62 research outputs found
First Experimental Demonstration of Gate-all-around III-V MOSFET by Top-down Approach
The first inversion-mode gate-all-around (GAA) III-V MOSFETs are
experimentally demonstrated with a high mobility In0.53Ga0.47As channel and
atomic-layer-deposited (ALD) Al2O3/WN gate stacks by a top-down approach. A
well-controlled InGaAs nanowire release process and a novel ALD high-k/metal
gate process has been developed to enable the fabrication of III-V GAA MOSFETs.
Well-behaved on-state and off-state performance has been achieved with channel
length (Lch) down to 50nm. A detailed scaling metrics study (S.S., DIBL, VT)
with Lch of 50nm - 110nm and fin width (WFin) of 30nm - 50nm are carried out,
showing the immunity to short channel effects with the advanced 3D structure.
The GAA structure has provided a viable path towards ultimate scaling of III-V
MOSFETs.Comment: IEEE IEDM 2011 pp. 769-772; Structures are valuable for
low-dimensional physics stud
Improving Simulation Efficiency of MCMC for Inverse Modeling of Hydrologic Systems with a Kalman-Inspired Proposal Distribution
Bayesian analysis is widely used in science and engineering for real-time
forecasting, decision making, and to help unravel the processes that explain
the observed data. These data are some deterministic and/or stochastic
transformations of the underlying parameters. A key task is then to summarize
the posterior distribution of these parameters. When models become too
difficult to analyze analytically, Monte Carlo methods can be used to
approximate the target distribution. Of these, Markov chain Monte Carlo (MCMC)
methods are particularly powerful. Such methods generate a random walk through
the parameter space and, under strict conditions of reversibility and
ergodicity, will successively visit solutions with frequency proportional to
the underlying target density. This requires a proposal distribution that
generates candidate solutions starting from an arbitrary initial state. The
speed of the sampled chains converging to the target distribution deteriorates
rapidly, however, with increasing parameter dimensionality. In this paper, we
introduce a new proposal distribution that enhances significantly the
efficiency of MCMC simulation for highly parameterized models. This proposal
distribution exploits the cross-covariance of model parameters, measurements
and model outputs, and generates candidate states much alike the analysis step
in the Kalman filter. We embed the Kalman-inspired proposal distribution in the
DREAM algorithm during burn-in, and present several numerical experiments with
complex, high-dimensional or multi-modal target distributions. Results
demonstrate that this new proposal distribution can greatly improve simulation
efficiency of MCMC. Specifically, we observe a speed-up on the order of 10-30
times for groundwater models with more than one-hundred parameters
Variability Improvement by Interface Passivation and EOT Scaling of InGaAs Nanowire MOSFETs
High-performance InGaAs gate-all-around (GAA) nanowire MOSFETs with channel length () down to 20 nm are fabricated by integrating a higher-k -based gate-stack with an equivalent oxide thickness of 1.2nm. It is found that inserting an ultrathin (0.5 nm) interfacial layer between the higher k and InGaAs can significantly improve the interface quality and reduce device variation. As a result, a record low subthreshold swing of 63 mV/dec is demonstrated at sub-80-nm for the first time, making InGaAs GAA nanowire devices a strong candidate for future low-power transistors.Chemistry and Chemical Biolog
A review on modelling methods, tools and service of integrated energy systems in China
An integrated energy system (IES) is responsible for aggregating various energy carriers, such as electricity, gas, heating, and cooling, with a focus on integrating these components to provide an efficient, low-carbon, and reliable energy supply. This paper aims to review the modeling methods, tools, and service modes of IES in China to evaluate opportunities for improving current practices. The models reviewed in this paper are classified as demand forecasting or energy system optimization models based on their modeling progress. Additionally, the main components involved in the IES modeling process are presented, and typical domestic tools utilized in the modeling processes are discussed. Finally, based on a review of several demonstration projects of IES, future development directions of IES are summarized as the integration of data-driven and engineering models, improvements in policies and mechanisms, the establishment of regional energy management centers, and the promotion of new energy equipment
Polyethyleneimine-coated MXene quantum dots improve cotton tolerance to Verticillium dahliae by maintaining ROS homeostasis
Verticillium dahliae is a soil-borne hemibiotrophic fungal pathogen that threatens cotton production worldwide. In this study, we assemble the genomes of two V. dahliae isolates: the more virulence and defoliating isolate V991 and nondefoliating isolate 1cd3-2. Transcriptome and comparative genomics analyses show that genes associated with pathogen virulence are mostly induced at the late stage of infection (Stage II), accompanied by a burst of reactive oxygen species (ROS), with upregulation of more genes involved in defense response in cotton. We identify the V991-specific virulence gene SP3 that is highly expressed during the infection Stage II. V. dahliae SP3 knock-out strain shows attenuated virulence and triggers less ROS production in cotton plants. To control the disease, we employ polyethyleneimine-coated MXene quantum dots (PEI-MQDs) that possess the ability to remove ROS. Cotton seedlings treated with PEI-MQDs are capable of maintaining ROS homeostasis with enhanced peroxidase, catalase, and glutathione peroxidase activities and exhibit improved tolerance to V. dahliae. These results suggest that V. dahliae trigger ROS production to promote infection and scavenging ROS is an effective way to manage this disease. This study reveals a virulence mechanism of V. dahliae and provides a means for V. dahliae resistance that benefits cotton production
The Semantic Reader Project: Augmenting Scholarly Documents through AI-Powered Interactive Reading Interfaces
Scholarly publications are key to the transfer of knowledge from scholars to
others. However, research papers are information-dense, and as the volume of
the scientific literature grows, the need for new technology to support the
reading process grows. In contrast to the process of finding papers, which has
been transformed by Internet technology, the experience of reading research
papers has changed little in decades. The PDF format for sharing research
papers is widely used due to its portability, but it has significant downsides
including: static content, poor accessibility for low-vision readers, and
difficulty reading on mobile devices. This paper explores the question "Can
recent advances in AI and HCI power intelligent, interactive, and accessible
reading interfaces -- even for legacy PDFs?" We describe the Semantic Reader
Project, a collaborative effort across multiple institutions to explore
automatic creation of dynamic reading interfaces for research papers. Through
this project, we've developed ten research prototype interfaces and conducted
usability studies with more than 300 participants and real-world users showing
improved reading experiences for scholars. We've also released a production
reading interface for research papers that will incorporate the best features
as they mature. We structure this paper around challenges scholars and the
public face when reading research papers -- Discovery, Efficiency,
Comprehension, Synthesis, and Accessibility -- and present an overview of our
progress and remaining open challenges
Aggregation-Induced Emission (AIE), Life and Health
Light has profoundly impacted modern medicine and healthcare, with numerous luminescent agents and imaging techniques currently being used to assess health and treat diseases. As an emerging concept in luminescence, aggregation-induced emission (AIE) has shown great potential in biological applications due to its advantages in terms of brightness, biocompatibility, photostability, and positive correlation with concentration. This review provides a comprehensive summary of AIE luminogens applied in imaging of biological structure and dynamic physiological processes, disease diagnosis and treatment, and detection and monitoring of specific analytes, followed by representative works. Discussions on critical issues and perspectives on future directions are also included. This review aims to stimulate the interest of researchers from different fields, including chemistry, biology, materials science, medicine, etc., thus promoting the development of AIE in the fields of life and health
Space advanced technology demonstration satellite
The Space Advanced Technology demonstration satellite (SATech-01), a mission for low-cost space science and new technology experiments, organized by Chinese Academy of Sciences (CAS), was successfully launched into a Sun-synchronous orbit at an altitude of similar to 500 km on July 27, 2022, from the Jiuquan Satellite Launch Centre. Serving as an experimental platform for space science exploration and the demonstration of advanced common technologies in orbit, SATech-01 is equipped with 16 experimental payloads, including the solar upper transition region imager (SUTRI), the lobster eye imager for astronomy (LEIA), the high energy burst searcher (HEBS), and a High Precision Magnetic Field Measurement System based on a CPT Magnetometer (CPT). It also incorporates an imager with freeform optics, an integrated thermal imaging sensor, and a multi-functional integrated imager, etc. This paper provides an overview of SATech-01, including a technical description of the satellite and its scientific payloads, along with their on-orbit performance
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