130 research outputs found
Author Correction: Solution-processed hybrid perovskite photodetectors with high detectivity.
This Article contains an error in Equation 2 in that the denominator is inverted. This has not been fixed in the PDF or HTML versions of the Article but can be seen in the associated Correction
Solution-processed small-molecule solar cells: breaking the 10% power conversion efficiency.
A two-dimensional conjugated small molecule (SMPV1) was designed and synthesized for high performance solution-processed organic solar cells. This study explores the photovoltaic properties of this molecule as a donor, with a fullerene derivative as an acceptor, using solution processing in single junction and double junction tandem solar cells. The single junction solar cells based on SMPV1 exhibited a certified power conversion efficiency of 8.02% under AM 1.5 G irradiation (100 mW cm(-2)). A homo-tandem solar cell based on SMPV1 was constructed with a novel interlayer (or tunnel junction) consisting of bilayer conjugated polyelectrolyte, demonstrating an unprecedented PCE of 10.1%. These results strongly suggest solution-processed small molecular materials are excellent candidates for organic solar cells
A polymer tandem solar cell with 10.6% power conversion efficiency.
An effective way to improve polymer solar cell efficiency is to use a tandem structure, as a broader part of the spectrum of solar radiation is used and the thermalization loss of photon energy is minimized. In the past, the lack of high-performance low-bandgap polymers was the major limiting factor for achieving high-performance tandem solar cell. Here we report the development of a high-performance low bandgap polymer (bandgap <1.4 eV), poly[2,7-(5,5-bis-(3,7-dimethyloctyl)-5H-dithieno[3,2-b:2',3'-d]pyran)-alt-4,7-(5,6-difluoro-2,1,3-benzothia diazole)] with a bandgap of 1.38 eV, high mobility, deep highest occupied molecular orbital. As a result, a single-junction device shows high external quantum efficiency of >60% and spectral response that extends to 900 nm, with a power conversion efficiency of 7.9%. The polymer enables a solution processed tandem solar cell with certified 10.6% power conversion efficiency under standard reporting conditions (25 °C, 1,000 Wm(-2), IEC 60904-3 global), which is the first certified polymer solar cell efficiency over 10%
[CLS] Token is All You Need for Zero-Shot Semantic Segmentation
In this paper, we propose an embarrassingly simple yet highly effective
zero-shot semantic segmentation (ZS3) method, based on the pre-trained
vision-language model CLIP. First, our study provides a couple of key
discoveries: (i) the global tokens (a.k.a [CLS] tokens in Transformer) of the
text branch in CLIP provide a powerful representation of semantic information
and (ii) these text-side [CLS] tokens can be regarded as category priors to
guide CLIP visual encoder pay more attention on the corresponding region of
interest. Based on that, we build upon the CLIP model as a backbone which we
extend with a One-Way [CLS] token navigation from text to the visual branch
that enables zero-shot dense prediction, dubbed \textbf{ClsCLIP}. Specifically,
we use the [CLS] token output from the text branch, as an auxiliary semantic
prompt, to replace the [CLS] token in shallow layers of the ViT-based visual
encoder. This one-way navigation embeds such global category prior earlier and
thus promotes semantic segmentation. Furthermore, to better segment tiny
objects in ZS3, we further enhance ClsCLIP with a local zoom-in strategy, which
employs a region proposal pre-processing and we get ClsCLIP+. Extensive
experiments demonstrate that our proposed ZS3 method achieves a SOTA
performance, and it is even comparable with those few-shot semantic
segmentation methods.Comment: 8 pages,6 figure
VDD: Varied Drone Dataset for Semantic Segmentation
Semantic segmentation of drone images is critical to many aerial vision tasks
as it provides essential semantic details that can compensate for the lack of
depth information from monocular cameras. However, maintaining high accuracy of
semantic segmentation models for drones requires diverse, large-scale, and
high-resolution datasets, which are rare in the field of aerial image
processing. Existing datasets are typically small and focus primarily on urban
scenes, neglecting rural and industrial areas. Models trained on such datasets
are not sufficiently equipped to handle the variety of inputs seen in drone
imagery. In the VDD-Varied Drone Dataset, we offer a large-scale and densely
labeled dataset comprising 400 high-resolution images that feature carefully
chosen scenes, camera angles, and varied light and weather conditions.
Furthermore, we have adapted existing drone datasets to conform to our
annotation standards and integrated them with VDD to create a dataset 1.5 times
the size of fine annotation of Cityscapes. We have developed a novel DeepLabT
model, which combines CNN and Transformer backbones, to provide a reliable
baseline for semantic segmentation in drone imagery. Our experiments indicate
that DeepLabT performs admirably on VDD and other drone datasets. We expect
that our dataset will generate considerable interest in drone image
segmentation and serve as a foundation for other drone vision tasks. VDD is
freely available on our website at https://vddvdd.com
The feasibility and safety of sharp recanalization for superior vena cava occlusion in hemodialysis patients: A retrospective cohort study
Introduction: Hemodialysis catheter‐related superior vena cava (SVC) occlusions can cause considerable morbidity for patients and be challenging to treat if refractory to conventional guide wire transversal. This pilot study assessed the feasibility and safety of sharp recanalization of SVC occlusion in hemodialysis patients.Methods: This study retrospectively enrolled hemodialysis patients treated in West China Hospital diagnosed with SVC occlusion who failed traditional guide wire transversal from January 2014 to November 2017. In brief, a guide wire from the femoral approach was advanced to the lower end of the obstructive lesion to act as a target, while the stiff end of hydrophilic wire was advanced though a jugular approach. Under fluoroscopic guidance in biplane imaging, the occlusive SVC lesion was penetrated with the stiff wire that was snared and pulled through. Graded dilation of the SVC and subsequent tunneled‐cuffed catheter implantation were performed. Demographic information and clinical outcomes were recorded and evaluated.Findings: Sixteen patients with a mean age of 62 ± 13 years (13 females and 3 males) who received SVC sharp recanalization were included in this study. The sharp recanalization procedure was successfully performed in 14 patients (87.5%). Two patients were complicated with SVC laceration and hemopericardium but remained asymptomatic and required no surgical repair. One patient suffered ventricular fibrillation during procedure. Despite the return of spontaneous circulation, the patient unfortunately died of gastrointestinal tract bleeding after 3 days in ICU. Follow‐up suggested the 6‐month catheter patency to be 92.85% and 12‐month catheter patency to be 58.33%. No long‐term procedure‐related complications were recorded.Discussion: Sharp recanalization might be a feasible strategy in managing SVC occlusion in hemodialysis patients. The potential life‐threatening complications (cardiac arrhythmia and SVC laceration) necessitate strict eligibility screening, skillful operation, and avoidance of over‐dilation of SVC.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153765/1/hdi12804.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153765/2/hdi12804_am.pd
Envisioning a Next Generation Extended Reality Conferencing System with Efficient Photorealistic Human Rendering
Meeting online is becoming the new normal. Creating an immersive experience
for online meetings is a necessity towards more diverse and seamless
environments. Efficient photorealistic rendering of human 3D dynamics is the
core of immersive meetings. Current popular applications achieve real-time
conferencing but fall short in delivering photorealistic human dynamics, either
due to limited 2D space or the use of avatars that lack realistic interactions
between participants. Recent advances in neural rendering, such as the Neural
Radiance Field (NeRF), offer the potential for greater realism in metaverse
meetings. However, the slow rendering speed of NeRF poses challenges for
real-time conferencing. We envision a pipeline for a future extended reality
metaverse conferencing system that leverages monocular video acquisition and
free-viewpoint synthesis to enhance data and hardware efficiency. Towards an
immersive conferencing experience, we explore an accelerated NeRF-based
free-viewpoint synthesis algorithm for rendering photorealistic human dynamics
more efficiently. We show that our algorithm achieves comparable rendering
quality while performing training and inference 44.5% and 213% faster than
state-of-the-art methods, respectively. Our exploration provides a design basis
for constructing metaverse conferencing systems that can handle complex
application scenarios, including dynamic scene relighting with customized
themes and multi-user conferencing that harmonizes real-world people into an
extended world.Comment: Accepted to CVPR 2023 ECV Worksho
Enhanced photodynamic therapy through multienzyme-like MOF for cancer treatment
Overcoming resistance to apoptosis is a major challenge in cancer therapy. Recent research has shown that manipulating mitochondria, the organelles critical for energy metabolism in tumor cells, can increase the effectiveness of photodynamic therapy and trigger apoptosis in tumor cells. However, there is currently insufficient research and effective methods to exploit mitochondrial damage to induce apoptosis in tumor cells and improve the effectiveness of photodynamic therapy. In this study, we present a novel nanomedicine delivery and therapeutic system called PyroFPSH, which utilizes a nanozymes-modified metal-organic framework as a carrier. PyroFPSH exhibits remarkable multienzyme-like activities, including glutathione peroxidase (GPx) and catalase (CAT) mimicry, allowing it to overcome apoptosis resistance, reduce endogenous glutathione levels, and continuously generate reactive oxygen species (ROS). In addition, PyroFPSH can serve as a carrier for the targeted delivery of sulfasalazine, a drug that can induce mitochondrial depolarization in tumor cells, thereby reducing oxygen consumption and energy supply in the mitochondria of tumor cells and weakening resistance to other synergistic treatment approaches. Our experimental results highlight the potential of PyroFPSH as a versatile nanoplatform in cancer treatment. This study expands the biomedical applications of nanomaterials as platforms and enables the integration of various novel therapeutic strategies to synergistically improve tumor therapy. It deepens our understanding of multienzyme-mimicking active nanocarriers and mitochondrial damage through photodynamic therapy. Future research can further explore the potential of PyroFPSH in clinical cancer treatment and improve its drug loading capacity, biocompatibility and targeting specificity. In summary, PyroFPSH represents a promising therapeutic approach that can provide new insights and possibilities for cancer treatment
一种太阳能驱动处理赤泥污水的绿色节能装置
Alumina production will produce a large amount of red mud wastewater every year, which will cause great harm to the surrounding environment. In this study, a solar evaporator using biochar as photothermal material for red mud wastewater treatment was designed. Driven by sunlight, the device can recover water from red mud wastewater and absorb harmful substances in wastewater. This study provides a new idea for green and energy saving treatment of red mud wastewater
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