Metal halide perovskites have aroused burgeoning interest in the field of photovoltaics owing to their versatile optoelectronic properties. The outstanding power conversion efficiency, high specific ...power (i.e., power to weight ratio), compatibility with flexible substrates, and excellent radiation resistance of perovskite solar cells (PSCs) enable them to be a promising candidate for next‐generation space photovoltaic technology. Nevertheless, compared with other practical space photovoltaics, such as silicon and III‐V multi‐junction compound solar cells, the research on PSCs for space applications is just in the infancy stage. Therefore, there are considerable interests in further strengthening relevant research from the perspective of both mechanism and technology. Consequently, the approaches used for and the consequences of PSCs for space applications are reviewed. This review provides an overview of recent progress in PSCs for space applications in terms of performance evolution and mechanism exploration of perovskite films and devices under space extreme environments.
Perovskite solar cells (PSCs) are considered as promising candidates for next‐generation space photovoltaic technology. Key space environments and specific requirements for space photovoltaics are outlined. Some recent advances in terms of performance evolution and mechanism exploration of perovskite films and devices under space extreme environments are summarized. Progress and challenges associated with space applications of PSCs are highlighted.
The electron-phonon coupling (EPC) in a material is at the frontier of the fundamental research, underlying many quantum behaviors. van der Waals heterostructures (vdWHs) provide an ideal platform to ...reveal the intrinsic interaction between their electrons and phonons. In particular, the flexible van der Waals stacking of different atomic crystals leads to multiple opportunities to engineer the interlayer phonon modes for EPC. Here, in hBN/WS
vdWH, we report the strong cross-dimensional coupling between the layer-breathing phonons well extended over tens to hundreds of layer thick vdWH and the electrons localized within the few-layer WS
constituent. The strength of such cross-dimensional EPC can be well reproduced by a microscopic picture through the mediation by the interfacial coupling and also the interlayer bond polarizability model in vdWHs. The study on cross-dimensional EPC paves the way to manipulate the interaction between electrons and phonons in various vdWHs by interfacial engineering for possible interesting physical phenomena.
Falls can easily cause major harm to the health of the elderly, and timely detection can avoid further injuries. To detect the occurrence of falls in time, we propose a new method called ...Patch-Transformer Network (PTN) wearable-sensor-based fall detection algorithm. The neural network includes a convolution layer, a Transformer encoding layer, and a linear classification layer. The convolution layer is used to extract local features and project them into feature matrices. After adding positional coding information, the global features of falls are learned through the multi-head self-attention mechanism in the Transformer encoding layer. Global average pooling (GAP) is used to strengthen the correlation between features and categories. The final classification results are provided by the linear layer. The accuracy of the model obtained on the public available datasets SisFall and UnMib SHAR is 99.86% and 99.14%, respectively. The network model has fewer parameters and lower complexity, with detection times of 0.004 s and 0.001 s on the two datasets. Therefore, our proposed method can timely and accurately detect the occurrence of falls, which is important for protecting the lives of the elderly.
Background
We investigated the superiority of the 8th edition of the tumor-node-metastasis (TNM) system for patients in China with gastric cancer.
Methods
The survival outcomes of 1663 patients with ...gastric cancer undergoing radical resection were analyzed.
Results
In the 8th edition system, homogeneous 5-year survival rates among different pathological TNM (pTNM) categories belonging to the same stage were observed. However, in the 7th edition system, the differences of 5-year survival rate among pTNM categories belonging to the same stage were observed in stages IIB (
P
= 0.010), IIIB (
P
= 0.004), and IIIC (
P
< 0.001). For patients in the pT1-3 (
P
< 0.001) and pT4a (
P
< 0.001) categories, there were significant differences in survival between patients in the pN3a and pN3b categories. Furthermore, partial cases (pT4bN0M0/T4aN2M0) of stage IIIB were downstaged to stage IIIA in the 8th edition system, and the 5-year survival rate of these patients was significantly better than that of patients in stage IIIB in the 8th edition system. Similarly, the 5-year survival rate of patients in p4bN2M0/T4aN3aM0 downstaged from stage IIIC to IIIB was significantly better than that of patients in stage IIIC. Compared with the 7th edition system, the 8th edition system had a higher likelihood ratio and linear trend chi-squared score and a smaller Akaike information criteria value.
Conclusions
The 8th edition system is superior to the 7th edition system in terms of homogeneity, discriminatory ability, and monotonicity of gradients for Chinese patients with gastric cancer.
The strong surface hydration layer of nonfouling materials plays a key role in their resistance to nonspecific protein adsorption. Poly(ethylene glycol) (PEG) is an effective example of materials ...that can resist nonspecific protein adsorption and cell adhesion. Thus, the strong interaction between water molecules and PEG was investigated through each T 2 component in water/PEG mixtures using multiexponential inversion of T 2 relaxation time measured by the Carr–Purcell–Meiboom–Gill (CPMG) sequence of low-field nuclear magnetic resonance (LF-NMR). Results show that about one water molecule is tightly bound with one ethylene glycol (EG) unit, and additional water molecules over 1:1 ratio mainly swell the PEG matrix and are not tightly bound with PEG. This result was also supported by the endothermic behavior of water/PEG mixtures measured by differential scanning calorimetry (DSC). It is believed that the method developed could be also applied to investigate various interactions between macromolecules and other small molecules without using deuterium samples, which might open a novel route to quantitatively measure guest–host interactions in the future.
The successful fabrication of a two-dimensional boron sheet, which features a triangular lattice with periodic hole arrays, has stimulated great interest in its specific structure as well as ...properties such as possible superconductivity. Here, we report a study on the vibrational spectra and electron–phonon coupling (EPC) in monolayer boron sheets by in situ Raman and tip-enhanced Raman spectroscopy (TERS) at low temperature and ultrahigh vacuum. The gap-mode TERS gives a 3 × 109 selective enhancement on vertical vibrational Raman modes. A spatial resolution of 1 nm is achieved in this system. Combined with first-principle calculations, the vibrational properties as well as EPC in borophene are determined. The results are helpful for further study on the mechanical, electronic, and possible superconducting properties of two-dimensional boron.
With the upgrading of urbanization and improvement of living standards, the volume of municipal solid waste (MSW) is increasing in China. The waste-to-energy (WTE) incineration industry promotes the ...harmless disposal and recycling of MSW. It is an important part of the energy conservation and emission reduction tasks of “12th Five-Year Plan” period (2011–2015). Based on the development status of WTE plants in China, this paper makes an analysis of the WTE incineration industry from two aspects. The one is the analysis of political, economic, social and technological factors that influence the external environment of this industry. The other one is the discussion of technologies, costs and performances of some WTE plants in China, including a detailed cost-benefit analysis. It proves that the external environment is conducive to the development of WTE incineration industry and this industry is faced with good market prospects. Also, the net profit margin and return on investment (ROI) of WTE plants is attractive, up to 25% and 18% respectively. The pay back period is 12.73 years and the internal rate of return (IRR) is 10.94%. Thus, WTE plant has good profitability and economic benefit. Besides, WTE incineration has significant environmental benefits.
An efficient copper‐promoted difluoromethylthiolation of aryl and heteroaryl diazonium salts is described. The reaction is conducted under mild reaction conditions and various functional groups were ...compatible. In addition, reactions of heteroaryl diazonium salts such as pyridyl, quinolinyl, benzothiazolyl, thiophenyl, carbazolyl, and pyrazolyl diazonium salts occurred smoothly to afford the medicinally important difluoromethylthiolated heteroarenes. Furthermore, a more practical one‐pot direct diazotization and difluoromethylthiolation protocol was developed, and it converts the aniline derivatives into difluoromethylthiolated arenes. The utility of the method is demonstrated by difluoromethylthiolation of a number of natural products and drug molecules.
A dose of salt: The title reaction is conducted under mild reaction conditions and various functional groups are compatible. (Hetero)aryl diazonium salts reacted smoothly to afford the medicinally important difluoromethylthiolated (hetero)arenes. A practical one‐pot direct diazotization and difluoromethylthiolation protocol was developed for aniline derivatives to generate difluoromethylthiolated arenes.
The strong surface hydration layer of nonfouling materials plays a key role in their resistance to nonspecific protein adsorption. Poly(sulfobetaine methacrylate) (polySBMA) is an effective material ...that can resist nonspecific protein adsorption and cell adhesion. About eight water molecules are tightly bound with one sulfobetaine (SB) unit, and additional water molecules over 8:1 ratio mainly swell the polySBMA matrix, which is obtained through the measurement of T 2 relaxation time by low-field nuclear magnetic resonance (LF-NMR). This result was also supported by the endothermic behavior of water/polySBMA mixtures measured by differential scanning calorimetry (DSC). Furthermore, by comparing both results of polySBMA and poly(ethylene glycol) (PEG), it is found that (1) the hydrated water molecules on the SB unit are more tightly bound than on the ethylene glycol (EG) unit before saturation, and (2) the additional water molecules after forming the hydration layer in polySBMA solutions show higher freedom than those in PEG. These results might illustrate the reason for higher resistance of zwitterionic materials to nonspecific protein adsorptions compared to that of PEGs.
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