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51.
由于N-杂环卡宾结构的多样性,以及它们的金属络合物良好的稳定性和催化活性,近年来受到了人们的广泛关注。本文对N-杂环卡宾及其金属络合物的性质和合成方法进行了综述。参考文献30篇。  相似文献   
52.
The title compound, 5-N-i-propyl-2-(2′-nitrobenzenesulfonyl)-glutamine, was synthesized and its structure was confirmed by IR, MS, 1H NMR, and elemental analysis. The single crystal structure of the title compound was determined by X-ray diffraction. The crystal belongs to Monoclinic, space group P2 (1), with a = 0.69281(11) nm, b = 0.76508(12), c = 1.5843(3) nm, = 90°, β = 90.941(3)°, γ = 90°, V = 0.8397(2) nm3, Z = 2, Dc = 1.477 g/cm3, μ = 0.236 mm-1, F(000) = 392, R = 0.0297, and wR = 0.0664.  相似文献   
53.
2-Chloro-N-{2-fluoro-5-[N-(phenylsulfonyl)phenylsulfonamido]phenyl}benzamide was synthesized and its crystal structure was also determined by X-ray single-crystal diffraction. The title compound(C25H18ClFN2O5S2) belongs to monoclinic, space group P21/n with a=0.7377(3) nm, b=1.2036(5) nm, c=2.6846(11) nm, β=90.895(9)°, V=2.3833(16) nm3, Mr=544.98, Z=4, Dc=1.519 g/cm3, μ=0.385 mm–1, F(000)=1120, R1=0.0632, and wR2=0.1438. Its crystal structure belongs to a novel class that has not been reported yet, and its preliminary herbicidal activity was also tested. Its inhibition rate to seedling growth of barnyard grass reaches 15.1% at 100 μg/mL.  相似文献   
54.
Ag-PVP复合薄膜的制备及其光谱特性   总被引:1,自引:0,他引:1  
在聚乙烯吡咯烷酮 ( PVP)乙醇溶液中以硝酸银为原料 ,采用旋涂法 ( spin coating)原位合成了 Ag- PVP复合薄膜。由于薄膜表面 Ag胞质团的共振吸收 ,所以在 430~ 45 0 nm范围内薄膜的吸收光谱有一较尖锐的吸收峰 ,随热处理温度的升高 ,吸收峰增强、变宽。采用复合介质理论计算了 Ag- PVP复合薄膜的吸收光谱 ,实验结果和理论计算相一致。  相似文献   
55.
L-shell partial production cross sections of Lα-, Lβ-, Lγ- rays by electron impact were measured by observing the counts of X-ray from impacted thin tungsten target. Total production cross sections and mean ionization cross sections were deduced from these measured results. The electron beam energy range was from 11 to 36 keV. Tungsten was sputtered onto a carbon backing to reduce bremsstrahlung of the backing. The effect of electrons reflected by the backing has been corrected. Comparison with two theoretical calculations has performed. The experimental results agree rather well with the theoretical predications.  相似文献   
56.
The purpose of this paper is to analyse theoretically and numerieally the coupled vibration of an ideal fiuid with a linear elastie structure.It is proved in the paper that the natural frequencies of the coupled vibration do exist and are all real positive. The paper presents an efficient method to transform a coupled fluid-structure system to the structure with added mass and the ribrational analysis of the former is replaced by the latter in vacuum only. Numerical solution is outlined for the transformed problem and a compact frequecy equation is derived in which fluid variables do not appear. This simplifies the analysis significanily. A convergent proof has been given to guarantee the reliability of the solution. The paper also offers a general algorithm combined with Ritz method, boundary element method, and finite element method to analyse the transformed problem. Based on this algorithm, one can apply a known structural analysing program, with a little modification, to solve many different kinds  相似文献   
57.
聚合物的静电纺丝   总被引:12,自引:0,他引:12  
李岩  黄争鸣 《高分子通报》2006,(5):12-19,51
静电纺丝法是聚合物溶液或熔体在静电作用下进行喷射拉伸而获得纳米级纤维的纺丝方法.由纳米纤维制得的无纺布,具有孔隙率高、比表面积大、纤维精细程度与均一性高、长径比大等优点,从而赋予了静电纺丝纤维广泛的应用前景,它已在国内外引起了广泛的关注.本文介绍了静电纺丝的装置、基本原理及静电纺丝制备纳米纤维的研究进展,同时也叙述了其在各个领域的应用,最后展望了静电纺丝制备纳米纤维的发展方向及前景.  相似文献   
58.
Thirteen novel phenyl substituted isoxazolecarboxamides were synthesized, and their structures were characterized by 1H NMR, elementary analysis and high-resolution mass spectrometry(HRMS) techniques. Their evaluated insecticidal activities against oriental armyworm(Mythimna separata) indicate that the phenyl substituted isoxazolecarboxamides exhibited moderate insecticidal activities, among which compounds 9c and 9k showed comparatively higher activities.  相似文献   
59.
2-(Dimethylamino)-1,3-dithiocyanatopropane(1) has been prepared as a key intermediate synthesizing a natural insecticide Cartap by the reaction of 1-dimethylamino-2,3-dichloropropane with sodium thiocyanate. The crystal structures of compound 1 and its isomer 1-(dimethylamino)-2,3-dithiocyanotopropane(2) formed during the reaction were determined by X-ray single-crystal diffraction. Bond lengths in both the compounds are common and fall within normal ranges. There are some weak C―H×××N hydrogen bonds in the lattice of compound 1, which makes it form a three-dimensional network, which stabilize the crystal structure. No classic hydrogen bonds were founded in its isomer(2), only van der Waals forces contribute to the stability of the structure. In addition, DFT and MP2 calculations with 6-311+G(d, p) basis set have also been carried out to investigate the thermodynamic properties of compounds 1 and 2. The research will be applied to the further investigation of the tautomerization of compounds 1 and 2.  相似文献   
60.
A series of new sulfonylureas incorporating 1,2,4-triazolinone moiety was synthesized, which were further bio-assayed for the herbicidal activity against four herbs, representative of monocotyledons and dicotyledons. Some of them exhibited high potency to inhibit the growth of dicotyledons(Bassica napus and Amaranthus retroflexus) in the pot experiment. Compounds 9a and 9b also displayed an excellent herbicidal activity against Bassica napus at a concentration of 15 g/hectare, which were comparable with commercial triasulfuron.  相似文献   
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