中国营造学社的学术之路——"纪念中国营造学社成立80周年学术研讨会"综述

中国营造学社成立于1929年,在其成立以后的10余年间,学社在朱启钤先生的领导与梁思成、刘敦桢两位先生的鼎力支持下,取得了极其丰硕的学术成果,使原本在世界建筑史学领     

基于并联机构的三维动力吸振器各向同性设计及减振特性研究

针对动力机械设备的多维线谱耦合振动控制问题,提出一种基于并联机构的三维动力吸振器,它具有模块化、附加质量小等优点。构造出采用一组关节坐标刻画的动力学方程,在此基础上推导出该新型动力吸振器的模态解析解,得到动力学各向同性条件,并据此设计出一款可抑制50 Hz线谱振动的动力吸振器。探讨了该动力吸振器在动力机械设备多维线谱耦合振动控制中的有效性及优势。分析结果表明：不同于单向动力吸振器仅能抑制其自由度方向的线谱振动,新型三维动力吸振器在三个垂直方向上对50 Hz附近线谱振动的最大减振效果均高于7 dB。     

Association and dissociation kinetics of bobwhite quail lysozyme with monoclonal antibody HyHEL-5

The anti-hen egg lysozyme monoclonal antibody HyHEL-5 and itscomplexes with various species-variant and mutant lysozymeshave been the subject of considerable experimental and theoreticalinvestigation. The affinity of HyHEL-5 for bobwhite quail lysozyme(BWQL) is over 1000-fold lower than its affinity for the originalantigen, hen egg lysozyme (HEL). This difference is believedto arise almost entirely from the replacement in BWQL of thestructural and energetic epitope residue Arg68 by lysine. Inthis study, the association and dissociation kinetics of BWQLwith HyHEL-5 were investigated under a variety of conditionsand compared with previous results for HEL. HyHEL-5–BWQLassociation follows a bimolecular mechanism and the dissociationof the antibody–antigen complex is a first-order process.Changes in ionic strength (from 27 to 500 mM) and pH (from 6.0to 10.0) produced about a 2-fold change in the association anddissociation rates. The effect of viscosity modifiers on theassociation reaction was also studied. The large differencein the HEL and BWQL affinities for HyHEL-5 is essentially dueto differences in the dissociation rate constant.     

Two fast tree-creation algorithms for genetic programming

Genetic programming is an evolutionary optimization method that produces functional programs to solve a given task. These programs commonly take the form of trees representing LISP s-expressions, and a typical evolutionary run produces a great many of these trees. For this reason, a good tree-generation algorithm is very important to genetic programming. This paper presents two new tree-generation algorithms for genetic programming and for “strongly typed” genetic programming, a common variant. These algorithms are fast, allow the user to request specific tree sizes, and guarantee probabilities of certain nodes appearing in trees. The paper analyzes these two algorithms, and compares them with traditional and recently proposed approaches     

Engine knock and combustion characteristics of a spark ignition engine operating with varying hydrogen and carbon monoxide proportions

Varying proportions of hydrogen and carbon monoxide (synthesis gas) have been investigated as a spark ignition (SI) engine fuel in this paper. It is important to understand how various synthesis gas compositions effect important SI combustion fundamentals, such as knock and burn duration, because in synthesis gas production applications, the compositions can vary significantly depending on the feedstock and production method.A single cylinder cooperative fuels research (CFR) engine was used to investigate the knock and combustion characteristics of three blends of synthesis gas (H₂/CO ratio); 1) 100/0, 2) 75/25, and 3) 50/50, by volume. These blends were tested at three compression ratios (6:1, 8:1, and 10:1), and three equivalence ratios (0.6, 0.7, and 0.8).It was revealed that the knock limited compression ratio (KLCR) of a H₂/CO mixture increases with increasing CO fraction, for a given spark timing. For a given equivalence ratio and spark timing, a 50%/50% H₂/CO mixture produced a KLCR of 8:1 compared to a 100% H₂ condition, which produced a KLCR of 6:1. The burn duration and ignition lag is also increased with increasing CO fraction. The results from this work are important for those considering using synthesis gas as a fuel in SI engines. It reveals that although CO is a slow burning fuel, higher CO fractions in synthesis gas can be beneficial, because of its increased resistance to knock, which gives it the potential of producing higher indicated efficiencies through the utilization of an engine with a higher compression ratio.     

Synthesis,characterization and comparative OFET behaviour of indenofluorene–bithiophene and terthiophene alternating copolymers

The synthesis of alternating copolymers of tetraalkylindenofluorene with bithiophene and terthiophene using Suzuki polycondensation route is reported. We report on the optical and electrochemical properties of these copolymers. AFM analysis of the microscopic morphology of thin deposits showed that the copolymer with terthiophene units produced the more ordered films, with well-defined fibrillar structures, resulting from highly-regular dense packing due to strong π–π interchain interactions, in contrast to the amorphous bithiophene copolymer. Upon testing these materials in FETs the terthienyl copolymers displayed the higher charge mobilities among the studied compounds, with values of over 10^?4 cm² V^?1 s^?1 being obtained.     

An examination of inclusion and exclusion criteria in the predoctoral internship selection process.

A number of studies have examined factors that influence an individual being accepted into a predoctoral internship position such as practicum experience, the interview, the type of doctoral program attended, and letters of recommendation. Rodolfa et al. (1999), for example, detailed 36 inclusion and exclusion criteria used in the internship selection process. The current study revisits this research in order to identify changes in these criteria from the time of the original study. While a number of traditional factors remained influential to the selection process, such as the fit between applicant goals and site opportunities and supervised clinical experience, a greater emphasis on personality characteristics of the applicant was found in the current study. The top three inclusion criteria found in the present study were fit between applicant goals and site opportunities, the interview, and professional demeanor of applicant. Interview, fit, and letters of recommendation were the top exclusion criteria. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time-Dependent Reliability Analysis of FRP Rehabilitated Pipes

The goal of this paper is to present work that demonstrates the application of probabilistic modeling to evaluate the long-term performance of fiber-reinforced polymer (FRP) rehabilitated piping components. The time-dependent reliability index is evaluated for a fully deteriorated piping component rehabilitated with FRP considering the demands of internal fluid pressure, external soil pressure, and traffic loading. Carbon FRP (CFRP) and glass FRP (GFRP) composites are compared and the influence of material deterioration, fiber volume fraction (FVF), and variation in thickness of the composite are assessed using a first order reliability method and compared to a steel pipe under similar loading. A CFRP rehabilitation scheme having a FVF greater than 40% would be needed to exceed the as-built reliability index of a steel pipe under time-dependent composite deterioration, while no practical GFRP FVF can achieve the performance of steel pipe in the presence of time-dependent composite deterioration. Variations in the coefficient of variation (COV) can adversely affect the safety of both FRP rehabilitation schemes where an increase in COV from 10 to 30% result in decreases in the reliability index by 39.4% for CFRP (40% FVF) and 39.7% for GFRP (40% FVF).