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Chinese Journal of Chemistry 2004年第7期22卷 714-718,615页

作者：魏琴吴丹杜斌张慧欧庆瑜lanzhou Institute of Chemical Physics Chinese Academy of sciences lanzhou Gansu 730000 china school of Chemistry & Chemical Engineering Jinan University Jinan Shandong 250022 China Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou Gansu 730000 China school of Chemistry & Chemical Engineering Jinan University Jinan Shandong 250022 China

The application of 5'-nitrosalicylfluorone (5'-NSF)-molybdenum(VI) complex as a spectroscopic probe was studied. In the buffer medium of HOAc-NaOAc at 3.45 and in the presence of PVA 124 microemulsion, 5'-NSF-Mo(VI) complex combines protein rapidly to form a stable compound, leading to an absorbance decrease at 525 nm of 5'-NSF-Mo(VI) complex. According to this change, microdetermination of protein has been described. Bovine serum albumin (BSA) could be determined in the linear range of 0—16 g昺L-1 with the detection limit of 11 ngmL-1. Many amino acid and metal ions studied do not interfere with the assay. The method possesses high sensitivity as well as high selectivity. It can be used to determine protein in human urine and milk powder successfully. The relative standard deviations are in all instances less than 4.7%, and the recoveries are between 97.6% and 106.0%. Moreover, the binding number of BSA with the complex, which is determined by using molar ratio, Rosenthanl graphic and slope ratio methods, is in good agreement with each other.

关键词： protein spectrophotometry 5'-NSF-Mo(VI) complex microemulsion

The time and energy signals,counter plateau,energy resolution and gas gains performances of a new kind of micro-pattern gaseous detector-Micromegas

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science china(Technological sciences) 2008年第12期51卷 2208-2212页

作者： ZHANG XiaoDong1,2,YANG HeRun1,XU HuShan2,DUAN LiMin2,HU BiTao1,LI ChunYan2 & LI ZuYu2 1 school of Nuclear science and Technology,lanzhou university,lanzhou 730000,china 2 Institute of Modern Physics,Chinese Academy of sciences,lanzhou 730000,china school of Nuclear science and Technology Lanzhou University Lanzhou China Institute of Modern Physics Chinese Academy of Sciences Lanzhou China

In present paper,a new Micromegas detector is developed,and its time and energy signals are obtained in the figure *** rising time of fast time signal is less than 2 ns due to the very fast collection of avalanche electrons,and the rising time of the energy pulse is about 100 ns,which is corresponding to the total collecting time of the electrons and ions in the avalanche *** counter plateau,energy resolution and the gas gains of the detector have been compared with other groups' experimental results and the Garfield simulation result.

关键词： micro-mesh gaseous structure time and energy signals energy resolution gas gain counter plateau

THE SAND WEDGE AND MIRABILITE OFTHE LAST ICE AGE AND THEIR PALEOCLIMATICSIGNIFICANCE IN HEXI CORRIDOR

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Chinese Geographical science 2001年第1期11卷 80-86页

作者： HU Gang, WANG Nai-ang (school of Resources and Environment, lanzhou university, lanzhou 730000, P. R. china Cold and Arid Regrons Environment and Engineering Research Institute, the Chinese Academy of Scienes, lanzhou 730000, P. R. china) school of Resources and Environment Lanzhou University Lanzhou P. R. China Cold and Arid Regrons Environment and Engineering Research Institute the Chinese Academy of Sciences Lanzhou P. R. China

The sand wedges in Hexi Corridor occur in the alluvial gravel stratum of bajada and high terraces. The 14C ages of eolian sand in sand wedges prove that they formed during the Last Ice Age, with the mean annual air temperature about ? 5.6°C. The common 14C and AMS 14C dating ages of terrestrial branch relicts in Huahai clay-mirabilite interlayer are (11 600 ± 280) a B. P. and (1118 ± 54) a B. P. respectively, proving that the mirabilite formed at the cold episode of the Last Glacial Maximum(LGM) and Younger Dryers(YD) in Huahai Lake. It is pointed out that the mean annual air temperature in Hexi Corridor during LGM was about ?3°C – ?7°C, 11°C – 15°C lower than that of present, and that during YD was about 0°C – 2°C, 6°C – 8°C lower than at present. This decreasing temperature values are generally coincident with those inferred by pollen, sand wedge and ice core in the northern china, and also with the research on temperature-falling amplitude of middle and high latitude on the Northern Hemisphere recently.

关键词： sand wedge Last Ice Age Hexi Corridor paleoclimate

On Rhetorical Skills in English Newspaper Advertisement

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兰州大学学报（社会科学版） 2000年第S1期28卷 242-249页

作者： Du Juan 1 Lu Jun 2 (1 school of Foreign Languages, lanzhou university, lanzhou, 730000, china 2 Blue Star Memtec Water Treatment Technology Co., Ltd. lanzhou, 730060, china)

Through a careful analysis and comparison of advertisements presented in English newspapers and magazines the paper makes an exploration of the rhetorical skills and stylistic features commonly used in English adverti... 详细信息

关键词： advertisement features figures of speech styles

Enthalpy and entropy interaction parameters of sodium chloride with some monosaccharides in water

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science china Chemistry 2004年第1期47卷 59-66页

作者： ZHUO Kelei, WANG Jianji, BAI Guangyue, YAN Haike & WANG Hangingschool of Chemistry and Environmental science, Henan Normal university, Xinxiang 453002, china Institute of Chemistry, Chinese Academy of sciences, Beijing 100080, china lanzhou Institute of Chemical Physics, Chinese Academy of sciences, lanzhou 730000, china school of Chemistry and Environmental science Henan Normal University Xinxiang China Institute of Chemistry Chinese Academy of Sciences Beijing China lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou China

Dilution enthalpies of sodium chloride and some monosaccharides (glucose, galactose, xylose, arabinose, and fructose) in water and mixing enthalpies of aqueous sodium chloride and these monosaccharide solutions were measured by using an improved precision semimicro-titration calorimeter. Transfer enthalpies of sodium chloride from water to aqueous saccharide solutions were evaluated as well as enthalpy interaction parameters of sodium chloride with these monosaccharides in water. Combined with Gibbs energy interaction parameters, entropy interaction parameters were also obtained. The results show that interactions of the saccharides with sodium chloride depend on the stereochemistry of saccharide molecules. These interaction parameters can identify stereochemical structure of saccharide molecules. Keywords sodium chloride - monosaccharide - enthalpy interaction parameter - entropy interaction parameter - calorimetry

关键词： sodium chloride, monosaccharide, enthalpy interaction parameter, entropy interaction parameter, calorimetry.

Impacts of permafrost changes on alpine ecosystem in Qinghai-Tibet Plateau

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science china Earth sciences 2006年第11期49卷 1156-1169页

作者： WANG Genxu1,3 , LI Yuanshou2 , WU Qingbai2 & WANG Yibo3 1. Institute of Mountain Hazards and Environment, Chinese Academy of sciences, Chengdu 610041, china 2. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of sciences, lanzhou 730000, china 3. Resource and Environment school, lanzhou university, lanzhou 730000, china Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu China Resource and Environment school Lanzhou University Lanzhou China Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China

Alpine cold ecosystem with permafrost environment is quite sensitive to climatic changes and the changes in permafrost can significantly affect the alpine ecosystem. The vegetation coverage, grassland biomass and soil nutrient and texture are selected to indicate the regime of alpine cold ecosystems in the Qinghai-Tibet Plateau. The interactions between alpine ecosystem and permafrost were investigated with the depth of active layer, permafrost thickness and mean annual ground temperature (MAGTs). Based on the statistics model of GPTR for MAGTs and annual air temperatures, an analysis method was developed to analyze the impacts of permafrost changes on the alpine ecosystems. Under the climate change and human engineering activities, the permafrost change and its impacts on alpine ecosystems in the permafrost region between the Kunlun Mountains and the Tanggula Range of Qinghai-Tibet Plateau are studied in this paper. The results showed that the per- mafrost changes have a different influence on different alpine ecosystems. With the increase in the thickness of active layer, the vegetation cover and biomass of the alpine cold meadow exhibit a significant conic reduction, the soil organic matter content of the alpine cold meadow ecosystem shows an exponential decrease, and the surface soil materials become coarse and gravelly. The alpine cold steppe ecosystem, however, seems to have a relatively weak relation to the permafrost environment. Those relationships resulted in the fact that the distribution area of alpine cold meadow decreased by 7.98% and alpine cold swamp decreased by 28.11% under the permafrost environment degradation during recent 15 years. In the future 50 years the alpine cold meadow ecosystems in different geomorphologic units may have different responses to the changes of the permafrost under different climate warming conditions, among them the alpine cold meadow and swamp ecosystem located in the low mountain and plateau area will have a relatively

关键词： permafrost environment, alpine cold ecosystem, statistics relationship, climate change, impacts, Qinghai-Tibet Plateau.

Impact of land-use change on hydrological processes in the Maying River basin, china

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science china Earth sciences 2006年第10期49卷 1098-1110页

作者： WANG Genxu1,3, ZHANG Yu2, LIU Guimin2 & CHEN Lin3 1. Institute of Mountain Hazards and Environment, Chinese Academy of sciences, Chengdu 610041, china 2. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of sciences, lanzhou 730000, china 3. Resource and Environment school, lanzhou university, lanzhou 730000, china Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu China Resource and Environment school Lanzhou University Lanzhou China Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China

Since the 1960s, dramatic changes have taken place in land-use patterns characterized by the persistent expansion of cultivated land and a continuous decrease in natural woodland and grassland in the arid inland river basins of china. It is very important to assess the effects of such land-use changes on the hydrological processes so vital for water resource management and sustainable development on the catchment scale. The Maying River catchment, a typical arid inland watershed located in the middle of the Hexi Corridor in northwest china, was the site chosen to investigate the hydrological responses to land-use changes. The annual runoff, base flow, maximum peak flow, and typical seasonal runoff in both spring and autumn flood periods were selected as the variables in the hydrological processes. Statistical-trend analysis and curvilinear regression were utilized to detect the trends in hydrological variables while eliminating the climatic influence. The relationship between cultivated land-use and hydrological variables was analyzed based on four periods of land-use variation data collected since 1965. A runoff model was established composed of two factors, i.e., cultivated land use and precipitation. The impact of land use changes, especially in the large ar- eas of upstream woodland and grassland turned into cultivated lands since 1967, has resulted in a mean annual runoff decrease of 28.12%, a base flow decline of 35.32%, a drop in the maximum peak discharge of 35.77%, and mean discharge decreases in spring and autumn of 36.05% and 24.87% respectively, of which the contribution of cultivated land expansion to the influence of annual runoff amounts to 77%-80%, with the contribution to the influence of spring discharge being 73%-81%, and that to the influence of base flow reaching 62%-65%. Thus, a rational regulation policy of land use patterns is vitally important to the sustainable use of water resources and the proper development of the entire catchment.

关键词： land-use change, arid inland river catchment, hydrological process, impact, Maying River.

Guided wave propagation in multilayered piezoelectric structures

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science china(Physics,Mechanics & Astronomy) 2009年第7期52卷 1094-1104页

作者： GUO YongQiang1, CHEN WeiQiu2,3 & ZHANG YongLiang4 1 Key Laboratory of Mechanics on Disaster and Environment in Western china, Ministry of Education, and school of Civil Engineering and Mechanics, lanzhou university, lanzhou 730000, china 2 Key Laboratory of Soft Soils and Geoenvironmental Engineering, Ministry of Education, and Department of Civil Engineering, Zhejiang university, Hangzhou 310058, china 3 Department of Engineering Mechanics, Zhejiang university, Hangzhou 310027, china 4 school of Civil Engineering, lanzhou Jiaotong university, lanzhou 730070, china Key Laboratory of Mechanics on Disaster and Environment in Western china Ministry of Education and School of Civil Engineering and Mechanics Lanzhou University Lanzhou China Key Laboratory of Soft Soils and Geoenvironmental Engineering Ministry of Education and Department of Civil Engineering Zhejiang University Hangzhou China Department of Engineering Mechanics Zhejiang University Hangzhou China school of Civil Engineering Lanzhou Jiaotong University Lanzhou China

A general formulation of the method of the reverberation-ray matrix (MRRM) based on the state space formalism and plane wave expansion technique is presented for the analysis of guided waves in multilayered piezoelectric structures. Each layer of the structure is made of an arbitrarily anisotropic piezoelectric material. Since the state equation of each layer is derived from the three-dimensional theory of linear piezoelectricity, all wave modes are included in the formulation. Within the framework of the MRRM, the phase relation is properly established by excluding exponentially growing functions, while the scattering relation is also appropriately set up by avoiding matrix inversion operation. Consequently, the present MRRM is unconditionally numerically stable and free from computational limitations to the total number of layers, the thickness of individual layers, and the frequency range. Numerical examples are given to illustrate the good performance of the proposed formulation for the analysis of the dispersion characteristic of waves in layered piezoelectric structures.

关键词： multilayered piezoelectric structures the method of reverberation-ray matrix guided waves dispersion characteristic

Dynamic learning rates algorithm for BPNN to forecast time series of dam security

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Progress in Natural science:Materials International 2007年第12期17卷 1527-1530页

作者： Hu Daiping1, Wu Ruiming1, Lei Aizhong1 and Wang Qi2(1. Antai College of Economics & Management, Shanghai Jiaotong university, Shanghai 200052, china 2. Graduate school, lanzhou university, lanzhou 730000, china) Antai College of Economics and Management Shanghai Jiaotong University Shanghai 200052 China Graduate school Lanzhou University Lanzhou 730000 China

Time series data of dam security have a large number of observed values and should be forecasted accurately in time. Neural networks have the powerful approach ablilities of arbitrary functions and have been broadly utilized in many domains. In this paper, a dynamic learning rate training algorithm of back-propagation neural networks for time series forecasting is proposed and the networks with this algorithm are built to forecast time series of dam security. The application results demonostrate the efficiency of modelling and the effictiveness of forecasting.

关键词： neural network dynamic learning rate forecasting dam security.

Wear Behavior of Cu Matrix Composites Reinforced with Mixture of Carbon and Carbon Nanotubes

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Journal of Wuhan university of Technology(Materials science) 2009年第2期24卷 254-257页

作者：姜金龙 school of science Lanzhou University of Technology State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences

In order to improve wear resistance and decrease the cost, carbon and carbon nanotubes reinforced copper matrix composites were fabricated by the power metallurgy method. The effects of carbon （carbon and carbon nanotubes） volume fraction and applied load on the friction coefficient and wear rate under dry sliding of the composites were investigated at room temperature. By scanning electron microscopy （SEM）, the worn surfaces and debris were observed, and wear mechanism was also analyzed and discussed. The experimental wear process consists of the run-in, steady wear and severe wear process with the increasing of sliding distance. Both the friction coefficient and wear rate of the composites first decrease and then increase with the increasing of carbon volume fraction. The minimum friction coefficient and wear rate are obtained when carbon is 4.0vo1%. The wear mechanisms of the composites change from the adhesive wear and delamination wear to abrasive wear with the increasing of carbon volume fraction.

关键词： C/Cu matrix composite power metallurgy wear behavior