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Three high temperature superconducting (HTS) Maglev measurement systems were successfully developed in the Applied Superconductivity Laboratory (ASCLab) of Southwest Jiaotong University, P. R. China. These systems include liquid nitrogen vessel, Permanent Magnet Guideway (PMG), data collection and processing, mechanical drive and Autocontrol features. This chapter described the three different measuring systems along with their theory of operations and workflow. The SCML-01 HTS Maglev measurement system can make real time measurement of Maglev properties between one or many YBCO bulks and employ a PM or PMG. Also the trapping flux of high Tc superconductors can be measured in the scanning range of 100 mm×100 mm. It was especially employed to develop the on board HTS Maglev equipment which travels over one or two PMGs. The on board Maglev equipment includes a rectangular-shaped liquid nitrogen vessel and YBCO bulk superconductors. Based on the original research results from the SCML-01, the first man-loading HTS Maglev test vehicle in the world was successfully developed in 2000. In order to make more thorough and careful research investigations, the HTS Maglev, HTS Maglev Measurement System (SCML-02) was subsequently developed with even more function capabilities and a higher precision to extensively investigate the Maglev properties of YBCO bulk samples over a PM or PMG. The new features included: higher measurement precision, instant measurement at movement of the measured HTS sample, automatic measurement of both levitation and guidance forces, dynamic rigidity, ability for the measured HTS sample to be moved along the three principal axes all at once, relaxation measurements of both levitation and guidance forces, and so on. The main specification of the system is: position precision ±0.05 mm. vertical force precision 2 ; horizontal force precision 1 ; and force measurement precision of 0.02 N. In order to investigate the dynamic characteristics behavior of the HTS Maglev engineering application, an HTS Maglev dynamic measurement system (SCML-03) was designed and successfully developed. The circular PMG is fixed along the circumferential direction of a big circular disk with a diameter of 1,500 mm. The maximum linear velocity of the PMG is about 300 km/h when the circular disk rotates round the central axis at 1280 rpm. The liquid nitrogen vessel with HTS bulks is placed above the PMG, and the vessel is allowed to move along the three main principal axes so that sensors can detect force variations stemming from the superconductors. The design, method, accuracy and results have allowed the successful development of these three measurement systems. All systems are calibrated by standard measurement technology, for which its reliability, stability, featured functions, and precision have also been validated through its long-term usage.

Seed reserves play vital roles in seed germination and seedling growth and their variation may be related to various environment factors, plant traits and phylogenetic history. Here, the evolutionary correlation associated with seed mass and altitude and carbon (C), nitrogen (N) and phosphorus (P) allocation of seeds among 253 alpine herbaceous plants was tested. In this study, phylogeny had strong limitations on nutrient allocation of seeds across species, and species from younger phylogenetic groups tended to have higher N and P contents, which might be considered as the evolutionary selection of seed plants. Higher seed N and P content would help seedlings to gain more survival chance and stronger competitive capacity, and their progeny would be more likely to be preserved. When phylogeny was considered, altitude only had a significant positive effect on P content, but the negative effects on seed mass were all expressed. The independent effects of altitude and seed mass suggest that the nutrient allocation of seeds might be affected by both environment and plant traits. In addition, altitude and seed mass displayed partial overlapping effects on nutrient allocation of seeds. The negative effects of seed mass were affected slightly by altitude, whereas altitude only had a significant positive effect on P content when seed mass was controlled. Above all, seed P content showed obvious and general correlations with seed mass, altitude and age of clade, which indicated that higher seed P content might be an adaptive selection of species associated with growth and survival of progeny.

The problem of frequency band of acoustic transducer is the key research field. By summarizing of Tonpilz and Janus-type transducer influence factors,such as transducer structure type, geometry parameters, the rule of redressing the mechanical quality factor Qm is investigated, and the trend of extending the frequency band by multi-mode coupling is got. By analyzing the multi-modal forms of vibration of double and triple resonance resonant, several types of extending frequency band of transducer are categorized under this forms. The advantages and disadvantages are investigated by general theory analysis of extending longitudinal vibration transducer, and the state of the art and the applications are displayed. So that the researchers are easier to understand the transducer, and can offer ideas for new design.

Twelve pilot-scale constructed wetlands with different configurations were set up in the field to evaluate the removal and factors that influence removal of sulfonamides (sulfadiazine, sulfapyridine, sulfacetamide, sulfamethazine and sulfamethoxazole) and trimethoprim from domestic sewage. The treatments included four flow types, three substrates, two plants and three hydraulic loading rates across two seasons (summer and winter). Most target antibiotics were efficiently removed by specific constructed wetlands; in particular, all types of constructed wetlands performed well for the degradation of sulfapyridine. Flow types were the most important influencing factor in this study, and the best removal of sulfonamides was achieved in vertical subsurface-flow constructed wetlands; however, the opposite phenomenon was found with trimethoprim. Significant relationships were observed between antibiotic degradation and higher temperature and redox potential, which indicated that microbiological pathways were the most probable degradation route for sulfonamides and trimethoprim in constructed wetlands.

The system which could be described as "trinity, seven subsystems" has realized automatic remote control of the machine working process with orientation, localization and formalization. At local place, it realized automatic position and pose online detection, automatic orientation tunneling, automatic section cutting and forming and adaptive control of cutting arm swaying speed. It was the first time that realized absolute measuring of roadheader frame position and pose error under coal mine working condition in our country which could avoid error accumulation in relative measuring and guarantee the high precision of orientation tunneling. In underground remote, it realized remote monitoring, wireless remote control and video surveillance, thus realized remote control with multiple angles, visualization and one-button control under the condition of dustiness and vibration. At any network access point on ground using mining ring network, it realized real-time monitoring and displaying of roadheader running state parameters, and realized the functions of remote fault diagnosis and alarming. The whole system has been tested many times underground. The application results show that it is stable and reliable. With the development of automation, intellectualization, and informatization and other high technology, this system will be more and more suitable for fully mechanized excavation face.

Experimental research was carried out to analyze the wear patterns of several tools which include high-speed steel (HSS), coated cemented carbide and ceramic tools, and to study the tool wear mechanism in milling resin sand mold materials. The main wear mechanism is abrasive wear and the dominant tool failure mode is flank wear. Different cutting parameters have different influence to the tool wear. In addition, it is essential to select suitable tool material with appropriate hardness. In this paper, the experiment results are contributive to choose proper cutting tool materials and parameters in milling resin sand mold material.

Work hardening is an important index for the evaluation of the machined surface quality in high-speed milling. The morphology of work hardening can be visually observed by the metallographic pictures of high-speed milling gained from the scanning electron microscope which includes the lattice distortion and cracks etc. Forming mechanism of lattice distortion and micro crack of micro morphology under the workpiece surface is analyzed according to the dislocation theory; meanwhile, the effects on surface quality of the microstructure of the work hardening layer are discussed, which have important guiding significances on improving the surface quality and prolonging the service life of the parts.

To eliminate the effects for section automatic cutting because of roadheader pose error, Control system of pose error compensation for roadheader was proposed. First, make the control strategy according to the coal mine actual working condition and the working ability of machine each actuator; Hardware system structure is proposed based on the control system and the corresponding sensors are installed; Last, according to the working way of roadheader, put forward the specific control methods of pitch attitude compensation control and cutting boundary compensation control. The above system has been tested on EBZ200 type roadheader and the testing results show that the system function is correct and reliable and the control precision is high. This system could eliminate the effects for section automatic cutting because of roadheader pose error efficiently and lays a foundation for remote control of roadheaders.

Different from other applications, this paper explores how to use the stable high-Tc superconducting (HTS) magnetic levitation (maglev) to lift the sculpture art to a high levitation position for satisfying the artists requirement for the light artistic concept. With a combination of the permanent magnet (PM) levitation and HTS maglev technologies, a sculpture model was built to sustain a stable levitation with a levitation height of over 80 mm. In this hybrid HTS maglev sculpture model, three PM rings are arranged as upper, middle, and bottom as a double-layer axial levitation structure; six rectangular YBaCuO bulks are fixed along the side of the PM rings upper-layer as a stabilizer component along the radial direction. When the bottom PM ring was driven up by the lifting bolt, the upper PM ring, which was fixed with the art, can be lifted much higher. Then the required artistic effect will be enhanced. After the model was designed and optimized by finite element method, it was experimentally validated by the HTS maglev measurement system. This levitation design is helpful to the realization of a real-scale levitation sculpture art, and can also provide references to superconducting radial magnetic bearing systems.

Work hardening reserches in metal cutting has an important significance in improving surface quality of the workpiece and the service performance of parts. The paper introduces current researches of the work hardening in metal cutting process, analyses the forming mechanism and influencing factors of the work hardening and discusses the effects of the work hardening on workpiece service performance. At last, the new trends of work hardening researches in metal cutting process are conclusively predicted.

In order to make the levitation performance of the high temperature superconducting (HTS) magnetic levitation (Maglev) vehicle more stable and safer, in this paper, using a cryogenic measurement system, we measured the levitation forces of YBCO bulk above halbach-type permanent magnet guideway (Halbach PMG) in the temperature range from 77 K to 60 K, then in the condition of deep cryogenic, the levitation forces of YBCO bulk at different field cooling heights (FCHs) were also measured, according to which the levitation stiffness were calculated. The results show that the levitation stiffness of HTS/PMG Maglev system is better at lower temperature. Moreover, when the temperature of YBCO bulk decreases from 77 K to 73 K, the levitation stiffness largely increases in any FCHs. However, after the temperature of the bulk decreases to 73 K, the rate of the levitation stiffness increased gradually reduces. The results are helpful to HTS Maglev vehicle application.

A mechanical model of surface roughness is established based on the Kragelskii-Drujanov theory of friction and wear and Hertz elastic contact theory. Effect of material flow stress on remnant height of the machined surface was investigated. Test showed that the machined surface morphology provides the phenomena of the side flow in the vertical direction of ploughing in high-speed machining. The remnant height values on the machined surface of the high-speed machining are obtained by DEFORM-3D simulation. Based on the results it can be concluded that the surface roughness values of the workpiece increase with material flow stress.

Surface roughness is an important parameter to evaluate the quality of high-speed machining (HSM). This paper establishes a mechanical model based on the molecular-mechanical theory of friction to study factors that influence the surface roughness in HSM. The relationship between flow stress and the remnant height on the machined surface is obtained. The HSM process of AISI-1045 steel is simulated by using finite element method (FEM) based on DEFORM-2D and the flow stress is obtained. The surface roughness of workpiece machined by HSM is calculated based on the value of flow stress and the mechanical model. The result shows that the surface roughness of workpiece in HSM is acceptable, and the mechanical model supplies a method to study the surface roughness in HSM.

The gear honing process is a widely used process for gear finishing after heat-treated. The honing ring is profiled by diamond dressing gear, which have the profile of the workpiece to be machined and bonded a single layer of diamond particles. The paper has inroduced the traditional manufacturing methods of diamond dressing gears, positive electroplating and negative electroplating. Then put forward a new manufacturing method, Electroless nickel coating. Composition and condition of electroless composite plating solution, process steps are given. Several diamond dressing gears are made by this new method. Honing experiment testified that it is an applied method and has many advantages.

Gear honing with globoid honing worms is seldom used because it has no distinct advantages to honing with internal geared honing rings. The paper puts forward a new process to honing gear with globoid honing worms on hobbing machines. First the globoid honing worm is profiled by diamond dressing gears, which has the same geometric parameters with the machined gears. Then the profiled globoid honing worm is used to hone workpieces. Both the profiling process and honing process are implemented on same hobbing machines. Meshing and Tooth contact analysis of globoid honing worm profiling has been considered. Meshing equation of profiling process and equation of globoid honing worm tooth flank after profiling are obtained. Experiment testified that it is an applied process and has many advantages.

The gear honing process is a widely used process for gear finishing after heat-treated, and may be divided into the variants “internal-tooth honing” and “external-tooth honing”. External- tooth honing is seldom used in gear finishing due to lower overlapping ratio and relatively low precision. But its process cost is much lower than internal-tooth honing and gear grinding. The paper puts forward a new method to improve the precision of external-tooth honing, i.e. honing ring is profiled by diamond dressing gears, which have the profile of the workpiece to be machined. Meshing and Tooth contact analysis of honing ring profiling has been considered. Meshing equation of profiling process and equation of honing ring tooth flank after profiling are obtained. Experiment testified that it is an applied method and has many advantages.

The gear plunge shaving process is a widely used process for soft finishing of gears in the gear manufacturing industry. But it is difficult and expensive to profile plunge shaving cutter, because the cutter must be ground by a cone grinding wheel on a special grinder. A new method, profiling gear shaving cutter on the shaving machine, i.e. a CBN dressing gear which has the same parameters with the machined gear is clamped in place of the workpiece on the shaving machine and profiling the cutter in shaving process, is put forward. Meshing and Tooth contact analysis of shaving cutter profiling has been considered. Meshing equation of profiling process and equation of shaving cutter gear blank after profiling are obtained. Experiment testified that it is an applied method and has many advantages.

This paper focuses on developing an empirical model for the prediction of milling forces in high-speed end milling of P20 die-mold steel. The spindle speed, feed rate, axial and radial depth of cut are considered as the affecting factors. The data for establishing the model are derived from high-speed end milling experiments conducted on a 5 axis machining center according to the principles of DOE (design of experiments) method. The influences of milling parameters on milling forces are investigated by analyzing the experimental curves. Consequently, multiple-regression analysis is applied in developing the empirical model. Furthermore, the significances of the regression equation and regression coefficients are statistically tested in this paper to validate the model.

An orthogonal cutting model was presented to simulate high-speed machining (HSM) process based on metal cutting theory and finite element method (FEM). The residual stresses in the machined surface layer were obtained with various cutting speeds using finite element simulation. The variations of residual stresses in the cutting direction and beneath the workpiece surface were studied. It is shown that the thermal load produced at higher cutting speed is the primary factor affecting the residual stress in the machined surface layer.

This paper proposes a numerical cutting model with the FEM to simulate the temperature field at the contact zone on the tool rake face. The analysis of the tool rake face temperature in orthogonal machining is studied based on heat transfer theory and calculus of variation. Then, the FEM simulation results of the temperature field on the rake face in various cutting speeds and the cutting speeds vs peak temperature curves are given. The results show that the highest temperature of the tool surface is located at a distance nearby the tool tip, and the higher cutting speeds can increase the tool rake face temperature obviously. In addition, the workpiece materials have a great effect on the peak temperatures at the rake face. Therefore, this study is helpful to investigate tool wear mechanism and optimize the machining parameters for the metal cutting processes.

When the situation, the hardness of coal and rock changes repidly (such as the existence of inter-band), appears, it's difficult to change cutting arm's pendulum speed timely and effectively by manual control, then the life of cutting head cutter and cutting motor will be affected seriously. By analyzing the relationship between v (the cutting arm swing speed), I (the motor current) and f (the hardness of coal and rock), this paper proposes PID-based automatic control strategy of cutting arm's pendulum speed and control precision made in accordance with relevant standards and regulations, aiming to replace artificial manipulation, protect the cutting head cutter and cutting motor and make the cutting motor be always loaded with the purpose of the work of constant power.