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Using various amounts of TiO 2 , the 0.65CaTiO 3 –0.35Sm 0.9 Nd 0.1 AlO 3 ceramics were prepared via the conventional solid-state reaction method. The relationships between the crystalline structure and microstructure, as well as the microwave dielectric properties, were investigated. The sintered ceramics formed a solid solution, and short-range ordering at B-site ions was detected by Raman spectroscopy. A slight amount of Al-rich secondary phase was observed along the grain boundary, which increased with the TiO 2 content. The additional TiO 2 promoted the densification of ceramics and positively affected the dielectric constant, ɛ r and the temperature coefficient of resonant frequency, τ f . Nevertheless, the excess Al-rich secondary phase destroyed the short-range ordering of the B-site ions and deteriorated the Q × f value. Considering all three parameters of the microwave dielectric properties, the 0.25 wt% TiO 2 -modified 0.65CaTiO 3 –0.35Sm 0.9 Nd 0.1 AlO 3 ceramic exhibited the best performance of ɛ r = 40.43, Q × f = 51531 GHz and τ f = −3.7 ppm/°C sintered at 1445 °C for 3 h.

0.65CaTiO3–0.35Sm0.9Nd0.1AlO3 (CTSA) ceramic nanopowders were synthesized via sol–gel method using the ethylene diamine tetraacetic acid as a chelating agent. Thermal analysis, Fourier transform infrared spectroscopy and X-ray diffraction were used to character the decomposition of precursor and phase transformation process of derived oxide powders. Single phase and well-crystallized 0.65CaTiO3–0.35Sm0.9Nd0.1AlO3 powders with particle size of 30–40 nm were obtained by calcination at 800 °C. Dense ceramic was successfully obtained from the ultrafine powders sintered at 1,325 °C, almost 100 °C lower than 1,415 °C required for conventional powders. Compared with those prepared by conventional solid-state method, the CTSA ceramics derived from sol to gel process sintered at a lower temperature showed better microwave dielectric properties of er ~ 39, Q × f over 50,000 GHz and small τf ~ −7.1 ppm/K.

The xCaTiO3–(1 − x)Sm0.9Nd0.1AlO3 (0.25 ≤ x ≤ 0.85) microwave dielectric ceramics were prepared by conventional solid state reaction method. The phase structures were characterized by X-ray diffraction, scanning electron microscope and Raman spectra. Solid solutions with the orthorhombic perovskite structure with octahedral tilting were formed from the x range of 0.25 to 0.85. Microwave dielectric properties of xCaTiO3–(1 − x)Sm0.9Nd0.1AlO3 ceramics were investigated systematically. The optimum property of the ceramics was obtained for x = 0.65 sintered at 1,415 °C for 3 h: relative permittivity er = 39.70, Q × f = 50,012 GHz, τ f = −6.8 ppm/°C. xCaTiO3–(1 − x)Sm0.9Nd0.1AlO3 ceramics provide a new promising material for application in the microwave technology with relative permittivity lying within the range from 39 to 44, high quality factor and near-zero τ f .

A three-component reaction of aryl bromides, potassium cyanate, and secondary amines takes place at 110 °C in MeCN under the catalysis of Cu2O and 2-(2,6-dimethylphenylamino)-2-oxoacetic acid potassium salt, giving N,N-disubstituted-N′-arylureas in good to excellent yields. A number of functionalized aryl bromides and secondary amines were compatible with these conditions, and thereby providing a facile method for diverse synthesis of trisubstituted ureas.

“Wonton” is one of the traditional Chinese food, especially popular in the south-east region such as the city Wuxi. There are numerous Wonton retailers around Wuxi, making it hard to analyze such abundant retailers. Consequently, I decide to highlight a specific area in Wuxi city, Binhu District, one of Wuxi’s biggest districts and then initiate research and paper. The purpose of this research is to investigate the extent to which the Wonton (dumpling soup) in Wuxi fulfills the characteristics of monopolistic competition. Individual retailers do not have significant market power, having a slight ability to fluctuating prices. The price is particularly of great significance in the Wonton market. Since there are no large-sized firms dominating the market, ample small retailers compete with each other. While some characteristics of monopolistic competition are present—different types of shops with various prices such as chain retailers and individual retailers—most of Wonton retailers in Binhu District have very similar prices. Secondary data have been polled through the internet, mostly from the official website for the local shop information section. To make sure the availability and accuracy of data, I went to each random-selected Wonton retailers’ stores and interviewed two owners and some consumers in the shops. To achieve a further understanding of consumers’ behaviors, 75 people were asked to complete two questionnaires (APPENDIX I II). After analyzing the information from the sample surveys, it provided me with insights into how consumer decisions influence the market.

Coupling of aryl halides with potassium cyanate takes place at 100–110 °C in alcohols under the catalysis of CuI (cuprous iodide) and 2-(2,6-dimethylphenylamino)-2-oxoacetic acid, affording the corresponding aryl carbamates with great diversity.

An efficient catalytic system of CuI/8-hydroxyquinalidine was developed for the coupling of aryl iodides and indole as well as some azoles. The reaction could be carried out at 90 degrees C under the condition of relatively low catalyst loading, affording various N-arylindoles and N-aryl azoles in good yields. The functionalized and hindered aryl iodides were suitable substrates for this transformation.

A Zinc coating was electroplated in choline chloride-ethylene glycol system at high current density in atmosphere. The crystal structure, surface and cross-section morphologies, chemical elements of electroplated zinc coating were analyzed by x-ray diffraction and scanning electron microscopy with line analysis, respectively. The bending and corrosion performances were also discussed in this study. The results indicate that the zinc coating presents a highly (110) texture with small flake zinc grains stacked on the surface. The zinc coating exhibits well bonding with the copper substrate though no obvious diffusion layer was observed. The corrosion performance of zinc coating displays a combine system of the electrode process and diffusion process without passivation process.

Tungsten (W) coatings were pulse reverse electroplated on low activation steel from Na2WO4-WO3 system in air atmosphere. The introduction of pulse reverse current could result in higher current efficiency and better surface quality of tungsten coatings than those obtained by pulse current plating from molten salt, while the preferential orientation changed from (200) plane to (211) plane. In addition, the ion composition of the Na2WO4-WO3 molten salt kept stable during the process of pulse reverse electrodeposition and a thick W coating could be pulse reverse electroplated from this system with long duration. The tungsten coating with columnar structure and good compactness exhibited a high thermal conductivity of 150.30 W m−1 K−1.

By depositing Mg vapor generated via carbothermal reduction on boron powder in the presence of different additives, dumbbell-like MgO nanofibers, NaCl particle-decorated MgO nanofibers and camphor tree stalk-like MgO fibers were produced. SEM, TEM and EDS analysis showed that the additives of Si and NaCl deposited in the sites of stacking faults in fiber, which resulted in the growth of different morphologies of decorated fibers.

The title reaction involves the copper-catalyzed coupling of aryl bromides and potassium cyanate to generate isocyanate intermediates which are trapped by secondary amines in a one-pot manner to yield unsymmetrical ureas.

It is found that CuI/DMPAO efficiently promotes the N-arylation of acyclic secondary amines.

DMPAO has been found to be a powerful ligand to enable copper-catalyzed coupling of aryl halides with aliphatic acyclic secondary amines take place under relatively mild conditions, and coupling of aryl halides with primary amines and cyclic secondary amines proceeds at low catalyst loading.