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中美博弈再升级！美国突然撤销对中企出口芯片许可，中国反制动作迅速，再减持448亿美元外汇。         Students from Xi'an University of Technology test a virtual reality-enabled emergency evacuation simulation system tailored for flood disasters on January 12, 2024. Photos: Courtesy of Xi'an University of TechnologyEditor's Note:
Extreme weather is increasingly a global challenge, and the key to addressing climate risks lies in earlier prediction, more precise action and smarter preparedness, with emerging technologies playing a vital role. The Global Times launches the "Climate Gambit" series, exploring how research teams are leveraging cutting-edge technologies, including artificial intelligence, high-performance computing and smart observation systems, to anticipate weather changes, enhance disaster early-warning and strengthen resilience against climate risks.
Inside a state key laboratory at Xi'an University of Technology, Northwest China's Shaanxi Province, there is a miniature but complete "water world" which simulated water channels, inland lakes and main rivers to recreate real flood scenarios and test their newly developed GPU Accelerated Surface Water Flow and Transport Model (GAST).
Known as a "super brain" for flood control, GAST can complete flood simulations involving more than 3 million computational units within 30 seconds, helping transform flood management from a reaction to emergency into active precautions since "flooding impacts can be predicted even before rainfall arrives."
At a time when extreme rainfall and summer flooding have become increasingly frequent, questions such as when the flooding will arrive, which roads may be submerged and when residents should evacuate have become increasingly important.
In an exclusive interview with the Global Times, Hou Jingming, a professor at Xi'an University of Technology and the leader of the research team, explained how the GAST model seeks to answer these questions by accurately predicting flood development and identifying vulnerable areas before disasters occur, and how the model helps authorities take preventive measures to reduce casualties and economic losses.
AI empowering 'flood drill'  
The water tank system in the lab was designed to create a controllable, repeatable and observable environment to simulate complex hydrological processes, including river flooding, urban water level changes, lake regulation, drainage pump operations and coordinated flood-control measures.
By adjusting variations such as upstream water inflow, rainfall intensity, downstream water levels and drainage conditions, scientists can recreate different flood scenarios. Meanwhile, water levels, flow speeds and other data are collected in real time and displayed on a digital twin platform.
"If a rainstorm and corresponding floods are an exam, GAST is like a 'drill,'" Hou said. "It can simulate how floods develop, where water will flow, which areas may be inundated and when river levels may rise, ensuring authorities are well but not overly prepared."
To answer the public's concern about "whether my neighborhood will be flooded when heavy rain arrives," the team developed new algorithms for urban surface water flow, including improvements in terrain slope and friction calculations.
These breakthroughs have improved simulation accuracy in complex urban environments. Compared with extensive monitoring data, GAST can keep simulation errors of key hydrodynamic factors within 15 percent. This means the model can provide not only general flood trends, but also quantitative information such as water depth, flow speed and inundation areas.
Combined with AI technologies, it can identify complex relationships between rainfall, water conditions, flood depth, flow velocity and affected areas, cutting simulations from hours in traditional methods to minutes or even seconds.
The faster calculation capability means that once meteorological authorities update forecasts, the model can quickly estimate flood risks in different parts of a city. 
"The earlier rainfall warnings are issued, the earlier we can identify potential flooding hotspots and high-risk areas," Hou said. "This saves valuable time for evacuation, traffic management and emergency deployment."
For smarter disaster response

Building an accurate flood prediction model also requires integrating large amounts of urban data other than weather forecasts, including urban terrain, drainage networks and infrastructure information.
For example, a model developed for Xi'an incorporates geographic data and drainage system information collected from relevant authorities and field surveys. After receiving rainfall forecasts, the system can quickly calculate possible flooding scenarios, showing when and where waterlogging may occur and highlighting vulnerable roads and areas through visual maps.
To demonstrate how the super brain works in case of possible flooding, the laboratory has set a virtual reality area where visitors can experience a simulated urban flooding evacuation in the Xiaozhai area of Xi'an. Wearing VR headsets, participants can see water levels gradually rising and follow emergency instructions to move toward higher ground.
The entire technological package has already been applied in real-world flood prevention.
    A 3D live-scene display lab in Xi'an that oversees stormwater drainage performance in Hengshui, North China's Hebei Province Photos: Courtesy of Xi'an University of Technology
During Typhoon Muifa in 2022, Haishu district in Ningbo, East China's Zhejiang Province, recorded a regional rainfall of 367 millimeters. Using GAST as its core technology, the local flood forecasting platform integrated weather forecasts, AI algorithms and real-time monitoring data to provide rolling three-hour flood risk predictions.
Post-event assessments showed that predicted risks at most locations matched actual flooding conditions. The average relative error between predicted and observed maximum water depths was 13 percent.
The GAST model was also integrated into a smart rain and flood management platform in Qinhan new city area in Xianyang of Shaanxi, and during a rainstorm warning in July 2022, the platform provided continuous monitoring and forecasts. Based on the results, local authorities shifted from routine inspections to targeted monitoring of flood-prone areas and optimized emergency drainage operations.
The model is also being applied to mountain torrent prevention, as it can simulate rapidly changing flows in complex terrain and, combined with machine learning, complete forecasts within seconds. For reservoirs and rivers, it supports sudden and gradual dam-break simulations.
In June 2026, the model was presented at a national symposium on flood risk mapping achievements. The technology has since been applied by water resources, emergency management and urban development authorities, expanding from Shaanxi to multiple provinces and regions across China.
Looking ahead, the research team is developing a framework that further keeps up with the pace focusing on AI technologies. "Currently, the system operates based on weather forecast, therefore, AI will increase efficiency by using historical cases and real-time monitoring data to correct errors and update forecasts dynamically," Hou said.
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据观察者网报道，综合多家外媒消息，近日，拜登政府进一步收紧了对中国企业华为的出口限制，宣布撤销美国芯片企业高通和英特尔公司向华为出售半导体的许可证。美国国会众议院外交事务委员会主席麦考尔表示，这是阻止中国开发先进人工智能的关键之举。此举将阻止美国英特尔和高通出售给华为任何芯片，还称这两家公司和中国“走得过近”。另据美国商务部证实，目前已“撤销了对华为的部分出口许可”。相关消息人士表示，美国针对华为的新举措，将影响华为手机和笔记本电脑芯片供应。

二 |

美国切断美企与华合作，实际上是在倒逼中国企业进一步扩大自研力度，加大中国企业的自主性，美国此举看似是阻碍中国发展，其实是“自断后路”。

三 | 近年来，随着中国企业的高速发展，美国“一家独大”的垄断地位逐渐被打破。对此毫无办法的拜登政府，便开始以损失自身企业的办法，打压中美正常的技术合作以及贸易往来。殊不知，这样的限制措施其实是“伤敌八百自损一千”。

四 |

面对咄咄逼人的美国政府，中国也并未选择逆来顺受。就在美国出台最新限制措施后不久，中国的反制来了。根据金融时报报道，近日，国家外汇管理局发布了最新统计数据，截至2024年4月，中国的外汇储备规模为32008亿美元，较3月减少448亿美元。

五 | 此外，在持续坚持减少美国外汇的同时，数据显示，中国已经连续18个月增持黄金。

六 | 可以发现，美西方越是对中国的高科技领域进行打压和遏制，中国对美元的需求就越缩减。拜登政府不想让中国获得领先，那美国自己也不想有好日子过。

从美国一次又一次加码对中国企业的制裁措施，我们可以发现两点。首先，美国部分极端政客野心巨大，持续鼓动拜登对华施加高压。这次直接撤销美企出口许可，就是其鼓动挑拨的结果。其次，美国对华的制裁并不成功，或者说根本没有达到美国想要的效果。要不然美国也不会像“打补丁”一样，不断更新对华打压措施，增加对中企的限制。

中国是一个不惧挑战和苦难的国家，最不怕外国的打压和限制。美西方那个的“小院高墙”再坚固，也挡不住中国坚持走自主创新的道路。事实已经并将继续证明，美国卡不了中国的“脖子”。美国如今对华关上合作的大门，实际上是将市场腾出来，拱手让给中国企业。

而就中国这次迅速地反制动作而言，我们或许早就料到了美国会走这步棋，已经提前有了应对策略。从这一点就可以看出，中国不会让美国或者别国肆意侵犯自身利益。我国商务部也已经发出警告：中方将采取一切措施，维护中方合法正当权益。新的“风暴”已经来临，中美竞争存在升温的趋势，这再一次证明，和美国讲道理是讲不通的，中方的反制必须“一拳到肉”。