检索结果-南通市图书馆

基于脱氧核酶-荧光共振能量转移效应的食品中铅离子快速检测

在线全文

学校读者我要写书评

暂无评论

现代食品科技 2022年第5期38卷 313-319,312页

作者：刘玉梅史雅辰任尧邓锐杰赵志峰何强四川大学轻工科学与工程学院四川成都610065

为实现食品中铅(Pb^(2+))污染的快速检测,该研究构建了一种基于Pb^(2+)依赖型脱氧核酶(DNAzyme)及荧光共振能量转移(Fluorescence resonance energy transfer,FRET)效应的“Turn on”型铅离子检测传感器。荧光猝灭基团BHQ1可以作为FRET... 详细信息

为实现食品中铅(Pb^(2+))污染的快速检测,该研究构建了一种基于Pb^(2+)依赖型脱氧核酶(DNAzyme)及荧光共振能量转移(Fluorescence resonance energy transfer,FRET)效应的“Turn on”型铅离子检测传感器。荧光猝灭基团BHQ1可以作为FRET受体猝灭EvaGreen的荧光。当Pb^(2+)存在时,底物链的特异性切割反应可以减弱BHQ1对EvaGreen的猝灭效果,BHQ1随底物链的断裂而释放,远离供体EvaGreen,因此FRET效应减弱,供体EvaGreen的荧光得以保留。该研究利用Pb^(2+)诱导的FRET效应的减弱及EvaGreen荧光信号的增强可以对铅离子进行定性、定量分析。当脱氧核酶臂长为15 nt~5 nt、EvaGreen浓度为1×、底物链与酶链的浓度分别为400 nmol/L与100 nmol/L时,探究了该方法的检出限及线性范围。该反应可在室温条件下3 min内完成,同时对铅离子具有高度的特异性,可以区分不同的金属离子,并且成功应用于新鲜鸡蛋及自来水中的铅离子定量分析,加标回收率为86.79%~113.32%。该研究设计的“Turn on”型铅离子检测传感器可于室温条件下进行一管混反应,无需扩增,反应迅速,为检测食品中的铅污染提供了一些思路。

关键词：食品安全铅离子脱氧核酶荧光共振能量转移

VFDB注释法在食源性金黄色葡萄球菌肠毒素基因分型分析中的应用

在线全文

学校读者我要写书评

暂无评论

中国食品卫生杂志 2022年第6期34卷 1218-1225页

作者：徐蕾蕊汪琦刘俊巴哈提古丽·马那提拜邓锐杰曾静孙震中国海关科学技术研究中心北京100026 成都海关四川成都610041 乌鲁木齐海关新疆乌鲁木齐830018 四川大学四川成都610042

目的应用VFDB注释法对食源性金黄色葡萄球菌肠毒素基因进行分型并评价其准确性。方法分别使用VFDB注释法和特异引物PCR方法对2009—2016年从北京地区食品中分离的53株金黄色葡萄球菌的18种肠毒素基因(包括传统肠毒素基因sea~see,新型... 详细信息

目的应用VFDB注释法对食源性金黄色葡萄球菌肠毒素基因进行分型并评价其准确性。方法分别使用VFDB注释法和特异引物PCR方法对2009—2016年从北京地区食品中分离的53株金黄色葡萄球菌的18种肠毒素基因(包括传统肠毒素基因sea~see,新型肠毒素基因seg~sej和类肠毒素基因sek~seu)携带情况进行分析。将VFDB注释法所得肠毒素基因序列上传至NCBI,使用BLASTX程序和refseq_protein数据库对注释结果进一步核对。结果 VFDB注释法和PCR方法都检测出53株金黄色葡萄球菌分离株中有45株携带1种或多种肠毒素基因,有8株未携带肠毒素基因,肠毒素基因的总携带率为84.91%(45/53),经典肠毒素基因的携带率为58.49%(31/53)。45株携带肠毒素基因的分离株中,16株菌(35.56%,16/45)肠毒素基因VFDB分型结果与PCR一致,29株菌(64.44%,29/45)的肠毒素基因VFDB分型结果与PCR不一致。经BLASTX核对,VFDB注释法可能误判的基因型包括sea/sed、sea/sej、sea/sep、sea/ser、seg/ser和sek/sei(VFDB注释/BLASTX核对)。结论 VFDB注释法可对食源性金黄色葡萄球菌肠毒素基因进行分型分析,但是对注释为sea、seg和sek的序列建议采用BLASTX程序和refseq_protein数据库进一步核对,以提高基因分型的准确性。

关键词： VFDB注释法金黄色葡萄球菌肠毒素基因分型

在线全文

学校读者我要写书评

暂无评论

烟芯材料吸湿特性评价技术研究进展

轻工学报 2024年第3期39卷 109-118页

作者：郑赛晶刘广超陈嘉彬高峄涵张轶辉邓锐杰上海新型烟草制品研究院有限公司上海201315 深圳新型烟草制品有限公司广东深圳457001 四川大学轻工科学与工程学院四川成都610065

针对烟芯材料在加工贮藏过程中极易受到环境湿度影响而产生吸湿或解湿的问题,对烟芯材料吸湿特性的评价技术进行梳理。指出:平衡含水率能够反映烟芯材料的持水能力,测试技术主要包括有损检测(烘箱法、气相色谱法、卡尔费休法、差量法)... 详细信息

针对烟芯材料在加工贮藏过程中极易受到环境湿度影响而产生吸湿或解湿的问题,对烟芯材料吸湿特性的评价技术进行梳理。指出:平衡含水率能够反映烟芯材料的持水能力,测试技术主要包括有损检测(烘箱法、气相色谱法、卡尔费休法、差量法)和无损检测(核磁法、微波法、红外法),前者具有较高的准确性,但耗时长;后者具有快速无损的优点,但易受样品形态、堆积状态等的影响。进一步地,水分赋存形态则可通过水分活度表征法和低场核磁共振法进行解析,水分活度反映了水分的可利用程度,而低场核磁共振法则能监测区分自由水和结合水,但会受其他含氢成分干扰。吸附热力学可通过等温吸湿曲线、吸附模型、吸附热进行探究,吸湿动力学可通过吸湿时间曲线及其相关模型进行探讨,但仅从热力学或动力学角度来评价吸湿特性可能存在评价维度的片面性、适用范围的局限性等问题。未来可将二者结合,以建立更为合理、适用性更广的烟芯材料吸湿特性评价技术,为烟草制品在加工贮藏过程中的吸湿特性研究提供参考。

关键词：吸湿特性烟芯材料动力学热力学评价技术

梨树始花期与气象因子的影响分析及预报模型建立

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

安徽农学通报 2024年第20期30卷 103-108页

作者：邓锐捷陈志龙蔡欣明赵桂琼成都市新津区气象局四川成都611432

为开展梨属植物开花期精细化气象服务,提升梨树始花期预报精度。本研究基于1999—2023年四川成都新津区梨树物候观测数据与气象资料,采用Julian日换算法分析梨树始花期特征,运用数理统计方法分析梨树始花期与气象因子的相关性。选取1999... 详细信息

为开展梨属植物开花期精细化气象服务,提升梨树始花期预报精度。本研究基于1999—2023年四川成都新津区梨树物候观测数据与气象资料,采用Julian日换算法分析梨树始花期特征,运用数理统计方法分析梨树始花期与气象因子的相关性。选取1999—2018年数据资料,利用逐步回归法建立梨树始花期预报模型,并利用2019—2023年数据进行模型预报检验。梨树始花期特征表明,梨树始花期在3月上旬至3月下旬,常年平均始花期在3月13日,始花期最早和最晚相差22 d,花期持续日数最短与最长相差14 d。相关性结果显示,始花期与花前14 d平均最低气温呈负相关(P<0.01),与花前21 d降水日数呈正相关(P<0.05),花前14 d的7日滑动平均气温稳定通过11.6℃后3~10 d为梨树进入始花期的气象指标;梨树花期持续日数与雨日、降水量、日照时数呈正相关(P<0.05),小雨天气有利于延长花期。预报模型建立和检验结果表明,通过当年1—2月≥0℃活动积温和1月最高气温能有效预报梨树始花期,较常年花期提前13 d进行预测。本研究为梨花观赏精准化的气象服务提供参考。

关键词：梨树始花期气象因子相关性分析气象预报模型

维普期刊数据库博看期刊

在线全文

学校读者我要写书评

暂无评论

成都市秋桂开花期气象指标及预测

中国农学通报 2022年第29期38卷 135-139页

作者：赵桂琼邓锐捷陈志龙蔡欣明陈乐成都市新津区气象局成都611430 成都市温江区气象局成都611130

为开展成都市秋桂花期精细化气象服务,建立秋桂花期气象预测模式,本研究基于成都市2004—2016年桂花物候观测与气象资料,运用数理统计法开展成都市秋桂花前、花期与气象因子的关系研究,结合桂树生育特性建立秋桂始花期预测模型。结果表... 详细信息

为开展成都市秋桂花期精细化气象服务,建立秋桂花期气象预测模式,本研究基于成都市2004—2016年桂花物候观测与气象资料,运用数理统计法开展成都市秋桂花前、花期与气象因子的关系研究,结合桂树生育特性建立秋桂始花期预测模型。结果表明:花前降雨充沛,5日滑动平均气温稳定通过23℃后,秋桂3~6天进入始花期;秋桂花期喜雨晴相间,花期日平均气温20~24℃,雨日、降水量、日照是影响花期长短的主要气象因子;秋桂始花早晚与2月下旬旬最高气温、旬日照时数和7月下旬雨日呈正相关;与10月下旬雨量、5月下旬雨日呈负相关。研究建立的成都市秋桂始花期预测模型经回代验证历史拟合率较高,具有较好的预报效果,能提前20天预测,可用于秋桂初花期中长期预报,为成都市桂花观赏提供精准化的气象服务。

关键词：桂花开花期气象指标预测

Data-driven design of Ni-based turbine disc superalloys to improve yield strength

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第24期155卷 175-191页

作者： Bin Xu Haiqing Yin Xue Jiang Cong Zhang ruijie Zhang Yongwei Wang Xuanhui Qu Zhenghua deng Guoqiang Yang Dil Faraz Khan Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology Beijing Beijing 100083 China Collaborative Innovation Center of Steel Technology University of Science and Technology Beijing Beijing 100083 China Beijing Key Laboratory of Materials Genome Engineering University of Science and Technology Beijing Beijing 100083 China Institute for Advanced Materials and Technology University of Science and Technology Beijing Beijing 100083 China School of Mechanical Engineering Chongqing Three Gorges University Chongqing 404000 China School of Mechanical and Equipment Engineering Hebei University of Engineering Handan 056038 China Department of Physics University of Science and Technology Bannu Bannu 28100 Pakistan

Increasing the thrust-weight ratio of aeroengines requires development of high-strength and stable high-temperature materials. A data-driven design of Ni-based turbine disc superalloys is performed to improve the yield strength to reach the target. Through first-principles calculations determining the design superalloy system, the theoretical models and Calculation of Phase Diagram (CALPHAD) screening compositions, and machine learning extrapolating prediction, 14 compositions are selected from 2,865,039 composition combinations. Ni-17Cr-8Co-1Mo-1W-6Al-3Ti-1Nb-1Ta is selected to verify the design accuracy. Experimental tests prove that the designed alloy has trade-offs of microstructure with satisfying design targets, and then, the yield strength is higher in the designed alloy than in commercial superalloys, reaching 728 MPa at 850 ℃. A scheme for increasing the performance of the designed alloy is proposed by discussing the strengthening mechanisms, machine learning process, and alloying chemistry effect. The cross-scale data-driven design is regarded as an accurate and efficient way to design novel high-strength Ni-based turbine disc superalloys, whose significance is the obvious reduction of trial-and-error tests.

关键词： Ni-based superalloys Data-driven design Machine learning CALPHAD First-principles calculation

The effects of DS blade's geometry features on material's creep strength

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

Propulsion and Power Research 2014年第3期3卷 143-150页

作者： Xiaojun Yan Kai Zhang Ying deng ruijie Sun Lianshan Lin Xiaoyong Zhang School of Energy and Power Engineering Beihang UniversityBeijing 100191China Oak Ridge National Laboratony Oak RidgeTN 37831United States

Because of the better creep performance,the directional solidification(DS)Nickel-based turbine blades have been widely used in advanced ***,the DS turbine blade's different abrupt geometrical changes at different regions cause a variation of temperature field at those ***,the variable temperature field is very likely to lead to a different grain structures at those different region,and those different grain structure finally give rise to a variation in material's creep performance at different region in DS turbine *** study the variation in creep strength among different regions of a DS turbine blade,this article designed and manufactured three types of DS specimens to simulate the geometry features of platform,shroud and body part of a typical DS turbine *** tests on these specimens were conducted under the stress level of 608 MPa and temperature of 850。C,the creep rupture life of platform-like and shroud-like specimens are 93%and 73%of body-like specimens'respectively,which support the assumption that there exists a certain variation in material's creep strength among different regions in DS turbine *** fracture positions of these specimens also support above *** is suggested that the material's creep strength variation among different locations of DS turbine blades should be considered in future turbine blade life design and prediction.

关键词： Creep strength Directional solidification Turbine blade Grain structure Geometry features

Clean water generation with switchable dispersion of multifunctional Fe3O4-reduced graphene oxide particles

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

Progress in Natural Science:Materials International 2018年第4期28卷 422-429页

作者： ruijie Zhao Jiale Xu Peng Tao Fenglei Shi Fan Yu Xiaoliang Zeng Chengyi Song Jianbo Wu Wen Shang Tao deng State Key Laboratory of Metal Matrix Composites School of Materials Science and Engineering Shanghai Jiao Tong University Guangdong Provincial Key Laboratory of Materials for High Density Electronic Packaging Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences

With the increased need for clean water and decreased supply of fresh water, purification of contaminated water can provide clean water that supplements the fresh water from nature. Physical adsorption, photo-degradation and solar-driven evaporation processes are promising ways to generate clean water with minimum environmental impact. However, different purification process requires different dispersion state of the treating agent to maximize its performance. Herein, we demonstrate that Fe3O4-reduced graphene oxide(MrGO) particles with switchable dispersion can be used as the multifunctional water treating agents to efficiently purify contaminated water through different processes. Under homogenously dispersed nanofluid mode, the MrGO particles have large exposed surface areas and can efficiently remove organic dye pollutants through physical adsorption. The uniform dispersion state also favors high contact efficiency facilitating decontamination of high concentration of organic compounds through solar-driven photocatalytic degradation by the MrGO particles. The excellent magnetic response of MrGO particles not only allows for easy collection of the treating agent from water but also enables assembly of MrGO at the air-water interface with external magnets. Under such interfacial assembled mode, clean water can be distilled out of the contaminated solution with high evaporation efficiency of 74.7% under simulated natural solar radiation. This work demonstrates that dispersion state can be used as another important means to optimize water purification performances.

关键词： Adsorption Photo-degradation Evaporation Dispersion state Water treatment

Highly Stretchable and Permeable Conductors Based on Shrinkable Electrospun Fiber Mats

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Advanced Fiber Materials 2021年第5期3卷 302-311页

作者： Qingsong Li Chen Ding Wei Yuan ruijie Xie Xiaomeng Zhou Yang Zhao Mei Yu Zijian Yang Jing Sun Qiong Tian Fei Han Hanfei Li Xinping deng Guanglin Li Zhiyuan Liu CAS Key Laboratory of Human‑Machine Intelligence‑Synergy Systems Shenzhen Institutes of Advanced TechnologyChinese Academy of Sciences(CAS)Shenzhen 518055China Printable Electronics Research Centre Suzhou Institute of Nano‑Tech and Nano‑BionicsChinese Academy of SciencesSuzhou 215123China

Wearable on-skin electrodes or conductors should be vapor permeable,strain-insensitive,isotropically stretchable and stable under cyclic *** strategies have been proposed to prepare the required conductors up to now;however,it is a challenge to fabricate them with above properties in a simple *** this paper,a highly permeable and stretchable conductor based on electrospun fluorine rubber fiber mat is *** fibers are pre-stretched in electric field during electrospinning,and they shrink isotropically by~35-40%in area after being detached from the *** obtained fiber mat conductor demonstrates high stretchability up to~170%,and the resistance changes only 0.8 under 60%strain,which is superior to many other strain-insensitive *** conductor possesses high stability,no cracks or structure damage are observed after washing and cyclic ***,the conductor is vapor permeable with a water vapor transmission rate of~850 g m−2 day−1,which is comparable to the normal water evaporation in ambient conditions,indicating that it would not disturb the sweat evaporation when being used on *** conductor is successfully used as stretchable yarns and electromyography(EMG)electrodes,showing high reliability in E-textiles and on-skin applications.

关键词： Electrospinning Shrinkable fiber mat Stretchable conductor Wearable E-textiles EMG signal recording