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Comparison between ozonesonde measurements and satellite retrievals over Beijing,China 被引量:1
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作者 Jinqiang Zhang Yuejian Xuan +5 位作者 Jianchun Bian Holger Vomel Yunshu Zeng Zhixuan Bai Dan Li Hongbin Chen 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第1期14-20,共7页
从2013年开始,作者团队使用自主研发电化学原理臭氧探空仪在华北平原北京地区进行每周一次观测.本研究首次使用2013-2019年期间北京地区臭氧探空数据评估Aqua卫星搭载大气红外探测仪(AIRS)和Aura卫星搭载微波临边探测器(MLS)反演垂直臭... 从2013年开始,作者团队使用自主研发电化学原理臭氧探空仪在华北平原北京地区进行每周一次观测.本研究首次使用2013-2019年期间北京地区臭氧探空数据评估Aqua卫星搭载大气红外探测仪(AIRS)和Aura卫星搭载微波临边探测器(MLS)反演垂直臭氧廓线,并对比臭氧探空,AIRS和Aura卫星搭载臭氧监测仪(OMI)臭氧柱总量结果.尽管臭氧探空与卫星反演垂直臭氧廓线在局部高度处差异较大,但整体来说两者较为接近(相对偏差大多<10%).臭氧探空,AIRS和OMI三种仪器测量臭氧柱总量的年变化特征较为一致,其年均臭氧柱总量分别为351.8±18.4 DU,348.8±19.5 DU和336.9±14.2 DU.后续对国内多站点观测数据分析将有助于进一步理解臭氧探空与卫星反演臭氧资料在不同区域的一致性. 展开更多
关键词 臭氧探空 卫星反演 垂直臭氧廓线 臭氧柱总量 华北平原
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ABSOLUTE CONTINUITIES OF EXIT MEASURES AND TOTAL WEIGHTED OCCUPATION TIME MEASURES FOR SUPER-α-STABLE PROCESSES
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作者 张静 任艳霞 《Acta Mathematica Scientia》 SCIE CSCD 2006年第2期358-370,共13页
Suppose X is a super-α-stable process in R^d, (0 〈 α〈 2), whose branching rate function is dr, and branching mechanism is of the form ψ(z) = z^1+β (0 〈0 〈β ≤1). Let Xγ and Yγ denote the exit measur... Suppose X is a super-α-stable process in R^d, (0 〈 α〈 2), whose branching rate function is dr, and branching mechanism is of the form ψ(z) = z^1+β (0 〈0 〈β ≤1). Let Xγ and Yγ denote the exit measure and the total weighted occupation time measure of X in a bounded smooth domain D, respectively. The absolute continuities of Xγ and Yγ are discussed. 展开更多
关键词 Super-α-stable process absolute continuity exit measure total weighted occupation time measure
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Mid-term outcomes of a kinematically designed cruciate retaining total knee arthroplasty
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作者 Jonathan L Katzman Akram A Habibi +4 位作者 Muhammad A Haider Casey Cardillo Ivan Fernandez-Madrid Morteza Meftah Ran Schwarzkopf 《World Journal of Orthopedics》 2024年第2期118-128,共11页
BACKGROUND Advances in implant material and design have allowed for improvements in total knee arthroplasty(TKA)outcomes.A cruciate retaining(CR)TKA provides the least constraint of TKA designs by preserving the nativ... BACKGROUND Advances in implant material and design have allowed for improvements in total knee arthroplasty(TKA)outcomes.A cruciate retaining(CR)TKA provides the least constraint of TKA designs by preserving the native posterior cruciate ligament.Limited research exists that has examined clinical outcomes or patient reported outcome measures(PROMs)of a large cohort of patients undergoing a CR TKA utilizing a kinematically designed implant.It was hypothesized that the studied CR Knee System would demonstrate favorable outcomes and a clinically significant improvement in pain and functional scores.AIM To assess both short-term and mid-term clinical outcomes and PROMs of a novel CR TKA design.METHODS A retrospective,multi-surgeon study identified 255 knees undergoing a TKA utilizing a kinematically designed CR Knee System(JOURNEY™II CR;Smith and Nephew,Inc.,Memphis,TN)at an urban,academic medical institution between March 2015 and July 2021 with a minimum of two-years of clinical follow-up with an orthopedic surgeon.Patient demographics,surgical information,clinical outcomes,and PROMs data were collected via query of electronic medical records.The PROMs collected in the present study included the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement(KOOS JR)and Patient-Reported Outcomes Measurement Information System(PROMIS■)scores.The significance of improvements in mean PROM scores from preoperative scores to scores collected at six months and two-years postoperatively was analyzed using Independent Samples t-tests.RESULTS Of the 255 patients,65.5%were female,43.8%were White,and patients had an average age of 60.6 years.Primary osteoarthritis(96.9%)was the most common primary diagnosis.The mean surgical time was 105.3 minutes and mean length of stay was 2.1 d with most patients discharged home(92.5%).There were 18 emergency department(ED)visits within 90 d of surgery resulting in a 90 d ED visit rate of 7.1%,including a 2.4%orthopedic-related ED visit rate and a 4.7%non-orthopedic-related ED visit rate.There were three(1.2%)hospital readmissions within 90 d postoperatively.With a mean time to latest follow-up of 3.3 years,four patients(1.6%)required revision,two for arthrofibrosis,one for aseptic femoral loosening,and one for peri-prosthetic joint infection.There were significant improvements in KOOS JR,PROMIS Pain Intensity,PROMIS Pain Interference,PROMIS Mobility,and PROMIS Physical Health from preoperative scores to six month and two-year postoperative scores.CONCLUSION The evaluated implant is an effective,novel design offering excellent outcomes and low complication rates.At a mean follow up of 3.3 years,four patients required revisions,three aseptic and one septic,resulting in an overall implant survival rate of 98.4%and an aseptic survival rate of 98.8%.The results of our study demonstrate the utility of this kinematically designed implant in the setting of primary TKA. 展开更多
关键词 total knee arthroplasty Cruciate retaining Kinematic design SURVIVORSHIP Bearing material Prosthetic design Clinical outcomes Patient-reported outcome measures
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High rate of clinically relevant improvement following anatomical total shoulder arthroplasty for glenohumeral osteoarthritis
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作者 Marc Randall Kristensen Nyring Bo Sanderhoff Olsen +1 位作者 Alexander Amundsen Jeppe Vejlgaard Rasmussen 《World Journal of Orthopedics》 2024年第2期156-162,共7页
BACKGROUND The minimal clinically important difference(MCID)is defined as the smallest meaningful change in a health domain that a patient would identify as important.Thus,an improvement that exceeds the MCID can be u... BACKGROUND The minimal clinically important difference(MCID)is defined as the smallest meaningful change in a health domain that a patient would identify as important.Thus,an improvement that exceeds the MCID can be used to define a successful treatment for the individual patient.AIM To quantify the rate of clinical improvement following anatomical total shoulder arthroplasty for glenohumeral osteoarthritis.METHODS Patients were treated with the Global Unite total shoulder platform arthroplasty between March 2017 and February 2019 at Herlev and Gentofte Hospital,Denmark.The patients were evaluated preoperatively and 3 months,6 months,12 months,and 24 months postoperatively using the Western Ontario Osteoarthritis of the Shoulder index(WOOS),Oxford Shoulder Score(OSS)and Constant-Murley Score(CMS).The rate of clinically relevant improvement was defined as the proportion of patients who had an improvement 24 months postoperatively that exceeded the MCID.Based on previous literature,MCID for WOOS,OSS,and CMS were defined as 12.3,4.3,and 12.8 respectively.RESULTS Forty-nine patients with a Global Unite total shoulder platform arthroplasty were included for the final analysis.Mean age at the time of surgery was 66 years(range 49.0-79.0,SD:8.3)and 65%were women.One patient was revised within the two years follow-up.The mean improvement from the preoperative assessment to the two-year follow-up was 46.1 points[95%confidence interval(95%CI):39.7-53.3,P<0.005]for WOOS,18.2 points(95%CI:15.5-21.0,P<0.005)for OSS and 37.8 points(95%CI:31.5-44.0,P<0.005)for CMS.Two years postoperatively,41 patients(87%)had an improvement in WOOS that exceeded the MCID,45 patients(94%)had an improvement in OSS that exceeded the MCID,and 42 patients(88%)had an improvement in CMS that exceeded the MCID.CONCLUSION Based on three shoulder-specific outcome measures we find that approximately 90%of patients has a clinically relevant improvement.This is a clear message when informing patients about their prognosis. 展开更多
关键词 Minimal clinically important difference Patient reported outcome measures Glenohumeral osteoarthritis Anatomical total shoulder arthroplasty Clinically relevant improvement
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Reliability of preoperative measurement with standardized templating in Total Knee Arthroplasty 被引量:3
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作者 Daniel Hernandez-Vaquero Ferran Abat +1 位作者 Juan Sarasquete Juan Carlos Monllau 《World Journal of Orthopedics》 2013年第4期287-290,共4页
AIM: To investigate the correlation between preoperative measurement in total knee arthroplasty and the prosthetic size implanted. METHODS: A prospective double-blind study of 50 arthroplasties was performed. Firstly,... AIM: To investigate the correlation between preoperative measurement in total knee arthroplasty and the prosthetic size implanted. METHODS: A prospective double-blind study of 50 arthroplasties was performed. Firstly, the reliability and correspondence between the size of said measurement and the actual implant utilized was determined. Secondly, the existing correlation between the intra- and interobserver determinations with the intraclass correlation coefficient was analyzed. RESULTS: An overall correspondence of 54%, improving up to 92% when the measured size admitted a difference of one size, was found. Good intra- and interobserver reliability with an intraclass correlation coefficient greater than 0.90(P < 0.001) was also discovered. CONCLUSION: Agreement between the preoperative measurement with standardized acetate templates and the prosthetic size implanted can be considered satisfactory. We thus conclude it is a reproducible technique. 展开更多
关键词 total KNEE ARTHROPLASTY TEMPLATING PREOPERATIVE measurEMENT PROSTHETIC size Correlation coefficient
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Influence of characteristics' measurement sequence on total ionizing dose effect in PDSOI nMOSFET
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作者 解鑫 毕大伟 +4 位作者 胡志远 朱慧龙 张梦映 张正选 邹世昌 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第12期551-558,共8页
The influence of characteristics’ measurement sequence on total ionizing dose effect in partially-depleted SOI nMOSFET is comprehensively studied. We find that measuring the front-gate curves has no influence on tota... The influence of characteristics’ measurement sequence on total ionizing dose effect in partially-depleted SOI nMOSFET is comprehensively studied. We find that measuring the front-gate curves has no influence on total ionizing dose effect.However, the back-gate curves’ measurement has a great influence on total ionizing dose effect due to high electric field in the buried oxide during measuring. In this paper, we analyze their mechanisms and we find that there are three kinds of electrons tunneling mechanisms at the bottom corner of the shallow trench isolation and in the buried oxide during the backgate curves’ measurement, which are: Fowler–Nordheim tunneling, trap-assisted tunneling, and charge-assisted tunneling.The tunneling electrons neutralize the radiation-induced positive trapped charges, which weakens the total ionizing dose effect. As the total ionizing dose level increases, the charge-assisted tunneling is enhanced by the radiation-induced positive trapped charges. Hence, the influence of the back-gate curves’ measurement is enhanced as the total ionizing dose level increases. Different irradiation biases are compared with each other. An appropriate measurement sequence and voltage bias are proposed to eliminate the influence of measurement. 展开更多
关键词 total ionizing dose(TID) silicon-on-insulator(SOI) measurement sequence tunneling effect
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Questions on Optimization of Measurement of Total Electron Content in Ionosphere with GPS
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作者 Arif Shafayat Mehdiyev Ramiz Ahmed Eminov +1 位作者 Hikmat Hamid Asadov Natig Hajiaga Javadov 《Positioning》 2014年第3期66-69,共4页
The analysis of existing method for calculation of total content of electrons (TEC) in ionosphere using GPS occultation method does show that due to different values of signal/noise ration in GPS signals ?and , the ne... The analysis of existing method for calculation of total content of electrons (TEC) in ionosphere using GPS occultation method does show that due to different values of signal/noise ration in GPS signals ?and , the new method of optimum measurements of relevant frequency components of TEC measured by phase and code methods should be developed. The optimum quantity of measurements of the above-mentioned frequency components is determined taking into account the limitation imposed on general number of necessary measurements. 展开更多
关键词 GPS RECEIVER IONOSPHERE OPTIMIZATION total Electron Content measurements
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Comparison of clinical outcomes between total hip replacement and total knee replacement
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作者 Alexander Green Alex Walsh Oday Al-Dadah 《World Journal of Orthopedics》 2023年第12期853-867,共15页
BACKGROUND Total hip replacements(THR)and total knee replacements(TKR)are effective treatments for severe osteoarthritis(OA).Some studies suggest clinical outcomes following THR are superior to TKR,the reason for whic... BACKGROUND Total hip replacements(THR)and total knee replacements(TKR)are effective treatments for severe osteoarthritis(OA).Some studies suggest clinical outcomes following THR are superior to TKR,the reason for which remains unknown.This study compares clinical outcomes between THR and TKR.AIM To compare the clinic outcomes of THR anad TKR using a comprehensive range of patient reported outcome measures(PROMs).METHODS A prospective longitudinal observational study of patients with OA undergoing THR and TKR were evaluated using a comprehensive range of generic and joint specific PROMs pre-and post-operatively.RESULTS A total of 131 patients were included in the study which comprised the THR group(68 patients)and the TKR group(63 patients).Both groups demonstrated significant post-operative improvements in all PROM scores(P<0.001).There were no significant differences in post-operative PROM scores between the two groups:Hip and Knee Osteoarthritis Outcome scores(P=0.140),Western Ontario and McMaster Universities Osteoarthritis Index pain(P=0.297)stiffness(P=0.309)and function(P=0.945),Oxford Hip and Knee Score(P=0.076),EuroQol-5D index(P=0.386)and Short-Form 12-item survey physical component score(P=0.106).Subgroup analyses showed no significant difference(P>0.05)between cruciate retaining and posterior stabilised prostheses in the TKR group and no significant difference(P>0.05)between cemented and uncemented fixation in the THR group.Obese patients had poorer outcomes following TKR but did not significantly influence the outcome following THR.CONCLUSION Contrary to some literature,THR and TKR are equally efficacious in alleviating the pain and disability of OA when assessed using a comprehensive range of PROMs.The varying knee prosthesis types and hip fixation techniques did not significantly influence clinical outcome.Obesity had a greater influence on the outcome following TKR than that of THR. 展开更多
关键词 OBESITY OSTEOARTHRITIS Patient reported outcome measures total hip arthroplasty total knee arthroplasty
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基于全站仪定位的辐射场测量方法研究
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作者 赵原 刘立业 +6 位作者 李华 刘学刚 程锦锋 王晓龙 龙泽宇 李会 陈凌 《辐射防护》 CAS CSCD 北大核心 2024年第4期336-342,共7页
在核设施检修或退役中,往往需要对现场的辐射剂量场进行测量。传统的剂量率仪不支持空间坐标测量,需要额外的坐标测量工具,且剂量测量和坐标测量不同步,使得测量效率受到限制。针对该问题,提出了一种基于全站仪定位的测量方法,可同时测... 在核设施检修或退役中,往往需要对现场的辐射剂量场进行测量。传统的剂量率仪不支持空间坐标测量,需要额外的坐标测量工具,且剂量测量和坐标测量不同步,使得测量效率受到限制。针对该问题,提出了一种基于全站仪定位的测量方法,可同时测量剂量率和对应的空间坐标,定位精度为mm级,研制了测量系统样机。使用样机对某个水泥固化放射性废物桶进行了测试实验,与蒙特卡罗计算结果进行对比,测量值与模拟值的相对偏差遵循正态分布,平均偏差为12.8%,标准偏差为9.37%,数量大约占96%的测量点位的相对偏差在[-30%,5%]的范围内,体现了较高的测量精度。对某核设施厂房的另外两个较为复杂的场景进行辐射场测量,使用对数变换普通克里金方法对离散的测量点进行辐射场插值计算,三维辐射场重构结果的平均相对偏差可控制在50%左右。结果表明通过基于全站仪的辐射场测量系统可对现场的三维辐射场进行重构,精度可以满足三维辐射场的应用需求。 展开更多
关键词 γ辐射场测量 三维辐射场重构 全站仪定位 辐射防护最优化
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基于点云切片算法的铁路钢桁拱桥线形分析
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作者 彭仪普 李剑 +5 位作者 韩衍群 汤致远 李子超 于风晓 陈立 邹魁 《华南理工大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第7期97-106,共10页
铁路桥梁线形测量对于桥梁健康检测与确保铁路安全运营具有重要作用。为提高运营铁路钢桁拱桥线形测量效率,以某3跨钢桁拱桥为例,运用地面激光扫描(TLS)技术对桥梁杆件进行整体化扫描,从桥梁线形测量精度、扫描完整性、点云个数等3方面... 铁路桥梁线形测量对于桥梁健康检测与确保铁路安全运营具有重要作用。为提高运营铁路钢桁拱桥线形测量效率,以某3跨钢桁拱桥为例,运用地面激光扫描(TLS)技术对桥梁杆件进行整体化扫描,从桥梁线形测量精度、扫描完整性、点云个数等3方面,分析出最佳的桥梁扫描测站数为10个。运用3DNDT点云配准算法将各测站一一配准,桥梁点云配准精度为2 mm,将桥梁点云投影至xoy平面,用半径滤波器进行噪声点的去除,得到完整“纯净”的桥梁点云模型。提出点云等距切片与点云平面切片算法提取桥梁线形,并将线形点云数据导出在AutoCAD中拾取坐标。将点云切片法提取的TLS测量值、全站仪法测量结果与原始成桥线形做比较分析,结果表明:在桥面线形分析中,两方法均在跨中处A5点测量出最大变形,分别为12.69 mm、10.29 mm,两方法的最大相互较差R为2.4 mm,相关系数优于99.93%;在拱轴线线形分析中,点云切片法与全站仪法在主桁上弦跨中B4点位测量的最大变形为6.2 mm、3.9 mm,在主桁下弦跨中B10点位测量的最大变形为5.9 mm、3.5 mm,两方法的最大互相较差R为3.2 mm,相关系数优于99.87%,验证了点云切片算法的有效性与TLS测量的高精度性。拱轴线横向线形未出现明显侧移,点云等距切片得到的19个吊杆垂直度保持良好,未发生扭转与偏移。该成果对于运营铁路钢桁拱桥的线形分析与点云处理方法可提供相应的思路和参考,具有重要的实用价值。 展开更多
关键词 地面激光扫描 点云切片 钢桁拱桥线形 全站仪测量
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结合光谱降维的IPSO-SVR水体总磷浓度预测模型
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作者 王彩玲 张国浩 《水土保持通报》 CSCD 北大核心 2024年第2期196-204,共9页
[目的]选择最优模型对水体中总磷浓度进行预测,为准确、实时、高效检测水资源状况提供支持。[方法]以2021年在长江中下游武汉—安徽地区采集的水质样本作为研究对象,首先,对采集到的长江光谱数据进行最大最小归一化和均值中心化两种预... [目的]选择最优模型对水体中总磷浓度进行预测,为准确、实时、高效检测水资源状况提供支持。[方法]以2021年在长江中下游武汉—安徽地区采集的水质样本作为研究对象,首先,对采集到的长江光谱数据进行最大最小归一化和均值中心化两种预处理操作以便统一数据的范围和均值点,并使用核主成分分析(KPCA)技术对预处理后的光谱数据进行降维操作。选取方差解释率为99.6%下的6个特征向量进行后续预测模型的训练,接着在原有粒子群算法的基础上引入自适应惯性权重更新公式和遗传—模拟退火变异思想,提高算法的寻优能力。使用改进的粒子群优化算法对支持向量回归模型中的超参数组合进行寻优,对支持向量回归模型使用输出的结果进行预测模型的训练,最后使用测试集数据进行总磷浓度的预测。[结果]提出了一种结合光谱降维的改进粒子群优化算法(IPSO)结合支持向量回归(SVR)的水体总磷含量预测模型。通过和当前预测性能较好的几种机器学习模型进行精度的比较发现,该试验模型对长江水体总磷浓度进行预测时决定系数(R^(2))为0.973920,均方根差(RMSE)为0.003012,平均绝对误差(MAE)为0.002105。[结论]使用光谱数据结合降维技术、粒子群优化算法和机器学习模型的算法融合模型检测水体总磷浓度可行性强,精确度高,且拟合效果良好。 展开更多
关键词 高光谱 IPSO-SVR模型 KPCA降维 长江水质 总磷浓度检测
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全髋关节置换前人工智能(AI)规划的作用与意义
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作者 闵美鹏 吴进 +5 位作者 URBA RAFI 张文杰 高嘉 王云华 何斌 范磊 《中国组织工程研究》 CAS 北大核心 2024年第9期1372-1377,共6页
背景:传统X射线胶片术前规划常常不准确,会导致一些术中和术后并发症,增加了手术时间和术中出血量,一定程度影响了全髋关节置换的手术效果。目的:研究人工智能(AI)术前规划在全髋关节置换术中的准确性和应用效果。方法:选取患侧初次行... 背景:传统X射线胶片术前规划常常不准确,会导致一些术中和术后并发症,增加了手术时间和术中出血量,一定程度影响了全髋关节置换的手术效果。目的:研究人工智能(AI)术前规划在全髋关节置换术中的准确性和应用效果。方法:选取患侧初次行全髋关节置换的患者60例,其中30例应用人工智能(AI)三维术前规划为试验组、30例应用传统X射线胶片二维术前规划为对照组,两组患者的性别、年龄、病情等一般资料比较,差异均无统计学意义(P>0.05)。比较两组患者术中实际安放假体与术前规划假体匹配情况、术中手术时间、术中出血量、术后即刻双侧股骨偏心距差值、双侧联合偏心距差值及双下肢长度差值和术后3个月Harris评分,分析两种术前规划的准确性和应用效果。结果与结论:①两组患者均获得术后4-6个月的随访,其中对照组有1例患者于术后5 d发生假体后脱位,行手法复位后恢复,无再次脱出,其余患者均未出现术后并发症及术后死亡;②髋臼侧、股骨侧假体完全匹配率:试验组明显优于对照组(P<0.05);③手术时间、术中出血量:试验组明显少于对照组(P<0.05);④两组患者术后双下肢长度差值比较差异有显著性意义(P<0.05),双侧股骨偏心距差值和双侧联合偏心距差值比较差异均无显著性意义(P>0.05);⑤试验组患者术后3个月Harris评分明显高于对照组患者(P<0.05);⑥结果说明,人工智能(AI)术前规划相较于传统胶片规划,更能准确预测假体型号、缩短手术时间、减少术中出血量、减少术后双下肢不等长发生、加快术后康复。 展开更多
关键词 人工智能(AI) 全髋关节置换术 术前规划 模板测量 假体
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间隙平衡器下平衡技术与测量截骨技术在全膝关节置换中的应用
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作者 黄雪黎 罗瑞琴 +4 位作者 陈晟 李晓武 陈海波 曾庆强 郑志辉 《中国组织工程研究》 CAS 北大核心 2024年第24期3822-3826,共5页
背景:目前测量截骨技术和间隙平衡技术是全膝关节置换术中最常用的技术,各有优缺点:间隙平衡技术通过调整截骨角度可以减少对软组织的松解,得到更平衡的屈伸间隙,临床效果更优,但缺乏工具的间隙平衡技术,易受术者手术经验及主观判断影响... 背景:目前测量截骨技术和间隙平衡技术是全膝关节置换术中最常用的技术,各有优缺点:间隙平衡技术通过调整截骨角度可以减少对软组织的松解,得到更平衡的屈伸间隙,临床效果更优,但缺乏工具的间隙平衡技术,易受术者手术经验及主观判断影响,存在更多的误差;测量截骨法学习曲线短,但依赖解剖标志,容易定位不准而出现多种并发症。近年来,许多器械公司相继研发并推出了间隙平衡工具以期提高手术质量,但目前关于该工具的相关报道仍较少。目的:对比结合间隙平衡器的间隙平衡技术与传统测量截骨应用于全膝关节置换的临床疗效,以探究间隙平衡器在全膝关节置换过程中的应用价值。方法:收集85例全膝关节置换患者的病历资料,根据手术方式分为2组,A组44例采用结合间隙平衡器的间隙平衡技术进行全膝关节置换;B组41例采用测量截骨技术进行全膝关节置换。比较两组患者手术时间、美国膝关节协会评分、膝关节活动度、下肢力线改变及术后并发症的发生情况,以评估结合间隙平衡器的间隙平衡技术在全膝关节置换中的应用效果。结果与结论:①85例患者均获得随访;②两组术后膝关节活动度均较术前提高(P<0.05),且A组较B组改善更明显(P<0.05);③两组术后美国膝关节协会评分均较术前提高(P<0.05),且术后2周、术后1,3个月和末次随访时,A组美国膝关节协会评分高于B组同期(P<0.05);④手术时间A组较B组稍短,但差异无显著性意义(P>0.05);⑤术后两组下肢力线均较其术前改善,但两组差异无显著性意义(P>0.05);⑥术后A组并发症发生率(2%)较B组(7%)低,但两组差异无显著性意义(P>0.05);⑦提示相较于测量截骨技术,结合间隙平衡器的间隙平衡技术可提高临床效果,改善膝关节功能及活动度。 展开更多
关键词 全膝关节置换 测量截骨技术 间隙平衡技术 间隙平衡器 骨性关节炎
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全站仪气象改正公式优化研究
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作者 刘晓东 缪东晶 +6 位作者 姚燕 王长云 王德利 李连福 刘洋 蔡晋辉 李建双 《计量学报》 CSCD 北大核心 2024年第3期386-394,共9页
为了提高全站仪长距离测距精度,提出一种全站仪气象改正公式的优化方法。对气象改正公式进行了分析,发现存在一定误差和优化的空间。为了降低改正公式引起的残余误差,以最小化残余误差之和为优化目标,将气象公式系数调整转化为最优化问... 为了提高全站仪长距离测距精度,提出一种全站仪气象改正公式的优化方法。对气象改正公式进行了分析,发现存在一定误差和优化的空间。为了降低改正公式引起的残余误差,以最小化残余误差之和为优化目标,将气象公式系数调整转化为最优化问题。借助野外长基线上部署的密集环境参数传感器阵列,实时记录全站仪长时间连续测距时的环境参数;利用测距数据构造优化函数,对改正公式系数的不同组合进行优化调整和验证,实验数据分析结果表明:优化后,测距误差均值可减小99.8%,误差的标准偏差减小81.2%。为验证所提出方法的有效性,将优化系数后的改正公式应用于其他测量时间段的测距补偿,结果显示,残余误差也同样得到有效降低,优化幅度达到37%以上。表明气象改正公式系数优化是显著降低野外测距误差的有效方法。 展开更多
关键词 几何量计量 标准基线 全站仪 长距离测量 气象改正公式 最优化算法
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提高煤系页岩储层TOC计算精度的改进方法
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作者 李梦蕾 张超谟 +3 位作者 石文睿 周雪晴 虞成 罗意淳 《石油物探》 CSCD 北大核心 2024年第4期817-825,共9页
总有机碳含量(TOC)是决定烃源岩质量的最重要参数。为了准确评价煤系页岩气储层的TOC参数,以四川盆地Q区龙潭组C1井海陆过渡相页岩气储层为例,对提高储层TOC参数计算精度的方法进行了研究。根据研究区的地质特点,结合自然伽马能谱测井数... 总有机碳含量(TOC)是决定烃源岩质量的最重要参数。为了准确评价煤系页岩气储层的TOC参数,以四川盆地Q区龙潭组C1井海陆过渡相页岩气储层为例,对提高储层TOC参数计算精度的方法进行了研究。根据研究区的地质特点,结合自然伽马能谱测井数据,对原始Δlog R方法进行改进,形成了基于自然伽马能谱测井的双Δlog R方法。首先,将岩心TOC数据按岩性分为煤层和非煤层,然后,将自然伽马能谱测井数据(钍钾比(Th/K)和钍铀比(Th/U))分别与煤层TOC和非煤层TOC进行相关性分析,各自选择最高相关性的数据与Δlog R拟合,计算煤层和非煤层的TOC。结果表明,基于自然伽马能谱测井的双Δlog R方法和传统方法相比,C1井煤层和非煤层TOC计算相关性最高可以提高到0.78和0.85,煤层和非煤层TOC的绝对误差最低都可以降到0.01%,煤层和非煤层TOC的相对误差降低到14.93%和12.53%。将基于自然伽马能谱测井的双Δlog R方法应用于四川盆地S区Y组C2井,取得了较好的效果。改进的方法适用于研究区页岩气储层黏土含量高,非均质性强,且存在黑色煤层的页岩储层,有效弥补TOC与铀(U)含量无明显相关性的不足,具有较好的适用性和推广性,可以有效辅助研究区页岩气储层的勘探开发。 展开更多
关键词 总有机碳含量 页岩气 煤系页岩 页岩储层 四川盆地 海陆过渡相
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Examining the“revisability”benefit of hip resurfacing arthroplasty
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作者 Jose George Adam J Taylor Thomas P Schmalzried 《World Journal of Orthopedics》 2024年第6期554-559,共6页
BACKGROUND Hip resurfacing arthroplasty(HRA)is an alternative to total hip arthroplasty(THA)that is typically reserved for young active patients because it preserves bone.However,the benefits of HRA only hold true if ... BACKGROUND Hip resurfacing arthroplasty(HRA)is an alternative to total hip arthroplasty(THA)that is typically reserved for young active patients because it preserves bone.However,the benefits of HRA only hold true if conversion THA after failed HRA provides acceptable outcomes.AIM To compare patient reported outcomes for conversion THA after HRA failure to primary THA.METHODS A retrospective review of 36 patients(37 hips)that underwent conversion THA for failed HRA between October 2006 and May 2019 by a single surgeon was performed.Patient reported outcomes[modified Harris Hip Score(mHHS),University of California Los Angeles(UCLA)activity score]were obtained via an email-based responder-anonymous survey.Outcomes were compared to normative data of a primary THA cohort with similar demographics.Subgroup analysis was performed comparing outcomes of conversion THA for adverse local tissue reaction(ALTR)vs all other causes for failure.RESULTS The study group had a lower mHHS than the control group(81.7±13.8 vs 90.2±11.6,P<0.01);however,both groups had similar UCLA activity levels(7.5±2.3 vs 7.2±1.6,P=0.51).Patients that underwent conversion for non-ATLR causes had similar mHHS(85.2±11.5 vs 90.2±11.6,P=0.11)and higher UCLA activity levels(8.5±1.8 vs 7.2±1.6,P<0.01)compared to the control group.Patients that underwent conversion for ATLR had worse mHHS(77.1±14.5 vs 90.2±11.6,P<0.01)and UCLA activity levels(6.1±2.3 vs 7.2±1.6,P=0.05)when compared to the control group.CONCLUSION Patient outcomes equivalent to primary THA can be achieved following HRA conversion to THA.However,inferior outcomes were demonstrated for ALTR-related HRA failure.Patient selection and perhaps further studies examining alternative HRA bearing surfaces should be considered. 展开更多
关键词 total hip arthroplasty Hip resurfacing arthroplasty Conversion total hip arthroplasty Adverse local tissue reaction Patient reported outcome measures
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图像全站仪同轴相机主距检校方法研究
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作者 阮从海 郑勇 +1 位作者 章后甜 陈虓 《工程勘察》 2024年第3期44-48,67,共6页
变形测量是图像全站仪目前应用最为广泛的领域。同轴相机主距是图像全站仪应用于变形测量所需检校的主要参数,其检校方法及精度直接关乎变形测量的精度与效率。针对现有检校方法涉及参数过多、求解过程复杂等问题,本文提出一种高效直观... 变形测量是图像全站仪目前应用最为广泛的领域。同轴相机主距是图像全站仪应用于变形测量所需检校的主要参数,其检校方法及精度直接关乎变形测量的精度与效率。针对现有检校方法涉及参数过多、求解过程复杂等问题,本文提出一种高效直观的检校方法,检校参数仅包括主距和畸变,可有效检测出不同测量距离上的主距变化,并建立相应的物距—主距函数模型,在实际测量中可由该模型直接获得不同物距对应的精确主距,有效提高将图像测量转换为实地形变测量的精度。针对研究建立的检校模型,设计了完整的检校实验流程,对物距(S)变化范围为2.46m至11.56m的徕卡TS60图像全站仪同轴相机的主距(f)进行精密检校实验,得到的物距与主距的函数模型为f=-3.8382*S^-3.9592+23.1997±0.0023cm。结果表明,本文方法的主距检校相对精度为10-4,所建立的函数模型可将主距误差引起的测角误差降低到0.2″以内。 展开更多
关键词 变形测量 图像全站仪 同轴相机主距 畸变 物距 函数模型
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基于全反射原理的透明液体浓度测量方法研究
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作者 肖恩赞 李兆麒 +4 位作者 徐佳利 钟晓娇 赵海超 王永康 秦海森 《科技创新与应用》 2024年第5期69-72,共4页
现如今有多种方法测量透明液体浓度,比重法、折射法(最小偏向角法)、超声光栅法等,以上的方法均需建立浓度与密度、折射率、声速及光损量之间的关系测量,从而得出测量浓度的一种表征。该文提出利用全反射原理中,即光从光密介质射向光疏... 现如今有多种方法测量透明液体浓度,比重法、折射法(最小偏向角法)、超声光栅法等,以上的方法均需建立浓度与密度、折射率、声速及光损量之间的关系测量,从而得出测量浓度的一种表征。该文提出利用全反射原理中,即光从光密介质射向光疏介质时,当入射角超过某一角度θc(临界角)时,折射光完全消失,只剩下反射光线的现象叫做全反射,以NaCl溶液为例,通过测量不同浓度的溶液所引起的全反射现象,进而引起入射光源的高度变化,通过实验探究得出“浓度-高度”呈线性的负相关,并利用此关系实现对透明液体浓度的测量。研究实验表明,拟合出相关系数R^(2)=0.9957,拟合效果好,测量精度达99%。 展开更多
关键词 透明溶液 浓度 全反射 测量 临界角
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基于风险评估理念的保温措施在腹腔镜下全子宫切除术中的临床效果
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作者 梁洋洋 刘苏玉 《河北医药》 CAS 2024年第6期953-956,共4页
目的研究基于风险评估理念的保温措施介入腹腔镜下全子宫切除术的临床效果。方法选取2022年1月至2023年4月共60例行腹腔镜下全子宫切除术的患者,年龄36~68岁,其中子宫腺肌病16例,子宫肌瘤44例,使用Excel表格生成随机数字分为对照组和研... 目的研究基于风险评估理念的保温措施介入腹腔镜下全子宫切除术的临床效果。方法选取2022年1月至2023年4月共60例行腹腔镜下全子宫切除术的患者,年龄36~68岁,其中子宫腺肌病16例,子宫肌瘤44例,使用Excel表格生成随机数字分为对照组和研究组,每组30例。对照组行医院手术室常规保温措施,研究组基于风险评估理念制定腹腔镜下全子宫切除术的保温措施,根据患者术中发生低体温的相关影响因素,对患者进行低体温的相关风险因素评估,从而制定包括动态监测体温、维持手术室合适的温度、输液及冲洗液加温、加盖棉被、使用保温装置的等保温措施,并将该保温措施贯穿于患者围手术期的整个过程,从术前到术后进行全程的风险评估及干预。比较患者全子宫切除术术中出血量、术中补液量拔管时间、术后苏醒情况、术中体温变化、低体温相关并发症的发生率、术后不同时间段患者的疼痛评分以及患者对手术的满意率。结果使用基于风险评估理念的腹腔镜下全子宫切除术保温措施后,患者手术中出血量明显减少、低体温及相关并发症发生率降低(P<0.05),研究组手术后1、6、12、2 h患者的疼痛评分均低于对照组,差异有统计学意义(P<0.05);患者对基于风险评估理念的保温措施满意度更高(P<0.05)。结论基于风险理念的保温措施,不仅能降低腹腔镜下全子宫切除术低体温的发生率,且能减少患者手术中的出血及低体温相关并发症的发生,提高患者的满意度,值得临床推广并应用。 展开更多
关键词 风险评估理念 保温措施 腹腔镜下全子宫切除术
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全膝关节置换术后深静脉血栓形成机制、危险因素及预防研究进展
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作者 黄玲 傅德杰 邓姝 《陕西医学杂志》 CAS 2024年第3期428-432,共5页
全膝关节置换术(TKA)是目前终末期膝骨关节病治疗的最有效方法。深静脉血栓(DVT)是手术后患者恢复期最常见并发症类型之一,栓子脱落后可形成肺栓塞,严重危及患者生命安全。因此,预防术后DVT形成在TKA围手术期至关重要。现就引发TKA术后... 全膝关节置换术(TKA)是目前终末期膝骨关节病治疗的最有效方法。深静脉血栓(DVT)是手术后患者恢复期最常见并发症类型之一,栓子脱落后可形成肺栓塞,严重危及患者生命安全。因此,预防术后DVT形成在TKA围手术期至关重要。现就引发TKA术后DVT形成的机制、危险因素及其预防措施进行总结,为TKA术后DVT的预防提供参考。 展开更多
关键词 深静脉血栓 全膝关节置换术 发病机制 危险因素 预防措施
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