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61.
对太阳实际光谱与连续氙灯的光谱进行了测试,结果显示氙灯发光光谱的红外部分占全部光谱的55.6%,与实际太阳光谱的28.4%有较大差别。依据这种差别进行光谱曲线拟合,得到925 nm最低点的透过率曲线。采用滤光片对氙灯发光光谱的红外部分光强进行适当过滤,测得过滤后的光谱达到标准匹配度。通过测试滤光后6个不同位置点的光谱发现,光谱最大偏差仅为12.5%,表明过滤后的氙灯光谱均匀性较好。利用电致发光检测有缺陷的硅电池进行电池的电性能测试,发现经过采用滤光片和未采用滤光片的连续氙灯光照测试的Ⅰ-Ⅴ电性能值不同,功率相差0.22 W,表明氙灯光谱匹配度直接影响电池电性能测试的准确度。 相似文献
62.
We present an implementation of localization based three-dimensional super-resolution imaging on a regular microscope. We retain the original arc lamp as the photoactivation light source, and incorporate an inexpensive diode laser for imaging. As alterations to the standard microscope is minimal, this optical setup can be easily adapted in a typical research laboratory and even undergraduate teaching experiments, providing an inexpensive system for students and research scientists who require such super resolution capabilities. With this simple design, a spatial resolution of better than 40 nm at a reasonable frame rate has been achieved, adequate for most routine applications. 相似文献
63.
Naphthalic anhydride derivatives: Structural effects on their initiating abilities in radical and/or cationic photopolymerizations under visible light 下载免费PDF全文
Pu Xiao Frédéric Dumur Jing Zhang Bernadette Graff Fabrice Morlet‐Savary Jean Pierre Fouassier Didier Gigmes Jacques Lalevée 《Journal of polymer science. Part A, Polymer chemistry》2015,53(24):2860-2866
Only one naphthalic anhydride derivative has been reported as light sensitive photoinitiator, this prompted us to further explore the possibility to prepare a new family of photoinitiators based on this scaffold. Therefore, eight naphthalic Naphthalic anhydride derivatives (ANH1‐ANH8) have been prepared and combined with an iodonium salt (and optionally N‐vinylcarbazole) or an amine (and optionally 2,4,6‐tris(trichloromethyl)‐1,3,5‐triazine) to initiate the cationic polymerization of epoxides and the free radical polymerization of acrylates under different irradiation sources, that is, very soft halogen lamp (~ 12 mW cm?2), laser diode at 405 nm (~1.5 mW cm?2) or blue LED centered at 455 nm (80 mW cm?2). The ANH6 based photoinitiating systems are particularly efficient for the cationic and the radical photopolymerizations, and even better than that of the well‐known camphorquinone based systems. The photochemical mechanisms associated with the chemical structure/photopolymerization efficiency relationships are studied by steady state photolysis, fluorescence, cyclic voltammetry, laser flash photolysis, and electron spin resonance spin‐trapping techniques. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2860–2866 相似文献
64.
A novel conductive biocomposite film (MWCNTs–DNA–cyt c) which contains multi-walled carbon nanotubes (MWCNTs) along with the incorporation of DNA and cytochrome c (cyt c) has been synthesized on glassy carbon electrode (GCE), gold (Au), indium tin oxide (ITO) and screen printed carbon electrode (SPCE) by potentiostatic methods. The presence of both MWCNTs and DNA in the biocomposite film enhances the surface coverage concentration (Γ), increases the electron transfer rate constant (Ks) up to 21% and decreases the degradation of cyt c during the cycling. The biocomposite film also exhibits a promising enhanced electrocatalytic activity towards the reduction of halogen oxyanions and oxidation of biochemical compounds such as ascorbic acid and l-cysteine. The cyclic voltammetry has been used for the measurement of electroanalytical properties of analytes by means of biocomposite film modified GCEs. The sensitivity of MWCNTs–DNA–cyt c modified GCE possess higher values than the values obtained for DNA–cyt c film modified GCE. Further, the reduction potentials of halogen oxyanions Epc, clearly shows that the activity of the biocomposite is dependent on the electronegativity of halogen oxyanions. Electrochemical quartz crystal microbalance studies revealed the enhancements in the functional properties of MWCNTs, DNA and cyt c. We have studied the surface morphology of the biocomposite films using scanning electron microscopy and atomic force microscopy, which revealed that DNA and cyt c have been incorporated on MWCNTs. Finally, the flow injection analysis has been used for the amperometric detection of analytes at MWCNTs–DNA–cyt c film modified SPCE. 相似文献
65.
Christoph Wlper Silvia Roca Piol Sara Durn Ibez Matthias Freytag Peter G. Jones Armand Blaschette 《无机化学与普通化学杂志》2008,634(9):1506-1516
Polysulfonylamines. CLXXXIV. Crystal Structures of Molecular Triphenylphosphanegold(I) Di(4‐X‐benzenesulfonyl)amides: Isomorphism and Close Packing (X = Me, F, Cl, NO2) vs. Structure‐Determining C–X···Au/O Halogen Bonds (X = Br, I) In order to study the structure‐determining influence that halogen bonding can exert during the course of crystallization, solid‐state structures are compared for two previously reported and four new molecular gold(I) complexes of the type Ph3P–Au–N(SO2–C6H4–4‐X)2, each featuring linear P,N coordination at gold and two phenyl rings with varying p‐substituents X = Me, F, Cl, NO2, Br or I. The compounds were synthesized by reactions of Ph3PAuX (X = Cl or I) with the corresponding silver di(arenesulfonyl)amides, crystallized from dichloromethane, and characterized by low‐temperature X‐ray diffraction. The Me, F, Cl and NO2 congeners are isomorphic and crystallize without solvent inclusion in the chiral orthorhombic space group P212121 (Z′ = 1). These structures are governed by isotropic close packing via three‐dimensional 21 symmetry, incidentally supported by an invariant set of C–H···O=S hydrogen bonds, CH/π interactions and π/π stackings of aromatic rings; in particular, the hard halogen atoms of the fluoro and the chloro homologues are not involved in X···Au, X···O or X···X interactions. The higher homologues, with soft halogen atoms, were obtained as a dichloromethane hemisolvate for X = Br and a corresponding monosolvate for X = I, each triclinic in the centrosymmetric space group (Z′ = 1). Here, the primary structural effect is implemented by infinite chains in which translation‐related molecules are connected for the bromo compound by a bifurcated Au···Br(2)···O=S interaction, for the iodo congener by an equivalent Au···I(2)···O=S interaction and a short halogen bond C–I(1)···O=S. The latter bond is stronger than a similar C–Br···O=S interaction and induces a conformational adjustment of the (CSO2)2N group from the normal twofold symmetry in the bromo compound to an energetically unfavourable asymmetric form in the iodo homologue. In both cases, pairs of antiparallel molecular catemers are associated into strands via sixfold phenyl embraces, the strands are stacked to form layers, the solvent molecules are intercalated between adjacent layers, and the crystal packings are reinforced by a number of C–H···O=S hydrogen bonds and interactions of aromatic rings. 相似文献
66.
Dr. Hongshuang Guo Dr. Chen Liang Dr. Tero-Petri Ruoko Dr. Henning Meteling Dr. Bo Peng Dr. Hao Zeng Prof. Arri Priimagi 《Angewandte Chemie (International ed. in English)》2023,62(43):e202309402
Shape-changing polymeric materials have gained significant attention in the field of bioinspired soft robotics. However, challenges remain in versatilizing the shape-morphing process to suit different tasks and environments, and in designing systems that combine reversible actuation and self-healing ability. Here, we report halogen-bonded liquid crystal elastomers (LCEs) that can be arbitrarily shape-programmed and that self-heal under mild thermal or photothermal stimulation. We incorporate halogen-bond-donating diiodotetrafluorobenzene molecules as dynamic supramolecular crosslinks into the LCEs and show that these relatively weak crosslinks are pertinent for their mechanical programming and self-healing. Utilizing the halogen-bonded LCEs, we demonstrate proof-of-concept soft robotic motions such as crawling and rolling with programmed velocities. Our results showcase halogen bonding as a promising, yet unexplored tool for the preparation of smart supramolecular constructs for the development of advanced soft actuators. 相似文献
67.
68.
采用量子化学中的密度泛函理论(DFT),在B3LYP/6-311 G(3df,2p)水平上全优化得到了单卤代二硫烷HSSX(X-H,F,Cl,Br)链型和分叉型两种异构体的平衡结构。计算结果表明.在热力学上,所有链型的HSSX为稳定构型.其能量分别较分叉型构型低109.8、60.2、74.8和73.1kJ/mol。同时,采用统计热力学方法,研究了两种平衡结构之间相互转化的化学热力学性质,发现异构化反应的平衡常数很小。 相似文献
69.
Andrew J. Taylor Dr. Robert Hein Sophie C. Patrick Prof. Jason J. Davis Prof. Paul D. Beer 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(6):e202315959
Anion sensing via either optical or electrochemical readouts has separately received enormous attention, however, a judicious combination of the advantages of both modalities remains unexplored. Toward this goal, we herein disclose a series of novel, redox-active, fluorescent, halogen bonding (XB) and hydrogen bonding (HB) BODIPY-based anion sensors, wherein the introduction of a ferrocene motif induces remarkable changes in the fluorescence response. Extensive fluorescence anion titration, lifetime and electrochemical studies reveal anion binding-induced emission modulation through intramolecular photoinduced electron transfer (PET), the magnitude of which is dependent on the nature of both the XB/HB donor and anion. Impressively, the XB sensor outperformed its HB congener in terms of anion binding strength and fluorescence switching magnitude, displaying significant fluorescence turn-OFF upon anion binding. In contrast, redox-inactive control receptors display a turn-ON response, highlighting the pronounced impact of the introduction of the redox-active ferrocene on the optical sensing performance. Additionally, the redox-active ferrocene motif also serves as an electrochemical reporter group, enabling voltammetric anion sensing in competitive solvents. The combined advantages of both sensing modalities were further exploited in a novel, proof-of-principle, fluorescence spectroelectrochemical anion sensing approach, enabling simultaneous and sensitive read out of optical and electrochemical responses in multiple oxidation states and at very low receptor concentration. 相似文献
70.
Rashmi Sharma Susmita Sarkar Sandip Chattopadhayay Dr. Jagannath Mondal Prof. Pinaki Talukdar 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(19):e202319919
Despite considerable emphasis on advancing artificial ion channels, progress is constrained by the limited availability of small molecules with the necessary attributes of self-assembly and ion selectivity. In this study, a library of small molecules based on 5-haloisophthalamide and a non-halogenated isophthalamide were examined for their ion transport properties across the lipid bilayer membranes, and the finding demonstrates that the di-hexyl-substituted 5-iodoisophthalamide derivative exhibits the highest level of activity. Furthermore, it was established that the highest active compound facilitates the selective chloride transport that occurs via an antiport-mediated mechanism. The crystal structure of the compound unveils a distinctive self-assembly of molecules, forming a zig-zag channel pore that is well-suited for the permeation of anions. Planar bilayer conductance measurements proved the formation of chloride selective channels. A molecular dynamics simulation study, relying on the self-assembled component derived from the crystal structure, affirmed the paramount significance of intermolecular hydrogen bonding in the formation of supramolecular barrel-rosette structures that span the bilayer. Furthermore, it was demonstrated that the transport of chloride across the lipid bilayer membrane is facilitated by the synergistic effects of halogen bonding and hydrogen bonding within the channel. 相似文献