复杂环境下氧化铝储槽定向爆破拆除

在较为复杂的环境下,爆破拆除钢筋混凝土氧化铝储槽。该储槽自重大、呈圆形,内有4根立柱支撑下料漏斗。为使储槽顺利定向倒塌,通过爆破方案选择、参数确定,采取梯形切口和预处理以及安全防护和减振措施,使储槽爆破拆除获圆满成功。     

定向长钻孔整体水力压裂增透技术在赵固二矿的应用

针对赵固二矿煤层透气性低、钻孔有效影响半径小，实施定向长钻孔代替底板岩巷进行区域瓦斯治理期间钻孔工程量大、瓦斯抽采效果不理想的问题。结合煤层赋存特征及钻孔施工情况，采用定向长钻孔整体水力压裂增透技术，理论分析了合理坐封位置、压裂参数，完成200 m煤巷条带一次整体压裂，最大泵注压力24.3 MPa、累计注水量1 613 m³。并基于煤层全水分变化，考察确定了单个钻孔压裂影响范围达到巷道两帮30 m，有效改善了煤体储层特性，提高了煤层瓦斯抽采效率。在实现定向钻孔对预抽煤巷条带可靠控制的同时，最大程度降低了钻孔工程量、缩短了瓦斯治理周期，为实现矿区“以孔代巷”及高效安全开采提供了技术支撑。     

The effects of the energy price reform on households consumption in Iran

The substantial subsidizing of energy prices over the years has led to high energy consumption, inefficiencies, fiscal pressures, and environmental problems in Iran. To address the increasing socio-economic problems associated with the energy subsidies, the government embarked on an aggressive energy price reform through which energy subsidies were removed and cash handouts were given to all households in 2010. In this paper, I analyze the effectiveness of the energy price reform in Iran by estimating energy demand elasticities for households in different income groups. I apply a two-stage consumer optimization model and estimate the system of energy expenditures shares using the household budget survey data for the period 2001–2008. The results show that the overall price elasticities of demand are small, but income elasticities are close to one. The results also indicate heterogeneous responses to energy price and income changes in different income groups. Specifically, the urban households show stronger response to price changes, but rural households, particularly mid-income households, to income changes. These findings suggest that the current policy of price increases would not solely be able to reduce energy consumption and, therefore, it should be geared towards increasing energy efficiency through a series of price and non-price measures.     

Retardation of Crystallization through the Addition of Dairy Phospholipids

The objective of this work was to identify the effects that milk phospholipids (PL) have on crystallization of anhydrous milk fat (AMF). Three mixtures were prepared by adding 0%, 0.01%, and 0.1% PL to AMF. Each mixture was crystallized for 90 min at 24, 26, and 28 °C. The solid fat content was measured as a function of time and fitted to the Avrami equation. Melting point, thermal behavior, viscoelastic properties, and crystal morphology were all measured at 90 min. All assays were repeated, as well as hardness, after being stored at 5 °C for 48 hours. Samples containing PL showed slower crystallization as concentration increased especially at higher temperatures (26 and 28 °C). The addition of PL caused a difference in crystal morphology resulting in visibly larger crystals at 90 min. The elasticity and hardness at 90 min were influenced by the addition of PL at 24 °C with lower values obtained in samples with PL compared to the AMF alone. No differences in hardness nor in elasticity was observed for samples crystallized at 26 and 28 °C. A decrease in melting enthalpy was observed in samples with PL indicating a reduction in crystallization at all temperatures, which was supported by crystal morphology.     

3-D Elasticity Solutions of Layered Rectangular Plates Subjected to Thermo-Loads

According to the exact three-dimensional (3D) thermoelasticity theory, the elasticity solution of the simply-supported layered rectangular plates subjected to steady temperature loads was studied. An analytical method was developed to solve the temperature, stress and displacement fields in the plate. Firstly, the general solutions of the temperature, displacements and stresses in a simply-supported isotropic layer were obtained by solving the 3-D heat conduction equation and the 3-D equations of elasticity respectively, which were expressed in the form of double Fourier series. Then, the temperature, displacement and stress relationships between the upper surface and the lower surface of the isotropic layer were derived. Based on the continuity of the temperature, the heat flux, the displacements and the stresses on the interface of two adjacent layers with different material properties, the recursive formulae of temperature, displacements and stresses between the bottom layer and the top layer of the layered plate were obtained by using the transfer matrix method. The unknown coefficients in the solutions for every layer were uniquely determined by the upper surface and lower surface conditions of the plate. The distributions of the temperature, displacements and stresses in the plate were given by substituting the unknown coefficients obtained back to the recurrence formulae and the solutions. The convergence of the solutions was checked with respect to the number of the terms of series. Comparing the results with those obtained from the finite element method, the correctness of the present method was verified. Finally, the effects of surface temperatures, plate thickness, layer number and material properties of each layer on the distributions of the temperature, displacements and stresses in the plates were discussed in detail.     

Exact and approximate solutions for the flexural buckling of columns with oblique rotational end restraints

This paper is concerned with the elastic flexural buckling of doubly symmetric columns with oblique restraints under concentric loading. Oblique restraints cause coupling between the principal axis deflections and rotations, and the flexural buckling mode involves simultaneous bending about both principal axes.The paper discusses the nature of oblique restraints, and presents exact and approximate solutions for the buckling loads of columns with rigid or elastic restraints against rotations at the ends. The exact solutions are obtained by solving the governing differential equations and boundary conditions, while the approximate solutions are based on energy solutions with assumed buckling displacements. The approximate solutions are sufficiently simple that they can be used in design, and are shown to be within 1% of the exact solutions.     

对国内外建筑法调整范围的比较分析及修改建议

我国《建筑法》的调整范围仅限于房屋建筑工程,这与其立法宗旨相悖,不仅与其作为建筑业母法的地位不符,也与其他建设法规不协调。因此《建筑法》在实施过程中,不仅使司法机关产生困惑,更导致了行政管理上的混乱。反观美、英、日本、韩国、我国台湾地区的建筑法,调整范围虽不相同,但均与其行政管理体制相符合,显得更为严谨。本文对此差异进行了比较和分析,建议将调整范围扩大为整个土木工程,使之与行政管理体制更吻合,并对于法条的修改提出了建议。     

清式建筑的砖檐

清式建筑砖檐种类繁多,多数根据砖檐的层数、外观呈现的形状、作法以及使用的材料命名。砖檐的出檐尺寸及适用范围是有一定规律的,适宜的出檐有基本的原则。操作中应注意砖缝排列、后口处理、檐子的砌筑、檐子的不同做法、砖的好楞朝向、灰浆饱满度等。带砖雕的砖檐由檐子所处的位置和建筑环境决定。砖檐花活的雕凿手法一般以平雕和“单片活”为主,图案多种多样。     

塑钢窗制作安装质量控制措施

塑钢窗与钢窗、铝合金窗、木窗的功能特性相比，不仅具有良好的保温、隔热、隔声、防火、防水性能，还具有气密性、抗风压性好，使用寿命长的优点，因此在工业与民用建筑中得到了广泛的应用。由于塑钢窗制作安装中存在的质量通病，影响了房屋的使用功能，针对这些问题，提出了解决方法和控制措施，在工程实践中收到了良好的效果。