排序方式: 共有49条查询结果,搜索用时 15 毫秒
1.
2.
3.
An efficient iodine-mediated cascade synthesis of 3-aza-bicyclo[3.1.0]hex-2-ene derivatives from easily prepared N-allyl enamines has been developed. The advantages of the reaction include facilitative preparation of substrates 3a–t, good functional group tolerance and transition-metal-free conditions. 相似文献
4.
着重研究了多孔介质BISQ模型中慢纵波的基本特性.给出了BISQ模型下慢纵波速度 和衰减的低频近似公式.与Biot理论对比,BISQ模型中慢纵波的衰减随频率降低急剧增大, 且随喷射流长度的减小而增加;相速度随喷射流长度的减小而增加,其低频极限值不是零; 孔隙流体位移与固相骨架位移之比的幅值随喷射流长度的增加而减小,其相位特点与Biot模 型预测的不同;在流体与孔隙介质的边界上可产生更大的渗流.为对比,同时也给出快纵波 的行为.依据BISQ模型可推断:非黏滞流体饱和孔隙介质中不存在喷射流机理;BISQ模型中
关键词:
多孔介质
喷射流
慢纵波
动力协调 相似文献
5.
Numerical Simulation of Shear-Horizontal-Wave-Induced Electromagnetic Field in Borehole Surrounded by Porous Formation 下载免费PDF全文
Seismoelectric fieM excited by purely torsional loading applied directly to the borehole wall is considered. A brief formulation and some computed waveforms show the advantage of using shear-horizontal (SH) transverseelectric (TE) seismoelectric waves logging to measure shear velocity in a fluid-saturated porous formation. By assuming that the acoustic field is not influenced by its induced electromagnetic field due to seismoeleetric effect, the coupling governing equations for electromagnetic field are reduced to Maxwell equations with a propagation current source. It is shown that this simplification is valid and the borehole seismoelectric conversion efficient is mainly dependent on the electrokinetic coupling coefficient. The receivers to detect the conversion electromagnetic field and to obtain shear velocity can be set in the borehole fluid in the SH-TE seismoelectric wave log. 相似文献
6.
Abstract The two 1-aryl-5-methyl-1,2,3-triazole derivatives were prepared by the 1-aryl-5-methyl-1,2,3-triazol-4-carboxylic acids 3. The yielded products 4a–b were confirmed by NMR, MS, IR spectra. We investigated the crystalline structure of compounds 4a and 4b. Compound 4a, C9H8BrN3, Mr = 238.09, crystallizes in the monoclinic space group P2(1)/n with unit cell parameters a = 11.660(2), b = 7.668(2), c = 11.818(2) ?, α = 90.00, β = 116.01(3), γ = 90.00o. V = 949.6(3) ?3, Z = 4, Dx = 1.665 Mg m−3. The final R was 0.0477. Compound 4b, C13H11N3, Mr = 209.25, crystallized in the orthorhombic space group Pbca with unit cell parameters a = 10.373(2) ?, b = 11.691(2) ?, c = 17.579(4) ?, α = 90.00o, β = 90.00o, γ = 90.00o, V = 2131.8(7) ?3, Z = 8, D
m = 1.304 Mg m−3. The final R was 0.0565.
Index Abstract The two 1-aryl-5-methyl-1,2,3-triazole derivatives were prepared by the 1-aryl-5-methyl-1,2,3-triazol-4-carboxylic acids 3. The yielded products 4a–b were confirmed by NMR, MS, IR spectra. We investigated the crystalline structure of compounds 4a and 4b. Compound 4a, C9H8BrN3, Mr = 238.09, crystallizes in the monoclinic space group P2(1)/n with unit cell parameters a = 11.660(2), b = 7.668(2), c = 11.818(2) ?, α = 90.00, β = 116.01(3), γ =90.00o. V = 949.6(3) ?3, Z = 4, Dx = 1.665 Mg m−3. The final R was 0.0477. Compound 4b, C13H11N3, Mr = 209.25, crystallized in the orthorhombic space group Pbca with unit cell parameters a = 10.373(2) ?, b = 11.691(2) ?, c = 17.579(4) ?, α = 90.00o, β = 90.00o, γ = 90.00o, V = 2131.8(7) ?3, Z = 8, D
m = 1.304 Mg m−3. The final R was 0.0565.
相似文献
7.
8.
2-(4-Decarboxydehydroabietyl)-5-p-toyl-[1,3,4]-oxadiazole, C28H34N2O, has been synthesized and characterized by IR, NMR, elemental analysis and single-crystal X-ray diffraction method. The crystal belongs to the orthorhombic system, space group P212121 with a = 6.1351(5), b = 14.8495(19), c = 25.9050(2) A, V = 2360.0(4) A3, Z = 4, Mr = 414.57, Dc = 1.167 Mg/m^3, 2 = 0.71073 A,μ(MoKa) = 0.070 mm^-1, F(000) = 896, the final R = 0.0452 and wR = 0.1076 for 1647 observed reflections with I 〉 2σ(I). There are five rings in the crystal structure of the title compound, but the oxadiazole ring is non-coplanar with the benzene ring D. 相似文献
9.
光活性[1]1-联萘酚(BINOL)的不对称合成 总被引:3,自引:1,他引:2
由于 1 ,1 -联萘酚 ( BINOL)可作为手性配体或手性催化剂的前体 ,在不对称合成反应中具有广泛的应用 [1,2 ] ,所以如何得到光学纯的 BINOL的研究吸引了许多化学家的注意 .制备光学活性的 BINOL的方法较多 ,但一般效果较好的是用拆分的方法[3,4] .通过 2 -萘酚不对称氧化偶联直接得到 BINOL的方法也有许多报道 [5 ,6 ] ,但结果都不理想 .近来 ,Kocovsky等 [7]用鹰爪金碱作为手性诱导试剂 ,在Cu Cl2 存在下 ,2 -萘酚偶联得 BINOL,其 ee值为 1 0 0 % ,但产率只有 1 4% ,且由于鹰爪金碱价格昂贵 ,限制了该法的应用 .在此基础上 ,我… 相似文献
10.
1,2,3-Triazole derivatives have been reported as inhibiting tumor proliferation, invasion, and metastasis[1]. The fused l,3,4-triazolo[3,4-b]-1,3,4-thiadiazoles derivatives show various biological effects such as antifungal[2], antibacterial, hypotensive and CNS depressant activities[3]. We have reported several 6-aryl-3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazolo[3,4-b]-1,3,4-thiadiazoles in the previous paper[4]. The novel 6-aryl-3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazolo[2,4-b]-1,3,4-thiadiazoles 6a-j have been synthesized by the condensation of 4-amino-5-mercapto-3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazole 5 with various aromatic carboxylic acids in the presence of phosphorus oxychloride. The mercaptotriazole 5 was prepared from 4,the latter being prepared from 1 throng 2 and 3. The title compounds 6 were depicted in scheme 1. The structures of these compounds were established by elemental analysis, NMR, MS and IR techniques. 相似文献