地质超前预报系统在栋梁坡隧道施工中的应用

基于地震反射波法超前预测系统的原理及主要技术手段,以栋梁坡隧道工程为实例,针对隧道复杂的地质条件,施工过程中将超前地质预报和地质素描调查相结合,先对隧道全段范围内地形、地层岩性等进行全面核查,然后结合核查结果运用地震反射波法预报掌子面前方的节理裂隙发育情况,围岩完整性等地质信息.开挖后验证情况与预测结果基本一致,为后续...     

Learning outdoors or with a computer: the contribution of the learning setting to learning and to environmental perceptions

ABSTRACT

Background: Outdoor learning and computer-based learning are two different alternatives to in-class conventional teacher-centered learning.

Purpose: This study compares the outdoor learning setting with computer-based learning in class. It examines the influence of the two different learning settings on academic achievements, the learning experience, and pro-environmental perceptions.

Sample: A total of 90 elementary school students (third and fourth-grade classes) participated in the study.

Design and methods: The academic knowledge of the study participants was tested through identical exams for both learning settings. In addition, in each group the students’ perceptions were examined by means of a questionnaire about environmental values and the learning experience.

Results: The study demonstrates that academic achievements in the two settings were similar, but the students expressed more enthusiasm about the outdoor learning experience than about in-class learning. In addition, the outdoor learning setting contributed more to promoting positive environmental perceptions even though students did not learn directly about environmental issues and sustainability.

Conclusions: These findings suggest that learning in the natural environment is valuable: Alongside the fostering of computerized learning, it is also important to promoteoutdoor learning settings and integrate both settings by implementing mobile technologies in the outdoor teaching.     

Testing and ideology: policy debates about literacy assessments for Colorado’s bilingual students

ABSTRACT

The Colorado Reading to Ensure Academic Development Act requires grade-level attainment in literacy in English for students in grades K-3. Its practical outcome, however, has been to pressure schools with bilingual programs to shift their instructional language allocations towards more English in the early grades. Proposed rule revisions debated by the state Board of Education sought to facilitate testing in students’ language of instruction for those in bilingual programs. Analysis of written and verbal opposition to the proposed rule revisions demonstrates the persistence of insidious ethnoculturalist discourses opposing bilingual education as well as the cooptation of liberal multiculturalist discourses that, while framing bilingualism as an asset, argue that it is underdeveloped in bilingual programs that do not include English instruction from the outset. Given that bilingual instruction has demonstrated time and again that it benefits students acquiring English in schools, such new discursive turns pose a threat that must be recognized to fend off further legislative and regulatory attempts against bilingual education.     

大学生计算思维能力培养水平实证研究——以全国大学生计算机设计大赛为例

计算思维是当前计算机教育重点研究方向之一,培养大学生计算思维能力是计算机教育的一项重要内容,通过鼓励大学生参加计算机大赛等综合实践活动,有利于启发和培养学生的计算思维能力。对大赛获奖数据进行分析,得到大学生计算思维能力培养现状。选取近 5 年参赛数据为样本,运用 SPSS 软件对我国高校大学生计算思维培养水平现状进行研究。结果发现,我国在大学生计算思维培养方面取得了积极成果,相关高校表现突出,经验值得借鉴和学习。     

基于关联分析的计算机软件数据挖掘技术

计算机软件蕴含大量工作信息,有效挖掘软件数据信息之间的内在关联是信息时代对软件应用的潜在要求。针对经典Apriori算法挖掘数据效率低、复杂度高的问题,提出一种改进Apriori算法用于挖掘计算机软件数据的关联规则。为计算机软件算法设置双重支持度阈值,即频繁项集与非频繁项集支持度阈值,快速获得强关联的频繁项集;在此基础上基于映射规则重构事务数据库,压缩数据库规模,减少算法的剪枝操作,降低计算机软件数据关联规则挖掘复杂度。以人力资源类计算机软件数据为例展开关联分析测试,结果显示,该算法挖掘的关联信息与人力资源实际管理情况一致,相比经典Apriori算法其效率有所提升。     

谈计算机辅助教学的教学效果及应用原则

现代教育技术特别是计算机辅助教学的应用对于提高教学质量,具有十分重要的意义.教学实践表明,CAI(计算机辅助教学)可以通过多种途径提高教学效果.为达到更好的教学效果应遵循演示型多媒体课件的课堂应用三原则:适度运用原则、适量信息原则、有机结合原则.     

雌激素受体(ER)与基因蛋白(P53、erbB-2)在胃癌中表达的研究

目的:探讨ER、erbB-2和P53在胃癌表达及相关性。方法:取胃癌手术标本119例,SP免疫组织化学染色。结果:ER、erbB-2和P53在胃癌表达率分别为63.87％,75.51％和73.11％;三者同时阳性者31.93％;ER与P53同时阳性者37.82％;ER与erbB-2同时阳性者33.61％;ER在高分化组阳性率高于低分化组(P<0.05);而erbB-2和P53在低分化组阳性率高于高分化组。70岁以上组P53、ER和erbB-2表达率均较高。结论:ER、P53和erbB-2在胃癌中表达率与癌瘤分化程度相关。P53和erbB-2有相关性,而且它们是胃癌预后不良的指标。     

2-（1，2-亚乙／1，3-亚丙二硫）亚甲基-3-羰基-N-芳（烷）基丁酰胺制备的新方法

以易制备的2-（1,2-亚乙／1,3-亚丙二硫）亚甲基-3-羰基丁酸1为原料,经与氯化亚砜的氯化反应后,与胺反应成功地以较好产率（40．5％-72．0％）合成重要的有机合成中间体2-（1,2-亚乙／1,3一亚丙二硫）亚甲基-3-羰基-N-芳（烷）基丁酰胺3．     

Polychlorinated dibenzo-p-dioxins and dibenzofurans in flue gas emissions from municipal solid waste incinerators in China

Polychlorinated dibenzo-p-dioxins and furans （PCDD/Fs） emissions in flue gas from two types of municipal solid waste incinerators （MSWIs） most commonly used in China were investigated in this study. The selected incinerators include two grate-type MSWIs： MSWI-A （350 t/d） and MSWI-B 050 t/d）, and two fluidized bed MSWIs： MSWI-C （400 t/d） and MSWI-D （400 t/d）, which are all equipped with semi-dry lime scrubber and bag filter except MSWI-D equipped with cyclone and wet scrubber （WS） as air pollutant control device （APCD）. Results indicated that the emission concentration and the international toxic equivalents （I-TEQs） of the PCDD/Fs from the stacks were in the range of 1.210-10.273 ng/Nm^3 and 0.019-0.201 ng I-TEQ/Nm^3, respectively. They were greatly lower than the emission regulation standard of PCDD/Fs in China （1.0 ng I-TEQ/Nm^3）. However, only the PCDD/Fs emission level from MSWI-C was below 0.1 ng I-TEQ/Nm^3. Although the homologue profiles were distinct, the contributions of the 2,3,7,8-subsituted congeners to the total I-TEQ were similar among all the investigated MSWIs. Two major 2,3,7,8-substituted congeners, 2,3,4,7,8-PeCDF and 1,2,3,7,8-PeCDD, account for 47% and 9% （average values） of the total I-TEQ values, respectively. The correlation between PCDD/Fs levels and composition of flue gas was also discussed.