Phys.org September 23, 2021 Starches, a storage form of carbohydrates, are a major source of calories in the human diet and a primary feedstock for bioindustry. Researchers in China designed an artificial route consisting of 11 core reactions to convert CO2 into starch with an efficiency 8.5-fold higher than starch biosynthesis in maize. They integrated chemical and biological catalytic modules to utilize high-density energy and high-concentration CO2. If the overall cost of the process can be reduced to a level economically comparable with agricultural planting in the future, it is expected to save more than 90% of cultivated land and […]
Tag Archives: S&T China
Stretching the capacity of flexible energy storage (w/video)
Nanowerk September 8, 2021 In spite of the excellent electrical and electrochemical properties, two-dimensional transition metal carbide (MXene) is often limited by the high stiffness for the direct implementation in next-generation stretchable and wearable energy storage devices. After screening for the thickness, researchers in China identified the crumpled MXene film of ∼3 μm in thickness as the optimal choice to mitigate the crack formations under large and repetitive mechanical strains. The as-prepared symmetric supercapacitor demonstrated a high specific capacitance of ∼470 mF cm–2, ultrahigh stretchability up to 800% area strain, and >90% retention of the initial capacitance after 1000 stretch–relaxation […]
China wants to build a spaceship that’s kilometers long
Phys.org September 1, 2021 Among the many proposals the country’s leaders are considering for its latest five-year plan, one involved creating an ultra-large spacecraft spanning kilometers. According to the project outline the spacecraft elements will be built on Earth and then launched individually to orbit to be assembled in space. They specify that this spacecraft will be a major strategic aerospace equipment for the future use of space resources, exploration of the mysteries of the universe and staying in long-term. There is a great deal of skepticism about this proposal. It would take an enormous number of launches to deploy […]
Exploring quantum correlations of classical light source for image transmission
Phys.org August 31, 2021 Researchers in China formulated a density matrix to fully describe two-photon state within a thermal light source in the photon orbital angular momentum (OAM) Hilbert space. They proved the separability, i.e., zero entanglement of the thermal two-photon state. Still, they revealed the hidden quantum correlations in terms of geometric measures of discord. By mimicking the original protocol of quantum teleportation, they demonstrated that the non-zero quantum discord can be utilized to transmit a high-dimensional OAM state at the single-photon level. It was found that the information of all parameters that characterize the original state can still […]
A new platform for integrated photonics
Phys.org August 25, 2021 The quality of photonic integrated circuits are limited due to the high density of crystal defects near growth interface. Researchers in China have fabricated an ultralow loss 4H-SiCOI platform with a record-high-Q factor of 7.1 × 106. The platform was prepared by wafer-bonding than thinning techniques, enabled the same crystalline quality as bulk high-pure 4H-SiC crystal. The high Q resonators were used to demonstrate various nonlinear processes including generation of multiple harmonics up to the fourth order. Broadband frequency conversions, including second-, third-, fourth- harmonic generation have been observed. Using a dispersion-engineered SiC microresonator, Kerr frequency […]
Precipitation in Central Asia shaped by sea surface temperature over tropical Pacific and North Atlantic
Phys.org August 26, 2021 Central Asia is one of the major food-producing regions in the world. Its agricultural production relies heavily on climate conditions, especially precipitation. Researchers in China found that both the decadal scale warming over the tropical Pacific and North Atlantic are favorable for wetter conditions over Central Asia. During the positive phase of tropical Pacific decadal variability (TPDV) (warm tropical Pacific), the sea surface temperature (SST) anomalies over tropical Pacific can lead to more precipitation over Central Asia, especially the southern and southeastern region. The warm phase of AMV (warm North Atlantic) can excite a circumglobal teleconnection […]
Scientists Discover How to Make Glass So Hard, It Can Even Scratch Diamond
Science Alert August 13, 2021 An international team of researchers (China, Sweden, USA – Harvard university, Germany, Russia) has discovered the critical proportion of crystallized and amorphous carbon needed to create a glass with remarkable properties that won’t weaken under intense pressure. By subjecting spheres of carbon atoms to intense pressure and baking at temperatures between 1,000 and 1,200 degrees Celsius they obtained glassy materials dubbed AM – I, II and III. After tests they mapped the way the atoms bonded with one another, showing they all operated as a semiconductor on a level comparable with amorphous silicon. After Vickers […]
Scientists realize noiseless photon-echo protocol
Phys.org August 16, 2021 The intense spontaneous noise emission generated by photon echo is a fundamental tool for the manipulation of electromagnetic fields. However, it has the same frequency as the signal, and it is impossible to separate them in principle. Researchers in China have implemented a noiseless photon echo (NLPE) protocol in Eu3+:Y2SiO5 crystal to serve as an optical quantum memory and applied a four-level atomic system to suppress the noise. They manipulated the spontaneous noise emission to have a different frequency from the signal making it easier to separate the signal from the noise emission. Though other noises […]
Non-line-of-sight imaging with picosecond temporal resolution
Phys.org August 12, 2021 Non-line-of-sight (NLOS) imaging enables monitoring around corners and is promising for diverse applications. The resolution of transient NLOS imaging is limited to a centimeter scale, mainly by the temporal resolution of the detectors. Researchers in China have constructed an up-conversion single-photon detector with a high temporal resolution of ∼1.4 ps and a low noise count rate of 5 counts per second (cps). The detector operates at room temperature, near-infrared wavelength. They demonstrated high-resolution and low-noise NLOS imaging. The system can provide a 180 μm axial resolution and a 2 mm lateral resolution, which is more than […]
China to release updated climate plans ‘in near future’: envoy
Phys.org August 3, 2021 Climate negotiators from 196 countries and the European Union as well as businesses, experts and world leaders will gather in Glasgow in November for the 2021 United Nations Climate Change Conference (COP26) summit. Under the Paris Agreement, countries are meant to have submitted updated 2030 climate targets ahead of COP26, but nearly half have yet to do so. China said they will soon release their updated plans. The United Nations is pushing for a global coalition committed to net zero carbon emissions by 2050 which will cover all countries. Many scientists now say 1.5 degrees must […]