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Based on the basic principles of electromagnetism, the application of Shanghai Fudan-day Welcomes UNESCO Instruments Ltd. THQHC-1 type Helmholtz coil magnetic field measuring instrument for measuring coil uniform magnetic field generates a magnetic field on the carrier to get round the coil axis, online circle center at (coordinate origin) at the maximum magnetic field strength. Starting from the coordinate origin, to the sides, the magnetic field lines accelerate the decline, when the distance exceeds the coil radius, the decelerating decline. Conclusions for the understanding of a uniform magnetic field reference.

The hydrothermal (HT) upgrading of bitumen with glucose, a model compound of biomass, as hydrogen donor was verified. A parametric study of glucose-promoted upgrading of bitumen, under HT conditions was carried out. The results confirmed the positive influence of glucose in the bitumen upgrading via the catalytic hydrogenation reactions. The optimum conditions for bitumen upgrading were: temperature 400 °C, glucose concentration 5 wt%, reaction time 90 min and catalyst amount 0.08 g. A proposed mechanism for bitumen upgrading with glycerin was discussed.

With the development of national economy and the increasing demand for the road transportation, the vehicles are widely used. The dynamic loads imposed by moving vehicles have variations due to the surface roughness and the larger dynamic loads can affect the pavement performance and life. In order to improve the accuracy of the reconstruction of the road roughness, the time series model—AR model was established based on the given standard pavement roughness PSD which can provide the theory conditions of vibration control and the interaction between vehicles and road.

In a single photoreactor, the degradation of rhodamine B (RhB) was studied on TiO2 and Co-doped TiO2 (Co-TiO2) films under visible light. The results show that the degradation rate of RhB by photocatalytic (PC) and photosensitization (PS) on Co-TiO2 films is quicker than that by PS degradation on TiO2 film. However, a fast N-de-ethylation leads to the increase in degradation rate unsatisfactory. When a bias potential was applied onto Co-TiO2 films, the degradation rate of RhB greatly increased. This can be attributed to the generation of more hydroxyl radicals on Co-TiO2 anodes and cathode. These OH⋅ radicals attack the chromophoric structure of RhB. In addition, with the bias potential application, the optimal Co2+ dopant concentration increases from 0.02 % to 0.4%.

Internet technology as the cutting-edge of the current information technology, it has penetrated into every aspect of human life, more and more government agencies, enterprises are using Internet to improve their office efficiency and to establish new business operation model, in order to improve its reaction ability in fierce competition. Internet has brought convenience for people to work, while the security problem of network also will follow. The internal network not only needs to ensure the security of their data, but also needs to exchange data with the external network, then by adopting network security isolation system which takes gatekeeper technology as its core technology, so that we can ensure that internal network and external network will have physical isolation at any time, meanwhile, according to business needs, it also has multiple forms of information and data’s exchanges.

The arrival of information age means the change of teaching and learning methods, with the development of computer technology, multimedia technology and network technology, the teaching mode of interaction through the network are also popular to carry out gradually. Changes have taken place in teaching methods, teaching means, teaching form and teaching idea through the application of computer in teaching. Distance education, online examination system, the development of online learning system and online homework system greatly promote the development of the educational business and also bring a huge change to modern education, profoundly affected the modern teaching domain. Applied-information technology plays an increasingly important role in contemporary teaching. To study the application of applied-information technology in teaching research has important theoretical and practical significance.At the same time of computer aided teaching, the arrangement and correcting homework are particularly important for checking the teaching achievements and the degree of students what have mastered.

Abrasive Flow Machining method is an effective means for the common rail inside the tiny hole and cross-hole debarring polishing and machining. In this article, using FLUENT software analysis Abrasive Flow Machining common rail runner and three-dimensional numerical aperture structure, in the inlet velocity for the next 60m / s condition, contrast single, bilateral Abrasive Flow Machining method, derived both steady-state pressure, image analysis and comparison of the results of the dynamic pressure, velocity and turbulence kinetic energy, properly using numerical calculation to guide production process procedures, provide a reference for the optimization of the abrasive flow processing..

Gas sensitivity of Sb-doped SnO2 nanograins co-precipitated respectively from ethanol and de-ionized water has been compared. Gas sensing stability of the Sb-SnO2 from ethanol (SnO2-E) was significantly superior to that of Sb-SnO2 from de-ionized water (SnO2-W): working temperature of sensor using SnO2-E was as high as 400 °C, whereas, 250 °C, for sensor using SnO2-W. Furthermore, resistance (R) of SnO2-E was less affected by annealing temperature: the ratio of air resistance annealed at 800 °C (R800) to 400 °C (R400) for SnO2-E and SnO2-W was 8 (4 kΩ/0.5 kΩ) and 1.4×105, 100 MΩ/0.7 kΩ) respectively.

Based on the solid - liquid two-coupling theory, Use abrasive medium viscosity-temperature characteristics related to the mathematical model, using solid - liquid two-phase solution method Mixture models and standards, turbulence model combining with common rail pipe hole as the research object, choose different initial temperatures and processing procedures, numerical analysis was carried out on the flow channel wall temperature and turbulent kinetic energy. Using numerical analysis software FLUENT Abrasive Flow Machining rail tube orifice structure was three-dimensional numerical analysis; obtain a steady-state pressure, dynamic pressure, velocity, turbulent kinetic energy image, to study Abrasive Flow Machining process provides a theoretical basis and technical support.

With the popularization of computer, the design of planetary gear trains is headed in the automatic direction. Based on the theoretical research of closed differential planetary gear transmission mechanism, a kind of software was developed to automatically calculate the tooth number with computer technology applied to the design of gear trains. Some research and analysis were done to the transmission mode of closed differential planetary gear transmission mechanism with the help of universal design method on gear trains. Five constraint conditions were summarized, which are gear ratio condition, adjacency condition, assembly condition, concentricity condition, and other conditions, and a optimum condition. With windows 7 as the platform, MyEclipse 8.5 as a tool, translating these conditional formulae into Java language, the software of the selection of tooth number for closed differential planetary gear transmission mechanism was developed. Multi-group datum of tooth number and also a set of optimal data can be obtained after running the software, which reduces the workload of manual calculation.

A particle swarm algorithm (PSO) based on boundary buffering-natural evolution was proposed for solving constrained optimization problems. By buffering the particles that cross boundaries, the diversity of populations was intensified; to accelerate the convergence speed and avoid local optimum of PSO, natural evolution was introduced. In other words, particle hybridization and mutation strategies were applied; and by combining the modified feasible rules, the constrained optimization problems were solved. The simulation results proved that the method was effective in solving this kind of problems.

Although class D amplifier has the merits of high efficiency, a little heat and small Bulk, its distortion is larger than linear counterparts due to switching behaviour of power transistors. Its principle and several new pivotal control technologies were presented in this paper. In this way, efficiency of 90% can be achieved and the degree of the distortion can be less than 0.4%.

The intelligent fuzzy control method in thermostatic process of the sand casting and gas forming tester was introduced in this paper. The delayed time of thermostatic control system of the tester was compensated by Smith predictor. The simulation testified that the control method of the research has a higher maneuverability, which is in line with the actual needs of the tester.

The temperature control model of an intelligent sand casting and gas forming tester is introduced in this paper. The thermostatic fuzzy control of the tester is simulated by the fuzzy control kit in Matlab. The result of the simulation indicates that the control method of the research has a intelligentized degree, which is more precise than conventional control method.

Simulation model of landing gear hydraulic system is built based on AMESim, several key influence factors of performance degradation of landing gear hydraulic system are analyzed, such as changes of restrictor orifice diameter, initial pressure of accumulator, viscosity and gas percentage of oil , etc. The simulation results bring valuable reference to aircraft maintenance.

The computer virtual control method for thermostatic process of sand casting and gas forming tester system is studied in this paper. The system software is designed based on LabVIEW, which includes the design of temperature controller interface, the construction of virtual system and the design of system interface. This paper is of certain directive significance to future exploitation of virtual control system.

With the actual flight of the airplane model pictured by two theodolites, in this paper, a cross matching method of flight trajectory was proposed on the basis of horizontal projection, which was also checked and simulated in the research. The simulation proved that: within a certain measuring range, this cross matching method can effectively enable the matching calculations to flight trajectories of large numbers of equidirectional airplane models, thus to meet the measuring needs of the airplane model in flight.

Active carbon and sodium silicate were produced simultaneously from pyrolyzed rice husk (PRH) by CO2 activation coupled with NaOH solution boiling. Doehlert matrix and Derringer's desirability function were applied to optimizing the boiling conditions to achieve a large specific surface area, a high silica extraction and low alkali consumption. In terms of this purpose, the optimum condition was determined as boiling CO2-activated char with 1mol/L NaOH solution at a liquid/solid ratio of 9.7 mL/g. Under this condition, the modulus of the sodium silicate and the specific surface area (SSA) of the active carbon were 2.62 and 897 m2/g, respectively. The values both reached their respective commercial levels. The pretreatment of the PRH with CO2 activation can markedly increase the SSA of active carbons.

A computer-assisted minimally invasive cochlear implant system is developed to help doctors perform minimally invasive cochlear implant to avoid disadvantages of traditional complex operation like large invasive and long time to recovery et al. Virtual space visualization, space mapping and operation path plan, mechanism for drill positioning and holding are realized with multi-use of computer navigation and virtual space visualization technology and screw theory. Totally 6 cadaveric skull specimen experiments are performed. In experiments, all cochleae are opened perfectly without facial nerves damaged. The results demonstrate that the computer-assisted minimally invasive cochlear implant system can meet the clinical operation demands.

In this paper, using the finite element method,check for the Ken Swart project sand flushing water all operating tower in static stability. First of all, select unit and a calculation model, establish the finite element model; Then analys the displacement distribution and stress distribution of the structure in the five conditions.

The anaerobic fermentation characteristic of rice straw pretreated by HCl was studied. The results showed that the test pH values of different pretreatment conditions mainly range from 5.09 to 7.52. The peak value of biogas production was attained of 2% HCl pretreatment on the 20th day, which is 1 180 mL. The test daily methane content of different pretreatment conditions mainly ranges from 3.2% to 58.1%. However, the cumulative biogas production by using HCl pretreatment of rice straw during anaerobic fermentation is poor.

To discuss the internal effect of urea (CO(NH2)2) pretreatment on anaerobic digestion biogas production of rice straw waste, a self-designed laboratory-scale continuous anaerobic biogas digester was used in this study. Anaerobic biogas slurry, urea pretreatment and anaerobic digestion were evaluated for biogas production from rice straw. The results showed that the peak value of biogas production was attained on the 17th day by using 6% urea pretreatment on rice straw. However, the highest CH4 content was 49.8% on the 15th day for the 8% urea-treated rice straw. The cumulative biogas production of 6% urea pretreatment was the highest, about 16 540 mL, which was followed by 2% urea (12 283 mL), 8% urea (9 883 mL), and 4% urea (5 668 mL).

The chemical pretreatment of rice straw was achieved via the liquid-state dissolution of CaCO3. Pretreatment effects on the biodegradability and subsequent anaerobic production of methane were investigated. The results showed that the peak value of biogas production was attained of 4% CaCO3 pretreatment on the 20th day, which is 1 589 mL. The test daily methane content of different pretreatment conditions mainly ranges from 3.4% to 47.4%. The cumulative biogas production of 6% CaCO3 pretreatment was the highest, about 19 917 mL.

Tunnel project plays an important role in many water conservancy and hydropower projects ,and a large number of water conservancy construction around the world in recent years promoting the rapid development of tunnel engineering theory and engineering technology. This paper intends to use the theory of hydrodynamic pressure Westgaard.HM hedge sand tower structure theory for simple analysis through water structure and anhydrous structural dynamic analysis and comparison to check their stress and strain and displacement of vibration in the water.

channel - masonry - concrete composite structures underpinning is a new type of underpinning technology, the two channel steel and the concrete of compression flange and the masonry between the channel combined into an overall flexural members, it can used in masonry structure underpinning the transformation of the wall, it has simple construction, safety and reliability, the combination of large carrying capacity and other characteristics. Through this combination of three members in bending tests, we can get, reinforced by setting off key, channel, masonry and concrete can form a combination of flexural members to work together, channels tensile stress, concrete bear stress, masonry between the channel improved stability of the web and shear capacity of the beam, we gives the flexural capacity calculation method of the composite structure through analysis.

In this paper, we depart from the basic vibration equation deduced from Vibro sand tower structure recurrence formula. Using ANSYS finite element software to simulate the red sand of the top ten tower structural vibration modal. Of which the first two modal solutions in accordance with the conventional prismatic cantilever closer to theoretical calculations, the results of the finite element solution proved authentic, we provide a theoretical basis for the use of finite element methods for solving the structural problems of sand washing tower.

This article generalizes the current condition of the MTR, introducing the “rail transit plus comprehensive land use” mode in detail. By analyzing this mode applied in Hong Kong, three feasible factors to the success of this mode in Hong Kong are found. According to the annual report of MTR, this mode brings great profit to MTR and has become the learning example to the rest of the world. In China, Shenzhen Metro Group co., Ltd, Hangzhou Metro Group co., Ltd and Beijing Subway are now learning this mode to alleviate the financial burden of government as well as to enlarging the metro by using their profit. In order to realize win-win situation, several suggestions should be put forward.

According to the first-stage geologic investigation reports of the line 1 and line 2 in Ningbo rail transit, the natural density (ρ) and the vane strength (Cu) probability distribution of the typical layers in Ningbo area were studied in this paper. Besides, the reliabilities of the typical layers foundation bearing capacity in Ningbo area were evaluated by the checking point method. It is found that (1) the natural densities of the typical layers in Ningbo area show good normal distribution as their corresponding variation coefficients (δ) are small. Unfortunately, the vane strengths of the typical soils in Ningbo area show poor normal distribution as their corresponding variation coefficients (δ) are large. (2) The soil parameters variation has significant influence on the reliability index β. Moreover, β is more sensitive to the variation of ρ than to the variation of Cu. (3) As the safety coefficient methods can not consider the influence of the soil parameters variation on the foundation stability, it is suggested that the foundation stability in Ningbo area should be evaluated by the reliability analysis method.

In this paper, foam glass as thermal insulation material was prepared from alkali-free glass powder, and silicon carbide was used as foaming agent in the process. The effect of silicon carbide and sodium carbonate was investigated. Thermal performance of the batch was investigated by using the TG/DSC simultaneous thermal analyzer. The morphology of the glass foams was evaluated by the scanning electron microscopy. The phase of the sample was studied through X-ray diffraction, and chemical composition of the samples was estimated by using X-ray fluorescence spectrum. The results show that, the pore diameter of sample increases gradually at first and then stabilizes with the increasement of silicon carbide. Sodium carbonate not only improves the foaming ability by reducing the glass viscosity but also influences the crystallization of the sample. The bulk density and compressive strength are decreasing while the content of sodium carbonate increasing.

An algorithm for multiple moving targets tracking in computer vision is put forward in this paper. The association between the tracking chains and new targets detected is mainly discussed. There are four situations. Among them, the most complicated is that several tracking chains exist and several new targets are detected. The distance between new targets and old targets is used to determine whether they are the same targets. When the tracking chain is found broken, it is seen that the target has passed the monitoring area, and begins to count. In the paper, the program code is shown, too. In the end of the paper, real images on the spot are used to test the algorithm. Its good effect can be proved from practical spot.

To develop high wear-resistant protective materials for magnesium alloy, high-silica Al-based alloy modified via P-element was fabricated by DC casting method. Microstructure of ingot samples was observed by using optical microscopy (OM), etc. The results demonstrated that Al-Si-0.01%P alloy with unique microstructure and without defects such as voids and rarefaction might be generated by processing control. Owing to modification by Al-P interalloy, primary crystal silicon phase in hypereutectic Al-Si alloy were refined effectively. Its size in Al-18Si-0.01%P alloy decreased from 50μm to 20μm, and distributed uniquely than that in Al-18Si alloy. Al-P acted as heterogeneous core of primary crystal silicon phase, which was the main mechanism for Al-P interalloy to modify primary crystal silicon in Al-Si alloy.

To explore the noise generated by bridges during operational period, the equivalent continuous sound pressure levels of 12 bridges in the city of Ningbo were measured and analyzed. The measured data show that (1) Although the measured sound levels of these bridges meet the requirement of Chinese codes, they are near the maximum limit and the vibration and noise reduction is necessary; (2) A-weighted sound level of bridge is close to that of the road nearby; (3) Z-weighted sound level of bridge is much greater than that of the road nearby, it indicates that the bridge noise contains much low frequency noise, so that A-weighted sound level can’t reflect the noise of bridge accurately, and Z-weighted sound level shall be used to evaluate the acoustic environment near bridges.

The permanent magnetic rotator of the dynamic gyro is driven by the energized radial and axial coils through the gimbal module. Angle and angle are the significant angles to describe the moving status of the dynamic gyro. By using the magnetism and mechanism principles, the driving torque of the dynamic gyro is figured out, and some important conclusions are provided. If angle, the rotating torque and the period mean procession torque; if angle, an additional torque will be produced to the rotating torque and the procession torque will be very complex. These conclusions are quite useful for controlling the dynamic gyro.

Through the advanced hydraulic control technology to solve many disadvantages of the present disassembly and assembly equipment of the buffer braking device, and the new disassembly and assembly equipment of the buffer braking device of the elevating mechanism of the heavy caliber ground artillery is designed, and it has a very important significance to improve the maintenance support efficiency of the equipment.

Based on a large quantity of experimental work and study of the two-dimensional MHD (Magnetohydrodynamic) simulation describing the implosion dynamics of X-pinch, at the same time taking basic physical processes of implosion into account, this paper seeks to build a two-dimensional MHD simulation model on implosion dynamics throughout the whole constriction evolution (including formation of dense plasma, compression, generation of hot spot, X-ray pulsed radiation), determine the target area for numerical simulation, as well as the initial time for simulation and plasma initial state. As for two-dimensional MHD models which indicate the physical process during different stages, a clear boundary condition is explored along with Lagrange-Euler numerical method which strives to reproduce the dynamics of the X-pinch implosion and better study the physical properties during the X-pinch implosion dynamics. Results of this thesis will enrich the X-pinch research areas of basic theories and analytical methods, which is of great theoretical significance and application value.

Characteristics of seed-setting of two Leymus chinensisecotypes under saline-alkali soil and sandy soil habitats on Songnen plain were studied, such as number of grains and seed-setting percentage. The results showed that number of grains and seed-setting percentage of two L. chinensisecotypes fluctuated within a certain range. Variation coefficients of single spike grain number and seed-setting percentage were 79.37% and 87.2% higher. The number of grains and seed-setting percentage of two L. chinensisecotypes under saline-alkali soil habitat were lower than those under sandy soil habitat. Significance test showed that seed-setting percentage of two L. chinensisecotypes, and the single spike grain number of grey-green L. chinensisecotypes between saline-alkali soil habitat and sandy soil habitat were significant or very significant. In results, the sexual reproduction of two L. chinensisecotype populations had a stronger adaptation for the habitats, the two ecotypes take the same adaptable reproduction strategy, due to the change of habitat condition, the characteristics of seed-setting have a plastic changes accordingly, and individual difference in population under the same habitat was resulted by microhabitat differences.

In this paper, a TCM constitution clinical decision support system is introduced. The features, functions, structure and working flow of this system are discussed and illustrated in detail. This system is composed of 5 modules. They are query module, investigation construction module, investigation modification module, investigation deletion module and data analysis module respectively. The property information, constitution information and tongue feature information are collected through investigation construction module. The constitution types of the testers can be automatically recognized and the prescriptions related to specific constitutions are automatically produced. Through data analysis module, specificities and sensitivities between the specific constitutions and the tongue features can be automatically obtained. The implementation of this system is of important value and guiding function during the process of TCM clinical diagnoses and treatments.

With a logical reasoning-realistic analysis binding methodology and the theories of internet of things and supply chain management, probes into the development trend of productive materials terminal distribution. From three perspectives, value process, technical platform and node selection, the research indicates the operation mechanism of terminal distribution, providing a theoretical support for dual promotion of efficiency and effectiveness in terminal logistics of productive materials.

Based on the integrated study of the outcrops, the seismic, drilling and logging data of Lianglitage formation in central Tarim Basin, the sequence stratigraphic framework of the platform margin is built, and the Lianglitage formation is divided into 3 third-order sequences. The vertical pattern and lateral distribution for carbonate reef-bank reservoir in sequence stratigraphic framework are analyzed. The reef-bank reservoir mainly developed in highstand system tract of sequence Ssq2, and distributed along the carbonate platform margin of the Middle-Late Ordovician in central Tarim Basin. The mudstone mound, organic reef, granule bank are vertically stacked. Laterally, the area of well shun3-shun4-shun2-shun6 are characterized by multiphase bank reservoir overlapping, and the area of well TZ82-TZ44 - TZ161-TZ24 - TZ26 are characterized by multiphase organic reef and bank overlapping. The reef-bank complexes in sequence Ssq2 are the main targets of exploration in central Tarim Basin.

Motor-driven on-load tap changers (OLTC) operational within power transformers are extensively used for voltage regulation in power systems, whose principal malfunctions or failures are of mechanical type. Hence, monitoring of the mechanical characteristics of OLTC is of utmost significance. Based on a rotating angular transducer as well as digital signal processing techniques, an on-line monitoring methodology is established to measure, analyze and evaluate the dynamic or transient changes of the rotating angle of the drive motor operational in an OLTC, which can effectively indicate the underlying deficiency or even potential fault of the mechanical drive system connected to the motor. Computer simulations and experiments are carried out respectively, both showing the proposed on-line monitoring scheme is feasible and applicable.

Halcon is a machine vision software. It can process all kinds of image processing problem. In this paper, Halcon is used to process moving targets detection, from which it can be seen how the software Halcon is used to process digital image. The algorithm includes region_ growing algorithm, image filtering and morphological operators, etc. The software Halcon can be used in digital signal, too. In the end, it is used to process pulse signal. The result shows that Halcon has powerful functions in digital data processing.

Tongue image extraction is a fundamental step in objective diagnoses and quantitive checking of tongues. The accuracy of tongue image extraction can directly influence the results of the succedent checking in objective diagnoses of tongues. In this paper, we improved random walk image segmentation algorithm and applied it to tongue image extraction. Firstly, we utilized toboggan algorithm which adopted new classification rules to segment initial regions. Secondly, a weighted-graph was built according to initial regions in which only those adjacent regions were connected. Thirdly, random walk algorithm was applied to make the final segmentation in which a new weight function was designed for calculating the weights between the nodes of adjacent regions. Fourthly, mathematical morphology operations, i. e. inflations and erosions, were carried out on the segmentation result of the third step in order to fill small holes on the tongue region. In the experiment, we compared our method with traditional random walk algorithm. As the experiment results show, our method achieved much better segmentation effects.

In this paper, four models of PVC composites reinforced with glass fabric were designed based on the arrangement of the V-structure, using V-structure discontinuous glass fabric as the sandwich structure and PVC resin as matrix. The acoustic insulation properties of the composites with V-structure discontinuous glass fabric as the sandwich structure were analyzed with a two-channel acoustic analyzer. The results show that the orientation of the V-structure has a strong effect on the acoustic insulation property. In the case where the raw material, thickness and density of the V-PVC composites are almost the same, the composite with the opening of the V-structure toward the source of sound shows better acoustic insulation than that with the opening of the V-structure away from the sound source. This difference is even more pronounced with increasing layers of glass fabric.

Non-linear finite element model of prestressed steel reinforced concrete(PSRC) beams were carried out by using software ABAQUS. The effects of the parameters of non-prestressed reinforcement ratio, prestressed reinforcement ratio, effective prestressed force and non-prestressed tendons yield strength on the ultimate strength and ductility of PSRC beam were investigated. It is found that increase of the tension reinforcement ratio has little impact on the ultimate deflection but can improve the ultimate capacity of PSRC beam. Increase of the prestressed steel ratio can significantly improve the cracking load, stiffness and ultimate capacity of PSRC beam. The effective prestressed force can improve the bearing capacity of PSRC beam.

Highly mesoporous active carbon for removing methylene blue (MB) from aqueous solution was prepared from pyrolyzed rice husk by combination of CO2activation and NaOH-solution boiling. The preparation method was found to be alkali-saving and equipment-friendly. The prepared active carbon exhibited high mesoporosity (79.1%), with mesopore volume and specific surface area up to 0.619 mL/g and 899 m2/g, respectively. At initial MB concentrations of 240-380 mg/L, the MB removal efficiency of the prepared active carbon ranged from 92% to more than 99%, fairly comparable to that of the highly mesoporous commercial active carbon used for reference. The adsorption of MB onto the prepared active carbon well followed the pseudo second-order kinetic model and Langmuir isotherm. This study indicated that highly mesoporous active carbon with large dye removal efficiency could be prepared from rice husk by an alkali-saving and equipment-friendly process.

Aluminum has higher conductivity, convection coefficient, and oxidability, which casuse low plasticity in high temperature compared to convectional low carbon steel. These properties make its welding numerical simulation much more difficult. Thermal simulation is the foundation of aluminums coupled calculations of thermo-elasto-plastic for welding. In this paper, a butt-joint of aluminum AA2024-T3s welding is numerical modeled based on surface effect element. And bilinear kinematic hardening is used to take into the Bauschinger effect. The simulation results agree well, which shows that node temperature calculation can be improved by this method.

Ring-seam joint pipe is more and more widely used in advanced auto-body assembly. However, Aluminums higher conductivity, higher convection coefficient, oxidability and low plasticity in high temperature compared to convectional low carbon steel make its welding numerical simulation much more difficult. Thermal simulation is the fundamental of aluminums coupled calculations of thermo-elasto-plastic for welding. In this paper, a pipe joint of ring seam for ZL114 aluminum alloy is numerically modeled based on birth-death element method and moving-heat-source function loading method. The simulation results agree well with the experiments, which shows that the double ellipsoid heat source model is most suitable for MIG welding simulation of aluminum alloy.

Based on the finite element method, three models are built: classical solid model, potential flow model and a combination of fluid-structure coupling model. Based on the above model the damping mechanism of tuned liquid damper has been investigated. Study focused on classical solid model and the boundary constrained potential fluid model respectively. After the completion of the above calculation, the analysis of bidirectional fluid-structure interaction model being carried out with the implicit dynamics algorithm. The results shows the contrast of the dynamic response of structure in the hydrated and anhydrous state. The calculations show that: the additional water mass can effectively reduce the natural vibration frequency of the structure, and it also can effectively reduce the displacement and velocity response of structure under vibration loads.

We demonstrate a Yb:YAG thin disk laser with multi-pass diode-pumped structure and direct water cooling device. In the pump system, four passes of the pump radiation are focused on the thin disk using a center-punched spherical lens. The thin disk serves as the window of a copper tank and is directly cooled with recycle water-contacted method. The thin disk laser has a low pump at the threshold of operation. We obtained 450 mW output power around 1030 nm in a simple F-P resonant cavity.

By Studying the Principle of Single Side-Band Mixing, a New Method Based on Quadrature Phase Shift for Generating High-Precision Offset Frequency was Proposed. Different Solutions of Precision Quadrature Phase Shift were Designed for Different Frequencies, Including Combining Analog Quadrature Splitter and Wire Delay for 10MHz, Combining Digital Phase Shift Module Using CPLD, Digital Delay Line Chip and Wire Delay for 10kHz. According to the Design Goal, the Design Parameters and Requirements of Narrow-Band Low-Loss Filter were Analyzed. Finally, an Offset Frequency Generator Whose Output Frequency is 9.99999MHz was Developed and an Experiment System is Constructed to Test the Performance of the High-Precision Offset Frequency Generator. According to the Experiment Results, the Following Conclusion can be Drawn that the Allan Deviation of the 9.99999MHz Offset Frequency Generator is 4.03e-13 which is close to the Frequency Stability of 10MHz Signal of Hydrogen Maser MHM-2010 of Sigma Tau Corporation. the High-Precision Offset Frequency Generator can be Used as a Common Source in Dual Mixer Time Difference and as a Reference Signal in Beat Frequency Method.