摘要：Based on the origin of message items and channel combination between transacting parties, and events and relations among events, this paper presents a concise, precise, and hierarchical model for general fair exchange protocols, formally specifies various security requirements which are able to reflect inherent requirements for fair exchange protocols more rigorously, and partition these security requirements with fine granularity. This work helps analyze, debug, and design multi-party fair exchange protocols more effectively and elaborately,

摘要：Network-on-chip(NoC) communication architectures present promising solutions for scalable communication requests in large system-on-chip(SoC) designs. Intellectual property(IP) core assignment and mapping are two key steps in NoC design, significantly affecting the quality of NoC systems. Both are NP-hard problems, so it is necessary to apply intelligent algorithms. In this paper, we propose improved intelligent algorithms for NoC assignment and mapping to overcome the drawbacks of traditional intelligent algorithms. The aim of our proposed algorithms is to minimize power consumption, time, area, and load balance. This work involves multiple conflicting objectives, so we combine multiple objective optimization with intelligent algorithms. In addition, we design a fault-tolerant routing algorithm and take account of reliability using comprehensive performance indices. The proposed algorithms were implemented on embedded system synthesis benchmarks suite(E3S). Experimental results show the improved algorithms achieve good performance in NoC designs, with high reliability.

摘要：The valuation of the hydraulic performance of a centrifugal pump with pre-whirl regulation of the inlet guide vanes was studied experimentally by varying the pre-whirl angle from -60° to 60° with distances between the inlet guide vanes and the impeller inlet of 280 mm, 380 mm and 460 mm. The efficiency-flow curves and the characteristic curves were obtained for the pump for various operation conditions. The experiment results demonstrated that the pre-whirl regulation widened the high efficiency zone and improved the hydraulic performance for off-design conditions with the proper pre-whirl angle. The axial distance between the inlet guide vanes and the impeller inlet influenced the pre-whirl regulation effect of the inlet guide vanes with the best pre-whirl regulation effect obtained for an axial distance of 380 mm. These results showed that an appropriate axial distance between the inlet guide vanes and the impeller inlet can improve the fluid flow at the impeller entrance with pre-whirl regulation for centrifugal pumps.

摘要：目前已有少量文献建立了光伏发电系统的小信号模型,并进行了动态过程灵敏度分析,但其建立的小信号模型未进行系统的小干扰稳定性分析和控制器参数的设计。为此,建立了包含光伏电池、逆变器、控制器及电网的完整的光伏发电系统小信号数学模型,利用特征值分析了系统遭受小干扰后的稳定性。利用参与因子分析得到每个特征模态对状态变量的敏感度,从而揭示出每个特征模态的起因和性质。通过计算特征值轨迹,设计了控制器参数。建立了基于Matlab/Simulink的仿真模型,仿真结果表明,系统遭受光照变化扰动后是稳定的,所设计的控制器参数是合理的,仿真结果与小信号分析结果一致,说明所进行的光伏发电系统小信号建模与分析是正确的。

摘要：The concurrent presence of different types of traffic in multimedia applications might aggravate a burden on the underlying data network, which is bound to affect the transmission quality of the specified traffic. Recently, several proposals for fulfilling the quality of service(QoS) guarantees have been presented. However, they can only support coarse-grained QoS with no guarantee of throughput, jitter, delay or loss rate for different applications. To address these more challenging problems, an adaptive scheduling algorithm for Parallel data Processing with Multiple Feedback(PPMF) queues based on software defined networks(SDN) is proposed in this paper, which can guarantee the quality of service of high priority traffic in multimedia applications. PPMF combines the queue bandwidth feedback mechanism to realise the automatic adjustment of the queue bandwidth according to the priority of the packet and network conditions, which can effectively solve the problem of network congestion that has been experienced by some queues for a long time. Experimental results show PPMF significantly outperforms other existing scheduling approaches in achieving 35--80% improvement on average time delay by adjusting the bandwidth adaptively, thus ensuring the transmission quality of the specified traffic and avoiding effectively network congestion.

摘要：A method to calculate the reflectivity of the coated cavity facet was proposed, and the distribution of the optical power near the two coated cavity facets was calculated for GaN-based laser diodes. A new design method for reducing the optical power at the two cavity facets without changing the output power of laser diodes was discussed, which is helpful to optimize the cavity facet coating and raise the threshold current at which catastrophic optical damage occurs.

摘要：OBJECTIVE:To explore the most effective parameters of Yi Zhi Chan Tuina manipulation for improving peripheral blood ***:A total of 45 volunteers were recruited from Pudong district in Shanghai,china,from October to December 2010,and randomly divided into nine groups using computer-generated random *** received Yi Zhi Chan Tuina manipulation on Chengjin(BL 56) acupoint;each group received a particular combination of manipulation force and treatment *** used a two-factor,three-level factorial design to examine the effects of force and treatment time on changes in popliteal artery average volume flow,pulsatility index,and vessel diameter to determine the optimal parameter *** were assessed at baseline and after Tuina manipulation by interviewers blind to treatment group ***:After manipulation,two of the nine groups showed an increase in popliteal artery volume *** inter-participants effect test showed that for main effect of time,F = 0.331,P = 0.720;for main effect of force,F = 2.934,P = 0.066;and for the force-time interaction effect,F = 1.072,P = 0.385,indicating no interaction between force and ***,a pairwise comparison of the three levels of time showed that a treatment time of 10 min was significantly more effective than that of 2 min(P = 0.024).A pairwise comparison of light force,medium force,and heavy force showed a statistically significant effect for medium force(P = 0.035).CONCLUSION:Yi Zhi Chan Tuina manipulation with vertical force of 9.31 N for 10 min is most effective in improving peripheral circulation.

摘要：The molecular structures of metal precursors in the impregnating solution were designed so as to prepare efficient Ni Mo/Al_2O_3 hydrodesulfurization(HDS) catalysts. At first, five typical impregnating solutions were designed; the existing metal precursors, such as [Mo4(citrate)2O11]^(4-)-like, [P2Mo18O62]^(6-)-like and [P2Mo5O23]^(6-)-like species in the solutions were confirmed by laser Raman spectroscopy(LRS). The UV-Vis spectra results indicated that the solutions containing both phosphoric acid and citric acid could change the existing form of nickel species. Five corresponding Ni Mo/Al_2O_3 catalysts were prepared by the incipient wetness impregnation method. The LRS analysis results of dried catalysts showed that the above metal precursors could be partly retained on alumina support after impregnation and drying, although the interface reaction between different metal precursors and alumina support unavoidably took place. Then the catalysts were sulfided and characterized by N2 physisorption, TEM and XPS analyses. The results showed that different metal precursors in impregnating solution could mainly result in the difference in both the morphology of(Ni)Mo S2 slabs and the promoting effect of Ni species. The catalyst prepared mainly with [P2Mo5O23]^(6-)-like species used as precursors exhibited worse dispersion of(Ni)Mo S2 slabs and lower ratio of Ni–Mo–S active phases than the one with [Mo4(citrate)2O11]^(4-)-like species. Promisingly, the catalyst prepared with co-existing [Mo4(citrate)2O11]^(4-)-like, [P2Mo18O62]^(6-)-like and [P2Mo5O23]^(6-)-like species showed better hydrodesulfurization activity for 4,6-DMDBT thanks to its more well-dispersed Ni–Mo–S active phases.

摘要：氢气是一种清洁能源,利用半导体光催化技术将水转化成氢气是解决全球能源危机和环境污染问题的有效途径之一.开发高效的光催化体系以实现水分解产氢是目前能源领域中的一个研究热点.六方相的ZnIn_2S_4 是一种三元金属硫化物,因其具有能够吸收可见光的窄带隙(约2.4 eV)和良好的化学稳定性,在光催化产氢方面得到了较好应用.在半导体光催化产氢体系中,往往需要加入助催化剂来提供产氢活性位并降低产氢反应的过电位,这种半导体/助催化剂体系中光催化产氢效率不仅取决于助催化剂的组成和结构,还受二者界面之间光生电子传输效率的影响.我们课题组前期研究发现,NiS作为一种廉价的非贵金属助催化剂能够提高ZnIn_2S_4 在可见光下的光催化产氢活性.考虑到碳量子点(CQDs)是一种具有良好导电能力的纳米材料,并已被负载于半导体光催化剂上来促进半导体表面光生电子的传输,本文将CQDs作为光生电子传输的"桥梁"引入到NiS/ZnIn_2S_4 体系中,用来促进光生电子从ZnIn_2S_4 到NiS的定向传输,从而提高其光催化产氢效率.实验首先合成Ni S/CQDs复合材料,然后在其存在下进行ZnIn_2S_4 的自组装制得Ni S/CQDs/ZnIn_2S_4 .利用X射线粉末衍射、扫描电镜、透射电镜、傅立叶红外光谱、X射线光电子能谱和紫外-可见漫反射光谱对催化剂的组成、结构及光学性质进行了详细表征,考察了其在可见光下以三乙醇胺(TEOA)为牺牲剂时的光催化分解水产氢性能.结果表明,含有CQDs的NiS/CQDs/ZnIn_2S_4 光催化剂在光照5 h后的产氢总量达到142μmol,分别为相同条件下ZnIn_2S_4 和NiS/ZnIn_2S_4 产氢总量的5.5和1.6倍.相比于通过将Ni S沉积在预先合成的CQDs/ZnIn_2S_4 上所获得的CQDs/NiS/ZnIn_2S_4 光催化剂, NiS/CQDs/ZnIn_2S_4 显示出更优越的光催化产氢活性.TEM观测发现,在NiS/CQDs/ZnIn_2S_4 中CQDs与ZnIn_2S_4 和NiS均有明显的接触,表明CQDs作为"桥梁"连接了ZnIn_2S_4 和NiS,这种结构有利于光生电子由ZnIn_2S_4 至NiS定向传输.而CQDs/NiS/ZnIn_2S_4 光催化剂中的CQDs和NiS没有直接接触.电化学交流阻抗实验发现, NiS/CQDs/ZnIn_2S_4 中电子的传导能力比CQDs/NiS/ZnIn_2S_4 中的强,说明相比于CQDs/NiS/ZnIn_2S_4 ,在NiS/CQDs/ZnIn_2S_4 中的CQDs更有效地促进了光生电子由ZnIn_2S_4 至NiS定向传输.该研究提供了一种以CQDs作为促进光生电子定向传输的"桥梁"来构筑高效产氢光催化体系的方法.

摘要：Bioactive scaffolds with interconnected porous structures are essential for guiding cell growth and new bone formation. In this work, we successfully fabricated three-dimensional (3D) porous $$\upbeta $$ -tricalcium phosphate ( $$\upbeta $$ -TCP)/calcium silicate (CS) composite scaffolds with different ratios by 3D printing technique and further investigated the physiochemical properties, in vitro apatite mineralization properties and degradability of porous $$\upbeta $$ -TCP/CS scaffolds. Moreover, a series of in vitro cell experiments including the attachment, proliferation and osteogenic differentiation of mouse bone marrow stromal cells were conducted to testify their biological performances. The results showed that 3D printed $$\upbeta $$ -TCP/CS scaffolds possessed of controllable internal porous structures and external shape. Furthermore, the introduction of CS decreased the shrinkage of scaffolds and improved the in vitro apatite formation activity and degradation rate. Meanwhile, compared with pure $$\upbeta $$ -TCP scaffold, the $$\upbeta $$ -TCP/CS composite scaffolds were more conducive to promote cell adhesion, spread and osteogenesis differentiation. However, when the content of CS was increased to 45%, the ions dissolution rate of the composite scaffolds was so high that leaded to the increase in pH value, which inhibited the proliferation of cells. Our results suggested that the introduction of appropriate CS into $$\upbeta $$ -TCP bioceramic is an effective strategy to prepare bioactive 3D printed bioceramic scaffolds for hard tissue regeneration.