试论"虚实相生"的艺术创作原则

本文通过对"虚实之论"的历史性回顾,揭示"虚"与"实"辩证统一的关系,指出艺术创作应虚实结合,不可偏废,而在中国传统的审美范畴中,犹应以虚为主,从而营造出一种"言有尽而意无穷"的艺术氛围.     

Tea saponins affect in vitro fermentation and methanogenesis in faunated and defaunated rumen fluid

INTRODUCTION Livestock is one of the largest sources of meth-ane emission with 80~115 million tons produced peryear, equivalent to 15%~20% of total anthropogenicmethane (IPCC, 2001). The global cattle population isresponsible for 73% of methane emissions of alllivestock, and methane produced during ruminalfermentation represents a loss of 2%~15% of grossenergy intake and may contribute to global warming(Johnson and Johnson, 1995). Many researches hadbeen carried out to find ways to low…     

Imitative learning in Japanese quail (<Emphasis Type="Italic">Coturnix japonica</Emphasis>) using the bidirectional control procedure

In the bidirectional control procedure, observers are exposed to a conspecific demonstrator responding to a manipulandum in one of two directions (e.g., left vs. right). This procedure controls for socially mediated effects (the mere presence of a conspecific) and stimulus enhancement (attention drawn to a manipulandum by its movement), and it has the added advantage of being symmetrical (the two different responses are similar in topography). Imitative learning is demonstrated when the observers make the response in the direction that they observed it being made. Recently, however, it has been suggested that when such evidence is found with a predominantly olfactory animal, such as the rat, it may result artifactually from odor cues left on one side of the manipulandum by the demonstrator. In the present experiment, we found that Japanese quail, for which odor cues are not likely to play a role, also showed significant correspondence between the direction in which the demonstrator and the observer push a screen to gain access to reward. Furthermore, control quail that observed the screen move, when the movement of the screen was not produced by the demonstrator, did not show similar correspondence between the direction of screen movement observed and that performed by the observer. Thus, with the appropriate control, the bidirectional procedure appears to be useful for studying imitation in avian species.     

Comparing Knowledge Bases and Reasoning Structures in Discussions of Mathematics and Pedagogy

While teaching, teachers need to access both their knowledge of mathematics and knowledge of pedagogy. Practice-based materials afford teachers opportunities to reason about both mathematics and pedagogy within the context of teaching. Accepted systems exist for explaining and reasoning in the domain of mathematics; logic, procedures, and representations all serve as instances of mathematics that bear common meaning in the domain. In contrast, there is not an accepted well-structured system for reasoning within the domain of pedagogy; rather, it is an inherently interpretive act. This paper explores differences in knowledge bases and reasoning by examining discourse about mathematics and pedagogy in a practice-based teacher education course. Mathematics conversations featured greater depth of conversation, more challenges, and more echoes of previous claims. Pedagogical conversations were denser and featured more qualified statements and more evidence from personal values or opinions. Implications for the design of teacher education and professional development experiences are presented.     

Comparison of low-molecular-weight-heparin and unfractionated heparin for acute PTE

INTRODUCTION Acute pulmonary thromboembolism(PTE)is serious pulmonary vascular disease with high mortality.The challenge is to make a correct diagnosiand give appropriate treatment(Nicolaides et al.2001).Effective treatment will decrease morbidityand mortality.This study compares the efficacy,adverse effects and costs of low-molecular-weightheparin(LMWH)and unfractionated heparin(UH).MATERIALS AND METHODS Materialss a or-sis al.,ity ad-ht-).All patients diagnosed as non-massiv…     

外墙外保温技术在某高层住宅楼施工中的应用

随着国家节能政策的深入贯彻及人们对室内环境舒适度要求的不断提高，采取有效的节能措施已被提上日程。外墙外保温已成为目前大力倡导的一种建筑隔热方法。该系统采用可靠的连接方式，将外保温层和基层牢固地连接在一起，具有消除冷桥、防水性能好、保护结构、增加室内面积、稳定内部环境及降低供热费用等优点。     

Computers in Reception Schools—A Case of Gaborone,Botswana

Computers are changing young children’s world in profound ways. Research shows that when computer technology is used appropriately in early years of life, it enhances virtually every aspect of development, i.e., cognitive, social, emotional, language and fine motor skills. Thus a very critical issue in today’s technologically advanced world is whether we in Botswana use computer technology for young children, and if so how do we use it. Hence the present study was conducted in the reception schools of Gaborone, Capital of Botswana. Out of 12 reception schools of Gaborone, data could be collected from nine schools only. The outcome of the study led to a few recommendations.     

Learned suppression of photopositive tendencies in<Emphasis Type="Italic">Drosophila melanogaster</Emphasis>

A task was designed to teach individual flies to avoid a lighted area after they had displayed an initial preference for it. The flies walked in a T-maze and chose between a lighted and a darkened alley leading, respectively, to a lighted and a darkened vial. Flies that were photopositive on a first trial were subjected to an aversive stimulus (a filter paper inserted into the lighted vial and wetted with a quinine solution), and they performed 16 training trials; they learned to avoid the lighted vial. The flies trained with water instead of quinine in the lighted vial still displayed avoidance of the lighted vial, but to a lesser extent. The flies trained with a dry filter paper in the lighted vial did not show any increase in avoidance during training. Like the flies trained with no quinine at all, those trained to avoid the lighted vial under a partial reinforcement condition (one half of the trials with quinine, the other half with a dry vial) did not master the task. Finally, removal of the quinine after an avoidance acquisition criterion was reached resulted in an extinction process.     

Study on the comprehensive combustion kinetics of MSW

The combustion behavior of typical components of MSW was examined with a thermal gravimetric analyzer (TGA). The experiments were done over the temperature range of room temperature to 1000℃ at a heating rate of 10 oC/min and in an oxidizing atmosphere. The results indicated that the entire weight loss process of each typical component of MSW consists of one to three distinct combustion stages. The combustion of typical components of MSW could be modeled by one to three independent reactions. The corresponding parameters of typical components of MSW such as activation energy, pre-exponential factor, and reaction order were determined. The calculated results using the comprehensive kinetic model composed of one to three independent and consecutive reactions, agreed well with experimental results.