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181.
Basar NB Liu H Negi D Sirat HM Morris GA Thomas EJ 《Organic & biomolecular chemistry》2012,10(9):1743-1745
The stereoselective reaction of an allyl bromide with an aldehyde mediated by a low valency bismuth species was the key reaction in stereoselective syntheses of (4S,6R,8R,10S,16S)- and (4S,6R,8R,10S,16R)-4,6,8,10,16-pentamethyldocosanes. (13)C NMR data for these compounds confirmed that the cuticular hydrocarbon isolated from the cane beetle Antitrogus parvulus was the (4S,6R,8R,10S,16S)-stereoisomer. 相似文献
182.
Naresh B. Kotadiya Anjana J. Kothari Devendra Tiwari Tapas K. Chaudhuri 《Applied Physics A: Materials Science & Processing》2012,108(4):819-824
A chemical bath deposition method of preparing photoconducting nanocrystalline lead sulphide (PbS) thin films at room temperature (RT) is described. The aqueous bath of lead acetate, thiourea, and ammonium hydroxide produce films of about 100?nm thicknesses in 45?minutes. X-ray diffraction (XRD) studies show that these films are nanocrystalline cubic PbS with 10?nm crystallite size. Atomic Force Microscope (AFM) and Scanning Electron Microscope (SEM) revealed that the films consist of spherical grains of sizes 100 to 200?nm. The transmission spectra of the films show onset of absorption edge around 850?nm and the bandgap is around 1.65?eV. The films are p-type with dark conductivity of 2.5×10?3?S/cm and mobility of 0.07?cm2/V?s. The photosensitivity is 6–7 for an illumination of 80?mW/cm2 from a halogen lamp (50?W, 12?V). Transient photoconductivity measurements reveal short and long life times of minority carriers. Thermoelectric and photothermoelectric studies show that photoconductivity in these films is mainly due to photogenerated majority carriers. 相似文献
183.
Devendra Kumar Rana Vanya SrivastavR. Pal B.S. Yadav 《Infrared Physics & Technology》2012,55(1):11-14
Transfer length method (TLM) structures were fabricated to characterize the Ni/Au/AuGe-n+-GaAs contacts for quantum dot infrared photodetector (QDIP). Low specific contact resistance of the order of 10−5 Ω cm2 indicates formation of a good Ohmic contact. The current-voltage measurements show that current transport is linear with no significant interfacial modification due to alloying of the contact metal. Low contact resistance makes this scheme suitable for the fabrication of heterostructure QDIP devices. 相似文献
184.
Gunjan Chauhan Suvarcha Chauhan Surbhi Soni Anand Kumar Devendra Singh Negi Indra Bahadur 《中国化学会会志》2023,70(4):879-893
CoS@MorphcdtH NPs and CoS@4-MPipzcdtH NPs were synthesized by precipitation method involving three mechanisms: inclusion, occlusion, and adsorption. The synthesized NPs were characterized with the help of UV-Vis spectroscopy, FESEM-EDAX, powder x-ray diffraction, TEM, ESIMS, TG/DSC analysis. The morphology of the CoS@MorphcdtH NPs and CoS@4-MPipzcdtH NPs were hexagonal and rectangular, and the particles were in the range 7–12 nm. UV–visible spectral measurements showed surface plasmon resonance at 320 nm–340 nm with band gap of 3.65 eV–3.86 eV. The catalytically active CoSNPs called were investigated for the reduction of 4-nitrophenol (4-NP) via hydrogenation using sodium borohydride (NaBH4) as a reducing agent. Both the CoS NPs successfully reduced 4-NP to 4- aminophenol (4-AP) in a short time, catalytic performances are almost unchanged for the first five cycles. Herein, we report the preparation and characterizations of efficient active CoS NPs consisting carbodithioic acid framework as a support/capping material, along with catalytic property. 相似文献
185.