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应用激光 2023年第8期43卷 122-130页

作者：贺旭文郭华玲郑宾刘辉崔缙贾庸斌中北大学电气与控制工程学院山西太原030051

针对小口径金属圆柱内部不同角度缺陷的检测,通过有限元方法对铝圆柱中横波的传播特性进行研究。通过横波方向性的研究确定横波的能量范围,在横波的主要能量范围设置内部不同角度的人工矩形缺陷,通过B-scan的方法对PRS波(与缺陷作用的... 详细信息

针对小口径金属圆柱内部不同角度缺陷的检测,通过有限元方法对铝圆柱中横波的传播特性进行研究。通过横波方向性的研究确定横波的能量范围,在横波的主要能量范围设置内部不同角度的人工矩形缺陷,通过B-scan的方法对PRS波(与缺陷作用的一次反射横波)的传播特性进行研究。通过对PRS波出现的扫查角度范围进行统计研究,确定PRS波的最佳探测角β(扫查角度范围内PRS波幅值最大的扫查角度)。根据扫查角度范围内最大幅值PRS波的到达时间与缺陷角度α关系对α角进行了反演,α角为30°时误差最大,误差为0.025,其他缺陷角度下误差均小于0.02。利用PRS波的扫查角度范围和最佳探测角β完成不同α角下PRS波的可视化,提出一种通过提取能量点评估α角的方法。以上研究结果为激光超声检测柱状材料内部缺陷提供了一定的参考。

关键词：激光超声横波柱状材料内部缺陷角度数值模拟

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A review of clay based photocatalysts: Role of phyllosilicate mineral in interfacial assembly, microstructure control and performance regulation

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CHEMOSPHERE 2021年 273卷 129723-129723页

作者： Li, Chunquan Zhu, Ningyuan Yang, Shanshan He, xuwen zheng, Shuilin Sun, Zhiming Dionysiou, Dionysios D. China Univ Min & Technol Beijing Sch Chem & Environm Engn Beijing 100083 Peoples R China Chinese Acad Sci Inst Soil Sci State Key Lab Soil & Sustainable Agr Zigui Ecol Stn Three Gorges Dam Project 71 East Beijing Rd Nanjing 210008 Peoples R China Peking Univ Sch Earth & Space Sci Beijing 100871 Peoples R China Univ Cincinnati Dept Chem & Environm Engn DCEE Cincinnati OH 45221 USA

Over the past decades, inspired by the outstanding properties of clay minerals such as abundance, low-cost, environmental benignity, high stability, and regularly arranged silica-alumina framework, researchers put much efforts on the interface assembly and surface modification of natural minerals with bare photocatalysts, i.e. TiO2, g-C3N4, ZnO, MoS2, etc. The clay-based hybrid photocatalysts have resulted in a rich database for their tailor-designed microstructures, characterizations, and environmental-related applications. Therefore, in this study, we took a brief introduction of three representative minerals, i.e. kaolinite, montmorillonite and rectorite, and discussed their basic merits in photocatalysis applications. After that, we summarized the recent advances in construction of stable visible-light driven photocatalysts based on these minerals. The structure-activity relationships between the properties of clay types, pore structure, distribution/dispersion and light absorption, carrier separation efficiency as well as redox performance were illustrated in detail. Such representative information would provide theoretical basis and scientific support for the application of clay based photocatalysts. Finally, we pointed out the major challenges and future directions at the end of this review. Undoubtedly, control and preparation of novel photocatalysts based on clays will continue to witness many breakthroughs in the arena of solar-driven technologies. (C) 2021 Elsevier Ltd. All rights reserved.

关键词： Clay mineral Composite photocatalysts Interface assembly Surface modification Structure-activity relationship

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Purines enrich root-associated Pseudomonas and improve wild soybean growth under salt stress

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NATURE COMMUNICATIONS 2024年第1期15卷 3520页

作者： zheng, Yanfen Cao, xuwen Zhou, Yanan Ma, Siqi Wang, Youqiang Li, Zhe Zhao, Donglin Yang, Yanzhe Zhang, Han Meng, Chen Xie, Zhihong Sui, Xiaona Xu, Kangwen Li, Yiqiang Zhang, Cheng-Sheng Chinese Acad Agr Sci Tobacco Res Inst Marine Agr Res Ctr Qingdao 266101 Peoples R China Shandong Univ Inst Marine Sci & Technol Qingdao 266200 Peoples R China Shandong Agr Univ Coll Resources & Environm Natl Engn Lab Efficient Utilizat Soil & Fertilizer Tai An 271018 Peoples R China

The root-associated microbiota plays an important role in the response to environmental stress. However, the underlying mechanisms controlling the interaction between salt-stressed plants and microbiota are poorly understood. Here, by focusing on a salt-tolerant plant wild soybean (Glycine soja), we demonstrate that highly conserved microbes dominated by Pseudomonas are enriched in the root and rhizosphere microbiota of salt-stressed plant. Two corresponding Pseudomonas isolates are confirmed to enhance the salt tolerance of wild soybean. Shotgun metagenomic and metatranscriptomic sequencing reveal that motility-associated genes, mainly chemotaxis and flagellar assembly, are significantly enriched and expressed in salt-treated samples. We further find that roots of salt stressed plants secreted purines, especially xanthine, which induce motility of the Pseudomonas isolates. Moreover, exogenous application for xanthine to non-stressed plants results in Pseudomonas enrichment, reproducing the microbiota shift in salt-stressed root. Finally, Pseudomonas mutant analysis shows that the motility related gene cheW is required for chemotaxis toward xanthine and for enhancing plant salt tolerance. Our study proposes that wild soybean recruits beneficial Pseudomonas species by exudating key metabolites (i.e., purine) against salt stress.

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基于磁控制的双谐振腔LLC谐振变换器

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电子器件 2022年第3期45卷 551-556页

作者：郑宏严序文袁雪凯秦润田尤涛江苏大学电气信息工程学院江苏镇江212013

LLC谐振变换器可以实现原边开关管的零电压开通和副边整流管的零电流关断,变换效率较高,但传统的LLC谐振变换器具有输入电压范围不宽、且在宽输入电压范围下效率较低的缺点。针对这个缺点,本文在拓扑和控制方法上做出改进,提出了一种利... 详细信息

LLC谐振变换器可以实现原边开关管的零电压开通和副边整流管的零电流关断,变换效率较高,但传统的LLC谐振变换器具有输入电压范围不宽、且在宽输入电压范围下效率较低的缺点。针对这个缺点,本文在拓扑和控制方法上做出改进,提出了一种利用磁控制的可变电感来实现定频模式下输出电压控制与调节的全桥双谐振腔LLC变换器,在没有牺牲效率的前提下,拓宽了输入电压的范围。并且制作了一台输入为120 V~400 V,输出为48 V/5 A的实验样机,验证了理论分析的正确性。

关键词： LLC谐振变换器磁控制双谐振宽输入电压高效率

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Compositional correlation and polymorphism in BaF2-PrF3 thin films deposited using electron-beam evaporation

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THIN SOLID FILMS 2019年 669卷 558-563页

作者： He, Weixiang zheng, Weimin Xie, Ping Li, Bin Lv, xuwen Jing, Chao Liu, Dingquan Shanghai Univ Dept Phys Shanghai 200444 Peoples R China Shandong Univ Sch Space Sci & Phys Weihai 264209 Peoples R China Chinese Acad Sci Shanghai Inst Tech Phys Shanghai 200083 Peoples R China Shanghai Tech Univ Sch Phys Sci & Technol Shanghai 200031 Peoples R China

Infrared low-index evaporation materials are essential in the broadband antireflection coatings to reduce Fresnel reflections on the surfaces of infrared optical components. Although the layers of praseodymium fluoride (PrF3) show an excellent transparency and the lower refractive index n and extinction coefficient k in the spectral range of thermal infrared, the tensile stress presented in the layers prohibits PrF3 from being used as infrared low-index coating materials. A practical solution to reduce stress is to directly evaporate the admixture of PrF3 with alkaline fluorides, such as barium fluoride (BaF2). However, due to the significant difference of vapor pressures between PrF3 and BaF2, it is commonly difficult to congruently deposit PrF3-BaF2 thin films utilizing evaporating directly from a single source. Moreover, more details are unknown about the phase compositions of PrF3-BaF2 thin films. In our investigation, BaF2-PrF3 thin films were deposited using electron beam evaporation from the sintered ingots of PrF3 admixed with BaF2. The compositions of thin films were characterized using energy dispersive X-ray spectroscopy (EDX), the crystallographic structures were explored by X-ray-diffraction (XRD). It was revealed that the concentration of BaF2 in thin films can be correlated to that in the admixtures. Moreover, in addition to PrF3 and BaF2, the phase compositions in thin films include also secondary phases, such as PrOF, PrF4, Pr2F2, BaPrF6, and that of elemental Ba.

关键词： Infrared low -index evaporation materials BaF2-PrF3 Electron beam evaporation Compositional correlation Polymorphism

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A combined generalized Warblet transform and second order synchroextracting transform for analyzing nonstationary signals of rotating machinery

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SCIENTIFIC REPORTS 2021年第1期11卷 1-12页

作者： Wei, Kai Jing, xuwen Li, Bingqiang Kang, Chao Dou, Zhenhuan Liu, Jinfeng Chen, Yu zheng, Hainan Jiangsu Univ Sci & Technol Sch Mech Engn Zhenjiang 212013 Jiangsu Peoples R China Shaanxi Diesel Heavy Ind LTD Xian Peoples R China

In recent years, considerable attention has been paid in time-frequency analysis (TFA) methods, which is an effective technology in processing the vibration signal of rotating machinery. However, TFA techniques are not sufficient to handle signals having a strong non-stationary characteristic. To overcome this drawback, taking short-time Fourier transform as a link, a TFA methods that using the generalized Warblet transform (GWT) in combination with the second order synchroextracting transform (SSET) is proposed in this study. Firstly, based on the GWT and SSET theories, this paper proposes a method combining the two TFA methods to improve the TFA concentration, named GWT-SSET. Secondly, the method is verified numerically with single-component and multi-component signals, respectively. Quantized indicators, Renyi entropy and mean relative error (MRE) are used to analyze the concentration of TFA and accuracy of instantly frequency (IF) estimation, respectively. Finally, the proposed method is applied to analyze nonstationary signals in variable speed. The numerical and experimental results illustrate the effectiveness of the GWT-SSET method.

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Medical Data Mining Course Development in Postgraduate Medical Education: Web-Based Survey and Case Study

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JMIR MEDICAL EDUCATION 2021年第4期7卷 e24027页

作者： Yang, Lin zheng, Si Xu, Xiaowei Sun, Yueping Wang, xuwen Li, Jiao Chinese Acad Med Sci & Peking Union Med Coll Inst Med Informat & Lib 3 Yabao Rd Beijing 100020 Peoples R China

Background: Medical postgraduates' demand for data capabilities is growing, as biomedical research becomes more data driven, integrative, and computational. In the context of the application of big data in health and medicine, the integration of data mining skills into postgraduate medical education becomes important. Objective: This study aimed to demonstrate the design and implementation of a medical data mining course for medical postgraduates with diverse backgrounds in a medical school. Methods: We developed a medical data mining course called "Practical Techniques of Medical Data Mining" for postgraduate medical education and taught the course online at Peking Union Medical College (PUMC). To identify the background knowledge, programming skills, and expectations of targeted learners, we conducted a web-based questionnaire survey. After determining the instructional methods to be used in the course, three technical platforms-Rain Classroom, Tencent Meeting, and WeChat-were chosen for online teaching. A medical data mining platform called Medical Data Mining - R Programming Hub (MedHub) was developed for self-learning, which could support the development and comprehensive testing of data mining algorithms. Finally, we carried out a postcourse survey and a case study to demonstrate that our online course could accommodate a diverse group of medical students with a wide range of academic backgrounds and programming experience. Results: In total, 200 postgraduates from 30 disciplines participated in the precourse survey. Based on the analysis of students' characteristics and expectations, we designed an optimized course structured into nine logical teaching units (one 4-hour unit per week for 9 weeks). The course covered basic knowledge of R programming, machine learning models, clinical data mining, and omics data mining, among other topics, as well as diversified health care analysis scenarios. Finally, this 9-week course was successfully implemented in an onlin

关键词： medical data mining course development online teaching postgraduate medical education

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Effect of a closed-loop medication order executive system on safe medication administration at a tertiary hospital: a quasi-experimental study

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THERAPEUTIC ADVANCES IN DRUG SAFETY 2024年 15卷

作者： Yin, xuwen Song, Haiyan Lu, Jieyu Yang, Jing Wang, Rong Lin, zheng Jiang, Shudi Yuan, Hui Wang, Xumei Xu, Dongmei Gao, Chunhong Zhou, Yuan Xu, Jiayi Chen, Chen Gu, Chenyu Diao, Qingqing Li, Fang Gu, Zejuan Nanjing Univ Chinese Med Sch Nursing Nanjing 210029 Peoples R China Nanjing Med Univ Affiliated Hosp 1 Dept Nursing Nanjing 210029 Peoples R China Nanjing Med Univ Sch Nursing Nanjing Peoples R China

Background: Closed-loop electronic medication management systems are effective measures for preventing medication errors (MEs). However, there is limited evidence supporting this, and few studies have evaluated the long-term effects of these systems on safe medication. Objective: To evaluate the long-term effects of implementing a closed-loop medication order executive system on the safe clinical use of medications. Design: A quasi-experimental design. Method: Data from 2017 to 2023 were extracted and retrospectively analyzed. The primary outcome indicator was the ME rate. Secondary outcome indicators were the accuracy of order verification and patient identification and the implementation rate of fresh medicine dispensing. The autoregressive integrated moving average (ARIMA) model in time-series analysis was used to evaluate the level and trend changes in ME rates using SPSS 25.0 before and after system implementation. Root cause analysis and descriptive statistics were used to assess changes in types, stages, and causes of ME rates. The independent samples t-test was used to analyze secondary outcomes. Results: Overall, 295 MEs were reported with a mean of 0.26 +/- 0.26 ME rates per month during 2017-2023. The ARIMA model showed a decrease in the average level of ME rates after system implementation, with no statistically significant decrease in the long term, and a significant drop in the ME rate in the short and medium term (p < 0.01). Nurses' administration accounted for more than 60% of errors post-implementation, and lack of communication was a prominent factor. The accuracy of order verification and patient identification and the implementation rate of fresh medicine dispensing all increased after implementation. Conclusion: Adopting a closed-loop executive system is beneficial for ensuring patient medication safety, but a single integrated system does not completely eliminate MEs. Optimizing system functionalities and applying structured handoff tools are r

关键词： closed-loop electronic medication management system medication error patient safety

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伪狂犬活/灭活病毒接种小鼠诱导免疫效力及差异因子比较

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南京农业大学学报 2023年第1期46卷 106-111页

作者：章晨昕于晓明侯立婷张元鹏乔绪稳侯继波黄克和郑其升陈瑾南京农业大学动物医学院江苏南京210095 江苏省农业科学院动物免疫工程研究所/国家兽用生物制品工程技术研究中心江苏南京210014 江苏省食品质量安全重点实验室-省部共建国家重点实验室培育基地江苏南京210014

[目的]本研究旨在比较活/灭活病毒进入体内后对免疫系统活化的差异,为免疫增强剂的筛选和评价建立高效动物模型。[方法]本试验利用伪狂犬病毒(PRV)Bartha-K61株建立小鼠伪狂犬人工感染模型,筛选活/灭活病毒接种小鼠后免疫相关差异因子。... 详细信息

[目的]本研究旨在比较活/灭活病毒进入体内后对免疫系统活化的差异,为免疫增强剂的筛选和评价建立高效动物模型。[方法]本试验利用伪狂犬病毒(PRV)Bartha-K61株建立小鼠伪狂犬人工感染模型,筛选活/灭活病毒接种小鼠后免疫相关差异因子。将PRV Bartha-K61活毒以不同剂量、不同方式感染小鼠,通过计算小鼠存活率确定最佳感染剂量与感染方式;将筛选的最佳剂量的伪狂犬病毒活毒与相同剂量下灭活病毒按照前述筛选的最佳感染方式接种小鼠,利用ELISA试剂盒检测免疫7 d后小鼠血清中TNF-α、IL-1β、IFN-β和IL-6水平;利用PRV gB ELISA检测免疫7 d后小鼠血清PRV特异性gB抗体水平;利用灭活PRV作为特异性抗原进行淋巴细胞增殖试验并计算各组淋巴细胞刺激指数(SI)。[结果]在保证小鼠存活的前提下,6~8周龄小鼠的PRV的安全感染剂量为5×104TCID50;同等剂量下,相比于肌肉和腹腔注射,皮下注射为最安全的感染方式;同等剂量的活毒和灭活病毒接种小鼠后,与灭活病毒组相比,活病毒感染7 d后小鼠血清中TNF-α、IL-1β和IFN-β水平显著升高(P<0.001,P<0.01),与灭活病毒组相比,活病毒组小鼠血清PRV gB特异性抗体IgG水平和SI也显著升高(P<0.05,P<0.001);不同灭活方式间各细胞因子和SI差异不显著(P>0.05)。[结论]成功建立小鼠伪狂犬人工感染模型,明确活/灭活伪狂犬病毒接种小鼠后,机体早期存在与免疫相关差异因子,为后续免疫增强剂的评价筛选提供依据。

关键词：伪狂犬病毒小鼠模型免疫效力差异因子

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Sequentially Triggered Bacterial Outer Membrane Vesicles for Macrophage Metabolism Modulation and Tumor Metastasis Suppression

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ACS NANO 2021年第8期15卷 13826-13838页

作者： Guo, Qin Li, xuwen Zhou, Wenxi Chu, Yongchao Chen, Qinjun Zhang, Yiwen Li, Chao Chen, Hongyi Liu, Peixin Zhao, Zhenhao Wang, Yu Zhou, zheng Luo, Yifan Li, Chufeng You, Haoyu Song, Haolin Su, Boyu Zhang, Tongyu Sun, Tao Jiang, Chen Fudan Univ Sch Pharm Dept Pharmaceut Key Lab Smart Drug DeliveryMinist EducState Key Shanghai 201203 Peoples R China

Metabolic interactions between different cell types in the tumor microenvironment (TME) often result in reprogramming of the metabolism to be totally different from their normal physiological processes in order to support tumor growth. Many studies have attempted to inhibit tumor growth and activate tumor immunity by regulating the metabolism of tumors and other cells in TME. However, metabolic inhibitors often suffer from the heterogeneity of tumors, since the favorable metabolic regulation of malignant cells and other cells in TME is often inconsistent with each other. Therefore, we reported the design of a pH-sensitive drug delivery system that targets different cells in TME successively. Outer membrane vesicles (OMVs) derived from Gram-negative bacteria were applied to coload paclitaxel (PTX) and regulated in development and DNA damage response 1 (Redd1)-siRNA and regulate tumor metabolism microenvironment and suppress tumor growth. Our siRNA@M-/PTX-CA-OMVs could first release PTX triggered by the tumor pH (pH 6.8). Then the rest of it would be taken in by M2 macrophages to increase their level of glycolysis. Great potential was observed in TAM repolarization, tumor suppression, tumor immune activation, and TME remolding in the triple-negative breast cancer model. The application of the OMV provided an insight for establishing a codelivery platform for chemical drugs and genetic medicines.

关键词： bacterial OMVs pH sensitive TAM polarization immune therapy cancer treatment

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