皮革中甲醛含量测量不确定度评估

依据GB/T 19941-2005标准,测定了皮革中的甲醛含量,对测量结果的不确定度来源进行了分析和评定,并计算出合成不确定度和有效自由度,最后根据JJF1059规范要求给出了甲醛测量不确定度表达式.     

Deflection of IR-radiation in n-InSb in the presence of temperature-electrical instability in a magnetic field

The formation of an S-shaped volt-ampere characteristic (VAC) during the heating of a specimen of n-type indium antimonide by a dc electric current in the presence of an external magnetic field is considered. In the calculation of the VAC the temperature dependences of the band gap width, the carrier density, the mobility, and the heat conductivity are taken into account. The angle of deflection of IR-radiation in indium antimonide is calculated using the density distribution over the cross section of the specimen derived from the integration of heat conductivity equation. The experimental and theoretical dependences of the deflection angle on the current are in agreement in order of magnitude and indicate that it is possible to use the temperature instability for the construction of laser radiation deflectors in the IR range.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 35–40, November, 1984.The authors are grateful to V. L. Bonch-Bruevich and I. P. Zvyagin for useful discussion and valuable critical remarks.     

Inhibition of corrosion of aluminium in presence of fluorescein in basic medium

The influence of Fluorescein in conjunction with calcium oxide on the corrosion of Aluminium in 1.0 N NaOH was studied by galvanostatic studies and weight loss studies. It has been found that the inhibition of corrosion of aluminium increased with the increasing concentration of the inhibitor. The maximum inhibition efficiency of fluorescein alone was found to be 30.80%. However, the addition of calcium oxide increased the maximum inhibition efficiency to 53.71%. The corrosion process was found to be under the anodic control, in the presence or in the absence of inhibitor. The inhibition was found to be mixed type. Paper presented at the 2nd International Conference on Ionic Devices, Anna University, Chennai, Inida, Nov. 28–30, 2003.     

腐植酸溶液的声化学降解研究

采用频率为1.8MHz的超声波在固定式声化学反应器内研究了声化学降解腐植酸的自由基氧化历程。通过采用TA溶液作为OH自由基捕获剂,吡啶溶液作HO2自由基捕获剂,以及KI溶液的I2释放法分别确定出实验条件下反应溶液中OH自由基的浓度为10^-7M,HO2自由基浓度为10^-5M及H2O2浓度为10^-5M。在此基础上研究了均相与多相催化条件下声化学降解腐植酸溶液的TOC削减情况。发现CeO2和Cu2O催化作用下腐植酸的降解效率分别较均相条件下提高40％和20％。并就反应机理和反应动力学过程进行了描述。     

Variations in bonding of iron in porous ferrisilicates

The ISAC post accelerator comprises an RFQ, DTL and SC-linac. The high energy beam lines connect the linear accelerators as well as deliver the accelerated beams to two different experimental areas. The medium energy beam transport (MEBT) line connects the RFQ to the DTL. The high energy beam transport (HEBT) line connects the DTL to the ISAC-I experimental stations (DRAGON, TUDA-I, GPS). The DTL to superconducting beam (DSB) transport line connects the ISAC-I and ISAC-II linacs. The superconducting energy beam transport (SEBT) line connects the SC linac to the ISAC-II experimental station (TUDA-II, HERACLES, TIGRESS, EMMA and GPS). All these lines have the function of transporting and matching the beams to the downstream sections by manipulating the transverse and longitudinal phase space. They also contain diagnostic devices to measure the beam properties.     

光谱学技术在稀奶油乳脂肪研究中的应用

乳脂肪是制备稀奶油的主要原料,不同产地的乳脂肪结构性能差异较大,进而影响稀奶油乳浊液各项性能。利用拉曼光谱动态光散射、近红外光稳定性分析等光谱学技术,研究了不同来源乳脂肪（MF-A, MF-B和MF-C）理化特性,并比较相应稀奶油的稳定性及粒径分布,以说明乳脂肪性能对稀奶油品质的影响。拉曼光谱结果显示：1 303和1 446 cm-1 -CH₂振动,2 800～3 000 cm-1 C-H振动,1 131 cm-1 C-C振动的峰信号强弱顺序MF-A>MF-B>MF-C（p<0.05）,说明MF-A饱和程度最高;1 657 cm-1 C=C振动,信号强弱顺序MF-C>MF-B>MF-A （p<0.05）,说明MF-C中顺式不饱和脂肪酸含量最高,三种乳脂肪均为顺式不饱和脂肪酸,无反式脂肪酸。同时,碘值分析进一步验证MF-A饱和度最高,相应乳脂肪硬度大、稳定性和可塑性佳。在0~40 ℃范围内,不同温度下固体脂肪含量（SFC）由高到低为MF-A>MF-B>MF-C（p<0.05）,说明相应的稀奶油宜在4 ℃贮藏,10~15 ℃打发并裱花。在25 ℃等温结晶1 h,用偏光显微镜观察三个样品,发现MF-A冷却时最先形成晶核并诱导周围脂肪不断结晶而聚集形成小而密的结晶网络。MF-B为细微球晶与针状晶组成的晶体簇,晶体数量少,结晶网络不完整;MF-C晶体分布较为稀疏,数量极少,且晶体平均直径小于20 μm。分别用三种乳脂肪制备稀奶油XMF-A,XMF-B,XMF-C,从粒径分布图中看出XMF-A基本为单峰,说明稀奶油乳浊液较稳定,脂肪球没有聚结,而XMF-B,XMF-C为双峰,说明脂肪球均发生了一定程度的聚结,且XMF-C平均粒径最大,所以XMF-C聚结程度高于XMF-B,平均粒径顺序为XMF-AXMF-B>XMF-C（p<0.05）。通过研究以连续相与分散相形式存在的乳脂肪理化特性,发现了脂肪组成、结构与结晶行为规律,探索了乳脂肪结晶对稀奶油品质的影响机制,旨在为制备不同需求乳制品提供原料选择的理论依据。     

Dynamics of processes occurring in laser ablation of metals in a liquid

We present the results of investigations undertaken to establish relationships between certain characteristics of the disintegration of metals in air and liquid under laser radiation and their thermophysical properties, as well as between the basic parameters of a gas cavity formed in a liquid and the energy of the laser ablation products of metals. Consideration is given to the possibilities of applying the dynamic properties of this cavity to control the time behavior of the radiation of solid-state lasers and to solve spectroanalytical problems. Institute of Molecular and Atomic Physics, Academy of Sciences of Belarus, 70, F. Skorina Ave, Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 5, pp. 668–673, September–October, 1997.     

Simulation of secondary processes in breakdown in air

The simulation of the buildup of a breakdown in air is made in a gap with an applied uniform electric field. The computer program is based on the classic determinist model of Townsend with account to secondary effects on the cathode and space charge effects in the gap. Nevertheless, this model takes into account the different ionic and electronic creative processes in the discharge. To the direct ionization must be added attachment, detachment and charge exchange processes. The continuity equation gouverning the densities is written for each charge carriers kind. The resolution of this system represents accurately the spatio-temporel evolution of the discharge. The results are in good agreement with the experimental results found in literature.     

Role of the velocity frame of reference in thermodiffusion in liquid mixtures

The role and significance of the velocity frame of reference in the interpretation, modeling and formulation of thermodiffusion in multicomponent liquid mixtures were investigated, focused on the nonequilibrium thermodynamics modeling approach. The effect of the velocity frame of reference on the phenomenological equations and thermodiffusion coefficients and expressions is explored. Theoretically and also by the aid of representative calculations, it is shown that while in binary mixtures transformation from one frame to another does not affect the sign and magnitude of the thermodiffusion coefficients, in multicomponent mixtures (ternary and higher), even the sign of the thermodiffusion coefficients may change when an alternative frame is used. This implies that in multicomponent mixtures for either experimental data or model estimations, the employed velocity frame for the thermodiffusion coefficients plays an important role in calculations. The Soret coefficients and the thermodiffusion factors are independent of the frame of reference.     

厚透镜近似下激光驻波场中原子动力学研究

研究了在厚透镜近似下 ,原子在激光驻波场中的动力学行为 .通过直接演化一维薛定谔方程 ,发现当激光的强度较大时 ,原子束将会聚焦形成几个焦点 .如果激光的强度更大 ,驻波场中的原子将会出现一种“隧道”现象 ,此时 ,原子受一些实验参数 (如焦平面位置、激光强度等 )的影响程度将大大降低 .这种现象有利于提高原子在驻波场中聚焦沉积的效果 . The dynamics of atoms in laser standing wave (SW) in the regime of over-focused immersion-lens is studied. Through directly evolving a one-dimensional Schrdinger equation, we find that multiple focusing appears when laser intensity is larger than that required for simple focusing. If laser intensity is much higher than that for the single focusing, a "channeling" phenomenon appears, which is insensitive to the variation of some parameters, such as focal plane position and laser intensity...     

Disclinations in nematics in the presence of flexoelectricity

The stability problems of wedge disclinations (with pure splay and bend distortions) in nematic liquid crystals (NLC) are considered in the presence of flexoelectricity. We write NLC director equations in the cylindrical coordinate system, taking into account flexoelectricity. These equations allow us to solve many interesting problems on the influence of flexoelectricity on the orientational structures of NLC. In particular, it is shown that the line of disclination with radial distribution of director can be stabilized in the presence of flexoelectricity even far from nematicsmectic phase transition point. For the disclination with azimuthal distribution of director for all physical sizes the line is not stable and escapes in the third dimension.     

Formation of structure in the zone of internal oxidation in copper-base alloys

The development of structure in the internal-oxidation zone of binary alloys formed between copper and various oxide-forming elements (Al, Be, Ti, or Si) as a result of the diffusion of oxygen into these is considered; so is the effect of small quantities of third elements on the process. As the internal-oxidation zone advances the size of the precipitates increases; in the presence of preferential crystallographic directions of growth, acicular precipitates develop, and a microscopically banded structure is created. The reason for the structural characteristics indicated apparently lies in the changing ratio of the number of oxygen atoms to the numbers of atoms of the oxidizing element at the reaction front as the latter advances. The addition of traces of third elements (Ti to Cu-Al, Be, Ti, and Zr to Cu-Si) affects the nucleation process and increases the degree of dispersion of the precipitates. This influences the diffusion of the reacting elements and hence the character of structure formation.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 95–100, May, 1975.     

ICP-MS在土壤元素污染评价中的应用

以云浮黄铁矿矿石作原料的某硫酸厂堆渣场土壤剖面为研究对象, 应用ICP-MS同时测定了污染元素和部分参考元素的含量,快速找出各元素的相关性,用富集因子评价了土壤的污染状态,并指出了污染元素的背景选择问题。结果表明：V已呈显著及高度污染,Co呈中度污染,并有显著污染的倾向,Cr, Mo和Cd在轻度和中度污染之间,Zn和Sb呈轻度污染,并有中度污染的潜在危险,Cu呈轻度污染。富集的高位点V和Cr在土壤剖面的上部(4.0～10. 5 cm)和深部(44.0～75. 5 cm),Co和Mo集中在土壤剖面表面(0～5.0 cm)、中上部(9.5～10.5 cm)和中部(29.5～46.0 cm),Cd和Cu集中在土壤剖面中部(29.5～46.0 cm)。高富集点的污染来自于以花岗岩为母质的亚热带强风化红壤的残余金属离子的淋溶淀积和堆渣场废渣中释放的金属元素在土壤中的迁移累积相互叠加的结果。其中V污染主要为土壤母质贡献,其次是硫酸生产过程失活催化剂挥发引入废渣的V淋溶淀积。     

Fluctuations in number of photons in region of unstable behavior in process of intracavity generation of second harmonic

Quantum fluctuations of the number of photons of the fundamental mode and of the second harmonic in the process of intracavity generation of the second harmonic in the unstable region of the system are studied. The distribution functions of the number of photons of interacting modes are calculated in the positive P-representation. The functions of the joint distribution of the number of photons of the fundamental mode and the number of photons in the second harmonic are also studied.     

Polarized fluorescence of radicals in photodissociation of disulfides in the gas phase

The polarization of the fluorescence of radicals formed in laser-induced photodissociation of some disulfides in the gas phase is measured. Experimental data obtained in the study are interpreted within the free recoil model. It is shown that polarization experiments carried out to investigate photodecay in vapors allow researchers to uniquely the intramolecular direction of the dipole moments of transitions with absorption and emission. Institute of Molecular and Atomic Physics of the National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 1, pp. 54–59, January–February, 1999.     

北京城市公园冬季声景特征

北京地区冬季气候寒冷干燥,植被郁闭度降低,地球物理声增加,生物声减少。为探测北京冬季声景变化基本特征,根据地图“十字型”筛选10个城市公园,记录分析绿地内冬季声景的构成情况和昼夜变化规律。结果表明：城市公园冬季声景中人工声较多,生物声明显著少于其他季节,而且人工声昼间少于夜间,生物声昼间多于夜间;在公园人工声源分类中,机械电子声最多,其次是话语声,活动声最少;冬季人工声峰值普遍存在于清晨6:00–7:00时,在昼间的波动变化明显,于夜间趋于稳定,生物声峰值出现在上午8:00–9:00时,谷值出现在凌晨3:00时左右;人工声与公园面积、公园年龄和时刻变化未见显著相关性,生物声与公园面积呈显著负相关。实验发现城市公园冬季声景呈现出与其他季节声景的显著不同,生物的节律性变化导致冬季声景产生了较为显著的变化。     

Analysis of the critical behaviour of curved regions in equilibrium shapes of in crystals

Crystal shapes near {111} facets have been analyzed on indium crystals in their equilibrium shape. These measurements are compared with two theoretical concepts of the critical behaviour of curved regions: the “Pokrovsky-Talapov transition” and the “mean field theory”. Taking into account, on the one hand, the inaccuracy of the experimental determination of the origin of the curved region and, on the other hand, the “window” of validity of the Pokrovsky-Talapov transition theory, the choice between the two theories is difficult. Nevertheless the analytical expression of the mean field theory reproduces surprisingly well all the points of the experimental profile.     

Determination of Charges of Superheavy Nuclei in Finding them in Nature

Bulletin of the Lebedev Physics Institute - The results of the search for tracks of heavy and superheavy nuclei of galactic cosmic rays in the charge range Z = 26 ? 129, identified in olivine...     

Value of RARE-MRI sequences in the diagnosis of lymphangiomatosis in children

Three patients suffering from extensive cavernous lymphangiomatosis are presented here. They were examined by MRI using RARE-MR hydrography (rapid acquisition with relaxation enhancement) as well as conventional spin-echo sequences. RARE sequences, which depict each fluid-filled lymphatic space, can be used for screening. RARE-sequences help to shorten investigation time, particularly in cases involving the skeleton. The imaging strategy can be changed according to the results of this sequence. It may be performed prior to spin-echo sequences and facilitates follow-up investigations. RARE sequences distinguish between lymphangiomatosis and hemangiomatosis, or a combination of the two.     

光学元件损伤在线检测中的图像处理

 利用在传统的边缘提取方法上加入灰度抑制,并在梯度计算中考虑每个像素与周围8个邻域的关系的图像处理方法,解决了在线检测中被检测元件以布儒斯特角放置、元件片数较多、CCD所采集的损伤图像噪声成分复杂等造成的像质较差的图像处理问题,并系统地进行了光学元件疵点分析和计算。分析计算结果表明:此图像处理方法得到的损伤疵点尺寸与实际尺寸相符,误差在检测的范围内;为大型光学系统中光学元件损伤的在线、自动化检测提供了一种有用的技术途径。