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As essential high-end equipment for nuclear emergency monitoring, the portable HPGe γ spectrometer currently lacks supporting in-situ measurement methods, limiting its role and value in emergency missions. For this practical problem, this paper studies the measurement of ground surface radioactivity by portable HPGe γ spectrometer in nuclear emergency monitoring in view of the particularity of nuclear emergency source items. Firstly, the detection efficiency of point sources at different horizontal distances when the spectrometer is installed at the height of 1 m from the center of the detector to the ground is calculated. Secondly, the concept of effective contribution distance is defined and analyzed. Thirdly, the point source detection efficiency is obtained using the numerical integration method of calculation. Integrate to calculate the detection efficiency of the surface source, and then calculate the radioactive surface activity of the surface. Finally, the effectiveness of the method is verified through experiments. [ABSTRACT FROM AUTHOR]

The growing volume of plastic waste resulting from human activities is suffocating our planet. To combat this escalating issue, this study delves into the formation of plastic reduction behavior among Swiss citizens using an extended theory of planned behavior model. Through an online survey, the study obtained 149 valid responses, which were analyzed using partial least squares-based structural equation modeling. The results indicate a significant and strong relationship between plastic risk perception and attitudes towards plastic reduction and environmental protection. Notably, the cognitive dimension (β = 0.802, p = 0.000) of plastic risk perception exhibits a tighter and stronger association with attitude compared to the emotional dimension (β = 0.406, p = 0.000). Among the three variables in the theory of planned behavior model, perceived behavioral control (β = 0.384, p = 0.000) emerges as the strongest determinant of behavioral willingness for plastic reduction. It is followed by attitude (β = 0.214, p = 0.030). However, no significant relationship is observed between subjective norm and behavioral willingness for plastic reduction (β = 0.07, p = 0.292). Finally, attitude fully mediates the relationship between plastic risk perception and behavioral willingness for plastic reduction. Theoretical and managerial implications are discussed. • Plastic reduction behavior of Swiss citizens is analyzed in this study. • Plastic risk perception is related to pro-environmental attitudes. • Risk perception's cognitive dimension affects attitude more than the emotional one. • Perceived behavioral control relates most to behavioral willingness. • Subjective norm is not related to plastic reduction willingness. [ABSTRACT FROM AUTHOR]

Second-hand clothing consumption has grown in popularity in recent decades and has also attracted extensive worldwide efforts to investigate the dynamics behind consumers' purchase behaviours. However, research regarding this topic is scarce in China, which has also witnessed the rapid growth of the second-hand market in recent years. In this regard, this study analyzed the motivations and barriers to Chinese consumers' purchase of second-hand clothes as well as their perceived problems with this industry. Specifically, the study conducted a semi-structured online survey with 127 consumers of three second-hand clothing stores in China. Results show that the vast majority (96%) of the investigated consumers are young people born in the 1990s and 2000s, and they are neither significantly driven by economic nor environmental protection motivations. Instead, their purchase is primarily motivated by treasure-hunting fun. Moreover, past overseas shopping experiences are found to be a significant booster to second-hand clothing consumption. Concerns about poverty association and the sanitation conditions of second-hand clothing are the main purchase barriers for the investigated Chinese young consumers. As for the second-hand clothing market, "unregulated industry" (10.29%), "fake identification" (8.09%), and "sanitation concern" (5.88%) are the three most mentioned problems in China. This study provides second-hand retailors and managers with valuable insights into developing successful marketing tactics to attract customers and improve the second-hand industry's performance in China. [ABSTRACT FROM AUTHOR]

• Investigate the usage of plastic bags in China after its 2020 plastic banning law. • Discover a boomerang effect of the pricing policy used in China. • Discover a widely divided usage pattern between old and middle-young consumers. • Recognize loopholes in the design and execution of plastic banning related policies. Reducing the usage of plastic bags has been a pressing task for governments around the world. In China, the government also makes extensive efforts to contrast the negative effects of plastic bag usage by issuing different laws and policies. Conducting an on-site counting of bags used by consumers, this study investigates the usage of plastic bags in China and evaluates the effectiveness of these policies within both supermarkets and vegetable markets (popular markets primarily for vegetables in China). Besides, 5 different factors are investigated to learn their potential influence on the usage of plastic bags, including generation, gender, the price for plastic carrier bags, the packaging style of products, and market type. Results show a boomerang effect of the pricing policy (i.e., charging for plastic carrier bags) in China. Specifically, the policy decreases the usage of plastic carrier bags by 44%. However, the total usage of plastic bags increases, rather than decreases due to the excessive usage of free inner plastic packaging bags used as alternatives to plastic carrier bags. Old and middle-young consumers are disproportionately affected by the pricing policy and behave significantly differently in their usage of plastic bags. Loopholes in management and policies are also discussed. [ABSTRACT FROM AUTHOR]

Background: Although thyroid function has been demonstrated to be associated with non-alcoholic fatty liver disease (NAFLD) in different population, the prevalence and features of NAFLD in hyperthyroidism have not been reported. The present study aims to investigate the prevalence of NAFLD and association of thyroid function and NAFLD in hyperthyroidism patients. Methods: This cross-sectional study was performed in Zhongshan Hospital, Fudan University, China. A total 117 patients with hyperthyroidism were consecutively recruited from 2014 to 2015. Thyroid function and other clinical features were measured, liver fat content was measured by color Doppler ultrasonically, NAFLD was defined in patients with liver fat content more than 9.15%. Statistical analyses were performed with SPSS software package version 13.0. Results: The prevalence of NAFLD was 11.97% in hyperthyroidism. Patient with NAFLD had lower free triiodothyronine (FT3) and free thyroxine (FT4) levels than patients without NAFLD (P < 0.05). After adjusting for age, gender, metabolic parameters and inflammation factors, higher FT3 were associated with lower liver fat content (β = − 0.072, P = 0.009) and decreased odds ratio of NAFLD (OR = 0.267, 95%CI 0.087–0.817, P = 0.021). Conclusions: FT3 level was negatively associated with the liver fat content in this population. These results may provide new evidence in the role of thyroid hormone on the regulation of liver fat content and NAFLD. [ABSTRACT FROM AUTHOR]

The internal structure of the HPGe γ-spectrometer will change with increasing use time, which will significantly impact the accuracy of the modelling simulation results. In this paper, the characterization method of the structural parameters of the HPGe γ-spectrometer is investigated, and the characterization results are presented. Experimental measurements and Monte Carlo simulations are performed at four different positions using six radioactive point sources covering low, medium, and high energies of γ-rays, respectively. The thickness of the dead layer on the front and lateral surface and cold finger on the front and lateral surface are adjusted sequentially according to the characterization algorithm. The thickness of the dead layer on the front surface is corrected to 0.21 cm, and the dead layer on the lateral surface is corrected to 0.08 cm. The thickness of the cold finger on the front surface and lateral surface does not change. The maximum relative deviation of the Monte Carlo simulation results from the experimental results was reduced from 72.7% before correction to 4.3%. • Characterization of the thickness of dead layer and cold finger on the front and lateral of a HPGe γ spectrometer. • Design a characterization algorithm and implement it through MC simulations and experiments. • The characterization can be considered valid when the maximum relative error is less than 5%. [ABSTRACT FROM AUTHOR]

The in-situ measurement method of ground surface radioactivity based on HPGe γ spectrometer in nuclear emergency response is studied. The key to measuring the surface activity of the ground is the calibrating of detection efficiency, which is obtained by the numerical integration method in this paper. The HPGe γ-spectrometer is set up at the height of 1 m from the ground, with the detector direction vertically downward. First, the experimental method obtains the point source detection efficiency of the spectrometer for different energies of γ-rays at different horizontal distances. Then, 95% of the maximum contribution of the count rate is defined as the effective contribution region. Finally, with the effective contribution region as the integration limit, the point source detection efficiency as the integrand, the detection efficiency of the spectrometer for surface radioactive sources is obtained by numerical integration. The surface activity is calculated based on the detection efficiency. The method is experimentally validated by stitching hexagonal radioactive surface sources with a side length of 1m. The relative deviation of the surface activity results obtained by the numerical integration method from the experimental standard value is 5.48%, which verifies the validity of the method. • HPGe γ spectrometer used for surface radioactivity measurement in nuclear emergency. • The efficiency calibration method based on numerical integration is simple and practical. • Experimental verification uses the spliced hexagonal radioactive surface source. [ABSTRACT FROM AUTHOR]

The mobile networks have increasingly facilitated our daily life but are also breeding grounds for malicious worms, which are considered as the main threat to cyber security. The purpose of this paper is to analyze the dynamics of worm propagation and to control the worm epidemic based on mobile-phone networks. Accordingly, we establish an SEIQR-type model to explore the worm epidemic with saturated incidence rate. This paper shows that if the basic reproduction number is less than 1, the worm-free equilibrium is asymptotically stable, and the epidemic of worm will eventually disappear and remain under control; in addition, if the basic reproduction number is greater than 1, the asymptotical stability of worm-existence equilibrium is derived to imply that the epidemic will remain persistent and uncontrollable. Our results give new insights to mobile network security, namely, that is predicting the worm spreading tendency, identifying the epidemic control strategies, and estimating the worm popularity level. Numerical experiments are conducted to show the rationality of our obtained results and the effectiveness of the control strategies. [ABSTRACT FROM AUTHOR]

An effective standoff alpha radiation measurement of surface contamination method is of great importance in radioactive waste disposal and decommissioning of nuclear facilities, nuclear accident emergency response and nuclear security. Here, we build an optical system for the implementation of standoff alpha radiation measurement based on radioluminescence. We present the results of the detection efficiency calibrating of standoff alpha radioactive sources using simulation and experiment. At the same time, a numerical integration-based surface contamination measurement method is designed, computed, and validated through experiments and simulations. Finally, the minimum detectable surface activity of the method is given for different measurement conditions. • A model for standoff alpha radiation measurement based on radioluminescence. • The validity of the MC simulated detector model was verified by experiments. • The performance of device is expressed in terms of MDSA under different conditions. [ABSTRACT FROM AUTHOR]

The α-particle detection has a pivotal role in radiation measurement. Standoff α-particle detection has advantages such as high efficiency and safety compared with the traditional method. However, the low yield of the characteristic signal significantly limits the broad application of this technique. To efficiently perform standoff detection of α-particle, the physical mechanism of α-particle interaction with air, the various secondary effects generated, and the yields are systematically analyzed in this paper. The results show that in addition to the radioluminescence, which is the focus of most current studies, the characteristic X-rays also meet the requirements as a characteristic signal for standoff detection. The processes of induced generation of these two secondary particles in the air are studied, the yields of characteristic X-rays of nitrogen and oxygen atoms and the yields of radioluminescence photons in the near-ultraviolet (UVA/UVB) and deep-ultraviolet (UVC) bands are given, respectively. The interference brought by the presence of β-particles and γ-particles to the α-detection when the radiation field is more complex is also quantitatively analyzed. • Standoff α-ray detection is possible based on characteristic X-rays and radioluminescence. • The characteristic X-ray yields of nitrogen and oxygen are calculated separately. • The radioluminescence yields of UVA/UVB and UVC photons are investigated separately. • The interference brought by β and γ rays to standoff α-ray detection is limited. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cu-PBA: Cu 2 Fe(CN) 6 · x H 2 O crystallites and K 2 CuFe(CN) 6 particles. • Cs+-adsorbed Cu-PBA: the occurrence of Cs 2 CuFe(CN) 6 and K+/Cu2+ release. • GO/CS/Cu-PBA: fully utilized Cu-PBA, electrostatic attraction of Cs+ by GO/CS. • The application of GO/CS/Cu-PBA as a bulk aerogel or in a fixed-bed column system. Efficient removal of 137Cs from various radioactive wastewater and contaminated environment is much meaningful for nuclear energy sustainable development and public health. Herein we used chitosan (CS) to induce the self-assembly of graphene oxide (GO) into a hydrogel (GO/CS) possessing a three-dimensional macroporous structure and produced a type of ternary composite hydrogel/aerogel named GO/CS/Cu-PBA by in situ growing potassium copper hexacyanoferrate(II) (Cu-PBA) nanoparticles onto the GO/CS via simple leaching. The adsorption behaviors of Cs+ by GO, Cu-PBA, and GO/CS/Cu-PBA in various matrice was systematically studied and compared. It was found that the GO/CS/Cu-PBA exhibited satisfactory sorption capacity for Cs+ (64.7 mg/g) and ultrafast kinetics. In addition, a fixed-bed column system could be employed for the cleanup of Cs+ from contaminated groundwater. Further FT-IR, XRD, XPS, and EXAFS analyses clarified the interaction mechanism between Cs+ and GO/CS/Cu-PBA. Highly selective fixation of Cs+ by Cu-PBA was accompanied by the release of K+/Cu2+ and a crystalline phase transition. The adsorption of Cs+ by GO was mainly correlated with the electrostatic attraction by –COO− and C-OH groups. The confinement of Cu-PBA by GO/CS aerogel is of much potential for the practical treatment of cesium-containing radioactive wastewater. [ABSTRACT FROM AUTHOR]