相关论文: Realization of ppm level pressure stability for pr…
Single pressure refractive index gas thermometry (SPRIGT) is a novel primary thermometry, jointly developed by TIPC of CAS in China and LNE-Cnam in France. To realize a competitive uncertainty of 0.25 mK for thermodynamic temperature…
On May 20th 2019, the World Metrology Day, the Bureau International des Poids et Mesures announced a major revision to the four more SI units. The base unit, the kelvin, is defined by fixing the value of Boltzmann constant as indicated in…
We demonstrate levitation and three-dimensionally stable trapping of a wide variety of particles in a vacuum chamber through the use of the thermophoretic force in the presence of a strong temperature gradient. Typical sizes of the trapped…
Thermal transpiration effects are commonly encountered in low pressure measurements with capacitance diaphragm gauges. They arise from the temperature difference between the measurement volume and the temperature stabilised manometer.…
The primary challenge in the field of high-temperature superconductivity in hydrides is to achieve a superconducting state at ambient pressure rather than the extreme pressures that have been required in experiments so far. Here, we propose…
The thermodynamic stability of the hard-sphere gas has been examined, using the formalism of scaled particle theory [SPT], and by applying explicitly the conditions of stability required by both the second and third laws of thermodynamics.…
By employing first-principles metadynamics simulations, we explore the 300 K structures of solid hydrogen over the pressure range 150-300 GPa. At 200 GPa, we find the ambient-pressure disordered hexagonal close-packed (hcp) phase transited…
We report the design and performance of a cryogen-free, pulse-tube refrigerator (PTR)-based scanning probe microscopy (SPM) system capable of operating at the base temperature of near 5K. We achieve this by combining a home-made interface…
In this work, we propose indirect evaluation methods to check the accuracy and the uncertainty of ab initio calculated virial coefficients. To this end, we have used single-pressure refractive-index gas thermometry (SPRIGT) to estimate the…
A class of iridium hydrides, IrH_x (x=0.5, 1-4, 6), is calculated at ab-initio level using the DFT. A number of hydrides are predicted to stabilize in the excess hydrogen environment and upon compression. The threshold pressure for…
We introduce a spectroscopic approach to primary gas thermometry, harnessing precise optical cavity resonance frequencies and ab initio molecular line intensity calculations. By utilizing CO (3-0) vibrational band lines and cavity mode…
We have produced and observed metastable solid helium-4 below its melting pressure between 1.1 K and 1.4 K. This is achieved by an intense pressure wave carefully focused inside a crystal of known orientation. An accurate density map of the…
The phase diagram of oxygen is investigated for pressures from 50 to 130~GPa and temperatures up 1200 K using first principles theory. A metallic molecular structure with the $P6_3/mmc$ symmetry ($\eta^{'}$ phase) is determined to be…
We report on compact, gaseous 3He NMR probes for precision magnetometry of magnetic fields B > 0.1 T in the temperature range from ambient temperatures down to 4 Kelvin. The gas is polarized at thermal equilibrium under pressures up to 100…
We present a first-principles study of the energy and elastic properties of solid helium at pressures below the range in which is energetically stable. We find that the limit of mechanical stability in hcp 4He is $P_{s}$ = -33.82 bar, which…
We report the controlled injection of near-isolated micron-sized liquid droplets into a low temperature He-Ne steady-state rf plasma at atmospheric pressure. The H2O droplet stream is constrained within a 2 mm diameter quartz tube. Imaging…
A concentration-saturated helium mixture at the melting pressure consists of two liquid phases and one or two solid phases. The equilibrium system is univariant, whose properties depend uniquely on temperature. Four coexisting phases can…
Legged locomotion has received increasing attention from the robotics community. In this respect, contact stability plays a critical role in ensuring that robots maintain balance, and it is a key element for balancing and walking…
The design, manufacture and characterisation of an inexpensive, temperature controlled vacuum chamber with millikelvin stability for electrical transport measurements at and near room temperature is reported. A commercially available…
Calibration is one area in measurement where our country is still in the process of improvement. The absence of confirmed approaches and actions for identifying the features of calibration baths by numerous laboratories disallowed them to…