冷轧平整机机前甩尾轧制工艺的开发与应用

本文介绍了柳钢冷轧板带厂1550 mm单机架平整机机前甩尾轧制的工艺。改进前轧制每卷钢卷生产效率低,钢卷成材率低,改进后生产效率、成材率明显提高,部分规格的钢卷能实现带尾剪切长度为零。     

高温氨化合成GaN微晶

分别利用Ga2O3粉末和Ga2O3凝胶作为Ga源,采用NH3为N源,在950℃下,分别将两种反应物与流动的NH3反应20 min合成了GaN微晶。用X射线衍射(XRD)、扫描电子显微镜(SEM)、选择区电子衍射(SAED)对微晶进行结构、形貌的分析,特别是对两种不同途径合成GaN微晶的XRD进行了分析比较。结果表明,当Ga源温度为950℃时两种不同的合成途径均可得到六方纤锌矿结构的GaN单晶颗粒,在氮化温度为850℃和900℃时,利用Ga2O3粉末作为Ga源,仅有少量的Ga2O3转变为GaN;而采用Ga2O3凝胶作为Ga源,在相同的温度下,大部分凝胶经过高温氨化反应均可转化为GaN。     

Preparation of glucose oxidase immobilized in different carriers using radiation polymerization

Glucose oxidase (EC 1.1.3.4) was immobilized on different polymeric materials using different immobilization techniques (entrapping by γ‐irradiation, and covalent binding using epichlorohydrin). Studies were carried out to increase the thermal stability of glucose oxidase (GOD) for different applications. The activity and stability of the resulting biopolymers have been compared with those of free GOD. The effect of different polyvinyl alcohol/polyacrylamide (PVA/PAAm) compositions of the copolymer carrier on the enzymatic activity of the immobilized GOD was studied. The maximum enzymatic activity was obtained with the composition ratio of PVA/PAAm of 60:40. The behaviour of the free and immobilized enzyme was analysed as a function of pH. A broadening in the pH profile (5.5–8) was observed for immobilized preparations. The activity and stability of the resulting biopolymers produced by immobilization of GOD onto different carriers have been compared, in both aqueous and organic media, with those of the free GOD. The enzyme's tolerance toward both heat and organic solvent was enhanced by immobilization onto polymers. The addition of different concentrations of organic solvents (10–50%, v/v) to the enzyme at higher temperature (60 °C) was found to stabilize the enzyme molecule. The strongest stabilizing effect on the enzymatic activity was achieved at a concentration of 10%. Copyright © 2005 Society of Chemical Industry     

Control and diagnosis in the biotechnical systems of artificial clearance

Controlling and diagnostic processes in the bioengineering artificial clearance systems despite of the procedures applied, their functional use and design seem to occur in the artificial organs, each of them consists of controlling and actuating processors ensuring their homogeneous (material, energy-producing, informational) or combined interaction with the patient's body. Centralized control over artificial clearance is proposed by using universal controlling processes which are informationally connected with the operator, the central computer and other controlling processes of the bioengineering system.     

Control of locomotion in the marine mollusc Clione limacina. XI. Effects of serotonin

The locomotor activity in the marine mollusc Clione limacina has been found to be strongly excited by serotonergic mechanisms. In the present study putative serotonergic cerebropedal neurons were recorded simultaneously with pedal locomotor motoneurons and interneurons. Stimulation of serotonergic neurons produced acceleration of the locomotor rhythm and strengthening of motoneuron discharges. These effects were accompanied by depolarization of motoneurons, while depolarization of the generator interneurons was considerably lower (if it occurred at all). Effects of serotonin application on isolated locomotor and non-locomotor pedal neurons were studied. Serotonin (5 x 10(-7) to 1 x 10(-6) M) affected most pedal neurons. All locomotor neurons were excited by serotonin. This suggests that serotonergic command neurons exert direct influence on locomotor neurons. Effects of serotonin on nonlocomotor neurons were diverse, most neurons being inhibited by serotonin. Some effects of serotonin on locomotor neurons could not be reproduced by neuron depolarization. This suggests that, along with depolarization, serotonin modulates voltage-sensitive membrane properties of the neurons. As a result, serotonin promotes the endogenous rhythmical activity in neurons of the C. limacina locomotor central pattern generator.     

有机盐聚合醇氯化钾钻井液的应用

霍尔果斯背斜构造极其复杂,内应力极高,地层倾角大,断层、破碎带多,并存在高低压互层;安集海河组的灰绿色软泥岩水化严重并具有粘弹塑性.该区块重点探井霍003井三开、四开井段选用有机盐聚合醇氯化钾钻井液,同时为保证钻井液在高密度下（2.55 g/cm^3）具有好的流变性,使用活化铁矿粉、活化重晶石加重.应用结果表明,由于采用了强抑制和多元封堵的措施,该钻井液具有良好的流变性和较强的携带能力,钻进中曾携带出重2.8 kg和5.1kg的大掉块;滤失量低,泥饼质量好,封堵能力强,造壁能力强,减轻了井下阻卡程度;有良好的储层保护能力;在室内研究的基础上,经过现场合理使用和维护钻井液,霍003井提高了机械钻速,缩短了钻井周期,井身质量优于邻井.指出在高密度下,未选出适合有机盐聚合醇氯化钾钻井液的稀释剂,钻井液流动性较差.     

Removal of E. coli and helminth eggs in UASB: Polishing pond systems in Brazil.

Ponds following anaerobic reactors, such as Upflow Anaerobic Sludge Blanket (UASB) reactors, have been termed polishing ponds in the literature. The present paper analyses the removal of E. coli and helminth eggs in five UASB-polishing pond systems in Brazil. Since there were ponds in series, the total number of ponds was 10. The ponds had average retention times varying from 2 to 21 days, and depths ranging from 0.40 to 2.00 m. The shallow ponds in series, even with low retention times, were able to produce effluents complying with the coliform WHO guidelines for unrestricted irrigation (< or = 1000 MPN/100 ml). An equation for the coliform decay coefficient was proposed: Kb (dispersed flow) = 0.710H(-0955) (20 degrees C). The equation highlights the inverse relationship between the pond depth and the decay coefficient. All polishing pond systems were able to produce effluents with helminth eggs concentrations predominantly equal to zero, and satisfying the WHO guidelines for unrestricted and restricted irrigation (< or = 1 egg/L, arithmetic mean). The approximate range of helminth eggs removal efficiency was predicted satisfactorily.