6,727 research outputs found
Generic regularity of conservative solutions to the Novikov equation
In this paper, we concentrate on the Novikov equation. For an open dense set
of C 3 initial data, we prove that the solution is piecewise smooth in the t-x
plane, while the gradient uux can blow up along finitely many characteristic
curves. And we provide a description of the solution in a neighborhood of each
singular point
Splitting of surface defect partition functions and integrable systems
We study Bethe/gauge correspondence at the special locus of Coulomb moduli
where the integrable system exhibits the splitting of degenerate levels. For
this investigation, we consider the four-dimensional pure
supersymmetric gauge theory, with a half-BPS surface defect constructed
with the help of an orbifold or a degenerate gauge vertex. We show that the
non-perturbative Dyson-Schwinger equations imply the Schr\"odinger-type and the
Baxter-type differential equations satisfied by the respective surface defect
partition functions. At the special locus of Coulomb moduli the surface defect
partition function splits into parts. We recover the Bethe/gauge dictionary for
each summand.Comment: 34 pages, 2 figures; v2. published versio
Research progress in ultrasound use for the diagnosis and treatment of cerebrovascular diseases
Cerebrovascular diseases pose a serious threat to human survival and quality of life and represent a major cause of human death and disability. Recently, the incidence of cerebrovascular diseases has increased yearly. Rapid and accurate diagnosis and evaluation of cerebrovascular diseases are of great importance to reduce the incidence, morbidity and mortality of cerebrovascular diseases. With the rapid development of medical ultrasound, the clinical relationship between ultrasound imaging technology and the diagnosis and treatment of cerebrovascular diseases has become increasingly close. Ultrasound techniques such as transcranial acoustic angiography, doppler energy imaging, three-dimensional craniocerebral imaging and ultrasound thrombolysis are novel and valuable techniques in the study of cerebrovascular diseases. In this review, we introduce some of the new ultrasound techniques from both published studies and ongoing trials that have been confirmed to be convenient and effective methods. However, additional evidence from future studies will be required before some of these techniques can be widely applied or recommended as alternatives
Assessment of the spatial and temporal variations of water quality for agricultural lands with crop rotation in China by using a HYPE model
Many water quality models have been successfully used worldwide to predict nutrient losses from anthropogenically impacted catchments, but hydrological and nutrient simulations with little data are difficult considering the transfer of model parameters and complication of model calibration and validation. This study aims (i) to assess the performance capabilities of a new and relatively more advantageous model-hydrological predictions for the environment (HYPE) to simulate stream flow and nutrient load in ungauged agricultural areas by using a multi-site and multi-objective parameter calibration method and (ii) to investigate the temporal and spatial variations of total nitrogen (TN) and total phosphorous (TP) concentrations and loads with crop rotation using the model for the first time. A parameter estimation tool (PEST) was used to calibrate parameters, which shows that the parameters related to the effective soil porosity were most sensitive to hydrological modeling. N balance was largely controlled by soil denitrification processes, whereas P balance was influenced by the sedimentation rate and production/decay of P in rivers and lakes. The model reproduced the temporal and spatial variations of discharge and TN/TP relatively well in both calibration (2006–2008) and validation (2009–2010) periods. The lowest NSEs (Nash-Suttclife Efficiency) of discharge, daily TN load, and daily TP load were 0.74, 0.51, and 0.54, respectively. The seasonal variations of daily TN concentrations in the entire simulation period were insufficient, indicated that crop rotation changed the timing and amount of N output. Monthly TN and TP simulation yields revealed that nutrient outputs were abundant in summer in terms of the corresponding discharge. The area-weighted TN and TP load annual yields in five years showed that nutrient loads were extremely high along Hong and Ru rivers, especially in agricultural lands
VDialogUE: A Unified Evaluation Benchmark for Visually-grounded Dialogue
Visually-grounded dialog systems, which integrate multiple modes of
communication such as text and visual inputs, have become an increasingly
popular area of investigation. However, the absence of a standardized
evaluation framework poses a challenge in assessing the development of this
field. To this end, we propose \textbf{VDialogUE}, a \textbf{V}isually-grounded
\textbf{Dialog}ue benchmark for \textbf{U}nified \textbf{E}valuation. It
defines five core multi-modal dialogue tasks and covers six datasets.
Furthermore, in order to provide a comprehensive assessment of the model's
performance across all tasks, we developed a novel evaluation metric called
VDscore, which is based on the Analytic Hierarchy Process~(AHP) method.
Additionally, we present a straightforward yet efficient baseline model, named
\textbf{VISIT}~(\textbf{VIS}ually-grounded d\textbf{I}alog
\textbf{T}ransformer), to promote the advancement of general multi-modal
dialogue systems. It progressively builds its multi-modal foundation and
dialogue capability via a two-stage pre-training strategy.
We believe that the VDialogUE benchmark, along with the evaluation scripts
and our baseline models, will accelerate the development of visually-grounded
dialog systems and lead to the development of more sophisticated and effective
pre-trained models
Flg22-Triggered Immunity Negatively Regulates Key BR Biosynthetic Genes
In plants, activation of growth and activation of immunity are opposing processes that define a trade-off. In the past few years, the growth-promoting hormones brassinosteroids (BR) have emerged as negative regulators of pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI), promoting growth at the expense of defense. The crosstalk between BR and PTI signaling was described as negative and unidirectional, since activation of PTI does not affect several analyzed steps in the BR signaling pathway. In this work, we describe that activation of PTI by the bacterial PAMP flg22 results in the reduced expression of BR biosynthetic genes. This effect does not require BR perception or signaling, and occurs within 15 min of flg22 treatment. Since the described PTI-induced repression of gene expression may result in a reduction in BR biosynthesis, the crosstalk between PTI and BR could actually be negative and bidirectional, a possibility that should be taken into account when considering the interaction between these two pathways
Entanglement Structure: Entanglement Partitioning in Multipartite Systems and Its Experimental Detection Using Optimizable Witnesses
Creating large-scale entanglement lies at the heart of many quantum
information processing protocols and the investigation of fundamental physics.
For multipartite quantum systems, it is crucial to identify not only the
presence of entanglement but also its detailed structure. This is because in a
generic experimental situation with sufficiently many subsystems involved, the
production of so-called genuine multipartite entanglement remains a formidable
challenge. Consequently, focusing exclusively on the identification of this
strongest type of entanglement may result in an all or nothing situation where
some inherently quantum aspects of the resource are overlooked. On the
contrary, even if the system is not genuinely multipartite entangled, there may
still be many-body entanglement present in the system. An identification of the
entanglement structure may thus provide us with a hint about where
imperfections in the setup may occur, as well as where we can identify groups
of subsystems that can still exhibit strong quantum-information-processing
capabilities. However, there is no known efficient methods to identify the
underlying entanglement structure. Here, we propose two complementary families
of witnesses for the identification of such structures. They are based on the
detection of entanglement intactness and entanglement depth, each requires only
the implementation of solely two local measurements. Our method is also robust
against noises and other imperfections, as reflected by our experimental
implementation of these tools to verify the entanglement structure of five
different eight-photon entangled states. We demonstrate how their entanglement
structure can be precisely and systematically inferred from the experimental
data. In achieving this goal, we also illustrate how the same set of data can
be classically postprocessed to learn the most about the measured system.Comment: 21 pages, 13 figure
Productivity prediction of fractured horizontal wells with low permeability flow characteristics
Horizontal well and large-scale fracturing are revolutionary technologies in petroleum industry. The technologies bring obvious economic benefits to exploiting unconventional oil and gas reservoirs with low permeability, ultra-low permeability and shale gas. With the increasingly extensive application of these technologies, other correlated technologies have also gained great development. However, low-permeability reservoirs exhibit complicated features and horizontal well fractures have complex shape. The existing methods for the productivity prediction of fractured horizontal well in low-permeability reservoirs rarely consider the influencing factors in a comprehensive manner. In this paper, a horizontal well seepage model of casing fracturing completion was established according to the superposition principle of low-permeability reservoir and the relationship between potential and pressure, by which model the seepage characteristics of low-permeability reservoirs could be fully described. Based on the established new seepage model, a new targeted model with coupling seepage and wellbore flow was established for the productivity prediction of low-permeability fractured horizontal well. Finally, the new targeted model was verified through field experiment. The experimental results confirmed the reliability of productivity prediction by the proposed model. Sensitivity analysis was then performed on the parameters in the proposed model
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