Synthesis and Crystal Structure of a New Complex [Cd(C_(20)H_(14)N_4)_2Cl_2]

The title compound [Cd（C20H14N4）2Cl2] 1 was synthesized via the hydrothermal reaction of CdCl2·7H2O and NaOH with 1,3-bis（benzimidazol-2-yl）benzene （BMB）, and characterized by elemental analysis and infrared spectra. The crystal of 1 crystallizes in monoclinic, space group C2/c with a = 21.021（6）, b = 9.489（3）, c = 18.302（6）, β = 108.686（6）o, V = 3458.2（19）3, Z = 4, C40H28CdN8Cl2, Mr = 804.01, Dc = 1.544 g/cm3, F（000） = 1624 and μ（MoKα） = 0.829 mm-1. The final R = 0.0306 and wR = 0.0779 for 3334 observed reflections with I 〉 2σ（I） and R = 0.0796 and wR = 0.0360 for all data. The cadmium atom is four-coordinated by the BMB ligands and Cl atom with a tetrahedral geometry. The extensive N-H···N hydrogen bonding interactions are observed in the structure, which further extend the [Cd（C20H14N4）2Cl2] units into a 1D structure. The thermogravimetric analysis measurement showed that compound 1 has thermal stability as no strictly clean weight loss step occurred below 425 ℃.

RiSw:resistant to incomplete shooting watermarking scheme

Leaking data through screen-shooting has become the main way of modern leaks.Digital watermarking technology can trace the leaker through the watermark information after the data is leaked.The current screen-shooting watermarking scheme can resist part of the distortion in the screen-shooting process,but it faces two problems.On the one hand,the watermark capacity is small.On the other hand,when the shot watermarked image is incomplete,high watermark extraction accuracy cannot be guaranteed.Based on the above problems,we propose a resistant to incomplete shooting watermarking(Ri Sw)scheme.Specifically,we design a set of codecs that can embed binary images as watermarks into carrier images and extract them,which not only ensures good visual effects of watermarked image,but also greatly increases watermark capacity.To resist incomplete shooting,we propose an incomplete shooting layer to simulate the situation of incomplete shooting in the screen-shooting process.Robustness to incomplete shooting can be achieved through end-to-end training.Extensive experiments show that the scheme proposed in this paper has superior performance.Even if the watermarked image lacks 50%pixels,it can still maintain a stable extraction accuracy.

Crystal structures and thermal decomposition kinetics of lanthanide complexes with 3,4,5-trimethoxybenzoic acid and 1,10-phenanthroline

A series of lanthanide complexes with the 3,4,5-trimethoxybenzoic acid （3,4,5-tmoba） and 1,10-phenanthroline（phen）, [Ln（3,4,5-tmoba）3phen]2（Ln = Pr（l）, Nd （2） and Ho（3））, have been synthesized and characterized by a series of techniques including elemental analysis, IR spectra, X-ray crystallography and TG/DSC-FTIR technology. The three complexes have two kinds of coordination modes, in which the Pr3＋ and Nd3＋ cations are nine-coordinated and the Ho3＋ cation is eight-coordinated. The three-dimensional IR accumulation spectra of gaseous products for complexes 1-3 were analyzed and the gaseous products were identified by the typical IR spectra obtained from the 3D surface graphs. Meanwhile, we obtained the activation energy E of the first steps of complexes 1-3 by the integral isoconversional non-linear （NL-INT） method and discussed the non-isothermal kinetics of complexes 1-3 using the Malek method. Finally, SB（m, n） was defined as the kinetic method of the first-step thermal decomposition. The thermodynamic parameters △G≠, △H≠ and △S≠ of activation at the peak temperature were also calculated.

Determination of methylene blue by resonance light scattering method using silica nanoparticles as probe

A simple and novel method was developed to determine methylene blue（MB） by resonance light scattering（RLS） using silica nanoparticles（SiO2NPs） as the probe.It was found that MB could enhance the RLS intensity of SiO2NPs.Moreover,the increase in RLS intensity was linear with the concentration of MB over the range of 0.01-3.0 μg mL^-1.The limit of detection（LOD） was as low as 4.36 ng mL^-1（3σ） and the relative standard deviation（RSD） was 2.4%（n=6）.Under the optimum experimental conditions,this proposed method was successfully applied for the determination of MB in aquaculture samples with recoveries between 96.3% and 107%.Possible mechanisms for the RLS enhancement of SiO2NPs in the presence of MB were also discussed.

Double network hydrogel with high mechanical strength:Performance,progress and future perspective

With high water content(～90 wt%) and significantly improved mechanical strength(～MPa),double network(DN) hydrogels have emerged as promising biomaterials with widespread applications in biomedicine.In recent years,DN hydrogels with extremely high mechanical strength have achieved great advance,and scientists have designed a series of natural and biomimetic DN hydrogels with novel functions including low friction,low wear,mechanical anisotropy and cell compatibility.These advances have also led to new design of biocompatible DN hydrogels for regeneration of tissues such as cartilage.In this paper,we reviewed the strategies of designing high-strength DN hydrogel and analyzed the factors that affect DN hydrogel properties.We also discussed the challenges and future development of the DN hydrogel in view of its potential as biomaterials for their biomedical applications.