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pH值及土壤质地对土壤中Cd吸收与运移的影响(英文)

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pH值及土壤质地对土壤中Cd吸收与运移的影响(英文)

2009水资源与可持续发展高层论坛

作者： Huang Shuang~1,Zhang Renduo~2,Zhang Jiaying~2 1 State Key Laboratory of Water Resources and Hydropower engineering science,school of Water Resources and Hydroelectric engineering,Wuhan university,Wuhan 430072,china 2 school of environmental science and engineering,sun yat-sen university,guangzhou 510275,china

To better understand the adsorption and transport of Cdin soils,column experiments were conducted with various soils and inflow solutions with different pH values. Breakthrough curves(BTCs)of the column tests were fitted using both the equilibrium and non-equilibrium models installed in the program of *** showed that the equilibrium model fitted most of BTCs reasonably *** of the retardation factor(R) and the distribution coefficient(k)for Cdadsorption and transport increased with increasing pH values of the inflow solution and of the ***,the clay content was not a key factor to affect R and k for Cdadsorption and *** dispersivity values decreased with increasing sand content of the soils.

关键词： Cadmium pH soil texture adsorption and transport

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灌溉效率对土壤化学溶质迁移的影响(英文)

灌溉效率对土壤化学溶质迁移的影响(英文)

Spontaneous chiral-symmetry breaking of lattice QCD with massless dynamical quarks

2009水资源与可持续发展高层论坛

作者： WANG Kang~1,ZHANG RenDuo~(2*),and SHENG Feng~2 1 State Key Lab.of Water Resources and Hydropower engineering science,Wuhan university,Wuhan 430072,china 2 school of environmental science and engineering,sun yat-sen(Zhongshan) university,guangzhou 510275,china

＜正＞Irrigation practices greatly affect sustainable agriculture *** this study, we investigated the effects of irrigation efficiency on water flow and chemical transport in soils,which had significant impact on the *** dye staining experiments were conducted at different soils with various irrigation *** analysis was

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来源： cnki会议评论

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science china(Physics,Mechanics & Astronomy) 2007年第1期50卷 6-14页

作者： LUO XiangQian Department of Physics,school of Physics and engineering,sun yat-sen university,guangzhou 510275,china 1. Department of Physics School of Physics and Engineering Sun Yat-Sen University Guangzhou 510275 China

One of the most challenging issues in QCD is the investigation of spontaneous chiral-symmetry breaking, which is characterized by the non-vanishing chiral condensate when the bare fermion mass is zero. In standard methods of the lattice gauge theory, one has to perform expensive simulations at multiple bare quark masses, and employ some modeled functions to extrapolate the data to the chiral limit. This paper applies the probability distribution function method to computing the chiral condensate in lattice QCD with massless dynamical quarks, without any ambiguous mass extrapolation. The results for staggered quarks indicate that this might be a promising and efficient method for investigating the spontaneous chiral-symmetry breaking in lattice QCD, which deserves further investigation.

关键词： lattice QCD spontaneous chiral-symmetry breaking dynamical quarks

A provable secure fuzzy identity based signature scheme

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science china(Information sciences) 2012年第9期55卷 2139-2148页

作者： WANG ChangJi 1,2 1 school of Information science and Technology,sun yat-sen university,guangzhou 510275,china 2 Guangdong Province Information Security Key Laboratory,sun yat-sen university,guangzhou 510275,china 1. school of Information science and Technology Sun Yat-sen University Guangzhou 510275 China2. Guangdong Province Information Security Key Laboratory Sun Yat-sen University Guangzhou 510275 China

To use biometrics identities in an identity based encryption system,Sahai and Waters first introduced the notion of fuzzy identity based encryption(FIBE) in *** et *** it to digital signature and introduced the concept of fuzzy identity based signature(FIBS) in 2008,and constructed an FIBS scheme based on Sahai and Waters's FIBE *** this paper,we further formalize the notion and security model of FIBS scheme and propose a new construction of FIBS scheme based on bilinear *** proposed scheme not only provides shorter public parameters,private key and signature,but also have useful structures which result in more efficient verification than that of Yang et al.'s FIBS *** proposed FIBS scheme is proved to be existentially unforgeable under a chosen message attack and selective fuzzy identity attack in the random oracle model under the discrete logarithm assumption.

关键词： identity based cryptosystem fuzzy identity based encryption fuzzy identity based signature

A distribution space for Hilbert transform and its applications

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science china Mathematics 2008年第12期51卷 2217-2230页

作者： YANG LiHua school of Mathematics and Computing science, sun yat-sen university, guangzhou 510275, china school of Mathematics and Computing science Sun Yat-Sen University Guangzhou 510275 China

In this paper, a new distribution space is constructed and the definition of the classical Hilbert transform is extended to it. It is shown that is the biggest subspace of on which the extended Hilbert transform is a homeomorphism and both the classical Hilbert transform for L p functions and the circular Hilbert transform for periodic functions are special cases of the extension. Some characterizations of the space are given and a class of useful nonlinear phase signals is shown to be in . Finally, the applications of the extended Hilbert transform are discussed.

关键词： Hilbert transform distribution time-frequency analysis 44A15 46F12

High norbornene incorporation in ethylene-norbornene copolymerization with a bis(α-alkyloxoimine) titanium-MAO catalyst

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science china Chemistry 2010年第8期53卷 1634-1640页

作者： GAO HaiYang1,2,HU Hao1 & WU Qing1,2 1Institute of Polymer science,school of Chemistry and Chemical engineering,sun yat-sen (Zhongshan) university,guangzhou 510275,china 2Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education sun yat-sen (Zhongshan) university,guangzhou 510275,china 1. Institute of Polymer science School of Chemistry and Chemical Engineering Sun Yat-Sen (Zhongshan) University Guangzhou 510275 China2. Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education Sun Yat-Sen (Zhongshan) University Guangzhou 510275 China

A novel bis(α-alkyloxoimine) titanium(IV) complex was synthesized and used as a catalyst precursor to catalyze homo-and copolymerization of ethylene and *** titanium complex activated with methylalumoxane exhibits good activities for the homopolymerizations of ethylene and norbornene under high temperature to produce high-molecular-weight linear polyethylene and vinyl-type polynorbornene,***-norbornene copolymers with high molecular weight can also be produced by this *** incorporation of norbornene from 0 to 76 mol% in the copolymers can be controlled by varying the charged norbornene.13C NMR analyses show that the microstructures of the ethylene-norbornene copolymers with low norbornene incorporation are predominantly alternated and isolated norbornene units,while those with high norbornene incorporation are random polymers containing long norbornene sequences.

关键词： catalyst ethylene norbornene polymerization copolymerization

Twisted Ate pairing on hyperelliptic curves and applications

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science china(Information sciences) 2010年第8期53卷 1528-1538页

作者： ZHANG FangGuo 1,2 1 school of Information science and Technology, sun yat-sen university, guangzhou 510275, china 2 Guangdong Key Laboratory of Information Security Technology, guangzhou 510275, china 1. school of Information science and Technology Sun Yat-Sen University Guangzhou 510275 China2. Guangdong Key Laboratory of Information Security Technology Guangzhou 510275 China

In this paper we show that the twisted Ate pairing on elliptic curves can be generalized to hyperelliptic curves, and give a series of variations of the hyperelliptic Ate and twisted Ate pairings. Using the hyperelliptic Ate pairing and twisted Ate pairing, we propose a new approach to speeding up the Weil pairing computation. For some hyperelliptic curves with high degree twist, computing Weil pairing by our approach may be faster than Tate pairing, Ate pairing, and all other known pairings.

关键词： Ate pairing Weil pairing hyperelliptic curves pairing-based cryptosystems twisted curves

Chemical weathering and chemical runoffs in the seashore granite hills in South china

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science china Earth sciences 2010年第8期53卷 1195-1204页

作者： GAO QuanZhou & TAO Zhen school of Geography and Planning, sun yat-sen university, guangzhou 510275, china 1. school of Geography and Planning Sun Yat-sen University Guangzhou 510275 China

Surface runoffs and the contents of major ions and dissolved silicon were surveyed and analyzed based on weekly sampling for one year in a granite watershed of Zhuhai City, Guangdong Province. The results demonstrated that the slope runoff played an essential role in feeding the rivulet during precipitation, whereas the groundwater was more important for the rivulet in the non-raining stages. Dissolved silicon, Na+, HCO3-, and Clions constituted the major chemical components of the rivulet water. Atmospheric CO2 and H2SO4 sourced from the oxidation of pyrite were the main erosive mediums in the natural chemical weathering. Natural chemical weathering, the wet and dry deposition of sea-salt, and acids precipitation contributed approximately equal shares of anions to the rivulet water. The ratio of NO3- to SO42- was more than 1.0 in the runoff of the studied seashore watershed, whereas it is less than 1.0 in the Xijiang River that is adjacent to the study area. This implied that the chemical composition of runoff is controlled mainly by the differences in atmospheric acid precipitation caused by human activities and lithology within the catchments under the same bio-climate zone. The CO2 flux consumed by the rock chemical weathering processes within the seashore granite watershed in South china was (0.35-1.37)×105 mol km-2 a-1.

关键词： chemical weathering granite ion sea-salt acid deposition CO2

On the diophantine equation X^2-(1+a^2)Y^4 =-2a

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science china Mathematics 2010年第8期53卷 2143-2158页

作者： YUAN PingZhi 1 & ZHANG ZhongFeng 2 1 school of Mathematics,South china Normal university,guangzhou 510631,china 2 school of Mathematics & Computational science,sun yat-sen university,guangzhou 510275,china 1. school of Mathematics South China Normal University Guangzhou 510631 China2. School of Mathematics & Computational Science Sun Yat-Sen University Guangzhou 510275 China

Let a≥1 be an *** this paper,we will prove the equation in the title has at most three positive integer solutions.

关键词： algebraic approximations continued fractions elliptic curves quartic equations