检索结果-内蒙古大学图书馆

30th Annual International Solid Freeform Fabrication Symposium - An Additive Manufacturing Conference, SFF 2019

作者： Hagen, Deborah Chen, Alex Beaman, Joseph J. Kovar, Desiderio Department of Mechanical Engineering Materials Science and Engineering Program University of Texas at Austin AustinTX78712 United States

Selective laser flash sintering (SLFS) combines a uniform electric field with a localized, scanning laser as the only external heating source. The presence of a large uniform electric field can greatly increase the sintering rate and lower the sintering temperature for ceramics. The combination of lower sintering temperature and faster sintering rates may allow SLFS to be used for ceramic additive manufacturing. In this work, we study the effects of moisture on SLFS of yttria-stabilized zirconia ceramic. We compare the effects of processing parameters on the initiation of SLFS for samples exposed to a range of moisture levels. © Solid Freeform Fabrication 2019: Proceedings of the 30th Annual International Solid Freeform Fabrication Symposium - An Additive Manufacturing Conference, SFF 2019. All rights reserved.

关键词： Moisture

来源：评论

学校读者我要写书评

暂无评论

High-Density Cationic Defects Coupling with Local Alkaline-Enriched Environment for Efficient and Stable Water Oxidation

引用

Angewandte Chemie 2023年第26期135卷

作者： Zheng Li Prof. Yangen Zhou Dr. Minghao Xie Hao Cheng Tao Wang Jian Chen Yao Lu Prof. Zhongliang Tian Prof. Yanqing Lai Prof. Guihua Yu School of Metallurgy and Environment Central South University Changsha 410083 China Materials Science and Engineering Program and Walker Department of Mechanical Engineering The University of Texas at Austin Austin TX 78712 USA

The inferior activity and stability of non-noble metal-based electrocatalysts for oxygen evolution reaction (OER) seriously limit their practical applications in various electrochemical energy conversion systems. Here we report, a drastic nonequilibrium precipitation approach to construct a highly disordered crystal structure of layered double hydroxides as a model OER catalyst. The unconventional crystal structure contains high-density cationic defects coupled with a local alkaline-enriched environment, enabling ultrafast diffusion of OH − ions and thus avoiding the formation of a local acidic environment and dissolution of active sites during OER. An integrated experimental and theoretical study reveals that high-density cationic defects, especially di-cationic and multi-cationic defects, serve as highly active and durable catalytic sites. This work showcases a promising strategy of crystal structure engineering to construct robust active sites for high-performance oxygen evolution in an alkaline solution.

关键词： Alkaline-Enriched Environment Cationic Defects Layered Double Hydroxides Stability Water Oxidation

来源：评论

学校读者我要写书评

暂无评论

Balanced depth completion between dense depth inference and sparse range measurements via KISS-GP

arXiv

引用

arXiv 2020年

作者： Yoon, Sungho Kim, Ayoung Robotics Program KAIST Daejeon Korea Republic of Department of Civil and Environmental Engineering KAIST Daejeon Korea Republic of

Estimating a dense and accurate depth map is the key requirement for autonomous driving and robotics. Recent advances in deep learning have allowed depth estimation in full resolution from a single image. Despite this impressive result, many deep-learning-based monocular depth estimation (MDE) algorithms have failed to keep their accuracy yielding a meter-level estimation error. In many robotics applications, accurate but sparse measurements are readily available from Light Detection and Ranging (LiDAR). Although they are highly accurate, the sparsity limits full resolution depth map reconstruction. Targeting the problem of dense and accurate depth map recovery, this paper introduces the fusion of these two modalities as a depth completion (DC) problem by dividing the role of depth inference and depth regression. Utilizing the state-of-the-art MDE and our Gaussian process (GP) based depth-regression method, we propose a general solution that can flexibly work with various MDE modules by enhancing its depth with sparse range measurements. To overcome the major limitation of GP, we adopt Kernel Interpolation for Scalable Structured (KISS)-GP and mitigate the computational complexity from O(N3) to O(N). Our experiments demonstrate that the accuracy and robustness of our method outperform state-of-the-art unsupervised methods for sparse and biased measurements. Copyright © 2020, The Authors. All rights reserved.

关键词： Optical radar

来源：评论

学校读者我要写书评

暂无评论

Spatiotemporal T cell dynamics in a 3D bioprinted immunotherapy model

引用

Bioprinting 2022年 28卷

作者： Morley, Cameron D. Flores, Catherine T. Drake, Jeffery A. Moore, Ginger L. Mitchell, Duane A. Angelini, Thomas E. University of Florida Herbert Wertheim College of Engineering Department of Mechanical and Aerospace Engineering Gainesville 32611 FL United States University of Florida Brain Tumor Immunotherapy Program Preston A. Wells Jr. Center for Brain Tumor Therapy Lillian S. Wells Department of Neurosurgery University of Florida 1149S Newell Dr L2-100 Gainesville 32611 FL United States University of Florida Herbert Wertheim College of Engineering Department of Materials Science and Engineering Gainesville 32611 FL United States University of Florida Herbert Wertheim College of Engineering J. Crayton Pruitt Family Department of Biomedical Engineering Gainesville 32611 FL United States

3D bioprinting-focused research is often driven by the aspiration to manufacture functional tissues and organs for implantation, yet decades of additional research is likely needed to develop such technologies, broadly. By contrast, we currently have 3D bioprinting tools capable of generating precise, spatially defined distributions of different cell types that can be used in fundamental and applied research, without delay. Here, we demonstrate this capability by 3D printing adoptive immunotherapy models using KR158B cells (murine glioma), hematopoietic stem cells (HSCs), and tumor-reactive T cells. We leverage a recently developed material made from packed microgel particles that serves simultaneously as a 3D printing support material and a 3D culture medium. With this approach we create well-defined 3D cell distributions and investigate the interactions between the different cell populations with time-lapse confocal microscopy. We find that 3D printed tumor spheroids containing HSCs recruit T cells more rapidly than those lacking HSCs, where T cell motion appears to be guided by diffusing cytokines originating at the tumor spheroid surface. After the T cells interact with the glioma structures, we collect the different cell populations by running our 3D bioprinter in reverse and perform transcriptomic analysis. We find that the differences in gene expression, comparing tumor spheroids printed with and without HSCs, are consistent with those found in a murine model. These results establish a path forward for developing validated 3D printed models for pre-clinical testing. © 2022 Elsevier B.V.

关键词： Adoptive Cell Transfer (ACT) Bioprinting Cell migration Microgel

来源：评论

学校读者我要写书评

暂无评论

High-nickel, low-cobalt cathodes for lithium-ion batteries

High-nickel, low-cobalt cathodes for lithium-ion batteries

引用

Battery Chemistries for Automotive Applications 2019

作者： Manthiram, Arumugam Materials Science and Engineering Program Texas Materials Institute Department of Mechanical Engineering University of Texas Austin United States

ISBN: (纸本)9781510893542

• Nickel is the only probable candidate to reduce cobalt without sacrificing energy • Cycle life, thermal stability, and air-sensitivity are the challenges with increasing Ni - Capacity fade is due to particle cracking and aggressive surface reactions - dissolved transition-metals crossover to anode and trap active-lithium at anode - metal dissolution depends on composition;Mn enhances Ni and Co dissolution - Al3+ or Mg2+ doping improves cycle life, thermal stability, and air stability - new electrolytes tune the electrode-electrolyte interphase, enhancing cyclability, low- and high-temperature performances, and thermal stability • Capacities of as high as ∼ 220 mAh/g (with Ni contents of 94%) with high volumetric energy density and long cycle life have been realized. © Battery Chemistries for Automotive Applications 2019, Held at AABC 2019. All rights reserved.

关键词： Thermodynamic stability

来源：评论

学校读者我要写书评

暂无评论

Stability and electronic properties of edges of SnS2

引用

Physical Review B 2020年第15期102卷 155306-155306页

作者： Tao Yan Pratap M. Rao N. Aaron Deskins Materials Science and Engineering program Worcester Polytechnic Institute Worcester Massachusetts 01609 USA Department of Mechanical Engineering Worcester Polytechnic Institute Worcester Massachusetts 01609 USA Department of Chemical Engineering Worcester Polytechnic Institute Worcester Massachusetts 01609 USA

Because of its two-dimensional structure and semiconducting properties, tin disulfide (SnS2) is of interest for many applications, such as photocatalysis, photovoltaics, sensing, and electronics. While the atomic and electronic structure of bulk and monolayer SnS2 have been studied, much less is known about the edges of layers. Such edges could have a major influence on the performance of SnS2. This paper reports on density functional theory (DFT) simulations of the atomic and electronic structure of the edges of SnS2. We modeled several different edge terminations at various S coverages and orientations, as well as performed thermodynamic analysis of edge terminations. Our results show that edges with 0% and 50% S atoms are most stable and that higher S coverage are unstable. We directly link edge stability with environmental temperature and pressure, which will guide the experimental synthesis of SnS2 materials. We found all the edges to be semiconducting, unlike other metal chalcogenides, and that the band gap energy decreased with increasing S coverage. Semiconducting edges could lead to lower charge recombination rates and better photocatalytic performance. Our calculations also show that edges may have direct or indirect band gaps, depending on the edge termination. Finally, we examined the reactivity of edges through hydrogen dissociation and found edges to be more reactive than basal planes. Our work provides important details on the nature of SnS2 edges and how these edges influence the electrical and chemical features of SnS2.

关键词： Dichalcogenides Surfaces Density functional theory

来源：评论

学校读者我要写书评

暂无评论

TRIFLEX U - Kinematic and Error Analysis of a Self-aligned Translational Parallel Manipulator PRRU

TRIFLEX U - Kinematic and Error Analysis of a Self-aligned T...

引用

作者： Maletz, Elias Renã Meneghini, Luan Grando, Marcel Tômas Martins, Daniel Simoni, Roberto Simas, Henrique Department of Mechanical Engineering Robotics Laboratory Federal University of Santa Catarina Florianópolis Brazil Department of Mobility Engineering Federal University of Santa Catarina Joinville Brazil

In some applications, a parallel manipulator with fewer than 6 DoF is enough. Better accuracy due to less cumulative joint errors is the most common feature in parallel manipulators than serial ones. In this work is presented a new conception and the direct kinematic of an isotropic translational parallel manipulator denominated as Triex U, that has three identical PRRU legs being that prismatic joints actuated, and its remain joints contribute to the self-alignment property. This work applies a technique developed to select which region inside its workspace is less affected by geometric and constructive errors. With this in mind the workspace was identified and a graphical analysis inside an useful volume shows the best regions for more precise applications or that suffer less influences of geometric and constructive errors. © 2019, Springer Nature Switzerland AG.

关键词： Manipulators

来源：评论

学校读者我要写书评

暂无评论

Molecular Contrastive Learning of Representations via Graph Neural Networks

arXiv

引用

arXiv 2021年

作者： Wang, Yuyang Wang, Jianren Cao, Zhonglin Farimani, Amir Barati Department of Mechanical Engineering Carnegie Mellon University PittsburghPA15213 United States Machine Learning Department Carnegie Mellon University PittsburghPA15213 United States Robotics Institute Carnegie Mellon University PittsburghPA15213 United States Department of Chemical Engineering Carnegie Mellon University PittsburghPA15213 United States

Molecular Machine Learning (ML) bears promise for efficient molecule property prediction and drug discovery. However, labeled molecule data can be expensive and time-consuming to acquire. Due to the limited labeled data, it is a great challenge for supervised-learning ML models to generalize to the giant chemical space. In this work, we present MolCLR: Molecular Contrastive Learning of Representations via Graph Neural Networks (GNNs), a self-supervised learning framework that leverages large unlabeled data (∼10M unique molecules). In MolCLR pre-training, we build molecule graphs and develop GNN encoders to learn differentiable representations. Three molecule graph augmentations are proposed: atom masking, bond deletion, and subgraph removal. A contrastive estimator maximizes the agreement of augmentations from the same molecule while minimizing the agreement of different molecules. Experiments show that our contrastive learning framework significantly improves the performance of GNNs on various molecular property benchmarks including both classification and regression tasks. Benefiting from pre-training on the large unlabeled database, MolCLR even achieves state-of-the-art on several challenging benchmarks after fine-tuning. Additionally, further investigations demonstrate that MolCLR learns to embed molecules into representations that can distinguish chemically reasonable molecular similarities. Copyright © 2021, The Authors. All rights reserved.

关键词： Molecules

来源：评论

学校读者我要写书评

暂无评论

In situ printing of liquid superlenses for subdiffraction-limited color imaging of nanobiostructures in nature

引用

Microsystems & Nanoengineering 2019年第1期5卷 695-707页

作者： Boliang Jia Feifei Wang Hoyin Chan Guanglie Zhang Wen Jung Li Department of Mechanical Engineering City University of Hong KongHong KongHong Kong S.A.R.China Shenzhen Academy of Robotics Shenzhen 518000China Department of Chemistry Stanford UniversityStanfordCA 94305USA

The nanostructures and patterns that exist in nature have inspired researchers to develop revolutionary components for use in modern technologies and our daily *** nanoscale imaging of biological samples with sophisticated analytical tools,such as scanning electron microscopy(SEM)and transmission electron microscopy(TEM),has afforded a precise understanding of structures and has helped reveal the mechanisms contributing to the behaviors of the samples but has done so with the loss of photonic ***,we present a new method for printing biocompatible“superlenses”directly on biological objects to observe subdiffraction-limited features under an optical microscope in *** demonstrate the nanoscale imaging of butterfly wing scales with a super-resolution and larger field-of-view(FOV)than those of previous dielectric microsphere *** approach creates a fast and flexible path for the direct color observation of nanoscale biological features in the visible range and enables potential optical measurements at the subdiffraction-limited scale.

关键词： printing structures diffraction

来源：评论

学校读者我要写书评

暂无评论

Using eye-tracking data to predict situation awareness in real time during takeover transitions in conditionally automated driving

arXiv

引用

arXiv 2021年

作者： Zhou, Feng Yang, X. Jessie de Winter, Joost The Department of Industrial and Manufacturing Systems Engineering University of Michigan Dearborn 4901 Evergreen Rd. DearbornMI48128 United States The Department of Industrial and Operations Engineering University of Michigan Ann Arbor 1205 Beal Avenue Ann ArborMI48109 United States The Cognitive Robotics Department Faculty of Mechanical Maritime and Materials Engineering Delft University of Technology Mekelweg 2 Delft2628 CD Netherlands

Situation awareness (SA) is critical to improving takeover performance during the transition period from automated driving to manual driving. Although many studies measured SA during or after the driving task, few studies have attempted to predict SA in real time in automated driving. In this work, we propose to predict SA during the takeover transition period in conditionally automated driving using eye-tracking and self-reported data. First, a tree ensemble machine learning model, named LightGBM (Light Gradient Boosting Machine), was used to predict SA. Second, in order to understand what factors influenced SA and how, SHAP (SHapley Additive exPlanations) values of individual predictor variables in the LightGBM model were calculated. These SHAP values explained the prediction model by identifying the most important factors and their effects on SA, which further improved the model performance of LightGBM through feature selection. We standardized SA between 0 and 1 by aggregating three performance measures (i.e., placement, distance, and speed estimation of vehicles with regard to the ego-vehicle) of SA in recreating simulated driving scenarios, after 33 participants viewed 32 videos with six lengths between 1 and 20 s. Using only eye-tracking data, our proposed model outperformed other selected machine learning models, having a root-mean-squared error (RMSE) of 0.121, a mean absolute error (MAE) of 0.096, and a 0.719 correlation coefficient between the predicted SA and the ground truth. The code is available at https://***/refengchou/Situation-awareness-prediction. Our proposed model provided important implications on how to monitor and predict SA in real time in automated driving using eye-tracking data. © 2021, CC BY.

关键词： Forecasting

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：