Display omitted
•A new thiophene-based dual functional sensor TSA was designed and synthesized.•Sensor TSA exhibits colorimtric response for Cu2+ and fluorimetric response for Al3+.•Sensor TSA shows ...low detection limit of 0.217 μM for Cu2+ and 49 nM for Al3+.•Sensor TSA was used for detection of Al3+ and Cu2+ in water, food samples and test strips.•Sensor TSA was applied to image intracellular Al3+ in live HeLa cells.
A new thiophene-based colorimtric and fluorimetric dual functional sensor TSA was synthesized, which can highly sense Al3+ and Cu2+ ions in aqueous solution through two approaches: a significant fluorescence enhancement caused by Al3+ and a visible color change from colorless to yellow induced by Cu2+. The sensor TSA showed a highly binding affinity only toward Al3+ and Cu2+ even in the presence of other competitive metal ions with low detection limits of 49 nM and 0.217 μM, respectively. The mechanisms of TSA for sensing Al3+ and Cu2+ were based on the metal ions coordination of TSA, which have been demonstrated by HR ESI-MS and 1H NMR titration. In addition, sensor TSA was successfully applied to quantify Al3+ and Cu2+ in environmental water and food samples with good precision and accuracy. Moreover, the TSA-based test stips/silica can conveniently and practically detect and discriminate Al3+ and Cu2+ in water. Furthermore, sensor TSA has also been applied to detect Al3+ in live HeLa cells. This work provides a new approach with easily synthetic route and economically cheap for ultrasensitive, selective, quantitative and differentiable detection of Al3+ and Cu2+ in environmental, food and biological systems.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We report a miniature optical fiber photothermal (PT) gas sensor with high sensitivity, fast response and large dynamic range. The sensing region is an air gap formed between the cleaved ends of two ...single mode fibers (SMFs). Theoretical formulations of photothermal phase modulation and interferometric phase detection are presented. Numerical simulation and experimental investigation are carried out to optimize the system parameters to maximize the photothermal signal. A gas sensor with an air gap of 130 µm demonstrates a noise equivalent concentration of 45 parts per billion and dynamic range of <inline-formula><tex-math notation="LaTeX">\text{2} \times \text{10}^7</tex-math></inline-formula> for acetylene detection, with a response time of 0.9 s. The sensor is simple to construct and may be used for real-time gas detection in a confined space.
The ballistic performance of ultra-high molecular weight polyethylene (UHMWPE) fiber-reinforced laminates is investigated experimentally and numerically. Several failure modes have been identified by ...examining the post-test targets, involving delamination, fiber fracture and bulging deformation. With the increase of impact velocity, the fiber recoil of the upper laminate becomes more evident, but the bulging deformation of the lower laminate is alleviated. A three-dimensional numerical model was developed to analyze the evolution of the whole ballistic response and the effects of projectile nose shape, spacing size and pitch angle on the ballistic behavior. Numerical results indicate that targets exhibit superior ballistic resistance under the impact of flat-nosed projectile. The ballistic performance of targets would be degraded with the increase of spacing size between two laminates. There exists a deactivation value for the spacing size to affect the ballistic behavior. Increasing the pitch angle between the sub-laminates could slightly improve the ballistic performance of targets by enhancing the delamination behavior and the development of bulging deformation.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The production of green hydrogen by water splitting from renewable energy is of great significance for achieving sustainable energy development. Alkaline water electrolysis (AWE) is the most ...economical and feasible route at present due to its earth-abundant catalysts, but it is desirable and crucial to improve the efficiency and purity of hydrogen production. Hydrogen production purity and energy consumption affect the fluctuation range of input power and economy respectively. In this paper, an electrolyzer with independent fluid flow path (IFP) is designed, which improves the problem of shutting current, hydrogen purity and hydrogen production efficiency. It has the characteristics of bipolar plate, zero gap and IFP. A test platform was built to verify its performance. The results showed that the IFP structure significantly improved the purity of hydrogen production, and the energy efficiency value increased by more than 3.29%.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Display omitted
•Conductive and shape-changing PPy-PU sponges are prepared by a sugar-templated method.•The hierarchical structure of PPy-PU sponges facilitates the wide-range force sensing.•The ...assembled array of PPy-PU sponges can realize the locus detection
Porous conductive polyurethane (PU) sponges were prepared by combining a sugar-templated fabrication of porous polyurethane elastomer and the in-situ polymerization of pyrrole inside the sponges. The conductive sponges had a uniform porous structure similar to the sugar cube templates and a unique micro-wrinkled structure of polypyrrole (PPy). Moreover, the conductive sponges exhibited good mechanical properties and electrical conductivity by the combination of elastomeric PU and conductive PPy, which make the conductive PPy-PU sponges as good candidates for pressure and strain sensitive materials. It was shown that a single PPy-PU conductive sponge was not only sensitive to large forces, but also sensitive to the tiny deformation by small forces such as 0.1 N, thus realizing a wide-range detection of pressure forces from 0.1 N to 200 N. Furthermore, the detection range could be further enlarged to more than 800 N by assembling a sponge array. A PPy-PU sponge matrix was also designed and showed potential application in multi-site position detection. These sugar-templated conductive sponges may find application for sensors in human physiological movement and intelligent monitoring.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
At present, high-resolution drought indices are scarce, and this problem has restricted the development of refined drought analysis to some extent. This study explored the possibility of calculating ...the standardized precipitation index (SPI) with short-term precipitation sequences in China, based on data from 2416 precipitation observation stations covering the time period from 1961 to 2019. The result shows that it is feasible for short-sequence stations to calculate SPI index, based on the spatial interpolation of the precipitation distribution parameters of the long-sequence station. Error analysis denoted that the SPI error was small in east China and large in west China, and the SPI was more accurate when the observation stations were denser. The SPI error of short-sequence sites was mostly less than 0.2 in most areas of eastern China and the consistency rate for the drought categories was larger than 80%, which was lower than the error using the 30-year precipitation samples. Further analysis showed that the estimation error of the distribution parameters β and q was the most important cause of SPI error. Two drought monitoring examples show that the SPI of more than 50,000 short-sequence sites can correctly express the spatial distribution of dry and wet and have refined spatial structure characteristics.
Liquid metals (LMs) possess tremendous potential applications in flexible electronic devices, heat flow management, and smart actuators. Splitting the bulk LMs into microspheres is of great ...significance to fabricate free-standing and microscale LM-based functional materials and devices. However, it is difficult to disperse the bulk LMs into microspheres because of their large surface tension and high density. In this work, the capillary-based microfluidic chip is employed to continuously and automatically generate LM microspheres in a large scale. The capillary-based microfluidic fabrication is universally applicable in ionic aqueous solution, hydrophobic solution, and the polymeric aqueous solution. The precise size control of LM microspheres can be easily realized by the co-flowing configuration in the microchannels. The coefficient of size variation of monodispersed LM microspheres can be controlled to as low as 0.47%. The free-standing LM microspheres can be used as functional microelectrodes within a wide temperature range from −19.8 to 20 °C and to fabricate tunable integrated circuits with different output powers. Most importantly, the LM microspheres exhibit photothermal property, which is used to make the optical sensor with linear response and to conduct the solar energy harvesting. The capillary-based microfluidic fabrication of LM microspheres provides a facile and templated methodology for processing bulk LMs into microscale units. The LM microspheres with excellent electrical conductivity and photothermal property hold great promise for the development of miniature soft electronics, light-driven actuators, and energy conversion medium.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
CO2 absorption-microalgae conversion (CAMC) system is a promising carbon capture and utilization technology. However, the use of HCO3− as a carbon source often led to a slower growth rate of ...microalgae, which also limited the application of CAMC system. In this study, the assimilation efficiency of HCO3− in CAMC system was improved through mixotrophic, and the potential mechanism was investigated. The HCO3− assimilation efficiency and biomass under mixotrophic were 34.79% and 31.76% higher than that of control. Mixotrophic increased chlorophyll and phycocyanin content, which were beneficial to capture more light energy. The content of ATP and NADPH reached 566.86 μmol/gprot and 672.86 nmol/mgprot, which increased by 31.83% and 27.67% compared to autotrophic. The activity of carbonic anhydrase and Rubisco increased by 18.52% and 22.08%, respectively. Transcriptome showed that genes related to photosynthetic and respiratory electron transport were up-regulated. The synergy of photophosphorylation and oxidative phosphorylation greatly improved energy metabolism efficiency, thus accelerating the assimilation of HCO3−. These results revealed a potential mechanism of promoting the HCO3− assimilation under mixotrophic, it also provided a guidance for using CAMC system to serve carbon neutrality.
Display omitted
•Mixotrophic improved the assimilation rate of HCO3− by Spirulina in CAMC system.•The ATP and NADPH content increased by 31.83% and 27.67%.•Mixotrophic promoted carbonic anhydrase and Rubisco activity.•Mixotrophic upregulated the photophosphorylation and oxidative phosphorylation.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Bioherbicide terpinolene is widely employed in the agricultural field because of its unique phytotoxic properties. However, little is known about the toxicity of bioherbicide on harmful algal blooms ...(HABs) and its mechanisms. Therefore, in this study, the inhibiting effect of bioherbicide terpinolene on the growth and physiological change of Microcystis aeruginosa was determined. Results showed that the cell density and photosynthetic activity of microalgae were significantly inhibited by terpinolene. Activities of nitrate reductase (NR) and glutamine synthetase (GS) were decreased separately by 25.38% and 42.75% after 4 d of exposure to 1.47 mM terpinolene, suggesting the inhibiting effect of terpinolene on algal nitrogen metabolism. However, the transcript abundance of genes related to membrane protein cytochrome c oxidase subunit II (COX II) and ATP-binding cassette transporters (ABC transporter) were enhanced separately by 3.15 and 1.69-fold compared with control, suggesting the resistance response of cells to terpinolene stress. Additionally, terpinolene not only increased the content of endogenous phytohormones including indole-3-acetic acid (IAA), zeatin, and brassinolide, but also inhibited the expression of genes related to calcium-binding protein (CaBPs), one kind of calcium (Ca2+) sensors, suggesting its regulation on algal signal molecules. These findings helped to understand the ecotoxicity of terpinolene and guide the rational use of bioherbicide in agriculture.
Display omitted
•Terpinolene affected the expression of gene related to membrane proteins•Terpinolene stimulated the antioxidant system of M. aeruginosa•Terpinolene inhibited the activity of nitrogen metabolism-related enzymes•Content of endogenous IAA, zeatin, and brassinolide were increased by terpinolene
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
500.
Recent Developments on Espnet Toolkit Boosted By Conformer Guo, Pengcheng; Boyer, Florian; Chang, Xuankai ...
ICASSP 2021 - 2021 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP),
2021-June-6
Conference Proceeding
Open access
In this study, we present recent developments on ESPnet: End-to- End Speech Processing toolkit, which mainly involves a recently proposed architecture called Conformer, Convolution-augmented ...Transformer. This paper shows the results for a wide range of end- to-end speech processing applications, such as automatic speech recognition (ASR), speech translations (ST), speech separation (SS) and text-to-speech (TTS). Our experiments reveal various training tips and significant performance benefits obtained with the Conformer on different tasks. These results are competitive or even outperform the current state-of-art Transformer models. We are preparing to release all-in-one recipes using open source and publicly available corpora for all the above tasks with pre-trained models. Our aim for this work is to contribute to our research community by reducing the burden of preparing state-of-the-art research environments usually requiring high resources.
PDF
