Vibration measurement in a metro depot with trains running in the top story

Metro depots are places for subway train to get parked and maintained. To avoid the waste of large city areas occupied by depots, there is a need of developing depots for commercial and/or residential use as well, and in that case the train-induced vibrations become the major concern. This paper presents a unique case study on the vibration measurement in a 3-story metro depot, where the first two stories are developed for offices and shops and the third story is used as the maintenance garage with trains moving in/out through the connecting viaducts. Acceleration time histories of rails and floors in the three stories were measured. Amplitudes and frequency contents of the vibrations at different locations are compared through the corresponding frequency spectra and 1/3 octave band root-mean-square (RMS) spectra. The influence of track positions on floor vibration is investigated, and the vibration level of the building is evaluated using two indicators. Finally, numerical simulation is carried out so as to provide some references to the vibration control

Unified Field Theory and Topology of Nuclei

Abstract This paper proposes that a nucleus has a lattice configuration. A nucleus can not be seen visually. The configuration of a nucleus is studied in theoretical models, such as lattice, NCFC, and water drop. There are a few theories study many body interactions in a nucleus, such as Ab initio calculation, BCS formalism, and SEMF. However, the precise structure of an isotope is not known. According to Unified Field Theory (UFT), a proton has the shape of an octahedron. Since the strong forces are along the axes of the octahedron of protons and neutron, the structure of ground state isotopes of any given element can be logically induced. Furthermore, only two of three axes of the octahedron nucleus possess interactive forces. Therefore, any nuclear structure has one layer only. Our results demonstrate that there is a configuration for any isotope. Mass, stability and configuration of an isotope are related. We anticipate our essay to be a starting point of new method that provides precise configuration for each isotope, theoretical mass calculation for an unknown isotope, and nuclear characteristics/stability analysis for a given configuration. For example, the best symmetrical lattice of an isotope can be selected from all possible lattices. The selected lattice for the isotope can decide the stability of the isotope

Analysis on the influence of rotational speed to aerodynamic performance of vertical axis wind turbine

AbstractA two dimensional vertical axis wind turbine's model was established in this paper, and two dimensional unsteady incompressible N-S equations and Realizable kɛ− turbulence model were solved with software FLUENT. SIMPLC algorithm was applied, combined with the sliding grid technology; the influence of rotational speed to the flow structure of vertical axis wind turbine was discussed. The results showed that, the rotation of wind turbine had significant influence on wake, and higher the rotational speed, the greater reduction of the wake velocity. The wake velocity restored gradually away from the rotational part. There was much larger turbulent kinetic energy near the tail of the wind turbine's blade. The value of turbulent kinetic energy reduced gradually away from the rotational part, and the flow restored the stratospheric state gradually. With the increase of wind turbine's rotational speed, the value of turbulent kinetic energy in calculation domain increased too. The results showed that the flow structure of vertical axis wind turbine's rotational process could be revealed effectively by numerical simulation, provided theoretical reference for the engineering design of the vertical axis wind turbine

Recursively Summarizing Enables Long-Term Dialogue Memory in Large Language Models

Most open-domain dialogue systems suffer from forgetting important information, especially in a long-term conversation. Existing works usually train the specific retriever or summarizer to obtain key information from the past, which is time-consuming and highly depends on the quality of labeled data. To alleviate this problem, we propose to recursively generate summaries/ memory using large language models (LLMs) to enhance long-term memory ability. Specifically, our method first stimulates LLMs to memorize small dialogue contexts and then recursively produce new memory using previous memory and following contexts. Finally, the LLM can easily generate a highly consistent response with the help of the latest memory. We evaluate our method using ChatGPT and text-davinci-003, and the experiments on the widely-used public dataset show that our method can generate more consistent responses in a long-context conversation. Notably, our method is a potential solution to enable the LLM to model the extremely long context. Code and scripts will be released later

The NS1 protein of influenza a virus interacts with heat shock protein Hsp90 in human alveolar basal epithelial cells: Implication for virus-induced apoptosis

<p>Abstract</p> <p>Background</p> <p>Our previous study showed that the NS1 protein of highly pathogenic avian influenza A virus H5N1 induced caspase-dependent apoptosis in human alveolar basal epithelial cells (A549), supporting its function as a proapoptotic factor during viral infection, but the mechanism is still unknown.</p> <p>Results</p> <p>To characterize the mechanism of NS1-induced apoptosis, we used a two-hybrid system to isolate the potential NS1-interacting partners in A549 cells. We found that heat shock protein 90 (Hsp90) was able to interact with the NS1 proteins derived from both H5N1 and H3N2 viruses, which was verified by co-immunoprecitation assays. Significantly, the NS1 expression in the A549 cells dramatically weakened the interaction between Apaf-1 and Hsp90 but enhanced its interaction with cytochrome c (Cyt c), suggesting that the competitive binding of NS1 to Hsp90 might promote the Apaf-1 to associate with Cyt c and thus facilitate the activation of caspase 9 and caspase 3.</p> <p>Conclusions</p> <p>The present results demonstrate that NS1 protein of Influenza A Virus interacts with heat hock protein Hsp90 and meidates the apoptosis induced by influenza A virus through the caspase cascade.</p

Wear Behaviors of a Ti-Based Bulk Metallic Glass at Elevated Temperatures

Bulk metallic glasses (BMGs) often offer excellent physical, chemical, and mechanical properties such as high strength, high hardness, and good wear/corrosion resistance, stemming from their unique atomic configuration. These properties enable them to be a potential engineering material in a range of industrial applications. However, the wear behaviors must be considered in structural applications. Here, the wear tests of a TiZrNiCuBe bulk metallic glass at high temperatures were carried out. As the testing temperature increases, the wear rate of the studied BMG sample gradually decreases and the sample surface becomes smoother. Meanwhile, a higher applied normal load causes a higher wear rate. The wear mechanism evolves from the abrasive to adhesive mode with increase in the testing temperature. The results obtained here could shed more insights into the deformation mechanism of BMGs and thus extend their industrial uses in high-temperature environments

Quantum key distribution and beyond: introduction

This feature issue presents a collection of recent theoretical and experimental developments in the field of quantum key distribution (QKD) and its extension to other quantum cryptography protocols and devices. It encompasses work on a variety of QKD protocols, including continuous-variable, measurement-device independent, and twin-field QKD, as well as other newly proposed protocols, in platforms ranging from optical fiber through to wireless indoor and satellite links. It covers examples of hacking strategies and their countermeasures as well as applications of machine learning techniques in designing quantum networks. It also includes new developments in efficient superconducting photon-number resolving detectors as well as fast quantum random number generators. Distinctively, this feature issue demonstrates how different expertise in science and engineering can come together to produce an outcome that hopefully takes us one step closer to the wide-scale deployment of quantum communications technologies