66 research outputs found
Face-StyleSpeech: Improved Face-to-Voice latent mapping for Natural Zero-shot Speech Synthesis from a Face Image
Generating a voice from a face image is crucial for developing virtual humans
capable of interacting using their unique voices, without relying on
pre-recorded human speech. In this paper, we propose Face-StyleSpeech, a
zero-shot Text-To-Speech (TTS) synthesis model that generates natural speech
conditioned on a face image rather than reference speech. We hypothesize that
learning both speaker identity and prosody from a face image poses a
significant challenge. To address the issue, our TTS model incorporates both a
face encoder and a prosody encoder. The prosody encoder is specifically
designed to model prosodic features that are not captured only with a face
image, allowing the face encoder to focus solely on capturing the speaker
identity from the face image. Experimental results demonstrate that
Face-StyleSpeech effectively generates more natural speech from a face image
than baselines, even for the face images the model has not trained. Samples are
at our demo page https://face-stylespeech.github.io.Comment: Submitted to ICASSP 202
ZET-Speech: Zero-shot adaptive Emotion-controllable Text-to-Speech Synthesis with Diffusion and Style-based Models
Emotional Text-To-Speech (TTS) is an important task in the development of
systems (e.g., human-like dialogue agents) that require natural and emotional
speech. Existing approaches, however, only aim to produce emotional TTS for
seen speakers during training, without consideration of the generalization to
unseen speakers. In this paper, we propose ZET-Speech, a zero-shot adaptive
emotion-controllable TTS model that allows users to synthesize any speaker's
emotional speech using only a short, neutral speech segment and the target
emotion label. Specifically, to enable a zero-shot adaptive TTS model to
synthesize emotional speech, we propose domain adversarial learning and
guidance methods on the diffusion model. Experimental results demonstrate that
ZET-Speech successfully synthesizes natural and emotional speech with the
desired emotion for both seen and unseen speakers. Samples are at
https://ZET-Speech.github.io/ZET-Speech-Demo/.Comment: Accepted by INTERSPEECH 202
Solution phase treatments of SbSe heterojunction photocathodes for improved water splitting performance
Antimony selenide (SbSe) is an auspicious material for solar energy conversion that has seen rapid improvement over the past ten years, but the photovoltage deficit remains a challenge. Here, simple and low-temperature treatments of the p–n heterojunction interface of SbSe/TiO-based photocathodes for photoelectrochemical water splitting were explored to address this challenge. The FTO/Ti/Au/SbSe (substrate configuration) stack was treated with (NH)S as an etching solution, followed by CuCl treatment prior to deposition of the TiO by atomic layer deposition. The different treatments show different mechanisms of action compared to similar reported treatments of the back Au/SbSe interface in superstrate configuration solar cells. These treatments collectively increased the onset potential from 0.14 V to 0.28 V vs. reversible hydrogen electrode (RHE) and the photocurrent from 13 mA cm to 18 mA cm at 0 V vs. RHE as compared to the untreated SbSe films. From SEM and XPS studies, it is clear that the etching treatment induces a morphological change and removes the surface SbSe layer, which eliminates the Fermi-level pinning that the oxide layer generates. CuCl further enhances the performance due to the passivation of the surface defects, as supported by density functional theory molecular dynamics (DFT-MD) calculations, improving charge separation at the interface. The simple and low-cost semiconductor synthesis method combined with these facile, low-temperature treatments further increases the practical potential of SbSe for large-scale water splitting
Functional B-1 progenitor cells are present in the hematopoietic stem cell-deficient embryo and depend on Cbfβ for their development
The fetal liver is a major hematopoietic site containing progenitor cells that give rise to nearly all blood cells, including B-1 cells. Because the fetal liver is not a de novo site of hematopoietic stem cell (HSC) or progenitor-cell emergence, it must be seeded by yolk sac (YS)-derived erythromyeloid progenitors at embryonic day (E) 8.5-E10 and aorta-gonado-mesonephros (AGM)-derived HSCs at E10.5-E11.5. Although the B-1 progenitor cell pool in the fetal liver is considered to be of HSC origin, we have previously proposed that YS-derived B-1 progenitors may also contribute to this pool. Until now, it has been impossible to determine whether HSC-independent B-1 progenitor cells exist in the fetal liver. Here, we demonstrate the presence of transplantable fetal-liver B-1 and marginal zone B progenitor cells in genetically engineered HSC-deficient embryos. HSC-deficient YS and AGM tissues produce B-1 progenitors in vitro and thus may serve as sites of origin for the B-1 progenitors that seed the fetal liver. Furthermore, we have found that core-binding factor beta (Cbfβ) expression is required for fetal-liver B-1 progenitor cell maturation and expansion. Our data provide, to our knowledge, the first evidence for the presence of B-1 progenitor cells in the fetal liver that arise independently of HSCs and implicate Cbfβ as a critical molecule in the development of this lineage
Crystal orientation-dependent etching and trapping in thermally-oxidised Cu<sub>2</sub>O photocathodes for water splitting
Ammonia solution etching was carried out on thermally-oxidised cuprous oxide (TO-Cu2O) in photocathode devices for water splitting. The etched devices showed increased photoelectrochemical (PEC) performance compared to the unetched ones as well as improved reproducibility. -8.6 mA cm-2 and -7 mA cm-2 photocurrent density were achieved at 0 V and 0.5 V versus the reversible hydrogen electrode (VRHE), respectively, in the champion sample with an onset potential of 0.92 VRHE and a fill factor of 44 %. An applied bias photon-to-current efficiency of 3.6 % at 0.56 VRHE was obtained, which represents a new record for Cu2O-based photocathode systems. Capacitance-based profiling studies showed a strong pinning effect from interfacial traps in the as-grown device, and these traps were removed by ammonia solution etching. Moreover, the etching procedure gave rise to a diverse morphology of Cu2O crystals based on the different crystallographic orientations. The distribution of crystallographic orientations and the relationship between the crystal orientation and the morphology after etching were examined by electron backscatter diffraction (EBSD) and scanning electron microscopy (SEM). The high-index crystal group showed a statistically higher PEC performance than the low-index group. X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) revealed metallic copper at the Cu2O/Ga2O3 interface, which we attribute as the dominant trap that limits the PEC performance. It is concluded that the metallic copper originates from the reduction of the CuO impurity layer on the as-grown Cu2O sample during the ALD process, while the reduction from Cu2O to Cu is not favorable
Solution-Processed CuS Nanostructures for Solar Hydrogen Production
CuS is a promising solar energy conversion material due to its suitable optical properties, high elemental earth abundance, and nontoxicity. In addition to the challenge of multiple stable secondary phases, the short minority carrier diffusion length poses an obstacle to its practical application. This work addresses the issue by synthesizing nanostructured CuS thin films, which enables increased charge carrier collection. A simple solution-processing method involving the preparation of CuCl and CuCl molecular inks in a thiol-amine solvent mixture followed by spin coating and low-temperature annealing was used to obtain phase-pure nanostructured (nanoplate and nanoparticle) CuS thin films. The photocathode based on the nanoplate CuS (FTO/Au/CuS/CdS/TiO/RuO) reveals enhanced charge carrier collection and improved photoelectrochemical water-splitting performance compared to the photocathode based on the non-nanostructured CuS thin film reported previously. A photocurrent density of 3.0 mA cm at −0.2 versus a reversible hydrogen electrode (V) with only 100 nm thickness of a nanoplate CuS layer and an onset potential of 0.43 V were obtained. This work provides a simple, cost-effective, and high-throughput method to prepare phase-pure nanostructured CuS thin films for scalable solar hydrogen production
Impedance spectroscopy of Sb<sub>2</sub>Se<sub>3</sub> photovoltaics consisting of (Sb<sub>4</sub>Se<sub>6</sub>)<sub><i>n</i></sub> nanoribbons under light illumination.
Sb2Se3, consisting of one-dimensional (Sb4Se6)n nanoribbons has drawn attention as an intriguing light absorber from the photovoltaics (PVs) research community. However, further research is required on the performance-limiting factors in Sb2Se3 PVs. In this study, we investigated the charge carrier behavior in Sb2Se3 PVs by impedance spectroscopy (IS) under light illumination. (Sb4Se6)n nanoribbons with two different orientations were used to investigate the effect of crystal orientation on the device performance. Regardless of the (Sb4Se6)n orientation, negative capacitance was observed at forward bias, representing a recombination pathway at the TiO2/Sb2Se3 interface. A comparison of the recombination resistances and lifetimes of two different Sb2Se3 PVs showed that a better interface could be formed by placing the (Sb4Se6)n ribbons parallel to the TiO2 layer. Based on these observations, an ideal structure of the Sb2Se3/TiO2 interface is proposed, which will enhance the performance of Sb2Se3 PVs toward its theoretical limit
Post-Synthetic Silver Ion and Sulfurization Treatment for Enhanced Performance in Sb2Se3 Water Splitting Photocathodes
In the past decade, antimony selenide (Sb2Se3) has made significant progress as a solar energy conversion material. However, the photovoltage deficit continues to pose a challenge and is a major hurdle that must be overcome to reach its maximum solar conversion efficiency. In this study, various post-synthetic treatments are employed, of which the combination of a solution phase silver nitrate treatment and sulfurization has shown to be the most effective approach to mitigate the photovoltage deficit in this Sb2Se3-based device. A significant enhancement in the photovoltage is observed after the treatments, as evident by the increase in the onset potential from 0.18 to 0.40 V versus reversible hydrogen electrode. Multiwavelength Raman shows that combining these two treatments removes amorphous Se and metallic Sb from the surface and yields a high-quality surface layer of Sb2(S1−x, Sex)3 on the bulk Sb2Se3 photoabsorber layer. X-ray photoelectron spectroscopy with depth profiling reveals extensive incorporation of silver into the film. Density functional theory calculations suggest that silver ions can intercalate between the [Sb4Se6]n ribbons and remain in the Ag+ state. This effective treatment combination brings the practicality of the Sb2Se3 photocathode for water splitting one step closer to large-scale applications
Dendritic Cells as Danger-Recognizing Biosensors
Dendritic cells (DCs) are antigen presenting cells that are characterized by a potent capacity to initiate immune responses. DCs comprise several subsets with distinct phenotypes. After sensing any danger(s) to the host via their innate immune receptors such as Toll-like receptors, DCs become mature and subsequently present antigens to CD4+ T cells. Since DCs possess the intrinsic capacity to polarize CD4+ helper cells, it is critical to understand the immunological roles of DCs for clinical applications. Here, we review the different DC subsets, their danger-sensing receptors and immunological functions. Furthermore, the cytokine reporter mouse model for studying DC activation is introduced
- …