本钢1700毫米宽带钢热连轧机精轧机改造技术分析     

夏翠莉  于漫子 《辽宁科技学院学报》2003,5(4):23-26

分析了本钢连轧厂七架普通四辊精轧机的改造．对所采用的工作辊弯辊装置和轧辊轴向横移装置的工作原理进行了研究，结果表明．产品板型得到控制，质量显著提高。  相似文献   

冷轧板带机运行中的板形控制     

史华 《鞍山师范学院学报》2005,7(2):41-43

分析了热轧过程、冷轧、轧机压下量均匀程度、轧辊变形、压扁量与金属恒流动等影响板材板型的主要因素；介绍了采用液压AGC系统控制板厚及板形、通过轧辊有载辊缝的控制进行板形控制、采用板形控制新技术和采用新型轧机等板形控制的途径和方法．  相似文献   

负反馈放大器计算分析     

聂永廷 《周口师范学院学报》1999,(2)

以射极输出器为例分析负反馈放大器的各种计算方法;方框图分解法之商榷．  相似文献   

激波衰减的实验研究   总被引：2，自引：0，他引：2  

张京平 《科技通报》1999,15(5):373-376

通过量纲分析,用实验的方法获得了激波在ＣＯ２中衰减的规律,为激波管的使用和设计提供了参考依据。  相似文献   

钢管混凝土柱节点的研究现状     

傅鹏斌 《河北职业技术学院学报》2010,(1)

论述了目前钢管混凝土柱节点的常见型式,分析了加强环式节点、穿心牛腿环梁节点、钢筋贯通式刚接节点、锚定式节点、十字板式节点、分层式节点和环梁式节点的构造特点和各自的优缺点。指出钢管混凝土柱节点在理论研究和实际应用中的一些问题。  相似文献   

Contract cheating in UK higher education: A covert investigation of essay mills          下载免费PDF全文

Dominic Medway  Stuart Roper  Leah Gillooly 《British Educational Research Journal》2018,44(3):393-418

Contract cheating is currently a concern for universities and the higher education (HE) sector. It has been brought into the spotlight in recent years through the growth of online essay mills, where students can easily commission and purchase written assessment responses. This study contributes to the wider literature on academic integrity in HE by examining the phenomenon of contract cheating from a supply‐side perspective, thereby considering the essay mill offering and student interaction with it. The authors covertly engage with five essay mills, before successfully completing an assignment purchase with two of these providers. The pre‐purchase stage of an assignment transaction is first examined, unpacking ten reassurance cues used by essay mill providers in the text of their websites. These reassurance cues help to ensure the attractiveness of the essay mill product to potential student consumers. The analysis then moves to explore the ethical discourses around academic integrity that essay mills provide, revealing inconsistencies in their stance towards the potential for academic misconduct from the use of essay mill services. Finally, the article explores the quality of the essay mill product, through grading and Turnitin^® reports for the two purchased essay mill assignments. Following recent calls for the outlawing of essay mills, this article provides a timely addition to current understanding of this phenomenon, and the associated challenges of contract cheating in HE.  相似文献   

Concept modeling of tapered thin-walled tubes     

Yu-cheng Liu  Michael L. Dag 《浙江大学学报(A卷英文版)》2009,10(1):44-53

This paper presents a method to create concept models for the tapered thin-walled tubes using beam elements and spring elements. Developed concept tapered beam models with different taper angles and cross sections are compared with those detailed models through impact analyses. Important crash results are recorded and compared, and the relatively good agreement is achieved between these analyses. Concept modeling steps are illustrated in detail, and a general concept modeling method for such thin-walled tubes is summarized and presented.  相似文献   

砂砾含水层成井工艺的反冲淘沙法     

唐泽华 《大众科技》2013,(1):35-36

当前在砂砾含水层的成井工艺中,均采用常规程序。即在所设计的砂砾含水层部位,配置相应的滤管,滤管外仍采用缠丝,再包扎尼龙滤网。管外投填滤砂。用活塞提拉或空压抽水洗井。此为传统工艺。由于受传统工艺束缚,缺乏对砂砾含水层结构的具体分析。施工工艺的针对性、对策性欠妥。多数成井井阻大,产水效率低。笔者在施工中,改变传统理念。提出反冲淘砂法成井。取得极为理想的效果,且施工工艺简单,井阻系数小,绝大部分为超完善井,产水效果佳。可视作砂砾含水层成井之新工艺。  相似文献   

The effects of transport by pneumatic tube system on blood cell count,erythrocyte sedimentation and coagulation tests     

Fatma Emel Ko?ak  Mustafa Y?ntem  ?zlem Yücel  Mustafa ?ilo  ?zlem Gen?  Ayfer Meral 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2013,23(2):206-210

Introduction:

Today, the pneumatic tube transport system (PTS) is used frequently because of its advantages related to timing and speed. However, the impact of various types of PTS on blood components is unknown. The aim of this study was to examine the influence of PTS on the quality of routine blood cell counts, erythrocyte sedimentation, and certain blood coagulation tests.

Materials and methods:

Paired blood samples were obtained from each of 45 human volunteers and evaluated by blood cell count, erythrocyte sedimentation, and several coagulation tests, including prothrombin time (PT) and activated partial thromboplastin time (aPTT). Blood samples were divided into 2 groups: Samples from group 1 were transported to the laboratory via the PTS, and samples from group 2 were transported to the laboratory manually. Both groups were evaluated immediately by the tests listed above.

Results:

The blood sample test results from groups 1 and 2 were evaluated and compared. No statistically significant differences were observed (P = 0.069–0.977).

Conclusion:

The PTS yielded no observable effects on blood cell counts, erythrocyte sedimentation, or PT and aPTT test results. We concluded that the PTS can be used to transport blood samples and yield reliable results for blood cell counts, erythrocyte sedimentation, and several coagulation tests.  相似文献   

螺旋隔板花瓣管单管换热器的数值模拟     

徐涛 《广东轻工职业技术学院学报》2006,5(1):6-8

采用FLUENT6．0软件对整个螺旋隔板花瓣管单管换热器的一段的流场、温度场进行数值模拟，结果显示壳程内的主体流动趋势仍是螺旋状，但在翅片附近速度场的大小和方向变化较大，证明翅片的存在激发了流体的边界层分离和湍动，从而强化了传热。  相似文献