An investigation on the detection of pigments using shell-isolated nanoparticle-enhanced Raman spectroscopy based on atomic layer deposition

以原子层沉积技术(ALD)制备出的壳层厚度为1; nm的Ag@Al_2O_3核壳纳米粒子为基底,采用壳层隔绝纳米粒子增强拉曼光谱(SHINERS)技术对色素检测进行探究。对Ag@Al_2O_3粒; 子的最佳粒径、色素检出限做了研究,并对实际样品中日落黄和柠檬黄的色素添加进行SHINERS检测。结果表明,对日落黄和柠檬黄具有最佳SHINERS; 效果的Ag@Al_2O_3粒子的最佳粒径为300 nm,方法对日落黄和柠檬黄标准溶液的检出限分别为10 mug/L和100; mug/L,对液体饮料中日落黄和柠檬黄标准品的SHINERS检出限分别为10 mg/L和50; mg/L,对所选实际样品中部分样品的日落黄和柠檬黄添加不符合国家标准。This study investigated the detection of pigment based on Ag@Al_2O_3; core-shell nanoparticles with shell-isolated nanoparticle-enhanced Raman; spectroscopy (SHINERS). The Ag@Al_2O_3 core-shell nanoparticles, which; shell thickness was 1 nm, was made by using atomic layer deposition; (ALD) technique. The study explored the best particle size of Ag@Al_2O_3; with best SHINERS effect and the SHINERS LOD of pigment. The method was; also applied to detect pigments in drink and food samples. The results; showed that the best size of Ag@Al_2O_3 nano particle with best SHINERS; effect of sunset yellow and lemon yellow was 300 nm, the SHINERS LOD of; standard solutions of sunset yellow and lemon yellow were 10 mug/L and; 100 mug/L,respectively,the SHINERS LODs of sunset yellow and lemon; yellow in drink were 10 mg/L and 50 mg/L,respectively, and sunset yellow; and lemon yellow in some of the selected real samples do not meet the; national standards.国家自然科学基金; 福建省自然科学基

Three-dimensional Porous Cu_6Sn_5 Alloy Anodes for Lithium-ion Batteries

以三维多孔泡沫铜为基底,通过直接电沉积的方法制备锂离子电池Cu6Sn5合金负极材料.发现合金表面大量的微孔和“小岛”不仅增大电极的表面积,而且显著缓解充放电过程中的体积变化.测得三维多孔Cu6Sn5合金的初始放电(嵌锂)容量为620mAh·g-1,充电(脱锂)容量为560mAh·g-1,库仑效率达到90.3%,具有较好的循环性能.扫描电子显微镜(SEM)结果显示,在泡沫铜基底上制备的Cu6Sn5合金电极具有比通常的铜片基底更好的结构稳定性,经过50周充放电循环后无明显的脱落现象.Three-dimensional porous Cu6Sn5 alloy electrodes were prepared by electroplating using copper foam as current collector.The micro-holes and small islands on surface of the Cu6Sn5 alloy increased largely the surface area of the electrode,and improved significantly the ability of the electrode in buffering the volume change in process of charge/discharge when the Cu6Sn5 alloy was employed as anode in a lithium-ion battery.Galvonostatic charging/discharging results demonstrated that the initial discharge(lithiation)and charge(delithiation)specific capacities of the Cu6Sn5 alloy electrode were 620 mAh·g-1 and 560 mAh·g-1,respectively.It demonstrated that the Cu6Sn5 alloy electrode exhibited a large initial coulomb efficiency(90.3%)and good capacity retention.SEM(scanning electron microscope)results illustrated that the Cu6Sn5 alloy deposited on copper foam substrate was more stable than that on a conventional copper substrate,and displayed no obvious exfoliation after 50 charge/discharge cycles.国家重点基础研究发展规划项目(973)(2002CB211804)资

Preparation and Capacity Fading Mechanism of Tin Thin Film as Anode of Lithium-ion Battery

以电镀的方法在铜基底上沉积薄膜锡作为锂离子电池负极材料.运用X射线衍射、扫描电镜、电化学循环伏安、电化学充放电和交流阻抗等多种方法对其结构和性能进行表征和研究.结果表明所制备的薄膜锡电极主要为四方晶系结构,其初始放电(嵌锂)容量为709mAh?g-1,充电(脱锂)容量为561mAh?g-1.电化学循环伏安研究发现在嵌/脱锂过程中薄膜锡经历了多种相变过程.电化学阻抗谱结果说明,首次嵌锂过程中当电极电位达到1.2V在电极表面形成SEI膜,而当电极电位低于0.4V表面SEI膜出现破裂,归因于体积膨胀所致.SEM研究表明30次充放电循环后薄膜锡负极出现龟裂现象.Tin thin film coated on Cu substrate as anode of lithium-ion battery was prepared by electroplating. Its structure and properties were characterized and studied by X-ray diffration, scanning electron microscopy, cyclic voltammetry, charging/discharging test and AC impedence method. XRD patterns indicate that the tin thin film exhibits a structure of tetragonal crystal. The first discharge and charge capacities of the tin thin film electrode were determined to be 709 and 561 mAh?g-1, respectively. Cyclic voltammetric results illustrated that multi-phase changes occurred during the lithiation and delithiation. Electrochemical impedance spectros- copy (EIS) results indicated that SEI film was begun to form on the surface of tin thin film electrode at 1.2 V, and then break down below 0.4 V because of large volume expansion. SEM investigations revealed that the tin thin film electrode appeared serious cracks after 30 charging and discharging cycles.国家重点基础研究和发展规划(973项目)(No.2002CB211804)资助项目

Structure and Properties of Three-dimensional Reticular Sn-Co Alloy Electrodes as Anode Material for Lithium Batteries

应用电沉积技术制备了三维网状结构的Sn-Co合金负极材料,采用XRD、SEM和电化学方法考察了该负极材料的结构和性能.XRD分析表明,该三维网状结构的Sn-Co合金镀层为六方固溶体结构.其电化学性能测试表明:三维网状结构Sn-Co合金微晶电极的性能稳定,其首次放电容量高达493.4mAh·g-1,首次库仑效率达80.03%,而平面结构Sn-Co合金电极的首次库仑效率为63.47%.经50周充放电循环后,三维网状结构Sn-Co合金电极的放电容量为329.6mAh·g-1,放电容量保持率为66.8%;SEM分析表明:三维网状Sn-Co合金电极表面是由大小不一、高低不同的“岛”紧密排列在一起;“岛”和多孔结构的存在,缓冲了锂嵌入时体积的膨胀,部分抑制了材料结构的变化,减缓了电极容量的衰减,改善了电极的循环性能.The three-dimensional reticular Sn-Co alloy deposits were prepared by electroplating.The structure and electrochemical performance of the electroplated three-dimensional reticular Sn-Co alloys have been investigated in detail.Experimental results show that the Sn-Co alloy film is of hexagonal solid solution,with Sn as the solvent,Co as the solute.Electrochemical tests show that the three-dimensional reticular Sn-Co alloy coating electrodes can deliver a discharge capacity of 493.4 mAh·g-1 in the first cycle.At the 50th cycle the charge was 329.6 mAh·g-1.The three-dimensional reticular structure in Sn-Co alloy electrode was beneficial in reducing the irreversible capacity of Sn-Co alloy electrode at initial charge-discharge,and in relaxing the volume expansion during cycling,which improved the cyclability of Sn-Co alloy electrode.They are also beneficial to diffusion of Li into /out of macroporous materials,and improve coulomb efficiency in charge-discharge cycle.国家重点基础研究和发展规划(973项目,2002CB211804)资助项

Preparation and capacity fading mechanism of tin thin film as anode of lithium-ion battery

Tin thin film coated on Cu substrate as anode of lithium-ion battery was prepared by electroplating. Its structure and properties were characterized and studied by X-ray diffration, scanning electron microscopy, cyclic voltammetry, charging/discharging test and AC impedence method. XRD patterns indicate that the tin thin film exhibits a structure of tetragonal crystal. The first discharge and charge capacities of the tin thin film electrode were determined to be 709 and 561 mAh(.)g(-1), respectively. Cyclic voltammetric results illustrated that multi-phase changes occurred during the lithiation and delithiation. Electrochemical impedance spectroscopy (EIS) results indicated that SEI film was begun to form on the surface of tin thin film electrode at 1.2 V, and then break down below 0.4 V because of large volume expansion. SEM investigations revealed that the tin thin film electrode appeared serious cracks after 30 charging and discharging cycles

Structure and properties of three-dimensional reticular Sn-Co alloy electrodes as anode material for lithium batteries

The three-dimensional reticular Sn-Co alloy deposits were prepared by electroplating. The structure and electrochemical performance of the electroplated three-dimensional reticular Sn-Co alloys have been investigated in detail. Experimental results show that the Sn-Co alloy film is of hexagonal solid solution, with Sn as the solvent, Co as the solute. Electrochemical tests show that the three-dimensional reticular Sn-Co alloy coating electrodes can deliver a discharge capacity of 493.4 mAh center dot g(-1) in the first cycle. At the 50th cycle the charge was 329.6 mAh center dot g(-1). The three-dimensional reticular structure in Sn-Co alloy electrode was beneficial in reducing the irreversible capacity of Sn-Co alloy electrode at initial charge-discharge, and in relaxing the volume expansion during cycling, which improved the cyclability of Sn-Co alloy electrode. They are also beneficial to diffusion of Li into/out of macroporous materials, and improve coulomb efficiency in charge-discharge cycle

类泛素蛋白及其中文命名

泛素家族包括泛素及类泛素蛋白,约20种成员蛋白.近年来,泛素家族领域取得了迅猛发展,并已与生物学及医学研究的各个领域相互交叉.泛素家族介导的蛋白质降解和细胞自噬机制的发现分别于2004和2016年获得诺贝尔奖.但是,类泛素蛋白并没有统一规范的中文译名. 2018年4月9日在苏州召开的《泛素家族介导的蛋白质降解和细胞自噬》专著的编委会上,部分作者讨论了类泛素蛋白的中文命名问题,并在随后的\"泛素家族、自噬与疾病\"(Ubiquitinfamily,autophagy anddiseases)苏州会议上提出了类泛素蛋白中文翻译草案,此草案在参加该会议的国内学者及海外华人学者间取得了高度共识.冷泉港亚洲\"泛素家族、自噬与疾病\"苏州会议是由美国冷泉港实验室主办、两年一度、面向全球的英文会议.该会议在海内外华人学者中具有广泛影响,因此,参会华人学者的意见具有一定的代表性.本文介绍了10个类别的类泛素蛋白的中文命名,系统总结了它们的结构特点,并比较了参与各种类泛素化修饰的酶和它们的生物学功能.文章由45名从事该领域研究的专家合作撰写,其中包括中国工程院院士1名,相关学者4名,长江学者3名,国家杰出青年科学基金获得者18名和美国知名高校华人教授4名.他们绝大多数是参加编写即将由科学出版社出版的专著《泛素家族介导的蛋白质降解和细胞自噬》的专家

3D-printed integrative probeheads for magnetic resonance

射频探头前端作为核磁共振设备的核心部件之一，极大程度的决定着系统实验性能的优劣。探头前端通常由射频线圈、射频电路及样品检测管道等部分组成。现有的射频线圈制作技术主要是通过手工或机械手段按照所需的线圈形状进行绕制。但是，当线圈结构较为复杂、不规则，或体积尺寸较小时，常规绕制方法便难以满足结构设计和制造的精度需求，因此造成线圈性能的劣化，增大检测区域的射频场不均匀性，对核磁共振检测产生负面影响。本研究中，利用3D打印熔融沉积制造或光敏树脂选择性固化技术精确加工出一体化磁共振探头前端，使用常温液态金属填充线圈模型管路形成射频线圈，搭建出稳定的一体化磁共振射频探头。利用高精度3D打印和液态金属灌注技术制备出包含有射频线圈和定制化样品管道结构在内的一体化磁共振射频探头前端，克服了传统磁共振三维微型线圈成型困难、与样品腔匹配程度差等问题，提高了探头的信噪比，为定制化的磁共振检测提供了新思路。 该工作由厦门大学电子科学与技术学院陈忠教授、游学秋副研究员和孙惠军高级工程师共同指导完成，博士研究生谢君尧为论文第一作者。厦门大学电子科学与技术学院黄玉清高级工程师、王忻昌副教授、倪祖荣助理教授、硕士研究生张德超，化学化工学院杨朝勇教授、博士研究生李星锐，萨本栋微米纳米科学技术研究院陈宏教授为合作作者。【Abstract】Magnetic resonance (MR) technology has been widely employed in scientific research, clinical diagnosis and geological survey. However, the fabrication of MR radio frequency probeheads still face difficulties in integration, customization and miniaturization. Here, we utilized 3D printing and liquid metal filling techniques to fabricate integrative radio frequency probeheads for MR experiments. The 3D-printed probehead with micrometer precision generally consists of liquid metal coils, customized sample chambers and radio frequency circuit interfaces. We screened different 3D printing materials and optimized the liquid metals by incorporating metal microparticles. The 3D-printed probeheads are capable of performing both routine and nonconventional MR experiments, including in situ electrochemical analysis, in situ reaction monitoring with continues-flow paramagnetic particles and ions separation, and small-sample MR imaging. Due to the flexibility and accuracy of 3D printing techniques, we can accurately obtain complicated coil geometries at the micrometer scale, shortening the fabrication timescale and extending the application scenarios.The work is supported by the National Natural Science Foundation of China (Grants U1632274, 11761141010, U1805261, 11475142, 22073078, and 61801411), and China Postdoctoral Science Foundation (2017M622075).研究工作得到国家自然科学基金、中国博士后科学基金等项目支持

Rapidly detection of sulfur fumigated traditional Chinese medicine decoction pieces using surface-enhanced raman scattering spectroscopy

将金纳米粒子溶液直接滴加在中药饮片的表面,利用表面增强拉曼散射(SERS)可直接对硫磺熏蒸导致的Na2SO3残留进行检测,并对检测条件进行了优化。使用本法对硫磺熏蒸和无硫磺熏蒸的10组中药饮片分别进行测定,结果均具有显著差异。The sulfur-fumigated process was widely used during TCM process,which was demonstrated to possess destructive effect to inherent quality of Chinese medica,and bring damage to patients. A new surface-enhanced Raman scattering( SERS) method was developed for direct detection of residuary sodium sulfite in TCM decoction pieces only by dropping solution of gold particles onto sample surfaces. With no pretreatment process in this simple method,the method is extremely suitable for on-site rapid detection. 10 groups of TCM decoction pieces including sulfur fumigated and non-sulfur fumigated ones were detected,and dramatic differences were obtained

不同灌溉处理下冬小麦水平衡与灌溉增产效率研究

水资源是华北平原冬小麦、夏玉米种植区最重要的生产制约因素,农业水资源高效利用具有重大的社会需要。通过设置冬小麦不同灌溉处理,分析了各处理的水分平衡、产量和灌溉增产效率。结果显示:1)不同灌溉处理具有不同的水分平衡过程,雨养农田、充分灌溉处理、返青水胁迫处理、拔节抽穗水胁迫处理和灌浆水胁迫处理的蒸散量分别为251±58 mm、482±48 mm、352±44 mm、388±22 mm和324±53 mm;2)灌溉量对于小麦产量的增加具有明显的正效应,拔节-抽穗水胁迫对作物产量有较大影响,灌浆水胁迫和返青水胁迫均没有对小麦产量造成明显影响;雨养农业的经济产量为2 950±635 kg.hm-2,充分灌溉下的经济产量约为5 994±994 kg.hm-2;冬小麦返青期、拔节抽穗期、灌浆期施加适度的水分胁迫,产量分别为5 163±885 kg.hm-2、5 047±1 180 kg.hm-2、5 249±975 kg.hm-2,与充分灌溉相比,没有明显的产量下降;3)小麦的灌溉增产效率存在明显的年际差异,在丰水年或特丰水年,灌溉增产效率为1.9 kg.m-3,在枯水年为0.4 kg.m-3,平水年为1.6 kg.m-3