Results 101 to 110 of about 17,764,059 (293)

Effects of high-latitude atmospheric gravity wave disturbances on artificial HF radar backscatter [PDF]

open access: yes, 2006
International audienceObservations of HF radar backscatter from artificial field-aligned irregularities in an ionosphere perturbed by travelling disturbances due to atmospheric gravity waves are presented.
Tim K. Yeoman (7583066)   +14 more
core   +2 more sources

HIGH-FREQUENCY RADAR FOR COASTAL AREAS MONITORING

open access: yesJournal of the Russian Universities. Radioelectronics, 2019
Introduction. The modern approach for ensuring marine activities of necessary quality related to the assessment of current information on the state of the ocean environment in Russia is clearly insufficient. The development of operational methods and instruments of observation, as well as the assessment of the state of the ocean and its forecast ...
V. I. Veremyev   +4 more
openaire   +3 more sources

Surface‐Spin‐Induced Magnetic Loss Enhancement in Ultralight Electromagnetic Absorbers

open access: yesAdvanced Science, EarlyView.
Fe3O4 nanoparticles with different hollow rates were synthesized to demonstrate the key role of surface moment in magnetic loss process. Using the same volume filling ratio, the 54.1% hollow Fe3O4 absorber represents about 20% enhancement in the imaginary part (μ'') than solid particles due to the coexisting magnetic resonance of inside and outside ...
Ruimin Ren   +5 more
wiley   +1 more source

Strategy of Triple‐Gradient in Binary Pixels for Flexible Pressure Sensing with High Sensitivity and Wide‐Range Linearity

open access: yesAdvanced Science, EarlyView.
A flexible pressure sensor with triple‐gradient design of conductivity, modulus, and dimension in binary micro‐dome pixels is proposed. Based on precisely‐designed CNT/PDMS matrix, the device exhibits a linear sensitivity of 974.1 kPa−1 across range up to 1.8 MPa (R2 > 0.99), offering an effective strategy for potential applications in healthcare ...
Yifan Liu   +9 more
wiley   +1 more source

Investigation of Coupling Mechanisms for Efficient High Power and Low Phase Noise E-Band Quadrature VCOs in 130nm SiGe

open access: yesIEEE Journal of Microwaves
This article compares two SiGe Colpitts quadrature voltage-controlled oscillators (QVCO) with different coupling techniques in the low E-Band, intended to be used as signal sources for push-push frequency doublers.
David Starke   +4 more
doaj   +1 more source

Multitask Deep Learning Model for Predicting Lymph Node Metastasis and Disease‐Free Survival From Cytology Images in Bladder Cancer: A Multicenter Study With Pan‐Cytology Validation

open access: yesAdvanced Science, EarlyView.
Through self‐supervised pretraining and supervised fine‐tuning on large‐scale cytology image datasets, CytoNet predicts lymph node metastasis and survival. Across independent cohorts, this multitask framework demonstrates robust performance, improves risk stratification beyond radiological assessment, and provides interpretable evidence to support ...
Guibin Hong   +14 more
wiley   +1 more source

Mesoscale observations of Joule heating near an auroral arc and ion-neutral collision frequency in the polar cap E region [PDF]

open access: yes, 2011
We report on the first mesoscale combined ionospheric and thermospheric observations, partly in the vicinity of an auroral arc, from Svalbard in the polar cap on 2 February 2010. The EISCAT Svalbard radar employed a novel scanning mode in order to obtain
McCrea IW   +32 more
core   +1 more source

High-Accuracy Linearity Measurement of Broadband Frequency Chirps

open access: yesIEEE Open Journal of Instrumentation and Measurement
High-resolution radar systems use fast and broadband frequency chirps to enable high resolutions with short measurement times. One challenge in these radar systems is minimizing the linearity error in the generated frequency chirps, directly influencing ...
Bent Walther   +3 more
doaj   +1 more source

A Global Methane Observation System to Reduce Uncertainty for Anthropogenic and Natural Sources and Sinks for Detecting and Attributing Climate Feedbacks

open access: yesAdvanced Science, EarlyView.
Conceptual illustration of a Global Ecosystem Methane Observing System (GEM‐OS) integrating satellites, aircraft, atmospheric networks, and ecosystem measurements to quantify methane emissions from anthropogenic and natural sources. The multi‐scale observing framework improves source attribution, reduces uncertainty in regional methane budgets, and ...
P. Ciais   +32 more
wiley   +1 more source

Introducing Inharmonic Radar: Tag Detection in the Automotive Bands of Present and Future at 76–81/134–141 GHz via Fractional Multiplication

open access: yesIEEE Journal of Microwaves
Harmonic radar systems are highly effective at distinguishing specific targets from surrounding clutter. Therefore, the reception of a tag response, conventionally at the second harmonic, is utilized.
Tobias T. Braun   +4 more
doaj   +1 more source

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