|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | 磁赤铁矿的几种类型与特点分析显示文摘随着环境磁学的广泛开展和应用,最近20年来磁赤铁矿(γ-Fe2O3)被人们所日益熟悉.现在它已经被发现是一种地表十分常见的矿物,与磁铁矿常常相伴随,是氧化透水通气环境的很好指示矿物.它也是制造音乐和录像磁带的重要磁性材料,在工业有很广泛的用途.磁赤铁矿的人工合成一般由磁铁矿通过在低于300℃的氧化环境中加热几个小时甚至几天时间来形成.它受热不稳定而产生化学变化的磁学性质是其重要特点,即加热到250℃之后该矿物一般就会被不同程度转变成为赤铁矿.因此实际上无法测量其居里点.后来对人工合成磁赤铁矿样品研究进一步发现,该矿物受热可以部分热稳定,居里温度约为645℃.本文通过不同粒度人工磁铁矿系列样品进行热磁测量实验时发现,超细粒级(假单畴(PSD)和多畴(MD)细粒)磁铁矿在快速加热过程中,形成了完全热稳定的磁赤铁矿.而且,用同样的样品在另外加热炉中快速加热到700℃高温,并且在该温度停留10min,然后冷却下来,也可以达到相同的效果.即由此两个过程形成的磁赤铁矿,再从室温加到700℃的居里温度测量过程几乎达到百分之百可逆,即完全对热稳定性特点.我们用X衍射和穆斯堡尔谱技术来鉴定和确认加热前的磁铁矿和快速加热形成的磁赤铁矿(和赤铁矿),并且比较其磁铁矿的磁滞迴线、高温磁化强度、低温热退磁和低温磁化率特性,结果表明,这种过程通过超细磁铁矿加热快速氧化形成完全可逆具有热稳定性质的磁赤铁矿,可能暗示着在某些加热环境形成的磁赤铁矿也可能携带热剩磁.根据磁赤铁矿是否受热不稳定及其表现形式,将它详细分成4种类型探讨分析.受热后部分稳定和完全稳定的磁赤铁矿应当具备携带热剩磁的能力.人工合成磁赤铁矿的温度与其反应时间可能有个互补关系.磁赤铁受热后稳定与否可能与多种因素有关,如受纯度大小、受热温度高低和时间长短等影响,粒度大小可能也是重要因素之一.磁赤铁矿可能如同磁铁矿,也有不同粒级超顺磁(SP)、单畴(SD)和MD对应着不同的磁学特点.细粒PSD氧化的人工磁铁矿在低温磁学测量显示为Verwey转换被'抑制'的现象,其根本原因可能是,氧化后磁铁矿的内核直径实际上已经达到或者接近该矿物的SD粒径,所以它的Verwey转换显得被'抑制'. | 刘秀铭 John SHAW 蒋建中 Jan BLOEMENDAL Paul HESSE Tim ROLPH 毛学刚 | 2010 | 中国科学:地球科学2010,40,5: | 20 |
| 2 | Current status of laparoscopic and robotic ventral mesh rectopexy for external and internal rectal prolapse显示文摘External and internal rectal prolapse with their affiliated rectocele and enterocele, are associated with debilitating symptoms such as obstructed defecation, pelvic pain and faecal incontinence. Since perineal procedures are associated with a higher recurrence rate, an abdominal approach is commonly preferred. Despite the description of greater than three hundred different procedures, thus far no clear superiority of one surgical technique has been demonstrated. Ventral mesh rectopexy(VMR) is a relatively new and promising technique to correct rectal prolapse. In contrast to the abdominal procedures of past decades, VMR avoids posterolateral rectal mobilisation and thereby minimizes the risk of postoperative constipation. Because of a perceived acceptable recurrence rate, good functional results and low mesh-related morbidity in the short to medium term, VMR has been popularized in the past decade. Laparoscopic or robotic-assisted VMR is now being progressively performed internationally and several articles and guidelines propose the procedure as the treatment of choice for rectal prolapse. In this article, an outline of the current status of laparoscopic and robotic ventral mesh rectopexy for the treatment of internal and external rectal prolapse is presented. | Jan J van Iersel Tim JC Paulides Paul M Verheijen John W Lumley Ivo AMJ Broeders Esther CJ Consten | 2016 | World Journal of Gastroenterology2016,22,21: | 20 |
| 3 | Unique,Persistent,Resolvable:Identifiers as the Foundation of FAIR显示文摘The FAIR principles describe characteristics intended to support access to and reuse of digital artifacts in the scientific research ecosystem.Persistent,globally unique identifiers,resolvable on the Web,and associated with a set of additional descriptive metadata,are foundational to FAIR data.Here we describe some basic principles and exemplars for their design,use and orchestration with other system elements to achieve FAIRness for digital research objects. | Nick Juty Sarala M.Wimalaratne Stian Soiland-Reyes John Kunze Carole A.Goble Tim Clark | 2020 | Data Intelligence2020,2,1: | 11 |
| 4 | The second European evidence-based Consensus on the diagnosis and management of Crohn’s disease: Definitions and diagnosis显示文摘 | Gert Van Assche Axel Dignass Julian Panes Laurent Beaugerie John Karagiannis Mathieu Allez Thomas Ochsenkühn Tim Orchard Gerhard Rogler Edouard Louis Limas Kupcinskas Gerassimos Mantzaris Simon Travis Eduard Stange | 2009 | Journal of Crohn’s and Colitis2009,,1: | 10 |
| 5 | Record-Setting Ocean Warmth Continued in 2019显示文摘Human-emitted greenhouse gases(GHGs)have resulted in a long-term and unequivocal warming of the planet(IPCC,2019).More than 90%of the excess heat is stored within the world's oceans,where it accumulates and causes increases in ocean temperature(Rhein et al.,2013;Abram et al.,2019). | Lijing CHENG John ABRAHAM Jiang ZHU Kevin ETRENBERTH John FASULLO Tim BOYER Ricardo LOCARNINI Bin ZHANG Fujiang YU Liying WAN Xingrong CHEN Xiangzhou SONG Yulong LIU Michael EMANN | 2020 | Advances in Atmospheric Sciences2020,37,2: | 7 |
| 6 | Analysis of roof and pillar failure associated with weak floor at a limestone mine显示文摘A limestone mine in Ohio has had instability problems that have led to massive roof falls extending to the surface. This study focuses on the role that weak, moisture-sensitive floor has in the instability issues.Previous NIOSH research related to this subject did not include analysis for weak floor or weak bands and recommended that when such issues arise they should be investigated further using a more advanced analysis. Therefore, to further investigate the observed instability occurring on a large scale at the Ohio mine, FLAC3 D numerical models were employed to demonstrate the effect that a weak floor has on roof and pillar stability. This case study will provide important information to limestone mine operators regarding the impact of weak floor causing the potential for roof collapse, pillar failure, and subsequent subsidence of the ground surface. | Murphy Michael M. Ellenberger John L. Esterhuizen Gabriel S. Miller Tim | 2016 | International Journal of Mining Science and Technology2016,26,3: | 5 |
| 7 | Liver Transplantation for Nonresectable Liver Metastases From Colorectal Cancer显示文摘 | Morten Hagness Aksel Foss P?l-Dag Line Tim Scholz P?l Foyn J?rgensen Bjarte Fosby Kirsten Muri Boberg ?ystein Mathisen Ivar P. Gladhaug Tor Skatvedt Egge Steinar Solberg John Hausken Svein Dueland | 2013 | Annals of Surgery2013,,5: | 4 |
| 8 | Ampullary cancer of intestinal origin and duodenal cancer-A logical clinical and therapeutic subgroup in periampullary cancer显示文摘Periampullary cancers include pancreatic, ampullary, biliary and duodenal cancers. At presentation, the majority of periampullary tumours have grown to involve the pancreas, bile duct, ampulla and duodenum. This can result in difficulty in defining the primary site of origin in all but the smallest tumors due to anatomical proximity and architectural distortion. This has led to variation in the reported proportions of resected periampullary cancers. Pancreatic cancer is the most common cancer resected with a pancreaticoduodenectomy followed by ampullary(16%-50%), bile duct(5%-39%), and duodenal cancer(3%-17%). Patients with resected duodenal and ampullary cancers have a better reported median survival(29-47 mo and 22-54 mo) compared to pancreatic cancer(13-19 mo). The poorer survival with pancreatic cancer relates to differences in tumour characteristics such as a higher incidence of nodal, neural and vascular invasion. While small ampullary cancers can present early with biliary obstruction, pancreatic cancers need to reach a certain size before biliary obstruction ensues. This larger size at presentation contributes to a higher incidence of resection margin involvement in pancreatic cancer. Ampullary cancers can be subdivided into intestinal or pancreatobiliary subtype cancers with histomolecular staining. This avoids relying on histomorphology alone, as even some poorly differentiated cancers preserve the histomolecular profile of their mucosa of origin. Histomolecular profiling is superior to anatomic location in prognosticating survival. Ampullary cancers of intestinal subtype and duodenal cancers are similar in their intestinal origin and form a logical clinical and therapeutic subgroup of periampullary cancers. They respond to 5-FU based chemotherapeutic regimens such as capecitabine-oxaliplatin. Unlike pancreatic cancers, KRAS mutation occurs in only approximately a third of ampullary and duodenal cancers. Future clinical trials should group ampullary cancers of intestinal origin and duodenal cancers together given their similarities and their response to fluoropyrimidine therapy in combination with oxaliplatin. The addition of anti-epidermal growth factor receptor therapy in this group warrants study. | Manju D Chandrasegaram Anthony J Gill Jas Samra Tim Price John Chen Jonathan Fawcett Neil D Merrett | 2017 | World Journal of Gastrointestinal Oncology2017,9,10: | 4 |
| 9 | Gemcitabine-based or capecitabine-based chemoradiotherapy for locally advanced pancreatic cancer (SCALOP): a multicentre, randomised, phase 2 trial显示文摘 | Somnath Mukherjee Christopher N Hurt John Bridgewater Stephen Falk Sebastian Cummins Harpreet Wasan Tom Crosby Catherine Jephcott Rajarshi Roy Ganesh Radhakrishna Alec McDonald Ruby Ray George Joseph John Staffurth Ross A Abrams Gareth Griffiths Tim Maugh | 2013 | Lancet Oncology2013,,4: | 4 |
| 10 | 英格兰和威尔士地区儿童恶性肿瘤与高压输电线距离的关系:一项病例-对照研究显示文摘目的 确定英格兰和威尔士地区儿童白血病及其他癌症发病率是否与其出生时家庭地址与高压电线的距离存在关系。设计 病例-对照研究。设置 癌症登记处和国家电力供应网的记录。对象1962-1995年,英格兰和威尔士地区出生的0-14岁的29081名癌症患儿中包括9700名白血病患儿。对照组依照性别、大致相同的出生日期、出生登记处等予以个体匹配。并不强求积极参与。主要结果测定 儿童出生时的家庭地址与当时最近的高架高压输电线问的距离(以下有时简称为距离)。结果 与生活在距输电线超过600米的儿童相比,距输电线200米之内的儿童患白血病的相对危险度为1.69(95%可信区间为1.13-2.53);200-600米间的发病相对危险度为1.23(1.02-1.49)。白血病发病风险与输电线相互距离的倒数存在显著相关性(P〈0.01)。毗邻输电线未发现增加儿童其他癌症的额外发病风险。结论 儿童白血病发病风险与出生时家庭地址距高压电线的远近存在相关关系,且风险程度超出了以往研究的预期。在英格兰和威尔士地区,出生时生活在距离高压输电线600米内的白血病患儿约占4%。如果这种相关是偶然的,那么在该地区约1%的儿童白血病是由于高压输电线导致的,尽管这种估计在统计学上具有相当的不确定性。没有其他可接受的生物学机制来解释这些流行病学结果;事实上这种联系可能源于偶然或混杂。 | Gerald Draper Tim Vincent Mary E Kroll John Swanson 李勇 | 2005 | 英国医学杂志中文版2005,8,6: | 4 |
| 11 | Physiological roles of NAADP-mediated Ca^(2+) signaling显示文摘Nicotinic acid dinucleotide phosphate(NAADP) is unique amongst Ca2+ mobilizing messengers in that its principal function is to mobilize Ca2+ from acidic organelles.Early studies indicated that it was likely that NAADP activates a novel Ca2+ release channel distinct from the well characterized Ca2+ release channels on the(sarco) -endoplasmic reticulum(ER) ,inositol trisphosphate and ryanodine receptors.In this review,we discuss the emergence of a novel family of endolysosomal channels,the two-pore channels(TPCs) ,as likely targets for NAADP,and how molecular and pharmacological manipulation of these channels is enhancing our understanding of the physiological roles of NAADP as an intracellular Ca2+ mobilizing messenger. | Antony GALIONE John PARRINGTON Tim FUNNELL | 2011 | Science China(Life Sciences)2011,54,8: | 4 |
| 12 | Analysis on variety and characteristics of maghemite显示文摘Maghemite (γ-Fe2O3) is a very common mineral at the earth’s surface and also an important material for making music and video tapes. Maghemite is usually synthesized from magnetite under oxidizing conditions after a few hours or a few days below a temperature of 300°C. The magnetic property of thermal instability and the chemical action after heating is an important character for maghemite. That is, it will become hematite in certain proportion after being heated above 250°C. Maghemite is therefore actually unable to have its Curie temperature measured. But late using synthetic sample, maghemite was further found partially thermal stable with a measurable Curie temperature ~645°C. During our thermally magnetic experiments for a set of synthetic magnetite, we found that extra fined grain size (pseudo single domain (PSD) and small multi-domain (MD), mainly 1-10 μm) magnetite was formed to a completely thermally stable maghemite. This maghemite can also be produced by heating the same powder up to 700°C in an oven and keeping this temperature for 10 min, then cooling it down. When the generated maghemite by these two ways is heated from room temperature to 700°C, it shows almost fully reversible, or thermally stable. We used X-ray powder diffraction and Mssbauer spectroscopy to confirm the identity of this maghemite and compared its magnetic hysteresis, high temperature magnetization, low temperature thermal demagnetization, and low temperature susceptibility with those of the original preheated magnetite. Such quickly oxidized maghemite by heating to high temperature implies some types of maghemite formed in certain natural condition can carry a thermal remnant magnetization (TRM). Four types of maghemite were characterized and discussed according to their thermal stability. Among them, partially stable and fully thermally stable maghemite after heating should possess capability of carrying TRM. There is possibly a compensation of synthetizing maghemite between heating temperature and heating duration. The thermal stability of maghemite may be affected by a few factors, such as its purity (stoichiometry), heating temperature and duration. The grain size may be one of important factors. Maghemite might be similar to magnetite, having various magnetic properties corresponding to its grain size categories such as superparamagnetic (SP), single domain (SD) and MD. Low temperature measurement for PSD fine grain of synthetic magnetite shows a phenomenon of Verwey transition 'suppressed', its fundamental causes could be that the core diameter of oxidized magnetite is actually reach or approach SD size, so that its Verwey transition is shown 'suppressed'. | SHAW John BLOEMENDAL Jan HESSE Paul ROLPH Tim | 2010 | Science China Earth Sciences2010,53,8: | 3 |
| 13 | Upper Ocean Temperatures Hit Record High in 2020显示文摘The long-term warming of the ocean is a critical indicator of both the past and present state of the climate system. It also provides insights about the changes to come, owing to the persistence of both decadal variations and secular trends,which the ocean records extremely well(Hansen et al., 2011;IPCC, 2013;Rhein et al., 2013;Trenberth et al., 2016;Abram et al., 2019). | Lijing CHENG John ABRAHAM Kevin ETRENBERTH John FASULLO Tim BOYER Ricardo LOCARNINI Bin ZHANG Fujiang YU Liying WAN Xingrong CHEN Xiangzhou SONG Yulong LIU Michael EMANN Franco RESEGHETTI Simona SIMONCELLI Viktor GOURETSKI Gengxin CHEN Alexey MISHONOV Jim REAGAN Jiang ZHU | 2021 | Advances in Atmospheric Sciences2021,38,4: | 2 |
| 14 | Anterior Approach Versus Conventional Approach Right Hepatic Resection for Large Hepatocellular Carcinoma: A Prospective Randomized Controlled Study显示文摘 | Chi Leung Liu Sheung Tat Fan Siu Tim Cheung Chung Mau Lo Irene O. Ng John Wong | 2006 | Annals of Surgery2006,,2: | 2 |
| 15 | Perforated jejunal ulcer associated with gastric mucosa in a jejunal diverticulum显示文摘Jejunal diverticula are rare and subsequent complications even more so. The usual small bowel diverticulum encountered by general surgeons is a Meckel's. These are embryological remnants of the vitello-intestinal duct and are on the anti-mesenteric surface of the terminal ileum. They may contain heterotopic gastric or pancreatic mucosa. Herein we explore the case of a young girl who presented with features of peritonitis secondary to a complication from a jejunal diverticulum. The case, pathology, complications and treatment of jejunal diverticulosis and heterotopic gastric mucosa in the jejunum are explored. | John Bunni Helen L Barrett Tim A Cook | 2014 | World Journal of Clinical Cases2014,2,6: | 2 |
| 16 | Systemic chemotherapy with or without cetuximab in patients with resectable colorectal liver metastasis: the New EPOC randomised controlled trial显示文摘 | John Primrose Stephen Falk Meg Finch-Jones Juan Valle Derek O’Reilly Ajith Siriwardena Joanne Hornbuckle Mark Peterson Myrddin Rees Tim Iveson Tamas Hickish Rachel Butler Louise Stanton Elizabeth Dixon Louisa Little Megan Bowers Sian Pugh O James Garden D | 2014 | Lancet Oncology2014,,6: | 2 |
| 17 | B/M极性转换过程与虚磁极转移路径显示文摘利用超导磁力仪对西峰黄土剖面记录的布容/松山(B/M)地磁极性转换过程的高分辨率研究表明,B/M极性转换经历了由负极性到正极性的五次反复倒转;转换过程中地磁场的强度衰减到正常值的约30%,场强的衰减是极性转换的前奏,而地磁场方向完全倒转后的场强恢复,是转换的最后一幕;极性转换所需的时间约2万年,从场强的开始衰减到反向恢复则需要更长的时间;极性转换的虚地磁极(VGP)转移路径大多连续,并落于一定的径度带内,包括美洲径度带、大西洋径度带和非洲径度带。西峰剖面记录的B/M转换VGP路径并未落入美洲和印度洋这两个高密径度带内。 | 孙东怀 John Shaw 郑洪波 马醒华 Tim Rolph | 1994 | 自然科学进展(国家重点实验室通讯)1994,4,4: | 2 |
| 18 | An evidence-based clinical guideline for the diagnosis and treatment of lumbar disc herniation with radiculopathy显示文摘 | D. Scott Kreiner Steven W. Hwang John E. Easa Daniel K. Resnick Jamie L. Baisden Shay Bess Charles H. Cho Michael J. DePalma Paul Dougherty Robert Fernand Gary Ghiselli Amgad S. Hanna Tim Lamer Anthony J. Lisi Daniel J. Mazanec Richard J. Meagher Robert C | 2014 | The Spine Journal2014,,: | 2 |
| 19 | Reduced striatal volumes in Parkinson’s disease:a magnetic resonance imaging study显示文摘Background:The presence and extent of structural changes in the brain as a consequence of Parkinson’s disease(PD)is still poorly understood.Methods:High-resolution 3-tesla T1-weighted structural magnetic resonance images in sixty-five PD and 27 age-matched healthy control participants were examined.Putamen,caudate,and intracranial volumes were manually traced in the axial plane of 3D reconstructed images.Striatal nuclei volumes were normalized to intracranial volume for statistical comparison.Disease status was assessed using the Unified Parkinson’s Disease Rating Scale and Hoehn and Yahr scale.Cognitive status was assessed using global status tests and detailed neuropsychological testing.Results:Both caudate and putamen volumes were smaller in PD brains compared to controls after adjusting for age and gender.Caudate volumes were reduced by 11%(p=0.001)and putamen volumes by 8.1%(p=0.025).PD striatal volumes were not found to be significantly correlated with cognitive or motor decline.Conclusion:Small,but significant reductions in the volume of both the caudate and putamen occur in PD brains.These reductions are independent of the effects of age and gender,however the relation of these reductions to the functional loss of dopamine,which is characteristic of PD,remains unclear. | Toni L Pitcher Tracy R Melzer Michael R MacAskill Charlotte F Graham Leslie Livingston Ross J Keenan Richard Watts John C Dalrymple-Alford Tim J Anderson | 2012 | Translational Neurodegeneration2012,1,1: | 2 |
| 20 | TRUST VIOLATION IN ELECTRONIC COMMERCE: CUSTOMER CONCERNS AND REACTIONS显示文摘 | Goles Tim Lee Simon Rao Srinivasan V Warren John | 2009 | The Journal of Computer Information Systems2009,,4: | 2 |