集双高速公路桥梁水文分析方法综述

以吉林省集双高速公路通化—东丰段工程项目为依托,介绍了项目途经区域的水文现状,论述了水文分析流程及其在桥梁设计中的作用,阐明了桥梁水文计算中对结果影响较大的敏感性参数。     

桥涵水文计算程序的开发

针对开发水文计算软件的必要性，分析了水文计算的过程，介绍了基本程序的编制方法，并对程序调试过程中的疑难问题提出了解决方法，有利于提高水文计算工作效率，缩短桥涵设计周期。     

沁河特大桥设计流量及设计水位计算

结合水文观测资料和历史考证资料，介绍了沁河特大桥设计流量以及桥位断面设计水位的计算方法，对其他公路桥梁设计供水的分析与计算具有一定的参考意义。     

长西铁路桥梁勘察与设计

以长西铁路建设为工程背景,分析了该工程中的桥梁结构特点,结合客货共线铁路设计特点,简要介绍了桥涵的水文计算方法,并从桥梁类型的选择、基础设计原则及结构耐久性设计等方面,对该线桥梁设计方法作了阐述,为类似桥梁设计提供了思路。     

公路排水设计及计算实例

介绍了公路网建设运营过程中的常见水害,结合实际情况与设计经验,探讨了处理水害的有效措施,并对各种常见排水结构物进行水文、水力计算,总结了水文计算中应注意的事项,以供参考。     

关于合理进行桥位设计的探讨

以磁左公路某桥为例，对正确合理行桥位设计作了探讨，阐述了水文计算及桥孔净长的确定，并提出设计时应注意的一些问题和几点认识，为同类工程提供借鉴。     

偃师伊洛河桥水力学问题模型设计

本文简要介绍了伊洛河桥水文概况,列出了模型设计的各项相似条件,并进行了模型比尺设计的计算,提出了模型制作方法及量测手段。     

浅谈岚漪河大桥的设计和施工

通过对岚漪河大桥工程地质、河流断面的分析及水文、结构计算,确定了桥梁跨径、上部、下部结构及基础形式,并对桥梁施工要点及注意事项进行了阐述,以期为同类桥梁设计与施工提供指导。     

利用Excel计算大悟县城区设计洪峰流量方法的探讨

本文提出了利用Excel软件推求大悟县城区不同频率洪峰流量设计值,频率计算、点绘经验频率点据、绘制P-Ⅲ型理论频率曲线以及优选水文变量统计参数的方法。该方法不需要编写程序代码,直接利用Excel软件内置的函数进行计算,利用Excel软件图表功能输出频率曲线图。该方法计算快捷、操作简便、简单易学、出图美观,在水文计算中有较高的实用价值。     

关于汉中地区小流域尾矿库调洪演算

1前言尾矿库小流域调洪演算一直是尾矿工作者常忽略的一件事,本文以陕西省汉中地区为例,对小流域尾矿库的调洪演算作一研究。2设计洪水计算尾矿库沟道汇水面积0.14km2,沟道比降15.68%,沟道长0.454km,设计洪水频率分别为50年一遇及200年一遇。采用《汉中地区实用水文手册》(以下简称《手册》)介绍的"经验公式"和"推理公式法"分别进行计算。比较"经验公式法"及"推理公式法"的计算结果,两者计算结果相差不大,从安全的角度出发,选取较大的计算结果进行设计为宜。因此选择"经验公式"的计算结果进行洪水设计,即初期设计洪峰流量为5.23m3/s,中、后期设计洪峰流量为7.12m3/s进行设防。3设计洪水过程线由于尾矿库汇流面积相对较小,本次设计洪水过程线采用三角概化法。     

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。