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1.
The blue shift of optical transmittance edges were observed in amorphous semiconductor Ge(S, Se)2 chalcogenide films with light illumination. The shift in well-annealed films could be recovered by annealing the films near the glass-transition temperature again. The photocrystallization was also observed in amorphous Ge(S,Se)2 films with light illumination by the transmitting electron microscope measurement. The photoinduced phenomina of the amorphous Ge(S,Se)2 films could be applied to designing some new kinds of optical storage materials.  相似文献   

2.
合成了紫杉醇侧链的赤式外消旋体,首次采用(- )-α-苯基乙胺为拆分剂,拆分得到紫杉醇侧链的(2S,3S) 和(2R,3R) 两种立体异构体.光学纯度超过90 % .  相似文献   

3.
本研究以手性(S)-3-羟基-丁酸甲酯为原料,经TBSCl保护羟基、DIBAL-H还原及烯丙基锌试剂反应后合成(2S,4R/S)-6-庚烯-2,4-二醇中间体,利用anti/syn-1,3-二醇在进行丙酮叉保护以及脱丙酮叉保护时反应动力学性能上的差异,并通过高立体选择性的动力学拆分法合成出目标产物(2S,4S)和(2S,4R)-6-庚烯-2,4-二醇.  相似文献   

4.
采用一种适用于共价晶体的含双共价因子(即Nt≠Ne)的能量矩阵计算方法,研究了V^2+离子在ZnS,ZnSe,ZnTe系列中的光谱,从中可看出一些有趣的趋势,并对结果进行了讨论。  相似文献   

5.
以天然产物中提取的L-苯丙氨酸为原料,经氨基保护、重氮化反应、氯化和还原反应后合成了(2S,3S)-N-苄氧羰基-4-苯基-3-氨基-1-氯-2-丁醇。并以高效液相色谱-质谱联用技术、单晶X射线衍射等方法对产品进行了分析和结构表征。  相似文献   

6.
文章利用超微铂电极,结合循环伏安法和电化学阻抗谱,研究了所制备的一碘化N-(2-羟乙基)乙二胺盐(HEEDAI)中,不同I2浓度对溶液中I3-的氧化还原行为及Pt电极/电解质溶液界面的影响;将HEE-DAI和1-甲基-3-丙基咪唑碘(MPII)分别作为I-供体,组成纯离子液体电解质组装成染料敏化太阳电池(DSSC),并比较了相应DSSC的光伏性能。结果表明,随着HEEDAI中I2浓度的增加,溶液中I3-的扩散系数逐渐减小;I2浓度为0.15 mol/L的HEEDAI所组装成的DSSC表现出较好的光伏性能;且与MPII相比较,HEEDAI所组装的DSSC具有较高的开路电压和填充因子。  相似文献   

7.
The Al_2O_3, MnS, and TiN inclusions in bearing steel will deteriorate the steel's mechanical properties. Therefore, elucidating detailed characteristics of these inclusions in consumable electrode during the electroslag remelting process is important for achieving a subsequently clean ingot. In this study, a confocal scanning violet laser microscope was used to simulate the remelting process and observe, in real time, the behaviors of inclusions. The obtained images show that, after the temperature exceeded the steel solidus temperature, MnS and TiN inclusions in the specimen began to dissolve. Higher temperatures led to faster dissolution, and the inclusions disappeared before the steel was fully liquid. In the case of an observed Al_2O_3 inclusion, its shape changed from angular to a smooth ellipsoid in the region where the solid and liquid coexisted and it began to dissolve as the temperature continued to increase. This dissolution was driven by the difference in oxygen potential between the inclusion and the liquid steel.  相似文献   

8.
The Al2O3, MnS, and TiN inclusions in bearing steel will deteriorate the steel's mechanical properties. Therefore, elucidating de-tailed characteristics of these inclusions in consumable electrode during the electroslag remelting process is important for achieving a subse-quently clean ingot. In this study, a confocal scanning violet laser microscope was used to simulate the remelting process and observe, in real time, the behaviors of inclusions. The obtained images show that, after the temperature exceeded the steel solidus temperature, MnS and TiN inclusions in the specimen began to dissolve. Higher temperatures led to faster dissolution, and the inclusions disappeared before the steel was fully liquid. In the case of an observed Al2O3 inclusion, its shape changed from angular to a smooth ellipsoid in the region where the solid and liquid coexisted and it began to dissolve as the temperature continued to increase. This dissolution was driven by the difference in oxygen potential between the inclusion and the liquid steel.  相似文献   

9.
在点电荷模型基础上,考虑屏蔽效应以及电子云膨胀效应,计算了掺杂的CaF2与SrF2晶体中Ce^3+离子的晶场能级,计算结果较前人结果有较大改进,绝大部分能级与实验值吻合较好.研究表明,Ce^3+离子4f电子云膨胀效应和5s,5p电子壳层屏蔽效应在CaF2和SrF2中都不能忽略.  相似文献   

10.
在MP2/6-311++G**基组水平下对苯水体系,苯硫化氢体系和苯硒化氢体系可能存在的结构进行了全自由度能量梯度优化,找到了三个能量极小的π氢键结构BW,BS和BSe,它们的结合能分别是-10.25kJ/mol,-9.12kJ/mol,-9.83kJ/mol.通过电荷分析发现了电荷的流向从苯环流向给体的小分子.  相似文献   

11.
Gd2O3 :Eu3+ downconversion luminescent powder was prepared using the homogeneous precipitation method. Its optical properties were analyzed and it was introduced into a dye-sensitized solar cell (DSSC). As a luminescence medium, Gd2O3 :Eu3+ improved light harvesting via conversion luminescence and increased the photocurrent of the DSSC. As a p-type dopant insulating rare earth oxides form an energy barrier, and the Gd2O3 :Eu3+ elevated the energy level of the oxide film and increased the photovoltage. The photoelectric conversion efficiency for a DSSC with Gd2O3 :Eu3+ doping (6 : 100) reached 7.01%, which was 17.4% higher than the photoelectrical conversion efficiency of a DSSC without Gd 2 O 3 :Eu 3+ doping.  相似文献   

12.
文章对比分析了Si3N4单层减反射膜与TiO2/SiO2双层减反射膜对单晶硅太阳电池性能的影响,发现Si3N4单层减反射膜单晶硅太阳电池短路电流Isc较高。并对这两种减反射膜的批量产品进行抽样检测,结果表明采用TiO2/SiO2双层减反射膜电池总体品质(主要从效率看)相当于或略优于Si3N4单层减反射膜太阳电池,说明TiO2/SiO2双层减反射膜仍比较适于单晶硅太阳电池。  相似文献   

13.
We report for the first time the preparation method of compact TiO2 film using titanium butox-ide-petroleum ether solution, by means of dipping and sintering. Our estimation of the component of this thin film was confirmed by XPS test. Studies of AFM showed the influence of preparation condition upon surface morphology. The transmitted spectrum of this compact TiO2 film was also investigated, which presented an excellent transmittance of this film in the visible light region. We arrive at a conclusion, according to the Ⅰ-Ⅴ characteristics of solid-state Gratzel solar cells utilizing this kind of compact film, that this compact TiO2 film functions well in secluding the conducting substrate from the hole-conducting material.  相似文献   

14.
研究了(CH3)2S2和Cl2在水中的反应机理,得到了总速率方程为d[HCl]/dt=k[Cl2][(CH3)2S2],在15 ℃和常压下测定了反应体系电导率κ随时间t的变化,得到反应开始瞬间和反应达到稳定态时的κ=f(t)的图形,均与此反应机理得到的结论相一致,用此反应机理能很好地解释反应中颜色变化、产热速率等现象和也可用来指导生产.  相似文献   

15.
SnO2:(Sb,In)透明导电薄膜的制备及其性能研究   总被引:4,自引:0,他引:4  
采用溶胶凝胶(Sol-Gel)技术制备了SnO2∶(Sb,In)薄膜,优化了制备工艺参数,应用差示扫描量热仪-热重分析仪(DSC-TGA)、X射线衍射仪(XRD)等手段对薄膜进行了表征.结果表明,氯化亚锡、乙醇和水摩尔比为1∶20∶4时成胶状态最佳,当锑和铟的掺杂量分别为7 %和4 %时,在500 ℃氮、氢混合气氛下煅烧2 h制备的薄膜表面平整,方块电阻大约为40.5 Ω,紫外-可见光透射率达88 %.  相似文献   

16.
首次合成了新型配位化合物(FeCp2)0.13[Ni(C3S5)(C3S7)],配体为具有12个S原子的杂戊烯,通过EA、ICP、IR、1HNMR、UV对这种化合物进行了表征,并通过循环伏安法和变温四探针法对其电化学性质进行了研究.结果表明,硫链增长及二茂铁阳离子的引入使配合物的宣温导电性能有了一定的改善.  相似文献   

17.
(R)- and(S)-2-Allyl-1,3,2-dinaphtho (α,β) [d.f] dioxaborepin ((R)-2 and(S)-2) have been first prepared by the reaction of(R)-(+)- or(S)-(−)-1, 1′-bi-2-naphthol and triallylborane in THF at room temperature, respectively.(S)-2 and(R)-2 are sensitive to moisture and oxygen in air and disproportionate easily to triallylborane and 1,1′-bi-2 naphthyl bis (1,1′-bi-2-naphtholborate) at ambient temperature. However, THF is a stabilizer for them. The reactions of(R)-2 or(S)-2 and some aliphetic or aromatic aldehydes in CH2Cl2 at −78°C for several hours afforded β-alkylenyl alcohols in up to 84.8%ee. Among them, optically active 1-(3, 5-dichlorophenyl)-3-butenol and 1-(2-methoxyphenyl)-3-butenol were first prepared Foundation item: Supported by the National Natural Science Foundation of China (29972033) Biography: Liu Dejun (1973), male, Ph. D, research direction: asymmetric synthesis  相似文献   

18.
比较系统的总结了AT,S(2)的各种表示,与此同时,给出AT,S(2)的三个新的表达式,AT,S(2)=[E1GA E2]-1[E10]G或AT,S(2)=G(F1 0)-1(AGF1 F2)以及AT,S(2)=-1/β0((GA)s-1+βs-1(GA)s-2+…+β2(GA)+β1In)G=-1/β0G((AG)s-1+βs-1(AG)s-2+…+β2(AG)+β1In)利用前两种表达式,我们给出AT,S(2)逆的Gauss-Jordan消去法的求法.  相似文献   

19.
用Na4[Re6Se8(CN)6]与1,3-丙二胺(tn)和氯化镍反应得到化合物[Ni(tn)3]2 [Re6 Se8(CN)6], 对其进行了X-Ray射线晶体结构测定,表明化合物属三斜晶系、P1-空间群,晶胞参数为a=10.7511(4) (A), b=10.7813(6) (A), c=12.7072(8) (A), α=66.294(3)°, β=74.610(3)°, γ=88.801(3)°. Z=1, R=0.0985, wR2 = 0.2386.  相似文献   

20.
室温下,通过[(PPh3)2Cu(NO3)]与二硫化碳在甲醇和二氯甲烷混合溶剂中反应合成了铜(I)配合物[(PPh3)2Cu(S2COMe)],研究了配合物的物理化学性质和光谱性质,并经X-射线结构分析确定了配合物的分子结构,中心铜离子分别与来自三苯基膦的两个P原子和S2COMe-阴离子中的2个硫原子形成四面体结构.配合物属正交晶系,空间群P212121,晶胞参数如下:a=0.951 3(2)nm,b=1.807 5(4)nm,c=1.996 8(3)nm;V=343.34(12)nm3,Z=4,F(000)=1 440,Dcalcd=1.345 g.cm3,μ=0.880 mm-1,R=0.048 7,Rw=0.093 5.  相似文献   

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