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Effects of a new nitrification inhibitor 3,4-dimethylpyrazole phosphate(DMPP) on nitrate and potassium leaching in two soils

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Journal of Environmental sciences 2007年第7期19卷 841-847页

作者： WU Shao-fu WU Liang-huan SHI Qi-wei WANG Zhong-qiang CHEN Xian-you LI Yong-shan Ministry of Education Key Lab of Environmental Remediation and Ecosystem Health College of Environmental and Resource Sciences Zhefiang University Hangzhou 310029 China. Agricultural Extension Station of Shaoxing City Shaoxing 312000 China Agricultural Extension Station of Shaoxing Country Shaoxing 312000 China

In this study, soil column was used to study the new nitrification inhibitor 3,4-dimethylpyrazole phosphate （DMPP） on nitrate （NO3^-- N） and potassium （K） leaching in the sandy loam soil and clay loam soil. The results showed that DMPP with ammonium sulphate nitrate （ASN）（（NH4）2SO4 and NHaNO3） or urea could reduce NO3^--N leaching significantly, whereas ammonium （NH4^＋-N） leaching increased slightly. In case of total N （NO3^--N＋NH4^＋-N）, losses by leaching during the experimental period （40 d） were 37.93 mg （urea）, 31.61 mg （urea＋DMPP）, 108.10 mg （ASN）, 60.70 mg （ASN＋DMPP） in the sandy loam soil, and 30.54 mg （urea）, 21.05 mg （urea＋DMPP）, 37.86 mg （ASN）, 31.09 mg （ASN＋DMPP） in the clay loam soil, respectively. DMPP-amended soil led to the maintenance of relatively high levels of NH4^＋ -N and low levels of NO3^--N in soil, and nitrification was slower. DMPP supplementation also resulted in less potassium leached, but the difference was not significant except the treatment of ASN and ASN＋DMPP in the sandy loam soil. Above results indicate that DMPP is a good nitrification inhibitor, the efficiency of DMPP seems better in the sandy loam soil than in the clay loam soil and lasts longer.

关键词： 3,4-dimethylpyrazole phosphate (DMPP) nitrate potassium leaching sandy loam soil clay loam soil

Optical and electrical properties of N-doped ZnO and fabrication of thin-film transistors

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Journal of Semiconductors 2009年第3期30卷 15-18页

作者：朱夏明吴惠桢王双江张莹莹蔡春锋斯剑霄原子健杜晓阳董树荣 Department of Physics Zhejiang University State Key Laboratory of Modern Optical Instrumentations Zhejiang University ESD Laboratory Institute of Microelectronics and PhotoelectronicsZhejiang University

Using NH3 as nitrogen source gas, N-doped ZnO （ZnO：N） thin films in c-axis orientation were deposited on glass substrates by radio frequency magnetron sputtering at room temperature. The ZnO：N thin films display significant increase of resistivity and decrease of photoluminescence intensity. As-grown ZnO：N material was used as active channel layer and Si3N4 was used as gate insulator to fabricate thin-film transistor. The fabricated devices on glasses demonstrate typical field effect transistor characteristics.

关键词： ZnO N-doping resistivity photoluminescence thin film transistors

Design and fabrication of an embedded wire-grid nanograting

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Journal of Semiconductors 2009年第1期30卷 34-38页

作者：周立兵朱伟 Zhejiang Yangtze Delta Region Institute of Tsinghua University

An embedded wire-grid nanograting was designed and fabricated for using as a broadband polarizing beam splitter to reflect s-polarized light and transmit p-polarized light. A protected cladding layer of the same material as the grating＇s was deposited on the ridge, whereas the wire-grid is deposited in the grating trenches, which makes it more firm during application. High polarization extinction ratios of above 40 and 20 dB for transmission and reflection, respectively, with a broad wavelength range for the whole optical communication bandwidth （850 -1700 nm） and a wide angular tolerance （〉 ±20 °） are obtained by optimization of the designed structures, and the grating period is 200 nm.

关键词： polarizing beam splitter wire-grid nanograting extinction ratio

Structural Analysis and Magnetic Properties of Gd-Doped Li-Ni Ferrites Prepared Using Rheological Phase Reaction Method

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Journal of Rare Earths 2007年第1期25卷 79-83页

作者：蒋静李良超徐烽 Department of Chemistry Institute of Physical Chemistry Zhejiang Normal UniversityJinhua 321004 China

A series of Gd-doped Li-Ni ferrites with the formula of LiNi0.5GdxFe2-xO4 where x = 0.00 - 0.08 in steps of 0.02, were prepared by thermolysis of oxalate precursors obtained by rheological phase reaction. The structure, morphology, and the magnetic properties of the samples were characterized by powder X-ray diffraction （XRD）, atomic force microscopy （AFM） and a vibrating sample magnetometer （VSM）. A single spinel phase was obtained in the range of x = 0.00 - 0.04. The lattice parameters of the Gd-doped samples were larger than that of pure Li-Ni ferrite, and increased in the range of 0.00 ≤ x ≤ 0.04, then decreased up to x = 0.08, because of the formation of the secondary phase （Gd- FeO3）. All samples were spheric particles with an average size of about 100 nm, but agglomerated to some extent. The hysteresis loops indicated that the saturation magnetization decreased gradually with increasing Gd content, while the variation of coercivity was related to the microstructure of the Gd-doped samples.

关键词： rheological phase Li-Ni ferrite Gd-doped structure magnetic properties rare earths

GIS-based logistic regression method for landslide susceptibility mapping in regional scale

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Journal of Zhejiang University-science A(Applied Physics & Engineering) 2006年第12期7卷 2007-2017页

作者： ZHU Lei HUANG Jing-feng Department of Natural science. Zhejiang University Hangzhou 310029 China Institute of Agricultural Remote Sensing and Information Technology Application Zhejiang University Hangzhou 310029 China Shandong Agriculture Administrators College Jinan 250100 China

Landslide susceptibility map is one of the study fields portraying the spatial distribution of future slope failure sus- ceptibility. This paper deals with past methods for producing landslide susceptibility map and divides these methods into 3 types. The logistic linear regression approach is further elaborated on by crosstabs method, which is used to analyze the relationship between the categorical or binary response variable and one or more continuous or categorical or binary explanatory variables derived from samples. It is an objective assignment of coefficients serving as weights of various factors under considerations while expert opinions make great difference in heuristic approaches. Different from deterministic approach, it is very applicable to regional scale. In this study, double logistic regression is applied in the study area. The entire study area is first analyzed. The logistic regression equation showed that elevation, proximity to road, river and residential area are main factors triggering land- slide occurrence in this area. The prediction accuracy of the first landslide susceptibility map was showed to be 80%. Along the road and residential area, almost all areas are in high landslide susceptibility zone. Some non-landslide areas are incorrectly divided into high and medium landslide susceptibility zone. In order to improve the status, a second logistic regression was done in high landslide susceptibility zone using landslide cells and non-landslide sample cells in this area. In the second logistic regression analysis, only engineering and geological conditions are important in these areas and are entered in the new logistic regression equation indicating that only areas with unstable engineering and geological conditions are prone to landslide during large scale engineering activity. Taking these two logistic regression results into account yields a new landslide susceptibility map. Double logistic regression analysis improved the non-landslid

关键词： Landslide Susceptibility Logistic regression GIS Spatial analysis

Strategic games on a hierarchical network model

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Journal of Zhejiang University-science A(Applied Physics & Engineering) 2008年第2期9卷 271-278页

作者： Yi-xiao LI Xiao-gang JIN Fan-sheng KONG Hui-lan LUO Institute of Artificial Intelligence Zhejiang University Hangzhou 310027 China Ningbo Institute of Technology Zhejiang University Ningbo 315100 China

Among complex network models,the hierarchical network model is the one most close to such real networks as world trade web,metabolic network,WWW,actor network,and so *** has not only the property of power-law degree distribution,but also the scaling clustering coefficient property which Barabási-Albert(BA)model does not *** model is a model of network growth based on growth and preferential attachment,showing the scale-free degree distribution *** this paper,we study the evolution of cooperation on a hierarchical network model,adopting the prisoner's dilemma(PD)game and snowdrift game(SG)as metaphors of the interplay between connected *** model provides a unifying framework for the emergence of *** interestingly,we found that on hierarchical model,there is no sign of cooperation for PD game,while the fre-quency of cooperation decreases as the common benefit decreases for *** comparing the scaling clustering coefficient prop-erties of the hierarchical network model with that of BA model,we found that the former amplifies the effect of *** different performances of PD game and SG on complex network,we also found that common benefit leads to cooperation in the *** our study may shed light on the emergence of cooperation in both natural and social environments.

关键词： Complex network Hierarchical network model Barabási-Albert (BA) model Prisoner's dilemma (PD) game Snowdrift game (SG)

Enhancement of the thermostability of β-1,3-1,4-glucanase by directed evolution

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Journal of Zhejiang University-science A(Applied Physics & Engineering) 2006年第11期7卷 1948-1955页

作者： ZHANG Xiu-yan RUAN Hui MU Lin HE Guo-qing TANG Xing-jun CHEN Qi-he Department of Food science and Nutrition Zhejiang University Hangzhou 310029 China

In order to improve the thermostability of β- 1,3-1,4-glucanase, evolutionary molecular engineering was used to evolve the β-1,3-1,4-glucanase from Bacillus subtilis ZJF-1A5. The process involves random mutation by error-prone PCR and DNA shuffling followed by screening on the filter-based assay. Two mutants, EGsl and EGs2, were found to have four and five amino acid substitutions, respectively. These substitutions resulted in an increase in melting temperature from Tm=62.5℃ for the wild-type enzyme to Tm=65.5℃ for the mutant EGsl and 67.5℃ for the mutant EGs2. However, the two mutated enzymes had opposite approaches to produce reducing sugar from lichenin with either much higher （28%） for the former or much lower （21.6%） for the latter in comparison with their parental enzymes. The results demonstrate that directed evolution is an effective approach to improve the thermostability of a mesophilic enzyme.

关键词： Directed evolution Error-prone PCR DNA shuffling β- 1 3-1 4-glucanase Thermostability

SHARP BOUNDS FOR NEUMAN-SNDOR MEAN IN TERMS OF THE CONVEX COMBINATION OF QUADRATIC AND FIRST SEIFFERT MEANS

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Acta Mathematica Scientia 2014年第3期34卷 797-806页

作者：褚玉明赵铁洪宋迎清 School of Mathematics and Computation sciences Hunan City University Department of Mathematics Hangzhou Normal University

In this article, we prove that the double inequality αP（a,b）＋（1-α）Q（a,b）〈M（a,b）〈βP（a,b）＋（1-β）Q（a,b）holds for any a,b 〉 0 with a ≠ b if and only if α≥1/2 and β≤[π（√2 lov （1＋√2）-1]/[√2π-2） log （1＋√2）]=0.3595…,where M（a, b）, Q（a, b）, and P（a, b） ave the Neuman-Sandor, quadratic, and first Seiffert means of a and b, respectively.

关键词： Neuman-Sandor mean quadratic mean first Seiffert mean

The Influence of Localized Slumping on Groundwater Seepage and Slope Stability

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Journal of Earth science 2013年第1期24卷 104-110页

作者：孙红月钟杰赵宇沈水进尚岳全 Department of Ocean science and Engineering Zhejiang University Department of Civil Engineering Zhejiang University

Transverse cracks and localized slumps frequently occur within loose deposits slopes when the slope base is removed either from natural or manmade processes. Although the contribution of rainfall to the slope failures was intensely discussed, the influence of localized slumps on hydrogeological conditions has received less attention. Usually, loose deposits slopes are composed of soil layers with different permeability; localized slumps may cause flow paths partly blocked in the permeable layer that is adversely confined between impermeable layers. In this study, a case history of such failure, Xiaodan （/J~ ~__） landslide, is introduced in detail. The localized slump caused the pressure head in the permeable layer to increase substantially, which reduced the stability of the slope. To quantify the influence, Ber- noulli equations are used to analytically study the increase of the pressure head with a hydrogeologicai model simplified from the slope. The factor of safety assessed by limit equilibrium methods may decrease up to 20% when the 80% of flow path is blocked. Thus, we should pay attention not only to changes of stress filed due to localized slumps but also to the influence of seepage variation on the slope stability.

关键词： deposits slope slump groundwater seepage pressure head slope stability.