含引发机制的A_(f-)A_g型缩聚反应的标度研究

讨论了含引发机制的Af-Ag型缩聚反应体系,根据该反应体系的数量分布函数,导出凝胶点附近分布函数和高分子矩的渐进表示式,进一步应用标度变换,得到了描述溶胶-凝胶相变的广义标度律,揭示出含引发机制的Af-Ag型缩聚反应体系的固化过程是一个相变过程。     

Simulation support for performance assessment of building components

The determination of performance metrics for novel building components requires that the tests are conducted in the outdoor environment. It is usually difficult to do this when the components are located in a full-scale building because of the difficulty in controlling the experiments. Test cells allow the components to be tested in realistic, but controlled, conditions. High-quality outdoor experiments and identification analysis methods can be used to determine key parameters that quantify performance. This is important for achieving standardised metrics that characterise the building component of interest, whether it is a passive solar component such as a ventilated window, or an active component such as a hybrid photovoltaic module.     

Feed water pretreatment for desalination plants

Effective membrane pretreatment is a crucial requirement for trouble free and cost effective RO desalination. Pretreatment construction costs are significant and may reach as much as 10%-20% of the total desalination plant capital costs. This paper presents a general review of the central factors involved in assessing raw water quality. The main foulant categories are described and the various unit operations commonly applied are reviewed. Pretreatment aspects of desalination offer fertile grounds for advancing desalination technologies. Promising research directions are highlighted.     

低能量系统在时间限制下的同时通讯和处理器频率选择

This paper presents a method to reduce the energy consumption of multi-core systems characterized by processor cores and buses with discrete frequency levels under timing constraints. The proposed method takes the transformations of the original task graphs, which include dependent tasks located in different iterations, as inputs. The proposed method utilizes mapping selection as well as joint processor and communication frequency scaling to implement energy reduction. We conduct experiments on several random task graphs. Experimental results show that the proposed method can achieve substantial energy reduction compared with previous work under the same hard timing constraints.     

Replacing the Equations of Fano and Fisher for Cased Charge Blast Equivalence – I Ductile Casings

The initial velocity of casing fragments from bombs, shells etc. was first calculated by R. W. Gurney in 1943 [1]. Subsequent to this derivation by Gurney, which was based on a reasonable simplification of the case and gas dynamics, his wartime co‐worker, U. Fano [2], claimed to have calculated the proportion of kinetic energy remaining with the explosive gases following energy partition with the casing. This paper shows that both Fano’s equation for cased charge blast equivalence and a further derivation by Fisher in 1953 [3], based on Fano’s, are in fact inconsistent with Gurney’s reasonable physical model. Neither of these two reports has ever been the subject of independent peer‐review, despite having been extensively cited. This paper identifies the error made by Fano and copied by Fisher and draws attention to an alternate equation recently published by the author which gives similar predictions to that of Fisher, while being consistent with Gurney’s original derivation. Also, this paper establishes for the first time that the use of such equations for cased charge blast impulse equivalence is valid.     

空压机冷却器结垢原因分析及清洗

针对空压机长时间运行会在冷却器中产生水垢,使冷却器堵塞导致进、排气温度升高,空气不能被冷却到预定温度,将严重影响空压机运行效率,分析了屯兰矿空压机房的2台ZH10000离心式空压机冷却器结垢的原因,阐述了其清洗原理、清洗溶液的配置浓度、搭建循环清洗冷却器的装置及清洗流程等。通过清洗,除垢效果、腐蚀率等指标均达到了空压机运行要求,确保了空压机的安全经济运转,为该矿井下压风系统的可靠稳定运行提供了保障。     

Reduction of seawater scale forming potential using the fluidized bed crystallization technology

A fluidized bed crystallization technology was found to be a feasible method for the reduction of scaling tendency of seawater. Seeded crystallization experiments in a pilot plant fluidized bed crystallizer were conducted. The obtained results for seawater, with initial salinity of 55.75 g/kg and initial pH of 8.23 at a constant temperature of 50 °C, have proven that the Ryznar Stability Index of seawater has been changed dramatically from its initial value of 4.77 (in the range of high scaling potential) to the value of 5.10 (in the range of middle to small scaling potential) over a time period of 180 min.     

Interpolation formula for particle reflection coefficient of keV light ions obliquely incident on heavy solids

The particle reflection coefficient of light keV ions backscattered from heavy solids as a function of the ion incidence angle has been determined by a suitable interpolation formula. The formula has two fitting parameters which are obtained by using results from two limiting analytic approaches: by the single collision model - in case of nearly perpendicular incidence; and by the small-angle multiple scattering theory - in case of glancing angles of incidence. The obtained interpolation formula is a universal function of the scaled transport cross section and the angle of incidence. Comparison of our calculations with Monte Carlo simulation data and the experimental results of other authors gives good agreement for particle reflection coefficient.     

Analysis of applied forces and electromyography of back and shoulders muscles when performing a simulated hand scaling task

Hand scaling is a physically demanding task responsible for numerous overexertion injuries in underground mining. Scaling requires the miner to use a long pry bar to remove loose rock, reducing the likelihood of rock fall injuries. The experiments described in this article simulated “rib” scaling (scaling a mine wall) from an elevated bucket to examine force generation and electromyographic responses using two types of scaling bars (steel and fiberglass-reinforced aluminum) at five target heights ranging from floor level to 176 cm. Ten male and six female subjects were tested in separate experiments. Peak and average force applied at the scaling bar tip and normalized electromyography (EMG) of the left and right pairs of the deltoid and erectores spinae muscles were obtained. Work height significantly affected peak prying force during scaling activities with highest force capacity at the lower levels. Bar type did not affect force generation. However, use of the lighter fiberglass bar required significantly more muscle activity to achieve the same force. Results of these studies suggest that miners scale points on the rock face that are below their knees, and reposition the bucket as often as necessary to do so.