螺杆分配机头口模出口高度变化对流场的影响

为了研究口模出口高度变化对螺杆分配机头内部流场和挤出均匀性的影响,参数化有限元分析技术贯穿于螺杆分配机头CAE仿真的全过程,采用VISUAL C＋＋和APDL语言开发出专用有限元前处理程序和特殊加载宏,调用ANSYS对螺杆分配机头流道内部流场进行三维有限元模拟与分析。分析结果表明：口模出口高度变小将增加流道内的流动阻力,显著增大狭缝流道内各部分区域过渡截面中间层节点的压力值和口模出口的挤出速度值。当口模出口高度调节较大时,有必要重新调节阻尼块以提高速度分布的均匀性。     

快速逆向工程系统及其关键技术

本文论述了快速逆向工程的系统框架及其关键技术，系统集成是逆向工程的核心，关键技术是其支撑。简要阐述了逆向工程的基本内涵及其工作过程；构建了快速逆向工程系统结构框架；重点分析了快速逆向工程的关键技术-快速仿形测量、曲面重构与快速原型技术；最后对快速逆向工程中存在的问题进行了讨论。     

A study of thyroid status in hyperemesis gravidarum

Study was undertaken to assess thyroid status in hyperemesis gravidarum. 150 women pregnant with <20 weeks of gestation were selected randomly and out of these 100 women presenting with hyperemesis formed study group while 50 normal pregnant women served as controls. 53% of hyperemetic pregnant women were primigravidae and 82% of pregnant women presented with vomiting at less than 12 weeks of gestation. Statistically significant, 22% of hyperemetic women had increased serum T₃ levels while T₄ levels were increased in 67% of women in study group as compared to 8% and 16% respectively in control group. TSH levels were decreased in 18% of hyperemetic women as compared to 8% in control group with decrease in mean TSH level statistically significant. 22% of hyperemetic women had electrolyte disturbances and 7% were ketonuric. In clinically euthyroid women, biochemically altered thyroid function can attribute to vomiting and its prolongation to second trimester     

Thyroid hormone status in protein energy malnutrition in Indian children

Thyroid hormonal status was measured in 80 malnourished children of different grades (I–IV) of protein energy malnutrition (PEM). Serum levels of tri-iodo thyronine (T₃), thyroxine (T₄) and thyroid stimulating hormone (TSH) were measured by radioimmunoassay. The results were compared with 20 healthy, age and sex matched controls. Levels of T₃ and T₄ were significantly low in PEM cases whereas TSH levels were similar in PEM cases when compared to controls.     

Model-based testing with UML applied to a roaming algorithm for Bluetooth devices

INTRODUCTION The Unified Modeling Language (UML)(Eriksson, 2003) is a visual language supporting thedesign and development of complex object-orientedsystems. While UML models focus primarily on thedefinition of system structure and behavior, theyprovide only limited means for describing test ob-jectives and test procedures. Furthermore, thegrowing system complexity increases the need forsolid testing. Thus, in 2001, the Object Manage-ment Group issued a Request for Proposal (U…     

Development and validation of the International Baccalaureate Learner Profile Questionnaire (IBLPQ)

The Learner Profile (LP) frames International Baccalaureate (IB) learning outcomes across the three programme levels and, as such, plays a key role in measuring the success of the rapidly growing number of IB schools in the Asia-Pacific Region. Our aim was to develop an instrument to measure the IBLP and validate the instrument through a series of psychometric procedures. Results showed solid construct validity and measurement reliability, alongside content validity from our Delphi studies and cross-validation with different samples. Given the growing number of IB schools in the Asia-Pacific, we believe that the development of the IBLP questionnaire (IBLPQ) contributes to the international research community and educators interested in exploring the relationship between student outcomes and the LP. Importantly, given the current absence of systematically designed and tested survey instruments to measure the LP, we expect the IBLPQ will become a key initial resource for a wide range of stakeholders.     

Is there a real diagnostic impact of elastosonography and contrast-enhanced ultrasonography in the management of thyroid nodules?

Ultrasonography(US) and the new applications US elastography(USE) and contrast-enhanced US(CEUS) are used in the screening of thyroid nodules,for which fine-needle aspiration biopsy(FNAB) is the best single diagnostic test.The aim of the study was to compare the sensitivity,specificity,positive predictive value(PPV),and accuracy of the four examinations in nodules with cytological and histological diagnoses.The study used data from US,FNAB,USE(elasticity(ELX 2/1) index),and CEUS(Peak index and time to peak(TTP) index) evaluated in 73 thyroid nodules in 63 consecutive patients likely to undergo surgery.Cytological-histological correlation was available for 38 nodules.No correlation emerged between nodule size and cytological results.A significant(P=0.03) positive correlation between cumulative US findings and cytological results was found.In addition,significant correlations between cumulative US findings and cytology(P=0.02) and between cumulative US findings and histology(P<0.0001) were found.US showed the best specificity and PPV,and FNAB the best sensitivity.There was no significant difference in the ELX 2/1 index,Peak index,or TTP index among nodules subdivided according to cytological scores.No significant correlation was found between ELX 2/1 index,Peak index,and TTP index,on the one hand,and nodule size,US cumulative findings,cytology,and histology on the other hand.The sensitivity of the ELX 2/1 index was high,but its specificity was very low.The accuracy and PPV of USE were lower than those of the other procedures.Only the correlation between Peak index and cumulative US findings reached a value close to significance.Our ultimate aim is to minimise unnecessary thyroidectomy.US and FNAB continue to play a central diagnostic role.The use of a US score showed high specificity and PPV.The specificity of FNAB was low in this selected series because of the numbers of indeterminate cytological responses.USE and CEUS are innovative techniques that need to be standardized.The ELX 2/1 index,Peak index,and TTP index seem to be unrelated to histology.The best statistical data on USE and CEUS concerned their sensitivity and PPV,respectively.At present,USE and CEUS are too time-consuming and of limited utility in selecting patients for surgery.     

Work-time profile,blood lactate concentration and rating of perceived exertion in the 1998 Greco-Roman wrestling World Championship

The aim of this study was to examine work-time profiles, blood lactate concentrations and perceived exertion among Greco-Roman wrestlers in the 1998 World Championship. Forty-two senior wrestlers from nine nations were studied in 94 matches. Each match was recorded with a video camera (Panasonic AG 455, film rate: 25 Hz) and analysed for duration of work (wrestling) and rest (interrupt) periods. Blood lactate concentration was determined with an electrochemical device (Analox P-LM5) and a rating of perceived exertion scale (Borg) was used to estimate general exertion and exertion in the extremity and trunk muscles. The mean duration of the matches was 427 s (range 324-535 s), with mean durations of work and rest of 317 and 110 s, respectively. The mean periods of work and rest were 37.2 and 13.8 s, respectively. Mean blood lactate concentration was 14.8 mmol · l -1 (range 6.9-20.6). The difference in mean blood lactate concentration between the first- and final-round matches was not significant ( P > 0.05). Blood lactate concentration was significantly higher ( P ? 0.04) in matches of long duration than in those of short duration. The mean general rating of perceived exertion for all matches was 13.8 according to the scale used. Most of the wrestlers (53.3%) perceived exertion to be highest in the flexors of the forearm, followed by the deltoids (17.4%) and the biceps brachii muscles (12.0%). In addition to a relatively high rating of perceived exertion in the arm muscles, this indicates a high specific load on the flexor muscles of the forearm.     

Exploring patterns of Latino/a children's school readiness at kindergarten entry and their relations with Grade 2 achievement

This study contributed to the school readiness literature by taking an intrachild perspective that examined the relations between Latino/a children's school readiness profiles and later academic achievement. Teachers rated the school readiness of 781 Latino/a kindergartners during the first month of school using the Kindergarten Student Entrance Profile (KSEP). Latent class analysis (LCA) examined KSEP profiles across social-emotional, physical, and cognitive domains and identified five distinct school readiness classes that described students’ strengths and weaknesses at kindergarten entry. Among the predictors examined, gender was the only significant difference among the top two readiness classes, with girls less likely to be in the lower of these two classes (OR = 0.38). In addition, children in the bottom three readiness classes were significantly less likely than students in the top readiness class to have preschool experience (ORs = 0.02–0.19) and had significantly lower levels of English proficiency (ORs = 0.51–0.72). Class membership was significantly associated with scores on the Grade 2 California Standards Tests and only the top two readiness classes had reading fluency rates near or above a national benchmark at the end of Grade 2. The variation of early achievement found across readiness classes also showed that considering the pattern of a child's social-emotional and cognitive readiness might enhance school readiness assessment. Implications for integrating universal school readiness screeners within a comprehensive multigating assessment model are also discussed.