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First Total Synthesis of Four Benzodioxane Neolignans

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Chinese Chemical Letters 2000年第10期11卷 875-878页

作者： Jing, XB Gu, WX Bie, PY Ren, xf Pan, xf Lanzhou Univ Dept Chem Natl Lab Appl Organ Chem Lanzhou 730000 Peoples R China

Four 1,4-benzodioxane neolignans were first synthesized from pyrogallol, in which the Claisen rearrangement was used to afford three important C-6-C-3 units.

关键词： synthesis neolignans Eusiderin K Eusiderin J Eusiderin E Eusiderin F

Structural Characterization and Chemical Modification of a Glucan from Spores of Ganoderma lucidum

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Chinese Chemical Letters 2001年第11期12卷 967-970页

作者： Bao, xf Fang, JN Chinese Acad Sci Shanghai Inst Biol Sci Shanghai Inst Mat Med Shanghai 200031 Peoples R China

A linear alpha -D-(1-->3)-glucan, named PSG, was obtained from the spores of Ganoderma lucidum. The synthesis of positively and negatively charged polyelectrolytes from PSG was developed. Amine groups and carboxymethyl groups were introduced through nucleophilic substitution with 3-chloropropylamine or chloroacetic acid, respectively, Reaction conditions were varied to obtain insight into the influence of variables on the degree of substitution.

关键词： alpha-D-(1 -> 3)-glucan chemical modification aminopropylation carboxymethylation

AN IMPROVED SYNTHESIS OF NIMBIDIOL

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Chinese Chemical Letters 1995年第8期6卷 657-660页

作者： Zhou, R Wang, xf Tian, Y Pan, xf Lanzhou Univ Natl Lab Appl Organ Chem Lanzhou 730000 Peoples R China Acad Sinica Kunming Inst Bot Lab Phytochem Kunming 650204 Peoples R China

Nimbidlol 1 and epi-6-oxonimbidiol 2 have been efficiently and stereospecifically synthesized from 3-isopropoxy-5,5-dimethyl-2-cyclohexenone and iodide 3 which are readily available.

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Synthesis and light absorption of benzotellurazole crown ether cyanine dye

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Chinese Journal of Chemistry 1995年第4期13卷 340-348页

作者： LUO, XH LIU, xf XU, HS WUHAN UNIV DEPT CHEMWUHAN 430072PEOPLES R CHINA

Various methods for synthesis of 2-methyl-5,6-(1,4, 7,10,13-pentaoxatridecamethylene)benzotellurazole (8) are described. Under different conditions, alkylation of compound 8 with methyl iodide gave telluronium salt 1,2-dimethyl-5,6-(1,4,7,10,13-pentaoxatridecamethylene)benzotellurazolium iodide (15) or quaternary ammonium salt 2,3-dimethyl-5,6-(1,4,7,10,13-pentaoxatridecamethylene)benzotellurazolium iodide (14) in high yields, repectively. The cyanine dye 3,3'-dimethyl-5,6,5',6'-bis(1,4,7,10,13-pentaoxatridecamethylene)telluracarbocyanine iodide (16) is obtained by condensation of 14 with ethyl orthoformate in acetic anhydride, The visible absorption of the cyanine dye is also discussed.

关键词： CROWN ETHER BENZOTELLURAZOLE CYANINE DYE SPECTRAL SENSITIZER SYNTHESIS

Effect of Austenite Ageing on Martensitic Transformation

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Journal of Materials Science & Technology 1997年第6期13卷 508-514页

作者： Chen, QZ Wu, xf Wei, LY Ke, J Univ Sci & Technol Beijing Dept Mat Phys Beijing 100083 Peoples R China

The effect of austenite ageing on martensite transformation in an iron and nickel alloy was studied. Attention was paid to the variation of dislocation configurations in austenite before martensite transformation, The clusters or precipitates produced during austenite ageing and the alteration of dislocation configurations affect together the consequent martensite transformation. Dispersed fine clusters and precipitates cripple nucleus role of special dislocation configurations and drop M-s. Coarse precipitates make M-g rise again. Densely piled up dislocations in nuclei lead to rise of M-s. All the changes in austenite are of benefit to small martensite plates.

关键词： Iron alloys

STUDIES ON THE SYNTHESES OF FAVELINES

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Chinese Chemical Letters 1996年第2期7卷 107-108页

作者： Lin, G Wang, XC Pan, xf LANZHOU UNIV NATL LAB APPL ORGAN CHEMDEPT CHEMLANZHOU 730000PEOPLES R CHINA

A novel and efficient convergent synthesis of 13-demethyldeoxofaveline. a key intermediate for deoxofaveline, faveline and faveline methyl ether, was achieved by Wittig reaction and selective oxidation. And a novel si...

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The Novel Selective Reduction of the C-C Triple Bond

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Chinese Chemical Letters 2000年第10期11卷 847-848页

作者： Gu, WX Wu, AX Pan, xf Lanzhou Univ Natl Lab Appl Organ Chem Dept Chem Lanzhou 730000 Peoples R China

A novel reduction system is reported here in which the compounds with terminal C-C triple bond and disubstituted C-C triple bond react with NaBH4/Pd(PPh3)(4) in a base condition and only terminal C-C triple bond is re... 详细信息

关键词： selective reduction C-C triple bond Pd(PPh3)(4)

Study of Origin of Shape Memory Effect for TiNi Alloy byPositron Annihilation

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Journal of Materials Science & Technology 1998年第4期14卷 368-370页

作者： Wang, JC You, FQ Qi, JL Tang, xf Shanghai Iron & Steel Res Inst Shanghai Key Lab Met Funct Mat Shanghai 200940 Peoples R China Shanghai Iron & Steel Res Inst Res Ctr Shanghai 200940 Peoples R China Tongji Univ Dept Phys Shanghai 200092 Peoples R China

A number of specimens of Ti-51Ni (at. pet) alloy showing reversible shape memory effect (RSME) have been measured as to reversibility and S-lineshape parameter of positron annihilation. It is found that the Ti-51Ni specimens showing good memory effect contain structural defects. Not all specimens including structural defects (or structural imperfection) are able to exhibit good memory effect. The structural defects have to be appropriate in density, neither too much nor too little. With no or too much structural defects a good RSME could not take place. It is fully as important that the structural defects exist as it is for the structural defects to be appropriate in density in order to obtain a good RSME.

关键词： Titanium alloys

Production of Nanometer Powders with an Electrohydrodynamic Technique

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Journal of Materials Science & Technology 1997年第3期13卷 211-214页

作者： Yu, xf Hu, ZQ Liu, X Cheng, LZ NORTHEASTERN UNIV SHENYANG 110006 PEOPLES R CHINA

The principle of producing nanometer powders with the electrohydrodynamic technique and the apparatus were described. The effects of the geometry and size of the cathode and anode. and the applied voltage on the emitted current and the mean size of the nanometer powders were *** results show that with the decreasing in the diameter of the cylindrical cathode and in the calibre of the spiral cathode, the mean size of the nanometer powders decreases. The effect of the calibre of the spiral cathode is more remarkable. In addition, the mean size of the nanometer powders decreases with decrease in the internal and external diameter of the anode and the increase in the applied voltage.

关键词： Nanotechnology