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A New Bisabolane Sesquiterpene from Cremanthodium Discoideum

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Chinese Chemical Letters 1998年第6期9卷 545-547页

作者： Ying ZHU Qi Xiu ZHU Zhong Jian JLA(department of Chemistry, National haboratory of Applied Organic Chendstry,lanzhou university,{3.) department of Chemistry Natl. Lab. of Appl. Organ. Chemistry Lanzhou University Lanzhou 730000 China

A new bisabolane sesquiterpene was isolated from Cremanthodium discoideum. The structure was elucidated by spectroscopic methods including the 2D-NMR technique.

关键词： Cremanthodium discoideum Compositae sesquiterpene cholorobisabolane

POSITIVE　SOLUTIONS　FOR　DIRICHLET　PROBLEMS　OF　SINGULAR　SEMILINEAR　ELLIPTIC　EQUATIONS

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Systems Science and Mathematical Sciences 1995年第3期8卷 203-208页

作者： CUI Shangbin(department of Mathematics, lanzhou university, lanzhou 73.000, China) 兰州大学数学系甘肃兰州

ＰＯＳＩＴＩＶＥＳＯＬＵＴＩＯＮＳＦＯＲＤＩＲＩＣＨＬＥＴＰＲＯＢＬＥＭＳＯＦＳＩＮＧＵＬＡＲＳＥＭＩＬＩＮＥＡＲＥＬＬＩＰＴＩＣＥＱＵＡＴＩＯＮＳ￥ＣＵＩＳｈａｎｇｂｉｎ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉ... 详细信息

ＰＯＳＩＴＩＶＥＳＯＬＵＴＩＯＮＳＦＯＲＤＩＲＩＣＨＬＥＴＰＲＯＢＬＥＭＳＯＦＳＩＮＧＵＬＡＲＳＥＭＩＬＩＮＥＡＲＥＬＬＩＰＴＩＣＥＱＵＡＴＩＯＮＳ￥ＣＵＩＳｈａｎｇｂｉｎ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＬａｎｚｈｏｕＵｎｉｖｅｒｓ...

关键词： Singular semilinear elliptic equation Dirichlet problem positive solution.

The Regularity of Lagrangians f(x,ξ) = |ξ|^(α(x)) with Holder Exponents α(x)

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Acta Mathematica Sinica,English Series 1996年第3期12卷 254-261页

作者： Fan Xianling, department of Mathematics lanzhou university lanzhou, {3. China department of Mathematics lanzhou university lanzhou 730000 China

In this paper the regularity of the Lagrangians f（x,ζ）=|ζ|α（x）（11 α（x） α2α（x） is regular. This result gives a negative answer to a conjecture of V. Zhikov.

关键词： Lagrangians Integrals Sobolev spaces Regularity

THE CLAR FORMULAS OF REGULAR t-TIER STRIP BENZENOID SYSTEMS

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Systems Science and Mathematical Sciences 1995年第4期8卷 327-337页

作者： ZHANG Heping(department of Mathematics,lanzhou university,lanzhou 73.000,China) 兰州大学数学系甘肃兰州

ＴＨＥＣＬＡＲＦＯＲＭＵＬＡＳＯＦＲＥＧＵＬＡＲｔ－ＴＩＥＲＳＴＲＩＰＢＥＮＺＥＮＯＩＤＳＹＳＴＥＭＳＴＨＥＣＬＡＲＦＯＲＭＵＬＡＳＯＦＲＥＧＵＬＡＲｔ－ＴＩＥＲＳＴＲＩＰＢＥＮＺＥＮＯＩＤＳＹＳＴＥＭＳ￥ＺＨＡＮＧ... 详细信息

ＴＨＥＣＬＡＲＦＯＲＭＵＬＡＳＯＦＲＥＧＵＬＡＲｔ－ＴＩＥＲＳＴＲＩＰＢＥＮＺＥＮＯＩＤＳＹＳＴＥＭＳＴＨＥＣＬＡＲＦＯＲＭＵＬＡＳＯＦＲＥＧＵＬＡＲｔ－ＴＩＥＲＳＴＲＩＰＢＥＮＺＥＮＯＩＤＳＹＳＴＥＭＳ￥ＺＨＡＮＧＨｅｐｉｎｇ（Ｄｅｐａｒｔｍｅｎｔ...

关键词： Benzenoid system perfect matching Clar formula.

Synthesis of substituted benzoxazoles by the iron(Ⅲ)-catalyzed aerobic oxidation process

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Science China Chemistry 2010年第1期53卷 130-134页

作者： CAO Ke,TU YongQiang & ZHANG FuMin P State Key Laboratory of Applied Organic Chemistry and department of Chemistry,lanzhou university,lanzhou 73.000,China State Key Laboratory of Applied Organic Chemistry and department of Chemistry Lanzhou University Lanzhou China

The FeCl3.catalyzed aerobic oxidation process for the synthesis of benzoxazoles,benzothiazole and benzimidazole has been *** method has proved to be effective to a wide range of substrates,and it has been applied for ... 详细信息

关键词： iron oxidation benzoxazole JTP-426467 carbon-heteroatom bond formation

Effects of sunspot cycle length and CO_2 on air temperature along Qinghai-Xizang railway and air temperature's trend prediction

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Science China Earth Sciences 2004年第Z1期47卷 131-141页

作者： LI Dongliang, QUO Hui, WANG Wen & WEI LiCold & Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Science, lanzhou 73.000, China department of Atmospheric Sciences, lanzhou university, lanzhou 73.000, China Cold & Arid Regions Environmental and Engineering Research Institute Chinese Academy of Science Lanzhou China department of Atmospheric Sciences Lanzhou University Lanzhou China

There are well coherences between annual averaged air temperatures at every meteorological station along the Qinghai-Xizang railway, and its 10-year moving average correlation coefficient is 0.92. Thus, the regional averaged annual mean temperature series along the Qinghai-Xizang railway (Trw) from 193. to 2000 are constructed. The investigation is suggested that: Trw had significant responses to the 5-year lagged sunspot cycle length (SCL) and 15-year lagged concentration of atmospheric carbon dioxide (CO2), and the correlation coefficients between them are -0.76 (SCL) and 0.88 (CO2), respectively. The future SCL is predicted by the model of average generated function constructed with its main cycles of 76a, 93., 108a, 205a and 275a. The result shows that the SCL would be becoming longer in the first half of the 21st century, and then it could be becoming shorter in the second half of the 21st century. Based on the natural change of SCL and the effect of double CO2 concentration, Trw in the 21st century is forecasted. It could warm up about 0.50℃ in the first half of the 21st century compared with the last decade of last century. The mean maximum air temperature could be likely about 0.20℃ in July and from 0.40℃ to 1.10℃ in January. The annual air temperature difference would likely reduce 0.3.1.00℃. The probability of above predictions ranges from 0.64 to 0.73.

关键词： Qinghai-Xizang railway, annual mean air temperature, sunspot cycle length (SCL), atmospheric carbon dioxide concentration (CO2), prediction.

A DNMR study on the ring inversion of oxazolidines

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Chinese Journal of Chemistry 1990年第5期8卷 430-434页

作者： YANG,Li The National Laboratory on Applied Organic Chemistry,lanzhou university,lanzhou {3.GAO,Kun KONG,Su-Ling CHEN,Yao-Zu department of Chemistry,lanzhou university,lanzhou {3. National Laboratory on Applied Organic Chemistry Lanzhou University Lanzhou 730000 department of Chemistry Lanzhou University Lanzhou 730000

Ring inversion of eight substituted 2-phenyl-4,4-dimethyloxazolidines in o-dichloro- benzene-d_4 was studied by ~H *** high inversion barriers((?)G_c(?)=86.7—93.4 kJ·mol^(-1)) were found for these oxazolidine *** magnitude of the inversion barrier is dependent on the polarity of the substituent on the phenyl group.A linear correlation is present between the (?)G_c(?) of the inversion and the substituent constant,σ^+,of the substituent.

关键词： ring A DNMR study on the ring inversion of oxazolidines

Microenvironmental control of photochemica reactions Ⅱ.Fluorescence quenching of naphthalene and 1,3.di-(a-naphthyl)propane by RNA and bases in aqueous methanol

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Chinese Journal of Chemistry 1990年第4期8卷 340-349页

作者： LEI, Xue-Gong XIE, Rui-Qiang LIU, You-Cheng department of Chemistry, lanzhou university, lanzhou 73.000 department of Chemistry Lanzhou University Lanzhou 130000

The fluorescence quenching of naphthalene (2)and 1, 3.di(α-naphthyl)propane (1) by RNA and bases in methanol-water (v:v=1:1) binary solvents in the presence or absence of cyclodex- trin (CD) has been investigated. The results show that both the monomer and excimer fluorescence of 1 can be quenched by these quenchers. The quenching and rates depend on the quencher and tem- perature. It is shown that there is a critical temperature (Tc) for each quencher. Below Tc, the excimer fluorescence spectra show vibrational structures and the Stern-Volmer plots are straight lines (for ura- cil and cytosine); while above the Tc, the vibrational structures disappear and the Stern-Volmer plots deviate from linearity and curve upward. The former is a static process; while the latter is a mixture of both static and dynamic processes. The addition of α-CD has no effect on the fine structure, whereas β-CD prevents the appearance of this structure efficiently. The quenching rates both for the monomer and excimer of 1 by bases except cytosine in the presence of β-CD at ambient temperature are not changed; the quenching of fluorescence of 1 by RNA in the presence of β-CD, however, is hindered. Time-resolved fluorescence study shows that the excimer fine structures appear from the zero time. The intensity of fine structures depend on the fraction of water (φ) in binary solvents, and it is independent of the pH value of the solvents. It is suggested that bases and RNA induced aggregates (perhaps microcrystal) are formed, in which the motion of molecules 1 is limited.

关键词： Fluorescence quenching of naphthalene and 1,3.di Microenvironmental control of photochemica reactions RNA

Synthesis and Characterizations of New Ferrocenyl Schiff Base with NLO Responses

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Chinese Chemical Letters 2000年第7期11卷 583-586页

作者： Bang Jing LI Wan Yi LIU Tong XIE Guo Sheng HUANG Yong Xiang MA(department of Chemisty, lanzhou university, lanzhou 73.000) department of Chemisty Lanzhou University Lanzhou 730000 China

A series of new stable (thermal and photochemical) ferrocenyl derivatives containing C=N bond and benzene ring in long conjugated chains have been synthesized and characterized by (HNMR)-H-1(400MHz), IR, and elemental analysis. Pull-push ferrocenyl complexes that we have prepared have strong NLO responses identified by electronic absorption spectrum.

关键词： ferrocenyl Schiff base NLO C=N