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1.
Gurjaspreet Singh Satinderpal Singh Mangat Jandeep Singh Aanchal Arora Ramesh K. Sharma 《Tetrahedron letters》2014
The copper-catalyzed ‘click silylation’ has been exploited for the chemical modification of γ-azidopropyltriethoxysilane (AzPTES) with a wide range of terminal alkynes (1a–1v) in a one-pot operation. The novel 1,2,3-triazole-triethoxysilane derivatives (2a–2v) were synthesized by this procedure and comprehensively characterized by IR spectra, 1H and 13C NMR, and HRMS studies. 相似文献
2.
Single crystals of CuBr with zincblende structure, deformed in compression at a strain rate 2×10-4 s-1 between room and liquid-nitrogen temperatures, exhibit two well-defined regions in the critical resolved shear stress (CRSS) versus temperature relationship. At rather low temperatures in the range from 78 to 150 K, the slope d ln
/dT of the straight line fitted to the data points plotted in log-linear coordinates is found to be 2.9 times greater than that at temperatures between 150 and 300 K. Similar behaviour is also observed in the case of temperature dependence of activation volume associated with the CRSS. Data analysis in terms of the kink-pair nucleation model of plastic flow shows that stress-assisted thermally-activated escape of screw dislocations trapped in Peierls troughs induces slip below about 150 K. At temperatures above 150 K, CRSS is determined by the unpinning of edge-dislocation segments from groups of randomly dispersed point defects, e.g. residual gaseous and metallic impurities, deformation-induced defects formed during the pre-yield stage etc. 相似文献
3.
In this work, the effect of an axial external moveable magnetic field on the output power of a CuBr laser with small-bore tube has been investigated. In all experiments, by applying an EMF along the tube axis, the laser output power has been decreased and by moving the EMF toward the cathode region, more substantial decrease of output power has been observed. The effect is more significant at a magnetic field intensity of 1100 G, Ne gas pressure of 35 Torr, frequency of 19 kHz and voltage of 3.8 kV, such that there was no laser emission when the EMF was placed around the cathode. 相似文献
4.
复合腔CuBr激光器中的模式研究 总被引:1,自引:1,他引:0
本文报道了在两种结构的多镜复合腔中CuBr激光器的纵模淬灭现象,并得到了重复频率几倍于基频纵模间隔的多重锁模脉冲串,最高重复频率可达440MHz.实验结果表明,通过调整复合腔的结构参数,可以在不缩短增益介质长度的条件下,实现CuBr激光多重锁模脉冲高重复频率的大范围调节. 相似文献
5.
MENG Zhicong ZHANG Guiyan SONG Xiudong JIANG Jianhua LIN Fucheng 《Chinese Journal of Lasers》1997,6(1):91-96
l.IntroductionTheideaofusingahigh-gainactivemediumtoformbrightness-enhancedmicroscofr-.icimageswasproposedmorethan2oyearsago[1:.Introductionofbrightnessamplifierintousua1oPticalsystemwouldPermittoovercomethewellknownrestrictionaccordingtowhichthebrightnessattheoutputoftheopticalsystemcannotexceedthatatthein-put[zJ.SomepulsedmetalvaporlaserssuchasthecopPervaPOrlaser(CVL)havebeenusedasimage-brightnessamplifiersinvariousopticalprojectionsystem[3j-lnthiscase,wecanbenefitfromthattheactivemedium… 相似文献
6.
Mohammad Hosein Sayahi Seyyed Jafar Saghanezhad Saeed Bahadorikhalili Mohammad Mahdavi 《应用有机金属化学》2019,33(1)
A novel methodology is presented for the synthesis of 3‐substituted 2‐thioxo‐2,3‐dihydroquinazolin‐4(1H)‐one derivatives based on an efficient tandem multicomponent reaction using copper bromide as catalyst. This methodology is based on the multicomponent one‐pot reaction of methyl 2‐bromobenzoate, phenylisothiocyanate derivatives and sodium azide in the presence of copper bromide and l ‐proline under basic conditions. To show the generality of the method, various phenylisothiocyanates bearing electron‐donating or electron‐withdrawing functionalities were used and the desired products were obtained in high isolated yields. 相似文献
7.
Solvothermal reactions of the flexible ligand 1,6-Bi(benzotriazole)hexane with CuI and KI or CuBr and KBr in ethanol generate two hybrid compounds, namely, {(HETA)[(Cu6I7)(ETA)2]}n(1) and {K(Cu6Br7)(BBTH)}n(2) (ETA=N-ethylbenzotriazole, HETA=protonated N-ethylbenzotriazole, BBTH=1,6-bi(benzotriazole)hexane). In 1, two [Cu3I4] vertex missing cubane-like subunits link each other by sharing one I atom to give a [Cu6I7] cluster, which further form novel 1D [Cu6I7]nn− anionic chain. Two in-situ generated ETA ligands finished the 4-coordinated environments of copper centers and another one discrete protonated ETA ligand keeps the charge neutrality for 1. In complex 2, bowl-shaped [Cu5Br4] clusters and rhomboid [Cu2Br2] dimers link each other to generate a [Cu6Br7]nn− 1D chain. BBTH ligands complete the tetrahedral spheres of Cu(I), and 7-coordinated K atoms further extend the 1D chain motifs to a 2D hybrid layer of 2. The UV-vis diffuse reflectance spectrum and luminescence measurements show that compound 1 and 2 both are potential semiconductor and photoluminescence materials. 相似文献
8.
<正>Quinazoline derivatives were synthesized fromα-iminoesters via a cascade imino-Diels-Alder and then oxidation reaction catalyzed with CuBr_2.This method provided a new strategy for preparing quinazoline derivatives which may be useful in the synthesis of heterocyclic intermediates. 相似文献
9.
溴化铜对异丙醇铝存在下原子转移自由基聚合的影响 总被引:2,自引:0,他引:2
研究了以2-溴异丁酸乙酯为引发剂、溴化亚铜(CuX)/联二吡啶(bPy)/异丙醇铝[Al(OPri)3]为三元复合催化体系,40℃下甲基丙烯酸甲酯(MMA)在环己酮中的原子转移自由基聚合,详细研究了溴化酮对聚合反应的影响.实验结果表明,以异丙醇铝为助催化剂,MMA可在较低温度下进行活性聚合;随着CuBr2浓度的提高,自由基浓度降低,终止反应受到抑制;不加CuBr2时,聚合物的分子量分布较宽(Mw/Mn);加入CuBr2时,聚合物的分子量分布较窄(Mw/Mn=1.2~1.5),而且对数转化率与时间呈线性关系. 相似文献
10.