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Robust paleomagnetic results through geological time are one of the keys to understand the drift history of the eastern Qiangtang terrane (EQT). Here, we presented comprehensive petrographic observations and rock magnetic and paleomagnetic analyses of the early Carboniferous Upper Zaduo (ZD) limestone Formation (C1z2) from the Sulucun (SLC) section in the Zaduo area, EQT, to investigate its magnetic originality and geological significance. A total of 12 sites (131 samples) were collected. Photomicrograph observations indicate that the limestone samples were characterized by widespread carbonate veinlets. Electron microprobe and energy dispersive spectrometry analyses confirm that authigenic magnetite formed after pyrite. Rock magnetic analyses reveal the dominant magnetic minerals of pyrite and magnetite, with ‘wasp-waisted’ hysteresis loops and close to the “remagnetization trend” hysteresis parameters. Based on both thermal and alternating field demagnetizations, the characteristic remanent magnetization directions for most samples were isolated: Dg = 6.3°, Ig = 50.1°, kg = 54.9, α95 = 6.2° in-situ, and Ds = 330.2°, Is = 58.9°, ks = 5.9, and α95 = 20.5° after 2-step tilt correction. The κ (α95) value decreases (increases) after tilt-correction, and the ChRM directions failed both the McFadden (1990), Watson and Enkin (1993) fold tests, indicating post-folding magnetizations. The 11 site-mean directions yield a mean in-situ paleopole of 84.4°N, 200.3°E, and A95 = 6.8°, which is coincident with the post ∼53 Myr (especially around 40 Ma) paleopoles of the region. We therefore interpreted that these early Carboniferous limestone samples contain remagnetized magnetizations and that they were obtained after 53 Ma, most likely around 40 Ma, due to the far-field effect of the India–Eurasia collision.

In order to satisfy the requirement of automatic driving of outdoor unmanned vehicle, an automatic driving algorithm composed of integrated navigation and guidance control is proposed. The integrated navigation algorithm, which is fused with IMU, GNSS receiver and odometer, is designed based on SCKF with second-order fixed nonlinear expansion as the measurement model. The guidance control algorithm divides the expected route into segments and calculates the lateral and angular deviation between unmanned vehicle and the segmented route according to the longitude, latitude, heading angle and the key points sequence of the electronic map. The algorithm eliminates the deviation by incremental PID controller to realize the route tracking segment by segment. The simulation experiment results show that the accuracy of the integrated navigation algorithm based on SCKF is better than that based on SKF. The outdoor experiment verifies the effectiveness of the proposed automatic driving algorithm.

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London Over the last two decades or so, metal matrix composites (MMCs) have been drawing the attention of the industry due to their potentials in fulfilling demands for high performance industrial materials, products and advanced engineering applications. On the other hand, the high precision machining is becoming one of the most effective methods for enabling these difficult-to-machine composites to be applied particularly in precision engineering. Therefore, in-depth scientific understanding of MMC precision machining is essential and much needed so as to fulfil the gap between fundamental issues in precision machining of MMCs and their industrial scale applications. This thesis focuses on development of a multiscale multiphysics based approach to investigating the machinability of particulate MMCs and the machining process optimisation. In order to investigate the surface generation in relation to the process variables, this PhD study covers the key fundamental issues including chip formation process, dynamic cutting force, cutting temperature partition and tool wear by means of combining modelling, simulation and experimental study. The chip formation mechanisms and the minimum chip thickness in precision machining of SiCp/Al and B4Cp/Al MMCs by using PCD tools are investigated through a holistic approach. Minimum chip thickness (MCT) value is firstly identified based on the modified mathematical model. The certain threshold of the uncut chip thickness, i.e. chips starting to form at this chip thickness point, is then established. The chip formation process including the matrix material breakage, particles fracture, debonding, sliding or removal and their interfacial interactions are further simulated using finite element analysis (FEA). The minimum chip thickness and chip formation simulations are evaluated and validated via well-designed experimental trials on a diamond turning machine. The chips and surface profiles formed under varied process variables in periodic material removals are inspected and measured in order to obtain a better understanding on MMC chip formation mechanisms. The improved dynamic cutting force model is developed based on the micro cutting mechanics involving the size effect, undeformed chip thickness effects and the influence of cutting parameters in the micro scale. Cutting process variables, particle form, size and volume fraction at different scales are taken into account in the modelling. The cutting force multiscale modelling is proposed to have a better understanding on the MMCs cutting mechanics and to predict the cutting force accurately. The cutting forces are modelled and analysed in three cutting regimes: elastic recovery zone, ploughing zone and shearing zone. A novel instantaneous chip thickness algorithm including real chip thickness and real tool trajectory is developed by taking account of the tool runout. Well-designed cutting trials are carried out under varied process variables to evaluate and validate the force model. In order to obtain the actual cutting forces accurately, transfer function technique is employed to compensate the measured cutting forces. The cutting force model is further applied to correlate the cutting tool wear and the prediction of the machined surface generation. Multiphysics coupled thermal-mechanical-tribological model and FE analysis are developed to investigate the cutting stress, cutting temperature, tool wear and their intrinsic relationships in MMCs precision machining process. Heat generation, heat transfer and cutting temperature partition in workpiece, chips and cutting tool are simulated. A modified tool wear rate model is proposed, tool wear characteristics, wear mechanisms and dominate tool wear are further investigated against the real machining process. Cutting tool wear is monitored and assessed offline after machining experiments. The experimental study on the machined surface generation is presented covering cutting force, tool wear, tool life, surface roughness and machining efficiency. Process optimisation is explored by considering the variation of cutting parameters, cutting tool conditions and workpiece materials in order to achieve the desired outcomes and machinability.