饱和软黏土中开孔防沉板基础上拔特性研究

在软黏土地基中,开孔能有效降低防沉板基础上拔阻力,减小防沉板基础回收难度。对6种具有不同开孔形式的防沉板模型进行了饱和软黏土中的上拔试验,测定了上拔过程中防沉板与土体接触面间的吸附力,揭示了上拔阻力的构成与发展规律,阐明了开孔率和有效宽度对上拔阻力和接触面间吸附力的影响规律。采用有限元方法模拟了防沉板基础的上拔过程,建立了上拔力作用下饱和软黏土地基的破坏模式,构建了采用极限分析法计算防沉板上拔阻力的机动场,推导了上拔阻力的上限解,得到了可以同时考虑防沉板开孔率和有效宽度的上拔阻力系数Nc的计算公式。对比验证结果表明:与Skempton公式不同,求解的上拔阻力随开孔率的增加呈非线性降低规律。     

铁路上盖开发研究

结合铁路发展的现状,阐述了铁路上盖开发的意义,分析了铁路对上盖的控制因素及上盖对铁路的影响,提出了铁路上盖物业需特别处理的问题和方法,以期创造出功能齐全、服务便捷的城市综合体。     

浅析新课程下初中英语新教材的特点

新课程的英语教材,在总体设计上有五大突破,体现了国家基础教育课程改革的基本思想;在理念和目标上体现了更多的人文精神与灵活性、开放性、指导性;在内容上更趋丰富、合理,形式上灵活多样,体现了互动。新教材的难度降低了,但知识面加宽了,对教师的要求提高了,需要教师有宽厚的知识积累和深厚的阅读功底。     

综采工作面上隅角瓦斯积聚自动监控处理方法

试验测定并分析了综采工作面上隅角瓦斯分布规律,研制出了综采工作面上隅角瓦斯积聚自动监控处理装置及小型液压玻璃钢风扇;阐述了自动监控处理系统的原理及特点,结合戊-21191综采工作面上隅角(回风隅角)瓦斯涌出及分布特点,合理布置了综采工作面上隅角瓦斯积聚自动监控处理系统并进行了试验应用;应用结果表明,综采工作面上隅角瓦斯积聚自动监控处理系统设计合理,动作可靠,实现了综采工作面上隅角瓦斯积聚的自动监控处理.     

轮对压装机的力学行为分析研究

叙述了对轮对压装机进行力学分析的必要性,采用UG建立了轮对压装机上连接梁的三维实体模型,对压装机上连接梁在压装工况下的受力情况进行了分析,分别求出了上连接梁的应力分布和变形并进行了比较。结果表明上连接梁在压装工况下的最大应力均小于许用应力,证明了上连接梁的强度和刚度满足轮对压装的强度要求。     

中央苏区时期毛泽东文化教育思想的价值及现实意义

中央苏区时期毛泽东文化教育思想包括学校教育、文学艺术、体育卫生事业等内容,他丰富了马克思主义文化教育思想,为党的新民主主义文化教育理论的形成积累了丰富的思想资料。其现实意义体现为:战略上高度重视文化教育事业,道路上开拓了传统文化现代化的一条新路,理论上坚持马克思主义与中国革命实际相结合,行动上充分发动广大人民群众的积极性,业务上充分发挥专业人才的领军和骨干作用,实践上展现了鲜明的创新性。     

浅议如何进行工程项目的质量管理

结合施工实际,探讨了影响工程质量的人员、材料、施工方法及施工设备四大因素的控制,从组织上、管理上、技术上和经济上提出了对工程项目进行质量控制的措施,以提升工程质量,创造品牌工程,提高企业的竞争力。     

浅议城市中心功能的离散及新功能的产生

回眸历史上的城市与当今的城市,城市中心无论在功能上还是形态上都发生了翻天覆地的变革。本文从城市中心精神核心功能出发解释了城市中心功能的离散,论述了城市中心文化体系的形成及其积聚优势,从产业经济学及信息传播学上阐述了创新是现代城市中心的终极功能。     

上吹上吸式排风罩影响的数值模拟及试验研究

利用建模试验,分析了上吹上吸式排风罩的工作步骤和危害,并将其与传统排风罩进行了比较。上吹上吸式排风罩不仅能有效控制有害物质的扩散,还能远程采集有害物质,以较小的排气速度释放有害物质。新型上吹上吸排风罩在射流作用下用吸气流来控制气流,利用条缝从上往下射流,吸气流从下往上。文章采用ICEM软件对不同工况下的气流分布进行模拟分析,研究了环境因素(横向气流、条缝宽度、从吸出口到炉膛的距离)对排气气流的影响。     

疫情时期中职开放课堂线上教学策略研究——以“跟我一起学制图”为例

疫情防控特殊期间,教育部门提出"停课不停学"。面对全新的线上教学挑战,梳理了疫情中遇到的问题,以"跟我一起学制图"同步课程线上教学为例,提出了"线上+开课",实现线上教学组织、管理;"线上+学材",助学学材成为线上教学主要载体;"线上+互动",开展导学、辅学、拓学的线上教学活动;"线上+评价",构建线上教学评价指标和制度,最终打造同步课程支撑下全方位、立体式的中职开放课堂,促成线上教与学的系统性变革与学习质量提升。     

Vanadium in foods and in human body fluids and tissues

Using neutron activation analysis, vanadium was analysed in a range of foods, human body fluids and tissues. On the basis of these results and those of other workers, it was concluded that daily dietary intake amounts to some tens of micrograms. Analysis of body fluids (including milk, blood and excreta) and organs and tissues provided an estimate for the total body pool of vanadium in man of about 100 μg. Vanadium was not detectable in blood and urine at the level of 0.3 ng/g, while low levels were found in muscle, fat, bone, teeth and other tissues. The relationship between dietary intake to pulmonary absorption is discussed in relation to the occurrence of vanadium in man-made air particulates. The very low levels found in milks and eggs suggest minimal vanadium requirements in growth. The findings are discussed in the light of previous results and also in relation to the possible essentiality of vanadium.     

Iodine-129 in thyroid and urine in Ukraine and Denmark

Human thyroids collected from Gomel in Belarus, sheep thyroid from Jutland and human urine from Zealand in Denmark were analysed for 129I and 127I concentrations. The ratios of 129I/127I in human thyroid in Gomel are 2.65-11.0 x 10(-9) with an average of 7.21 x 10(-9), which is one order of magnitude higher than those from Asia and South America (10(-10)), but significantly lower than those observed in west Europe (10(-8)). A weak negative correlation (P < 0.05) between 129I/127I ratio in human thyroid and the age of the subjects was observed in Gomel. The average ratio of 129I/127I in sheep thyroids from Jutland of Denmark is 1.81 x 10(-7), which is two orders of magnitude higher than those in south hemisphere, and Asia. It is also significantly higher than those observed in other west European countries before 1984 and that in human thyroid in Gomel. The high thyroid 129I level in Jutland is attributed to the release of reprocessing plants in France and UK. The 129I/127I ratios in human urine in Zealand of Denmark are 0.86-2.86 x 10(-8). The possibility of using urine 129I to evaluate the thyroid exposure to 129I is investigated.     

儿童青少年近视的防控研究进展

儿童青少年近视率一直处于高位并持续上升,严重影响了我国儿童青少年的学习和生活,本研究通过查阅国内外治疗儿童青少年近视相关著作及文献,针对目前儿童青少年近视防控手段的进展,对各治疗方案进行分析和研究。     

德国城乡景观与中国景观问题

2003年,笔者获得德国DAAD(德国国际学术交流基金会)奖励资助,作为访问学者在德国逗留了4个月(4月～8月).在这期间,笔者还考察了法国、丹麦、瑞典和意大利,但我认为还是德国的景观最为优雅和美丽.     

广义文脉与规划设计教育

城市规划设计教育不仅应关注历史化,还应关注自然、社会和经济;不仅应关注地方和传统,还应关注全球和未来。城市规划教育应掌握正确的发展观和方法论,肩负起发展地万脉的历史使命,保护社会公众的利益,推动城市持续发展。     

Perchlorate in raw and drinking water sources in England and Wales

A well‐known use of perchlorate is as a rocket fuel propellant; however, more widespread uses include in munitions and fireworks, and it also occurs naturally. Perchlorate suppresses the thyroid, which can lead to a variety of adverse effects. It is a widespread contaminant in the United States, but limited occurrence data in the United Kingdom exist, and even less for drinking water. Monitoring of 20 raw and treated drinking water sites in England and Wales, covering four seasonal periods, showed that perchlorate is a low‐level background contaminant of raw and treated drinking water. Low concentrations (treated drinking water: <0.020–2.073 μg/L, mean 0.747 μg/L) were detected at every higher‐risk site. The concentrations were comparable in each of the four sampling exercises and no significant trends were apparent relating to the time of year, the type of risk or the method of chlorination. Limited data showed that removal by ion exchange and granular‐activated carbon may occur.     

Lead and cadmium contents in cereals and pulses in north-eastern China

It is known that, unlike Japanese, Koreans or southern Chinese who depend on rice as a major source of energy for daily life, people in north-eastern China rely not only on rice, but on wheat and other cereals and to a lesser extent also on pulses. Cereal and pulse samples were collected from open markets in north-eastern China, and analyzed by inductively-coupled plasma spectrometry (ICP-MS) for two potentially hazardous heavy metals — lead (Pb) and cadmium (Cd). The average Pb level in cereals (31.3 ng Pb/g as a geometric mean) and that of pulses (25.7 ng Pb/g) were similar to each other with no significant difference. Among the cereals, Pb contents were higher in foxtail millet (54.3 ng/g) and lower in maize (35.4 ng Pb/g; grain and flour in combination), wheat flour (28.8 ng Pb/g) and rice flour (22.7 ng Pb/g). Lead levels in two important types of pulses, kidney bean and soybean (24.6 and 30.8 ng Pb/g, respectively), were comparable to the levels in rice and wheat. In contrast, Cd levels were substantially higher in pulses (55.7 ng Cd/g) than in cereals (9.2 ng Cd/g), and among the pulses, Cd in soybean (55.7 ng Cd/g) was significantly higher than that in kidney bean (23.8 ng Cd/g). The possible public health implication of the Pb and Cd levels, especially the high Pb level in foxtail millet (54.3 ng Pb/g) and the high Cd level in soybean (73.5 ng Cd/g), is discussed.     

创新创业教育在高校实践教学中的研究与探索

大学生创新创业教育的开展对高校人才培养体系的完善具有非常重要的意义。针对目前我国高校创新创业教育模式的问题与不足进行探讨,分析研究了创新创业教育的实质,最后重点阐述了在实践教学中如何加强创新思路的引导,建立有效激励机制,开展创新及创业教育的应对策略,促进对大学生实践创新能力、创业就业能力和持续发展能力的培养。     

武汉城市景观文化生态保护建设的问题与对策

城市文化生态是形成城市特色的文化要素。历史古迹,优秀建筑,空间形态,环境特色,作为城市文化生态的显现部分,既是城市文化底蕴直观生动的反映,也是市民的情感港湾和精神家园。理应得到珍惜和保护。该文在系统地概括武汉景观文化生态特点的基础上,重点分析了当前武汉城市景观规划建设中的文化生态问题,提出了武汉今后改进城市景观文化生态规划建设的对策建议。