Effects of Exchange Benefits, Security Concerns and Situational Privacy Concerns on Mobile Commerce Adoption

Few empirical studies have examined both privacy and security concerns in the context of mobile commerce (m-commerce) while accounting for the effects of situational privacy concerns specific to the context of m-commerce. This research fills this gap in research by exploring users’ exchange perceptions specific to the context of m-commerce in China and by examining the inhibitors and drives of m-commerce adoption in China from the perspectives of social exchange. Particularly, this research develops an integrated research model in which users’ perceptions on value added of and usefulness of m-commerce, and users’ privacy concerns and security concerns of m- commerce are examined. The research model is empirically tested by using the survey data collected in a large city in China. Our findings confirmed the conceptualization of the research model and indicated that users’ perceived exchange benefits are the drivers of m-commerce use. Users’ security concerns hinder their intention to conduct m-commerce. Surprisingly, users’ privacy concerns seem not to have a significant impact on users’ favorable attitude toward m- commerce, but situational privacy concerns including location tracking and personalized use of user information significantly impact users’ general privacy concerns

优质护理服务在玻璃体切除术中的应用及效果评价

Objective: To explore the effect of good nursing care on vitrectomy. Methods: Focus on preoperative clinical interview, intraoperative safety and postoperative follow-up. Results: The patient is recovering well from the surgery due to good nursing care and close cooperation during the operation. Conclusion: Good nursing care before and after the surgery is the key to the success of the operation.目的  探讨优质护理服务在玻璃体切除术中的应用。方法  做好术前访视，术中安全及术后随访。结果  手术室工作人员的热情服务及术中密切配合，使手术顺利完成。患者十分合作，术后恢复良好。结论  术前、术中及术后的优质护理是手术成功的重要保证

UAV-enabled wireless power transfer with base station charging and UAV power consumption

Wireless power transfer (WPT) is a promising charging technology for battery-limited sensors. In this paper, we study the use of an unmanned aerial vehicle (UAV) as a charger for WPT. Unlike the previous works, our study takes into account the power consumption of the UAV (power consumption during hovering and flight), the charging process from a base station (BS) to the UAV and the conversion loss of the energy harvester. Both one-dimensional (1D) and two-dimensional (2D) WPT systems are considered. The sum-energy received by all sensors is maximized to find the optimal strategy for UAV deployment. Two different charging schemes are proposed. Numerical results show that the sum-energy received by all sensors is determined by sensors' topology, the flight speed of the UAV and the transmit power. They also show that, when the BS charging process and the UAV power consumption are considered in the optimization, the optimal location of the UAV in the 1D and 2D WPT systems is closer to the BS than in the previous works that ignore these two practical factors

Prediction of Stable Ground-State Lithium Polyhydrides under High Pressures

Hydrogen-rich compounds are important for understanding the dissociation of dense molecular hydrogen, as well as searching for room temperature Bardeen-Cooper-Schrieffer (BCS) superconductors. A recent high pressure experiment reported the successful synthesis of novel insulating lithium polyhydrides when above 130 GPa. However, the results are in sharp contrast to previous theoretical prediction by PBE functional that around this pressure range all lithium polyhydrides (LiHn (n = 2-8)) should be metallic. In order to address this discrepancy, we perform unbiased structure search with first principles calculation by including the van der Waals interaction that was ignored in previous prediction to predict the high pressure stable structures of LiHn (n = 2-11, 13) up to 200 GPa. We reproduce the previously predicted structures, and further find novel compositions that adopt more stable structures. The van der Waals functional (vdW-DF) significantly alters the relative stability of lithium polyhydrides, and predicts that the stable stoichiometries for the ground-state should be LiH2 and LiH9 at 130-170 GPa, and LiH2, LiH8 and LiH10 at 180-200 GPa. Accurate electronic structure calculation with GW approximation indicates that LiH, LiH2, LiH7, and LiH9 are insulative up to at least 208 GPa, and all other lithium polyhydrides are metallic. The calculated vibron frequencies of these insulating phases are also in accordance with the experimental infrared (IR) data. This reconciliation with the experimental observation suggests that LiH2, LiH7, and LiH9 are the possible candidates for lithium polyhydrides synthesized in that experiment. Our results reinstate the credibility of density functional theory in description H-rich compounds, and demonstrate the importance of considering van der Waals interaction in this class of materials.Comment: 34 pages, 15 figure

A review of the open charm and open bottom systems

Since the discovery of the first charmed meson in 1976, many open-charm and open-bottom hadrons were observed. In 2003 two narrow charm-strange states $D_{s0}^*(2317)$ and $D_{s1}(2460)$ were discovered by the BaBar and CLEO Collaborations, respectively. After that, more excited heavy hadrons were reported. In this work, we review the experimental and theoretical progress in this field.Comment: Review accepted by Reports on Progress in Physics, 161 pages, 53 figures, 23 tables, more references added and review on heavy baryons adde