无理数字典码的测试数据压缩方案

提出了一种无理数字典码的测试数据压缩方案,能有效地压缩芯片测试数据。方案利用无理数序列建立字典,编码时只需进行相容性检查,无需填充无关位,简化了操作步骤;同时,选择局部压缩率最大的一组数据作为最终编码结果,保证压缩效果可以达到局部最优。对ISCAS 89标准电路Mintest集的实验结果显示,该方案的压缩效果优于传统压缩方法,如Golomb码、FDR码、混合定变长码等。     

神经网络-光度法同时测定食品中防腐剂和甜味剂

根据食品中常用防腐剂本甲酸和山梨酸及甜味剂糖精钠在紫外区均有吸收的特点，建立了一种以紫外分光光度法为基础对该三组分同时测定的方法，光谱数据采用作者自编的径向人工神经网络MATLAB程序进行处理，苯甲酸、山梨酸和糖精钠的平均标准偏差分别为1.60%、5.23%和1.21%，回收率大为95.0-102.0%之间，将该法应用于食品中二组分的测定，获得较为满意的结果。     

三峡工程用中热硅酸盐水泥品质指标控制的意义及方法

为确保用于大坝工程中水泥的质量, 1998年中国长江三峡工程开发总公司 (以下简称"总公司" )委托国家水泥质量监督检验中心对供应三峡大坝水泥的生产厂进行驻厂监督三峡工程用中热硅酸盐水泥 R2O和 MgO指标,并根据各厂的实际情况订出具体监控办法。笔者作为国家水泥质量监督检     

20%单氰乳剂剂型研究

本文所叙述的单氰乳剂，是一种新的复配农药制剂。它不仅增效作用显著，对为害农作物的蚜虫和红蜘蛛有很强的杀灭作用；而且其剂型独特，为国内尚不多见的水包油型的复配农药新制剂－微乳剂。该制剂生产工艺简单，产品性能稳定，常温贮存一年，有效成分分解率低于１．５％；在６０℃至－５℃范围内，其产品均为均相透明的液体，且乳化性能十分优良。目前该品种已取得农药登记，正式投产。     

Kinetics of the peracetic acid decomposition: Part II: pH effect and alkaline hydrolysis

The effect of pH on the decomposition of peracetic acid in an aqueous solution was studied. It was found that three potential reactions, namely i) the spontaneous decomposition, ii) the hydrolysis and iii) the transition metal catalysed decomposition, are responsible for the consumption of peracetic acid. The spontaneous decomposition reaches its maximum at pH 8.2, while both the hydrolysis and metal ion catalysed decomposition increase as the pH increases. At pH 10.5 and higher, the hydrolysis becomes dominant when the metal ion catalysed decomposition is minimized by the addition of DTMPA. The kinetics of the peracetic acid hydrolysis was developed, which can very well predict the development of peracetic acid and hydrogen peroxide during the decomposition reaction.     

Stresses of cohesionless granular flows in liquids

We construct constitutive relations for friction stress, slide stress and collision stress of cohesionless granular flows. We propose that the friction stress and slide stress could be neglected when τ_c/τ_e < 0.02, where τ_c represents the interval time experienced by a given particle between two consecutive binary collisions and τ_e the particle relaxation time. We applied these constitutive relations to a simulation of solid-liquid flow in an inclined chute and found the simulation results agree with experimental data.     

Preparations and properties of thermosensitive terpolymers of N‐isopropylacrylamide,sodium 2‐acrylamido‐2‐methyl‐propanesuphonate,and N‐tert‐butylacrylamide

Terpolymers based on N‐isopropylacrylamide, sodium 2‐acrylamido‐2‐methyl‐propanesulfonate, and N‐tert‐butylacrylamide were synthesized by free‐radical copolymerization with 2,2′‐azobisisobutyronitrile as an initiator. The lower critical solution temperatures (LCSTs) of the linear polymer aqueous solutions were determined by the measurement of the transmittance on UV at different temperatures. The influence of the polymer concentration, polymer composition, and ionic strength on the LCSTs of the linear polymers was investigated. The LCST decreased with increases in the hydrophobic monomer N‐tert‐butylacrylamide, polymer concentration, and ionic strength. The phase transition became sharp when the polymer concentration and ionic strength increased. Meanwhile, the crosslinked hydrogels were prepared with the same recipe used for the linear terpolymers, but a crosslinker was added to the reaction system. The swelling ratios of the hydrogels at various temperatures and salt solutions were determined. The hydrogels possessed both high swelling ratios and thermosensitivity. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

HS－900有机硅密封抗渗防水剂性能的研究

ＨＳ－９００有机硅密封抗渗防水剂是一种新型的有机硅改性硅酸盐防水材料。具有良好的抗渗性能和耐酸碱腐蚀能力。将其涂于低标号混凝土材料上，效果尤其明显。     

不同缝面形态下诱导缝开裂效果对比研究

一些采用径向扭缝的碾压混凝土拱坝工程中,出现了诱导缝周边坝体混凝土开裂而诱导缝本身未张开的现象,因此需定量分析不同空间形态缝面对诱导缝开裂的影响效果。根据碾压混凝土拱坝应力变化特点以及诱导缝开裂变化规律,本文拟定含不同缝面空间形态的有限大平板和圆筒拱坝算例,利用虚拟裂纹闭合法和Richard脆性断裂准则获取空间缝面等效应力强度因子,研究缝面应力强度因子随缝面夹角的变化规律;通过对归一化后的应力强度因子求倒数,获取不同缝面夹角条件下诱导缝等效强度的修正系数即缝面空间形态影响因子,以反映不同缝面空间形态下诱导缝开裂效果。研究表明,随着缝面夹角的不断增大,缝面越不容易张开,这就意味着缝面的等效强度在逐渐增大。因此,在实际碾压混凝土拱坝设计中,诱导缝应尽量采用竖向垂直缝布置;若要布置成径向扭缝,则缝面夹角最大不宜超过10°。     

高温浓硫酸液下泵的故障分析及处理

安徽铜都铜业股份有限公司金昌冶炼厂新建 300 kt／a铜冶炼烟气制酸装置干燥塔入口烟气温度(30±2)℃,烟气ψ(SO_2)9％±1％。干燥塔循环槽采用2台单级单吸离心立式悬臂液下泵,型号为LSB780-30B,一开一备。吸收塔循环槽液下泵型号也为LSB780-30B,为2台泵并联。