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家禽体外寄生虫的控制

中国家禽 2008年第12期30卷 12-16页

作者： P.E.Kaufman P.G.Koehler j.f.Butler 佛罗里达州立大学

虱子、恙虫、家禽壁虱和鸡蚤是家禽业中常见的体外寄生虫。虽然禽舍苍蝇不是寄生虫,但是备受家禽生产者的关注,尤其对于笼养蛋鸡生产者。这些体外寄生虫对家禽业的危害日益得到重视。本专题就上述几种体外寄生虫的生活习性和药物控制措... 详细信息

虱子、恙虫、家禽壁虱和鸡蚤是家禽业中常见的体外寄生虫。虽然禽舍苍蝇不是寄生虫,但是备受家禽生产者的关注,尤其对于笼养蛋鸡生产者。这些体外寄生虫对家禽业的危害日益得到重视。本专题就上述几种体外寄生虫的生活习性和药物控制措施进行总结,希望为广大读者提供借鉴。

关键词：体外寄生虫药物控制家禽业笼养蛋鸡生活习性生产者虱子苍蝇

GEOMECHANICAL CHALLENGES WITHIN THE fRAMEWORK Of THE fRENCH 2006 PLANNING ACT ON THE SUSTAINABLE MANAGEMENT Of RADIOACTIVE WASTE

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GEOMECHANICAL CHALLENGES WITHIN THE FRAMEWORK OF THE FRENCH ...

Spectra and Spin Polarization of the Valence Band Auger Emission from Cr （100） Surface

第二届废物地下处置学术研讨会

作者： C.Bauer P.Lebon j.Delay L.Londe f.Plas Andra French National Agency for Radioactive WasteChtenay-MalabryFrance

The Planning Act of 28 june 2006 concerning the sustainable management of radioactive waste marks a new step in french *** sets 2015 as the deadline to submit the statutory application for the commissioning of a deep geological and reversible repository for high-level and long-lived radioactive waste by *** this paper,some of the major milestones envisioned for the upcoming repository design phase are *** and studies pertaining to site selection and evaluation for the license application are briefly *** is put on the geomechanical program,in particular on the tests and experiments planned in the french Meuse/Haute-Marne underground research laboratory,and on the associated stakes in view of Performance Assessment.

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Chinese Physics Letters 2003年第10期20卷 1864-1867页

作者：袁建民 L.fritsche j.Noffke DepartmentofAppliedPhysics NationalUniversityofDefenseTechnologyChangsha410073 InstitutfuerTheoretischePhysik TUClausthalD-38678Clausthal-ZellerfeldF.R.Germany

Calculations have been carried out on spin-polarized Auger electron emission from a seven-layer chromium (100)-film. The core and valence states concerning the Auger transition are obtained from a self-consistent full-potential linearized augmented plane wave calculation by using a repeated slab geometry. The calculations refer to experiments on the L3M23V- and L3VV-transitions that have recently been carried out by Heinzmann et al. The Auger spectrum obtained for the L3VV transition agrees relatively well with our calculations whereas the observed L3M23V-Auger structure is considerably wider than that predicted by our theory. Nevertheless, the spin-polarization in the latter case, which is about -13%, is in fair agreement with the experiment, different from the L3VV-transition where the experiment yields -10% as opposed to the theoretical value of -25%. We give possible reasons for the origin of these discrepancies.

关键词： Spectra theoretical value full potential emission Spiral wood bits Auger electron spectra Valence band chromium Spin polarization

INVESTIGATION Of LASER BEAM WELDING PROCESS Of AZ61 MAGNESIUM-BASED ALLOY

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Acta Metallurgica Sinica(English Letters) 2006年第4期19卷 287-294页

作者： H.Y. Wang Z.j. Li Industrial Center Shenzhen Polytechnic Shenzhen 518055 China

Laser welling process of AZ61 magnesium alloys is investigated using a special CO2 laser experimental system. The effect of processing parameters including laser power, welling speed, and protection gas flow at the top and bottom is researched. The results show that an ideal well bead can be formed by choosing the processing parameters properly. An optimized parameter range is obtained by a large number of experiments. Among them, laser power and welling speed are the two main parameters that determine the well width and dimensions. The protect gas flow rate has a slight effect on the well width, but it directly effects the surface color of the well. The test results for typical welds indicate that the microhardness and tensile strength of the well zone are better than that of the base metal A fine-grained well region has been observed and no obvious heat-affected zone is found. The well zone mainly consists of small α-Mg phase, （α ＋ Al12Mg17）, and other eutectic phases. The small grains and the eutectic phases in the joint are believed to play an important role in the increase of the strength of wells for AZ61 magnesium alloys.

关键词： magnesium alloy laser beam welding laser power welling speed

Two-flavor hybrid stars with the Dyson-Schwinger quark model

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Chinese Physics C 2017年第11期41卷 110-116页

作者：魏金标陈欢 H.-j.Schulze School of Mathematics and Physics China University of Geosciences INfN Sezione di Catania Dipartimento di FisicaUniversitá di Catania

We study the properties of two-flavor quark matter in the Dyson-Schwinger model and investigate the possible consequences for hybrid neutron stars,with particular regard to the two-solar-mass *** find that with some extreme values of the model parameters,the mass fraction of two-flavor quark matter in heavy neutron stars can be as high as 30 percent and the possible energy release during the conversion from nucleonic neutron stars to hybrid stars can reach 1052 erg.

关键词： hybrid stars quark matter equation of state Dyson-Schwinger equations

Closed 3-stop Center and Periphery in Graphs

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Acta Mathematica Sinica,English Series 2012年第3期28卷 439-452页

作者： Linda EROH Ralucca GERA Steven j. WINTERS Department of Mathematics University of Wisconsin Oshkosh Department of Applied Mathematics Naval Postgraduate School

A delivery person must leave the central location of the business, deliver packages at a number of addresses, and then return. Naturally, he/she wishes to reduce costs by finding the most efficient route. This motivates the following： Given a set of k distinct vertices S = {x1, x2,..., xk } in a simple graph G, the closed k-stop-distance of set S is defined to be

关键词： Central appendage number peripheral appendage number Steiner distance

Early developmental exposure to inorganic mercury does not alter affiliative behavior of adult prairie voles(Microtus ochrogaster)

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Integrative Zoology 2018年第6期13卷 761-768页

作者： Yue CHEN Robert LEWIS j.Thomas CURTIS Department of Pharmacology and Physiology Oklahoma State University Center for Health SciencesTulsaOklahomaUK

Mercury chloride exposure through drinking water in adult male prairie voles(Microtus ochrogaster)has been shown to alter their social ***,we examined the potential disruption of adult social behavior in prairie voles that were exposed to 60 ppm mercury during early *** used a cross-fostering approach to test the effects of mercury exposure:(1)from conception until birth;(ii)from birth until weaning;and(iii)from conception until weaning,on adult affiliative *** and mercury-treated voles were given the option of remaining in an empty cage or affiliating with a same-sex conspecific in a 3-h choice *** found that early developmental mercury exposure had little if any effect on the reproductive success of breeder pairs or on affiliative behavior by either sex when subjects were tested as *** results suggest that,at least in the context of the behavior tested,the effects of early developmental exposure to mercury do not permanently alter adult prairie vole affiliative behavior,or do so in a way that is too subtle to be detected using the current testing paradigm.

关键词： behavioral testing metals toxicity social behavior prairie vole

Conspecific negative density dependence in American beech

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forest Ecosystems 2017年第3期4卷 174-181页

作者： Benjamin S.Ramage Isabel j.Mangana Biology Department Randolph-Macon College

Background： One of the most important drivers of forest biodiversity is conspecific negative density dependence（CNDD）, a reduction in performance when conspecific densities are high. While the majority of CNDD research has focused on tropical forests, evidence is mounting that CNDD may also play an important role in temperate *** further explore the potential reach of this phenomenon, we investigated CNDD in American beech（fagus grandifolia）in a mature mid-Atlantic ***： We used bivariate point pattern analyses to examine spatial relationships between large beech trees and conspecific saplings, and we also contrasted these patterns with comparable patterns for heterospecifics. In addition, to address the possibility of dispersal limitation and the associated effects on spatial patterns, we analyzed seedling density as a function of adult conspecific ***： We found that beech saplings were more repel ed from large conspecifics than large heterospecifics, despite the fact that beech seedling density was positively correlated with beech basal area. However, saplings of other canopy tree species were also repel ed from adult beech trees, suggesting a general suppressive effect. Nonetheless, the discrepancy between beech seedling and sapling densities beneath adult conspecifics suggests that beech seedling survival rates were reduced in vicinity of conspecific ***： Regardless of the extent to which beech inhibits heterospecific trees, a negative effect on conspecific recruits may be critical for biodiversity maintenance. Without this conspecific suppression, a dense layer of shade-tolerant beech saplings could form beneath adult beech trees. If this were to occur, beech would have a substantial head-start fol owing canopy disturbance, and this late-successional species could potential y dominate a stand in perpetuity,through repeated disturbance cycles.

关键词： Biodiversity Disturbance Dispersal limitation Diversity fagus grondifolia janzen-Connell effects Mid-Atlantic Point pattern analysis Regeneration Temperate forest

SEMI-SOLID MICROSTRUCTURE AND ITS EVOLUTION Of WROUGHT ALUMINUM ALLOY BY DIRECTLYHEATING-ISOTHERMAL TREATMENT

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Acta Metallurgica Sinica(English Letters) 2004年第6期17卷 856-861页

作者： X.T.Liu j.Z.Cui TheKeyLaboratoryofElectromagneticProcessingofMaterials MinistryofEducationNortheasternUniversityShenyang110004China

Microstructure evolution of wrought aluminum alloy extruded rods and the mechanism of liquid phase formation during reheating were investigated. And the relation between the volume fraction of liquid phase and the recrystallization microstructure was proposed. The results show that increase in reheating temperature and time can augment the volume fraction of liquid phase and accelerate the grain spheroidization, as a result of which the requirement of semi-solid forming can be satisfied. Due to the higher aberration energy of grain boundary, the melting point is lowered as a result of the easy diffusion of atoms. At higher reheating temperature the grain boundary melts, the growth of the recrystallized grain is inhibited and the grain is refined. The composition of the low melt-point phase along the recrystallized grains was determined using EDS. It can be seen from the experimental results that when the extrusion rod of the wrought aluminum alloy is reheated at 610℃ for 20min, perfect fine equiaxial grains can be obtained, the average grain size is about 66.34μm and the volume fraction of solid phase is about 68%.

关键词： wrought aluminum alloy hot extrusion reheating mechanism of micro- structual evolution spheroidization volume fraction of solid phase