数字功率跟随技术在风光互补发电系统中的应用

风能、太阳能作为无污染的绿色能源具有广阔的发展前景,但是其随机性和不稳定性是风光互补发电系统中应尽可能克服的问题。本文介绍了以ATMEGA8单片机为核心组成风机和太阳能发电的功率跟随技术,以最大限度的利用风能和太阳能。     

一类状态空间图表示的产生式系统的prolog求解

本文介绍了产生式系统和状态空间图,结合Prolog提出了一种生成产生式系统的一个通用模型,最后通过对几个实例进行了计算机模拟,结果表明,该模型具有良好的适用性.     

浅谈形态构成基础教学

自从上个世纪20年代,荷兰构成主义派、"风格派"代表人物杜斯柏格将构成教学带到设计学府包豪斯之时,世界的设计格局无可置疑的会产生翻天覆地的变化。而当我们在2004级建筑设计与城镇规划专业以及建筑装饰专业将构成课作为主要专业基础课程开设之时,我才真正理解构成作为现代设计最基础最重要的教学内容应该如何出现在我校的教学之中。     

荧光熄灭的氟离子光化学敏感膜的研究

基于氟离子对固定于聚氯乙烯(PVC)膜中的8羟基喹啉铝(Alq3)有不可逆的荧光熄灭作用,研制成测定氟离子的选择性光化学敏感膜,并对其性能进行了初步探讨.该膜制作简单,成本低,对于氟离子在5×10-6～5×10-2mol/L浓度范围内时,其荧光强度降低值与氟离子浓度具有良好的线性关系,检出限为2.5×10-6mol/L,相对标准偏差RSD为2.0%,适合于水相中的氟化物测定.     

Skraup法合成8-羟基喹啉

以邻硝基苯酚、邻氨基苯酚、甘油为原料,在浓硫酸催化下,用Skraup法合成8-羟基喹啉.对该反应进行了全面的研究,找出了最佳反应条件,提高了产物的收率且重现性好.     

PIC16F737单片机在UPS同步控制中的应用

本文提出了用PIC16F737实现在线式UPS同步控制。给出了电路结构,分析了工作原理,展示了主要的软件流程图,并对基准正弦波形成电路做了阐述。     

THEORETICAL AND PHILOSOPHICAL PERSPECTIVES TO PROBLEM SOLVING

No abstract available for this article.     

在生物学原理教学中培养学生的科学素养

生物学原理是生物科学素养的主要载体,而生物学原理的教学则构建了培养学生生物科学素养的主要平台.现就生物学原理的特征、生物学原理教学的策略及设计例析等方面对培养学生的生物科学素养进行初步研究.     

鄂尔多斯盆地环县地区长8储层特征及评价

鄂尔多斯盆地环县地区延长组长8储层是该地区主要的产油层,也是典型的低孔、低渗透储层。根据岩心观察、铸体薄片及压汞曲线等资料,对环县地区长8储层的岩石学特征、孔喉特征和成岩作用等进行了研究,并对储层进行了综合评价。利用储层物性和孔隙结构参数将长8划分为四类储层,并计算了各类储层的面积,为研究区油气富集规律的深入认识提供了依据。     

Investigation of the association between all-trans-retinol dehydrogenase (RDH8) polymorphisms and high myopia in Chinese

Retinoic acid level in the retina/choroid is altered in induced myopia models. All-trans-retinol dehydrogenase (RDH8) is an important enzyme of retinoic acid metabolism. This study aimed to investigate the association of the RDH8 gene with high myopia. Three single nucleotide polymorphisms (SNPs) [RDH851 (rs2233789), RDH8E5a (rs1644731), and RDH855b (rs3760753)] were selected, based on the linkage disequilibrium pattern of RDH8 from a previous study, and genotyped for 160 Han Chinese nuclear families with highly myopic (−10 diopters or worse) offspring as well as in an independent group with 166 highly myopic cases (−10 diopters or worse) and 211 controls. Family-based association analysis was performed using the family-based association test (FBAT) package, and genotype relative risk (GRR) was calculated using the GenAssoc program. Population-based association analysis was performed using Chi-square test. These SNPs were in linkage equilibrium with each other. SNPs RDH851 (rs2233789) and RDH8E5a (rs1644731) both did not show association with high myopia. SNP RDH855b (rs3760753) demonstrated significant association (P=0.0269) with a GRR of 0.543 (95% confidence interval=0.304–0.968, P=0.038). The association became statistically insignificant, however, after multiple comparison correction. Haplotype analysis did not show a significant association either. Population-based association analysis also showed no significant association (P>0.05). Our family- and population-based data both suggest that the RDH8 gene is unlikely to be associated with high myopia in Chinese.