杂氮硅三环化合物(Ⅰ)和(Ⅱ)晶体结构的研究

杂氮硅三环化合物Ⅰ和的分子结构用直接法解,经全矩阵最小二乘修正,得到它们的晶体学参数。并对它们的结构进行了比较和讨论。     

聚苯胺的合成及其摩擦学行为的研究

选择合适的ＳＤＢＳ／ 苯胺／ 水三组分Ｏ／Ｗ 微乳液与苯胺单体共存的两相体系,以单体相为单体源,在Ｏ／Ｗ 三组分微乳液中进行了苯胺聚合,成功地制备出了能够稳定分散于石腊油的聚苯胺微粒。并在四球试验机上研究合成条件、负荷、浓度对其摩擦学行为的影响。结果表明：聚苯胺有一定的减摩抗磨效果     

焙烧温度对铁基催化剂催化浆态床F-T合成反应性能的影响

 采用连续共沉淀与喷雾干燥成型技术相结合的方法制备了微球形Fe-Cu-K-SiO2催化剂,并考察了焙烧温度对催化剂的结构和织构性质的影响. 结果表明,催化剂具有较好的织构和结构热稳定性,粘结剂SiO2起到了分散和稳定α-Fe2O3晶相的作用. 随着焙烧温度的升高,催化剂的比表面积逐渐减小,α-Fe2O3晶粒逐渐增大,催化剂体相中的Cu和K原子向表面富集,且Cu向表面的迁移更明显; 同时,催化剂中的α-Fe2O3和CuO相发生了一定程度的离析,Cu的助剂作用减弱,使催化剂在合成气气氛下难于还原碳化. 催化剂在n(H2)/n(CO)=0.67,GHSV=2.0 L/(g·h),p=1.5 MPa和θ=250 ℃下的浆态床F-T合成反应评价结果表明,升高焙烧温度,催化剂的初活性和最高活性下降,但运行稳定性提高,而且有效地抑制了CH4的生成,明显促进了烃产物向高碳数方向移动. 反应600 h后卸载下的催化剂的形貌观测表明,催化剂的磨损主要是由化学磨损引起的,提高焙烧温度可明显改善其抗磨损性能,焙烧温度高于400 ℃时,催化剂具有较好的抗磨损性能.     

Track initiation with ant colony optimization

Since the issue of track initiation belongs to the NP-hard problem in the bearings-only multi-sensor-multi-target tracking system, a novel proposed track initiation technique is proposed in this paper. The proposed track initiation technique is based upon an ant colony optimization (ACO) algorithm, a kind of heuristic optimization method. Observing that each target is of the characteristic of uniform rectilinear motion, we develop a new cost function derived from the thought of Hough transform. Numerical simulation results show that the proposed ACO-based track initiation method not only meets the requirement of real time, but also performs better than other traditional techniques, especially in the scenario that all targets move in parallel.     

The Geodesic Problem in Quasimetric Spaces

In this article, we study the geodesic problem in a generalized metric space, in which the distance function satisfies a relaxed triangle inequality d(x,y)≤σ(d(x,z)+d(z,y)) for some constant σ≥1, rather than the usual triangle inequality. Such a space is called a quasimetric space. We show that many well-known results in metric spaces (e.g. Ascoli-Arzelà theorem) still hold in quasimetric spaces. Moreover, we explore conditions under which a quasimetric will induce an intrinsic metric. As an example, we introduce a family of quasimetrics on the space of atomic probability measures. The associated intrinsic metrics induced by these quasimetrics coincide with the d _α metric studied early in the study of branching structures arisen in ramified optimal transportation. An optimal transport path between two atomic probability measures typically has a “tree shaped” branching structure. Here, we show that these optimal transport paths turn out to be geodesics in these intrinsic metric spaces. This work is supported by an NSF grant DMS-0710714.     

8～10轮AES-128的biclique攻击

高级加密标准(AES)是信息安全中实现数据加密、认证和密钥管理的核心分组密码算法,其安全性分析是密码学的重要课题之一.本文利用AES独立的相关密钥差分,构造了3轮biclique;基于该biclique,使用重计算技术,针对8~10轮AES-128给出新攻击.研究结果表明,攻击8轮AES-128所需的数据复杂度为264选择密文,时间复杂度为2125.29次加密;攻击9轮AES-128所需的数据复杂度为264选择密文,时间复杂度为2125.80次加密;攻击10轮AES-128所需的数据复杂度为264选择密文,时间复杂度为2126.25次加密.与已有的同轮攻击结果相比,新分析所需要的时间复杂度或数据复杂度降低.     

Estimation of Lyapunov spectrum and model selection for a chaotic time series

The estimation of the Lyapunov spectrum for a chaotic time series is discussed in this study. Three models: the local linear (LL) model; the local polynomial (LP) model and the global radial basis function (RBF) model, are compared for estimating the Lyapunov spectrum in this study. The number of neighbors for training the LL model and the LP model; the number of centers for building the RBF model, have been determined by the generalized degree of freedom for a chaotic time series. The above models have been applied to three artificial chaotic time series and two real-world time series, the numerical results show that the model-chosen LL model provides more accurate estimation than other models for clean data set while the RBF model behaves more robust to noise than other models for noisy data set.     

Selective sensing of H(2)PO(4)(-) (Pi) driven by the assembly of anthryl pyridinium ligands

Synthesis of a simple amidopyridinium-based sensor (F1) and its fluorescence behavior toward H(2)PO(4)(-) (Pi) were investigated. The anthryl group in F1 exhibited a strong excimer emission via Pi-directed assembly of F1; other anions showed a negligible effect. The Pi-induced assembly of F1 was rationalized by photophysical experiments and DFT calculation.     

Identity-Based Quantum Designated Verifier Signature

International Journal of Theoretical Physics - Designated verifier signatures are very useful in the applications such as e-voting and auction. In this paper, an identity-based quantum designated...     

30cm大屏幕高分辨率X光电视光学系统研究

本研究发表了30cm大屏幕高分辨率电视光学系统所采用的参数、系统设计、结构特点和所能达到的性能指标。该系统已通过广研制并投入批量生产。