Man I really didn’t write this reply right. That should be “the turbine is just trying to mitigate the efficiency cost of going partial* vacuum”.
News on China's scientific and technological development.
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No - lets do some back of the envelop math. The average lightening bolt contains about a billion joules of energy, this roughly translates to 278kwh of electrical power - about enough to power a small house about 7 days(average American household usage of 800kwh a month). Or 7 houses for 1 day.
Theres no where near enough lightning strikes in a small concentrated area that you can reliability harvest lightening power year round to make this kind of energy harvest system economically feasible.
The reason of using permanent magnet may be due to the principle of how this application works, flux pinning. I don't know much detail, can't say if it is possible and cost efficiently to do as what you propose.
The HTS version is developed by SW university and CRRC. SW university is located in Chongqing, Sichuan. There is no Chengdu version.
The other EMS version is also by CRRC, its subsidiary Sifang Factory in Qingdao, Shandong.
I suggest that we only refer the two programs by EMS and HTS to avoid confusion. Sifang Factory is subsidiary of CRRC, while SW university's railroad department was subsidiary of CRRC and still acting as so today.
Actually, SW Jiaotong University is in Chengdu. The prototype was unveiled in Chengdu this year.
I think I believe China's maglev plans will play out as follows. After considering the power requirements, it makes sense for their low-medium speed maglevs (<=180km/h) to act as low cost subway alternatives and regional metropolitan links for satellite cities. Their EMS high speed maglevs are cost efficient up to a speed of around ~400-450km/h to link nearby cities just as high speed rail does now. Such maglevs are more practical for mountainous areas that require tighter turning radius with steep gradients. Finally, their HTS maglevs can link the main urban agglomerations and serve the same purpose as hub and spoke systems for airlines. With this implementation, it would comprehensively complete China's transportation network, except for the most isolated areas.
Thanks for the correction, I mixed SW University with SW Jiaotong University.
- Developers say the Zuchongzhi device can do in just over an hour a task that supercomputers would take years to achieve
- Results surpass those produced by Google’s Sycamore processor in an experiment two years ago, they say
Published: 11:00pm, 13 Jul, 2021Updated: 11:43pm, 13 Jul, 2021
Chinese physicist Pan Jianwei is part of a team pushing the limits of quantum computing. Photo: Weibo
Scientists in China have claimed another benchmark in computing, saying their takes just 72 minutes to do a task that would take the most powerful supercomputer at least eight years.
In a non-peer-reviewed paper released late last month, the team led by Pan Jianwei, a physicist from the University of Science and Technology of China in Hefei, said the Zuchongzhi quantum processor set a record to challenge “classical computing”.
“Our experiment unambiguously established a computational task that can be completed by a quantum computer in 1.2 hours but will take at least an unreasonable time for any supercomputers,” the team said in the paper published on pre-print service ArXiv.org.
The experiment was described by news service Phys.org as being about “100 times more challenging than one carried out” by
two years ago.
The Chinese scientists said they used random quantum circuit sampling as a metric to evaluate the power of their quantum processor.
“Our experimental results of random quantum circuit ... on Zuchongzhi quantum processor established a new record to challenge the classical computing capability,” they said in the paper.
“We also expect this large-scale, high-performance quantum processor could enable us to pursue valuable [noisy intermediate-scale quantum] applications beyond classical computers in the near future.”
The researchers also compared Zuchongzhi’s task with the one previously performed by Sycamore.
“The computational cost of the classical simulation of this task is estimated to be two to three orders of magnitude higher than the previous work on 53-qubit Sycamore processor,” they said, referring to the amount of time required to complete an operation.
In 2019, Google said in the journal Nature that Sycamore took about 200 seconds to sample one instance of a quantum circuit a million times, whereas the world’s fastest supercomputer would need about 10,000 years to produce similar output.
The Chinese superconducting quantum processor contains 66 qubits – the basic unit of quantum information – and is named after Zu Chongzhi, a fifth-century Chinese mathematician and astronomer.
Using rudimentary counting sticks, Zu pinned down pi to seven decimal places, an accuracy that was unsurpassed globally for more than 800 years.
More than 50 scientists are involved with the quantum project and some are affiliated with institutes including the Chinese Academy of Sciences and quantum information technology developer QuantumCTek.
Earlier this year, a group of researchers from the University of Science and Technology of China designed and made the computer prototype of Zuchongzhi with 62 functional qubits, the largest number in the world, state broadcaster CGTN reported.
In a report in the journal Science in May, the team, also led by Pan, said the work was “a milestone in the field, bringing future larger-scale quantum applications closer to realisation for noisy intermediate-scale quantum processors”.
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- Researchers used aerodynamic model that contributed to China’s latest space missions
- Official timeline aims by 2035 to operate a fleet of hypersonic aircraft that can transport 10 passengers to anywhere on Earth within an hour
in Beijing
Published: 4:00am, 14 Jul, 2021
Updated: 4:26am, 14 Jul, 2021
The design of the plane included some features with similarities to a Concorde. Photo: Beijing Institute of Technology
China is developing a hypersonic aircraft larger than a Boeing 737, according to a study by scientists involved in the nation’s
and missions.
At 45 metres (148 feet), the plane would be nearly a third longer than a 737-700, with two air-breathing engines mounted on top of its main body. The design has a pair of delta wings similar to those of the Concorde, but with tips pointing up.
Such a complex design can bring multiple aerodynamic challenges when the aircraft goes hypersonic, or faster than five times the speed of sound.
The researchers used a new aerodynamic model that has been proven effective in China’s latest space missions to evaluate the plane’s performance at high altitudes.
They found areas on the plane that required extra protection or strengthening, because these spots would be most likely to suffer sudden spikes of heat and pressure when the plane reaches Mach 6 (six times the speed of sound – 7,344km/h or 4,447mph).
Their findings would find “applications in similar engineering projects”, said Liu Rui, of the Beijing Institute of Technology, and collaborators from the Institute of Spacecraft System Engineering in a paper published in the journal Physics of Gases last week.
Liu is a key scientist in China’s Mars landing and lunar rock sample missions, according to state media. Both missions required spacecraft to travel in the atmosphere at hypervelocity – which China had lacked first-hand data about for the red planet, having never been there.
The moon mission, too, was challenging, because the samples were returned at a speed faster than any Chinese spacecraft had reached previously.
Liu used his models to help Chinese space authorities improve their spacecraft’s aerodynamic design and flight path planning, according to Science and Technology Daily. The success of the two space missions – the first time any country had completed either mission at the first attempt – showed the method worked.
Hypersonic aircraft are prominent in China’s hi-tech plans and it has continued to pour money and resources into the sector.
A Boeing-737 size hypersonic plane under development in China. Photo: Beijing Institute of Technology
By 2025, it aims to complete its experiments to verify all the key components of hypersonic flight, including a new generation of air-breathing engine that can push an aircraft to rocket speed, according to an official timeline revealed last month.
Ten years after that, China aims to be operating a fleet of hypersonic aircraft that can transport 10 passengers to anywhere on Earth within an hour. And by 2045, these planes will carry more than 100 passengers per flight, according to the plans.
Hypersonic planes draw oxygen from the air, so can operate at 100th of the cost of rockets. They will enable China to deliver more than 10,000 tonnes of cargo and more than 10,000 passengers per year to space stations in near-Earth orbit or on the moon, according to the plans.
For now, the planes are being used only by the military. Despite its huge size, there is little room for passengers, with its enormous engine and air inlets taking up most of the space in its body.
Travelling in the current version of the plane would not be the smoothest of flights, with strong turbulence causing extreme heat and vibration.
China has deployed at least one type of hypersonic weapon, according to openly available information. At the National Day parade in 2019, the military revealed a fleet of DF-17 missiles for the first time.
Although Western countries had a head start in hypersonic weapon development, China and Russia have taken the lead in recent years. China is running the world’s most powerful hypersonic wind tunnel and is building another that is much bigger still. Planes or missiles travelling at hypersonic speed cannot be stopped by any existing air defence system.
In 2019, the US military said China was conducting more hypersonic flights in a year than it had in a decade.
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