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Vortices motion in the anisotropic turbulent flow of cyclones makes a vital impact on flow stability and collection performance. Nevertheless, there remains a lack of clarity in the overall feature of vortices motion. In this work, a numerical analysis was conducted to clarify the complex motion of the vortex core in a cyclone separator. The validity of the numerical model was demonstrated by comparing the computational results with experimental data in the literature. As revealed by the results, the vortex core not only has a precession motion about the geometrical center axis but also does a nutation motion in the axial direction. The frequencies of the precession motions show two main peaks. And the magnitudes of the precession and nutation motions have non-uniform distributions in the cyclone. Moreover, the precession-nutation motions of the vortex cores exhibit a similar fluctuant pattern to the dust ring on the separator wall. The inlet gas velocity and the inlet solid loading show vital effects on the magnitudes and frequencies of precession and nutation motion.

Piezoelectric energy harvesting has attracted significant attention in recent years due to their high-power density and potential applications for self-powered sensor networks. In comparison to dense piezoelectric ceramics, porous piezoelectric ceramics exhibit superiority due to an enhancement of piezoelectric energy harvesting figure of merit. This paper provides a detailed examination of the effect of pore morphology on the piezoelectric energy harvesting performance of porous barium calcium zirconate titanate 0.5Ba(Zr0.2 Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (BCZT) ceramics. Three different pore morphologies of spherical, elliptical, and aligned lamellar pores were created via the burnt-out polymer spheres method and freeze casting. The relative permittivity decreased with increasing porosity volume fraction for all porous BCZT ceramics. Both experimental and simulation results demonstrate that porous BCZT ceramics with aligned lamellar pores exhibit a higher remanent polarization. The longitudinal d33 piezoelectric charge coefficient decreased with increasing porosity volume fraction for the porous ceramics with three different pore morphologies; however, the rate of decrease in d33 with porosity is slower for aligned lamellar pores, leading to the highest piezoelectric energy harvesting figure of merit. Moreover, the peak power density of porous BCZT ceramics with aligned lamellar pores is shown to reach up to 38 μW cm-2 when used as an energy harvester, which is significantly higher than that of porous BCZT ceramics with spherical or elliptical pores. This work is beneficial for the design and manufacture of porous ferroelectric materials in devices for piezoelectric energy harvesting applications.

To evaluate the efficacy of paclitaxel-coated balloon (PCB) in the treatment of extra-long femoropopliteal artery atherosclerotic disease (30 ​cm).Forty-nine patients with extra-long femoropopliteal artery atherosclerotic disease were treated with PCB alone in a single center from July 2016 to May 2018. Primary patency and freedom from clinically driven target lesion revascularization (FF-CDTLR) rates during 12 months were analyzed retrospectively.All patients were followed up for 18.2 ​± ​7.5 months, and the mean treated lesion length was 34.9 ​± ​3.7 ​cm. The primary patency rates were 87.8% (43/49) and 71.4% (35/49) at 6 and 12 months, respectively. FF-CDTLR was 91.8% (45/49) and 77.6% (38/49) at 6 and 12 months, respectively. No mortality or amputation occurred in these patients during the follow-up period.PCB has favorable clinical efficacy in patients with extra-long femoropopliteal artery atherosclerotic lesions.

This paper proposes a computational framework for the design optimization of stable structures under large deformations by incorporating nonlinear buckling constraints. A novel strategy for suppressing spurious buckling modes related to low-density elements is proposed. The strategy depends on constructing a pseudo-mass matrix that assigns small pseudo masses for DOFs surrounded by only low-density elements and degenerates to an identity matrix for the solid region. A novel optimization procedure is developed that can handle both simple and multiple eigenvalues wherein consistent sensitivities of simple eigenvalues and directional derivatives of multiple eigenvalues are derived and utilized in a gradient-based optimization algorithm - the method of moving asymptotes. An adaptive linear energy interpolation method is also incorporated in nonlinear analyses to handle the low-density elements distortion under large deformations. The numerical results demonstrate that, for systems with either low or high symmetries, the nonlinear stability constraints can ensure structural stability at the target load under large deformations. Post-analysis on the B-spline fitted designs shows that the safety margin, i.e., the gap between the target load and the 1st critical load, of the optimized structures can be well controlled by selecting different stability constraint values. Interesting structural behaviors such as mode switching and multiple bifurcations are also demonstrated., 77 pages, 44 Figures

This paper studies a multi-armed bandit problem where the decision-maker is loss averse, in particular she is risk averse in the domain of gains and risk loving in the domain of losses. The focus is on large horizons. Consequences of loss aversion for asymptotic (large horizon) properties are derived in a number of analytical results. The analysis is based on a new central limit theorem for a set of measures under which conditional variances can vary in a largely unstructured history-dependent way subject only to the restriction that they lie in a fixed interval.

The effects of temperature on corrosion behavior, wettability, and surface conductivity of 304 stainless steel (SS304) in simulated cathode environment of proton exchange membrane fuel cells (PEMFC) are investigated systematically using electrochemical tests and surface analyses. The results indicate that although the corrosion resistance of SS304 is decreased with the rising of solution temperature, the current density of SS304 at the working potential in the simulated PEMFC cathode environment can still meet the 2025 U.S. Department of Energy (DOE) technical target (icorr

In this article, we design a new control scheme to investigate the finite-time lag synchronization (FTLS) of inertial neural networks (INNs) with mixed infinite time-varying delays and state-dependent switching. Several novel and easily verified conditions are gained guaranteeing the FTLS of INNs via the finite-time stability theory and nonsmooth analysis. Moreover, it is worth emphasizing that here we directly analyze INNs without using variable substitution, which is different from the reduced-order approach used in correspondingly previous works. At last, a numerical example and an application in image encryption are given to verify the correctness and practicability of the obtained results.

In this study, phytic acid (PA) surface treatment was used to prepare iron-based soft magnetic composites (SMCs). The composition and microstructure of the SMCs were analyzed to assess changes in the magnetic properties. As the treatment time increased, the insulating layer on the powder surface gradually thickened, changing the internal morphology and conductive path of the annular samples after compacting. The changes in the magnetic properties and core loss were attributed to the increased resistivity and enhancement of the magnetic dilution effect. The optimal soft magnetic performance (μm = 389, Pt = 235.1 mW/g measured at 100 kHz and 50 mT) was obtained by adjusting the processing time. This reduces the loss by 52.96% compared to the untreated sample and improves the application potential of soft magnetic composites at medium and high frequencies.

We report a simple and effective method to realize desirable interfacial property for inverted planar perovskite solar cells (PSCs) by using small molecule ethanediamine for the construction of a novel polyelectrolyte hole transport material (P3CT-ED HTM). It is found that P3CT-ED can not only improve the hole transport property of P3CT-K but also improve the crystallinity of adjacent perovskite film. In addition, the introduction of ethanediamine into P3CT realigns the conduction and valence bands upwards, passivates surface defects and reduces nonradiative recombination. As a consequence, compared to P3CT-K hole transport layer (HTL) based devices, the average power conversion efficiency (PCE) is boosted from 17.2% to 19.6% for the counterparts with P3CT-ED, with simultaneous enhancement in open circuit voltage and fill factor. The resultant device displays a champion PCE of 20.5% with negligible hysteresis.

Frequent solid-solid interaction results in unpredicted hydrodynamic behaviors in solid-liquid two-phase flow, and the presence of liquid phases causes the interaction to be more complicated, giving rise to non-contact solid-solid interaction. In this work, we measured the micro non-contact interaction force between falling particles and plates in viscous fluids, the micro hydrodynamic behaviors of settling particles near plates were investigated, and interaction height, non-contact interaction force and collision force were quantitatively evaluated. When fluid moving front induced by settling particles contacts plates, non-contact interaction between them occurs, which is significantly strengthen by plate surface roughness, and “break effect” on interstitial fluid was observed, resulting in non-contact force peaks. Three correlations were established to quantitatively characterize the interaction height, non-contact interaction force and collision force, and good agreement is anticipated at the regimes of 9.93

To improve the photocatalytic activity of TiO2 NBs under irradiation of solar light, an immobilized Z-scheme composite photocatalyst CdS/Au/TiO2 NBs has been constructed. For the unique architectures, the TiO2 NBs provide more absorption and reaction sites, the CdS nanoparticles enhance overall light harvesting, and Au acts as the electron transfer mediator, promoting the interfacial charge transfer and efficient separation of electrons and holes. The morphology, elements, crystal structure, optical and photoelectrochemical properties, and photocatalytic activity of CdS/Au/TiO2 NBs were characterized. Results showed that CdS/Au/TiO2 NBs possesses higher photocatalytic activity toward the degradation of antibiotic norfloxacin under irradiation of simulated sunlight, which is attributed to the synergetic interaction of increased light absorption and separation of photogenerated electrons and holes. Besides, the degradation of norfloxacin was promoted by HCO3-, but inhibited by NO3- and Cl-. The radicals trapping experiments proved that superoxide radicals (O2-) was the dominating active species during the photocatalysis process. The photocatalytic degradation products of norfloxacin was analyzed, and nine intermediates were identified. Moreover, the photocatalytic degradation mechanism and photostability of CdS/Au/TiO2 NBs were analyzed in detail. The matched energy levels and unique ternary Z-scheme design are the key for improved photocatalytic activity. The deactivation of CdS/Au/TiO2 NBs after recycles mainly due to the release of CdS by photocorrosion and the loss of deposited Au.

Background Early graft failure can affect the short- and long-term outcomes of patients undergoing coronary bypass grafting surgery (CABG). The aim of our study was to explore the predictive value of transit-time flow measurement (TTFM) parameters for early graft failure (before discharge) after CABG in different coronary territories and calculate the TTFM cut-off values. Methods We analyzed a total of 761 grafts (360 patients) that were evaluated by intraoperative TTFM and computed tomography angiography prior to discharge. Logistic model was established to detect the parameters of TTFM to predict early graft failure and receiver operating characteristic curve analysis was used to calculate the cut-off values. Results The overall early graft failure was 3.5%. The results demonstrated that compared with off-pump CABG, mean graft flow volume was higher (28.0 vs 21.0 mL/min, p = 0.000), but pulse index (PI) (2.3 vs 2.5, p = 0.049) and diastolic flow fraction (DF) (68.0% vs 71.0%, p = 0.001) were lower in on-pump CABGs. DF (73.0% vs 65.5%, p = 0.000) of arterial grafts was higher than that of venous grafts. DF (72.0% vs 62.0%, p = 0.000) in left was higher than that in the right coronary artery territories. The results of multivariate logistic analysis showed that not only in the overall (OR 1.18, 95% CI 1.07–1.30, p = 0.001), but also the left (OR 1.21, 95% CI 1.03–1.41, p = 0.017) and right (OR 1.15, 95% CI 1.03–1.29, p = 0.017) coronary artery target territories, PI was a risk factor for early graft failure and the cut-off value was 3.4, 3.4, and 3.6, respectively. For grafts in left target territories, the results showed that DF (OR 0.94, 95% CI 0.91–0.97, p = 0.000) just in the univariate analysis was a risk factor that affected graft failure. Conclusions The overall early graft failure was about 3.5%. High PI value is a risk factor for early graft failure in not only overall grafts but in grafts of different target territories. DF might be more useful for the quality evaluation of grafts in left than in right target territories.

The titanium dioxide-based varistor is generally equivalent to a combination of resistor and capacitor, whereas, for the titanium dioxide-based composite with negative permittivity, it can be composed of a resistor, capacitor, and inductor. In this work, ac conductivity, real permittivity, and reactance of copper/titanium dioxide (Cu/TiO2) percolating composites are investigated in detail in the frequency of 10 kHz - 1 MHz. As Cu content increases, percolation occurs in composites, accompanied by the transformation of electron transport mechanism from localization to delocalization. Furthermore, the regulation of permittivity by compositions and microstructures is specifically analyzed. It suggests that the enhanced permittivity before percolation ascribes to the enhancement of interfacial polarization, when reaching the excessively percolating state, plasma-like negative permittivity is achieved, consequently, revealing the low-frequency plasmonic state. Moreover, reactance analyses indicate the negative permittivity is ascribed to the inductive characteristics, and the stronger the inductance, the greater the contribution to the negative permittivity.