基于主色偏差矩阵的图像检索方法

颜色特征是图像检索领域中最为重要的视觉特征之一.对于基于颜色的图像检索系统,其性能在很大程度上取决于颜色特征的描述和匹配方法的有效性.本文使用主色偏差矩阵来描述颜色特征,并使用相关系数进行相似性度量.经实验证明,该方法对于图像的几何变换和空间变换,具有较高的检索查全率.     

基于电子舌技术的辛味中药材鉴别研究

为检验电子舌对辛味中药材种类与质量的鉴别能力,应用传感器矩阵系统ASTREE电子舌分别对不同种类,不同产地以及不同生产批次的辛味中药材进行检测,所得数据用主成分分析法(PCA)进行分析处理。结果表明:该电子舌不仅可以很好地区分6种不同的辛味中药材,而且对于同种类型不同产地,不同生产批次的中药材样本也有很好的辨识能力。由此可见,电子舌在辛味中药材的种类鉴别中有巨大的应用潜力。     

Evidence of the vital role of the pore network on various catalytic conversions of N2O over Fe-silicalite and Fe-SBA-15 with the same iron constitution

Fe-silicalite and Fe-SBA-15 with similar iron content have been characterized by N₂ adsorption, small angle X-ray scattering (SAXS), wide-angle X-ray scattering (WAXS), scanning electron microscopy (SEM), high-resolution transmission electron micrographs (HRTEM), UV–vis–DRS and EPR, and tested in direct N₂O decomposition, N₂O reduction by CO and N₂O-mediated propane oxidative dehydrogenation. Both catalysts contain almost exclusively isolated Fe³⁺ sites of similar concentration and structure, which are, however, stabilized in markedly different pore geometries (intersecting channels of ca. 0.55 nm diameter in Fe-silicalite versus parallel linear pores of ca. 7.5 nm diameter in Fe-SBA-15). This aspect is of vital importance in order to exclusively ascribe different catalytic performances to the environment where the iron species are stabilized. Fe-silicalite revealed to be much more active than Fe-SBA-15 in all reactions studied. This clearly illustrates that the confinement of the iron species in pores of suitable geometry (structure and size) is essential to originate their remarkable catalytic properties. The large pores in ordered mesoporous materials apparently do not generate the required intimate contact between potentially active Fe sites and reactant molecules.     

Comparative psychology 25 years after.

Examined articles published in the Journal of Comparative and Physiological Psychology (JCPP) and Animal Behavior (AB) in the 25 yrs since F. A. Beach first surveyed the literature in 1950. In the JCPP, the number of species studied remained relatively low in view of the greatly increased number of articles published, while the reverse was true of AB, whose articles were also more diversified in terms of number of species. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Formation mechanism of nano-diamond films from energetic species: From experiment to theory

In this paper, a particular class of nano-diamond films deposited by energetic species is described. Deposition is carried out using the direct-current glow-discharge (DC GD) deposition technique from a methane/hydrogen mixture. In this method, film growth occurs from energetic species being accelerated and incorporated into the film surface. The growth of the nano-diamond film occurs on top of a preferentially oriented graphitic precursor with its basal planes perpendicular to the substrate surface. The nano-diamond films consist of an agglomerate of diamond particles with particle sizes in the 3-5 nm range with amorphous grain boundaries. The hydrogen concentration in the graphitic precursor is only a few percent; however, it increases to ∼15-20 at.% in the nano-diamond film.From a microscopic perspective nano-diamond film and growth from energetic species is explained as a sub-surface process in terms of a four-step cyclic process. The DC GD-deposited nano-diamond films were comprehensively explored by a number of complementary techniques. The hydrogen content and its role in nano-diamond film formation were assessed. The experimental methods used in our studies comprise near-edge X-ray adsorption fine structure (NEXAFS) to prove the short-range coordination of the carbon films and indirectly their phase composition. The surface and grain boundary phase composition were investigated by a combination of electron energy loss spectroscopy (EELS) measured as a function of incident electron energy and hydrogen etching experiments. By transmission electron microscopy (TEM), the micro-structural evolution and their visualization were achieved. The density evolution of the films was determined by X-ray reflectivity (XRR). The hydrogen content and its distribution in the films were studied by secondary ion microscopy spectroscopy (SIMS) and elastic recoil detection (ERD). The hydrogen bonding was investigated by high-resolution electron energy loss spectroscopy (HREELS).Most likely, hydrogen is bonded within the amorphous grain boundaries and saturates the nano-diamond particles. The surface of the films is amorphous in nature.     

基于模式聚类的二级电压控制分域方法研究

为更好解决二级电压控制分域问题,研究一种基于可视化自组织特征映射网络聚类技术的分域方法.根据自组织特征映射网络的拓扑保持、信息融合和高维数据矢量量化的特性,建立系统电压分域可视拓扑映射模型,以拓扑映射图为基础进行二级电压控制分域.在此基础上,提出以熵作为测度搜索主导节点.该分域算法融合了节点电压、相角和灵敏度等信息,利于分区间的控制解耦.该方法可离线训练,在线计算.     

荫生植物专类园的规划设计及其探讨

湖南省森林植物园位于长沙市雨花区洞井铺，建 于1985年.在此基础上，1992年又建成了“天际岭国 家森林公园”，隶属湖南省林业厅.全园面积140h扩， 森林覆盖率达90%，林相整齐，植物生长旺盛，森林环 境优美.该园海拔50一106m，属低丘岗地地貌，丘岗 坡度平缓，坡度在20度以下     

A Comparative Study of the Use of Visual Communicative Signals in Interactions Between Dogs (Canis familiaris) and Humans and Cats (Felis catus) and Humans.

Dogs' (Canis familiaris) and cats' (Felis catus) interspecific communicative behavior toward humans was investigated. In Experiment 1, the ability of dogs and cats to use human pointing gestures in an object-choice task was compared using 4 types of pointing cues differing in distance between the signaled object and the end of the fingertip and in visibility duration of the given signal. Using these gestures, both dogs and cats were able to find the hidden food; there was no significant difference in their performance. In Experiment 2, the hidden food was made inaccessible to the subjects to determine whether they could indicate the place of the hidden food to a naive owner. Cats lacked some components of attention-getting behavior compared with dogs. The results suggest that individual familiarization with pointing gestures ensures high-level performance in the presence of such gestures; however, species-specific differences could cause differences in signaling toward the human. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

对台湾水土保持草种引种的观察分析

通过对引进台湾省的10种水土保持草种的生物性状指标测定分析，表明除肯塔基F31、班德草出苗后全部枯死外，其余各草种均正常萌发生长，其中类地毯草、假俭草、罗滋草、赛刍豆在各个时期的性状表现比较优良，完全适合红壤坡地气候条件，可以作为江西省水土保持的应用草种．     

我国跗线螨科2新种和7种国内新记录种（蜱螨亚纲：跗线螨科）

近年来，在国内土壤、植物及螨瘿内，采到大量的螨类标本，经制片和鉴定后，发现有一批跗线螨科的螨类，其中有２新种和７种国内新记录种。本文就新种的形态特征及其与近似种之间的鉴别特征作了描述。模式标本保存于沈阳农业大学植保系。