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531.
ZHENG Yue qing * 《高等学校化学研究》1999,(3)
IntroductionPreviously,wereportedthecrystalstructureofK2[Ni(CO3)2(H2O)4][1],whichcrystallizedinthebaylissitetypestructureandwasfoundtobeisostructuralwithK2[Co(CO3)2(H2O)4][2]andK2Mg(CO3)2·4H2O[3].Inordertosystematicallyinvestigatetheoccurrenceoftheco… 相似文献
532.
IntroductionAmrinon,asyntheticbipyridinederivative,nonglycosideandnoncatecholaminecar-diotonicstimulant,iscurrentlyusedinthetreatmentoftheheartfailureandforcardiovascu-larsupportinpediatricpatients.Itpossessespotentcardiacandbloodvesselspreadingef-fe… 相似文献
533.
1 INTRODUCTIONRecently,anumberofderivativesofbenzothiazepinehavebeenpreparedandstudiedfortheirpharmacologicalactivities〔15〕.Inourpreviouswork,wehaveincorporatedtheβlactamringinto1,5benzothiazepinebyreactionof1,5benzothiazepinewithsomeacylchlorid… 相似文献
534.
采用第一性原理的密度泛函方法,研究了利用表面修饰来调制GaAs纳米线的电子结构. 在计算中考虑了几种不同的表面钝化材料(H、F、Cl、Br 和I)对GaAs纳米线电子结构的影响. 计算结果表明,不同的原子修饰GaAs 纳米线时对其能带结构的调制主要取决于它们对纳米线表面态的饱和能力. 表面修饰不仅可以调节GaAs纳米线的能隙大小,而且也可以调制其能隙类型. GaAs纳米线的电子结构由表面效应和量子限制效应共同来决定. 使用不同材料修饰表面的GaAs纳米线的能隙随直径的变化幅度并不相同. 表面修饰为实现同种直径和同种结构的GaAs纳米线的能带工程提供了一种新的途径. 相似文献
535.
Hong Bo CHEN Jing Dong LIN Jun YI Yun CAI Guang WEI Yin Zhong LIN Dai Wei LIAO * Department of Chemistry Department of Oceanography State Key Lab of Physical Chemistry on Solid Surfaces Institute of Physical Chemistry 《中国化学快报》2001,(12)
The preparation of silicon nanotubes is a subject of great importance for both the theoretical and experimental work in the nanotube research field since it could lead to a wealth of new physics and chemistry because of the unique properties of silicon as compared with its carbon analogue. Some structures of nanoscale silicon and silicon composites, such as silicon nanowire1, silicon nano-clusters2 and SiC nanorods3 have been discovered and investigated. The silicon nanotubes, however, have … 相似文献
536.
Hai Zhou LI Rong Wei TENG Chong Ren YANG* Kunming Institute of Botany Chinese Academy of Sciences Kunming 《中国化学快报》2001,(1)
There are extensive chemical studies on the roots of Panax notoginseng (Burk.) F. H. Chen, a famous traditional Chinese medicine called San-Qi or Tian-Qi, thirty-three dammarane saponins were isolated and their structures were identified by our group and other scientists1-8. Further chemical investigation on this plant led to the isolation of a novel hexanordammarane glycoside, named notoginsenoside R10 (1).Notoginsenoside R10 (1), white powder, negative HRFAB-MS showed a quasimolecular… 相似文献
537.
Hui WANG Zhou LU Fan Ao KONG* The State Key Lab of Molecular Reaction Dynamics the Center for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing 《中国化学快报》2001,(11)
NOx is a major pollutant product from combustion processes. In hydrocarbon combustion there are a number of radicals as CH2, C2H, CH3 and C2H3 can react with NO1-3. A large amount of CH3 exists in natural gas combustion flame. Therefore the reaction of CH3 with NO is very important. A rate constant (k =1.510-11exp(-60k/T) cm3molecule-1s-1) of the overall CH3+NO reaction was measured with laser flash photolysis/absorption spectroscopy over the temperature range 296-509 K and at pre… 相似文献
538.
Shui Hua TANG Li Zhen GAO Bao Chun LIU He LI Bo Lan ZHANG Liang Fu ZHANG Zuo Long YU* Chengdu Institute of Organic Chemistry Chinese Academy of Sciences Chengdu Institute of Chemical Engineering Materials CAEP Mianyang 《中国化学快报》2001,(11)
With the diminution of fossil fuel resources and the increase in pollution, energy and environment have become a public concern. Mankind is in need of a new but clean energy resource. The use of hydrogen appears to be the answer. One of the technical challenges in hydrogen utilization is H2-storage. At present, materials for storing hydrogen are alloys such as LaNi5 and FeTi; the storage capacity is around 1.4 wt%, too low for practical application. Another problem with these alloys is… 相似文献
539.
Qian Yong XU Tong Xing WU Xin Fu PAN* Department of Chemistry National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 《中国化学快报》2001,(12)
Although the asymmetric additions of diethylzinc to aldehydes have been extensively studied in the presence of chiral catalyst, most of the chiral ligands tested are b-amino alcohols1. In this report, the synthesis of chiral gamino alcohols 1-4 from the reaction of (+)-camphor and (-)-menthone with 2-lithiomethyl-6-methyl-pyridine or 2-picolly- lithium2, which give a single diasteromer as determined by 1H NMR with high yields (Scheme 1)3, and their application in the enantioselective additio… 相似文献
540.
Yu Liang ZHANG Ming Xing QIAN Ren HE* State Key Laboratory of Fine Chemicals Dalian University of Technology Dalian 《中国化学快报》2001,(12)
Transition-metal-catalyzed oligomerzation of ethylene is an important process to provide a-olefins in the C6~C20 range. In recent years, the catalytic behavior of late transition metal complexes containing bi- and tri-dentate ligands for oligomerization of ethylene to a-olefins has attracted much attention. When oligomerization of ethylene catalyzed by nickel diimine and Fe(II), Co(II) 2,6-bis(imino)pyridine catalysts, the oligomers with high average molecular weight were obtained1-5. Eth… 相似文献