加油站的火灾危险性及其防火对策

一、加油站的火灾危险性加油站是为机动车充装汽油、柴油的专门场所,其所经营的汽油按研究法辛烷值(RON)可分为90号、93号和97号等牌号,柴油根据沸点范围的不同可以分为轻柴油和重柴油两种。由于柴油危险性较低,且在实际中柴油发生火灾事故相对较少,下面仅以汽油作为重点进行论述。1.站内储存油品易燃易爆汽油是加油站储存的主要油品,一般为无色或淡黄色透明液体,密度为730kg/m3,比水轻且不溶     

国际视点：是科学在推动石油价格涨落吗？

英国加油站95号无铅汽油的平均标价,终于在上周首次突破了每升1英镑的心理大关,有些加油站的标价甚至达每升1.09英镑。过去,英国人的父辈们用1英镑就可以加满一箱含铅汽油的好日子早已变成了美好的回忆,如今,用五六十英镑加满一箱油的现象几乎比比皆是。"国际市场的原油供应是充足的,肯定没有发生短缺。"欧佩克秘书长阿布杜勒·巴德里在上周四信誓旦旦地说,"油价上涨是由投机推动的,石油已     

铅污染及无铅汽油

从97年6月1日起,北京和上海逐步禁止出售含铅汽油,这无疑是我国在大力发展经济的同时,注重环境保护的又一重大举措．那么缘何停售含铅汽油？这要从铅的污染谈起．铅（Ph）,是一种蓝白色的重金属元素是重要的工业原料,广泛运用于冶炼、印刷、焊接、陶瓷、橡胶和涂料、油漆、杀虫剂及机动车燃料中．目前,全世界每年约消耗400万吨铅．铅是一种有用又有毒的元素,它既为人类服务又毒害、摧残着人类．80年代以来,随着汽车的增加和含铅汽油的大量使用,汽车排铅正成为城市铅污染的主要来源,从1985～1995年的10年之间,我国累计有15813吨…     

铅对人类的危害及防治

铅对人体中枢和周围神经系统、血液及造血系统和肾脏等都有严重危害，防治铅污染应从治理工业生产尾气、使用无铅汽油、不使用含铅农药、多食绿色食品、绿化环境等方面着手。     

汽油抗爆剂MMT调合汽油的研究

MMT是一种提高辛烷值的添加剂,通过对几种汽油调合组分对MMT提高辛烷值感受性,以及加入MMT后汽油质量变化的研究,发现MMT调合汽油的规律及其对产品质量的影响程度。     

乙醇汽油

乙醇是一种具有较高辛烷值(辛烷值高达115)的含氧化合物,将其按适当的比例调入汽油中可以提高汽油的辛烷值,增加汽油中的氧含量,减少发动机内的碳沉淀及一氧化碳和碳氢化合物的排放。同时乙醇是一种可再生能源,有着良好的发展前景。因此世界上已有很多国家将乙醇作为汽油的调配组分,推广应用。     

为什么提倡用无铅汽油?

最近几年我们国家汽车越来越多,国家多次大力提倡无铅汽油。汽油中加错可作为防爆剂,但对农作物及人体会带来不良影响,会带来越来越严重的环境污染。铅污染对人体影响：铅在大气中浓度过高时,会引起人急性中毒;长期处于低浓度含铅空气中,也会引起慢性中毒。轻度铅中毒症状一般为：多梦、头晕、失眠。记忆减退、四肢无力、关节疼,进一步发展有腹痛、腹泻、食欲不振、手足麻痹等,有些人出现尿铅及血铅现象。铅能使人血液中原叶琳代谢及血色素合成障碍,所以铅中毒者大部分有贫血及血细胞异常症状。此外,铅还可置换骨胳中的钙。重度中…     

几种提高汽油辛烷值的添加剂

本文结合作者的试验,综述了近十年来,提高汽油辛烷值的新型添加剂国外进展情况.提出了尽快发展我国新型抗爆震添加剂生产,以适合国内外汽车工业发展以及节约能源的建议.     

让儿童远离铅毒害

铅是一种具有强烈神经毒性的重金属元素,而儿童的大脑正处于快速发育阶段,对铅毒特别敏感。即使儿童是处在极低水平的铅环境中,也会造成智力下降和行为异常。要解决铅对儿童健康的危害,最好的办法是彻底消除环境中的铅污染。例如,1997年在北京、上海等大都市,推广使用无铅汽油,就是为保护环境、造福儿童所做的一件实事。但是,铅的用途极其广泛,含铅汽油仅仅是环境铅污染的一个方面,所以实行了汽油无铅化,不等于解决了环境铅污染的所有问题。目前,如果能做到以下方面,在一定程度上可以减少铅毒对儿童的危害。1.勤洗手俗话说“病从口入”,铅也…     

甲醇汽油添加剂对甲醇汽油性能影响的研究

研究车用甲醇汽油经过添加剂处理后对其性能的影响。参照GB17930—1999《车用无铅汽油》国家标准,调制成不同配比的甲醇汽油,并对其加入不同添加剂的主要使用性能指标进行测试。实验表明通过加入不同添加剂以及不同的加入量。可以改善甲醇汽油的抗水性、馏程、铜片腐蚀、溶胀性和硫醇性硫含量等性能,使甲醇汽油满足国家标准的要求。     

内蒙古资本市场发展定位与策略研究

改革开放30年来,以上市公司为引领的内蒙古资本市场在打造自治区优势产业和知名品牌、调整经济结构、优化资源配置功能等方面发挥了巨大作用,并使内蒙古经济发展处于全国前列。但内蒙古资本市场发展中存在着金融资源配置功能发挥滞后、融资渠道单一、上市公司带动地区经济辐射能力低下等问题。内蒙古资本市场发展的定位是围绕内蒙古六大支柱产业,做强作大优势产业和上市公司、积极培育后备企业,构建多层次的资本市场体系,拓宽融资渠道。     

Self-system concomitants of discrepancies between children's and teacher's evaluations of academic competence

The purpose of this study was to elucidate the psychological concomitants of discrepancies between fourth- to sixth-grade children's perceptions of academic competence and 2 measures of their "actual" competence in this domain: teacher ratings and achievement test scores. Over-, under-, and congruent child raters were identified on the basis of the 2 external standards and then compared on child and teacher ratings of self-esteem, self-regulatory style, and coping with perceived failure. 6 teachers and 121 lower- to upper-middle-class suburban students participated. As predicted, no differences were obtained between congruent and distorted (combined over- and under-) raters on these self-system variables. Consistent with previous research, overrating children showed higher self-esteem on self- and teacher ratings than underraters. After controlling for level of perceived competence, overraters scored higher on anxiety, and, when overrating occurred against the teacher standard, these children were rated by teachers as having lower self-esteem, poorer coping strategies, and less internalized self-regulatory styles. Comparing the 2 standards, self-reported difficulties were associated with underrating against the teacher's standard but not the achievement standard. Teacher reported difficulties were associated with the opposite pattern of underrating against the 2 standards. Motivational factors contributing to patterns of discrepancies are discussed, as are the educational implications of mismatches between teacher and student perceptions of objective and intrapsychic aspects of school experience.     

Generalizability and Validity of the Use of a Case Analysis Assessment to Make Visible the Quality of Teacher Candidates

The use of case analysis as an accountability measure for demonstrating teacher candidates abilities to meet targeted course, institutional, and state teaching standards for student motivation and classroom management was evaluated. The findings supported the generalizability of case analysis ratings made using a standards-based scoring rubric, and the ratings were shown to differentiate levels of performance in accordance with those standards. Support for the content representativeness of the performance assessment was also obtained using criteria suggested by Crocker (1997), including the realism, frequency, necessity, and importance of the targeted teaching behaviors to actual teaching practice. The findings also provided initial support for the predictive validity of the case analysis assessment for appraising candidates overall abilities to manage a public school classroom.     

Testing for Differences between two brands of Cookies

This article presents two class activities for use with hypothesis testing. The first has students collecting data to test for a difference in the mean number of chocolate chips per cookie between two brands. Data are also collected to test for a difference in taste ratings.     

Investigating the Psychometric Properties of the ACEI Global Guidelines Assessment,Third Edition (GGA) in Nine Countries

The Third Edition of the ACEI Global Guidelines Assessment (GGA) was evaluated for its effectiveness as an international assessment tool for use by early childhood educators to develop, assess, and improve program quality worldwide. This expanded study was conducted in nine countries [People’s Republic of China (2 sites), Guatemala, India, Italy, Mexico (2 sites), Peru (2 sites), Taiwan, Thailand, United States] to continue the investigation of the psychometric properties of the GGA. A total of 346 programs and 678 early care and education professionals participated in this study. Results primarily confirmed the findings of the previous study, (Hardin et al. in Early Child Educ J 41(2): 91–101, 2013), indicating that the GGA showed strong to moderate internal consistency and interrater reliability for subscale ratings across this larger number of countries and programs. The congruence of item ratings and written evidence to support ratings was acceptable, although some programs had lower participation in providing evidence. To test concurrent validity of ratings, external raters also evaluated a subset of programs (n = 44 from Peru and United States) on both the GGA and the Early Childhood Environment Rating Scale-Revised that showed moderate positive correlations. Patterns of program practices were also identified within and across the participating sites and countries. Results suggest that the GGA can be used as an onsite evaluation method that can help stakeholder participants (teachers and administrators) increase their awareness of program quality standards and serve as an assessment method for their own programs. In particular, the results suggest the GGA is a reliable and useful instrument that can be used effectively by early childhood stakeholders for assessing and improving program quality worldwide (Bergen and Hardin in Child Educ 91(4): 259–264, 2015).     

论邓小平的创造价值观

本从价值和创造性实践辨证统一的理论视角,以邓小平开创并领导的建设有中国特色的社会主义实践为现实基础,论述了邓小平的价值观是以、建设有中国特色的社会主义”为价值目标,以不断探索和创新的创造性实践为实现途径和实现动力,以、三个有利于”为价值评价标准的创造价值观,并分析了邓小平创造价值观的精髓是“解放思想,实事求是”,其基本特征是求真务实,注重实效。     

Multiple Perspectives on Family Relationships: A Latent Variables Model

Many scholars are skeptical of family member reports on their interpersonal relationships. Familial reports are assumed to be biased by social desirability as well as other factors. In this study, a latent variables modeling approach was employed to evaluate rater reliability and bias in mother, father, and child ratings of parent-child negativity. Results based on 78 clinical families demonstrate that family member ratings contain a significant "true score" component that correlates with observer ratings of parental behavior. The presence of systematic rater effects is also demonstrated. The latent variables approach, which provides statistical control for rater effects, is recommended for the analysis of this type of data.     

Factors Most Likely to Contribute to Positive Course Evaluations

The purpose of this study was to determine the extent to which students differentially rated ten factors likely to affect their ratings on overall course evaluations. Students (N = 148) in several sections of an undergraduate educational psychology course indicated their preferences among several designated factors. We found remarkable similarity in the ratings across a variety of subgroups (i.e., high vs. low grades, high vs. low test scores, upper vs. lower classmen, and gender). Good grade emerged as the most highly rated factor for every subgroup, whereas high course standards fell among the less-favored factors.