大型铜矿山发展趋势

采选装备大型化是普遍趋势,半自磨工艺得到广泛应用且有新的变化,立式磨机I、SA磨等选择性磨矿设备正逐步普及,浮选机单槽容积不断变大,大型浮选机数量快速增长,浮选柱再次被广泛应用并成为最佳最终精选设备,伴生元素回收得到重视并为矿山创造了巨大效益。     

广钢60 t直流电弧炉热调试及生产概况

介绍广钢60t电炉的选型及热调试的情况,并对生产概况进行了分析.一年的生产情况表明,60t炉的选型是对的,热调试是成功的,生产的情况是良好的,最高日产23炉,最高班产9炉,最高月产3.23万t,达到了设计能力.     

Mechanistic study on carboxymethyl hydroxyethyl cellulose as fluid loss control additive in oil well cement

The working mechanism of carboxymethyl hydroxyethyl cellulose (CMHEC, M_w 2.6 × 10⁵ g/mol) as fluid loss control additive (FLA) for oil well cement was investigated. First, characteristic properties of CMHEC such as anionic charge amount, intrinsic viscosity in cement pore solution, and static filtration properties of cement slurries containing CMHEC were determined at 27°C and 70 bar. Effectiveness of the FLA was found to rely on reduction of cement filter cake permeability. Consequently, the working mechanism is ascribed to constriction of cement filter cake pores. Zeta potential measurements confirm that at low CMHEC dosages (0–0.3% by weight of cement, bwoc), adsorption of the polymer onto the surface of hydrating cement occurs. However, at dosages of 0.4% bwoc and higher, an associated polymer network is formed. This was evidenced by a strong increase in hydrodynamic diameter of solved CMHEC molecules, an exponential increase in viscosity and a noticeable reduction of surface tension. Thus, the working mechanism of CMHEC changes with dosage. At low dosages, adsorption presents the predominant mode of action, whereas above a threshold concentration of ～ 10 g/L (the “overlapping concentration”), formation of associated polymer networks is responsible for effectiveness of CMHEC. Addition of anionic polyelectrolytes (e.g., sulfonated melamine formaldehyde polycondensate, M_w 2.0 × 10⁵ g/mol) to cement slurries containing CMHEC greatly improves fluid loss control. Apparently, the presence of such polyelectrolytes causes the formation of colloidal associates from CMHEC to occur at lower dosages. Through this mechanism, effectiveness of CMHEC as cement fluid loss additive is enhanced. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

The Influence of a Simple Electrolyte KCI on Surfactant - Dye Interactions in Water Solution

Abstract

The influence of a simple electrolyte KCI on the interactions between the anionic dyes C. I. Acid Orange 7 (AO7) and the cationic surfactant N-cetylpyridinium chloride (CPCl) in water solutions was studied.

To determine the equilibrium association constants, which enabled us to make the conclusions about the strength of interactions the Method of Continuous Variations was used.

The light absorption of mixed dye and surfactant solutions in the visible absorption range at 25°C was measured. The concentration of the dye in the measured solutions was up to 6· 10^?5 mol-1^?1 and the concentration of the surfactant was up to 1.2· 10^?4 mol· 1^?1, which is below the critical micelle concentration of surfactant in pure water. The molal concentrations of KCl in the measured solutions were 0, 0.1, 0.5 and 1 mol/kg.

It was found that the addition of KCI reduces the tendency of the dye AO7 and the surfactant CPC1 to associate.     

Age differences in repeated learning tasks in schizophrenic subjects.

This experiment was designed to study age differences in the learning of paired associates in serial order and a card-sorting task over 9 different sessions. The Ss consisted of 2 groups, 15 younger-aged (20-29) and 15 middle-aged (40-56), male, hospitalized schizophrenics. The results indicated that the younger-aged-group's performance was superior on both tasks for the 1st session. Over the 9 learning sessions the middle-aged group showed significantly greater improvement on the paired-associate task, while the differences between the age groups in card-sorting speed remained fairly constant over the 9 sessions. It was concluded that the learning deficit in middle-aged and schizophrenic Ss is something that is not a fixed and immutable one for all tasks but may be modified through practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

False Memories: Young and Older Adults Think of Semantic Associates at the Same Rate, but Young Adults Are More Successful at Source Monitoring.

Two experiments explored whether the higher vulnerability to false memories in the DRM (J. Deese, 1959; H. L. Roediger & K. B. McDermott, 1995) paradigm in older compared to young adults reflects a deficit in source monitoring. In both experiments, adding together the number of falsely recalled critical lures and the number of critical lures produced on a post-recall test asking participants to report items that they had thought of but did not recall, indicated that the critical lures were activated during the experiment equally often in young and older adults. However, older adults were more likely than young adults to say that they had actually heard the lures. When strongly encouraged to examine the origin of memories (Experiment 2), the warning substantially reduced false recall in young but not older adults. These results are consistent with the idea that older adults have more difficulty later identifying the source of information that was activated as a consequence of intact semantic activation processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Color-object paired associates in deaf and hearing children with and without response competition.

Deaf and hearing Ss, aged 6 and 10, were compared in 2 nonverbally presented paired-associates tasks. One condition used neutral color stimuli unrelated to toy response objects and another condition had colors systematically related to the same objects to provide interfering response competition. Age differences were observed, while task interacted with deafness such that hearing but not deaf Ss were impeded by the interference condition relative to the neutral condition. It was concluded that deaf Ss showed no perceptual rigidity and that covert verbalizations of hearing Ss or experiential poverty in deaf Ss produced the differential task effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus context effects, associative strength, and word frequency as determiners of free recall in paired-associate learning.

Two levels of response word frequency and three levels of associative strength of paired-associates were used to form six lists. One level of low associative strength between pairs to be learned was created by re-pairing stimuli and responses from high associative strength lists. Both the high associative strength condition and the re-paired condition produced superior recall of response items. Results suggested that the development of response availability in paired-associate learning depends in part not only upon the strength of the initial relationship between each stimulus and response pair to be learned, but also upon the context provided by other stimuli in the list. The meaning of "present at input" in studies evaluating the principle of encoding specificity (Tulving & Thompson, 1973) was questioned. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

铅锌矿选矿工艺流程改造试验

针对五台山铅锌矿矿石难选、技术经济指标不理想的现状，本研究课题通过小型试验及工业试验，添加调整剂T6与捕收剂D3及现场一系列的改造，使铅、锌及其伴生金、银的精矿品位和回收率均有较大的提高，年新增经济效益206．67万元。     

To Correct an Omission: Comment.

In reviewing the excellent article by Cacioppo and Petty (May 1981), an important omission in the development of the psychophysiological measurement of cognitive processes became apparent--the valuable work conducted by R. B. Malmo and his associates at McGill University. (PsycINFO Database Record (c) 2010 APA, all rights reserved)