检索结果-南通市图书馆

ATR-FTIR study of Bacillus sp. and Escherichia coli settlements on the bare and Al_2O_3 coated ZnSe internal reflection element

引用

Chinese Chemical Letters 2019年第1期30卷 115-119页

作者： rongqiao chen Chune Guo Wubo Chu Nan Jiang He Li Key Laboratory of Marine Materials and Related Technologies CAS Zhejiang Key Laboratory of Marine Materials and Protective Technologies Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Nano Science and Technology Institute University of Science and Technology of China

Marine microorganism accumulated on the surface of ships or pipelines would accelerate fouling organisms, such as mussels and barnacles, adhered on the surface. It was significant to understand the bio-interaction between the microorganisms and the surface. Attenuated total reflection(ATR) Fourier transform infrared(FTIR) spectroscopy was used to study the initial stages of marine microorganism adhering to surfaces, because it could probe the microorganism interaction to the surface regardless of the water interference. Bacillus sp. and Escherichia coli were selected to study the initial attachment on different surfaces, because they were typical fouling microorganisms and showed opposite Gram stain results. The assays were conducted respectively in dried and settled bacteria on two different surfaces(ZnSe, Al2 O3 coated on ZnSe). IR spectra of settled bacteria showed amide I band red shift and amide II band blue shift in aqueous environment on both surfaces compared with the dry bacteria. The reasons of amide bands shift were investigated and it was discovered that the hydrogen bond between the water and the protein of the bacteria led to the protein secondary structure change. ATR-FTIR provided an approach to study the attachment process and showed dynamic changing process on the surface, and it could be an appropriate approach to study the interaction between proteins and chemicals.

关键词： FTIR-ATR Bacteria settlement Secondary structure Surface interaction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

改进QuEChERS-气相色谱-质谱法测定不同脂肪含量牛奶中19种酯类风味物质

引用

现代食品科技 2024年第3期40卷 281-288页

作者：梁明胡均鹏陈荣桥冼燕萍吴玉銮白卫东戴航侯向昶广州质量监督检测研究院广州市食品安全风险动态监测与预警研究中心广州市食品安全检测技术重点实验室广东广州511447 仲恺农业工程学院轻工食品学院广东省岭南特色食品科学与技术重点实验室广东广州510225

采用改进 QuEChERS- 气相色谱 - 质谱法(GC-MS)技术测定不同脂肪含量牛奶中 19 种酯类风味物质,研究牛奶中酯类风味物质与脂肪含量的关系。样品中的酯类风味物质经乙腈提取和 PSA 净化,净化后的样液经滤膜过滤后采用气相色谱 - 质谱... 详细信息

采用改进 QuEChERS- 气相色谱 - 质谱法(GC-MS)技术测定不同脂肪含量牛奶中 19 种酯类风味物质,研究牛奶中酯类风味物质与脂肪含量的关系。样品中的酯类风味物质经乙腈提取和 PSA 净化,净化后的样液经滤膜过滤后采用气相色谱 - 质谱法测定。19 种酯类风味物质经 DB-FFAP 色谱柱分离,单离子监测模式测定,外标法定量。结果表明, 19 种酯类风味物质在 5.0~500.0 μg/L 质量浓度范围内具有很好的线性关系,相关系数均高于 0.999。通过牛奶样品的加标回收试验,19 种酯类风味物质的平均回收率在 74.7%~109.2% 之间,日内精密度(n=6)在 1.9%~8.5% 之间,方法检出限和定量限分别为 3.5~14.0 μg/kg 和 10.0~40.0 μg/kg。实际样品检测发现牛奶中检出的 δ- 葵内酯、γ- 十二内酯和 δ- 十二内酯的含量与脂肪含量正相关,且全脂纯牛奶>低脂纯牛奶>脱脂纯牛奶;此外,部分牛奶样品可能添加有香精香料,导致 γ- 壬内酯和 γ- 十一内酯的含量明显升高。该方法快速简便、准确度高、重现性好,可满足不同脂肪含量牛奶中 19 种酯类风味物质的检测要求。

关键词：酯类风味物质牛奶 QuEChERS 气相色谱-质谱法

来源：

维普期刊数据库博看期刊

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

γ-癸内酯的生物合成途径及产量提升策略研究进展

引用

现代食品科技 2024年第9期40卷 379-387页

作者：胡均鹏陈荣桥梁明冼燕萍吴玉銮白卫东侯向昶广州质量监督检测研究院广州市食品安全风险动态监测与预警研究中心广州市食品安全检测技术重点实验室广州市NQI-质量安全科技协同创新中心广东广州511447 仲恺农业工程学院广东省岭南特色食品科学与技术重点实验室广东广州510225

γ-癸内酯(γ-Decalactone,GDL),是一种含有椰子、奶油和桃子风味的内酯类化合物,天然存在于水果及发酵产品中,广泛应用在食用香料、化妆品和化工等行业。自然界中γ-癸内酯的存量已经不能满足消费者日益增长的需求,化学合成的γ-癸内... 详细信息

γ-癸内酯(γ-Decalactone,GDL),是一种含有椰子、奶油和桃子风味的内酯类化合物,天然存在于水果及发酵产品中,广泛应用在食用香料、化妆品和化工等行业。自然界中γ-癸内酯的存量已经不能满足消费者日益增长的需求,化学合成的γ-癸内酯是没有光学活性的消旋体,安全性低,对环境不友好,而通过微生物合成的γ-癸内酯,与从植物、水果中提取获得的天然γ-癸内酯相比,结构相似,具有天然等同性,深受消费者喜爱。因此,微生物合成γ-癸内酯具有广阔的研究前景。该文综述了γ-癸内酯的生物合成途径,并对目前的产量提升策略如基因工程、菌株诱变、增加底物分散度、优化发酵条件、细胞固定化和原位分离技术等进行了总结,并在最后讨论了生物合成γ-癸内酯存在的问题和未来的展望。

关键词： γ-癸内酯生物合成途径产量提升策略 β-氧化

来源：

维普期刊数据库博看期刊

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于表面增强拉曼光谱技术测定聚亚苯基砜奶瓶中4,4′-联苯二酚的迁移量

引用

包装工程 2024年第7期45卷 130-136页

作者：胡均鹏奚晓翔陈荣桥梁明冼燕萍吴玉銮侯向昶戴航广州质量监督检测研究院.广州市食品安全风险动态监测与预警研究中心广州511447 广州质量监督检测研究院广州市食品安全检测技术重点实验室广州511447 广州质量监督检测研究院广州市NQI-质量安全科技协同创新中心广州511447

目的基于Ag纳米粒子(Ag nanoparticles,AgNPs)的表面增强拉曼光谱(Surface enhanced Raman spectroscopy,SERS)技术,建立测定聚亚苯基砜奶瓶中4,4′-联苯二酚迁移量的方法。方法参照GB 31604.1—2015、GB 5009.156—2016,对聚亚苯基砜奶瓶中4,4′-联苯二酚的迁移行为进行研究,将获得的迁移液经0.22μm滤膜过滤后,与AgNPs混合,然后进行SERS测试,并采用高效液相色谱法(High performance liquid chromatography,HPLC)进行验证。结果所制备的AgNPs分布均匀、重现性好,针对4,4′-联苯二酚的最低检测质量浓度可达1 mg/L。在质量浓度范围1~50 mg/L内,1278 cm−1处的峰强度与4,4′-联苯二酚的浓度具有良好的线性关系,相关系数为0.9904。在聚亚苯基砜奶瓶中4,4′-联苯二酚的回收率为88.6%~92.8%,相对偏差为4.02%~6.50%,且与HPLC方法的结果基本一致。结论该方法具有快速、准确、操作简单等优点,可为食品接触材料及制品中的4,4′-联苯二酚检测提供技术参考。

关键词：表面增强拉曼光谱 4,4′-联苯二酚银纳米颗粒聚亚苯基砜奶瓶迁移量

来源：

维普期刊数据库

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

Profile of *** chen

引用

Science China(Life Sciences) 2024年第10期67卷 2062-2063页

作者： chen, Songlin Yellow Sea Fisheries Res Inst Qingdao Peoples R China

For decades,*** has been engaged in fish germplasm preservation,sex control and research focusing on molecular breeding for disease *** discovered the first sex-specific molecular marker of fish(chen et al.,2007),deciphered the first fish genome(Chinese tongue sole)in China,revealed the sex determination mechanism in fish(chen et al.,2014),and created molecular sex control *** also discovered the molecular mechanism of metamorphosis in flatfish(Shao et al.,2017)and developed China's first fish disease-resistant breeding gene chip,“YUXIN No.1”.

关键词： technology breeding

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of Reclamation on the Groundwater-Lake Water Interaction in chen Lake

引用

Journal of Earth Science 2024年第3期35卷 1083-1086页

作者： Kun Lei Teng Ma Liuzhu chen Zhenxing Li Yu chen School of Environmental Studies State Key Laboratory of Biogeology and Environmental GeologyChina University of GeosciencesWuhan 430078China

0 INTRODUCTION To relieve the short supply of suitable land for residing,cultivating,and commerce,it is accepted to reclaim land from lakes,river estuaries,and coastal regions in many countries(Mancini et al.,2020).The large-scale reclamation activities have an irreversible effect on the mico-geomorphology and hydrodynamic system of seasonally flooded areas(Zhang et al.,2019;Yu et al.,2018).For example,coastal regions reclaimed extended the groundwater flow paths,as well as created groundwater level rise,resulting in water-logging in the reclaimed area(Hu et al.,2008).Similar changes in groundwater flow systems may alter groundwater-lake water interactions,and it can ultimately affect the water cycle in the lake ***,such detailed studies are presently *** addition,natural exchanges between the lake and groundwater systems can be strongly affected by physical hydrological processes(Javadzadeh et al.,2020),chemical properties(Kamtchueng et al.,2015),and bioto behavior(Hancock et al.,2005).

关键词： groundwater coastal logging

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Meridional deflection of global eddy propagation derived from tandem altimetry: Mechanism and implication

引用

Science China Earth Sciences 2024年第3期67卷 811-825页

作者： Ge chen Xiaoyan chen Frontiers Science Center for Deep Ocean Multispheres and Earth System School of Marine TechnologyOcean University of ChinaQindao 266100China Laboratory for Regional Oceanography and Numerical Modeling Laoshan LaboratoryQindao 266237China

A common view on meridional deflection of eddy propagation is poleward for cyclones and equatorward for anticyclones. This widely accepted polarity-sensitive pattern has been increasingly undermined given that it is systematically violated on both zonal and regional scales as recently reported. Here, we approach the problem by exploring these violations in terms of eddy effects of spatiotemporal geostrophy, thermal fading, and flow dragging, yielding the following main conclusions.(1) The polarity-dependent deflection discrepancy is a pseudo feature resulting from a biased fit to the normalized eddy tracks which are spatially asymmetric(though azimuthally symmetric) between the two signs;Instead, the primary pattern of eddy deflection appears to be geographically correlated and polarity independent.(2) Geostrophic adjustment plays a critical role in defining the meridional movement of an eddy. Specifically, a consistent poleward(equatorward) trajectory bending of spatially(temporally) ageostrophic eddies is observed irrespective of their polarity.(3) The mechanism of eddy deflection is also determined by its zonal propagation direction. Westward propagating eddies are substantially affected by thermal fading, while opposite ones by flow dragging. A realistic and comprehensive understanding of eddy deflection mechanisms serves as a significant contribution to the prediction of eddy trajectory, and the protection of ocean environment.

关键词： Mesoscale eddies Eddy propagation Eddy meridional deflection Satellite observation Geostrophic adjustment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A refined representation method of the particle size distribution curve based on grading entropy

引用

Particuology 2024年第5期88卷 302-311页

作者： Xing Li Qun chen Zhaozhao Liu cheng Zhou chen Wang chen chen State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China

The particle size distribution(PSD)curve is an important expression of the basic properties of the *** characteristic parameters such as median particle size D_(50),effective particle size D_(10),and some combinations of characteristic parameters can only represent some points of the PSD curve,failing to represent all information of the PSD *** this paper,a fraction characteristic parameter F that could reflect the fraction size variation of the PSD curve was introduced based on grading *** a new presentation method of the A-B-F three parameters was proposed for a refined representation of the PSD *** was found that the newly constructed model not only better represents the differences in the width of PSD curves but also has a higher sensitivity than the A-B two-parameter model proposed by Lő*** PSD curves with similar distributions,the new presentation method has a higher degree of discrimination than that of the D_(50)-C_(u)-C_(c) three-parameter or the four-parameter combination G_(c) proposed by ***,the application of this new method in describing the spatial nonuniformity distribution of depositions and predicting the soil hydraulic conductivity was *** research results can provide a reference for the refined representation of PSD curves.

关键词： Grading entropy Particle size distribution curve Refined representation

来源：

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

Track correlation algorithm based on CNN-LSTM for swarm targets

引用

Journal of Systems Engineering and Electronics 2024年第2期35卷 417-429页

作者： chen Jinyang WANG Xuhua chen Xian Research Institute for National Defense Engineering Academy of Military SciencesLuoyang 471023China Information Engineering University Zhengzhou 450001China School of Computer Science and Technology Xidian UniversityXi’an 710071China

The rapid development of unmanned aerial vehicle(UAV) swarm, a new type of aerial threat target, has brought great pressure to the air defense early warning system. At present, most of the track correlation algorithms only use part of the target location, speed, and other information for *** this paper, the artificial neural network method is used to establish the corresponding intelligent track correlation model and method according to the characteristics of swarm ***, a route correlation method based on convolutional neural networks (CNN) and long short-term memory (LSTM)Neural network is designed. In this model, the CNN is used to extract the formation characteristics of UAV swarm and the spatial position characteristics of single UAV track in the formation,while the LSTM is used to extract the time characteristics of UAV swarm. Experimental results show that compared with the traditional algorithms, the algorithm based on CNN-LSTM neural network can make full use of multiple feature information of the target, and has better robustness and accuracy for swarm targets.

关键词： track correlation correlation accuracy rate swarm target convolutional neural network(CNN) long short-term memory(LSTM)neural network

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Two-stage Planning Method for Energy Router Considering Its Optimal Operation in Distribution Networks

引用

CSEE Journal of Power and Energy Systems 2024年第2期10卷 605-616页

作者： Meifu chen Mingchao Xia Qifang chen School of Electrical Engineering Beijing Jiaotong UniversityBeijing 100044China

An energy router can effectively optimize the network loss and power quality of distribution networks. The optimal configuration of the energy router is relatively complex because issues dynamically influence each other, such as the location of the energy router, optimal number and capacity of its ports, and building new distribution lines for the ports. Presently, there has been very few research studies on the practical problems for the energy router. In this paper, a planning model of an energy router combined with the distribution network is established, which fully exploits the active and reactive power control abilities of the energy router to optimize the operation of the grid. The configuration problem is decoupled into two stages. The upper layer determines the location of the energy router and the parameters of the candidate new distribution lines for the ports. The lower layer calculates the optimal configuration of the energy router by minimizing the total annual cost. Because of the same rated bus voltage in the distribution network, the existing structure of the energy router is changed to be more applicable for the distribution network, and then the power flow model of the energy router is also modified. Due to the nonlinearity of the model, the planning model is converted into a mixed-integer second-order cone model to solve efficiently. In addition, some core factors influencing the optimal scheme of the energy router are also analyzed in this paper. Simulation results show that the optimal scheme of the energy router can significantly improve the economic deployment of the energy router, and optimize the network loss and power quality of the distribution network.

关键词： Capacity allocation distribution network energy router optimal operation

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：