China recently announced that it was putting new controls on the export of rare earth elements, sparking a new round in the country’s ongoing trade war with the US.

Donald Trump responded by threatening to ramp up tariffs on Chinese goods by a further 100%. This will all be under discussion when China’s president Xi Jinping and Trump meet on October 30 at the Asia Pacific Economic Conference in South Korea.

China has built an effective monopoly over rare earth metals, the 17 metallic elements that are not actually rare but are very difficult to mine and process. Most electric vehicles (EVs), smartphones or solar panels depend on these rare earths.

China mines 70% and refines 92% of these increasingly important metals, and manufactures 98% of the world’s rare earth magnets used in EVs, electronics, medical devices and other clean tech. In recent years, these essential minerals have become a crucial part of China’s economic agenda as it tries to focus on “high quality development” in advanced and green technology

The recent announcement from Beijing has raised concerns about global access to these essential minerals. If the supply of rare earths available to the outside world diminishes, the cost of manufacturing green tech would rise and drive up prices worldwide. If there is anything that would stall the development of the green economy, this could be it.

In response to the announcement, Trump initially suggested he might cancel an upcoming meeting with Chinese president Xi. However, the meeting now looks set to go ahead, and access to rare earths is likely to be high on the agenda.

Trump had also announced that he was considering a ban on exports to China of all products made with US software such as laptops and jet engines, and industrial equipment. This might reduce Beijing’s ability to design essential components for AI chips, hampering its bid for dominance in clean tech.

Prior to Trump’s latest threats, electric vehicles coming from China had already been hit by a 100% US tariff, while import duties for solar cells and lithium batteries stood at 50% and 25% respectively.

But the result might have surprised Trump. As US-made goods are exempt from tariffs from paying tariffs, Chinese firms have set up production sites in the US to circumvent Trump’s tariffs. Instead of helping domestic US companies, Trump’s policies have done the opposite.

For instance, the solar manufacturing capacity of Chinese firms based in the US has grown so large that it now accounts for 39% of all solar panel energy output in the country versus only 24% from US firms.

But even if Chinese clean tech sales in US were severely affected by the tariffs, most of China’s green tech is heading elsewhere.

Based on my estimations using data from the energy thinktank Ember, Chinese green tech exports globally in 2024 were valued at US$184.06 billion (£139 billion), while total exports to the US stood at US$20.66 billion. The US market accounted for only 11.2% of the total proportion of total Chinese green tech exports, while that number from January to September 2025 has dipped to 7.8%.

Compared to the EU (29.95%) and Asian market (27.97%) in 2024, the US market appears relatively small. So higher tariffs would harm China’s economy, but the damage may not be as substantial as Trump might imagine. However, the EU’s plans to meet climate targets is massively dependent on these Chinese exports.

Problems for Beijing?

The US has already put restrictions on which technologies China can buy from the US. China can still manufacture electric vehicles, solar panels and wind turbines without US software. But without the most advanced technologies from the US, Chinese firms will have fewer options.

While there are indications that the tech gap between Washington and Beijing may be shrinking, the US still possesses some of the most advanced technologies that are crucial for green tech development. These include advanced semiconductors, which are needed to make AI chips.

Such components and machinery are essential to China’s claim to green leadership since they allow users to automate EVs, solar panels and wind turbines, while ensuring their efficiency and optimizing energy use. Simply put, without the best semiconductors and the AI chips, China won’t be able to create world-leading clean tech.

China may have metals but without US chips and software, its green economic momentum might stall—at least until China’s semiconductor and AI tech catches up with the US. Chinese economic progress and its green leadership may be dependent on gaining better trade deals, even if it does still have a massive advantage.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

In railroad tracks, rail ties hold the rails in place and ensure that their separation does not change. Modern concrete ties warp and crack through repeated use, leading to safety concerns including derailment if not regularly maintained.

Research from The Grainger College of Engineering at the University of Illinois Urbana-Champaign shows that damage to concrete ties can be mitigated using shape memory alloys (SMAs), metals with the ability to return to their original shape after they are deformed.

In a study led by civil and environmental engineering professor Bassem Andrawes, ties warped by simulated rail traffic were shown to return to their original state with the help of SMAs activated by induction heating. The paper, “Experimental Testing of Concrete Crossties Prestressed with Shape Memory Alloys,” is published in the Journal of Transportation Engineering, Part A: Systems.

“We’re doing something that I think is unprecedented in rail transportation engineering,” Andrawes said. “We’re working with a commercial supplier of concrete rail ties to implement and test our designs. For our publication, we went beyond laboratory experiments and demonstrated compliance with rail industry standards. We’re very excited to continue our industrial partnership and develop a practical, working design.”

Degradation in concrete is traditionally prevented through the process of prestressing, in which pre-tensioned steel rods are inserted to exert forces which counteract the effects of heavy loads. While this technique is applied in rail ties, the difficulty is that different parts of the tie experience different stresses. In addition, the ties shift as the ballast—the gravel bed distributing weight and providing drainage—settles in response to traffic.

Andrawes believes that SMAs are an ideal solution because they can be inserted into ties then independently controlled with self-contained heat sources. The reinforcement they provide could quickly adapt to the specific circumstances the tie is experiencing at different locations in its structure.

“SMAs are examples of what we call ‘smart materials,'” Andrawes said. “You can deform them, twist them into wild new shapes, but they retain the memory of their original state in the molecular structure. When you apply heat, they know to return to that state. So, if you just have a heat source, then the SMA can guide a concrete structure back to the desired shape stored in the alloy’s memory.”

Working with Illinois Grainger Engineering civil and environmental engineering graduate student Ernesto Pérez-Claros, Andrawes decided to use induction heating, in which the heat to restore the SMAs to their original shape is provided by a time-varying electromagnetic field. This was done to ensure that the electrical hardware would not need to be inserted inside the tie.

The research proceeded in three phases. First, the researchers worked with Rocla Concrete Tie, Inc., to cast their design in commercially available concrete rail ties. Second, the researchers conducted laboratory experiments to quantify the impacts of different lengths of SMAs in the ties. Finally, ties were subjected to stress tests simulating rail traffic, and the prototypes exceeded the standards of the American Railway Engineering and Maintenance-of-Way Association (AREMA).

“It was important to us that we actually make something that goes out of the lab and into practice,” Andrawes said. “Showing that our design meets and even exceeds AREMA specifications means that it’s not just academic research. This is something that railroads can use, and we intend to guide it to the point where it can be adopted.”

The researchers plan to continue working with Rocla to commercialize the technology. They also plan to submit their prototypes for full testing with real rail traffic at the Federal Railroad Administration Transportation Technology Center in Pueblo, Colorado.

Microsoft on Wednesday reported its quarterly sales grew 18% to $77.7 billion, beating Wall Street expectations while also surprising some investors with the huge amounts of money it is spending to expand its cloud computing infrastructure and meet demand for artificial intelligence tools.

The software maker said it spent nearly $35 billion in the July-September quarter on capital expenditures to support AI and cloud demand, nearly half of that on computer chips and much of the rest related to data center real estate.

That overshadowed Microsoft’s report of a 22% increase in quarterly profit to $30.8 billion, or $4.13 per share, which easily beat Wall Street expectations for the period. Microsoft said those results excluded the impacts of money it invested in OpenAI, in an attempt to “help clarify” how those losses affected Microsoft’s core business.

Microsoft was expected to earn $3.67 per share on revenue of $75.38 billion, according to analysts surveyed by FactSet Research.

The results came a day after a new deal with OpenAI pushed Microsoft to $4 trillion in valuation for the second time this year. But shares in Microsoft then dropped in the hours before it disclosed its earnings Wednesday as the company battled an outage affecting its Azure cloud computing platform. They dropped further—by more than 3%—in after-hours trading Wednesday as investors considered the significance of the earnings report.

Driving investor enthusiasm on Tuesday was the announcement of Microsoft’s revised business deal with its longtime partner OpenAI, maker of ChatGPT and now the world’s most valuable startup. While no longer OpenAI’s exclusive cloud provider, a relationship that helped bankroll the startup’s early growth, Microsoft will retain commercial rights to OpenAI products through 2032 and get a roughly 27% stake in OpenAI’s new for-profit arm.

Microsoft also said Wednesday that it has already invested $11.6 billion of the total $13 billion it has committed to OpenAI.

Microsoft’s valuation previously passed $4 trillion in July, making it the second company after Nvidia to reach the milestone. Microsoft again and Apple for the first time crossed $4 trillion this week, while Nvidia went on to achieve a different milestone: the first $5 trillion company.

The sky-high valuations highlight the investor frenzy around artificial intelligence, which some fear could turn into a bust if AI products aren’t as transformative or profitable as promised.

Quarterly revenue from Microsoft’s cloud-focused business segment was $30.9 billion, up 28% from the same time last year and just slightly above what analysts were expecting. Revenue from Microsoft’s workplace software, which includes its email and word processing tools, was up 17% to $33 billion.

Microsoft’s recent focus has centered around pitching its flagship AI assistant Copilot to help with a variety of work tasks, and last week gave it a new animated avatar exterior called Mico.

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