钛铁矿常压微波消解溶样方法研究

由于钛铁矿稳定的结构特点,在分析其组分含量时,溶样成为分析方法中较难的一个环节。本实验根据X-射线衍射仪分析钛铁矿组成和结构的结果,利用钛铁矿显著吸收微波的介电特性,使用改装后的800 W家用微波炉,在常压下选择中低火加热温度(160℃左右),分别用磷酸和磷硫混酸在微波辐照下消解粒度小于0.125 mm的矿样,可快速将矿样消解完全。与传统方法比较,该法具有简便、快速、低耗等优点,可应用于大批量样品分析。     

微波辐照对铅锌矿力学强度影响的试验研究

采用特制的脉冲微波设备,研究脉冲微波功率、脉宽、辐照时间对湖南某铅锌矿力学强度的影响规律。铅锌矿经脉冲微波辐照后,矿物内部和外部缺陷明显增多,矿物强度降低很明显,其抗压强度下降值随脉冲微波功率、脉宽、辐照时间的增加而增大。铅锌矿未经微波辐照时抗压强度平均值为9.24 MPa,当微波功率为40 k W,脉宽为1000μs,辐照时长为40 s时,其抗压强度弱化程度最大,抗压强度平均值为5.12 MPa,相比微波处理前下降了44.6%。铅锌矿经相同微波参数辐照后,喷水冷却较自然冷却导致的铅锌矿强度弱化程度更高,其抗压强度平均值为4.35 MPa,比自然冷却强度下降值增加了8.3%,更加有助于铅锌矿强度的弱化。扫描电镜(SEM)分析结果表明:经过微波辐照处理的铅锌矿在有用矿物和脉石间产生了裂纹,能够有效地促进矿物与脉石的解离,导致了铅锌矿强度的降低,有利于后续磨矿的进行。     

钛精矿球磨活化微波还原试验

研究攀枝花低品位钛精矿的球磨活化-微波还原。采用激光粒度及X衍射研究不同球磨条件下钛铁矿的粒度和物相变化并进行分析,结果表明磨矿活化使矿物颗粒逐渐减小、特征峰宽化、晶粒变细;研究了活化物料的升温和还原行为,并对还原产物微观形貌和物相进行分析,表明活化物料有良好的微波吸收性能和还原效应。证实在反应过程中存在"热点"。球磨8 h的混合物料在温度900℃、反应时间30 m in条件内金属化率超过90%。     

微波辅助碳热还原法制备氮化钒

以微波辅助碳热还原法对五氧化二钒进行还原氮化。测定了炭黑、活性碳和石墨作为还原剂的混合物料在微波场的升温曲线,并采用热重分析法考察了微波场中不同输入电流对物料还原程度的影响。结果表明,3种还原剂中炭黑的吸波性能和还原性能最佳,在输入电流为16 A、微波辐照时间105 min时,炭黑物料的还原度为0.96,当辐照时间延长至120 min时,氮化反应迅速,此时样品氮含量为16.36%。     

微波加热浸出法从钛铁矿中提取钛

以钛铁矿和硫酸铵为主要原料,通过熔融反应法使钛铁矿中的钛转化成易溶于稀硫酸的硫酸氧钛,利用煅烧产生的氨气和水解产生的废酸生成硫酸铵,可循环使用。本试验主要是用微波浸出法替代工艺中的水浴浸出,采用单因素试验和正交试验考察微波功率、微波时间、浸出温度、硫酸浓度对钛浸出的影响。结果表明,在矿物粒度-0.053mm、微波功率4kW、浸出时间5h、硫酸浓度30%、浸出温度70℃的条件下,钛浸出率达到了96.99%,最终产品钛白粉中金红石型二氧化钛结晶度达到70.75%。     

微波加热配碳还原分解铁酸锌的工艺及机理研究

研究了利用微波配碳还原焙烧分解铁酸锌的工艺及机理。利用碳气化控制、化学控制及扩散控制模型研究了样品中铁酸锌分解的动力学行为,并考察了微波功率、反应温度、配碳比和粒度对铁酸锌分解率的影响。结果表明,样品的微波加热碳热还原试验的控制步骤为碳气化控制,活化能为39.21kJ/mol,在微波加热温度850℃、C/ZnFe2O4质量比为1∶4、粒径74～89μm、微波功率1.8kW、加热时间60min的条件下,铁酸锌的分解率达到90%。     

钛渣在微波加热过程中的升温特性和吸收行为

微波加热钛渣制备人造金红石具有均匀高效、能耗较低等突出优势。在不同条件下,钛渣在微波场中呈现出不同的升温特性,以钛渣为研究对象,系统地分析了微波输出功率、钛渣粒度以及物料量等参数对其微波吸收性能的影响,研究表明,增加微波输出功率有利于增加钛渣在微波场中温度升高的速率;物料量增多会导致钛渣在微波场中温度升高的速率变慢;钛渣粒度减小同样不利于其在微波场中加速升温。     

新型捕收剂YS-1对攀枝花某钛铁矿的浮选试验研究

针对攀枝花钛铁矿粒度较细,且矿样中含有少量硫化矿的特点,对矿样采用预先脱硫,选钛作业采用自主研发的YS-1药剂作钛捕收剂,进行了一系列浮选试验研究。试验结果表明,YS-1药剂对该矿样的浮选具有良好的适应性,实验室浮选闭路试验可获得含产率40.54%、Ti O2品位为47.17%、回收率为85.83%的钛精矿,工业试验进一步验证了YS-1药剂具有良好的应用性。     

电焊条用钛铁矿的介电特性及微波加热特征

电焊条用含钛原料的介电特性研究对于拓宽焊条制造原料来源和发展微波加热制备还原钛铁矿具有重要的指导意义.采用同轴探头反射法测定了钛铁矿粉末（含TiO237%～47%）在2.45 GHz频率下和20～80℃之间的介电特性,并测定钛铁矿在微波场下的温升特性.研究结果表明：钛铁矿的介电常数和介电损耗因子及损耗角正切随着温度的上升而增加,介电特性总体随着含钛品位增高逐渐增强.钛铁矿的穿透深度在40～80℃之间随温度增加逐渐降低,微波加热钛铁矿的最佳物料厚度为3～6 cm.微波场下钛铁矿的升温曲线表明温度和微波加热时间具有一个非线性关系.     

应用响应面设计分析法研究碳酸锰吸收微波的性能

以碳酸锰为微波吸收材料,考察了微波输出功率、微波辐射时间、样品堆积厚度和样品质量等因素对微波吸收率的影响。基于单因素条件影响试验结果,采用响应面法进行试验设计、方差分析、曲面分析及模型优化。结果表明,各因素影响显著程度为:微波功率>样品堆积厚度>样品质量>辐射时间,且交互影响不显著。当微波功率为675W、作用时间为131.5s、样品堆积厚度为15.4mm、样品质量为153.6g时,碳酸锰的微波吸收率模拟值最优为6.28%,与实际试验结果(5.89%)能较好吻合,误差约为6.6%。响应面分析法对矿物微波处理过程的因素影响程度有较好的预测性。     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

Comparison of the results of surgical and conservative treatment of fractures of the diaphysis of the tibia

In this paper is treated the fundamental problematic of the fracture of the diaphysis of the tibia and the therapeutic results after the conservative and operative treatment are confronted. Among 518 patients with 433 open fractures and 35 with closed fractures of the diaphysis of the tibia, successful treatment of more 2/3 was obtained in the period from 1968 to 1972. Following our casuistics and literature, whose results are similar, we find out that the average total treatment of the osteosynthesis of the fracture of the diaphysis was shortened for 2,5 months depending upon the type and the localisation of the fracture. Apolied methods of the operative and conservative and conservative treatment in relation to the velocity of the medical cure as well as to the extreme anatomical-functional results are analised. We noticed that osteosynthesis, made by the intermedullary nail and the extension of the canals or by a small AO table, by the achieved stability makes conditions of immediate motions and an early rehabilitation. Because of that it gives the best functional results.     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

参与式农业基地建设行动方案设计

为了编制实用性强的基地建设行动方案,首先,确定参与式发展的主体,搭建一个"决策框架";其次,针对行动目标,提出不同参与主体,如管理者、农民、消费者等团队与个人的目标及行动内容;最后,工作应向重塑伙伴式合作关系,挖掘农民自我发展潜力,完成三大角色的转换,打造农业基地文化等方向推进.