News on China's scientific and technological development.
- Thread starter Quickie
- Start date
Quickie
Colonel
We'll see how long it takes to get this stuff into commercial usage:
2023-10-31 09:01:53Global Times Editor : Li Yan
“Whether in real life or in the world of nature and animals there is a lot of 'invisibility', and this is not magic, is a scientific means,” Chu Junhao, infrared physicist and the academician of the Chinese Academy of Sciences, said at a scientific event on Saturday evening. (Photo/Sina Weibo)
"Whether in real life or in the world of nature and animals there is a lot of 'invisibility', and this is not magic, is a scientific means,"Chu Junhao, infrared physicist and the academician of the Chinese Academy of Sciences, said at a scientific event on Saturday evening.
In fact, today's technological developments have opened the door to the possibility that Harry Potter's invisible cloak could go from magic to reality. Chu demonstrated the "invisibility" at the event, and he made his legs disappear directly with the help of a magical material called "lenticular grating" that allows light to be refracted regularly. The magical scene elicited gasps from the audience at the scene.
This is a special kind of material, made up of rows of tiny cylindrical convex lenses arranged into a cylindrical convex lens, each cylindrical convex lens will compress the object behind the object into a thin strip, and enough lenses break the object into an infinite number of identical thin strips, giving people a kind of illusion of invisibility.
"In addition, refractive index can also be used to 'invisibility', for example, objects with high borosilicate glass materials can also be 'invisible' when moving in glycerol with a refractive index close to its own," Chu noted.
This is actually one of the principles of realizing the "invisible cloak", when the fabric of a garment and the air refractive index are the same, people can be freely "invisible" after wearing it, said the expert.
Chu further said that the current exploration of the forefront of "invisibility" cannot only avoid the naked eye, but also avoid infrared monitoring.
With the increasing diversification of modern detection means, for a single spectrum, such as visible light, infrared light, or for a single type of detector, such as radar, laser detection has long been unable to meet people's needs for "invisibility".
"The real 'perfect invisibility' requires that the above detection means can be avoided, and its essence is the low detectability of any electromagnetic wave,"Chu added.
The advent of "metamaterials" provides a new solution for the perfect invisibility of any electromagnetic wave. It is a man-made composite material that changes the conventional properties of light and electromagnetic waves by designing and reorganizing the fine structure of the material.
"In the future, with the gradual maturity of technology and 'metamaterials', the 'invisibility 'fantasy in science fiction works will gradually come to reality." Chu said that it is believed that there will be more "invisibility" equipment to change our lives in the future, such as invisible rooms with better privacy and invisible hearing aids.
"When I read Harry Potter as a child, I never thought that one day someone would be able to appear in front of me wearing such a cloak of invisibility, and now I look at the day may not be too far away,"one netizen said on Chinese social media platform Sina Weibo. If this technology does become widespread, won't it mean the cost of crime will fall? The law should also be improved to prevent similar situations from happening, said another.
Does the invisibility only go one way from one side? The cloak would be more useful that way rather than the invisibility going both ways.
Xiaomi is really taking this smart home and HyperOS stuff up a notch.
It's unveiling special smart study light
Smart air conditioner with natural wind
If you want to know all the stuff it sells, it can found here in its 11/11 sales channel goals
and of course, the phone sales are off the hook good
It's unveiling special smart study light
Smart air conditioner with natural wind
If you want to know all the stuff it sells, it can found here in its 11/11 sales channel goals
floor sweeper, water heater, rice cooker, printer, smart sound box, washing machine, mopping machine, drying machine, projector, air purifier, smart lock, TV, wearables
and of course, the phone sales are off the hook good
Yiyi is one of several deaf children who scientists in China say are the first people ever to have their natural hearing pathway restored in a dramatic new demonstration of the possibilities of gene therapy. The feat is even more remarkable because until now, no drug of any kind has ever been able to improve hearing.
Why would anyone opt for a Xiaomi over a Huawei?
have you used Xiaomi 14 and Mate 60? If you have not, then how can you make that statement?
btw, have spoken to apparently someone who owns all these devices. Apparently, Xiaomi 14 has gotten a lot better over 13, but Huawei is still smoother experience. I guess maybe some independent comparisons will come out.
In terms of price, Xiaomi 14 is 3999 start off and Mate 60 (non-pro) is 5999. Kind of hard to argue M60 is a better deal
Xiaomi has always been value for money and Huawei has always been the best you can get for money. In other words, Xiaomi is cheaper but still really good. Having used both and am right now typing this on a Xiaomi and wearing a Huawei watch, both are great. Depends on what your looking for. One size does not fit all.
The Huawei Mate 60 is like 50% more expensive than the Xiaomi 14. It is not the same phone category that is for sure.
Specs wise they are close in performance. The Huawei Mate 60 has slightly better display (larger and with more colors) and higher quality sound, while the Xiaomi 14 has more recent specs for some of the I/O like it supports UFS 4.0 and Bluetooth 3.2.
Specs wise they are close in performance. The Huawei Mate 60 has slightly better display (larger and with more colors) and higher quality sound, while the Xiaomi 14 has more recent specs for some of the I/O like it supports UFS 4.0 and Bluetooth 3.2.
Last edited:
CAS built a free piston thermoacoustic stirling engine prototype that passed the 100kW output milestone for the first time in the world. When heated by molten salt to 530 dgree Celsius, the prototype engine's power output reached 102kW.
Advantages of free piston thermoacoustic stirling engines include: system of less components, less moving parts thus quieter and less vibration, high thermal efficiency, able to fit with different kinds of heat sources.
But due to thermodynamic challenges and difficulties in machining certain parts, power output of free piston thermoacoustic stirling engines used to be low and had very limited practical uses.
News story:
记者2日从中国科学院理化技术研究所获悉，该所成功研制国际首套百千瓦级自由活塞热声斯特林发电样机。专家组现场测试结果显示，在热源温度为530摄氏度时，发电样机实测最大发电功率达102千瓦。
自由活塞热声斯特林发电技术是一种新型热发电技术。基于该技术研制的发电机，主要由自由活塞热声发动机和直线电机两部分组成。发动机主要组成部件为加热器、热声换能器（传统称回热器）、冷却器等，直线电机主要组成部分为动力活塞、永磁体、线圈等。
外部热源通过加热器向发动机输入热量，提高加热器的温度；外部冷源则从冷却器带走热量，使之维持在较低的温度。“当加热器和冷却器之间的温差达到一定值、热声换能器内部形成一定的温度梯度时，发动机内部的气体就会产生自激声振荡，也就是气体往复运动，将热能转化为声波形式的机械能。”中国科学院理化所研究员罗二仓说，发动机产生的声波又会推动直线电机的动力活塞往复运动，带动永磁体改变线圈中的磁通量，感应出交流电，从而完成机械能到电能的转化。
不同于汽轮机、燃气轮机和内燃机等传统的热机动力系统，该类型发电机中的热声斯特林发动机没有压缩机、膨胀机等机械运动部件。“它主要是利用声波压力的交替升高和降低实现气体的压缩和膨胀，同时通过气体的往复运动与处于不同位置的高、低温换热器壁面进行换热，完成能量转化。”中国科学院理化所研究员胡剑英告诉记者。
罗二仓表示，自由活塞热声斯特林发电机优点突出。“一是系统简单，机械运动部件少，可靠性高；二是理论振动小、噪声低；三是理论效率高；四是热源适应性好，可以利用太阳能、余热、生物质能等各种不同形式的热源。”罗二仓说。
然而，由于自由活塞热声斯特林发电技术存在复杂的热动力学问题，且涉及多项高难度加工及制备技术，单机最大功率一直难以获得进一步的突破。同时，较小的单机功率也极大地制约了该技术的推广应用。
在中国科学院先导项目支持下，理化所研究团队创建了先进的热声分析和设计理论，阐明了热声转换、声场调节、声电匹配等机理问题，突破了高功率交变换热、高精度气体间隙密封、气浮支撑多项关键技术，研制成功了国际首套百千瓦级自由活塞热声斯特林发电系统。
胡剑英表示，自由活塞热声斯特林发电机功率的突破极大地拓展了其应用领域，使之成为太阳能热发电、生物质发电以及分布式能源领域具有广泛应用前景的新一代能源动力转换技术。
News release:
Advantages of free piston thermoacoustic stirling engines include: system of less components, less moving parts thus quieter and less vibration, high thermal efficiency, able to fit with different kinds of heat sources.
But due to thermodynamic challenges and difficulties in machining certain parts, power output of free piston thermoacoustic stirling engines used to be low and had very limited practical uses.
News story:
百千瓦级自由活塞热声斯特林发电样机研制成功
记者2日从中国科学院理化技术研究所获悉，该所成功研制国际首套百千瓦级自由活塞热声斯特林发电样机。专家组现场测试结果显示，在热源温度为530摄氏度时，发电样机实测最大发电功率达102千瓦。
自由活塞热声斯特林发电技术是一种新型热发电技术。基于该技术研制的发电机，主要由自由活塞热声发动机和直线电机两部分组成。发动机主要组成部件为加热器、热声换能器（传统称回热器）、冷却器等，直线电机主要组成部分为动力活塞、永磁体、线圈等。
外部热源通过加热器向发动机输入热量，提高加热器的温度；外部冷源则从冷却器带走热量，使之维持在较低的温度。“当加热器和冷却器之间的温差达到一定值、热声换能器内部形成一定的温度梯度时，发动机内部的气体就会产生自激声振荡，也就是气体往复运动，将热能转化为声波形式的机械能。”中国科学院理化所研究员罗二仓说，发动机产生的声波又会推动直线电机的动力活塞往复运动，带动永磁体改变线圈中的磁通量，感应出交流电，从而完成机械能到电能的转化。
不同于汽轮机、燃气轮机和内燃机等传统的热机动力系统，该类型发电机中的热声斯特林发动机没有压缩机、膨胀机等机械运动部件。“它主要是利用声波压力的交替升高和降低实现气体的压缩和膨胀，同时通过气体的往复运动与处于不同位置的高、低温换热器壁面进行换热，完成能量转化。”中国科学院理化所研究员胡剑英告诉记者。
罗二仓表示，自由活塞热声斯特林发电机优点突出。“一是系统简单，机械运动部件少，可靠性高；二是理论振动小、噪声低；三是理论效率高；四是热源适应性好，可以利用太阳能、余热、生物质能等各种不同形式的热源。”罗二仓说。
然而，由于自由活塞热声斯特林发电技术存在复杂的热动力学问题，且涉及多项高难度加工及制备技术，单机最大功率一直难以获得进一步的突破。同时，较小的单机功率也极大地制约了该技术的推广应用。
在中国科学院先导项目支持下，理化所研究团队创建了先进的热声分析和设计理论，阐明了热声转换、声场调节、声电匹配等机理问题，突破了高功率交变换热、高精度气体间隙密封、气浮支撑多项关键技术，研制成功了国际首套百千瓦级自由活塞热声斯特林发电系统。
胡剑英表示，自由活塞热声斯特林发电机功率的突破极大地拓展了其应用领域，使之成为太阳能热发电、生物质发电以及分布式能源领域具有广泛应用前景的新一代能源动力转换技术。
News release:
Last edited: