该研究建立了一种QuEChERS净化结合超高效液相色谱串联质谱法(ultra performance liquid chromatography tandem mass spectrometry,UPLC-MS/MS)快速测定动物源性食品中溴虫氟苯双酰胺残留量的分析方法。样品使用QuEChERS吸附净化,经含0...该研究建立了一种QuEChERS净化结合超高效液相色谱串联质谱法(ultra performance liquid chromatography tandem mass spectrometry,UPLC-MS/MS)快速测定动物源性食品中溴虫氟苯双酰胺残留量的分析方法。样品使用QuEChERS吸附净化,经含0.1%(体积分数)甲酸的乙腈提取,MgSO_(4)、C18及N-丙基乙二胺净化,净化液离心后过膜上机测定。UPLC-MS/MS法以乙腈和5 mmol/L乙酸铵(含体积分数0.1%甲酸)水溶液为流动相,以0.300 mL/min的流速进行梯度洗脱,使用ACQUITY UPLC BEH C18色谱柱进行分离,电喷雾离子源正离子模式电离,多反应监测模式检测,基质匹配标准曲线外标法定量。结果表明:溴虫氟苯双酰胺在0.200~100μg/L范围内呈良好线性,相关系数(R^(2))均大于0.999,方法的定量限为0.5~1.0μg/kg;以动物源性食品为基质,在低中高(2.0、10.0和50.0μg/kg)添加水平下,溴虫氟苯双酰胺的平均加标回收率为93.9%~102%,相对标准偏差为2.25%~5.86%。该方法便于操作,实验过程短,检测准确性高,可以填补动物源性食品中溴虫氟苯双酰胺的检测方法的空白,并可为动物源性食品中溴虫氟苯双酰胺农药残留限量值的制定提供技术支撑。展开更多
为系统研究谷子(Setaria italica)参与DNA甲基化修饰相关酶类的编码基因,本研究以测序品种‘豫谷1’为材料,水稻(Oryza sativa L.) DNA甲基化修饰相关酶类基因作为参考,运用序列比对和系统进化树构建的方法,得到13个参与谷子DNA甲基化...为系统研究谷子(Setaria italica)参与DNA甲基化修饰相关酶类的编码基因,本研究以测序品种‘豫谷1’为材料,水稻(Oryza sativa L.) DNA甲基化修饰相关酶类基因作为参考,运用序列比对和系统进化树构建的方法,得到13个参与谷子DNA甲基化修饰相关的酶类基因,这些基因与水稻的相应基因相似度为64%~80%。谷子与水稻中DNA甲基化修饰相关酶类基因在系统进化树上主要分成了三个进化枝,并且同功的DNA甲基化修饰相关酶类基因在分枝上彼此相邻。同时,实时荧光定量PCR筛选出13对在谷子中能成功扩增的引物,并对实时荧光定量PCR的程序进行确立和优化。本研究为深入开展谷子的表观遗传学研究提供了科学依据。展开更多
The flourishing age of China,the great beauty of Zhangzhou.Across the Taiwan Strait and Chinese mainland,we share the joy,Jiu Longbi stone add its splendor.On May 16,2019,China.Zhangzhou Cross-Strait Viewing Stone App...The flourishing age of China,the great beauty of Zhangzhou.Across the Taiwan Strait and Chinese mainland,we share the joy,Jiu Longbi stone add its splendor.On May 16,2019,China.Zhangzhou Cross-Strait Viewing Stone Appreciation Cultural Exchange Exhibition held a grand opening ceremony at Zhangzhou Museum of Art,Fujian Province.展开更多
Interfacial water is of fundamental importance in many technological fields, such as biological processes, chemical reactions and lubrications. A prevalent way to study the structure and dynamics of interfacial water ...Interfacial water is of fundamental importance in many technological fields, such as biological processes, chemical reactions and lubrications. A prevalent way to study the structure and dynamics of interfacial water is carrying out molecular dynamics simulations with empirical potential water models. However, discrepant results have been reported due to their different charge geometries and target properties. Here we investigated the interfacial water structures on smooth surfaces of varying hydrophobicity at low temperatures by comprehensive molecular dynamics simulations with the prevailing water models. It is shown that the choice of the water model can significantly change the water structure on the hydrophilic surface, while has a minor effect on the contact angle on a hydrophobic surface. Furthermore, zero-dimensional ice pyramids and one-dimensional icicles were formed under the regulation of external charges injected to the substrate or imposed electric field, respectively. These results offer new insights into the water structures on different surfaces and reasonable choice of parameters in molecular simulations, and the development of water models.展开更多
Boron nitride(BN) nanomaterials share the same atomic structures as their carbon counterparts, with mechanical and thermal properties second only to carbon counterparts. Especially, the iconicity of B-N bonds results ...Boron nitride(BN) nanomaterials share the same atomic structures as their carbon counterparts, with mechanical and thermal properties second only to carbon counterparts. Especially, the iconicity of B-N bonds results in exceptionally high thermal stability and corrosion resistance, making BN nanomaterials a compelling contender for fabricating devices that can operate under harsh environments. However, all pristine BN nanomaterials are electric insulators and lack semiconductive functionality.How to efficiently regulate the electronic properties of BN nanomaterials has impeded the way of delivering their potential into applications. Here, we report an overview of key progress in functionalizing BN nanostructures by means of multi-physical-field coupling at nanoscale. In particular, we present how the chemical doping, electric fields, elastic strains and interfaces can modify the band structures and hence lead to narrowed bandgap and even magnetism in various BN nanostructures. We also discuss the effect of these modulation methods on charge carrier motility as well as potential challenges of their experimental implementation. Without applied doping, strain and electric field, employing inherent BN polarity to form electrically polarized interfaces is proposed to functionalize BN nanostructures towards controlled electronic properties combined with high carrier motility. We finally discuss recent progress of experimental synthesis of quality h-BN samples in large area.展开更多
文摘为系统研究谷子(Setaria italica)参与DNA甲基化修饰相关酶类的编码基因,本研究以测序品种‘豫谷1’为材料,水稻(Oryza sativa L.) DNA甲基化修饰相关酶类基因作为参考,运用序列比对和系统进化树构建的方法,得到13个参与谷子DNA甲基化修饰相关的酶类基因,这些基因与水稻的相应基因相似度为64%~80%。谷子与水稻中DNA甲基化修饰相关酶类基因在系统进化树上主要分成了三个进化枝,并且同功的DNA甲基化修饰相关酶类基因在分枝上彼此相邻。同时,实时荧光定量PCR筛选出13对在谷子中能成功扩增的引物,并对实时荧光定量PCR的程序进行确立和优化。本研究为深入开展谷子的表观遗传学研究提供了科学依据。
文摘The flourishing age of China,the great beauty of Zhangzhou.Across the Taiwan Strait and Chinese mainland,we share the joy,Jiu Longbi stone add its splendor.On May 16,2019,China.Zhangzhou Cross-Strait Viewing Stone Appreciation Cultural Exchange Exhibition held a grand opening ceremony at Zhangzhou Museum of Art,Fujian Province.
文摘Interfacial water is of fundamental importance in many technological fields, such as biological processes, chemical reactions and lubrications. A prevalent way to study the structure and dynamics of interfacial water is carrying out molecular dynamics simulations with empirical potential water models. However, discrepant results have been reported due to their different charge geometries and target properties. Here we investigated the interfacial water structures on smooth surfaces of varying hydrophobicity at low temperatures by comprehensive molecular dynamics simulations with the prevailing water models. It is shown that the choice of the water model can significantly change the water structure on the hydrophilic surface, while has a minor effect on the contact angle on a hydrophobic surface. Furthermore, zero-dimensional ice pyramids and one-dimensional icicles were formed under the regulation of external charges injected to the substrate or imposed electric field, respectively. These results offer new insights into the water structures on different surfaces and reasonable choice of parameters in molecular simulations, and the development of water models.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11772153 and 11402115)the NSF of Jiangsu Province(Grant No. BK20190018)+1 种基金the Fundamental Research Funds for the Central Universities (Grant No. NE2018002)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Boron nitride(BN) nanomaterials share the same atomic structures as their carbon counterparts, with mechanical and thermal properties second only to carbon counterparts. Especially, the iconicity of B-N bonds results in exceptionally high thermal stability and corrosion resistance, making BN nanomaterials a compelling contender for fabricating devices that can operate under harsh environments. However, all pristine BN nanomaterials are electric insulators and lack semiconductive functionality.How to efficiently regulate the electronic properties of BN nanomaterials has impeded the way of delivering their potential into applications. Here, we report an overview of key progress in functionalizing BN nanostructures by means of multi-physical-field coupling at nanoscale. In particular, we present how the chemical doping, electric fields, elastic strains and interfaces can modify the band structures and hence lead to narrowed bandgap and even magnetism in various BN nanostructures. We also discuss the effect of these modulation methods on charge carrier motility as well as potential challenges of their experimental implementation. Without applied doping, strain and electric field, employing inherent BN polarity to form electrically polarized interfaces is proposed to functionalize BN nanostructures towards controlled electronic properties combined with high carrier motility. We finally discuss recent progress of experimental synthesis of quality h-BN samples in large area.
