PdFe Ultrathin Nanosheets for Highly Sensitive Detection of Nitrite

PdFe ultrathin nanosheets (NSs) were prepared by one‐step hydrothermal route. PdFe NSs showed superior catalytic activity towards the oxidation of nitrite due to the large surface area of 2 dimensional (2D) nanostructure and the synergetic effect between Pd and Fe. A sensitive and selective electrochemical nitrite sensing platform was designed base on PdFe NSs and the amperometric technique. The limit of detection (LOD) was found to be 0.12 μM (S/N=3), with a linear relationship between nitrite concentration and response current in the range of 1–160 μM. The nitrite sensor was applied to analysis of nitrite in tap water and sausage successfully.     

N2/H2 Non-thermal Transferred arc Plasma Nitriding Treatment of Stainless Steel at Atmospheric Pressure

Plasma Chemistry and Plasma Processing - In the paper, a novel metal surface nitriding method is presented by using an atmospheric pressure non-thermal transferred arc plasma technique. In the...     

Interfacial Dilational Properties of Two Different Structure Demulsifiers at Oil–Water Interfaces

The dilational properties of demulsifiers PE1 and PE2 at the decane-water interface were investigated. Meanwhile, the influence of demulsifiers on interfacial dilational modulus of 5% crude oil also was explored. The experimental results indicate that the diffusion process is still not the main factors to control the properties of interfacial film even at large concentration. The dilational modulus of demulsifier PE2 passes through a maximum with the increasing concentration, and that of demulsifier PE1 changes a little with the increasing concentration at the decane-water interface. The dilational moduli of crude oil inerfaces decrease with the addition of both demulsifiers. At low concentration, the effect on reducing the dilational modulus of crude oil is stronger for PE1, which maybe caused by its higher substitution ability. For PE2, the ability to decrease interfacial dilational modulus gets stronger with increasing bulk concentration, which might be explained by that the adsorption increases with increasing concentration. The results of relaxation experiments support those obtain by oscillating barriers method.     

Aggregation of Sodium 2,4,5-(tri-n-Alkyl)-benzene Sulfonates in Aqueous Solution: Micellization and Microenvironment Characteristics Studied by Electron Paramagnetic Resonance and Steady-State Fluorescence Quenching

The aggregation behaviors and microenvironmental characteristics of five sodium tri-n-alkylbenzene sulfonates (STABS) micelles have been investigated by electron paramagnetic resonance (EPR) and steady-state fluorescence quenching (SSFQ) techniques. The results indicated that the micropolarity of STABS micelles was less sensitive to the increase of the alkyl chain length, and showed slight decrease with the increasing solution concentration. The microviscosity of STABS micelles increased with the increase of the long alkyl chain length, decreased with the increase of the short alkyl chain length, and exhibited little increase when increase the solution concentration. The salinity of added inorganic salt exhibited obvious effect on the decrease of micropolarity and increase of microviscosity of STABS. These results suggested that these different alkyl chains showed different effects on the micellization of STABS and the salinity's effect was even bigger.     

Alkaline‐Earth Metal Doped K‐V Catalysts for Diesel Soot Combustion–Preparation,Characterization and Catalytic Properties

The K‐V‐alkaline‐earth metal catalysts supported on α‐alumina ceramic substrate have been prepared. The morphology of the soot particulates deposited on prepared catalysts supported on α‐alumina ceramic substrate was described by scanning electron microscopy (SEM). The XRD was used to characterize the catalysts and their catalytic activities were evaluated by soot oxidation reaction using the TPR system. The SEM photographs presented that soot particles have a particle size of about 100 nm in diameter forming a loose contact with catalyst, which is resemble to the real situation for the catalyst application. The XRD and TPR study showed that the catalytic activities of the catalysts were improved through the cooperation of KNO₃ and some alkaline earth metal compounds. The soot onset ignition temperature at 310°C is the lowest by the cooperation of the crystalline phases KNO₃, KCaVO₄, and Ca₃(VO₄)₂ for the K‐V‐Ca catalyst with a molar ratio of 6:1:1. In addition, the catalyst containing higher KNO₃ content has an adsorption for CO₂. The all prepared K‐V‐Ba catalysts can adsorb more CO₂ at room temperature.     

辐射热波实验观察

 以强激光加热腔靶形成的强X光辐射烧蚀Al薄膜介质，在国内首次用软X光能谱时间高分辨诊断技术观察到了辐射热波，测得了质量烧蚀率。实验还观察到了X光辐射驱动的冲击波信号，得到了相应的冲击波压力。     

Two New C—glucoside Flavonoids from Leaves of Crataegus pinnatifida Bge. var. major N.E.Br.

Two new C-glucoside flavonoids,namely 8-C-β-D-（2″-O-acetyl) glucofuranosyl apigenin and 3″-O-acetylvitexin, were isolated from beaves of Crataegus pinnatifida Bge. var. major N.E.Br.Their structures were elucidated by the spectroscopic means and chemical evidence.     

Properties of polyethylene glycol (23) lauryl ether with cetyltrimethylammonium bromide in mixed aqueous solutions studied by self-diffusion coefficient NMR

NMR self-diffusion coefficient measurements have been used to study the properties of polyethylene glycol (23) lauryl ether (Brij-35) with cetyltrimethylammonium bromide (CTAB) in the mixed aqueous solutions with different mole fractions of CTAB. By fitting the self-diffusion coefficients to the two-state exchange model, the critical micelle concentrations of the two solutes in the mixed solutions (cmc*1 and cmc*2) were obtained. The critical mixed micelle concentrations (cmc*) were then evaluated by the sum of cmc*1 and cmc*2, which are in good agreement with the results measured by the surface tension method. The cmc* values are lower than those of the ideal case of mixing, which indicates that the behavior of the CTAB/Brij-35 system is nonideal. Moderate interactions between CTAB and Brij-35 in their mixtures can be deduced from the interaction parameters (betaM) based on the cmc* obtained by the NMR self-diffusion method. The compositions (x1) of the mixed micelles at different total surfactant concentrations were also evaluated. By using these results, a possible mechanism of mixed micellar formation and a picture of the formation of nonsimultaneous CTAB/Brij-35 binary mixed micelle were proposed. In contrast to the case of CTAB/TX-100 system, Brij-35 molecules have a tendency to form micelles first at any mole fraction of CTAB. The mixed micellar self-diffusion coefficients (Dm) increase slightly at lower CTAB molar ratios, and then speed up with increasing CTAB mole fraction.     

The size-dependent thermoelectric response of tungsten-constantan thermocouple in the sub-micro scale

We present the behavior of the thermoelectric response in a nanoscale tungsten-constantan (Cu 58%, Ni 42%) thermocouple (TC). The TC is tip-section typed and fabricated by the stepping method. The thermal electromotive force (emf) showed nearly linear behavior versus temperature over the range from 0 to 100^∘C. For the thermocouples with contact radius below 300 nm, the Seebeck coefficient decreased with the size of thermocouples turning smaller. According to the theory based on the free-electron model, the size-dependence thermal electric response may be ascribed to the change of electronic property in nanoscale.     

补偿法测光电流

用电流补偿法做成零内阻电流计测量光电流，用自检法对光进行相对定量控制，研究了硅光电池的充电转换特性。