Hydrothermal synthesis of 3D NixCo1−xS2 particles/graphene composite hydrogels for high performance supercapacitors

In this work, three dimensional (3D) Ni_xCo_1−xS₂/graphene composite hydrogels with different Ni contents (denoted as Ni_xCo_1−xS₂/GH (x = 0, 0.31, 0.56, 0.66, 1)) have been synthesized by a simple one-step hydrothermal method and utilized as the active materials of supercapacitors. The as-prepared samples present a 3D interconnected porous network with the pore sizes in the range of several to tens micrometers. Interestingly, the Ni_xCo_1−xS₂ particles are uniformly located on the graphene network and the particle size is evolved from ∼50 nm to ∼1.5 μm with the increase of Ni content. The electrochemical measurements revealed that the specific capacitance, rate capability and cyclability of different Ni_xCo_1−xS₂/GH electrodes are strongly affected by their different Ni content. Among these, the 3D Ni_0.31Co_0.69S₂/GH composite has the highest specific capacitance of 1166 F/g at a current density of 1 A/g. Furthermore, a specific capacitance of 559 F/g can be still maintained at high current density of 20 A/g. After 1000 charge–discharge cycles at 5 A/g, the specific capacitance remains a high value of 755 F/g.     

In2O3:Ga and In2O3:P-based one-electrode gas sensors: Comparative study

Gas sensing characteristics of one-electrode sensors based on the In₂O₃ ceramics doped by gallium and phosphorus have been discussed. In₂O₃-based ceramic was prepared by sol–gel technology. Ozone, CO, CH₄ and H₂ were used as tested gases. The doping concentration effect on the sensor parameters such as magnitude of response, operating temperature, response and recovery times, sensitivity to the air humidity, and selectivity have been analyzed. It was shown that In₂O₃ doping by Ga and P could be used for the sensor performance optimization. It was assumed that the appearance of the second phase (InPO₄ and Ga₂O₃) and the change of structural parameters, taking place during doping process, were the main factors controlling the change of operating characteristics in In₂O₃:P and In₂O₃:Ga-based sensors.     

Excited-state absorption of meso-tetrasulfonatophenyl porphyrin: Effects of pH and micelles

The influence of the environment on the excited state transitions of meso-tetrakis(p-sulfonatophenyl) porphyrin (TPPS) is reported. TPPS was investigated in protonated and non-protonated forms, and in the presence of the cationic cetyltrimethylammonium bromide (CTAB) micelles. The singlet excited-state absorption spectra were measured by using the white-light continuum Z-scan technique and the triplet–triplet absorption spectra were acquired employing an association of laser flash photolysis and Z-scan techniques. Our results show that the perseveration of the molecular symmetry, upon excitation, depends on the state of multiplicity of the molecules, as well as on the environment and structural characteristics of the porphyrin. Additionally, it was observed that for excited molecules, the ring distortion caused by the protonation of porphyrin ring has great influence on the changes observed for the symmetry and vibronic structure. The results clearly show that the porphyrin investigated is a promising candidate for optical limiting applications for all investigated environments.     

餐饮废油生物柴油低温流动性的改进研究

使用气-质联用仪测定餐饮废油生物柴油(WCME)和-10号柴油(-10PD)的组成,使用冷滤点试验器和运动黏度试验器测定WCME的低温流动性,同时使用调合、添加低温流动性改进剂的方法改进WCME的低温流动性。实验结果表明,WCME主要由饱和脂肪酸甲酯和不饱和脂肪酸甲酯组成,质量分数分别为27.63%和71.81%;WCME冷滤点为0℃,运动黏度(40℃)为4.41mm2/s;WCME与-10PD调合后,冷滤点降低,其中B20的冷滤点最低,为-13℃,运动黏度随着WCME的体积分数的减少,逐渐接近-10PD的运动黏度。通过添加低温流动性改进剂,WCME,B10,B20的冷滤点分别从0,-8,-13℃降至-4,-26,-25℃。     

Bond characteristics,vibrational spectrum and optimized microwave dielectric properties of chemically substituted NdNbO4

Coordination chemistry, bond state and vibrational spectrum of co-substituted microwave dielectric NdNb_1-x(Zr_0.5W_0.5)_xO₄ ceramics (x = 0.01∼0.05) were investigated. Raman spectra and XRD refinement showed a solid solution was formed. The compressed and elongated chemical bonds are responsible for the variations of crystal parameters and cell volume. Calculated chemical bond parameters indicated bond covalency, lattice energy and Nb-site bond energy act on the fluctuations of the permittivity, quality factor and temperature coefficient, respectively. Meanwhile, the infrared vibrational spectrum is fitted to quantify the contributions of observed IR mode to the intrinsic loss. Compact ceramic possesses excellent properties: ε_r ∼ 19.2, Q × f ∼ 55282 GHz and τ_f ∼ -11.36 ppm/°C with x = 0.04, at 1250°C.     

Polyaniline-based networks combined with Fe3O4 hollow spheres and carbon balls for excellent electromagnetic wave absorption

Polyaniline (PANI)-based networks combined with Fe₃O₄ hollow spheres and carbon balls (FCP) for improved electromagnetic wave (EMW) absorption were investigated using an easy-to-industrialize solvothermal and physical method. Hollow structure Fe₃O₄ spheres with a lower density than that of the common solid sphere were prepared. As a thin and light magnetic material, Fe₃O₄ hollow spheres generate magnetic loss, carbon balls and PANI networks generate dielectric loss. The magnetic and conductive parts play appropriate roles in achieving complementarity in the EMW absorption. The relatively high specific surface area introduced by PANI networks promotes interfacial polarization and further supports dielectric loss. In conclusion, the above reasons provide multiple attenuation mechanisms. Samples FCP1 (?65.109 dB, at 12.800 GHz, 1.966 mm, from 5.6 to 18.0 GHz) and FCP2 (?61.033 dB, at 8.480 GHz, 3.328 mm, from 4.3 to 18.0 GHz) demonstrated a wide bandwidth, a small thickness, a minimum reflection loss (R_L), and a low loading ratio (25%) in paraffin-based composites. Specifically, their loading ration of 25% is much lower than the loading ratio of conventional materials (usually 50% and above). In addition, the bandwidth is excessively wide, above 12 GHz, possessing good absorption performance in continuous intervals with different thicknesses. Such excellent characteristics have rarely been reported in literature.     

Combating Biofilm Associated Infection In Vivo: Integration of Quorum Sensing Inhibition and Photodynamic Treatment based on Multidrug Delivered Hollow Carbon Nitride Sphere

Recently, quorum sensing (QS) inhibitors (QSIs) have been combined with antibiotics to enhance antibiofilm efficacy in vitro and in vivo. However, targeting QS signals alone is not enough to prevent bacterial infections. Drug resistance and recurrence of biofilms makes it difficult to eradicate. Herein, photodynamic therapy (PDT) is selected to unite QSIs and antibiotics. A synergistically antibiofilm system, which combines QSIs, antibiotics, and PDT based on hollow carbon nitride spheres (HCNSs) is envisaged. First, HCNS provides the multidrug delivering ability, enabling QSIs and antibiotics to be released in sequence. Subsequently, multistage releases sensitize bacteria effectively, potentiating the chemotherapeutic effects of the antibiotics. Finally, the integration of QSIs and PDT not only minimizes the possibility of drug resistance, but also overcomes the problem of limited mass and extension of PDT. Even after 48 h of incubation, the bacterial biofilm is obviously inhibited. And its biofilm disperse efficiency exceeds 48% (compared with QSI‐potentiated chemotherapy group) and 40% (compared with PDT group). Besides, the inhibition of the QS system influences phenotypes related to virulence factor production and surface hydrophobicity, which weaken biofilm invasion and formation. Eventually, this system is applied to disperse bacterial biofilm in vivo. Overall, PDT and QS modulation are devoted to eradicate drug resistance and recurrence of the biofilm.     

Citation recommendation based on citation tendency

Scientometrics - Due to the development of academic, more and more attentions are paid to citation recommendation. To solve the citation recommendation problem, researchers begin to focus on the...     

KJS-Y系列矿用水动力降尘器的改进设计

针对当前KJS-Y系列降尘器效率低的问题,通过调整叶轮轴向间隙与径向间隙参数,分别对不同安装参数的降尘器进行数值模拟,通过数值模拟分析特定截面压力分布情况,确定了叶轮最佳安装参数,大大提高了降尘器的工作效率,同时降低了设计成本。