Parallel and Series Connection of Dark Electric Current in Liquid and Second Law of Thermodynamics

Liquid in contact with two asymmetrical spiral-shape aluminum electrodes behaves like a still weak source of electrical energy. Almost the only way to increase the efficiency of such a source of electrical energy is to reduce internal resistance. Reducing internal resistance is equivalent to using multiple sources of electrical energy connected in series or in parallel. To check this for such unusual sources it is first necessary to study the properties of each source, which is the voltage drop across the load resistance and the internal resistance of each source. Detailed analysis of experimental data shows that the process of forming the dark current is different from a chemical one.

DOA Estimation for Sources with Large Power Differences

Sources with large power differences are very common, especially in complex electromagnetic environments. Classical DOA estimation methods suffer from performance degradation in terms of resolution when dealing with sources that have large power differences. In this paper, we propose an improved DOA algorithm to increase the resolution performance in resolving such sources. The proposed method takes advantage of diagonal loading and demonstrates that the invariant property of noise subspace still holds after diagonal loading is performed. We also find that the Cramer–Rao bound of the weak source can be affected by the power of the strong source, and this has not been noted before. The Cramer–Rao bound of the weak source deteriorates as the power of the strong source increases. Numerical results indicate that the improved algorithm increases the probability of resolution while maintaining the estimation accuracy and computational complexity.

About the quantum Fisher information of nearly pure quantum statistical models

We address nearly pure quantum statistical models, i.e. situations where the information about a parameter is encoded in pure states weakly perturbed by the mixing with a parameter independent state, mimicking a weak source of noise. We show that the symmetric logarithmic derivative is left unchanged, and find an approximate analytic expression for the quantum Fisher information (QFI) which provides bounds on how much a weak source of noise may degrade the QFI.

Low CO₂ evasion rate from the mangrove surrounding waters of Sundarban

Globally, water bodies adjacent to mangroves are considered sources of atmospheric CO2. We directly measured the partial pressure of CO2 in water, pCO2(water), and other related biogeochemical parameters with very high (1-min) temporal resolution at Dhanchi Island in India’s Sundarbans during the post-monsoon season. We used elemental, stable isotopic, and optical signatures to investigate the sources of dissolved inorganic carbon (DIC) and organic matter (OM) in these waters. Diel mean pCO2(water) was marginally oversaturated in creeks (efflux, 69 ± 180 µmol m−2 h−1) and undersaturated along the island boundary and in the main river (influx, −17 ± 53 and −31 ± 73 µmol m−2 h−1, respectively) compared to the atmospheric CO2 concentration. The possibility in earlier studies of over- or underestimating the CO2 flux because of an inability to capture tidal minima and maxima was minimized in the present study, which confirmed that the waters surrounding mangroves in this region can act as a sink or a very weak source of atmospheric CO2. δ13C values for DIC suggest a mixed DIC source, and a three-end-member stable isotope mixing model and optical signatures of OM suggest negligible riverine contribution of freshwater to OM. We conclude that the CO2 sink or weak source character was due to a reduced input of riverine freshwater [which usually has high pCO2(water)] and the predominance of pCO2-lean water from the coastal sea, which eventually increases the buffering capacity of the water as evidenced by the Revelle factor. Up-scaling the CO2 flux data for all seasons and the entire estuary, we propose that the CO2 evasion rate observed in this study is much lower than the recently estimated world average. Mangrove areas having such low emissions should be given due emphasis when up-scaling the global mangrove carbon budget from regional observations.

Multiple Sound Sources Localization with Frame-by-Frame Component Removal of Statistically Dominant Source

Multiple sound sources localization is a hot topic in audio signal processing and is widely utilized in many application areas. This paper proposed a multiple sound sources localization method based on a statistically dominant source component removal (SDSCR) algorithm by soundfield microphone. The existence of the statistically weak source (SWS) among soundfield microphone signals is validated by statistical analysis. The SDSCR algorithm with joint an intra-frame and inter-frame statistically dominant source (SDS) discriminations is designed to remove the component of SDS while reserve the SWS component. The degradation of localization accuracy caused by the existence of the SWS is resolved using the SDSCR algorithm. The objective evaluation of the proposed method is conducted in simulated and real environments. The results show that the proposed method achieves a better performance compared with the conventional SSZ-based method both in sources localization and counting.

Research on Gamma Camera Imaging Characteristics

Gamma camera imaging technology is a non-destructive passive radiation imaging technology, which can quickly find the unknown source location, search the exact number of radioactive sources and relative intensity. Therefore, it is very important and widely used in the fields of effective regulation of radioactive sources, handling of various nuclear emergencies, nuclear arms control and other fields. In the practical application of gamma camera, it often faces the imaging difference caused by the difference of radiation source intensity, detection time and detection distance. It is helpful to study the change of imaging characteristics under different experimental conditions for the practical application of gamma camera under different scenes. In this paper, the structure and imaging principle of gamma camera are analyzed in detail. Using the Cartogam portable gamma camera, a set of comparative experiments are carried out to study the time characteristics, distance characteristics and source intensity characteristics of the gamma camera. The results show that the imaging quality of gamma camera is positively correlated with the time source intensity, negatively correlated with the distance. For a milliCurie source, the gamma camera has very good fast-position resolution at a distance of 1 meter from the radioactive source and can form a more complete hot spot image within 5 minutes. When the distance becomes larger, the radioactive source needs at least 20 minutes to form a more accurate hot spot image. The hot spot is no longer as complete as a concentric circle structure, but can achieve precise positioning. For a strong source of more than ten milliCurie, immediate imaging within two minutes can be basically achieved within two meters. Under multi-source conditions, when the source intensities differ greatly and the distance between sources is relatively close, the detection of weak source can not be achieved by increasing the measurement time. However, by observing the counting images in a short period of time, the possibility of existence of a weak source can be deduced. Therefore, in the practical application of the gamma camera, it is necessary to constantly adjust its imaging conditions to ensure the detection of weak source verification. In this paper, the Monte Carlo model of gamma camera is set up to simulate the imaging. Compared with the actual imaging hot spots, the simulated images can correctly reflect the hot spot graph’s level distribution, which has the value of further research.