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Spatial and temporal variations in pH and total alkalinity at the beginning of the rainy season in the Changjiang Estuary, China

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Acta Oceanologica Sinica 2005年第5期 72-81页

作者： GAO Xuelu1, 2. 3. SONG Jinming1*, LI Xuegang1, YUAN Huamao1, LI Ning1, 3.. institute of Oceanology, chinese {2. of Sciences, Qingdao 2.6071, China2. South China Sea institute of Oceanology, chinese {2. of Sciences, Guangzhou 5103.1, China3. Graduate School of chinese {2. of Sciences, beijing 10003., China

The results of field observation carried out in May 2.03.were used to examine pH and total alkalinity behaviors in the Changjiang Estuary. It was showed that pH and total alkalinity took on clear spatial variations in values with the minima in the low salinity region. Like salinity, transect distributions of pH and total alkalinity (TA) in a downriver direction had a sharp gradient each. These gradients appeared in such a sequence that the TA gradient was earlier than salinity and pH gradients, and the salinity gradient was earlier than the pH gradient. These distribution characteristics seemed to be strongly influenced by the mixing process of freshwater and seawater, for both pH and total alkalinity had significant linear relationships with salinity and temperature. For pH, phytoplankton activities also had a significant impact upon its spatial distribution. During a period of 48 h, pH and total alkalinity changed within wide ranges for every layer of the two anchor stations, namely, Stas 13.and 2., which were located at the mixed water mass and seawater mass, respectively. For both Stas 13.and 2., pH and TA fluctuation of every layer could be very wide during a 4 h period. As a whole, the data of the two anchor stations showed that neither variations in salinity and temperature nor phytoplankton activities were the main factors strongly influencing the total alkalinity temporal variability on a small time scale. The data of Sta. 2. implied that both salinity variation and phytoplankton activities had a significant influence on pH temporal variability, but the same conclusion could not be drawn from the data of Sta. 13.

关键词： Changjiang Estuary pH total alkalinity spatial and temporal variations

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Development and improvement of mass flux convection parameterization scheme and its applications in the seasonal climate predication model

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chinese Science Bulletin 2003年第10期48卷 1006-1015页

作者： PING Fan, GAO Shouting & WANG Huijun institute of Atmosphere Physics, chinese {2. of Sciences, {3. 10002., China institute of Atmosphere Physics Chinese Academy of Sciences Beijing 100029 China

The features of Gregory cumulus parameterization scheme, which is used in British Weather Office, are researched and then this scheme is developed and improved according to the characteristics of area precipitation over China. Firstly, the influence of the large-scale convergence in lower tropopause upon cumulus convection is directly taken into account in a 揵ulk?cloud model. The organized entrainment and detrainment is considered in the model. Secondly, the initial mass flux is revised. Thirdly, the effects of subcooling water upon saturation vapour pressure are considered. Eventually, the drown-draft air is regulated. For several years, the numerical forecast of seasonal precipitation in China has been carried out by using the modified Gregory scheme. The result shows that the model with improved Gregory scheme well simulates the precipitation over China and the prediction result is good.

关键词：质量流量对流参数化季侯风应用大规模收敛对流层

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Oxygen Permeation Behaviors and Hardening Effect of Titanium Alloys at High Temperature

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Journal of Materials Science & Technology 2004年第6期20卷 719-723页

作者： Hongyan MA, Maocai WANG and Weitao WUState Key Laboratory for Corrosion and Protection, institute of Metai Research, chinese {2. of Sciences, Shenyang 110016, ChinaGraduate School of the chinese {2. of Sciences, beijing 10003., China Lab. for Corrosion and Protection Inst. of Metal Res. Chinese Acad. of Sci. Shenyang 110016 China Graduate Sch. Chinese Acad. of Sci. Beijing 100039 China

In order to improve the surface hardness and wear resistance of Ti and Ti alloy components, an oxygen permeation treatment (OPT) was developed. The oxygen permeation behaviors of three Ti alloys, TA2. TB5 and TC11, treated in air with O-P medium at high temperature have been studied. The results show that the 0-P treatment can significantly improve the surface hardness of Ti alloys. The oxidation mass-gain of β-Ti alloy (TB5) is much higher than α-Ti alloy (TA2. under the same condition, while α+β Ti alloy (TC11) is the lowest. All the Ti alloys treated at this condition produce two surface layers: the outer layer consists mainly of TiO2. as well as trace of other oxides, and the inner layer consists of a Ti-O interstitial solid solution formed by the diffusion of oxygen in α crystal lattice. Thick scales of β Ti alloy (TB5) are easily formed depending mainly on the poor solid solution content of oxygen, while deep solution layer can be formed since partial β phase has been transformed into α phase. The scales of α-β Ti alloy (TC11) are very thin and compact. Aluminum-rich zone, as well as deficient zone, is found in oxide layers. A crystallographic characterization of oxygen solution layer has been performed and evaluated by crystallographic lattice constant.

关键词： Microstructure Oxygen permeation Titanium Solid solution

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Structural studies of dicycloplatin,an antitumor supramolecule

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Science China chemistry 2010年第6期53卷 1346-1351页

作者： YANG XuQing1,2.JIN XiangLin2.SONG QinHua1,TANG KaLuo2.YANG ZhenYun1,ZHANG XiaoFeng1 & TANG YouQi2.1beijing Suo Pu Xing Da Pharmaceutical Co.Ltd.,beijing 100081,China 2.ollege of {2. and Molecular Engineering,Peking University,beijing 100871,China 1. beijing Suo Pu Xing Da Pharmaceutical Co. Ltd. Beijing 100081 China2. College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

The solubility and stability of platinum-based anticancer agents have a direct bearing on their activity and *** research has been conducted over the past decades in order to prepare drugs such as cisplatin and carboplatin with improved efficacy and reduced *** on the premise that supramolecular platinum agents may have superior physicochemical properties,we successfully designed a novel anticancer agent,dicycloplatin,which has proven to be active against a number of human *** crystal structure of dicycloplatin has been *** aqueous solution of dicycloplatin was also studied using electrospray ionization mass spectrometry (ESI-MS).Based on the experimental observations,a model of the structure in aqueous solution is proposed which explains both the higher solubility and higher stability of dicycloplatin compared with carboplatin.

关键词： dicycloplatin crystal structure supramolecule anticancer

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Nd isotope as the tracer of seawater evolution of early Miocene in the eastern Pacific Ocean

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chinese Science Bulletin 2003年第B06期48卷 106-110页

作者： LIU Jihua~(1,2.3., CHEN Lirong~1, WANG Yingxi~4 & HAN Jianxiu~5 1. institute of Oceanology, chinese Acadcmy of ences, Qingdao 2.6071. China 2. Key Lab of Marine Sedimentology and Environmental Geology, First institute of Oceanograpgy, State Oceanic Administration, Qingdao 2.6061. China 3. Graduate School, chinese academy of Sciences, beijing 10003.. China 4. Modern Analysis Center, Nanjing University. Nanjing 2.0093. China 5. Guangzhou Marine Investigation Bureau, Guangzhou 510760. China 1. institute of Oceanology Chinese Academy of Sciences 266071 Qingdao China 2. Key Lab of Marine Sedimentology and Environmental Geology First Institute of Oceanograpgy State Oceanic Administration 266061 Qingdao China 3. Graduate School Chinese Academy of Sciences 100039 Beijing China 4. Modern Analysis Center Nanjing University 210093 Nanjing China 5. Guangzhou Marine Investigation Bureau 510760 Guangzhou China

Fifty-six samples of nannofossil ooze were collected from Core PC5794 in the northern equatorial Pacific at 5 cm intervals. With the methods of mass spectrometer (VG3.4) and ICP, the Nd isotopic compositions (εNd(t)), Mn contents and Mg/Sr ratios of carbonate phase have been analyzed. CaCO3.contents of bulk sediments were obtained by dissolution of 0.5 mol/L HCl. Based on these data, the high-resolution εNd(t) profile of seawater in early Miocene with core depth(or time) have been established. The values of εNd(t) range from -6.2.to -2.97 and 4 fluctuation cycles existed during 2..06-2..02.Ma. 4 low εNd(t) values (about -6.4) correspond to high CaCO3.contents, which implicates that there were 4 cold epochs or 4 times of Antarctic Bottom Water activity. They occurred at the time of 2..06 Ma, 2..85 Ma,2..88 Ma and 2..2. Ma, respectively. High εNd(t) values correspond to the high Mn contents and high values of Mg/Sr ratio, which indicates the existence of 4 intense hydrothermal activity periods during 2..06-2. Ma, the durations of them are 4.05-2..98 Ma, 2..69-2..15 Ma, 2..74-2..3. Ma and 2..06-2..02.Ma, respectively.

关键词：同位素钕示踪原子海水演化中新世太平洋微化石分光计持续期海水样品

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Gene expression and molecular characterization of a thermostable trehalose phosphorylase from Thermoanaerobacter tengcongensis

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Science China(Life Sciences) 2005年第3期48卷 221-227页

作者： REN Yuanyuan 1,2., DAI Xiuyu 1 , ZHOU Jian 1 , LIU Jingfang 1 , PEI Huadong 1,2.& XIANG Hua 1 1. State Key Laboratory of Microbial Resources and Center for Molecular Microbiology, {3. of Microbiology, {2. {3. of Sciences, beijing 100080, China 2. Graduate School of {2. {3. of Sciences, beijing 10003., China 1. State Key Laboratory of Microbial Resources and Center for Molecular Microbiology Institute of Microbiology Chinese Academy of Sciences 100080 Beijing China 2. Graduate School of chinese academy of Sciences 100037 Beijing China

A gene encoding the trehalose phosphorylase (TreP), which reversibly catalyzes trehalose degradation and synthesis from α-glucose-1-phosphate (α-Glc-1-P) and glucose, was cloned from Thermoanaerobacter tengcongensis and successfully expressed in Escherichia coli. The overexpressed TreP, with a molecular mass of approximately 90 kDa, was determined by SDS-PAGE. It catalyzes trehalose synthesis and degradation optimally at 70℃ (for 3. min), with the optimum pHs at 6.0 and 7.0, respectively. It is highly thermostable, with a 77% residual ac- tivity after incubation at 50℃ for 7 h. Under the optimum reaction conditions, 50 μg crude en- zyme of the TreP is able to catalyze the synthesis of trehalose up to 11.6 mmol/L from 2. mmol/L α-Glc-1-P and 12. mmol/L glucose within 3. min, while only 1.5 mmol/L out of 2.0 mmol/L tre- halose is degraded within the same time period. Dot blotting revealed that the treP gene in T. tengcongensis was upregulated in response to salt stress but downregulated when trehalose was supplied. Both results indicate that the dominant function of the T. tengcongensis TreP is catalyzing trehalose synthesis but not degradation. Thus it might provide a novel route for indus- trial production of trehalose.

关键词： gene expression, Thermoanaerobacter tengcongensis, trehalose phosphorylase, dot blot.

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Pollution characteristics of atmospheric fine particles and their secondary components in the atmosphere of Shenzhen in summer and in winter

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Science China chemistry 2006年第5期49卷 466-474页

作者： NIU Yuwen1,2.HE Lingyan1,2.HU Min2.ZHANG Jing2.& ZHAO Yunliang2.1. Shenzhen Graduate School of Peking University,Shenzhen 518055,China 2. State Joint Key Laboratory of Environmental Simulation and Pollution Control,College of Environmental Sciences,Peking University,beijing 100871,China 1. Shenzhen Graduate School of Peking University Shenzhen 518055 China 2. State Joint Key Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences Peking University Beijing 100871 China

Two field measurements for atmospheric fine particles were conducted in Baoan district of Shenzhen during the summer and winter in 2.04. Totally 3. sets of 2. h samples were collected, and then the mass concentrations and chemical compositions were determined. The seasonal varia- tions and secondary pollution characteristics of fine particles during the sampling periods were dis-cussed with meteorological factors. The results show that seasonal variations of atmospheric particles are significant in Shenzhen. The average mass concentrations of PM2.5 and PM10 in summer were 3. μg·m-3.and 57 μg·m-3. respectively, and those in winter were 99 μg·m-3.and 13. μg·m-3. respec-tively. The concentrations of both PM2.5 and PM10 in winter increased 184% and 13.%, respectively, compared to those in summer. PM2.5 accounted for 61% and 75% of PM10 in summer and in winter, respectively, indicating severe fine particle pollution in Shenzhen. During the summer and winter sampling periods, the mean OC/EC ratios were 3.4 and 1.6, respectively. The estimated secondary organic carbon (SOC) averagely accounted for 56% and 6% of the total OC in summer and in winter, respectively, which implies a major contribution of SOC to OC in summer. During the continuous high temperature period in summer, both the concentrations and fractions of secondary aerosol compo-nents in PM2.5 were highly elevated, suggesting severe secondary pollution again. The prevailing wind was from South China Sea in summer, and the air quality was good. The prevailing wind in winter was from China's Mainland to the north, and the polluted air mass led to poor air quality.

关键词： PM2.5, mass concentration, secondary pollution, seasonal variation, Shenzhen.

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On the rigidity of solitary waves for the focusing mass-critical NLS in dimensions d≥2

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Science China Mathematics 2012年第1期55卷 385-434页

作者： LI Dong1 & ZHANG XiaoYi2.1Department of Mathematics,University of British Columbia,Vancouver,BC,V6T 1Z3.Canada 2.0} of Applied Mathematics,academy of Mathematics and System Sciences,{2. 100190,China 1. Department of Mathematics University of British Columbia Vancouver BC V6T 1Z3 Canada2. Institute of Applied Mathematics Academy of Mathematics and System Sciences Beijing 100190 China

For the focusing mass-critical NLS iut + △u =-|u| 4/d u,it is conjectured that the only global nonscattering solution with ground state mass must be a solitary wave up to symmetries of the *** this paper,we settle the conjecture for Hx1 initial data in dimensions d = 2.3.with spherical symmetry and d 4 with certain splitting-spherically symmetric initial data.

关键词： Schrdinger equation mass critical rigidity

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A lumped mass finite element method for vibration analysis of elastic plate-plate structures

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Science China Mathematics 2010年第6期53卷 1453-1474页

作者： LAI JunJiang1,HUANG JianGuo2.3.& SHI ZhongCi4 1Department of Mathematics,Minjiang University,Fuzhou 3.0108,China 2.epartment of Mathematics,Shanghai Jiao Tong University,Shanghai 2.02.0,China 3.ivision of Computational Science,E-institute of Shanghai Universities,Shanghai Normal University,Shanghai 2.02.4,China 4institute of Computational Mathematics,{2. of Mathematics and Systems Science,{3. {2. of Sciences,beijing 100190,China 1. Department of Mathematics Minjiang University Fuzhou 350108 China2. Department of Mathematics Shanghai Jiao Tong University Shanghai 200240 China3. Division of Computational Science E-Institute of Shanghai Universities Shanghai Normal University Shanghai 200234 China4. Institute of Computational Mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China

The fully discrete lumped mass finite element method is proposed for vibration analysis of elastic plate-plate *** the space directions,the longitudinal displacements on plates are discretized by conforming linear elements,and the transverse displacements are discretized by the Morley *** means of the second order central difference for discretizing the time derivative and the technique of lumped masses,a fully discrete lumped mass finite element method is obtained,and two approaches to choosing the initial functions are also *** error analysis for the method in the energy norm is established,and some numerical examples are included to validate the theoretical analysis.

关键词： vibration analysis plate-plate structures lumped mass FEM error analysis

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Contradiction between strong lensing statistics and a feedback solution to the cusp/core problem

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Research in Astronomy and Astrophysics 2010年第12期10卷 1215-1222页

作者： Stacy McGaugh Department of Astronomy University of MarylandCollege Park

Standard cosmology has many successes on large scales, but faces some fundamental difficulties on small, galactic scales. One such difficulty is the cusp/core problem. High resolution observations of the rotation curves for dark matter domi- nated low surface brightness （LSB） galaxies imply that galactic dark matter halos have a density profile with a flat central core, whereas N-body structure formation simula- tions predict a divergent （cuspy） density profile at the center. It has been proposed that this problem can be resolved by stellar feedback driving turbulent gas motion that erases the initial cusp. However, strong gravitational lensing prefers a cuspy density profile for galactic halos. In this paper, we use the most recent high resolution observations of the rotation curves of LSB galaxies to fit the core size as a function of halo mass, and compare the resultant lensing probability to the observational results for the well defined combined sample of the Cosmic Lens All-Sky Survey （CLASS） and Jodrell Bank/Very Large Array Astrometric Survey （JVAS）. The lensing probabilities based on such density profiles are too low to match the observed lensing in CLASS/JVAS. High baryon densities in the galaxies that dominate the lensing statis- tics can reconcile this discrepancy, but only if they steepen the mass profile rather than making it more shallow. This places contradictory demands upon the effects of baryons on the central mass profiles of galaxies.

关键词： cosmology: theory -- dark matter -- galaxies: halos -- gravitationallensing: strong

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