SE-Bridge: Speech Enhancement with Consistent Brownian Bridge

We propose SE-Bridge, a novel method for speech enhancement (SE). After recently applying the diffusion models to speech enhancement, we can achieve speech enhancement by solving a stochastic differential equation (SDE). Each SDE corresponds to a probabilistic flow ordinary differential equation (PF-ODE), and the trajectory of the PF-ODE solution consists of the speech states at different moments. Our approach is based on consistency model that ensure any speech states on the same PF-ODE trajectory, correspond to the same initial state. By integrating the Brownian Bridge process, the model is able to generate high-intelligibility speech samples without adversarial training. This is the first attempt that applies the consistency models to SE task, achieving state-of-the-art results in several metrics while saving 15 x the time required for sampling compared to the diffusion-based baseline. Our experiments on multiple datasets demonstrate the effectiveness of SE-Bridge in SE. Furthermore, we show through extensive experiments on downstream tasks, including Automatic Speech Recognition (ASR) and Speaker Verification (SV), that SE-Bridge can effectively support multiple downstream tasks

Optical vortices enabled by structural vortices

The structural symmetry of solids plays an important role in defining their linear and nonlinear optical properties. The quest for versatile, cost-effective, large-scale, and defect-free approaches and materials platforms for tailoring structural and optical properties on demand has been underway for decades. We experimentally demonstrate a bottom-up self-assembly-based organic engineered material comprised of synthesized molecules with large dipole moments that are crystallized into a spherulite structure. The molecules align in an azimuthal direction, resulting in a vortex polarity with spontaneously broken symmetry leading to strong optical anisotropy and nonlinear optical responses. These unique polarization properties of the judiciously designed organic spherulite combined with the symmetry of structured optical beams enable a plethora of new linear and nonlinear light-matter interactions, including the generation of optical vortex beams with complex spin states and on-demand topological charges at the fundamental, doubled, and tripled frequencies. The results of this work are likely to enable numerous applications in areas such as high-dimensional quantum information processing, with large capacity and high security. The demonstrated spherulite crystals facilitate stand-alone micro-scale devices that rely on the unique micro-scale spontaneous vortex polarity that is likely to enable future applications for high-dimensional quantum information processing, spatiotemporal optical vortices, and a novel platform for optical manipulation and trapping

Potential Diagnostic Applications of Multi-Delay Arterial Spin Labeling in Early Alzheimer’s Disease: The Chinese Imaging, Biomarkers, and Lifestyle Study

Background: Cerebral blood flow (CBF) alterations are involved in the onset and progression of Alzheimer’s disease (AD) and can be a potential biomarker. However, CBF measured by single-delay arterial spin labeling (ASL) for discrimination of mild cognitive impairment (MCI, an early stage of AD) was lack of accuracy. Multi-delay ASL can not only provide CBF quantification but also provide arterial transit time (ATT). Unfortunately, the technique was scarcely applied to the diagnosis of AD. Here, we detected the utility of ASL with 1-delay and 7-delay in ten regions of interest (ROIs) to identify MCI and AD. Materials and Methods: Pseudocontinuous ASL (pCASL) MRI was acquired on a 3T GE scanner in adults from the Chinese Imaging, Biomarkers, and Lifestyle (CIBL) Study of AD cohort, including 26 normal cognition (NC), 37 MCI, and 39 AD. Receiver operating characteristic (ROC) analyses with 1-delay and 7-delay ASL were performed for the identification of MCI and AD. The DeLong test was used to compare ROC curves. Results: For CBF of 1-delay or 7-delay the AUCs showed moderate-high performance for the AD/NC and AD/MCI comparisons (AUC = 0.83∼0.96) (p 0.05). Conclusion: The combination of CBF and ATT with 7-delay ASL showed higher performance for identification of MCI than CBF of 1-delay, when adding to sex, age, APOE ε4 carrier status, and education years, the diagnostic performance was further increased, presenting a potential imaging biomarker in early AD

Manufacturer’s Encroachment and Carbon Emission Reduction Decisions Considering Cap-and-Trade Regulation and Consumers’ Low-Carbon Preference

Carbon emission reduction and achieving carbon neutrality has become an inevitable trend in the sustainable development era. We investigate the manufacturer’s encroachment and carbon emission reduction decisions considering government cap-and-trade regulations and consumers’ low-carbon preference. The equilibrium decisions for the four scenarios are analytically obtained and compared based using the Stackelberg game. A comparison with and without cap-and-trade regulation under two encroachment decisions regarding member’s profits and carbon emission reduction levels are conducted. It is shown that the encroachment decision is always advantageous for the manufacturer if the government decides not to implement cap-and-trade regulation, and the retailer always loses profit. Moreover, if the carbon quota is sufficient, cap-and-trade regulation benefits the manufacturer. Otherwise, the manufacturer’s encroachment decision depends on the appropriate initial unit amount of carbon emission and unit carbon price. The retailer’s profit may not always be hurt by the manufacturer’s encroachment with cap-and-trade regulation; unless the unit carbon price exceeds a certain threshold, a higher consumer’s low-carbon preference in the encroachment scenario reduces more carbon emissions than in the no-encroachment scenario for the manufacturer. Further, the rising platform commission rate causes the platform profit to increase first and then decrease; the platform profit will slightly decrease if both products become more substitutes

Synergistic Modulation of Sn-Based Perovskite Solar Cells with Crystallization and Interface Engineering

A high-quality Sn-based perovskite absorption layer and effective carrier transport are the basis for high-performance Sn-based perovskite solar cells. The suppression of Sn2+ oxidation and rapid crystallization is the key to obtaining high-quality Sn-based perovskite film. And interface engineering is an effective strategy to enhance carrier extraction and transport. In this work, tin fluoride (SnF2) was introduced to the perovskite precursor solution, which can effectively modulate the crystallization and morphology of Sn-based perovskite layer. Furthermore, the hole-transporting layer of PEDOT:PSS was modified with CsI to enhance the hole extraction and transport. As a result, the fabricated inverted Sn-based perovskite solar cells demonstrated a power conversion efficiency of 7.53% with enhanced stability

Experimental and DFT research for the effects of sodium on the heterogeneous reaction between NO and semichar derived fromO

The excessive emission of NO is endangering the ecological environment and the health of humans. In-depth research on the reduction mechanisms of NO is crucial to regulating NO emissions. In this research, the influence of sodium on the heterogeneous reaction of NO by semichar derived from O2/CO2 pretreatments were investigated through the experimental and density functional theory (DFT) method. According to the results of atomic dipole corrected Hirshfeld atomic charge (ADCH), the additional Na and oxygen-containing compound altered the semichar's charge distribution of. The additional Na weakened the positive effects of the marginal hydrogen. And the charge of the carbon, which was attached to the phenol group, changed from negative to positive due to the strong electron-trapping ability of the phenol group. The energy potential diagrams between NO and semichars derived from O2/CO2 pretreatments without/with sodium addition reflected that sodium was beneficial to reduce NO. Compared with pure O2/CO2 pretreatments, the additional sodium decreased the energy gap of the NO reduction by 144.68 kJ/mol. On the other hand, the temperature-programmed reduction (TPR) results were performed to identify the accuracy of the calculation results. The experimental results illustrated that adding sodium enhanced the NO reducibility of semichar, expressing great consistency with the theoretical results

Urbanization-driven changes in land-climate dynamics : A case study of Haihe River Basin, China

Urbanization changes the land surface environment, which alters the regional climate system. In this study, we took the Haihe River Basin in China as a case study area, as it is highly populated and experienced rapid urbanization from 2000-2015. We investigated how land use and cover change (LUCC) was driven by urban land development affects land-climate dynamics. From 2000-2015, we collected data from the land use and cover database, the remote sensing database of the Moderate Resolution Imaging Spectroradiometer (MODIS) series, and the meteorological database to process and generate regional datasets for LUCC maps. We organized data by years aligned with the selected indicators of land surface, normalized difference vegetation index (NDVI), albedo, and land surface temperature (LST), as well as of regional climate, cloud water content (CWC), and precipitation (P). The assembled datasets were processed to perform statistical analysis and conduct structural equation modelling (SEM). Based on eco-climatology principles and the biophysical process in the land-climate dynamics, we made assumptions on how the indicators connected to each other. Moreover, we testified and quantified them in SEM. LUCC results found that from 2000-2015 the urban area proportion increased by 214% (2.20-6.91%), while the agricultural land decreased by 7.2% (53.05-49.25%) and the forest increased by 4.3% (10.02-10.45%), respectively. This demonstrated how cropland intensification and afforestation happened in the urbanizing basin. SEM results showed that the forest had both positive and negative effects on the regional hydrological cycle. The agricultural land, grassland, and shrub had indirect effects on the P via different biophysical functions of LST. The overall effects of urbanization on regional precipitation was positive (pathway correlation coefficient = 0.25). The interpretation of how urbanization drives LUCC and alters regional climate were herein discussed in different aspects of socioeconomic development, biophysical processes, and urbanization-related atmospheric effects. We provided suggestions for further possible research on monitoring and assessment, putting forth recommendations to advance sustainability via land planning and management, including agricultural land conservation, paying more attention to the quality growth of forest rather than the merely area expansion, integrating the interdisciplinary approach, and assessing climatic risk for extreme precipitation and urban flooding.</p