Distribution and mode of occurrences of radionuclides in phosphogypsum from the Aqaba and Eshidiya fertilizer plants, Jordan

Phosphogypsum is a waste by-product of the phosphate fertilizer industry that has relatively high concentrations of some U decay-series radionuclides such as ^226Ra and ^210Pb. The distribution and environmental mobility of radionuclides in phosphogypsum are an important concern because this gypsum by-product is used for wallboard, in agriculture and as a soil amendment. This study determined the distribution of ^226Ra, ^210Pb, within phosphogypsum stacks of varying age and among three size fractions （coarse： 〈0.212 mm; medium： 0.212-0.053 mm; fine： 〈0.053 mm）, in phosphogypsum derived from Aqaba and Eshidiya fertilizer plants. The results indicated that ^226Ra and ^210Pb were generally uniformly distributed in phosphogypsum stacks and showed no significant difference in the concentration of these elements with the age of stack. In the Aqaba phosphogypsum ^226Ra was slightly 10% enriched in the coarse fraction, while ^210Pb was 10% enriched in the free size fraction. In the Eshidiya phosphogypsum ^226Ra and ^210Pb contents were both relatively enriched （10%） in the fine size fraction.     

泥晶灰岩地层孔壁坍塌掉块现象及处理

在灰岩地区钻探施工过程中，常见孔壁坍塌、掉块现象，尤其在含泥晶灰岩地层分布区钻进过程中，这种现象尤为突出，轻则影响钻探施工效率，重则造成钻探孔内事故。针对孔内坍塌、掉块现象的征兆及特点，提出了相对应的处理办法。     

爆破夯实技术在水下地基处理中的应用

以某杂货码头和集装箱重力式码头水下地基处理工程为例，介绍了其地基处理的爆夯试验过程，得出了一次性爆破夯实厚层块石抛石基床的爆夯参数，并对其施工过程进行了监测。总结了类似工程施工的经验与教训。     

粉煤灰垫层与夯扩灌注桩联合处理高层建筑地基

利用夯扩灌注桩对桩端持力层的加密作用，可解决水下填筑问题，利用粉煤灰的可压密性和夯扩灌注桩承载力高的特点，可大幅提高复合地基承载力，减少工程投资。以河南洛阳某高层建筑为例，介绍了粉煤灰垫层和夯扩灌注桩组成的刚性桩复合地基在高层建筑地基中的应用。     

复合土钉墙支护技术在某大型软土基坑围护中的应用

根据拟建建筑基坑的工程地质条件、周边环境条件、基坑开挖深度等特点综合考虑，对基坑分段采用超前微型桩支护加土钉墙、放坡加土钉墙2种复合支护方案。实践证明，该工程所采用的多种复合式支护实施方案，技术安全可靠，经济合理。     

射水法结合高压喷射技术在堤基防渗处理中的应用

通过工程实例介绍了在特殊条件下射水法和高压喷射两种工艺相结合进行堤基防渗处理的施工工艺及实施的效果。     

新近沉积粉细砂层地基的试验与评价

通过对邯郸市某车间地基的勘察．分析和探讨了新近沉积粉细砂地层的勘察手段、其物理力学性质，及其利用载荷试验确定承载力的标准取得了较为满意的结果，提出的一些分析方法，对新近沉积的粉细砂地层的勘察具有一定的借鉴作用。     

Application of membrane technology for water treatment： Ultrasound-associated cleaning of fouled microfiltration membranes

The use of membranes is a widely employed, versatile, and effective separation process. One of the limiting aspects in applying microfiltration （MF） for wastewater treatment is that of problems with membrane fouling and consequent flux reduction. Membrane fouling occurs by the irreversible deposition of retained particles, colloids, macromolecules, salts, etc. at the membrane surface and/or inside the membrane. The predominant fouling mechanisms observed with MF membranes are classified as three categories： the build-up of a cake layer on the membrane surface, blocking of membrane pores, and adsorption of fouling material on the membrane surface or in the pore walls. Although many techniques have been developed to overcome fouling, studies on membrane cleaning still seem to be insufficient for practical membrane filtration systems. Current membrane cleaning technologies include hydraulic, chemical, and mechanical methods. Ultrasound （US） has been widely used as a method of cleaning materials because of the cavitation phenomenon. In this study, US cleaning technique was applied to removing the fouling of polyvinglidenefluoride （PVDF） MF membrane, which was used to treat yeast cell and isolated soybean protein （ISP） solution, respectively. The US employed 40 kHz frequency and the output power of 1.43-2.85 W/cm^2. The evolution of the cleaning effect is followed by the measurements of the flux recovery rate （FRstat） and the cleaning time cycle. Results showed that the membrane property, which was fouled by yeast cell solution, could be recovered by water cleaning with US irradiation. And the cleaning time with the same FRstat decreased with the increase of US intensity.     

新型导线在水电工程测量中的应用

结合山岭重丘地区的一水电工程,根据其特殊的地形条件,采用新型的导线布网形式,避免树木的大量砍伐,确保通视良好;再利用全站仪观测,按导线的严密坐标平差方法,运用MATLAB6.1软件对测量数据进行处理,计算出各控制点的坐标,得到满意的结果.