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1.
A homogeneous neuron-like medium with close nonlocal coupling between the positive center and the negative surroundings is used for image processing. The input image is transformed into a stationary structure dependent on the form of the coupling function and the type of the element's response to external action. Using the idea of plausible activity structures, we can determine the model parameters needed to extract the features of the medium such as the contour, the lines of definite direction, the ends of lines, the central axes of the image, the negative, the points of intersection of lines, the texture boundaries, and the objects of definite scale as well as the parameters that permit reconstruction of broken lines, smoothing of lines, automatic determination of image scales, and binarization of the initial image by a medium with a tunable coupling function.Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 37, No. 8, pp. 1053–1061, August, 1994.  相似文献   

2.
In the specialized literature, two previous studies [S. Zhao, G.S.P. Castle, K. Adamiac, The effect of space charge on the performance of an electrostatic induction charging spray nozzle, J. Electrostat., 63 (2005) 261–272; S. Zhao, G.S.P. Castle, K. Adamiac, Comparison of conduction and induction charging in liquid spraying, J. Electrostat., 63 (6–10) (2005) 871–876] aim to clarify, by theoretical and experimental means, the following aspects concerning the charge through conduction and induction: charging mechanism, distribution of electrical field, conversion of energy and effect of spatial charge. This paper presents the energetic balance of the two systems, namely induction and conduction charge systems, with the purpose of establishing the quantitative energetic aspects of the phenomena that take place and, most of all, establishing the contribution to the energetic value of the drops that end up on the target and come from the high voltage source supplying power to the system and from the air flow that contributes to spraying and transporting particles to the target. At the same time, the energetic balance of a device which uses electrostatic induction for measuring electrical field intensity and high voltage is presented for exemplification. The device scheme, the way of functioning, the equivalent electrical schemes and the expression of the electrical current generated by the device as a consequence of the electrostatic induction are presented, and it is demonstrated that the electrical energy of the generated current does not result from the energy stored in the electrical field which is being measured, respectively of the one generating the electrostatic induction, but from the mechanical energy, by conversion, consumed by the motor which sets in motion the mobile part of this device.  相似文献   

3.
Instrumental neutron activation analysis (INAA) was used for the determination of major, minor and trace elements in samples of bottom sediments of the inflows of the Selenga river basin to assess the impact of the contamination from the industrial complex Erdenet and other industrial enterprises in Mongolia. A total of 42 elements (Na, Mg, Cl, K, Ca, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Sr, Rb, Sr, Zr, Nb, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Tb, Dy, Tm, Hf, Ta, W, Au, Hg, Th, and U) was determined by combination of conventional and epithermal neutron activation analysis at the IBR-2 reactor, FLNP JINR, Dubna. For the first time such a large set of elements was used for characterization of the bottom sediments as accumulating media which may reflect industrial contamination of the water basin. The concentrations of heavy metals and other trace elements in the samples from three inflows of the Selenga river basin were compared with data from the previous studies. It was shown that the industrial zone of the Erdenet Mining Corporation (EMC) and gold mining zone Zaamar are the sources of strong environmental contamination. The concentrations of Cu and Sb determined in sediment samples of the River Khangal and Govil near the EMC exceed average crustal rock and soil values by factors of 50 and 15, respectively. In the area of the gold mining zone Zaamar concentrations of Au, As, and Sb exceed crustal rock and soil values by factors of 4, 25, and 6, respectively. The relatively high levels of As, V, Zn, V, and Sr in the sediments of the studied rivers are obviously due to the discharges of untreated wastewater of desalination plant, electrical power station, textile industry and mining activities as well as domestic wastewater.  相似文献   

4.
A number of phenomena that determine the nature of the fluorescence of free complex molecules and the possibility of its analytical application are considered. Attention is specially paid to the specific features of the energetics of radiationless transitions, the role of statistical factors in the formation of spectral properties and the interrelationship among the luminescence-spectrum characteristics of rarefied vapors of complicated molecules, and the processes of energy transfer in collisions. The properties of polarized fluorescence of hot and jet-cooled vapors, the processes of relaxation of anisotropy in time and during collision reorientation, and transfer of anisotropy in photodisintegration are analyzed. Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 5, pp. 620–634, September–October, 1998.  相似文献   

5.
An investigation has been made of the electrical and adhesional properties, thermal stability, brazeability, and structure of vacuum-deposited films of aluminum, nickel, cobalt, copper, and a copper-based alloy containing 2.45 wt.% Cr, 4.89 wt.% Al. It was shown that the resistivity of pure metal films is greater than that of the original massive sample. The resistivity of films based on the alloy of the investigated composition is less than that of the original material. The introduction into the original alloy of Cr and Al as alloying elements facilitates reduction of the grain size D and of the height H of the surface microirregularities of the films by comparison with the same parameters for copper-based thin films. Alloying of the original alloy with chromium and aluminum makes possible a substantial improvement in the adhesion of the films to the plastic-laminate substrate and increase in the thermal stability of the alloy-based film elements. Recommendations are made for the practical application of the results.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 52–56, August, 1971.In conclusion, the authors wish to express their gratitude to colleagues at the A. A. Baikov Institute of Metallurgy, to Professor A. M. Korol'kov, Doctor of Technical Sciences, and to Junior Scientific Officer E. V. Lysova, for their help given in the execution of this work.  相似文献   

6.
陈书赢  王海斗  马国政  康嘉杰  徐滨士 《物理学报》2015,64(24):240504-240504
孔隙是等离子喷涂涂层原生性结构, 对涂层的耐磨损、耐腐蚀、耐高温等性能具有显著影响, 是涂层参数优化的重要指标之一. 因此, 对涂层孔隙结构特征参数的全面表征对于更加精确地评价涂层质量具有重要意义. 本文将概率统计方法、分形方法与数字图像分析技术相结合, 研究了等离子喷涂涂层原生性孔隙数量、形态、尺寸及其分布等结构特征参数表征方法及孔隙的成形机理. 首先通过改变喷涂功率得到不同孔隙状态的Fe基合金涂层, 随后采用数字图像分析技术对涂层截面孔隙的扫描电子显微形貌图进行处理, 最后通过Weibull统计模型分析了孔隙周长及面积的尺寸分布特征, 并利用基于分形思想的面积-周长幂率研究了孔隙不规则形态的定量表征方法. 在实验过程中, 为了分析涂层孔隙的成形机理, 采用Spraywatch在线监测喷涂粒子的飞行状态. 结果表明: 分形维数能够表征孔隙的不规则形态, 分形维数越大, 孔隙面积越大或边界形态越复杂, 并且其与孔隙的成形机理之间存在良好的映射关系; 孔隙面积及周长的尺寸分布均服从明显的两项Weibull分布特征, 孔隙尺寸较小时, 形状参数β 较大, 而孔隙尺寸较大时, 则反之; 喷涂功率对孔隙尺寸的聚集特点产生不同程度的影响, 随着喷涂功率的增加, 粒子的融化状态逐渐改善, 孔隙的尺寸明显降低; 而当孔隙面积(周长)小于特征值时, 相同尺寸的孔隙概率密度值则越来越接近, 说明孔隙功率的变化对小尺寸孔隙出现的概率影响较小.  相似文献   

7.
大气湍流像差散焦和像散与高斯涡旋光束焦面光强   总被引:1,自引:0,他引:1       下载免费PDF全文
分别研究了构成大气湍流波像差中的散焦和像散两个低阶像差对高斯涡旋激光束传输和成像的影响.采用菲涅耳-基尔霍夫衍射积分理论和大气湍流波相位结构函数的平方近似研究了聚焦高斯涡旋光束在大气湍流中散焦和像散影响下焦面光强的分布特性.导出了斜程传输条件下接收面上平均光强分布的积分表达式,并采用数值模拟方法研究湍流强度、传输距离和拓扑电荷对焦面光强的调制规律.结果表明:在弱湍流起伏区域,散焦和像散两类像差对高斯涡旋光束的光强分布影响都很小,可以忽略;在中等湍流区域,随着光束传输距离和湍流强度的增加,两类像差都导致高斯涡旋光束的光强峰值降低、束径扩展、中心暗斑扩大.当单拓扑电荷高斯涡旋光束传输时,在同等传输条件下,像散导致的光强峰值降低比散焦更严重,主亮斑区域外的次级亮环强度更大,光斑和中心暗斑扩展更明显.与单拓扑电荷光束相比较,散焦和像散导致双拓扑电荷光束的扩展更加明显,中心光斑更大,亮环区域外的次级亮环更明显;但是,由于光的相干性的降低和光束的偏折效应,像散导致光束中心的暗斑变为次级亮斑.  相似文献   

8.
Radio reception     
The last few decades saw considerable progress in the methods of reception of radio signals, in particular, in the short-wave part of millimeter wave range. Along with this, or, perhaps, owing to this, some views, concepts, and definitions in the theory of detection and mixing were changed. Consequently, for example, the concepts and the corresponding apparatus developed in the 1950s need at present certain corrections. Below we propose a nonstandard consideration of the detection and mixing processes on the basis of consistent observance of the principle of information theory on the energy character of signal reception and using the time-domain approach when describing the operation of superheterodyne converters. To my teacher in practical radiophysics, professor Izrail’ Lazarevich Bershtein with gratitude. Institute of Applied Physics of the Russian Academy of Sciences, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 41, No. 11, pp. 1378–1398, November, 1998.  相似文献   

9.
马正木  靳艳飞 《物理学报》2015,64(24):240502-240502
研究了二值噪声和周期信号共同激励下欠阻尼周期势系统的随机共振. 利用随机能量法计算了系统的平均输入能量和平均输出信号的振幅和相位差, 讨论了二值噪声对随机共振的影响. 发现随着噪声强度的增大, 平均输入能量曲线存在一个极小值和一个极大值, 系统出现先抑制后共振的现象; 同时, 系统信噪比曲线随噪声强度的增加出现单峰现象, 说明系统存在随机共振现象.  相似文献   

10.
年轮参数是树木生长的重要指标。目前年轮的检测方法主要有人工测量法、扫描仪法和X射线法等。这些方法费时费力、检测成本高、操作难度大。为此,提出采用可见光谱进行年轮参数检测的新方法。首先针对活立木年轮检测需求,设计了木芯专用可见光谱分析装置。装置采用宽光谱对称式光源,封闭式暗箱设计,彩色CCD外置、固定距离采集方式。进而采集样品全彩色图像,分别提取不同光谱通道数据进行分析,最终获得年轮特征光谱参数。以从松树活立木钻取的木芯为例,经打磨后的木芯水平固定于载物台,光源均匀照射样品,CCD采集木芯漫反射RGB图像,基于对木芯全彩色图像的不同光谱通道的分析,分别提取RGB三帧灰度图像的强度曲线,区分早晚材分界线,得到树木年轮各项指标,实现树木年轮参数的快速提取。实验首先将CCD采集的RGB图像转换至NTSC色彩空间,以扩大色彩域。在设置滤波窗滤除背景,截取出木芯图像后,通过提取木芯图像的R,G和B三灰度分量图像,发现木芯B灰度图的早晚材区域差异最分明。基于该特征,可提取出早晚材分界线的位置信息。对木芯B灰度分量图微分,得到灰度沿水平方向的空间梯度。确定灰度变化率极大值对应的各点,鉴于木芯生长特性,灰度变化率极大值对应空间位置首先取为窄像素区域,进而在窄像素区域取中间值,此即木芯年轮各早晚材的中心点。其中,早材中心点对应光谱曲线的极大值,晚材中心点对应光谱曲线的极小值。结合专家经验,建立早晚材中心点与分界线的灰度关系,可得各分界线的位置。通过早晚材分界线与年轮各参数的关系,可进一步得出年轮各项指标。对比3位林木育种专家人工识别结果,本方法检测结果除了在木芯靠近端点处的位置外,都具有极高的准确度。采用可见光谱通道的数据采集与分析方法检测树木年轮参数,检测过程可实现全自动,高效、无损,精度可达到0.1 mm,结果精确。相比于人工测量法、扫描仪法,检测效率更高;相比于X射线法,检测过程更加安全、低耗,操作更方便。是一种具有较强应用性的方法。  相似文献   

11.
本文主要介绍了化探样品相态分析中无火焰原子吸收光度法测定化探样品中的铜、铬、钴、镍、铅、镉的分析方法。近年来,随着地质找矿工作的发展,地球化探人员对相态分析技术越来越感兴趣,在相态分析中,不同相态同一种元素的含量相差很大,给溶液的提取,制备及测定工作带来了很多不便,加之,大量的常量元素的存在尤其是钙、镁、锰、铁等元素极易产生干扰,在水溶态,离子态的分析液中铜、铬、钴、镍、铅、镉的含量又很低,给测试带来了很大难度,在相态的提取过程中,如果做平行、样品分析的话一个样品至少要制备八份溶液,工作量很大,因此,找到一个简单,快捷而又稳定可靠的测试方法是十分必要的,在测定中采用了磷酸为基体改进剂,它不仅可以消除基体的干扰,并可使各种元素测定的精密度得到很大改善。  相似文献   

12.
Studies were made of heat-treated Ni-GaAs contacts, at which, prior to the electrochemical deposition of nickel, thin layers of gallium or arsenic were deposited. The physicochemical reactions at the interfaces were investigated, as well as the electrophysical characteristics of the diodes, the morphology of the metallic coatings, and the mechanical stresses. The phase composition of the contacts and the height of the barrier are seen to be practically independent of the introduction of excess Ga or As, whereas the thermal stability of the electrical parameters of the diodes varies considerably. This difference is associated with the effect of the Ga and As sublayers on the magnitude of the mechanical stresses arising at the metal-semiconductor interface.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 46–51, February, 1987.  相似文献   

13.
龙王山墓葬位于湖北省荆门市,属于大溪文化向屈家岭文化过渡的关键时期,距今约5 000年。该墓葬共出土玉器73件,玉器品质普遍较好。长江中游地区历来鲜少出土玉器,而时代更迭之期更是社会变革之际,无论是从地理位置还是从时期上来看,研究龙王山墓葬出土的玉器都具重大意义。采用相对密度检测,红外光谱仪(FTIR)及激光剥蚀电感耦合等离子体质谱仪(LA-ICP-MS)研究出土玉器的谱学及化学成分特征,鉴定其材质,并对用料水平及矿源进行了探究。红外光谱结果显示龙王山墓葬出土玉器的红外吸收谱图可分为两类:软玉类和玛瑙类。软玉类玉器的红外吸收峰表现为1 207, 1 123, 1 028, 928, 775, 700, 602, 488和425 cm-1处。玛瑙类玉器的红外吸收峰表现为1 158, 814, 790, 702, 572, 521及405 cm-1。软玉类玉器有71件,且品质都非常好,说明龙王山墓葬先民对玉料的分选能力很强。将龙王山墓葬的用料水平与同时期其他地区的考古学文化的用料水平进行对比,龙王山墓葬的用料水平远超同期;将龙王山墓葬的用料水平与...  相似文献   

14.
We present the most important results of investigations of lasers based on vapors and solutions of complex organic compounds. We investigated the effect of a foreign gas, the duration and intensity of the exciting pulse, the temperature of the active medium, and the spectroscopic parameters of the material on the generation characteristics of complex molecules in the gas phase. The special features of generation of radiation by a laser with distributed feedback in transition from a condensed to the gas phase in heating the active medium are considered. It is suggested that the polarization characteristics of the radiation generated by a vapor laser be used to investigate the laws that govern the relaxation of optically induced anisotropy of excited molecules of the active medium. Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 5, pp. 709–720, September–October, 1998.  相似文献   

15.
各种矿质元素在荆芥各器官间贮藏差异。从矿质元素角度了解荆芥合理的药用部位组成以及收时间。应用ICP-AES技术,测定并分析了在不同采收时间,荆芥的不同器官矿质元素含量、累积量和比例。结果显示, 在不同采收时间,(1)荆芥穗中常量矿质元素K, P和微量矿质元素Cu含量最高,荆芥叶中常量元素Mg, Ca, Na和微量元素Fe, Mn, Zn含量最高。(2)荆芥不同器官所含常量元素中Ca和K含量最高,Na含量最低;所含微量元素中Fe含量最高,Mo含量最低。(3)在荆芥茎中,K∶P最高,而Zn∶Cu则为最低;Ca∶Mg和Fe∶Mn在荆芥穗中最低。(4)随着采收时间的推移,各元素在荆芥不同器官中的含量变化并不显著。荆芥茎中各矿质元素含量均较低; 从矿质元素含量的角度看,在合理的采收时间范围内,荆芥的质量受时间影响不显著。  相似文献   

16.
利用电感耦合等离子质谱仪(ICP-MS)测定苹果酒发酵的不同时期主要矿质元素含量,分析在苹果酒发酵过程中主要矿质元素的吸收和释放的动态变化。结果表明:发酵液中含有的主要矿质元素有钾、钠、钙、镁、铁、锰、铜、锌、锶、硼等十种,其中钾元素的含量最高,在苹果汁中达到1 853.83 mg·L-1,经过发酵后的含量为1 654.38 mg·L-1。在发酵过程中,各种矿质元素的含量处于不断的动态变化之中,整体看来,在发酵进行72~120 h以及144~216 h,大部分矿质元素的含量变化波动较大;尤其在发酵进行到192 h,大部分矿质元素的含量都达到峰值或谷值,其中铁和锌元素的含量达到峰值,钾、钠、钙、镁、锰、硼六种元素的含量达到谷值。但在随后发酵结束前的24 h内,矿质元素的含量又剧烈反弹。经过发酵过程后,钾、镁、铜、锌、硼等元素的含量显著降低,钠、钙、锰、铁、锶等元素含量变化不显著。对十种元素进行相关性分析,结果表明钙元素和锰元素之间的相关性最高,pearson相关系数达到0.924。试验结果为调控酿酒过程,控制产品质量提供了理论依据。  相似文献   

17.
The method of elimination of the photodetector dichroism effect on the results of optical measurements is proposed. For this purpose, two polaroids are placed before the photodetector: the first, a compound one, consisting of two halves with mutually orthogonal filtering directions, and the second one, whose filtering direction is oriented at an angle of 45° to the filtering directions of both halves of the first polaroid. The interface of the compound parts of the first polaroid passes through the middle of the laser-beam cross section. Even if the light polarization is changed at the input of the polaroid system, the output polarization of light is retained, and so is the total intensity of the two halves of the laser beam. An experimental test of this method has been performed. Institute of Applied Physics of the Russian Academy of Sciences, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 41, No. 5, pp. 664–669, May, 1998.  相似文献   

18.
程秋虎  王石语  过振  蔡德芳  李兵斌 《物理学报》2017,66(18):180204-180204
仿真计算一直是研究激光器的重要手段,而激光理论是仿真计算的基础.虽然半经典激光理论能够精确地描述激光的产生过程,但是其复杂性导致仿真需要庞大的计算资源和计算时间.为了能够更加高效地对激光器进行仿真,提出了一种调Q固体激光器的仿真模型.基于此模型,研究了影响主动调Q激光产生过程的因素.这些因素包括抽运功率、抽运光分布和模式竞争.仿真计算结果与对照实验测量数据相符合,说明了模型的有效性.  相似文献   

19.
Sonolysis of chlorobenzene in aqueous solution: organic intermediates   总被引:6,自引:0,他引:6  
The ultrasonic degradation of 1.72 mM chlorobenzene was investigated. The sonolysis of chlorobenzene followed first-order kinetics. The influence of the pH of the aqueous solution and the effect of the saturating gás, air or argon, was measured. No pH effect was noticed, and saturation with the monoatomic argon accelerated the degradation. Furthermore, the addition of the radical scavenger benzoate demonstrated that no significant degradation took place in the bulk solution. For air-saturated solutions, the following organic degradation products were identified: methane, acetylene, butenyne, butadiyne, benzene, chlorophenols, phenylacetylene and other chlorinated and non-chlorinated monocyclic and dicyclic hydrocarbons. For argon-saturated solutions, the same products were found, except for the chlorophenols. The presence of the chlorophenols in the case of air-saturation only demonstrated the interaction between the radicals formed and oxygen, and no direct degradation by OH. radicals. The kinetics of several organic degradation products and chloride were determined for the sonolysis of air- and argon-saturated solutions.  相似文献   

20.
铁矿石是钢铁工业的重要原材料,我国是铁矿石进口需求型国家,是世界铁矿石消费第一大国。海关对进口铁矿石检验的主要目标是预防进口铁矿石中涉及安全、卫生、环保、欺诈等方面的风险。对进口铁矿石产地及品牌进行符合性验证,可以快速筛选掺杂、掺假、以次充好,支撑进口铁矿石的风险管理,保障贸易便利化。在前期研究基础上进行应用拓展,研究对象为澳大利亚、南非、巴西、哈萨克斯坦、印度5个国家、21个品牌的422份进口铁矿石样品。考察了波长色散-X射线荧光光谱无标样分析方法的准确度,对于测量过程中未检出的元素含量,选择了用检测限替代缺失值。对于测量过程中的异常值,使用基于剩余方差的F检验进行异常值的剔除,皮尔巴拉混合块、纽曼混合块铁矿、纽曼混合粉铁矿各有一组数据计算得出的F统计量大于F检验临界值(a=0.01),因此将这3组数据剔除。采用逐步判别法筛选出Fe,O,Si,Ca,Al,Mn,Ti,Mg,P,Na,Cr,K,Sr,S,Zn,V,Cu,Ba,Ni,Mo,Pb共21个元素的含量作为产地识别模型的特征变量,建立四维Fisher判别模型,实现了对铁矿石产地的识别;采用逐步判别法筛选出Fe,O,Si,Ca,Al,Mn,Ti,Mg,P,Na,Cr,K,Sr,S,Zr,Zn,V,Cu,Ba,Cl,Ni,Mo和Pb共23种元素含量作为品牌识别模型的特征变量,建立二十维Fisher判别模型,实现对21种品牌铁矿石的识别。考察了特征元素对分类识别模型的贡献,并分析了误判品牌铁矿石的元素特征。总结出进口铁矿石产地及品牌判别分析模型的整体数据处理流程。  相似文献   

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