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991.
采用激光熔覆技术在45钢表面制备316L合金涂层,分析了激光熔覆层的微观组织,测试了激光熔覆层的微观显微硬度。结果表明:激光熔覆区显微组织为细小树枝状结晶组织,熔覆区微观组织均匀致密以及存在着硬质点弥散分布,使得表面耐蚀性、硬度和耐磨性大幅度提高。熔覆层中残余应力一般是拉应力,随着熔覆层厚度的增加,应力回落并逐渐稳定下来,且基体残余应力较熔覆层小。  相似文献   
992.
孙玉希 《结构化学》2007,26(1):55-58
The title Schiff base compound,C19H19N3O3,a derivative of antipyrine,has been synthesized and characterized by elemental analysis,IR,and single-crystal X-ray diffraction.The crystal belongs to the monoclinic system,space group C2/c,with α = 27.935(5),b = 7.553(1),c =16.692(3) (A),β = 105.810(3)°,Z= 8,V= 3388.7(10) (A)3,Dc = 1.323 g/cm3,Mr = 337.37,λ(MoKα) =0.71073 (A),μ = 0.091 mm-1,F(000) = 1424,R = 0.0630 and wR = 0.1273.A total of 3513 unique reflections were collected,of which 2112 with I > 2σ(I) were observed.The molecular structure adopts a trans configuration about the C=N double bond.The pyrazoline and C(1)~C(6) pheny1 ring are approximately coplanar (mean deviation from the combined plane is 0.069(3) (A)),with the dihedral angle of 9.7(2)°.The preliminary biological tests show that the compound has high antibacterial activities.  相似文献   
993.
1 INTRODUCTION The bimetallic nanoclusters are of standing inte- rest since they can exhibit catalytic, electronic and optical properties distinct from those of corre- sponding pure nanoclusters[1~4]. Palladium and pla- tinum, well known for their catalytic properties, are often used as the catalyst in different fuel cells[5~8]. Several experimental results illustrate that for the oxygen reduction reaction (ORR), which is one of the primary reactions taking place in many fuel cells and…  相似文献   
994.
A novel complex [Pb(qina)2(DMSO)]·H2O was synthesized, of which qina- is the quinaldic acid radical and DMSO the dimethyl sulfoxide. Elemental analysis, IR spectra, and X-ray single-crystal diffraction were carried out to determine the composition and crystal structure. This complex belongs to monoclinic system, space group P121/n1, with a = 7.1553(17), b = 17.543(2), c = 17.306(2)(A),β = 91.671(4)°, C22H20N2O6PbS, Mr = 647.65, Z = 4, V= 2171.5(6)(A)3, Dc= 1.981g/cm3,μ = 7.908 mm-1, F(000) = 1248, -9≤h≤6, -23≤k≤ 19, -22≤l≤22, R= 0.0221 and wR =0.0488. Weak coordinate bond is formed between oxygen atom in DMSO and Pb(Ⅱ ). There are also weak interactions, such as π-π interaction, hydrogen bonds and so on, among the complex molecules.  相似文献   
995.
The title compound (C30H27NO3) was synthesized via a one-pot procedure starting from β-benzoylthioacetanilide, benzaldehyde and 5,5-dimethyl-1,3-cyclohexanedione, and its struc- ture was determined by single-crystal X-ray diffraction analysis. The crystal belongs to triclinic system, space group P, with a = 6.325(2), b = 11.243(3), c = 17.553(4) , α = 87.306(4), β = 80.822(4), γ = 77.798(4)°, V = 1204.2(5) 3, Z = 2, Mr = 449.53, Dc = 1.240 g/cm3, μ = 0.080 mm-1, F(000) = 476, the final R = 0.0459 and wR = 0.0970 for 2301 observed reflections with I > 2σ(I).  相似文献   
996.
1,1'-Diacetoacetylferrocene 1 reacted with phenylene-1,3-dioxyactyl hydrazine 2 in absolute ethanol to give the macrocyclic ferrocenyl dipyrazole compound in moderate yield. Determined by X-ray structure analysis, it crystallizes in monoclinic system, space group P21/c with a = 13.7509(4), b = 8.1277(2), c = 21.7472(6) , β = 103.1030(10)°, V = 2367.25(11) 3, Z = 4, Dc = 1.505 g/cm3, R = 0.0353 and wR = 0.0811. The electrochemical studies reveal that redox of Fe+/Fe in ferrocene is a reversible one-electron process.  相似文献   
997.
In order to prove up the interaction between konjac glucomannan (KGM) and other amyloses, by using KGM, guaran gum and carrageenan as materials, their blending in different external conditions was modeled by means of molecular dynamics (MD) method. The result showed that 323 K was a significant turning point for the formation of hydrogen bond, and KGM and guaran gum were just juxtaposed together via intermolecular hydrogen bond; but with the addition of carrageenan, KGM, guaran gum and carrageenan were spirally twisted together, and when their blending proportion is 3:2:9 the combination was the most compact. Moreover, the research result has provided the sequent studies afterwards on amyloses with some references.  相似文献   
998.
The novel coordination polymer [Pr(BYBA)3(H2O)2]·[Pr(BYBA)3(H2O)] (BYBAH = 2-benzoylbenzoic acid) was yielded by hydrothermal synthesis, determined by single-crystal X-ray diffraction, and characterized by FT-IR and UV-Vis spectra. The crystal crystallizes in the triclinic system, space group P with a = 9.112(3), b = 14.644(5), c = 27.076(11) (A), α = 84.223(3), β = 87.816(4), γ = 88.902(4)o, V = 3592(2) (A)3, C84H60O21Pr2, Mr = 1687.14, Z = 2, F(000) = 1700, Dc = 1.560 g/cm3, μ = 1.419 mm-1, the final R = 0.0485 and wR = 0.1258 for 13035 observed reflections with I>2((I). The compound contains two different building units, [Pr2(BYBA)6(H2O)4] and [Pr2(BYBA)6(H2O)2]. It is noticeable that [Pr2(BYBA)6(H2O)4] is an isolated binuclear building block, in which the Pr3 ion centers are both located in an eight-coordinated environment. However, in [Pr2(BYBA)6(H2O)2] the Pr3 ion centers are located in a nine-coordinated environment and connected by BYBA ligands to form 1D chains.  相似文献   
999.
脉宽可控的腔倒空射频波导CO2激光器   总被引:1,自引:0,他引:1  
为了得到脉宽可控的腔倒空射频波导CO2激光器,采用了在陶瓷板上直接开波导槽的方法,构成了多通道Z折叠主本振激光器结构,并在主振波导进行CdTe电光晶体腔内调Q。在理论上计算了加载在CdTe上的高压脉冲下降时间的长短对腔倒空激光脉冲宽度的影响,并通过对高压脉冲电源等效负载参数的调整,得到了脉冲宽度可控的高重频腔倒空激光脉冲。在20kHz,40kHz,65kHz及70kHz的重频工作下,得到了半峰全宽约30ns、峰值功率在2kW以上的腔倒空激光脉冲。结果表明,这种新型腔倒空射频波导CO2激光器满足激光外差成像雷达系统参数要求。  相似文献   
1000.
微脉冲激光雷达测量大气水平能见度   总被引:2,自引:0,他引:2       下载免费PDF全文
为了改进乃至革新大气能见度的探测技术,探索新型、快速、准确测量大气能见度的方法,采用自行研制的能见度微脉冲激光雷达,进行了水平大气能见度测量实验,并同已经商品化的能见度仪NQ-1进行了同步对比测量。实验结果表明,在水平能见度较差时,微脉冲激光雷达和能见度仪具有很高的相关性,相关系数达到了0.88;在水平能见度较好的时候,相关系数保持在0.73以上。说明能见度微脉冲激光雷达系统可以应用于大气能见度的探测。  相似文献   
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