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大孔柚子型微结构光纤探针的表面增强拉曼散射性能研究

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光谱学与光谱分析 2024年第2期44卷 527-533页

作者：李佳轩付子珍曹茜清胡志国付兴虎付广伟金娃毕卫红燕山大学信息科学与工程学院河北省特种光纤与光纤传感重点实验室河北秦皇岛066004

随着光纤制备工艺以及纳米材料制备技术的发展,光纤探针已成为一种新型的表面增强拉曼散射(SERS)基底,通过在普通单模光纤或多模光纤上制备不同的结构并修饰相应的纳米材料,可以得到多种类型的光纤表面增强拉曼散射探针,并实现较好的检... 详细信息

随着光纤制备工艺以及纳米材料制备技术的发展,光纤探针已成为一种新型的表面增强拉曼散射(SERS)基底,通过在普通单模光纤或多模光纤上制备不同的结构并修饰相应的纳米材料,可以得到多种类型的光纤表面增强拉曼散射探针,并实现较好的检测效果。但受限于光纤本身的结构,普通光纤仅能利用端面或侧表面提供拉曼检测的“热点”区域,限制了其SERS性能的进一步提高。因此制备了大孔柚子型微结构光纤(MSF)表面增强拉曼散射(SERS)探针,其中大孔柚子型MSF SERS探针结构通过一段阶跃多模光纤与柚子型微结构光纤熔接制得。实验分别对自制的纳米银溶胶基底以及大孔柚子型MSF SERS探针的SERS性能进行检测。采用溶胶自组装法制备负载银纳米颗粒的MSF SERS探针,通过控制自组装时间制备不同光纤SERS探针(Ag/MSF-x,其中x为自组装时间,分别为15、30、45、60 min)。采用溶液检测方法,利用Ag/MSF-x探针对10^(-3) mol·L^(-1)的亚甲基蓝(MB)探针分子进行检测,通过比较相同条件下的增强效果筛选得到Ag/MSF-45探针。为进一步检测Ag/MSF-45探针的SERS性能,制备不同浓度的MB溶液,分别利用纳米银溶胶基底和Ag/MSF-45探针对其进行检测。实验结果表明,纳米银溶胶基底对MB的检测限(LOD)为10^(-6) mol·L^(-1),Ag/MSF-45探针对MB的检测限(LOD)为10^(-7) mol·L^(-1);拉曼信号的再现性结果表明纳米银溶胶基底以及Ag/MSF-45探针在各个特征峰处的RSD值均在合理范围内;在1619 cm^(-1)拉曼位移处对纳米银溶胶基底以及Ag/MSF-45探针检测MB的拉曼强度和浓度进行对数转换拟合,纳米银溶胶基底的拟合优度R2达0.91628,Ag/MSF-45探针的拟合优度R2达0.98848;纳米银溶胶基底和Ag/MSF-45探针的再现性结果表明,其在各个特征峰处的RSD值均处于合理范围,但Ag/MSF-45探针的各特征峰RSD值均小于纳米银溶胶基底,最大为13.89%;利用10^(-6) mol·L^(-1)的MB对Ag/MSF-45探针的增强因子(AEF)进行计算,Ag/MSF-45探针的AEF达到6.09×10^(6),表现出良好的增强效果。因此,基于大孔柚子型MSF SERS探针凭借独特的空气孔结构使其具有较高的灵敏度以及良好的再现性,且其SERS性能均优于纳米银溶胶基底,在农业、化学分析、生物检测等领域及大分子物质检测等方面应用前景广泛。

关键词：表面增强拉曼散射柚子型微结构光纤光纤探针纳米银溶胶亚甲基蓝

踏面与盘式两种制动模式温度分布特征的模拟分析

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润滑与密封 2024年第5期49卷 78-84页

作者：祁伟符蓉杨升大连交通大学连续挤压教育部工程研究中心辽宁大连116028

探究1∶1踏面制动与缩比盘式制动得到的温度场存在偏差的原因,有利于提高利用缩比制动模式评价制动摩擦副热负荷能力的精度。基于TM-I型缩比车辆制动试验台和1∶1制动试验台,采用ADINA有限元软件,在制动压力10、15、20 kN和初速度60、80... 详细信息

探究1∶1踏面制动与缩比盘式制动得到的温度场存在偏差的原因,有利于提高利用缩比制动模式评价制动摩擦副热负荷能力的精度。基于TM-I型缩比车辆制动试验台和1∶1制动试验台,采用ADINA有限元软件,在制动压力10、15、20 kN和初速度60、80、105 km/h条件下,模拟计算2种制动模式的温度场,并分析影响2种制动模式温度偏差的因素。结果表明:1∶1踏面制动模式和缩比盘式制动模式得到的温度存在明显差别,踏面制动的温度均高于缩比盘式制动的温度;2种制动模式的温度差别随压力的变化不明显,但随制动初速度增加而明显加大;踏面制动由于摩擦面积集中,散热程度不良,随初速度从60 km/h增加到105 km/h,制动温度增加幅度为56%~77%,盘式制动由于摩擦弧长沿盘半径方向的不均匀,散热面积大,制动温度随初速度增加幅度为32%~44%。

关键词：踏面制动盘式制动缩比制动模式摩擦温度场

21700锂离子电池在不同健康状态下的热失控实验研究

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储能科学与技术 2024年第3期13卷 971-980页

作者：朱亚宁张振东盛雷陈龙朱泽华付林祥毕青上海理工大学机械工程学院上海200093 常州兴炫德智能制造有限公司江苏常州213000

开展锂离子电池热失控研究,可为提升电池热安全、减少新能源汽车热灾害等提供重要帮助。针对高比能21700型NCM811锂离子电池热滥用、老化等因素引起的热失控问题,通过实验研究了电池健康状态(state of health,SOH)对电池充放电特性及自... 详细信息

开展锂离子电池热失控研究,可为提升电池热安全、减少新能源汽车热灾害等提供重要帮助。针对高比能21700型NCM811锂离子电池热滥用、老化等因素引起的热失控问题,通过实验研究了电池健康状态(state of health,SOH)对电池充放电特性及自身热失控行为的作用机制,量化分析了电池老化特性与热失控触发时间、表面温度、工作电压、燃爆特性、能量、TNT当量及破坏半径等特征参数。发现能量效率随着老化循环次数的增加而降低,电池热失控的温升幅度随SOH的减小而下降,同时其自产热起始温度、热失控触发温度与安全阀脱落温度均减小,这表明老化电池热失控触发所需的时间更短,60%SOH电池在608 s触发热失控,相比于100%SOH缩短了64.8%。SOH越小,电池热失控剧烈程度越弱,热失控后的质量损失也越小。电池热失控过程的峰值温度、释放的能量、TNT当量与破坏半径随SOH的减小而降低,表明老化电池较新鲜电池热失控破坏性降低。研究结果可为全生命周期21700电池热失控的行为特征分析、预警与火灾防控等提供参考。

关键词： 21700三元锂电池健康状态热失控温度能量破坏半径

D^(+)→π^(+)v■decay process within the QCDSR approach

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Chinese Physics C 2024年第6期48卷 69-81页

作者：陈宇付海冰钟涛吴胜波黄冬 Department of Physics Guizhou Minzu UniversityGuiyang 550025China Center of Experimental Training Guiyang Institute of Information Science and TechnologyGuiyang 550025China

In this paper,we investigate the charmed meson rare decay process D^(+)→π^(+)v■using an approach based on QCD sum ***,the pion twist-2,3 distribution amplitude(DA)moments|μ,are calculated up to the tenth and fourth orders,respectively,in the QCD sum rules according to the background field *** constructing the light-cone harmonic oscillator model for the pion twist-2,3 D As,we obtain their behaviors by matching the calculatedξ-***,the D→πtransition form factors(TFFs)are calculated using an approach based on QCD light-cone sum *** vector form factor at the large recoil region is f_(+)^(D)→^(π)(0)=0.627_(-0.080)^(+0.120).Using the rapidly converging simplified series expansion of z(q^(2),t),we present the TFFs and corresponding angular coefficients in the whole squared momentum transfer physical *** on nonstandard neutrino interactions,the■^(0)→π^(+)e■_(e)decay can be related to the■^(0)→π^(+)e■_(e)decay ***,we first describe the semileptonic decay process■^(0)→π^(+)e■_(e),differential decay widths,and branching fraction with B(■^(0)→π^(+)e■_(e))=0.308_(-0.066)^(+0.155)×10^(2).The■^(0)→π^(+)e■_(e)differential/total predictions for forward-backward asymmetry,q^(2)-differential flat terms,and lepton polarization asymmetry are also *** prediction for the D^(+)→π^(+)v■branching fraction isB(D^(+)→π^(+)v■)=1.85_(-0.46)+^(0.93)×10^(-8).

关键词： transition form factors pion LCDAs flavour changing neutral current transition heavy meson semileptonic decays QCD sum rule

Synthesis of carbon quantum dots decorating bi_(2)MoO_(6) microspherical heterostructure and its efficient photocatalytic degradation of antibiotic norfloxacin

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Chinese Chemical Letters 2024年第8期35卷 373-378页

作者： Meijuan Chen Liyun Zhao Xianjin Shi Wei Wang Yu Huang Lijuan fu Lijun Ma School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’an 710049China Key Lab of Aerosol Chemistry and Physics State Key Laboratory of Loess and Quaternary Geology(SKLLQG)Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China

In this study,three-dimensional microspherical CQDs/bi_(2)MoO_(6)heterostructures were synthesized using a simple alcohol-thermal *** was found that the CQDs/bi_(2)MoO_(6)had a large specific surface area of 56.0 m^(2)/g,and the introduction of CQDs extended the light absorption spectrum from 480 nm to 496 *** utilizing the synthesized CQDs/bi_(2)MoO_(6)composite for photocatalytic degradation of antibiotic nor-floxacin in a water environment,complete decay of norfloxacin and effective removal of total organic car-bon(TOC)were achieved within 30 *** the optimization of material synthesis and experimen-tal conditions,the optimal CQDs loading amount was determined as 200μL,the optimal CQDs/bi_(2)MoO_(6)dosage was 0.8 g/***,the CQDs/bi_(2)MoO_(6)worked well under a wide pH range of *** co-existence of HCO_(3)−enhanced the norfloxacin decay,while the presence of Cl^(−),NO_(3)^(−),and SO_(4)^(2−)slightly retarded *** synthesized CQDs/bi_(2)MoO_(6)had the great potential in removing and mineralizing nor-floxacin in real aquatic environments.

关键词： bi_(2)MoO_(6) CQDs Heterojunction Norfloxacin Photocatalysis

Jianpi-Huatan-Huoxue-Anshen formula ameliorates gastrointestinal inflammation and microecological imbalance in chemotherapytreated mice transplanted with H22 hepatocellular carcinoma

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World Journal of Gastrointestinal Oncology 2024年第10期16卷 4209-4231页

作者： Ya-Nan Wang Xiang-Yang Zhai Zheng Wang Chun-Ling Gao Sui-Cai Mi Wen-Li Tang Xue-Min fu Huai-Bang Li Li-Feng Yue Peng-Fei Li sheng-Yan Xi Department of TCM Xiang’an HospitalSchool of MedicineXiamen UniversityXiamen 361102Fujian ProvinceChina Faculty of Chinese Medicine and State Key Laboratory of Quality Research in Chinese Medicine Macao University of Science and TechnologyMacao 999078China Department of Radiotherapy Chenggong Hospital of Xiamen UniversityPLA 73rd Army HospitalXiamen 361003Fujian ProvinceChina Department of Oncology Xiamen Hospital of Traditional Chinese MedicineXiamen 361015Fujian ProvinceChina Dongzhimen Hospital Beijing University of Chinese MedicineBeijing 100700China

BACKGROUND Jianpi-Huatan-Huoxue-Anshen formula[Tzu-Chi cancer-antagonizing&lifeprotecting II decoction(TCCL)]is a Chinese medical formula that has been clinically shown to reduce the gastrointestinal side effects of chemotherapy in cancer patients and improve their quality of ***,its effect and mechanism on the intestinal microecology after chemotherapy are not yet *** To discover the potential mechanisms of TCCL on gastrointestinal inflammation and microecological imbalance in chemotherapy-treated mice transplanted with hepatocellular carcinoma(HCC).METHODS Ninety-six mice were inoculated subcutaneously with HCC *** week later,the mice received a large dose of 5-fluorouracil by intraperitoneal injection to establish a HCC chemotherapy ***-six mice were randomly selected before administration,and feces,ileal tissue,and ileal contents were collected from each *** remaining mice were randomized into normal saline,continuous chemotherapy,Yangzheng Xiaoji capsulestreated,and three TCCL-treated *** treatment,feces,tumors,liver,spleen,thymus,stomach,jejunum,ileum,and colon tissues,and ileal contents were *** changes,serum levels of IL-1β,IL-6,IL-8,IL-10,IL-22,TNF-α,and TGF-β,intestinal SIgA,and protein and mRNA expression of ZO-1,NF-κB,Occludin,MUC-2,Claudin-1,and IκB-αin colon tissues were *** effect of TCCL on the abundance and diversity of intestinal flora was analyzed using 16S rDNA *** TCCL treatment improved thymus and spleen weight,thymus and spleen indexes,and body weight,decreased tumor volumes and tumor tissue cell density,and alleviated injury to gastric,ileal,and colonic mucosal *** proteins and genes associated with inflammation,IL-10,TGF-β,SIgA,ZO-1,MUC-2,and Occludin were upregulated,whereas NF-κB,IL-1β,IL-6,TNF-α,IL-22,IL-8,and IκB-αwere ***,TCCL increased the proportions of fecal Actinobacteria,AF12,Adlercreutzia,Clostridium,Coriobac

关键词： Chinese medicine Chemotherapy H22 hepatocellular carcinoma Intestinal barrier function Intestinal microecological balance

Comparative study on emotional behavior and parental job stress of only-child and non-only-child preschool children

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World Journal of Clinical Cases 2024年第21期12卷 4642-4651页

作者： Zhi-Wei fu Kai-Li Wang Ning-Yu Du Yue-Jing Li Jing-Jing Duan sheng-Xia Zhao Department of Children's Health Shijiazhuang Maternity and Child Healthcare HospitalShijiazhuang 050000Hebei ProvinceChina

BACKGROUND Studies have revealed that Children's psychological,behavioral,and emotional problems are easily influenced by the family *** recent years,the family structure in China has undergone significant changes,with more families having two or three *** To explore the relationship between emotional behavior and parental job stress in only preschool and non-only preschool *** Children aged 3-6 in kindergartens in four main urban areas of Shijiazhuang were selected by stratified sampling for a questionnaire and divided into only and nononly child *** emotional behaviors and parental pressure were *** and non-only children were paired in a 1:1 ratio by class and age(difference less than or equal to 6 months),and the matched data were *** relationship between children's emotional behavior and parents'job stress before and after matching was *** Before matching,the mother's occupation,children's personality characteristics,and children's rearing patterns differed between the groups(P<0.05).After matching 550 pairs,differences in the children's parenting styles *** were significant differences in children's gender and parents'attitudes toward children between the two *** Strengths and Difficulties Questionnaire(SDQ)scores of children in the only child group and the Parenting Stress Index-Short Form(PSI-SF)scores of parents were significantly lower than those in the non-only child group(P<0.05).Pearson’s correlation analysis showed that after matching,there was a positive correlation between children's parenting style and parents'attitudes toward their children(r=0.096,P<0.01),and the PSI-SF score was positively correlated with children's gender,parents'attitudes toward their children,and SDQ scores(r=0.077,0.193,0.172,0.222).CONCLUSION Preschool children's emotional behavior and parental pressure were significantly higher in multi-child *** pressure in differently

关键词： Only child Family structure Children's emotional behavior Parental stress Tendency score

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数字化转型与跨国企业研发国际化投资模式

研究与发展管理 2024年第3期36卷 45-57页

作者：张婷刘晟勇毕晓方天津财经大学会计学院天津300222

数字化转型是推动企业配置全球创新资源、提升创新绩效的重大战略举措。投资模式选择影响跨国企业研发国际化的投资成本、收益分配以及风险水平。探讨数字化转型如何影响跨国企业研发国际化投资模式具有重要意义。基于信息加工理论,利... 详细信息

数字化转型是推动企业配置全球创新资源、提升创新绩效的重大战略举措。投资模式选择影响跨国企业研发国际化的投资成本、收益分配以及风险水平。探讨数字化转型如何影响跨国企业研发国际化投资模式具有重要意义。基于信息加工理论,利用中国上市跨国企业数据,考察数字化转型对跨国企业研发国际化投资模式的影响和作用机制。研究发现:数字化转型能够促进跨国企业选择独资模式而非合资模式展开研发国际化投资。作用机制分析表明,数字化转型通过发挥提质增效和成本降低作用促进跨国企业选择独资模式。在非国有跨国企业中、母国和东道国制度距离较低的情境下,数字化转型更能促进跨国企业选择独资模式。研究发现为理解跨国企业利用数字化转型优化研发国际化投资决策提供了理论依据,为跨国企业全面把握数字化转型的机遇和作用规律提供了管理启示。

关键词：数字转型研发国际化独资合资

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铁电陶瓷脉冲耐压失效分布及耐压可靠性

物理学报 2024年第10期73卷 315-320页

作者：张福平李玺钦杜金梅刘雨生叶福庆中国工程物理研究院流体物理研究所产品工程设计与制造中心绵阳621900

铁电陶瓷在高电场下的击穿问题是困扰铁电陶瓷应用的关键问题之一.本文统计了铁电陶瓷在正向脉冲电场(4.5 kV/mm)失效概率与脉冲次数的分布关系,对通过第10次脉冲耐压样品第11次的失效概率进行了分析,开展了铁电陶瓷经历万次以上的脉冲... 详细信息

铁电陶瓷在高电场下的击穿问题是困扰铁电陶瓷应用的关键问题之一.本文统计了铁电陶瓷在正向脉冲电场(4.5 kV/mm)失效概率与脉冲次数的分布关系,对通过第10次脉冲耐压样品第11次的失效概率进行了分析,开展了铁电陶瓷经历万次以上的脉冲耐压后压电常数与电滞回线测试研究.结果表明:铁电陶瓷的击穿概率与脉冲加电压次数曲线呈现典型的浴盆曲线分布,经历10次脉冲高压测试合格的样品,其脉冲耐压失效概率相比于未经历脉冲高压陶瓷样品,降低了4个数量级以上,且上述脉冲高压加载接近无损.考虑到裂纹扩展速度,多个缺陷导致的裂纹同时扩展并连通是铁电陶瓷在脉冲高电压下断裂的主要原因.

关键词：铁电陶瓷脉冲电场失效概率