Materials Physics and Chemistry

Synthesis of Novel Chalcone Derivatives by Organic Catalysis

Junlong Li, Ruocan Zhuang, Yinan Qian — Sat, 13 Jan 2024 00:00:00 +0000

Chalcone compounds have a wide range of biological activities. In this paper, nine kinds of novel chalcone compounds were synthesized by using transacrylone derivatives and anthrone as raw materials. The eï¬€ects of diï¬€erent catalysts and solvents on the yield of the products were investigated. The optimal catalyst was DABCO. The optimum solvent was dichloromethane with the highest yield of 71.6%. On this basis, the eï¬€ect of the co-catalyst on the yield was investigated. The yield was increased to 89.9%.

Mathematical Modeling of Hydraulic Resistance in Pipes With Rough Walls

Lobanov Lgor Evgenjevich — Wed, 31 Jan 2024 00:00:00 +0000

In recent years, the numbers of patents have been devoted to the development of rough pipes. The technique theoretical settlement determine of factor of hydraulic resistance for round pipes with rough walls is developed on the basis of a principle of a superposition of complete viscosity in turbulent a layer mainly distinguished from the existing theories. The received results of account for the extended range of determining parameters much distinguished from appropriate given for round pipes with turbulizers, specify a level Ð¸ intensification of heat exchange.

Research on Health Effects of Environmental Chemicals Based on Structure and Gene Association Analysis

Yinbing Zhang — Thu, 31 Oct 2024 00:00:00 +0000

China is a major producer and consumer of chemicals. The production and use of chemicals play a role in the development of the entire national economy. Therefore, effective chemical management has a huge impact on the development of the national economy. At present, chemical management guidelines have achieved a lot in chemical operations, but there are still many shortcomings. Relevant institutions should further improve the standard system, strengthen the coordination of subjective institutions, the supervision and management, establish information standards, complete information sharing, build a feedback system, strengthen the transformation of experimental results and trust training.

Classification, preparation process and its equipment and applications of piezoelectric ceramic

Quanlu Zhao, Juntao Zhao, Xiangfeng Tan — Thu, 11 Jan 2024 00:00:00 +0000

The so-called piezoelectric ceramic is a piezoelectric polycrystal, a functional ceramic material capable of inter-converting mechanical energy and electric energy. It belongs to inorganic nonmetallic materials. So far, the most widely used piezoelectric ceramic materials have both good piezoelectricity and ferroelectricity through the substitution and doping in a wide range to adjust its properties to meet the diï¬€erent needs of zirconium titanium lead (PZT) and its composite materials. Piezoelectric ceramic is also one of the prevailing piezoelectric materials, accounting for about 1/3 of the entire functional ceramic materials. It is mainly used for transducers, sensors, resonators and drives.

Multiple phases of nanocrystalline materials: Preparation with phase purity by a facile method and characterization

C. K. Mahadevan — Wed, 07 Aug 2024 00:00:00 +0000

There are many solid materials existing as different structural and other phases (polymorphs), when prepared with different conditions; they exhibit different physicochemical properties. It is important to consider the preparation of all these crystalline phases (along with amorphous phase), at nanoscale, in their pure form by using facile and cost-effective methods. Our study with nickel sulphide is considered here to illustrate this. Nickel sulphide exhibits three prominent phases which are: α-NiS, β-NiS and NiS_1.03. These crystalline (and amorphous NiS_1.03) nanophases along with doped α-NiS nanocrystals (doped with Cd²⁺, Fe²⁺ and O²⁻) have been successfully prepared in high purity using a facile solvothermal route (with the use of commercially availabe microwave oven); and they were charcterized physicochemically (chemically, structurally, optically, magnetically and electrically) using available standard methods. Obtained results indicate that the facile method adopted for the preparation is found to be an effective and cost-effective one. The role of XRD and TG/DTA measurements is found to be important in this preparation. A brief review is made in this direction.