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Vlasov Yu. G. Murzina Yu. G. Legin A. V. Ermolenko Yu. E. Schubert J. Schüoning M. J. Lut H. 《Russian Journal of Applied Chemistry》2002,75(3):351-356
Methods of silicon planar technology and pulsed laser deposition were applied to fabricate fully solid-state chemical sensors for determining ions of copper, lead, cadmium, thallium, and also sulfide and chloride ions on the basis of thin chalcogenide films as ion-sensitive membranes. 相似文献
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Tuning of Supramolecular Architectures of l‐Valine‐Containing Dicyanoplatinum(II) 2,2′‐Bipyridine Complexes by Metal–Metal, π–π Stacking,and Hydrogen‐Bonding Interactions 下载免费PDF全文
Heidi Li‐Ki Fu Dr. Charlotte Po Dr. Hexiang He Dr. Sammual Yu‐Lut Leung Prof. Kam Sing Wong Prof. Dr. Vivian Wing‐Wah Yam 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(33):11826-11836
A series of newly synthesized dicyanoplatinum(II) 2,2′‐bipyridine complexes exhibits self‐assembly properties in solution after the incorporation of the l ‐valine amino units appended with various hydrophobic motifs. These l ‐valine‐derived substituents were found to have critical control over the aggregation behaviors of the complexes in the solution state. On one hand, one of the complexes was found to exhibit interesting circularly polarized luminescence (CPL) signals at low temperature due to the formation of chiral spherical aggregates in the temperature‐dependent studies. On the other hand, systematic transformation from less uniform aggregates to well‐defined fibrous and rod‐like structures via Pt???Pt and π–π stacking interactions has also been observed in the mixed‐solvent studies. These changes were monitored by UV/Vis absorption, emission, circular dichroism (CD), and CPL spectroscopies, and morphologies were studied by electron microscopy. 相似文献
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Synthesis,Electrochemistry, and Photophysical Studies of Ruthenium(II) Polypyridine Complexes with D–π–A–π–D Type Ligands and Their Application Studies as Organic Memories 下载免费PDF全文
Ming‐Yi Leung Dr. Sammual Yu‐Lut Leung Dr. Di Wu Dr. Tao Yu Prof. Dr. Vivian Wing‐Wah Yam 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(39):14013-14021
A new class of ruthenium(II) polypyridine complexes with a series of D–π–A–π–D type (D=donor, A=acceptor) ligands was synthesized and characterized by 1H NMR spectroscopy, mass spectrometry, and elemental analysis. The photophysical and electrochemical properties of the complexes were also investigated. The newly synthesized ruthenium(II) polypyridine complexes were found to exhibit two intense absorption bands at both high‐energy (λ=333–369 nm) and low‐energy (λ=520–535 nm) regions. They are assigned as intraligand (IL) π→π* transitions of the bipyridine (bpy) and π‐conjugated bpy ligands, and IL charge‐transfer (CT) transitions from the donor to the acceptor moiety with mixing of dπ(RuII)→π*(bpy) and dπ(RuII)→π*(L) MLCT characters, respectively. In addition, all complexes were demonstrated to exhibit intense red emissions at approximately λ=727–744 nm in degassed dichloromethane at 298 K or in n‐butyronitrile glass at 77 K. Nanosecond transient absorption (TA) spectroscopy has also been carried out, establishing the presence of the charge‐separated state. In order to understand the electrochemical properties of the complexes, cyclic voltammetry has also been performed. Two quasi‐reversible oxidation couples and three quasi‐reversible reduction couples were observed. One of the ruthenium(II) complexes has been utilized in the fabrication of memory devices, in which an ON/OFF current ratio of over 104 was obtained. 相似文献
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Sadik O Land WH Wanekaya AK Uematsu M Embrechts MJ Wong L Leibensperger D Volykin A 《Journal of chemical information and computer sciences》2004,44(2):499-507
The need for rapid and accurate detection systems is expanding and the utilization of cross-reactive sensor arrays to detect chemical warfare agents in conjunction with novel computational techniques may prove to be a potential solution to this challenge. We have investigated the detection, prediction, and classification of various organophosphate (OP) nerve agent simulants using sensor arrays with a novel learning scheme known as support vector machines (SVMs). The OPs tested include parathion, malathion, dichlorvos, trichlorfon, paraoxon, and diazinon. A new data reduction software program was written in MATLAB V. 6.1 to extract steady-state and kinetic data from the sensor arrays. The program also creates training sets by mixing and randomly sorting any combination of data categories into both positive and negative cases. The resulting signals were fed into SVM software for "pairwise" and "one" vs all classification. Experimental results for this new paradigm show a significant increase in classification accuracy when compared to artificial neural networks (ANNs). Three kernels, the S2000, the polynomial, and the Gaussian radial basis function (RBF), were tested and compared to the ANN. The following measures of performance were considered in the pairwise classification: receiver operating curve (ROC) Az indices, specificities, and positive predictive values (PPVs). The ROC Az) values, specifities, and PPVs increases ranged from 5% to 25%, 108% to 204%, and 13% to 54%, respectively, in all OP pairs studied when compared to the ANN baseline. Dichlorvos, trichlorfon, and paraoxon were perfectly predicted. Positive prediction for malathion was 95%. 相似文献
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Sammual Yu‐Lut Leung Elizabeth Suk‐Hang Lam Dr. Wai Han Lam Dr. Keith Man‐Chung Wong Prof. Dr. Wing‐Tak Wong Prof. Dr. Vivian Wing‐Wah Yam 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(31):10360-10369
A new class of luminescent alkynylplatinum(II) complexes with a tridentate pyridine‐based N‐heterocyclic carbene (2,6‐bis(1‐butylimidazol‐2‐ylidenyl)pyridine) ligand, [PtII(C^N^C)(C?CR)][PF6], and their chloroplatinum(II) precursor complex, [PtII(C^N^C)Cl][PF6], have been synthesized and characterized. One of the alkynylplatinum(II) complexes has also been structurally characterized by X‐ray crystallography. The electrochemistry, electronic absorption and luminescence properties of the complexes have been studied. Nanosecond transient absorption (TA) spectroscopy has also been performed to probe the nature of the excited state. The origin of the absorption and emission properties has been supported by computational studies. 相似文献
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We demonstrate gas detection based on evanescent-wave photoacoustic (PA) spectroscopy with tapered optical fibers. Evanescent-field instead of open-path absorption is exploited for PA generation, and a quartz tuning fork is used for PA detection. A tapered optical fiber with a diameter down to the wavelength scale demonstrates detection sensitivity similar to an open-path system but with the advantages of easier optical alignment, smaller insertion loss, and multiplexing capability. 相似文献
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A miniature fiber-tip pressure sensor was built by using an extremely thin graphene film as the diaphragm. The graphene also acts as a light reflector, which, in conjunction with the reflection at the fiber end-air interface, forms a low finesse Fabry-Perot interferometer. The graphene based sensor demonstrated pressure sensitivity over 39.4 nm/kPa with a diaphragm diameter of 25 μm. The use of graphene as diaphragm material would allow highly sensitive and compact fiber-tip sensors. 相似文献
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We introduce a femtosecond-laser-based technique for selective opening of airholes in photonic crystal fibers (PCFs). With this technique, selective filling and inflation of the airholes in the PCF cladding are demonstrated. The technique may find important applications in tailoring or altering PCF characteristics and make it possible to seamlessly integrate various components/functions into PCFs. 相似文献