电解槽烟气实施干法净化综合节能治理

本文简述了我国即将淘汰的自焙槽烟气状况、改造的有效途径，以及中铝河南分公司电解厂采用逆向二段干法烟气净化新技术进行综合节能治理，在工业试验及正常运行中所取得的成绩。     

甲烷制备高纯度氢气的实验研究

对甲烷制备可供质子交换膜燃料电池(PEMFC)用的高纯度氢气进行了实验研究，得出了不同蒸汽／碳比值时甲烷的转化率、不同过量空气系数对制备气体成分的影响、不同压差时氢气在选择性膜中的渗透率以及不同系统压力对氢气反应焓的影响规律．研究结果表明，在蒸汽与甲烷中的碳比例一定时，蒸汽重整反应器内的反应速率和它出口处CO的浓度，随甲烷的流量的增加而提高．提高甲烷蒸汽重整系统的工作温度和压力，可以提高甲烷的转化率，在S／C比值不变的情况下，仅提高温度可提高甲烷的转化率约10％；而将工作压力由0．1MPa提高到0．6MPa，甲烷的转化率提高约21％．甲烷的理论转化率为84．6％，本文实验研究中的最大实际转化率为78．03％，实验研究系统的系统完善度为92．23％，说明该系统还有待完善之处，还可以进一步提高甲烷的转化率．增大PEMFC中选择性膜两侧的压差或提高氢气的纯度，均利于提高氢气混合物的渗透率．该研究为制备符合PEMFC使用条件的氢气提供了可靠依据，同时为综合利用煤层气提供了新的途径。     

流场尺寸对质子交换膜燃料电池性能的影响

流场的形状和尺寸是设计双极板的核心。合理的流场既要确保电极各处均能获得充足的反应剂供应,同时又要保证反应产物水的排出。研究了不同流场尺寸对质子交换膜燃料电池性能的影响。实验结果表明:在一定范围内,随着开孔率的增加,电极与流场本相及接触电阻也逐渐增加;开孔率相近时,这一电阻相差不大。在相同开孔率的情况下,沟槽尺寸越小,电池性能越好。     

Influence of Powder Morphology and Chemical Composition on Metallic Foams produced by SlipReactionFoamSintering (SRFS)‐ Process

The SlipReactionFoamSintering (SRFS)‐ process is a metallurgical method to produce open‐cell metallic foams of iron based materials, steels and nickel based materials. In this process several chemical reactions take place. Through the most influential parameter, the morphology of the metallic powder, different properties of the foam can be adjusted, such as the viscosity of the slip, the cell structure and the mechanical properties. Several examples are presented in this paper. Moreover, the thermal conductivity of three foams is measured with the transient‐heat‐source‐technique.     

Investigation of Structure and Hydriding Properties of La0.6 Nd0.4 Ni4.8 Mn0.2 Cux Alloys

The structure and hydriding performance of La0.6Nd0.4Ni4.8Mn0.2Cux (x = 0 ～ 0.4) alloys were investigated in order to develop suitable materials for metal hydride air conditioner. The effect of Cu addition on the crystal structure,equilibrium pressure, hydrogen capacity and hysteresis as well as hydrogen absorption/desorption kinetics were systematically studied by using the measurement of P-C isotherms, X-ray diffraction and scanning electron microscopy. As the amount of Cu increases, the plateau pressure increases and hydrogen absorption/desorption kinetics is improved, but the effective hydrogen storage capacity decreases. It is shown that variations in the basal plane parameter a can be used as an indication for the plateau pressure changes. With the increase of parameter a, the plateau pressure decreases. For La0.6 Nd0.4Ni4.8Mn0.2Cux(x = 0 ～ 0.4) alloys there is a relationship between the effective hydrogen storage capacities and the ratios of their unit cell parameters c and a. The effective hydrogen storage capacity decreases with increase of a/c.     

双层属性网络及其推理

人脑是对客观世界的反映,研究人脑必须先建立起能反映客观世界的数学模型。文章为此在属性神经网络和行为属性理论的基础上建立双层属性网络模型,将属性存储与关系存储分开,以属性环形式组织数据。并给出了它的学习方法,方便实现互动式学习方式。引入多线程技术,实现了网络自动推理。     

Computer-based determination of size and shape in living cells

Measurement of cell volume in living epithelial cells has become an important technique in studies of membrane transport processes that function in cell volume regulation. Planimetry of video images of optical sections enables the measurement of the cross sectional area of each section. Cell volume is calculated from the measured area of each section and the known focus displacements. In the past the measurement of cross section area has been done by manual positioning of a cursor superimposed on the video image. Each experiment generates approximately 200 images in which two or more cells may be analysed. We have developed a computer-based method that uses one image as a template, and allows automated area determination of successive images by template matching and digital image processing. This new method is comparable to the older method in speed and accuracy, but requires much less effort from the experimenter.     

Backscattered electron imaging of the undersurface of resin-embedded cells by field-emission scanning electron microscopy

In this study backscattered electron (BSE) imaging was used to display cellular structures stained with heavy metals within an unstained resin by atomic number contrast in successively deeper layers. Balb/c 3T3 fibroblasts were cultured on either 13-mm discs of plastic Thermanox, commercially pure titanium or steel. The cells were fixed, stained and embedded in resin and the disc removed. The resin block containing the cells was sputter coated and examined in a field-emission scanning electron microscope. The technique allowed for the direct visualization of the cell undersurface and immediately overlying areas of cytoplasm through the surrounding embedding resin, with good resolution and contrast to a significant depth of about 2 μm, without the requirement for cutting sections. The fixation protocol was optimized in order to increase heavy metal staining for maximal backscattered electron production. The operation of the microscope was optimized to maximize the number of backscattered electrons produced and to minimize the spot size. BSE images were collected over a wide range of accelerating voltages (keV), from low values to high values to give ‘sections' of information from increasing depths within the sample. At 3–4 keV only structures a very short distance into the material were observed, essentially the areas of cell attachment to the removed substrate. At higher accelerating voltages information on cell morphology, including in particular stress fibres and cell nuclei, where heavy metals were intensely bound became more evident. The technique allowed stepwise ‘sectional’ information to be acquired. The technique should be useful for studies on cell morphology, cycle and adhesion with greater resolution than can be obtained with any light-microscope-based system.     

Simplified nerve cell counting in the rat brainstem with the physical disector using a drawing-microscope

A simple modification of the physical disector is presented, which is used to count the number of neurons in the hypoglossal nucleus of the rat in a series of paraffin sections. One disector consists of two adjacent sections (6 μm thick) that have been Nissl-stained with cresyl fast violet. In the first step of the procedure each of the two sections is investigated separately with a drawing-microscope. The boundary of the hypoglossal nucleus and the position of neurons devoid of, or containing a part of, the cell nucleus in the plane of the section are marked on transparent paper. In the second step, these two drawings are placed one upon another, aligned and the number of cell profiles that show a cell nucleus in one but not in both drawings counted. This modification of the disector method for cell counting needs no specialized equipment, simply a light microscope with drawing apparatus, and can be combined with histochemical studies of other sections from the same tissue block.     

Vertical sections of cultivated anchorage-dependent cells for electron microscopy

A method is described for electron microscopic preparation of cultivated cells for vertical sections using the test chamber system TCSC-1. The cells are cultivated on a special foil. They can be fixed and embedded directly in the chamber. After polymerization of the resin, the foil can be easily taken off and a second resin layer is poured upon the embedded cells. Then distinct cells can be marked under an inverted light microscope. The bilayer of the resin allows optimal conditions for vertical sections of anchorage-dependent cells.