especially in the condition of high air flow rate and low submergence ration.

Abstract:To study the indoor environment parameters dynamic response to the instantaneous variation of outdoor meteorological conditions in Lanzhou，a standard k-ε turbulent model of CFD is adopted to numerically analyze the pollutant concentration field and airflow distribution in an office when the unsteady heat transfer through outer walls is considered.The velocity field，temperature field and pollutant concentration field of two air supply modes，ceiling air supply and lateral air supply，are obtained.The results indicate that the pollutant concentration field and migration characteristics are affected significantly by the solar radiation resulting from stimulating the natural convention heat transfer in the room.Under the same air supply mode，the indoor pollutant concentration is more uniform at 16:00 than that at 8:00.And the average value of pollutant concentration at 8:00 is relatively higher than that at 16:00.At the same air supply parameters，the ceiling air supply mode is more beneficial to lower the indoor pollutant concentration.

Abstract:Complex mode analysis method is used to establish a water-lubrication rubber bearing alloy system simulation model in order to research the influence of structural parameters of water-lubrication rubber alloy bearing on friction noise under low speed and heavy load condition.The probability of producing friction noise under the conditions of different friction coefficients and structure parameters is analyzed by using professional simulation software, and then the effect of structure parameters on friction noise is studied.The friction noise contrast experiment of the flat and circular arc structure of the water-lubrication rubber alloy bearing is carried out.Analysis and computation results show that the groove radius, friction surface shape and the friction coefficient of friction pair are key influential factors on the frictional noise of water-lubricated rubber alloy bearing, while the effect of flume shape is very small.For the water-lubricated rubber alloy bearing with a certain structure and size, 4 mm groove radius with flat pattern friction area is optimal to reduce the possibility of bearing friction noise appearance.This computation result is verified by corresponding experiment.

Abstract:Selective laser melting (SLM), a kind of layer by layer processing technology, has significant performance advantages on preparation of porous materials. SLM provides an effective method to reduce the elastic modulus and the stress shielding effect of TC4 titanium alloys for medical implants.However, there is still no convincing biological safety evaluation before practical application. In this paper, TC4 alloy with a relative density of 99.5% is prepared in the adoption of SLM.We examine corrosion resistance and biocompatibility for TC4 alloy prepared by SLM via electrochemical, hemolysis and cytotoxicity test.Comparison between TC4 alloy prepared by SLM and traditional cast rolling process is discussed.The results show that TC4 alloy prepared by SLM has better corrosion resistance and more excellent biocompatibility than traditional process, and it has tremendous application in futures on biomedical implants.

Abstract:In order to generate a driving cycle for evaluation of vehicles emissions, extensive emission data and driving activity data are collected by using a Portable Emission Measurement System (PEMS) and a GPS device.The collected data are preprocessed and the evaluation criterion for microtrips is proposed.Two heuristic algorithms, Genetic Algorithm (GA) and Discrete Simultaneous Perturbation Stochastic Approximation (DSPSA) are given to search the best microtrips automatically.The prediction of vehicle emissions using generated driving cycle is validated.Research results show that both heuristic algorithms are able to solve the problem of automatic generation of driving cycles.The driving cycle developed by GA is more representable and it can predict the total vehicle emissions with a relatively small error.Therefore, GA is recommended for the generation of driving cycles in other cities.

Abstract:To solve the problem of engineering in infrastructure failure caused by irrational topological destruction, the concepts of social network analysis(SNA) method are introduced into topology infrastructure network evaluation, including density, cohesive subgroups, K-core, Lambda-set,tangent pointand center of computing concepts, and a network evaluation system is put forward, which is constituted by the indexes of completeness, levels of border league degree, local stability composition ratio, node vulnerability,operation load balance index and so on. Empirical research on Changshou suggests that stability of network topology and network operation can be evaluated, overload points can be found effectively, and compact extent and completeness degree of topology can be evaluated byusing SNA model.

Abstract:In order to obtain the design approach for local buckling of steel members at elevated temperatures, an established finite element model is verified by experiment. The calibrated model is used to study the effect of temperature, width to thickness ratio, initial imperfection and interaction between web and flange on the local buckling stress of H shaped axially compressed members. Simplified design approach and limited ratio of width to thickness is proposed on Q235 steel and Q460 steel H shaped axially compressed members at elevated temperature.The study shows that the local buckling stress decreases rapidly with the increase of width to thickness ratio, and the ultimate stress decreases slowly when width to thickness ratio is large enough.The influence of initial imperfection on local buckling stress is insignificant. Restrained effect of the flange on the web at elevated temperature is more obvious than that at room temperature; and the limited ratio of width to thickness at elevated temperature is different with that at room temperature.

Abstract:According to in-situ direct shear test and indoor direct shear test, the shear strength features of solidification gangues are researched. The experimental curve of shearing strength-shearing displacement shows that with the increase of the moisture content of the sample, the solidification gangue sample has shown obvious characteristics of viscoplastic body. Based on the on-site sieve grading of gangue samples, the moisture content and compactness of samples are adjusted to determine the influence of the changes on the shear strength of solidification gangue, and meanwhile the influence mechanism of the fine particle states changes on the shearing strength of solidification gangues is under research. The last, by the comparison of the shear strength test parameters of in-situ direct shear test and indoor direct shear test of gangue samples, the main causes of differences in shear strength parameters of consolidation gangue samples is analyzed.

Abstract:4-benzoyl-4-methoxyldiphenylethylene, 4-benzoyl-3,4-dimethoxyldiphenylethylene, and 4-benzoyl-3,4,5-Trimethoxyldiphenylethylene are studied as near-ultraviolet photoinitiators. Light trigger property is studied systematically via illumination experiment and Photo-DSC, and the influence of photoinitiativity is studied by different amount of methoxyl groups, illumination time and concentration of photoinitiator. The results show that the monomer polymerization rate of three compounds measured by the Photo-DSC are 0.065 32 s -1, 0.102 01 s -1 and 0.163 23 s -1. Thus photoinitiation of photoinitiators can be effectively increased by increasing the number of attached methoxy groups. The ratio of photopolymerization yield between two photoinitiators gradually decreases with the increase of illumination time or concentration of photoinitiator, and it tends to be stable.

Abstract:A new tailings pond of Pingchuan iron Co., Ltd. located in Yanyuan county of Sichuan province has been used for the project instance in this research. The dry slope’s geometric features and particles’ distribution rule of the tailings dam are obtained by a model test of building tailings dam, and so do the mechanical properties of tailings by the soil test. Based on the discrete element theory, we obtain the mesomechanics parameters by comparing the results of biax test numerical simulation with PFC 2D to the mechanical properties obtained by the soil test. Also the contact forces among particles, particles’ motion and deformation characteristics of tailings dam model have been studied. The results clearly show that: 1)There are some big and stable force chains in initial dam, and which directions are almost inclined upward with 45°. The particles’ contact forces in subdam grow with the increase of depth, and the contact forces near the embossment point of bedrock are much bigger and more intensive than those in other area. 2)The particles’ motions in initial dam are insignificant. The motions of particles in subdam near the inner slope of initial dam are significant, which directions are almost upward along the inner slope of initial dam. Some particles in the surface of subdam tumble along the slope, which motions are much significant. There is a typical slip plane in subdam, and the motions of the particles above the slip plane are much obvious. 3)The structural change of initial dam is small, but the structural deformation of subdam near initial dam’s inner slope is much significant.

Abstract:Based on a heavy oil reservoir in Bohai oilfield, a numerical simulation model of cyclic steam stimulation is built based on the characteristics of offshore oilfields. The orthogonal experimental design and numerical simulation are used to optimize the steam injection intensity, steam injection rate, bottom hole steam quality, steam temperature, soaking time and liquid producing capacity. The visual analysis and variance analysis are used to analyze the results. The results show the optimized injection and production parameters are steam strength 20 t/m, steam injection rate 250 m 3/d, the bottom steam quality 0.5, steam injection temperature 340 ℃, soaking time 5d, and the production rate 200 m 3/d. The influence factors on the effect of steam soaking decreased gradually in the following order: steam strength, the bottom steam quality, the production rate, steam injection rate, steam injection temperature, and soaking time. The results can provide theoretical guidance for injection and production parameters optimization of steam huff and puff in offshore heavy oil reservoirs.

Abstract:The offshore, deepwater and equipment concentration development trends of port requires better windbreak capacity of port handing equipments. The portal crane is taken as research object, and the wind field’s characteristics and whole crane wind load of the portal crane under sudden strong winds or gusts are researched. The CFD theory and FSI analysis methods are used to analyze the distribution of pressure and velocity in the apron fluid field. According to the results, the fluid structure interaction analysis function of ADINA software are used to make numerical wind tunnel simulation and analysis, and quantify wind load’s composite force and moment in each coordinate direction of the crane. Base on above results, the ways of port windbreak are analyzed and the results will provide management strategy and theoretical basis for windbreak safety of port crane.

Abstract:The traditional solar street lamp controller is constrained with the low charging efficiency and the low precision of the constant current source. A novel solar street lamp controller based on the multi-channel PWM constant current technology is designed. A composite DC-DC converter is adopted to realize charging and discharging efficiently through controlling multi-channel PWM signals. During the charging stage, the efficiency of charging is improved by tracking the maximum power point with the perturbation and observation method. During the discharging stage, the duty cycle of the relevant PWM signals are used to implement the high precision constant current source for driving the LED street lamp, which can be adjusted automatically through real-time detecting of the lamp’s actual current. The test results show that the charging efficiency of the street lamp controller can be improved evidently, and the charging speed increases 4% to 7%. Furthermore, the precision of the constant current source reaches a high level of 2.5%.

Abstract:Cutting-carrying mechanism of CO2 is basic for rational hydralics design, which helps to achieve safe and efficient use of drilling with supercritical carbon dioxide. In this view, change law of partical size distribution and influences of drilling parameters on cutting-carrying efficiency is simulated and analyzed, with consideration of the influences of physical parameters change of CO2. Results show that there is no positive correlation between change law of partical size distribution and partical diameter for the existence of mutual interference, which demonstrates Oulerian method used to analyze cutting-carrying mechanism feasible. Pressure and temperature influences the change law of partical size distribution, and the cutting-carrying efficiency increases as the increase of pressure and the decrease of temperature, which agrees with experimental results. Larger displacement and lower ROP helps to improve cutting-carrying efficiency, and actual critical displacement is larger than theoretical value calculated with Ahemd method. The cutting-carrying efficiency decreases as eccentricity increases and then increases as the eccentricity is beyond 0.8. Outcomes offers important basis for the improvement of practical skills.

Abstract:The main factors of fault slip are analyzed in this paper.A simplified model of thrust fault is constructed by FLAC 3D and the basic change law of elastic energy,vertical stress,shear stress and slippage of fault plane in the conditions of different distance from the fault,different fault dips and different throws is analyzed.And then the influence law of fault activation induced by coal extraction based on the characteristic parameters of thrust faults is revealed.The study results show that the elastic energy near faults will decrease with the distance increases from faults and will increase with fault dips or fault throws increase in the hanging wall or the footwall mining.But the focus level of elastic energy is high in the footwall mining.Vertical stress and shear stress variation of the different characteristic parameters is complicated.In a word,the increase of shear stress is obvious and the variation of vertical stress is not obvious.And the situation is prone to faults activation. Fault slippage will decrease with the distance increase from faults in the hanging wall mining or the footwall mining.And fault slippage will increase with fault dips increase and will decrease with fault throws increase in the hanging mining.If faces are mined in the footwall,the reverse results will show.

Abstract:The influence factors of biochar stability are discussed on the basis of its concept,and the research methods and prediction models of biochar stability are comparatively analyzed.The results show that the stability of biochar is attributed to highly aromatic structure and protective effect of soil aggregates.The main factors affecting biochar stability are temperature,raw materials and environmental conditions.The optimal evaluation method for biochar stability is to combine the isotope labeling with double exponential model.Then,it is pointed out that different types of soil,crop rotations and prediction model is the development direction of current biochar stability research.

Abstract:Coal seam appears dislocated when mining encounters a fault, and stripping ratio will drastically change, then mining engineering is difficult to be continued. In order to maintain the stability of stripping and mining, mine engineering transition succession and stripping ratio should be controlled when mining through faults. Mathematic models of mining stripping ratio and coal seam thickness, fault angle and fault throw are built to analyze the impact of different unexploited coal pillar widths on slope stability. The relationship between the pace of development and simultaneous coal mining beach is analyzed and the dynamic drawdown speed is determined to ensure a smooth transition succession in mining engineering. Combing with the surface mine problems that occur in fault area, this paper takes Shengli East No.2 Surface Mine mining through F61 fault as a case study. The results show that the stripping ratio is balanced and the production keeps stability, moreover, the economic benefit is improved with the method of mining through faults and production capacity succession.

Abstract:Aiming at the problem that there are many switching delay and switching times in fuzzy control system, a fuzzy control based vertical handoff algorithm is proposed to solve the problem of handoff. The received signal strength is adopted to set up the threshold, and the ability of decision is improved. The network parameters and service type are set as decision factors, and analytic hierarchy process is combined with the parallel fuzzy control system to shorten decision time and select the best suitable network for users. The simulation result shows that the algorithm can reduce the time and frequency of handoff and enhance the performance of the system. Compared with the traditional handover algorithm, the algorithm considers comprehensive decision factors, and it not only takes the use of the environment and the cost of the user terminal into account, but effectively ensures the quality of service of the network.

Abstract:In the smoky foggy hazy and other harsh outdoor conditions, scene images captured severely suffer from poor contrast and visibility. Aiming at the problem, an improved method is proposed to overcome the dark region expansion quickly on dark-channel prior. By calculating difference of dark channel, the method can effectively distinguish the different depth of fields in adjacent area approximately and estimate transmissivity. Experimental results demonstrate that the new method provides more speed and higher dehazing quality than other techniques.

Abstract:Pre-established end-to-end paths between the source and destination nodes are necessary in traditional routing protocols, and the quality of service will be affected by the frequent re-routings while the wireless channel is unstable. To support the real time voice service, an opportunistic routing mechanism is proposed in this paper. Without pre-established end-to-end paths, multiple Route Request (RREQ) and Route Reply (RREP) messages are exploited to construct the forwarding table, and nodes within the forwarding table have opportunities to forward the packets they overheard; moreover, the number of forwarded data packets can be restricted according to the priorities of forwarding nodes. Simulation results show that the proposed mechanism can effectively reduce the end-to-end delay and enhance the packet delivery ratio for the real-time voice service, thus the quality of service can be dramatically improved over the unstable wireless channel.

Abstract:The Pr 3+/TiO2 photocatalyst with different amounts of doped Pr 3+ and calcination temperatures are synthesized by sol-gel method and characterized by XRD, FT-IR and SEM. Basic fuchsin experiment is chosen to evaluate photocatalyst activity. The results show that the synthesized samples are anatase TiO2 with the Pr 3+ doped. While it has been found that rare earth interrupts the transformation from anatase to rutile. Photocatlytic experiment results show when the sample is calcined at 400 ℃, containing 0.2% Pr 3+ /TiO2 and 1 mL 30%H2O2, without lighting, and t=120 min,the degradation rate is 100%

Abstract:Temperature is the main factor that affects the stability of magnolia rostrata extract. The thermal stability of magnolia rostrata extract is studied. The contents of honokiol and magnolol in the extract obtained by CO2-supercritical fluid extraction(SFE-CO2)were determined by HPLC during the drying process at different temperatures, and the degradation equations of these two ingredients were explored. The degradation reactions of magnolol and honokiol in the drying process were first-order, and the rate of degradation was faster at 100℃. Higher temperatures were selected to examine the accelerated degradation isothermally, and the shelf lives of honokiol and magnolol were found to be 1125.6 h and 975.7 h at 25℃. In order to guarantee the preparation quality lower temperature and shorter time during drying and storage for the SFE-CO2 extract of magnolia rostrata is preferable.

Abstract:The average per-hop distance is one of the factors which affect the positioning accuracy in DV-Hop algorithm. Aiming at positioning errors caused by the average distance per hop, the average distance per hop of anchor nodes and unknown nodes have been improved and optimized in this paper. First, the average per hop distance of anchor nodes is computed by introducing genetic algorithm; Then the average distance per hop of the unknown node is weighted by using the average distance per hop of anchor nodes which hop count is less than or equal to 3 to reduce errors caused average distance per hop. Ultimately the accuracy of positioning is improved. Simulation results show that without additional hardware cost, the improved algorithm can effectively improve the positioning accuracy of the algorithm and has good stability.