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Combined with the research of dynamic mechanical properties of concrete under earthquake action by lots of scholars home and abroad, research status of rate-dependent test within the scope of the Earthquake strain rate (10-4/s~10-1/s) on common concrete materials is reviewed, including the dynamic uniaxial compressive properties, dynamic uniaxial tensile properties, as well as multi-axis dynamic performance. The influence of the Earthquake strain rate on concrete strength, energy absorption capability and deformation capacity such as the elastic modulus, Poisson's ratio, peak strain, and ultimate strain are discussed intensively. Results show that the tensile strength, compressive strength and energy absorption capability of concrete increase with the increase of strain rate, while the results of the various parameters of the deformation ability are not consistent, the reason is that different test results caused by different test conditions. In this paper, the reference for the further study on rate-dependent of concrete in the future is provided.

Based on the fatigue damage mechanism, fatigue life, stiffness degradation, crack width change, bending, shear fatigue properties and other aspects, this paper introduces the research progress of the fatigue properties of ordinary reinforced concrete beams. And the existing reinforced concrete beam flexural, shear fatigue properties of research ideas, methods and results are summarized, providing the basis for further study on the fatigue performance of reinforced concrete beams. At present, the research results show that the fatigue damage of reinforced concrete beam is basically in accordance with the law of the three stages. In the early stage of fatigue, the tensile concrete cracks and exits, and the damage develops rapidly. In the middle of fatigue crack growth, fatigue damage is developed into a more moderate linear growth. In the late stage of fatigue, fatigue fracture occurs in the steel bar, and the bearing capacity of the beam is quickly lost.

Introducing research progress of rate-dependent tests by domestic and foreign scholars, strain-rate effect on dynamic mechanical properties of concrete are reviewed. Classified descriptions of research results on dynamic load tests of concrete at home and abroad are provided, including uniaxial compression tests, uniaxial tensile tests, and multi-axis tests; strain-rate effects on concrete strength and deformation properties in each test are respectively discussed; and strain-rate effect on concrete energy absorption capability are described.

3,3-Dinitroazetidinium hydrochloride (DNAZ·HCl) is a novel insensitive high energy explosive. The density functional theory (DFT) method of the Amsterdam density functional (ADF) was used to calculate the geometry and frequencies. The detonation velocity (D) and detonation pressure (P) of DNAZ·HCl were estimated using the nitrogen equivalent equation according to the experimental density. Results showed that the initial decomposition step of DNAZ·HCl is the loss of NO2from C2 and Cl is the point of molecular reactivity.DandPare 6881.40 m·s-1and 20.85GPa, respectively.

3-Amino-4-aminoximidofurazan (AAOF) and 3-Amino-4-chloroximidofurazan (ACOF) are important precursor of synthesizing new furazanon (furoxano) energetic compounds. The density functional theory (DFT) method of the Amsterdam density functional (ADF) was used to calculate the geometry and frequency of AAOF and ACOF. The detonation velocity (D) and pressure (P) of the two compounds were estimated using the nitrogen equivalent equation according to the experimental density. Results showed that the initial decomposition step of AAOF and ACOF is the loss of OH from N4, the changed in group have some effect on HOMO, but this have little effect on HOMO, AAOF has better thermal stability and detonation performance than ACOF.

The effect of solvents on ethanolysis of SPC was investigated. Heptane, cyclohexanethe, ether and MTBE were selected because of their satisfactory propertities. Under the certain reaction conditions, ether and MTBE have an higher conversion of SPC and yield of GPC than the other two because of their slightly higher polar and lower viscosity.

3-Amino-4-aminoximidofurazan (AMF) and 3-Amino-4-cyanofurazan (ACF) are important precursor of synthesizing new furazanon (furoxano) energetic compounds. The density functional theory (DFT) method of the Amsterdam density functional (ADF) was used to calculate the geometry and frequency of AMF and ACF. The detonation velocity (D) and pressure (P) of the two compounds were estimated using the nitrogen equivalent equation according to the experimental density. Results showed that the initial decomposition step of AMF and ACF is the loss of NH2 from C2, N3 is the point of molecular reactivity of AMF and ACF, the changed in group have little effect on HOMO and LUMO. AMF has better thermal stability than ACF, but the detonation performance of ACF is finer than AMF.

N-benzoyl-3,3-dinitroazetidine (BDNAZ) is a insensitive high energy explosive. The detonation velocity (D) and pressure (P) of BDNAZ were estimated using the nitrogen equivalent equation according to the experimental density. The density functional theory (DFT) method of the Amsterdam density functional (ADF) was used to calculate the geometry and frequencies. Results showed thatDandPare 5568.08 m·s-1and 12.34 GPa, respectively, the initial decomposition step of BDNAZ is the loss of NO2from C2 and O5 is the point of molecular reactivity

Studies on size effect of plastic hinge of RC members are still rare at the present stage. This paper explores the development and failure characteristics of plastic hinge of pure bending section and analysis relevant mechanical parameters of size effect. Measured tests data show that plastic hinge equivalent length is close to the depth of beam which has no obvious size effect. However, plastic rotation capacity of plastic hinge has a significant size effect. Plastic rotation capacity decreases with section size increases if evaluate it based on ultimate load state, and increases with section size increases if evaluate it based on measured max load state.

Studies on size effect around deformation performance of RC members are carried out relatively fewer at present. This article evaluated bending deformation capacity and size effect characteristics of RC cantilever beams by means of test method. And decomposed various deformation components with size effect factors considered, including bending, shear and bar-slip deformation and so on. The article focus on discussing bending deformation components at different loading stage and putting forward corresponding distribution functions. Calculation and experimental results show that bending deformation characteristics have significant differences on specimen dimensions, especially in nonlinear loading stage after longitudinal reinforcement yielding. Large size members have a significant concrete crushing process. ductility reserves show a growing trend with specimens size increasing. Bending deformation ability depends on average stiffness along overall beam before longitudinal reinforcement yielding. After plastic hinge forming, its bending performance will be decided by average stiffness within hinge region equivalent length.

It is become a relative mature technique now that Active Power Filter can do harmonic suppression and reactive compensation to alternating current net of nonlinear load. This paper contrasts passive and active filter technology in harmonic suppression, and introduces the classification of passive filter as well as working principle. This paper also discusses current-source APF consisting of multi-modular and phase shifted SPWM converters and cascade multilevel converters applied in current-source APF which can carry out high switch frequency effect under the lower switch frequencies. Finally, this paper gives a comprehensive discussion on APF technique and prospects its development in China.

Experimental studies on size effect of flexural behavior of reinforced concrete beams are not carried out fully. Standard values are based on test results of small-size components, which are different from large-size components in practical engineering. For size effect on quasi-brittle materials such as concrete, related researches have been carried out for many years, but related test study combined with concrete structures or components are not sufficient. This article is based on experimental study of 13 reinforced concrete free beams, obtaining test data during different loading stage, such as carrying capacity, deflection, steel and concrete strain etc. Test results show that size effect of flexural behavior of RC free beams is mainly reflected in reinforcement yielding stage and concrete crushing stage. The negative size effect due to concrete material is not significant. Yet internal force arm and longitudinal reinforcement have a positive size effect on flexural behavior, strength and ductility reserves show a growing trend with specimen size increasing. The safety of calculation theory of bearing capacity in code is verified indirectly.

Analysis and calculation methods of reinforced concrete structure at present are based on test results of small-size component. This paper carried out test research on size effect of flexural capacity of RC cantilever beams. Sectional height of the biggest experimental specimen is 1000 mm. Obtaining detailed test data during different loading stage, such as carrying capacity, deflection, steel and concrete strain etc. Through observing test phenomenon and analyzing test data, verifying the safety to calculation formulas for ultimate bearing capacity of flexural members. Strength and ductility reserves show a growing trend with specimen size increasing.

In order to research on seismic performance of full-scale beam-column joints of RC frames under low cyclic loading, finite element software ABAQUS is used to nonlinear analysis. Analysis results show that: the process of load carrying and fracture development of beam-column joints are simulated using concrete damage plasticity model; nonlinear finite element method is easy to obtain stress-strain relationship; and can effective analyses the complex mechanical behavior of core areas of joints.

Size effect, referring to mechanical properties of materials change with the geometry changes, is the basic characteristic of brittle and quasi-brittle materials. Researches show that for the concrete material, compressive strength, split tensile strength and tensile strength decrease with the size of components increases, for RC structures, size effect also exists. The development and current situation in size effect are presented from three aspects, including concrete, RC members and the application of the code. And then, the developing trends of size effect of RC members are proposed.

Considering nonlinearity, time-variation and inertia during temperature control of large supercritical extraction units, especially under the disturbance of system flow and pressure, a multi-artificial neural network (ANN) predictive control policy was proposed. It contains a radial basis function (RBF) ANN, aiming to approach nonlinear extraction temperature object and predicting output variable based on this model. There is also a back propagation (BP) ANN controller, seeking the optimal controlling signal by feedback correction and rolling optimization on purpose to overcome the time-variation and inertia. The experimental results indicate that this control strategy has excellent dynamic response performance, small steady state error and strong robustness.

In view of the insufficiency of central air-conditioning system that FCU, water pumps and air blower’s movement connot match with the actual operating load when varying duty, an energy saving control system for central air-conditioning based on terminal temperature measuring and frequency conversion control technology is proposed. This system can real-time measure different floors’ and nods’ temperatures in the building, and export orders to control the frequency of FCU, chilled water pump, cooling water pump and cooling tower air blower. To overcome big delay, large inertia and variable condition of control object, the dnamic fzzy nural network algorithm(DFNN), is applied into the control system. According to the practical running situations, the energy saving control system has advantages as high energy saving rate, high stability, good maintainability, which may be promoted the application vigorously.