不同比例有机无机肥配施土壤腐殖质组分的光谱学特征

以16年长期定位试验为基础,探讨不同比例有机无机肥配施对土壤腐殖质特征的影响。通过分离纯化腐殖质中的胡敏酸（HA）和富里酸（FA）组分,并利用元素分析、红外光谱和核磁共振研究分析了F1（70%化肥+30%有机肥）、F2（50%有机肥+50%化肥）和F3（100%有机肥）三种施肥方式下的HA和FA含量及结构变化。结果表明,F3对于提升HA和FA含量的效果优于F1和F2处理,说明有机肥的施用量越高,土壤腐殖质组分的含量就越高。元素分析表明,不同配比的有机无机肥对HA和FA各元素含量及原子比影响不同。F2和F3都提高了HA的缩合度,降低了氧化度和极性,其中F3的效果更加明显;有机肥的施用还能促进HA中含氮化合物的形成,并且在F2中的效果最好;有机肥的施用同样提高了FA的缩合度而降低了氧化度和极性并促进了含氮化合物的形成,尤其在F2处理中尤为明显。腐殖质红外光谱分析表明,与F1相比,F2和F3提高了HA中脂肪族化合物、碳水化合物物质的含量,FA的羧基基团、脂肪基团含量也增加,且在F3处理中表现最为显著;F2处理则降低了HA中脂肪烃物质的含量,FA中的碳水化合物则达到最高。13C核磁共振波谱分析显示,在三种处理中,有机肥的施用提高了HA和FA的脂化度而降低其芳化度,其中F2处理中HA官能团变化更加显著,FA在F3处理中则变化更加明显。综上所述,有机肥显著提高了土壤腐殖质组分含量,并且提高了HA和FA的脂化度降低其芳化度,但是不同用量有机肥下HA和FA的形成机制不同。     

2D-Mueller-matrix tomography of optically anisotropic polycrystalline networks of biological tissues histological sections

A new technique of Mueller-matrix mapping of the birefringent structure of biological preparations of human organs tissues is suggested. The algorithms of reconstruction of average values and magnitude of fluctuations of the phase (birefringence) and amplitude (dichroism) of optically anisotropic structure of myocardium and connective tissue component of the vaginal wall histological section are proposed. The magnitudes and ranges of changes in the statistical moments of the 1st-4th order that characterize the distribution of average values and magnitude of fluctuations of birefringence and dichroism of the myocardium and connective tissue of the vaginal tissues histological sections were determined. Joint studies of distributions of the characteristics of phase and amplitude of the anisotropy of myocardium and connective tissue component of the vaginal wall tissues of different states were performed. The cases of various necrotic changes in the myocardium and pathological conditions of the vagina wall (prolapse of the genitals) are examined. Balanced accuracy of the method of Mueller-matrix polarization-phase and diffuse tomography of optically anisotropic polycrystalline networks in the differentiation of necrotic and pathological changes in human organs is determined.     

Low-frequency magnetoelectric effect in a Galfenol-PZT planar composite structure

The forward and inverse magnetoelectric (ME) effects are experimentally studied in a two-layer planar structure containing mechanically coupled Galfenol and PZT plates. The process of production of polycrystalline Galfenol plates and their magnetic and magnetostriction characteristics are described. For the forward ME conversion, the dependences of the amplitude of the voltage generated by the structure on the magnitude and orientation of a dc magnetic field and the frequency and amplitude of a modulating magnetic field are measured. For the inverse ME conversion, the dependences of the amplitude of the change in the magnetic induction of the structure on the dc magnetic field and the frequency of an ac electric field applied to the structure are measured. The efficiencies of the forward and inverse ME conversion are estimated for the case of low-frequency field modulation and under conditions of the resonance excitation of bending and longitudinal mechanical vibrations in the structure.     

相对湿度和氧气浓度对滑动弧放电特性影响研究

本文通过检测背景气体不同含氧量和相对湿度下的放电电流强度和臭氧浓度,分析氧气和水汽对滑动弧放电特性的影响.结果表明,背景中氧气是臭氧的主要发生源,臭氧随氧气浓度的增大而增大.水汽的离解反应与臭氧发生反应存在竞争关系,同时其生成的OH粒子会与臭氧发生反应,因此水汽对臭氧的产生起抑制作用.由于氧气和水的电子结合系数都很高,水与电子还会发生离解结合反应,因此背景气体氧气浓度和水汽含量增大会减少等离子体区域的电子数量,降低放电电流强度.     

Surface chemistry of nanodiamonds

The experimental data available in the literature and the results obtained by the author in research into the structure of nanodiamonds and the physicochemical and chemical properties of their surface are generalized. An account is given of the problems concerning the chemical state and modification of the nanodiamond surface in gaseous and liquid media and the infiuence of modification on the sorption and catalytic properties of nanodiamonds, their compactibility, and sintering. The similarity and difference in the behavior of nanodiamonds and diamond macrocrystals in oxidation processes are discussed. The activation energies of oxidation of nanodiamonds by different reagents are determined in the absence and presence of catalysts.     

电网智能单元加密算法效率评估

随着智能电网发展和电力终端设备智能化和网络化的提升,基于TCP/IP协议的数据通信面临着传统的网络安全隐患;智能电网单元是电网控制的关键组成部分,负责电网业务数据的采集处理、控制指令的收发和执行等工作,涉及大量数据传输,如何保证数据的机密性,是电网系统正常运作的关键因素之一;针对智能单元的传输规约和传输数据的特点,通过模拟智能单元计算环境,在保密性需求的基础上,结合智能单元计算资源的实际情况,综合分析电力行业和国内常见密码算法,包括对称算法和非对称算法,从运算时间及稳定性,数据长度相关性,密钥长度相关性和加密模式几个方面对算法的性能进行综合性评估;为不同智能单元的机密性保护尤其是加密算法的选取提供理论基础和实验数据。     

线偏振拉盖尔-高斯光束的远场发散特性

利用稳相法和矢量结构理论, 导出了线偏振拉盖尔-高斯光束的矢量结构项TE项和TM项在远场的解析表达式. 进而利用TE项和TM项的远场能流分布, 给出了TE项和TM项的功率占总功率比例的度量式,同时还给出了线偏振拉盖尔-高斯光束、TE项和TM项三者远场发散角的解析式以及三者远场发散角间的关系式. 所得到的公式不仅适用于傍轴情形,而且还适用于非傍轴情形. 通过数值计算, 分析了TE项和TM项在远场的功率占总功率的比例与参数f和模数间的依赖关系;还分析了拉盖尔-高斯光束、TE项和TM项的远场发散角随参数f、模数和线偏振角的变化关系.这一研究从矢量结构本性揭示了线偏振拉盖尔-高斯光束的远场发散特性, 丰富了对其传输特性的认识.     

激光二极管阵列端面抽运复合棒状激光器热效应的有限元法分析

建立了激光二极管阵列(LDA)端面抽运棒状激光介质的数值模型.考虑到介质与空气的对流换热和介质的热力学参数随温度的变化,根据经典热传导方程和热弹性方程,运用有限元法得出了复合棒状介质和未复合棒状介质内瞬态温度、热应力和应变的时空分布,分析了温度、热应力和应变随抽运功率、换热系数和时间的变化规律.结果表明,复合棒的最高温度、最大张应力和最大轴向应变的位置与未复合棒不同,并且数值分别为未复合棒的73%,60%和33%.由此可知,利用复合棒可极大地减小热效应的影响.理论分析结果可为LDA抽运固体激光器的结构优化设计和实验研究提供理论参考.     

非对称量子点中极化子的声子平均数

采用线性组合算符和幺正变换方法研究非对称量子点中强、弱耦合极化子的声子平均数的性质,导出了量子点中强、弱耦合极化子的声子平均数和振动频率随量子点的横向和纵向受限强度、电子-声子耦合强度的变化关系。对RbCl晶体进行数值计算,结果表明非对称量子点中强耦合极化子的振动频率和声子平均数随量子点的横向和纵向的受限强度的增强而迅速增大,随电子-声子耦合强度的增强而增大。     

几种硝基苯类炸药在外电场作用下的分子特性

采用密度泛函理论中的B3LYP方法,在6-31G*水平上研究了外电场对一些硝基苯类炸药分子的总能量、偶极矩、分子轨道能级和前线轨道能量差等分子特性的影响;考察了在外电场作用下分子前线轨道能量差与炸药的电火花感度之间的关系.结果表明,在外电场作用下分子总能量降低,偶极矩增大、前线轨道能量差减小;分子前线轨道能量差与炸药的电火花感度之间几乎线性相关,且外电场对这种线性相关性无明显影响.     

双外场对费米气体Joule-Thomson效应的调控

研究匀强电场和谐振场构成的双外场对带电费米粒子系统化学势和Joule-Thomson系数的调控作用．在满足Thomas-Fermi近似的条件下,给出有限温度范围内匀强电场和谐振场中带电费米粒子系统的化学势和内能随温度变化的显式函数关系,分析双外场对带电费米粒子系统焦耳-汤姆逊系数的调控作用.研究结果表明：随着温度的升高,带电费米粒子系统的焦汤系数值逐渐由负变正,且临界温度Tc随外电场增强而降低;在适当温度下,外势场的存在会使带电费米粒子系统产生焦耳-汤姆逊正效应.     

Changes in the surface phase composition of sulfide minerals upon irradiation by high-power nanosecond pulses

The effect of high-power (high-voltage) nanosecond pulses on the phase composition and chemical state of atoms of surface layers of sulfide minerals with different semiconductor properties (galenite, molybdenite, and sphalerite) is investigated by means of XPES. Common patterns and characteristic features of the structural phase transformations of sulfide surfaces under the pulsed energetic effect are the formation and growth of a surface layer by the nonstoichiometric sulfur-enriched sulfide phase and Zn and Mo oxides and hydroxides; the staged character of the transformation of sulfur atoms in the composition of galenite and sphalerite surface layers; and the stability of the chemical state of sulfur in the molybdenite composition and lead atoms in the galenite composition.     

Siliconization for Wall Conditioning in the HL-2A Tokamak

The sputtering of impurities is caused by the interactions between plasma and the first wall, and the recycling of the gas affects the particle and energy transport of plasmas with a complicated mechanism in plasma operation. It is important for present tokarnaks to achieve a good confinement and high performance plasmas by means of controls of the vacuum condition, usage of low Z materials, control of the recycling of neutral particles and suppressions of the appearances and yield of impurities. For higher plasma parameters, some of the first wall of HL-2A is covered with graphite materials and carbon fiber tiles. Hence the studies on the in-situ coating application and development, and the interactions between the coating film and plasma are needed to effectively control the impurity, improve plasma confinement and achieve high performance plasma.     

Monitoring of electrostatic fire and explosion hazards at the inlet to electrostatic precipitators

The paper deals with the continuous monitoring of electrostatic fire and explosion hazards that can occur at the inlet to electrostatic precipitators (ESPs) when highly charged dust particles are transported by a gas carrier that can be the mixtures of both incombustible and combustible flue gases. The risk of ignition and even explosion is especially high in the presence of an explosive mixture of oxygen and, e.g., hydrocarbons, carbon monoxide, etc. To avoid the danger of electrostatic discharges and their consequences for a whole installation including an electrostatic precipitator a method and a specially designed and built system should effectively enable the continuous monitoring of the hazards and should immediately manage any automatic control system or some other control elements. Some theoretical considerations concerning the method proposed, the physical quantities that must be measured, and the derivation of a novel dynamic safety criterion for assessing the risk of hazardous electrostatic discharges are presented. Finally, the author presents and discusses the possible practical application of the microprocessor-based measuring system verified experimentally in the past to the continuous monitoring of the hazards and to the management of an automatic control system to be put into operation. The paper presents a certain idea and proposal of the problem's solution based on the author's many years' experience in the field of pneumatic transport of dusts, powders and granular materials, of the electrostatic measurements of electric and mechanical quantities characteristic of the particulate transport, and of the risk and prevention of discharges of static electricity in transporting pipes and silos, vessels, etc.     

Determination of avocado and mango fruit properties by ultrasonic technique

A nondestructive ultrasonic measurement system was developed for the assessment of some transmission parameters which might have quantitative relations with the maturity, firmness and other quality-related properties of avocado and mango fruits. The system utilizes a set of low-frequency probes arranged to measure the ultrasonic signal transmitted and received over a short distance across the peel. The attenuation of the ultrasonic waves, transmitted through the peel and the attached fruit tissue, changes as a result of the progressive ripening and softening of the fruit during the fruiting season and in the course of storage. The present study quantitatively addressed the linkage between the ultrasonic attenuation and the physiological parameters of the flesh of the fruits. Results were obtained in the time and frequency domain, and the data set was analyzed statistically to identify the relations between the major physiological indices and the ultrasonic parameters. Quantitative relations were developed to describe the linkage between ultrasonic parameters and the maturity, firmness and other quality-related properties in mango and avocado fruits.     

强耦合半无限极性晶体中磁极化子的激发能量

采用线性组合算符和幺正变换,利用变分法计算了多原子半无限极性晶体中由电子和光学声子强耦合相互作用所产生的磁极化子的第一激发能量及平均声子数,并通过适当的数值计算图示了它们与磁场的关系。结果表明:在不同的磁场条件下,电子无限接近晶体表面和电子处于晶体深处时,磁极化子的第一激发能量和平均声子数都有所不同。     

Modeling and analysis of the in-plane vibration of a complex cable-stayed bridge

The in-plane vibration of a complex cable-stayed bridge that consists of a simply-supported four-cable-stayed deck beam and two rigid towers is studied. The nonlinear and linear partial differential equations that govern transverse and longitudinal vibrations of the cables and transverse vibrations of segments of the deck beam, respectively, are derived, along with their boundary and matching conditions. The undamped natural frequencies and mode shapes of the linearized model of the cable-stayed bridge are determined, and orthogonality relations of the mode shapes are established. Numerical analysis of the natural frequencies and mode shapes of the cable-stayed bridge is conducted for various symmetrical and non-symmetrical bridge cases with regards to the sizes of the components of the bridge and the initial sags of the cables. The results show that there are very close natural frequencies when the bridge model is symmetrical and/or partially symmetrical, and the mode shapes tend to be more localized when the bridge model is less symmetrical. The relationships between the natural frequencies and mode shapes of the cable-stayed bridge and those of a single fixed–fixed cable and the single simply-supported deck beam are analyzed. The results, which are validated by commercial finite element software, demonstrate some complex classical resonance behavior of the cable-stayed bridge.     

洱海上覆水DOM荧光特征及对富营养化的指示意义

湖泊溶解性有机物（DOM）组成特征对水质具有重要的影响,研究上覆水DOM组成特征对指示湖泊富营养化现状具有重要意义。采用荧光光谱区域体积积分分析法（FRI）定量分析洱海上覆水DOM组分时空变化,以及DOM组分与水质因子间的关系,对比分析不同来源入湖水体、不同富营养化程度高原湖泊上覆水DOM组分荧光特征。结果表明,洱海上覆水体DOM主要以类腐殖酸为主,其次为类富里酸,洱海DOM总量及类腐殖酸组分中部较高,色氨酸和络氨酸等类蛋白质DOM南部较高,类富里酸DOM北部较高。藻华易发期（10月）类蛋白质和类富里酸DOM较低,类腐殖酸DOM显著增加,DOM生物源降低,DOM生物活性降低。洱海沉积物内源释放和入湖河流主要影响上覆水中类腐殖酸DOM,湿沉降主要增加类蛋白质DOM。在湖泊贫营养阶段类富里酸DOM对水质影响较大,在富营养阶段类腐殖酸DOM对水质影响较大。随着湖泊富营养化程度的加剧,上覆水类蛋白质和类富里酸DOM所占比例呈下降趋势,微生物降解产物和类腐殖酸DOM所占比例呈增加趋势。DOM荧光组分占比变化对湖泊富营养化具有指示作用。     

Hydrostatic pressure,impurity position and electric and magnetic field effects on the binding energy and photo-ionization cross section of a hydrogenic donor impurity in an InAs Pöschl-Teller quantum ring

Using the variational method and the effective mass and parabolic band approximations, the behaviour of the binding energy and photo-ionization cross section of a hydrogenic-like donor impurity in an InAs quantum ring, with Pöschl-Teller confinement potential along the axial direction, has been studied. In the investigation, the combined effects of hydrostatic pressure and electric and magnetic fields applied in the direction of growth have been taken into account. Parallel polarization of the incident radiation and several values of the applied electric and magnetic fields, hydrostatic pressure, and parameters of the Pöschl-Teller confinement potential were considered. The results obtained can be summarised as follows: (1) the influence of the applied electric and magnetic fields and the asymmetry degree of the Pöschl-Teller confinement potential on the donor binding energy is strongly dependent on the impurity position along the growth and radial directions of the quantum ring, (2) the binding energy is an increasing function of hydrostatic pressure and (3) the decrease (increase) in the binding energy with the electric and magnetic fields and parameters of the confinement potential (hydrostatic pressure) leads to a red shift (blue shift) of the maximum of the photo-ionization cross section spectrum of the on-centre impurity.     

火成岩中长石含量与其特征光谱间响应关系研究

长石是地表岩石最重要的造岩矿物,在地壳中的比例高达60%,几乎是所有火成岩的主要矿物成分。随着高光谱技术的发展,国内外众多学者研究主要造岩矿物含量与其特征光谱的响应关系,对遥感岩矿识别以及矿化蚀变信息提取提供了多种可能性。该研究以USGS光谱库里18个火成岩样本为基础数据,研究长石的特征光谱及其与含量之间的定量关系。通过原始光谱反射率及其变换(包括小波三层分解高频分量、小波二层分解、去包络线后光谱、去包络线后小波三层分解高频分量及去包络线后小波二层分解),研究其与长石的含量之间的相关关系,结果表明：(1)分析六种光谱反射率的变换,去包络线后小波三层分解高频分量的光谱反射率与长石含量的相关关系最好,且相关系数正负不断变化,根据相关系数极值获得长石的特征谱带为431,570,972,1 456,1 856,2 292.9和2 481 nm;(2)原始光谱反射率与长石含量的相关性曲线趋势较为平缓,而经小波分解得到的高频分量后,趋势明显,经去包络线及小波分解得到高频分量后,相关性曲线的变化趋势愈加明显,由此可见,自变量的微小变化就会引起因变量变化,当岩石中长石的含量极小时,小波分解处理能够提高模型的精度。将长石含量与特征光谱的关系量化,运用多元逐步线性回归分析以及最小二乘法建模,建立6个线性回归模型和6个最小二乘法回归模型,结果表明：(1)去包络线后的光谱比原始光谱建立的回归模型精度更高,经过小波二层分解后的低频分量建模的回归模型精度优于未进行小波分解的光谱,其中去包络线后小波二层分解低频分量建立的回归模型效果最佳。(2)多元线性回归建立的模型精度优于最小二乘法,同时筛选对因变量影响较大的自变量,972,1 456,1 856,2 292.9以及2 481 nm。因此选择去包络线后的光谱进行多元线性回归法进行分析长石含量与光谱反射率之间关系,考虑到不同的特征吸收波段对长石含量的影响因子不同,可以利用长石的特征光谱定量反演某一区域内的长石的含量,对识别矿物具有重要意义。