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基于振动超声调制的混凝土裂缝行为表征试验研究

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武汉理工大学学报（交通科学与工程版） 2023年第3期47卷 510-514页

作者：陈小佳金京文武汉理工大学交通与物流工程学院武汉430063

基于振动-超声调制方法,利用低频振动和超声表面波对加载—卸载循环下的混凝土板梁纯弯段受拉区开展试验研究.提出采用调制旁频谐波能量值与两基波能量值乘积之比作为调制指标参数,用来表征混凝土裂缝在加载和卸载过程中开启和闭合过程... 详细信息

基于振动-超声调制方法,利用低频振动和超声表面波对加载—卸载循环下的混凝土板梁纯弯段受拉区开展试验研究.提出采用调制旁频谐波能量值与两基波能量值乘积之比作为调制指标参数,用来表征混凝土裂缝在加载和卸载过程中开启和闭合过程中的非线性超声调制特征.结果表明:随着荷载的增大,裂缝逐步张开,调制指标参数表现出增大趋势;但随着裂缝的张开扩大,调制指标参数逐步下降.试验结果揭示了在不同荷载作用下裂缝的开合程度对调制指标参数的影响.高阶谐波两侧产生的调制旁频可作为表征裂缝张开和闭合活动的特征参数.

关键词：混凝土裂缝开合振动-超声调制调制指标参数调制旁频

Ultrasensitive and stable X-ray detection using zero-dimensional lead-free perovskites

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Journal of Energy Chemistry 2020年第10期29卷 299-306页

作者： xiaojia Zheng Wei Zhao Peng Wang Hairen Tan Makhsud I.Saidaminov Shujie Tie Ligao chen Yufei Peng Jidong Long Wen-HuZhang Sichuan Research Center of New Materials Institute of Chemical MaterialsChina Academy of Engineering PhysicsChengdu 610200SichuanChina Institute of Fluid Physics China Academy of Engineering PhysicsMianyang 621900SichuanChina National Laboratory of Solid State Microstructures Jiangsu Key Laboratory of Artificial Functional MaterialsCollege of Engineering and Applied SciencesNanjing UniversityNanjing 210093JiangsuChina Departments of Chemistry and Electrical&Computer Engineering Centre for Advanced Materials and Related Technologies(CAMTEC)University of VictoriaVictoria V8P 5C2BCCanada

Sensitive and reliable X-ray detectors are essential for medical radiography,industrial inspection and security screening.Lowering the radiation dose allows reduced health risks and increased frequency and fidelity of diagnostic technologies for earlier detection of disease and its recurrence.Three-dimensional(3 D)organic-inorganic hybrid lead halide perovskites are promising for direct X-ray detection-they show improved sensitivity compared to conventional X-ray detectors.However,their high and unstable dark current,caused by ion migration and high dark carrier concentration in the 3 D hybrid perovskites,limits their performance and long-term operation stability.Here we report ultrasensitive,stable X-ray detectors made using zero-dimensional(0 D)methylammonium bismuth iodide perovskite(MA3Bi2I9)single crystals.The 0 D crystal structure leads to a high activation energy(Ea)for ion migration(0.46 e V)and is also accompanied by a low dark carrier concentration(~10^6 cm^-3).The X-ray detectors exhibit sensitivity of 10,620μC Gy-1 air cm-2,a limit of detection(Lo D)of 0.62 nG yairs-1,and stable operation even under high applied biases;no deterioration in detection performance was observed following sensing of an integrated X-ray irradiation dose of^23,800 m Gyair,equivalent to>200,000 times the dose required for a single commercial X-ray chest radiograph.Regulating the ion migration channels and decreasing the dark carrier concentration in perovskites provide routes for stable and ultrasensitive X-ray detectors.

关键词： X-ray detector Zero-dimensional perovskite Lead-free Carrier concentration Stability Limit of detection Sensitivity

Traceability and Quality Control in Traditional Chinese Medicine:From Chemical Fingerprint to Two-dimensions

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Traceability and Quality Control in Traditional Chinese Medi...

Tailoring the electronic structure of PdAg_(x) alloy nanowires for high oxygen reduction reaction

第十四届全国中药和天然药物学术研讨会

作者： Yong Cai Xiwen Li Mei Li xiaojia chen Hao Hu Jingyun Ni Yitao Wang University of Macau Information Technology College of Beijing Normal University Zhuhai Campus China Academy of Chinese Medical Sciences

＜正＞Chemical fingerprinting is current widely used tool that enables rapid and accurate evaluation of Traditional Chinese Medicine（TCM）.However chemical fingerprints are not amenable to information storage,recognition and retrieval,which limit its use in Chinese medicine traceability.In this study,samples of seven kinds of herbs from sixteen batches were selected

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Chinese Journal of Structural Chemistry 2023年第6期42卷 8-14页

作者： Fan Yang Ruiqin Ren xiaojia Zhang Muhammad Waqas Xinglan Peng Limin Wang Xiaotian Liu Du-Hong chen Youjun Fan Wei chen Guangxi Key Laboratory of Low Carbon Energy Materials School of Chemistry and Pharmaceutical SciencesGuangxi Normal UniversityGuilin541004China

Lowering the cost while maintaining the highly catalytic performance is greatly beneficial for the development of commercial fuel cells and metal-air batteries.Compared with platinum,palladium holds a stronger oxygen affinity and high abundance on earth,endowing it a promising alternative to platinum in anion-exchange membrane fuel cells.However,the sluggish oxygen reduction reaction of palladium still remains a great issue and requires the design of stable and efficient palladium-based electrocatalysts.Here,we report the solvothermal/hydrothermal reduction method to prepare a series of PdAg_(x)nanowires.The prepared PdAg_(x)NWs exhibit hollow structure,which greatly improves the utilization of Pd atoms,offering an outstanding ORR performance.Specifically,PdAg_(2)NWs exhibit an onset potential of 0.92 V and mass activity of 350.7 mA mgPd^(-1)at 0.7 V vs.RHE for ORR in 0.1 M KOH solution.This work provides a novel approach for the construction of hollow NWs and their subsequent applications in other electrocatalytic reactions.

关键词： Hollow nanowire Palladium catalyst Tailoring the electronic structure Oxygen reduction reaction Composition-performance relationship

Modeling of Micropores Drilling Force for Printed Circuit Board Micro-holes Based on Energy Method

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Journal of Donghua University(English Edition) 2023年第5期40卷 525-530页

作者：郑小虎阮浩陈宏博刘骁佳刘正好 Institute of Artificial Intelligence Donghua UniversityShanghai 201620China Shanghai Industrial Big Data and Intelligent Systems Engineering Technology Center Shanghai 201620China College of Mechanical Engineering Donghua UniversityShanghai 201620China Shanghai Institute of Aerospace Precision Machinery Shanghai 201600China

The quality of printed circuit board(PCB)micro-hole processing directly determines the stability of the inner and outer circuit connections.Micro-hole drilling technology is a typical method for PCB micro-hole processing.The problem of optimal control of its drilling force is one of the main factors affecting the quality of micro-hole machining.To address this problem,the thrust forces and torques in PCB drilling were first modeled and analyzed,and the corresponding prediction models were established.The drilling force analysis was carried out through the micro-hole drilling experiment,the specific cutting energy under different feed rates was calculated,the influence of the size effect was clarified,and the accuracy of the prediction model was verified.The result shows that during the drilling of glass fiber cloth,changes in the material removal mechanism are induced as the feed per revolution is varied.When the feed per revolution is less than the tool edge radius,the glass fiber is not cut by the main cutting edge,but is crushed and broken.When the feed per revolution is greater than the radius of the tool edge,the glass fiber is cut by the main cutting edge.At the same time,the established analytical model can accurately reflect the influence of the size effect on the drilling torque in PCB micro-hole drilling,and the error is within 10%.This method has certain practical application value in controlling PCB micro hole processing quality.

关键词： printed circuit board(PCB) micro-hole drilling predictive model size effect multi-layer material

Effect of chitooligosaccharides on cyclin D1,bcl-xl and bcl-2 mRNA expression in A549 cells using quantitative PCR

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Chinese Science Bulletin 2011年第15期56卷 1629-1632页

作者： LI Xian WANG Ju chen xiaojia TIAN JinHuan LI LiHua ZHAO MingYan JIAO YanPeng ZHOU ChangRen Department of Materials Science and Engineering Jinan University Guangzhou 510632 China1 Bioengineering Institute Jinan University Guangzhou 510632 China

Chitooligosaccharide (COS) is derived from the chemical and enzymatic hydrolysis of chitosan and has been reported to have potent antitumor activity.Our study investigated the effects of five chitooligomers ranging from the dimer form to the hexamer form (chitobiose,chitotriose,chitotetraose,chitopentaose,chitohexaose) on the expression of cyclin D1,bcl-2 and bcl-xl mRNA in A549 cells using reverse transcription quantitative real-time PCR.We demonstrated that,of the five chitooligomers used,chitohexaose (COS6) had the most potent inhibitory effect on A549 cell proliferation.COS6 also significantly down regulated cyclin D1 and bcl-xl mRNA expression levels.Our data suggested that COS6 exerts its antitumor activity by two different mechanisms:(1) COS6-mediated inhibition of Cyclin D1 levels leads to suppression of tumor cell proliferation;and (2) COS6-mediated down-regulation of the pro-survival protein,Bcl-xl,promotes the apoptosis of tumor cells.

关键词：细胞周期蛋白D1 mRNA表达水平 A549细胞壳寡糖定量PCR 肿瘤细胞凋亡抗肿瘤活性 cyclin

The effects of luminescent ruthenium（Ⅱ） polypyridyl functionalized selenium nanoparticles on bFGF-induced angiogenesis and AKT/ERK signaling

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The effects of luminescent ruthenium（Ⅱ） polypyridyl funct...

第八届全国化学生物学学术会议

作者： Dongdong Sun Yanan Liu Qianqian Yu Yanhui Zhou Rong Zhang xiaojia chen An Hong Jie Liu Department of Chemistry Jinan University Department of Biology The Chinese University of Hong Kong National Engineering Research Center of Genetic Medicine Guangdong Provincial Key Laboratory of BioengineeringMedicineBiomedicine Institute of Jinan University Department of Cell Biology Jinan University

＜正＞Anti-angiogenesis is an efiective strategy for cancer treatment because uncontrolled tumor growth depends on tumor angiogenesis and sufficient blood supply.Thus, blocking angiogenesis could be a strategy to arrest tumor growth.The function and mechanism of luminescent ruthenium-modified selenium nanoparticles（Ru-SeNPs）in angiogenesis have not been elucidated to date.Here,we found that Ru-SeNPs significantly inhibited human umbilical vascular endothelial cell（HUVEC） proliferation,migration and tube formation.Ru-SeNPs was also tested in vivo in the

关键词： Vascular endothelial growth factor Angiogenesis Selenium Ru（Ⅱ）-polypyridyl complexes

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塞奥多西一世的统治特点

历史教学:下半月 2023年第9期 10-18页

作者：陈志强董晓佳南开大学世界近现代史研究中心天津300350 湖北大学历史文化学院湖北武汉430062

塞奥多西一世在乱世中消除蛮族军事威胁、平息内战分裂势力、维护帝国统一、深化君士坦丁一世开国的各项改革、推进以基督教尼西亚信经为核心的正统意识形态发展,成功避免了“三世纪大危机”中军阀割据局面的重现,扶大厦于不倒。他以强... 详细信息

塞奥多西一世在乱世中消除蛮族军事威胁、平息内战分裂势力、维护帝国统一、深化君士坦丁一世开国的各项改革、推进以基督教尼西亚信经为核心的正统意识形态发展,成功避免了“三世纪大危机”中军阀割据局面的重现,扶大厦于不倒。他以强硬的政治手段延续和发展了帝国皇帝专制统治为核心的中央集权政治,并进一步推进帝国基督教化、改善军事作战体系、健全行政财政制度、力争拜占庭帝国社会物质和精神统一,对帝国千年发展做出贡献。

关键词：拜占庭帝国塞奥多西一世统治

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快速波谱成像用于急性缺血性脑卒中

中国医学影像技术 2022年第2期38卷 172-176页

作者：吴伟陈婷吴小佳罗银灯重庆医科大学附属第二医院放射科重庆400010

目的评价快速波谱成像(TSI)技术用于急性缺血性脑卒中(AIS)的价值。方法对40例AIS患者行TSI及常规多体素化学位移波谱成像(CSI),采用对应频谱拟合脚本获得N-乙酰天冬氨酸(NAA)、肌酸复合物(Cr)、胆碱复合物(Cho)、乳酸(Lac)峰下面积及NA... 详细信息

目的评价快速波谱成像(TSI)技术用于急性缺血性脑卒中(AIS)的价值。方法对40例AIS患者行TSI及常规多体素化学位移波谱成像(CSI),采用对应频谱拟合脚本获得N-乙酰天冬氨酸(NAA)、肌酸复合物(Cr)、胆碱复合物(Cho)、乳酸(Lac)峰下面积及NAA、Cho、Lac与Cr的比值;将TSI和CSI拟合后获得的NAA和Lac分布伪彩图分割后与弥散加权成像(DWI)相融合,分析其匹配程度。结果相比周边正常脑组织,梗死边缘区NAA稍降低,梗死核心区NAA降低程度大于梗死边缘区,Lac则呈相反趋势;梗死周边正常脑组织存在少量Lac分布。TSI与CSI数据经拟合的代谢物分布差异无明显统计学意义(P均>0.05)。TSI与CSI分别显示33例及32例NAA伪彩图暗区分布小于DWI高信号区,Lac伪彩图高亮区明显大于DWI高信号区。结论采用TSI可在较短时间内完成采集,并获得与常规CSI基本一致的代谢物分布数据。AIS患者代谢物分布伪彩图可能与DWI高信号区不匹配。

关键词：脑卒中磁共振成像磁共振波谱