能量转化与守恒定律的建立     

付仁栋 《雁北师范学院学报》2004,20(5):103-106

该文介绍了能量转化与守恒定律发现的背景,并以迈耳、亥姆霍兹、焦耳等重要人物为线索,论述了能 量转化与守恒定律的发现过程.  相似文献   

用粉煤灰替代部分粘土原料生产32.5R普通水泥     

陈潮华 《闽西职业技术学院学报》2007,9(2):86-88

生产实践表明,通过优化原材料的配方,改进工艺过程,利用粉煤灰,替代部分粘土原料,稳定生产32.5R普通硅酸盐水泥是可能的。  相似文献   

从阮冈纳赞的分面分类理论看情报检索语言的发展     

陈立华 《德州学院学报》2001,17(3):102-105

以阮冈纳赞的分面分类理论为切入点，阐述分面组配式分类法的特性、主题法及整个情报检索语言的发展趋势等问题。  相似文献   

Expression of TGF-β1 and TGF-β R II in colorectal adenomas of varying stages     

Wang Da  He Chao  Ding Wei  Wang Hui-ping 《浙江大学学报(A卷英文版)》2001,2(1):107-110

To study the function of transforming growth factor β₁ (TGF-β₁) and transforming growth factor-β type II receptor (TGF-βR II) in varying stages of colorectal adenoma during neoplastic transformation, fiftyfive cases of resected colorectal adenomas were examined immunohistochemically. Our results showed that the expression of TGF-β₁ ranged from high to low, with the progression of low-grade to high-grade dysplasia of adenomas to carcinoma. And there was significantly different expression of TGF-β₁ between moderate and high dysplasia adenomas (P<0.05), but no significantly different expression of TGF-β R II was found among varying stages of adenomas. Our results suggested that the quantities of TGF-β₁ secreted by adenoma cells decrease dramatically in moderate to severe dysplasia colorectal adenomas. It is the decreased secretion of TGF-β₁, rather than the mutated TGF-βR II that may play an important role in transforming colorectal adenomas to adenocarcinomas.  相似文献   

Software Packages for Bayesian Multilevel Modeling     

Yujiao Mai 《Structural equation modeling》2018,25(4):650-658

Multilevel modeling is a statistical approach to analyze hierarchical data that consist of individual observations nested within clusters. Bayesian method is a well-known, sometimes better, alternative of Maximum likelihood method for fitting multilevel models. Lack of user friendly and computationally efficient software packages or programs was a main obstacle in applying Bayesian multilevel modeling. In recent years, the development of software packages for multilevel modeling with improved Bayesian algorithms and faster speed has been growing. This article aims to update the knowledge of software packages for Bayesian multilevel modeling and therefore to promote the use of these packages. Three categories of software packages capable of Bayesian multilevel modeling including brms, MCMCglmm, glmmBUGS, Bambi, R2BayesX, BayesReg, R2MLwiN and others are introduced and compared in terms of computational efficiency, modeling capability and flexibility, as well as user-friendliness. Recommendations to practical users and suggestions for future development are also discussed.  相似文献   

MV-代数、R0-代数、格蕴涵代数、FI-代数、BL-代数与剩余格   总被引：1，自引：0，他引：1  

胡明娣  吴洪博  于鹏 《西安文理学院学报》2006,9(1):56-60

基于剩余格的理论与方法给出了MV-代数、R0-代数、格蕴涵代数、FI-代数、BL-代数与剩余格代数的定义的等价形式;进一步指出了各种逻辑代数的剩余格的代数本质.说明了剩余格在逻辑代数系统中的重要地位;分析了MV-代数、R0-代数、格蕴涵代数、FI-代数、BL-代数以及基础R0代数之间的相互关系,为进一步的研究奠定了必要的基础.  相似文献   

Numerical Modeling of the Performance of R22 and R290 in Adiabatic Capillary Tubes Considering Metastable Two-Phase Region--Flow Characteristics and Parametric Analysis of R22 and R290     

Zhou Guobing  ZHANG Yufeng  HAO Hong 《天津大学学报(英文版)》2005,11(4)

Characteristics of R22 and its new alternative refrigerant R290 flowing through adiabatic capillary tubes are investigated based on the homogeneous model.Extensive flow variables along tube length such as pressure, temperature, viscosity, velocity, Reynolds number, friction factor and vapor quality etc are compared between the two fluids under the same operating condition. Two cases are considered, namely, either the same tube length or the same mass flow rate as inlet condition. The results show that the mass flow rate in the capillary tube of R290 is 40% lower than that of R22 due to the differences of physical properties between the two fluids. Further, a parametric analysis is performed and it appears that effects of geometric and thermodynamic parameters on mass flow rate of R290 are weaker than that of R22. When the condensing temperature is increased from 40 ℃ to 50 ℃, the mass flow rate for R22 is increased by 16%, while the increasing rate for R290 is 13%.  相似文献   

如何通过泛读提高英语学习能力--谈谈《大学英语》的学习方法     

陶涛 《湖北大学成人教育学院学报》2003,21(2):57-60

本文主要通过简要分析泛读对我国英语学习者的重要性，重点介绍SQ3R的方式，以帮助大学生提高学习大学英语的效率。  相似文献   

A comparison of sentence-learning errors in children of different achievement levels     

Joel R. Levin  Elizabeth S. Ghatala  Bruce G. Bender 《Contemporary educational psychology》1978,3(4):358-366

Theoretical analyses of the multiple-choice test format suggest that a test constructor should give serious consideration to the form in which correct and incorrect alternatives are presented. In this experiment, third and fourth graders were tested for previously exposed information by multiple-choice items in which: (a) correct alternatives were stated in either verbatim or synonym form; and (b) incorrect alternatives consisted of plausible responses that were either familiar or new. Comparisons of errors and error patterns were made between high and low achieving students who had been given one of two different information-processing strategies. Based on a dual test function argument, it was concluded that synonym correct alternatives combined with plausible new responses are the most desirable of the four multiple-choice variations studied here. In particular, such items were sensitive to achievement level and strategy differences without systematically increasing students' likelihood of retaining misinformation.  相似文献   

含参量积分连续的一个充分条件     

邓朝阳 《宁德师专学报(自然科学版)》2007,19(3):229-230,234

研究了含参量积分的连续性的问题，利用一致（R）可积的定义，给出了一个新的可积充分条件，推广了通常的连续性条件．  相似文献