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中国冶金 2024年第2期34卷 61-68页

作者：吕明薛魁习晓峰郭红民梁少鹏张朝晖西安建筑科技大学冶金工程学院陕西西安710055 陕西龙门钢铁有限责任公司陕西韩城715405

直接轧制工艺中常存在铸坯头尾温差大的问题,控制铸坯温度的均匀性有利于减小棒材性能波动,对棒材生产具有重要意义。利用数值模拟研究了铸坯切断后不同部位的温度场变化,发现3 m/min拉速下,铸坯切断后头尾表面温差约为85℃,且其随运输... 详细信息

直接轧制工艺中常存在铸坯头尾温差大的问题,控制铸坯温度的均匀性有利于减小棒材性能波动,对棒材生产具有重要意义。利用数值模拟研究了铸坯切断后不同部位的温度场变化,发现3 m/min拉速下,铸坯切断后头尾表面温差约为85℃,且其随运输时间增加而减小,但运输时间过长会导致铸坯温度无法满足轧制要求。针对铸坯头尾温差大的问题,提出了在连铸切割机后增设阶段冷却装置,同样利用数值模拟研究了增设阶段冷却装置对铸坯温度场的影响。结果表明,增设阶段冷却装置可有效减小连铸坯头尾温差,水流密度与铸坯长度基本呈抛物线关系,出冷却装置时的连铸坯头尾温差降低至约35℃,粗轧机入口处铸坯中部的芯表温差减小约9℃,尾部的芯表温差增大约19℃,阶段冷却装置对芯表温差的影响基本消除。根据计算结果对阶段冷却装置的关键工艺参数进行设计,利用某企业生产线进行阶段应用试验,对棒材屈服强度和抗拉强度等力学性能进行研究,发现屈服强度和抗拉强度的波动范围为30 MPa,棒材性能均匀性得到有效控制,同时棒材屈服强度远高于415 MPa的要求,为减少炼钢过程的合金消耗提供了有利条件。研究结果为阶段冷却装置实际应用提供参考和依据,同时为钢铁企业控制铸坯头尾温差和棒材性能均匀性提供了新思路。

关键词：方坯连铸直接轧制数值模拟头尾温差力学性能

Comparison of Minimal Skin Incision Technique in living Kidney Transplantation and Conventional Kidney Transplantation

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Chinese Medical Journal 2016年第8期129卷 917-921页

作者： Sang-Dong Kim Ji-II Kim In-Sung Moon Sun-Cheol park Department of Surgery Division of Vascular and Transplant Surgery College of Medicine The Catholic University of Korea Seoul 137-040 Korea

Background：Recently,the most common incision for kidney transplantation （KT） is an inverted J-shaped incision known as the ＆quot;hockey-stick.＆quot; however,demands for minimally invasive surgery in KT are increasing as in other various fields of ***,we evaluated whether there is difference between minimal skin incision technique in kidney transplantation （MIKT） and conventional KT （CKT）.Methods：Between June 2006 and March 2013,a total of 452 living kidney transplant patients were *** MIKT group included 17 young unmarried women whose body mass index was 〈25 kg/m^2 and had no anatomic *** CKT group included 435 *** MIKT operation technique restricted to the 10 cm-sized skin incision in the lower right abdomen from laterally below the anterior superior iliac spine to the midline just above the pubis was *** compared the baseline clinical characteristics and postoperative results between two *** proper comparison,propensity score matching was ***：There was no difference in graft function,survival,and postoperative complication rate between MIKT and CKT groups （all P 〉 0.05）.The 5-year graft survival was 92.3% and 85.7% in MIKT and CKT groups,respectively （P =0.786）.Conclusions：Our results indicated that MIKT showed more favorable cosmetic results,and there were no statistical differences in various postoperative factors including graft function,survival,and complications compared with ***,we suggested that MIKT is an appropriate method for selected patients in living KT.

关键词： Kidney Transplantation Minimal Skin Incision: Conventional Kidney Transplantation

Calcium channel blocker monotherapy versus combination with reninangiotensin system inhibitors on the development of new-onset diabetes mellitus in hypertensive Korean patients

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Journal of Geriatric Cardiology 2019年第6期16卷 439-447页

作者： Yong hoon Kim Ae-Young her Seung-Woon Rha Byoung Geol Choi Se Yeon Choi Jae Kyeong Byun Yoonjee park Dong Oh Kang Won Young Jang Woohyeun Kim Woong Gil Choi Tae Soo Kang Jihun Ahn Sang-ho park Ji Young park Min-ho lee Cheol Ung Choi Chang Gyu park hong Seog Seo Division of Cardiology Department of Internal Medicine Kangwon National University School of Medicine Chuncheon South Korea Cardiovascular Center Korea University Guro Hospital Seoul South Korea Department of Medicine Korea University Graduate School Seoul South Korea Cardiology Department Konkuk University Chungju Hospital Chungju South Korea Department of Internal Medicine Cardiovascular Division Dankook University Hospital Cheonan South Korea Department of Cardiology Soonchunhyang University Gumi Hospital Gumi South Korea Cardiology Department Soonchunhyang University Cheonan Hospital Cheonan South Korea Division of Cardiology Department of Internal Medicine Cardiovascular Center Nowon Eulji Medical Center Eulji University Seoul South Korea Department of Cardiology Soonchunhyang University College of Medicine Seoul South Korea

Background In real practice, two or more antihypertensive drugs are needed to achieve target blood pressure. We investigated the comparative beneficial actions of combination therapy of renin-angiotensin system inhibitors (RASI), with calcium channel blockers (CCB) over CCB monotherapy on the development of new-onset diabetes mellitus (NODM) in Korean patients during four-year follow-up periods. Methods A total of 3208 consecutive hypertensive patients without a history of diabetes mellitus who had been prescribed CCB were retrospectively enrolled from January 2004 to December 2012. These patients were divided into the two groups according to the additional use of RASI (the RASI group, n = 1221 and the no RASI group, n = 1987). Primary endpoint was NODM, defined as a fasting blood glucose ≥ 126 mg/dl or hemoglobin A1c ≥ 6.5%. Secondary endpoint was major adverse cardiac events (MACE) defined as total death, myocardial infarction (MI) and percutaneous coronary intervention (PCI). Results After propensity score-matched (PSM) analysis, two propensity- matched groups (939 pairs, n = 1878, C-statistic = 0.743) were generated. The incidences of NODM (hR = 1.009, 95% CI: 0.700–1.452, P = 0.962), MACE (hR = 0.877, 95% CI: 0.544–1.413, P = 0.589), total death, MI, PCI were similar between the two groups after PSM during four years. Conclusions The use of RASI in addition to CCB showed comparable incidences of NODM and MACE compared to CCB monotherapy in non-diabetic hypertensive Korean patients during four-year follow-up period. however, large-scaled randomized controlled clinical trials will be required for a more definitive conclusion.

关键词： Calcium channel blocker Diabetes mellitus Renin-angiotensin system inhibitors

Recent advances in metasurface design and quantum optics applications with machine learning,physics-informed neural networks,and topology optimization methods

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光:科学与应用(英文版) 2023年第8期12卷 1494-1509页

作者： Wenye Ji Jin Chang he-Xiu Xu Jian Rong Gao Simon Groblacher h.Paul Urbach Aurele J.l.Adam Department of Imaging Physics Delft University of TechnologyLorentzweg 12628 CJ DelftThe Netherlands Department of Quantum Nanoscience Delft University of TechnologyLorentzweg 12628 CJ DelftThe Netherlands Shaanxi Key laboratory of Flexible Electronics(KloFE) Northwestern Polytechnical University(NPU)127 West Youyi RoadXi'an 710072China SRON Netherlands Institute for Space Research Niels Bohrweg 42333 CA LeidenThe Netherlands

As a two-dimensional planar material with low depth profile,a metasurface can generate non-classical phase distributions for the transmitted and reflected electromagnetic waves at its ***,it offers more flexibility to control the wave front.A traditional metasurface design process mainly adopts the forward prediction algorithm,such as Finite Difference Time Domain,combined with manual parameter ***,such methods are time-consuming,and it is difficult to keep the practical meta-atom spectrum being consistent with the ideal *** addition,since the periodic boundary condition is used in the meta-atom design process,while the aperiodic condition is used in the array simulation,the coupling between neighboring meta-atoms leads to inevitable *** this review,representative intelligent methods for metasurface design are introduced and discussed,including machine learning,physics-information neural network,and topology optimization *** elaborate on the principle of each approach,analyze their advantages and limitations,and discuss their potential *** also summarize recent advances in enabled metasurfaces for quantum optics *** short,this paper highlights a promising direction for intelligent metasurface designs and applications for future quantum optics research and serves as an up-to-date reference for researchers in the metasurface and metamaterial fields.

关键词： optics quantum topology

高压辊磨强化粗粒铁矿粉制备高品质球团的规律

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中国冶金 2024年第5期34卷 89-97页

作者：吕浩甘敏文小平赵改革谢路奔范晓慧张凯中南大学资源加工与生物工程学院湖南长沙410083 湖南华菱湘潭钢铁有限公司湖南湘潭411101 湘潭瑞通球团有限公司湖南湘潭411101 成都利君实业股份有限公司四川成都610045

利用粗粒铁矿粉替代部分铁精矿生产氧化球团可降低原料成本,然而粗粒铁矿粉中粗颗粒含量高、成球与焙烧性能不佳,导致其制备的球团强度低,因此难以大量配加。研究了高压辊磨预处理对粗粒铁矿粉制备氧化球团的影响。结果表明,高压辊磨后... 详细信息

利用粗粒铁矿粉替代部分铁精矿生产氧化球团可降低原料成本,然而粗粒铁矿粉中粗颗粒含量高、成球与焙烧性能不佳,导致其制备的球团强度低,因此难以大量配加。研究了高压辊磨预处理对粗粒铁矿粉制备氧化球团的影响。结果表明,高压辊磨后粒度大于1 mm粒级的粗粒铁矿粉含量显著降低,微细粒含量增加,比表面积增大;相较于提高辊磨压力,增加辊磨次数更有利于粗颗粒的破碎,此外粗粒铁矿粉的适宜给料水分较低。高压辊磨可以改善颗粒表面性质,增强粗粒铁矿粉的亲水性与成球性,有利于生球质量的提高;同时,在机械力作用下含铁矿物发生晶体活化,当辊磨压力提高至12 MPa以上时机械活化作用更强,这有利于颗粒间固相反应的进行,从而提高球团强度。采用粒度小于1 mm粒级的粗粒铁矿粉进行球团试验,与未处理的粗粒铁矿粉相比,经辊磨压力14 MPa、给料水分(质量分数)3.5%、两次开路辊磨处理后,在相同的球团制备工艺下,粗粒铁矿粉配比(质量分数)可由15%提高至30%;当保持粗粒铁矿粉配比为15%时,焙烧球强度可提高589 N/个。研究结果为拓宽球团原料种类、降低预处理能耗与球团成本提供了理论和技术指导。

关键词：粗粒铁矿粉高压辊磨机械活化氧化球团抗压强度

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An integrative multivariate approach for predicting functional recovery using magnetic resonance imaging parameters in a translational pig ischemic stroke model

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Neural Regeneration Research 2021年第5期16卷 842-850页

作者： Erin E.Kaiser J.C.Poythress Kelly M.Scheulin Brian J.Jurgielewicz Nicole A.lazar Cheolwoo park Steven l.Stice Jeongyoun Ahn Franklin D.West Regenerative Bioscience Center University of GeorgiaAthensGAUSA Neuroscience Biomedical and Health Sciences InstituteUniversity of GeorgiaAthensGAUSA Department of Animal and Dairy Science College of Agricultural and Environmental SciencesUniversity of GeorgiaAthensGAUSA Department of Statistics Franklin College of Arts and SciencesUniversity of GeorgiaAthensGAUSA

Magnetic resonance imaging(MRI)is a clinically relevant,real-time imaging modality that is frequently utilized to assess stroke type and ***,specific MRI biomarkers that can be used to predict long-term functional recovery are still a critical ***,the present study sought to examine the prognostic value of commonly utilized MRI parameters to predict functional outcomes in a porcine model of ischemic *** was induced via permanent middle cerebral artery *** 24 hours post-stroke,MRI analysis revealed focal ischemic lesions,decreased diffusivity,hemispheric swelling,and white matter *** deficits including behavioral abnormalities in open field and novel object exploration as well as spatiotemporal gait impairments were observed at 4 weeks *** graphical models identified specific MRI outputs and functional recovery variables,including white matter integrity and gait performance,that exhibited strong conditional *** correlation analysis revealed a prognostic relationship between lesion volume and white matter integrity and novel object exploration and gait ***,these analyses may also have the potential of predicting patient recovery at chronic time points as pigs and humans share many anatomical similarities(e.g.,white matter composition)that have proven to be critical in ischemic stroke *** study was approved by the University of Georgia(UGA)Institutional Animal Care and Use Committee(IACUC;Protocol Number:A2014-07-021-Y3-A11 and 2018-01-029-Y1-A5)on November 22,2017.

关键词： behavior testing canonical correlation analysis gait analysis Gaussian graphical models ischemic stroke magnetic resonance imaging pig model principal component analysis

Primary needle-knife fistulotomy for preventing post-endoscopic retrograde cholangiopancreatography pancreatitis:Importance of the endoscopist’s expertise level

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World Journal of Clinical Cases 2021年第17期9卷 4166-4177页

作者： Sung Yong han Dong hoon Baek Dong Uk Kim Chang Joon park Young Joo park Moon Won lee Geun Am Song Division of Gastroenterology and hepatology Internal Medicine and Biomedical Research InstitutePusan National University HospitalBusan 49241South Korea

BACKGROUND Needle-knife fistulotomy(NKF)is used as a rescue technique for difficult ***,the data are limited regarding the use of NKF for primary biliary cannulation,especially when performed by *** To assess the effectiveness and safety of primary NKF for biliary cannulation,and the role of the endoscopist’s expertise level(beginner vs expert).METhODS We retrospectively evaluated the records of 542 patients with naïve prominent bulging papilla and no history of pancreatitis,who underwent bile duct cannulation at a tertiary referral *** patients were categorized according to the endoscopist’s expertise level and the technique used for bile duct *** assessed the rates of successful cannulation and adverse *** The baseline characteristics did not differ between the experienced and lessexperienced *** incidence rate of post-endoscopic retrograde cholangiopancreatography(ERCP)pancreatitis(PEP)was significantly affected by the endoscopist’s expertise level in patients who received conventional cannulation with sphincterotomy(8.9%vs 3.4%for beginner vs expert,P=0.039),but not in those who received *** the multivariable analysis,a lower expertise level of the biliary endoscopist(P=0.037)and longer total procedure time(P=0.026)were significant risk factor of PEP in patients who received conventional cannulation with sphincterotomy but only total procedure time(P=0.004)was significant risk factor of PEP in those who received *** Primary NKF was effective and safe in patients with prominent and bulging ampulla,even when performed by less-experienced *** need to confirm which level of endoscopist’s experience is needed for primary NKF through prospective randomized study.

关键词： Needle-knife fistulotomy Primary biliary cannulation Endoscopic retrograde cholangiopancreatography Expertise levels Pancreatitis

还原剂和水蒸汽对钯催化NO还原反应性能的影响

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贵金属 2024年第2期45卷 52-58页

作者：吴柄贤王成雄徐滢覃庆高郭律赵云昆昆明贵金属研究所稀贵金属综合利用新技术国家重点实验室昆明650106 昆明贵研催化剂有限责任公司贵金属催化技术与应用国家地方联合工程研究中心昆明650106

为满足严格的排放法规,在控制好NO_(x)排放的同时,也需减少N_(2)O、Nh_(3)等二次污染物的排放。为探究尾气组分对NO_(x)还原产物的影响,本文用催化活性模拟评价装置,对自制单钯三效催化剂,进行了还原剂种类、CO浓度及水蒸汽浓度对NO转... 详细信息

为满足严格的排放法规,在控制好NO_(x)排放的同时,也需减少N_(2)O、Nh_(3)等二次污染物的排放。为探究尾气组分对NO_(x)还原产物的影响,本文用催化活性模拟评价装置,对自制单钯三效催化剂,进行了还原剂种类、CO浓度及水蒸汽浓度对NO转化效率及N_(2)O和Nh_(3)生成产物的影响研究。结果表明,CO催化还原NO是导致N_(2)O生成的主要原因,其内在本质在于催化剂表面活性氧物种的协同作用,Nh_(3)的生成量在150~400℃范围内与反应温度正相关;水蒸汽的加入会促进N_(2)O和Nh_(3)的生成,h2O分子在催化剂表面吸附作用抑制了活性氧物种的消耗;增加CO浓度可抑制N_(2)O生成但会促进Nh_(3)生成。

关键词：单钯催化剂一氧化碳水蒸汽一氧化二氮氨

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柱前荧光衍生化法检测降尘样品中的不饱和醛

分析科学学报 2024年第2期40卷 153-158页

作者：黄露杰徐静汪耀吕敏崔玉洁何振宇林亚维武汉理工大学化学化工与生命科学学院湖北武汉430070 武汉市疾病预防控制中心湖北武汉430060

本研究发展了一种柱前荧光衍生化方法,实现了重要环境污染物不饱和醛类化合物的高灵敏度、高选择性分析。该方法使用4-丁基羟氨-7-羟基香豆素(hAhC)作为荧光衍生试剂,结合高效液相色谱-荧光检测法(hPlC-FlD)实现了6种二烯醛的定性、定... 详细信息

本研究发展了一种柱前荧光衍生化方法,实现了重要环境污染物不饱和醛类化合物的高灵敏度、高选择性分析。该方法使用4-丁基羟氨-7-羟基香豆素(hAhC)作为荧光衍生试剂,结合高效液相色谱-荧光检测法(hPlC-FlD)实现了6种二烯醛的定性、定量分析。在实际样品分析中成功从积尘样品中检测出(E,E)-2,4-庚二烯醛、(E,E)-2,4-辛二烯醛、(E,E)-2,4-十一烷二烯醛。这种柱前衍生化法具有动态范围宽(2~2500nmol/l)、灵敏高(检出限为0.2nmol/l)、精密度好(日内相对标准偏差为2.17%~3.33%,日间相对标准偏差为2.28%~5.04%)等优点,且无需固相萃取等复杂前处理步骤,为痕量醛类污染物检测提供了有效手段。

关键词：硝酮化衍生法不饱和醛高效液相色谱-荧光检测法 4-羟氨基丁基-7-甲氧基-香豆素