中国比较文学复兴四十年学科方法论整体观

中国比较文学学科自1978年复兴以来,已经取得了40年的长足进展。但也出现了一些值得注意的现象和偏失。本文首先结合西方比较文学学科史与国内比较文学研究新趋势,归纳与中国比较文学发展相生相伴的两种不良倾向,那就是影响研究难免影响解读的囿限,造成所谓“影响研究的神话化”,同时注意文学理论和文学作品美学品格共时研究的平行研究,也因选题随意、不注重可比性原则、失去文学性底线等原因而被“妖魔化”了,影响研究和平行研究有被对立起来的趋势。文章进而在梳理影响研究与平行研究两者间辩证关系的基础上,对比较文学的几种主要研究类型进行综合论述,重新界定了比较文学的“可比性”与“知识装备”两个重要概念;最后则尝试展望全球比较文学第三阶段样态与特点,表明中国比较文学历经40年跨越式发展,相对于比较文学教学和研究实践的蓬勃发展,我国学界在比较文学方法论建构上依然任重道远。     

The Fifty Percent Machines—A Short History of Influence Machines and an Elementary Theory of Their Efficiency: An Attempt

Presenting the devices invented by Toepler, Holtz, Wimshurst, and Wommelsdorf, the history of the influence machines, the progress made, and the remaining deficits are discussed. The theoretical considerations published in the literature lack generalizable statements on the efficiency. Based on R. W. Pohl's model (1927), an elementary analysis is made, with the result that the upper limit of the theoretically achievable efficiency of influence machines is only 50%.     

The chloro-substituent enhances performance of 2,4-bis (imino)pyridylchromium catalysts yielding highly linear polyethylene

The five unsymmetrical 2-[1-(2,4-dibenzhydryl-6-chlorophenylimino)ethyl]-6-[1-(arylimino)ethyl]pyridine compounds (aryl: 2,6-Me₂Ph L1 , 2,6-Et₂Ph L2 , 2,6-ⁱPr₂Ph L3 , 2,4,6-Me₃Ph L4 and 2,6-Et₂–4-MePh L5 ) were prepared and characterized with FT-IR and ¹H/¹³C NMR spectroscopy as well as elemental analysis. The treatment of L1 – L5 with CrCl₃·3THF affords the corresponding chromium chloride complexes ( Cr1 – Cr5 ) in excellent yields. The molecular structures of Cr2 and Cr3 characterized by X-ray diffraction show a distorted octahedral geometry with three nitrogen atoms and three chlorine atoms around the metal center. On activation with either MAO or MMAO, Cr1 – Cr5 collectively display high activity (up to 14.96 × 10⁶ g (PE) mol⁻¹ (Cr) h⁻¹ at 60 °C) affording highly linear polyethylene with low molecular weight distribution (M_w/M_n) ranging from 1.06 to 2.81. An in-depth catalytic evaluation of Cr1 was conducted in order to investigate how the cocatalyst type and its amount, reaction temperature and polymerization time affect the catalytic activities and polymer properties.     

合肥市出租车数量确定的模型及应用研究

本提取了十个城市出租车数量的合理因素，运用非线性规划，建立了确定合肥市出租车数量的动态数学模型，计算出影响出租车数量因素的权重，最终得到了一个比较符合实际的结果，该结果已为合肥市出租车数量的控制提供了决策支持。     

A COMPARISON BETWEEN TWO ROBUST REGRESSION ESTIMATORS BY MEANS OF ROBUST COVARIANCES

Two classes of Mallows GM-estimators with invariance are considered in the stochastic linear regression model. Some of their asymptotic properties are described, and the fittedvalue influence and variance components are compared by means of robust covariances,     

Minimum distance estimation in linear regression with unknown error distributions

This paper discusses minimum distance (m.d.) estimators of the paramter vector in the multiple linear regression model when the distributions of errors are unknown. These estimators are defined in terms of L₂-distances involving certain weighted empirical processes. Their finite sample properties and asymptotic behavior under heteroscedastic, symmetric and asymmetric errors are discussed. Some robustness properties of these estimators are also studied.     

Solution properties of exocellular polysaccharides of rhizobium leguminosarum. Static and dynamic light-scattering: Characterization in dilute solution

Three polysaccharides, Rhizobium leguminosarum 8002 EPS(I), Rhizobium trifolii TA1-EPS (II), Rhizobium leguminosarum 127K87 EPS (III), produced by bacteria of Rhizobium genus have been investigated by static and dynamic light scattering combined with chirooptical measurements. All three polymers have the same backbone but differ in the length of the side chains and in the content of minor substituents. An isothermal conformational transition coil → helix was observed with I and II by adding salt (NaCl). The molecular parameters of the polysaccharides in the ordered state were determined by light-scattering data. Increasing the ionic strength a shrinking of the helix was observed accompanied by a corresponding decrease in the radius of gyration. An extraordinary chain stiffness in terms of Kuhn segment lengths was found in both cases, similar to that already observed for other microbial polysaccharides. In the case of III no disorder → order transition was induced by the salt, and the scattering behavior corresponds to that of a rather flexible polymer with a characteristic ratio C_∞ = 24. The incapability of III to form a helical structure is attributed to the effect of the very long side chain. The analysis of the time correlation functions revealed typical flexible chain behavior for all three polysaccharides. This behavior for the two ordered polymers is in agreement with a recent theory by Maggs and is due to bending modes of the rods. ©1995 John Wiley & Sons, Inc.     

Large-dimensional light-emitting elements with printed electroluminophore

In the paper, the influences of design and manufacturing technology on the performance of large-dimensional light-emitting elements with screen-printed luminophore are presented. The luminophore is based on Cu activated and Cl co-activated zinc sulphide ZnS. A particular instability when exposed to moisture and at rated electric load has been observed.     

Energy analysis on small to medium sized H-bonded complexes

Summary Dimers (water-methanol, guanine-cytosine) as well as trimers (methanol-water-imidazole, formamide-methylformate-formamide), are studied as H-bonded complexes of increasing complexity. All the investigated conformations have been fully optimized. In particular, it is the first time that all the intra-and intermolecular parameters of the guanine-cytosine complex are left variable. In minimal basis sets, the planar conformation has been found to be a first-order critical point. The minimal basis set MINI-1 has been adapted to provide nearly planar amides. The stability of the complexes is accounted for by four energy components of the same order: the first-order term (electrostatic + exchange), the polarization, the charge transfer and the correlation terms. In the case of the studied trimers, the energy components, apart from the electrostatic one, have been found to be nearly additive.