火花源原子发射光谱法分析钢中超低碳硫

研究了火花源原子发射光谱法测定钢中超低C、S新方法,对影响分析结果准确度和精密度的因素进行了探讨。并进行了精度测试与准确度验证,同时还比较了采用超低C、S工作曲线对低碳和低硫精密度和准确度的影响。结果表明,本法准确、可靠,实现了用火花源原子发射光谱仪对钢中超低C、S的快速、准确的测定,满足了工艺生产的在线控制。     

样品制备在实验室工作流程自动化解决方案中的重要性

近年来,钢铁工业中用于过程控制的金属试样制备已经取得了显著进展。铣削法成为首选的样品制备技术,为使用者提供了新的机遇：首先,专业从事此领域的中国制造商提供专为此目的设计的试样制备机器;另一方面,数控加工中心的普遍使用扩大了可用解决方案的范围。现代试样制备机器是全自动化实验室的一部分,回顾分析影响试样制备机的最重要参数有助于理解它所起的作用。新一代自动化光电发射光谱仪（OES）、X射线荧光光谱仪（XRF）和火试金分析仪（FAA）的紧密集成可以最大化扩展现代试样制备系统在分析速度、样品处理量、灵活性、拥有成本以及使用寿命等方面的潜力。     

高频红外法测定钨粒中痕量碳硫研究

对选用的高频燃烧红外吸收(HFIR)仪的部分电路、气路及操作技术进行了必要的改进,降低其噪声,提高其灵敏度和稳定性;选用与试样基体接近的国际级低C,S标样,以不同的C,S量校正仪器,确定痕量C,S工作曲线的线性与校正系数;试验确定了试样的高频加热燃烧和CO2,SO2准确测量的最佳条件,建立新的钨粒中痕量C,S的HFIR分析法,测定下限均降至1.0μg/g的新水平,优于现行国标方法和以前的HFIR法研究工作.     

球铁金相试样制备过程的影响因素分析

在金相试样的制备过程中,常常会出现磨面不平、粗大或者细小划痕较多、拖尾划痕难以抛去、石墨破碎、浸蚀时间过长或过短、晶界过浅、过深或不均匀等制样缺陷,为了提升球墨铸铁金相试样制备质量,设计了球磨铸铁金相试样制备过程的L(3×53)的混合水平正交实验,根据金相试样的制备标准对28组试样进行打分。采用极差分析法对实验数据进行分析,研究四个影响因素对试样制备的影响程度和影响规律并选出最优组合。实验数据结果显示,影响评分的制样因素的重要程度为：A抛光时间>B浸蚀时间>C打磨次数>D打磨压力,制样参数的最优组合为A₁B₂C₃D₄。能促进金相教学和提高金相试样的制备技能水平。     

高频燃烧—红外吸收测定电解金属锰中低碳低硫

对高频燃烧—红外吸收法测定电解金属锰中的低碳低硫进行了研究.实验就几种助熔剂用量、试样量进行了研究,实验结果表明:在0.4g锡铁混合助熔剂+1.5g钨粒助熔剂,试样量0.5g的条件下,电解金属锰中碳硫检出限为C％=0.001 5,S％=0.000 21,准确度和精密度高于国家标准方法,标样回收率碳94％～105％,硫9...     

慢走丝线切割加工对Ti(C,N)基金属陶瓷抗弯强度的影响

采用液压万能试验机研究了慢走丝线切割加工对Ti(C,N)基金属陶瓷——Ti(C,N)-7%WC-20%Ni-7%Mo的抗弯强度影响。采用SEM、EDS对切割表面形貌和成分,以及变质层的显微组织进行了观察和分析。结果表明,慢走丝线切割加工造成了明显的电蚀变质层,显著降低了试样的抗弯强度,增大了强度散差。变质层的组织中存在大量微裂纹、孔洞、晶粒脱落等显微缺陷。     

SiC晶须的原位生长及其在C/C复合材料抗氧化涂层中的应用

以三氯甲基硅烷(CH3SiCl3,MTS)为先驱体原料,采用化学气相沉积法在C/C复合材料基体上原位生长碳化硅晶须(SiCw),制备CNT-SiCw抗氧化涂层,并在1 100℃、空气中对该氧化涂层进行10 h抗氧化实验,研究SiCw的制备工艺以及SiCw在C/C复合材料抗氧化涂层中的作用。结果表明:制备碳化硅晶须的最佳工艺为:温度1 100℃、常压、载气和稀释气体流量均为100 mL/min。在此工艺下,沉积时间为15 min时,能制备出高长径比、平均直径约100 nm的碳化硅晶须。有CNT-SiCw涂层C/C复合材料试样在空气中氧化后的质量损失率仅0.7%,没有涂层的试样的质量损失率约为15%。     

辉光放电光谱法快速分析生铸铁的研究

通过对生铸铁标样在不同直流辉光放电光源参数下的放电行为研究,优化了辉光光源参数-放电电流、放电电压、预溅射时间和积分时间,建立了辉光放电光谱法同时测定生铸铁中C,Si,Mn,P,S等12个元素的快速分析方法.分析生铸铁试样时,发现了不同灰口铸铁在碳分析结果方面存在偏差,并通过制样条件和光源参数的调整有效地减小偏差.对不同生铸铁样品进行准确度和精密度实验,结果表明本方法快速、准确,适合生铸铁中多元素的快速分析.     

薄壁小口径管材中常规元素的光谱测定

利用直读光谱仪,对薄壁小口径管材中C、Si、Mn、P、S、Ni、Cr、Cu、Al等常规元素进行测定.对样品制备、分析条件、标准曲线的拟合等问题进行了讨论.分析结果准确度、精密度好.本方法实现了对薄壁小口径管材的快速分析,在满足生产要求的同时,为轧制状态钢材的分析开发出一条实用的新途径.     

添加纳米Ti(C,N)对粗晶WC-8Co硬质合金微观组织和力学性能的影响

将粒度为0.2μm的Ti(C,N)纳米粉末添加到粗晶WC-8Co硬质合金中，采用低压烧结技术制备了WC-xTi(C,N)-8Co系列硬质合金。利用XRD、SEM和EDS研究了添加纳米Ti(C,N)的硬质合金试样的物相组成和微观组织，并分析和讨论了合金的钴磁、矫顽磁力、洛氏硬度和抗弯强度等性能。结果表明，添加纳米Ti(C,N)烧结后的合金均出现了典型的Ti(C,N)芯-环结构，提高了硬质合金的硬度。然而，微量的Ti(C,N)添加会导致合金的力学性能下降，当添加量达到5%时，合金的综合力学性能最好，但当添加量达到15%以上时，基体出现脱碳相，导致合金的抗弯强度大幅下降。     

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。     

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.     

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。     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.