检索结果-南通市图书馆

China Foundry 2015年第4期12卷 269-276页

作者： Zhi Hu Yan Hong Yuan-sheng Rao Hong-xu Qiu Xian-ming Ruan Institute of Advanced Forming Nanchang University

The influence of Sm （Samarium） content on microstructure and mechanical properties of recycled die-cast YLl12 aluminum alloys was investigated. The results show that many small Sm-rich particles form in the recycled die-cast YLl12 alloys with Sm addition. At the same time, the secondary dendrite arm spacing in the YLl12 alloys modified with Sm is smaller than that of the unmodified alloy. The eutectic Si of recycled die- cast YL112-xSm alloys transforms from coarse acicular morphology to fine fibres. Mechanical properties of the investigated recycled die-cast YLl12 aluminum alloys are enhanced with Sm addition, and a maximal ultimate tensile strength value （276 MPa） and elongation （3.76%） are achieved at a Sm content of 0.6wt.%. Due to the modification of eutectic Si by Sm, numerous tearing ridges and tiny dimples on the fractures of tensile samples are observed.

关键词： rare earth aluminum alloy die casting samarium microstructure eutectic Si nano particles mechanical properties

EEG-controlled functional electrical stimulation rehabilitation for chronic stroke:system design and clinical application

在线全文

学校读者我要写书评

暂无评论

Frontiers of Medicine 2021年第5期15卷 740-749页

作者： Long Chen Bin Gu Zhongpeng Wang Lei Zhang Minpeng xu Shuang Liu Feng He Dong ming Neural Engineering&Rehabilitation Laboratory Department of Biomedical EngineeringCollege of Precision Instruments and Optoelectronics EngineeringTianjin UniversityTianjin 300072China Academy of Medical Engineering and Translational Medicine Tianjin UniversityTianjin 300072China

Stroke is one of the most serious diseases that threaten human life and *** is a major cause of death and disability in the *** strategies for motor rehabilitation after stroke are undergoing *** aimed to develop a novel artificial neural rehabilitation system,which integrates brain--computer interface(BCI)and functional electrical stimulation(FES)technologies,for limb motor function recovery after *** conducted clinical trials(including controlled trials)in 32 patients with chronic *** were randomly divided into the BCI-FES group and the neuromuscular electrical stimulation(NMES)*** changes in outcome measures during intervention were compared between groups,and the trends of ERD values based on EEG were analyzed for BCI-FES *** showed that the increase in Fugl Meyer Assessment of the Upper Extremity(FMA-UE)and Kendall Manual Muscle Testing(Kendall MMT)scores of the BCI-FES group was significantly higher than that in the sham group,which indicated the practicality and superiority of the BCI-FES system in clinical *** change in the laterality coefficient(LC)values based onμ-ERD(ΔLCm-ERD)had high significant positive correlation with the change in FMA-UE(r=0.6093,P=0.012),which provides theoretical basis for exploring novel objective evaluation methods.

关键词： brain-computer interface functional electrical stimulation electroencephalogram laterality coefficient chronic stroke

基于自适应迭代学习控制的永磁同步电动机稳态转速脉动抑制策略

在线全文

学校读者我要写书评

暂无评论

机械工程师 2024年第1期 19-25,28页

作者：陈明杨建中陈文峰郝勇许光达华中科技大学机械科学与工程学院武汉430074 武汉智能设计与数控技术创新中心武汉430040

为了提高永磁同步电动机转速控制的性能,抑制其稳态下的转速波动,设计了一种并联于传统速度PI控制器的自适应迭代学习控制器,用于对转速波动进行补偿。针对传统迭代学习控制器对非周期信号抗扰能力差的问题,提出了Fal函数与迭代学习控... 详细信息

为了提高永磁同步电动机转速控制的性能,抑制其稳态下的转速波动,设计了一种并联于传统速度PI控制器的自适应迭代学习控制器,用于对转速波动进行补偿。针对传统迭代学习控制器对非周期信号抗扰能力差的问题,提出了Fal函数与迭代学习控制器结合的方法,保证了系统在调速时仍具备良好的响应特性;针对迭代学习控制器迭代增益系数的整定问题,提出了一种控制参数自适应的迭代学习控制方法。实验结果表明,所提出的Fal函数与迭代学习控制器结合的方法能有效提升系统的抗扰能力;同时,提出的参数自适应方案也能提升迭代学习控制器对转速波动抑制的能力。

关键词：永磁同步电动机迭代学习控制转速波动抑制

在线全文

学校读者我要写书评

暂无评论

矿井通风系统可靠性动态评价方法研究

能源与环保 2024年第1期46卷 46-53页

作者：何敏徐明游春林王泽华郝天轩张攀河南能源集团永煤集团股份有限公司新桥煤矿河南永城476600 河南理工大学安全科学与工程学院河南焦作454000 煤炭安全生产与清洁高效利用省部共建协同创新中心河南焦作454000

为对矿井通风系统可靠性进行跟踪动态评价,采用改进的AHP(层次分析法)算法确定主观权重,熵权法确定客观权重,通过Scott-Hinsley算法进行风网解算获取通风系统参数。为解决多次跟踪动态评价时计算量大、所需评价专家数量多的问题,引入二... 详细信息

为对矿井通风系统可靠性进行跟踪动态评价,采用改进的AHP(层次分析法)算法确定主观权重,熵权法确定客观权重,通过Scott-Hinsley算法进行风网解算获取通风系统参数。为解决多次跟踪动态评价时计算量大、所需评价专家数量多的问题,引入二维云模型进行可靠性评价,建立矿井通风系统可靠性动态评价二维云模型,可实现通风系统可靠性的动态跟踪快速评价。应用实例表明,该方法评价结果科学可靠,能反映出通风系统可靠性变化状态;进行多次评价时,评价过程更简洁,能实现快速准确评价,可为矿井通风管理工作提供技术支持。

关键词：二维云模型通风系统可靠性风网解算动态评价

Microplate chemiluminescence enzyme immunoassay for the quantitative evaluation of carbohydrate antigen 72-4 in human serum

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2008年第19期53卷 2958-2963页

作者： JIN Hui WANG xu XIN TianBing GAO Peng LIN Jin-ming LIANG Shuxuan College of Chemistry and Environmental Science Hebei University Baoding 071002 China Department of Chemistry Tsinghua University Beijing 100084 China Beijing Chemclin Biotech Co. Ltd. Beijing 100094 China

A highly sensitive and specific microplate chemiluminescence enzyme immunoassay (CLEIA) was developed for the quantitative evaluation of carbohydrate antigen 72-4 (CA72-4) in human serum, using luminol-H2O2 catalyzed by horseradish peroxidase (HRP) as the chemiluminescence system. The simple and quick determination was accomplished through a sandwich reaction mode. Several physico-chemical parameters of the immunoreaction, including incubation conditions, antibody coating conditions, dilution ratio of anti-CA72-4-HRP conjugate, and chemiluminescence reaction time, were studied and optimized. The proposed method exhibited a linear range of 0―200 U/mL with correlation coefficient and detection limit of 0.9995 and 0.18 U/mL, respectively. The inter-assay and intra-assay coeffi-cients of variation (CV) were both less than 10%. The average recovery of two clinical sera with low and high concentration CA72-4 was 99.3% and 98.7%, respectively. Normal tumor markers, including AFP, CEA, CA24-2, CA19-9 and CA15-3, did not cross-react with each other. The method's stability was evaluated by assessing its analytical performance after storing the immunoreagents at 4℃ and 37℃ for 7 days. Little difference was found, indicating satisfactory stability of the method. The present method has been successfully applied to the detection of CA72-4 human serum, and showed a good correlation with the commercially available ELISA kit (r 2=0.9383). This method showed great potential in the fabrication of diagnostic kit for CA72-4, and could be well used in diagnosis of cancer in clinical practice.

关键词：化学发光酶学免疫检测肿瘤标记

拟人工黑体结构的带隙设计阵列化降噪特性研究

在线全文

学校读者我要写书评

暂无评论

节能技术 2024年第4期42卷 291-298,305页

作者：杨嘉明许如航李小斌李凤臣天津大学机械工程学院先进内燃动力全国重点实验室天津300350

为了解决噪声污染对人居环境带来的不利影响,基于声子晶体带隙原理,受人工黑体结构启发,提出了拟人工黑体结构的开口管状阵列的带隙降噪结构设计,利用平面波在阵列之间以及管状结构内部的干涉相消达到降噪效果。使用数值模拟和实验研究... 详细信息

为了解决噪声污染对人居环境带来的不利影响,基于声子晶体带隙原理,受人工黑体结构启发,提出了拟人工黑体结构的开口管状阵列的带隙降噪结构设计,利用平面波在阵列之间以及管状结构内部的干涉相消达到降噪效果。使用数值模拟和实验研究的方法,对比分析了不同因素对降噪效果的影响,从晶体阵列排布形式、法向排数及开口角度大小等角度出发,进行了参数化影响因素分析。结果表明,该带隙设计的阵列化结构可有效降低噪声。其中高频段传输损失可达100 dB以上,低频段也可达30~45 dB。该研究对典型场景的降噪需求的设计具有重要参考价值。

关键词：降噪拟人工黑体声子晶体阵列布置带隙设计频谱分析

维普期刊数据库博看期刊

Comparative effectiveness of first-line therapies for eradication of antibiotic-resistant Helicobacter pylori strains:A network metaanalysis

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2022年第35期10卷 12959-12970页

作者： Shu-Peng Zou Qian Cheng Cheng-Yang Feng Chan xu ming-Hui Sun Department of Pharmacy Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430000Hubei ProvinceChina

BACKGROUND As a first-line treatment regimen for Helicobacter pylori(***)infection,antibiotic therapy is widely used ***,the question of increasing antibiotic resistance must be *** this issue,we need to find ways to reduce drug *** study examined all currently available first-line regimens and compared them with standard triple treatment through a network meta-analysis of randomized controlled trials(RCTs).AIM To compare first-line treatment regimens for eradication of antibiotic-resistant *** *** To compare the effectiveness of the first-line regimens for treating *** infection,a Bayesian network meta-analysis was applied to process data extracted from *** plausible ranking for each regimen was assessed by the surface under the cumulative ranking curve(SUCRA).In addition,we conducted a relevant search by reference citation *** Twenty-five RCTs involving 12029 participants[including 1602 infected with clarithromycin(CAM)-resistant strains and 1716 infected with metronidazole(MNZ)-resistant strains]were included,in which a total of seven regimens were used for *** *** results showed that dual therapy containing a high-dose proton pump inhibitor(HDDT)[odds ratio(OR):4.20,95%confidence interval(CI):2.29-8.13]was superior to other therapies for all patients,including those with CAM/MNZ-resistant *** *** the comparative effectiveness ranking,for CAM-resistant ***,HDDT(OR:96.80,95%CI:22.46-521.9)had the best results,whereas standard triple therapy ranked last(SUCRA:98.7%vs 0.3%).In the subgroup of high cure rates(≥90%),HDDT was also generally better than other *** For the eradication of CAM-and MNZ-resistant *** strains,HDDT exhibited considerable *** studies of CAM-resistant *** were based on small samples due to a lack of antibiotic sensitivity tests in many RCTs,but the results showed that all patients,including

关键词： Helicobacter pylori Clarithromycin resistance First-line therapy Proton pump inhibitors

血清CD4^(+)/CD8^(+)T淋巴细胞比值结合MRA与脑梗死再发的关系研究

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

国际检验医学杂志 2024年第2期45卷 199-203页

作者：刘娜彭爱妮吴晶徐寿成于明镇江市第一人民医院神经内科江苏镇江210031 江苏大学附属江滨医院神经内科江苏镇江210031

目的探讨血清CD4^(+)/CD8^(+)T淋巴细胞比值结合磁共振血管造影(MRA)与脑梗死再发的相关性及预测作用。方法选取镇江市第一人民医院2021年1月至2022年2月收治的急性脑梗死患者153例,测定患者CD4^(+)/CD8^(+)T淋巴细胞比值,MRA评估血管... 详细信息

目的探讨血清CD4^(+)/CD8^(+)T淋巴细胞比值结合磁共振血管造影(MRA)与脑梗死再发的相关性及预测作用。方法选取镇江市第一人民医院2021年1月至2022年2月收治的急性脑梗死患者153例,测定患者CD4^(+)/CD8^(+)T淋巴细胞比值,MRA评估血管狭窄评分、侧支循环充盈评分,对患者进行1年随访,其中34例脑梗死再发患者作为脑梗死再发组,107例脑梗死未再发患者作为脑梗死未再发组,排除其他各种原因失访12例患者,并绘制各指标用于预测患者脑梗死再发的受试者工作特征(ROC)曲线。结果脑梗死再发组CD4^(+)/CD8^(+)T淋巴细胞比值明显高于脑梗死未再发组(P<0.05);脑梗死再发组血管狭窄评分、侧枝循环充盈评分均低于脑梗死未再发组(P<0.05)。患者脑梗死再发与CD4^(+)/CD8^(+)T淋巴细胞比值、血管狭窄评分、侧枝循环充盈评分均有关(P<0.05)。ROC曲线分析显示,CD4^(+)/CD8^(+)T淋巴细胞比值、血管狭窄评分、侧枝循环充盈评分预测患者脑梗死再发的曲线下面积(AUC)分别为0.975、0.889、0.935,三者联合预测患者脑梗死再发的AUC为0.994,显著高于各指标单独预测患者脑梗死复发的AUC。结论血清CD4^(+)/CD8^(+)T淋巴细胞比值结合MRA血管狭窄评分、侧支循环充盈评分诊断脑梗死再发效能较高,对脑梗死再发具有预测价值。

关键词： CD4^(+)/CD8^(+)T淋巴细胞比值磁共振血管造影血管狭窄评分侧支循环充盈评分脑梗死再发

Synthesis and characterization of a new chromophor with acid/base-sensitive fluorescence emission

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2011年第9期22卷 1051-1054页

作者： Hai guang Zhang xu Tang Tao Kao Shan Chen Chun xue Yuan Shi Na Yan Min Hua Jiang College of Chemistry Science Qufu Normal University Qufu 273165 China State Key Laboratory of Crystal Materials Shandong University Jinan 250100 China School of Life Science Shandong University Jinan 250100 China

A new two-photon absorption compound, 2-{4-[（dicyanomethylidene-5,5-dimethylcyclohexl）vinyl]phenyl}imidazo[4,5- f][1,10]phenanthroline （DDVPIP）, was synthesized and characterized. The one-photon excited fluorescence （OPEF） and two- photon excited fluorescence （TPEF） of DDVP1P are sensitive to the acid/base of the solution, which are enhanced in basic solution but weakened in acidic solution. Charge-transfer （CT） states of DDVPIP were calculated through theory methods to explain its acid/ base-sensitive fluorescent properties.

关键词： Imidazo[4,5-f][ 1,10]phenanthroline Two-photon absorption Two-photon fluorescence

Off-on-off luminescent switching of a dye containing imidazo[4,5-f][1,10]phenanthroline

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2011年第6期22卷 647-650页

作者： Hai guang Zhang xu Tang Tao Kao Shan Chen Chun xue Yuan Shi Na Yan Min Hua Jiang College of Chemistry Science Qufu Normal UniversityQufu 273165China State Key Laboratory of Crystal Materials Shandong UniversityJinan 250100China School of Life Science Shandong UniversityJinan 250100China

A new acid-base fluorescent switch containing both imidazo[4,5-f][1,10]-phenanthroline and triphenylamine groups has been *** fluorescence emissions and absorptions can be reversibiy changed through protonation/deprotonation of imidazole and amine moiety by controlling the intramolecular charge transfer（ICT） process,leading to off-on-off fluorescent molecular switching.

关键词： Fluorescence switch Imidazo[4 5-f][1 10]phenanthroline Triphenylamine Intramolecular charge transfer(ICT)