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A series of Sm3+-activated Ca3Gd(AlO)3(BO3)4 red-emitting phosphors were prepared by a traditional high-temperature solid-state approach. They were characterized by XRD refinements, TEM, SEM, EDS, DRS, FTIR, Raman spectra, photoluminescence (PL) spectra, and fluorescence decay curves. The microstructure of the cation-borate phosphors and the presence of Sm3+ dopants, and their impact at the Ca and Gd sites were studied. All the samples exhibited bright red emissions caused by intra-4f transitions of Sm3+ ions when excited at 404 nm. The optimum dopant concentration was 4mol%, and the concentration quenching (CQ) process was driven by dipole-dipole interaction using Inokuti-Hirayama, and Dexter theories. Interestingly, the temperature-dependent PL spectra manifested that the resulting phosphor had excellent thermal stability with an activation energy of 0.234 eV. Ultimately, the investigated phosphor demonstrated excellent chemical stability. The Sm3+-doped CGAB:Sm3+ phosphor can convert NUV LED chips into intense red emission with Commission Internationale de l’Eclairage (CIE) diagrams of 0.615, 0.382 and high color purity of up to 95.6%. The WLED containing CG0.96AB:0.04Sm3+ merged with the commercial phosphors revealed low correlated color temperature (CCT≈4197 K) and high color rendering index (CRI≈89.7).

Hot compression tests of AZ80 and AZ80-Ce alloys were conducted on a Gleeble-3800 simulator at strain rates of 0.01–10 s−1 and deformation temperatures of 340–420 °C. The effects of Ce addition on hot deformation behavior and microstructure evolution of AZ80 magnesium alloys were investigated. The rare earth phase formed with added Ce hindered movement of the dislocations and grain boundaries, causing higher peak stress of AZ80-Ce alloy than that of AZ80 alloy. Existing large-size Al4Ce particles as second phase in AZ80-Ce alloy increased the driving force of recrystallization, promoting dynamic recrystallization and reducing dislocation density. After hot compression, AZ80 alloy showed a fiber texture with the c-axis parallel to the compression direction, and addition of Ce caused texture-weakening. The constitutive equations and processing maps of AZ80 and AZ80-Ce alloys were constructed and analyzed. Adding Ce reduced deformation activation energy and Zener-Hollomon parameter, and enlarged non-instability zone in processing maps of AZ80 alloy.

In this paper, a new Taylor-type differentiation formula is investigated for the first-order derivative approximation to generate higher numerical accuracy in the implementation of zeroing neural network model discretization. Then, two novel discrete-time zeroing neural network models are first developed, analyzed and verified for online solving time-varying nonlinear optimization problem. Moreover, the 0-stability, consistency and convergence reveal that the developed discrete-time zeroing neural network models converge to the theoretical solution to the time-varying nonlinear optimization problem with the residual error O ( τ 4 ) , where τ signifies the sampling gap. In addition, according to the smooth solution accuracy, the proposed discrete-time zeroing neural network models have better performance than traditional computing models by adopting the Taylor-type computational differentiation formula with O ( τ 3 ) pattern. Finally, two illustrative numerical examples are further provided to demonstrate the efficiency and superiority of the proposed discrete-time zeroing neural network models for time-varying nonlinear optimization problems solving compared with the classical neural network models, furthermore, the proposed models are also applied on two-link mechanical arm with motion generation.

Time-invariant/varying Yang-Baxter-type matrix equation problems in the presence of noises often arise in the fields of scientific computation and engineering implementation. Noises are ubiquitous and unavoidable in real systems but most existing models carry out the time-invariant/varying Yang-Baxter-type matrix equation problem with an indispensable precondition that the solving process is free of noises. In this paper, a noise-tolerant zeroing neural network model (NTZNNM) is first proposed, analyzed and verified by feat of a classical zeroing neural network model (ZNNM) from a control-theoretic viewpoint, and note that NTZNNM behaves efficiently in online solving the time-invariant/varying Yang-Baxter-type matrix equation problem with different measurement noises. Moreover, a general noise-tolerant zeroing neural network model (GNTZNNM) derived from a general noise-tolerant zeroing neural dynamic model (GNTZNDM) is developed and utilized to accelerating the convergent rate and enhancing the robustness. Then, theoretical results further demonstrate that the presented NTZNNM owns the ability to globally/exponentially converge with different measurement noises. Furthermore, the global convergence of GNTZNDM with different monotonically-increasing odd activation functions is also investigated and analyzed in detail. Besides, numerical results are provided to substantiate the efficiency, availability and superiority of the developed NTZNNM and GNTZNNM for time-invariant/varying Yang-Baxter-type matrix equation problems with inherent tolerance to noises.

In this paper, zeroing neural network models are redesigned and analyzed from a control-theoretical framework for online solving time-varying full-rank Moore-Penrose inversions. To solve time-varying full-rank Moore-Penrose inverse problems with different noises in real time, some modified zeroing neural network models are developed, analyzed and investigated from the perspective of control. Furthermore, the proposed zeroing neural network models globally converge to the theoretical solution of the full-rank Moore-Penrose inverse problem without noises, and exponentially converge to the exact solution in the presence of noises, which are demonstrated theoretically. Moreover, in comparison with existing models, numerical simulations are provided to substantiate the feasibility and superiority of the proposed modified neural network for online solving time-varying full-rank Moore-Penrose problems with inherent tolerance to noises. In addition, the numerical results infer that different activation functions can be applied to accelerate the convergence speed of the zeroing neural network model. Finally, the proposed zeroing neural network models are applied to the motion generation of redundant robot manipulators, which illustrates its high efficiency and robustness.

Zero-mean circular Gaussian statistics is a well-known model for coherent electromagnetic wave scattered by random media. Applying Kullback-Leibler Divergence to measure the deviation of the simulation scattering field probability distribution from this model, the formation of zero-mean circular Gaussian statistics is investigated quantitatively in two-dimensional random media based on finite element method. Increasing the scattering and randomness in the media, the transmission electric field gradually approaches zero-mean circular Gaussian statistics, however, the deviation from a perfect statistics distribution has a limit which is only determined by the number of random electric field variables used for estimates the probability distribution; besides, field amplitude forming stable statistics faster than field phase.

Marangoni instability in well-defined non-spherical sessile droplet of 0.65cSt silicone oil evaporating at constant contact line mode is investigated through a series of experiments. Droplets of typical regular geometries (such as triangular, square, pentagonal and elliptical) and exotic shapes (such as kidney and positive-positive curvature) are tested. Cell patterns of Benard-Marangoni instability are distributed along the azimuthal direction non-uniformly in the droplets. These cells always occur first at the region where the curvature of the three-phase contact line (kcl) is the largest and they do not fill the whole droplet at once. Different from that in spherical droplet, there is no such a steady state in the non-spherical droplets and these BM cells always drift from the lower kcl regions towards the higher ones. The influences of kcl, the substrate temperature and the contact angle on the patterns of the Benard-Marangoni instability are analyzed. The critical contact angles for the onset of Marangoni instability are determined.

A molecularly imprinted polymer (MIP) anchored on the surface of CdTe quantum dots (QDs) was fabricated and used as a fluorescent probe for sulfadiazine (SDZ) detection in seawater. CdTe QDs was used as photoluminescent material, SDZ as the template, 3-aminopropyltriethoxysilane (APTES) as the functional monomer and tetraethyl orthosilicate (TEOS) as the cross-linking agent. Characterizations of MIP-QDs were analyzed by Fourier transform infrared (FT-IR), Transmission electron microscopy (TEM) and Scanning electron microscope (SEM). The conditions were optimized for the detection of MIP-QDs to SDZ. The mechanism of fluorescence quenching was studied by UV–Vis absorption spectroscopy and fluorescence spectroscopy. Under optimal conditions, the fluorescence intensity of MIP-QDs decreased linearly between 4‐ and 20 μM SDZ with a good correlation coefficient of 0.995. The limit of detection is 0.67 μM and the recovery is between 91.8 and 109.4% with RSD lower than 3.9%. These results indicated that MIP-QDs for SDZ detection in seawater was developed successfully.

Perchlorate, as an oxidizer, has many applications such as explosives and pyrotechnics, especially in rocket propellants and missile motors. Because it was found in water including wells and drinking water in the US, its effect on human health was being noted. However, the reproductive toxic effect on perchlorate is still unclear. In present study, the effects of repeated exposure to perchlorate on reproductive toxicity were evaluated in Wistar rats. The rats were treated orally with perchlorate at doses of 0.05, 1.00 or 10.00 mg/kg body weight (b.w.) daily for 8 weeks. The levels of T3 and T4 hormones in the rat serum were detected by radioimmunoassay kit. The indexes of reproduction, percentage of organ in body weight (%) and frequency of abnormal sperm cells were also analyzed in this study. DNA damage in testicular cells was evaluated by Comet assay. The levels of MDA, GSH and SOD were examined in testicle tissues of rats by ELISA. The expression of c-fos and fas protein was examined in testicle tissues by immunohistochemistry. The results showed that perchlorate did not affect the body weight of rats. Perchlorate also significantly decreased indexes of live birth and weaning in the groups of 1.00 and 10.00 mg/kg, and viability index only in the 10.00 mg/kg group (P

Marangoni instabilities of a sessile droplet of 0.65 cSt silicone oil evaporating at constant contact line mode are experimentally investigated in a wide range of the substrate temperatures (Tw) from those lower than room temperature (Ta) to those higher than it. For Tw > Ta, the Benard-Marangoni convection cells are observed and the cell patterns vary from the quasi-steady state to irregular oscillatory state with the droplet evaporation. For Tw Ta. When Tw is higher than 14.3 °C three kinds of convection mode, i.e. the travelling hydrothermal waves, the coexistence of hydrothermal waves and irregular oscillatory Benard-Marangoni convection, and the irregular oscillatory Benard-Marangoni convection, occur successively with droplet evaporating. The critical contact angles for the incipience of these Marangoni instabilities are determined.

Graphene has aroused continual and tremendous interest in gas sensing applications because of its unique properties. However, the graphene-based sensors still meet limitations such as inconvenient device fabrication, sustained power supply, specific measuring equipment, etc. Here, we find that fluorinated graphene (FG) shows an obvious color change (from white to dark yellow) in the presence of NH3 which can be observed directly by the naked eye. PL measurement shows that the sensitivity of color change can reach a high value of ca. 4.05% ppm−1. The density functional theory calculations reveal that the F atoms on FG increase the adsorption ability and charge transfer of NH3 molecules, resulting in the efficient color change. This work develops a naked-eye sensor which needs no device fabrication, power supply or measuring equipment, thus, can be potentially used to manufacture a cheap, sensitive and miniaturized NH3 sensor.

Organochlorine pesticides (OCPs) are endocrine-disrupting chemicals and may alter male reproductive hormone concentrations.To explore the associations between multiple OCP exposures and serum testosterone concentrations among Chinese men.We investigated 421 men who provided serum samples from an infertility clinic in Wuhan, China. Each man completed a questionnaire concerning demographic characteristics and lifestyle habits. Serum concentrations of 18 OCPs and total testosterone were measured. Linear regression models were used to explore whether serum OCP levels were associated with altered testosterone concentrations, and potential effect modifications by age and body mass index (BMI) were also examined.After adjusting for potential confounders, elevated dieldrin and p,p'-DDD levels had monotonically negative and positive exposure-response associations with testosterone concentrations, respectively (-30.98 ng/dL, 95% CI: -72.34, 10.37; P for trend = 0.12 and 41.31 ng/dL, 95% CI: -0.32, 82.93; P for trend = 0.06 for the highest vs. non-detectable exposure category, respectively). After stratification by age and BMI, dieldrin in relation to decreased testosterone concentrations was more pronounced among men aged30 years old, and p,p'-DDD in relation to increased testosterone concentrations was stronger among men aged ≥30 years old and among men with a BMI24 kg/mThe study found evidence that serum dieldrin and p,p'-DDD concentrations might be associated with altered serum testosterone concentrations.

Prenatal exposure to metals has been linked with adverse pregnancy outcomes. Oxidative stress and epigenetic changes are potential mechanisms of action.We aimed to examine the associations of individual and mixtures of metal exposures with oxidative stress and DNA methylation among pregnant women.We measured a panel of 16 metals and 3 oxidative stress biomarkers including 8-hydroxydeoxyguanosine (8-OHdG), 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA) and 8-isoprostaglandin F2α (8-isoPGF2α) in urine from 113 pregnant women in a Chinese cohort. Biomarkers of global DNA methylation including Alu and long interspersed nucleotide element-1 (LINE-1) in cord blood were measured. Multivariable linear regression and Bayesian kernel machine regression (BKMR) models were separately applied to estimate the associations between individual and mixtures of metal exposures and biomarkers of oxidative stress and global DNA methylation.In single-metal analyses, we observed positive associations between 11 metals [arsenic (As), cadmium (Cd), thallium (Tl), barium (Ba), nickel (Ni), vanadium (V), cobalt (Co), zinc (Zn), copper (Cu), selenium (Se) and molybdenum (Mo)] and at least one of oxidative stress biomarkers (all FDR-adjusted P-values0.05). In mixture analyses, we found positive overall associations of metal mixtures with 8-OHdG and 8-isoPGF2α, and Se was the most important predictor. There was no evidence on associations of urinary metals as individual chemicals and mixtures with Alu and LINE-1 methylation.Urinary metals as individual chemicals and mixtures were associated with increased oxidative stress, especially Se.

Human studies on association between bisphenol A (BPA) exposure and semen quality, mostly based on single urinary measurement, are inconsistent. There is limited human evidence on BPA analogues such as bisphenol F (BPF) and bisphenol S (BPS), and little is known on potential effects of bisphenol mixtures. We aimed to explore whether individual or mixtures of BPA, BPS and BPF assessed in repeated urinary measurements were associated with semen quality among 984 Chinese men from an infertility clinic. We found that higher BPA exposure was associated with increased odds ratios (ORs) of having below-reference sperm concentration, total sperm count, progressive motility and total motility (all P for trends