首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
A novel typography technique was developed to in situ synthesize oligonucleotide arrays on glass slide,which has the celerity,high spatial resolution,lower cost,reliable operation,and high synthetic efficiency.The principle and process of the typography technique for fabricating gene-chips have been described in detail.A suit of poly(terafluoroethylene)devices for synthesizing oligonucleotide arrays were designed and prepared,and the fiber tubes with a number of nano-or micron-channels were em- ployed.The oligonucleotide arrays of 16 and 160 features with four different probes were synthesized using the typography technique.The four specific oligonucleotide probes including the matched and the mismatched by the fluorescent target sequence gave obviously different hybridization fluorescent signals.It was indicated that the gene-chip fabricated by the typography method could be used to rapidly screen single-nucleotide polymorphisms(SNP)and to detect mutations.  相似文献   

2.
A terylene membrane which kept pH〉12 in cathode compartment was used to construct a divided cell with a carbon/polytetrafluoroethylene(C/PTFE) O2-fed cathode. The concentrations of hydrogen peroxide (H2O2) and hydroxyl radical (HO^-)in the catholyte were 8.3 mg/L and 2.15 μmol/L, respectivel.y, which were determined by permanganate titration, electron spin resonance (ESR) spectrum and the fluorescence spectra. ;The efficiency of the removal of phenol achieved 100% as a result of these two kinds of stronger oxidizer.  相似文献   

3.
Polymer light-emitting electrochemical cells (PLECs) employ a thin layer of a luminescent conjugated polymer admixed with an ionic source and an ionic conductor for the in-situ formation of p-i-n junction and subsequent efficient injections of both electrons and holes.The junction formation enables the use of air-stable conductors as the cathode and a relatively thick emissive polymer layer that is more compatible with low-cost solution-based processes.This paper overviews the operation mechanism of the PLECs,the properties and drawbacks of the devices.The employment of crosslinkable ionic conductors to stabilize the p-i-n junction is reviewed.The resulting static junction electroluminesces light at high brightness,high efficiency,and prolonged lifetime.Silver paste and carbon nanotubes can be used as the cathode,thus,PLECs were fabricated by lamination.Using single wall carbon nanotubes coated elastic substrate as both anode and cathode,the PLECs can be made highly stretchable.  相似文献   

4.
Efficient white light emitting polymers were synthesized based on poly(9,9-dioctylfluorene-co-dibenzothiophene-S,S-dioxide) as blue emitter and a bisphenylamine functionalized 2,1,3-benzothiadiazole (DPABT) as red emitter. It was found that the incorporation of hole-transporting carbazole moiety into polymer main chain could effectively reduce the hole injection barriers, which can lead to distinctly improved charge balance in the emissive layer. Additionally, the hole-transporting carbazole units may form efficient bipolar host with electron-transporting dibenzothiophene-S,S-dioxide units. The white light emitting diodes based on single polymer PFSOCzDPABT showed the maximum luminous efficiency of 3.3 cd/A with the maximum luminance of 10282 cd/m2 , and the luminous efficiency showed only 24% roll off at current density of 400 mA/cm2 . These Commission Internationale d’Enclairage (CIE) coordinates of the devices changed slightly with the driving voltages increasing from 8 V to 12 V, and were very close to National Television System Committee (NTSC) standard white light emission of (0.33, 0.33). The results indicated that the incorporating bipolar host and low band gap DPABT unit was a promising way to achieve efficient single white light emitting copolymers.  相似文献   

5.
Microporous carbon nanofibers(MCNFs) derived from polyacrylonitrile nanofibers were fabricated via electrospinning technology and phase separation in the presence of polyvinylpyrrolidone(PVP).PVP together with a mixed solvent of N,N-Dimethylformamide and dimethyl sulfoxide was used as poreforming agent.The influences of PVP content in casting solution on the structure and electrochemical performance of the MCNFs were also investigated.The highest capacitance of 200 F/g was obtained on a three-electrode system at a scan rate of 0.5 A/g.The good performance was owing to the high specific surface area and the large amount of micro-pores,which enhanced the absorption and the transportation efficiency of electrolyte ion during charge/discharge process.This research indicated that the combination of electrospinning and phase separation technology could be used to fabricate microporous carbon nanofibers as electrode materials for supercapacitors with high specific surface area and outstanding electrochemical performance.  相似文献   

6.
Wastewater discharged from chemical oxygen demand(COD) testing instrument was generally difficult to treat due to its high content of heavy metals and very low pH. In this study, a kind of cysteine-functionalized magnetic nanoparticles(MNPs-Cys) was synthesized and used to treat the wastewater. The synthesized MNPs-Cys as the adsorbent for heavy metal removal from aqueous solutions were systematically investigated. The adsorption dynamic process fit the Langmuir isotherms well with a maximum adsorption capacity of 76.92 mg/g for Cu(Ⅱ). The adsorbent could be easily regenerated by 0.1 mol/L HNO3, which exhibited a high adsorption performance within 10 cycles. This adsorbent, combined with a developed pretreatment approach, could make Cr(Ⅲ), Hg(Ⅱ) and Ag(Ⅰ) in the wastewater discharged from COD testing instrument effectively removed and the removal efficiency is more than 99%. This work gave a new insight into the design and synthesis of high-performance materials for treating wastewater with heavy metals.  相似文献   

7.
A series of alcohol soluble amino-functionalized carbazole-based copolymers were synthesized via Suzuki coupling reaction.The pendent amino groups endow them high solubility in polar solvents,as well as efficient electron injection capability from high work-function metals.The relationships between the photophysical and electrochemical properties and the polymer backbone structure were systematically investigated.These alcohol-soluble carbazole-based copolymers were used as cathode interlayers between the high work-function metal Al cathode and P-PPV emissive layer in polymer light-emitting diodes with device structure of ITO/PEDOT:PSS/P-PPV/interlayer/Al.The resulting devices exhibited improved performance due to the better electron injection/transporting ability of the designed copolymers from Al cathode to the light-emitting layer.  相似文献   

8.
Wei  Qingbo  Ye  Zhangwen  Ren  Xiaodong  Fu  Feng  Yang  Zhou  Liu  Shengzhong  Yang  Dong 《中国科学:化学(英文版)》2020,63(6):818-826
The active absorber layer plays a crucial role in a perovskite solar cell.Herein,we used high boiling pointγ-butyrolactone(GBL)as the main solvent,Pb(SCN)_2 and dimethyl sulfoxide(DMSO)as an effective additive in the FA_(0.83)MA_(0.17)Cs_(0.05)PbI_((3-x))Br_x solution to improve the quality of perovskite films.The GBL will delay the crystallization speed of the perovskite,and lead to the grain growth assisted by thiocyanate.The synergistic effect of the solvent engineering and additive engineering is beneficial to the slow growth of the grain size.It is found that the addition of Pb(SCN)_2 increases Gibbs free energy barrier for the nucleation,leading to the formation of fewer nuclei,which results in a high quality of perovskite absorbers with larger grains and smoother surfaces.The synergistic effect of solvents and Pb(SCN)_2 on the morphology and photovoltaic performances is investigated.Compared to devices without the additive,the efficiency of devices with 5% Pb(SCN)_2-doped FA_(0.83)MA_(0.17)Cs_(0.05)PbI_((3-x))Br_x is raised to 19.01% from 15.21%.We believe this breakthrough regarding high efficiency perovskite solar cells will help for their transitions.  相似文献   

9.
A new amorphous small-molecule material, in which the electron-donating carbazole units are connected to the backbone by flexible side chains, has been synthesized and utilised in the photovoltaic(PV) field. This material exhibits the amorphous feature, higher thermal stability and good film forming ability. The influence of the heat-treatment on the morphology and the performance of PV devices were studied. Eventually, a relatively high photovoltaic conversion efficiency was achieved. At the same time, the PV device displayed an ideal open-circuit voltage(over 1 V) which is very close to the upper limit of its theoretical value.  相似文献   

10.
In the "cycloketyl radical mediated living polymerization"(CMP) process, a cycloketyl compound, [9,9′]bixanthenyl-9,9′ diol(BIXAN) was ultilized as initiator and mediator. The cycloketyl(CK) radical was used as the dormant radical to achieve the increase of molecular weight. Herein, a series of cycloketyl thioketones were synthesised by Lawesson's reagent by one step reaction with high yeild,and we found that, when a special cycloketyl thioketone compound, thioxanthene-9-thione(TXT), was added to a routine radical polymerization system, TXT could capture chain radical, and simultaneously formed an radical analogous to CK radical in structure,which could trigger the growth of polymer chains. This simple system was efficient to initiate the polymerization of methyl methacrylate(MMA) and in all cases the molecular weights increased with the increase of conversions. By the end-group analysis with 1 H-NMR and MALDI-TOF MS, it was confirmed that the P-STXT radical was used to control the polymerization. The re-initiating reactions were achieved when PMMA was used as the macro-initiator.  相似文献   

11.
Two polythiophene derivatives using fluorine atoms and hexyl or hexyloxy group as electron-withdrawing and donating substituents have been synthesized. The introduction of fluorine atoms to the polythiophene backbones simultaneously lowers the HOMO and narrows the bandgap, and the stronger electron-donating ability of hexyloxy side chain further reduces the bandgap. As a result, poly[3-hexylthiophene-2,5-diyl-alt-3,4-difluorothiophene] (PHTDFT) shows HOMO and bandgap of -5.31/1.83 eV and poly[3,4-dihexyloxythiophene-2,5-diyl-alt-3,4-di- fluorothiophene] (PDHOTDFT) shows HOMO and bandgap of -5.14/1.68 eV, both are lower than --4.76/2.02 eV of P3HT. Benefiting from the lower HOMO, PHTDFT:PC61BM (1 " 1) polymer solar cells obtain a power conversion efficiency of 1.11% and an impressed open-circuit voltage of 0.79 V under solar illumination AM1.5 (100 mW/cm2).  相似文献   

12.
We have studied the effect of silicon nanocrystals (SiNCs) as a third component on performance of organic bulk heterojunction solar cells composed of poly[2-methoxy,5-(2'-ethylhexyloxy)-l,4-phenylene vinylene] (MEH- PPV):[6,6]-phenyI-C61-butyric acid methyl ester (PCBM) blend film. By adding suitable amounts of SiNCs into MEH-PPV:PCBM blend, the device performance such as external quantum efficiency, short circuit current density (Js(), and power conversion efficiency (PCE) improved. Incorporation of 2.5% SiNCs in the blend led to 13.6% improvement of Jsc, which in turn resulted in 18% improvement of PCE up to 2.28%. The improved performance was mainly due to the improvements both in the charge generation from the interface of MEH-PPV/SiNCs and the charge collection at the cathode.  相似文献   

13.
A series of donor-acceptor oligomer OBTThn (n = 1- 7) and polymer PBTThl and PBTTh2 composed of al- ternative 2,1,3-benzothiadiazole and 3-hexylthiophene have been designed and synthesized for the purpose of in- vestigation on the effect of chain length and side-chain regioregularity on their basic properties and photovoltaic performance. In the OBTThn oligomers and PBTThl polymer, all the hexyl side chains on thienyl units orient to- ward the same direction. Upon elongation of the chain length, the intramolecular charge transfer (ICT) absorption band in solution gradually redshifts from 398 nm for OBTThl to 505 nm for OBTThT, then to 512 nm for PBTThl polymer. Meanwhile, the HOMO energy level increases from -5.45 eV (OBTTh0 to -5.08 eV (OBTThT) and -5.09 eV (PBTThl), and the LUMO energy level decreases from -3.11 eV (OBTTh0 to -3.30 eV (OBTThT) and -3.33 eV (PBTThl), thus giving a smaller and smaller energy bandgap for higher oligomers and polymers. Theo- retical calculation suggests straight line-like backbone geometry for this series of oligomers and polymer. On the other hand, polymer PBTTh2 possesses a different side-chain regioregularity, in which every two neighbor hexyl side chains are arranged in different orienting direction. It is theoretically suggested to have curved line-like back- bone geometry. In solution, it shows similar photophysical and electrochemical properties as PBTThl. However in film state, it displays a less redshift in the ICT band as refer to that in solution than PBTThl. In combination with [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM), these oligomers and polymers were used as donor material to fabricate organic bulk heterojunction solar cells. Again, chain length-dependent device photovoltaic performance was observed. The device based on OBTTh4 showed a power conversion efficiency of 0.16%, while it increased to 0.36% and 0.49% for the devices based on OBTTh6 and PBTThb respectively. However, the side-chain regio- regularity has less influence on the device photovoltaic output since the device based on PBTTh~ displayed an effi- ciency of 0.52%, comparable to that of PBTThl.  相似文献   

14.
A ladder-type diindenopyrazine (IPY) was synthesized and used as a building block for constructing conjugated copolymers. Three copolymers based on the IPY moiety were obtained via the Suzuki coupling reaction with dif- ferent monomers, including 4,7-dithien-2-yl-2,1,3-benzothiadiazole (DBT), 5,8-dithien-2-yl-2,3-diphenylquinoxa- line (DTQ), and 5,8-dithien-2-yl-2,3-di(4-fluorophenyl)quinoxaline (DFTQ). The obtained polymers were charac- terized by 1H NMR spectroscopy, UV-Vis absorption spectroscopy, cyclic voltammetry, and gel permeation chro- matography (GPC). Owing to the four solubilizing alkyl chains on the IPY unit, all the three copolymers have good solubility in common solvents. These polymers have deep-lying HOMO energy levels in the range of-5.55-5.60 eV, and exhibit field-effect mobilities as high as 0.006 cm2.V-l.s i. Photovoltaic applications of these polymers as light-harvesting and hole-conducting materials were investigated in conjunction with [6,6]-phenyl-C6rbutyric acid methyl ester (PC61BM). Both conventional and inverted devices were fabricated based on these three polymers. A power conversion efficiency (PCE) of 2.53% and a high open-circuit voltage of 1.00 V were obtained under simu- lated solar light AM 1.5 G (100 mW/cm2) from an inverted solar cell with an active layer containing 25 wt% lad- der-type IPY containing copolymer (PIPYDTQ) and 75 wt% PC61BM. Moreover, a high open-circuit voltage of 1.02 V and a PCE of 2.40% were achieved from a conventional solar cell based on PIPYDTQ.  相似文献   

15.
The title compound, [NiL]5[V34O82·8H2O (1, L=5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane), has been synthesized under hydrothermal conditions and structurally characterized by EA, IR, XPS, TG and single-crystal X-ray diffraction. It crystallizes in the monoclinic system, space group C2/c with a=33.061(4), b=15.3457(17), c=33.902(4), β=101.930(2)°, Mr=4904.08, V=16828(3)3 , Z=4, Dc=1.936 g/cm3 , F(000)=9832, μ=2.425 mm-1 , the final R=0.0402 and wR=0.0969. The mixed valence vanadium clusters of [V34O82]10- bridges [NiL]2+ to form a one-dimensional chain in 1. To the best of our knowledge, the title complex is the first example of organic-inorganic hybrid material involving the largest vanadium cluster of [V34O82]10-.  相似文献   

16.
A cluster compound V2S6O2Cu6(3-MePy)6(3-MePy = 3-methyl pyridine) has been synthesized by using skiving method and the crystal structure was characterized by X-raydiffraction: space group P1, Z = 1, a = 9.7278(4), b = 10.4180(5), c = 11.9230(6) , α = 108.240(3), β = 98.120(2), γ = 99.500(2)o, R = 0.052 and wR = 0.104. The NLO properties were studied by Z-scan technique with 8 ns pulsed laser at 532 nm. The cluster exhibits strong NLO absorptive ability(α2 = 1.7 × 10–10 m·W–1) and effective self-focusing performance(n2 = 1.27×10–18 m2·W–1) in a 1.58 × 10–4 mol·dm–3 DMF solution.  相似文献   

17.
研究了酸性介质中五价钒氧离子(VO)、强碱性阴离子交换树脂负载钒(V)(BAEV)、硫酸氧钒(VOSO4)、杨梅形聚羧酸氧钒(IV)(APCV)、杨酸形聚亚氨二乙酸氧钒(IV)(APIV)、杨梅形聚得偕亚氨二乙酸氧钒(IV)(APOV)、笼形聚羧酸氧钒(IV)(CPCV)和笼形聚肟偕亚氨二乙酸氧钒(IV)(CPOV)等与硫脲(TU)配住生成活性种并引发丙烯腈(AN)聚合反应。表观聚合速度(Rp)分别是:VO-TU:Rp=2.8X105e-14200/RTC2.2'(AN)c.20(HNO3)c0(V5+)c1.3(TU)BAEV-TU:Rp=1.9X104e-6860/RTc1.2(AN)c1.0'(HNO3)c0.44(PV)c1.0(TU)VOSO4-TU:Rp=0APCV-TU:Rp=2.3X104e-4100/Rtc1.5(AN)c1.5(HNO3)c0.5(PV)c2.0(TU)APIV-TU:RP=2.2X105e-6860/RTc1.0(AN)c2.0(H2SO4)c0.5(PV)c1.5(TU)APOV-TU:RP=1.9X108e-10800/RTc.10(AN)c1.0(HNO3)c0.6(PV)c1.5(TU)CPCV-TU:Rp=9.7X105e-10500/RTc1.0(AN)c1.5(HNO3)c0.5(PV)c0.76(TU)CPOV-TU:Rp=1.0X108e-10500/RTc1.0(AN)c3.0(HNO3)c1.0(PV)c1.5(TU)根据实验结果,认为:(一)钒化合物与硫脲在酸性介质中通过“逐步配位—质子转移”机理产生引发种;(二)钒络合物及其活化后所产生的阳离子自由基(i=0,1,2,…,n)处于大分子引力场内进行链引发,在某些情况下,原地进行键增长反  相似文献   

18.
Ferdov S  Reis MS  Lin Z  Ferreira RA 《Inorganic chemistry》2008,47(21):10062-10066
A new vanadium(III) phosphate, Na3V(OH)(HPO4)(PO4), has been synthesized by using mild hydrothermal conditions under autogeneous pressure. This material represents a very rare example of sodium vanadium(III) phosphate with a chain structure. The crystal structure has been determined by refinement of powder X-ray diffraction data, starting from the atomic coordinates of an isotypic compound, Na3Al(OH)(HPO4)(PO4), which was obtained under high temperature and high pressure. The phase crystallizes in monoclinic space group C2/m (No. 12) with lattice parameters a = 15.423(9) A, b = 7.280(0) A, c = 7.070(9) A, beta = 96.79(7) degrees, V = 788.3(9) A(3), and Z = 4. The structure consists of one-dimensional chains composed of corner-sharing VO5(OH) octahedra running along the b direction. They are decorated by isolated PO4 and HPO4 tetrahedra sharing two of their corners with the ones of the vanadium octahedra. The interconnection between the chains is assured by three crystallographically distinct Na(+) cations. Magnetic investigation confirms the 3+ oxidation state of the vanadium ions and reveals an antiferromagnetic arrangement between those ions through the chain.  相似文献   

19.
Two macrocyclic zinc(II) complexes {[ZnL(VO3)2]·0.33H2O}n(1) and [ZnL(H2O)2][Ni(CN)4](2)(L = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) have been obtained from the reactions of [ZnL](ClO4)2 with NH4VO3 and K2[Ni(CN)4], respectively, and structurally characterized by elemental analysis, IR, XRPD, TG and X-ray diffraction. Single-crystal X-ray diffraction analyses indicated that the Zn(II) atom lies on an inversion center and is octahedrally coordinated by four nitrogen atoms of the tetradentate macrocyclic ligand in the equatorial plane and two oxygen atoms of [VO4] tetrahedra in the axial positions in 1, and two oxygen atoms of two water molecules in 2. Complex 1 shows a three-dimensional structure, which is constructed by the links of [VO3]nn- chains with [ZnL]2+, forming one-dimensional channels occupied by guest water molecules. The monomers of [ZnL(H2O)2]2+ and [Ni(CN)4]2- are connected through the intermolecular hydrogen bonds to form a two-dimensional sheet in complex 2.  相似文献   

20.
SynthesisandCrystalStructureofPyridine-2,6-dicarboxylateVanadiumComplex:[(Pyridine-2,6-dicarboxylate)VO_2]_2[4,4'-bipyridine]·...  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号