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Drag on Hydroid-Fouled Nets – An Experimental Approach

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China Ocean Engineering 2015年第3期29卷 369-389页

作者： Pl lADER David W. FREDRIKSSON Jana GUENTHER Zsolt VOlENT Nina BlOCHER David KRISTIANSEN lars GANSEl Jud DECEW SINTEF Fisheries and Aquaculture United States Naval Academy University of New Hampshire

The present study investigated the drag increase on aquaculture nets due to biofouling of the colonial hydroid Ectopleura larynx. It had two main parts： firstly the growth characteristics of E. larynx were investigated by use of field tests at a Norwegian aquaculture site; secondly the hydrodynamic drag on the fouled twines was studied in a towing tank by using fabricated models of net twines with artificial hydroid fouling. In the field tests, the growth of the hydroids was first measured after three weeks of immersion and then again after six weeks. During this interval, the density of hydroids and the thickness of the hydroid stem were almost constant（1.4 hydroids/mm and 0.29 mm, respectively）, while the average length of the hydroids increased from 6.4 to 11.2 mm. The hydroid length followed a Rayleigh distribution, while the thickness was normal（Gaussian） distributed. Replicas of twines with three different levels of hydroid growth were made（1.5 hydroids/mm twine, hydroid length 9 mm, 16 mm and 20 mm）, and the drag on these twines was measured at different towing velocities（0.1 to 1.4 m/s） and with different twine configurations. For the twine with the shortest hydroids（9 mm）, the drag was from 1.5 times（Re=4000） to 2.2 times（Re=1000） the drag on a clean twine. For the longest hydroids（21 mm）, the drag was 2 times and 3.8 times, respectively.

关键词： hydroid biofouling aquaculture net hydrodynamic drag

A Quantitative Analysis of Mn Segregation at Partitioned Ferrite/Austenite Interface in a Fe-C-Mn-Si Alloy

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Journal of Materials Science & Technology 2009年第3期25卷 383-388页

作者： H. Guo S.W. Yang C.J.Shang X.M. Wang X.l. He Department of Materials Physics and Chemistry University of Science and Technology Beijing Beijing 100083 China

Mn segregation at austenite/ferrite interface is studied in a Fe-C-Mn-Si alloy held at 656℃. Mn is partitioned during the growth of ferrite and as a result, a Mn pile-up exists in front of interface on the matrix side. An approach to evaluate Mn segregation quantitatively is developed by combining STEM raster window scanning and simulation of the interaction of the electron beam with the sample to subtract the contribution of Mn pile-up and obtain pure Mn segregation value. The evaluated maximum Mn interfacial segregation is in the order of a half-monolayer.

关键词： Interfacial segregation Phase transformation STEM Beam broadening

Coquitlam大坝抗震能力提高设计(英文)

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岩土工程学报 2008年第11期30卷 1669-1678页

作者： J.K. lou l. Yan Gentechnical Consultant Vancouver BC Canada (formerly Generation Engineering BC Hydro) Project Engineer Specialist Civil Design - Geotechnical Generation Engineering BC Hydro Bumaby BC Canada

Coquitlam 大坝建于 1913 年,坝高 30 m,为吹填土石坝。大坝位于加拿大 BC 省高地震危险带。风险人口数以万计。根据现行标准,大坝的抗震能力不符合要求,坝体冲填土和某些部位地基土松散,容易液化。在中度至重度的地震情况下,大坝将会... 详细信息

Coquitlam 大坝建于 1913 年,坝高 30 m,为吹填土石坝。大坝位于加拿大 BC 省高地震危险带。风险人口数以万计。根据现行标准,大坝的抗震能力不符合要求,坝体冲填土和某些部位地基土松散,容易液化。在中度至重度的地震情况下,大坝将会遭受严重的损坏,并有可能溃决。提高大坝的抗震能力很有必要。选择最高设计地震为里氏7.5 级地震,地震地面水平峰值加速度 0.66g。在设计中,还需要对以下一些提高抗震能力的设计方案进行评估,包括结构修复、大坝重建、限制水库运行及退役。在综合考虑技术、社会、环境和经济因素的基础上,选择了兴建一座新的下游堤坝以提高其抗震能力,减少 Coquitlam 大坝的地震风险。新建坝包括一座土质心墙堆石堤坝和一个位于左坝肩的混凝土过渡带。新建堤坝大部分是建在具有承载力的淤泥土上,而混凝土过渡带则完全建在基岩上。由于现场和施工条件的限制,座落在现有大坝下游坝壳部分的新建堤坝上游坡的下部一小部分为沿原河道的液化砂砾石冲积层。先进的地震稳定性和变形分析结果表明,由于有足够的超高、厚厚的反滤体以及过渡带,大坝所产生的变形是可以接受的。为了控制基础渗流和出逸坡降,设计采用了塑性混凝土防渗墙、帷幕灌浆以及在下游增设一套减压井相结合的方案。为了监测新建坝的性态,在施工期和运行期的仪器监测设计中采用了基于破坏模式的方法。主要介绍了 Coquitlam新建堤坝的设计,包括大坝安全监测系统的设计。

关键词：土石坝水力冲填结构抗震能力提高大坝缺陷及除险加固

催化氢化Mycoepoxydiene制备Hexahydromycoepoxydiene

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中山大学学报（自然科学版） 2005年第3期44卷 122-123页

作者：陈海燕戚平林永成陈光英王立 VRIJMOED l l P 中山大学化学与化学工程学院广东广州510275 海南师范大学化学系海南海口571158 香港城市大学生物及化学系

Mycoepoxydiene是从南海海洋红树内生真菌1893号中分离得到一个具有抗肿瘤活性的化合物。对mycoepoxydiene进行了催化氢化,得到一个新化合物hexahydromycoepoxydiene,其结构通过UV,IR,FABMS,1HNMR,13CNMR等证实。

关键词： Mycoepoxydiene Hexahydromycoepoxydiene 催化氢化

Mechanical Properties of a low-thermal-expansion Aluminum/Silicon Composite Produced by Powder Metallurgy

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Journal of Materials Science & Technology 2014年第4期30卷 417-422页

作者： Y.Q.liu S.H.Wei J.Z.Fan Z.l.Ma T.Zuo National Engineering & Technology Research Center for Nonferrous Metal Matrix Composites Beijing General Research Institute for Nonferrous Metals

AI matrix composite containing high volume fraction silicon has been promising candidate for lightweight and low-thermal-expansion components. Whereas, optimization of its mechanical properties still is an open challenge. In this article, a flexile powder metallurgy processing was used to produce a fully dense AI-4.0Cu （wt%） alloy composite reinforced with 65 vol.% Si particles. In this composite, Si particles were homogenously distributed, and the particle size was refined to the range of 3-15 μm. Tensile and flexural strength of the composite were 282 and 455 MPa, respectively, about 100% and 50% higher than the best properties reported in literature. The measured fracture toughness of the composite was 4.90 MPa m1/2. The improved strength of 65%Si/AI was attributed to the optimized particle characteristics and matrix properties. This investigation is expected to provide a primary understanding of the mechanical behaviors of Si/AI composites, and also promote the structural applications of this low-thermal-expansion material.

关键词： Aluminum matrix composite Powder metallurgy Mechanical properties Coefficient of thermal expansion Fracture

Modified Advanced life Support in Obstetrics course: Feasibility, trainee satisfaction, and sustainability potential

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Family Medicine and Community Health 2017年第1期5卷 71-77页

作者： Anjali Aggarwal Jason l.Salemi Bernice Yap Jennifer l.Matas Sameer Naik Roger J.Zoorob Hamisu M.Salihu Department of Family and Community Medicine Baylor College of MedicineHoustonTXUSA College of Public Health University of South FloridaTampaFLUSA

Objective:The main objective of this initiative was to present evaluation results from an inno-vative adaptation of the Advanced life Support in Obstetrics(AlSO)training *** modified the traditional AlSO curriculum in our institution by adding hands-on training in laceration repairs and simulation scenarios on acute maternity ***:The modified AlSO provider course was designed to enhance cognitive and proce-dural skills of health care professionals in managing obstetric ***-nine participants attended this course and completed a posttraining *** statistics were used to de-scribe the participant-reported assessment scores for the AlSO course on three domains(subject knowledge,organization and clarity,and teaching effectiveness)for each of 12 course ***:Evaluation of the results showed a high rate of trainee satisfaction as evidenced by the mean assessment scores across all topics ranging from 4.80 to 4.98(out of 5.00).All trainees said they would refer others to the *** modified AlSO course effectively addressed the important needs of primary care physicians involved in maternity care,especially in underserved communities where specialized obstetric care is not readily *** simulation scenarios and workshops using simulated human tissue provide a better foundation before formal ***:Given the changing legal and regulatory climate,we expect that learning to treat complex obstetric situations on the job will become increasingly *** this in mind,both simulation scenarios and workshops using simulated human tissue will provide a better foundation before formal training.

关键词： Advanced life Support in Obstetrics(AlSO) training hands-on laceration re-pair simulated human tissue

Basic features of the multiscale interaction between tearing modes and slab ion-temperature-gradient modes

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Chinese Physics B 2019年第12期28卷 237-247页

作者： l Wei Z X Wang J Q li Z Q Hu Y Kishimoto Key laboratory of Materials Modification by laser Ionand Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024China Southwestern Institute of Physics Chengdu 610041China Graduate School of Energy Science Kyoto UniversityGokashoUjiKyoto 1-0011Japan

Nonlinear interaction between tearing modes(TM) and slab ion-temperature-gradient(ITG) modes is numerically investigated by using a landau fluid model. It is observed that the energy spectra with respect to wavenumbers become broader during the transition phase from the ITG-dominated stage to TM-dominated stage. Accompanied with the fast growth of the magnetic island, the frequency of TM/ITG with long/short wavelength fluctuations in the electron/ion diamagnetic direction decreases/increases respectively. The decrease of TM frequency is identified to result from the effect of the profile flattening in the vicinity of the magnetic island, while the increase of the frequencies of ITG fluctuations is due to the eigenmode transition of ITG induced by the large scale zonal flow and zonal current related to TM. Roles of zonal current induced by the ITG fluctuations in the instability of TM are also analyzed. Finally, the electromagnetic transport features in the vicinity of the magnetic island are discussed.

关键词： magnetic reconnection tearing modes magnetohydrodynamics drift waves nonlinear phenomena

Heavy fermions in high magnetic fields

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Chinese Physics B 2019年第1期28卷 25-38页

作者： M Smidman B Shen C Y Guo l Jiao X lu H Q Yuan Center for Correlated Matter and Department of Physics Zhejiang UniversityHangzhou 310058China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China

Heavy fermion materials are prototypical strongly correlated electron systems, where the strong electron–electron interactions lead to a wide range of novel phenomena and emergent phases of matter. Due to the low energy scales, the relative strengths of the Ruderman–Kittel–Kasuya–Yosida(RKKY) and Kondo interactions can often be readily tuned by non-thermal control parameters such as pressure, doping, or applied magnetic fields, which can give rise to quantum criticality and unconventional superconductivity. Here we provide a brief overview of research into heavy fermion materials in high magnetic fields, focussing on three main areas. Firstly we review the use of magnetic fields as a tuning parameter,and in particular the ability to realize different varieties of quantum critical behaviors. We then discuss the properties of heavy fermion superconductors in magnetic fields, where experiments in applied fields can reveal the nature of the order parameter, and induce new novel phenomena. Finally we report recent studies of topological Kondo systems, including topological Kondo insulators and Kondo–Weyl semimetals. Here experiments in magnetic fields can be used to probe the topologically non-trivial Fermi surface, as well as related field-induced phenomena such as the chiral anomaly and topological Hall effect.

关键词： heavy fermions high magnetic fields quantum phase transitions heavy fermion superconductivity topological Kondo systems

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富铁橄榄石的高温变形实验研究

岩石学报 2005年第3期21卷 999-1004页

作者：赵永红 Zimmerman M Kohlstedt D l 北京大学地球物理学系北京100871 明尼苏达大学地质与地球物理系

利用高精度Paterson气体介质变形装置对(Mg0.5,Fe0.5)2SiO4和(Mg0.7,Fe0.3)2SiO4橄榄石集合体进行了高温三轴压缩变形试验。首先用人工合成了纯铁橄榄石Fe2SiO4,然后用合成的纯铁橄榄石与天然圣卡罗橄榄石按一定比例混合烧结合成了含铁... 详细信息

利用高精度Paterson气体介质变形装置对(Mg0.5,Fe0.5)2SiO4和(Mg0.7,Fe0.3)2SiO4橄榄石集合体进行了高温三轴压缩变形试验。首先用人工合成了纯铁橄榄石Fe2SiO4,然后用合成的纯铁橄榄石与天然圣卡罗橄榄石按一定比例混合烧结合成了含铁量分别为50％和30％的富铁橄榄石集合体Fo50和Fo70。三轴压缩蠕变变形试验在温度1223-1473 K和围压 300 MPa的条件下进行,差应力为10-300 MPa,应变率为10-7-10-4s-1,每个试件的最大变形量为20％．利用三维非线性方法对蠕变数据进行拟合,得出的流动律中,Fo50应力指数为4．1,活化能为499kJ／mol;Fo70应力指数为4．3,活化能为510kJ／ mol。将实验结果与Fo90圣卡罗橄榄石集合体的强度进行对比,发现含铁量的增加使橄榄石的强度明显下降,Fo50橄榄石集合体比Fo70的粘性低一个量级,Fo70比Fo90的粘性低一个量级。从而得到了含铁量对橄榄石的粘性(强度)影响的初步试验结果。

关键词：富铁橄榄石高温蠕变三轴压缩实验研究