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Fluorescence fluctuation spectroscopy and its artifacts:simulations and tests

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Science China(Physics,Mechanics & Astronomy) 2005年第3期48卷 336-344页

作者： MENG Fanbo 1 , CHEN Bo 1 , LIU Guang 1 , DING Jianying 1 & MA Hui 2.1 1. Department of Physics and Key Laboratory of Atomic and Molecular Nano Sciences, Ministry of Educa- tion, Tsinghua University, beijing 100084, China 2. Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China 1. Department of Physics and Key Laboratory of Atomic and Molecular Nano Sciences Ministry of Education Tsinghua University 100084 Beijing China 2. Graduate School at Shenzhen Tsinghua University 518055 Shenzhen China

Fluorescence fluctuation spectroscopy (FFS) technique is capable of monitoring changes in concentration, mass, size and structure of fluorescent-labeled bio-molecules in microscopic volume and is suitable for measuring biological interactions in living cells. FFS data may be affected by many experimental factors in complicated biological systems. Using a Monte Carlo approach, we generate fluorescence fluctuation data for different experimental systems. This approach helps to separate the contributions by different experimental factors in a complicated fluorescence fluctuation spectrum. It also helps to validate new theoretical models and new fitting formulations. We describe the algorithm of the simulation program and tests on its statistical performance. The program is then used successfully to study the effects of several experimental factors on FFS detection.

关键词： fluorescence fluctuation spectroscopy, fluorescence correlation spectroscopy, Monte Carlo simulation.

Leading Edge Film Cooling Enhancement for an Inlet Guide Vane with Fan-Shaped Holes

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Journal of Thermal Science 2010年第6期19卷 514-518页

作者： Jian-Jun LIU, Bai-Tao AN, Jie LIU and Zhan W institute of Engineering Thermophysics, chinese {2. of Sciences, P. O. Box 2.06, {3. 100190, China Professor,PhD institute of Engineering Thermophysics Chinese Academy of Sciences Beijing China

This paper describes the improvement of leading edge film cooling effectiveness for a turbine inlet guide vane by using fan-shaped film cooling holes. The modification details are presented in comparison with the base-line configuration of cylindrical holes. Numerical simulations were carried out for the base-line and modified configurations by using CFX, in which the k-ε turbulence model and scalable wall function were chosen. Contours of adiabatic film cooling effectiveness on the blade surfaces and span-wise distributions of film cooling effectiveness downstream the rows of cooling holes interested for the different cooling configurations were compared and discussed. It is showed that with the use of fan-shaped cooling holes around the leading edge, the adiabatic film cooling effectiveness can be enhanced considerably. In comparison with the cylindrical film cooling holes, up to 40% coolant mass flow can be saved by using fan-shaped cooling holes to obtain the comparable film cooling effectiveness for the studied inlet guide vane.

关键词： Inlet Guide Vane Film Cooling Effectiveness Fan-Shaped Hole Leading Edge

Rheological behaviour of semi-solid succinonitrile-camphor alloy

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Journal of University of Science and Technology beijing 2003年第1期10卷 25-29页

作者： Zhenyao WangState Key Laboratory for Corrosion and Protection, institute of Metal Research, chinese {2. of Sciences, Shenyang 110016, China Lab. for Corrosion and Protection Inst. of Metal Res. Chinese Acad. of Sci. Shenyang 110016 China

Rheology experiments were carried out on succinonitrile-4% (mass fraction) camphor alloy, using a Haake VT550 viscometer. The results showed that the steady state viscosity of succinonitrile-4% camphor alloy in semi-solid process can be described well by the classical power law of viscosity versus shear rate, η= kγm, and the test method can be used to simulate the semi-solid processing for metals. The viscosity of the organic alloy decreases with increasing shear rate at a given temperature within liquid-solid range, and the viscosity of the organic alloy slurries increases with decreasing temperature, decreases with decreasing cooling rate. The structure and viscosity of organic alloy during solidification are strongly influenced by shear rate.

关键词： rheology semi-solid processing viscosity organic alloy microstructure

Sample stacking in capillary electrophoresis

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Sample stacking in capillary electrophoresis

A SUSY THEORY OF FLAVORS AND ITS ASTROPHYSICAL IMPLICATIONS

3.th International Symposium on Capillary Chromatography、4th GC×GC Symposium、16th National Symposium and Exhibition on Chromatography,i.e. 1st Dalian International Symposium and Exhibition on Chromatography

作者： Yi Chen~* Yanli Han Xiaoyu Wang Lab of Analytical chemistry for Life Science institute of chemistry {3. academy of Sciences beijing 100080 China

＜正＞Sample stacking（SS）is actually a technique to concentrate solutes by some special principles and/or techniques, highly useful for the introduction of samples in capillary electrophoresis（CE）and/or mass spectrometry（MS）of diluted solutes with especially a salted *** several SS approaches have been available such as solid phase extraction（SPE）,electric field amplification（EFA）,sweeping,transient isotachophoresis（t-ITP）and so forth,few can directly be hyphenated to either CE or *** explore some other techniques that may be better than the existed is thus necessary and has been conducted in this laboratory by mainly using CE as a testing model.A novel method has hence been obtained called acid-base titration anti-salt stacking（ATAS）and shown applicable to direct CE of biological *** online ATAS injection（ATASI）of 9-fluorenylmethyl- chloroformate-labeled standard amino acids（FMOC-AAs）,the method was demonstrated to be able to bear at least 500 mM inorganic salts such as NaCI,with a concentrating factor up to 103.fold.A sample of 10 nM FOMC-AA becomes detectable now by *** Glu and Asp in real biological samples such as rat brain microdialysate,rat serum and human saliva were hence directly determined by ATASI-CE-UV,with intraday relative standard deviations of 1.8-9.6％（peak area）and recoveries of 80-12.％.Also,ATAS is potentially applicable to the direct MS of biofluids and will also be discussed.

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A SUSY THEORY OF FLAVORS AND ITS ASTROPHYSICAL IMPLICATIONS

Distribution of possible sunshine durations over rugged terrains of China

“基于羊八井平台的交叉学科研究”首届研讨会

作者： Chun Liu institute of Theoretical Physics, chinese {2. of Sciences{3., China

An understanding of the lepton masses within the framework of low energy SUSY is presented. A family symmetry is introduced. Sneutrino VEV breaks this symmetry. The tau mass is due to the Higgs VEV, and muon mass purely from the sneutrino VEV. A viable model is constructed, which predicts (1-10) MeV VT. Its implications to supernova explosion and the dark matter are discussed.

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Progress in Natural Science:Materials International 2003年第10期 41-44+81页

作者： ZENG Yan 1, QIU Xinfa 2.*, MIAO Qilong 2.and LIU Changming 1(1. institute of Geographic Sciences and Natural Resources Research, {3. {2. of Sciences, {3. 100101, China 2. Department of Geography, Nanjing institute of Meteorology, Nanjing 2.0044, China) institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Department of Geography Nanjing Institute of Meteorology Nanjing 210044 China

Based on the digital elevation model (DEM), a new model for calculating possible sunshine duration (PSD) is completely described. Using this model, monthly PSD with resolution of 1 km×1 km for the rugged topography of China is calculated. Results suggest that terrain has robust effect on PSD, particularly in winter when a lower sun elevation angle exists. Besides, the proposed model taking the DEM data as the input has an ability to process mass of data and is applicable to satellite image processing platforms or Geographic Information System (GIS). The PSD (in hours) is provided in the same way as other kinds of spatial information and can be employed as basic geographic data for relevant studies as well.

关键词： possible sunshine duration (PSD) rugged terrains spatial distributions digital elevation model (DEM).

Binary population synthesis study of the supersoft X-ray phase of single degenerate type Ia supernova progenitors

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Research in Astronomy and Astrophysics 2011年第8期11卷 965-973页

作者： Xiang-Cun Meng Wu-Ming Yang School of Physics and chemistry Henan Polytechnic University Jiaozuo 454000 China Department of Astronomy Beijing Normal University Beijing 100875 China

In the single degenerate （SD） scenario for type Ia supernovae （SNe Ia）, a mass-accreting white dwarf is expected to experience a supersoft X-ray source （SSS） phase. However, some recent observations showed that the expected number of massaccreting WDs is much lower than that predicted from theory, regardless of whether they are in spiral or elliptical galaxies. In this paper, we performed a binary population synthesis study on the relative duration of the SSS phase to their whole mass-increasing phase of WDs leading to SNe Ia. We found that for about 40% of the progenitor systems, the relative duration is shorter than {3. and the evolution of the mean relative duration shows that it is always smaller than 5%, both for young and old SNe Ia. In addition, before the SNe Ia explosions, more than 55% of the progenitor systems were experiencing a dwarf novae phase and no more than 10% were staying in the SSS phase. These results are consistent with the recent observations and imply that both in early- and late-type galaxies, only a small fraction of mass-accreting WDs resulting in SNe Ia contributes to the supersoft X-ray flux. So, although our results are not directly related to the X-ray output of the SN Ia progenitor, the low supersoft X- ray luminosity observed in early type galaxies may not be able to exclude the validity of the SD model. On the contrary, it is evidence to support the SD scenario.

关键词： stars: white dwarfs -- stars: supernovae: general

Tidally induced upwelling off Yangtze River estuary and in Zhejiang coastal waters in summer

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Science China Earth Sciences 2007年第3期50卷 462-473页

作者： L XinGang1,2.3.4, QIAO FangLi1,2. XIA ChangShui1,2.& YUAN YeLi1,2.1 The First institute of Oceanography, State Oceanic Administration, Qingdao 2.6061, China 2.Key Laboratory of Marine Science and Numerical Modeling (MASNUM), State Oceanic Administration, Qingdao 2.6061, China 3.institute of Oceanology, {2. {3. of Sciences, Qingdao 2.6071, China 4 Graduate University of the {2. {3. of Sciences, beijing 10003., China 1. The First institute of Oceanography State Oceanic Administration Qingdao 266061 China 2. Key Laboratory of Marine Science and Numerical Modeling (MASNUM) State Oceanic Administration Qingdao 266061 China 3. institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China 4. Graduate University of the chinese academy of Sciences Beijing 100039 China

MASNUM wave-tide-circulation coupled numerical model (MASNUM coupled model, hereinafter) is de-veloped based on the Princeton Ocean Model (POM). Both POM and MASNUM coupled model are ap-plied in the numerical simulation of the upwelling off Yangtze River estuary and in Zhejiang coastal waters in summer. The upwelling mechanisms are analyzed from the viewpoint of tide, and a new mechanism is proposed. The study suggests that the tidally inducing mechanism of the upwelling in-cludes two dynamic aspects: the barotropic and the baroclinic process. On the one hand, the residual currents induced by barotropic tides converge near the seabed, and upwelling is generated to maintain mass conservation. The climbing of the residual currents along the sea bottom slope also contributes to the upwelling. On the other hand, tidal mixing plays a very important role in inducing the upwelling in the baroclinic sea circumstances. Strong tidal mixing leads to conspicuous front in the coastal waters. The considerable horizontal density gradient across the front elicits a secondary circulation clinging to the tidal front, and the upwelling branch appears near the frontal zone. Numerical experiments are de-signed to determine the importance of tide in inducing the upwelling. The results indicate that tide is a key and dominant inducement of the upwelling. Experiments also show that coupling calculation of the four main tidal constituents (M2. S2. K1, and O1), rather than dealing with the single M2.constituent, im-proves the modeling precision of the barotropic tide-induced upwelling.

关键词： upwelling dynamic mechanism numerical simulation tidal movement tidal mixing front

Purification of a Novel Antibacterial Short Peptide in Earthworm Eisenia foetida

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Acta Biochimica et Biophysica Sinica 2004年第4期36卷 297-302页

作者： Yan-Qin LIU1,2. Zhen-Jun SUN1*, Chong WANG1, Shi-Jie LI2. and Yu-Zhi LIU2.College of Resource and Environment Science, China Agricultural University, {3. 100094, China 2.ollege of Animal Science, Hebei Agricultural University, Baoding 071001, China College of Resource and Environment Science China Agricultural UniversityBeijing 100094 China College of Animal Science Hebei Agricultural UniversityBaoding 071001 China

A novel antimicrobial short peptide was purified from earthworm (Eisenia foetida) by a five-step protocol including ammonium sulfate precipitation, ultrafiltration, DE-52.ion exchange chromatography, Sephadex G-10 column chromatography, and C-18 reversed-phase HPLC techniques. The purified peptide was applied to the MALDI-TOF MS to determine the molecular mass and was also subjected to TOF MS-MS analysis to determine the amino acid sequence. As a result, a novel antibacterial peptide, named OEP3.2., was obtained, with the molecular mass of 510.8 Da and the sequence being “ACSAG”.

关键词： antibacterial peptide earthworm purification