784 research outputs found
Factors Influencing Purchase Intention under Indent Buying Model on Wechat
Indent buying on Wechat is a new e-commerce model in China. Product trade is different from ordinary online shopping under this model. We conducted an empirical study and found that trust, information quality and perceived value have significant impact on consumers’ intention to purchase indent buying products. Information quality and word of mouth significantly influence consumers’ perceived value
Theoretical Analysis on Effect of Anomalous Low Friction in Rock Mass Based on Block Model
The block model of effect of anomalous low friction in rock mass was established based on plasticity kinetics and theoretical analysis. And the normal stress formulas of contact interface between rock stratum and roof on elastic stage and elastic-plasticity stage were presented. The theoretical analysis indicates that under dynamic loading, the normal stress of contact interface between rock stratum and roof on elastic stage and elastic-plasticity stage of simple beam both reduce, and the reduction amplitude are both great. The friction force of the contact interface reduces sharply, therefore the existence of effect of anomalous low friction in rock mass is proved. Compared to the normal stress of contact interface on elastic-plasticity stage, the normal stress of contact interface on elastic stage reduces greater, which illustrates when the beam is on elastic stage, contact interface between rock stratum and roof become occur effect of anomalous low friction easier
Bayesian Non-parametric Hidden Markov Model for Agile Radar Pulse Sequences Streaming Analysis
Multi-function radars (MFRs) are sophisticated types of sensors with the
capabilities of complex agile inter-pulse modulation implementation and dynamic
work mode scheduling. The developments in MFRs pose great challenges to modern
electronic reconnaissance systems or radar warning receivers for recognition
and inference of MFR work modes. To address this issue, this paper proposes an
online processing framework for parameter estimation and change point detection
of MFR work modes. At first, this paper designed a fully-conjugate Bayesian
non-parametric hidden Markov model with a designed prior distribution (agile
BNP-HMM) to represent the MFR pulse agility characteristics. The proposed model
allows fully-variational Bayesian inference. Then, the proposed framework is
constructed by two main parts. The first part is the agile BNP-HMM model for
automatically inferring the number of HMM hidden states and emission
distribution of the corresponding hidden states. An estimation error lower
bound on performance is derived and the proposed algorithm is shown to be close
to the bound. The second part utilizes the streaming Bayesian updating to
facilitate computation, and designed an online work mode change detection
framework based upon a weighted sequential probability ratio test. We
demonstrate that the proposed framework is consistently highly effective and
robust to baseline methods on diverse simulated data-sets.Comment: 15 pages, 10 figures, submitted to IEEE transactions on signal
processin
Propagating Surface Plasmon Polaritons: Towards Applications for Remote-Excitation Surface Catalytic Reactions
Plasmonics is a well-established field, exploiting the interaction of light and metals at the nanoscale; with the help of surface plasmon polaritons, remote-excitation can also be observed by using silver or gold plasmonic waveguides. Recently, plasmonic catalysis was established as a new exciting platform for heterogeneous catalytic reactions. Recent reports present remote-excitation surface catalytic reactions as a route to enhance the rate of chemical reactions, and offer a pathway to control surface catalytic reactions. In this review, we focus on recent advanced reports on silver plasmonic waveguide for remote-excitation surface catalytic reactions. First, the synthesis methods and characterization techniques of sivelr nanowire plasmonic waveguides are summarized, and the properties and physical mechanisms of plasmonic waveguides are presented in detail. Then, the applications of plasmonic waveguides including remote excitation fluorescence and SERS are introduced, and we focus on the field of remote-excitation surface catalytic reactions. Finally, forecasts are made for possible future applications for the remote-excitation surface catalysis by plasmonic waveguides in living cells
Class Information Guided Reconstruction for Automatic Modulation Open-Set Recognition
Automatic Modulation Recognition (AMR) is a crucial technology in the domains
of radar and communications. Traditional AMR approaches assume a closed-set
scenario, where unknown samples are forcibly misclassified into known classes,
leading to serious consequences for situation awareness and threat assessment.
To address this issue, Automatic Modulation Open-set Recognition (AMOSR)
defines two tasks as Known Class Classification (KCC) and Unknown Class
Identification (UCI). However, AMOSR faces core challenges in terms of
inappropriate decision boundaries and sparse feature distributions. To overcome
the aforementioned challenges, we propose a Class Information guided
Reconstruction (CIR) framework, which leverages reconstruction losses to
distinguish known and unknown classes. To enhance distinguishability, we design
Class Conditional Vectors (CCVs) to match the latent representations extracted
from input samples, achieving perfect reconstruction for known samples while
yielding poor results for unknown ones. We also propose a Mutual Information
(MI) loss function to ensure reliable matching, with upper and lower bounds of
MI derived for tractable optimization and mathematical proofs provided. The
mutually beneficial CCVs and MI facilitate the CIR attaining optimal UCI
performance without compromising KCC accuracy, especially in scenarios with a
higher proportion of unknown classes. Additionally, a denoising module is
introduced before reconstruction, enabling the CIR to achieve a significant
performance improvement at low SNRs. Experimental results on simulated and
measured signals validate the effectiveness and the robustness of the proposed
method.Comment: 14 pages, 11 figure
The conformation change of Bcl-2 is involved in arsenic trioxide-induced apoptosis and inhibition of proliferation in SGC7901 human gastric cancer cells
<p>Abstract</p> <p>Background</p> <p>Arsenic trioxide has been established as a first-line agent for treating acute promyelocytic leukemia. Experimental data suggest that arsenic trioxide also can have a potential use as chemotherapeutic agent for other malignancies. The precise mechanisms of action of arsenic trioxide have though not been elucidated. As the role of Bcl-2 in arsenic trioxide-mediated cell apoptosis and conformation change of Bcl-2 in response to arsenic trioxide treatment has not been studied. The aim of the present study was to determine whether conformation change of Bcl-2 is involved in the action of arsenic trioxide.</p> <p>Methods</p> <p>Human gastric cancer SGC7901 cells were exposed to different concentrations of arsenic trioxide. Proliferation was measured by using the Kit-8 cell counting assay. Analysis of nuclear morphology was observed by DAPI staining. The apoptosis rates of cells treated with arsenic trioxide were analyzed by flow cytometry using Annexin V-FITC staining. The conformation change of Bcl-2 and Bax activation were detected by immunostaining and Western blot analysis. Total expression of Bcl-2 and Bax were examined by Western blot analysis.</p> <p>Results</p> <p>Arsenic trioxide inhibited the growth of human gastric cancer SGC7901 cells and induced apoptosis. There were two Bcl-2 phenotypes coexisting in SGC7901 cells and the Bcl-2 cytoprotective phenotype could change into a cytodestructive phenotype following conformational change of Bcl-2, triggered by arsenic trioxide exposure. Bax activation might also be involved in arsenic trioxide-induced Bcl-2 conformational change. Arsenic trioxide did not change levels of total Bcl-2 expression, but up-regulated total Bax expression for the treatment time ranging from 3 to 24 hours.</p> <p>Conclusion</p> <p>Arsenic trioxide induces apoptosis through induction of Bcl-2 conformational change, Bax activation and up-regulation of total Bax expression rather than affecting total Bcl-2 expression in human gastric cancer SGC7901 cells. The conformational change of Bcl-2 may be a novel described mechanism of arsenic trioxide-induced apoptosis in cancer cells.</p
Rheumatoid meningitis: a rare neurological complication of rheumatoid arthritis
ObjectiveTo describe the clinical and neuroimaging characteristics of rheumatoid meningitis (RM) in Chinese patients. MethodsThe patients admitted to our hospital with the diagnosis of RM in the past 8 years were retrospectively analyzed. ResultsSix patients with RM were identified among 933 patients admitted with rheumatoid arthritis (RA). The symptoms of meningitis occurred after onset of arthritis in five patients and before onset in one. Headache (n=6), hyperacute focal neurological deficits (n=4) and seizures (n=3) were the most prevalent symptoms. The nadir modified Rankin Scale score was ≥3 in five patients. Rheumatoid factor was elevated in all patients, and interleukin-6 levels in cerebrospinal fluid were dramatically elevated in three of four tested patients. Magnetic resonance imaging of the brain revealed that the meninges were affected in all patients and the cerebral parenchyma was affected in one patient. The lesions were generally located in the frontoparietal region and showed restricted diffusion along the adjacent subarachnoid space. RM occurred during disease-modifying therapy in four patients. In the acute episode, three patients improved on tocilizumab and the other three improved on pulse corticosteroids. For maintenance therapy, two patients received combined therapy of tocilizumab and other immunosuppressive agents, one received adalimumab and methotrexate, and two received low-dose oral corticosteroids with an immunosuppressive agent. Five patients had a good outcome, and one died of Pneumocystis jirovecii pneumonia after stabilization of his neurologic conditions. No relapse of RM occurred on immunotherapy during follow-up. ConclusionsChinese patients with RM share some remarkable clinical and neuroimaging features and respond well to appropriate immunotherapy. Tocilizumab could be a treatment option for this severe complication of RA
Ly Emission Line Profiles of Extreme [OIII] Emitting Galaxies at : Implications for Ly Visibility in the Reionization Era
JWST observations have recently begun delivering the first samples of
Ly velocity profile measurements at , opening a new window on the
reionization process. Interpretation of line profiles is currently
stunted by limitations in our knowledge of the intrinsic Ly profile
(before encountering the IGM) of the galaxies that are common at .
To overcome this shortcoming, we have obtained resolved ()
Ly spectroscopy of galaxies at with similar properties
as are seen at . We quantify a variety of Ly profile statistics as
a function of [OIII]+H EW. Our spectra reveal a new population of
galaxies with large [OIII]+H EWs () and a
large fraction of Ly flux emerging near the systemic redshift (peak
velocity km s). These spectra indicate that low density
neutral hydrogen channels are able to form in a subset of low mass galaxies
() that experience a burst of star formation
(sSFR Gyr). Other extreme [OIII] emitters show weaker Ly
that is shifted to higher velocities ( km s) with little
emission near line center. We investigate the impact the IGM is likely to have
on these intrinsic line profiles in the reionization era, finding that the
centrally peaked Ly emitters should be strongly attenuated at
. We show that these line profiles are particularly sensitive to the
impact of resonant scattering from infalling IGM and can be strongly attenuated
even when the IGM is highly ionized at . We compare these
expectations against a new database of galaxies with robust
velocity profiles measured with JWST/NIRSpec.Comment: 28 pages, 11 figures, accepted by Ap
Mining-induced damage evaluation method of buildings based on surface sensitive deformation and housing factors
In view of unreasonable evaluation factors and limitations of regional evaluation results of the current mining-induced building damage, a method is proposed for assessing building damage based on surface sensitive deformation and housing factors. Mining-induced building damage evaluation is studied by means of theoretical analysis, numerical simulation and field investigation. Firstly, numerical simulation method is used to reveal the influence rule of surface deformation, building structure type, the angle between the main deformation direction and the long axis of the building on the building damage. The results show that ① when the deformation along the long axis of the building increases, the degree of damage to the building increases. It is obtained the critical value of surface deformation for the accelerated damage of one-story bungalow building is curvature K=0.6 mm/m2 and horizontal deformation ε=6 mm/m. ② The damage degree of buildings with different structures is different, in which the buildings with ring beams or structural columns have a strong deformation resistance. This study has determined the critical surface deformation value of the damage degree of the two-story brick-concrete structure with ring beams and structural columns. ③ The building is more sensitive to the surface deformation in the direction of its long axis, affecting the damage is large. However, the deformation of the perpendicular direction to the long axis of the building is not very sensitive, and the damage degree at the oblique intersection of principal deformation direction and the long axis of houses is in between the two. Secondly, the unascertained measure model of mining-induced building damage is established, and a total of 7 evaluation indicators are selected based on surface sensitive deformation factors, principal deformation direction, and house factors, then the weight is assigned to each indicator using the Analytic Hierarchy Process (AHP) according to its importance. Finally, it is applied to the building damage cases of three villages in the Fengfeng Mining Area and the Xuzhou Mining Area, and the application shows that the prediction accuracy is above 80% in the evaluation of more than 140 buildings in 50 households selected. The prediction accuracy is higher than the traditional method, and the prediction effect is good, which makes up for the shortcomings of traditional evaluation methods and verifies the reliability of the evaluation index selection and the evaluation model
Multi-stage generation of tile images based on generative adversarial network
Deep learning techniques have been recently widely used in the field of texture image generation. There are still two major problems when applying them to tile image design work. On the one hand, there is still lack of enough diverse ceramic tile images for the training process. On the other hand, the output image is difficult to control and adjust, and cannot meet the designer’s requirements of interactivity. Therefore, we propose a multi-stage generation algorithm of tile images based on generative adversarial network(GAN). First, the multi-scale attention GAN is applied to generate controllable texture image. Then, the SWAG texture synthesis GAN is also applied to obtain controllable and diverse image style. And finally, through the style iteration mechanism and the multiple step magnification method based on image super-resolution reconstruction network, the final tile images can be automatically generated with larger-size and higher-precision. The relevant experiments demonstrate that our method can not only generate high-quality tile images in a relatively short period of time, but also consider human interaction to a certain extent, and maintain a certain degree of control over the main texture and style of the final generated tile images. It has good and wide application value
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