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Weld parameter is an important factor affecting micrographic structure and mechanical properties of weld joints. It was investigated by metallographic experiments and mechanical property experiments for the influence of weld heat input on dissimilar steel weld joint of penstock using B610CF and 16MnR steel in water conservancy and hydropower engineering using shielded metal arc welding method and mixed active gas arc welding method. Metallographic experimental results show that in weld metal with the increase of weld heat input the quantity of bainite decreases and crystalline grain is larger when using the same welding method; but in both B610CF and 16MnR steel heat affected zone, there is no distinct difference in microstructure. Mechanical property experimental results show that in weld metal with the increase of weld heat input the impact toughness decreases when using the same welding method, but in both B610CF and 16MnR heat affected zone, there is less difference in impact toughness; and there is no distinct difference in tensile strength and plasticity of weld joint. So moderate weld heat input is recommended.

Under the action of surface-underground unite mining, Slope stability is related to underground mining location and mining space dimension, This paper studies the underground mining of slope outer region on slope stability influence characteristic; With the increase of mining width stability coefficient increases, when mining width reach a certain value stability coefficient tends to constant; With the increase of mining depth stability coefficient increases, when mining depth reaching a certain value stability coefficient began to decrease; this show that the underground mining has a direct effect on slope stability, its size needs a combination of their relative spatial position relation and mining geometric size to determine.

Microorganisms to improve oil recovery technology is a comprehensive technology of using beneficial activities and metabolites to enhance oil recovery. The obvious effect of field application and good economic benefits make it be active in the field of oilfield development in the long term. In this paper, through indoor experiments in different concentrations of microorganisms bacteria, different concentrations of nutrient solution and function time, evaluate oil sands de-oiling efficiency. Based on test results, optimize the compound of bacteria that from different sources and find out when the ratio of field and lab bacteria is 1:7, the de-oiling efficiency reach the peak of 86.47%, which further expand the mechanism of microorganisms enhanced oil recovery.

In order to investigate the effect on manufacturing quality of focus position misalignment between laser beam and powder convergence in laser metal deposition shaping (LMDS) processing, several experiments including single-track monolayer, straight thin-wall and ring thin-wall were made. The measurements and analysis on shape, size and surface quality of the experiment parts were carried out. An omnidirectional detecting method to check the misalignment of focus position was brought forward and tested. The results indicate that the misalignment of focus position directly affects the quality of shaping parts and shows the regularity, the detecting method can easily detect the focus position misalignment on random direction and angle and guide the adjustment on them.

Using SiO₂ – Al₂O₃ – B₂O₃ – K₂O – Na₂O system glaze as base material, adding silicon powder or alumina powder with grain size 15μm by the mass percent of 10%, 20%, 30%, respectively, melting properties of glaze were investigated. Slilica solution as binder, the anti-oxidation coating were prepared. Oxidation resistance was determined by coating to the surface of the Al2O3-C specimens. The results show that additives can raise flow temperature prominently, but has little influence on softening point and semi-sphere point; Glazing temperature ranges are obtained with different additive contents; Glazing temperature rises with addition of silicon; Glazing temperature range widens with silicon adding; Glazing temperature ranges were not strictly corresponding with softening temperature point and flow temperature point; But differences were not tremendous; glazing temperature ranges can be estimated from softening temperature point and flow temperature point. Alumina has not prominent influence on glazing temperature, but glaze forms smoothly with alumina, and oxidation resistance was good.

The relationship between heat treatment processes and grinding performance of cold die steel 9Mn2V had been built in this paper. Serious meshy segregation of carbide, excessive amounts of retained austenite, coarse and inhomogeneous distribution of material structure were significant causes of grinding burn and grinding crack. In order to improve the abrasion-resistance and mechanical properties of workpiece material, cryogenic and tempering treatment were added. Disappear of meshy segregation of carbide, network carbide was within second grade, retained austenite content was within 4%, martensite became much more fine and homogeneous, all of these advantages could be obtained by adopting cryogenic and tempering treatment in twice. The grinding experiment results indicated that workpiece material 9Mn2V which using this process could provide superior grinding performance.

Colored binder was prepared by mixing aromatic oil with petroleum resin and functional polymers. Then the colored binder combined with pigment, aggregates, and additives resulted in colored asphalt mixture. Futher modification by nano-montmorillonite or coupling agent, higher pavement performance was chieved. The paving technical indexes of the mixture such as physical properties, moisture susceptibility, and high temperature stability were tested. The results demonstrate that the high temperature stability and moisture susceptibility can be satisfied with the requirements of hardscape projects including asphalt driveways, asphalt walkways, asphalt streets, asphalt bike paths, and asphalt walking paths.

In this paper, numerical simulation technology was applied to comprehensively analyze and study the mechanical properties of the derrick. The three-dimensional finite elements analysis model of the derrick structure was established, which provided the physical model of the numerical simulation and the optimization of the three-dimensional derrick. The finite element simulation method was applied to analyze and optimize the mechanical and deformation of the three-dimensional derrick structure, so that the theoretical method to study and design the three-dimensional derrick using finite element method was established.

Detecting community structure from complex networks has triggered considerable attention in several application domains. This paper proposes a new community detection method based on improved genetic algorithm (named CDIGA), which tries to find the best community structure by maximizing the network modularity. String encoding is used to realize genetic representation. Parts of nodes assign their community identifiers to all of their neighbors to ensure the convergence of the algorithm and eliminate unnecessary iterations when initial population is created. Crossover operator and mutation operator are improved too, one-way crossover strategy is introduced to crossover process, the Connect validity of mutation node is ensured in mutation process. We compared it with three other algorithms in computer generated networks and real world networks, Experiment Results show that the improved algorithm is highly effective for discovering community structure.

Hot stamping represents an innovative manufacturing process for forming of advanced high strength steels, implying a sheet at austenite temperature being rapidly cooled down and formed into a die at the same time (quenching). This affords the opportunity to manufacture components with complex geometric shapes, high strength and a minimum of springback which currently find applications as crash relevant components in the automotive industry. With regard to the numerical modeling of the process, the knowledge of thermal and thermo-mechanical properties of the material is required. The material model under hot stamping condition of advanced high strength steel should be set up. The Finite Element Analysis is an essential precondition for a good process design including all process parameters. This paper presents the finite element simulation of a hot stamping process and describes a number of procedures for the simulation of hot stamping. In addition, the development direction is pointed out at the end of this paper.