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161.
Ammonia-treated activated carbon has been studied as a support of Ru-Ba catalyst for ammonia synthesis. It is shown that the
introduction of nitrogen leads to a decrease of ammonia synthesis activity for the catalysts with a low Ba/Ru molar ratio,
while no significant changes are obtained for the catalysts with a high Ba/Ru molar ratio, confirming that electronegative
impurities suppress the activity in ammonia synthesis and consume part of the promoters.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
162.
合成了螺[异苯并呋喃-1(3H),9'-(9H)-2'-N,N-二苄胺基-6'-二乙胺基占吨]-酮-3,C_(37)H_(34)N_2O_3,单斜晶系,空间群Cc,晶体学参数为a=16.826(4),b=10.648(4),c=17.618(7),β=92.25(2)°,V=3154(2),Z=4,M_r=566.7,D_x=1.19g/cm3,F(000)=1200。结构由直接法解出,偏离因子R=0.080。分子由占吨和异苯并呋喃两部分组成Y形结构,占吨部分相连的苄基的两个苯环位于占吨部分的两侧。 相似文献
163.
Xiu Yang LU Qi JING Zhun LI Lei YUAN Fei GAO Xin LIU 《中国化学快报》2006,17(6):841-844
High temperature liquid water (HTLW), as an environmentally benign medium, has drawn increasing attention for organic chemical reactions and biomass conversion1-3. HTLW has a strong tendency to ionize and can act as an acid and/or base catalyst. In addition, HTLW can dissolve organic compounds to some extent allowing for a homogenous reaction within an aqueous phase. Extensive researches4-10 have been pursued on acid/base-catalysis reactions in HTLW without addition of acid or base. Howe… 相似文献
164.
用两种相似多糖类手性固定相拆分阿托品外消旋对映体的比较 总被引:1,自引:0,他引:1
分别涂敷纤维素-三(3,5-二甲基苯基氨基甲酸酯)(CDMPC)与直链淀粉-三(3,5-二甲基苯基氰基甲酸酯)(ADMPC)于自制的球形氨丙基硅胶上,制备了两种多糖类手性崮定相。用高效液相色谱法(HPLC)在正相条件下,用两种固定相直接拆分了阿托品(atmpine)外消旋体、在正己烷中加入了不同的醇类改性剂对阿托品进行拆分,并优化了流动相中醇类改性剂的比例:结果发现,阿托品在CDMPC固定相上可以得到基线拆分,而在ADMPC固定相上只能得到部分拆分。 相似文献
165.
The composites with nano-particles of Ni-Fe alloys dispersed on the nano-layers of expanded graphite (EG) were prepared by the impregnation of EG with ethanol solutions of nickel and iron acetates, followed by drying and reduction in H2. The square nano-particles of Ni-Fe alloys with particle sizes of mainly 20~40 nm were found to be well spread on the layers of EG. The alloy nano-particles exhibited high shielding effectiveness (SE) for electromagnetic radiations at low frequencies due to their high magnetic conductivity. Since EG is electronically conductive and displayed high SE at high frequencies, the composites exhibited good SE at wide range of frequencies. The electric and magnetic conductivities of the composites could be monitored through regulating the loadings of alloy nano-particles on EG, and it was found that the composites with 20%~40% of the alloys exhibited good SE. Specifically, the composite 27%Ni-3%Fe-EG showed the excellent SE from 66 to 110 dB at the frequencies from 300 kHz to 1.5 GHz. 相似文献
166.
The construction of metallic nanostructures with customizable morphologies and complex shapes has been an essential pursuit in nanoscience. DNA nanotechnology has enabled the fabrication of increasingly complex DNA nanostructures with unprecedented specificity, programmability and sub-nanometer precision, which makes it an ideal approach to rationally organize metallic nanostructures. Here we report an Assemble, Grow and Lift-Off (AGLO) strategy to construct robust standalone gold nanostructures with pre-designed customizable shapes in solution, using only a simple 2D DNA origami sheet as a versatile transient template. Gold nanoparticle (AuNP) seeds were firstly assembled onto the pre-designed binding sites of the DNA origami template and then additional gold was slowly deposited onto the AuNP seeds. The growing seed surfaces eventually merge with adjacent seeds to generate one continuous gold nanostructure in a pre-designed shape, which can then be lifted off the origami template. Diverse customized patterns of templated AuNP seeds were successfully transformed into corresponding gold nanostructures with the target structure transformation percentage over 80%. Moreover, the AGLO strategy can be incorporated with a magnetic bead separation platform to enable the easy recycling of the excess AuNP seeds and DNA components.The AGLO strategy generates complex gold nanostructures with user-designed morphologies in solution, using only a simple 2D DNA origami sheet as a versatile transient template. The products are robust and stable as standalone gold nanostructures. 相似文献
167.
测定了Pt-Sn型催化剂浸渍状态下的Sn-119、Pt-195的多核核磁共振。当SnCl2/DCl溶液体系中加入H2PtCl6以后,出现了Sn(Ⅳ)和另外一种Sn(Ⅱ)的构型,Sn-119峰向高场位移,说明部分Sn(Ⅱ)被氧化成Sn(Ⅳ),H2PtCl6的量对这种氧化性影响较小。而H2PtCl6/D2O溶液体系中加入SnCl2以后部分Pt(Ⅳ)被还原成Pt(Ⅱ),随着SnCl2量的增加,Pt(Ⅱ) 相似文献
168.
169.
Study on the Phase Diagram of CsCl-CeCl3-HCl(11%)-H2O System and the Properties of the Compounds 总被引:2,自引:0,他引:2
The equilibrium solubility of CsCl-CeCl3-HCl(11%)-H2O qua-ternary system at 25℃ has been determined by the physicchemical analysis method ,and the phase diagram was plotted, Two new double salts 3CsCl.CeCl3.3H2O and CsCl.CeCl3.4H2O obtained from the complicated system were identified and characterized by XRD,TG-DTA ,DSC,UV and fluorescence spectroscopy, Studies on the fluorescence excitation and emission show that 3CsCl.CeCl3.3H2O and CsCl.CeCl3.4H2O have upconversion luminescence of infrared-visible range,and the upconversion emission intensity increases with the increase of ratio of CeCl3 in CsCl. 相似文献
170.
气相色谱法研究配位化合物的热稳定性——ⅩⅢ.普鲁士蓝化合物的热分解及其加氢反应研究 总被引:2,自引:0,他引:2
普鲁士蓝化合物的热分解过程,可分为三个阶段:(1)脱水;(2)Fe3+还原至Fe2+;(3)C≡N-键的断裂。H2气中的热分解由于发生了一系列的加氢反应,分解产物及所对应的分解温度都不同于He气中的情况,其产物的种类增加,C≡N-键的断裂温度降低。普鲁士蓝化合物中,CN-呈典型的双端基配位,可看作是一种双金属配位的活化模型,与CN-呈单端基配位的K3[Fe(CN)6]相比,C≡N-键的活化程度增加,不仅断裂温度降低,且能发生更深度的加氢反应。 相似文献