Results 81 to 90 of about 9,774,707 (312)

Spacetime and the Philosophical Challenge of Quantum Gravity [PDF]

open access: yes, 2001
We survey some philosophical aspects of the search for a quantum theory of gravity, emphasising how quantum gravity throws into doubt the treatment of spacetime common to the two `ingredient theories' (quantum theory and general relativity), as a 4 ...
Butterfield, Jeremy   +3 more
core   +1 more source

Research on 1/6 g Environment Simulation System Based on Magnetic Levitation Suspension

open access: yesIEEE Access
The 1/6g environment simulation system is essential in scientific research, exploration, and future space development. The system is technically demanding and must accurately simulate a low-gravity environment while ensuring the reliability and precision
Lei Ma   +3 more
doaj   +1 more source

Multistage, Self‐Sensing Artificial Muscles With Coordination From Liquid Crystal Elastomer‐Graphene Composite Fibers

open access: yesAdvanced Functional Materials, EarlyView.
Inspired by skeletal muscles’ precision and endurance, CoilLCE integrates a self‐sensing liquid crystal elastomer/graphene artificial muscle with an embedded Joule‐heating copper coil, enabling closed‐loop multistage actuation with programmable intermediate states (strain accuracy of 2%), and antagonistic coordination (32% total strain). These features
Ziyun Zhang   +9 more
wiley   +1 more source

Thermoresponsive Liquid Crystalline Polymer Coatings Programmed by Field‐Induced Topological Defects for Tunable Optical and Topographical Responses

open access: yesAdvanced Functional Materials, EarlyView.
Resonant standing waves generate large‐area lattices of liquid‐crystal topological defects that are permanently encoded into polymer coatings by photopolymerization. The preserved director architecture produces thermally reconfigurable surface topographies while maintaining programmable optical functionality, demonstrating a scalable strategy for ...
Jacques A. Peixoto   +6 more
wiley   +1 more source

Controlling for heterogeneity in gravity models of trade and integration [PDF]

open access: yes
This paper compares various specifications of the gravity model of trade as nested versions of a general specification that uses bilateral country-pair fixed effects to control for heterogeneity.
Howard J. Wall, I-Hui Cheng
core   +2 more sources

Microscale Patterning of Ultrahigh‐Viscosity Metallic‐Polymer Composites via Embedded Droplet Writing

open access: yesAdvanced Functional Materials, EarlyView.
A hybrid additive manufacturing platform integrates direct droplet writing of metallic composite with VAT photopolymerization to fabricate architected soft magnetic composites. This approach enables microscale patterning of high‐viscosity materials for programmable actuators, adaptive fluidic devices, and switchable adhesives, offering tunable ...
Yeowon Yoon   +4 more
wiley   +1 more source

The GOCE observations for detecting the full extent of the crust to mantle section brought to the surface in the Kohistan Arc, Himalaya

open access: yes, 2012
The aim of this work is to use the GOCE observations in a geologically unique part of the Himalayan orogen, which is the Kohistan arc. Here the entire section of the crust from the mantle-crust transition, to the volcanic deposits in the upper crust are ...
SINCICH, EVA   +3 more
core  

Adaptive robust control of quadrotor with a 2-degree-of-freedom robotic arm

open access: yesAdvances in Mechanical Engineering, 2018
The control of quadrotor equipped with a robotic arm has received growing challenges. This article proposes a new adaptive control strategy of quadrotor equipped with a 2-degree-of-freedom robotic arm.
Ran Jiao   +3 more
doaj   +1 more source

CO2‐to‐CO Conversion in a Gas‐Fed, Zero‐Gap, PEM Electrolyzer Enabled by Polycations and Nitrogen‐Doped Carbon‐Supported Cobalt Nanoparticles

open access: yesAdvanced Functional Materials, EarlyView.
A gas‐fed, zero‐gap, PEM CO2 electrolyzer is realized by incorporating PDDA+ ions onto the carbonaceous Co/N‐C electrocatalyst, with gaseous H2 and CO2 fed into the anode and cathode, respectively. Operating without an aqueous electrolyte, the system sustains a peak FECO of 65.1% at 100 mA cm−2. ABSTRACT Electrochemical carbon dioxide reduction (ECO2R)
Yuen Leong Chow   +6 more
wiley   +1 more source

Drag-free and attitude control for the GOCE satellite [PDF]

open access: yes, 2008
The paper concerns Drag-Free and Attitude Control of the European satellite Gravity field and steady-state Ocean Circulation Explorer (GOCE) during the science phase.
Canuto, Enrico
core   +1 more source

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