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A novel design of circularly polarized broadband slot antenna with high gain, low profile, and low radar cross‐section (RCS) is proposed by employing polarization conversion metasurface (MS). By introducing sawtooth corner‐truncated square MS with diagonal gaps, a compact circularly polarized antenna composed of 4 × 4 unit cells is presented. It is found that a smaller MS slot antenna can achieve an impedance bandwidth of 42.9% (3.7–5.72 GHz) and a 3‐dB axial ratio (AR) bandwidth of 22.8% (4.55–5.72 GHz). Simultaneously, the MS can realize polarization conversion. The MS and its orthogonal units were arranged in a chessboard‐type pattern and applied as the radiator of a larger MS slot antenna, which was fed by a sequentially rotated feeding network. In addition, owing to the anti‐phase cancellation and scattering, the 5‐dB average RCS reduction can be obtained within the frequency range from 3.8 to 6.9 GHz. For verification, the proposed larger circularly polarized antenna was fabricated and tested. The operating bandwidth was measured as 44% (3.78–5.91 GHz) with a 3‐dB AR bandwidth of 39.6% and a high gain of 10.3 dBic. Furthermore, the larger antenna produces a useful RCS reduction from 3.7 to 6.7 GHz. The simulated and measured results are in good agreement. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to examine how the usage of enterprise social media (ESM) affects eventual employee turnover. Design/methodology/approach: This study developed a theoretical model based on the proposition that different ESM usage behaviors (utilitarian use, hedonic use and social use) have different effects on employee turnover, and job type and job level can moderate the effect of ESM usage on turnover. The model was examined empirically using 1,791 employee samples from a large high-tech manufacturing enterprise deploying ESM. Findings: The results indicate that the utilitarian and social use of ESM has negative effects on turnover, but the hedonic use of ESM has positive effects on turnover. Furthermore, for employees working in different job types and job levels, there are significant differences concerning the effect of ESM usage on their turnover. Practical implications: ESM managers should encourage employees to use ESM for utilitarian needs and social support but restrict excessive use of ESM for leisure. In addition, different ESM use policies depending upon job types and job levels could be adopted to retain valuable employees. Originality/value: Few studies have focused on how usage of ESM affects eventual employee turnover. Given the lack of theoretical research and empirical evidence, the authors developed a theoretical model and conducted an empirical study to fill the research gap. [ABSTRACT FROM AUTHOR]

The substructure of cross-sea bridge has its unique structural form, the calculation of drag force is related to working, designing, constructing and maintaining of the bridge in the marine environment. So in order to guarantee the construction and use safely, accurate and convenient calculation method of drag force is necessary. The calculation method of drag force theory is studied in this paper, with using shear stress transport model to set up eddy viscosity model, which is adopted to establish the numerical water tank and analysis the whole process of eddy generation and shedding in the wake area. Considering the features of cross-sea bridge substructure, the effect of the flow velocity, the depth of water and the section form of pier on the drag force is researched. The difference between the superposition method and integral calculation method, which are used for calculating the drag force of group pile cap composite structure, is studied. The results show that the water flow velocity is square relation with the drag force, and the depth of water is linear relation with the drag force. The drag coefficient CD of round-ended pier is 1.35, which is between the values of circular pier and rectangular pier. Due to the shield and interference with each component, the drag force calculated by integral method is less than the other one, and the lift force can be considered in the integral method. [ABSTRACT FROM AUTHOR]

The aim of this study was to optimize the concentrations of l-cysteine ( l-cys), composite phosphate ( CP) and sucrose ester of fatty acid ( SE-15) in the immersion solution to inhibit the yellowness and to maintain sensory score of cooked rice during storage. The well-fitted regression equations both for the yellowness and for the sensory score of cooked rice were obtained, with the R2 values of 0.946 and 0.881, respectively. The predicted lowest yellowness and highest sensory score were 5.619 and 82.801, and the optimized concentrations of l-cys, CP and SE-15 were 0.03, 0.16 and 0.15%, respectively. The verification results showed that the lowest yellowness and highest sensory score were 5.633 and 82, which was in accordance with the predicted value. Practical Applications Cooked rice is one of the most important ready-to-eat meals in human daily life. But during storage, it is easy for them to undergo non-enzymatic browning reaction, which has an influence on the color and sensory quality of cooked rice and reduce the commercial value for cooked rice. The main utility of this research is the application of food additive combinations based on l-cysteine in cooked rice, which can be considered a novel technique to maintain the quality of cooked rice during storage. The color and sensory analyses on stored cooked rice can confirm that the combined food additives of l-cysteine, composite phosphate and sucrose ester of fatty acid could inhibit the yellowness and maintain sensory score of cooked rice during storage. The use of this technique could maintain the quality of cooked rice and increase its commercial value. [ABSTRACT FROM AUTHOR]

Deng, S., 2020. Marine human resource supply mechanism based on innovation demand. In: Li, L. and Huang, X. (eds.), Sustainable Development in Coastal Regions: A Perspective of Environment, Economy, and Technology. Journal of Coastal Research, Special Issue No. 112, pp. 174-176. Coconut Creek (Florida), ISSN 0749-0208. With the economic development entering the new normal, China's coastal marine industry is gradually transforming and upgrading, which requires a large number of marine professional human resources. By supporting the optimization of talent team, talent innovation has become the competitive theme of the times, which will lead to severe test of marine professionals. With the "overcapacity" of middle and low-end marine talents, the problem of talent homogenization has become the main problem. Therefore, based on the innovation demand of marine industry, we should improve the supply mechanism of marine human resources, which will cultivate more skilled talents and high-level innovative scientific and technological talents. Under the strategic background one belt, one road, the demand for marine human resources will continue to increase, which needs to improve the supply mechanism of human resources. Combined with the marine economic industry and professional division of labor, we can improve the training output of marine economy advanced human resources based on innovation demand, which will strengthen the human resources supply mode shared by colleges and enterprises. Finally, some suggestions are put forward. [ABSTRACT FROM AUTHOR]

A battery thermal management system (BTMS) ensures that batteries operate efficiently within a suitable temperature range and maintains the temperature uniformity across the battery. A strict requirement of the BTMS is that increases in the battery discharge rate necessitate an increased battery heat dissipation. The advantages of heat pipes (HPs) include a high thermal conductivity, flexibility, and small size, which can be utilized in BTMSs. This paper experimentally examines a BTMS using HPs in combination with an aluminum plate to increase the uniformity in the surface temperature of the battery. The examined system with high discharge rates of 50, 75, and 100 A is used to determine its effects on the system temperature. The results are compared with those for HPs without fins and in ambient conditions. At a 100 A discharge current, the increase in battery temperature using the heat pipe with fins (HPWF) method is 4.8 °C lower than for natural convection, and the maximum temperature difference between the battery surfaces is 1.7 °C and 6.0 °C. The pulse circulation experiment was designed considering that the battery operates with a pulse discharge and temperature hysteresis. The depth of discharge is also considered, and the states-of-charge (SOC) values were 0.2, 0.5, and 0.8. The results of the two heat dissipation methods are compared, and the optimal heat dissipation structure is obtained by analyzing the experimental results. The results show that when the ambient temperature is 37 °C, differences in the SOC do not affect the battery temperature. In addition, the HPWF, HP, and natural convection methods reached stable temperatures of 40.8, 44.3, and the 48.1 °C, respectively the high temperature exceeded the battery operating temperature range. [ABSTRACT FROM AUTHOR]

Nonpiggable multiproduct pipelines lack effective methods for detecting the pipe's external defects (PEDs). Therefore, a pipeline remote magnetic detection (PRMD) technology for buried small-diameter pipelines was developed, which can achieve trenchless detection of PEDs. In this paper, an external pipe defect remote detection model is established to reveal the features of the three-dimensional magnetic gradient signal of PEDs. The quantitative relationship between the magnetic gradient modulus and defect depth was analyzed, and the influence of some factors was obtained. Furthermore, a PRMD method was established to detect a 3.56-km buried small-diameter multiproduct pipeline. The diagnostic indicator Fd based on the magnetic gradient modulus is proposed to determine damage levels of defective pipes, which was validated by the excavation inspection results. The results show that the magnetic gradient modulus G reaches a peak at PEDs. The maximum magnetic gradient modulus Gmax has an exponential relationship with the defect depth. Finally, 10 Level II defects and 19 Level III defects were found in the 3.57-km buried pipeline. [ABSTRACT FROM AUTHOR]

The article presents a language-action perspective study on the use of text analytics and design science to support sense-making in online discourse and social media. Topics include the need for greater coherence and better understanding of actions in online discourse, and the interest of organizations in understanding social media participants' actions and intentions.

We compared plaque characteristics between symptomatic and asymptomatic sides in patients with bilateral carotid vulnerable plaques using magnetic resonance imaging (MRI). Participants (n = 67; mean age: 65.8 ± 7.7 years, 61 males) with bilateral carotid vulnerable plaques were included. Vulnerable plaques were characterized by intraplaque hemorrhage (IPH), large lipid-rich necrotic core (LRNC), or fibrous cap rupture (FCR) on MRI. Symptomatic vulnerable plaques showed greater plaque burden, LRNC volume (median: 221.4 vs 134.8 mm3, P =.003), IPH volume (median: 32.2 vs 22.5 mm3, P =.030), maximum percentage (Max%) LRNC (median: 51.3% vs 41.8%, P =.002), Max%IPH (median: 13.4% vs 9.5%, P =.022), cumulative slices of LRNC (median: 10 vs 8, P =.005), and more juxtaluminal IPH and/or thrombus (29.9% vs 6.0%, P =.001) and FCR (37.3% vs 16.4%, P =.007) than asymptomatic ones. After adjusting for plaque burden, differences in juxtaluminal IPH and/or thrombus (odds ratio [OR]: 5.49, 95% CI: 1.61-18.75, P =.007) and FCR (OR: 2.90, 95% CI: 1.16-7.24, P =.022) between bilateral sides remained statistically significant. For patients with bilateral carotid vulnerable plaques, symptomatic plaques had greater burden, more juxtaluminal IPH and/or thrombus, and FCR compared with asymptomatic ones. The differences in juxtaluminal IPH and/or thrombus and FCR between bilateral sides were independent of plaque burden. [ABSTRACT FROM AUTHOR]

In this paper, an efficient numerical model for predicting the torsional fretting wear is developed, which considers the evolution of surface profile variables with the number of fretting cycles. The major advantage of this model is that it simulates the rough surface contact problems based on a semi-analytical method (SAM). The SAM is employed for calculating the pressure distribution and the relative displacement amplitude in the contact zone, combined with updating the surface profile based on the calculated nodal wear depth using a modified Archard׳s equation. The discrete convolution-fast Fourier transform (DC-FFT) technique and the conjugate gradient method (CGM) are adopted to improve the solving efficiency of the contact problem. At the same time, torsional fretting wear tests are carried out under a ball-on-flat configuration to obtain the wear coefficient and wear profiles. Finally, the wear profiles predicted by the numerical model for different loading cases have been compared with the corresponding experimental results. [ABSTRACT FROM AUTHOR]

Recently, health-related social media services, especially online health communities, have rapidly emerged. Patients with various health conditions participate in online health communities to share their experiences and exchange healthcare knowledge. Exploring hot topics in online health communities helps us better understand patients’ needs and interest in health-related knowledge. However, the statistical topic analysis employed in previous studies is becoming impractical for processing the rapidly increasing amount of online data. Automatic topic detection based on document clustering is an alternative approach for extracting health-related hot topics in online communities. In addition to the keyword-based features used in traditional text clustering, we integrate medical domain-specific features to represent the messages posted in online health communities. Three disease discussion boards, including boards devoted to lung cancer, breast cancer and diabetes, from an online health community are used to test the effectiveness of topic detection. Experiment results demonstrate that health-related hot topics primarily include symptoms, examinations, drugs, procedures and complications. Further analysis reveals that there also exist some significant differences among the hot topics discussed on different types of disease discussion boards. [ABSTRACT FROM AUTHOR]