Heterogeneous catalysisHeterogeneous catalysis is catalysis where the phase of catalysts differs from that of the reactants or products. The process contrasts with homogeneous catalysis where the reactants, products and catalyst exist in the same phase. Phase distinguishes between not only solid, liquid, and gas components, but also immiscible mixtures (e.g. oil and water), or anywhere an interface is present. Heterogeneous catalysis typically involves solid phase catalysts and gas phase reactants.
Northern ExpeditionThe Northern Expedition was a military campaign launched by the National Revolutionary Army (NRA) of the Kuomintang (KMT), also known as the "Chinese Nationalist Party", against the Beiyang government and other regional warlords in 1926. The purpose of the campaign was to reunify China, which had become fragmented in the aftermath of the Revolution of 1911. The expedition was led by Generalissimo Chiang Kai-shek, and was divided into two phases.
Beijing dialectThe Beijing dialect (), also known as Pekingese and Beijingese, is the prestige dialect of Mandarin spoken in the urban area of Beijing, China. It is the phonological basis of Standard Chinese, the official language in the People's Republic of China and one of the official languages of Singapore and the Republic of China (Taiwan). Despite the similarity to Standard Chinese, it is characterized by some "iconic" differences, including the addition of a final rhotic -r / 儿 to some words (e.g. 哪儿).
Bicarbonate buffer systemThe bicarbonate buffer system is an acid-base homeostatic mechanism involving the balance of carbonic acid (H2CO3), bicarbonate ion (HCO), and carbon dioxide (CO2) in order to maintain pH in the blood and duodenum, among other tissues, to support proper metabolic function. Catalyzed by carbonic anhydrase, carbon dioxide (CO2) reacts with water (H2O) to form carbonic acid (H2CO3), which in turn rapidly dissociates to form a bicarbonate ion (HCO ) and a hydrogen ion (H+) as shown in the following reaction: As with any buffer system, the pH is balanced by the presence of both a weak acid (for example, H2CO3) and its conjugate base (for example, HCO) so that any excess acid or base introduced to the system is neutralized.
