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石笼堰的稳定性

水利科技 1981年第4期 76-82页

作者： d.stephenson 夏云翔刘建成长江流域规划办公室江西省水利科学研究所

石笼已成功地用于建造低坝、溢流堰,护面等水工建筑物,其结构对抗滑与抗倾覆具有一定的稳定性,一方面可从理论上进行探讨,另方面可通过模型上进行试验验证。本文对于建立在倾斜面和水平面上的或堆积在一个斜面上的石笼,提供了计算公式... 详细信息

石笼已成功地用于建造低坝、溢流堰,护面等水工建筑物,其结构对抗滑与抗倾覆具有一定的稳定性,一方面可从理论上进行探讨,另方面可通过模型上进行试验验证。本文对于建立在倾斜面和水平面上的或堆积在一个斜面上的石笼,提供了计算公式和图表,供设计参考。石笼(gabion)一词,源于拉丁文“Cavea”或“Cave”(洞穴),如今指的是填石铁丝笼。最初的石笼是在埃及用于堵口,现代的石笼已成功地用于挡土结构,特别是已用于水利工程,诸如护岸、渠道的衬砌、堰、挑水坝和消能设备等。

关键词：石笼水深抗倾覆水文要素石笼结构

Some stromatic pyrenomycetous fungi from northern ***,Camillea and Hypoxylon(Xylariaceae)

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Fungal diversity 2012年第4期55卷 65-76页

作者： L.N.Vasilyeva S.L.stephenson K.d.Hyde A.H.Bahkali Institute of Biology and Soil Science Far East Branch of the Russian Academy of SciencesVladivostok 690022Russia University of Arkansas FayettevilleAR 72701USA Institute of Excellence in Fungal Research Mae Fah Lung UniversityChiang Rai 57100Thailand School of Science Mae Fah Lung UniversityChiang Rai 57100Thailand Botany and Microbiology department College of ScienceKing Saud UniversityRiyadh 11442Saudi Arabia

Fourteen species of stromatic pyrenomycetous fungi(family Xylariaceae)collected in northern Thailand are *** of these(Biscogniauxia lithocarpi,Camillea malaysiensis ***,Hypoxylon juventuterubrum,***,***,and ***)are described as taxa new to *** of these taxa are provided,and they are compared with similar taxa known from the Western Hemisphere.

关键词： Ascomycota SE Asia Taxonomy Xylariales

The role of Ca,Al and Zn on room temperature ductility and grain boundary cohesion of magnesium

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Journal of Magnesium and Alloys 2021年第5期9卷 1536-1551页

作者： Supriya Nandy Shao-Pu Tsai Leigh stephenson dierk Raabe Stefan Zaefferer Max-Planck Institut für Eisenforschung Düsseldorf 40237Germany

It is know from literature that small additions(<1 wt%)of Ca,Al and Zn significantly improve the intrinsic ductility of *** exact role of each element,both qualitatively and quantitatively,and their combined effects,h... 详细信息

It is know from literature that small additions(d Zn significantly improve the intrinsic ductility of *** exact role of each element,both qualitatively and quantitatively,and their combined effects,however,are poorly *** we achieved a much clearer view on the quantitative role of each element with respect to ductility improvement and on the collaborative effect,particularly of Ca and Zn in *** of our findings and conclusions are in disagreement with data and interpretation found in *** different alloys,namely,Mg-0.1 Ca,Mg-0.1 Ca-1 Al,Mg-0.05 Ca-1 Al,Mg-0.1 Ca-2 Al-1 Zn(all are in wt%)were selected for this *** alloys were treated such that *** grain sizes and textures were *** largely excludes the effect of extrinsic factors on ***-guided slip trace analyses reveal that the addition of Ca eases activation of prismatic and pyramidal II slip *** in-situ deformation experiments in SEM and atom probe tomography observations of grain boundaries direct evidence is given for the individual and synergetic effects of Ca and Zn on grain boundary cohesion as an important contribution to improve the ductility of these *** conclude that Ca reduces the slip anisotropy and ameliorates ductility,however,the weak grain boundary cohesion in the Mg-0.1 wt%Ca alloy limits the material’s tensile *** addition of Zn alters the Ca segregation at the grain boundaries and helps to retain their cohesive strength,an effect which thus enables higher ductility and *** further addition of Al primarily improves the *** results show that the balanced influence of reduced slip anisotropy on the one hand and increased grain boundary cohesion on the other hand allow to design a high strength high ductility rare-earth free Mg alloy.

关键词： Magnesium–Calcium–Zinc alloys ductility Slip system determination grain boundary cohesion

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Microchimerism in recurrent miscarriage

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Cellular & Molecular Immunology 2014年第6期11卷 589-594页

作者： Hilary S Gammill Mary d.stephenson Tessa M Aydelotte J Lee Nelson Clinical Research division Fred Hutchinson Cancer Research Center Seattle WA USA department of Obstetrics & Gynecology University of Washington Seattle WA USA department of Obstetrics and Gynecology University of Chicago Chicago IL USA and Department of Obstetrics and Gynecology University of Illinois at Chicago Chicago IL USA division of Rheumatolegy University of Washington Seattle WA USA

Maternal-fetal cell exchange during pregnancy results in acquisition of microchimerism, which can durably persist in both recipients. Naturally acquired microchimerism may impact maternal-fetal interaction in pregnancy. We conducted studies to ask whether microchimerism that a woman acquired from her own mother is detectable before or during pregnancy in women with recurrent miscarriage. Fetal microchimerism was also assayed. Women with primary idiopathic recurrent miscarriage （n=23） and controls （n=31） were studied. Genotyping was conducted for probands, their mothers and the fetus, a non-shared polymorphism identified and quantitative polymerase chain reaction performed to measure microchimerismin peripheral blood mononuclear cells. Preconception comparisons were made between recurrent miscarriage subjects and controls, using logistic regression and Wilcoxon rank sum. Longitudinal microchimerism in subsequent pregnancies of recurrent miscarriage subjects was described. There was a trend toward lower preconception detection of microchimerism in recurrent miscarriage versus controls, 6% vs. 19% （1/16 vs. 6/31, P=0.2）. during pregnancy, 3111 （27%） of recurrent miscarriage subjects who went on to have a birth had detection of microchimerism from their own mother, whereas neither of two subjects who went on to miscarry had detection （0/2）. This initial data suggest that microchimerism from a woman＇s own mother, while detectable in women with recurrent miscarriage, may differ from controls and according to subsequent pregnancy outcome. Further studies are needed to determine the cell types,quantities and any potential functional role of microchimerism in recurrent miscarriage.

关键词： microchimerism pregnancy recurrent miscarriage reproduction

ELId超精密磨削砂轮表面氧化膜形成过程的建模和仿真

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工具技术 2008年第5期42卷 11-14页

作者：朱育权马保吉 d.J.stephenson 西安工业大学 Cranfield University

砂轮表面氧化膜的形成规律与特性对ELId超精密磨削质量有着重要的影响。为了研究在ELId磨削中氧化膜的形成规律,基于电化学基本原理,建立了砂轮表面氧化膜形成过程的一般模型,并对金刚石砂轮电解预修整过程中氧化膜的生长过程进行了仿... 详细信息

砂轮表面氧化膜的形成规律与特性对ELId超精密磨削质量有着重要的影响。为了研究在ELId磨削中氧化膜的形成规律,基于电化学基本原理,建立了砂轮表面氧化膜形成过程的一般模型,并对金刚石砂轮电解预修整过程中氧化膜的生长过程进行了仿真。在此基础上,对控制氧化膜生长的主要因素进行了理论分析。为了验证模型和仿真结果的正确性,采用与仿真过程同样的控制参数,对氧化膜的生长特性进行了实验研究。结果表明仿真结果与实验结果基本吻合。

关键词： ELId磨削电解在线砂轮修整金刚石砂轮

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Convolutional neural network-assisted recognition of nanoscale L1_(2) ordered structures in face-centred cubic alloys

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npj Computational Materials 2021年第1期7卷 60-68页

作者： Yue Li Xuyang Zhou Timoteo Colnaghi Ye Wei Andreas Marek Hongxiang Li Stefan Bauer Markus Rampp Leigh T.stephenson Max-Planck Institut für Eisenforschung GmbH Max-Planck-Straße 140237 DüsseldorfGermany Max Planck Computing and data Facility Gießenbachstraße 285748 GarchingGermany State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing100083 BeijingChina Max Planck Institute for Intelligent Systems Max-Planck-Ring 472076 TübingenGermany

Nanoscale L12-type ordered structures are widely used in face-centered cubic(FCC)alloys to exploit their hardening capacity and thereby improve mechanical *** fine-scale particles are typically fully coherent with matrix with the same atomic configuration disregarding chemical species,which makes them challenging to be *** distribution maps(SdMs)are used to probe local order by interrogating the three-dimensional(3d)distribution of atoms within reconstructed atom probe tomography(APT)***,it is almost impossible to manually analyze the complete point cloud(>10 million)in search for the partial crystallographic information retained within the ***,we proposed an intelligent L1_(2)-ordered structure recognition method based on convolutional neural networks(CNNs).The SdMs of a simulated L1_(2)-ordered structure and the FCC matrix were firstly *** simulated images combined with a small amount of experimental data were used to train a CNN-based L1_(2)-ordered structure recognition ***,the approach was successfully applied to reveal the 3d distribution of L1_(2)–typeδ′–Al3(LiMg)nanoparticles with an average radius of 2.54 nm in a FCC Al-Li-Mg *** minimum radius of detectable nanodomain is even down to 5Å.The proposed CNN-APT method is promising to be extended to recognize other nanoscale ordered structures and even more-challenging short-range ordered phenomena in the near future.

关键词： alloys ordered cubic

ELId超精密磨削砂轮表面氧化膜形成行为的实验研究

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铸造技术 2008年第8期29卷 1113-1115页

作者：朱育权马保吉 d.J.stephenson 西安工业大学机电工程学院陕西西安710032 School of Industrial and Manufacturing Science Cranfield UniversityBedfordUK

为了研究在ELId超精密磨削中不同工艺条件下砂轮表面氧化膜的生长行为,以氧化膜厚度和氧化膜的生长速率作为表征氧化膜形成过程特性指标,对电压、占空比和砂轮转速等工艺参数对金属结合剂砂轮表面氧化膜形成特性的影响进行了研究。结果... 详细信息

为了研究在ELId超精密磨削中不同工艺条件下砂轮表面氧化膜的生长行为,以氧化膜厚度和氧化膜的生长速率作为表征氧化膜形成过程特性指标,对电压、占空比和砂轮转速等工艺参数对金属结合剂砂轮表面氧化膜形成特性的影响进行了研究。结果表明,氧化膜厚度随着砂轮预修整时间的增加而增长,生长率在起始阶段较快,随后逐渐降低并趋于稳定。氧化膜厚度和生长率随着占空比和电压的增加而增加。达到稳态氧化膜生长率需要的时间在低占空比条件下比高占空比条件下更长。在1 000 r/min到4 000 r/min范围内,砂轮转速对氧化膜的生长特性没有影响。

关键词： ELId磨削砂轮修整金刚石砂轮表面氧化膜

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Neuromyelitis optica spectrum disorders and anti-myelin oligodendrocyte glycoprotein positive optic neuropathies

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International Journal of Ophthalmology(English edition) 2022年第7期15卷 1095-1107页

作者： Patrick Murtagh Amy Coman Kirk stephenson Maria Gaughan david Ryan Graeme McNeill Christopher McGuigan Lorraine Cassidy Royal Victoria Eye and Ear Hospital Adelaide RoadDublin 2D02 XK51Republic of Ireland St Vincent’s University Hospital Elm ParkDublin 4D04 N2E0Republic of Ireland

AIM: To describe the clinical characteristics and treatments associated with antibody positive optic neuropathies including anti-myelin oligodendrocyte glycoprotein(MOG) and anti-aquaporin 4(AQP4), alongside diagnostic modalities, investigations, and outcomes. METHOdS: A cross-sectional single-centre retrospective case series consisting of 16 patients including 12 antiMOG positive patients and 4 anti-AQP4 positive patients. Each of these patients had clinical signs and symptoms of optic neuritis and consisted of all patients who had a positive blood antibody result in our centre. Clinical findings including presence of a relative afferent pupillary defect, colour vision and disc assessment were recorded. Structured clinical exam and multimodal imaging was undertaken sequentially on each. Optical coherence tomography(OCT) scanning was preformed to examine the correlation between ganglion cell layer(GCL) thickness and visual acuity(VA) at presentation and as a determinant of final visual outcome in both groups. Initial and long-term treatment is also summarised. RESULTS: A total of 16 patients were included in the study consisting of 12 anti-MOG and 4 anti-AQP4 positive patients. Nine of the 16 patients were female and the average age of onset was 29.2 y in the MOG group and 42 y in the AQP4 group. There was no statistically significant correlation(Pearson correlation) between GCL thickness and presenting and final VA [r(10)=0.081, P=0.08 and r(10)=0.089, P=0.34 respectively]. The same statistical analysis was performed for the correlation between retinal nerve fibre layer(RNFL) and VA and similar outcomes wereobserved [r(10)=0.04, P=0.22 and r(10)=0.09, P=0.04]. No correlation was seen for initial RNFL thickness and final visual outcome in this group either [r(2)=0.19, P=0.38]. Visual field testing and radiological findings for each group are described. CONCLUSION: No correlation between initial VA or RNFL and final visual outcome is identified. A broad range of visu

关键词： neuromyelitis anti-myelin oligodendrocyte glycoprotein antibody anti-aquaporin 4

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关于食品进口对牙买加农业发展的影响研究

关于食品进口对牙买加农业发展的影响研究

作者： Hortense Natasha stephenson 江西财经大学

学位级别：硕士

随着食品进口的贸易自由化,这意味着货物可以进入一个国家的边界没有太多的障碍,这是贸易保护主义措施的结果。因此,在调查食品进口对牙买加农业发展的影响有两个方面。本文将从宏观经济影响和对国内农业的影响两个方面进行研究。对进... 详细信息

随着食品进口的贸易自由化,这意味着货物可以进入一个国家的边界没有太多的障碍,这是贸易保护主义措施的结果。因此,在调查食品进口对牙买加农业发展的影响有两个方面。本文将从宏观经济影响和对国内农业的影响两个方面进行研究。对进口国的当地消费者的宏观经济利益即是获得较低价格的食品。廉价食品是自由贸易的好处,因为进口食品进入国内市场,关税相关费用很少或没有。实际上,自由贸易允许国家集中精力生产具有比较优势的商品。由于进口食品,例如批发和配送中心,也创造了新的行业和就业机会。因此,短期食品进口影响经济增长和创新产业。进口关税,许可证收费,对接费和集装箱费等形式的收入都是货币性收益。除进口产品外,还有半成品和工厂进口生产的原材料,通常由制造商进口,用于制造本地消费和再出口的成品。在经济上,牙买加的食品业从这种进口收入和增长方面受益。有时国内市场没有这种技术加上气候条件可能不适合生产特定种类的货物,所以通过进口这些产品在当地市场上可以买到。粮食进口弥补了国内农业留下的空白,为人民提供了粮食安全。在微观经济视角下,人均市民可以少量进口食物,帮助他们节省一些钱,支持他们的营养需求或者为个人经济增长投入储蓄。食品进口的宏观和微观经济效益很重要,但对当地农业有很多不利影响。食品进口通过在国内市场供应便宜和补贴的食品来影响当地农业。廉价食品是当地食物生产者的强大竞争对手,生产缺陷并没有比较优势。对较便宜的食品需求增加,对本地生产的食品的需求下降,收入也将下降。宏观经济上的损失是,收入减少意味着对劳动力,土地,资本和企业家精神的再投资减少。没有足够的收入,工厂裁员这样的事情就会发生,一贯的就业可能导致暴力犯罪和大规模迁移到城市。国内农业产值增长放缓,影响国内生产总值和出口额和收入。此外,继续在这一行业中的动力将会慢慢减少,因此,国家在国内保障粮食安全的能力将面临风险。食品进口将当地农业暴露于植物和动物疾病,如果农业检疫官员没有妥善检查,可能会造成严重后果。一种植物病害可以破坏整个农场或柑橘产业,积累了数百万美元的收入或治疗费用。另外,如果人类食用受污染的进口食品,可能会导致病情恶化,从而对国内医疗行业造成进一步压力。共有六个独立变量和一个因变量包括回归估计分析。有两个不同结果的回归分析和一个对回归有重要意义的控制变量。平均汇率对GdP的农业百分比值有显着影响,而在可变平均汇率每上涨1%的情况下,农业部门GdP的百分比值将上升77%或49%。从回归结果来看,出口收益对农业产生积极影响,将导致行业行业GdP百分比增长26%。外债股票被认为是显著,与GdP这里农业百分比值将下降至71%。食品进口和外商直接投资变动1%,当地农业生产总值百分比值分别下降14%和12%。因此,我们可以假设牙买加大多数的直接外资都是流入了非农业部门。事实上,牙买加的大部分外国直接投资都是流入当地的服务和旅游部门。根据回归结果,产出增长对于行业发展至关重要,在此基础上,我提出了在本研究的最后一章全面解释的建议。为了减少土地的损耗,使用可在户外进行的垂直耕作方式,这是一种非常具有成本效益的方法。帮助农民升级自己的农场,从而降低与时间和延误相关的成本。对每一美元的外币购买征收JMd 3.00美元的费用来购买有当地替代品的商业食品。制定和引入牙买加作为独特竞争优势和零评级项目的物品配额制度。例如,胡萝卜,卷心菜和番茄,尽管有100%的税率,当地也有产量,但还有很大一部分是进口的。但通过与食品进口商合作,投资农业设备和土地来支持当地农民,从而提高生产力,并保持供应的一致性。虽然政府增加了农户贷款的数量和利用率,但利率是许多农民利用这些贷款的障碍。因此,赠款的可用性可以帮助农民面临财务挑战。修改酒店投资和激励政策,包括联合本地国内农业食品采购。这项研究有助于未来的研究和文献,因为回归分析结果的新的经验数据表明,食品进口确实影响到农业的GdP百分比值。回归估计的结果表明,食品进口成本与GdP的农业百分比值呈负相关。虽然关系是负面的结构性政策修改可以将结果改变为积极的,从而缩小食品出口和进口之间的差距。最后,将食品进口组成主要由原材料组成,农业投入物和本地不栽培的食品可以改变回归分析的结果。这里的结论是,通过合作并纳入一些新政策来对粮食进口进行适当管理和监测,而不是妨碍国内农业增长。所以结果应该对两个行业都有一定的后果。本研究的以下章节包括进一步讨论关于食品进口动机及其对农业发展的影响的信息和支持性数据。

关键词：农业发展农业农业生产食品进口出口国内生产总值(GdP)国际贸易回归分析贸易协议