激光超声检测技术及其工业应用前景

阐述了激光超声的基本理论,综述了激光超声检测技术的发展,重点介绍了激光超声检测技术在工业中的相关应用,如：材料性质的无损评价、对复合材料构件进行评估、在高温有辐射等恶劣环境下对样品进行检测、非接触测量固体材料厚度等.对激光超声应用于纳米材料中的研究概况也作了简要说明.同时指出了激光超声检测技术的工业应用前景.     

固体中激光超声的机理及应用研究

在固体中利用激光产生超声波,可作为超声测量和材料无损检测的一种新方法。介绍了激光超声的机理,光激超声波信号的检测方法及其应用。     

固体中激光超声的机理及应用研究

在固体中利用激光产生超声波,可作为超声测量和材料无损检测的一种新方法.介绍了激光超声的机理,光激超声波信号的检测方法及其应用.     

混凝土无损检测技术发展及工程应用

混凝土无损检测是在不影响混凝土构件或结构物完整性的前提下开展的一种性能检测技术,目前采用的主要方法有回弹法、超声法、超声回弹综合法等。本文总结了混凝土无损检测技术的特点、适用范围和分类,综述了该项技术的发展历程及在工程实践中的应用情况,指出了该项技术未来的发展趋势和应用领域。     

超声相控阵无损检测自动成像系统的设计与应用

利用Microsoft.net作为开发平台,完成超声相控阵无损检测自动成像系统的开发和设计。该系统可以通过USB接口控制相控阵电路硬件系统阵元发射,完成数据实时采集和数据实时成像任务。系统同时支持A扫、B扫和S扫等多种超声相控阵扫查方式,同时成像参数、成像方式可以通过界面参数进行选择,并能实现图像放大缩小、光标定位、图像标尺标定和实时系统参数校正,采集到的数据可根据不同的扫查方式,实现3种格式的文件存储。通过自主开发超声线控阵无损检测自动成像系统节约了成本并拥有独立的知识产权。该系统方便灵活,加深了对超声相控阵信号成像的直观理解,有助于推动相控超声技术在无损检测中的应用。该系统也可以植入便携式设备,方便检测人员的使用。     

无损检测技术在军用飞机修理中的应用

介绍了军用飞机修理中应用无损检测技术的特点,简要论述了磁粉检测、渗透检测、超声波检测等5种常规无损检测方法在军用飞机修理中的应用情况,以及CR/DR检测技术及复合材料超声波检测技术的应用情况。     

水浸超声C扫描在特殊铝合金模锻件中的应用

利用水浸超声C扫描无损检测技术,进行了特殊铝合金模锻件材料中间加工件超声检测工艺试验研究。能可靠检测出铝合金模锻件中的材料缺陷。综合分析材料缺陷种类及分布情况,得出分析结果,对批量生产的成功发挥了重要的作用。     

压力容器无损检测技术的原理及应用

介绍当前压力容器制造和使用过程中所采用的无损检测技术,包括射线、超声、磁粉、渗透等常规技术和声发射、磁记忆等新技术,并论述他们的工作原理、优缺点和应用范围.     

涡流无损检测技术及其应用

涡流无损检测技术是材料无损检测的一种重要手段，是目前人们所关注的一种重要的检测方法。本文详细介绍了涡流检测的基本原理、检测方法及其在实际中的应用。     

新型超声红外热像无损检测实验系统研制

设计并实现了一套适于教学使用的新型结构无损检测实验系统,介绍了实验原理和实验系统的设计。该实验系统以低功率压电陶瓷换能器为核心构建硬件系统。教学实践表明,该实验系统在获得良好实验效果的同时,具有实验装置安装方便、实验内容设置灵活和实验风险较小且可控等优点,有效解决了传统超声红外热像实验系统在教学应用方面的不足,为学生学习掌握超声红外热像无损检测技术提供了先进、适用的教学手段和实验条件。     

H2S对兔左心室心肌细胞电生理特性的影响

目的:探讨硫化氢(H2S)对兔左心室心肌细胞电生理特性的影响.方法:用标准微电极细胞内记录技术,观测硫化氢对兔左心室心肌细胞电生理特性的影响.观测指标:静息电位(resting potential,RP)、超射值(over-shoot,OS)、动作电位幅值(amplitude of action po-tential,APA)、0相最大除极速率(maximal rate of depolarization,Vmax)、复极20%、50%和90%时间(20%、50%and 90% of duration of action potential,APD20、APD50and APD90)及复极化平均速度(average rate of repolarization).结果:(1)用50μmol/L NaHS 灌流时,和正常对照组相比,APD50、APD90缩短(P＜0.01),复极化平均速度增快(P<0.05).(2)100μmol/L NaHS与对照组比较,APD50、APD90缩短(P＜0.01),复极化平均速度增快(P<0.05).和50μmol/L NaHS相比APD50缩短(P＜0.01)、APD90缩短(P＜0.05)、复极化平均速度增快(P<0.05).(3)200μmol/L NaHS、400μmol/L、1 000μmol/L NaHS可浓度依赖性的使 APA、RP、OS减小(P<0.01),APD20、APD50、APD90缩短(P＜0.01),复极化平均速度增快(P<0.01).结论:H2S可浓度依赖性的影响兔左心室心肌细胞电生理特性.     

高校初任英语教师身份认同困惑个案研究

该文选取杭师大钱江学院《综合英语》课题组这个教研团队中的六位初任英语教师为研究对象,研究其在"教研团队"这个特定语境中的"教师身份认同困惑",经过访谈发现该六位教师面临身份认同困惑,笔者解读原因为:1)扮演多重角色身心疲惫;2)将教师角色与研究者角色割裂;3)缺乏职业安全感;4)渴望工作与生活融合却力不从心。笔者从内外因素两方面提出实现身份认同的对策:1)外部因素:高校教育改革应重视教师成长,帮助初任教师应对改革带来的挑战;2)内部因素:教师群体应加强团队合作型组织文化建设,真实面对自我与学生,加强教师自身反思性和合作性实践。     

春秋"吴头楚尾"界说

“吴头楚尾”,顾名思义,是吴国与楚国的交界的地区。吴国与楚国交界之事,全在春秋时期。“吴头楚尾”,在今河南省、湖北省、湖南省的东界之东,即在今安徽省、江西省境内。“吴头楚尾”的争战之事。主要发生在今安徽省的北部与中部。吴国攻取和占领艾邑（今赣西北地区）的时间,在公元前504年至公元前495年之间。从公元前495年至公元前473年。是吴楚边界的稳定时期。吴国辖有番邑（令赣东北地区）和艾邑（今赣西北地区）;今江西中部和南部地区,大致属于楚国。（在令安徽境内）楚国的东界：乾溪、城父（今毫州市）——胡（今阜阳市）——英（今金寨县）——舒庸（今霍山县）——今宿松县。（在今安徽境内）吴国的西界：房钟（今蒙城县）——州来（今凤台县）——六（今六安市）——舒（今舒城县）——灊（今潜山县）。     

高校图书馆读者需求论

研究和探讨读者需求,是为了更好地为读者服务,提升高校图书馆文献的利用率,文章分别对学生和教师的阅读需求特征作了分析。学生阅读需求特征为:1.阶段性;2.集中性;3.广泛性。教师的阅读需求特征为:1.全面系统;2.专深具体;3.新颖及时。     

Effects of fructose-1,6-diphosphate on concentration of calcium and activities of sarcoplosnic Ca^2＋-ATPase in cardiomyocytes of Adriamycin-treated rats

Objective: To observe the effects of fructose-1,6-diphosphate (FDP) on serum levels of cardiac troponin 1 (cTnl) and creatine kinase-MB (CK-MB), as well as the concentration of calcium in cardiomyocytes (Myo[Ca2 ]) and activity of sarcoplosnic Ca2 -ATPase (SRCa2 -ATPase) in Adriamycin (ADR)-treated rats. Methods: Rats were intraperitoneally injected with ADR (2.5 mg/kg every other day for 6 times) and then with different dosages of FDP (every other day for twenty-one times). Bi-antibodies sandwich Enzyme linked immune absorption assay (ELISA) was performed to detect serum level of cTnl. CK-MB was detected by monoclonal antibody, Myo[Ca2 ] was detected by fluorescent spectrophotometry and the activity of SRCa2 -ATPase was detected by inorganic phosphate method. Results: FDP (300, 600, 1200 mg/kg) significantly reduced the serum levels of cTnl and CK-MB, while at the same time decreased calcium concentration and increased SRCa2 -ATPase activity in cardiomyocytes of ADR-treated rats (P<0.01). Conclusions: FDP might alleviate the cardiotoxic effects induced by ADR through decreasing calcium level as well as increasing SRCa2 -ATPase activity in cardiomyocytes.     

Clinicopathological features of atypical lipomatous tumors of the laryngopharynx

Atypical lipomatous tumor (ALT) of the laryngopharynx is rare. Here we report five cases to demonstrate their clinicopathological features. The patients were four males and one female, aged 41 to 69 years (median 53.6 years). All tumors (two in the hypopharynx and three in the larynx) presented as a slowly growing, painless mass. Symptoms included dysphagia (2/5), dysphonia (3/5), and the feeling of a foreign body in the throat (5/5). Tumors were well circumscribed or focally infiltrative, ranging from 2.0 to 5.0 cm (median, 3.4 cm) in size, and microscopically showed the typical features of lipoma-like ALT. Immunohistochemically, tumor cells were stained with S-100, vimentin, murine double minute 2 (MDM-2), and cyclin-dependent kinase 4 (CDK4). Two patients had local tumor recurrences at 6 and 14 months after initial surgery during follow-up. ALT of laryngopharynx is an indolent tumor. Immunohistochemical staining for MDM-2 and CDK4 is helpful in pathological diagnosis.     

Hypothetical mode of action of earthworm extract with hepatoprotective and antioxidant properties

The hepatoprotective potential of earthworm extract (EE) (Lampito mauritii, Kinberg) was evaluated against paracetamol-induced liver injury in Wistar albino rat, in comparison with silymarin, the standard hepatoprotective drug. We observed a reduction in liver antioxidants, such as glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx),and catalase (CAT) and in serum total protein, and an increase in serum alkaline phosphatase (ALP), serum aspertate aminotranferase (AST), serum alanine aminotranferase (ALT), bilirubin and liver thiobarbituric acid reactive substances (TBARS) due to liver injury in the paracetamol-administered rats (2 g/kg). On the contrary, increased activities of liver GSH, SOD, GPx,CAT and serum total protein level, and decrease in the contents of serum ALP, AST, ALT, bilirubin and liver TBARS were observed in rats administered with different doses of EE (100, 200 and 300 mg/kg), which are similar to the activities of hepatoprotective drug silymarin (150 mg/kg). The mode of action of EE as evidenced by the above parameters may suggest that EE, on the one hand, prevents the formation of the reactive oxygen groups, or scavenges these groups, thereby preventing the damage on the hepatic cells, and, on the other hand, modulates the genes responsible for synthesis of antioxidant enzymes such as GPx, CAT and SOD in liver tissue and decreases the serum enzymatic activities such as ALP, AST and ALT.     

三线摆周期的近似公式

首先给出三线摆运动周期的两个公式，中公式(1)和(2)，根据献[1]的部分结论，通过一级近似，得出三线摆大摆角运动时周期的近似公式(8)和(9)，利用比较的方法，证明公式(8)和(9)是成功的．     

Simultaneous testing of four decades of academic self-concept models

In separate studies on academic self-concept, previous research has shown: (1) the distinctiveness of a cognitive and an affective component, (2) the domain specificity of self-concepts, (3) the reciprocal effects of self-concept and achievement, (4) the internal/external frame of reference in self-concept development, (5) the reciprocal effects of the internal/external frame of reference, (6) the big-fish-little-pond effect, and (7) the interrelatedness of self-concepts in similar domains. The present study demonstrates that all of these seven findings are replicable and may be synthesized in a single study with a sample of students in Singapore. Secondary 1 students (7th graders; N = 275) were surveyed with 24 items about their academic self-concepts in physics, English, and math in two components (cognitive and affective), and their respective achievement scores were recorded over two time points. Confirmatory factor analysis found that the cognitive and affective components of academic self-concept were separable. The students’ self-concepts in different curriculum domains were distinct, supporting the domain specificity of self-concepts. The frame of reference and reciprocal effects were both supported, but only for the cognitive component of self-concept. Positive and statistically significant correlations between physics and math suggest that these curriculum domains were interrelated. Results of self-concept studies in schools can encourage and guide the design of interventions that could enhance students’ self-concept for positive sustainable effects on desirable educational outcomes. Attempts to improve learning outcomes should emphasize an enhancement of specific components of academic self-concept in domain-specific and related curriculum domains for optimal effects.     

关于全矩阵代数的几类子代数的中心

根据有限维代数的理论以及域K上矩阵的性质，给出域K上全矩阵代数Mn(K)的子代数对角矩阵代数Dn(K)、若当代数Jn(K)、上三角矩阵代数Tn(K)以及独生子代数K[A]的中心。