浮游植物分布对强台风尼格的响应

研究调查了Ekman流对浮游植物生态动力过程的驱动机制。采用新的光学遥感算法提取浮游植物光学有效信息。该算法结合了近红外波段的浮游植物荧光信号以及可见光部分的弹性散射的辐射传输模型,通过两次迭代优化算法,提取浮游植物光学信号。采用辐射传输软件Hydrolight对海水水下光场进行了数值模拟,并结合新算法对模拟数据进行了对比分析。结果表明,新算法较好地表征了浮游植物叶绿素光学参数。利用MERIS光学遥感数据并结合了动力学参数,利用该算法分析了强台风尼格对我国海域浮游植物分布的影响。研究结果表明,Ekman流是我国海域浮游植物分布异常的原因之一。     

Structural and mechanical stability of the nano-crystalline Ni–Ti (50.9 at.% Ni) shape memory alloy during short-term heat treatments

In this study, the nano-crystalline Nitinol (50.9 at.% Ni) was prepared by 40% cold deformation. Subsequently it was subjected to 15-min-heat treatments at 300–550 °C. Changes of the structure and mechanical properties were studied by transmission electron microscopy, micro X-ray diffraction, differential scanning calorimetry, Vickers hardness measurements, tensile and bend-type fatigue testing. It was shown that the cold drawn material contains textured nano-crystalline B2 grains of 50 nm in thickness and a high concentration of lattice defects. Its tensile strength, hardness and fatigue life were 1521 MPa, 421 HV0.05 and 2435 bending cycles to fracture, respectively. After heat-treatment up to 450 °C/15 min the material underwent Ni₄Ti₃ precipitation and partial recovery processes. Heat-treatments at above 450 °C induced recrystallization, grain and precipitate growth. Hardness and fatigue lives showed maxima of 692 HV0.05 and 5883 cycles, respectively, after heat-treatments at 450 °C/15 min. In contrast, both tensile strength and B2 → B19′ transformation stress decreased with increasing heat-treatment temperature, but a decrease of the tensile strength after heat-treatments at 300–450 °C was slow (tensile strength after heat-treatment at 450 °C/15 min was 1486 MPa). The observed variations of mechanical characteristics were discussed in relation to structural changes observed.     

Experimental investigation on the effect of ambient pressure on thermal runaway and fire behaviors of lithium‐ion batteries

To investigate the impacts of ambient pressure on thermal runaway and fire behaviors of lithium‐ion battery (LIB), experimental measurement and theoretical analysis with serial conditions are conducted at two altitudes. The well‐designed experimental equipment and operating conditions have enabled the accurate evaluation of ambient pressure effects. Results show that the first abrupt temperature change in Hefei (ambient pressure 100.8 kPa) is higher than that in Lhasa (64.3 kPa). The difference in ambient pressure at two altitudes leads to different relief valve crack temperature and time. The average burning rate in Hefei is larger than that in Lhasa, and the estimated pressure effect factor is quite different for detailed pack conditions and varies within the range of 0.083‐1.39. The ambient pressure has a greater effect on the heat release rate and total heat release than the mass loss, and the effective combustion heat under the low pressure is lower than that in normal condition. This work can provide more comprehensive and useful data for the safety management of LIBs at low pressure environments.     

基于光纤-无线网络的协同计算卸载算法

随着无源光网络的发展,光纤-无线网络能同时支持集中式云和边缘云计算技术,成为一种具有发展前景的网络结构。但是,现有的基于光纤-无线网络的任务协同计算卸载研究主要以最小化移动设备的能耗为目标,忽略了实时性高的任务的需求。针对实时性高的任务,提出了以最小化任务的总处理时间为目标的集中式云和边缘云协同计算卸载问题,并对其进行形式化描述。同时,通过将该问题归约为装箱问题,从而证明其为NP难解问题。提出一个启发式协同计算卸载算法,该算法通过比较不同卸载策略的任务处理时间,优先选择时间最短的任务卸载策略。同时,提出一个定制的遗传算法,获得一个更优的任务卸载策略。实验结果表明,与现有的算法相比,本文提出的启发式算法得到的任务卸载策略平均减少4.34%的任务总处理时间,而定制的遗传算法的卸载策略平均减少18.41%的任务总处理时间。同时,定制的遗传算法的卸载策略与本文提出的启发式算法相比平均减少14.49%的任务总处理时间。     

Understanding continuance usage of mobile shopping applications in India: the role of espoused cultural values and perceived risk

We drew on the unified theory of acceptance and use of technology (UTAUT2) model, and perceived risk construct to propose an integrated model to explain continuance usage of mobile shopping applications. Espoused national cultural values of individualism/collectivism, masculinity/femininity, power distance, uncertainty avoidance, and long-term/short-term orientation act as moderators to examine the influence of within-culture variation on app usage. Findings reveal habit as the strongest predictor of both continuance intention and use behaviour, but interestingly perceived risk did not influence the post-acceptance behaviour of users significantly. Individualism/collectivism, masculinity/femininity, and long-term/short-term orientation espoused cultural values significantly moderated the relationships in the model. Noteworthy theoretical and managerial implications of the research are discussed further.     

Mobile Agent-Based Memory Tracer Using Host-Based Intrusion Detection System for Safeguarding Critical Memory

ABSTRACT

Intrusion in a host may cause damage to the critical memory, which contains important official files or databases. The mobile agent, a piece of code that makes parallel run on host, migrates through the network and performs the requested action. In this paper, we declare a new intrusion detection model using Host-Based Intrusion Detection System (HIDS) for identification and recovery strategies. A memory trace model has been designed to identify the intrusion detection by using a memory tracer mobile agent. Memory Checksum plays a vital role in the identification of the intrusion. This model is designed for intrusion into a host, which alters the critical memory.     

风-光-柴-储互补发电能源车系统关键技术研究

针对偏远地区用电难问题,设计了一种基于风力发电、光伏发电、柴油发电机组和蓄电池的移动电源车,充分考虑了电源车的技术特性、安全等问题。通过对风光柴储互补发电系统关键技术的研究,达到提高可再生能源利用率,降低排放和燃油消耗,增加移动电源系统的有效使用时间,降低系统对燃油的依赖程度,提高系统稳定性和灵活性等目标。     

A survey of ‘young social’ and ‘professional’ users of location-based services in the UK

The objective of this study was to assess the response to location-based services (LBS) by three key demographic groups within the United Kingdom. This study took the form of a survey of relevant demographics, attitudes and consumer behaviour undertaken via a web-based survey. Results are based on over 1200 respondents, filtered and segmented into three demographic groups who are typically early adopters of new technology. There were positive attitudes towards a range of LBS, with the major exception being location-based advertising. There were mixed views towards location-based gaming and safety camera information. There were low levels of awareness of many services. The levels of use were typically under 20% for all types of LBS.     

多被叫业务开展分析

基于互联网点对多点通信技术理念提出的多被叫业务，实现了一个主叫用户对多个被叫用户话音通信的同时建立，有效地改善了传统话音业务点对点通信效率的不足，提高了主叫用户的呼叫接通率．具有较强的应用价值。     

Development of a Compact and User-friendly Ion Irradiation System Controlled Remotely through the Internet

A compact and user-friendly ion irradiation system controlled remotely through the Internet was developed for the execution of collaboration experiments together with researchers at remote sites. Several hardware instruments and software programs were constructed and provided for the remote control of the system and for its connection to the Internet. Surface modification and analysis experiments with this system were remotely performed through the Internet. It was confirmed from the experiments that the present ion irradiation system was precisely controlled through the Internet and could be easily and safely used for the surface modification and analysis, that the normal communication speed of around 10Mbps for the Internet was fast enough for the execution of such typical remote-controlled experiments, and also that an access to the system by a mobile phone was convenient and useful enough to check the condition of the system and experimental data.