电感耦合等离子体原子发射光谱法测定精制铝箔中铅镉砷

试样用硝酸、盐酸溶解,用电感耦合等离子体原子发射光谱(ICP-AES)法测定铅、镉;用盐酸、硝酸、硫酸溶解,在盐酸介质中以四氯化碳萃取去除铝,然后用ICP-AES法测定砷。测定时选择283.306 nm,226.502 nm,197.262 nm分别作为铅、镉、砷的分析线,基体铝对铅、镉测定的影响采用基体匹配方法克服。对于5μg/mL的As,Pb,Cd,20倍量的Zn,Si,Mn,V,Ti,Mg无干扰。铅、砷的检出限均为0.01μg/mL,镉的检出限为0.001μg/mL。用本法测定铝箔样品中铅、镉、砷,     

石墨炉原子吸收光谱法测定磷酸中铅镉

研究了使用超声振荡混匀试液,通过计算扣除试样空白的石墨炉原子吸收光谱测定磷酸中铅、镉的方法。实验发现硝酸具有与硝-磷混酸相同的基体改进效果,从而在校准曲线溶液中仅使用硝酸,而无需再使用磷酸即可以克服基体干扰。室温下,试样在硝酸中超声搅拌1h,试液可完全混匀。试液中铅和镉用石墨炉原子吸收光谱仪直接测定,检出限为0.19ng/mL(铅)和0.068 ng/mL(镉),回收率为100%~113%(铅)和94%~112%(镉)。该方法适用于测定磷酸中铅镉。     

电感耦合等离子体原子发射光谱法测定硅系铁合金中砷铅

采用电感耦合等离子体原子发射光谱法对硅系铁合金中As,Pb元素进行了分析。以氢氟酸和硝酸分解样品,高氯酸冒烟分离硅,用盐酸溶解残留物后定容测定。测定时选择193.696 nm和220.353 nm分别作为砷和铅的分析线,基体铁不产生谱线重叠干扰。砷和铅的质量浓度在0~1.0μg/mL范围内有良好线性关系,相关系数分别为0.999 4和0.999 5。对11份空白进行测定,得到砷和铅的检出限分别为0.004μg/mL和0.003μg/mL。用本方法测硅系铁合金中砷、铅的回收率在93.5%~105.0%之间;     

石墨炉原子吸收光谱法测定高纯二硫化钼中铜铅

用硝酸和盐酸溶解高纯二硫化钼样品 ,磷酸二氢铵及硝酸镁溶液作为基体改进剂 ,石墨炉原子吸收光谱法测定高纯二硫化钼中铜、铅。检出限分别为铜 :0.68μg/L ,铅 :1 5 7μg/L。该法快速、简便、准确 ,结果满意     

石墨炉原子吸收法测定低合金钢中铅

提出了一种石墨炉原子吸收测定钢中痕量铅的方法。本方法对仪器的最佳分析条件、升温程序、背景干扰及消除的情况进行了研究。采用稀硝酸溶解试样,1%NH4H2PO4＋0.3%Mg（NO3）2为基体改进剂,在优化的实验条件下,铅的质量浓度在0~0.1μg/mL范围内呈良好的线性关系,定量下限为0.002μg/mL,加标回收率为92.86%~105.96%。采用本方法对4种钢铁标准样品进行测定,结果显示准确度、精密度均满足要求。     

微波加热酸浸提—原子吸收光谱法测定重晶石中铅镉

使用微波消解仪,在密闭升温增压条件下,以王水浸提重晶石中铅和镉,用火焰原子吸收光谱法测定铅,石墨炉原子吸收光谱法测定镉。浸取率比用同样酸的常压敞开浸提法高,样品空白值低;处理样品的速度比用高压坩埚酸浸提法快;试样中的铅和镉损失比碳酸钠融熔处理法少。方法检出限:铅为0.069μg/mL,镉为0.087μg/mL。样品中铅、镉的加标回收率分别为95.1%～99.5%,97.1%～104.4%;相对标准偏差分别为1.3%～3.2%,1.6%～2.8%。     

铋和二氧化锰共沉淀分离-火焰原子吸收光谱法测定铅锭中铋

铅锭样品经硝酸(1+3)溶解,分别用氨水和硝酸(1+3)调节溶液的pH值约为3.1,加入10mL 100g/L硝酸锰溶液,于70℃的温度下,在0.47~0.70mol/L硝酸中加入10mL10g/L高锰酸钾溶液并不断搅拌,利用二氧化锰与铋共沉淀的特性实现了铋与基体铅的分离,将过滤所得沉淀用盐酸双氧水混合酸(49+2)溶解,以10%~25%(V/V)盐酸为测定溶液介质,选择223.1nm为测定波长,建立了火焰原子吸收光谱法(FAAS)测定铅锭样品中铋的方法。在选定的仪器条件下,铋在0.50~5.00μg/mL范围内和其对应的吸光度呈良好的线性关系,相关系数r=0.999 8,铋的方法检出限为0.002 8μg/mL。干扰试验表明,铅锭中分离后余下的铅及其他元素不干扰对铋的测定。将实验方法应用于4个质量分数为0.000 39%~0.062%的铅锭标准样品中铋的测定,结果与认定值基本一致,相对标准偏差(RSD,n=11)在0.67%~8.1%之间,加标回收率为98%~102%。     

石墨炉原子吸收光谱法测定生铁中痕量锡

报告了采用热解涂层石墨管,塞曼扣背景的石墨炉原子吸收光谱法测定生铁中痕量锡的方法。用硝酸溶解样品,抗坏血酸作为基体改进剂,锡的灰化和原子化的温度分别为800℃和2400℃。在上述条件下测定锡的灵敏度比较高,检测信号稳定,共存元素对锡的测定影响较小。该方法测定锡的线性范围为0～160μg/L,检出限为0.014ng/mL,方法用于生铁中锡的测定,相对标准偏差为4.0%～4.7%,平均加标回收率为96%～106%。     

电感耦合等离子体原子发射光谱法测定Sn-Ag-Cu系焊锡中铅和镉

样品用盐酸、过氧化氢溶解,在少量硫酸存在下,以盐酸和氢溴酸挥锡,电感耦合等离子体原子发射光谱法测定铅和镉的含量。优化了仪器的工作参数,对溶样酸和锡基体等影响因素进行了试验。本法测铅和镉的线性范围分别为0.50～5.00 μg/mL和0.050～0.50 μg/mL ,检出限分别为13.2 μg/L和0.9 μg/L,样品测定结果的相对标准偏差(n=6)均小于4 %,用标准加入法测得回收率分别为97 %～108 %和90 %～96 %。     

电感耦合等离子体发射光谱法测定金精矿中铜铅锌镉

采用盐酸-硝酸-高氯酸混合酸消解样品,盐酸为介质,电感耦合等离子体发射光谱法测定金精矿中铜、铅、锌、镉。方法检出限分别为Cu 0.002 2μg/m L、Pb 0.014 0μg/m L、Zn 0.004 2μg/m L、Cd 0.003 5μg/m L,加入标准物质回收率分别为Cu 97.67%~102.25%、Pb 96.97%~105.07%、Zn 97.00%~105.50%、Cd 95.00%~105.00%,测定结果的相对标准偏差分别为Cu 3.03%~3.79%、Pb 1.24%~4.52%、Zn 1.62%~3.91%、Cd 1.94%~4.16%。该方法操作简单、准确可靠,满足实验室检测需求,适合大批量样品的测定。     

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。     

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。     

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。     

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.     

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.