Li X.-E.,Lanzhou Commercial College
Advanced Materials Research | Year: 2011
Nanosized CoFe2O4 powders of 12nm particle size were directly prepared by solution SHS method at room temperature. The overall process involves three steps: formation of homogeneous sol; formatiom of dried gel; and combustion of the dried gel. Experiments revealed that CoFe 2O4 dried gel derived from citrate and nitrate sol exhibited self-propagation combustion(SHS) at room temperature once it was ignited in air. After self-propagating combustion, the gel directly transforms into nanosized CoFe2O4 particles. The self-propagating combustion was considered as a heat-induced exothermic oxidation-reduction reaction between nitrate ions and carboxyl group. Differential thermal analysis-thermogravimetry (DTA-TG) was used to study the decomposition of the precursor. The structure of the nanosized CoFe2O4 powders was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). © (2011) Trans Tech Publications, Switzerland.
Meiling A.,China Institute of Technology |
Yangui D.,Lanzhou Commercial College
Advanced Materials Research | Year: 2013
The pipe thread forming machine was innovatively designed in the article, using Pro/E as a design tool, we built the structural model of the pipe thread forming machine and performed interference detection and movement simulation for it, on the basis of this, we made a physical prototype. And our experiment showed the complete machine has the characteristics of high efficiency, tight structure, small volume and light weight, and it was easy to move. © (2013) Trans Tech Publications, Switzerland.
Wang J.N.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research |
Wan Y.K.,Lanzhou commercial college |
Dong S.C.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research
Applied Mechanics and Materials | Year: 2014
After the reform of China's tax system, in the case of an established local fiscal revenue, due to the differences in local infrastructure, under the influence of different investment and tourism-oriented input and output levels, the crowding-out effect of tourism industry varies. This paper validates this inference, and concludes that the crowding-out effect of tourism over other industries is small in areas with larger tourism scale such as Beijing which is either historical and cultural city, or political and economic center, with an emphasize on tertiary industry development; while the crowding-out effect of tourism over other industries is the largest in areas with smaller travel size, which is either landlocked but rich in tourism resources, or lacks of tourism resources but plays the key position of foreign trade. Regions of medium tourism scale are mostly dominated by secondary industry. Although the investment in tourism has increased in recent years, the propensity of government and private investment is firstly towards local leading industries, thus the production factors needed for development of the tourism industry have been occupied by local leading industries. And finally, the corresponding development strategies have been proposed for tourism industry with different crowding-out effect. © (2014) Trans Tech Publications, Switzerland.
Mi H.,Lanzhou Commercial College
2011 3rd International Workshop on Intelligent Systems and Applications, ISA 2011 - Proceedings | Year: 2011
The density at a data point is defined based on kernel function. And we introduce weight to refine rough k-means algorithm. Then we construct the formula for calculating local outlier score based on the clusters generated by the refined rough k-means algorithm. We use a synthetic data set and a real-world data set to verify that the new technique for local outliers detection is not only accurate but also efficient. © 2011 IEEE.
Jiping S.,Lanzhou Commercial College
International Journal of Physical Sciences | Year: 2011
This study evaluated the anti-oxidant potential of salvia extracts in enhance training rats. The salvia extracts were administered to endurance exercise rats by gavage for 28 days. In addition to antioxidant enzymes activities evaluation, several functional enzymes assays (e.g., LDH, CK and CHE activities) were employed to examine the effects of salvia extracts on the oxidative injury in endurance exercise rats. The results from this study demonstrated that salvia extracts treatment significantly reduced lipid peroxidation, LDH, CK activities levels, enhanced antioxidant enzymes, and CHE activities in the skeletal muscle of endurance exercise rats. Taken together, the salvia extracts may decrease oxidative injury induced by endurance training and display strong antifatigue effect. © 2011 Academic Journals.
Shen J.,Lanzhou University |
Yang Z.,Lanzhou Commercial College |
Liu X.,Lanzhou University |
Shi Y.,Lanzhou University |
And 3 more authors.
Plasma Science and Technology | Year: 2015
In this paper, an experimental study of collinear geometry double-pulse femtosecond LIBS was performed on a Ni sample in ambient air in an effort to clarify the contributing processes responsible for the signal enhancement observed in comparison with the single-pulse case. Double-pulse LIBS spectra show a very clear enhancement when an optimum inter-pulse delay was used. The influences of the inter-pulse delay between two pulses on the LIBS signal intensity, electron temperature and density were investigated. It is most remarkable that the evolutions of signal enhancement and electron temperature versus the inter-pulse delay showed the same behavior and revealed two main regimes of interaction. These results provide additional insight into the possible emission enhancement mechanisms in the double pulse configuration.
Li X.,Lanzhou Commercial College |
Li Y.,Lanzhou Commercial College
ICCASM 2010 - 2010 International Conference on Computer Application and System Modeling, Proceedings | Year: 2010
The study of syllable duration is the basis of prosodic models and speech synthesis systems. This article does the statistical analysis on the syllable duration of Lhasa dialect from three levels: the vocabulary, rhyme style, discourses of news. The results show that: the distribution of vocabulary duration in male and female voices is concentrated; as the vocabulary duration increases, the average duration of syllable gradually becomes smaller, the rate of decline reduces; the form of love songs, verse with motto category is fixed and they have more obvious rhythm, and the difference between the average duration of syllable in different sentences is significant; the average duration of syllable in News Corpus is smallest, followed by verses, the vocabulary duration is largest; in the three levels, the average duration of syllable in female voices is larger than the average male duration. The statistical analysis on syllable duration laid a good foundation for the Tibetan language model and prosodic model. © 2010 IEEE.
Zhang Y.,Lanzhou Commercial College |
Zhao S.,Lanzhou Commercial College
Proceedings - 2011 19th International Conference on Geoinformatics, Geoinformatics 2011 | Year: 2011
The paper employs Stochastic Frontier Approach to analyze the allocation efficiency of R&D resources in 31 countries by Frontier 4.1 software. It reveals that U.S.A, Japan, Germany and Britain are the big power of R&D input and output, yet their R&D efficiency is not so high; Switzland, Sweden, South Korea, Canada and Australian have the highest R&D efficiency, and the R&D efficiency of China, India, Brazil and South Africa are relatively high. With the global R&D activities transferring to the region of lower cost and high efficiency, R&D Emerging Economies are arising. According to output elasticity of R&D resources, human labor is much stronger than that of funds. Furthermore, the output elasticity of human labor in high-income countries is stronger than that of middle-income countries, but the output elasticity of funds in high-income countries is weaker than that of middle-income countries. © 2011 IEEE.
Wu J.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute |
Wu J.,Justus Liebig University |
Ding Y.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute |
Ye B.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute |
And 3 more authors.
Environmental Earth Sciences | Year: 2010
An intensive investigation of the spatial and temporal variations of δD and δ18O in precipitation was conducted during 2002-2004 in six sites in the Heihe River Basin, Northwestern China. The δD and δ18O values for 301 precipitation samples ranged from +59 to -254 and +6.5 to -33.4‰, respectively. The relationship between δD and δ18O defines a well-constrained line given by δD = 7.8δ18O + 7.63, which is nearly identical to the meteoric water line in the Northern China. This wide range indicates that stable isotopes in precipitation were primarily controlled by different condensation mechanisms as a function of air temperature and varying sources of moisture. The results of backward trajectory of each precipitation day at Xishui show that the moisture of the precipitation in cold season (October-March) mainly originated from the west while the moisture source was more complicated in warm season (April-September). The simulation of seasonal δ18O variation shows that the stable isotope composition of precipitation tended to a clear sine-wave seasonal variation. The spatial variation of δ18O shows that the weighted average δ18O values decreases with the increasing altitude of sampling sites. The great difference of air temperature which led to the differences of condensation mechanisms and local recycled continental moisture may have influence upon the isotopic composition of rain events in different sites. © 2010 Springer-Verlag.
Gao X.,Chinese Academy of Sciences |
Gao X.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute |
Ye B.S.,Chinese Academy of Sciences |
Ye B.S.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute |
And 4 more authors.
Science China Earth Sciences | Year: 2010
Using monthly precipitation and temperature data from national meteorological stations, 90 m resolution DEM and a digital vector map of modern glaciers from the Chinese Glacier Inventory, the glacier mass balance and glacier runoff in the Tarim River Basin (TRB), China, were estimated based on a monthly degree-day model for 1961-2006. The results suggest that the modified monthly degree-day model can simulate the long-term changes in glacier mass balance and glacier runoff, which have been confirmed by short-term observation data and other results in literatures. The characteristics and trends of mass balance and glacier runoff variation were analyzed. It was found that the mean annual glacier mass balance during 1961-2006 was -139.2 mm per year and the cumulative mass balance over the 46 year period was -6.4 m in the TRB. The glacier mass balance displayed a clear decreasing trend over the entire TRB during 1961-2006. The average annual glacier runoff in the TRB was 144.16×108 m3 for 1961-2006. The results also show that glacier runoff has increased in the last 46 years, especially since the 1990s with 85.7% of the increased river flow being derived from the increased glacier runoff caused by loss of ice mass. Over the entire TRB, glacier runoff accounts for 41.5% of the total river flow during 1961-2006. The impact of glacier runoff on river flow has increased in the TRB as a result of glacier shrinkage. © Science China Press and Springer-Verlag Berlin Heidelberg 2010.