1. High-quality competition: Core journals usually only accept high-quality, innovative and academic papers. Therefore, papers submitted to core journals need to have high academic level and research value, which leads to fierce competition.
2. Strict review process: The review process of core journals is usually very strict, and reviewers will carefully review the papers to ensure the quality of the papers. This process may be long, sometimes even delayed for years.
3. Language and cultural differences: For research papers from non-English-speaking countries, there may be language and cultural differences. This may lead to problems in grammar, vocabulary and structure of the paper, thus affecting the readability and acceptability of the paper.
4. Format requirements: Core journals usually have strict format requirements, including font, font size, line spacing and margins. Papers that do not meet the requirements may be rejected directly.
5. Limited number of publications: The limited number of core journals means that only a few papers can be published in these journals every year. This leads to more intense competition and more difficulty in publishing papers.
6. Time and resources investment: Publishing a core paper requires a lot of time and resources investment, including conducting experiments, collecting data, writing papers, and revising and perfecting them. This is a challenge for many researchers.
7. Academic reputation and career development: In academic circles, papers published in core journals are regarded as the embodiment of academic achievements and career development. Therefore, scholars may be under great pressure when publishing their papers to ensure their successful publication.
In a word, the main reasons why it is difficult to publish core papers are high quality, strict review process, language and cultural differences, format requirements, limited number of publications and the challenge of time and resources investment. It takes a lot of effort and time to successfully publish a core paper.