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Topic Review
Soyuz TMA-03M
Soyuz TMA-03M was a spaceflight to the International Space Station (ISS). It launched on 21 December 2011 from Site One at the Baikonur Cosmodrome, Kazakhstan, carrying three members of Expedition 30 to the ISS. TMA-03M was the 112th flight of a Russian Soyuz spacecraft, since the first in 1967, and the third flight of the modernised Soyuz-TMA-M version. The docking with the International Space Station took place at 19:19 Moscow Time on 23 December, three minutes ahead of schedule. The crew were Oleg Kononenko (Russia , commander), André Kuipers (the Netherlands) and Donald Pettit (United States ). The Soyuz remained aboard the space station for the Expedition 30 increment to serve as an emergency escape vehicle if needed. The capsule used in the mission can be seen at the Space Expo visitors center at the European Space Research and Technology Centre in Noordwijk, Netherlands.
  • 505
  • 05 Dec 2022
Topic Review
Orion
Orion, one of the most recognizable constellations in the night sky, is steeped in mythology and astronomical significance. Named after the legendary hunter from Greek mythology, Orion is adorned with bright stars, including the famous Orion's Belt, and hosts a plethora of celestial wonders, such as the Orion Nebula, making it a favorite among stargazers.
  • 504
  • 15 Mar 2024
Topic Review
Loopholes in Bell Test Experiments
In Bell test experiments, there may be problems of experimental design or set-up that affect the validity of the experimental findings. These problems are often referred to as "loopholes". See the article on Bell's theorem for the theoretical background to these experimental efforts (see also John Stewart Bell). The purpose of the experiment is to test whether nature is best described using a local hidden variable theory or by the quantum entanglement theory of quantum mechanics. The "detection efficiency", or "fair sampling" problem is the most prevalent loophole in optical experiments. Another loophole that has more often been addressed is that of communication, i.e. locality. There is also the "disjoint measurement" loophole which entails multiple samples used to obtain correlations as compared to "joint measurement" where a single sample is used to obtain all correlations used in an inequality. To date, no test has simultaneously closed all loopholes. Ronald Hanson of the Delft University of Technology claims the first Bell experiment that closes both the detection and the communication loopholes. (This was not an optical experiment in the sense discussed below; the entangled degrees of freedom were electron spins rather than photon polarization.) Nevertheless, correlations of classical optical fields also violate Bell's inequality. In some experiments there may be additional defects that make "local realist" explanations of Bell test violations possible; these are briefly described below. Many modern experiments are directed at detecting quantum entanglement rather than ruling out local hidden variable theories, and these tasks are different since the former accepts quantum mechanics at the outset (no entanglement without quantum mechanics). This is regularly done using Bell's theorem, but in this situation the theorem is used as an entanglement witness, a dividing line between entangled quantum states and separable quantum states, and is as such not as sensitive to the problems described here. In October 2015, scientists from the Kavli Institute of Nanoscience reported that the Quantum nonlocality phenomenon is supported at the 96% confidence level based on a "loophole-free Bell test" study. These results were confirmed by two studies with statistical significance over 5 standard deviations which were published in December 2015. However, Alain Aspect writes that No experiment can be said to be totally loophole-free.
  • 505
  • 10 Oct 2022
Topic Review
On Ghost Imaging Studies for Information Optical Imaging
To understand, study, and optimize optical imaging systems from the information-theoretic viewpoint has been an important research subfield. However, the "direct point-to-point" image information acquisition mode of traditional optical imaging is lacking in "Coding-decoding" operation on the image information, and limits the development of further imaging capabilities. On the other hand, ghost imaging (GI) systems, combined with modern light-field modulation and digital photoelectric detection technologies, behave more in line with the modulation–demodulation information transmission mode compared to traditional optical imaging. This puts forward imperative demands and challenges for understanding and optimizing ghost imaging systems from the viewpoint of information theory, as well as bringing more development opportunities for the research field of information optical imaging. Here, several specific GI systems and studies with various extended imaging capabilities will be briefly reviewed. 
  • 503
  • 14 Nov 2022
Topic Review
Miles-Phillips Mechanism
In physical oceanography and fluid mechanics, the Miles-Phillips mechanism describes the generation of wind waves from a flat surface by the use of two distinct mechanisms. Both mechanisms are applied on the gravity-capillary waves and have in common that waves are generated by a resonance phenomenon. The Miles mechanism is based on the hypothesis that waves arise as an instability of the sea-atmosphere system. The Phillips mechanism assumes that turbulent eddies in the atmospheric boundary layer induce pressure fluctuations at the sea surface.
  • 505
  • 13 Oct 2022
Topic Review
Hinode
Hinode (/ˈhiːnoʊdeɪ/; Japanese: ひので, IPA: [çinode], Sunrise), formerly Solar-B, is a Japan Aerospace Exploration Agency Solar mission with United States and United Kingdom collaboration. It is the follow-up to the Yohkoh (Solar-A) mission and it was launched on the final flight of the M-V-7 rocket from Uchinoura Space Center, Japan on 22 September 2006 at 21:36 UTC (23 September, 06:36 JST). Initial orbit was perigee height 280 km, apogee height 686 km, inclination 98.3 degrees. Then the satellite maneuvered to the quasi-circular sun-synchronous orbit over the day/night terminator, which allows near-continuous observation of the Sun. On 28 October 2006, the probe's instruments captured their first images. The data from Hinode are being downloaded to the Norway , terrestrial Svalsat station, operated by Kongsberg a few kilometres west of Longyearbyen, Svalbard. From there, data was transmitted by Telenor through a fibre-optic network to mainland Norway at Harstad, and on to data users in North America, Europe and Japan.
  • 503
  • 15 Nov 2022
Topic Review
Traditional Chinese Timekeeping
The traditional Chinese time systems refers to the time standards for divisions of the day used in China until the introduction of the Shixian calendar in 1628 at the beginning of the Qing dynasty.
  • 502
  • 30 Oct 2022
Topic Review
Soyuz TMA-20
Soyuz TMA-20 was a human spaceflight to the International Space Station (ISS) and was part of the Soyuz programme. It lifted off from the Baikonur Cosmodrome in Kazakhstan on December 15, 2010, and docked with the ISS two days later. The three-person crew of Soyuz TMA-20 – Dmitri Kondratyev, Catherine Coleman and Paolo Nespoli – represented the ISS partner organizations of Roscosmos, NASA and the European Space Agency (ESA). Soyuz TMA-20's crew represented half of the members of Expedition 27; the other three members of the expedition arrived at the station on board Soyuz TMA-21 on April 6, 2011. The COSPAR ID of Soyuz TMA-20 was 2010-067A. It is ISS flight 25S. On May 24, 2011, after spending 159 days in space, the Soyuz TMA-20 descent module landed safely in Zhezkazgan, Kazakhstan, carrying Kondratyev, Coleman and Nespoli.
  • 502
  • 17 Nov 2022
Topic Review
PENG-Based Non-Invasive Medical Sensors
Piezoelectric nanogenerators (PENGs) not only are able to harvest mechanical energy from the ambient environment or body and convert mechanical signals into electricity but can also inform people about pathophysiological changes and communicate this information using electrical signals, thus acting as medical sensors to provide personalized medical solutions to patients.
  • 502
  • 19 Jan 2023
Topic Review
Two-Dimensional Nanostructures as Surface-Enhanced Raman Scattering Substrates
Two-dimensional nanostructures (2DNS) attract tremendous interest and have emerged as potential materials for a variety of applications, including biomolecule sensing, due to their high surface-to-volume ratio, tuneable optical and electronic properties. Advancements in the engineering of 2DNS and associated technologies have opened up new opportunities. Surface-enhanced Raman scattering (SERS) is a rapid, highly sensitive, non-destructive analytical technique with exceptional signal amplification potential. Several structurally and chemically engineered 2DNS with added advantages (e.g., π–π* interaction), over plasmonic SERS substrates, have been developed specifically towards biomolecule sensing in a complex matrix, such as biological fluids. 
  • 500
  • 11 Jan 2023
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