A space hurricane over the Earth's polar ionosphere.

In Earth's low atmosphere, hurricanes are destructive due to their great size, strong spiral winds with shears, and intense rain/precipitation. However, disturbances resembling hurricanes have not been detected in Earth's upper atmosphere. Here, we report a long-lasting space hurricane in the polar ionosphere and magnetosphere during low solar and otherwise low geomagnetic activity.

The intensification of metallic layered phenomena above thunderstorms through the modulation of atmospheric tides.

We present a multi-instrument experiment to study the effects of tropospheric thunderstorms on the mesopause region and the lower ionosphere. Sodium (Na) lidar and ionospheric observations by two digital ionospheric sounders are used to study the variation in the neutral metal atoms and metallic ions above thunderstorms. An enhanced ionospheric sporadic E layer with a downward tidal phase is observed followed by a subsequent intensification of neutral Na number density with an increase of 600 cm in the mesosphere.

The Trends in Global Gene Expression in Mouse Embryonic Stem Cells During Spaceflight.

The environment in space differs greatly from the environment on the ground. Spaceflight causes a number of physiological changes in astronauts, such as bone loss and immune system dysregulation. These effects threaten astronauts' space missions, and understanding the underlying cellular and molecular mechanisms is important to manage the risks of space missions.

Buildup of a highly twisted magnetic flux rope during a solar eruption.

The magnetic flux rope is among the most fundamental magnetic configurations in plasma. Although its presence after solar eruptions has been verified by spacecraft measurements near Earth, its formation on the Sun remains elusive, yet is critical to understanding a broad spectrum of phenomena. Here we study the dynamic formation of a magnetic flux rope during a classic two-ribbon flare.

Turn on the super-elastic collision nature of coronal mass ejections through low approaching speed.

It has been proved from the observations and numerical simulations that the collision between solar coronal mass ejections (CMEs), the largest plasmoids in the heliosphere, could be super-elastic. This finding suggests that the CMEs' magnetic energy and thermal energy could be converted into kinetic energy through a more efficient way. However CME collisions are not always super-elastic, which means that this distinct property of plasmoids is probably excited conditionally.

Wave-driven butterfly distribution of Van Allen belt relativistic electrons.

Van Allen radiation belts consist of relativistic electrons trapped by Earth's magnetic field. Trapped electrons often drift azimuthally around Earth and display a butterfly pitch angle distribution of a minimum at 90° further out than geostationary orbit. This is usually attributed to drift shell splitting resulting from day-night asymmetry in Earth's magnetic field.

Ensemble downscaling in coupled solar wind-magnetosphere modeling for space weather forecasting.

Unlabelled: Advanced forecasting of space weather requires simulation of the whole Sun-to-Earth system, which necessitates driving magnetospheric models with the outputs from solar wind models. This presents a fundamental difficulty, as the magnetosphere is sensitive to both large-scale solar wind structures, which can be captured by solar wind models, and small-scale solar wind "noise," which is far below typical solar wind model resolution and results primarily from stochastic processes. Following similar approaches in terrestrial climate modeling, we propose statistical "downscaling" of solar wind model results prior to their use as input to a magnetospheric model.

Complementary compressive imaging for the telescopic system.

Conventional single-pixel cameras recover images only from the data recorded in one arm of the digital micromirror device, with the light reflected to the other direction not to be collected. Actually, the sampling in these two reflection orientations is correlated with each other, in view of which we propose a sampling concept of complementary compressive imaging, for the first time to our knowledge. We use this method in a telescopic system and acquire images of a target at about 2.

Generation of proton aurora by magnetosonic waves.

Earth's proton aurora occurs over a broad MLT region and is produced by the precipitation of low-energy (2-10 keV) plasmasheet protons. Proton precipitation can alter chemical compositions of the atmosphere, linking solar activity with global climate variability. Previous studies proposed that electromagnetic ion cyclotron waves can resonate with protons, producing proton scattering precipitation.

High-speed secure key distribution over an optical network based on computational correlation imaging.

We present a protocol for an optical key distribution network based on computational correlation imaging, which can simultaneously realize privacy amplification and multiparty distribution. With current technology, the key distribution rate could reach hundreds of Mbit/s with suitable choice of parameters. The setup is simple and inexpensive, and may be employed in real networks where high-speed long-distance secure communication is required.

True random number generator based on discretized encoding of the time interval between photons.

We propose an approach to generate true random number sequences based on the discretized encoding of the time interval between photons. The method is simple and efficient, and can produce a highly random sequence several times longer than that of other methods based on threshold or parity selection, without the need for hashing. A proof-of-principle experiment has been performed, showing that the system could be easily integrated and applied to quantum cryptography and other fields.

Thermal light optical coherence tomography for transmissive objects.

We report an experimental demonstration of optical coherence tomography for transmissive objects utilizing second-order correlation ghost imaging with thermal light. To evaluate the longitudinal resolution of our system, the concept of the imaging longitudinal coherence length is introduced, which is more accurate for judging the image quality of ghost imaging with unequal optical paths than the conventional point-to-point longitudinal coherence length. Our work should help clarify our understanding of the longitudinal coherence of thermal light, as well as provide a scheme for performing optical coherence tomography on objects that are not highly reflective.

[Spectral calibration of the atmosphere ultraviolet imaging spectrograph using a PtNe lamp].

The atmospheric ultraviolet imaging spectrograph (AUVIS) is an ultraviolet imaging spectrograph that uses a two-dimensional charge-coupled device detector to collect both the spectrum and the swath perpendicular to the flight direction. The design of the system components, the principle, and the main specifications of the AUVIS are introduced. The calibration theory was studied.

Energetic electrons associated with magnetic reconnection in the magnetic cloud boundary layer.

Here is reported in situ observation of energetic electrons (∼100-500 keV) associated with magnetic reconnection in the solar wind by the ACE and Wind spacecraft. The properties of this magnetic cloud driving reconnection and the associated energetic electron acceleration problem are discussed. Further analyses indicate that the electric field acceleration and Fermi-type mechanism are two fundamental elements in the electron acceleration processes and the trapping effect of the specific magnetic field configuration maintains the acceleration status that increases the totally gained energy.

Fusion of color microscopic images based on bidimensional empirical mode decomposition.

A novel image fusion algorithm based on bidimensional empirical mode decomposition (BEMD) applied to multi-focus color microscopic images is proposed in this paper. The fusion scheme is implemented in YIQ color model, aiming at achieving a balanced result between local feature enhancement and global tonality rendition. In the proposed algorithm, image decomposition is performed on luminance component by BEMD which can perform fully two-dimensional decomposition adaptively without using a priori basis.

[Spectral response measurement of FUV image intensifier].

It is possible to obtain some space weather parameters such as the electron flux and mean energy of the precipitating electrons from the far ultraviolet (FUV) radiance of the aurora observed in a nadir viewing geometry, and the FUV image intensifier is one of the key equipment that used for observation the FUV radiance of the aurora in a nadir viewing geometry. The capability of this equipment will affect the whole purpose of the detection. And the responsibility to the wavelength is the most important parameter of image intensifier.

[The study of aluminium diffuser calibration in the UV].

A bi-directional reflectance distribution function (BRDF) measurement setup in the ultraviolet spectral range was established. The BRDF of the aluminium diffusers at a given orientation was measured. The relative accuracy of the BRDF measurement is better than 2.

Experimental study on temperature distribution within a wide-gap continuous free-flow electrophoresis chamber.

The temperature distribution within a wide-gap (3 mm) continuous free-flow electrophoresis (CFFE) chamber was investigated by direct measurements. The walls of the chambers consisted of Plexiglas and thermocouples were used as temperature sensors. The study of different operating and heat dissipating conditions revealed that lateral temperature gradients arise in CFFE chambers in addition to an axial increase in temperature of 0.