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A three-dimensional variational ocean data assimilation system:Scheme and preliminary results

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Science china Earth Sciences 2006年第11期49卷 1212-1222页

作者： ZHU Jiang1,2, ZHOU Guangqing1, YAN Changxiang1, FU Weiwei1 & YOU Xiaobao1,3.1. International Center for Climate and Environment Sciences, Institute of Atmospheric Physics, Chinese Academy of Sciences, beijing 10002., china 2. Jiangsu Key Laboratory of Meteorological Disaster, Nanjing University of Information Science and Technology, Nanjing 21004., china 3. {3. Institute of applied meteorology, beijing 10002., china 1. International Center for Climate and Environment Sciences Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China 2. Jiangsu Key Laboratory of Meteorological Disaster Nanjing University of Information Science and Technology Nanjing 210044 China 3. beijing Institute of applied meteorology Beijing 100029 China

A new 3.VAR-based Ocean Variational Analysis System (OVALS) is developed. OVALS is capable of assimilating in situ sea water temperature and salinity observations and satellite altimetry data. As a component of OVALS, a new variational scheme is proposed to assimilate the sea surface height data. This scheme considers both the vertical correlation of background errors and the nonlinear temperature-salinity relationship which is derived from the generalization of the linear balance constraints to the nonlinear in the 3.VAR. By this scheme, the model temperature and salinity fields are directly adjusted from the altimetry data. Additionally, OVALS can assimilate the temperature and salinity profiles from the ARGO floats which have been implemented in recent years and some temperature and salinity data such as from expendable bathythermograph, moored ocean buoys, etc. A 21-year assimilation experiment is carried out by using OVALS and the Tropical Pacific circulation model. The results show that the assimilation system may effectively improve the estimations of temperature and salinity by assimilating all kinds of observations. Moreover, the root mean square errors of temperature and salinity in the upper depth less than 4.0 m reach 0.63. and 0.3. psu.

关键词： data assimilation, 3.VAR, sea surface height, ARGO floats.

Proton induced X-ray emission (PIXE) analysis of sources of porcelain body of Ru Guan and Jun Guan porcelains

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Science china(Physics,Mechanics & Astronomy) 2006年第4期49卷 411-420页

作者： LI Guoxia1, ZHAO Weijuan1, LI Rongwu2, SUN Hongwei1, GUO Min1, WANG Yanfang1, LIU Hui1, ZHAO Qingyun3. SUN Xinmin3. ZHAO Wenjun3.& CHENG Huansheng4.1. Faculty of Physical Engineering, Zhengzhou University, Zhengzhou 4.0052, china 2. Department of Physics, {4. Normal University, {4. 100875, china 3. Institute of Cultural Relic and Archaeology of Henan Province, Zhengzhou 4.0000, china 4. Institute of Modern Physics, Fudan University, Shanghai 2004.0}, china Faculty of Physical Engineering Zhengzhou University Zhengzhou 450052 China Department of Physics Beijing Normal University Beijing 100875 China Institute of Cultural Relic Archaeology of Henan Province Zhengzhou 450000 China Institute of Modern Physics Fudan University Shanghai 200433 China

3. samples of Ru Guan porcelain body and 50 samples of Jun Guan porcelain body (both kinds being in different body colors) were selected with the purpose of finding out the source of raw materials and their classification relationship so as to search for ways of non-destructive discrimination. Proton induced X-ray emission (PIXE) has been applied to these samples to determine their chemical elements. The data of seven major chemical elements collected from these samples were further studied through fuzzy cluster analysis. Results indicate that the origin of raw materials of Jun Guan porcelain body samples is comparatively more concentrated in certain places, while that of Ru Guan porcelain body samples is scattered about. The places of origin of raw materials of the majority of Ru Guan and Jun Guan porcelain body samples have something in common, but some differences still exist. It might be an important way for non-destructive discrimination among Ru Guan and Jun Guan porcelains by combining PIXE with fuzzy cluster analysis.

关键词： Ru Guan and Jun Guan porcelain, source of porcelain body, PIXE, fuzzy cluster analysis, non-destructive discrimination.

Approximation of dense-n/2-subgraph and table compression problems

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Science china Mathematics 2005年第9期48卷 1223-1233页

作者： XU Dachuan~1 HAN Jiye~2 & DU Dongle~3.1. College of applied Sciences,beijing University of Technology,beijing {3.,china 2. Institute of applied Mathematics,Academy of Mathematics and Systems Science,Chinese Academy of Sciences,beijing 100080,china 3. Faculty of Administration,University of New Brunswick,P.O.Box 4.00,Fredericton,NB E3. 5A3.Canada College of applied Sciences Beijing University of Technology Beijing 100022 China Institute of applied Mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China Faculty of Administration University of New Brunswick P.O. Box 4400 Fredericton NB E3B 5A3 Canada

We develop improved approximation algorithms for two NP-hard problems: the dense-n/2-subgraph and table *** on SDP relaxation and advanced rounding techniques,we first propose 0. 5982 and 0. 5970-approximation algorithms respec- tively for the dense-n/2-subgraph problem (DSP) and the table compression problem (TCP). Then we improve these bounds to 0. 624.0}and 0. 6708 respectively for DSP and TCP by adding triangle inequalities to strengthen the SDP *** results for TCP beat the 0. 5 bound of a simple greedy algorithm on this problem,and hence answer an open question of Anderson in an affirmative way.

关键词： dense-n/2-subgraph problem(DSP) table compression problem(TCP) SDP approximation ratio

A new DNA algorithm to solve graph coloring problem

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Progress in Natural Science:Materials International 2007年第6期17卷 733-738页

作者： Jiang Xingpeng1, Li Yin2, Meng Ya3.and Meng Dazhi2(1. National Laboratory of Pattern Recognition,Institute of Automation, Chinese Academy of Sciences, beijing 100080, china 2. College of applied Sciences, beijing University of Technology, beijing 10002., china 3. School of Science, beijing Institute of Technology, beijing 100081, china) National Laboratory of Pattern Recognition Institute of Automation Chinese Academy of Sciences Beijing 100080 China College of applied Sciences Beijing University of Technology Beijing 100022 China School of Science Beijing Institute of Technology Beijing 100081 China

Using a small quantity of DNA molecules and little experimental time to solve complex problems successfully is a goal of DNA computing. Some NP-hard problems have been solved by DNA computing with lower time complexity than conventional computing. However, this advantage often brings higher space complexity and needs a large number of DNA encoding molecules. One example is graph coloring problem. Current DNA algorithms need exponentially increasing DNA encoding strands with the growing of problem size. Here we propose a new DNA algorithm of graph coloring problem based on the proof of four-color theorem. This algorithm has good properties of needing a relatively small number of operations in polynomial time and needing a small number of DNA encoding molecules (we need only 6R DNA encoding molecules if the number of regions in a graph is R).

关键词： DNA computing NP-hard problem graph coloring problem.

X-ray spectra induced in highly charged 4.Ar^q+ interacting with Au surface

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Science china(Physics,Mechanics & Astronomy) 2006年第2期49卷 203-212页

作者： ZHANG Xiao’an1,2, XIAO Guoqing1, YANG Zhihu1, CHEN Ximeng3. ZHAO Yongtao1, LI Fuli4. ZHANG Yinping1, CUI Ying3. ZHANG Hongqiang3. XU Xu3. SHAO Jianxiong3.& ZHAN Wenlong11. Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 73.000, china 2. Department of Physics, Xianyang Normal University, Xianyang 712000, china 3. Department of Modern Physics, Lanzhou University, Lanzhou 73.000, china 4. Department of {3. Physics, Xi’an Jiaotong University, Xi’an 71004., china 1. Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China 2. Department of Physics Xianyang Normal University Xianyang 712000 China 3. Department of Modern Physics Lanzhou University Lanzhou 730000 China 4. Department of applied Physics Xi’an Jiaotong University Xi’an 710049 China

By use of optical spectrum technology, the spectra of X-ray induced by highly charged 4.Arq+ ions interacting with Au surface have been studied. The results show that the argon Kα X-ray were emitted from the hollow atoms formed below the surface. There is a process of multi-electron exciting in neutralization of the Ar16+ion, with electronic con-figuration 1s2 in its ground state below the solid surface. The yield of the projectile Kα X-ray is related to its initial electronic configuration, and the yield of the target X-ray is related to the projectile kinetic energy.

关键词： highly charged ion hollow multi-electron excitation X- ray.

Integrated precise orbit determination of Shenzhou IV unmanned spacecraft

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Science china(Technological Sciences) 2004年第5期47卷 518-525页

作者： L Congmin1,2, GU Yidong3. LIN Baojun3.& GUO Jiong3.1. Center for Space Science and applied Research, Chinese Academy of Sciences, {4. 100080, china 2. Graduate School of the Chinese Academy of Sciences, {4. 10003., china 3. General Establishment of Space Science and Application, Chinese Academy of Sciences, {4. 100080, china Correspondence should be addressed to L Congmin 1. Center for Space Science and applied Research Chinese Academy of Sciences 100080 Beijing China 2. Graduate School of the Chinese Academy of Sciences 100039 Beijing China 3. General Establishment of Space Science and Application Chinese Academy of Sciences 100080 Beijing China

Considering the characteristic orbit of Shenzhou IV spacecraft and the advantages and disadvantages of several types of domestic orbit measurements, a scheme of IPOD is determined, which uses GPS, SLR and USB observation data jointly plus precise ionosphere corrections to GPS observation data. IPOD system and mathematic models of OD are introduced. The results of different joint OD are analyzed using true observation data, and show that radial accuracy is better than 2 m.

关键词： Shenzhou IV unmanned spacecraft integrated precise orbit determination GPS SLR USB.

A trust region algorithm for bilevel programing problems

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Chinese Science Bulletin 1998年第10期43卷 820-824页

作者： LIU Guoshan 1, HAN Jiye 2 and WANG Shouyang 3.1. Department of Mathematics, beijing Normal University, beijing 100875, china 2. Institute of {3. Mathematics, Chinese Academy of Sciences, beijing 100080, china 3. Institute of Systems Science, Chi Department of Mathematics Beijing Normal University Beijing China Institute of applied Mathematics Chinese Academy of Sciences Beijing China Institute of Systems Science Chinese Academy of Sciences Beijing China

A trust region algorithm is proposed for solving bilevel programming problems where the lower level programming problem is a strongly convex programming problem with linear constraints. This algorithm is based on a tr... 详细信息

关键词： bilevel programming problem trust region algorithm global convergence.

藏羊血红蛋白抗氧化肽模拟酶解筛选及活性验证

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食品与发酵工业 2024年

作者：刘鑫罗唐君韩丽娟桂林生侯生珍孙胜男赵成周 1.青海大学医学部药学系 2.青海大学农牧学院 3.青海大学藏医学院青海大学藏医学院青海大学农牧学院青海大学医学部药学系

Based on the theoretical basis of bioinformatics， this paper used the computer to simulate the enzymatic digestion of Tibetan sheep hemoglobin， using online activity scoring， activity prediction， and molecular docking techniques to screen their antioxidant peptides and verify their antioxidant properties by DPPH free radical and ABTS cationic radical scavenging rate experiments. The amino acid sequences of Tibetan sheep hemoglobin were screened using the Uni Prot database to evaluate its potential bioactivities， ExPASy Peptide Cutter online tool was applied to enzymatically digest the screened peptide chains， Peptide Ranker was applied to score the bioactivity prediction， and the online tools Innovagen， ToxinPred， iBitter-SCM， A11erTOP， and AdmetSAR for solubility， toxicity， bitterness， sensitization and ADMET， molecular docking using Keap1 receptor for activity prediction， and finally validation of the screened antioxidant peptides of Tibetan sheep hemoglobin using DPPH free radical and ABTS cationic radical scavenging rate assay. Results showed that five Tibetan sheep hemoglobin chains contained 20 amino acids， and a total of 258 peptides （4.5 peptides） were obtained by enzymatic digestion， and 110 peptides （194.peptides） with ratings greater than 0.5 were screened out by the bioactivity scoring system， and 18 peptides with good solubility， non-toxicity， non-bitterness， and non-allergenicity were obtained through the prediction of their activities， and the molecular docking was carried out for the 10 peptides that had a better intestinal absorption， and the top three peptides with molecular docking scores， KRM， FPL， and FL， were subjected to in vitro antioxidant activity assay， and the results showed that the free radical scavenging ability of FPL and KRM exceeded that of the positive control， with IC50of 0.125 0±0.012 3. 0.3.9 1±0.03. 4. 0.256 5±0.014.1，（0.3.4.6±0.04. 1） mg/mL， respectively， and the free radical scavenging ability of FL reached 88.90% and 94.4.%

关键词：藏羊血红蛋白虚拟酶解模拟筛选抗氧化肽分子对接

Prediction method for October 2003.solar storm

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Science china(Technological Sciences) 2006年第5期49卷 629-640页

作者： XIE Yanqiong1, 2, 3. WEI Fengsi1, FENG Xueshang1 & ZHONG Dingkun1, 2 1. State Key Laboratory of Space Weather, Center for Space Science and applied Research, Chinese Academy of Sciences, beijing 100080, china 2. Graduate School, Chinese Academy of Sciences, beijing 10003., china 3. Institute of meteorology, PLA University of Science and Technology, Nanjing 211101, china State Key Laboratory of Space Weather Center for Space Science applied Research Chinese Academy of Sciences Beijing 100080 China Graduate School Chinese Academy of Sciences Beijing 100039 China Institute of meteorology PLA University of Science Technology Nanjing 211101 China

Aiming at two intense shock events on October 28 and 29, 2003. this paper presents a two-step method, which combines synoptic analysis of space weather ——“observing” and quantitative prediction ——“palpating”, and then uses it to test predictions. In the first step of “observing”, on the basis of observations of the solar source surface magnetic field, interplanetary scintillation (IPS) and ACE spacecraft, we find that the propagation of the shocks is asymmetric relative to the normal direction of their solar sources, and the Earth is located near the direction of the fastest speed and the greatest energy of the shocks. As the two fast ejection shock events, the fast explosion of coronal mass of the extremely high temperature, the strong magnetic field, and the high speed background solar wind are also helpful to their rapid propagation. In the second step of “palpating”, we adopt a new membership function of the fast shock events for the ISF method. The predicted results show that for the onset time of the geomagnetic disturbance, the relative errors between the observational and the predicted results are 1.8% and 6.7%; and for the magnetic disturbance magnitude, the relative errors are 4.1% and 3.1%, re- spectively. Furthermore, the comparison among the predicted results of our two-step method with those of five other prevailing methods shows that the two-step method is advantageous. The results tell us that understanding the physical features of shock propagation thoroughly is of great importance in improving the prediction precision.

关键词： solar storm, interplanetary shock, interplanetary scintillation, two-step method, ISF method.