科研成果

This paper reports a novel self-powered three-dimension motion sensor capable of independently detecting contact trajectory, pressure and velocity based on triboelectrification and electrostatic induction synchronously. Motion trajectories in the full plane can be identified by using a unique net-cross electrodes configuration design. In addition, the patterned silver nanowires (AgNWs) electrodes are sprayed onto the polydimethylsilane (PDMS) substrate to achieve good transparency and stretchability. By attaching the 3D motion sensor on human skin or robot surface directly, the 3D motion information of the object could be acquired including pressure, velocity and trajectory. The self-powered 3D motion sensor is a promising candidate in terms of human-computer interaction, anti-counterfeiting signatures, etc.

Abstract Surface tensions (STs) are of critical importance to numerous natural phenomena and practical applications while most existing ST correlations are in the empirical formulations and limited to the bulk phase. In this study, a new semi-analytical correlation based on the perturbation theory from the statistical thermodynamics is initially developed to calculate the STs of the various components in bulk and nanoconfined pores. The newly developed ST correlation is validated to be accurate and generalized in bulk and nanoconfined pores in comparison with the experimentally measured results at a wide range of temperatures. Furthermore, three important patterns with respect to the STs are determined: first, the STs are found to be reduced with the temperature increase but increase when the components become heavier in both bulk and nanoconfined pores; second, the STs of the mixtures tend to be more sensitive to the feed ratios at higher temperatures; last but not least, the nanoscale STs of the pure components are slightly lower than the bulk results at the same conditions.

Glyoxal (GLY) acts as a key contributor to tropospheric ozone production and secondary organic aerosol (SOA) formation on local to regional scales. The detection of GLY provides useful indicators of fast photochemistry occurring in the lower troposphere. The fast and sensitive detection of GLY is thus important, while traditional chemical ionization such as the proton-transfer reaction (PTR) is extremely limited by the poor detection limit and extensive fragmentation. To address these limitations, electron attachment reaction (EAR) ionization was applied to detect GLY. The generation of parent anions (GLY–) without fragmentation was observed, and cryogenic photoelectron imaging spectroscopy further characterized the structure of GLY–. The detection limit was estimated to be as low as (52 ± 1) pptv (parts per trillion by volume) with 1 min measurements. Other components in ambient air, such as water, carbon dioxide, and trace gases (acetone, propanal, etc.) have no effect on the detection of GLY. The EAR ionization is more promising than PTR ionization in detecting GLY. The detection of GLY in ambient air by the EAR ionization has been demonstrated.

Technetium (99Tc) typically exists as pertechnetate (TcO4−) and hydrated oxide (TcO2·nH2O) in soil and groundwater. While the former, Tc(VII), is very soluble and mobile in the environment, the latter is considered sparingly soluble and immobile. Consequently, immobilization of Tc(VII) can be achieved through conversion of Tc(VII) into Tc(IV). In this study, carboxymethyl cellulose (CMC) stabilized FeS nanoparticles (CMC-FeS) were prepared and tested for reductive immobilization of Tc(VII). Effects of nanoparticle dosage and water chemistry, including pH, humic acid and Ca2+ ions, were examined. At a dosage of 100 mg/L of CMC-FeS as Fe, CMC-FeS rapidly removed >96% of 1.2 μM of Tc(VII) within 1 h, with a retarded first-order rate constant (ka) of 150.32 h-1. Higher pH in the range of 5.0–9.0 favored the reaction, with an optimal pH range of 8.0–9.0. While Ca2+ (up to 2 mM) only modestly affected the Tc(VII) removal, high concentrations of humic acid (up to 10 mg/L as TOC) showed increased inhibition on the Tc(VII) removal rate. FTIR and XPS analyses indicated that CMC-FeS immobilized TcO4− through reductive conversion of TcO4− into TcO2(s) and formation of Tc2S7 precipitate. The immobilized Tc remained insoluble when aged for 100 days under anoxic conditions, whereas up to 22.9% of the immobilized Tc was remobilized when it was exposed to air for 100 days.

Background: A strong association of serum 25-hydroxyvitamin-D levels (25(OH)D) with all-cause mortality has been shown previously and 25(OH)D could be a useful aging marker. Methods: The analysis was performed in a population-based, cohort study from Germany with 9,940 participants, aged 50-74 years at baseline. A general linear model was used to assess associations of 25(OH)D levels with chronological age and the aging markers leukocyte telomere length (LTL), epigenetic age acceleration, and 8-isoprostane levels. A multivariate Cox regression model was applied to explore the independent and combined associations of these biomarkers with all-cause mortality (2,204 deaths occurred during a median follow-up of 14.3 years). Results: On average, study participants lost 2.9 nmol/L 25(OH)D each 10 years of age. Increasing 25(OH)D levels were significantly associated with decreasing levels of 8-isoprostane levels but neither with LTL nor epigenetic age acceleration. The association of 25(OH)D quartiles with mortality was almost unchanged after adjusting for all aging markers (1.6-fold increased mortality in bottom quartile compared with top quartile). All aging markers were independent mortality predictors and subjects with unfavorable values for 4, 3, 2, and 1 aging marker(s) had 4.3-, 2.9-, 2.2, and 1.4-fold increased mortality, respectively. Conclusions: The 25(OH)D level can be regarded as an aging marker because it is linearly associated with age and an independent mortality predictor. Mechanisms linking vitamin D to healthy aging are unique and can neither be fully explained by aging of the epigenome, loss of telomeres, or antioxidative effects of vitamin D metabolites.

{BACKGROUND: Whole-body and thoracic ionizing radiation exposure are both associated with the development of renal dysfunction. However, whether low-level environmental radiation from air pollution affects renal function remains unknown. OBJECTIVES: We investigated the association of particle radioactivity (PR) with renal function defined by the estimated glomerular filtration rate (eGFR) and chronic kidney disease (CKD) in the Normative Aging Study. METHODS: This longitudinal analysis included 2491 medical visits from 809 white males enrolled between 1999 and 2013. The eGFR was calculated using the CKD-EPI and MDRD equations, and CKD cases were identified as those with an eGFR <60mL/min/1.73m(2). Gross beta activity measured by five monitors of the U.S. Environmental Protection Agency's RadNet monitoring network was utilized to represent PR. RESULTS: Ambient PR levels from 1 to 28days prior to clinical visit demonstrated robust negative associations with both forms of eGFR, but not with the increased odds of CKD. An interquartile range higher 28-day average ambient PR level was significantly associated with 0.83-mL/min/1.73m(2) lower eGFR estimated by the CKD-EPI equation (95% confidence interval: -1.46, -0.20

Abstract: In this study, a series of BUC-21/titanate nanotube (BT-X) composites were facilely fabricated via ball-milling of 2-dimensional (2D) metal-organic framework (MOF) BUC-21 and titanate nanotubes (TNTs). The BT-X composites were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), UV–visible diffuse-reflectance spectroscopy (UV–vis DRS), X-ray photoelectron spectrometer (XPS) and high resolution transmission electron microscopy (HRTEM). Both the photocatalytic reduction from Cr(VI) to Cr(III) and adsorptive removal of formed Cr(III) of BT-X composites were systematically investigated under different conditions including pH values and co-existing inorganic ions. It was found that BUC-21 (100 mg)/TNTs (100 mg) (BT-1) composites demonstrate remarkable ability of photocatalytic Cr(VI) reduction and adsorptive Cr(III) removal, as well as good reusability and stability. It is believed that the introduction of TNTs could capture the formed Cr(III) from the surface of BUC-21, which provided more active sites exposed to enhance the Cr(VI) reduction.

Nowadays, waste water treatment plants (WWTPs) are regarded as the pollution sources of nitrogen and pharmaceutical and personal care products (PPCPs). In the present study, the simultaneous removal of nitrogen and typical PPCPs, ibuprofen and triclosan, was evaluated in a poly-3-hydroxybutyrate-co-3- hydroxyvalerate (PHBV) based solid-phase denitrification (SPD) system. Results after 602 days showed that simultaneous nitrification and denitrification (SND) process occurred with average 83.85 +/- 13.09% NH4 (+) -N and 93.88 +/- 10.19% NO3- -N removals in the SPD system. Interestingly, the system achieved average 79.69 +/- 6.35% and 65.96 +/- 7.62% removals of ibuprofen and triclosan, respectively, under stable influent conditions of 50 mu g L-1. Cometabolic activities of heterotrophic denitrifying bacteria and ammonia oxidizing bacteria (AOB) probably played a role in the biodegradation of the two PPCPs. Illumina MiSeq sequencing results revealed that microbial composition enhanced the simultaneous removal of nitrogen and PPCPs in the SPD system.

The number and mass size distributions of refractory black carbon (rBC) cores in particles emitted from a diesel vehicle were investigated as a function of particle mobility diameter (d(mob)) using a single particle soot photometer (SP2) and a differential mobility analyzer (DMA). The thickness and mass of coatings on the rBC cores were characterized. On the basis of the SP2 and DMA results, the physical properties of particles containing rBC, including effective density (rho(eff)), mass-mobility scaling exponent (D-m), dynamic shape factor (chi), and mass absorption cross section (MAC), were derived as a function of d(mob). At each d(mob), the count median diameter (CMD) of the rBC cores was essentially the same as their mass median diameter (MMD), which increased linearly with d(mob). The mass of the rBC cores was proportional to the cubic of their d(mob). However, coating thickness on rBC cores remained unchanged with d(mob), with an average thickness of 28.72 +/- 4.81 nm. For particles containing rBC, rho(eff) decreased and chi increased with d(mob). The D-m of particles containing rBC was calculated to be 2.09. At 355 and 532 nm wavelengths, the MAC of the diesel particles containing rBC was inversely dependent on d(mob).

Sensors with multifunctions have attracted great attention for their extensive application value, among which humidity sensing and pressure sensing are necessary to electronics undoubtedly because of the complex physical environment we live in. Inspired by the structure of skin, in this article, we design a new method to combine wrinkle structure with porous sponge structure and achieve a novel, flexible, compressible, and bifunctional sensor based on carbon nanotube–polydimethylsiloxane (CNT–PDMS) with functions of humidity sensing and pressure sensing. The performance of the humidity sensing part can be controlled by the ultraviolet and ozone (UVO) treatment time and CNT concentration, while the sensitivity of the pressure sensing part can be controlled by the CNT concentration and grinding time of sugar granules. The bifunctional sensorcan easily sense approaching and touching of a hand, which shows great potential of alarming and protecting some electronics. Moreover, the bifunctional sensor can also be used in detecting human joint motions and breath conditions as a wearable and flexible health monitor.

In this paper, a comprehensive analysis on small-signal modeling of mm-wave transistor in 22nm FDSOI technology is presented. The model is constructed based on experimental S-parameters up to 110 GHz of a 22FDX® thick-oxide n-MOSFET and analytical parameter extraction approach. The non-quasi static effect is addressed thoroughly in the equivalent circuit model for high frequency validity. The bias-dependent series source and drain resistances are considered to account for the overlap regions between the gate and the highly doped source/drain regions. In addition, a simple RC network is included at the output to model the innegligible substrate coupling at mm-wave frequencies. Excellent agreements between model prediction and measurement are observed in the interested bandwidth for various bias conditions.

DNA methylation may play a critical role in aging and age-related diseases. DNA methylation phenotypic age (DNAmPhenoAge) is a new aging biomarker and predictor of chronic disease risk. While smoking is a strong risk factor for chronic diseases and influences methylation, its influence on DNAmPhenoAge is unknown. We investigated associations of self-reported and epigenetic smoking indicators with DNAmPhenoAge acceleration in a longitudinal aging study in eastern Massachusetts. DNA methylation was measured in whole blood samples from multiple visits for 692 male participants in the Veterans Affairs Normative Aging Study during 1999-2013. Acceleration was defined using residuals from linear regression of the DNAmPhenoAge on the chronological age. Cumulative smoking (pack-years) was significantly associated with DNAmPhenoAge acceleration, whereas self-reported smoking status was not. We observed significant validated associations between smoking-related loci and DNAmPhenoAge acceleration for 52 CpG sites, where 18 were hypomethylated and 34 were hypermethylated, mapped to 16 genes. The AHRR gene had the most loci (N = 8) among the 16 genes. We generated a smoking aging index based on these 52 loci, which showed positive significant associations with DNAmPhenoAge acceleration. These epigenetic biomarkers may help to predict age-related risks driven by smoking.