Knowledge Mapping of Opuntia Milpa Alta Since 1998: A Scientometric Analysis

Opuntia Milpa Alta is a cactus cultivated,domesticated,hybridized and selected from the plant Opuntia ficusindica by Mexican agricultural experts,which can be used as fruit and vegetable.Opuntia Milpa Alta leaves and fruit are superior to wild varieties and suitable for storage and transportation.In 1998,Opuntia Milpa Alta was introduced to China from Mexico by the Quality Product Development Center of the Ministry of Agriculture of China.Up to now,the Opuntia Milpa Alta has been cultivated on a certain scale in China.This study aims to identify the research progress and development trends of Opuntia Milpa Alta in China.Papers published between 1998 to 2019 from two major Chinese academic databases(CNKI and Wangfang)with a topic search related to Opuntia Milpa Alta were collected.The research progress and development trends were analyzed based on CiteSpace software of text mining and visualization.The analysis found that Opuntia Milpa Alta has gone through three obvious research phases after being introduced to China.In the first phase,the researchers paid attention to its cultivation method.Subsequently,researchers began to use extraction methods to extract some of its components,such as polysaccharides and flavonoids.Finally,these extracted ingredients began to be used in some biomedical research.

Ferroelectric polarization effect on the photocatalytic activity of Bi_(0.9)Ca_(0.1)FeO_(3)/CdS S-scheme nanocomposites

BiFeO_(3)(BFO),as a kind of narrow band-gap semiconductor material,has gradually emerged advantages in the application of photocatalysis.In this paper,Ca doped BFO nanoparticles Bi_(0.9)Ca_(0.1)FeO_(3)(BCFO)were prepared by sol-gel method.And BCFO and CdS nanocomposites with two morphologies were obtained by controlling the time of loading CdS under a low temperature liquid phase process.It is found that the band gap becomes narrower after doping Ca into BFO,which is conducive to the absorption of visible light.Among all the samples,the composite of CdS nanowires and BCFO nanoparticles obtained by reaction time of 10 min has the best photocatalytic performance.The degradation rate of Methyl Orange solutionwas 94%after 90min under visible light irradiation,whichwasmuch higher than that of pure BCFO and CdS.Furthermore,significant enhancement in the degradation rate(100%degradation in 60 min)can be achieved in poled samples after electric polarization process.The highest degradation rate is due to the promoted separation of photogenerated carriers induced by the internal polarization field and the formation of S-scheme heterostructure between BCFO and CdS.Such BCFO-CdS nanocomposites may bring new insights into designing highly efficient photocatalyst.