混凝土面板堆石坝自振周期的简化公式

针对用原有的计算堆石坝自振周期经验公式与实测值有一定差别的问题，以混凝土面板堆石坝（ＣｏｎｃｒｅｔｅＦａｃｅｄＲｏｃｋｆｉｌｌＤａｍｓ，以下简称为ＣＦＲＤ）为研究对象，考虑坝高、堆石材料性质、面板和边坡坡比等对ＣＦＲＤ自振周期的影响，结合已建的ＣＦＲＤ堆石材料动力特性，提出了ＣＦＲＤ自振周期简化公式。这一公式对ＣＦＲＤ，尤其是ＣＦＲＤ高坝的抗震设计和地震反应分析具有实用价值。     

研究高聚物结构的广角X射线衍射系列方法

全面论证了广角Ｘ射线（ＷＡＸＤ）系列方法：分峰ＭＰＳ、径向分布函数（ＲＤＦ）（Ｒ）、圆柱分布函数ＣＤＦ（Ｒ，α）、取向分布函数ＯＤＦ（α）、对称透射径向ＷＡＸＳ方位角扫描、对称反射径向ＷＡＸＳ扫描等分析法的基础理论、实验方法、计算程序及其可获得的结构参数，阐明了笔者建立ＷＡＸＤ测试分析高聚物聚集态结构专家系统的有关工作，这一研究架构的具体实现，将使得ＷＡＸＤ系列方法研究高聚物物理中的核心领域，即高     

DRS/SDS/NF体系中合成聚丁二烯胶乳的表观反应速率的研究

在以岐化松香皂（ＤＲＳ）、十二烷基硫酸钠（ＳＤＳ）和间次甲基萘磺酸盐（ＮＦ）组成三元复合乳化剂体系中，研究了丁二烯（Ｂｄ）中炔烃，二聚体（Ｄｉ），ＤＲＳ中的松香酸（ＲＡ），水相中的碳酸盐浓度及３种乳化剂复合比对ＡＢＳ用聚丁二烯胶乳（ＰＢＬ）的表观反应速率的影响。     

超大比表面积活性炭纤维对氮的多段吸附机理

研究了超大比表面积ＡＣＦ（Ｋ－ＡＣＦ）对氮的多吸附机理。通过各样品孔径结构（基于ＤＦＴ）和吸附过程（ＤＲ曲线描述）比较分析,探讨不同孔径结构对Ｋ－ＡＣＦ的多段吸附的影响,结合前人工作提出了超大比表面积ＡＣＦ的多段充填机理,并重点分析了极微孔中的吸附过程（第一吸附段）,解释了Ｋ－ＡＣＦ的ＤＲ曲线偏离理想ＤＲ曲线的原因。     

ROLAND（罗兰）XP—80音乐工作站操作简介

前面板说明Ａ部分（ＳＯＵＮＤＰＡＬＥＴＴＥ声音调制部分）采用４个参数推子，其中左起第一个是（ＣＵＴＯＦＦ）截止，第二个是（ＲＥＳＯ）共振，第三个是（ＡＴＴＡＣＫ）上升，第四个是（ＤＥＣＡＹ）衰减，利用这４个推子可实时地对音色进行调制操作。ＦＩＬＴＥＲ...     

增效膨胀阻燃聚乙烯的制备与性能研究

将ＺＥＯ（分子利）作为膨胀阻燃增效剂,分别引入ＡＰＰ／ＰＥＲ（聚磷酸铵／季戊四醇）和ＡＰＰ／ＤＰＥＲ（聚磷酸胺／双季戊四醇）两个ＩＦＲ（膨胀型阻燃剂）中,用于阻燃ＰＥ。结果表明：这一方法显著提高了ＩＦＲ的阻燃效率,ＩＦＲ－ＰＥ的ＬＯＩ（极限氧指数）又分别提高了２．４和６．５,达到２８．９和３０．９。研究了ＺＥＯ型号及用量对增效作用的影响。进一步利用ＴＧ（热重分析）和ＤＴＡ（差热分析）研究ＩＦＲ－ＰＥ的热降解行为,探讨了ＺＥＯ的增效作用原理。     

CSF－1R部分基因在大肠杆菌中表达、抗融合蛋白血清制备及丝氨酸／苏氨酸磷酸化的初步研究

鼠巨噬细胞集落刺激因子－１受体（ｍＣＳＦ－１Ｒ）部分序列与质粒ｐＧＥＸ－２Ｔ谷胱苷肽转移酶（ＧＳＴ）融合，融合蛋白ＧＳＴ－ＣＤ－Ｐｓｔ（胞浆区），ＧＳＴ－ＣＴｅｒｍ（Ｃ－末端）和ＧＳＴ－ＫＩ（激酶插入区）成功地在大肠杆菌ＪＭ１０９株表达。初步结果指出：（１）ＧＳＴ－融合蛋白在体外激酶分析中可以作为底物；（２）由ＰＫＡ导致的磷酸化可能具有生理学意义；（３）ｍＣＳＦ－１Ｒ被ＣＫＩＩ磷酸化。３２Ｐ标记ＧＳＴ－ＣＤ－Ｐｓｔ的磷酸氨基酸分析证实，ｍＣＳＦ－１Ｒ的胞浆区丝氨酸上被磷酸化，已制备抗ＧＳＴ－ＣＴｅｒｍ，ＧＳＴ－ＫＩ和ＧＳＴ－ＣＤ－Ｐｓｔ兔抗体。抗血清的筛选通过野生型３２Ｄ－ＣＳＦ－１Ｒ转染子免疫沉淀进行。     

采用替代工质的吸收式制冷运行特性

运用热力学第一定理、质量守恒定理及相平衡原理,建立了一套可用于模拟采用新工质的吸收制冷系统的运行特性的程序。程序中系统各部件的数学模型采用集总参数法建立,系统中制冷剂气液相之间的平衡用改进型ＰＴ方程＾［１］计算,溶液与上方蒸气之间的相平衡用活度系数模型ＵＮＩＦＡＣ法来预测。运用该程序,分别计算了以Ｒ１３４ａ＋Ｒ３２（摩尔比３：７）／ＤＭＦ和Ｒ２２／ＤＭＦ为工质对时的运行特性,并对计算结果进行了系统     

复合钙钛矿Pb（Fe1／2Nb1／2）O3的弛豫特性

制备了纯钙钛矿相Ｐｂ（Ｆｅ１／２Ｎｂ１／２）Ｏ３（ＰＦＮ）陶瓷，研究其介电性能表明，ＰＦＮ陶瓷无论退火与否都存在弥散性相变（ＤＰＴ）现象，未退火试样εｍａｘ对应的温度Ｔｍ不随测量频率变化，退火试样的Ｔｍ随频率变化，即表现出Ｔｍ频率色散现象，结合ＸＲＤ分析，指出ＰＦＮ应属弛豫铁电体。     

混合制冷工质

混合制冷工质ＤＡＤｉｄｉｏｎＮＩＳＴ，ＧａｉｔｈｅｒｓｂｕｒｇＭＤ，ＵＳＡ工业上为了填补由于一些重要的ＣＦＣｓ（如Ｒ１１和Ｒ１２）被取消使用而导致的空白，初步的方法是发展对臭氧层破坏作用较小或没有破坏作用的其它单组分的工质（如ＨＣＦＣ１２３和ＨＦＣ１...     

An analytic expression for the first shell of the radial distribution function

A simple analytical expression for the first shell of the radial distribution function (RDF) is proposed. This expression, which has only three adjustable parameters, satisfies all the limiting cases of the hard-sphere RDF at high temperatures, the ideal gas RDF at zero density, the dilute-gas RDF at low densities, and the location of the peak in the first shell. The only requirement is the introduction of a potential function into the model. This theory has been applied to the Lennard Jones, Kihara, and square-well pair intermolecular potential energy functions. The first-shell RDF results are in good agreement with the available computer simulation data for the RDF of the Lennard Jones fluid and the experimental data for argon. By introducing the radius of truncation for the RDF, it is shown that information on the first shell of the RDF is sufficient to predict macroscopic properties of fluids. Calculations of radii of truncation of RDF for various properties indicate that they are always in the range of the first shell of RDF.     

Subcritical and Supercritical Water Radial Distribution Function

A theoretical and analytic expression for the first shell, and an analytic empirical expression for the whole radial distribution function (RDF) of water are introduced. All the asymptotic limits and functionalities of the RDF with temperature and density are incorporated in these expressions. An effective Kihara pair potential function is presented for water intermolecular interactions which incorporates the hydrogen bonding by using the chain association theory. The intermolecular pair potential parameters are adjusted to the experimental x-ray diffraction data of water RDF at various temperatures. The predicted first-shell results for water near critical and in supercritical conditions compare satisfactorily with the available neutron diffraction RDF data, with the simulation RDF results, and with the empirical RDF curves. The empirical expression initially proposed for the RDF of the Lennard–Jones fluid is extended to predict the RDF and the isothermal compressibility of water to conditions where experimental or simulated data are not available. Comparison with the Lennard–Jones fluid shows that the height of the first peak of water RDF changes much less at subcritical and supercritical conditions compared to that of the Lennard–Jones fluid which decreases appreciably going from subcritical to supercritical conditions.     

原子径向分布函数在材料结构研究中的应用

介绍了原子径向分布函数的基本理论,综述了原子径向分布函数在有机高分子材料、无机碳材料、金属材料等不同类型材料结构研究中的最新进展。阐明了原子径向分布函数相对于传统结构研究方法的特点和优势,并展望了该方法在碳纤维结构研究中的应用前景,该方法能够从原子级别揭示整个碳纤维制备过程中结构的演变规律,这对制备高性能碳纤维具有重要的指导作用。     

Investigation of short range ordering in polymers by means of radial distribution functions derived from X-ray diffraction

Two samples of bisphenol-A polycarbonate, showing marked differences in impact behaviour due to different thermal histories, were investigated by radial distribution function (RDF) methods. The RDF patterns were virtually identical and showed that the short range order (0 to 10 Å) in the samples had been essentially unaffected by the annealing procedures. Most of the intra-molecular distances in the polymer repeat unit were successfully resolved in the RDF pattern. However, there were only suggestions of broad peaks at r 5.5 Å and r 10 Å attributable to intermolecular ordering, indicating that little intermolecular ordering had occurred in either sample. Explanations of the different impact properties of the two samples which assume a significant short range re-ordering on annealing are thus ruled out on the available evidence.A more highly annealed sample was examined to assess the sensitivity of the RDF method to short range intermolecular ordering. The RDF plot of this sample showed a marked periodicity peaking at intervals of 5.5 Å which was attributed to intermolecular ordering, thus confirming the above conclusion.     

Pyrolysis characteristics and mechanism of hydrocarbon compounds for RDF

Abstract

With the help of pyrolysis gas chromatography–mass spectrometry (Py-GC-MS), high resolution thermogravimetric instrument and CHONS elemental analyzer, the pyrolysis products of refuse-derived fuel (RDF) in different months in one year are studied in this article. And the three kinds of RDF are denoted as A, B and C, respectively. High resolution thermogravimetric tests showed that obvious chemical reactions took place for RDF samples in the temperature ranges of 433–623?K, 623–773?K and 773–1173?K. RDF samples were tested by Py-GC-MS under 623?K, 773?K or 1173?K while He was as the balance gas, and the qualitative and semi-quantitative analysis results were obtained by introducing pyrolysis products into gas chromatography–mass spectrometry. According to the Py-GC-MS tests, the kinds and contents of pyrolysis products increased with the rising of the temperature, and RDF pyrolysis finished prior to 1173?K. Primary discussion for pyrolysis mechanism is progressed according to main pyrolysis products and the change of their relative contents, which can be used to provide the significant fundamental research of homogeneous reduction for NO_x removal.     

A structural study of glassy polystyrene

X-ray scattering from three polystyrene glasses and from a partially devitrified specimen has been measured. The intensity data are identical for quenched and slowly cooled atactic polystyrene but differ for isotactic polystyrene quenched to the glassy state. Radial Distribution Functions (RDF) exhibit five principal peaks centred at 1.5, 2.5, 5, 6, and 10Å for all of the glasses. A model RDF based on the published crystal structure is shown to compare well with the RDF obtained experimentally for devitrified isotactic polystyrene. On the basis of this model, peaks in the RDFs are assigned. It is shown that both inter- and intramolecular scattering contributes to the polystyrene RDF at distances beyond 3.7Å. The structure is dominated by steric interaction of the phenyl groups, affecting both chain conformation and molecular packing.     

Molecular-dynamics study of nanofragmentation during relaxation in after-loaded solids

The possibility of nanofragmentation development during the initial relaxation stage in the subsurface layer of a solid after preliminary loading is studied by computer simulation using the molecular dynamics method. It is established that disoriented nanoblocks can form in the initial stage of relaxation. This fragmentation arises in the region of strain localization in the vicinity of stress concentrators and then spreads in depth of the material. In the region of strain localization, the radial distribution function (RDF) of atomic density exhibits smeared maxima corresponding to peaks in the RDF of the ideal fcc crystal structure. In the crystal region free of strain localization, the RDF peaks exhibit splitting caused by the strain-induced symmetry breakage. The obtained results suggest that fragmentation is the possible mechanism of relaxation of internal stresses in loaded solids.     

Structural investigation of boron-containing metallic glasses

Structural investigations have been made of high boron-containing alloy glasses of compositions Co_100–x B _x withx=34, 36, 38 and 40 at % measured by X-ray diffraction. The characteristic second-peak splitting in the radial distribution function (RDF) is found for all samples presently investigated. The shoulders are also observed near the distances of 0.20 and 0.34 nm. The partial radial distribution functions of Co-Co and Co-B pairs have been derived from the measured total RDF data by applying the concentration method with the anomalous scattering technique, and the contributions from different atomic pairs to total RDF have been discussed. The calculation by the relaxed dense random packing model has been made for Fe-B alloy glasses with three different boron concentrations, i.e., 15, 25, and 40 at % boron and a comparison between the calculated and experimentally determined data is presented. The present model calculation could give the possible representation for the compositional dependence of the X-ray RDF for amorphous Fe-B alloys with boron contents of up to 40 at % as well as the different peak profile observed in the total RDF of X-ray data between Fe-B and Fe-P glasses.     

X-ray diffraction radial distribution function studies on bone mineral and synthetic calcium phosphates

An investigation of the molecular structure of bone mineral and synthetic calcium phosphates was carried out using radial distribution function (RDF) techniques. The X-ray data were collected using CuK and MoK radiation to insure the validity of the RDFs. Synthetic preparations of hydroxyapatite (HA) varying in their crystal size and crystallinity, and amorphous calcium phosphate (ACP), were studied, as well as bone samples from a 1-year-old chicken and 16-day embryonic chicks. Mixtures of embryonic bone and synthetic ACP were also investigated. The RDFs of bone and crystalline HA samples are similar in peak position, and show evidence of an atomic order extending to 2.5 nm and beyond. The RDF of ACP differs from that of HA, showing only short range order up to 0.9 nm, as well as small differences in peak shape. The decrease in intensity of the RDF function with increasing distance (r), observed with both HA and bone samples can be related to a decrease in crystallinity and crystal size. The RDF data indicate there is no significant amount of ACP in either very young or mature bone. The RDFs of the embryonic bone + synthetic ACP mixtures showed that a small amount of ACP can be readily detected in a sample of bone with a poorly crystalline mineral phase; from this we estimate the threshold for detection of ACP in bone to be 12% or less.