分类给定的10篇文章，确定哪些是科学类文章，哪些不是。


1. “The Science of Sleep: Understanding Sleep Cycles and Importance”
2. “The Top 10 Restaurants in New York City”
3. “The Psychology of Happiness: Understanding the Science Behind Joy”
4. “10 Tips for Maintaining a Healthy Lifestyle”
5. “The Economics of Climate Change: Understanding the Costs of Environmental Policy”
6. “10 Best Books of 2021: Fiction and Non-Fiction Recommendations”
7. “The Effects of Social Media on Mental Health: An Overview”
8. “The Physics of Time Travel: Concepts and Controversies”
9. “10 Reasons Why Meditation is Good for You”
10. “The Impact of Artificial Intelligence on Society: Opportunities and Challenges”
科学类文章：1, 3, 5, 7, 8, 10

非科学文章：2, 4, 6, 9