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Efficient treatment of wastewater is of paramount importance for protecting the ecosystem. In this work, we prepared a low-grade sepiolite with low Na/La salt loadings (Na/La-Sep) and employed it for the simultaneous removal of ammonia (N) and phosphate (P) species in the wastewater. The key factors influencing the nutrient removal efficiency of Na/La-Sep, such as the concentration of the La/Na salt solution, the co-existing ion type, and surface zero charges, were investigated. Na/La-Sep exhibits excellent N and P adsorption capability and reduced the N and P concentrations in the spiked and real-world wastewaters to below the allowable N and P discharge limits. Due to the extraordinarily low cost of low-grade sepiolite and the low loading of Na/La salts, Na/La-Sep has a substantially lower cost when compared to other reported clay mineral adsorbents. Furthermore, the N and P removal mechanisms by Na/La-Sep were unraveled by combining the kinetic studies, the molecular dynamics (MD) simulation, and the electron density difference. The present findings might shed light on a new way to develop cost-efficient and high-efficiency adsorbents for alleviating eutrophication and deepen the understanding of N and P removal at a molecular level.

The poor light-harvesting capability and fast charge recombination of Bi-based photocatalysts weaken their photocatalytic activity. In this study, graphene quantum dot (GQD) modified Bi2WO6 (BWO) composites (GQDs/BWO) were prepared by a facile microwave-assisted hydrothermal method. GQDs/BWO exhibited an excellent photocatalytic activity by degrading 97.3% of phenol in 60 min under visible-light irradiation. The mechanism of reinforcing the separation of hole–electron (h+/e−) pairs was unraveled by applying the DFT calculation, indicating that the excited electrons in the GQDs/BWO composites have an extra transfer route from the Bi 6p and O 2p orbitals of BWO to GQDs instead of localization in the BWO crystal. Furthermore, GQDs with controllable size were synthesized by altering the parameters of reflux, and the size effect of GQDs on the visible light absorption capability and the charge separation property of GQDs/BWO was discussed.

In this paper, a new optimal guidance law with terminal constraints on miss distance and intercept angle is proposed for a missile with time-varying velocity against a maneuvering target. The proposed optimal guidance law is obtained by solving a linear quadratic optimal control problem. Miss distance and intercept angle costs are weighted by variants of hyperbolic tangent function and energy cost is weighted by a power of time-to-go. The rule for determining a key parameter in the variant of hyperbolic tangent function is studied using the theory of second order differentiation, and its validity is verified by numerical simulation. In the purpose of easy implementation, an analytical solution of the proposed optimal guidance law is derived using assumption of constant velocity when calculating integral of missile's velocity from current time to final time. The significant contribution of this paper lies in that it is the first time a variant of hyperbolic tangent function is developed and employed as weighting coefficients of constraints on miss distance and intercept angle. Therefore, the proposed optimal guidance law can reduce acceleration command at the initial phase and increase missile's terminal velocity. Nonlinear numerical simulations clearly demonstrate effectiveness of the proposed optimal guidance law.

Epigallocatechin-3-gallate (EGCG) is a pivotal effective component of green tea. It is known that EGCG has antioxidant activity, anti-angiogenesis, anti-tumor, cardiovascular protection and blood lipid regulation functions. Forkhead box-O1 (FOXO1) is one of the downstream signals of protein kinase B (AKT) and takes part in adipogenesis. The purpose of this study is to investigate the effects of EGCG on adipose differentiation and the likely mechanisms. 3T3-L1 cells were induced by DMI for 2, 4, 6 and 8 days, respectively. During induction, the cells were treated with EGCG (5 μM, 10 μM, 50 μM and 100 μM) or DMSO for the first 2 days. In addition, another batch of 3T3-L1cells were treated with SC-3036 (PI3K activator, 10 µM), or LY294002 (PI3K inhibitor, 10 µM) alone or combined with EGCG (100 μM) for the indicated times. Medium glucose concentration, lipid accumulation, the levels of TNF-α, resistin, adiponectin and leptin and the expression of FOXO1, phosphorylated-FOXO1 (P-FOXO1), PPARγ, fatty acid synthase (FAS) were detected, respectively. The present study demonstrated that EGCG inhibited glucose uptake, lipid accumulation and adipokine secretion in a concentration-dependent manner during adipogenesis, which suggests that EGCG inhibits adipocyte's differentiation, maturation and functions. Moreover, EGCG also down-regulated the expression levels of PPARγ and P-FOXO1. Conversely, the PI3K activator reversed these changes caused by EGCG, suggesting that the inhibitory effects of EGCG may be mediated by PI3K-AKT-FOXO1 pathway to negatively regulate the expression of PPARγ. The findings will provide a solid foundation for EGCG to prevent and cure the obesity-associated diseases.

A series of methylene-bridged salicylaldiminato tridentate [ONS] ligands bearing different alkylthio sidearms and the corresponding binuclear titanium complexes (Ti 2 a , Ti 2 b , Ti 2 c ) were synthesized and characterized by elemental analysis, ESI-MS, FT IR, 1H and 13C NMR. To the best of our knowledge, these were the first non-metallocene tridentate binuclear Ti complexes reported. When activated by modified methylaluminoxane (MMAO), these binuclear Ti complexes displayed extremely high activities in the range of 106 g mol−1 h−1 atm−1 for ethylene polymerization and ethylene/α-olefins copolymerization at atmospheric pressure, producing high molecular weight polymers with narrow polydispersity. Both the catalytic behavior and the spectroscopic characterization indicated that the catalysts assumed symmetric structure and contained single-site active species. Most importantly, the catalytic activities towards ethylene (co)polymerization as well as comonomer incorporation ratios were much higher than that of the corresponding mononuclear complexes. Meanwhile, the properties of polymers and the comonomer incorporation ratios can be effectively tuned by the reaction conditions and the alkylthio side group on ligands. Complex Ti 2 c bearing the long octylthio sidearm showed significantly higher activity for ethylene polymerization than the methylthio functionalized Ti 2 a , presumably due to the increased solubility of the catalyst in the reaction medium. While for copolymerization, complex Ti 2 a demonstrated the highest catalytic activity and comonomer incorporation ratio, due the small steric hindrance of the methylthio side group.

As a flavonoid, naringin (Nar) has been shown to have multiple pharmacological effects including lowering blood cholesterol, reducing thrombus formation and improving microcirculation. However, effects of Nar on function and autophagy of vascular endothelial cells under high glucose and high fat (HG/HF) stress are largely unclear. This study was designed to investigate such effects of Nar in human umbilical vein endothelial cells (HUVECs) and to determine whether such effects are related to autophagy. Our present results show that 86 μM of Nar inhibits the autophagy levels and protects the cells against the dysfunction induced by HG/HF stress. Moreover, Nar increases the phosphorylation levels of phosphatidylinositol-3-kinase (PI3K), protein kinase B (Akt) and mammalian rapamycin target protein (mTOR). However, pretreatment with rapamycin (RAPA, 5 μM, autophagy inducer), LY294002(10 μM, PI3K inhibitor) and Akt inhibitor Ⅳ (0.5 μM, Akt inhibitor) partially abrogates the protective effects of Nar, suggesting that the protective effects of Nar are achieved by activating the PI3K-Akt-mTOR pathway to inhibit autophagy. In conclusion, Nar improves the function of HUVECs under HG/HF stress through activating the PI3K-Akt-mTOR pathway to inhibit autophagy. The findings offer an insight into HG/HF stress-induced autophagy and indicate that Nar might have potential to prevent and treat the diabetic angiopathy.

Osteopontin (OPN), a secreted glycoprotein, is involved in various pathophysiological processes including immune response, inflammation, tumor formation, and metabolism. OPN exists in 2 forms, secreted-OPN (sOPN) and intracellular-OPN (iOPN). While they might have different biological activities, it remains largely unknown whether sOPN and iOPN induce the differentiation of brown adipocytes. To test this possibility, 3T3-L1 cells were induced by DMI induction with or without recombinant human OPN (rhOPN, 10, 50, 100, 200 μM), respectively. Meanwhile, another batch of 3T3-L1 cells were infected with Ad-GFP-ap2-OPN and followed by DMI differentiation. Subsequently, the infected cells were treated with either anti-CD44 antibody or immunoglobulin G (Ig G). Accumulation of lipid droplets was visualized by Oil red O staining and protein levels were assayed by western blotting analysis. The results showed that sOPN and not rhOPN, notably increased the accumulation of lipid droplets and the expression of brown adipocyte-related genes. Moreover, neutralization of CD44 partially abrogated the effects induced by sOPN. These data demonstrate that sOPN and not rhOPN has the capacity to induce the differentiation of white preadipocytes into brown adipocytes through a CD44-dependent mechanism. The findings might provide a potential target for sOPN to combat obesity.

This paper is concerned with the question of, for a missile interception with impact angle constraints, how to design a guidance law. Firstly, missile interception with impact angle constraints is modeled; secondly, a novel guidance law using fast terminal sliding mode control based on extended state observer is proposed to optimize the trajectory and time of interception; finally, for stationary targets, constant velocity targets and maneuvering targets, the guidance law and the stability of the closed loop system is analyzed and the stability of the closed loop system is analyzed, respectively. Simulation results show that when missile and target are on a collision course, the novel guidance law using fast terminal sliding mode control with extended state observer has more optimized trajectory and effectively reduces the time of interception which has a great significance in modern warfare.

A three dimensional integrated guidance and control law with impact angle constraint is developed, using the dynamic surface control and extended state observer techniques, for the bank to turn (BTT) missile attacking a ground fixed target in the presence of input saturation and actuator failure. Firstly, a novel three dimensional integrated guidance and control model based on Coriolis theorem is built without assuming the angle between line of sight and missile velocity is small or almost constant. Then, to analyze the effect of input saturation on missile's integrated guidance and control system, a smooth tangent function, a Nussbaum function, and an auxiliary system are introduced. The actuator failure, modeling error, and aerodynamic parameters perturbation are viewed as the lumped system uncertainty. Three extended state observers are designed to estimate uncertainty. With the signal generated by the auxiliary system and uncertainty estimate from extended state observer, a robust controller is designed using dynamic surface control technique to track the desired impact angle. The stability of system is proved using Lyapunov theory. Numerical simulations are implemented to demonstrate the effectiveness and robustness of the integrated guidance and control law.

A novel extended state observer, which feeds back the output estimation error via both nonlinear and switching terms, is put forward for the first time in this paper. No longer neglecting the lumped uncertainty׳s first time derivative, the problem of disturbance observer design is transformed into the problem of state observer design in the presence of external disturbance. The switching term of the output estimation error is employed to counteract the adverse effect of external disturbance. The newly developed extended state observer provides an attractive solution to the issue of high precision motion control system. Both numerical simulation and experimentation on a speed turntable with temperature box are implemented to verify the performance of the proposed newly developed extended state observer.

In this paper, a nonsingular, essentially continuous and finite-time convergent impact angle constrained guidance law for intercepting stationary, constant speed, and maneuvering targets is developed using advanced terminal sliding mode control schemes and extended state observer. In order to achieve the specified intercept angle in finite time without singularity, the nonsingular fast terminal sliding mode control algorithm is employed to construct sliding surface. The fast terminal sliding mode control technique is used to establish the reaching law, so the system trajectory converges quickly from initial state to the switching surface in the whole reaching phase and the proposed guidance law is essentially continuous. Noticing the interception of a maneuvering target, the unknown target acceleration is estimated and compensated using extended state observer. Due to its inherent attribute of singularity-free, continuity, and faster convergence rate, no approximation is necessary in the implementation of the proposed guidance law, so better tracking accuracy of the desired intercept angle in a shorter time with a smoother guidance command can be guaranteed compared with conventional terminal sliding mode guidance law. A large number of numerical simulations are implemented to justify the effectiveness of the proposed guidance law.

Under the existence of the unknown target acceleration, guidance law that guarantees imposing a predetermined impact angle relative to a maneuvering target’s flight direction is proposed in this paper. The prespecified impact angle is defined in terms of a time-varying desired line of sight angle for a maneuvering target. Then, the problem of impact angle guidance law design is transformed to a problem of state tracking. To deal with the unknown target acceleration, an extended state observer is utilized to estimate it instead of simply treating it as zero. In order to avoid the singularity in the terminal phase of guidance and eliminates the need of a priori knowledge of the uncertainty upper bound, an adaptive nonsingular terminal sliding mode control scheme is adopted to design the sliding surface. The switching gain is not necessary to be determined in advance but adjusted according to the adaptive rule. Numerical simulations are implemented to demonstrate the effectiveness of the proposed guidance law.

/ACF) as photocatalyst. The influence of key factors, including Fe doping amount and power density ofdual-frequency ultrasounds (20/40 kHz), on the degradation efficiency was investigated. The degradationefficiency rises to 98.7% in 60 min accompanied by the color removal of CR liquid samples from yellow tocolorless transparent at optimal conditions. A synergy index of 1.40 was yielded by comparison with singleultrasound assisted photocatalysis (SUAP) and the photocatalysis without ultrasound assisted (UV/TiO

To control a slide to turn (STT) missile which attacks a ground moving target in the presence of input saturation, a three dimensional (3D) integrated guidance and control (IGC) law based on dynamic surface control and linear extended state observer (LESO) techniques is developed. Firstly, a novel 3D IGC model is built without assuming that the angle between line of sight (LOS) and missile velocity is small or almost constant. Then, to analyze the effect of input saturation, a Nussbaum function, a smooth tangent function, and an auxiliary system are introduced. The modeling error, acceleration of target and aerodynamic parameters perturbation are viewed as the overall system uncertainty which three linear extended state observers are designed to estimate. With the signal generated by the auxiliary system and uncertainty estimated from LESO, a robust controller utilizing dynamic surface control technique is designed to track the target. Besides, the stability of system is proved. Simulation results demonstrate the effectiveness of the law.

The purification of crude titanium tetrachloride (TiCl4) with vanadium impurities (mainly as VOCl3 and VCl4) was investigated by treatment with a mixture of Al powder and white mineral oil (WMO). L9 orthogonal array and analysis of variance (ANOVA) were applied to determine the optimal condition and most significant factors. In comparison with the conventional purification processes by adding WMO or Al powder alone, with WMO or Al powder as purification agent, the present process showed obvious advantages in saving the reaction time and improving the purification efficiency. Scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS) were further used to measure the residue after purification. The results showed that VOCl3 was converted to insoluble VOCl2 by reduction of TiCl3 through the reaction of Al powder with TiCl4 and active carbon produced from the pyrolytic cracking of WMO.

Considering a class of skid-to-turn (STT) missile with fixed target and constrained terminal impact angles, a novel three-dimensional (3D) integrated guidance and control (IGC) scheme is proposed in this paper. Based on coriolis theorem, the fully nonlinear IGC model without the assumption that the missile flies heading to the target at initial time is established in the three-dimensional space. For this strict-feedback form of multi-variable system, dynamic surface control algorithm is implemented combining with extended observer (ESO) to complete the preliminary design. Then, in order to deal with the problems of the input constraints, a hyperbolic tangent function is introduced to approximate the saturation function and auxiliary system including a Nussbaum function established to compensate for the approximation error. The stability of the closed-loop system is proven based on Lyapunov theory. Numerical simulations results show that the proposed integrated guidance and control algorithm can ensure the accuracy of target interception with initial alignment angle deviation and the input saturation is suppressed with smooth deflection curves.

On the basis of nonlinear dynamic inversion theory, a novel scheme combining sliding-mode control and backstepping is proposed for missile attitude control. In order to handle matched and unmatched uncertainties caused by unmodeled dynamics and variations of aerodynamic coefficients, a linear extended state observer (LESO) is introduced to estimate the uncertainties and the evaluated errors are compensated at each step of the backstepping design procedure. The stability of the closed-loop system is demonstrated based on Lyapunov theory. Simulation results show that the proposed scheme can guarantee the excellent tracking performance and the strong robustness against aerodynamic derivative variations.

The integrated guidance and control (IGC) technology of aircraft has been developing for more than 30 years, and it mainly focused on the research in single plane. Due to the exigent requirement on the three-dimensional IGC technology in current researches, the mathematical modeling in three-dimensional space is considered and analyzed in order to solve the primary problem during the design period of three-dimensional IGC. The three-dimensional guidance model of line-of-sight (LOS) and dynamics model of aircraft are respectively established, and then they are cooperatively united as an original state-space model. Based on some feasible simplifications, the original model is further transformed into a simplified state-space model with strict feedback form, which is propitious for the design of IGC scheme. The proposed state-space model can be directly applied to explore the advanced three-dimensional IGC approaches for unpowered sliding-to-turn (STT) aircraft with fixed target. Moreover, it also possesses higher application value.

This study explores the guidance law against maneuvering targets with the intercept angle constraint. The limitation of the traditional guidance law, which simply treats the unknown target acceleration as zero, has been analyzed. To reduce this limitation, a linear extended state observer is constructed to estimate the acceleration of the maneuvering target to enhance the tracking performance of the desired intercept angle. Furthermore, a nonsingular terminal sliding mode control scheme is adopted to design the sliding surface, which is able to avoid the singularity in the terminal phase of guidance. Simulation results have demonstrated that the proposed guidance law outperforms the traditional guidance law in the sense that more accurate intercept angle can be achieved.