浅述电子清纱器检测头电磁铁的设计

在电子清纱器检测头工作原理的基础上,引入了对电磁铁的介绍,并运用拍合式电磁铁工作原理对磁路进行了分析、计算,并得出了电磁铁吸合力的计算方法。明确了电磁铁吸合力的计算、实验是电子清纱器检测头设计的重要基础环节,进而对电子清纱器检测头电磁铁的设计方法给出指导意见。     

模糊数值函数Henstock-Stieltjes积分

研究模糊数值函数关于实值函数的Henstock-Stieltjes积分.运用模糊数空间上的hausdorff距离和模糊数值函数关于实值函数的Henstock-Stieltjes积分的定义,引入了此类积分的定义.给出了线性、依积分区间的可加性等基本性质,证明了模糊数值函数Henstock-Stieltjes积分可积的存在性定理.推广了模糊数值函数关于实值函数的Henstock积分的相关结论.     

海红果中总黄酮提取工艺研究

以海红果为原料,在单因素试验的基础上,采用二次回归正交旋转组合设计,研究了提取海红果中总黄酮的最佳工艺参数。结果表明,4个参试因素对海红果中总黄酮的提取率影响大小顺序依次为：料液比〉乙醇浓度〉提取时间〉提取温度;其最佳提取工艺条件为乙醇浓度60%、料液比1∶50、提取温度40℃、提取时间150min。在此优化条件下,提取的海红果中总黄酮含量可达0.2900%。     

The use of ferrites as highly active oxygen storage materials for chemical looping hydrogen production under intermediate temperature

Shifting chemical looping from high temperatures to intermediate temperatures could mitigate the materials from sintering and benefit for longer durability as well as process economy. However, oxygen carriers cannot perform sufficiently due to the degrading effect at lower temperatures, resulting in the decrease of hydrogen production ability. Although doping precious metals can improve the poor performance at intermediate temperatures, the high cost impeded their large-scale application. In this paper, a range of oxygen carrier materials consisted of earth abundant elements were prepared for chemical looping hydrogen production. The results indicated that CoFe₂O₄ exhibited the highest hydrogen yield of 11.9 mmol·g⁻¹ and hydrogen production rate of 0.051 mmol g⁻¹·s⁻¹ at 650 °C, which was 1.7 times higher than that of Fe₂O₃. A combined experimental and DFT calculation method was used to understand the mechanism behind the performance. The results indicated that the synergistic effect between Co and Fe increased the reactivity of the ferrite materials. The enhanced hydrogen production performance was attributed to the high reduction degree and reversible phase change. This study can be also extended to develop more active oxygen carrier for chemical looping processes at intermediate temperatures.     

具有加强诊断措施的Filippov HIV/AIDS传染病模型（英）

本文建立 Filippov HIV/AIDS 传染病模型,用以刻画如下诊断措施：一旦已诊断 HIV 感染者数量超过某一水平,便启用加强的诊断措施;否则实施普通的诊断措施．应用等效控制法讨论了所建立模型的滑动模式区域和滑动动力学,在此基础上通过定性分析讨论了模型的全局动力学．数值结果表明,当阈值水平足够高或足够低时,HIV 感染者数量最终稳定在一个相对较高或较低的水平;若选取一个恰当的阈值,HIV 感染者数量最终会围绕该阈值波动．这说明阈值水平的选取对控制 HIV 至关重要,据此可确定是否有必要实施加强的诊断措施．     

基于乐观和悲观策略的犹豫模糊粗糙集方法

已有的犹豫模糊粗糙集并未考虑多源信息处理的需要.为了解决这一问题,文中分别提出乐观多粒度犹豫模糊粗糙集模型和悲观多粒度犹豫模糊粗糙集模型,并详细分析这两种模型的理论性质.最后通过一个多源信息系统的实例对比分析乐观和悲观形式下的近似集.     

子结构中的次极大子和次极小子

在子结构中引入了次极大子和次极小子的概念,讨论了它们的性质,并得到子的如下分解定理：子结构中的任一子都可表示为一些次极大（小）子的交（并）,特别地,在满足子降链条件的子结构中,每个子都可表示为有限个次极大子的交。     

基于新模型的动态多目标优化进化算法

在动态多目标优化中,各目标通常相互冲突,其最优解往往有无穷多个,如何在时间连续发生变化的情况下依然能求出分布均匀且数量多的Pareto最优解供决策者选择十分重要.对动态多目标优化问题连续变化的时间变量区间进行了任意划分,在得到的每个时间子区间上把动态多目标优化问题近似为静态多目标优化问题,进而在每个子区间上定义了种群的静态序值方差和静态密度方差,然后把目标个数任意的动态多目标优化问题转化成一个双目标静态优化问题.在给出的一种能自动检测时间变化的自检算子下,提出一种新的动态多目标优化进化算法,并且证明了算法的收敛性.计算机仿真表明新算法对动态多目标优化问题求解十分有效.     

Enabled/disabled predicate encryption in clouds

Predicate encryption is a cryptographic primitive that provides fine-grained control over access to encrypted data. It is often used for encrypted data search in a cloud storage environment. In this paper, we propose an enabled/disabled predicate encryption scheme, which is the first work that provides timed-release services and data self-destruction (they correspond to the terms “enabled” and “disabled,” respectively). Owing to these properties, the sender can set the readable/unreadable time of the files to be sent to the receiver. The receiver can read the sent file only after the readable time. After the unreadable time, the structure of the file will be destroyed and the file will become unreadable. Furthermore, for practical usage purposes, the extended scheme, which is based on the proposed scheme, provides not only timed-release services and data self-destruction but also long message encryption and undecryptable search. In the extended scheme, the length of encrypted messages does not depend on the order of the group. Moreover, the cloud server can obtain only the matched ciphertexts after the search.