The CCD instrument background of the SMILE SXI

The ESA and CAS SMILE mission orbit is highly elliptical and will pass through multiple radiation environments.The Soft X-ray Imager(SXI)instrument aboard has a radiation shutter door designed to close when the surrounding radiation flux is high.The shutter door will close when passing below an altitude threshold to protect against trapped particles in the Earth’s Van Allen Belts.Therefore,two radiation environments can be approximated based on the shutter door position:open and closed.The instrument background for the CCDs(Charge-Coupled Devices)that form the focal plane array of the SXI were evaluated for the two environments.Due to the correlation of the space environment with the solar cycle,the solar minima and maxima,the background was also evaluated at these two extremes.The results demonstrated that the highest instrument background will occur during solar minima due to the main contributing source being Galactic Cosmic Rays(GCRs).It was also found that the open background was highest for solar minima and that the closed background was highest during solar maxima.This is due to the radiation shutter door acting as a scattering centre and the changes in the energy flux distribution of the GCRs between the two solar extremes.

STABILITY OF TRANSONIC SHOCKS TO THE EULER-POISSON SYSTEM WITH VARYING BACKGROUND CHARGES

This paper is devoted to studying the stability of transonic shock solutions to the Euler-Poisson system in a one-dimensional nozzle of finite length.The background charge in the Poisson equation is a piecewise constant function.The structural stability of the steady transonic shock solution is obtained by the monotonicity argument.Furthermore,this transonic shock is proved to be dynamically and exponentially stable with respect to small perturbations of the initial data.One of the crucial ingredients of the analysis is to establish the global well-posedness of a free boundary problem for a quasilinear second order equation with nonlinear boundary conditions.

Characteristics of Lightning Activity in Southeast China and its Relation to the Atmospheric Background

Based on the lightning observation data from the Fengyun-4A(FY-4A)Lightning Mapping Imager(FY-4A/LMI)and the Lightning Imaging Sensor(LIS)on the International Space Station(ISS),we extract the“event”type data as the lightning detection results.These observations are then compared with the cloud-to-ground(CG)lightning observation data from the China Meteorological Administration.This study focuses on the characteristics of lightning activity in Southeast China,primarily in Jiangxi Province and its adjacent areas,from April to September,2017–2022.In addition,with the fifth-generation European Centre for Medium-Range Weather Forecasts reanalysis data,we further delved into the potential factors influencing the distribution and variations in lightning activity and their primary related factors.Our findings indicate that the lightning frequency and density of the FY-4A/LMI,ISS-LIS and CG data are higher in southern and central Jiangxi,central Fujian Province,and western and central Guangdong Province,while they tend to be lower in eastern Hunan Province.In general,the high-value areas of lightning density for the FY-4A/LMI are located in inland mountainous areas.The lower the latitude is,the higher the CG lightning density is.High-value areas of the CG lightning density are more likely to be located in eastern Fujian and southeastern Zhejiang Province.However,the high-value areas of lightning density for the ISS-LIS are more dispersed,with a scattered distribution in inland mountainous areas and along the coast of eastern Fujian.Thus,the mountainous terrain is closely related to the high-value areas of the lightning density.The locations of the high-value areas of the lightning density for the FY-4A/LMI correspond well with those for the CG observations,and the seasonal variations are also consistent.In contrast,the distribution of the high-value areas of the lightning density for the ISS-LIS is more dispersed.The positions of the peak frequency of the FY-4A/LMI lightning and CG lightning contrast with local altitudes,primarily located at lower altitudes or near mountainsides.K-index and convective available potential energy(CAPE)can better reflect the local boundary layer conditions,where the lightning density is higher and lightning seasonal variations are apparent.There are strong correlations in the annual variations between the dew-point temperature(Td)and CG lightning frequency,and the monthly variations of the dew-point temperature and CAPE are also strongly correlated with monthly variations of CG lightning,while they are weakly correlated with the lightning frequency for the FY-4A/LMI and ISS-LIS.This result reflects that the CAPE shows a remarkable effect on the CG lightning frequency during seasonal transitions.

Comparative Analysis of Energy Characteristics of Two Southwest Vortices in Sichuan Under Similar Circulation Backgrounds

Based on ERA5 reanalysis data,the present study analyzed the thermal energy development mechanism and kinetic energy conversion characteristics of two extreme rainstorm processes in relation to the shallow southwest vortex in the warm-sector during a“rain-generated vortex”process and the deep southwest vortex in a“vortex-generated rain”process.The findings were as follows:(1)During the extreme rainstorm on August 11,2020(hereinafter referred to as the“8·11”process),intense surface heating and a high-energy unstable environment were observed.The mesoscale convergence system triggered convection to produce heavy rainfall,and the release of latent condensation heat generated by the rainfall promoted the formation of a southwest vortex.The significant increase(decrease)in atmospheric diabatic heating and kinetic energy preceded the increase(decrease)in vorticity.By contrast,the extreme rainstorm on August 16,2020(hereinafter referred to as the“8·16”process)involved the generation of southwest vortex in a low-energy and highhumidity environment.The dynamic uplift of the southwest vortex triggered rainfall,and the release of condensation latent heat from rainfall further strengthened the development of the southwest vortex.The significant increase(decrease)in atmospheric diabatic heating and kinetic energy exhibited a delayed progression compared to the increase(decrease)in vorticity.(2)The heating effect around the southwest vortex region was non-uniform,and the heating intensity varied in different stages.In the“8·11”process,the heating effect was the strongest in the initial stage,but weakened during the vortex's development.On the contrary,the heating effect was initially weak in the“8·16”process,and intensified during the development stage.(3)The available potential energy of the“8·11”process significantly increased in kinetic energy converted from rotational and divergent winds through baroclinic action,and the divergent wind energy continued to convert into rotational wind energy.By contrast,the“8·16”process involved the conversion of rotational wind energy into divergent wind energy,which in turn converted kinetic energy back into available potential energy,thereby impeding the further development and maintenance of the southwest vortex.

Gravitational Waves Background, as Well as Some UFO, FRB and Supernova Flares, Are Due to Compressibility of the Spacetime (CoST)

The recently observed gravitational wave background is explained in terms of the quantum modification of the general relativity (Qmoger). Some UFO, FRB and supernova flares also can be explained in terms of Qmoger.

Optimal Insurance with Background Risk under the Ambiguity and Belief Heterogeneity Structure

In this paper, we discuss the optimal insurance in the presence of background risk while the insured is ambiguity averse and there exists belief heterogeneity between the insured and the insurer. We give the optimal insurance contract when maxing the insured’s expected utility of his/her remaining wealth under the smooth ambiguity model and the heterogeneous belief form satisfying the MHR condition. We calculate the insurance premium by using generalized Wang’s premium and also introduce a series of stochastic orders proposed by [1] to describe the relationships among the insurable risk, background risk and ambiguity parameter. We obtain the deductible insurance is the optimal insurance while they meet specific dependence structures.

Ratio of Gravitational Force to Electric Force from Empirical Equations in Terms of the Cosmic Microwave Background Temperature

Previously, we presented several empirical equations using the cosmic microwave background (CMB) temperature. Next, we propose an empirical equation for the fine-structure constant. Considering the compatibility among these empirical equations, the CMB temperature (Tc) and gravitational constant (G) were calculated to be 2.726312 K and 6.673778 × 10−11 m3∙kg−1∙s−2, respectively. Every equation could be explained in terms of the Compton length of an electron (λe), the Compton length of a proton (λp) and a. Furthermore, every equation could also be explained in terms of Avogadro’s number and the number of electrons in 1 C. However, the ratio of the gravitational force to the electric force cannot be uniquely determined when the unit of the Planck constant (Js) is changed. In this study, we showed that every equation can be described in terms of Planck constant. From the assumption of minimum mass, the ratio of gravitational force to electric force could be elucidated.

Correspondence Principle for Empirical Equations in Terms of the Cosmic Microwave Background Temperature with Solid-State Ionics

Previously, we presented several empirical equations using the cosmic microwave background (CMB) temperature that were mathematically connected. Next, we proposed an empirical equation for the fine-structure constant. Considering the compatibility among these empirical equations, the CMB temperature (Tc) and gravitational constant (G) were calculated to be 2.726312 K and 6.673778 × 10-11 m3·kg-1·s-2, respectively. Every equation can be explained in terms of the Compton length of an electron (λe), the Compton length of a proton (λp) and α. However, these equations are difficult to follow. Using the correspondence principle with the thermodynamic principles in solid-state ionics, we propose a canonical ensemble to explain these equations in this report. For this purpose, we show that every equation can be explained in terms of Avogadro’s number and the number of electrons in 1 C.

A Statistical Algorithm for Retrieving Background Value of Absorbing Aerosol Index Based on TROPOMI Measurements

The ultraviolet aerosol index(UVAI) is essential for monitoring the absorbing aerosols during aerosol events. UVAI depends on the absorbing aerosol concentration, the viewing geometry, and the temporal drift of radiometric sensitivity. To efficiently detect absorbing aerosols with the highest precision and to improve the accuracy of long-term UVAI estimates,the background UVAI must be examined through the UVAI retrieval. This study presents a statistical method that calculates the background value of UVAI using TROPOspheric Monitoring Instrument(TROPOMI) observation data over the Pacific Ocean under clear-sky scenes. Radiative transfer calculations were performed to simulate the dependence of UVAI on aerosol type and viewing geometry. We firstly applied the background UVAI to reducing the effects of viewing geometry and the degradation of the TROPOMI irradiance measurements on the UVAI. The temporal variability of the background UVAI under the same viewing geometry and aerosol concentration was identified. Radiative transfer calculations were performed to study the changes in background UVAI using Aerosol Optical Depth from the Moderate Resolution Imaging Spectroradiometer(MODIS) and reflectance measurements from TROPOMI as input. The trends of the temporal variations in the background UVAI agreed with the simulations. Alterations in the background UVAI expressed the reflectance variations driven by the changes in satellite state. Decreasing trends in solar irradiance at 340 and 380 nm due to instrument degradation were identified. Our findings are valuable because they can be applied to future retrievals of UVAI from the Environmental Trace Gases Monitoring Instrument(EMI) onboard the Chinese GaoFen-5 satellite.

Establishing environmental background values of selected trace elements and environmental quality assessment of fi negrained sediments in the Jiaozhou Bay catchment,China

With the development of economy,the impact of human activities on ecological environment is increasing,and environmental protection work is important.Trace elements(Co,Ni,Cu,Pb,Zn,Cd,Cr,and Sc)in surface fi ne-grained sediment samples from the Jiaozhou Bay catchment were selected to evaluate their 2015 environmental background values and the environmental quality.Using statistical analysis,the environmental background values(ranges)of Sc,Co,Ni,Cu,Pb,Zn,Cd,and Cr were calculated,being 13.1(10.8-15.4),12.4(8.6-16.2),32.0(22.9-41.2),29.6(13.5-64.9),24.1(13.0-44.6),77.6(38.5-156.5),0.07(0.02-0.20),and 82.5(66.5-104.0)mg/kg,respectively.The enrichment factor,contamination factor,and pollution load index were used to evaluate the pollution status of the Jiaozhou Bay catchment.The environmental background values of most elements are higher than those of the upper continental crust and lower than those of global shale.At present,the pollution in the eastern Jiaozhou Bay is much higher than that in the western part.The results shall be helpful for future management for trace element pollution monitoring in the Jiaozhou Bay catchment.

Multiple Object Tracking through Background Learning

This paper discusses about the new approach of multiple object track-ing relative to background information.The concept of multiple object tracking through background learning is based upon the theory of relativity,that involves a frame of reference in spatial domain to localize and/or track any object.Thefield of multiple object tracking has seen a lot of research,but researchers have considered the background as redundant.However,in object tracking,the back-ground plays a vital role and leads to definite improvement in the overall process of tracking.In the present work an algorithm is proposed for the multiple object tracking through background learning.The learning framework is based on graph embedding approach for localizing multiple objects.The graph utilizes the inher-ent capabilities of depth modelling that assist in prior to track occlusion avoidance among multiple objects.The proposed algorithm has been compared with the recent work available in literature on numerous performance evaluation measures.It is observed that our proposed algorithm gives better performance.

Uranium Series Disequilibrium and Precision Measurement of Radionuclides Activity in Sediment Sample Using Low Background Gamma Spectrometry

Low background gamma spectrometry was used to measure the radionuclides activity of 238U, 232Th, and 235U series as well as 40K and 137Cs in a sediment sample. The goal of the study was to measure the 238U (63.3 keV peak of 234Th;1001 keV peak of 234mPa) and 235U (143.76 keV, 163.33 keV, and 205.31 keV peaks) activity by low background gamma spectrometry in sediment sample. 235U activity in environmental samples is difficult to accurately measure by gamma spectrometry due to its low abundance in nature and low gamma line intensities at 143.76 keV, 163.33 keV, and 205.31 keV. We have shown that by using low background gamma spectrometry, it is possible to accurately measure the 235U activity in sediment samples. The 235U activity was measured without using the major peak of 185.7 keV (Iγ = 57.2%) which requires interference correction from 186.21 keV of 226Ra. 226Ra activity was determined by measuring 222Rn daughters (214Pb and 214Bi). The precision and accuracy of the gamma activity measurement in the sediment sample were verified by using the HPGe detectors with Certified Reference Material (CRM) Irish Sea Sediment (IAEA-385). The results obtained for the 63.33 keV energy line of 234Th are compared with the 1001 keV energy line of 234mPa. The values of 238U and 235U activities, as well as 40K, 137Cs, and 226Ra, agreed with the certificate values of CRM. The results show that the 238U is in equilibrium with its daughters (234Th, 234mPa, and 210Pb). 232Th is also in equilibrium with its daughters (228Ra, 212Pb, 212Bi and 208Tl). 235U/238U activity ratio of 0.046 ± 0.007 in the sediment is constant in nature but fluctuates due to geological processes. A value of 0.055 ± 0.008 was found in our sediment sample.

The Origin of Cosmic Microwave Background Radiation

This paper explains the Olbers paradox and the origin of cosmic microwave background radiation (CMBR) from the viewpoint of the quantum redshift effect. The derived formula dispels the Olbers paradox, confirming that the CMBR originates from the superposition of light radiated by stars in the whole universe, not the relic of the Big Bang. The dark-night sky and CMBR are all caused by Hubble redshift—the physical mechanism is the quantum redshift of the photon rather than cosmic expansion. So this theory supports the infinite and steady cosmology.

Analysis of the Standardization of Administrative Management in Colleges and Universities Under the Background of Information Technology

In the development of the information age,universities should recognize the significant impact of information technology on their own development.In practice,it is possible to effectively improve the efficiency and quality of work by dealing with and constructing information-based methods,innovating administrative management models,and adopting more efficient and scientific methods to address various problems and shortcomings encountered in work.As an important part of university management,administrative management is a complex task.Establishing a standardized management model through information technology can further improve the comprehensive efficiency of administrative management.In this regard,the administrative standardization in universities under the background of information technology is analyzed and studied in this paper.

习近平文化思想的法治底蕴、底色和底气

习近平文化思想和习近平法治思想分别构成了习近平新时代中国特色社会主义思想的“文化篇”和“法治篇”。法治文化是两种思想在习近平新时代中国特色社会主义思想两个独立分领域的耦合之处生发出的、具有高度关联性和契合性的思想精华,激活了习近平文化思想的法治底蕴、底色和底气。习近平文化思想的法治底蕴植根马克思主义法治文化观,深扎中华优秀传统法律文化,汲取世界法治文化精华,延绵红色法治文化,不断发展和创新中国特色社会主义法治文化建设的伟大实践。习近平文化思想的法治底色凸显了良法之治、公平之治、信仰之治、制度之化、精神之化、人本之化的价值理念,实现了文化中的法治与法治中的文化休戚与共。习近平文化思想的法治底气源自科学立法、严格执法、公正司法、全民守法的全过程,推动习近平文化思想和习近平法治思想深入人心、指导实践,为建设社会主义文化强国和法治强国提供坚定的信念伟力、持久的思想定力和巨大的前进动力。

基于CLAHE的铝模天花样本图像增强算法研究

在拍摄铝模天花图片过程中,光线暗、曝光不足都是造成图片整体亮度偏低的原因,使得图片丢失边缘细节信息。为了改善图像视觉效果,设计一种改进的直方图均衡化技术,即限制对比度自适应直方图均衡(CLAHE)算法。从计算初始直方图开始,对每个像素的出现频率都进行记录,汇总后得到初始直方图。在初始直方图的基础上,计算出正规化直方图和累计直方图并且求均衡化的映射关系,然后将结果写入新图像中。实验结果表明,经过CLAHE增强处理后,抑制了干扰区域,突出了图片中的特征点。与单独的直方图均衡算法相比,CLAHE能非常有效地提高铝模天花图像的清晰度与对比度。该算法易于实现,经济划算,具有实际应用价值。与当前主流算法相比,CLAHE算法效果更佳。

P-and SV-wave dispersion and attenuation in saturated microcracked porous rock with aligned penny-shaped fractures

P-and SV-wave dispersion and attenuation have been extensively investigated in saturated poroelastic media with aligned fractures.However,there are few existing models that incorporate the multiple wave attenuation mechanisms from the microscopic scale to the macroscopic scale.Hence,in this work,we developed a unified model to incorporate the wave attenuation mechanisms at different scales,which includes the microscopic squirt flow between the microcracks and pores,the mesoscopic wave-induced fluid flow between fractures and background(FB-WIFF),and the macroscopic Biot's global flow and elastic scattering(ES)from the fractures.Using Tang's modified Biot's theory and the mixed-boundary conditions,we derived the exact frequency-dependent solutions of the scattering problem for a single penny-shaped fracture with oblique incident P-and SV-waves.We then developed theoretical models for a set of aligned fractures and randomly oriented fractures using the Foldy approximation.The results indicated that microcrack squirt flow considerably influences the dispersion and attenuation of P-and SV-wave velocities.The coupling effects of microcrack squirt flow with the FB-WIFF and ES of fractures cause much higher velocity dispersion and attenuation for P waves than for SV waves.Randomly oriented fractures substantially reduce the attenuation caused by the FB-WIFF and ES,particularly for the ES attenuation of SV waves.Through a comparison with existing models in the limiting cases and previous experimental measurements,we validated our model.

A Deep Learning Framework for Mass-Forming Chronic Pancreatitis and Pancreatic Ductal Adenocarcinoma Classification Based on Magnetic Resonance Imaging

Pancreatic diseases, including mass-forming chronic pancreatitis (MFCP) and pancreatic ductal adenocarcinoma(PDAC), present with similar imaging features, leading to diagnostic complexities. Deep Learning (DL) methodshave been shown to perform well on diagnostic tasks. Existing DL pancreatic lesion diagnosis studies basedon Magnetic Resonance Imaging (MRI) utilize the prior information to guide models to focus on the lesionregion. However, over-reliance on prior information may ignore the background information that is helpful fordiagnosis. This study verifies the diagnostic significance of the background information using a clinical dataset.Consequently, the Prior Difference Guidance Network (PDGNet) is proposed, merging decoupled lesion andbackground information via the Prior Normalization Fusion (PNF) strategy and the Feature Difference Guidance(FDG) module, to direct the model to concentrate on beneficial regions for diagnosis. Extensive experiments inthe clinical dataset demonstrate that the proposed method achieves promising diagnosis performance: PDGNetsbased on conventional networks record an ACC (Accuracy) and AUC (Area Under the Curve) of 87.50% and89.98%, marking improvements of 8.19% and 7.64% over the prior-free benchmark. Compared to lesion-focusedbenchmarks, the uplift is 6.14% and 6.02%. PDGNets based on advanced networks reach an ACC and AUC of89.77% and 92.80%. The study underscores the potential of harnessing background information in medical imagediagnosis, suggesting a more holistic view for future research.

Cultural Background Knowledge and English Teaching

Culture background knowledge in English teaching arose in eighties of the twentieth century. It has been closely linked with the reformation and open in China. With the increase of exchange between China and English speaking countries resulting from the reform and opening policy to the outside world, people have come to find that due to the lack of profound knowledge of the culture of the English speaking, "cultural shock"or "cultural conflict" often arises when Chinese people communicate with Westerners, which leads to the realization that the pure-linguistic centered English teaching form cannot meet the demands of the social development any longer. Culture teaching must be introduced into English teaching in order to learn English language well and communicate well.This essay explains the importance of the cultural background knowledge teaching through analyzing the relationship of the language and culture as well as communicating barrier caused by the cultural differences, and it also submits falsifiable suggestions about how to introduce background knowledge into English teaching.

Dynamical Dark Energy in Light of Cosmic Distance Measurements.Ⅰ.A Demonstration Using Simulated Datasets

We develop methods to extract key dark energy information from cosmic distance measurements including the BAO scales and supernova(SN) luminosity distances.Demonstrated using simulated data sets of the complete DESI,LSST and Roman surveys designed for BAO and SN distance measurements,we show that using our method,the dynamical behavior of the energy,pressure,equation of state(with its time derivative) of dark energy and the cosmic deceleration function can all be accurately recovered from high-quality data,which allows for robust diagnostic tests for dark energy models.