Weak Radiation Research Articles

Discovery and Timing of Millisecond Pulsars in the Globular Cluster M5 with FAST and Arecibo

We report on a comprehensive multiwavelength study of the pulsars in the globular cluster (GC) M5, including the discovery of M5G, a new compact noneclipsing “black widow” pulsar. Thanks to the analysis of 34 yr of radio data taken with the Five-hundred-meter Aperture Spherical radio Telescope and Arecibo telescopes, we obtained new phase-connected timing solutions for four pulsars and improved those of the other three. These have resulted in, among other things, (a) much improved proper motions for five pulsars, with transverse velocities (relative to the cluster) that are smaller than their respective escape velocities; (b) 3σ and 1.5σ detections of Shapiro delays in M5F and M5D, respectively; and (c) greatly improved measurement of the periastron advance in M5B, whose value of implies that M5B is still likely to be a heavy () neutron star. The binary pulsars M5D, M5E, and M5F are confirmed to be in low-eccentricity binary systems, the low-mass companions of which are newly identified to be He white dwarfs using Hubble Space Telescope data. Four pulsars are also found to be associated with X-ray sources. Similarly to the eclipsing pulsar M5C, M5G shows little or no nonthermal X-ray emission, indicative of weak synchrotron radiation produced by intrabinary shocks. All seven pulsars known in M5 have short spin periods (<8 ms), and five are in binary systems with low orbital eccentricities. These characteristics differ from the overall GC pulsar population but confirm the expectations for the pulsar population in a cluster with a small rate of stellar encounters per binary system.

Inhibition of cutaneous heat-sensitive Ca2+ -permeable transient receptor potential vanilloid 3 channels alleviates UVB-induced skin lesions in mice.

Ultraviolet B (UVB) radiation causes skin injury by trigging excessive calcium influx and signaling cascades in the skin keratinocytes. The heat-sensitive Ca2+ -permeable transient receptor potential vanilloid 3 (TRPV3) channels robustly expressed in the keratinocytes play an important role in skin barrier formation and wound healing. Here, we report that inhibition of cutaneous TRPV3 alleviates UVB radiation-induced skin lesions. In mouse models of ear swelling and dorsal skin injury induced by a single exposure of weak UVB radiation, TRPV3 genes and proteins were upregulated in quantitative real-time PCR and Western blot assays. In accompany with TRPV3 upregulations, the expressions of proinflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were also increased. Knockout of the TRPV3 gene alleviates UVB-induced ear swelling and dorsal skin inflammation. Furthermore, topical applications of two selective TRPV3 inhibitors, osthole and verbascoside, resulted in a dose-dependent attenuation of skin inflammation and lesions. Taken together, our findings demonstrate the causative role of overactive TRPV3 channel function in the development of UVB-induced skin injury. Therefore, topical inhibition of TRPV3 may hold potential therapy or prevention of UVB radiation-induced skin injury.

Cosmic muons as PMT and SiPM detector background signals

Photomultiplier tube (PMT) and Silicon Photo Multiplier (SiPM) are often used for detecting small number of photons or very weak radiations. A light guide usually connects these photodetectors to the test space. In this article, we investigate the effect of background signals caused by cosmic muons scintillation or interactions with PMT and SiPM, their light guide or input window materials. We study such interactions by making simulations using GATE software package and undertaking experiments using detector circuits developed as in [1]. The background cosmic muons can generate photons which will lead to errors in low radiation and single photon detection experiments especially if standard scintillators are not used. For such experiments, we conclude that the most useful method for cutting down the cosmic muons background should be by conducting the experiments deep underground or inside tunnels with several tens of meters of materials above it.

Super weak Electromagnetic Radiation in Bio and Inorganic Systems

This article provides a comparative analysis of data on ultra-weak electromagnetic radiation (WEEM) obtained at different times from bio and inorganic systems. The unifying physical principle was the presence of hybrid orbitals in the outer electron shells in the systems under study and the generation of coherent radiation in them. The data of a model experiment on ultra weak radiation of metals and semiconductors in the long-wavelength region of the optical spectrum are presented, indirectly confirming this hypothesis.

Immunogenic Radiation Therapy for Enhanced Antitumor Immunity via a Core-Shell Nanosensitizer-Mediated Immunosuppressive Tumor Microenvironment Modulation.

Due to the immunosuppressive tumor microenvironment (TME) and weak radiation absorption, the immune response triggered by radiation therapy (RT) is limited. Herein, a core-shell nanosensitizer UiO@MnS (denoted as UM) was genuinely constructed for the amplification of RT efficacy and induction of immunogenicity via integrating MnS-reprogrammed TME with Hf-based UiO-sensitized RT. The acid-sensitive MnS would produce H2S under acidic TME to improve oxygenation through inhibition mitochondrial respiration and reducing metabolic oxygen consumption, leading to decreased HIF-1α expression and enhanced radiosensitization. In addition, the generated H2S inhibited the catalase activity to increase the H2O2 level, which subsequently enhanced the Mn2+-mediated Fenton-like reaction, resulting in G2/M cell cycle arrest to improve the cellular sensitivity for radiation. This impressive tumor oxygenation, cell cycle arrest, and radiosensitization procedure boosted RT efficacy and resulted in strong antitumor immunogenicity. Taken together, combining the immunosuppressive TME modulation with a sensitizing radiation strategy shows great promise for magnifying immunogenic RT outputs.

Nanotip-based CMOS photosensitive architecture for highly sensitive near-infrared imaging detection

A type of nanotip-based photosensitive architecture for near-infrared imaging detection is effectively constructed by tightly coupling a chip of common photosensitive complementary–metal–oxide–semiconductor (CMOS) and a silicon nanotip optical antenna. Benefiting from the stimulated surface-wave nano-accumulating over silicon nanotips, the detectors exhibit a highly sensitive near-infrared detection feature with a stable normalized detectivity (D*) of ∼3.25 × 1010 cm·Hz1/2·W−1 and also the maximum value of ∼4.86 × 1011 cm·Hz1/2·W−1 corresponding to weak near-infrared radiation with a nW-level power. Moreover, a polarization sensitive character of the nanotip-based CMOS photosensitive architecture, enabling imaging grayscale closely related to incident radiation level being locally elevated, is also explored. The proposed antenna-based imaging detection approach exhibits a wider radiation response range as well as higher imaging contrast and definition. It can be expected that the imaging detection method will present a further developing potential according to the nanotip-based polarized imaging detection strategy.

Temperature Effect of Railway PC Part Cable-stayed Bridge Based on Long-term Monitoring

The natural environment in which bridges are located varies widely. In order to ensure the normal use of the pylon structure, it is necessary to study the influence of different external environmental factors on the temperature field and temperature effect of the pylon. The purpose of this paper is to study the temperature effect of a cable-stayed bridge in the PC part of the railway based on long-term monitoring. The relevant theories of temperature field and temperature stress analysis are summarized, and the main girder section temperature monitoring scheme is designed according to the interpolation fitting criteria. As the comparative weak radiation day temperature data, the temperature variation law of the box girder section is analyzed, and the temperature gradient fitting curve is obtained by the regression fitting method. The temperature boundary is established according to astrophysics and heat transfer theory, and the temperature field distribution and temperature stress state of the main beam are analyzed by ANSYS two-dimensional box girder section model and Midas/Civil full bridge model. The experimental results show that the solar short-wave radiation is a The main factor that causes the temperature difference of box girder section.

Nonlinear Approximation for Mixed Convection Flow From a Vertical Plate With Exponentially Decaying Internal Heat Generation and Nonlinear Thermal Radiation

Abstract This study considered dynamic features of mixed convection flow over a vertical plate influenced by nonlinear thermal radiation and exponentially decaying internal heat generation. The importance of the nonlinear density variation with temperature (NDT) and convective heating is also analyzed. The governing equations are transformed into ordinary differential equations using the similarity variables and solved in MAPLE 2022 by a Runge–Kutta Ferhlberg fourth-fifth order scheme. The results obtained show that, with an increase in the convection process, the internal heat generation convects more fluid away and consequently reduced the rate of heat flowing back into the plate. For a weak internal heat generation λx=0.5, the plate temperature is less than one (1) and the heat is observed to flow from the plate into the fluid on the surface of the right plate. Furthermore, for weak convection and nonlinear thermal radiation effects, the rate at which the heat flows into the plate increases with the convective heat transfer parameter increase. However, for a strong nonlinear thermal radiation effect, the rate at which the heat flows out of the plate increases. The flow feature is not only governed by the rate of internal heat generation but the generation as well reverses the heat flow from the plate since the temperature of the near the plate surface T is much higher than the environmental temperature Tf.

Variation of carbon source and sink along the environmental gradient from lakeside to highlands in Yuanchi swamp wetlands, Changbai Mountains, China.

Lacustrine wetlands have long-term carbon storage capacity and contribute significantly to regional carbon cycle, but it is unclear how its carbon sinks respond to climate change. We measured soil heterotrophic respiration carbon emissions (CO2 and CH4), vegetation carbon sequestration, and related environmental factors (temperature, water level, etc.) of five kinds of natural swamps (Phragmites marsh-L, Carex schmidtii marsh-C, Rhododendron capitatum swamp-D, Betula fruticose swamp-H, Larix olgensis swamp-LT)by using static chamber gas chromatography and relative growth equation methods, along the water environmental gradients from lakeside to highlands in Yuanchi of Changbai Mountains. We quantified the carbon source/sink function (CSS) and global warming potential (GWP) of various swamp types by estimating ecosystem net carbon balance, and revealed the variation patterns and formation mechanisms of CSS and GWP along the environmental gradients, aiming to explore the response of carbon source/sink of lakeside wetland in high altitude area to climate change. The results showed that marshes (L and C) were weak sources (-1.018 and -0.090 t C·hm-1·a-1) at the lower habitats of the water environment gradient, shrub swamps (D and H) were strong or weak sinks (1.956 and 0.239 t C·hm-1·a-1) at the middle habitats, forest swamp (LT) was strong source (-3.214 t C·hm-1·a-1) at the upper habitat. The spatial changes were promoted by water level and suppressed by soil temperature. For GWP, strong thermal radiation for marshes (from 44.682 to 59.282 t CO2·hm-1·a-1), cold radiation for shrub swamps (from -0.920 to -7.008 t CO2·hm-1·a-1), and weak thermal radiation for forest swamp (11.668 t CO2·hm-1·a-1), and their GWP was only promoted by soil temperature. Under current climate change background, marshes and forest swamp at both ends of the water environment gradient from lakeside to highlands played a positive feedback effect due to the increases of CH4 or CO2 emissions, while the middle shrub swamp still maintained a negative feedback effect in Yuanchi located the high-altitude area of the temperate Changbai Mountains.

Research on 3D image reconstruction of sparse power lines by array GM-APD lidar

Power lines and other tiny obstacles in the air are deadly hazards to safe aircraft flight. However, existing detection methods have difficulty sensing power lines’ weak radiation signals submerged in noise, making power lines detection an international research hotspot. To solve this problem, this paper proposes the use of array Geiger-mode avalanche photodiode (GM-APD) light detection and ranging (lidar) with single photon detection sensitivity to achieve remote three-dimensional (3D) imaging detection of power lines (GM-PLTR). We focus on solving the problem of noise filtering for sparse power lines under low Signal-to-noise ratio (SNR) conditions and completing 3D image reconstruction. Firstly, we propose a method based on adaptive thresholding and waveform density discrimination combined with spatial dependency to remove the pixel-wise noise, including environmental light, noise echoes from neighboring pixels, and dark count noise. Then we obtain the high SNR depth image of the targets. Secondly, we use an improved DBSCAN algorithm to separate the power lines from the background noise in the depth image to improve the reconstruction effect. Finally, we use a one-directional template matching method to fill in the missing shapes of the power lines. Experimental results show that the algorithm improves the SNR of the power lines echo signal by an average of 2.3 times and achieves sparse power lines imaging detection at 340.95 m. Moreover, the Hough transform confirms the possibility of high-precision detection of power lines, significantly reducing the difficulty of detecting small targets. Finally, it will help unmanned aerial vehicles (UAVs) complete the inspection of power lines.

Extended-bandwidth solar nano-concentrator integrated with graphene-metamaterial for photovoltaic energy harvesting applications

Concentration photovoltaics are used to achieve solar energy focusing on small-area solar cells, thus obtaining a high efficiency at a reasonable cost. An array of gold plasmonic concentrator cells is proposed here, which can nano-focus the solar radiation down to 60 nm spot size. It works over the entire solar energy bandwidth up to 2400 nm wavelength, which is extended beyond the conventional solar cells known maximum operating wavelength of 1800 nm. The concentrator consists of a coaxial waveguide with a tapered section that can plasmonically nano-focus solar radiation, followed by a straight waveguide section to propagate focused light along a graphene metamaterial for optical absorption. The metamaterial is integrated within the 60 nm gap of the straight waveguide section. The metamaterial consists of 10 concentric graphene shell layers, which are cross-connected by 5 horizontal graphene annuli. The concentrator and metamaterial design maximizes the solar optical absorption efficiency within the graphene metamaterial. The graphene optical absorption is enhanced up to 27 times with an almost flat response covering most of the solar bandwidth. The plasmonic absorption within the gold surfaces of the structure is found to be reasonable. The enhanced optical absorption of the weak solar radiation received within the extended band (1800–2400 nm) can reach up to 50%. The concentrator device is polarization insensitive with a 120o field-of-view. The enhanced optical power absorption in graphene metamaterial could be used in photovoltaic energy harvesting applications.

Research on accurate non-contact temperature measurement method for telescope mirror.

Non-contact temperature measurement for a solar telescope mirror is critical for improving the mirror seeing and thermal deformation of solar telescopes, a long-standing challenge in astronomy. This challenge arises from the telescope mirror's inherent weak thermal radiation, often overwhelmed by reflected background radiations due to its high reflectivity. In this work, an infrared mirror thermometer (IMT) is equipped with a thermally-modulated reflector, and a measurement method based on an equation for extracting mirror radiation (EEMR) has been developed for probing the accurate radiation and temperature of the telescope mirror. Using this approach, we can extract the mirror radiation from the instrumental background radiation via the EEMR. This reflector has been designed to amplify the mirror radiation signal incident on the infrared sensor of IMT, while inhibiting the radiation noise from the ambient environment. In addition, we also propose a set of evaluation methods for IMT performance based on EEMR. The results reveal that the temperature measurement accuracy of IMT to the solar telescope mirror using this measurement method can be achieved better than ±0.15°C.

Estimation of Inactivation time for the SARS-CoV-2 virus from the UV biometer in South Korea.

The coronavirus disease 2019 (COVID-19) is a result of the infection by "severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and has caused various social and economic effects over the globe. As the SARS-CoV-2 is effectively inactivated by the exposure to the UV-B radiation (shorter than 315nm), the exposure time for inactivation of the SARS-CoV-2 was estimated using the broadband UV observation instrument over 11 observation sites in South Korea. For the limitation of the UV biometer, which has limited spectral information, the coefficient for conversion from the erythemal UV (EUV) to the radiation for virus inactivation was adopted before estimating the inactivation time. The inactivation time of SARS-CoV-2 is significantly dependent on seasonal and diurnal variations due to the temporal variations of surface incident UV irradiance. The inactivation times in summer and winter were around 10 and 50min, respectively. The inactivation time was unidentified during winter afternoons due to the weak spectral UV solar radiation in winter. As the estimation of inactivation time using broadband observation includes the uncertainty due to the conversion coefficient and the error due to the solar irradiance, the sensitivity analysis of the inactivation time estimation was also conducted by changing the UV irradiance.

Heat Waves Can Cause Hypoxia in Shallow Lakes

AbstractWe assessed how warm air temperatures, high solar radiation, and weak wind speeds might induce hypoxia in a shallow lake during a heat wave. We simulated bottom‐water dissolved oxygen concentrations and compared concentrations in 2022 with the average for the previous 30 years. We found that hypoxia was most sensitive to wind speeds. When the wind speed was low, convection was insufficient to prevent hypoxia, but there was no hypoxia if the wind speed equaled the average speed during the previous 30 years. However, if solar radiation and air temperatures equaled the respective averages during the previous 30 years, hypoxia did not occur, even if wind speeds were low. We conclude that the combined effects of weak winds and either high solar radiation or air temperatures induced hypoxia during the heat wave of 2022.

Three-dimensional multimodal porous graphene-carbonized wood for highly efficient solar steam generation

Recently, solar steam generation systems have become a promising solar energy technology that can alleviate the energy crisis and reduce water pollution. However, because of weak solar radiation energy, rapid heat loss, and negative environmental impacts, there are still numerous challenges that must be overcome before solar steam generation systems can be used for practical energy utilization. Inspired by natural tree transpiration, this paper reports a 3D carbonized wood (hydrophilic)-based photothermal system coated with 2D porous reduced graphene oxide (hydrophobic) to promote solar steam generation. Wood with vertically aligned microchannels and high hydrophilicity is used to efficiently pump water, which is then spread to a 2D porous reduced graphene oxide layer with a sufficient evaporation surface. The unique 3D micro-sized water reservoirs formed between the wood and reduced graphene oxide maximize the thermal energy use of the graphene layer by preventing heat loss from its transference to the water and reducing light reflection. The evaporation rate and solar energy conversion efficiency were 1.492 kg⋅m−2⋅h−1 and 94.7% under 1 sun illumination, respectively. Moreover, our solar steam evaporator maintained its original evaporation rate after 20 h. This work provides new insights into the structural design for highly efficient solar steam generation devices.

Evaluating the impact of sky view factor and building shadow ratio on air temperature in different residential and commercial building scenarios: A case study of Beijing, China

The urban building morphology is one of the most important effects of urban thermal environment (UTE). The sky view factor (SVF) is a crucial structure index of buildings and it combines height and density attributes. These attributes have impacts on the air temperature(Tair). However, there are few studies on the association between SVF and Tair across block scales. In this paper, we designed ten scenarios according to the characteristics of Beijing's commercial and residential buildings. Furthermore, we used ENVI-met, a microclimate simulation model, to simulate the Tair in designed scenarios and evaluate the impact of SVF on the Tair of each component. A number of significant observations were noted based on the experimental results: (1) from 10:00 to 17:00, there is a positive correlation between SVF and Tair; from 18:00 to 9:00 the next day, there is a negative correlation between SVF and Tair (2) the relationship between building shadow ratio (BSR) and Tair is not a single negative correlation: at sunrise, BSR is the maximum in a day, but the cooling effect of BSR on Tair is not obvious because of the weak solar radiation. In addition, the arrangement of building directions has a great influence on the relationship between BSR and Tair (3) for the same building scenario, BSR decreases with the increase of SVF (4) the synergistic effect of SVF and BSR on Tair in the daytime can be divided into two periods, the separation time points are 7:00 and 14:00. This study can provide instructions for urban design in optimizing building layout and mitigating the urban heat impact on human health.

Accelerate the Time-Reversal Computing of Lightning Location Using GPU and Phase-Difference Filter

Time-reversal (TR) technique has been proved to be an effective method to locate the lightning sources, which could get much more accurate results and is capable of finding the weak radiation sources. However, the huge amount of calculation makes it not meet the fast localization requirement of the lightning map array. To accelerate the localization speed of TR, this article proposes to use graphics processing unit (GPU) parallel computing and shared memory to calculate the radiation source directions. Then, the phase difference is combined with TR to filter out the less relevant direction points thus to further speed up the computation. Finally, as for the real lightning data received by the antennas, not every sliding window contains the radiation signals during the TR calculation, we use the signal-interference energy ratio to judge whether a sliding window has the radiation signal, thus, we only need to calculate the windows of which the ratios are above the threshold. Experiments show that, in simulation, by using the first two skills, the computing speed is greatly improved by more than 1700 times than a single CPU serial computing; in 500 ms real lightning data localization, our method is 263 times faster than the original CPU methods, meanwhile, the location result is as good as the latter.

Research and application of park multi-source synergistic and complementary heating system and its coordinated control method

The integration of solar thermal collectors (STC) and air source heat pump (ASHP) heating systems has been widely used for building heating. However, these systems have the problems that the STC cannot fully utilize the solar energy at weak radiation, and the ASHP has insufficient output as well as low coefficient of performance (COP) under extreme cold conditions. In this study, a multi-source synergistic and complementary heating system (MSSCHS) with a heating mode selection model based on belief rule base and evidential reasoning (BRB-ER) method is designed. First, the MSSCHS composed of the STC and the ASHP as the main heat sources, and the water source heat pump as the auxiliary heat source, along with its three heating modes under different operating conditions were proposed. Then, a system heating mode selection model based on the BRB-ER method was establish to achieve mode switching. Finally, the MSSCHS with BRB-ER heating mode selection model was tested experimentally. The results show that compared with the conventional ASHP + STC heating system, the solar energy utilization rate of the MSSCHS had increased by 19.3 %, 16.6 % and 8.2 % respectively in three typical days, and the ASHP's COP had increased by 37.7 %- 55.6 % under extreme cold conditions. The high efficiency and stability of the MSSCHS were verified through operational tests during the heating period. Furthermore, by applying in different types of buildings, it is verified that the MSSCHS can meet different heating requirements and has a good applicability. It was demonstrated that the proposed MSSCHS has more efficient heating mode and more accurate mode selection method, which can provide a new research idea for building heating.

The IP Transformation of Independent Bookstores in the New Media Environment: A Case Study of Pioneer Bookstore

In an era of digital reading where the paper medium is in decline, the survival of independent bookshops is under pressure as never before. In response to the rise of digital media, some of the city’s traditional bookstores are making creative digital transformations. Pioneer Bookstore is an iconic landmark in Nanjing, which is renowned for its composite marketing, audience connections, and cross-border collaboration. Using the interview method, this study found that the Pioneer Bookstore has a wide range of fragmented blind boxes, a single variety of co-branded artistic creations, weak cultural radiation, and a lack of intelligent services. In order to achieve sustainable development in the era of the visual shift, independent bookstores need to develop a creative marketing matrix and strengthen three-dimensional marketing; in addition, they should create original products that audiences will enjoy as well as focus on the quality of content; utilizing regional advantages and leveraging the city’s cultural radiation capacity; utilizing the experience of other industries, maximizing intelligent services for bookstores, and actively adapting to the new media environment and completing the independent bookstore era in the new media era by utilizing intelligent services. Furthermore, the bookstore should learn from the experience of other industries and optimize its intelligent services.

Filaments in the OMC-3 cloud and uncertainties in estimates of filament profiles

Context.Filamentary structures are an important part of star-forming interstellar clouds. The properties of filaments hold clues to their formation mechanisms and their role in the star-formation process.Aims.We compare the properties of filaments in the Orion Molecular Cloud 3 (OMC-3), as seen in mid-infrared (MIR) absorption and far-infrared (FIR) dust emission. We also wish to characterise some potential sources of systematic errors in filament studies.Methods.We calculated optical depth maps of the OMC-3 filaments based on the MIR absorption seen inSpitzerdata and FIR dust emission observed withBerscheland the ArTéMiS instrument. We then compared the filament properties extracted from the data. Potential sources of error were investigated more generally with the help of radiative transfer models.Results.The widths of the selected OMC-3 filament segments are in the range 0.03–0.1 pc, with similar average values seen in both MIR and FIR analyses. Compared to the widths, the individual parameters of the fitted Plummer functions are much more uncertain. The asymptotic power-law index has typically valuesp ~3 but with a large scatter. Modelling shows that the FIR observations can systematically overestimate the filament widths. The effect is potentially tens of per cent at column densities aboveN(H2) ~ 1022cm–2but is reduced in more intense radiation fields, such as the Orion region. Spatial variations in dust properties could cause errors of similar magnitude. In the MIR analysis, dust scattering should generally not be a significant factor, unless there are high-mass stars nearby or the dust MIR scattering efficiency is higher than in the tested dust models. Thermal MIR dust emission can be a more significant source of error, especially close to embedded sources.Conclusions.The analysis of interstellar filaments can be affected by several sources of systematic error, but mainly at high column densities and, in the case of FIR observations, in weak radiation fields. The widths of the OMC-3 filaments were consistent between the MIR and FIR analyses and did not reveal any systematic dependence on the angular resolution of the observations.