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On the ratio of different norms of caloric functions and related eigenfunctions of an integral operator

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Science china Mathematics 2012年第8期55卷 1597-1612页

作者： DING YuTao 1,2.& ZHANG LiQun 1,2.1 institute of Mathematics,academy of Mathematics and Systems Science,Chinese academy of sciences,beijing 100190,china 2.Hua Loo-Keng Key Laboratory of Mathematics,Chinese academy of sciences,beijing 100190,china institute of Mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing China Hua Loo-Keng Key Laboratory of Mathematics Chinese Academy of Sciences Beijing China

We investigate the ratio of L 1 and L 2.norms of the Cauchy problem solutions of heat equations with compact support initial *** related asymptotic behavior of the eigenvalues and eigenfunctions of certain integral op... 详细信息

关键词： integral operators eigenvalues heat equation

Relationships between tree-ring width index and NDVI of grassland in Delingha

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Chinese Science Bulletin 2006年第9期51卷 1106-1114页

作者： HE Jicheng1,3 & SHAO Xuemei1,2.. institute of Geographical sciences and Natural Resources Research, Chinese {2. of sciences, beijing 100101, china 2. institute of Tibetan Plateau Research, Chinese {2. of sciences, beijing 100085, china 3. Graduate School of Chinese {2. of sciences, beijing 100039, china institute of Geographical sciences and Natural Resources Research Chinese Academy of Sciences Beijing China Graduate School of Chinese academy of sciences Beijing China institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China

Using five well-replicated Qilian juniper (Sabina przewalskii Kom.) tree-ring width index se- ries, monthly normalized difference vegetation index (NDVI) of grassland, and climatic data from 1982.to 2.01, the relationships between tree-ring width index, NDVI of grassland, and climatic data were analyzed firstly. Then, the relationship between tree-ring width index and NDVI of grassland was explored. The re- sults showed that: (1) Temperature and precipitation in June influenced tree-ring width index and NDVI of grassland deeply in Delingha. (2. There were sig- nificant relationships between five tree-ring width index series (DLH1-DLH5) and monthly NDVI of grassland from June to September, with the most significant relationship being between tree-ring width index series and NDVI of grassland in August. (3) The PC1 (the first principal component derived from DLH1-DLH5 series) exhibited good agreement with monthly NDVI of grassland in the grass growth sea- son (from June to September) and the averaged NDVI in the growth season, which was attributed to their common responses to water-supply limit in Delingha. This study may allow an increase in studying the past dynamics of grassland in Delingha in that the variation of grassland NDVI during the last millennium has been reconstructed from PC1.

关键词：圆柏祁连山 NDVI 草原年轮宽度指数

The lepton flavor violating signal of the extra gauge boson Z′in photon-photon collision at the ILC

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Science china(Physics,Mechanics & Astronomy) 2010年第11期53卷 1992-1997页

作者： LIU GuoLi 1,2.1 Physics Department,Zhengzhou University,Zhengzhou 450001,china 2.Kavli institute for Theoretical Physics china,Chinese academy of sciences,beijing 100190,china Physics Department Zhengzhou University Zhengzhou China Kavli institute for Theoretical Physics china Chinese Academy of Sciences Beijing China

The hitherto unconstrained lepton flavor mixings,induced by the new gauge boson Z ,which are the prediction of many new physics models,such as topcolor-assisted technicolor (TC2. models and flavor-universal TC2.models,may lead to the lepton flavor violating productions of τμˉ,τeˉ and μeˉ in photon-photon collision at the proposed International Linear Collider (ILC).Through a comparative analysis of these processes,we find that the better channel to probe the new physics models is the production of τμˉ or τeˉ which occurs at a much higher rate than μeˉ production due to the large mixing angle and the large flavor changing coupling,and may reach the detectable level of the ILC for a large part of the parameter *** the rates predicted by the Standard Model are far below the detectable level,these processes may serve as a sensitive probe for such new physics models.

关键词： new gauge boson Z lepton flavor violating processes photon-photon

Photogeneration of the free radicals and singlet oxygen by chrysophanol from rheum

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Science china Chemistry 2004年第5期47卷 381-387页

作者： RAO Jing1,2. XIE Jie1, ZHAO Jingquan1 & ZHU Teng2.1. Key Laboratory of Photochemistry, Center for Molecular Science, institute of Chemistry, The Chinese academy of {2., beijing 100080, china 2. University of Science and Technology beijing, beijing 10083, china Key Laboratory of Photochemistry Center for Molecular Science Institute of Chemistry The Chinese Academy of Sciences Beijing China University of Science and Technology beijing Beijing China

In the current work, chryosphanol (MHAQ) was isolated and purified from rheum, and the photosensitization activities were studied. In nitrogen-saturated DMSO solution, irradia- tion of chryosphanol (MHAQ) with visible light (>430 nm) produced the semiquinone radical anions (MHAQ??), which was intensified significantly by an electron donor NADH, suggesting electron transfer between the excited and ground state photosensitizer molecules. In an air-saturated DMSO solution, superoxide radical anions (O2.), trapped by DMPO, were detected. ?? It was proved that O2.was not originated from the singlet oxygen (1O2. but dependent on DMPO, ?? chrysophanol, oxygen and the irradiation time. The singlet oxygen and OH could also be pro- ? duced by the photosensitization of the photosensitizer. These suggest that chrysophanol pos- sesses the photosensitization activity via Type I mechanism and Type II mechanism. To evaluate the photosensitization activities of MHAQ, emodin and mixed anthraquinone derivatives ex- tracted from rheum, the relative productivities of O2.were estimated to be 1.8, 1.1 and 1.0 re- ?? spectively and the quantum yields for singlet oxygen to be 0.36, 0.53 and 0.14 respectively. Therefore, these low-cost pigments may be potentially used as phototherapeutic medicine for some kind of vascular diseases or photo-activated pesticides.

关键词： chrysophanol, ESR, semiquinone radical anions, superoxide radical anions, hydroxyl radical, singlet oxygen.

Lithospheric seismic fabrics of Sulu ultrahigh-pressure metamorphic belt

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Science china Earth sciences 2005年第5期48卷 585-600页

作者： YANG Wencai 1 , YANG Wuyang 1 , JIN Zhenmin 2.& CHENG Zhenyan 1 1. institute of Geology, Chinese academy of Geological {2., beijing 100037, china 2. china University of Geo{2., Wuhan 430074, china Chinese academy of Geological sciences Institute of Geology Beijing China china University of Geosciences Wuhan China

Calibration of seismic reflectors appearing in the crust of the Chinese continent sci- entific drilling site can be completed through the correlation studies between direct evidences, such as the drill cores, and geophysical signatures; therefore the interpretation of geophysical data could produce reliable results of crustal structure and composition. On the other hand, there are two Cenozoic volcanoes close to the scientific drilling site; analyzing composition of xenoliths existent in the volcanoes and evaluating their seismic velocities can also offer information about the mantle and lower crust. After the calibration via cores and well-logging data, the seismic re- flectors appearing in the UHP belt can be caused by lithological changes within the UHP rock slice, ductile shearing rock-suites, and later fracture zones. Among these sources, ductile shearing resulted in displacement and detachment of original rock-sheets, producing some rock-interbeds of several hundred meters thick that are named the ductile shearing rock-suites. A suite consists of mylonized gneiss and eclogite slices that underwent shearing, becoming the major mechanism responsible to generate regional strong reflections. The UHP rock-slice is characterized by complicated structures and high density, high seismic velocity and high electri- cal resistivity, its thickness is usually less than 11 km. Velocity and density of the gneiss-layer beneath gradually tend to normal with increasing depth. Based on the xenoliths we can infer that the middle crust contains a lot of gneisses, and the lower crust consists of different granulites. The lithospheric mantle has multi-layer structures and consists mainly of spinal lherzolite and harzburgite, implying late Mesozoic lithospheric thinning. The seismic fabrics with different ori- gins were possible products of different geodynamic processes. For instance, the UHP rock-slice was produced by the UHP metamorphic process and the exhumation of subducted supe

关键词： deep seismic reflection, ultrahigh-pressure belt, Sulu china, calibration of reflectors, lithospheric fabrics.

Antitumor activity of a novel recombinant mutant human tumor necrosis factor-related apoptosis-inducing ligand

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Acta Pharmacologica Sinica 2005年第11期26卷 1373-1381页

作者： Fang FANG~2. Ai-ping WANG~2. Shi-fang YANG~3 ~2.institute of Materia Medica, Chinese academy of Medical {2. and Peking Union Medical College, beijing 100050 ~3 beijing Sunbio Biotech LTD, beijing 100081, china institute of Materia Medica Chinese Academy of Medical Sciences and Peking Union Medical College Beijing China beijing Sunbio Biotech LTD Beijing China

Aim: To investigate the antitumor activity and safety of a novel recombinant mutant human tumor necrosis factor-related apoptosis-inducing ligand (rmh TRAIL). Methods: Antitumor activity of rmh TRAIL was evaluated by using several tumor cell lines by MTT assay in vitro, and by using a mouse xenograft model in vivo, rmh TRAIL-induced apoptosis in tumor cells was detected by cell death enzyme-linked immunosorbent assay (ELISA), TdT-mediated dUTP nick-end labeling (TUNEL) assay and flow cytometry. The safety of rmh TRAIL was also evaluated in several normal human cell lines. Results: At the concentration of 0.32.1 000 ng/mL, rmh TRAIL remarkably inhibited the proliferation of 5 tumor cell lines from lung, colon, and breast cancer compared with wild type (wt TRAIL) in vitro, whereas at the concentration of 1 ng/mL-10 μg/mL, rmh TRAIL showed no or mild cytotoxicity in the normal cell lines, rmh TRAIL (3,15 mg/kg, ip, once daily for 10 d) exerted a significant inhibition on the growth of xenograft tumor NCI-H460 in nude mice compared with the saline group (P<0.01), and was more potent than wt TRAIL, a positive control. The apoptosis of NCI-H460 cells was markedly induced in a concentration-dependent and time-dependent manner after rmh TRAIL treatment. The percentage of apoptotic cells induced by rmh TRAIL in NCI-H460 cells was significantly higher than that by wt TRAIL. Conclusion: rmh TRAIL provided potent antitumor activity in vivo and in vitro, whereas most normal human cells were resisitant to rmh TRAIL. The results suggested that rmh TRAIL might be a useful anticancer agent in future.

关键词： antineoplastic agents tumor necrosis factorrelated apoptosis-inducing ligand apoptosis flow cytometry NCI-H460 cells

Numerical study on scanning radiation acoustic field in formations generated from a borehole

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Science china(Physics,Mechanics & Astronomy) 2005年第2期48卷 247-256页

作者： CHE Xiaohua1, ZHANG Hailan1, QIAO Wenxiao2.& JU Xiaodong2.1. institute of Acoustics, Chinese academy of {2., beijing 100080, china 2. Faculty of Natural Resources & Information Technology, University of Petroleum, beijing 102.49, china institute of Acoustics Chinese Academy of Sciences Beijing China Faculty of Natural Resources & Information Technology University of Petroleum Beijing China

Numerical study on scanning radiation acoustic field in formations generated by linear phased array transmitters in a fluid-filled borehole is carried out using a real axis integration (RAI) method. The main lobe width of the acoustic beams and the incident angle on the borehole wall can be controlled by means of adjusting parameters, such as the element number and the delay time between the neighboring array elements of linear phased array transmitter. The steered angle of longitudinal waves generated in the formation satisfies the Snell’s law for plane waves when the incident angle on the borehole wall is less than the first critical angle. When the lobe width of the acoustic beams is narrow and the steered angle is less than the first critical angle, the acoustic field in the formation can be approximately calculated given that the linear phased array is put in the formation without borehole. The technique of scanning radiation acoustic field can be applied to enhancing investigation resolution and signal-to-noise ratio in crosswell seismic survey and borehole acoustic reflection imaging.

关键词： formation, linear phased array transmitter, steered angle, RAI, scanning radiation.

Zonal propagation of kinetic energy and convection in the South china Sea and Indian monsoon regions in boreal summer

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Science china Earth sciences 2004年第12期47卷 1076-1084页

作者： CHEN Longxun 1 ,GAO Hui 2.,HE Jinhai 2.,TAO Shiyan 3 & JIN Zuhui 3 1.Chinese academy of Meteorological sciences,{2. 100081,china 2.Nanjing institute of Meteorology,Nanjing 2.0044,china 3.institute of Atmospheric Physics,Chinese academy of sciences,{2. 10002.,china Chinese academy of Meteorological sciences Beijing China Nanjing institute of Meteorology Nanjing China Chinese academy of sciences Institute of Atmospheric Physics Beijing China

Zonal propagation of kinetic energy (KE) and convection in the South china Sea (SCS) and Indian summer monsoon areas are examined in present study. Results suggest that the SCS and Indian summer monsoon prevailed regions (5 —15°N) are dominated by the southwesterly wind, however, the disturbances of KE at 850 hPa and convection are observed mainly coming from the western Pacific Ocean (140—150°E), after passing through the SCS, and westward propagated into the Bay of Bengal (90—100°E). In the Indian summer monsoon domain, where the disturbances of KE are found mainly coming from the Arabian Sea (AS) and eastward propagated into the Bay of Bengal. Therefore, the SCS and the Indian summer mon- soon are quite different in zonal propagation of KE and convection. The SCS summer monsoon is mainly affected by the KE and convection coming from the tropical western Pacific. The Indian summer monsoon, however, can be partly influenced by the AS and the SCS summer monsoon. The analysis also suggests that the interaction region between the SCS and the Indian summer monsoon is around 90—95°E, rather than 105°E as proposed by earlier studies.

关键词： zonal propagation of KE and convection, East Asian monsoon, Indian monsoon.

SHRIMP zircon U-Pb age and Nd isotopic study on the Nyainqêntanglha Group in Tibet

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Science china Earth sciences 2005年第9期48卷 1377-1386页

作者： HU Daogong1, WU Zhenhan1, JIANG Wan1, SHI Yuruo2. YE Peisheng1 & LIU Qisheng1 1. institute of Geomechanics, Chinese academy of Geological {2., beijing 100081, china 2. institute of Geology, Chinese academy of Geological {2., beijing SHRIMP Centre, beijing 100037, china institute of Geomechanics Chinese Academy of Geological Sciences Beijing China institute of Geology Chinese Academy of Geological Sciences Beijing SHRIMP Centre Beijing China

The Nyainqêntanglha Group is traditionally viewed as the oldest metamorphic basement in the Lhasa block, but its formation age and tectonic setting remain debate. Zircons extracted from the metamorphic sequence of volcanics and intrusions of the Nyainqêntanglha Group, 10 km west of Nam Co in northern Lhasa block, have been investigated by cathodolu- minescence (CL), backscattered (BSE) and dated by ion microprobe (SHRIMP). We conclude that the U-Pb age of 787±9 Ma of zircons from the trondhjemite imposes a constraint on maxi- mum protolith age, and minimum formation age of the Nyainqêntanglha Group is constrained by U-Pb age of 748±8 Ma of zircons from the granite. The formation age of the Nyainqêntanglha Group is consistent with sedimentary age of Greater Himalayan rocks, showing that they devel- oped coevally in an arc-basin tectonic setting of Neoproterozoic active continental margin along the northern margin of the India shield. The inherited zircons from the tholetiite and granite give older 2.7Pb/2.6Pb ages from 947 to 1766 Ma. The positive εNd( t ) value indicates that the mafic rocks were derived from the depleted mantle, but contaminated by the older continental crustal material. Integrated Nd model age and U-Pb age data provide excellent evidence for the exis- tence of Mesoproterozoic basement in the Lhasa block during Neoproterozoic time.

关键词： Nyainqêntanglha Group, SHRIMP dating, Nd isotope, Neoproterozoic, Tibet.