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A significant amount of research on the vibration and sound radiation of the cylindrical shell has been carried out and reported. The cylindrical shell was usually assumed to be submerged in an infinite fluid. However, the fluid region surrounding the cylindrical shell is bounded. Free vibration and forced vibration characteristics of finite cylindrical shells semi-submerged are studied in this paper, based on energy functional variational principle. The combined form of the triangular series and the Fourier series is used for the displacement of the cylindrical shell, then the orthogonality can be used to eliminate the other two directions after the variation, and only the radial displacement is kept. The relationships between the amplitudes of fluid load and the amplitudes of the radial displacement are established by the orthogonal processing of the continuous conditions of the solid-liquid coupling contact surface and the boundary conditions of the free liquid surface. Finally, the fluid structure coupling control equation is obtained. The results show that the method is correct and effective, in addition, providing a new thought for solving similar problem.

Cognitive radio can improve the spectrum utilization efficiency of spectrum band. So spectrum sensing is the key technology in cognitive radio network. Our main task is to design a cyclic detector with better detection performance than energy detector. This paper studies single-user spectrum detector in cognitive radio networks, including cyclic spectrum detector and energy detector. We firstly analyzed the energy spectrum sensing mathematic model for comparison, then we proposed the new simulation model and detailed simulation steps of this cyclic spectrum sensing detector. Simulation results demonstrate that the cyclic spectrum detector has better performance than energy detector while the SNR of channel condition is low.

This paper describes the composition and working principle of aircraft parts flexible automatic assembly platform, and gives the detailed analysis and design of flexible automatic assembly platform of mechanical structure and motion adjusting control system. The two types of multi plane assembly shows that automatic assembly platform automatic adjusting is reliable, operation control system and motion mechanism runs stable, this system can meet the various needs of automatic assembly platform of aircraft components, and it realizes the work mode of assembly and products in one to many during the aircraft components Assembly process.

The main task of spectrum sensing in cognitive radio network is to decide whether the primary user is occupying the specific spectrum band or not. So the main purpose of spectrum sensing is to design a detector with better detection performance. This paper studies a spectrum sensing method with clustering under cognitive radio networks. We studied the cooperative spectrum sensing model with clustering by hard fusion rule, and also proposed the simulation model and steps of this cluster-based spectrum sensing problem under Majority rule. Simulation results show that the spectrum sensing method with clustering has better performance than the other methods.

This paper proposes a kind of method of socket programming combining matlab and VB based on COM component aimed at socket programming. An example has been illustrated to declare the application of this method. It shows user-friendly graphics interface applied in VB, and graphic display in matlab.

Aiming at the disadvantages of current error measuring instruments of ball screw helix, a new screw helical line error measuring device is developed, moreover, a new method called electronic generative metrology (EGM) is introduced. The problem of measuring head deformation has been settled down because of installation of two driving motors on the instrument, so it is easy to achieve dynamic high precision measurement. Taking the long grating and circular grating as length and angle measurement datum respectively, the torque motor and linear motor are able to form position close-loop control. The measuring head frame is installed on air flotation slider which has characters of high kinematic accuracy and stability, so it guarantees high measurement accuracy. Then, the measurement accuracy analysis of the device is given. And the last, the EGM is developed by using this new research tool. Related experimental studies are conducted to verify the feasibility of the new method.

The lateral longitudinal beam is one of the most important mechanical parts in secondary protection equipment of electrical power system. Basing on the simulation analysis platform of ANSYS Workbench, the standardization of the modular hole of the lateral longitudinal beam is studied in this research. The static and dynamic finite element analysis of the lateral longitudinal beam are used to obtain Von-Mises equivalent stress, deformation data, the natural frequency and vibration mode of five orders. The contrastive analysis of the results of finite element analysis provides a kind of theoretical instruction for the dimension selection of the modular hole.

With a bridge which appearing disease cause a insufficient carrying capacity as background, this paper used bridge finite element analysis software combined with field loading test to analyze Prestressed Carbon Fiber Plate reinforcement effect .The results show that the reinforcement method has a remarkable effect in improving the structure stiffness and the natural frequency of vibration , improving the carrying capacity of old bridge and overall security.

Two coupling models, the fluid-structure coupling and the acoustic-structure coupling, have been studied in this paper, in order to describe the free vibration of a fluid-filled cylindrical shell under internal pressure from two different angles. For both models, a new approach to solve the characteristic equation is presented, using the Galerkin method to obtain the natural frequency of each mode. The comparison shows the results of two models are in good agreement. Although the two models are based on different mechanical theories, the mathematic essences are confirmed to be the same, both derived from Bessel functions.

In this paper, based on the parabolic interpolation function of nonlinear Lagrange, we establish the mathematical model of business translation graphical teaching method. In order to verify the availability and reliability of the model and algorithm, we test the performance of graphic business English translation platform. After testing the mixed signal of platform, the current with fault is lower than circuit without fault. The peak voltage of triangular wave is about-6V and 6V. According to the response curves of English translation circuit, different sequencers realize the parallel translation. It improves business English translation speed, and provides the technical reference for the innovation cultivation of business English talents.

As a representative application of Web 2.0, microblog is now becoming one of the most popular social networks. There has been an increasing number of research about user interest in social networks. Based on these related works, an improved user interest model for microblog user recommendation is presented in this paper. By fetching user data, generating datasets, building user interest models and combining these models, a recommended user list is generated to help people find users they interested. Experimental results show the effectiveness of the combined model.

For the poor ride comfort performance of the articulated dump truck, the dynamic model of ADT was built and its dynamic characteristics were also studied through finite element and multi-body system dynamic theory. According to the modal neutral file generated by finite element software with the flexible processing, the flexible coupling virtual prototyping model was set up for the multi-body dynamics simulation in ADAMS to obtain and analyze the data about the ADT ride comfort. This paper provided references for the design, redesign and optimization of the ADT.

This paper analyzed a blind source separation algorithm based on cyclic frequency of complex signals. Under the blind source separation model, we firstly gave several useful assumptions. Then we discussed the derivation of the BSS algorithm, including the complex signals and the normalization situation. Later, we analyzed the complex WCW-CS algorithm, which was compared with NGA, NEASI and NGA-CS algorithms. Simulation results show that the complex WCW-CS algorithm has the best convergence and separation performance. It can also effectively separate mixed image signals, whose performance was better than NGA algorithm.

Risk assessment of debris flow is the core content for debris flow disaster forecasting and prevention work. And then, risk assessment of debris flow also becomes the key method in potential debris flow hazards forecast. However, kinds of hazard-affected indictors will be referred during the risk assessment process. In this study, set pair analysis model for risk assessment of the debris flow gully in Tibet southeast is established. With the model final outputs, it can successfully solve the problem of considering all the weight values of the hazard-affected indictors in debris flow evaluation system. Finally, risk assessment of typical debris flow gullies in Tibet southeast area are conducted out by the set pair analysis model, and the model outputs also give a well agreement to the actual.

As the span became longer and the accumulation of service period of bridges, the problem that deflection of main span has also clearly emerged. To reduce long term deflection of large-span prestressed concrete continuous rigid frame bridges, tendon group-additional bending moment influence matrix method is proposed to optimize the design of prestressed reinforcement. Based on elasticity assumption, an optimum prestressed tendon arrangement can be derived by least square method. The new design is tested to be effective considering shrink and creep effect which fulfills the practical application.

Anti-seismic property was essential in the progress of bridge designing and construction due to destructive power of earthquake disaster and increasing span of bridge. This paper elaborated theory method of analysis, taking five spans continuous cable-stayed bridge which was half floating system as an engineering background, and using method of special finite element analysis to calculating dynamic characteristics and seismic response respectively which also considered longitudinal limit damping and stiffness of cable under longitudinal, transverse, vertical and three-dimensional seismic oscillation. Fundamental frequency of cable-stayed bridge was affected significantly with considering longitudinal limit damping, so connection measures would be determined reasonably in designing and analyzing anti-seismic property of long-span cable-stayed bridge. When response spectrum analysis was adopted, longitudinal and vertical displacement were larger than lateral displacement under longitudinal seismic oscillation, lateral seismic oscillation only affected the structural lateral displacement, and vertical seismic oscillation affected vertical and longitudinal displacement.

The inertial force and torque produced by the crank-rod mechanism is an important factor of vibration in single-cylinder internal combustion engine. Based on MATLAB software, the analysis model of crank-connecting rod-piston mechanism of S195 diesel engine is established, and the dynamic characteristic parameters of the main parts can be obtained. The results showed that the simulation analysis can get the kinematic and dynamic data of the mechanism conveniently and accurately, which provides a feasible advanced method for the design and development of diesel engine.

An eco-innovative product design method integrating the concept of green design, process technology, product structure, material selection and other effects. Eco-innovative design evaluates how a product impacts the environment during its entire life cycle. Each system will thus follow one or more patterns of evolution as given by Altshuller. This paper attempts to indicate how TRIZ tools and MEMS (microelectromechanical systems) can be used in eco-innovative design research activities. An idea generation support method by using TRIZ is proposed.

A macromoleclar polymer (Sulfonated polystyrene - Polyhydromethylsilane, SPS-PMHS) was synthesized from polystyrene by sulfonation, acylation, amination and hydrosilylation. Characterization of the hydrosilylation process was performed with attenuated total reflectance-fourier transform infrared (ATR-FTIR) spectroscopy. The SPS-PMHS was homogeneously dispersed in the Nafion matrix with doping level of 33.3 wt %. Experimental results show that the yield tip-displacement values of the polymer nanocomposite have not been enhanced, but the nonaqueous working time is 2.7 times higher than that of the virgin nafion.

A novel three-dimensional MnO2 catalyst have been successfully prepared by a facile hydrothermal route. They were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). In addition, they showed excellent catalytic activity over the aqueous degradation of methylene blue (MB).

According to the TTCP geometry, change the wrap-around fins to the planar fins. Construct the flow-field then generate the grid. Utilizing the computational fluid dynamics method, the lift, drag and roll moment coefficients are computed in different angles of attack. The roll moment coefficients are computed from the flow field solution and compared with the experimental results. The results show good agreement with the experimental measurements for various flight Mach numbers. The aerodynamic characteristics of these two fins are similar to each other from the numerical solution. If consider the lift, drag and center of pressure coefficients merely, these two kinds of fins can be interchanged .But the roll moment coefficient in Wrap-Around fins and planar fins are different. They need to calculate separately.

Because of changes of the epoxy amount in syringe and air compressibility, the time-pressure dispensing has proven to be a challenging task in achieving a high degree of consistency in the dispensed liquid dots volume. Taking residual pressure and non-Newtonian fluid into consideration, a self-adaptive model of the dispensed liquid dots volume was developed for the whole dispensing process. Based on the liquid dots volume model, combined with the syringe air chamber volume prediction model, a time-pressure switch control method was put forward following the principle of time preference control. Numerical simulation has been conducted in the MATLAB using the conventional PI algorithm. Results show that the self-adaptive model can be very well response to the influences of air chamber volume changes to the dispensed liquid dots volume and the proposed control method can significantly improve the dots volume consistency.

To study the value of humanity in the development of electrical engineering, the paper initially explores the role of humanity in electrical engineering, holding that humanity is the reason why electrical engineering strives for and the object that electrical engineering focuses on. About the advantages of humanity in electrical engineering, the paper considers that humanity will do good to electrical engineers, electrical engineers, electrical enterprises as well as the harmony of society. To guarantee the charm of humanity in electrical engineering, the paper confirms the necessity of obtaining teachings from traditions, acquiring experiences from other countries and learning lessons from mistakes. Briefly, humanity is a key to the development of electrical engineering and its value cannot be ignored.

A novel architecture of tightly-coupled SINS/ GPS integrated navigation system based on FPGA for target missile is proposed in this paper.The whole system is built on a single single FPGA chip containing a Nios II soft-core processor. In addition, the embedded real-time operating system μC/OS-IIis transplanted to the Nios II processor for managing each module in the system. The system can still provide the high-precision navigation data to integrated control computer of target missile when the number of available satellites is less than 4 by means of processing the pseudorange and pseudorange rate seprately. Therefore, the system has the strong application significance in terms of reducing the route shortcut of target missile.

After changing the bearing box on a desulfurization booster fan, its horizontal vibration value is over 185μm beyond the standard. Through the test, it is decided that fan diaphragm coupling misalignment is the main reason for vibration. The vibration eliminates after readjusting the center.

It had not been explored which real-time magnitude can meet the requirement of the simulation object in computer simulation system. Taking time delay into consideration, the influence of time delay on the stability of the low-altitude and low-speed small Unmanned Aircraft Systems (UAS) flight control system had been analyzed and the real-time magnitude of the miniature hardware-in-loop (HIL) simulation system was determined. Then a miniature HIL simulation system of the UAS flight control system was designed to prove the real-time magnitude feasibility. The result shows the real-time magnitude by time delay analysis can meet the requirements of flight control system.

In order to ensure the quad-rotor can track moving targets or desire trajectory accurately and quickly when face external disturbance, sliding mode control is used to overcome the system uncertainties and external disturbances. A fuzzy controller is introduced to decrease the chattering and improve performance of the system. The simulation considering external disturbance is used to test the performance of the fuzzy sliding mode trajectory tracking controller and the result shows that the fuzzy sliding mode trajectory tracking controller is feasible.

Envelope analysis is the popular fault diagnosis method of rolling bearing. It can diagnosis rolling bearing fault, such as inner race fault and outer race fault. The traditional envelope analysis is set up on the measured acceleration signal. It is influenced by noise seriously, especially in bearing early fault stage. Research shows that the amplitude modulation phenomenon can be enlarged if the envelope analysis is done for the auto-correlation signal. Vibration test was done for a driving motor with fault rolling bearing. Factors influencing the effect of envelope analysis were analyzed.

According to bent position and size on two HP-IP bent rotor,and combined with maintenance schedule,this paper puts forward two vibration control methods of low speed dynamic balance on site and high speed dynamic balance after turning.For the bent position in the turbine middle,on the basis of mode decomposition in bent rotor,the research show that balance weight according to a scale in the both ends and middle mainly of the turbine can achieve good results.

The implementation of bridge blasting process for ground burst unit of Corps Engineers is complex with lots of impact factors, and it is difficult to determine the blasting program. In order to better solve the problem, the author in this paper proposes a new assessing approach of bridge blasting program based on combination of intuitionist fuzzy set theory and TPOSIS, and defines the optimal solution as well as worst solution of intuitionist fuzzy concept, building the evaluation index system of bridge blasting program majors in blasting target, the implementation staff for blasting, blasting tools and equipments. In this way, the author establishes the model of corps engineers of bridge blasting program based on intuitionist fuzzy sets and TOPSIS method, and verifies the model through the use of instances to prove the feasibility and effectiveness of the model with this method.

Laser differential confocal sensor (LDCS) is a high precision and high integrated measurement system. In order to meet the demand of the LDCS, a novel implementation method of high precision conditioning circuit is studied. This circuit consists of photoelectric conversion, secondary amplification and signal operation. The photoelectric conversion is designed to detect the light intensity signal and transform it into a voltage signal. In order to adapt the test for different samples, the magnification is adjustable in secondary amplification unit. The two-way light intensity signals of the LDCS are differentially subtracted in signal operation unit. The noise characteristics of the photoelectric conversion unit were analyzed and the methods for decreasing noise were presented. The experimental results show that signal to noise ratio (SNR) of the conditioning circuit is better than 1160 and the sensitivity of LDCS reaches 2.168V/μm, which has the advantages of low noise, high stability and high integration and can widely used in many kinds of high precision photoelectric measurement systems.

The friction stir welding technology is a new type of welding technology of solid phase, with advantages of high quality, few defects, and small deformation in joint, which has obvious advantages in welding light alloys of aluminum, magnesium and other new materials, which will replace the traditional resistance spot welding and riveting technology to be one of the main manufacturing methods of aerospace industry, and has wide application prospects in this industry, which have great significance in upgrading the manufacturing level of aerospace industry, reduce the production cost and improve our manufacturing technology.

With higher requirements on energy-saving and environmental protection of diesel engine in the modern times, the loads on main bearing and connecting rod bearing of diesel engine are continuously increased, and also working conditions are even more critical. Bearings are the key moving parts of diesel engine, and play an important influence on reliability, service life and other performances of diesel engine. Therefore, the reasons for fatigue damages to its bearings greatly affect fatigue life. In traditional designs, effects of the problem are studied few. In this paper, therefore, this problem is studied for discussing the formation reasons and solutions for it theoretically.

For image guided missile, in order to avoid frame collision, the maximum needed frame-angle of the seeker should not exceed the maximum available frame-angle in flight. Subjected to diameter and volume of the seeker, the required frame-angle needs to be reduced. By combination signal of frame-angle, three different improved guidance laws are discussed. By using of special developed optimization scheme, the integral proportional guidance is selected finally for its best effect. For purpose of reducing required overload of the missile, further improvement of the guidance law is generated by using variable proportional factors. The simulation results show that after using of the final improved guidance law, the maximum required frame-angle is reduced by 1.5, the required overload of the missile at the beginning of tracking is reduced from 5.8 to 2.4. According to the results, the effectiveness of the improved guidance law is verified.

The virtual instrument technology and auto test system software architecture for the Signal-Oriented test are first introduced, and then the requirement of virtual instrument driver module is analyzed. Finally, the design scheme of virtual instrument driver module based on Component Object Model component technology is given. Using the scheme, we developed 22 kinds of the test instruments driver. Experiment results show that the scheme improved the driver scalability, maintainability and reusability greatly.

Based on the communicating vessel principle, we present a new instrument for the measurement of bearing elevation change. A number of cups are attached to the bearings. They are linked with pipes and joints together to constitute a measurement network. Special features of the instrument to make the measurement easily and reliable, such as cup design, are presented. The instrument is used to monitor and analyze the elevation change of a 1000MW turbo-generator during the vacuum setup process. We find that the influence of vacuum on the elevation of bearing located on the exhaust cylinder is large. The maximum value is 1.8mm when vacuum changes from 0KPa to 90KPa. It causes unload of bearing #5~#8 and overload of bearing #2~#4. Adjustment project is given in the last of the paper to solve rub and pad fragment fault occurred in the unit. It is verified that the elevation adjustment for such kind of fault is valuable.

This paper presents a system modeling based control scheme of an ultra precision positioning system for a grating ruling machine. Since the positioning system having a long stroke with ultra precision, the positioning system consists of a coarse positioning stage driven by a servo motor and a fine positioning stage driven by a piezoelectric ceramic. In order to improve positional accuracy and remove the noise components of motion, a hybrid control scheme based on the system modeling is implemented. Considering position-dependent and time-dependent behaviors of the stages, a model based LQ controller is utilized to the coarse stage and a PID feedback controller based on neural network is utilized to the fine stage. Experiment results reveal the efficient and robust of the control scheme and show that the positional accuracy has been readily achieved within 8.6 nm.

3D scanning probe is a kind of measuring instrument that is an indispensable part of Gear Measuring Center. It’s used for obtaining micro-displacement in three directions through the deformation of the three mutually vertical parallel springs. The accuracy of the probe system has critical influence on Gear Measuring Center. Because of the limitation of the structure of parallel spring, the installation errors of the probe and the influence of environmental factors, the parallel springs in three directions are not always strictly vertical, the interference and coupling among X,Y,Z directions exist. This problem is very difficult to be solved by adjusting the mechanical structure of 3D scanning probe system. However, the accuracy of probe system can be improved by adopting software-compensation through calibration. In the paper, the calibration matrix of the probe system is generated by fitting the points sampled on the standard ball with the method of the least square. The points are sampled through controlling the probe to touch standard ball in several given directions. The experimental results show that the measurement errors caused by the coupling among the three perpendicular directions can be effectively decreased by the coefficient matrix mentioned above. The method of calibration is practical and effective for improving the measurement accuracy of 3D scanning probe.

In this paper, the finite element model of piezoelectric ceramics in line with the experiment results was established according to piezoelectric structure field and the coupling of the electric field, deformation of representative PZT piezoelectric ceramics under the voltage was analysed in using finite element analysis software ADINA according to establishing geometric model, defining boundary conditions and materials, Coupling calculation. Consistency between simulation results and experimental results is improved and lay the foundation for the realization of the piezoelectric ceramic shapes and vibration control.

Copper and aluminium alloy could be welded by friction stir welding (FSW) but it is quite difficult to achieve a defect-free welding joint for welding dissimilar materials because of the enormous difference of their thermo-physical performances. In this paper, another friction stir tool was applied as a heating source to preheat the copper side to 150~200°C in the welding direction. Preheating temperature can make up the lost heat, improve the temperature of copper plate before the FSW process, achieve the refining grains, and then obtain a high quality welding joint. We concentrated on hybrid heat-source equipments design and procedure optimization in our studies. The microstructure, mechanical properties and phase constituents of FSW joints were studied through mechanical test and metallographic analysis. The results indicated that the hybrid FSW technology with preheating for copper T2/aluminium 5A06 dissimilar materials can not only improve the welding efficiency, but also obtain the high quality welding joint. This special welding technology could solve the welding problems of Al-Cu dissimilar materials and had a good potential for application in aerospace manufacturing.

A square shaped silicon ingot was cast by cold crucible continuous casting. The grain growth behaviors during different growth stages were investigated. In the first, grains nucleate at the base surface in the centre and in the three phase junction at periphery, and then grow upwards and inclined upwards separately. In the second, grain grow competitively, two distinguished zones are formed. In the final, a cap is formed on the liquid free surface, and precipitates are present.

In order to overcome the contradiction of the CMA with a constant step-size between the convergence rate and the residual mean square error(MSE), on the basis of analyzing the idea of variable step-size, the feature of Support Vector Machine(SVM) and Wavelet Transform, a Variable step-size Wavelet transform Support vector machine Constant Modulus blind equalization Algorithm (VWSCMA) is proposed. In the proposed algorithm, the variable step-size is used to solve the contradiction between the convergence rate and the residual MSE, SVM is employed to optimize the weight vector of equalizer, and wavelet transform is used to reduce the autocorrelation of input signals of equalizer. Simulation results show that the proposed algorithm can effectively overcome the contradiction between the convergence rate and the residual error and has good equalization performance.

The CO-OFDM single-mode optical fiber system is constructed by the Matlab coupled with the Optisystem. And the influence of different channel algorithm on the receiver of system is researched. The simulation results show that the system performance is improved by using LS or LMMSE channel algorithm. And the LMMSE channel algorithm can provide better performance than the LS channel algorithm. Compared with LS algorithm, the required receiver OSNR is reduced by about 1 dB using improved LMMSE algorithm at bit-error-rate (BER) =10-4 in the CO-OFDM single-mode optical fiber system.

How to quickly and accurately detect the error of NC machine has become a hot issue for domestic and foreign scholars. Based on GPS principle, a laser tracker is adopted the multi-station and time-sharing measurement to rapidly and accurately detect the geometric accuracy of NC machine. The machine is controlled to move in the preset path, and a laser tracker is used to measure the same motion trajectory of the machine successively at different base stations. The position of base station and the space coordinates of measuring points can be determined based on large amount of measured data. The algorithms of multi-station and time-sharing measurement are given, and the influencing factors of measurement results are discussed in the paper. Meanwhile, a detection system of machine error is developed based on the platform of Matlab, which can quickly process the measured data and shows each error of machine intuitively.

In this paper, a novel architecture of a real-time CNC interpolation ASIC for Pythagorean Hodograph curve based on FPGA is proposed. The ASIC built on a single FPGA chip contains a NikosⅡprocessor core. It uses a two-stage interpolation scheme to reduce the computational burden of PH curve interpolation. Firstly, the 1st-stage interpolation program is operated on the NikosⅡprocessor. The FPGA hardware logic performs the 2nd-stage interpolation and outputs two groups of pulses for the motion control of actuators (two stepper motors)

This paper gives a detailed study of temperature distribution on Ti46Al0.5W0.5Si alloy directionally solidified by cold crucible. Based on experiment and numerical calculation, the heating process under different power was investigated, and the operating efficiency of cold crucible was roughly calculated. Further, the temperature field of Ti46Al0.5W0.5Si alloy under high power was numerically calculated, the finite element model predicted the temperature distribution at different moment. The results give a significance guide on cold crucible directional solidification.

High phase noise and low phase noise have been consideration in CO-OFDM systems, respectively. The hybrid mitigation algorithm is optimized to approach to high phase noise and low phase noise environment, and a hybrid half-blind phase noise compensation algorithm is proposed, which could be suitable to shifty DFB laser linewidth. 4QAM and 16QAM are used to modulate binary signal. The new proposed phase noise compensation algorithm is considered a mitigation method which has the ability of half-blind self-adaptation. It deduces the coefficient matrix in high and low phase noise compensation matrix and could improve performance under high or low modulation index situation.

The ingot of Ti47Al alloy was prepared by a newly developed rapid directional solidification, the microstructure and compressive properties of the ingot was observed and tested. The results show that the macrostructure consisted mainly of coarse columnar grains parallel to the axial direction, with the size of 0.5mm wide and 10mm in length. The direction of lamellar is almost perpendicular to the growth direction in the longitudinal section and no dendritic core is found. The average ultimate compressive strength of the specimens with grain growth parallel/perpendicular to the compressive direction is 1233.3 and 861.7 MPa respectively. The fracture mode for specimens with grain growth parallel to the compressive direction exhibits predominantly translamellar fracture, however, that for specimens with grain growth perpendicular to the compressive direction exhibits predominantly delamenation or interlamellar fracture.

Two turbine generator units with unstable vibration faults caused by unreasonable bearing elevation distribution are presented. Using the communicating vessel principle, elevation change among bearings with condenser vacuum and power are measured and analyzed. We found that elevation of bearings on low pressure cylinder in high vacuum state is the lowest among bearings. Shaft alignment in the cold state is not unreasonable. We pre-compensated and adjusted bearing elevation in the cold state on the base of the measured bearing elevation data. Vibration faults of two units were solved successfully. Vibration phenomenon, bearing elevation change monitoring data and fault troubleshooting method are presented. It is verified that bearing elevation pre-compensation method for solving such kind of faults is valuable.

Coal mining causes the failure of overburden strata and forms caving and water-conducting crack zones,meaning “two regions”.The reliability of the monitoring result of fracturing height of overburden strata is a key factor to define the upper bound of safely mining.Because of the strain energy released during the formation of two regions,the corresponding weak seismic wave is made at the same time. Through the microseismic monitoring analysis of the fracturing height of overburden strata in 3up 107 coal face of Luxi Coal Mine , the distances of the uppermost 10 percent microseismic events of the overburden strata are relatively large and the energy is relatively small, so it is difficult to form the effective cracks conducting water.According to that, the fracturing height of overburden strata is determined as 38 m which is better consistent with the 36.2m which is defined by the in-site measuring method.Microseismic monitoring technology is proved to be available in determining the fracturing height of overburden strata of coal face.