Role of cetyltrimethyl ammonium bromide, crystal violet and humic acid in the degradation of diclofenac under simulated sunlight irradiation

The photodegradation of diclofenac in the absence/presence of cetyltrimethyl ammonium bromide,crystal violet and humic acid under simulated sunlight has been studied.Under the study conditions,it is apparent that cetyltrimethyl ammonium bromide and crystal violet concentrations inhibit effects on the photodegradation of diclofenac.Humic acid has no distinct effect on the photodegradation of diclofenac.Crystal violet has an obvious antagonistic action for humic acid and a similar antagonistic action between cetyltrimethyl ammonium bromide and crystal violet.Cetyltrimethyl ammonium bromide and humic acid have synergistic effect.An antagonistic action is present between cetyltrimethyl ammonium bromide,crystal violet and humic acid.Moreover,a simple linear model which describes the obtained results is shown.     

Two ZnII Metal‐Organic Frameworks with Coordinatively Unsaturated Metal Sites: Structures,Adsorption, and Catalysis

Assembly of Zn(NO₃)₂ with the tripodal ligand H₃TCPB (1,3,5‐tri(4‐carboxyphenoxy)benzene) affords two porous isoreticular metal‐organic frameworks, [Zn₃(TCPB)₂?2DEF]? 3DEF ( 1 ) and [Zn₃(TCPB)₂?2H₂O]? 2H₂O?4DMF ( 2 ). Single‐crystal X‐ray diffraction analyses reveal that 1 crystallizes in the monoclinic space group P2₁/c and possesses a 2D network containing 1D microporous opening channels with an effective size of 3.0×2.9 Ų, whereas 2 crystallizes in the trigonal space group ${P\bar 3}$ c1 and also possesses a 2D network containing 1D channels, with an effective aperture of 4.0×4.0 Ų. TOPOS analysis reveals that both 1 and 2 have a (3,6)‐connected network topology with the Schläfli symbol of (4³?6¹²) (4³)₂. According to the variable‐temperature powder X‐ray diffraction patterns, the solid phase of 1 can be converted into that of 2 during a temperature‐induced dynamic structural transformation, thus indicating that the framework of 2 represents the most thermally stable polymorph. Desolvated 2 exhibits highly selective adsorption behaviors toward H₂/N₂, CO₂/N₂, and CO₂/CH₄; furthermore, it displays size‐selective catalytic activity towards carbonyl cyanosilylation and Henry (nitroaldol) reactions.     

Chemical profiling of constituents of Smilacis glabrae using ultra-high pressure liquid chromatography coupled with LTQ Orbitrap mass spectrometry

A reliable LC-MS method has been applied for the separation and identification of major constituents of the rhizome of Smilacis glabrae. Identification of the constituents was carried out by interpretation of their retention time, and MS and MS/MS data, especially by comparing these with Sarcandra glabra under the same LC-MS conditions, as well as the data provided by the literature. Thirty-three compounds, including catechin derivatives, flavanonols, phenolic acid derivatives and phenylpropanoid glycosides were either identified or tentatively characterized. Among them, compound 12 was deduced to be a new phenylpropanoid-substituted catechin. Fragmentation behaviors of the three major categories of compounds were also investigated. This UPLC-PDA/ESI-MS(n) method was effective for the separation and identification of the constituents and could be the basis for the comprehensive quality control of Smilacis glabrae.     

SiO2对低温烧结压电陶瓷PMNNS的性能影响

在烧结温度为1020℃下,采用固相二步合成法制备了Pb(Ni1/3Nb2/3)0.05(Mn1/3Nb2/3)0.04(Mn1/3Sb2/3)0.01(Zr1/2Ti1/2)0.9O3(PMNNS)压电陶瓷,研究了加入不同掺杂量的SiO2对陶瓷的结构与机电性能的影响。结果表明:加入SiO2可以明显地降低烧结温度;而且当SiO2的掺杂量为0.1%时,陶瓷的性能最佳,其性能如下:d33=331 pC/N,tanδ=0.0041,kp=0.62,Qm=1326,εr=917。     

Synchronization of brushless DC motors based on LaSalle invariance principle

An adaptive synchronization control method is proposed for the chaotic brushless DC motors based on the LaSalle invariance principle. We show explicitly with numerical proofs that the synchronization error system between the driving and response systems can be asymptotically stable using only a single variable feedback. The present controller is simple in comparison with previous methods. Computer simulation results show that the proposed method is effective.     

An Active Set Modified Polak–Ribiére–Polyak Method for Large-Scale Nonlinear Bound Constrained Optimization

In this paper, we propose an active set modified Polak?CRibiére?CPolyak method for solving large-scale optimization with simple bounds on the variables. The active set is guessed by an identification technique at each iteration and the recently developed modified Polak?CRibiére?CPolyak method is used to update the variables with indices outside of the active set. Under appropriate conditions, we show that the proposed method is globally convergent. Numerical experiments are presented using box constrained problems in the CUTEr test problem libraries.     

Global existence and blow-up phenomena for a periodic 2-component Camassa–Holm equation

We first establish local well-posedness for a periodic 2-component Camassa?CHolm equation. We then present two global existence results for strong solutions to the equation. We finally obtain several blow-up results and the blow-up rate of strong solutions to the equation.     

Recurrence in β-expansion over formal Laurent series

In this paper, we study the quantitative recurrence and hitting sets of β-transformation T _β on the unit disk I of formal Laurent series field $$E_\phi:= \{x\in I: \|T_\beta^nx - x\| < \|\beta\|^{-\phi(n)}\,\,\,{\rm infinitely\,often}\}$$ and $$F_\phi:=\{x\in I: \|T_\beta^nx-x_0\|<\|\beta\|^{-\phi(n)}\,\,\,{\rm infinitely\,often}\},$$ where x ₀ is any fixed point in I and ${\phi}$ is any positive function defined on ${\mathbb{N}}$ with ${\phi(n)\to\infty}$ as n → ∞. We completely determine the Hausdorff dimensions of these sets: $$\dim_{\rm H} E_{\phi}=\dim_{\rm H}F_\phi=\frac{1}{1+\liminf\limits_{n\to\infty}\frac{\phi (n)}{n}}.$$      

Global weak solutions for a periodic two-component?μ-Hunter–Saxton system

This paper is concerned with global existence of weak solutions for a periodic two-component?μ-Hunter–Saxton system. We first derive global existence for strong solutions to the system with smooth approximate initial data. Then, we show that the limit of approximate solutions is a global weak solution of the two-component?μ-Hunter–Saxton system.