基于不同还原剂体系银粉的可控制备

以硝酸银为原料,在不同温度条件下,分别以无机和有机还原剂,制备了不同形貌的银粉颗粒,采用扫描电子显微镜以及X射线衍射对其形貌与结构进行了表征。在此基础上,重点研究了不同还原体系对银粉颗粒形貌的影响,并提出了相应的机理。研究结果表明,以七水合硫酸亚铁作为还原剂时,银颗粒形貌由铁离子浓度控制,在高浓度,低反应速度条件下可得到花状银颗粒。随着体系浓度的下降,表面由粗糙花状变为光滑球状,导电性能并随之升高。以抗坏血酸作为还原剂,硫酸根为保护剂时,硫酸根浓度对银粉形貌有着很大的影响,随着硫酸根浓度的增加,银颗粒由球形变为枝片状。导电性能有所升高。     

Syntheses,Structures, and Properties of Three Coordination Polymers: [Cd_2(bpp)_(1.5)(Hbpp)(phen)_2]_n, [Mn_3(Htptc)_2(phen)_2(H_2O)_2]_n,and {[Cu(btc)_(0.5)(1,4-bib)]·2H_2O}_n

Hydrothermal reactions of three aromatic polycarboxylic acids and the transitional metal cations in the presence of phen and 1,4-bib afford three new coordination polymers: [Cd2(bpp)1.5(Hbpp)(phen)2]n(1), [Mn3(Htptc)2(phen)2(H2O)2]n(2), and {[Cu(btc)0.5(1,4- bib)]·2H2O}n(3)(H2bpp = 2,6-bis(4'-carboxyphenyl)-4-phenylpyridine, H4tptc = terphenyl-2,5,2',5'-tetracarboxylic acid, H4btc = biphenyl-2,2',4,4'-tetracarboxylic acid, phen = 1,10-phenanthroline, and 1,4-bib = 1,4-bis(1H-imidazol-1-yl)benzene). Their structures have been determined by singlecrystal X-ray diffraction analyses, elemental analyses, IR spectra, and powder X-ray diffraction(PXRD) analyses. In compound 1, the CdII cations are linked by bpp2- to form one ladder structure, based on which a 3D network is constructed with the help of non-covalent interactions. The topology of 2 is a 3D(3,4,5)-connected framework with the Point Schl?fli symbol of(42.6)32(4.62.8)(45.64.8)2. Compound 3 shows an unprecedented 3D(4,4)-connected framework with the Point Schl?fli symbol of(64.82)2(65.8). Moreover, the luminescent property of 1 has been investigated.     

HPLC–MS/MS法测定南美白对虾苗中硝基呋喃类代谢物残留

研究了南美白对虾苗中4种硝基呋喃代谢物呋喃唑酮代谢物(AOZ)、呋喃它酮代谢物(AMOZ)、呋喃妥因代谢物(AHD)、呋喃西林代谢物(SEM)的高效液相色谱–串联质谱(HPLC–MS/MS)测定方法。以水解衍生并添加4种同位素内标的方法对样品进行处理,补偿了衍生化效率,提高了定量的准确性。实验结果表明,AOZ,AMOZ的检出限为0.10μg/kg,SEM,AHD的检出限为0.25μg/kg;AOZ,AMOZ的定量下限为0.40μg/kg,SEM,AHD的定量下限为0.50μg/kg。方法加标回收率在88.2%~97.6%之间,相对标准偏差在4.6%~8.1%(n=6)之间。该法检测灵敏度高,测量结果的精密度和准确度满足药物残留检测要求。     

Atomic-Scale Insight into Exsolution of CoFe Alloy Nanoparticles in La0.4Sr0.6Co0.2Fe0.7Mo0.1O3−δ with Efficient CO2 Electrolysis

In situ exsolution of metal nanoparticles in perovskite under reducing atmosphere is employed to generate a highly active metal–oxide interface for CO₂ electrolysis in a solid oxide electrolysis cell. Atomic-scale insight is provided into the exsolution of CoFe alloy nanoparticles in La_0.4Sr_0.6Co_0.2Fe_0.7Mo_0.1O_3−δ (LSCFM) by in situ scanning transmission electron microscopy (STEM) with energy-dispersive X-ray spectroscopy and DFT calculations. The doped Mo atoms occupy B sites of LSCFM, which increases the segregation energy of Co and Fe ions at B sites and improves the structural stability of LSCFM under a reducing atmosphere. In situ STEM measurements visualized sequential exsolution of Co and Fe ions, formation of CoFe alloy nanoparticles, and reversible exsolution and dissolution of CoFe alloy nanoparticles in LSCFM. The metal–oxide interface improves CO₂ adsorption and activation, showing a higher CO₂ electrolysis performance than the LSCFM counterparts.     

Steric Mixed-Cation 2D Perovskite as a Methylammonium Locker to Stabilize MAPbI3

The reduced dimension perovskite including 2D perovskites are one of the most promising strategies to stabilize lead halide perovskite. A mixed-cation 2D perovskite based on a steric phenyltrimethylammonium (PTA) cation is presented. The PTA-MA mixed-cation 2D perovskite of PTAMAPbI₄ can be formed on the surface of MAPbI₃ (PTAI-MAPbI₃) by controllable PTAI intercalation by either spin coating or soaking. The PTAMAPbI₄ capping layer can not only passivate PTAI-MAPbI₃ perovskite but also act as MA⁺ locker to inhibit MAI extraction and significantly enhance the stability. The highly stable PTAI-MAPbI₃ based perovskite solar cells exhibit a reproducible photovoltaic performance with a champion PCE of 21.16 %. Such unencapsulated devices retain 93 % of initial efficiency after 500 h continuous illumination. This steric mixed-cation 2D perovskite as MA⁺ locker to stabilize the MAPbI₃ is a promising strategy to design stable and high-performance hybrid lead halide perovskites.     

在线固相萃取-液相色谱-串联质谱法检测蘑菇中毒患者尿液中痕量α -鹅膏毒肽

建立了在线固相萃取-液相色谱-串联质谱（online SPE-LC-MS/MS）测定蘑菇中毒患者尿液中痕量α -鹅膏毒肽的分析方法。样品经甲酸酸化的乙腈-甲醇（5：1,v/v）沉淀蛋白质,反相液液微萃取去除样品提取液中的有机溶剂,毒素经ODS微柱（5 mm×2.1 mm,5 μm）在线SPE净化,XBridge^TM BEH C₁₈ 色谱柱（150 mm×3.0 mm,2.5 μm）分离,MS/MS测定。采用基于定量环的快速阀切换技术作为在线SPE和LC-MS/MS模块的接口,使得两个分离模块互相独立,无论是流动相还是压力,都不会互相干扰,保证了系统的稳定性;在线系统的精准净化,有效消除了后续质谱检测的基质效应,确保了尿液中痕量水平α -鹅膏毒肽的定性定量检测。尿液中α -鹅膏毒肽在0.1~50 μg/L范围内线性关系良好,相关系数（r ² ）为0.9983;检出限（LOD）为0.03 μg/L;α -鹅膏毒肽的加标（0.1、2.0和20 μg/L）平均回收率为84.3%~91.7%,相对标准偏差（RSD）为3.8%~7.2%。体内鹅膏毒肽代谢迅速,生物基质中痕量水平毒素的检测是其中毒实验室鉴定的主要难题,通过实际样品检测,证明该法操作简单,准确、灵敏;溶剂沉淀蛋白质和反相液液微萃取去除有机相和脂溶性基质的简单操作,可以作为水溶性毒素在线SPE-LC-MS/MS检测时快速且有效的配套前处理方法;基于在线SPE精准净化技术,可以实现尿液中α -鹅膏毒肽的高灵敏度测定（LOD为0.03 μg/L）,解决了中毒时患者体内痕量水平α -鹅膏毒肽定性确证的难题,部分患者α -鹅膏毒肽中毒实验室鉴定的时间可以扩展到90 h以上;同时,痕量水平的定量检测技术,可以为中毒后迅速代谢的α -鹅膏毒肽在体内的剂量反应关系研究提供可靠的技术支撑。     

Construction of mixed carboxylate and pyrogallate building units for luminescent metal-organic frameworks

A metal-organic framework,Ce-FDM-50,was constructed by employing gallic acid featuring both carboxylate and pyrogallate as the coordinating sites and Ce(Ⅲ).The co-assembly of the carboxylates and pyrogallates with two metal ions have achieved a new type of paddle wheel secondary building unit.These building units were further joined by organic struts to obtain frameworks in sql topology.This synthetic approach could be expanded to five different lanthanide metals(Nd,Eu,Gd,Tb,Yb)for the construction of a series of isoreticular MOFs based on FDM-50,and even MTV-MOFs in which mixed lanthanide metals with specific ratios were distributed.In addition,featuring the lanthanide metals as the inorganic nodes in the network,Tb-FDM-50 showed distinct luminescence properties that could be furtherly tuned for variable applications.     

Steric Mixed‐Cation 2D Perovskite as a Methylammonium Locker to Stabilize MAPbI3

The reduced dimension perovskite including 2D perovskites are one of the most promising strategies to stabilize lead halide perovskite. A mixed‐cation 2D perovskite based on a steric phenyltrimethylammonium (PTA) cation is presented. The PTA‐MA mixed‐cation 2D perovskite of PTAMAPbI₄ can be formed on the surface of MAPbI₃ (PTAI‐MAPbI₃) by controllable PTAI intercalation by either spin coating or soaking. The PTAMAPbI₄ capping layer can not only passivate PTAI‐MAPbI₃ perovskite but also act as MA⁺ locker to inhibit MAI extraction and significantly enhance the stability. The highly stable PTAI‐MAPbI₃ based perovskite solar cells exhibit a reproducible photovoltaic performance with a champion PCE of 21.16 %. Such unencapsulated devices retain 93 % of initial efficiency after 500 h continuous illumination. This steric mixed‐cation 2D perovskite as MA⁺ locker to stabilize the MAPbI₃ is a promising strategy to design stable and high‐performance hybrid lead halide perovskites.     

β-环糊精与苯基偶氮(4-偶氮-1)-2-萘酚(苏丹红Ⅲ)相互作用的光谱研究

利用分光光度法研究了苯基偶氮(4-偶氮-1)-2-萘酚(苏丹红Ⅲ)与β-环糊精的包合机理。用红外光谱法确认了主体分子对客体分子的包合深度。结果表明:苯基偶氮(4-偶氮-1)-2-萘酚与β-环糊精形成1∶1的包容络合物,包合常数为7.95×102L/mol,求出了包合反应热力学参数ΔG,ΔH及ΔS,整个包合过程受熵变控制。     

中国鲎壳结构特征与甲壳素晶型表征

本文分析了中国鲎壳的氨基酸组成,17种氨基酸的总量约占干重的64%,7种人体必需氨基酸(色氨酸未分析)约为27%。鲎壳坚硬,与酪氨酸含量较高有关。傅立叶红外光谱(FT-IR)显示鲎壳甲壳素的酰胺I谱带在1660.9 cm-11、627.5 cm-1处有吸收。X射线衍射证实在2θ=9.22°、19.38°、20.91°、23.47°四处有特征结晶峰,鲎壳甲壳素与虾、蟹甲壳素相似,证实均为α晶型。