High-throughput Exploration of Glass Formation via Laser Deposition and the Study of Heterogeneous Microstructure in a Bulk Metallic Glass Alloy

Bulk metallic glasses are a relatively novel class of engineering alloys characterized by a disordered atomic structure devoid of long-range translational symmetry. Compared to crystalline alloys, the confluence of metallic bonding and amorphous structure imbues bulk metallic glasses with a unique set of properties that makes them particularly attractive for a wide variety of structural applications. Such properties include exceptional yield strengths, high elastic resilience, resistance to corrosion, and in particular, the unparalleled ability among metals to be thermoplastically formed across a wide range of length scales when heated above the glass transition temperature. Formation of metallic glass from a molten liquid depends on whether cooling is sufficiently rapid to bypass crystallization and vitrify into an amorphous solid; for a given alloy composition, the ease with which full vitrification can occur upon cooling from the liquid state is termed the alloy\u27s glass forming ability. Unfortunately, relatively few excellent glass formers have been reported in the vast, multicomponent composition space in which they reside. The apparent slowness of progress may be attributed largely to the inefficiency of the one-at-a-time experimental approach to discovery and design. In this thesis work, a high-throughput combinatorial methodology was developed to expedite the discovery process of new bulk metallic glasses. Laser deposition was used to fabricate continuously-graded composition libraries of Cu-Zr and Cu-Zr-Ti alloys. By processing the libraries with a range of laser heat input, the best glass formers in each alloy system could be efficiently and systematically deduced. Furthermore, instrumented nanoindentation performed on the libraries enabled rapid evaluation of mechanical property trends. Despite boasting high strengths, monolithic bulk metallic glasses generally suffer from an intrinsic lack of damage tolerance compared to other high performance alloys. Recent studies indicate that the macroscopic deformation behavior of the material may be controlled by structural heterogeneities, although the exact nature and origin of the heterogeneities remain ambiguous. To further the present knowledge, the heterogeneous microstructure of a zirconium-based bulk metallic glass was investigated with instrumented nanoindentation and dynamic modulus mapping. Significant spatial variations in the mechanical properties measured by both techniques suggests a hierarchical arrangement of structural/mechanical heterogeneities in bulk metallic glasses. Moreover, a previously unobserved elastic microstructure, comprising an interconnected network of elastic features, was revealed by dynamic modulus mapping. Despite the absence of visible contrast when imaged with electron microscopy, the aligned morphology of the elastic features and their sensitivity to thermal processing conditions imply the occurrence of spinodal decomposition in the supercooled liquid prior to glass formation. Finally, based on analysis of load-displacement data from nanoindentation experiments performed throughout the thesis work, a new parameter, the plastic work ratio, was proposed as a figure of merit for quantifying the intrinsic plasticity of monolithic metallic glass alloys

Hyacinth6B: A large language model for Traditional Chinese

This research's primary motivation of this study is to address the high hardware and computational demands typically associated with LLMs.Therefore,our goal is to find a balance between model lightness and performance,striving to maximize performance while using a comparatively lightweight model. Hyacinth6B was developed with this objective in mind,aiming to fully leverage the core capabilities of LLMs without incurring substantial resource costs, effectively pushing the boundaries of smaller model's performance. The training approach involves parameter efficient finetuning using the LoRA method.Comment: 14page

Imaginary polarization as a way to surmount the sign problem in ab initio calculations of spin-imbalanced Fermi gases

From ultracold atoms to quantum chromodynamics, reliable ab initio studies of strongly interacting fermions require numerical methods, typically in some form of quantum Monte Carlo calculation. Unfortunately, (non)relativistic systems at finite density (spin polarization) generally have a sign problem, such that those ab initio calculations are impractical. It is well-known, however, that in the relativistic case imaginary chemical potentials solve this problem, assuming the data can be analytically continued to the real axis. Is this feasible for nonrelativistic systems? Are the interesting features of the phase diagram accessible in this manner? By introducing complex chemical potentials, for real total particle number and imaginary polarization, the sign problem is avoided in the nonrelativistic case. To give a first answer to the above questions, we perform a mean-field study of the finite-temperature phase diagram of spin-1/2 fermions with imaginary polarization.Comment: 5 pages, 2 figures; published versio

Important Issues in Implementing Global networks

Global communication networks are used by multinational companies for instant access to information and communications. Many advantages can be obtained from implementing a global network; however, many challenges exist in designing and implementing a network that encompasses different countries. This article presents some key issues for the design and implementation of a global network

The First Protocol Of Reaching Consensus Under Unreliable Mobile Edge Computing Paradigm

Mobile Edge Computing (MEC) is an emerging technology that enables computing directly at the edge of the cloud computing network. Therefore, it is important that MEC is applied with reliable transmission. The problem of reaching consensus in the distributed system is one of the most important issues in designing a reliable transmission network. However, all previous protocols for the consensus problem are not suitable for an MEC paradigm. It is the first time an optimal protocol of reaching consensus is pro- posed for MEC paradigm. The protocol makes all fault-free nodes communicate with each other and collect the exchanged messages to decide a common value. Based on the common value, the protocol ensures all fault-free nodes reach consensus without the influence of unreliable transmission. Finally, we proved theoretically that the proposed protocol can tolerate the maximum number of faulty components and using only two rounds of message exchanges

Stopper-Bearing System – A Solution to Displacement Control of Bridge Decks

Bridges play an important role in society, especially during the post-earthquake period that enables emergency vehicles and traffic for safe egress and ingress to minimize the loss of property and life. However, some past earthquakes have resulted in large horizontal displacements on the superstructure that have lead to unseating of bridge spans and unexpected pounding forces that damaged critical components such as bearings and anchor bolts. To this end, a new bearing system, referred to as a stopperbearing system (SBS), is proposed as one solution to address the vulnerability of bridge bearings and other components. The horizontal displacement of a deck can be limited to a desired range using the SBS. The nonlinear load-deformation behavior of the SBS is obtained from ABAQUS and used to define the SBS within reinforced concrete analytical bridge models developed in SAP2000, which are subjected to the 1999 Chi- Chi, Taiwan earthquake ground motion (1.01g - E-W component and 0.43g - N-S component). The results from the nonlinear time history analyses show that the SBS is effective in limiting bridge deck displacements and pounding effects. Preliminary analytical modeling of the SBS shows promise as a solution to displacement control of bridge decks for overall enhancement of bridge performance during seismic events

CALIBRATION OF PRESSURE SENSORS FOR HAND GRIP MEASUREMENT

The purpose of this study was to assess the accuracy of grip force sensors. Methods: Several standard weights were used to calibrate the grip sensor in the static condition, The descriptive statistics and linear regression were used to present the accuracy and errors. Results: Results of this study showed a high level of sensing areas linear relationship under static loading. Conclusion: Data from this study showed high accuracy of the pressure sensor. The pressure sensor could te used for hand grip measurement