基于Markov过程和伪极坐标快速傅里叶变换的重采样篡改检测

针对图像中的重采样篡改操作导致的离散余弦变换(DCT)系数之间相关性的变化,提出了一种新的图像重采样篡改检测方法。首先,提取Markov特征,利用高阶统计量分析重采样图像中离散余弦变换系数之间的关系;然后,将图像所在的笛卡儿坐标映射到伪极坐标(Pseudo-Polar)轴上提取图像的光滑度作为纹理特征,利用纹理特征检测图像的重采样操作;最后,将提取的两类特征输入到支持向量机(SVM)中训练和分类,从而检测出图像中的重采样篡改操作。实验结果表明:所提方法可以检测出图像中的重采样篡改操作,并具有较好的检测率,且对于一定范围内的加噪处理也具有鲁棒性。

经尿道双极等离子分叶解剖性前列腺剜除术治疗良性前列腺增生的疗效

目的 探究经尿道双极等离子分叶解剖性前列腺剜除术(PKERP)及前列腺电切术(PKRP)用于良性前列腺增生(BPH)治疗中的疗效及并发症发生率。方法 选取2015年1月至2018年1月收治的120例BPH患者临床资料进行分析,将60例行PKRP治疗者设作对照组,60例行PKERP治疗者设作研究组,比较两组最大尿流率(Qmax)、国际前列腺评分(IPSS)、残余尿量(RUV)及并发症。结果研究组Qmax、IPSS、RUV均优于对照组(P<0.05);研究组并发症总发生率较对照组低(6.67%比23.33%)(P<0.05)。结论 BPH在PKERP术治疗后可有效改善患者尿道功能以及前列腺功能,且术后并发症较少,可推广应用于临床。

解读瓮安生物群中一类奇妙的具极叶动物胚胎化石

贵州这个西南部欠发达省份,在人们的心目中也许或多或少与贫穷联系在一起。但对于科学家,特别是研究地球早期生命的古生物学家来说,贵州又是一个极为富有的宝地。二十多年前,古生物学家在贵州瓮安地区新元古代陡山沱组磷酸盐岩中发现了大量的微型球状化石,经过长期的研究,一系列改变人类对早期动物演化看法的成果呈现在世人的面前。

基于伪极傅里叶变换和ROA融合的SAR图像边缘检测算法

提出了基于伪极傅里叶变换和融合的SAR图像边缘检测算法.首先采用伪极傅里叶变换提取较弱的图像边缘特征,并利用Ratio边缘检测算法抑制相干斑噪声对SAR图像边缘特征的影响.然后利用两种算法所得到系数的幅值、方向和角度信息构建置信指派函数,引入D-S证据理论实现两种边缘检测算法的最优融合,获取了SAR图像最佳的边缘特征.仿真结果表明,该算法所提取的边缘特征完整、定位准确.

金秋的树叶

俗话说:"一叶知秋。"从第一片树叶落地的那一刻开始,宜人的秋天也就飘然而至了。我与小伙伴们怀着愉快的心情来到了我们梦想中的乐园--秋天的树林。哇!林子里遍地似金。枯黄的树叶落在地上,层层叠叠的,踩上去软绵绵的,多舒服哇!"瞧!"随着小伙伴的招唤声,我们把目光转移到了"大火球"身上。不用说,那红彤彤的一定是枫树啦!在秋风的吹拂下,枫叶轻轻摇曳着,如一簇簇烈火燃烧着。那像红蝴蝶一样翩翩起舞的,是落地时轻盈旋转的枫叶,多美呀!当你站在枫树下,看着无数片枫叶缓缓落下时。

采用小世界免疫克隆算子的频率域图像配准

为满足智能寻位加工中对零件图像配准速度和配准精度的高要求,提出了一种采用伪极快速傅里叶变换(PPFFT)和小世界-克隆选择算法(SWCSA)的图像配准方法(PPFFT-SWCSA).首先对图像进行伪极快速傅里叶变换,然后利用变换后获取的频谱特征信息设计优化算法的代价函数,最后采用SWCSA算法得到2幅图像间的配准参数.采用PPFFT降低了运算复杂性,提高了运算速度;采用SWCSA算法,克服了图像配准中常用的相位相关法无法检测到图像间较小偏移量的缺点.实验结果表明,PPFFT-SWCSA方法的配准角度精度可以达到空间0.2°,在对图幅为256×256像素的图像配准实验中,PPFFT-SWCSA方法的配准速度比基于离散极坐标傅里叶变换和相位相关法的配准速度快2倍.

The Structure of Oryza Embryos and Their Dimorphic Cotyledons

It has been generally held in botany that Oryza sativa L. is a monocotyledon. Based on studies of rice embryo development we confirmed that rice embryo has two dimorphic cotyledons rather than just one cotyledon. In the present study we attempt to know if the morphology of embryos in other species of Oryza differs from O. sativa and if these embryos have dimorphic cotyledon. Two types of embryo structures were observed in 22 species and/or subspecies of genus Oryza under the scanning electron microscope. Type 1, the O.sativa type, which is characterized by ventral scale and lateral scales, was found in 16 species. Type 2, the O. meyeriana (Zoll. et Mor. ex Steud.) Baill. ssp. tuberculata W. C. Wu et Y. G. Lu, G. C. Wang type, with no ventral scale and lateral scales, was found in 6 species and subspecies. The embryogenic process of O.sativa and O.meyeriana sub. tuberculata showed that the scutellum primordium, coleorhiza primordium, coleoptile primordium and shoot apical meristem directly differentiate from proembryo. The former two later develop into the embryo envelope, which is the outside cotyledon; the coleoptile primordium develops into the coleoptile with the shape of inverted empty cone surrounding and covering the growth cone, which is the apical cotyledon. Both types of rice embryos have dimorphic cotyledons. The structural difference between them is that the scutellum primordium of the young embryo in type 2 does not differentiate ventral scale and lateral scales while the embryo of type 1 does. The dimorphic cotyledons of embryo of Oryza plants originate from the dorsiventrality of proembryo.

Chemical comparison of Artemisia borealis and three Chinese Artemisia plants

Aim To compare the chemical constituents of A rtemisia borealis with three other A rtemisia plants which are generally used in traditional Chinese medicine. Method The chemical components of essential oil from the leaves of A. borealis were analyzed by GC- MS and the chemical components of water extracts of the four plants were compared by HPLC fingerprint method. Conclusion From the essential oil of A. borealis, 52 peaks were separate, 48 of them were identified by GC-MS analysis, indicative that aromadendrane-4-ol is the highest constituent, which made up 24.73% of the total essential oil. In addition the chief constituents of the leaves of A.borealis are similar to the three other plants but its pattern of HPLC fingerprint is different. The content of chlorogenic acid in aerial part of A. annus and A. scapillaries, leaves ofA. borealis and A. argyi are 0.065, 0.192, 0.617and 0.178 % respectively.

On a Class of p-valent Analytic Functions

In this paper we consider the extreme points of closed convex hull of the class T σ(p,α) and then it is used to determine the coefficient bounds. Some other interesting properties of the class T σ(p,α) are also investigated.

奇迹男孩脚下的奇迹

如果这个世界上少了足球,半数以上的人的生活会变得索然无味;如果这个世界上少了小罗,半数以上的人的生活会远离足球;如果这个世界上少了小罗脚下的球鞋……“Joga Bonito”出自球王贝利之口,意为“美丽足球”。它所体现的并不是作为竞技项目、只追求比赛结果的足球,而是最原始的足球含义。Joga Bonito包含了技巧、荣誉、快乐、全情投入和团队精神,而它又不只是这些,每个人都能诠释属于自己的Joga Bonito。小罗嘴上总是挂着灿烂的笑容,他的Joga Bonito是快乐;赛场上的鲁尼激情四溢,不可阻挡,他的Joga Bonito是全情投入;小小罗拥有一双会跳舞的双脚,他的Joga Bonito是技巧!他们演绎着足球的新主张,令我们看到了足球的激情和希望,感受到了美丽足球最原始的快乐!

天使帝国Ⅲ

大宇资讯今年再度强片出击,将于2002年末推出大受玩家好评知名系列续作——“天使帝国三“,这是所有玩家引颈期盼的热门游戏作品,更是天使迷不容错过必玩的战略游戏。故事背景爱斯嘉大陆,一个广大美丽而且拥有不断变化的人文与战争历史,内陆面积广大幅员辽阔,而在这美丽的土地上有三个主要的民族,其中,爱尔达民族位于大陆中央,她们崇拜生命女神“莎拉Sala”,生命女神创造了12棵生命之树,爱尔达人便是从生命之树上诞生,渐渐的发展成12个公国。然而这12个公国的历史是不断改革与战争。

Transcriptional,post-transcriptional and post-translational regulations of gene expression during leaf polarity formation

Leaf morphogenesis requires the establishment of adaxlal-abaxlal polarity after primordium initiation from the snoot apical meristem （SAM）. Several families of transcription factors are known to play critical roles in promoting adaxial or abaxial leaf fate. Recently, post-transcriptional gene silencing pathways have been shown to regulate the establishment of leaf polarity, providing novel and exciting insights into leaf development. For example, microRNAs （miR 165/166） and a trans-acting siRNA （TAS3-derived tasiR-ARF） have been shown to repress the expression of several key transcription factor genes. In addition, yet another level of regulation, post-translational regulation, has been revealed recently by studies on the role of the 26S proteasome in leaf polarity. Although our understanding regarding the molecular mecha- nisms underlying establishment of adaxial-abaxial polarity has greatly improved, there is still much that remains elusive. This review aims to discuss recent progress, as well as the remaining questions, regarding the molecular mechanisms underlying leaf polarity formation.

Foliar modifications induced by inhibition of polar transport of auxin

The effects of auxin polar transport inhibitors, 9-hydroxy-fluorene-9-carboxylic acid (HFCA); 2, 3, 5-triiodobenzoic acid (TIBA) and trans-cinnamic acid (CA)on leaf pattern formation were investigated with shoots formed from cultured leaf explants of tobacco and cultured pedicel explants of Orychophragmus violaceus, and the seedlings of tobacco and Brassica chinensis. Although the effective concentration varies with the inhibitors used, all of the inhibitors induced the formation of trumpet-shaped and/or fused leaves. The frequency of trumpet-shaped leaf formation was related to the concentration of inhibitors in the medium.Histological observation of tobacco seedlings showed that there was only one main vascular bundle and several minor vascular bundles in normal leaves of the control, but there were several vascular bundles of more or less the same size in the trumpet-shaped leaves of treated ones.These results indicated that auxin polar transport played an important role on bilateral symmetry of leaf growth.

The Arabidopsis AS2 Gene Encoding a Predicted Leucine-zipper Protein Is Required for the Leaf Polarity Formation

The asymmetric leaves2 ( as2) is a classical Arabidopsis thaliana (L.) Heynh. mutant that shows leaf lobes and leaflet-like structures from the petioles of leaves. Genetic and molecular analyses have demonstrated that the AS2 function is required for repression of meristem-related homeobox genes in leaves. In this study, we describe phenotypic characterizations of new as2 alleles that are in the Landsberg erecta (Ler) genetic background. In addition to the as2 phenotypes reported previously, the new as2 mutants have some leaves with petiole growth underneath the leaf blade, showing a lotus-leaf structure. More severe rosettes leaves of the as2 mutants form a filament-like structure, reflecting a loss of the adaxial-abaxial polarity in leaves. Among as2 mutants analyzed in different genetic backgrounds, only those that are in the Ler genetic background resulted in a high frequency of the lotus-leaf structure. We have isolated the AS2 gene by map-based gene cloning. The predicted AS2 protein contains a leucine-zipper motif, and its N-terminus shares high levels of sequence similarity to those of a group of predicted proteins with no known biological functions. AS2 transcripts were detected in leaves, flowers and fruits, but absent in stems, consistent with the mutant phenotypes.

Unusual hydrocarbon waxes detected in Salix oritrepha leaf from Nianbaoyeze Mountains, eastern Qinghai-Tibetan Plateau

Plant biomarkers, such as hydrocarbon waxes, are frequently found in various sediments and could be adopted as paleovegetation and paleoclimate indicators. Nevertheless, scarce researches have focused on leaf waxes in higher plants of alpine region.Herein, hydrocarbon leaf wax components of Salix oritrepha, which flourish in Nianbaoyeze Mountains in eastern Tibetan Plateau were fully discussed. The n-alkane distribution in leaves ranges from n-C_(21) to nC_(29) with maxima at n-C_(25), which were entirely different with Salix taxa displayed in previous surveys in non-alpine regions. The unusual even carbon nalkenes from n-C_(22:1) to n-C_(30:1), which were thought to appear only in aquatic organisms, were firstly reported in an alpine plant. Additionally, iso-(2-methyl) alkanes, ranging from i-C_(23) to i-C_(29) with maxima at i-C_(25), which have been commonly reported in microorganisms, were also identified in an alpine plant for the first time. Unusual hydrocarbon distribution detected in Salix oritrepha leaf from Nianbaoyeze Mountains is most likely due to the extreme environment in such alpine region.

Phytoplankton abundance and community structure in the Antarctic polar frontal region during austral summer of 2009

The Antarctic polar front region in the Southern Ocean is known to be most productive. We studied the phytoplankton community structure in the Indian sector at this frontal location during late austral summer (February, 2009) onboard R/V Akademic Boris Petrov. We used the phytoplankton and microheterotrophs abundance, as also the associated physico-chemical parameters to explain the low phytoplankton abundance in the study region. This study emphasizes the shift of phytoplankton, from large (>10 μm) to small (<10 μm) size. The phytoplankton abundance appears to be controlled by physical parameters and by nutrient concentrations and also by the microheterotrophs (ciliates and dinoflagellates) which exert a strong grazing pressure. This probably reduces small (<10 μm) and large (>10 μm) phytoplankton abundance during the late austral summer. This study highlights the highly productive polar front nevertheless becomes a region of low phytoplankton abundance, due to community shifts towards pico-phytoplankton (<10 μm) during late austral summer.

Quick Fluorescence Method for the Distinguishing of Vegetable Oils

This paper presents the possibilities offered by fluorescence spectroscopy for the identification of vegetable oils such as soybean, sunflower, flax, walnut, corn, almond, sesame, olive and pumpkin oils. The probes under study have been excited with two types of sources： a laser diode （LD） and light-emitting diodes （LEDs） emitting in the UV and in the visible range. Total luminescence spectra were recorded by measuring the emission spectra in the range 350-720 nm at excitation wavelengths from 375 to 450 nm. The excitation-emission matrices have been obtained and two basic fluorescence regions in the visible have been outlined. On this basis the fluorescence spectra of the oils have been subdivided into three categories depending on the prevalence of the fluorescence maxima. The samples show differences in their fluorescence spectra. The latter fact shows that fluorescence spectroscopy can be used for the quick identification of edible oils. The fatty acid, the tocopherol, the beta-carotene and chlorophyll contents in the analyzed oils have been studied. It is shown that some of the types of oils differ significantly from each other by the first derivatives of their fluorescence spectra. There also exist color differences between the groups of vegetable oils under study.

Electrochemical performance of interfacially polymerized polyaniline nanofibres as electrode materials for non-aqueous redox supercapacitors

H+ doped polyaniline nanofibre(PH) was synthesized by interfacial polymerization and polyanilines doped with Li salt(PLI and PHLI) were prepared by immersing emeraldine base(EB) and H+ doped polyaniline in 1 mol/L LiPF6/(EC-EMC-DMC),respectively.PH,PLI and PHLI were all characterized by scanning electron microscopy(SEM) and Fourier transform infrared(FT-IR) spectrometry.With 1 mol/L LiPF6/(EC-EMC-DMC) as electrolyte,PH,PHLI and PLI were used as the active materials of symmetric non-aqueous redox supercapacitors.PLI shows the highest initial specific capacitance of 120 F/g(47 F/g for PH and 66 F/g for PHLI) among three samples.After 500 cycles,the specific capacitance of PLI remains 75 F/g,indicating the good cycleability.

A Novel Algorithm Based on 3D-MUSIC Algorithm for Localizing Near-Field Source

A novel 3-D MUSIC algorithm based on the classical 3D-MUSIC algorithm for the location of near-field source was presented. Under the far-field assumption of actual near-field, two algebraic relations of the location parameters between the actual near-field sources and the far-field ones were derived. With Fourier transformation and polynomial-root methods, the elevation and the azimuth of the far-field were obtained, the tracking paths can be developed, and the location parameters of the near-field source can be determined, then the more accurate results can be estimated using an optimization method. The computer simulation results prove that the algorithm for the location of the near-fields is more accurate, effective and suitable for real-time applications.

Electrocatalytic Oxidation of Calcium Folinate on Carboxyl Graphene Modified CuxO/Cu Electrode

Carboxyl graphene modified CuxO/Cu electrode was fabricated. The bare copper electrode was firstly anodic polarized in 1.0 mol/L NaOH solution in order to get CuxO nanoparticles, then the carboxyl graphene （CG） was electrodeposited on the CuxO/Cu electrode by cyclic potential sweeping. The electrocatalytic oxidation behaviors of calcium folinate （CF） at the graphene modified CuxO/Cu electrode were investigated by cyclic voltammetry. A positive scan polarization reverse catalytic voltammetry was used to obtain the pure catalytic oxidation current. The graphene modified CuxO/Cu electrode was served as the electrochemical sensor of CF, a highly sensitivity of 22.0μA.（μmol/μL）^-1cm^-2 was achieved, and the current response was linear with increasing CF concentration in the range of 2.0×10^-7 mol/L to 2.0×10^-5 mol/L, which crossed three orders of magnitude, and the detection limit was found 7.6×10^-5 mol/L （S/N=3）. In addition, the proposed sensor was successfully applied in determination of CF in drug sample.