酶解鲐鱼蛋白制取低分子肽的进一步研究

确定了用胰蛋白酶－木瓜蛋白酶混合酶法水解鲐鱼蛋白制取低分子肽的最适工艺条件为：胰蛋白酶和木瓜蛋白酶的酶量比为１：４（Ｗ／Ｗ），肉水比为１：１，温度５５℃，ｐＨ７．０。在加酶量为鱼糜中蛋白质含量的１．２５％，反应时间６ｈ的条件下，制得的低分子肽无苦味，氮利用率可达７８．５％，平均链长为２．８０，游离氨基酸含量为２６．５７％，必需氨基酸含量占总氨基酸的４１．８％，且比例合理，富含镁，是一种很有开发前途的功能食品原料。     

三维空间中的有理样条插值

对三维空间某个多面体区域的四面体剖分，通过在每个四面体胞腔的棱和顶点设置适当的插值结点．本文给出了（１，１）型Ｃ⁰及Ｃ¹光滑的非奇异有理样条存在的充分必要条件．     

一种新型的固着磨料抛光片──WBN抛光片的制作工艺及其特性

本文描述了用冲击合成方法得到的超硬材料纤锌矿型氮化硼（ＷＢＮ）制作的一种新型抛光片。在光学玻璃抛光中的初步应用显示：这种新型的ＷＢＮ抛光片具有比传统的ＣｅＯ２。抛光片更大的切削力、更短的抛光时间和更好的表面粗糙度及更长寿命等优点。     

Rotational isomeric-state approximation for the unperturbed dimensions of a POLA polyester

Rotational isomeric-state theory has been applied to investigate chain configurations of a polyester prepared from 4′,5-(1,1,3-trimethyl-3-phenylindan) dicarboxylic acid and 2,2-bis(4′-hydroxyphenyl) propane (POLA polyester). Independent conformations for each repeat monomer unit of the chain have been assumed in the calculations of the unperturbed dimensions. Rotations about the oxygen-phenylene-carbon (O? ?? C) bonds are considered to be free with twofold symmetric potentials. The trans and cis conformations of the carbonyl-phenylene-carbon (O?C? ?? C) and the indan-carbonyl residues are assumed to have equal probability. Two rotational states, trans and cis, are assigned to the ester C? O bonds. Calculation of the reduced unperturbed dimensions (〈r₀²〉/M)_∞ with conformations thus assigned for the bonds in the repeat unit, and comparison with experiment (0.72 ± 0.02 Ų/g) indicate that the conformation in the ester C? O bonds is predominantly trans. An equation for the conformational potential as a function of rotational angle about the ester C? O bond has been formulated using data on potential barriers for low molecular weight compounds. This equation, yielding a potential difference between the cis the trans isomers of 2.5–3.0 kcal/mole, is in good agreement with the prediction made from the calculation of the unperturbed dimensions where a cis/trans ratio of 0.01 for the ester C? O bonds was obtained.     

Dilute solution behavior of polyelectrolytes. Intrinsic viscosity and light scattering studies

The conformational character of a random copolymer of ethyl acrylate and acrylic acid (mole ratio 3:1) has been examined by intrinsic viscosity and light scattering in organic and in aqueous media. The unperturbed dimensions of this copolymer in its un-ionized state in an organic theta solvent are 1.3 to 1.4 times those obtained for the fully ionized polymer in an aqueous theta solvent. The data also suggest that a change in conformation from a swollen random coil to a compact random coil occurs in aqueous media as a function of ionic strength. These results are interpreted in terms of the hydrophobic interaction of the ester groups on the chain. An application of the wormlike chain model shows that viscosity data can be used to predict the light scattering results well with in experimental error.     

Scattering of plane, elastic waves by a plane crack of finite width

The diffraction of time-harmonic, vertically polarized, plane elastic waves by a crack of finite width is investigated with the aid of the integral-equation method. Using the integral representation for the particle displacement of the scattered field together with the constitutive equation, it is shown that the resulting integral equations uncouple for this kind of obstacle. In them, the amount by which the components of particle displacement jump across the crack occur as unknown quantities. The integral equations are solved numerically. Normalized power scattering characteristics and scattering cross-sections are computed.The research reported in this paper has been supported by the Netherlands organization for the advancement of pure research (Z.W.O.).     

Relativistic corrections and very small g-shifts in solids

The relativistic Breit-Margenau correction to the Zeeman-interaction has been calculated for a group of atoms in the periodic table with Herman Skillman wave functions and potentials. The results are applied to the S-state ions Mn²⁺ and Gd³⁺, to the F-center and V_k-center, and to the shallow donors in Si.     

Magnetohydrodynamic Couette flow with transpiration cooling

Transpiration cooling with magnetohydrodynamic effects is studied in a porous-wall Couette flow of a steadily moving, incompressible, electrically conducting fluid. The flow, induced by the motion of the moving wall, is subject to a uniform transverse magnetic field. A coolant fluid, with the same properties as the main-stream fluid, is uniformly injected into (or extracted from) the flow through a porous stationary wall. Solutions are presented for the velocity and induced magnetic field distributions across the parallel walls, the pressure difference induced by the magnetic drag, and the friction factor in such a flow configuration. Considerations are further given to the heat transfer characteristics wherein viscous and Ohmic heating are significant. In this connection, the recovery factor and the Nusselt number are also presented over a wide range of blowing and suction rates.Nomenclature B magnetic field vector with components (B _x , B _y , B _z ) in (x, y, z) directions - B _x dimensionless magnetic field, B _x /B ₀ - B ₀ uniform applied magnetic field - C _p specific heat at constant pressure - E electric field vector - dimensionless electric field, E _z /U ₁ B ₀ - Ek Eckert number, U ₁ ² /C _p (T ₁–T ₀) - f friction factor, ₀/U ₁ ² - h heat transfer coefficient - I total electric current across parallel walls - J electric current density - L distance between parallel walls - M Hartmann number, B ₀ L - Nu Nusselt number, hL/ - p pressure - dimensionless pressure, pL/U ₁ - Pr Prandtl number, C _p / - Pm magnetic Prandtl number, Rm/Re - q ₀ heat flux density at stationary lower wall - r recovery factor, (T _r –T ₁)/(U ₁ ² /C _p ) - Re Reynolds number, U ₁ L/ - Rm magnetic Reynolds number, _e U ₁ L - T temperature, with T ₀ and T ₁ as temperatures of the lower and upper walls - dimensionless temperature, (T–T ₀)/(T ₁–T ₀) - T _r recovery temperature - U ₁ uniform velocity of upper wall - dimensionless velocity, u/U ₁ - V fluid velocity vector with components (u, v, w) in (x, y, z) directions - dimensionless velocity, v/U ₁=v ₀/U ₁ - v ₀ velocity of injection or suction at the walls - (x, y, z) rectangular coordinates - dimensionless height, y/L - viscous dissipation function - thermal conductivity - _e magnetic permeability - kinematic viscosity - fluid density - electrical conductivity - ₀ shear stress at stationary lower wall