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1.
Simon Neumann Pin Hu Felix Bretschneider Holger Schmalz Andreas Greiner 《大分子材料与工程》2021,306(7):2100090
In this study, blends of the bio-based poly(limonene carbonate) (PLimC) with different commodity polymers are investigated in order to explore the potential of PLimC toward generating more sustainable polymer materials by reducing the amount of petro- or food-based polymers. PLimC is employed as minority component in the blends. Next to the morphology and thermal properties of the blends the impact of PLimC on the mechanical properties of the matrix polymers is studied. The interplay of incompatibility and zero-shear melt viscosity contrast determines the blend morphology, leading for all blends to a dispersed droplet morphology for PLimC. Blends with polymers of similar structure to PLimC (i.e., aliphatic/aromatic polyester) show the best performance with respect to mechanical properties, whereas blends with polystyrene or poly(methyl methacrylate) are too brittle and polyamide 12 blends show very low elongations at break. In blends with Ecoflex (poly(butylene adipate-co-terephthalate)) and Arnitel EM400 (copoly(ether ester)) with poly(butylene terephthalate) hard and polytetrahydrofuran soft segments) a threefold increase in E-modulus can be achieved, while keeping the elongation at break at reasonable high values of ≈200%, making these blends highly interesting for applications. 相似文献
2.
药物相互作用改变了剂量效应关系,可能会降低疗效或增加毒性,是临床应用中合并用药治疗时重要的考虑因素。预测具有临床意义的药物相互作用是药物研发过程中获益风险评估的重要环节。本文概述了药物研发过程中药物相互作用研究的目的和意义,体内和体外研究的主要内容;梳理分析了2020年国家药品监督管理局(National Medical Products Administration, NMPA)和美国食品药品监督管理局(Food and Drug Administration, FDA)批准上市的新药药物相互作用研究情况,旨在为我国药物研发过程中药物相互作用研究及其监管审评提供参考。 相似文献
3.
Sergey Tkachev Miguel Monteiro João Santos Ernesto Placidi Mohamed Ben Hassine Pedro Marques Paulo Ferreira Pedro Alpuim Andrea Capasso 《Advanced functional materials》2021,31(33):2103287
Graphene-based materials have attracted significant attention in many technological fields, but scaling up graphene-based technologies still faces substantial challenges. High-throughput top-down methods generally require hazardous, toxic, and high-boiling-point solvents. Here, an efficient and inexpensive strategy is proposed to produce graphene dispersions by liquid-phase exfoliation (LPE) through a combination of shear-mixing (SM) and tip sonication (TS) techniques, yielding highly concentrated graphene inks compatible with spray coating. The quality of graphene flakes (e.g., lateral size and thickness) and their concentration in the dispersions are compared using different spectroscopic and microscopy techniques. Several approaches (individual SM and TS, and their combination) are tested in three solvents (N-methyl-2-pyrrolidone, dimethylformamide, and cyrene). Interestingly, the combination of SM and TS in cyrene yields high-quality graphene dispersions, overcoming the environmental issues linked to the other two solvents. Starting from the cyrene dispersion, a graphene-based ink is prepared to spray-coat flexible electrodes and assemble a touch screen prototype. The electrodes feature a low sheet resistance (290 Ω □−1) and high optical transmittance (78%), which provide the prototype with a high signal-to-noise ratio (14 dB) and multi-touch functionality (up to four simultaneous touches). These results illustrate a potential pathway toward the integration of LPE-graphene in commercial flexible electronics. 相似文献
4.
针对呼吸道系统疾病与大气 PM2:5、 SO2 浓度序列的相关性特征, 应用多重分形消除趋势波动分析法
(MF-DCCA), 对张家界市永定区呼吸道系统疾病患病人数与大气 PM2:5、 SO2 浓度序列进行了研究。结果发现该地区
呼吸道系统疾病患病人数与大气 PM2:5、 SO2 浓度的相关性具有长期持续特征和多重分形特征。随后对它们相关性
多重分形特征的动力来源进行了分析, 通过随机重排和相位随机处理, 结果表明在不同时间尺度上的长期持续性影响
是其主要动力来源。进一步研究发现该地区呼吸道系统疾病与大气 PM2:5、 SO2 浓度序列的相关性在四个季节均具
有长期持续性的多重分形特征, 且夏季多重分形特征相对强于其他季节。 相似文献
5.
Recently, single image super-resolution (SISR) has been widely applied in the fields of underwater robot vision and obtained remarkable performance. However, most current methods generally suffered from the problem of a heavy burden on computational resources with large model sizes, which limited their real-world underwater robotic applications. In this paper, we introduce and tackle the super resolution (SR) problem for underwater robot vision and provide an efficient solution for near real-time applications. We present a novel lightweight multi-stage information distillation network, named MSIDN, for better balancing performance against applicability, which aggregates the local distilled features from different stages for more powerful feature representation. Moreover, a novel recursive residual feature distillation (RRFD) module is constructed to progressively extract useful features with a modest number of parameters in each stage. We also propose a channel interaction & distillation (CI&D) module that employs channel split operation on the preceding features to produce two-part features and utilizes the inter channel-wise interaction information between them to generate the distilled features, which can effectively extract the useful information of current stage without extra parameters. Besides, we present USR-2K dataset, a collection of over 1.6K samples for large-scale underwater image SR training, and a testset with an additional 400 samples for benchmark evaluation. Extensive experiments on several standard benchmark datasets show that the proposed MSIDN can provide state-of-the-art or even better performance in both quantitative and qualitative measurements. 相似文献
6.
In the recent advancements in image and video analysis, the detection of salient regions in the image becomes the initial step. This plays a crucial role in deciding the performance of such algorithms. In this work, a Multi-Resolution Feature Extraction (MRFE) technique that makes use of Discrete Wavelet Convolutional Neural Network (DWCNN) for generating features is employed. An Enhanced Feature Extraction (EFE) module extracts additional features from the high level features of the DWCNN, which are used to frame both channel as well as spatial attention models for yielding contextual attention maps. A new hybrid loss function is also proposed, which is a combination of Balanced Cross Entropy (BCE) loss and Edge based Structural Similarity (ESSIM) loss that effectively identifies and segments the salient regions with clear boundaries. The method is tested exhaustively with five different benchmark datasets and is proved superior to the existing state-of-the-art methods with a minimum Mean Absolute error (MAE) of 0.03 and F-measure of 0.956. 相似文献
7.
8.
Zhongchao Fu Xiaodong Li Mu Zhang Qi Zhu Ji-Guang Li Jiao He Xing'an Wang Xudong Sun 《Journal of the American Ceramic Society》2021,104(6):2689-2701
An easy albeit quite effective deionization suspension treatment was adopted to alleviate the detrimental effects related to the hydrolysis of Y2O3 in an aqueous medium. Fabrication of highly transparent Y2O3 ceramics with a fine grain size via air pre-sintering and post–hot isostatic pressing (HIP) treatment without using any sintering additive was achieved using the treated suspensions. The hydrolysis issue of Y2O3 powder in an aqueous medium was effectively alleviated by using deionization treatment, and a well-dispersed suspension with a low concentration of dissolved Y3+ species was obtained. The dispersed suspensions were consolidated by the centrifugal casting method, and the green bodies derived from the suspension of 35.0 vol% solid loading showed an improved homogeneity with a relative density of 52.1%. Fully dense Y2O3 transparent ceramic with high transparency was obtained by pre-sintering consolidated green compacts at a low temperature of 1400°C for 16 h in air followed by a post-HIP treatment at 1550°C for 2 h under 200 MPa pressure. The sample had a fine average grain size of 690 nm. The in-line transmittance of the sample reached 83.3% and 81.8% at 1100 nm and 800 nm, respectively, very close to the theoretical values of Y2O3. 相似文献
9.
Lalitha Kodumudi Venkataraman Tingting Zhu Monica Pinto Salazar Kathrin Hofmann Aamir Iqbal Waidha J. C. Jaud Pedro B. Groszewicz Jürgen Rödel 《Journal of the American Ceramic Society》2021,104(5):2201-2212
Na1/2Bi1/2TiO3-based materials have been earmarked for one of the first large-volume applications of lead-free piezoceramics in high-power ultrasonics. Zn2+-doping is demonstrated as a viable route to enhance the thermal depolarization temperature and electromechanically harden (1-y)Na1/2Bi1/2TiO3-yBaTiO3 (NBT100yBT) with a maximum achievable operating temperature of 150 °C and mechanical quality factor of 627 for 1 mole % Zn2+-doped NBT6BT. Although quenching from sintering temperatures has been recently touted to enhance TF-R, with quenching the doped compositions featuring an additional increase in TF-R by 17 °C, it exhibits negligible effect on the electromechanical properties. The effect is rationalized considering the missing influence on conductivity and therefore, negligible changes in the defect chemistry upon quenching. High-resolution diffraction indicates that Zn2+-doped samples favor the tetragonal phase with enhanced lattice distortion, further corroborated by 23Na Nuclear Magnetic Resonance investigations. 相似文献
10.
In recent years, artificial intelligence (AI) is being increasingly utilised in disaster management activities. The public is engaged with AI in various ways in these activities. For instance, crowdsourcing applications developed for disaster management to handle the tasks of collecting data through social media platforms, and increasing disaster awareness through serious gaming applications. Nonetheless, there are limited empirical investigations and understanding on public perceptions concerning AI for disaster management. Bridging this knowledge gap is the justification for this paper. The methodological approach adopted involved: Initially, collecting data through an online survey from residents (n = 605) of three major Australian cities; Then, analysis of the data using statistical modelling. The analysis results revealed that: (a) Younger generations have a greater appreciation of opportunities created by AI-driven applications for disaster management; (b) People with tertiary education have a greater understanding of the benefits of AI in managing the pre- and post-disaster phases, and; (c) Public sector administrative and safety workers, who play a vital role in managing disasters, place a greater value on the contributions by AI in disaster management. The study advocates relevant authorities to consider public perceptions in their efforts in integrating AI in disaster management. 相似文献