After bikes and umbrellas are made sharable across China, some companies started eyeing the fitness market, so shared gym rooms have hit the streets in Beijing.

Unlike common gyms that provide large, open spaces for many members to share at the same time, the newly built shared gym rooms are small, stand-alone rooms for a person to use, often set up near living communities.

Every four-square-meter room is equipped with a treadmill (跑步机), an air cleaner, a mirror, a television and an air conditioner, and users can let down the curtains for privacy. When exercising, users can listen to music, watch movies and check emails by connecting to the Internet by the screen fixed on the treadmill. There’s no shower or washbasin.

Similar to using a shared bike, users can locate a shared gym room by smartphone application, book a room in advance and then need to scan a QR code for use. A refundable deposit (保证金) of 99 yuan is required, and users are charged 1 yuan every 5 minutes.

The shared gym rooms are created by Misspao, a Beijing-based technology company founded in July. Within several months since it was founded, the company has already raised over 100 million yuan, Yicai Global reports. The idea of the shared fitness experience is not entirely nascent. Last December, the Shanghai-based technology company VRUN set up shared treadmills in office and apartment buildings.

The sharing economy is still becoming popular in China. According to Yicai Global, confident investors are pouring millions into sharing start-ups. In March, the State Information Center published a report which predicts that the total value of China’s sharing economy will see a yearly growth of 40% in the coming years, and it is expected to make a great contribution to the country’s GDP.

In the modern age, social media platforms have emerged as powerful tools for communication, networking, and self-expression. With billions of active users worldwide, these platforms have profoundly influenced the human interaction. Recent psychological studies have delved into understanding the influence of prolonged (长期的) social media usage on individual self-esteem (自尊) and identity formation.

Social media platforms, including Weibo, WeChat Moments, Douyin, and Little Red Book, offer ways for individuals to project curated versions of their lives. While this can serve as a medium of affirmation, it also compares one’s daily life against the specially edited highlights of others, which could potentially lead to feelings of failure and unsatisfactory.

A study conducted among adolescents aged 13-19 showed that extreme social media use correlates with lower self-esteem scores. Participants who spent over five hours daily on these platforms demonstrated significant tendencies towards self-devaluation (自我贬低) and negative self-perception (自体感受). The study believed that the constant exposure of idealized images and lives leads to an involuntary (不自主的) comparison, often placing the individual on the lesser end of the spectrum.

For adolescents, a critical time of identity formation happens during the teenage years. Social media can often blur the lines (模糊界限) between personal identity and digital persona (面貌，形象). A study tracked teenagers for five years and found that heavy social media users often experienced identity confusion. Their digital avatars, formed under societal pressures, sometimes overshadowed their real personalities, leading to internal conflicts and a confusion to real selfhood.

While the negative influence of social media on mental well-being are evident, it’s also essential to highlight its potential benefits. Platforms can help to add a sense of belonging, provide informational support, and serve as outlets for creative expression. Future research could explore potential interventions (介入，干涉) to reduce the negative effects.

In conclusion, while social media offers a huge number of opportunities and ways for expression, it’s important that teenagers approach it with awareness. The psychological landscape it shapes is hard to understand, and understanding its depths requires continued research, empathy (共鸣), and active measures.

The time a person spends on different smartphone apps is enough to identify them from a larger group in more than one in three cases, say researchers.

Researchers analyzed smartphone data from 780 people. They fed 4,680 days of app usage data into statistical models. Each of these days was paired with one of the 780 users so that the models learned people’s daily app use patterns.

The researchers then tested whether models could identify an individual when provided with only a single day of smartphone activity that was anonymous (匿名的). The models, which were trained on only six days of app usage data per person, could identify the correct person from a day of anonymous data one third of the time.

That might not sound like much, but when the models predict who the data belonged to, it could also provide a list of the most to the least likely candidates. It was possible to view the top 10 most likely individuals that a specific day of data belonged to. Around 75% of the time, the correct user would be among the top 10 most likely individuals.

In practical terms, a law enforcement (执法机构) investigation seeking to identify a criminal’s new phone with these models could reduce a candidate pool of approximately 1,000 phones to 10 phones, with a 25% risk of missing them.

Consequently, the researchers warn that software given access to a smartphone’s standard activity logging could make a reasonable prediction about a user’s identity even when they were logged-out of their account. An identification is possible without monitoring conversations or behaviors within apps themselves.

Therefore, it is important to acknowledge that app usage data alone, which is often collected by a smartphone automatically, can potentially reveal a person’s identity. While providing new opportunities for law enforcement, it also poses risks to privacy if this type of data is misused.