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Estimates of N_2O Emissions and Mitigation Potential from a Spring Maize Field Based on DNDC Model

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Journal of Integrative Agriculture 2012年第12期11卷 2067-2078页

作者： LI Hu qiu Jian-jun WANG Li-gang XU Ming-yi LIU Zhi-qiang WANG Wei Key Laboratory of Non-Point Source Pollution Control Ministry of Agriculture/CAAS-UNH Joint Laboratory for Sustainable Agro-Ecosystems Research/Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Dalian Academy of Agricultural Sciences

Agricultural production plays an important role in affecting atmospheric nitrous oxide （N20） concentrations. Field measurements were conducted in Dalian City, Liaoning Province in Northeast China from two consecutive years （2009 and 2010） to estimate NzO emissions from a spring maize field, a main cropping system across the Chinese agricultural regions. The observed flux data in conjunction with the local climate, soil and management information were utilized to test a process-based model, DeNitrification-DeComposition （DNDC）, for its applicability for the cropping system. The validated DNDC was then used for exploring strategies to reduce N20 emissions from the target field. The results showed that the major N20 pulse emissions occurred with duration of about 3-5 d after fertilizer application in both years 2009 and 2010, which on average accounted for about 60% of the total N20 emissions each year. Rainfall and fertilizer application were the major factors influencing the N20 emissions from spring maize field. The average N20 flUXeS from the CK （control plot, without fertilization） and FP （traditional chemical N fertilizer） treatments were 23.1 and 60.6 gg m-2 h-~ in 2009, respectively, and 21.5 and 64.3 gg m-2 h-~ in 2010, respectively. The emission factors （EFs） of the applied N fertilizer （270 kg N ha-1） as N20- N were 0.62% in 2009 and 0.77% in 2010, respectively. The comparison of modeled daily NzO emission fluxes against observations indicated that the DNDC model had a good performance even if without adjusting the internal parameters. The modeled results showed that management practices such as no-till, changing timing or rate of fertilizer application, increasing residue incorporation, and other technically applicable measures could effectively reduce N20 emissions from the tested fields. Our study indicated that avoiding application of N fertilizers at heavy rainfall events or splitting the fertilizer into more applications would be the most feasible appr

关键词： spring maize N20 DNDC mitigation measures Northeast China

NUMERICAL SIMULATION OF FISH SWIMMING WITH RIGID PECTORAL FINS

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Journal of Hydrodynamics 2012年第2期24卷 263-272页

作者： XU yi-gang WAN De-cheng State Key Laboratory of Ocean Engineering School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

The numerical simulation of the self-propelled motion of a fish with a pair of rigid pectoral fins is presented.A Navier-Stokes equation solver incorporating with the multi-block and overset grid method is developed to deal with the multi-body and moving body *** lift-based swimming mode is selected for the fin *** the lift-based swimming mode,the fin can generate great thrust and at the same time have no generation of lift *** can be found when a pair of rigid pectoral fins generates the hydrodynamic moment,it may also generate a lateral force opposite to the centripetal direction,which has adverse effect on the turn motion of the ***,the periodic vortex structure generation and shedding,and their effects on the generation of hydrodynamic force are also demonstrated in this article.

关键词： pectoral fins lift-based swimming mode self-propelled motion overset grid method

Poroelastic behaviors of the osteon: A comparison of two theoretical osteon models

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Acta Mechanica Sinica 2013年第4期29卷 612-621页

作者： Xiao-gang Wu Wei-yi Chen College of Mechanics Taiyuan University of Technology

In the paper, two theoretical poroelastic osteon models are presented to compare their poroelastic behaviors, one is the hollow osteon model （Haversian fluid is neglected） and the other is the osteon model with Haversian fluid con- sidered. They both have the same two types of imperme- able exterior boundary conditions, one is elastic restraint and the other is displacement constrained, which can be used for analyzing other experiments performed on similarly shaped poroelastic specimens. The obtained analytical pressure and velocity solutions demonstrate the effects of the loading fac- tors and the material parameters, which may have a signifi- cant stimulus to the mechanotransduction of bone remodel- ing signals. Model comparisons indicate：（1） The Haversian fluid can enhance the whole osteonal fluid pressure and ve- locity fields. （2） In the hollow model, the key loading fac- tor governing the poroelastic behavior of the osteon is strain rate, while in the model with Haversian fluid considered, the strain rate governs only the velocity. （3） The pressure ampli- tude is proportional to the loading frequency in the hollow model, while in the model with Haversian fluid considered, the loading frequency has little effect on the pressure ampli- tude.

关键词： Osteon ~ Poroelasticity ~ Haversian fluid - Porepressure ~ Annular cylinder

TDDFT-SOS Studies on the Polarizabilities and Second-order Hyperpolarizabilities of Zn_3O_3 II-VI Semiconductor Clusters

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Chinese Journal of Structural Chemistry 2006年第11期25卷 1359-1364页

作者： qiu Yong-Qing LIU yi-Chun Advanced Center for Opto-electronic Functional MaterialResearch Northeast Normal University Changchun 130024 China Key Laboratory of Excited State Physics Change＇hun Institute of OpticsFine Mechanics and Physics The Chinese Academy of Sciences Changchun 130021 China

The geometrical structure of semiconductor clusters including Zn3O3 was optimized by the DFT B3LYP method. With the same basis sets, dipole moments, polarizabilities and secondorder hyperpolarizabilities have been calculated and compared with the results obtained by TDDFT B3LYP method combined with sum-over-state （SOS） formula. The calculation results indicate that the dipole moments of the ground state depend on the atom radius and electronegative differences between elements and are their balance point as well. The polarizabilities of the clusters accord with the rule of the corresponding energy transformation from ground to excited state. The results predict an increase of second-order hyperpolarizabilities with increasing the distances between atoms in the clusters as well as a decrease of the polarizabilities and second-order hyperpolarizabilities in the same serial of semiconductor clusters with increasing the dipole moments of the ground states. The changes of dipole moments in ground states are inconsistent with transition moments. Spatial structure, charge transfer and other factors play an important role in composing the transition moments.

关键词： Ⅱ-Ⅵ semiconductor clusters TDDFT method polarizabilities second-order hyperpolarizabilities

Algorithm for transient growth of perturbations in channel Poiseuille flow

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Applied Mathematics and Mechanics(English Edition) 2017年第11期38卷 1635-1650页

作者： Jianlei ZHANG gang DONG yi LI National Key Laboratory of Transient Physics Nanjing University of Science and Technology School of Mathematics and Statistics University of Sheffield

This study develops a direct optimal growth algorithm for three-dimensional transient growth analysis of perturbations in channel flows which are globally stable but locally unstable. Different from traditional non-modal methods based on the Orr- Somrnerfeld and Squire （OSS） equations that assume simple base flows, this algorithm can be applied to arbitrarily complex base flows. In the proposed algorithm, a re- orthogonalization Arnoldi method is used to improve orthogonality of the orthogonal basis of the Krylov subspace generated by solving the linearized forward and adjoint Navier-Stokes （N-S） equations. The linearized adjoint N-S equations with the specific boundary conditions for the channel are derived, and a new convergence criterion is pro- posed. The algorithm is then applied to a one-dimensional base flow （the plane Poiseuille flow） and a two-dimensional base flow （the plane Poiseuille flow with a low-speed streak） in a channel. For one-dimensional cases, the effects of the spanwise width of the chan- nel and the Reynolds number on the transient growth of perturbations are studied. For two-dimensional cases, the effect of strength of initial low-speed streak is discussed. The presence of the streak in the plane Poiseuille flow leads to a larger and quicker growth of the perturbations than that in the one-dimensional case. For both cases, the results show that an optimal flow field leading to the largest growth of perturbations is character- ized by high- and low-speed streaks and the corresponding streamwise vortical structures. The lift-up mechanism that induces the transient growth of perturbations is discussed. The performance of the re-orthogonalization Arnoldi technique in the algorithm for both one- and two-dimensional base flows is demonstrated, and the algorithm is validated by comparing the results with those obtained from the OSS equations method and the cross- check method.

关键词： transient growth Poiseuille flow Arnoldi method Krylov subspace adjoint equation

Spin-Rotation Coupling in Gravitation with Torsion

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Communications in Theoretical Physics 2007年第3X期48卷 473-476页

作者： qiu Shu-Xia SHAO Cheng-gang Department of Physics Huazhong University of Science and Technology Wuhan 430074 China

Based on the theory of gravitation with torsion developed by Hammond [Rep. Prog. Phys. 65 （2002） 599], thc interaction between the intrinsic spin of a particle and the mass source is calculated. It is shown that spin can interact with the gravitimagnetic field created by a rotational mass, where the spin-rotation coupling is also discussed. According to the recent torsion pendulum experiment with polarized electrons by Heckel et al. [Phys. Rev. Left. 97 （2006） 021603], we set a new limit on the value of the torsion coupling constant K as K E [0.53, 0.95], which has improved many orders than the constraints from the early spln-spin experiment with K 〈 2 × 10^14.

关键词： torsion spin-rotation torsion coupling constant

Analysis of lycopodiastrum casuarinoides transcriptome discovers lycodine-type alkaloid biosynthetic genes and genetic markers

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中国药理学与毒理学杂志 2018年第4期32卷 274-275页

作者： gang CHEN qiu-mei LIN Lin ZENG yi-ping ZOU Key Laboratory of Natural Active Pharmaceutical Constituents Yichun University Yichun 336000 China College of Chemistry and Bioengineering Yichun University Yichun 336000 China

OBJECTIVE o facilitate the basic acquaintance with the bioactive lycodine-type alkaloids biosynthetic pathways,we conducted the transcriptome analysis of *** by illumina *** The plant of *** was collected and was subjected to RNA isolation,cDNA library construction,and illumina sequencing before bioinformatics *** sequencing,the clean reads were obtained for de novo assembly by using Trinity software,and then further processed with TGICL sequencing clustering software to generate unigenes,The unigenes are aligned by Blast X alignment to six public protein *** addition,all unigenes are functionally annotated by GO,KEGG and characterized putative genes involved in lycopodium alkaloids *** In total,124,524 high-quality unigenes were obtained with an average sequence length of 601 *** the *** transcripts,61,304 showed significant similarity(E-value<1 e-5) to the known proteins in the public *** the total 124 524 unigenes,47,538 open reading frame(ORFs) were *** on the bioinformatics analysis,all possible enzymes involved in the Lycodine-type alkaloids biosynthetic pathway of *** were identified,including primary amine oxidase(PAO),and Malonly-CoA *** addition,a total of 64 putative cytochrome P450(CYP450) and 827 transcription factors were selected as the candidates of Lycodine-type *** ***,a total of 13 352 simple sequence repeats(SSRs) were identified from the 124,524 unigenes,of which dinucleotide motifs AG/CT(50.1%),were the most *** This transcriptome analysis of ***,provides many valuable candidate genes *** in the biosynthesis of novel secondary metabolites but also lays the foundation for genetic diversity analysis via SSRs markers in ***.

关键词：番茄碱生物碱生物活性药物分析

Microstructure and mechanical property of Sn–Ag–Cu solder material

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Rare Metals 2017年第3期36卷 193-197页

作者： yi-gang Kong Zhi-gang Kong Feng-Min Shi School of Mechanical Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China Research Laboratory of Electrical Contacts Beijing University of Posts and TelecommunicationsBeijing 100876China Technology Department Jinan No.10 Radio Factory Co.Ltd.Jinan 250100China

Among the lead-free solder materials,Sn-Ag-Cu alloys have many advantages,such as good wetting property,superior interfacial properties and high creep *** this article,the organization and welding performance of Sn-Ag-Cu material were *** surface morphology of the two alloys was observed by stereoscopic microscope and scanning electron microscope （SEM）.Chemical constitution was examined by X-ray energy-dispersive spectroscopy （EDS）.The mechanical properties of Sn-Ag-Cu solder were evaluated systematically compared with those of Sn-Cu *** results show that Sn-Ag-Cu solder based on different solder pads has different welding *** thickness of intermetallic compound （IMC） at the interface increases with aging *** the gold-plated pads,there are a large number of IMC graphic,and in the welding interface,it can reduce the reliability of electrical *** Sn-Ag-Cu solder joints show a superior mechanical property over the traditional Sn-Cu *** number of dimples decreases and that of cavities increases for Sn-Cu0.7 alloy and the fracture surfaces of Sn-Ag3.0-Cu0.5 alloy have many small size dimples which are homogeneously distributed.

关键词： Lead-free solder Organization Weldingperformance Intermetallic compound

Distributional Dimension of Fractal Sets in Local Fields

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Acta Mathematica Sinica,English Series 2008年第1期24卷 147-158页

作者： Hua qiu Wei yi SU Department of Mathematics Nanjing University Nanjing 210093 P. R. China

The distributional dimension of fractal sets in R^n has been systematically studied by Triebel by virtue of the theory of function spaces. In this paper, we first discuss some important properties about the B-type spaces and the F-type spaces on local fields, then we give the definition of the distributional dimension dimD in local fields and study the relations between distributional dimension and Hausdorff dimension. Moreover, the analysis expression of the Hausdorff dimension is given. Lastly, we define the Fourier dimension in local fields, and obtain the relations among all the three dimensions. Keywords local field, B-type space, F-type space, distributional dimension, Hausdorff dimension Fourier dimension

关键词： local field B-type space F-type space distributional dimension Hausdorff dimension,Fourier dimension