罗杰·查尔斯·路易斯·吉莱明

A racemic mixture, or racemate, is an equimolar mixture of enantiomers of a molecule that can be separated using their unique interaction with chiral molecules or media. Racemic mixtures are denoted by the (±)- prefix. This ‘optical rotation descriptor’ applies to the whole solution of a racemic mixture rather than a specific stereoisomer. Enantiomers typically have the same physical and chemical properties. Hence, they are not easily separable. However, enantiomers can exhibit...

Lithium dialkyl cuprate, also known as Gilman reagents, selectively reduces acid halides to ketones. The acid chloride is treated with Gilman reagent at −78 °C in the presence of ether solution to produce a ketone in good yield.
As shown below, the mechanism proceeds in two steps. First, one of the alkyl groups of the reagent acts as a nucleophile and attacks the acyl carbon of the acid chloride to form a tetrahedral intermediate. This is followed by the reformation of the...

When current flow is opposed in a DC or AC circuit, it is referred to as resistance or impedance, respectively. Impedance plays a key role in determining the performance of AC circuits. It is represented by Z, which is a combination of resistance and reactance, and depends upon the angular frequency, measured in ohms.
Thus, the magnitude of the impedance is given by the following equation,

Internal forces and the center of gravity are fundamental concepts in mechanics, playing a crucial role in understanding the behavior and stability of structures and objects under various conditions. A comprehensive understanding of these principles is essential for engineers, architects, and designers to create safe and efficient systems.
Internal forces are generated within a body due to the interaction between its particles. These forces can be categorized into tension, compression, and...

Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...

Impression management encompasses individuals' deliberate efforts to shape how others perceive them during social interactions. This behavior is often employed to conform to social norms, secure approval, or pursue specific goals. While it involves selective self-presentation, it is not necessarily deceptive; individuals frequently present authentic aspects of themselves that align with situational demands.Common strategies include:Ingratiation: where individuals use flattery or agreeableness...