百年中国儿童文学跨学科拓展的依据、路径与反思

在中国儿童文学领域“重提”跨学科实践,旨在于文学发展的内源性和时代演进的外源性同构的基石上,从学科界分的角度重审其概念的本体意涵,探寻跨学科拓展的知识学依据。中国儿童文学不仅是一个描述性的概念,还是一个结构与关系的概念。这种概念与学科的特殊性内在地驱动了学科互涉的转向。总体而言,中国儿童文学的跨学科拓展路径包含了内部“贯通”与外部“联动”两个层级。在世界儿童文学与百年中国文学的整体格局中,将这种跨学科实践纳入系统论的视野,超越“纯文学本质主义”与“非文学工具主义”的理论偏狭,在坚守学科本位的同时有效地开启学科间的对话交流,促进学科知识的整合,进而推动百年中国儿童文学向纵深方向发展。     

社会整体性的表征：卡勒“理论”的生产性

关于“理论”,乔纳森·卡勒做过若干界定,解释性是其特性之一。“理论”的反思性、批判性恰恰是通过其解释性而实现的。在卡勒那里,文化研究与“理论”是两个可以相互置换的概念。这两者产生于文学研究但却挤压和排斥了文学研究,从而实现了方法论的转变,将文学解释为社会整体性的表征。于是对文学对象的阅读就有了诗学模式/解释学模式、恢复解释学/怀疑解释学、表征性解释/症候性解释等一系列不同类型、不同层次的区分。本文通过对于这些错综复杂、欲理还乱的关系的厘定和归置,揭示了“理论”作为一种人文学科的新文类,具有显著的观念生产、知识增长和学术建构的功效。     

Unsupervised 3D ring template searching as an ideas generator for scaffold hopping: use of the LAMDA, RigFit, and field-based similarity search (FBSS) methods

Crystal structures taken from the Cambridge Structural Database were used to build a ring scaffold database containing 19 050 3D structures, with each such scaffold then being used to generate a centroid connecting path (CCP) representation. The CCP is a novel object that connects ring centroids, ring linker atoms, and other important points on the connection path between ring centroids. Unsupervised searching in the scaffold and CCP data sets was carried out using the atom-based LAMDA and RigFit search methods and the field-based similarity search method. The performance of these methods was tested with three different ring scaffold queries. These searches demonstrated that unsupervised 3D scaffold searching methods can find not only the types of ring systems that might be retrieved in carefully defined pharmacophore searches (supervised approach) but also additional, structurally diverse ring systems that could form the starting point for lead discovery programs or other scaffold-hopping applications. Not only are the methods effective but some are sufficiently rapid to permit scaffold searching in large chemical databases on a routine basis.     

Predicting the Outcome of Photocyclisation Reactions: A Joint Experimental and Computational Investigation

Photochemical oxidative cyclodehydrogenation reactions are a versatile class of aromatic ring‐forming reactions. They are tolerant to functional group substitution and heteroatom inclusion, so can be used to form a diverse range of extended polyaromatic systems by fusing existing ring substituents. However, despite their undoubted synthetic utility, there are no existing models—computational or heuristic—that predict the outcome of photocyclisation reactions across all possible classes of reactants. This can be traced back to the fact that “negative” results are rarely published in the synthetic literature and the lack of a general conceptual framework for understanding how photoexcitation affects reactivity. In this work, we address both of these issues. We present experimental data for a series of aromatically substituted pyrroles and indoles, and show that quantifying induced atomic forces upon photoexcitation provides a powerful predictive model for determining whether a given reactant will photoplanarise and hence proceed to photocyclised product under appropriate reaction conditions. The propensity of a molecule to photoplanarise is related to localised changes in charge distribution around the putative forming ring upon photoexcitation. This is promoted by asymmetry in molecular structures and/or charge distributions, inclusion of heteroatoms and ethylene bridging and well‐separated or isolated photocyclisation sites.     

How much does the SI,namely the proposed “New SI”, conform to principles of the Metre Treaty?

The International System of Units (SI) was first adopted in 1960, as the more recent implementation of the Metre Treaty signed in 1875. Basic features of the original SI are that (a) seven units are chosen as “base units”, all the others being “derived units”, and (b) the definitions of the base units should not create interdependence. This way, the SI conforms to the basic principle of the Metre Treaty that each signatory country can realise its choice of primary national standards of the very definitions of the units without needing to resort to calibrations obtained from another country, and without obligation to have them realised for all the units. A mismatch already occurs to some extent with respect to the above features in the present definitions of SI base units. This contribution, strictly based on metrological considerations, illustrates how the present proposal concerning new definitions for the base units, called “New SI”, would extend the mismatch. In this frame, also the meaning is discussed of the concepts of hierarchy and traceability in metrology. By outlining some of the consequences, a discussion is stimulated related to the status of base unit, to the meaning of calibration at the level of the standards of the unit definitions, and to the interdependence of countries’ standards.     

Programming Organic Molecules: Design and Management of Organic Syntheses through Free‐Radical Cascade Processes

Cascade, domino, or tandem processes, that link together two or more transformations in one pot, are increasing in popularity because they lead to improvements in synthetic efficiency and decreases in environmental impact. Not only do these cascades contain choice mechanistic gems but they also deliver compact and elegant syntheses of complex natural products. Longer cascades require more functional groups precisely configured within carefully designed initial molecular architectures. Such “purposeful” molecules can be thought of as chemical algorithms.This article surveys the phenomenal range of unimolecular free‐radical cascades. A convenient system for classifying free‐radical cascades is described that is useful for evaluating and comparing cascades and aids the design of synthetic routes to polycyclic structures.Double cyclization cascades lead to cyclopentylcyclopentane or bicyclo[3.3.0]octane derivatives. Precursors that contain a ring as a template have been used to control stereochemistry in syntheses of triquinanes and many related compounds. Of the cascades containing ring‐cleavage steps, the most useful are the ring expansions which have opened up new synthetic routes to medium ring polycycles.The key design features of three‐stage unimolecular free‐radical cascades that yielded steroid structures, are linear arrays of radical acceptor units associated with methyl groups distributed every fifth C‐atom in the precursor polyenes. Ring cleavage is the reverse of cyclization. In special, symmetrical structures, therefore, this led to sequences that were reversible, thus launching endlessly repeating cascades supported by delightfully fluxional structures. The science of “programming” organic molecules to achieve particular target structures is maturing rapidly. Coordination and classification of the welter of information in this area is intended to facilitate design and hence to extend the range and complexity of attainable structures.     

Concept system on ‘quantity’: formation and terminology

The third edition of the International Vocabulary of Metrology occasions continued useful discussion. A Commentator, in four recent papers, presents viewpoints on the generic division of ‘property’, ‘quantity’, and ‘ordinal quantity’, as well as a perceived problem of inheritance. Alternative terms for ‘kind-of-quantity’, ‘kind-of-quantity with chosen sort of component’, and ‘dedicated kind-of-quantity’ are suggested to be formed by prefacing “quantity” with the respective adjectival modifiers “generic”, “subgeneric”, and “specific”. Furthermore, a neoterm for ‘quantity expressed by a measurement unit’ and a redefinition of ‘property’ are offered. The Commentator’s proposals and arguments are discussed with emphasis on ways of constructing concept systems to ensure proper inheritance. Some formal and semantic problems of the proposed alternative terms and definitions are advanced. Terminological concepts are defined in an Appendix.     

Static atomistic modelling of the structure and ring dynamics of bulk amorphous polystyrene

A detailed static atomistic model of dense, glassy polystyrene is simulated using a well established technique that previously proved successful for simple vinyl polymers. Initial chain conformations that are generated using a Monte Carlo technique including periodic continuation conditions are “relaxed” by potential energy minimization. In total 24 microstructures at densities of 1,07 g/cm³ were obtained with a cube-edge length of 18,65 Å. Detailed analysis of the minimized structures indicates that intermolecular packing influences create a large variety of chain conformations different from the purely intramolecular ground states. The systems are amorphous, exhibiting random coil behavior. The described structures have been used for a quasistatic simulation of localized motions. These motions include stepwise rotation and oscillation of the phenyl groups. The frequency distribution for the simulated ring motions covers many orders of magnitude. It is very rare that an energy barrier with a reorientation angle indicating a ring “flip” is overcome. Motions with small reorientation of the phenyl rings, and therefore not leading to a ring “flip”, dominate with an average reorientation angle of 16° (±12°). The intermolecular effects of the analyzed processes were found very important and far-reaching, widely influencing the cooperative motions of molecular groups.     

Modern concepts on catalysis of hydroprocessing and synthesis of alcohols from syngas by transition metal sulfides

A concept on the dynamic nature of active centers (AC) of the catalysts based on transition metal sulfides is described. The concept formed the basis of a “dynamic” model, according to which AC formed and functioning under the reaction conditions can oscillate between layers of promoted molybdenum sulfide. The model assumes the existence of “rapid” and “slow” AC and the possibility of their intertransformation due to the reversible migration of sulfur and promoter between the crystallite layers in a hydrogen atmosphere. The frequency of these migrations (oscillations) determines the catalyst activity. An assumption is substantiated that the hydrogenation sites are localized at the rims of Co(Ni)MoS₂ crystallites and desulfurization (hydrodesulfurization) sites are localized on the edges. The proposed model makes it possible to develop criteria for the evaluation of the efficiency of catalytic performance for hydrodesulfurization of hydrocarbon raw materials of various types and for synthesis of higher alcohols from syngas.     

Gezielte Konformationsänderungen an cyclischen Systemen, 1. Mitt.: Das Isokonformationskonzept

By means of the “isoconformational concept” it is shown that a correlation of conformations of ring compounds with the corresponding patern of signs for their torsional angles and an equal number of torsional degrees of freedom is feasible, as far as geometrically required conformational changes are concerned (i.e. disregarding secondary, system inherent effects). The applicability of the concept is studied by means of 1- and 1,10-substituted [2.2]metacyclophanes, the conformations of which can be deduced from the “geometric behaviour” of cyclohexane.     

[Fe(H2O)5(NO)]2+, the “Brown‐Ring” Chromophore

Although the “brown‐ring” ion, [Fe(H₂O)₅(NO)]²⁺ ( 1 ), has been a research target for more than a century, this poorly stable species had never been isolated. We now report on the synthesis of crystals of a salt of 1 which allowed us to tackle the unique bonding situation on an experimental basis. As a result of the bonding analysis, two stretched, spin‐polarised π‐interactions provide the Fe–NO binding—and challenge the concept of “oxidation state”.     

Dosimetric concepts in photobiology

Abstract —The effectiveness of an irradiation at non-ionizing wavelengths for producing photochemical changes in a transparent sample can be characterized by any one of four different quantities. The utility of each depends on the information available about the sample and the kind of analysis intended. Nomenclature for these quantities is troubled. All four have been called “dose” in the literature, with or without modifying adjectives. In addition, incompatibility between the terminology for ionizing and non-ionizing radiations leaves the concept of “dose” ambiguous in the vacuum ultraviolet. Rather than abandon the term altogether, nomenclature restricting its use is suggested here, together with measurement units and symbols for the quantities. The use of dosimetric quantities implies certain assumptions about the system being irradiated which are not always fulfilled.     

中国现当代文学学科研究的一个新视域—五四时期至1950年代初期中国籍作者的域外华文书写

五四时期至1950年代初期,中国籍作者在海外创作了大量的华文书写,这些作品已然成为中国现当代文学的域外延伸部分。然而长期以来,中国大陆学术界并未将其整体性地纳入中国现当代文学学科研究领域,而是笼统地将其归类于海外华文文学学科,由此局囿了中国现当代文学学科研究的广度和深度。从历史角度和客观史实来看,本时段的域外华文书写具有无可争辩的中国文学属性,并且是中国现当代文学“主潮”跨越国家疆域后所开拓的“海外支流”。同时由于特殊的历史原因,本时段的域外华文书写具有“双重归属”的特性,即其一方面属于中国现当代文学学科的“华侨文学”,另一方面又属于海外华文文学领域的“华人文学”。在跨越国家疆域和学科分类的视角下,将其整体性地纳入中国现当代文学学科的研究领域,可以为中国现当代文学学科提供新的研究视域并开拓新的研究空间。     

A new statistical thermodynamic theory for substoichiometric fluorite structure compounds and its application: I. An order-disorder model theory for the thermodynamic functions of substoichiometric fluorite structure compounds

In this work an attempt is made of constructing the (G, T, x) curves for the case of substoichiometric oxides of the fluorite structure on the basis of a statistical model. Considering the fluorite structure as a repitition of oxygen ions tetrahedrically coordinated, the hypothesis is made of a local bond between the reduced cations and the oxygen vacancy in the tetrahedron (“tetrahedral defect”).This “tetrahedral defect” constitutes the building block of the low temperature sub-phases often encountered in these systems; at higher temperatures its packing in the lattice gives rise to “residual structures”.One can express all thermodynamic functions, at given oxygen/metal ratio, as a function of an “ordering parameter” p, representing larger and larger packings of the tetrahedral defects, in such a way making this model a typical order-disorder treatment.Introducing the formalism of chemical equilibria in the equilibria between the various defect species it is also possible to obtain thermodynamic functions by the solution of a system of pseudo-chemical equilibrium equations, when probability functions f are employed in place of the activities of the defects species.     

Lattice-dynamical calculations for tetracene and pentacene

Lattice-dynamical, calculations for evidently non-rigid molecules of aromatic hydrocarbons have been carried out on tetracene and pentacene. In these substances, “out-of plane” vibrations mix extensively with lattice vibrations, and significant differences can be noted between results from a “rigid-body” and a “non-rigid” treatment. For tetracene crystals, whose Raman spectral data are given in the literature, the agreement with experiment is satisfactory. This confirms the validity of such procedures for interpreting and/or predicting spectroscopic behaviour, starting from empirical atom—atom potentials and valence force fields.     

Formal Cycloadditions Driven by the Homolytic Opening of Strained,Saturated Ring Systems

The field of strain-driven, radical formal cycloadditions is experiencing a surge in activity motivated by a renaissance in free radical chemistry and growing demand for sp³-rich ring systems. The former has been driven in large part by the rise of photoredox catalysis, and the latter by adoption of the “Escape from Flatland” concept in medicinal chemistry. In the years since these broader trends emerged, dozens of formal cycloadditions, including catalytic, asymmetric variants, have been developed that operate via radical mechanisms. While cyclopropanes have been studied most extensively, a variety of strained ring systems are amenable to the design of analogous reactions. Many of these processes generate lucrative, functionally decorated sp³-rich ring systems that are difficult to access by other means. Herein, we summarize recent efforts in this area and analyze the state of the field.     

The structural theory and physical organic chemistry

Woolley's revolutionary proposal that quantum mechanics does not sanction the concept of “molecular structure”—which is but only a “metaphor”—has fundamental implications for physical organic chemistry. On the one hand, the Uncertainty Principle limits the precision with which transition state structures may be defined; on the other, extension of the structure concept to the transition state may be unviable. Attempts to define transition states have indeed caused controversy. Consequences for molecular recognition, and a mechanistic classification, are also discussed.     

Beiträge zur Chemie der Pyrrolpigmente, 49. Mitt.

From kinetic and equilibrium measurements the activation and thermodynamic parameters of diastereomeric 2,3-dihydrobilatrienes-abc in positions “4” and “15” are deduced. Compared to bilatrienes-abc a pronounced thermal lability of these diastereomers is observed—the exocyclic double bond of the saturated lactam ring being the more labile one. This feature may be of relevance to the thermal cascades and dark reactions observed for phytochrome.     

新生代价值观和行为模式研究的新路径

通过聚焦新生代价值观念及其行为模式的研究,为理解文化结构如何产生价值观念和行为模式提供一个框架。既有研究存在两点疏失：其一,既有新生代价值观和行为模式研究缺乏聚焦性实质理论。为此,文章将代际秩序纳入社会秩序的考量中,试图从权力遵从、规范共享和利益契约三大经典社会秩序理论出发,观照现有较为零散的青年及代际关系研究。其中,“秩序”作为本质要素,突破了原本仅对青年亚群体的研究囿于中观或微观层面的局限。其二,既有研究在因果机制解释方面,忽略了“文化结构”对社会成员个体或群体价值观及行为模式的传导和塑造。因此,有必要在常规的宏观经济结构变迁引发微观个体价值观形成抑或变动的共识性理解中,借助文化社会学理论工具,增加“文化结构”这一中介传导维度,以完善既有的因果解释路径。并将中国社会的文化结构具体操作化为传统话语体系、社会主义话语体系和市场话语体系的并存。关注这一文化结构的中介作用,对理解中国新生代价值观及行为模式的形成至关重要。