亨通光电与联通网研院签署量子通信战略合作协议

百度 　　电子密度是衡量电离层的重要物理量，其决定于两个相反的过程：一个是中性大气吸收太阳辐射而电离的过程；另一个是正负带电粒子碰撞而复合成中性粒子的过程。

People play Go game, known as Weiqi in Chinese, at a temporary shelter in Tumd Left Banner of Hohhot, north China's Inner Mongolia Autonomous Region, Aug. 1, 2025. Recent torrential rains have caused flooding in Tumd Left Banner, resulting in the evacuation of 17,000 residents. Local authorities have set up 22 temporary shelters and provided daily necessities such as beds, food, drinking water, and medicines to flood-affected people. (Xinhua/Bei He)

People play Xiangqi, a traditional Chinese board game also known as the Chinese chess, at a temporary shelter in Tumd Left Banner of Hohhot, north China's Inner Mongolia Autonomous Region, Aug. 1, 2025. Recent torrential rains have caused flooding in Tumd Left Banner, resulting in the evacuation of 17,000 residents. Local authorities have set up 22 temporary shelters and provided daily necessities such as beds, food, drinking water, and medicines to flood-affected people. (Xinhua/Bei He)

A staff member (1st R) helps a resident at a temporary shelter in Tumd Left Banner of Hohhot, north China's Inner Mongolia Autonomous Region, Aug. 1, 2025. Recent torrential rains have caused flooding in Tumd Left Banner, resulting in the evacuation of 17,000 residents. Local authorities have set up 22 temporary shelters and provided daily necessities such as beds, food, drinking water, and medicines to flood-affected people. (Xinhua/Bei He)

Medical workers (L) offer free consultation services at a temporary shelter in Tumd Left Banner of Hohhot, north China's Inner Mongolia Autonomous Region, Aug. 1, 2025. Recent torrential rains have caused flooding in Tumd Left Banner, resulting in the evacuation of 17,000 residents. Local authorities have set up 22 temporary shelters and provided daily necessities such as beds, food, drinking water, and medicines to flood-affected people. (Xinhua/Bei He)

Workers fill sandbags outside a village in Tumd Left Banner of Hohhot, north China's Inner Mongolia Autonomous Region, Aug. 1, 2025. Recent torrential rains have caused flooding in Tumd Left Banner, resulting in the evacuation of 17,000 residents. Local authorities have set up 22 temporary shelters and provided daily necessities such as beds, food, drinking water, and medicines to flood-affected people. (Xinhua/Bei He)

A water pump drains flood water outside a village in Tumd Left Banner of Hohhot, north China's Inner Mongolia Autonomous Region, Aug. 1, 2025. Recent torrential rains have caused flooding in Tumd Left Banner, resulting in the evacuation of 17,000 residents. Local authorities have set up 22 temporary shelters and provided daily necessities such as beds, food, drinking water, and medicines to flood-affected people. (Xinhua/Bei He)