The transformation and the catalytic activity of iron sulfide in lignite liquefaction

The Mössbauer effect was used to study the decomposition of pyrite in the presence of tetralin and hydrogen atmosphere. Iron sulfide catalysts with different amounts of sulphur are prepared and their transformations and catalytic activities in coal hydroliquefaction are examined.     

线性模型中相依误差下回归系数最小二乘估计的相合性

本文研究了线性模型y_i=X_i’β+e_i,i=1,2,…中回归系数β=(β_1,…,β_n)’的最小二乘估计的相合性.文章前一部分考虑了随机误差序列{e_i}相依情况下的(?)的γ-阶平均相合性,改进了胡舒合在[1]中的有关结果.文章后一部分推广陈希孺在[2]中的(?)的强相合性于相依情形.     

相对滴定法的研究Ⅱ．电位滴定法测定多种弱酸的混合溶液

本实验研究了两种弱酸混合溶液中的相对滴定法。利用该法可分别检测ｐＫａ值相差１的两种弱酸混合溶液中的两种弱酸。     

A locking-free nonconforming triangular element for planar elasticity with pure traction boundary condition

A new nonconforming triangular element for the equations of planar linear elasticity with pure traction boundary conditions is considered. By virtue of construction of the element, the discrete version of Korn’s second inequality is directly proved to be valid. Convergence rate of the finite element methods is uniformly optimal with respect to λ. Error estimates in the energy norm and L²-norm are O(h²) and O(h³), respectively.     

Stokes问题的一个非协调有限元

<正>1引言定常Stokes问题是流体力学中的一种重要问题,是标准的混合问题,速度与压力同时计算.关于该问题有限元求解的文章很多([1],[2],[4],[5],[6],[8],[9]),分析的难点在于单元必须满足离散的Babuska-Brezzi([2])条件.在([4])中提出了著名的非协调Crouzeix-Raviart     

Thermoresponsive hydrophobic copolymer grafted on agar microspheres for all‐aqueous bioseparations

Agar microspheres were prepared by water–oil emulsification and cross‐linked under alkaline condition. The thermoresponsive hydrophobic copolymer, poly(N‐isopropylacrylamide‐co‐lauryl methacrylate‐co‐acrylamide), was grafted on the agar microspheres via atom transfer radical polymerization. The agar microspheres grafted with copolymers were characterized by light microphotography, elemental analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and X‐ray photoelectron spectroscopy. The chain lengths and hydrophobic monomer ratio of the grafting linear polymer had significant effects on the hydrophobicity and adsorption capacity of agar microspheres at different temperatures. The thermoresponsive microspheres were used for separation of proteins and showed binding and release behavior by change of temperatures without change in mobile phase composition. Thus, we suggest thermoresponsive agar microspheres as an alternative separation media for all‐aqueous bioseparations.     

基于灰色网络组合优化的年增油量预测

老井措施增油成为油田稳产、降低油田区块开发成本的必然选择。针对多项式回归预测的局限性、灰色理论不能反映影响因素特征、神经网络需求数据多且数据敏感性差等特征,通过建立最优控制模型,实现GM（1,1）灰色理论与神经网络的高精度组合预测。以某油田区块2011-2018年的措施增油为例,对影响措施增油量的因素进行识别,建立了最优控制灰色神经网络模型对老井措施年增油量进行预测,相比多项式回归预测、GM（1,1）预测及BP神经网络预测方法,新模型模拟效果更好,预测精度更高。新方法对2018年措施年增油量的预测精度达97.34%。基于最优控制的灰色神经网络模型可以作为一种人工智能组合最优化模型预测措施年增油量,为准确预测措施增油效果,指导油田开发决策提供了新的思路。     

多色脉冲激光光源研究

采用钛宝石锁模飞秒激光器作为泵浦光源,利用1.8 μm纤芯的保偏光子晶体光纤的高非线性特性产生超连续谱,通过调节泵浦光源和光子晶体光纤之间的耦合,在可见光区,获得了中心波长分别在431 nm, 497 nm, 520 nm, 575 nm的mW量级的不同颜色的激光输出,并且测量输出的脉冲序列重复频率与泵浦光的一致,具有良好的稳定性.     

带有记忆项的半线性板方程解的衰变估计

研究多维空间Rⁿ(n≥1)中带有记忆项的半线性板方程的初值问题.在傅里叶空间中,得到线性问题解的衰变估计.介绍了一系列时间加权索伯列夫空间,运用压缩映射定理,在足够小的初值假设下,得到半线性问题解的全局存在及最佳衰变估计.     

Spontaneous asymmetric crystallization of a quartz-type framework from achiral precursors

An enantioenriched three-dimensional quartz-type framework {[Ni(1.5)(tzdc)(H(2)O)(3)]·3H(2)O}(n) (H(3)tzdc = 4H-1,2,4-triazole-3,5-dicarboxylic acid) possessing chiral channels is obtained through spontaneous asymmetric crystallization without any enantiopure additive.