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111.
Surface‐Enhanced Raman Scattering Based on Controllable‐Layer Graphene Shells Directly Synthesized on Cu Nanoparticles for Molecular Detection 下载免费PDF全文
Hengwei Qiu Dr. Yanyan Huo Zhen Li Dr. Chao Zhang Peixi Chen Prof. Shouzhen Jiang Dr. Shicai Xu Prof. Yong Ma Prof. Shuyun Wang Hongsheng Li 《Chemphyschem》2015,16(14):2953-2960
Graphene shells with a controllable number of layers were directly synthesized on Cu nanoparticles (CuNPs) by chemical vapor deposition (CVD) to fabricate a graphene‐encapsulated CuNPs (G/CuNPs) hybrid system for surface‐enhanced Raman scattering (SERS). The enhanced Raman spectra of adenosine and rhodamine 6G (R6G) showed that the G/CuNPs hybrid system can strongly suppress background fluorescence and increase signal‐to‐noise ratio. In four different types of SERS systems, the G/CuNPs hybrid system exhibits more efficient SERS than a transferred graphene/CuNPs hybrid system and pure CuNPs and graphene substrates. The minimum detectable concentrations of adenosine and R6G by the G/CuNPs hybrid system can be as low as 10?8 and 10?10 M , respectively. The excellent linear relationship between Raman intensity and analyte concentration can be used for molecular detection. The graphene shell can also effectively prevent surface oxidation of Cu nanoparticles after exposure to ambient air and thus endow the hybrid system with a long lifetime. This work provides a basis for the fabrication of novel SERS substrates. 相似文献
112.
The magnetocaloric effect(MCE) in EuCu1.75P2 compound is studied by the magnetization and heat capacity measurements.Magnetization and modified Arrott plots indicate that the compound undergoes a second-order phase transition at TC ~ 51 K.A large reversible MCE is observed around TC.The values of maximum magnetic entropy change(-△SxMma) reach 5.6 J·kg-1·K-1 and 13.3 J·kg-1·K-1 for the field change of 2 T and 7 T,respectively,with no obvious hysteresis loss in the vicinity of Curie temperature.The corresponding maximum adiabatic temperature changes(△Tadmax) are evaluated to be 2.1 K and 5.0 K.The magnetic transition and the origin of large MCE in EuCu1.75P2 are also discussed. 相似文献
113.
114.
建立以凝胶渗透色谱法(GPC)和固相萃取法(SPE)及气相色谱法(GC)联用技术测定大豆中10种二硝基苯胺类除草剂(氟乐灵、乙氟灵、环丙氟、氯乙氟灵、仲丁灵、异乐灵、二甲戊乐灵、二硝胺、氨基丙氟灵和磺乐灵)多残留检测方法.目标农药经正己烷饱和的乙腈提取,凝胶渗透色谱除去大豆中大部分油脂及色素,再经Florisil柱净化和富集,依次用6 mL二氯甲烷和6 mL二氯甲烷+丙酮(99+1)洗脱.目标农药采用电子捕获检测(GC/ECD),外标法定量,并经质谱(MS)确证.两个添加水平重复6次,回收率分别为74%~105%和59%~105%;相对标准偏差<20%;检出限为1.8~7.6 μg/kg;定量限为6~38 μg/kg. 相似文献
115.
Zhang D Tang D Wang X Qiao ZA Li Y Liu Y Huo Q 《Dalton transactions (Cambridge, England : 2003)》2011,40(36):9313-9319
We chose dipicolinic acid as a tridentate chelating unit featuring ONO donors to react with lanthanide(III) ions to yield tight and protective N(3)O(6) environments around the lanthanide(III) ions. We immobilized the lanthanide(III)-dipicolinic acid complexes on colloidal mesoporous silica with diameter smaller than 100 nm by a covalent bond grafting technique and obtained nearly monodisperse luminescent Eu-dpa-Si and Tb-dpa-Si functionalized hybrid mesoporous silica nanomaterials. These hybrid nanomaterials were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, nitrogen adsorption-desorption, and photoluminescence spectroscopic techniques. The hybrid mesoporous silica nanoparticles exhibit intense emission lines upon UV-light irradiation, owing to the effective intramolecular energy transfer from the chromophore to the central lanthanide Eu(3+) and Tb(3+) ions. Furthermore, the functionalized nanomaterials can be turned to white light materials after annealing at high temperature. 相似文献
116.
Lihong Liu Prof. Bin He Dr. Qian Liu Dr. Zhaojun Yun Xueting Yan Dr. Yanmin Long Prof. Guibin Jiang 《Angewandte Chemie (International ed. in English)》2014,53(52):14476-14479
We have developed a new method for the identification and accurate size characterization of nanoparticles (NPs) in complex media based on capillary electrokinetic (CE) separation coupled to inductively coupled plasma mass spectrometry (ICP‐MS). Through mass scanning and Gaussian fitting of electropherogram peaks, we can obtain multidimensional information on chemical compositions, size distributions, and ionic species of multiple NPs in a single run. The results are more accurate than those obtained by using conventional methods. This method provides a powerful tool for investigating polydisperse NP systems and rapid screening of NP‐containing products. 相似文献
117.
S. V. Kuzin S. V. Shestov A. A. Pertsov A. A. Reva S. Yu. Zuev A. Ya. Lopatin V. I. Luchin H. Zhou T. Huo 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2008,2(4):527-530
The telescope at a wavelength of 13.2 nm of the TESIS device of the CORONAS-PHOTON satellite is intended for imaging hot plasma (T ~ 10 MK) of the solar corona. In this paper, calibration of optical elements of the telescope is described. The transmittance of multilayer Zr/Si filters and the sensitivity and radiation resistance of the CCD-array-based detector were measured. The transmittance of filters in the operating wavelength range was 40–50% (for filters of various thicknesses); the spectral dependence of the transmittance was close to the calculated one. The transmittance of filters in the visible region was (1–2) × 10?6. The detector sensitivity was 0.01–0.1 analog-to-digital units per photon (adu/photon), the radiation resistance was better than 109 rad. 相似文献
118.
119.
Self‐Assembly of Five 8‐Hydroxyquinolinate‐Based Complexes: Tunable Core,Supramolecular Structure,and Photoluminescence Properties 下载免费PDF全文
Prof. Dr. Guozan Yuan Weilong Shan Xuelong Qiao Li Ma Prof. Dr. Yanping Huo 《化学:亚洲杂志》2014,9(7):1913-1921
Five new ZnII complexes, namely [Zn3(L)6] ( 1 ), [Zn2(Cl)2(L)2(py)2] ( 2 ), [Zn2(Br)2(L)2(py)2] ( 3 ), [Zn(L)2(py)] ( 4 ), and [Zn2(OAc)2(L)2(py)2] ( 5 ), were prepared by the solvothermal reaction of ZnX2 (X?=Cl?, Br?, F?, and OAc?) salts with a 8‐hydroxyquinolinate ligand (HL) that contained a trifluorophenyl group. All of the complexes were characterized by elemental analysis, IR spectroscopy, and powder and single‐crystal X‐ray crystallography. The building blocks exhibited unprecedented structural diversification and their self‐assembly afforded one mononuclear, three binuclear, and one trinuclear ZnII structures in response to different anions and solvent systems. Complexes 1 – 5 featured four types of supramolecular network controlled by non‐covalent interactions, such as π???π‐stacking, C? H???π, hydrogen‐bonding, and halogen‐related interactions. Investigation of their photoluminescence properties exhibited disparate emission wavelengths, lifetimes, and quantum yields in the solid state. 相似文献
120.
Determination of medroxyprogesterone acetate residues by CE immunoassay with chemiluminescence detection 总被引:1,自引:0,他引:1
A rapid and simple method is developed for the determination of medroxyprogesterone acetate (MPA) by CE immunoassay with chemiluminescence (CL). This method is based on the competitive reactions between horseradish peroxidase (HRP)-labeled MPA (MPA-HRP) and free MPA with anti-MPA antiserum. The influencing factors on the electrophoresis and CL detection were studied completely and the optimal conditions of separation and determination were obtained. The linear range was 2.0-50 nmol/L and the LOD for MPA was 0.9 nmol/L. The present method was applied to the analysis of pork tissues. 相似文献