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无营养性甜味剂——替代糖

化学教育（中英文） 2024年第2期45卷 1-12页

作者：黄柯郑积敏杨春霞北京师范大学化学学院北京100875

在过去的几十年里,消费者比过去更关注自己的健康,特别是在食品、饮料和药物中,使用甜味剂来代替糖是一种有效的策略。替代糖属于食品甜味添加剂的一种,也被称为无营养甜味剂(non-nutritive sweeteners,NNS),包括人工替代糖和天然替代... 详细信息

在过去的几十年里,消费者比过去更关注自己的健康,特别是在食品、饮料和药物中,使用甜味剂来代替糖是一种有效的策略。替代糖属于食品甜味添加剂的一种,也被称为无营养甜味剂(non-nutritive sweeteners,NNS),包括人工替代糖和天然替代糖。这些替代糖具有低卡路里或零热量的特点,使得消费者对这类甜味剂的需求急剧增长。利用低成本原料生产低热量替代糖成为最近的研究热点。然而,随着对其需求量和使用量的急剧增加,过度使用替代糖同样也会导致厌食症和肥胖相关疾病的产生。本文总结了人工替代糖的分类和合成工艺以及天然替代糖的提取手段,同时讨论了这些替代糖所带来的健康益处及潜在的不良影响。

关键词：替代糖无营养甜味剂人工替代糖天然替代糖

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刈割对三尖叶猪屎豆养分积累与再生性的影响

南方农业学报 2024年第1期55卷 169-178页

作者：赵志平杨丽萍刘忠妹杨春霞云南省热带作物科学研究所/云南省天然橡胶可持续利用研究重点实验室/天然橡胶良种选育与栽培技术国家地方联合工程研究中心云南西双版纳666100

【目的】探究三尖叶猪屎豆养分积累、再生性对刈割方式(刈割时期和频次)和留茬高度的响应,为橡胶园覆盖绿肥管理提供理论和技术指导。【方法】在树龄为3年的橡胶园中设12个处理:年刈割时期和频次为营养期刈割1次和2次、花期刈割1次,每... 详细信息

【目的】探究三尖叶猪屎豆养分积累、再生性对刈割方式(刈割时期和频次)和留茬高度的响应,为橡胶园覆盖绿肥管理提供理论和技术指导。【方法】在树龄为3年的橡胶园中设12个处理:年刈割时期和频次为营养期刈割1次和2次、花期刈割1次,每个刈割时期和频次留茬高度为20.0、30.0、40.0和50.0 cm,监测不同刈割方式和留茬高度三尖叶猪屎豆的产量及干物质、氮、磷、钾、钙和镁积累量,以及刈割后1~4个月的萌发再生情况。【结果】刈割方式对三尖叶猪屎豆产量、干物质和养分积累量均具有显著影响(P<0.05,下同),营养期刈割2次/年处理三尖叶猪屎豆的产量、干物质和养分积累量均显著高于营养期刈割1次/年和花期刈割1次/年处理,产量分别提高102.44%~159.62%和54.96%~149.71%,干物质积累量分别提高103.19%~161.44%和50.46%~142.72%,氮积累量分别提高102.44%~159.62%和53.58%~209.70%,磷积累量分别提高100.44%~161.62%和-1.52%~65.73%,钾积累量分别提高101.42%~160.64%和-14.95%~108.59%,钙积累量分别提高104.42%~157.64%和46.65%~206.53%,镁积累量分别提高99.62%~155.44%和81.62%~223.57%。留茬高度对三尖叶猪屎豆产量、干物质和养分积累量具有显著影响,其中,花期刈割1次/年处理、留茬高度30.0 cm三尖叶猪屎豆的产量、干物质和养分积累量均最高;营养期刈割2次/年处理、留茬高度40.0 cm三尖叶猪屎豆的产量、干物质和养分积累量及再生性均最佳。方差分析结果表明,刈割方式和留茬高度及其互作,对猪屎豆的干物质和养分积累量均具有极显著影响(P<0.01)。【结论】刈割方式和留茬高度均显著影响三尖叶猪屎豆的产量、干物质和养分积累量及再生性。橡胶园间种三尖叶猪屎豆的最佳刈割方式为营养期刈割2次/年,留茬高度40.0 cm。

关键词：三尖叶猪屎豆刈割时期刈割频次留茬高度产量养分积累再生性

Theoretical and experimental investigations on single-atom catalysis:Pt1/FeOx for water-gas shift reaction Shan-Fei Wang1,§,yangyang Li2,3,§,Haiyan Wang1,Jin-xia Liang1(✉),chun Zhu1

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Nano Research 2024年第9期17卷 8627-8637页

作者： Shan-Fei Wang yangyang Li Haiyan Wang Jin-xia Liang chun Zhu Botao Qiao School of Chemistry and Chemical Engineering Guizhou UniversityGuiyang 550025China CAS Key Laboratory of Science and Technology on Applied Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100049China

Oxide-supported metal single-atom catalysts(SACs)have exhibited excellent catalytic performance for water-gas shift(WGS)***,we report the single-atom catalyst Pt1/FeOx exhibits excellent medium temperature catalytic performance for WGS reactions by the density functional theory(DFT)calculations and experimental *** calculations indicate that H_(2)O molecules are easily dissociated at oxygen vacancies,and the formed*OH and*O are adsorbed on Pt1 single atoms and the adjacent O atoms,*** studying four possible reaction mechanisms,it is found that the optimal WGS reaction pathway is proceeded along the carboxyl mechanism(pathway III),in which the formation of*COOH intermediates can promote the stability of Pt1/FeOx SAC and the easier occurrence of WGS *** energy barrier of the rate-determining step during the entire reaction cycle is only 1.16 eV,showing the high activity for the medium temperature WGS reaction on Pt1/FeOx SAC,which was verified by experimental ***,the calculated turnover frequencies(TOFs)of CO_(2)and H_(2)formation on Pt1/FeOx at 610 K(337℃)can reach up to 1.14×10^(-3)s^(-1)·site^(-1)through carboxyl *** this work,we further expand the application potential of Pt1/FeOx SAC in WGS reaction.

关键词： water-gas shift(WGS)reaction single-atom catalyst(SAC) density functional theory(DFT) thermocatalysis

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高扬程泵站虹吸式出水流道虹吸形成过程分析

水电能源科学 2024年第4期42卷 160-163,177页

作者：杨春霞苏圣致刘绍谦郑源张千旭河海大学电气与动力工程学院江苏南京211100 黄河勘测规划设计研究院有限公司河南郑州450003

为研究高扬程泵站虹吸式出水流道虹吸形成过程,以某高扬程泵站的出水流道及出水池为研究对象,建立三维模型并使用Fluent仿真计算了虹吸管流态变化。针对3种出水池水位使用VOF模型计算其压力、流速等参数。驼峰段原角度为段前150°、段后... 详细信息

为研究高扬程泵站虹吸式出水流道虹吸形成过程,以某高扬程泵站的出水流道及出水池为研究对象,建立三维模型并使用Fluent仿真计算了虹吸管流态变化。针对3种出水池水位使用VOF模型计算其压力、流速等参数。驼峰段原角度为段前150°、段后160°,在虹吸段顶端使用DN350的真空破坏阀,同时改变驼峰段角度进行优化,发现将段前角度增加10°后,虹吸形成时间为448 s,相较于优化前缩短了56 s,改善了泵启动过程。分析发现,不同水位下虹吸形成时压力分布较为均匀;水位较低时流速分布不均,不良流态产生,低水位造成的负面影响远大于高水位;在驼峰段安装DN350真空阀能减小水力损失,对虹吸形成过程起到促进作用;真空阀会影响经典断面处流速分布,产生高流速区,出水池水位较低时,该现象使得流速分布不均。

关键词：高扬程虹吸式出水管气液两相流虹吸形成时间数值模拟

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2014~2019年北京某三甲医院腹腔感染革兰阴性菌的耐药情况与合理用药的探讨

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中国合理用药探索 2024年第7期21卷 30-41页

作者：陈曦毛熠王鹏刘慧宇杨春霞首都医科大学附属北京朝阳医院感染和临床微生物科北京100020 默沙东(中国)投资有限公司全球医学事务部上海200233

目的:通过对北京某三甲医院2014~2019年期间采集的腹腔感染革兰阴性菌的鉴定和对常用抗菌药物的药敏测试,为近年院内腹腔感染革兰阴性菌的流行病学和耐药情况提供参考依据。方法:使用定制药敏板通过Trek系统进行抗菌药物敏感性测试并依... 详细信息

目的:通过对北京某三甲医院2014~2019年期间采集的腹腔感染革兰阴性菌的鉴定和对常用抗菌药物的药敏测试,为近年院内腹腔感染革兰阴性菌的流行病学和耐药情况提供参考依据。方法:使用定制药敏板通过Trek系统进行抗菌药物敏感性测试并依据CLSI2021标准进行药敏判读。结果:2014~2019年期间共收集革兰阴性菌464株,其中肠杆菌目细菌355株,社区获得性感染菌株123株、医院获得性感染菌株341株,ICU收集的菌株187株。药敏试验显示:该院碳青霉烯类抗菌药物耐药菌中,大肠埃希菌对目前国内常用的12种抗菌药物几乎都呈现不敏感状态,仅阿米卡星的敏感率为81.8%;除黏菌素外,肺炎克雷伯菌几乎无抗菌药物可选择;铜绿假单胞菌目前对环丙沙星、头孢吡肟、阿米卡星的敏感率均为75.0%。该院喹诺酮类抗菌药物耐药菌中,对大肠埃希菌治疗有效率达到82.5%及以上的抗菌药物有厄他培南、亚胺培南、美罗培南、阿米卡星和黏菌素;亚胺培南、美罗培南和阿米卡星对肺炎克雷伯菌的敏感率仅在65.0%左右;对于铜绿假单胞菌,可选的抗菌药物有头孢他啶、头孢吡肟和阿米卡星(敏感率均为66.7%)。该院第三代头孢菌素耐药菌中,大肠埃希菌对亚胺培南、美罗培南、阿米卡星和黏菌素的敏感率均在93.0%以上;肺炎克雷伯菌对亚胺培南、美罗培南和阿米卡星的敏感率在71.4%~79.2%;铜绿假单胞菌对环丙沙星、美罗培南、阿米卡星和黏菌素的敏感率在83.3%以上。无论是碳青霉烯类抗菌药物耐药鲍曼不动杆菌,还是喹诺酮类抗菌药物耐药鲍曼不动杆菌,或者是第三代头孢菌素耐药鲍曼不动杆菌,除黏菌素的敏感率为97.6%~100.0%外,几乎无常规抗菌药物可供选择。结论:腹腔感染革兰阴性菌总体耐药形势比较严峻,持续监测本地区医院病原菌检出率和合理选择对耐药菌株有效的抗菌药物治疗非常重要。

关键词：革兰阴性菌肠杆菌目细菌不发酵糖革兰阴性菌抗菌药物耐药

Electrochemical Study and Application on Shikonin at Poly（diallyldimethylammonium chloride） Functionalized Graphene Sheets Modified Glass Carbon Electrode

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Chemical Research in Chinese Universities 2013年第4期29卷 798-805页

作者： AN Jing LI Ji-ping CHEN Wen-xia yang chun-xia HU Fang-di WANG chun-ming School of Pharmacy Hospital of Lanzhou University College of Chemistry and Chemical Engineering Lanzhou University Lanzhou 730000 P. R. China

The electrochemical behaviors of shikonin at a poly（diallyldimethylammonium chloride） functionalized graphene sheets modified glass carbon electrode（PDDA-GS/GCE） have been investigated. Shikonin could exhibit a pair of well-defined redox peaks at the PDDA-GS/GCE located at 0.681 V（Epa） and 0.662 V（Epc）[vs. saturated calo- mel electrode（SCE）] in 0.1 mol/L phosphate buffer solution（pH=2.0） with a peak-to-peak separation of about 20 mV, revealing a fast electron-transfer process. Moreover, the current response was remarkably increased at PDDA- GS/GCE compared with that at the bare GCE. The electrochemical behaviors of shikonin at the modified electrode were investigated. And the results indicate that the reaction involves the transfer of two electrons, accompanied by two protons and the electrochemical process is a diffusional-controlled electrode process. The electrochemical para- meters of shikonin at the modified electrode, the electron-transfer coefficient（a）, the electron-transfer number（n） and the electrode reaction rate constant（ks） were calculated to be as 0.53, 2.18 and 3.6 s^-1, respectively. Under the optimal conditions, the peak current of differential pulse voltammetry（DPV） increased linearly with the shikonin concentra- tion in a range from 9A72×10^-8 mol/L to 3,789×10^-6 mol/L with a detection limit of 3,157× 10^-8 mol/L. The linear regression equation was Ip=O.7366c＋0.7855（R=0.9978; lp： 10-7 A, c： 10-8 mol/L）. In addition, the modified glass carbon electrode also exhibited good stability, selectivity and acceptable reproducibility that could be used for the sensitive, simple and rapid determination of shikonin in real samples. Therefore, the present work offers a new way to broaden the analytical application of graphene in pharmaceutical analysis.

关键词： Shikonin Poly(diallyldimethylammonium chloride) functionalized graphene sheets modified glass carbon electrode(PDDA-GS/GCE) Cyclic voltammetry Differential pulse voltammetry Electrochemical sensor

Electronic structure regulation and built-in electric field synergistically strengthen photocatalytic nitrogen fixation performance on Ti-BiOBr/TiO_(2)heterostructure

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Rare Metals 2024年第3期43卷 1125-1138页

作者： Ru-Qi Li Yu-Jie Bian chun-Ming yang Li Guo Tao-xia Ma Chuan-Tao Wang Feng Fu Dan-Jun Wang College of Chemistry and Chemical Engineering Yan’an UniversityYan’an Key Laboratory of Green Catalysis and Quality Improvement and Utilization of Low Rank CoalYan’an716000China

At present,industrial synthetic ammonia was still obtained through the Hubble-Bosch process,with large energy *** is a research hotspot to realize green synthetic ammonia by using solar *** difficulty of photocatalytic ammonia synthesis was that the photo-excited electrons have not enough energy to active N≡*** this study,Ti was doped into BiOBr by one-step hydrothermal method,which was oxidized into TiO_(2)when the doping amount reaches the maximum,in situ forming Ti_(0.31)B_(0.69)OB/TiO_(2)*** from the synergistic effect of Ti doping and S-scheme heterojunction,the synthetic ammonia efficiency of Ti_(0.31)B_(0.69)OB/TiO_(2)-11.96 reached 1.643 mmol·g_(cat)^(-1)at mild conditions and without hole scavenger for up to 7 h,the efficiency of synthetic ammonia is 115 times,10.5 times and 3.3 times of that of BiOBr,Ti_(0.31)B_(0.69)OB and TiO_(2),***,DFT calculation confirms that Ti doping accurately refine the electronic structure of BiOBr,facilitate nitrogen adsorption activation and reduce hydrogenation reaction energy barrier,thus accelerating the reaction kinetics of photocatalytic nitrogen reduction(NRR),Meanwhile,constructing S-scheme heterojunction boosts the separation and transfer of photogenerated electron-hole pairs,improving the reduction ability of electrons in the conduction band of TiO_(2)and the oxidation ability of holes in the valence band of Ti_(0.31)B_(0.69)OB.

关键词： S-scheme heterostructure Electronic structure regulation Built-in electric field Synergistical stren4gthening Photocatalytic nitrogen fixation

Computational Screening of Pt1@Ti_(3)C_(2)T_(2)(T=O,S)MXene Catalysts for Water-Gas Shift Reaction

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Precision Chemistry 2024年第2期2卷 70-80页

作者： yang Meng Haiyan Wang Jin-xia Liang chun Zhu Jun Li School of Chemistry and Chemical Engineering Guizhou UniversityGuiyang 550025China Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry Southern University of Science and TechnologyShenzhen 518055China Department of Chemistry and Engineering Research Center of Advanced Rare-Earth Materials of Ministry of Education Tsinghua UniversityBeijing 100084China

Single-atom catalysts(SACs)provide an oppor-tunity to elucidate the catalytic mechanism of complex reactions in heterogeneous *** low-temperature water-gas shift(WGS)reaction is an important industrial technology to obtain high purity ***,we study the catalytic activity of Pt1@Ti_(3)C_(2)T_(2)(T=O,S)SACs,where one subsurface Ti atom with three T vacancies in the functionalized Ti_(3)C_(2)T_(2)(T=O,S)MXene is substituted by one Pt atom,for the low-temperature show that Pt1@Ti_(3)C_(2)T_(2)provides an excellent platform for the WGS reaction by its bowl-shaped vacancy derived from the Pt1 single atom and three T defects surrounding ***,Pt1@Ti_(3)C_(2)S_(2)SAC has higher catalytic performance for the WGS reaction,due to the weaker electronegativity of the S atom than the O atom,which significantly reduces the energy barrier of H*migration in the WGS reaction,which is often the rate-determining *** the most favorable redox mechanism of the WGS reaction on Pt1@Ti_(3)C_(2)S_(2),the rate-determining step is the dissociation of OH*into O*and H*with the energy barrier as low as 1.12 *** results demonstrate that Pt1@Ti_(3)C_(2)S_(2)is promising in the application of MXenes for low-temperature WGS reactions.

关键词： single-atom catalyst(SAC) density functional theory(DFT) water gas shift(WGS)reaction defective MXene thermocatalysis

中国社区中老年人夜间睡眠时长与抑郁的相关性研究

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现代预防医学 2024年第11期51卷 2061-2065页

作者：汪玥杉龙文成彭介入沈晓丽张璐张绮文董尧黄祖波余葱葱王超周浩杨春霞四川大学华西公共卫生学院/华西第四医院流行病与卫生统计学系四川大学华西第四医院陈志潜慢性病研究中心成都市妇女儿童中心医院四川省中西医结合医院亚健康研究中心

目的探讨中国社区中老年人睡眠情况与抑郁的相关性，为提升中老年人睡眠质量、心理健康及生活质量提供参考。方法本研究数据来自中国健康与养老追踪调查（China Health and Retirement Longitudinal Study,CHARLS）2013和2018年资料... 详细信息

目的探讨中国社区中老年人睡眠情况与抑郁的相关性，为提升中老年人睡眠质量、心理健康及生活质量提供参考。方法本研究数据来自中国健康与养老追踪调查（China Health and Retirement Longitudinal Study,CHARLS）2013和2018年资料，经过筛选数据，最终纳入研究对象6 312例。将研究对象按其夜间睡眠时长进行分组，构建多因素线性回归模型及多元logistic回归模型，调整协变量，分析夜间睡眠时长与抑郁的关系。结果夜间睡眠时长过短或过长（7～<8 h为正常睡眠时长）的占76.81%;2018年的抑郁得分及检出率在不同夜间睡眠时长分组中差异具有统计学意义（F=30.127，χ2=67.928，均有P<0.001）。夜间睡眠时间与抑郁得分呈负相关（β=-0.278,P<0.001），进一步考虑协变量后，短时睡眠时长（≤5 h）是检出抑郁的风险因素（OR=1.621,95%CI:1.371～1.918），且女性相较男性风险更高（女性OR=1.673,95%CI:1.363～2.054；男性OR=1.501,95%CI:1.120～2.012）。结论中老年人的夜间睡眠与抑郁相关，并受到人口学、社会经济因素、健康行为因素等协变量影响，且中老年女性较男性、高龄较低龄有更高风险。应重视中老年人睡眠健康与心理健康，提高中老年人生活质量。

关键词：睡眠时间抑郁 CHARLS 老龄化