改进蚁群算法的局部信息动态路径规划

针对传统蚁群算法收敛速度慢、对动态路径变化适应性低的局限性,提出了一种基于局部信息获取策略的动态改进型蚁群算法。该算法利用局部信息获取策略,进行最优局部目标点的获取,然后调用改进蚁群算法获取局部区域内的最优路径,再重复循环获取新的最优局部目标点,直到找到全局目标点。与此同时,将提出的改进型蚁群算法应用于动态路径规划中的路径寻优与避障,仿真结果表明：提出的算法在具有与传统蚁群算法相当的路径优化效果的同时,能够有效适应障碍变化、大大提高了路径规划的收敛速度。     

Electronic structures of efficient MBiO_-3(M= Li,Na, K,Ag) photocatalyst

In order to deepen the understanding of the relationship between fundamental properties(including: microstructure and composition) and photocatalytic performance, four bismuthate compounds, including: LiBiO_3, NaBiO_3, KBiO_3, and AgBiO_3, are regarded as research examples in the present work, because they have particular crystal structures and similar compositions. Using density functional theory calculations, their structural, electronic, and optical properties are investigated and compared systematically. First of all, the calculated results of crystal structures and optical properties are in agreement with available published experimental data. Based on the calculated results, it is found that the tunneled or layered micro-structural properties lead to the stronger interaction between bismuth and oxygen, and the weaker interaction between alkaline-earth metal and [BiO_6] octahedron, resulting in the feature of multi-band gaps in the cases of LiBiO_3,NaBiO_3, and KBiO_3. This conclusion is supported by the case of AgBiO_3, in which the feature of multi-band gaps disappears, due to the stronger interaction between the noble metal and [BiO_6] octahedron. These properties have significant advantages in the photocatalytic performance: absorbing low energy photons, rapidly transferring energy carriers. Furthermore, the features of electronic structures of bismuthate compounds are well reflected by the absorption spectra, which could be confirmed by experimental measurements in practice. Combined with the calculated results, it could be considered that the crystal structures and compositions of the photocatalyst determine the electronic structures and optical properties,and subsequently determine the corresponding photocatalytic performance. Thus, a novel Bi-based photocatalyst driven by visible-light could be designed by utilizing specific compositions to form favorable electronic structures or specific micro-structures to form a beneficial channel for energy carriers.     

温度对松木屑气化液体产物组成的影响

利用傅里叶变换红外光谱(FT-IR)和气质联用(GC/MS)技术,研究了松木屑在400~900℃气化液体产物的主要组成成分和液体产物主要化学组成的来源与转化随气化温度变化的规律。结果表明,松木屑低温气化液体产物主要为酮、呋喃和愈创木酚等含氧化合物。随气化温度升高,液体产物的组成发生显著变化,400~ 500℃主要发生愈创木酚向酚类化合物的转变,500~600℃主要发生酮、呋喃向酚类化合物的转变,600~700℃主要发生酚类向茚和PAHs (多环芳烃)的转变,700~900℃主要发生酚类化合物向PAHs的转变,900℃液体产物的组成为大分子量的PAHs。     

氧化锌表面包覆Sn6O4(OH)4的制备及其在锌镍电池中的应用

采用水热-共沉淀法在氧化锌表面包覆锡化合物,利用扫描电子显微镜（SEM）、X射线衍射（XRD）和能谱分析对制备的包覆ZnO材料进行表征。结果表明：XRD表明附着在氧化锌表面的是Sn₆O₄（OH）₄,且结晶度较好;SEM测试显示在pH=12条件下,Sn₆O₄（OH）₄能够很好地附着在氧化锌颗粒表面;能谱分析显示组成物中的元素包含Zn、Sn、O三种元素。利用循环伏安曲线、电化学阻抗谱（EIS）、倍率充放电技术对包覆ZnO材料进行了电化学性能的测试,结果表明：包覆Sn₆O₄（OH）₄的ZnO可以提高锌负极的耐蚀性能,增大电荷转移电阻（R_ct）;锌电极覆Sn₆O₄（OH）₄量为3%时充放电效率最佳,在0.2C充放循环40次后充放电循环保持率仍有70%。     

氧化锌表面包覆Sn_6O_4(OH)_4的制备及其在锌镍电池中的应用

采用水热-共沉淀法在氧化锌表面包覆锡化合物,利用扫描电子显微镜(SEM)、X射线衍射(XRD)和能谱分析(EDS)对制备的包覆ZnO材料进行表征。结果表明:XRD表明附着在氧化锌表面的是Sn_6O_4(OH)_4,且结晶度较好;SEM测试显示在p H=12条件下,Sn_6O_4(OH)_4能够很好地附着在氧化锌颗粒表面;EDS显示组成物中的元素包含Zn、Sn、O三种元素。利用循环伏安曲线(CV)、电化学阻抗谱(EIS)、倍率充放电技术对包覆ZnO材料进行了电化学性能的测试,结果表明:包覆Sn_6O_4(OH)_4的ZnO可以提高锌负极的耐蚀性能,增大电荷转移电阻(Rct);锌电极覆Sn_6O_4(OH)_4量为3%时充放电效率最佳,在0.2C充放循环40次后充放电循环保持率仍有70%。     

Ti阳极上电沉积制备Pb-聚丙烯腈-碳化钨复合镀层及其电化学性能

通过在酒石酸钾钠体系中加入聚丙烯腈（PAN）、碳化钨（WC）和PbO固体颗粒,在Ti阳极上电沉积制得Pb-PAN-WC复合镀层。 主要研究了电沉积工艺条件(电流密度、温度等)对Pb-PAN-WC复合镀层沉积速度及析氧动力学参数的影响。 在ZnSO4-H2SO4体系中测定的阳极极化曲线表明,最佳工艺条件及固体颗粒加入量为：电流密度1.5 A/dm2,温度35 ℃,15 g/L的PAN,40 g/L的WC。 通过和纯铅镀层的阳极极化曲线和析氧动力学参数对比可知,Pb-PAN-WC复合镀层的电化学性能优于纯铅镀层。     

Magnetic properties of electrodeposited copper-nickel composition-modulated alloys

Pulsed potentiostatic deposition offers a new technology for the production and stabilization of composition-modulated alloy (CMA) structures. Using this new technology, a series of Cu-Ni-modulated structures with layer thickness in the to 6 nm range were prepared. The first transmission electron micrographs of electrodeposited CMA are presented, showing the existence of sharp interfaces. Magnetic properties of the CMA structures were measured by vibrating sample and SQUID magnetometers, and by ferromagnetic resonance.     

型空间中随机指数函数系的完备性

该文采用了新的方法来研究由整函数组成的满足 ( ∫∫_C| f(z)|^pe^-α(|z|)dm_z)^1/p <∞ (1 < p <∞) 的Fock型空间中随机指数函数系的完备性. 还对于实轴上的加权Banach 空间讨论了类似的问题     

高水热稳定的有序介孔硅铝分子筛的合成与表征

将焙烧后的SBA-15先后置于微孔BEA沸石前驱体的稀释液和甘油中进行两次高温再结晶, 成功地合成了高度有序的介孔硅铝分子筛MSAMS-4, 并用XRD, TEM, FTIR, NMR和氮气吸脱附等手段对其进行表征. 水热稳定性实验结果表明, 将MSAMS-4 在100 ℃的沸水中处理120 h或在800 ℃的高温蒸气中处理6 h后, 其有序介孔结构仍然保持得相当完好.     

An analysis of ductile rupture modes at a crack tip

An elastic-Viscoplastic model of a ductile, porous solid is used to study the influence of the nucleation and growth of micro-voids in the material near the tip of a crack. Conditions of small scale yielding are assumed, and the numerical analyses of the stress and strain fields are based on finite strain theory, so that crack tip blunting is fully accounted for. An array of large inclusions or inclusion colonies, with a relatively low strength, results in large voids near the crack tip at a rather early stage, whereas small second phase particles in the matrix material between the inclusions require large strains before cavities nucleate. Various distributions of the large inclusions, and various critical strains for nucleation of the small scale voids between the inclusions, are considered. Localization of plastic flow plays an important role in determining the failure path between the crack tip and the nearest larger void, and the path is strongly sensitive to the distribution of the large inclusions. Values of the J-integral and the crack opening displacement at fracture initiation are estimated, together with values of the tearing modulus during crack growth, and these values are related to experimental results.