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Hydrogel tissue adhesives that currently available are often fabricated by mixing two or more polymeric components. Single-component hydrogels afford injectability, strong and reversible adhesion remain a formidable challenge. This research describes the creation of the first single-component hyaluronic acid hydrogel adhesive-based on phenylboronic acid-diol ester linkages. Phenylboronic acid can not only serve as a cross-linker to form hydrogel, but also act as an adhesion site for glycosyl compounds found in biological cell membranes. The rheological and compressive tests for the hydrogel show that it has excellent self-healing properties, good injectability and strong compressive strength. Adhesion tests demonstrated that the hydrogel has significantly greater adhesion strength than commercial fibrin glue. These findings suggest that the rational design of hydrogel precursors facilitates the formation of single-component networks and multiple functionalities. In vivo studies further proved the hydrogel was an ideal bio-adhesive with biocompatibility, absorbed wound exudate and hemostasis, and accelerated wound closure.

A novel time calibration method for waveform sampling application specific integrated circuits (ASICs) based on switched capacitor arrays (SCAs) is proposed in this paper. Precision timing extraction using SCA ASICs has been proved to be a promising technique in many high energy physics experiments. However, such ASICs suffer from irregular sampling intervals caused by process variations. Therefore, careful calibration is required to improve the time resolution of such systems. We evaluated the limitation of a popular method using the proportionality between voltage amplitude and sampling interval of adjacent switched-capacitor cells responding to either a sawtooth wave or a sine wave . The new time calibration method presented here utilizes the relationship between sampling intervals and the known input signal period to establish overdetermined linear equations, and the roots of these equations correspond to the actual sampling intervals. We applied this new method to a pulse timing test with an ASIC designed by our team, and the test results indicate that the new time calibration method is effective.

Intrinsic degradation in 100 nm AlQ3 OLED device with strong luminescence was observed while nearly no degradation in 50 nm AlQ3 device with weak luminescence was observed for the same operation time. Based on the EL and PL measurements, it was suggested that penetration of AlQ3 molecules into NPB layer resulted in the increase of electron leakage current, and thus significant loss of current efficiency. A plausible Coulomb effect induced intrinsic degradation mechanism was therefore proposed to explain the experimental results.

The Raman spectra of two kinds of expansins KT-30 and DA-6 are measured and analyzed in the cases of pure solid-phase and in water solutions. The results show that, KT-30 has much richer and narrower Raman spectral peaks. The first, second, and third strong Raman peaks are respectively located 990.68738 cm−1, 1606.0975 cm−1, and 1327.9379 cm−1. Besides the dense and narrow Raman peaks below 1800 cm−1, there exist three weak peaks within 3050–3410 cm−1. In comparison, fewer spectral peaks can be observed for DA-6. The first and second strong peaks respectively appear at 2883.03760 cm−1 and 2848.4480 cm−1. There exist about 8 peaks below 1500 cm−1. In water solutions, bell-shaped and homogeneous fluorescence background will respectively superpose on the Raman spectra of KT-30 and DA-6 within 100–2500 cm−1 and 400–4000 cm−1. Parts of spectral peaks will be covered accordingly. Moreover, the peak position shifts of KT-30 are very slight. While DA-6 takes the opposite. Its largest shift can even be up to 63.4148 cm−1. The results can supply important fingerprint data for Raman detection of expansins in fruits and vegetables.

The forming/destruction mechanism of conducting filament is essential in understanding the behavior of resistance-memory device. On the basis of filamentary theory, we systematically studied the different electrical performances of both planar and vertical sandwich (metal/organic/metal) memory devices. Bias induced morphological change in gap devices are monitored using scanning electron microscopy system equipped with probes. The in situ images directly demonstrate that with bias increasing, metal clusters emerge inside the channel and further cause sudden switching of device resistance. After clarifying the roles of electrodes and sandwiched organic layer, we conclude a field-dependent filament formation and organics-assistant filament destruction mechanism for resistance memory phenomenon, which should generally exist in all organic electronic devices with metal electrodes.

The Yangtze River Basin (Changjiang Basin) hosts one of the most diverse freshwater mussel assemblages on Earth. However, due to human activities this fauna is dramatically imperiled in this region, highlighting the need for urgent conservation measures. To better protect and conserve these taxa, it is crucial to understand the main drivers that control the diversity patterns, as well as the anthropogenic influence on these patterns. Here, we estimated distinct diversity metrics (i.e. species richness and alpha, gamma, and beta diversity) to analyze the spatial freshwater mussel diversity changes across 16 tributaries and lakes from the middle and lower Yangtze River Basin, in two periods: past 1962–2012 and present. For the past, mussel records were compiled from previous studies, for the present, we surveyed 565 sites for freshwater mussel presence and abundance within the 16 selected areas. We also assessed several climatic and geographical parameters to try to identify the main factors that modulate species composition across the study area. We show that from the historical to the present periods, species diversity experienced a significant decrease, registering, per river/lake, an average of 5.4 extirpations of species native to China and 3.9 of the Yangtze River Basin endemics. The gamma diversity of the whole study area and the alpha diversity of each of the studied rivers and lakes have also decreased during this period. The beta diversity values indicated a significant trend towards taxonomic homogenization over the last decades. Poyang and Dongting Lakes should be considered for protection given due to their high diversity and species loss given that nestedness in these lakes represented the main component of beta diversity.

Two peaks are observed in the capacitance–voltage (C–V) characteristics of electron-transport fullerene (C60 or C70)/Bphen based devices. The experimental results suggest that the mobile carriers generated from unintentional doping and trapped carriers are the origins of these two peaks, just the same as those of hole-transport devices. In addition, the polarity of one C–V peak voltage (the voltage corresponding to the peak capacitance) reverses as the Bphen layer thickness increases. The transient photo-voltage (TPV) signals show a polarity reversal of the internal electric field, confirming the related phenomenon.

Capacitance–voltage ( C – V ) characteristics of organic molecular semiconductors attracted much research interest recently, but no convincing physical mechanism has been established so far. In this work, the C – V characteristics of pentacene-based devices have been systematically investigated at various frequencies. Only one peak occurs when the measuring frequency is less than 3 kHz or greater than 8 kHz. While within the frequency range between the two, two C – V peaks are observed with quite different dependence on temperature, which suggests that the origins of these two C – V peaks are respectively mobile holes and trapped carriers. This conclusion is also experimentally validated with the C – V characteristics of intentionally doped devices.

Polarization effects on optoelectronic behaviors in perovskite-based devices are difficult to address due to quick electronic polarization relaxation and ionic polarization from mobile ions. Here we show the effects of polarized excited states on photoluminescence and photocurrent in MAPbBr3 thin-film devices. We found optically polarized transition dipoles, oriented paralleled and perpendicular to device built-in field, give rise to significantly different photoluminescence and photocurrent outcomes. It provides a new understanding that controlling domain geometry can further enhance the light-emitting and photovoltaic performance of perovskite-based applications. The observation proves that the anisotropy of photoexcited transition dipoles is existed in the electronic states of MAPbBr3. Particularly, this indicates that photo-induced electronic polarization can be shown as photoinduced dielectric polarization at the dipolar polarization regime, which impacts device performance. We also observed that increasing photoexcitation intensity leads to a decreases on both field-induced photoluminescence quenching and field-induced photocurrent enhancing, which implies a cooperative interaction between transition dipoles of increased density that favors light emission but infavors charge dissociation. This provides a critical understanding on why organic-inorganic hybrid perovskites can function as efficient photovoltaic and light-emitting materials at low and high excitation intensities, respectively. Our estimation shows that, by manipulating the ratio of dipole orientation, the efficiencies of perovskite-based LEDs and solar cells could be improved by 50% and 18%, respectively. Clearly, the polarization effect presents a new insight on further controlling photovoltaic and light-emitting actions by manipulating the polarization of excited states in perovskite optoelectronics.