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991.
Zheng‐Ming Tang Ting Lei Ke‐Jian Jiang Prof. Yan‐Lin Song Prof. Jian Pei Prof. 《化学:亚洲杂志》2010,5(8):1911-1917
Two D ‐π‐A conjugated molecules, BzTCA and BzTMCA , were developed through facile synthetic approaches for dye‐sensitized solar cells. The investigation of the photophysical properties of BzTCA and BzTMCA both in dilute solutions and in thin films indicates that their absorption exhibits a wide coverage of the solar spectrum. The absorption features for BzTCA and BzTMCA commence at about 710 nm in solution, and at about 800 nm in the solid state. The absorption maxima (λmax) for both BzTCA and BzTMCA on TiO2 film are almost the same as those in dilute solution. Their HOMOs and LUMOs were found to partly overlap at the center of these dyes, which guarantees appreciable interactions between the donors and acceptors. The investigation of the performance of dye‐sensitized solar cells fabricated from BzTCA and BzTMCA indicated that the power‐conversion efficiencies are 6.04 % and 4.68 %, respectively, which could be comparable with the normal sensitizer N3. BzTMCA showed lower incident photon‐to‐electron conversion efficiency (IPCE) and Jsc values relative to BzTCA , which is probably because of the weaker driving force of dye regeneration and electron injection process of BzTMCA . The IPCE responsive area reached nearly 800 nm, which provides great potential for further improvement of the photocurrent density and power‐conversion efficiency. Our investigations demonstrate that both dyes BzTCA and BzTMCA could be promising candidates for dye‐sensitized solar cells. 相似文献
992.
Five sesquiterpenes, dehydrocostus lactone (1), santamarine (5), beta-cyclocostunolide (6), 4alpha-hydroxy-4beta-methyldihydrocostol (7) and 10alpha-hydroxyl-artemisinic acid (9), along with four other compounds, beta-sitosterol (2), daucosterol (3), 5-hydroxymethyl-furaldehyde (4), and trans-syingin (8), were isolated and identified from the roots of Saussurea lappa (Compositae). Based on previous reports and our study, sesquiterpene derivatives are common and characteristic constituents of the genus Saussurea. Among the nine compounds obtained, 9 is a new sesquiterpene. It is an artemisinic acid derivative, whose structural skeleton has not been reported for Saussurea species before, but artemisinic acid is a common compound in another Compositae species, Artemisia annua. Dehydrocostus lactone (1) is present in high-content and is a possible bioprecursor of 10alpha-hydroxyartemisinic acid (9). 相似文献
993.
碳/氧化铝(氧化钛)复合物具有独特的物理化学性质,在吸附和催化过程中有广泛应用.复合物中碳层对氧化物的相变有重要影响.在高温下通氧气焙烧碳/γ-Al2O3复合物可使γ-Al2O3迅速转变为α-Al2O3;而在惰性气氛中,碳层可显著抑制氧化铝的相变与烧结.碳/氧化钛体系中,碳层可明显提高氧化钛在惰性气氛中的热稳定性,在800℃以下碳层能有效阻止锐钛矿相向金红石相的转变;在含氧气氛中控制焙烧条件可将碳层完全除去而基本不影响氧化钛的物相组成及织构.因此,碳层可作为一种特殊的表面修饰剂,既可在高温下抑制氧化物的相变,又可避免在氧化物中引入掺杂元素. 相似文献
994.
A facile and efficient one‐pot synthesis of 1,4‐dihydropyridines from aldehyde, 1,3‐dicarbonyl compounds and ammonium acetate in the presence of Ce(SO4)2‐SiO2 at 80°C under solvent‐free conditions is described. Compared with the classical Hantzsch reaction, this novel method consistently has the advantages of excellent yields and short reaction time. 相似文献
995.
Pei Hua Shang Chang Mei Cheng Hua Wang Hong Chao Zheng Yu Fen Zhao Key Laboratory of Phosphorus Chemical Biology the Ministry of Education 《中国化学快报》2010,(2)
<正>An efficient and novel method for synthesizing 3′,5′-dithio-2′-deoxyguanosine was described.In this method normal guanosine was used as the starting material.A very efficient procedure was used to synthesize 2-O-tosylguanosine 1,which used 0.1 eq.DBTO instead of 2 eq.1 was treated with LTBH to give 9-(2-deoxy-β-D-threo-pentofuranosyl)guanine 2.2 could be easily turned to the target compound. 相似文献
996.
<正>A microwave-assisted solid phase synthesis for endothelin 1 is presented.Reduced endothelin 1 was synthesized efficiently on Wang resin under microwave irradiation using Fmoc/tBu orthogonal protection strategy.The whole peptide was cleaved from the resin and two disulphide bridges were formed under air oxidation at room temperature.The purity and efficiency of synthesizing the peptide is much higher than other methods used before. 相似文献
997.
Phase behavior of ternary system involving surfactant‐like ionic liquid 1‐dodecyl‐3‐methylimidazolium chloride ([C12mim]Cl), water, and nonionic surfactant PEO‐PPO‐PEO block copolymer (Pluronic L64) is investigated at 25°C. Hexagonal (H1) and lamellar liquid crystal phase (Lα) are found in [C12mim]Cl/H2O/L64 system by using polarized optical microscopy (POM), small‐angle X‐ray scattering (SAXS) techniques and 2H NMR spectra. The phase structure (H1 phase), which is formed in [C12mim]Cl/H2O binary system, is not changed when L64 with a low concentration is added. However, phase transitions will occur from hexagonal to multiphases of H1 and cubic phases (C), then to Lα+C phases with constant [C12mim]Cl/H2O ratio and increasing L64 concentration. Moreover, at given L64 (5%, 20%) concentration, the lattice parameter of H1 or Lα phase decreases with increasing [C12mim]Cl/H2O ratio. Fourier transform infrared (FTIR) spectra indicate that the H‐bonded network comprising an imidazolium ring, chloride ion and water formed in [C12mim]Cl/H2O binary system is disrupted upon addition of L64. This is helpful to the phase transition, due to the decreasing of interfacial curvature induced by dehydration of hydrated layer after the addition of PEO block of L64. 相似文献
998.
分析化学教学中知识点的树结构设计 总被引:2,自引:0,他引:2
依据中心教学法,通过对教材的深入分析和知识重组,设计和建立了分析化学中化学分析理论教学的知识点树结构图,该结构图以误差为主线,贯穿了教材整个内容的各个知识点。教学中着重于各知识点及其相互联系和思维方式的介绍,课后辅助各章节知识点总结归纳,以便于学生对整体知识的理解、自我建构和学习方法的掌握。 相似文献
999.
1000.
Organic small molecules(TPA-BT3T,TPA-PT3T,and TPA-DFBT3T)using triphenylamine as a donor unit,terthiophene as a bridge,and benzo-2,1,3-thiadiazole(BT),[1,2,5]thiadiazolo[3,4-c]pyridine(PT)or 5,6-difluorobenzo[c][1,2,5]thiadiazole(DFBT)as an acceptor unit were designed and synthesized through Suzuki coupling reactions.These molecules exhibited good thermal stability with decomposition temperatures over 380°C and broad absorption from 300 to 700 nm.Photovoltaic devices were fabricated with these small molecules as donors and PC71BM as an acceptor.The TPA-BT3T based devices exhibited a power conversion efficiency of 2.89%,higher than those of the TPA-PT3T-and TPA-DFBT3T-based devices(1.34%and1.54%respectively).The effects of electron-withdrawing units on absorption,energy level,charge transport,morphology,and photovoltaic properties also were investigated. 相似文献