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531.
Helicia nilagirica Beed. belongs to the plant of Proteaceae family. The seeds of the plant is for treatment of insomnia and neurasthenia in Jingpo nationality in Yunnan Province1. Helicid and helicidol were isolated from the seeds of the plant2,3, and the helicid was recorded in the Yunnan Pharmacopoea at the 1987 edition. The chemical constituents of the leaves of this plant has not been reported yet in the literature. This paper is concerning the study of the chemical component of the…  相似文献   
532.
Spherical foam growth in Al alloy melt   总被引:6,自引:0,他引:6  
The ultra light metal structure, realizing the light-ness and multifunction of structural material, has a bright future in high-tech and civil fields and is be-coming one of the hotspots in developed countries in 21 century[1―8]. Preparing Al foam by mel…  相似文献   
533.
534.
Today, batteries with high capacity, good cyclability, long life and environmental goodness are much required to meet some pressing demands of our modern society. In principle, lithium ion cells can satisfy these requirements1. But the properties of the cathode materials have limited the further development of the lithium ion cells. The studied cathode materials before were mainly LiCoO2, LiMn2O4, LiNiO2. The LiCoO2 has disadvantages including cost and environmental risk although it is…  相似文献   
535.
The interaction between ethyl orange (Eto, guest) and β-cyclodextrin dimers (1a~d, host) bridged with 2-t-butoxycarbonyl(Boc)-amino diacid was investigated. A remarkable synergic complexation of two cavities in host molecule was observed.  相似文献   
536.
Nano-materials have been extensively studied in the past[1]. The quantum effect makes the properties of nano-materials dif- ferent from that of bulk materials. A few of publications regard- ing the catalysis, electronic structure, and optics of the nanome…  相似文献   
537.
IntroductionBoth triazole derivatives and Schiff base have beenreported to possess significant antifungal[1—3]and plantgrowth regulatory activities[4—6].Triazole drugs are alsovery common in the medical field,which has given animmense impetus to the res…  相似文献   
538.
Histidine is one of the necessary basic amino acids in biological bases, which often controls the catalytic activity of enzymes and acts in holding the higher structure of proteins. Furthermore, it is also an important ingredient in pharmaceutical preparations used for treatment of hetpatosis and nephropathy. Therefore, the determination of histidine in biological fluids and pharmaceutical preparations is of great importance. Various methods have been proposed for the detection of histidine …  相似文献   
539.
Photoinduced electron-transfer (PET) reactions are fundamentally important in biology and technology1,2. Because of the complexity of PET in biological systems, many simple compounds were synthesized to look into its detailed mechanism3. In previous papers, we reported the electron transfer reaction in the supramolecular systems assembled by mono-6-p-nitrobenzoyl-b-cyclodextrin 6 and naphthalene derivatives in aqueous solution4. In the present paper the intermolecular electron transfer from …  相似文献   
540.
Organic molecules that can simultaneously absorb two or more photons in reaching theirexcited states have recently been the subject in various photon-electronic fields. Tomeet the criteria for various nonlinear optical applications, such as three-dimensionaloptical storage1 and up-converted lasing2, molecules with large two-photon absorption(TPA) cross-section σ are required and have been synthesized. These dyes generallybelong to the structural modes of D-π-D, A-π-A3 or D-π-A, where D…  相似文献   
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