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Entropy-stabilized oxides

ARTICLEOPENReceived8Apr2015|Accepted25Aug2015|Published29Sep2015Entropy-stabilized oxidesChristina M.Rost1,Edward Sachet1,Trent Borman1,Ali Moballegh1,Elizabeth C.Dickey1,Dong Hou1,Jacob L.Jones1,Stefano Curtarolo2&Jon-Paul Maria1Conﬁgurational disorder can be compositionally engineered into mixed oxide by populating asingle sublattice with many distinct cations.The formulations promote novel and entropy-stabilized forms of crystalline matter where metal cations are incorporated in new ways.Here,through rigorous experiments,a simple thermodynamic model,and aﬁve-componentoxide formulation,we demonstrate beyond reasonable doubt that entropy predominatesthe thermodynamic landscape,and drives a reversible solid-state transformation betweena multiphase and single-phase state.In the latter,cation distributions are proven tobe random and homogeneous.Theﬁndings validate the hypothesis that deliberateconﬁgurational disorder provides an orthogonal strategy to imagine and discover new phasesof crystalline matter and untapped opportunities for property engineering.1Department of Materials Science and Engineering,North Carolina State University,Raleigh,North Carolina27695,USA.2Department of Mechanical Engineering and Materials Science,Center for Materials Genomics,Duke University,Durham,North Carolina27708,USA.Correspondence and requests for materials should be addressed to J.-P.M.(email:jpmaria@)or to S.C.(email:stefano@).A grand challenge facing materials science is the continuoushunt for advanced materials with properties that satisfythe demands of rapidly evolving technology needs.The materials research community has been addressing this problem since the early1900s when Goldschmidt reported the‘the method of chemical substitution’1that combined a tabulation of cationic and anionic radii with geometric principles of ion packing and ion radius ratios.Despite its simplicity,this model enabled a surprising capability to predict stable phases and structures.As early as1926many of the technologically important materials that remain subjects of contemporary research were identiﬁed (though their properties were not known);BaTiO3,AlN,GaP, ZnO and GaAs are among that list.These methods are based on overarching natural tendencies for binary,ternary and quaternary structures to minimize polyhedral distortions,maximize spaceﬁlling and adopt polyhedral linkages that preserve electroneutrality1–3.The structure-ﬁeld maps compiled by Muller and Roy catalogue the crystallographic diversity in the context of these largely geometry-based predictions4.There are,however,limitations to the predictive power,particularly when factors like partial covalency and heterodesmic bonding are considered.To further expand the library of advanced materials and property opportunities,our community explores possibilities based on mechanical strain5,artiﬁcial layering6,external ﬁelds7,combinatorial screening8,interface engineering9,10and structuring at the nanoscale6,11.In many of these efforts, computation and experiment are important companions.Most recently,high-throughput methods emerged as a power-ful engine to assess huge sections of composition space12–17and identiﬁed rapidly new Heusler alloys,extensive ion substitution schemes18,19,new18-electron ABX compounds20and new ferroic semiconductors21.While these methods offer tremendous predictive power and an assessment of composition space intractable to experiment, they often utilize density functional theory calculations conducted at0K.Consequently,the predicted stabilities are based on enthalpies of formation.As such,there remains a potential section of discovery space at elevated temperatures where entropy predominates the free-energy landscape.This landscape was explored recently by incorporating deliberatelyﬁve or more elemental species into a single lattice with random occupancy.In such crystals,entropic contributions to the free energy,rather than the cohesive energy, promote thermodynamic stability atﬁnite temperatures.The approach is being explored within the high-entropy-alloy family of materials(HEAs)22,in which extremely attractive properties continue to be found23,24.In HEAs,however,discussion remains regarding the true role of conﬁgurational entropy25–28, as samples often contain second phases,and there are uncertainties regarding short-range order.In response to these open discussions,HEAs have been referred to recently as multiple-principle-element alloys29.It is compelling to consider similar phenomena in non-metallic systems,particularly considering existing information from entropy studies in mixed oxides.In1967Navrotsky and Kleppa showed how conﬁgurational entropy regulates the normal-to-inverse transformation in spinels,where cations transition between ordered and disordered site occupancy among the available sublattices30,31.These fundamental thermodynamic studies lead one to hypothesize that in principle,sufﬁcient temperature would promote an additional transition to a structure containing only one sublattice with random cation occupancy.From experiment we know that before such transitions,normal materials melt,however,it is conceivable that synthetic formulations exist,which exhibit them.Inspired by research activities in the metal alloy communities and fundamental principles of thermodynamics we extend the entropy concept toﬁve-component oxides.With unambiguous experiments we demonstrate the existence of a new class of mixed oxides that not only contains high conﬁgurational entropy but also is indeed truly entropy stabilized.In addition,we present a hypothesis suggesting that entropy stabilization is particularly effective in a compound with ionic character.ResultsChoosing an appropriate experimental candidate.The candi-date system is an equimolar mixture of MgO,CoO,NiO,CuO and ZnO,(which we label as‘E1’)so chosen to provide the appropriate diversity in structures,coordination and cationic radii to test directly the entropic ansatz.The rationale for selection is as fol-lows:the ensemble of binary oxides should not exhibit uniform crystal structure,electronegativity or cation coordination,and there should exist pairs,for example,MgO–ZnO and CuO–NiO, that do not exhibit extensive solubility.Furthermore,the entire collection should be isovalent such that relative cation ratios can be varied continuously with electroneutrality preserved at the net cation to anion ration of unity.Tabulated reference data for each component,including structure and ionic radius,can be found in Supplementary Table1.Testing reversibility.In theﬁrst experiment,ceramic pellets of E1are equilibrated in an air furnace and quenched to room temperature.The temperature spanned a range from700to 1,100°C,in50-°C increments.X-ray diffraction patterns showing the phase evolution are depicted in Fig.1.After700°C,two prominent phases are observed,rocksalt and tenorite.The tenorite phase fraction reduces with increasing equilibration temperature.Full conversion to single-phase rocksalt occurs between850and900°C,after which there are no additional peaks,the background is low andﬂat,and peak widths are narrow in two-theta(2y)space.Reversibility is a requirement of entropy-driven transitions. Consequently,low-temperature equilibration should transform homogeneous1,000°C-equilibrated E1back to its multiphase state(and vice versa on heating).Figure1also shows a sequence of X-ray diffraction patterns for such a thermal excursion;initial equilibration at1,000°C,a second anneal at750°C,andﬁnally a return to1,000°C.The transformation from single phase,to multiphase,to single phase is evident by the X-ray patterns and demonstrates an enantiotropic(that is,reversible with tempera-ture32)phase transition.Testing entropy though composition variation.A composition experiment is conducted to further characterize this phase tran-sition to the random solid solution state.If the driving force is entropy,altering the relative cation ratios will inﬂuence the transition temperature.Any deviation from equimolarity will reduce the number of possible conﬁgurations O(S c¼k B log(O)), thus increasing the transition temperature.Because S c(x i)is logarithmically linked to mole fraction via B x i log(x i),the com-positional dependence is substantial.This dependency underpins our gedankenexperiment where the role of entropy can be tested by measuring the dependency of transition temperature as a function of the total number of components present,and of the composition of a single component about the equimolar formulation.The calculated entropy trends for an ideal mixture are illustrated in Fig.2b,which plots conﬁgurational entropy for a set of mixtures having N species where the composition of an individual species is changed and the others(NÀ1)are keptequimolar.Two dependencies become apparent:the entropy increases as new species are added and the maximum entropy is achieved when all the species have the same fraction.Both dependencies assume ideal random mixing.Two series of composition-varying experiments investigate the existence of these trends in formulation E1.The ﬁrst experiment monitors phase evolution in ﬁve compounds,each related to the parent E1by the extraction of a single component.The sets are equilibrated at 875°C (the threshold temperature for complete solubility)for 12h.The diffraction patterns in Fig.2a show that removing any component oxide results in material with multiple phases.A four-species set equilibrated under these conditions never yields a single-phase material.The second experiment uses ﬁve individual phase diagrams to explore the conﬁgurational entropy versus composition trend.In each,the composition of a single component is varied by ±2,±6and ±10%increments about the equimolar composition while the others are kept even.Since any departure from equimolarity reduces the conﬁgurational entropy,it should increase transition temperatures to single phase,if thattransitionI n t e n s i t y2030405060702 (°)801.81,100N =5No ZnONo MgON =4No CuON =3No NiONo CoON =21,0501,000950T e m p e r a t u r e (°C )T e m p e r a t u r e (°C )T e m p e r a t u r e (°C )T e m p e r a t u r e (°C )T e m p e r a t u r e (°C )S /k B9008501,1001,0501,0009509008501,1001,0501,0009509008501,1001,0501,0009509008501,1001,0501,0009509008500.0X NX NiOX CuOX ZnOX MgoX CoO0.5 1.00.10.20.30.10.20.30.10.20.30.10.20.30.10.20.31.62223112202001111.41.21.00.80.60.40.20.0J14**********Figure 2|Compositional analysis.(a )X-ray diffraction analysis for a composition series where individual components are removed from the parent composition E1and heat treated to the conditions that would otherwise produce full solid solution.Asterisks identify peaks from rocksalt while carrots identify peaks from other crystal structures.(b )Calculated conﬁgurational entropy in an N -component solid solutions as a function of mol%of the N th component,and (c –g )partial phase diagrams showing the transition temperature to single phase as a function of composition (solvus )in the vicinity of the equimolar composition where maximum conﬁgurational entropy is expected.Error bars account for uncertainty between temperature intervals.Each phase diagram varies systematically the concentration of one element.L o g i n t e n s i t y750 °C750 °C800 °C850 °C900 °C1,000 °C2001111,000 °C 2 (°)T (200)T (002)T (110)T (200)T (002)T (110)Figure 1|X-ray diffraction patterns for entropy-stabilized oxide formulation E1.E1consists of an equimolar mixture of MgO,NiO,ZnO,CuO and CoO.The patterns were collected from a single pellet.The pellet was equilibrated for 2h at each temperature in air,then air quenched to room temperature by direct extraction from the furnace.X-ray intensity is plotted on a logarthimic scale and arrows indicate peaks associated with non-rocksalt phases,peaks indexed with (T)and with (RS)correspond to tenorite and rocksalt phases,respectively.The two X-ray patterns for 1,000°C annealed samples are offset in 2y for clarity.is in fact entropy driven.The speciﬁc formulations used are given in Supplementary Table 2.Figure 2c–g are phase diagrams of composition versus transformation temperature for the ﬁve sample sets that varied mole fraction of a single component.The diagrams were produced by equilibrating and quenching individual samples in 25°C intervals between 825and 1,125°C to obtain the T trans -composition solvus .In all cases equimolarity always leads to the lowest transformation temperatures.This is in agreement with entropic promotion,and consistent with the ideal model shown in Fig.2b.One set of raw X-ray patterns used to identify T trans for 10%MgO is given as an example in Supplementary Fig.1.Testing endothermicity .Reversibility and compositionally dependent solvus lines indicate an entropy-driven process.As such,the excursion from polyphase to single phase should be endothermic.An entropy-driven solid–solid transformation is similar to melting,thus requires heat from an external source 33.To test this possibility,the phase transformation in formulation E1can be co-analysed with differential scanning calorimetry and in situ temperature-dependent X-ray diffraction using identical heating rates.The data for both measurements are shown in Fig.3.Figure 3a is a map of diffracted intensity versus diffraction angle (abscissa)as a function of temperature.It covers B 4°of 2y space centred about the 111reﬂection for E1.At a temperature interval between 825and 875°C,there is a distinct transition to single-phase rocksalt structure—all diffraction events in that range collapse into an intense o 1114rocksalt peak.Figure 3b contains the companion calorimetric result where one ﬁnds a pronounced endotherm in the identical temperature window.The endothermic response only occurs when the system adds heat to the sample,uniquely consistent with an entropy-driven transformation 33.We note the small mass loss (B 1.5%)at the endothermic transition.This mass loss results from the conversion of some spinel (an intermediate phase seen by X-ray diffraction)to rocksalt,which requires reduction of 3þto 2þcations and release of oxygen to maintain stoichiometry.To address concerns regarding CuO reduction,Supplementary Fig.2shows a differential scanning calorimetry and thermal gravimetric analysis curve for pure CuO collected under the same conditions.There is no oxygen loss in the vicinity of 875°C.Testing homogeneity .All experimental results shown so far support the entropic stabilization hypothesis.However,all assume that homogeneous cation mixing occurs above the tran-sition temperature.It is conceivable that local composition ﬂuc-tuations produce coherent clustering or phase separation events that are difﬁcult to discern by diffraction using a laboratory sealed tube diffractometer.The solvus lines of Fig.2c–g support random mixing,as the most stable composition is equimolar (a condition only expected for ideal/regular solutions),but it is appropriate to ensure self-consistency with direct measurements.To characterize the cation distributions,extended X-ray absorption ﬁne structure (EXAFS)and scanning transmission electron microscopy with energy dispersive X-ray spectroscopy (STEM EDS)is used to analyse structure and chemistry on the local scale.EXAFS data were collected for Zn,Ni,Cu and Co at the Advanced Photon Source 12-BM-B 34,35.The ﬁtted data are shown in Fig.4,the raw data are given in Supplementary Fig.3.The ﬁtted data for each element provide two conclusions:the cation-to-anion ﬁrst-near-neighbour distances are identical (within experimental error of ±0.01Å)and the local structures for each element to approximately seven near-neighbour distances are similar.Both observations are only consistent with a random cation distribution.As a corroborating measure of local homogeneity,chemical analysis was conducted using a probe-corrected FEI Titan STEM with EDS detection.Thin ﬁlm samples of E1,prepared by pulsed laser deposition,are the most suitable samples to make the assessment.Details of preparation are given in the methods,and X-ray and electron diffraction analysis for the ﬁlm are provided in Supplementary Figs 4and 5.The sample was thinned by mechanical polishing and ion milling.Figure 5shows a collection of images including Fig.5a,the high-angle annular dark-ﬁeld signal (HAADF).In Fig.5b–f,the EDS signals for the K a emission energies of Mg,Co,Ni,Cu and Zn are shown (additional lower magniﬁcation images are included in Supplementary Fig.6).All magniﬁcations reveal chemically and structurally homogeneous material.1,100R 111R 111Mass change (%)510151,000900800700600500400300200DSC –30–20Endo DSC (mW) Exo35.536.537.52θ (°)–10010Mass100T e m p e r a t u r e (°C )T e m p e r a t u r e (°C )Figure 3|Demonstrating endothermicity.(a )In situ X-ray diffraction intensity map as a function of 2y and temperature;and (b )differential scanning calorimetry trace for formulation ‘E1’.Note that the conversion to single phase is accompanied by an endotherm.Both experiments were conducted at a heating rate of 5°C min À1.04k (Å–1)(k )×k 2 (Å–2)2ZnNiCuCo681012Figure 4|Extended X-ray absorption ﬁne structure.EXAFS measured at Advanced Photon Source beamlime 12-BM after energy normalization and ﬁtting.Note that the oscillations for each element occur with similar relative intensity and at similar reciprocal spacing.This suggests a similar local structural and chemical environment for each.X-ray diffraction,EXAFS and STEM–EDS probes are sensitive to 10s of nm,10s of Åand 1Ålength scales,respectively.While any single technique could be misinterpreted to conclude homogenous mixing,the combination of X-ray diffraction,EXAFS and STEM–EDS provide very strong evidence.We note,in particular,the similarity in EXAFS oscillations (both in amplitude and position)out to 12inverse angstroms.This similarly would be lost if local ordering or clustering were present.Consequently,we conclude with certainty that the cations are uniformly dispersed.DiscussionThe set of experimental outcomes show that the transition from multiple-phase to single phase in E1is driven by conﬁgurational entropy.To complete our thermodynamic understanding of this system,it is important to understand and appreciate the enthalpic penalties that establish the transition temperature.In so doing,the data set can be tested for self-consistency,and the present data are brought into the context of prior research on oxide solubility.First,we consider an equation relating the initial and ﬁnal states of the proposed phase transition:MgO ðRS ÞþNiO ðRS ÞþCoO ðRS ÞþCuO ðT ÞþZnO ðW Þ¼Mg ;Ni ;Co ;Cu ;Zn ðÞO ðRS ÞFor MgO,NiO and CoO,the crystal structures of the initial and ﬁnal states are identical.If we assume that solution of each into the E1rocksalt phase is ideal,the enthalpy for mixing is zero.For CuO and ZnO,there must be a structural transition to rocksalt on dissolution from tenorite and wurtzite,respectively.If we again assume (for simplicity)that the solution is ideal,the mixing energy is zero,but there is an enthalpic penalty associated with the structure transition.From Davies et al.and Bularzik et al.,we know the reference chemical potential changes for the wurtzite-to-rocksalt and the tenorite-to-rocksalt transitions of ZnO and CuO;they are 25and 22kJ mol À1,respectively 36,37.If we make the assumption that the transition enthalpies of ZnO(wurtzite)to ZnO(rocksalt E1)and CuO(tenorite)to CuO(rocksalt E1)are comparable,then the enthalpic penalty for solution into E1can be estimated.For ZnO and CuO,the transition to solid solution in a rocksalt structure involves an enthalpy change of (0.2)Á(25kJ mol À1)þ(0.2)Á(22kJ mol À1),a total of þ10kJ mol À1.This calculation is based on the productof the mol fraction of each multiplied by the reference transition enthalpy.This assumption is consistent with the report of Davies et al.who showed that the chemical potential of a particular cation in a particular structure is associated with the molar volume of that structure 36.Since the rocksalt phases of ZnO and CuO have molar volumes comparable to E1,their reference transition enthalpy values are considered suitable proxies.In comparison,the maximum theoretically expected conﬁg-urational entropy difference at 875°C (the temperature were we observe the transition experimentally)between the single species and the random ﬁve-species solid solution is B 15kJ mol À1,5kJ mol À1larger than the calculated enthalpy of transition.It is possible that the origins of this difference are related to mixing energy as the reference energy values for structural transitions to rocksalt do not capture that aspect.While the present phase diagrams that monitor T trans as a function of composition demonstrate rather symmetric behaviour about the temperature minima,it is unlikely that mixing enthalpies are zero for all constituents.Indeed,literature reports show that enthalpies of mixing between the constituent oxides in E1are ﬁnite and of mixed sign,and their magnitudes are on the same order as the 5kJ mol À1difference between our calculated predictions 36.This energy difference may be accounted for by ﬁnite and positive mixing enthalpies.Following this argument,we can achieve a self-consistent appreciation for the entropic driving force and the enthalpic penalties for solution formation in E1by considering enthalpies of the associated structural transitions and expected entropy values for ideal cation mixing.As a ﬁnal test,these predictions can be compared with experiment,speciﬁcally by calculating the magnitude of the endotherm observed by DSC at the transition from multiple-phase to single-phase states.Doing so we ﬁnd a value B 12kJ mol À1(with an uncertainty of ±2kJ mol À1).While we acknowledge the challenge of quantitative calorimetry,we note that this experimental result is intermediate to and in close agreement with the predicted values.Compared with metallic alloys,the pronounced impact of entropy in oxides may be surprising given that on a per-atom basis the total disorder per volume of an oxide seems be lower than in a high-entropy alloy,as the anion sublattice is ordered (apart from point defects).The chemically uniform sublattice is perhaps the key factor that retains cation conﬁgurational entropy.As an illustration,consider a comparison between random metal alloys and random metal oxide alloys.Begin by reviewing the case of a two-component metallic mixture A–B.If the mixture is ideal,the energy of interaction E A–B ¼(E A–A þE B–B )/2,there is no enthalpic preference for bonding,and entropy regulates solution formation.In this scenario,all lattice sites are equivalent and conﬁgurational entropy is maximized.This situation,however,never occurs as no two elements have identical electronegativity and radii values.Figure 6a illustrates a two-component alloy scenario A–B where species B is more electronegative than A.Consequently,the interaction energies E A–A ,E B–B and E A–B will be different.A random mixture of A–B will produce lattice sites with a distribution of ﬁrst near neighbours,that is,species A coordinated to 4-B atoms,2-A and 2-B atoms,etc y Different coordinations will have different energy values and the sites are no longer indistinguishable.Reducing the number of equivalent sites reduces the number of possible conﬁgurations and S .Now consider the same two metallic ions co-populating a cation sublattice,as in Fig.6b.In this case,there is always an intermediate anion separating neighbouring cation lattice sites.Again,in the limiting case where only ﬁrst near neighboursareFigure 5|STEM–EDS analysis of E1.(a )HAADF image.Panels labelled as Zn,Ni,Cu,Mg and Co are intensity maps for the respective characteristic X-rays.The individual EDS maps show uniform spatial distributions for each element and are atomically resolved.considered,every cation lattice site is ‘identical’because each has the same immediate surroundings:the interior of an oxygen octahedron.Differentiation between sites is only apparent when the second near neighbours are considered.From the conﬁgura-tional disorder perspective,if each cation lattice site is identical,and thus energetically similar to all others,the number of microstates possible within the macrostate will approach the maximum value.This crystallographic argument is based on the limiting case where ﬁrst-near-neighbour interactions predominate the energy landscape,which is an imperfect approximation.Second and third near neighbours will inﬂuence the distribution of lattice site energies and the number of equivalent microstates—but the impact will be the same in both scenarios.A larger number of equivalent sites in a crystal with an intermediate sublattice will increase S and expand the elemental diversity containable in a single solid solution and to lower the temperature at which the transition to entropic stabilization occurs.We acknowledge the hypothesis nature of this model at this time,and the need for a rigorous theoretical exploration.It is presented currently as a possibility and suggestion for future consideration and testing.We demonstrate that conﬁgurational disorder can promote reversible transformations between a poly-phase mixture and a homogeneous solid solution of ﬁve binary oxides,which do not form solid solutions when any of the constituents are removed provided the same thermal budget.The outcome is representative of a new class of materials called ‘entropy-stabilized oxides’.While entropic effects are known for oxide systems,for example,random cation occupancy in spinels 30,order–disorder transfor-mations in feldspar 38,and oxygen nonstoichiometry in layered perovskites 39,the capacity to actively engineer conﬁgurational entropy by composition,to stabilize a quinternary oxide with a single cation sublattice,and to stabilize unusual cation coordination values is new.Furthermore,these systems provide a unique opportunity to explore the thermodynamics and structure–property relationships in systems with extreme conﬁgurational disorder.Experimental efforts exploring this composition space are important considering that such compounds will be challenging to characterize with computational approaches minimizing formation energy (for example,genetic algorithms)or with adhoc thermodynamic models (for example,CALPHAD,cluster expansion)6.We expect entropic stabilization in systems where near-neighbour cations are interrupted by a common intermediateanion (or vice versa),which includes broad classes of chalcogenides,nitrides and halides;particularly when covalent character is modest.The entropic driving force—engineered by cation composition—provides a departure from traditional crystal-chemical principles that elegantly predict structural trends in the major ternary and quaternary systems.A companion set of structure–property relationships that predict new entropy-stabilized structures with novel cation incorporation await discovery and exploitation.MethodsSolid-state synthesis of bulk materials .MgO (Alfa Aesar,99.99%),NiO (Sigma Aldrich,99%),CuO (Alfa Aesar,99.9%),CoO (Alfa Aesar,99%)and ZnO (Alfa Aesar 99.9%)are massed and combined using a shaker mill and 3-mm diameter yttrium-stabilized zirconia milling media.To ensure adequate mixing,all batches are milled for at least 2h.Mixed powders are then separated into 0.500-g samples and pressed into 1.27-cm diameter pellets using a uniaxial hydraulic press at 31,000N.The pellets are ﬁred in air using a Protherm PC442tube furnace.Temperature evolution of phases .Ceramic pellets of E1are equilibrated in an air furnace and quenched to room temperature by direct extraction from the hot zone.Phase analysis is monitored by X-ray diffraction using a PANalytical Empyrean X-ray diffractometer with Bragg-Brentano optics including programmable diver-gence and receiving slits to ensure constant illumination area,a Ni ﬁlter,and a 1-D 128element strip detector.The equivalent counting time for a conventional point detector would be 30s per point at 0.01°2y increments.Note that all X-ray are collected using substantial counting times and are plotted on a logarithmic scale.To the extent knowable using a laboratory diffractometer,the high-temperature samples are homogeneous and single phase:there are no additional minor peaks,the background is low and ﬂat,and peak widths are sharp in two-theta (2y )space.Temperature-dependent diffraction data are collected with PANalytical Empyrean X-ray diffractometer with Bragg-Brentano optics includingprogrammable divergence and receiving slits to ensure constant illumination area,a Ni ﬁlter,and a 1-D 256element strip detector.The samples are placed in a resistively heated HTK-1200N hot stage in air.The samples are ramped at a constant rate of 5°C min À1with a theta–two theta pattern captured every 1.5min.Calorimetry data are collected using a Netzsch STA 449F1Jupiter system in a Pt crucible at 5°C min À1in ﬂowing air.Determining solvus lines .Five series of powders are mixed where the amount of one constituent oxide is varied from the parent mixture E1.Supplementary Table 2lists the full set of samples synthesized for this experiment.Each individual sample is cycled through a heat-soak-quench sequence at 25°C increments from 850°C up to 1,150°C.The soak time for each cycle is 2h,and samples are then quenched to room temperature in o 1min.After the quenching step for each cycle,samples are immediately analysed for phase identiﬁcation using a PANalytical Empyrean X-ray diffractometer using the conditions identiﬁed above.If more than one phase is present,the sample would be put through the next temperature cycle.The temperature at which the structure is determined to be pure rocksalt,with no discernable evidence of peak splitting or secondary phases,is deemed the transition temperature as a function of composition.Supplementary Fig.1shows an example of the collected X-raypatterns after each cycle using the E1L series with þ10%MgO.Once single phase is achieved,the sample is removed from the sequence.Note that this entire experiment is conducted two times.Initially in 50°C increments and longer anneals,and to ensure accuracy of temperature values and reproducibility,a second time using shorter increments and 25°C anneals.Findings in both sets are identical to within experimental error bar values.In the latter case,error bars correspond to the annealing interval value of 25°C.In the main text relating to Fig.2a we note that in addition to small peaks from second phases,X-ray spectra for N ¼4samples with either NiO or MgO removed show anisotropic peak broadening in 2y and skewed relative intensities where I (200)/I (111)is less than unity.This ratio is not possible for the rocksalt structure.Supplementary Table 3shows the result of calculations of structure factors for a random equimolar rocksalt oxide with composition E1.Calculations show that the 200reﬂection is the strongest,and that the experimentally measured relative intensities of 111/200are consistent with calculations.We use this information as a means too best assess when the transition to single phase occurs since the most likely reason for the skewed relative intensity is an incomplete conversion to the single-phase state.This dependency is highlighted in Supplementary Fig.1.X-ray absorption ﬁne structure .X-ray absorption ﬁne structure (XAFS)is made possible through the general user programme at the Advanced Photon Source in Lemont,IL (GUP-38672).This technique provides a unique way to probe the local environment of a speciﬁc element based on the interference between an emitted core electron and the backscattering from surrounding species.XAFS makes no assumption of structure symmetry or elemental periodicity,making it an ideal means to study disordered materials.During the absorption process,coreelectronsBFigure 6|Binary metallic compared with a ternary oxide.A schematic representation of two lattices illustrating how the ﬁrst-near-neighbour environments between species having different electronegativity (the darker the more negative charge localized)for (a )a random binary metal alloy and (b )a random pseudo-binary mixed oxide.In the latter,near-neighbour cations are interrupted by intermediate common anions.。

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ElettrologiaCircuiti a corrente continua e alternataCarica e scarica di un condensatoreMISURAZIONE DEI TEMPI DI CARICA E SCARICAUE3050105 09/16 JöS/UDFig. 1: Apparecchio di carica e scarica in funzione con coppia condensatore/resistenza esterna (sinistra) e interna (destra)BASI GENERALIIn un circuito a corrente continua, attraverso un conden-satore passa corrente solo durante l'accensione o lo spe-gnimento. Tramite la corrente, il condensatore viene cari-cato all'accensione, fino al raggiungimento della tensione applicata, e scaricato allo spegnimento, finché la tensione non ha raggiunto lo zero.Per un circuito a corrente continua con capacità C , resistenza R e tensione continua U 0 vale all'accensione(1) 0()(1)t U t U e -τ=⋅- e allo spegnimento(2) 0()t U t U e-τ=⋅con la costante di tempo(3) R C τ=⋅.Per verificare tale correlazione, nell'esperimento vengono mi-surati i tempi necessari al raggiungimento delle tensioni di con-fronto predefinite. Il cronometro viene pertanto avviato con la fase di carica o scarica e successivamente arrestato per mezzo di un comparatore non appena la tensione di confronto risulta raggiunta. La misurazione di diverse tensioni di confronto con-sente di analizzare punto per punto la curva di carica e scarica. Interessante dal punto di vista pratico è anche il tempo(4) 5%ln(5%)3t R C R C =-⋅⋅≈⋅⋅,in cui la tensione del condensatore in fase di scarica raggiungeil 5% del valore di default U0 e in fase di carica raggiunge il 95% del valore finale U0. Tramite la misurazione di t5% è possibile monitorare ad es. i parametri R e C.ELENCO DEGLI STRUMENTI1 Apparecchio di carica e di scarica@230V 1017781 (U10800-230) o1 Apparecchio di carica e di scarica@115V 1017780 (U10800-115) 1 Condensatore 1000 µF, 16 V,P2W191009957 1017806 (U333106)1 Resistenza 10 kΩ, 0,5 W,P2W19 1012922 (U333030) Ulteriormente consigliato:1 Multimetro digitale P1035 1002781 (U11806)MESSA IN FUNZIONE∙Collegare l'apparecchio di carica e scarica alla rete tramite l'alimentatore a spina fornito in dotazione.AVVERTENZE GENERALINelle posizioni INTERN 1, INTERN 2 o INTERN 3 il condensa-tore interno è collegato ai jack di ingresso per la capacità esterna. I condensatori interno ed esterno sono in questo caso collegati in parallelo.∙Per le misurazioni sulle coppie RC interne non collegare capacità esterne.Il tempo di carica e scarica misurato è influenzato da tempi di rimbalzo, amplificati da una mano insicura nel ruotare il com-mutatore di funzione.∙Ruotare il commutatore di funzione in maniera spedita.∙Per una determinazione più precisa del tempo, ripetere ciascuna misurazione almeno tre volte e ricavare il valore medio.∙Scegliere coppie R/C esterne con costante di tempo 4sR C⋅>.ESECUZIONEMisurazione su coppie condensatore/resistenza interne∙Rimuovere resistenze e condensatori esterni.∙Portare il selettore su INTERN 1, INTERN 2 o INTERN 3. Misurazione su coppie condensatore/resistenza esterne ∙Inserire resistenza e condensatore esterni.∙Portare il selettore su EXTERN.Misurazione del tempo di carica t C∙Portare il commutatore di funzione in posizione CHARGE – STOP. ∙Impostare l'interruttore passo-passo sul valore desiderato. ∙Premere brevemente il tasto RESET per azzerare il conta-tore digitale.∙Portare il commutatore di funzione in posizione CHARGE – START per avviare la carica e la misurazione del tempo. ∙Prendere nota del tempo misurato non appena il contatore si arresta.Misurazione del tempo di scarica t DC∙Procedere come per la curva di carica portando tuttavia il commutatore di funzione rispettivamente in posizione DI-SCHARGE – STOP e DISCHARGE – START. Determinazione del tempo t5%Il tempo t5% può essere determinato con una misurazione sia della carica sia della scarica (v. spiegazioni in merito all'equa-zione (4)). Una maggiore precisione è ottenibile mediante la determinazione della media delle due misurazioni:∙Misurare il tempo di carica t C, 5% per 9,5 V.∙Misurare il tempo di scarica t CC, 5% per 0,5 V.∙Calcolare la media (t C, 5% + t CC, 5%) / 2 = t5% .Registrazione della curva di carica∙Regolare l'interruttore passo-passo per tensione di con-fronto su 0,5 V e determinare il tempo di carica come indi-cato in "Misurazione del tempo di carica".∙Per misurare il valore successivo, girare l'interruttore passo-passo avanti di un livello e ripetere tutte le opera-zioni.Registrazione della curva di scarica∙Regolare l'interruttore passo-passo per tensione di con-fronto su 9,5 V e determinare il tempo di scarica come in-dicato in "Misurazione del tempo di scarica".∙Per misurare il valore successivo, girare l'interruttore passo-passo avanti di un livello e ripetere tutte le opera-zioni.Determinazione della capacità esterna/interna e delle resi-stenze interne∙Portare il selettore per coppia R/C in successione su IN-TERN 1, INTERN 2 e INTERN 3 e misurare rispettiva-mente tre volte i tempi t C, 5% e t CC, 5%, come descritto sopra.Riportare i valori nella Tab. 5 e determinare il tempo t5%. ∙Inserire il condensatore esterno. Portare il selettore per coppia R/C ad es. su INTERN 3 e misurare rispettiva-mente tre volte i tempi t C, 5% e t CC, 5%, come descritto sopra.Riportare i valori nella Tab. 5 e determinare il tempo t5%. ∙Inserire inoltre la resistenza esterna. Portare il selettore per coppia R/C su EXTERN e misurare rispettivamente tre volte i tempi t C, 5% e t CC, 5%, come descritto sopra. Riportarei valori nella Tab. 5 e determinare il tempo t5%.ESEMPIO DI MISURAZIONETab. 1: Tempi di carica e scarica della coppia R/C interna 1.Tab. 2:Tempi di carica e scarica della coppia R/C interna 2.Tab. 3: Tempi di carica e scarica della coppia R/C interna 3.Tab. 4:Tempi di carica e scarica della coppia R/C esterna.Tab. 5: T empi di carica e scarica t C,5% e t CC,5% delle tre coppie R/C interne, della coppia R/C interna 3 con collegamento in paral-lelo al condensatore esterno, della coppia R/C esterna e tempi t 5% derivanti dalla determinazione della media.3B Scientific GmbH, Rudorffweg 8, 21031 Amburgo, Germania,ANALISIRegistrazione delle curve di carica e scarica ∙Registrare graficamente le tensioni impostate U C rispetto ai tempi di carica e scarica misurati t C e t CC (Tab. 1 – 4).Le Figg. 2 e 3 mostrano in modo esemplare le curve di carica e scarica relative alla coppia R/C interna 3. L'andamento espo-nenziale previsto in base alle equazioni (1) e (2) risulta confer-mato.Determinazione della capacità esterna/interna e delle resi-stenze interneCon resistenza esterna nota R ext = 10 k Ω (tolleranza 5%), la capacità esterna C ext viene calcolata in base a (4) dal tempo t 5% = t 5%, ext (Tab. 5):(5) 5%,ext ext ext35,4s1180F 3310k t C R ===μ⋅⋅Ω.Tale valore corrisponde, nell'ambito di tolleranza specificato pari a 20%, con il valore nominale 1000 μF.Per i tempi t 5% determinati per la coppia R/C interne 3 con e senza collegamento al condensatore esterno, vale in base all'equazione (4):(6) 5%,3int,3int 3t R C =⋅⋅ e(7) ()5%,3ext int,3int ext 3t R C C =⋅⋅+.Fig. 2: Curva di carica della coppia RC interna 3 La divisione dell'equazione (7) per l'equazione (6) e l'inseri-mento dei tempi da Tab. 5 dà:(8)5%,3int ext 5%,3ext 5%,364,1s1180F 98,5s 64,1s 2199Ft C C t t =⋅=μ⋅--=μ.Tale valore corrisponde, nell'ambito di tolleranza specificato pari a 10%, con il valore nominale 2000 μF.Infine, le tre resistenze interne ancora ignote R int, i si ottengono dai rispettivi tempi di carica e scarica (Tab. 5) e dalla capacità interna determinata in precedenza C int :(9) 5%,int, i int3i t R C =⋅ mit i = 1, 2, 3Ne deriva:(10) int, 114,0s212232199FR ==Ω⋅μ.(11) int, 232,4s491132199FR ==Ω⋅μ.(12) int, 364,1s971732199FR ==Ω⋅μ.I valori coincidono con i valori nominali 2,2 k Ω, 5,1 k Ω e 10 k Ω.Fig. 3: Curva di scarica della coppia RC interna 3U / V t/ sU / V t / s。

柴油发动机活塞卡簧装配设备的研制

第3期2021年3月组合机床与自动化加工技术Modular Machine Tool & Automatic Manufacturing TechninueNo.3Mar.2021文章编号：1001 -2265（2021）03 -0113 -02DOI # 10.13462/j. cnki. mmwmt. 2021.03.027柴油发动机活塞卡簧设备的研制于明辉1>2，田志远1>2（1.滨州渤海活塞有限公司，山东滨州256600；2.. 发动机活塞摩擦副重点实验室，山东滨州 256600）摘要：为了改善柴油发动机活塞装卡簧装配设备的自动化程度不高的现状，提高活塞卡簧装配的精度及效率，因而研发了此动装配设备。

此设备对柴油发动机的装配的特点而设计，运用了压紧的结构形式；放用料仓的形式现，的夹用气动夹爪的夹松功能实现。

该设备在使用过操作人员只需要根据生产需要选择的配套工装，一启动，操作者操作，减少装配时对的，同时该设备具有高柔性，能应490mm 〜4180mm 缸径的活塞卡簧装配"关键词：；；装；气缸中图分类号:TH69；TG65 文献标识码:ADevelopmeet Of Piston Spring Assembly Equipmeet For Diesel EngineYU Ming-hui 1,2 ,TIAN Phi-yuan 1'2(1. Binzhou Bohai Piston Co. , Ltd. , Binzhou Shandong 256600, China ；2. Shandong Province Key Laboratc-re of Engine Piston FOctRn Pais ,Binzhou Shandong 256600,China )Abstrach : Spring in order i improve diesel engine piston assembly equipment automation degree is not high status , improve living Chandrasekhar spring assembly accuracy and efficiency , and thus developed ie circlip automation piston assembly equipment ie equipment of diesel engine live Chandrasekhar spring as sembly is designed according to ie characteristics of ie use of ie structure of compact form of evolution ；Circlip stored in ie form of bunker , spring clip wii the atization of ie function of ie rotating cylinder , ie equipment is in use process operators only need according to ie production need to choose ie appro priate supporting tooling , one key start , operation , convenient operators reduce spring assembly time of piston pin hot cut , at ie same time , the device has high flexibl , able to adapt to 490 mm 〜4180 mm diameter live Chandrasekhar spring assembly.Key wordt : piston pin hole ； clip spring ； spring tsembly ；cylinder0引言发动机内部，燃烧与连杆的连接方式是由销同销孔与连杆小头孔来固定的，而活销两端则是由卡簧来固定的，卡配的直接影响到活塞与连杆的连接。

Additel 761A自动高压测量仪说明书

Series Automated Pressure CalibratorsAdditel 761AAutomated and self-contained pressure generation and control to 1,000 psi ( 70 bar)Standard accuracy to 0.02%FSOptional precision accuracy models to 0.01%FSTwo removable internal pressure modules for multi-range selection Control stability to 0.003%FSPortable, designed for use in the field and in the lab Ability to measure two external pressure modules Wi-Fi, Bluetooth, USB and Ethernet communication HART and profibus communication Data logging and task managementPatented electric pump technology and improved speed OVERVIEWAt Additel, innovation and continuous improvement are part of our company's culture and the products we introduce. When we set out to deliver the Additel 761A series calibrators, we knew we needed to provide breakthrough improvements and additional value to the existing line of calibrators (Additel 761 series). The ADT761A has many improvements: increased pressure range to 1,000 psi (70 bar), removable internal pressure modules, optional precision models to 0.01%FS, increased speed to pressure, ability to read two external pressure modules, touch screen display, Wi-Fi, Bluetooth, and Ethernet communications, double the original battery life, and more!Just like the first generation, this second generation product is completely self-contained and automated with a built-in pump for pressure generation and precision control technology. Simply set the desired pressure and watch the calibrator do thework.ADT761A-LLPThe Additel 761A-LLP is designed for low pressure calibration and comes with a ±30 inH2O (±75 mbar) high range module and a low range module of your choice ranging from ±20 inH2O to as low as ±0.25 inH2O (±50 to ±0.62 mbar). This unit has an accuracy of 0.05%FS with control stability better than 0.005%FS. All measurements can be made in differential or gaugepressures.ADT761A-DThe Additel 761A-D also provides differential and gauge measurement which covers the range of -13.5 to 35 psi (-0.95 to 2.5 bar). This unit comes with a CP35 module (-13.5 to 35 psi) and one low range module of your choice rangeing as low as ±10 inH2O (25 mbar). Each ADT761A-D can be preconfigured with the modules that fit your need to give you the best precision at the pressures you perform calibrations.ADT761A-500The Additel 761A-500 will generate and control from vacuum pressures upto 500 psig (35 bar.g). Both gauge and absolute pressures can be realizeddue to a built-in barometer. Each unit comes with a CP500 module (-13 to500 psig) for the high range and the low range can be preconfigured basedon the variety of modules available down to 10 psig (0.7 bar.g).ADT761A-1KThe Additel 761A-1K will generate and control from vacuum pressures up to 1,000 psig (70 bar.g). This unit can typically achieve 1,000 psi in less than 45 seconds. Like the ADT761A-500, both gauge and absolute pressures can be realized due to a built-in barometer. Each unit comes with a CP1K module (-13 to 1,000 psig) for the high range and the low range can be preconfigured based on the variety of modules available down to 30 psig (2 bar.g).ADT761A-APXR Precision Accuracy OptionsThe Additel 761A series includes a precision accuracy option whichprovides an accuracy of 0.01%FS. This calibrator option includes a singlenon-removable sensor and can measure absolute and gauge pressures.Model configurations are available from 15 to 1,000 psig (1 to 7 bar.g).ADT761A-BPThe Additel 761A-BP is designed for calibration of barometer sensors. Witha range of 100 to 1200 hPa and an accuracy of 0.01%FS, this unit is idealfor calibration on the bench or in the field.Pressure SpecificationsElectrical Specifications[1] One year accuracy (including 1 year stability). FS specification applies to the span of the module range.[2] Specification based on gauge measurement. An additional 60 pa uncertainty will need to be included when measuring in absolute mode. Applicable only for use with the ADT761A-500 and ADT761A-1K* Additel 761A calibrators support 160A series intelligent digital pressure modules that are available for gauge, vacuum and absolute pressure from -15 psi to 60,000 psi (-1 bar to 4200 bar). For detailed specifications refer to the 160A series pressure modules data sheet.Internal Module Specification and Compatibility[1] FS specification applies to the span of the module range. Accuracy includes one-year stability, except for DP025 to DP10 modules.[2] Accuracy is a 6 months spec, 1-year long-term drift is 0.2%FS.[3] Accuracy is a 6 months spec, 1-year long-term drift is 0.1%FS.[4] Accuracy is a 6 months spec, 1-year long-term drift is 0.05%FS.[5] Specification based on gauge measurement. An additional 60 pa uncertainty will need to be included when measuring in absolute mode.Applicable only for use with the ADT761A-500 and ADT761A-1KPressure gauge / transmitter / switch calibrationGeneral SpecificationsPressure RangeHigh-Range Pressure ModuleLow-Range Pressure Module Accuracy RangeAccuracyDP30: -75 to 75 mbar 0.05%FSUser selectable fromDP20 to DP025See Internal ModuleTable CP35: -0.95 to 2.5 bar 0.02%FSUser selectable from DP10 to CP30See Internal ModuleTable Task ManualHigh Pressure Automated CalibrationORDERING INFORMATIONModel NumberNPressure Range。

侧身链条英语说法

侧身链条英语说法英文回答：Lateral Chains.Lateral chains are branched hydrocarbon chains that are attached to the main carbon backbone of an organic molecule. They can be aliphatic or aromatic, and they can vary in length and complexity. Lateral chains can have asignificant impact on the physical and chemical propertiesof an organic molecule.Aliphatic Lateral Chains.Aliphatic lateral chains are composed of saturated or unsaturated hydrocarbon chains. Saturated aliphatic lateral chains contain only single bonds between the carbon atoms, while unsaturated aliphatic lateral chains contain one or more double or triple bonds. The length and degree of unsaturation of an aliphatic lateral chain can affect thesolubility, boiling point, and other physical properties of an organic molecule.Aromatic Lateral Chains.Aromatic lateral chains are composed of benzene rings or other aromatic groups. Aromatic lateral chains are typically more stable and less reactive than aliphatic lateral chains. They can also affect the solubility,boiling point, and other physical properties of an organic molecule.Effects of Lateral Chains on Organic Molecules.Lateral chains can have a significant impact on the physical and chemical properties of organic molecules. For example, the presence of a lateral chain can:Increase the solubility of an organic molecule in a nonpolar solvent.Decrease the boiling point of an organic molecule.Alter the reactivity of an organic molecule.Influence the formation of intermolecular forces.Importance of Lateral Chains.Lateral chains are important in a wide variety of organic molecules, including:Hydrocarbons.Alcohols.Aldehydes.Ketones.Carboxylic acids.Esters.Amides.Amines.Lateral chains can also be found in many natural products and pharmaceuticals.中文回答：侧身链条。

3X FLAG 碱基序产品说明书

F4799dat Rev 07/211Product Information3X FLAG ® PeptideF4799Storage Temperature 2-8 °CProduct DescriptionThe 3X FLAG ® Peptide is a synthetic peptide of23 amino acid residues, with a calculated molecular weight of 2,864 Da, where theAsp-Tyr-Lys-Xaa-Xaa-Asp motif 1 is repeated three times in the peptide. The eight amino acids at the C-terminus make up the classic FLAG sequence(Asp-Tyr-Lys-Asp-Asp-Asp-Asp-Lys). The sequence of the 3X FLAG ® Peptide is as follows:N-Met-Asp-Tyr-Lys-Asp-His-Asp-Gly-Asp-Tyr-Lys-Asp-His-Asp-Ile-Asp-Tyr-Lys-Asp-Asp-Asp-Asp-Lys-CThis product is for use in competitive elution of3X FLAG ® fusion proteins from the ANTI-FLAG ® M2 monoclonal antibody in solution or bound to agarose on the ANTI-FLAG ® M2 agarose affinity gel.A working concentration of 100 µg/mL is commonly used to elute 3X FLAG ® fusion proteins from theANTI-FLAG ® M2 affinity gel.2,3 Five column volumes of this working solution are sufficient to elute most 3X FLAG ® fusion proteins. FLAG peptide (Cat. No. F3290) will not elute 3X FLAG ® fusion proteins.Other publications have used other concentrations of this 3X FLAG ® Peptide at varying concentrations, where we have not necessarily tested those different conditions, such as: •200 ng/mL 4•150 µg/mL 5•0.2 mg/mL 6•0.3 mg/mL (300 µg/mL)7•150 µM 8•340 µM 9•0.5 mg/mL 10Preparation InstructionsTo prepare a stock solution, dissolve in TBS(50 mM Tris-HCl, pH 7.4, with 150 mM NaCl) at a concentration of 5 mg/mL. Aliquot and store at –20 °C. Repeated freezing and thawing is not recommended.Storage/StabilityStore the product at 2–8 °C.Precautions and DisclaimerFor R&D use only. Not for drug, household, or other uses. Please consult the Safety Data Sheet for information regarding hazards and safe handling practices.ProcedurePeptide Elution of 3X FLAG ® Fusion Protein from ANTI-FLAG ® M2 Affinity GelNote: Affinity chromatography may be performed at room temperature. If, however, the 3X FLAG ® fusion protein is unstable or sensitive to protease,chromatography should be performed at 2-8 °C. Column Set-Up1.Place the empty chromatography column on afirm support.2.Attach a drainage tube to the column to controlthe flow rate. Limit the length of tubing to 25 cm.3.Remove the top and bottom tabs and rinse thecolumn twice with TBS. Allow the buffer to drain from the column. Leave residual TBS in the column to aid in packing the ANTI-FLAG ® M2affinity gel.F4799dat Rev 07/212Packing the Column1.Thoroughly suspend a vial of ANTI-FLAG ® M2affinity gel to make a uniform suspension of the gel beads.2.Immediately transfer the suspension tothe column.3.Allow the gel bed to drain and rinse the vialwith TBS.4.Add the rinse to the column and allow it to drainagain. The gel bed will not crack when excess solution is drained under normal circumstances,but do not let the gel bed run dry.Washing the ColumnWash the gel by loading three sequential 5 mL aliquots of 0.1 M glycine HCl, pH 3.5, followed by three sequential 5 mL aliquots of TBS. Avoiddisturbing the gel bed while loading. Let each aliquot drain completely before adding the next. Do not leave the column in glycine HCl for longer than 20 minutes. Binding the 3X FLAG ® Fusion Protein to the Column1.Proper binding of FLAG fusion proteins to theANTI-FLAG ® M2 affinity gel requires physiological ionic strength and neutral pH.Note: If the sample contains particulate material,centrifuge or filter prior to applying to the column.Viscous samples should be sonicated or treated with deoxyribonuclease I prior to loading on the column.2.Load the sample onto the column under gravityflow. Fill the column completely several times for large volumes. Depending upon the protein and flow rate, all of the antigen may not bind. Multiple passes over the column will improve the binding efficiency.3.After binding, wash the column three times with12 mL aliquots of TBS.Elution of 3X FLAG ® Fusion Proteins by Competition with 3X FLAG ® Peptide: 1.Allow the column to drain completely.2.Elute the bound 3X FLAG ®-BAP or the 3X FLAG ®fusion protein of interest by competitive elution with five one-column volume aliquots of a solution containing 100 µg/mL 3X FLAG ® peptide in TBS.Note: Column packing quality, flow rate, andspecific properties of the 3X FLAG ® fusion protein may influence the efficiency of protein elution.Recycling the Column3X FLAG ® peptide may not elute all of the 3X FLAG ® fusion protein bound to ANTI-FLAG ® M2 affinity gel. It is recommended the column be regeneratedimmediately after use by washing with three 5 mL aliquots of 0.1 M glycine HCI, pH 3.5. The columnshould be immediately re-equilibrated in TBS until the effluent is at neutral pH.Note: Do not leave the column in glycine HCl for longer than 20 minutes. Storing the Column1.Wash the column three times with 5 mL of TBS/A(TBS containing 0.02% sodium azide).2.Then add another 5 mL of TBS/A.3.Store at 2–8 °C without draining.References1.Miceli, R.M. et al., J. Immunol. Methods ,167(1-2): 279-287 (1994).2.Zheng, X., and Pincus, D., Bio. Protoc., 7(12):e2348 (2017).3.Fujii, K. et al., Mol. Cell., 72(6):1013-1020.e6 (2018).4.Kuliyev, E. et al., J. Neurosci ., 38(10):2615-2630 (2018).5.Chen, H. et al., STAR Protoc ., 1(1):100043 (2020).The life science business of Merck operates as MilliporeSigma in the U.S. and Canada.Merck FLAG, ANTI-FLAG, and Sigma-Aldrich are trademarks of Merck KGaA, Darmstadt, Germany or its affiliates. All other trademarks are the property of their respective owners. Detailed information on trademarks is available via publicly accessible resources. © 2021 Merck KGaA, Darmstadt, Germany and/or its affiliates. All Rights Reserved. F4799dat Rev 07/2136.Meller, N. et al., J. Biol. Chem., 279(36):37470-37476 (2004).7.Duan, S. et al., Nucleic Acids Res ., 48(12):6530-6546 (2020).8.Isom, D.G. et al., Proc. Nat. Acad. Sci. USA ,107(11): 4908-4913 (2010).9.Valdez-Sinon, A.N. et al., iScience , 23(5):101132 (2020).10.Huang, D. et al., Biochemistry , 59(16):1559-1564 (2020).NoticeWe provide information and advice to our customers on application technologies and regulatory matters to the best of our knowledge and ability, but without obligation or liability. Existing laws and regulations are to be observed in all cases by our customers. This also applies in respect to any rights of third parties. Our information and advice do not relieve ourcustomers of their own responsibility for checking the suitability of our products for the envisaged purpose. The information in this document is subject to change without notice and should not be construed as acommitment by the manufacturing or selling entity, or an affiliate. We assume no responsibility for any errors that may appear in this document.Technical AssistanceVisit the tech service page at /techservice .Standard WarrantyThe applicable warranty for the products listed in this publication may be found at /terms .Contact InformationFor the location of the office nearest you, go to /offices .。

Cold Spring Harb Perspect Biol-2010-Wente-

2010;2:a000562 originally published online July 14, 2010Cold Spring Harb Perspect Biol Susan R. Wente and Michael P. Rout The Nuclear Pore Complex and Nuclear Transport References/content/2/10/a000562.full.html#ref-list-1 This article cites 179 articles, 82 of which can be accessed free service Email alerting click here box at the top right corner of the article or Receive free email alerts when new articles cite this article - sign up in the Subject collections (29 articles)The Nucleus Articles on similar topics can be found in the following collections/site/misc/subscribe.xhtml go to: Cold Spring Harbor Perspectives in Biology To subscribe to Copyright © 2010 Cold Spring Harbor Laboratory Press; all rights reservedThe Nuclear Pore Complex and Nuclear TransportSusan R.Wente1and Michael P.Rout21Department of Cell and Developmental Biology,Vanderbilt University Medical Center,Nashville,T ennessee372322Laboratory of Cellular and Structural Biology,The Rockefeller University,New Y ork,New Y ork10065 Correspondence:susan.wente@ and rout@Internal membrane bound structures sequester all genetic material in eukaryotic cells.The most prominent of these structures is the nucleus,which is bounded by a double membrane termed the nuclear envelope(NE).Though this NE separates the nucleoplasm and genetic material within the nucleus from the surrounding cytoplasm,it is studded throughout with portals called nuclear pore complexes(NPCs).The NPC is a highly selective,bidirectional transporter for a tremendous range of protein and ribonucleoprotein cargoes.All the whilethe NPC must prevent the passage of nonspeciﬁc macromolecules,yet allow the free diffu-sion of water,sugars,and ions.These many types of nuclear transport are regulated at mul-tiple stages,and the NPC carries binding sites for many of the proteins that modulate and modify the cargoes as they pass across the NE.Assembly,maintenance,and repair of the NPC must somehow occur while maintaining the integrity of the NE.Finally,the NPC appears to be an anchor for localization of many nuclear processes,including gene acti-vation and cell cycle regulation.All these requirements demonstrate the complex designof the NPC and the integral role it plays in key cellular processes.T axonomically speaking,all life on earth falls into one of two fundamental groups,the prokaryotes and the eukaryotes.The prokar-yotes,theﬁrst group to evolve,are single cell organisms bounded by a single membrane. About1.5billion years later,a series of evo-lutionary innovations led to the emergence of eukaryotes.Eukaryotes have multiple inner membrane structures that allow for compart-mentalization within the cell,and therefore dif-ferentiation of the cell and regulation within it. Ultimately,the greater cellular complexity of eukaryotes allowed them to adopt a multicel-lular lifestyle,as seen in the plants,fungi and animals of today(reviewed in Field and Dacks 2009).Internal membrane bound structures se-quester all genetic material in eukaryotic cells. The most prominent of these structures,which gives the eukaryotes their Greek-rooted name,is the nucleus—the central“kernel”(gr.“karyo-”) of the cell.The nucleus is bounded by a double membrane termed the nuclear envelope(NE), which separates the nucleoplasm and geneticEditors:Tom Misteli and David L.SpectorAdditional Perspectives on The Nucleus available at Copyright#2010Cold Spring Harbor Laboratory Press;all rights reserved;doi:10.1101/cshperspect.a000562Cite this article as Cold Spring Harb Perspect Biol2010;2:a0005621material from the surrounding cytoplasm. However the genetic material in the nucleus is not totally isolated from the rest of the cell. Studded throughout the NE are portals called nuclear pore complexes(NPCs).The NPC is a highly selective,bidirectional transporter for a tremendous range of cargoes.Going into the nucleus,these cargoes include inner nuclear membrane proteins and all the proteins in the nucleoplasm.Going out are RNA-associated proteins that are assembled into ribosomal sub-units or messenger ribonucleoproteins(mRNPs). Once transported,the NPC must ensure these cargos are retained in their respective nuclear and cytoplasmic compartments.All the while the NPC must prevent the passage of nonspe-ciﬁc macromolecules,yet allow the free diffu-sion of water,sugars,and ions.These many types of nuclear transport are regulated at mul-tiple stages,providing a powerful extra level of cellular control that is not necessary in prokar-yotes.Assembly,maintenance,and repair of the NPC must somehow occur while maintain-ing the integrity of the NE.Finally,the NPC ap-pears to be an anchor for localization of many nuclear processes,including gene activation and cell cycle regulation(reviewed in Ahmed and Brickner2007;Hetzer and W ente2009). All these requirements demonstrate the com-plex design of the NPC and the integral role it plays in key cellular processes. STRUCTURE OF THE NPC:SET UP OF THE MACHINEThe speciﬁcations of the NPC’s transport mac-hinery represent a huge engineering challenge for evolution.No transitional forms of this elab-orate transport system have yet been found in modern day organisms to reveal how it evolved. However,recent clues show that the NPC itself retains in its core a fossil of its ancient origins, indicating that the same mechanism that gen-erated the internal membranes of eukaryotes might also have been responsible for the NPCs and the transport machinery.In the electron microscope,the NPC ap-pears as a complex cylindrical structure with strong octagonal symmetry,measuring some 100–150nm in diameter and50–70nm in thickness depending on the organism(reviewed in W ente2000;Lim et al.2008).This overall ap-pearance seems broadly conserved throughout all eukaryotes.The two membranes of the NE, the outer and inner membranes,join only in a specialized,sharply curved piece of“pore membrane”that forms a grommet in the NE within which the NPC sits.Within each NPC is a core structure containing eight spokes surrounding a central tube.This central hole ( 30nm diameter and 50nm long)is where the nucleoplasm connects to the cytoplasm and where macromolecular exchange occurs. Peripheralﬁlaments are attached to the core,ﬁlling the central hole as well as emanating into the nucleoplasm and cytoplasm.Theseﬁl-aments form a basket-like structure on the nuclear side of the NPC(Fig.1).One can envision the NPC as being com-prised of layers of interacting proteins,starting with the core structure,moving outwards through its peripheralﬁlaments,and then to associating clouds of soluble transport factors and peripherally associating protein complexes in the nucleus and cytoplasm(Rout and Aitch-ison2001).These protein interactions can oc-cur on radically different time scales.Some proteins form relatively permanent associations with the core structure,and so are termed nu-clear pore complex components or“nucleo-porins”(“Nups”).Other proteins associate transiently with the NPC,either constantly cycling on and off or attaching only at particular times in the cell’s life cycle.The NPC is covered in binding sites for these transiently associating proteins.Because the NPC is neither a motor nor an enzyme,the interactions provided by its binding sites wholly deﬁne the function of the NPC.Recent work,mainly in the yeast Saccharo-myces cerevisiae and in vertebrates,has begun to elucidate the molecular architecture of the NPC(Rout et al.2000;Cronshaw et al. 2002;Alber et al.2007b).Given its large size, the main body of the NPC comprises a surpris-ingly small number of 30unique proteins (Table1).However,because of the NPC’s eight-fold symmetry,these Nups are each present inS.R.Wente and M.P.Rout2Cite this article as Cold Spring Harb Perspect Biol2010;2:a000562multiple copies (usually 16per NPC)resulting in around 400polypeptides for each NPC in every eukaryote (Rout et al.2000;Cronshaw et al.2002;DeGrasse et al.2009).Further redun-dancy is evident from the recent mapping of the yeast NPC.Indeed,the NPC’s structure is mod-ular,consisting of a few highly repetitive protein fold types (Devos et al.2006;Alber et al.2007b;DeGrasse et al.2009).This suggests that the bulk of the NPC’s structure has evolved through multiple duplications of a small precursor set of genes encoding just a handful of progenitor Nups.T o understand its evolutionary origins,the NPC of the highly divergent Trypanosoma was recently characterized (DeGrasse et al.2009).Despite signiﬁcant divergence in primary struc-ture,the Trypanosome NPC consists mainly of the motifs and domains found in vertebrate and yeast NPCs,indicating on a molecular level that the basic structural components of the NPC are conserved across all eukaryotes.Importantly,this also strongly implies that the last common eukaryotic ancestor had many fea-tures in common with contemporary NPCs,and perhaps provided a key adaptive advantage CentralbasketCytoplasmic SymmetricFG nupsFigure 1.Major structural features of the NPC (based on the architectural map of Alber et al.(2007b);see Table 1and main text for details).Table 1.Nucleoporin homologs of yeast and vertebratesNPC substructure Y east components Vertebrate componentsOuter Ring Nup84subcomplex (Nup84,Nup85,Nup120,Nup133,Nup145C,Sec13,Seh1)Nup107-160complex (Nup160,Nup133,Nup107,Nup96,Nup75,Seh1,Sec13,Aladin,Nup43,Nup37)Inner Ring Nup170subcomplex (Nup170,Nup157,Nup188,Nup192,Nup59,Nup53)Nup155subcomplex (Nup155,Nup205,Nup188,Nup35)Cytoplasmic FG Nups and FilamentsNup159,Nup42Nup358,Nup214,Nlp1Lumenal Ring Ndc1,Pom152,Pom34Gp210,Ndc1,Pom121Symmetric FG Nups Nsp1,Nup57,Nup49,Nup145N,Nup116,Nup100Nup62,Nup58/45,Nup54,Nup98Linker Nups Nup82,Nic96Nup88,Nup93Nucleoplasmic FG Nups and FilamentsNup1,Nup60,Mlp1,Mlp2Nup153,TprNuclear Pore Complexes and Nuclear TransportCite this article as Cold Spring Harb Perspect Biol 2010;2:a0005623for this organism that has been retained,little changed,ever since.The structural proteins making up the bulk of the spokes and rings give the NPC its shape and strength(Fig.1).These core proteins of the NPC also maintain the stability of the nuclear envelope and facilitate the bending of the pore membrane into the inner and outer NE mem-branes.The most equatorial rings,termed the inner rings,are comprised of the Nup170com-plex(yeast)or Nup155complex(vertebrates) (Aitchison et al.1995;Grandi et al.1997;Miller et al.2000)(Fig.1).The inner rings are sand-wiched between the outer rings,which are com-prised of the Nup84complex(yeast)or Nup107 complex(vertebrates)(Table1)(Siniossoglou et al.1996;Fontoura et al.1999;Siniossoglou et al.2000;Belgareh et al.2001;Vasu et al. 2001).T ogether,these Nup complexes form a scaffold that hugs the curved surface of the pore membrane and helps form the central tube through which macromolecular exchange oc-curs(Alber et al.2007a;Alber et al.2007b).Nups in the core scaffold represent roughly half the mass of the whole NPC and are com-posed almost entirely of either b-propeller folds,a-solenoid folds,or a distinct arrange-ment of both in an amino-terminal b-propeller followed by a carboxy-terminal a-solenoid fold. The core scaffold of all eukaryotes appears to retain this basic fold composition(Devos et al.2004;Devos et al.2006;DeGrasse et al. 2009).Strikingly,there are similarities between the structures of the core NPC scaffold curving around the pore membrane and other mem-brane-associated complexes such as clathrin/ adaptin,COPI,and COPII(Fig.1)(Devos et al. 2004;Devos et al.2006).Clathrin/adaptin is involved in coat-mediated endocytosis at the plasma membrane,and COPI and COPII are responsible for coat-mediated vesicular trans-port between the plasma membrane and endo-membrane systems such as the Golgi and ER. Indeed,the similarities between core scaffold Nups and coating complexes have been borne out in numerous crystallographic studies(Berke et al.2004;Hsia et al.2007;Brohawn et al.2008; Debler et al.2008;Brohawn et al.2009;Leksa et al.2009;Seo et al.2009;Whittle and Schwartz 2009),although nearly2billion years of evolu-tion have made it difﬁcult atﬁrst glance to rec-ognize the common origin of these two groups. However,their common b-propeller and helix-turn-helix repeat structure is still unmistakable (Brohawn et al.2008;Field and Dacks2009). In NPCs the“coat”comprises the core scaffold of the NPC,where—analogous to the curved membrane of a vesicle being stabilized by a COP or clathrin coat—it stabilizes the curved pore membrane.These similarities also give a tantalizing glimpse into the deep evolutionary origins of eukaryotes.It seems early proto-eukaryotes distinguished themselves from their prokaryotes by acquiring a membrane-curving protein module,the“proto-coatomer”(likely composed of a simple b-propeller/a-solenoid protein),that allowed them to mold their plasma membranes into internal compartments. Modern eukaryotes diversiﬁed this module into many specialized membrane coating complexes, accounting for the evolution of their internal membrane systems(Devos et al.2004;Devos et al.2006).The framework of the NPC serves two key transport purposes:to form a barrier of deﬁned permeability within the pore,and to facilitate transport of selected macromolecules across it.Both processes are dependent on the correct positioning of critical Nups in the NPC architecture(Radu et al.1995;Strawn et al. 2004;Liu and Stewart2005).Attached to the inside face of the NPC core scaffold,facing the central tube’s cavity,are groups of nucleoporins termed“linker nucleoporins”(Fig.1).T ogether with the inner ring,these seem to form most of the attachment sites for a last set of nucleop-orins,termed“FG Nups”(Alber et al.2007b). These FG Nups,named for their phenylala-nine-glycine repeats,are the direct mediators of nucleocytoplasmic transport(Radu et al. 1995;Strawn et al.2004;Liu and Stewart2005) (see the following section).The core NPC scaffold is connected to a set of integral membrane proteins,which form an outer luminal ring in the NE lumen and anchor the NPC into the NE(Nehrbass et al.1996; Alber et al.2007a;Alber et al.2007b)(Fig.1). Oddly,the membrane nucleoporins seem poorlyS.R.Wente and M.P.Rout4Cite this article as Cold Spring Harb Perspect Biol2010;2:a000562conserved—if at all—across the eukaryotes.The fact that all the currently known pore mem-brane proteins in Aspergillus nidulans can seem-ingly be dispensed with for NPC function and assembly might indicate that there are not st-rong pressures for their conservation,and that there are other membrane proteins that can serve the role(Liu et al.2009).This fact also sets up a quandary—if most or all of the NPC’s presumed membrane anchors are dispensible, how then is the NPC reliably anchored to the membrane?Several groups are seeking the an-swer to this question(Hetzer and W ente2009). OPERATION OF THE MACHINE:THE SOLUBLE PHASEUnderstanding the transport machine requires resolving both its barrier and binding activities. How the NPC machine balances both of these selective functions has been a challenging mys-tery.Studies ofﬂuorescently labeled sized dex-trans or gold particles microinjected into cells (Feldherr and Akin1997;Keminer and Peters 1999)have deﬁned the practical permeability limits of the NPC,showing that under physio-logical time scales,macromolecules greater than 40kDa in size do not show any measureable redistribution between the nucleus and cyto-plasm and thus,no movement through the NPC.Conversely,metal ions,small metabolites, and molecules less than 40kDa in mass or 5 nm in diameter can pass relatively freely.NPC permeability is altered in several yeast nup mutants,pinpointing NPC structural elements, including core scaffold components,that are critical to the assembly or maintenance of this barrier(Shulga et al.2000;Denning et al.2001; Shulga and Goldfarb2003;Strawn et al.2004; Patel et al.2007).Larger macromolecules over-come this permeability barrier by interacting either directly with the NPC themselves or through soluble transport factors.These macro-molecules account for a tremendous variety of cargo including proteins,tRNAs,ribosomal subunits,and viral particles(reviewed in Mac-ara2001).Overall,the NPC is capable of trans-porting cargo up to39nm in diameter.This is on par with the size of the ribosomal subunits and viral capsids that are known to move as intact complexes(Pante and Kann2002).Mac-romolecules larger than this can still be trans-located across the NPC,including mRNPs (mRNAs coated with RNA-binding proteins) with masses reaching several hundred thousand daltons.EM images of Balbiani ring mRNP particles associated with the NPC show the posttranscriptional 50nm mRNA–protein particles to rearrange into rodlike structures,de-creasing their maximum diameter to 25nm (Mehlin et al.1992).Thus,cargoes above a limit-ing diameter must rearrange to pass through the selective barrier of the NPC(Daneholt2001).A transport signal and a shuttling receptor for that transport signal are the minimal require-ments for any facilitated translocation(reviewed in Mattaj and Englmeier1998;Pemberton and Paschal2005).The targeting of proteins into or out of the nucleus requires speciﬁc amino acid sequence spans,termed nuclear local-ization sequences(NLSs)or nuclear export sequences(NESs).All the information required to target a protein to the nucleus is within these short sequences.In fact,fusion of an NLS to a nonnuclear protein is sufﬁcient to mediate its transport and import to the nucleus(Goldfarb et al.1986).For proteins,there are many distinct types of NLSs and NESs.For example,the clas-sical NLS(cNLS)is the simpleﬁve amino acid peptide KKKRK,necessary and sufﬁcient for targeting its attached protein to the nucleus (Goldfarb et al.1986),whereas many proteins carry a more complex“bipartite”NLS con-sisting of two clusters of basic amino acids,sep-arated by a spacer of roughly10amino acids (Dingwall et al.1988).However,the full spec-trum of sequences recognized by each transport receptor has not yet been carefully and fully deﬁned.The most in depth analysis of NLS structural recognition by a transport receptor and extrapolation to predicting cargoes on a broader genome level has only been reported for one transport receptor(Lee et al.2006).The key parameters deﬁning an NLS or NES include critical tests for necessity and sufﬁciency in the endogenous protein.Importantly,some proteins undergo dynamic cycles of nuclear import and export and harbor both NLSs and Nuclear Pore Complexes and Nuclear TransportCite this article as Cold Spring Harb Perspect Biol2010;2:a0005625NESs.This can increase the complexity of iden-tifying the signals.Moreover,the recognition and accessibility of the signals can be controlled by signaling,cell cycle,and developmental events(reviewed in W eis2003;T erry et al.2007).During NPC translocation,soluble trans-port factors are required to either bring cargo to the NPC or modulate cargo translocation across the NPC.Most of these soluble transport factors come from the family of proteins known as the karyopherins(Table2).The karyopherins (also called importins,exportins,and tranpor-tins)were theﬁrst family of shuttling transport factors discovered.Fourteen karyopherin family members are found in Saccharomyces cerevisiae whereas at least20have been found in metazo-ans(reviewed in Fried and Kutay2003;Pember-ton and Paschal2005).Most karyopherins bind their cargoes directly.However,in some cases an adaptor protein is needed in addition to theTable2.Karyopherin transport factors of yeast and vertebratesÃS.cerevisiae KaryopherinsVertebrateKaryopherins Examples of Cargo(s):(v)–vertebrate,(sc)–S.cerevisiaeKap95Importin-b1Imports via sc-Kap60/v-importin-a adaptor proteinswith cNLS;Imports via v-Snurportin the UsnRNPs;with no adaptor,imports v-cargo SREBP-2,HIV Rev,HIV T A T,cyclin BKap104Transportin orTransportin2Imports sc-cargo–Nab2,Hrp1;v-cargo–PY-NLS proteins,mRNA-binding proteins,histones,ribosomal proteinsKap108/Sxm1Importin8Imports sc-cargo–Lhp1,ribosomal proteins;v-cargo–SRP19,SmadKap109/Cse1CAS Imports sc-cargo–Kap60/Srp1;v-cargo–importin a s Kap111/Mtr10Transportin SR1or SR2Imports sc-cargo–Npl3,tRNAs;v-cargo–SR proteins,HuRKap114Importin9Imports sc-cargo–TBP,histones,Nap1,Sua7;v-cargo–histones,ribosomal proteinsKap119/Nmd5Importin7Imports sc-cargo–Hog1,Crz1,Dst1,ribosomal proteins,histones;v-cargo–Smad,ERK,GR,ribosomalproteinsKap120HsRanBP11Imports sc-cargo–Rpf1Kap121/Pse1Importin5/Importinb3/RanBP5Imports sc-cargo–Yra1,Spo12,Ste12,Y ap1,Pho4, histones,ribosomal proteins;v-cargo–histones, ribosomal proteinsKap122/Pdr6-Imports sc-cargo–T oa1and T oa2,TFIIAKap123Importin4Imports sc-cargo–SRP proteins,histones,ribosomalproteins;v-cargo-Transition Protein2,histones,ribosomal protein S3aKap127/Los1Exportin-t Exports tRNAsKap142/Msn5Exportin5sc-cargo–imports replication protein A;exports Pho4,Crz1,Cdh1;v-cargo-exports pre-miRNAImportin13v-cargo–imports UBC9,Y14;exports eIF1ACrm1/Xpo1CRM1/Exportin1Exports proteins with leucine-rich NES,60S ribosomalsubunits(via NMD3adaptor),40S ribosomalsubunits—Exportin4v-cargo–imports SOX2,SRY;exports Smad3,eIF5A —Exportin6Exports proﬁlin,actin—Exportin7/RanBP16Exports p50-RhoGAPÃBased on references cited within and adapted from Tran et al.2007a and DeGrasse et al.2009.S.R.Wente and M.P.Rout6Cite this article as Cold Spring Harb Perspect Biol2010;2:a000562karyopherin to recognize signals.Not only do karyopherins have a cargo-binding domain,they also have an NPC-binding domain(s)as well as a binding domain at the amino-terminus for the small Ras-like GTPase Ran (see the fol-lowing paragraph)(reviewed in Macara 2001;Harel and Forbes 2004).Overall,karyopherin family members share only modest sequence homology,with the greatest similarity being withintheirRan-bindingdomains(Gorlichetal.1997).However,a hallmark architecture within the karyopherins,as determined by recent high-resolution structural studies,is the tandem HEA T-repeat fold formed by antiparallel heli-ces connected by a short turn (reviewed in Conti and Izaurralde 2001).The HEA T-repeats ar-range to form a superhelical structure,similar to a snail’s shell.This folding is reminiscent of the helix-turn-helix repeats found in the NPC’s core scaffold proteins.This similarity raises the intriguing possibility that karyopherins di-verged from a common structure involved in both stationary and soluble phases of transport.The association and dissociation of a karyo-pherin-cargo complex is regulated by direct binding of the small GTPase Ran (Fig.2)(reviewed in Fried and Kutay 2003;Madrid and W eis 2006;Cook et al.2007).In vitro bind-ing studies show that import complexes are dissociated by RanGTP binding.Conversely,export complexes are formed via RanGTP association (Rexach and Blobel 1995;Floer and Blobel 1996;Chi and Adam 1997;Floer et al.1997;Kutay et al.1997a;Kutay et al.1997b;Nakielny et al.1999).Based on the localizations of the Ran GTPase activating protein (RanGAP)in the cytoplasm and the Ran guanine nucleo-tide exchange factor (RanGEF)in the nucleo-plasm,cytoplasmic Ran is primarily in the GDP-bound state whereas nucleoplasmic Ran is kept primarily in the GTP-bound state (Fig.2).The gradient formed from these localizations has been elegantly demonstrated by imaging ﬂuorescence resonance energy transfer-based biosensors (Kalab et al.2002).The RanGTP gra-dient across the two faces of the NPC is essentialExport cycleImport cycle Figure 2.The nuclear transport cycle for karyopherins and their cargos.See main text for details.Nuclear Pore Complexes and Nuclear TransportCite this article as Cold Spring Harb Perspect Biol 2010;2:a0005627for establishing the directionality of karyophe-rin-mediated transport.The pathway for karyopherin-mediated tra-nslocation is well described(reviewed in W eis 2003;T erry et al.2007)(Fig.2).For import, a speciﬁc karyopherin recognizes its cognate cargo in the cytoplasm where RanGTP levels are low.The karyopherin mediates the binding of the import complex to the NPC and facili-tates translocation through the NPC.Once the complex moves through the NPC,release and dissociation of the karyopherin-cargo complex are stimulated by RanGTP in the nucleus.The karyopherin bound to RanGTP is then recycled back to the cytoplasm.Finally,GTP hydrolysis of Ran on the cytoplasmic side frees the karyo-pherin to interact with a second cargo molecule for further cycles of transport.Overall,Ran decreases the afﬁnity of the karyopherin for its cargo(reviewed in Macara2001;Cook et al. 2007).For export complexes,an analogous pro-cess occurs,but in this case,RanGTP binding increases the afﬁnity of the karyopherin b for the export cargo.For example,for the exporting karyopherin Crm1and an export cargo SPN1 (snurportin1adaptor for UsnRNPs),the Crm1afﬁnities for RanGTP and SPN1in the ternary RanGTP-Crm1-SPN1complex are increased 1000-fold(Paraskeva et al.1999; Monecke et al.2009).Actual movement thr-ough the NPC does not require energy input. The Ran afﬁnity switches provide the energy for efﬁcient cargo delivery and release.The only possible exception to this rule involves the import of large cargoes,where the presence of Ran and hydrolyzable GTP may be required for the import of cargoes.500kDa in vitro (Lyman et al.2002).It was also originally thought that an individual karyopherin was adapted for either import or export,but not both.However,there are now documented ex-amples of karyopherins functioning in both im-port and export,although with different cargoes in each direction(Y oshida and Blobel2001).In addition to protein import and export, karyopherins can also transport RNAs.For ex-ample,the karyopherins Crm1and exportin-t mediate the export of uridine-rich small nu-clear RNAs(U snRNAs)and tRNAs,respectively (Simos et al.2002;Rodriguez2004).Transport is accomplished via direct binding of karyo-pherins to RNA or to signal sequences within the protein components of the RNP complexes. For example,Crm1does not bind UsnRNAs directly and requires the adaptor PHAX that binds the cap-complex on the RNA(Ohno et al.2000).However,exportin-t directly inter-acts with tRNAs(Arts et al.1998;Hellmuth et al.1998;Kutay et al.1998;Lipowsky et al. 1999).Karyopherins are also involved in the export of some viral RNAs,including their mRNAs (Carmody and W ente2009).However,the primary mRNP export transport receptor is a nonkaryopherin designated Mex67in yeast and NXF1in metazoans,which heterodimer-izes with a protein termed respectively Mtr2 or p15/Nxt1(Erkmann and Kutay2004). Even though Mex67is unrelated in sequence and structure to the karyopherin family,it has all the requirements of a transport receptor: cargo binding,nucleocytoplasmic shuttling, and NPC-binding.The stoichiometry of the Mex67-Mtr2heterodimer per transported mRNP is unknown;Mex67-Mtr2either is re-cruited directly to the mRNA or interacts cotranscriptionally with proteins of the mRNP assembly(Erkmann and Kutay2004;Carmody and W ente2009).Like karyopherins,Mex67-Mtr2heterodimers bind directly to FG Nups, although it seems they prefer different subsets of FG Nups to their karyopherin counterparts, which might reﬂect how the karyopherin medi-ated transport pathways and mRNPexport path-ways are kept apart at the NPC(Strawn et al. 2001;T erry et al.2007;T erry and W ente2007).As mRNP is a major source of trafﬁc across the NPC,it is interesting that most of this tran-sit is facilitated by non-karyopherin carriers. Because Ran is not utilized to establish a gra-dient,directionality in the mRNA export path-way is conferred by proteins that modify the mRNPs as they cross the NPC.Chief among these is the protein Dbp5.Dbp5is a member of the SF2helicase superfamily of RNA-dependent A TPases(Snay-Hodge et al.1998; Tseng et al.1998)and carries a DEAD/H-box sequence motif.Such DEAD-box proteins areS.R.Wente and M.P.Rout8Cite this article as Cold Spring Harb Perspect Biol2010;2:a000562。

Quantabio repliQa

Quantabio, 100 Cummings Center Suite 407J, Beverly, MA 01915IFU-115.1 Rev01repliQa™ HiFi Assembly MixCat. No. 95190-010 95190-050Size:10 reactions 50 reactionsStore at -25°C to -15°CDescriptionThe repliQa™ HiFi Assembly Mix simplifies the construction of recombinant DNA through the simultaneous and seamless assembly of multiple DNA fragments possessing terminal regions of sequence overlap in a single, isothermal reaction. Similar in principle to the Gibson Assembly ® Method 1, the high efficiency repliQa HiFi Assembly Mix is ideal for a range of genetic engineering applications including routine molecular cloning, site-directed mutagenesis, assembly of large constructs for synthetic biology applications, and the construction of diverse sequence libraries for directed evolution studies. The concentrated, two-component format allows flexibility in design of assembly reactions and compatibility with less concentrated DNAsamples. The repliQa Mix has been optimized for use with a total input quantity of DNA fragments in the range of 0.03 to 0.5 pmols. The assembly of up to six DNA fragments is recommended, though the repliQa Mix has been successfully used for more complex assemblies.Double stranded DNA fragments for assembly can be generated by PCR amplification, chemical synthesis, or isolation of restriction fragments. When working with fragments PCR amplified from plasmid vectors, the included DpnI restriction endonuclease can be used for selectively digesting methylated, residual plasmid DNA to reduce background transformants. The repliQa mix is directly compatible with most common E. coli cloning hosts and generally provides a high yield of accurately assembled product.The DNA assembly occurs through the actions of three enzymes:• A non-thermostable 5' to 3' exonuclease that partially eliminates one strand of a DNA duplex to expose complementary overlap regions forhybridization.• A high-fidelity thermostable polymerase that fills the gaps remaining between the hybridized fragments of the overlapping regions.• A thermostable DNA ligase that covalently seals the resulting nicks at fragment junctions, generating double-stranded, assembled DNA moleculessuitable for transformation of cells.ComponentsReagent Description95190-01095190-050 repliQa HiFi Assembly Enzyme Mix Optimized formulation of enzymes for 5’-endresection, high fidelity 3’-end extension, and nick sealing.1 x 0.02 mL1 x 0.10 mLrepliQa 10X Assembly Reaction Buffer 10X reaction buffer containing dNTPs, magnesium, and cofactors.1 x 0.1 mL 1 x 0.50 mLDpnI (20 U/µl)Restriction endonuclease for the (optional) post-PCR digestion of residual unamplified plasmid template.1 x 0.05 ml 1 x 0.25 mlStorage and StabilityStore kit components in a constant temperature freezer at -25°C to -15°C upon receipt. For long term buffer storage (> 30 days) store buffer at -70°C. Refer to the product label or lot-specific Product Specification Sheet (PSF) available at /resources for applicable expiration date.A general diagram of assembly cloning is shown below:Additional reagents and materials that are not supplied• PCR-Grade, nuclease-free water (do not use DEPC-treated water)• High Fidelity DNA Polymerase (Enzymatics VeraSeq TM 2.0, P7511L or equivalent)• A heat block, thermocycler, or water bath capable of holding a temperature of 50 ± 2°C for one hour. • PCR or microcentrifuge reaction tubes.• PCR product purification kit (QIAGEN ® QIAquick ® PCR Purification Kit, 28104 or equivalent). •Competent E. coli cells and accessories as recommended by manufacturer.Before you begin• Design the DNA fragment sequences and assembly strategy. Guidelines are given in Appendix 1.• (Optional) Treat PCR reaction with DpnI if plasmid DNA was used as template for generating DNA fragments to be assembled. (Appendix 2).•(Recommended) After determining PCR fragment or restriction endonuclease-digested fragment size and purity by agarose gel electrophoresis, purify using a spin column-based cleanup or other method. This step is not required but is highly recommended to achieve highest efficiency of fragment assembly.• Measure the concentration of each isolated DNA fragment by absorbance at A 260 or by using a fluorometric quantitation reagent. Agarose gel electrophoresis with mass-calibrated size standards can also be used to quantify fragment mass and quality simultaneously. • Calculate the number of picomoles of each fragment using the following formula:pmols = (weight in ng) x 1000/(bp x 662).• Determine the number of pmols of each fragment to add to the assembly reaction. For cloning, highest efficiencies are achieved with 0.02 to 0.04 pmols of linear vector fragment (50 to 100 ng of 4 kb vector) and 2 to 8-fold molar excess of inserts. • Prepare outgrowth medium and culture plates with appropriate antibiotics for plasmid selection.•Equilibrate the heat block, thermal cycler, or water bath to 50°C for incubation of the assembly reactions .Protocol1. Thaw the repliQa HiFi Assembly Kit components, briefly vortex to mix, and place on ice.2. For each assembly, add reaction components in the order listed in the table below to chilled reaction tubes.The optimal amount of enzyme mix to add per assembly reaction depends on the total quantity of DNA fragments present.ComponentRxn. component volumes (µl) for varying amounts of total DNA≤ 0.125 pmol> 0.125 pmol but ≤ 0.25 pmol > 0.25 pmol Nuclease-free water(17.5 – X) µl (17.0 – X) µl (16.0 – X) µl repliQa 10X Assembly Reaction Buffer 2.0 µl 2.0 µl 2.0 µl DNA fragmentsX µl X µl X µl repliQa HiFi Assembly Enzyme Mix 0.5 µl 1.0 µl 2.0 µl Total volume20 µl20 µl20 µl3. Incubate reactions at 50°C in heat block, thermal cycler with heated lid (set to ~60-80°C), or covered water bath for 1 hr. Hold assembled product mix at 4°C until ready to proceed with transformations. If transformations cannot be performed on the same day, reactions can be stored at -20°C for up to one month.4. Competent E. coli should be transformed, recovered, and plated as per manufacturer guidelines or standard lab practices. Note: If electroporation is to be used for transforming cells, we recommend first diluting the assembly reaction 1:5 in high purity water. There is no need to dilute the assembly reactions prior to transformation of chemically competent cells.5. (Optional) Analyze a portion of the remaining assembly reaction by agarose gel electrophoresis. If DNA fragment assembly occurs properly, a ladder of higher molecular weight DNA bands would be generated.Note: For reactions using three or fewer fragments the incubation time in step 3 can be shortened to 15 minutes.Appendix 1 – Guidelines for Designing DNA Fragments for Assembly1.When designing the DNA fragment sequences and assembly strategy, allow for a region of sequence homology between adjacent DNA fragments.Be sure to avoid regions of repeated bases or repeated short DNA motifs in the design of these overlaps where possible. Regions of secondary structure such as hairpins or stem loops should also be avoided.2.The kit is optimized for the assembly of fragments with overlap regions between 15 – 60 bp. It is recommended that the overlaps be at least 20bp with a minimum of 25% GC content, however overlaps of 30 bp or longer size will provide higher efficiency assembly reactions.3.For generating PCR fragments to be assembled, design primers with a 5’ segment of homology to the adjacent fragment or vector. If the adjacentfragment is also generated by PCR amplification, the overlap can be split between two primers if desired. The 3’ segment of primers should contain sequence specific to the DNA target of interest. Amplify targets using a high-fidelity thermostable DNA polymerase such as VeraSeq 2.0 (Enzymatics, P7511L) or equivalent per manufacturer instructions.4.When designing synthetic gene fragments for assembly, ensure that the 5’ and 3’ segments contain regions of homologous overlap sequencebetween adjacent gene blocks, PCR fragments, or isolated restriction fragments.5.For site-directed mutagenesis applications, the assembly strategy should be designed such that the mutation of interest is centered betweenadjacent PCR fragments. Design the PCR primers as with the standard fragments above, except that the mutation (substitution, insertion, or deletion) should be included within the 5’ segments for both of the adjacent fragments.6.When designing DNA fragments to be assembled with isolated restriction fragments, be aware that any 5’ overlaps from staggered restriction cutswill be eliminated because of the 5’-->3’ nuclease present in the assembly mix, and so should not be included in the measurement of overlap size. If desired, design the 5’ overlap segment of the adjacent fragment to either preserve or eliminate the restriction site.Appendix 2 – DpnI treatment to remove residual plasmid DNAWhen plasmid vector is used as PCR template to generate a fragment for assembly, it is recommended that the reaction be treated with DpnI to eliminate residual methylated plasmid prior to setting up the assembly reaction.1.Add 1 µl DpnI (20U) directly to the PCR reaction (50 µl) following amplification of fragment.2.Incubate at 37°C for 1 hr.3.Heat inactivate DpnI by incubation at 80°C for 20 min.4.(Recommended) Purify the fragment using a spin column-based PCR purification kit.Quality ControlThe repliQa HiFi Assembly Mix is functionally tested for assembly of three 1-kb PCR fragments into 2kb and 3 kb products.The individual components of the repliQa HiFi Assembly Mix are tested to be free of contaminating DNase and RNase.Limited Label LicensesThis product was developed, manufactured, and sold for in vitro use only. The product is not suitable for administration to humans or animals. SDS sheets relevant to this product are available upon request.References1. Gibson, D.G., et al. (2009). Enzymatic assembly of DNA molecules up to several hundred kilobases. Nat. Methods 6, 343-5.。

柴达木盆地咸湖相烃源岩特征——以英西地区下干柴沟组上段为例

断块油气田FAULT-BLOCK OIL&GAS FIELD第28卷第2期2021年3月doi:10.6056/dkyqt202102007柴达木盆地咸湖相H源岩特征——以英西地区下干柴沟组上段为例舒豫川，胡广，庞谦，胡朝伟，夏青松，谭秀成（西南石油大学地球科学与技术学院，四川成都610500/摘要盐湖环境对油气生成具有重要的地质意义！国内外有诸多含油气盆地发育咸湖相？源岩！自新生代以来，在青藏高原的隆升作用下，柴达木盆地的海拔升高、湖盆逐渐封闭、持续的干寒气候及盐源的充分供应，使得柴达木盆地逐渐变成了一个典型的高原咸化湖盆，其中，下干柴沟组为柴达木盆地西部英西地区的主力？源岩层系！文中通过有机岩石学、有机地球化学及生物标志物地球化学研究，对英西地区下干柴沟组上段进行了？源岩评价，并探讨了其沉积环境及生？母质类型!研究结果表明：英西地区下干柴沟组上段？源岩总有机碳质量分数在0.31%〜1.49%,平均值为0.82%；氯仿沥青“A”质量分数在562.16x10-6~2999.65X10"6,平均值为1619.59x10^o?源岩生？母质为藻类、细菌和高等植物，以低等水生生物为主！有机质类型主要为！型，其次为"型，？源岩成熟度介于低成熟一成熟！英西地区下干柴沟组？源岩综合评价为好的？源岩！生物标志化合物特征表明，下干柴沟组上段？源岩沉积于水体盐度较高、还原性较强的湖相环境之中！关键词？源岩；生物标志化合物；下干柴沟组；英西地区；柴达木盆地中图分类号:TE13513；P618.13文献标志码:ACharacteristics of source rocks of salt lake facies in Qaidam Basin:taking XiaganchaigouFormation in Yingxi region as an exampleSHU Yuchuan?HU Guang,PANG Qian?HU Chaowei,XIA Qingsong?TAN Xiucheng(School of Geoscience and Technology?Southwest Petroleum University?Chengdu61O5OO?China) Abstract：Salt lake environment has important geological significance for oil and gas generation.There are many oil-bearing basins containing salt lake facies source rocks at home and abroad.Since Cenozoic era,with the uplift of the Tibetan Plateau,the Qaidam Basin has gradually become a typical plateau salt lake basin because of the altitude rise,the lake basin gradually closed,the persistent dry and cold climate,and the adequate supply of salt.In the basin,the Xiaganchaigou Formation is the main source rock series in the Yingxi region which located in the western part of Qaidam Basin.Based on study of organic petrology,organic geochemistry and biomarker geochemistry,the source rocks of the Xiaganchaigou Formation in the Yingxi region were evaluated, and their sedimentary environment and the types of hydrocarbon generating parent material were discussed.The results show that the total organic carbon content of source rocks in the Xiaganchaigou Formation in the Yingxi region is0.31%to1.49%,with an average value of0.82%.The value range of chloroform bitumen"A H is562.16X10"6to2,999.65X10"6,with an average of1,619.59x10"6.The source rocks are mainly composed of algae,bacteria and higher plants,mainly low aquatic organisms.The organic matter type is mainly type!,followed by type".The maturity of source rock is between low maturity and prehensive evaluation shows that the source rocks of the Xiaganchaigou Formation in the Yingxi region are good source rocks.The characteristics of biomarkers indicate that the source rocks of Xiaganchaigou Formation are deposited in the lacustrine environment which has high salinity and strong reducibility.Key words：source rocks;biomarker compounds;Xiaganchaigou Formation;Yingxi region;Qaidam Basin近年来，在咸湖相碳酸盐油气地质理论和三维地震攻关技术的助推下，柴达木盆地英西地区古近系盐下油气勘探获得重大突破，多口钻井在下干柴沟组上段盐间和盐下湖相碳酸盐岩中获得了日产超千吨的高产油气流，揭示了柴达木盆地古近系沉积体系所具有收稿日期：2020-07-30"改回日期：2021-01-07o第一作者：舒豫川，1993年生，男，在读硕士研究生，从事沉积岩石学方面的研究工作。

玛巴洛沙韦治疗流行性感冒的快速卫生技术评估

玛巴洛沙韦治疗流行性感冒的快速卫生技术评估Δ吴越 1＊，陈启庭 2，陈芳昭 1，卓超林 2，刘微 1，李学娟 1，陈泽彬 1 #（1.深圳市儿童医院药剂科，广东深圳　518038；2.深圳市第二人民医院中西医结合科，广东深圳　518035）中图分类号 R 978.7；R 956 文献标志码 A 文章编号 1001-0408（2023）19-2402-07DOI 10.6039/j.issn.1001-0408.2023.19.17摘要目的评价玛巴洛沙韦治疗流行性感冒（以下简称“流感”）的有效性、安全性和经济性，以期为医院新药引进和临床用药决策提供循证参考。

方法检索PubMed 、Embase 、Web of Science 、Cochrane Library 、Epistemonikos 、中国生物医学文献数据库、中国知网、维普网、万方数据库及卫生技术评估（HTA ）相关学术机构官方网站及数据库，经文献筛选、资料提取、质量评价后，对研究结果进行描述性分析。

结果共纳入11篇文献，包括6篇系统评价（SR ）/Meta 分析、5篇经济学研究。

与安慰剂相比，玛巴洛沙韦在缩短流感患者症状缓解时间（TTAS ）和退热时间（TTRF ）、降低治疗后24 h 和48 h 病毒滴度相对于基线的变化水平、降低支气管炎发生率等方面差异有统计学意义（P ＜0.05）。

与神经氨酸酶抑制剂（NAIs ）相比，玛巴洛沙韦在缩短流感患者TTRF ，降低流感并发症、肺炎、支气管炎发生率等方面差异无统计学意义（P ＞0.05）；多数研究认为玛巴洛沙韦在缩短TTAS 方面差异无统计学意义（P ＞0.05）；仅有极低质量文献认为玛巴洛沙韦可显著降低患者治疗后24 h 和48 h 病毒滴度相对于基线的变化水平。

安全性方面，玛巴洛沙韦与帕拉米韦、扎那米韦相比，不良事件（AEs ）发生率和药物相关不良事件（DRAEs ）发生率差异无统计学意义（P ＞0.05）。

汽车基础知识培训内外饰

Fuse Box
风窗清洗液壶 Washer T蓄an电k池标签Battery Caution 蓄电池（L电abel 瓶） Battery
零部件名称-底盘1
前减震器橡胶制动液壶
真空助力
垫
Brake Reserve 器
减尘震罩器防MRuobubnetring
Tank
轮胎 Tire
前减震器
减震弹簧
washer Nozzle-F ,
RH
顶盖 Roof panel
右前雨刮片
Windshield wiper blade-
F , RH
左前雨刮喷嘴
Windshield
washer Nozzle-F,
LH左前雨刮片
Windshield
wiper blade-F,
LH 引擎盖
Bonne
t
右前头灯（大灯） Fr head lamp, RH
右后门槛装饰板 Rr scuff plate, RH
右后门内开把手 Rr door inner handle, RH
右后门内开锁柄
Rr door inner lock,
RH 右后门密封胶条
Rr door
右wR后eHa门th锁er体strip, Rr door Latch,
RH
右后门儿童锁
开关
Child safety
左前侧内饰 Fr side trim, L票H据箱
右侧pi空lla调r 出风口trim
Right ven转ti向lat柱or 上 gri盖lle板
Column 转cov向er柱下盖up板per
Column
Clean
油c门ov踏er板
换bo档x 杆 AT change

27026594_超级火山喷发及其环境效应

１北京大学地球与空间科学学院，造山带与地壳演化教育部重点实验室，北京１００８７１２中国科学院地质与地球物理研究所，岩石圈演化国家重点实验室，北京１０００２９３中国科学院地质与地球物理研究所，新生代地质与环境重点实验室，北京１０００２９１ＭＯＥＫｅｙＬａｂｏｒａｔｏｒｙｏｆＯｒｏｇｅｎｉｃＢｅｌｔｓａｎｄＣｒｕｓｔａｌＥｖｏｌｕｔｉｏｎ，ＳｃｈｏｏｌｏｆＥａｒｔｈａｎｄＳｐａｃｅＳｃｉｅｎｃｅｓ，ＰｅｋｉｎｇＵｎｉｖｅｒｓｉｔｙ，Ｂｅｉｊｉｎｇ１００８７１，Ｃｈｉｎａ２ＳｔａｔｅＫｅｙＬａｂｏｒａｔｏｒｙｏｆＬｉｔｈｏｓｐｈｅｒｉｃＥｖｏｌｕｔｉｏｎ，ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｌｏｇｙａｎｄＧｅｏｐｈｙｓｉｃｓ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，Ｂｅｉｊｉｎｇ１０００２９，Ｃｈｉｎａ３ＫｅｙＬａｂｏｒａｔｏｒｙｏｆＣｅｎｏｚｏｉｃＧｅｏｌｏｇｙａｎｄＥｎｖｉｒｏｎｍｅｎｔ，ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｌｏｇｙａｎｄＧｅｏｐｈｙｓｉｃｓ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，Ｂｅｉｊｉｎｇ１０００２９，Ｃｈｉｎａ２０２２０１０３收稿，２０２２０３０３改回
７４０００年前印度尼西亚多巴火山喷发是第四纪以来规模最大的一次超级火山喷发事件（Ｃｈｅｓｎｅｒｅｔａｌ．，１９９１）。最新研究表明，其喷出岩浆的体积约５３００ｋｍ３ＤＲＥ，对应的ＶＥＩ＞９（Ｃｏｓｔａｅｔａｌ．，２０１４）。它向平流层注入的ＳＯ２总量是１９９１年皮纳图博火山喷发的１００倍左右，其火山灰在印度、东南亚、非洲、印度洋、中国南海等地都有发现（Ｃｏｓｔａｅｔａｌ．，２０１４）。气候模拟显示，多巴火山喷发后造成北美洲和亚洲大部分地区长达１０年的降温，部分地区降温甚至达到１０℃，同时还导致全球大部分地区降水减少（Ｂｌａｃｋｅｔａｌ．，２０２１）。

Calibration device for a helical spring scale

专利名称：Calibration device for a helical spring scale发明人：Frank Lee申请号：US10791324申请日：20040301公开号：US07009120B2公开日：20060307专利内容由知识产权出版社提供专利附图：摘要：A scale includes a housing, a first pressing element, a second pressing element,an adjusting unit, a spring, a carrying unit and an indicator. The housing includes agraduation provided thereon and has a lower portion. The adjusting unit is secured to the lower portion of the housing and has a first thread. The first pressing element is slidablysecured in said housing and has a second thread engaged with the first thread of said adjusting unit. The adjusting unit can be rotated relative to the first pressing element for moving the first pressing element in the housing in the direction where the spring can be compressed. The second pressing element is slidably received in the housing. The spring is received in the housing and between the first and second pressing elements. The carrying unit is suited for carrying an object to be weighed and is engaged with the second pressing element. The indicator is moved in concert with the second pressing element for aligning with the graduation and for indicating the weight of the object.申请人：Frank Lee地址：Taipei TW国籍：TW代理机构：J.C. Patents更多信息请下载全文后查看。

A SPRING TUBE AND A SPRING PACK FOR SPRING MATTRES

专利名称：A SPRING TUBE AND A SPRING PACK FOR SPRING MATTRESSES发明人：WELLS, Tom申请号：EP07729681.2申请日：20070530公开号：EP2150155A1公开日：20100210专利内容由知识产权出版社提供摘要：A spring tube (1) encloses in known way a plurality of springs (2) arranged side by side, with facing parts of the wall (11) of the tube (10) joined, between one spring (2) and a subsequent spring, by welding lines (12), so that each spring (2) is contained in a portion (13) of tube (10), closed and separated from adjacent portions (13). The welding lines (12) have a predetermined minimum width (L) and are cut from one side of the tube inwards, so that each of the closed portions (13), containing a spring (2), can be compressed without any effect on the adjacent portions (13). this improves comfort while using a mattress manufactured with grouped spring packs (S) obtained from the spring tube (1). According to a second preferred embodiment, the spring tube (1) is cut along the welding lines at both sides.申请人：Petrolati, Cesare,Rossi, Doriano地址：Via Moscatelli Fraz. Castiglioni 93 60010 Arcevia IT,Via Fontanelle 79 - Fraz. Castiglioni 60010 Arcevia IT国籍：IT,IT代理机构：Dall'Olio, Giancarlo更多信息请下载全文后查看。

日晡驾车余驾年：浙江日唐奔驾公司说明书

JEEP JK 1 3/4” SUSPENSION KITThank you for choosing Rough Country for all your suspension needs.Rough Country recommends a certified technician install this system. In addition to these instructions, professional knowledge of disassemble/reassembly procedures as well as post installation checks must be known. Attempts to install this system without this knowledge and expertise may jeopardize the integrity and/or operating safety of the vehicle.Please read instructions before beginning installation. Check the kit hardware against the parts list on this page. Be sure you have all needed parts and know where they go. Also please review tools needed list and make sure you have needed tools.PRODUCT USE INFORMATIONAs a general rule, the taller a vehicle is, the easier it will roll. Seat belts and shoulder harnesses should be worn at all times. Avoid situations where a side rollover may occur.Generally, braking performance and capability are decreased when larger/heavier tires and wheels are used. Take this into consideration while driving. Do not add, alter, or fabricate any factory or after-market parts to increase vehicle height over the intended height of the Rough Country product purchased. Mixing component brands is not recommended.Rough Country makes no claims regarding lifting devices and excludes any and all implied claims. We will not be re-sponsible for any product that is altered.If question exist we will be happy to answer any questions concerning the design, function, and correct use of our prod-ucts.This suspension system was developed using a 285/75/17 tire with factory wheels. Note if wider tires are used, offset wheels will be required and trimming will be required.NOTICE TO DEALER AND VEHICLE OWNERAny vehicle equipped with any Rough Country product should have a “Warning to Driver” decal installed on the inside of the windshield or on the vehicle’s dash. The decal should act as a constant reminder for whoever is operating the vehi-cle of its unique handling characteristics.INSTALLING DEALER - it is your responsibility to install the warning decal and forward these installation instructions on to the vehicle owner for review. These instructions should be kept in the vehicle for its serviceKit Contents:651 Kit Box2– Front Coil Spring Spacers 2– Rear Coil Spring Spacers 2- 658702 Fr N2.0 Nitro Shock 2– 658708 Rr N2.0 Nitro Shock92651N200Tools Needed:10mm Wrench 14mm Socket 16mm Wrench 16mm Socket 18mm Wrench 18mm Socket19mm Deep Well Socket JackJack StandsTorque Specs:Size Grade 5 Grade 8 5/16” 15 ft/lbs 20 ft/lbs 3/8” 30 ft/lbs 35 ft/lbs 7/16” 45 ft/lbs 60 ft/lbs 1/2” 65 ft/lbs 90 ft/lbs 9/16” 95 ft/lbs 130 ft/lbs 5/8” 135 ft/lbs 175 ft/lbs 3/4” 185 ft/lbs 280 ft/lbs Class 8.8 Class 10.9 6MM 5 ft/lbs 9 ft/lbs 8MM 18ft/lbs 23 ft/lbs 10MM 32ft/lbs 45ft/lbs 12MM 55ft/lbs 75ft/lbs 14MM 85ft/lbs 120ft/lbs 16MM 130ft/lbs 165ft/lbs 18MM 170ft/lbs 240ft/lbs1. Jack up the front of the vehicle and support the vehicle with jack stands, so that the front wheels are off the ground.Chock rear wheels.2. Remove the front tires/wheels , using a 19mm deep well socket3. Using a 18mm socket and wrench remove the bottom sway bar bolts. Retain hardware for later use. See PHOTO 14. Remove the lower shock bolt using a 18mm socket and wrench. Using a 14mm wrench unbolt the top of the shockand remove. See PHOTO 2.5. Push down on the axle to allow room for the coils to be removed. Remove coil springs, and factory spring isolator.6. Install the spacer over the factory bump stop with the lip of the spacer pointing down. See PHOTO 3.7. Reinstall the factory coil spring, and the factory spring isolator. Be sure to rotate the spring until the pigtail hits thestop. See PHOTO 4.8. Install the front shocks at this time. When tightening theupper shock mount, using a 14mm wrench tighten until the bushing starts to bulge. Use the factory bolt in the lower shock mount using a 18mm socket and wrench. See PHOTO 5.9. Reinstall the bottom sway bar bolt, using a 18mm socketand wrench.10. Reinstall the front tires/wheels .PHOTO 1PHOTO 2PHOTO 3PHOTO 4PHOTO 51. Jack up the rear of the vehicle and support the vehicle with jack stands, so that the rear wheels are off the ground.Chock front wheels and remove the rear tires/wheels , using a 19mm deep well socket.2. Remove the upper shock bolt using a 16mm socket and wrench. Remove the lower shock bolt using a 18mm socketand wrench and remove the factory shock. See PHOTO 1.3. Using a 18mm socket and wrench remove the bottom sway bar bolts. Retain hardware for later use. See PHOTO 2.4. Using a 10mm wrench remove the bolt holding the brake line to the frame. This is done to allow the rear axle to belowered enough to remove the coil springs. See PHOTO 3.5. Push down on the axle to allow the stock coil to be removed. Remove the stock coil spring and isolator.6. Install the new coil spring spacer on top of the stock coil with the lip of the spacer pointing down. The factory coilspring isolator will be re-used. See PHOTO 4.7. Install the top of the coil back into the coil seat. When installing the bottom of the coil into the seat rotate the coil untilthe pigtail hits the spring stop. See PHOTO 5.8. Reinstall the sway bar link using a 18mm socket and wrench using the stock hardware.9. Install the new rear shock using a 18mm socket and wrench on the bottom and a 16mm socket for the top, using thestock hardware. See PHOTO 6.10. Reinstall the rear tires/wheels and Lower the vehicle to the ground11.Reinstall the brake line bracket to the stock location with the stock bolt using a 10mm wrenchPHOTO 1PHOTO 2PHOTO 3PHOTO 4PHOTO 5PHOTO 61. Check all fasteners for proper torque. Check to ensure there is adequate clearance between all rotating, mobile,fixed and heated members. Check steering for interference and proper working order. Test brake system.2. Perform steering sweep. The distance between the tire sidewall and the brake hose must be checked closely. Cyclethe steering from full turn to full turn to check for clearance. Failure to perform inspections may result in component failure.3. Re torque all fasteners after 500 miles. Visually inspect components and re torque fasteners during routine vehicleservice.4. Readjust headlights to proper settings.Maintenance InformationIt is the ultimate buyers responsibility to have all bolts/nuts checked for tightness after the first 500 miles and then every 1000 miles. Wheel alignment steering system, suspension and driveline systems must be inspected by a qualified pro-fessional mechanic at least every 3000 miles。

BLAT--The BLAST-Like Alignment Tool

10.1101/gr.229202Access the most recent version at doi: 2002 12: 656-664Genome Res.W. James KentThe BLAST-Like Alignment Tool−−BLATReferences/content/12/4/656.full.html#related-urls Article cited in:serviceEmail alertingclick here top right corner of the article or Receive free email alerts when new articles cite this article - sign up in the box at the/subscriptions go to: Genome Research To subscribe to Cold Spring Harbor Laboratory PressBLAT—The BLAST-Like Alignment ToolW.James KentDepartment of Biology and Center for Molecular Biology of RNA,University of California,Santa Cruz,Santa Cruz,California95064,USAAnalyzing vertebrate genomes requires rapid mRNA/DNA and cross-species protein alignments.A new tool, BLAT,is more accurate and500times faster than popular existing tools for mRNA/DNA alignments and50 times faster for protein alignments at sensitivity settings typically used when comparing vertebrate sequences.missed and adjusts large gap boundaries that have canonical splice sites where feasible.This paper describes how BLAT was optimized.Effects on speed and sensitivity are explored for various K-mer sizes,mismatch schemes,and number of required index matches.BLAT is compared with other alignment programs on various test sets and then used in several genome-wide applications. hosts a web-based BLAT server for the human genome.Some might wonder why in the year2002the world needs another sequence alignment tool.The local alignment prob-lem between two short sequences was solved by the Smith-Waterman algorithm in1980(Smith and Waterman1981). The FASTA(Pearson and Lipman1988)and the BLAST family of alignment programs including NCBI BLAST(Altschul et al. 1990,1997),MegaBLAST(Zhang et al.2000),and WU-BLAST (Altschul et al.1990;Gish and States1993;States and Gish 1994)provide flexible and fast alignments involving large se-quence databases,and are available free on many web sites. Sim4(Florea et al.1998)does a fine job of cDNA alignment. The SAM program(Karplus et al.1998)and PSI-BLAST (Altschul et al.1997)slowly but surely find remote homologs. Gotoh’s many algorithms robustly deal with gaps(Gotoh 1990,2000).SSAHA(Ning et al.2001)maps sequence reads to the genome with blazing efficiency.In the process of assembling and annotating the human genome,I was faced with two very large-scale alignment prob-lems:aligning three million ESTs and aligning13million mouse whole-genome random reads against the human ge-nome.These alignments needed to be done in less than two weeks’time on a moderate-sized(90CPU)Linux cluster in order to have time to process an updated genome every month or two.To achieve this I developed a very-high-speed mRNA/DNA and translated protein alignment algorithm.The new algorithm is called BLAT,which is short for “BLAST-like alignment tool.”BLAT is similar in many ways to BLAST.The program rapidly scans for relatively short matches (hits),and extends these into high-scoring pairs(HSPs).How-ever,BLAT differs from BLAST in some significant ways. Where BLAST builds an index of the query sequence and then scans linearly through the database,BLAT builds an index ofscans linearly through the query se-hits.as separate alignments,BLAT stitches them together into a larger alignment.BLAT has special code to handle introns in RNA/DNA alignments.Therefore,whereas BLAST delivers a list of exons sorted by exon size,with alignments extending slightly beyond the edge of each exon,BLAT effectively“un-splices”mRNA onto the genome—giving a single alignment that uses each base of the mRNA only once,and which cor-rectly positions splice sites.BLAT is available in several forms.Since building an in-dex of the whole genome is a relatively slow procedure,a BLAT server is available which builds the index and keeps it in memory.A BLAT client can then query the index through the server.The client/server version is especially suitable for in-teractive applications,and is available via a web interface at .A stand-alone BLAT is also available, which is more suitable for batch runs on one or more CPUs. Both the client/server and the stand-alone can do compari-sons at the nucleotide,protein,or translated nucleotide level. RESULTSBLAT is currently used in three major applications in conjunc-tion with .BLAT is used to produce the human EST and mRNA alignments.The human EST align-ments compared1.75ן109bases in3.73ן106ESTs against2.88ן109bases of human DNA and took220CPU hours ona Linux farm of800MhZ Pentium IIIs.BLAT was used in translated mode to align a 2.5ןcoverage unassembled whole-genome shotgun of the mouse versus the masked hu-man genome.This involved7.51ן109bases in1.33ן107 reads and took16,300CPU hours.The client/server version of BLAT is used to power untranslated and translated interactive searches on .Researchers all over the world use BLAT to perform thousands of interactive sequence searches per day.The nucleotide server has sustained over 500,000search requests per day from program-driven queries. We do ask those researchers who are doing more than a fewArticle and publication are at /cgi/doi/10.1101/gr.229202.Article published online before March2002.Resource656Genome Research12:656–664©2002by Cold Spring Harbor Laboratory Press ISSN1088-9051/01$5.00; thousand program-driven queries to obtain a copy of BLAT to use on their own servers.The nucleotide server is not as effi-cient as the stand-alone program,since to save memory it does not keep the genome in memory,only the index.Theindex uses approximately 1gigabyte on unmasked DNA in untranslated mode,and approximately 2.5gigabytes on masked DNA in translated mode.The translated mode server by default is less sensitive than the default stand-alone set-tings.It requires three perfect amino acid 4-mers to trigger an alignment.The untranslated server usually responds to a 1000-base cDNA query in less than a second.The translated server usually responds to a 400-amino acid protein query in <5sec.Evaluating mRNA/DNA AlignmentsAs a test of BLAT ,I remapped 713mRNAs corresponding to genes that the Sanger Centre has annotated on chromosome 22(Dunham et al.1999)back to chromosome 22with BLAT and with Sim4(Florea 1998).When BLAT produced multiple alignments for an mRNA,only the highest scoring alignment was kept.In 99.99%of the annotated bases,the BLAT align-ment agreed with the Sanger annotations.There were 107bases in 10genes where there was disagreement.In five of the 10genes,the disagreement was only in the placement of non-standard splice sites.In two cases,BLAT did not find small (<32-base)initial exons.In one case,an exon of six bases was present and aligning fully,but in a different place than an-notated (where it also aligned fully,but with better flanking splice sites).In one case,BLAT positioned an intron to con-form with the consensus sequence on the wrong strand.That is,the gap corresponding to the intron was positioned to have CT/AC rather than GT/AG ends.The final case was a 38-base sequence that BLAT was unable to place because the middle contained some degenerate sequence.The BLAT alignments were done at the default settings and took 26sec.The Sim4alignments of the same data took 17,468sec (almost 5h).They agreed with the Sanger annotations in 99.66%of the bases.There were disagreements between the Sim4alignments and the Sanger annotations from various causes in 52of the genes.Most of these disagreements were small.Evaluating Mouse/Human Translated AlignmentsThough the translated modes of BLAT are relatively new,they are quick and effective.The translated mode of BLAT was in-spired by the Exofish research at Genoscope (Roest Crollius et al.2000).Exofish showed that a TBLASTX run using an iden-tity matrix (where matches were weighted +15and mis-matches מ12for all amino acids)and a word size of 5was quite effective in aligning coding regions conserved between Homo sapiens and Tetraodon nigroviridis .For human and mouse it has been shown that gapless alignments are in many ways preferable to gapped alignments for detecting coding regions (Wiehe et al.2001).Table 1shows the timings of BLAT and WU-TBLASTX run on a modest-sized data set at gapless Exofish-like settings.BLAT runs much faster,making it fea-sible to compare vertebrate genomes quickly enough to keep up with the vast output of today’s sequencing centers.Pankaj Agarwal provided a WU-TBLASTX alignment of 13million mouse genomic reads versus human chromosome 22run under a gapless setting that should theoretically be some-what more sensitive than the matrix used for the Exofish set-tings because of the use of the BLOSUM62matrix (P.Agarwal,m.).Table 2shows a comparison between this align-ment and a translated BLAT alignment done at the indicated setting.The results were quite comparable in sensitivity.Other Usage InformationBLAT can also be used in translated mode to align proteins or mRNA from one species against genomic DNA of another spe-cies.In translated mRNA/translated DNA mode,BLAT has to align only one strand of the query sequence,speeding it up by a factor of two.In this mode it also becomes more tolerant of intron-induced gaps.BLAT can do protein–protein align-ments as well,but it is not likely to be the tool of choice for these.The protein databases are still small enough that BLASTP can handle them easily,and BLASTP is more sensitive than BLAT .BLAT can handle very long database sequences effi-ciently.It is more efficient at short query sequences than long query sequences.It is not recommended for query sequences longer than 200,000bases.It is not necessary to mask the DNA for untranslated BLAT searches.Translated searches gen-BLAT —The BLAST -Like Alignment ToolGenome Research657erally produce much quicker,cleaner results if the sequence is masked for repeats and low complexity sequence.METHODSAlgorithmA simple and reasonably effective search stage is to look for subsequences of a certain size,k,which are shared by the query sequence and the database.In many practical imple-K:The K-mer size.Typically this is 8–16for nucleotide comparisons and 3–7for amino acid comparisons.M:The match ratio between homologous areas.This would be typically about 98%for cDNA/genomic alignments within the same species,about 89%for protein alignments between human and mouse.H:The size of a homologous area.For a human exon this is typically 50–200bases.G:The size of the database—3billion bases for the hu-man genome.Q:The size of the query sequence.A:The alphabet size;20for amino acids,4for nucleo-tides.Assuming that each letter is independent of the previous letter,the probability that a specific K-mer in a homologous region of the database matches perfectly the corresponding K-mer in the query is simply:p 1=M K(1)It is convenient to introduce a term that counts the number of nonoverlapping K-mers in the homologous region:T =floor ͑H րK ͒(2)The probability that at least one nonoverlapping K-mer in the homologous region matches perfectly with the corresponding K-mer in the query is:P =1−͑1−p 1͒T =1−͑1−M K ͒T(3)The number of nonoverlapping K-mers that are expected to match by chance,assuming that all letters are equally likely to occur is:F =͑Q −K +1͒*͑G րK ͒*͑1րA ͒K(4)Tables 3and 4show P and F values for various levels of se-quence identity and K-mer sizes.For EST alignments we might want the search phase to find at least 99%of sequences that have 5%or less sequencing noise.Looking at Table 3,to achieve this level of sensitivity using this simple search method,we would need to choose a K of 14or less.A K of 14results in 399regions passed on to the alignment phase by chance alone.Any smaller K would pass significantly more.Mouse and human sequences average 89%identity at the amino acid level (Makalowski and Boguski 1998).Looking at Table 4,to compare a translated mouse read and find at least 99%of the sequences at this level of identity we would need a K of 5or less,which would result in 62,625sequences passed on to the alignment stage.Depending on the cost of the align-ment stage,these simple search criteria may or may not be paring mouse and human coding sequences at the nucleotide level,where there is on average 86%base iden-tity (Makalowski and Boguski 1998),requires us to reduce our K to 7to find at least 99%of the sequences.This results in 13,078,962regions passed to the alignment stage,which would probably not be practical.Searching With Single Almost Perfect MatchesWhat if instead of requiring perfect matches with a K-mer to trigger an alignment,we allow almost perfect matches,that is,hits where one letter may mismatch?The probability that a nonoverlapping K-mer in a homologous region of the data-base matches almost perfectly the corresponding K-mer in the query is:p 1=K *M K −1*͑1−M ͒+M K(5)Kent658Genome ResearchAs with a single perfect hit,the probability that any nonover-lapping K-mer in the homologous region matches almost per-fectly with the corresponding K-mer in the query is:P =1−͑1−p 1͒T(6)Whereas the number of K-mers which match almost perfectly by chance are:F =͑Q −K +1͒*͑G րK ͒*͑K *͑1րA ͒K −1*͑1−͑1րA ͒͒+͑1րA ͒K ͒(7)Tables 5and 6show P and F for various levels of sequence identity and K-mer sizes.For the purposes of EST alignments,a K of 22or less would pass through over 99%of the truly homologous regions while on average passing less than one chance match through to the aligner.With a reasonably fast alignment stage,it would be feasible to look for mouse/human homologies at the nucleotide level using this tech-nique.A K size of 12detects over 99%of the mouse homolo-gies,and requires checking 275,671alignments.At the amino acid level,a K size of 8has the desired sensitivity and requires checking only 374alignments.Searching With Multiple Perfect MatchesAnother alternative search method is to require multiple per-fect matches that are constrained to be near each other.Con-sider a situation where the K size is 10and there are two hits—one starting at position 10in the query and 1010in the database,and another starting at position 30in the query and 1030in the database.These two hits could easily be part of a region of homology extending from positions 10–39in the query and 1010–1039in the database.If we subtract the query coordinate from the database coordinate,we get a “diagonal”coordinate.Consider the search criteria that there must be N perfect matches,each no further than W letters from each other in the target coordinate,and have the same diagonal coordinate (Fig.1).For N =1,the probability that a nonover-lapping K-mer in a homologous region of the database matches perfectly the corresponding K-mer in the query is simply as before:p 1=M K(8)The probability that there are exactly n matches within the homologous region isP n =p 1n *͑1−p 1͒T −n *T!ր͑n!*͑T −n ͒!͒(9)And the probability that there are N or more matches is the sum:P =P N +P N +1+…+P T(10)The number of sets of N perfect matches that occur by chance is a little complex to calculate.For N =1it is easy:F 1=͑Q −K +1͒*͑G րK ͒*͑1րA ͒K(11)The probability of a second match occuring within W letters after the first isS =1−͑1−͑1րA ͒K ͒W րK(12)because the second match can occur with any of the W/K nonoverlapping K-mers in the database within W letters after the first match.We can extend this reasoning to consider theBLAT —The BLAST -Like Alignment ToolGenome Research659chance that the N th match is within W letters after the (Nמ1)th match,which gives the more general relationshipF N=S*F N−1(13) which can be solved asF N=F1*S N−1(14) where F N represents the number of chance matches of N K-mers each separated by no more than W from the previous match.Tables7and8show the sensitivity and specificity for N values of2and3and various values of other parameters which approximate cDNA or mouse/human alignments.Selecting Initial Match CriteriaBoth single imperfect matches and multiple perfect matches have a sig-nificant advantage over single per-fect matches.They drastically re-duce the number of alignments which must be checked to achieve a given level of sensitivity,as shown in Tables9and10.The multiple-perfect match criteria can be modi-fied to allow small insertions anddeletions within the homologousarea by allowing matches to beclumped if they are near each otherrather than identical on the diago-nal coordinate.This improves real-world sensitivity at the expense ofincreasing the number of align-ments that must be done.Allowinga single insertion or deletion in-creases the alignments by a factorof three,whereas allowing twoincreases the alignments by a fac-tor of five.In general,two perfectmatches with the appropriate K sizegive specificity for a given level ofsensitivity similar to that given bythree or more perfect matches.The near-perfect match crite-rion overall is similar to the two perfect match criteria.Thenear-perfect criterion cannot accommodate insertions or de-letions,but it has superior performance on finding small re-gions of homology(Table11).For finding coding exons inmouse/human alignments,whichever strategy is used,greaterspecificity is seen at the amino acid rather than the nucleotidelevel.Since single-base insertions or deletions are relativelycommon artifacts of the sequencing process,nucleotide BLATuses the two perfect11-mer match criteria by default.Table12shows actual alignment times for nucleotide BLAT on a col-lection of ESTs at various settings.For protein matches,thedefault criterion is a single perfect5for the stand-alone pro-gram.This is because the extension phase of protein BLAT isextremely quick in the stand-alone program,so the false posi-tives generated by this approach have relatively little cost.Theclient/server protein BLAT uses three perfect4-mers by defaultbecause in the client/server version,a portion of the genomemust be loaded from disk for each false positive,a relativelytime-consuming operation.As a result,the client/server pro-tein BLAT is somewhat less sensitive than the stand-alone ver-sion.Clumping Hits and Identifying Homologous RegionsTo implement the match criteria,BLAT builds up an index ofnonoverlapping K-mers and their positions in the database.BLAT excludes K-mers that occur too often from the index,aswell as K-mers containing ambiguity codes and optionallyK-mers that are in lowercase rather than uppercase.BLAT thenlooks up each overlapping K-mer of the query sequence in theindex.In this way,BLAT builds a list of“hits”where the queryand the target match.Each hit contains a database positionand a query position.The following algorithm is used to ef-ficiently clump together multiple hits.The hit list is split intobuckets of64k each,based on the database position.Eachbucket is sorted on the diagonal(database minus query posi-tions).Hits that are within the gap limit are bundled togetherinto proto-clumps.Hits within proto-clumps are then sortedalong the database coordinate and put into real clumps if theyare within the window limit on the database coordinate.Toavoid missed clumps near the64k bucket boundary,un-clumped hits and clumps that are within the window limit are Figure1A pair of hits and two other hits.The hits a,b,c,and d areall K letters long.Hits d and b have the same diagonal coordinate andare within W letters of each other.Therefore they would match the“two perfect K-mer”search criteria.Kent660Genome Researchtossed into the next bucket for additional clumping opportu-nities.The sorting algorithm mSort ,which is related to qSort ,is used.The bucketing tends to keep N relatively small.Clumps with less than the minimum number of hits are discarded,and the rest are used to define regions of the data-base which are homologous to the query sequence.Clumps which are within 300bases or 100amino acids in the database are merged together.Five hundred additional bases are added on each side to form the final homologous region.Searching for Near Perfect MatchesBLAT has an option to allow one mismatch in a hit.This is implemented by scanning the index repeatedly for each K-mer in the query.Every possible K-mer that matches in all but one position,as well as the K-mer that matches at every po-sition,is looked up.In all,K*(A מ1)+1lookups are required.For an amino-acid search with K =8,this amounts to 153lookups.Because a straight index of 8-mers would require 208index positions or about 100billion bytes,it is necessary to switch to a hashing scheme rather than an indexing scheme,further cutting efficiency.As a consequence,for a given levelof sensitivity,the near-perfect match criterion runs 15ןmore slowly than the multiple-perfect match criterion in BLAT (Table 13).The near-perfect match criterion seems best suited for programs that hash the query sequence rather than the database.A query sequence is sufficiently small that each pos-sible nearly matching K-mer could be hashed,and therefore the index would not have to be scanned repeatedly.Alignment StageThe alignment stage performs a detailed alignment between the query sequence and the homologous regions.For histori-cal reasons,the alignment stage for nucleotide and protein alignments is quite different.Both have limitations,and are good candidates for future BLAT upgrades.On the other hand,both are quite useful in their present form for sequences which are not too divergent.Nucleotide AlignmentsThe nucleotide alignment stage is based on a cDNA alignment program first used in the Intronerator (http://www.cse.BLAT —The BLAST -Like Alignment ToolGenome Research661/∼kent/intronerator)(Kent and Zahler 2000).The al-gorithm starts by generating a hit list between the query and the homologous region of the database.Because the homolo-gous region is much smaller than the database as a whole,the algorithm looks for relatively small,perfect hits.If a K-mer in the query matches multiple K-mers in the region of homol-ogy,the K-mer is extended by one repeatedly until the match is unique or the K-mer exceeds a certain size.The hits are thenextended as far as possible allowing no mismatches,and over-lapping hits are merged.The extended hits that follow each other in both query and database coordinates are then linked together into an alignment.If there are gaps in the alignment on both the query and database side,the algorithm recurses to fill in these gaps.Because the gaps are smaller than the origi-nal query and database sequences,a smaller k can be used in generating the hit list.This continues until either the recur-sion finds no additional hits,or the gap is five bases or less.At this point,extensions through Ns,extensions that allow one or two mismatches if followed by multiple matches,and fi-nally extensions that allow one or two insertions or deletions (indels)followed by multiple matches are pursued.For mRNA alignments,it is often the case that there are several equiva-lent-scoring placements for a large gap in the query sequence.Generally such gaps correspond to an intron.Such gaps are slid around to find their best match to the GT/AG consensus sequence for intron ends.The nucleotide alignment strategy works well for mRNA alignments and the type of alignments needed for genomic assembly.In these cases,the sequence identity is typically 95%or better.The strategy starts to break down when baseidentity is below 90%,and is therefore not suitable for most cross-species alignments.Protein AlignmentsThe protein alignment strategy is simpler.The hits from the search stage are kept and extended into maximally scoring ungapped alignments (HSPs)using a score function where a match is worth 2and a mismatch costs 1.A graph is built with HSPs as nodes.If HSP A starts before HSP B in both query and database coordinates,an edge is placed from A to B.The edge is weighted by the score of B minus a gap penalty based on the distance between A and B.In the case where A and B overlap,a “crossover”point is selected which maximizes the sum of the scores of A up to the crossover and B starting at the cross-over,and the difference between the full scores and the scores just up to the crossover is subtracted from the edge score.A dynamic program then extracts the maximal-scoring align-ment by traversing this graph.The HSPs in the maximal-scoring alignment are removed,and if any HSPs are left the dynamic program is run again.The major limitation of this protein alignment strategy is that if there is an indel,part of the alignment will be lost unless the search stage manages to find both sides of the in-del.For the translated mouse versus translated human ge-nome job,which was the major motivation for protein BLAT ,this limitation is not as serious as it would be when searching for more distant homologs.Indeed in the translated mouse/translated human case,this limit on indels is actually useful in some ways as it reduces the amount of pseudogenes which are found by BLAT more than it reduces the amount of genes found.Even so,in the future we hope to replace this simplistic extension phase with a banded (only small gaps allowed)Smith-Waterman algorithm (Chao et al.1992).Stitching and Filling InIt is often the case that the alignment of a gene is scattered across multiple homologous regions found in the search phase.These alignments are stitched together using a minor variation of the algorithm used to stitch together protein HSPs.For DNA alignments at this stage,the gap penalty is equal to a constant plus the log of the size of the gap.For mRNA/genomic alignments,if after stitching there are gaps left between aligning blocks in both the database and query sequence,the nucleotide alignment algorithm is called on the gap to attempt to fill it in.This gives BLAT a chance to find small internal exons that are further away than 500bases from other exons,and which are too small to be found by the search stage.Since the sort time is O(N logN),that is,proportional to N times log N,where N is the number of hits to be sorted,and the dynamic program time is O(N 2)where N is the number of HSPs,an additional step is necessary to make BLAT efficient on longer query sequences.Untranslated nucleotide queries longer than 5000bases and translated queries longer than 1500bases are broken into subqueries that have approxi-mately 250bases of overlap.Each subquery is aligned as above,and the resulting alignments are stitched together.Currently this subdividing and stitching is only available for the stand-alone BLAT ,not the client/server version.DISCUSSIONAs shown above,BLAT is a very effective tool for doing nucleotide alignments between mRNA and genomic DNA taken from the same species.It is more accurate and orders of magnitude faster than Sim4.Sim4in turn is more accurate and orders of magnitude faster than other published tools such as est_genome (Mott 1997;Florea et al.1998).Although the alignment strategy BLAT uses for nucleotide alignments becomes less effective below 90%sequence identity,it effi-Kent662Genome Researchciently “unsplices”mRNA,and accommodates the level of sequence divergence introduced by sequencing error.BLAT is able to unsplice all the human mRNA in GenBank,including the ESTs,in less than a day on a 100-CPU computer cluster.Since the human,mouse,and other large genome projects are updating sequences at a rapid rate,and GenBank continues to grow at a rapid rate,rapid alignment is needed to keep ge-nome annotations in synchrony with improving genome as-semblies.BLAT working in translated mode is capable of rapidly aligning data across vertebrate species without significant compromise.While TBLASTX can be configured to be more sensitive than BLAT ,at settings commonly used for mammal–mammal comparisons,BLAT runs approximately 50times faster.Even using BLAT ,an alignment of public mouse whole-genome shotgun data took 12days on our 100-CPU cluster.It would be difficult to keep the mouse–human homology in-formation up to date with a slower tool.High-speed alignmentprograms have two major stages—a search stage that uses a heuristic to identify regions likely to be homologous,and an alignment stage that does detailed alignments of the previously defined homologous regions.To get adequate speed when operating at the scale of whole genomes,the search stage is crucial.An index of some sort is key to an efficient search stage.BLAT indexes the da-tabase rather than the query sequence.This more than any-BLAT —The BLAST -Like Alignment ToolGenome Research663。

Deep Sleep in the Arctic

Deep Sleep in the ArcticHARALD R(O)SCH【期刊名称】《中国科学院院刊（英文版）》【年(卷),期】2014(028)002【总页数】4页(P146-149)【作者】HARALD R(O)SCH【作者单位】【正文语种】英文Saving energy is crucial to the survival of animals living in the cold regions of the world. A small marmot-like rodent from the Arctic is world champion when it comes to energy saving. According to YAN Jun from the CAS-MPG Partner Institute for Computational Biology in Shanghai, this makes the Arctic ground squirrel extremely suitable for studying the changes that occur at the molecular level during rodent hibernation. Based on this, the scientist and his colleagues aim to discover exactly how the animals can attain such dramatic reductions in their metabolic activity. TEXT HARALD RÖSCHA lmost all of the life around Lake Toolik in North Alaska comes to a standstill on the arrival of winter. At temperatures of minus 50 degrees centigrade, icy storms sweep across the snow-covered mountain slopes, and the country descends into the darkness of the polar night. The factthat animals can survive in these extremely hostile conditions is nothing short of miraculous.Some of them survive this period only by drastically suppressing their metabolism: they simply sleep through the winter in snow caves or underground lairs. The Arctic ground squirrel (Urocitellus parryii) is one of these survival artists. However, this small rodent has taken energy-saving to a new extreme: it can reduce its metabolism to one or two percent of its normal rate.When these animals, which are found in Canada, Alaska and Siberia, have acquired sufficient fat reserves in autumn, they withdraw deep into their burrows and prepare for a long period of rest. Their hearts work at a gradually slower rate until they beat only once per minute. Their brains shut down almost completely and switch to a kind of stand-by mode. Their body temperature drops from 37 degrees to minus 3; however, their blood does not freeze. This makes them the animal kingdom’s unchallenged recordholders for lowest body temperature. They can survive like this for up to eight months. During this period, the ground squirrels wake up only twice per month for a few hours. It appears that, without these short arousal phases, their brains would suffer irreversible damage.This extreme metabolic adaptation makes the Arctic ground squirrel the perfect object of study for YAN Jun, a scientist from Shanghai. YAN has been work-ing closely with Brian Barnes, a scientist from the Institute of Arctic Biology in Fairbanks, Alaska, on the hibernation of the Arctic ground squirrel. Several dozen of these small rodents live in the laboratory at theInstitute of Arctic Biology in Fairbanks, and enjoy 16-hour light and 8-hour dark days at an indoor temperature of 20 degrees, over the course of which they feed on high-quality rodent food, apple slices and carrots.For their studies, they reduce the temperature in the laboratory to 5 degrees and switch off the light every day after just four hours. This gives the squirrels the signal to prepare for their winter sleep. While the animals sleep, the researchers take tissue samples and analyze their gene activity and protein volumes.In this way, they discovered that the squirrels boost or suppress the production of many proteins during hibernation. With the help of mass spectrometry, the scientists identified over 3,000 proteins in the animals’ livers. Production of approximately 500 of these is increased or decreased during winter: fewer of the proteins used to break down carbohydrates and form fatty acids are available during hibernation, while more proteins are formed for breaking down fatty acids. “This enables the animals to make use of their fat reserves to obtain energy during the long winter months. In summer, they need these proteins again to digest plant food so urces and to produce fats for the following winter,”explains YAN.The tests the researchers conducted also show that it is often impossible to draw conclusions about the volume of a given protein from the prevalence of a messenger RNA. These molecules are the transcripts of genes and provide the basis for proteins. Accordingly, the activity of a gene doesn’t necessarily say anything about the extent to which the corresponding protein is formed. Consequently, the squirrels must useother possibilities to regulate their protein production during hibernation.＞For this reason, the scientists examined socalled microRNA molecules (miRNAs) in greater detail. These small molecules, which have only 19 to 25 base pairs, can block the messenger RNAs. In this way, the miRNAs can hinder the formation of proteins themselves even though their genes are active and read. Thus, miRNAs are important regulator molecules, with which an organism’s different cell types control protein production.YAN Jun and his colleagues discovered over 200 miRNAs in the liver of the Arctic ground squirrel alone, of which 18 were previously unknown molecules. The extent to which a miRNA is formed depends on whether the animals are hibernating or not. For example, far fewer of the molecules are formed in the liver during the sleep and arousal phases. In contrast, others are produced in large volumes - but only when the animals are actually asleep. The values decline again during the short wake phases during hibernation. “Our analyses showed that som e of these miRNAs control cell growth. We assume that the animals can prevent the formation of tumors during hibernation in this way,” explains Yan.As a next step, the researchers compiled a comprehensive genetic profile of the Arctic ground squirrel during hibernation. Approximately 500 genes are activated during this period. “This is the genetic signature of hibernation in these animals,”says YAN. To find out more about the function of these genes, the scientists compared them with genes that are switched on in mice during periods of starvation, sleep deprivation and vascular disorders. Although each of these states differs from thephysiological conditions of hibernation, the squirrels experience them in a similar form during hibernation; the corresponding genetic profiles overlap accordingly. Hence, the fluctuations in the activities of genes during the transition from sleep to wake phases during hibernation correspond to those that arose in the mouse genes in response to day-night fluctuations and low ambient temperatures.Based on this, YAN and his colleagues established that mice that consumed only 10 to 40 percent of their normal calorie intake for weeks or months switch some of the same genes on or off as those activated or silenced by the Arctic ground squirrels during hibernation. For example, genesfor the formation of the energy-storage carbohydrate glucose are activated in both cases; in contrast, genes for the production of fatty acids are silenced. It appears that the transcription factor PPARα is involved in this change in fat metabolism. PPARα accelerates the breakdown of fatty acids and inhibits the formation of new energyconsuming fat molecules. In contrast to this, fat metabolism is not altered in the case of vascular disorders. In the torpor phase during hibernation, little or no blood circulates in the squirrel’s various tissues. During arousal phases, the blood flow increases significantly, similar to the way it increases during a heart attack or stroke. “Unlike in the case of a heart atta ck, however, this increase in circulation doesn’t cause any tissue damage in the sleeping ground squirrels. We assume that the raised fat metabolism prevents such damage.”Moreover, the genes that equip proteins with ubiquitin attachments, and thus release them for the cell’s decompositionmachinery, remain active in the squirrels during hibernation. These genes, however, are significantly less active in mice following undersupply with oxygen.The hibernation of the Arctic ground squirrel is therefore not only fascinating for zoologists, it can also teach researchers a lot about the human body and diseases. “The Arctic ground squirrels appear to survive long phases without food, at low body temperatures, and with restricted oxygen supply and blood circulation without coming to any harm. The knowledge about how they manage this could one day lead to new treatments for cardiovascular disorders, cardiac arrest and strokes,” says YAN.。

Natures Rx for Stress and Anxiety

Natures Rx for Stress and Anxiety In today's fast-paced and demanding world, stress and anxiety have become prevalent issues for many individuals. The constant pressure to perform, meet deadlines, and juggle various responsibilities can take a toll on one's mental and emotional well-being. Fortunately, nature offers a plethora of remedies that can help alleviate these symptoms and promote a sense of calm and relaxation. From soothing herbal teas to invigorating outdoor activities, incorporating nature's Rx for stress and anxiety into your daily routine can make a significant difference in your overall well-being. One of the most effective ways to combat stress and anxiety is by immersing oneself in nature. Spending time outdoors, whether it's taking a leisurely walk in the park, hiking in the mountains, or simply sitting by a tranquil lake, can have a profound impact on one's mental state. The sights, sounds, and smells of nature can help to ground and center the mind, providing a much-needed respite from the hustle and bustle of everyday life. Additionally, exposure to natural sunlight can boost the production of serotonin in the brain, which is known to elevate mood and promote a sense of calm. Incorporating physical activity into your daily routine is another essential aspect of nature's Rx for stress and anxiety. Engaging in activities such as yoga, tai chi, or simply going for a run in the great outdoors can help to release pent-up tension and promote relaxation. Physical exercise triggers the release of endorphins, which are natural mood lifters, and can help to reduce feelings of anxiety and depression. Furthermore, the rhythmic and meditative nature of many outdoor activities can help to quiet the mind and promote a sense of inner peace. In addition to physical activity, the use of herbal remedies can also be incredibly beneficial in managing stress and anxiety. Herbs such as chamomile, lavender, and passionflower have long been used for their calming properties and can be consumed in the form of teas, tinctures, or essential oils. These natural remedies work to soothe the nervous system, reduce muscle tension, and promote relaxation. Incorporating these herbs into your daily routine can provide a gentle and effective way to manage stress and anxiety without the need for pharmaceutical interventions. Furthermore, the simple act of connecting with nature through gardening can be a therapeutic and grounding experience. Whether it's tending to avegetable garden, cultivating a flower bed, or simply potting a few houseplants, the act of nurturing and caring for living things can have a profoundly calming effect on the mind. The physical act of gardening, coupled with the opportunity to connect with the earth and observe the cycle of growth and renewal, can provide a sense of purpose and fulfillment that can help to alleviate feelings of stress and anxiety. Another important aspect of nature's Rx for stress and anxiety is the practice of mindfulness and meditation in natural settings. Taking the time to sit quietly in nature, whether it's under a tree in the park, on a beach, or in a forest, can provide a peaceful and serene environment for introspection and self-reflection. The sounds of nature, such as birdsong, rustling leaves, and flowing water, can serve as a natural backdrop for meditation, helping to quiet the mind and promote a sense of inner stillness. Practicing mindfulness in nature can help to cultivate a sense of gratitude and appreciation for the world around us, fostering a greater sense of peace and well-being. Finally, incorporating natural elements into your living space can also have a positive impact on your mental and emotional well-being. Bringing elements of nature indoors, such as potted plants, natural materials, and soothing color palettes, can help to create a calming and nurturing environment that promotes relaxation. Additionally, incorporatingnatural scents, such as essential oils derived from plants and flowers, can help to create a tranquil and inviting atmosphere that can help to reduce feelings of stress and anxiety. In conclusion, nature offers a myriad of remedies for managing stress and anxiety, from spending time outdoors and engaging in physical activities to incorporating herbal remedies and practicing mindfulness in natural settings. By embracing nature's Rx for stress and anxiety, individuals can cultivate a greater sense of calm, relaxation, and well-being in their lives. Whether it's through immersing oneself in the great outdoors, tending to a garden, or simply bringing elements of nature into one's living space, the healing power of nature is readily available to all who seek it.。

汽车英语单词-终版

0.7.1.8发动机附件纵臂式悬架trailing arm type 行李箱盖trunk lid起动机starter减振器shock absorber前舱盖engine hood发电机alternator钢板弹簧leaf spring铰链hinge压缩机Ac compressor螺旋弹簧coil spring行李箱铰链hinge of trunk lid皮带Drive belt麦弗逊悬架Macpherson suspension引擎盖铰链hinge of engine hood惰轮Idler pulley顶盖边框内板roof side inner panel张紧轮Tensioner pulley0.7.1.10行驶-悬架系顶盖roof panel空滤器air filter/ cleaner横向稳定杆anti-roll bar顶梁upper frame进气歧管intake manifold滑柱shock strut车身覆盖件cover panel排气歧管exhaust manifold上控制臂upper control arm冲压件stamping parts三元催化three way catalyst下控制臂lower control arm前翼子板front fender前氧传感器upstream oxygen sensor 缓冲块bumper 后门内板rear door inner panel后氧传感器downstream oxygen sensor上跳缓冲块Jounce bumper后门内板加强板rear door inner panel reinforcement 碳罐canister扭杆弹簧torsion spring把手door handle消音器muffler副车架subframe门锁door latch/lock中冷器intercooler球铰Ball joint加油口盖Fuel filler lid散热器radiator减振器缓冲座top mount冷凝器condenser上跳bump07.1.12内饰干燥瓶dehydrator filter下跳rebound车内后视镜interior mirror飞轮flywheel轴承bearing前座椅front passenger seat离合器壳bell housing上/下连杆upper/lower link后坐椅rear seat悬架弹性元件suspension spring element座椅软垫seat cushion0.7.1.9传动系上跳极限full bump门孔密封条door opening seal悬架suspension上跳动量bump travel行李箱luggage compartment非独立悬架dependent suspension满载GVW（Gross vehicle weight)仪表板instrument panel独立悬架independent suspension设计载荷design mass仪表cluster meter可变刚度悬架variable rate suspension空载curb mass组合式悬架combination suspension下跳动量rebound travel遮阳板sunvisor纵置板簧式parallel leaf spring type下跳极限full rebound地毯carpet上置板簧式over slung type轮跳行程wheel travel地板floor下置板簧式under slung type07.1.11四门、两盖装饰条moulding双横臂式悬架double wishbone suspension 车门框架door frame A柱护板 A pillar trim panel门护板door trim panel07.1.16脚踏板pedal车速表speedometer附属装置accessories盘式制动Disc brake里程表odometer整体式车身integral body摩擦片friction lining燃油表fuel guage制动蹄brake shoe安全带固定点safety belt anchorage框架frame制动盘brake disc头枕headrest手制动hand brake鼓风机blower轮辋Rim蒸发器evaporator轮胎偏置距wheel offset喇叭horn全钢车身All-steel body轴承偏置距Bearing offset手套箱glover box驾驶室cabin制动盘偏置距Disc offset帘式安全气帘curtain airbag防火墙fire wall顶蓬headliner前防撞横梁Front beam bumper07.1.18传动中控台console变速器Gearbox/Transmission烟灰缸Ash tray水箱横梁water tank bracket离合器clutch 1/3灭火器fire extinguisher大灯横梁head lamp bracket膜片弹簧离合器diaphragm spring clutch钣金sheet metal传动轴propeller shaft07.1.15车身、装饰冲压pressing万向节Universal joint前保front bumper焊装welding等速万向节CVJ_constant velocity joint 后保rear bumper涂装paint传动轴（横向）drive shaft散热器格删radiator grille总装Assembly前/后桥front/rear axle轮罩wheel cover门槛压板sill plate主减速器和差速器final drive and differenttial 前风挡front windshield侧裙护板rocker cover压盘pressure plate后风挡rear windshield包裹架Parcel shelf从动盘driven plate天窗sunroof前纵梁front rail分离轴承release bearing半轴half shaft门限位器door stopper07.1.17制动储液罐reservoir气弹簧Gas spring轮速传感器wheel speed sensor前/后传动轴front/rear drive shaft镀洛装饰条chromed moulding防抱死系统Anti-lock braking system中间支撑轴承center support bearing风挡下装饰板cowl bar cover制动踏板brake pedal离合踏板clutch pedal碰撞吸能块crash absorber液压制动hydraulic brakes分离叉release fork车顶装饰条roof moulding制动分泵总成wheel brake cylinder桥壳axle housing玻璃升降器window regulator制动泵总成Master brake cylinder齿圈ring gear07.1.22转向系方向指示灯direction indicator lamp侧偏刚度cornering stiffness机械转向系manual steering system除霜/除雾defrost/demist特征/临界车速characteristic/critical speed 动力转向系power steering system驻车灯parking lamps静态储备系数static margin转向操纵机构steering control mechanism倒车灯reversing lamps侧倾力矩Roll moment转向盘steering wheel汽车电气设备Automotive electrical system悬架侧倾刚度suspension roll rate循环球式转向器ball and nut steeringgear/recirculating ball-type高位制动灯CHMSL center high-mounted stoplights侧倾总刚度Totall roll rate转向管柱steering column制动灯stop lamp总转向传动比overall steering ratio组合开关combination switch位置灯position lamp不足转向梯度understeer gradient管柱上/下护罩upper/lower cover制动开关brake switch侧倾角梯度Roll angle gradient质心侧偏角梯度sideslip angle gradient转向横拉杆steering tie rod07.1.24底盘最大侧向加速度max lateral acceleration四轮定位wheel alignment 簧载/非簧载质量sprung /unsprung mass转向传动轴steering inner articulated shaft车轮外倾角camber angle纵向/侧向/垂向longitudinal/Lateral/Vertical齿轮齿条式转向器rack and pinion steering gear主销后倾角caster angle横摆角速度增益Yaw gain液压油泵oil pump主销内倾角Kingpin inclination angle侧向加速度增益Lateral acceleration gain储油罐reservoir tank前束角Toe angle横摆角速度Yaw rate/speed/velocity压力油管pressure line主销偏距scrub radius阶跃输入试验step steer test回油管return line主销拖距caster trail双移线Double lane change转向节steering knuckle侧倾中心高度Roll center height固有/激振/共振频率Natural/exciting/resonant frequency抗抬头/抗塌尾(加速时)Anti-lift/Anti-squat轮距wheel track/tread07.1.23电气抗点头/抗抬尾(制动时)Anti-dive/Anti-rise NVH noise,vibration and harshness电池battery弹簧刚度spring rate 舒适性和操稳性Ride and handling前照灯headlamp轮胎刚度tyre rate稳态操稳steady-state handling灯泡bulb悬架刚度suspension/wheet rate瞬态操稳transient state handling后雾灯rear fog lamps轮胎和悬架的总刚度ride rate转向角(车轮)steer angle回复反射器reflex reflectors轮胎接地面tyre contact patch转向角(方向盘)steering wheel angle牌照灯registration plate lamps回正力矩Aligning torque阿克曼转角Ackerman steer angle 2/3线束wire harness俯仰/横摆/侧倾Pitch/Yaw/Roll跳动转向(梯度)Ride steer/Ride steer gradient 刮水器wiper轮胎侧偏角slip angle侧倾转向Roll steer/Roll steer gradient示宽灯width lamps质心侧偏角sideslip angle侧倾外倾系数Roll camber coofficient/gradient 车载诊断装置OBD=on-board diagnostic不足/中性/过多转向understeer/Neutal steer/oversteer制动转向Brake force steer加速度的加速度Jerk有效头部空间effective head room人体中心线driver centerline变速箱人机工程ergonomics2轮驱动2WD R点SgRP(seat referrence point)4轮驱动4WD全轮驱动AWD液力变矩器hydraulic torque convertor换档杆shift lever换档手柄knob分动器transfer case限滑差速器limited slip differential人机工程靠背角back/torso angle臀部角hip angle膝盖角knee angle脚踝角ankle angle上视角upper visibility angle下视角lower visibility angle靠背线back/torso line眼椭圆eyellypse脚锺点Acceleration Heel Point(AHP)大腿中心线thigh line小腿中心线lower leg line肩部空间shoulder room臀部空间hip room膝盖点knee pivot point加速踏板中心pedal reference point(PRP)头部轮廓head contour方向盘中心steering wheel center有效腿部空间effective leg room肘部空间elbow room3/3。

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ARBEITSKREIS-LASTENHEFTDezember 2008Federn und StabilisatorenAK-LH 07Anforderungen und Prüfungensprings and stabilizer bars; requirements and testingInhalt:1ANWENDUNGSBEREICH UND ZWECK1.1Zweck1.2Geltungsbereich2BEGRIFFE / WEITERE VORSCHRIFTEN3ZIELE4ANFORDERUNGEN VERSUCH / LABOR4.1Allgemeine Anforderungen4.2Offensichtliche Mängel4.3Anforderungen an das Vormaterial4.4Fertigungsvorschriften und Materialeigenschaften (für das Fertigteil)4.5Mechanische Eigenschaften (Fertigteil)4.6Korrosionsprüfung4.7Funktionseigenschaften an Federn (Fertigteil)4.8Funktionseigenschaften an Stabilisaoren (Fertigteil)4.9Dynamische Prüfung (Schwingfestigkeit)5ANFORDERUNG BERECHNUNG SCHRAUBENFEDER5.1Anwendungsbereich5.2Anforderungen an das Rechenmodell5.3Auswertung der Ergebnisse5.4Dokumentation6ZIEL-WERTE6.1Umweltverträglichkeit / Recycling6.2Qualität6.3Kosten6.4Gewicht6.5Termine7FREIGABEN / ÄNDERUNGEN8GEHEIMHALTUNGFortsetzung Seite 2 bis 28AK-LH: Arbeitskreis-LastenheftArbeitskreis der Firmen: Audi AG, Bayerische Motoren Werke AG, Daimler AG, Porsche AG, Volkswagen AG0. ÄnderungsdokumentationIndexÄ.-Nr.Kurzbeschreibung Datum Namea --Erstfassung12.93 Dr. Hutterb -- Pkt. 2: DIN EN 10 204 war DIN 50 049; Pkt. 4.7.3: LP1 bzw. FP1war Lprüfbzw. Fprüf ; LP2, FP2hinzu; Pkt. 4.8.3: Durchführung: "Die Bruchlast-spielzahl des Stabilisators wird mit dem Exzenter-Prüfstand bzw. bei ent-sprechendem Zeichnungseintrag mit dem Resonanzprüfstand ermittelt."(Satz entfällt); Prüfverschrängung 80 % (war 55 %), "Der maximal ...verifiziert" (Satz hinzu); "Es muß sichergestellt ... mit Stroboskop)."(Satz hinzu); Abb. 10: Formel "a/2" hinzu; Pkt. 5.2: DIN EN 10 204 warDIN 50 049;11.95 Dr. Hutterc -- Pkt. 2 und jeweilige Unterpunkte: DIN 50021, DIN 53167, E DIN55996-1 hinzu; Pkt. 4.4.3: Satz …Die Prüfung ... nicht zulässig.“ entfällt;Tab. 1 neu hinzu; Numerierg. nachfolgender Tab. entsprchd. geändert;Pkt. 4.4.4: Satz …Zundereinschlüsse ... zu vermeiden.“ entfällt; Pkt. 4.6,4.6.1, 4.6.2: redaktionell überarbeitet, Anforderungen neu definiert;Ritztest nach DIN 53167 neu hinzu; alternativ Multischlagprüfung n.DIN 55996-1 neu hinzu; Abb. 3 und 5 neu für Multischlagprüfung; Pkt.4.8.2: Amplitude Vorder-/ Hinterachse neu definiert, war …lt. Zchg.“ bzw.95 % (L OA-L UA); Pkt. 4.8.3: Prüfverschrängung 55% ... oder lt. Zchg.(war 80%);02.00 Engelmohrd -- Pkt. 5 …Anforderung Berechnung Schraubenfeder“ hinzu; Formatierunggeändert04.04 Witte -- Überarbeitung Pkt. 4.8 …Prüfanforderungen für dynamische Versuche anFedern und Stabilisatoren“-Naßprüfung hinzu; Setzfestigkeit der Federnhinzu10.05 WittredaktionelleÜberarbeitungder zitierten Normen 01.06 Wittf -- Überarbeitung 4.7.3: …Setzprüfung (Fließverhalten statisch)“ statt…Fließverhalten (statisch)“, …1.) Feder auf Lc+dmax/2 zusammendrücken– entlasten“ (Blocken) entfällt. LP1, LP2 werden ersetzt durch LoA, FP1,FP2 werden ersetzt durch FoA, LuA entfällt. …L c theoretischeBlocklänge der Feder lt. Zchg.“ entfällt.Überarbeitung 4.9.1 …statistische Auswertung“ : Anforderung fürEinstufenprüfung nass an Federn: 350.000 LW bei Pü= 85%. Text ab…Bei neuentwickelten Federn …“ inkl. Diagramm …Lg-normalverteiltesLebensdauernetz…) bis Beginn 4.9.2 entfernt. Ansatz von Hück zuKorrektur der Lastspielzahl in Abhängigkeit von der Frequenzaufgenommen.Neu hinzu: …4.9.4 Umweltsimulationsprüfung an Tragfedern(Verschmutzung und Korrosion im Federauflagebereich)“.09.07 Scheffel4.9.1 Tabelle 2: Zeile 2: …Min.“ vor …4 Prüfteile pro Los“ eingefügt.Unter Tabelle …*) gilt für logarithmische Normalverteilung“4.9.2: nach …sinusförmig um Normallage L N“ eingefügt: …Falls ausKinematikgründen nicht möglich, ist die Mittelpunktslage so zuverschieben, dass der geforderte Hub möglich wird.“10.07 Scheffel4.9.2 Frequenz: …Bei höheren Prüffrequenzen bis maximal 5 Hz ist die lt.Tabelle 2 geforderte Lastspielzahl mit dem folgenden Ansatz von Hückzu korrigieren“ ersetzt durch …Bei höheren Prüffrequenzen bis maximal 5Hz ist die erreichte Lastspielzahl mit dem folgenden Ansatz von Hück zukorrigieren“. N1 …geforderte Lastspielzahl“ ersetzt durch …korrigierteerreichte Lastspielzahl“. N2 …zu fordernde Lastspielzahl“ ersetzt durch…erreichte Lastspielzahl“.03.08 Scheffelg -- Überarbeitung der Normen, Ersatz von ungültigen durch neue Normen:DIN 50021 und DIN EN ISO 7253 ersetzt durch DIN EN ISO 9227,DIN 55996-1 ersetzt durch DIN EN ISO 20567-1, DIN 50017 ersetztdurch DIN EN ISO 6270-207.08 Scheffelh -- 4.9.3 Einstufenprüfung an Stabilisatoren - Überarbeitung Prüfaufbau 12.08 Günther1 Anwendungsbereich und Zweck1.1 ZweckDieses Lastenheft stellt eine Zusammenfassung der zur Freigabe von Fahrzeugtragfedern (Schraubendruckfedern / Formfedern / Tonnenfedern) und Stabilisatoren notwendigen Werk-stoffprüfungen, Funktions- und Betriebsfestigkeitsversuche, sowie die rechnerische Vorbemessung von Schraubenfedern dar.Das Ziel ist eine eigenverantwortliche Anlieferung des komplett vorgeprüften Lieferumfanges des Lieferanten.Alternative Prüfverfahren sind zulässig, nachdem die Korrelation hergestellt wurde.1.2 GeltungsbereichDas Lastenheft ist Teil der Zeichnung. Es gilt für alle Federn und Stabilisatoren, die einen entsprechenden Hinweis in der Zeichnung aufweisen.2 Begriffe / Weitere VorschriftenIm Lastenheft wird unterschieden zwischen - Tragfedern nach der Formgebung vergütet- Tragfedern aus vergütetem Vormaterial- warmgeformte Stabilisatoren- kaltgeformte Stabilisatoren.Soweit in der Zeichnung bzw. diesem Lastenheft nicht anders angegeben, gelten für Federn und Stabilisatoren sowie deren Werkstoffen die Anforderungen in Anlehnung an folgende Normen:Norm AK-LH Ausgabe TitelDIN 2095 1973-05 Zylindrische Schraubenfedern aus runden Drähten;DIN 2096-2 1979-01 Zylindrische Schraubendruckfedern aus runden Stäben;DIN 50014 1985-07 Klimate und ihre technische Anwendung; NormalklimateDIN 50602 1985-09 Metallographische Prüfverfahren; Mikroskopische Prüfung von Edelstählen aufnichtmetallische Einschlüsse mit Bildreihen;DIN 51200 1985-10 Werkstoffprüfmaschinen; Gestalten und Anwenden vonAufnahmevorrichtungen für Proben in Härteprüfgeräten;DIN EN 10002 2001-12 Metallische Werkstoffe; Zugversuch; Prüfverfahren;DIN EN 10089 2003-04 Warmgewalzte Stähle für vergütbaren Federn - Technische Lieferbedingungen;DIN EN 10204 2005-01 Metallische Erzeugnisse; Arten von PrüfbescheinigungenDIN EN 10218-2 1996-08 Stahldraht und Drahterzeugnisse - Allgemeines - Teil 2: Drahtmaße undToleranzen;DIN EN 10270-1 2001-12 Stahldraht für Federn - Teil 1: Patentiert-gezogenener unlegierterFederstahldraht;DIN EN 10270-2 2001-12 Stahldraht für Federn - Teil 2: Ölschlussvergüteter FederstahldrahtDIN EN ISO 3887 2003-10 Stahl - Bestimmung der Entkohlungstiefe;DIN EN ISO 6270-2 2005-09 Beschichtungsstoffe - Bestimmung der Beständigkeit gegen Feuchtigkeit - Teil2: Verfahren zur Beanspruchung von Proben in Kondenswasserklimaten DIN EN ISO 6507-1 2006-03 Metallische Werkstoffe - Härteprüfung nach Vickers - Teil 1: Prüfverfahren;DIN EN ISO 9227 2006-10 Korrosionsprüfungen in künstlichen Atmosphären – Salzsprühnebelprüfungen;DIN EN ISO 18265 2004-02 Metallische Werkstoffe - Umwertung von Härtewerten;DIN EN ISO 20567-1 2007-04 Beschichtungsstoffe - Prüfung der Steinschlagfestigkeit von Beschichtungen -Teil 1: Multischlagprüfung;VDA 621-415 1982-02 Anstrichtechnische Prüfungen; Prüfung des Korrosionsschutzes vonKraftfahrzeuglackierungen bei zyklisch wechselnder Beanspruchung;3 ZieleDie Einhaltung der Termin-, Qualitäts-, Kosten- und Gewichtsziele ist mit höchster Priorität zuverfolgen.4 Anforderungen Versuch / Labor4.1 Allgemeine AnforderungenFalls nicht anders angegeben, gelten die Anforderungen für Teile im Anlieferzustand.Kennzeichnung / Signierung: lt. Zchg.Durch die Kennzeichnung darf die Lebensdauer vonFeder und Stabilisator nicht beeinflußt werden.Transportschutz: lt.Versandvorschrift Allgemeiner Betriebstemperaturbereich: [°C] - 30 bis + 90Prüftemperatur, falls keine anderslautenden Angaben: Normalklima DIN 50014-23/50-2 Vor Durchführung der Prüfung sind die Teile 2 hder jeweiligen Prüftemperatur anzugleichen.Güteklasse (für Tonnenfedern): A (Q = 0,01) nach DIN 2096-2lt.Zchg.oder Güteanforderungen in DIN 2096-2 geltendann für Tonnenfedern, wenn sie ohne Ver-änderungen übertragen werden können.Maßgenauigkeitsklasse: C in DIN 2076Gütegrad: 2 in DIN 20954.2 Offensichtliche MängelOptische Schäden (Kerben, Lackschäden etc.) sind nicht zulässig.4.3 Anforderungen an das Vormaterial4.3.1 WerkstoffzusammensetzungFür die chemische Zusammensetzung werden die Werte der Schmelzanalyse gewährleistet (Angaben in Gewichtsprozent).Die chemische Zusammensetzung ist nach dem vom Chemikerausschuß des Vereins DeutscherEisenhüttenleute angegebenen Verfahren zu ermitteln (siehe DIN EN 10089).Nicht aufgeführte Elemente dürfen dem Stahl außer zum Fertigbehandeln der Schmelze nicht zugesetzt werden.Es sind alle angemessenen Vorkehrungen zu treffen, um die Zufuhr solcher Elemente aus demSchrott und anderen bei der Herstellung verwendeten Stoffen zu vermeiden, welche die Härt-barkeit, die mechanischen Eigenschaften und die Verwendbarkeit beeinträchtigen.4.3.1.1 Tragfedern - nach der Formgebung vergütetZchg. Werkstoff lt.Elementanteile (Gew.-%): entsprechend DIN EN 10089 oder lt. Zchg.Cu < 0,254.3.1.2 Tragfedern - aus vergütetem VormaterialZchg. Werkstoff lt.4.3.1.3 Warmgeformte StabilisatorenZchg. Werkstoff lt.Soweit nicht anders angegeben, gelten die Anforderungen nach DIN EN 10 089.4.3.1.4 Kaltgeformte StabilisatorenZchg. Werkstoff: lt.Es ist wahlweise - patentiert gezogener runder Federstahldraht- vergüteter Federstahldrahtoder - warmgewalzter Stahl für vergütbare Federnzu verwenden. Bezogen auf den jeweiligen Lieferanten ist derfreigegebene Werkstoff aber verbindlich.4.3.2 Reinheit des MaterialsBestimmung des Reinheitsgrades nach DIN 50602.Der Gehalt an Sulfiden (SS-Typen) ist über den Schwefelgehalt festgelegt; der Reinheitsgrad SS von 0.4 / 1.4 darf jedoch nicht überschritten werden. Für Oxide (Typen OA, OS, OG) ist folgender Summenkennwert für jede einzelne Schlackenart zulässig:Summenkennwert K4 < 404.3.3 OberflächeDie Oberfläche des Vormaterials muß dem Verwendungszweck entsprechend ausgeführt sein.4.4 Fertigungsvorschriften und Materialeigenschaften (für das Fertigteil)4.4.1 RißprüfungRißfreiheit der Teile muß durch 100 %-Prüfung - oder entsprechenden Fertigungsprozeß und Stichprobenprüfung - sichergestellt werden. Eine 100 %-Rißprüfung erfolgt nur, wenn dies ausdrücklich von den jeweiligen Automobil-Herstellern verlangt wird.4.4.2 Formgebung / BearbeitungDie Formgebung hat so zu erfolgen, daß eine gleichbleibende, lt. Lastenheft geforderte, Produkt-güte erzielt wird. Es dürfen dabei weder durch mechanische Bearbeitung noch durch Wärme-behandlungen Fehler entstehen, welche die Lebensdauer beeinträchtigen.Gleitmittelrückstände sind vor dem Vergütungsprozeß zu entfernen - bei möglichen negativen Einflüssen (u.a. Phosphate).Beim Schleifen von Endflächen dürfen keine Anlaßzonen bzw. Neuhärtezonen im Bereich derfedernden Windungen entstehen.4.4.3 RandabkohlungPrüfung nach DIN EN ISO 3887, Verfahren M.Tabelle 1maximal zulässige AbkohlungstiefenMaterial-∅Schraubenfedern Stabilisatoren< ∅ 15 mm < 50 µm < 150 µm≥∅ 15 mm bis ∅ 30 mm < 100 µm < 0,01 x ∅ (150 bis 300 µm) oder lt. Zchg.4.4.4 OberflächeNach dem Kugelstrahlen sind Überlappungen bis 40 µm zulässig.4.4.5 KugelstrahlenDurchführung und Anforderung nach den Richtlinien des Arbeitskreises "Kugelstrahlen" derDGM (DIN z. Zt. als Entwurf).4.5 Mechanische Eigenschaften (Fertigteil)Anforderung:Härte (Kern / Oberfläche) [HV 30] lt. Zchg.Prüfung:Härtebestimmung nach DIN EN ISO 6507-1Festigkeitswertung nach DIN EN ISO 18265Es sind exakte Prüfwerte zu ermitteln (Vermeiden der in DIN 51200 aufgezeigten Fehler-möglichkeiten).Alternativ ist die Ermittlung der Festigkeit im Zugversuch nach DIN EN 10002 zulässig.4.6 KorrosionsprüfungZur Sicherung des Prozesses der Oberflächenbeschichtung ist die Korrosionsprüfung an einemFedern- bzw. Stabilisatortyp mit gleichartigem Oberflächenschutz und vergleichbaren geo-metrischen Verhältnissen durchzuführen. Bei Änderung im Lackmaterial, -aufbau oderVerfahren erfolgt eine Nachprüfung in Absprache mit dem Abnehmer. Es sind mindestens 2Bauteile zu prüfen.Vor Durchführung der Korrosionsprüfung werden die Prüfteile zum einen mit einem Ritztestgemäß DIN EN ISO 9227, zum anderen mit definiertem Strahlmittel mechanisch vorgeschädigtdurch Steinschlagsimulation entsprechend Abbildung 1 oder Multischlagprüfung gemäßDIN EN ISO 20567-1 (Verfahren B). Das Strahlmittel ist nur für eine Prüfung zu verwenden.Die Ritzspur dient zur Beurteilung der Unterwanderungsbeständigkeit und Lackhaftung,während die Vorschädigung durch Aufschläge zur Beurteilung der Durchschlagfestigkeit desKorrosionsschutzes durchgeführt wird.Nach Durchführung der Prüfung sind die Teile visuell nach Grenzmuster zu beurteilen (sieheBeispiele Abbildung 2 bis Abbildung 5).Umfangsgeschwindigkeit des Antriebsrades [km/h] 60Strahlmittel Basaltsplit Körnung 2 bis 5einsetzbar in Asphalt,überwacht nach RGminStrahlmittelmenge [g]20060Prüfdauer [s]ca.Drehzahl des bestrahlten Bauteiles [min-1] 30Abbildung 1: Steinschlagsimulation - schematischer Aufbau4.6.1 Federna) Beurteilung der Unterwanderung und Lackhaftung:Durchführung Ritztest gemäß DIN EN ISO 9227anschließend 6 Zyklen Korrosionswechseltest nach VDA 621-415Anforderung max. zul. Unterwanderung 3 mmb) Beurteilung der Durchschlagfestigkeit des Korrosionsschutzes:Durchführung Steinschlagsimulation (nach Abbildung 1)anschließend 5 Zyklen Korrosionswechseltest nach VDA 621-415alternativ Multischlagprüfung nach DIN EN ISO 20567-1-Banschließend 48 h Salzsprühnebelprüfung nach DIN EN ISO 9227 - NSSAnforderung max. zul. Rostgrad entsprechend Grenzmuster,Abbildung 2 bzw. Abbildung 34.6.2 Stabilisatorena) Beurteilung der Unterwanderung und Lackhaftung:Durchführung Ritztest gemäß DIN EN ISO 9227anschließend 5 Zyklen Korrosionswechseltest nach VDA 621-415 Anforderung max. zul. Unterwanderung 3 mmb) Beurteilung der Durchschlagfestigkeit des Korrosionsschutzes:Die Steinschlagsimulation bzw. Multischlagprüfung erfolgt am geraden Teil des Rückens entsprechend Abbildung 4 und Abbildung 5.Durchführung Steinschlagsimulation (nach Abbildung 1)anschließend 3 Zyklen Korrosionswechseltest nach VDA 621-415 alternativ Multischlagprüfung nach DIN EN ISO 20567-1anschließend 48 h Salzsprühnebelprüfung nach DIN EN ISO 9227 - NSS Anforderung max. zul. Rostgrad entsprechend Grenzmuster,Abbildung 4 bzw. Abbildung 5Abbildung 2: Grenzmuster für max. zul. Rostgrad an pulverbeschichteten Federn bei Stein-schlagsimulation entsprechend Abbildung 2 und anschließend 6 Zyklen Korro-sionswechseltest nach VDA-Prüfblatt 621-415Abbildung 3: Grenzmuster für max. zul. Rostgrad an pulverbeschichteten Federn bei Multi-schlagprüfung nach DIN EN ISO 20567-1 und anschließend 48 h Salzsprüh-nebelprüfung nach DIN EN ISO 9227 - NSSAbbildung 4: Grenzmuster für max. zul. Rostgrad an Stabilisatoren bei Steinschlagsimulation entsprechend Abbildung 1 und anschließend 3 Zyklen Korrosionswechseltestnach VDA-Prüfblatt 621-415Abbildung 5: Grenzmuster für max. zul. Rostgrad an Stabilisatoren (Schenkel und Rücken) beiMultischlagprüfung nach DIN EN ISO 20567-1 und anschließend 48 hSalzsprühnebelprüfung nach DIN EN ISO 9227 - NSS4.7 Funktionseigenschaften an Federn (Fertigteil)Formelzeichen, Einheiten, Benennungen i.A. DIN 2096-2Die Anforderungen bezüglich Endwindungsdurchmesser und Gesamtzahl der Windungen nach DIN 2096-2 oder lt. Zchg. sind einzuhalten.Wird die Prüfung der Außermittigkeit der Feder gefordert, so ist dies in der Zeichnung zu vermerken.4.7.1 HüllkreisdurchmesserDer Hüllkreisdurchmesser (lt. Zchg.) muß über dem gesamten Federweg (Ein- und Ausfederunglt. Zchg.) eingehalten werden (siehe Pkt. 4.9.2).4.7.2 FederkennlinieAnforderung:Zchg. Kennlinienverlauf lt.Federrate R [N/mm] lt.Zchg.zul. Abweichung der Federkraft A F[N] DIN 2096-2 oder lt. Zchg.zul. Abweichung der Federrate A R[N/mm] DIN 2096-2 oder lt. Zchg.Prüfung:Der Kennlinienverlauf ist mittels Parallel-Einfederung oder lt. Zchg. zu ermitteln.Prüfung (im allgemeinen):DIN 2096-2 oder lt. Zchg.4.7.3 Setzprüfung (Fließverhalten, statisch) Anforderung:Zulässiger Baulängenverlust:[]%1000;48;0;⋅−−oA N N N L L L L a) bei Weg - konstanter Prüfung: ≤ 3 %.b) bei Kraft - konstanter Prüfung: ≤ 4 %.Prüfung:Das Fließverhalten ist mittels Parallel-Einfederung nach a) oder b) zu ermitteln.Ablaufschema :1.) Feder auf L N;0 fahren und F N;0 ermitteln - entlasten;2.) a) bei Weg-konstanter Prüfung:Feder anschließend 48 h bei konstant gehaltener Prüflänge L oA lt. Zchg. lagern (Relaxation tritt ein);b)bei Kraft-konstanter Prüfung:Feder anschließend 48 h bei konstant gehaltener Prüfkraft F oA lt. Zchg. lagern;3.) danach voll ausfedern und L N;48 bei der unter 1.) ermittelten Kraft F N;0 feststellen;Formelzeichen und Benennungen: L N Federlänge nach Zusammendrücken auf Stellung Normallage (zugeordnetder Prüfkraft F N ) ohne vorherige FedernbelastungL N;48 Federlänge nach Zusammendrücken auf Stellung Normallage (zugeordnetder Prüfkraft F N ) nach 48 h Federnbelastung mit F oA bzw. bei L oAF N Federkraft bei NormalbelastungF oA Federkraft bei Prüfbelastung (zugeordnet der Prüflänge L oA )L oAoberer Anschlag der Feder lt. Zchg., Federlänge nach Zusammendrücken auf StellungPrüflage (zugeordnet der Prüfkraft F oA )4.8 Funktionseigenschaften an Stabilisaoren (Fertigteil)Formelzeichen, Einheiten, Benennungen i.A. DIN 2096 T24.8.1 StabilisatorkennlinieAnforderung:Zchg. Kennlinienverlauf lt.Stabilisatorrate R [N/mm] lt.Zchg.Zchg.zul. Abweichung der Stabilisatorrate A R [N/mm] lt.Prüfung:Der Kennlinienverlauf ist mittels Verschränkung im System oder lt. Zchg. zu ermitteln.Prüfung (im allgemeinen): lt. Zchg.4.9 Dynamische Prüfung (Schwingfestigkeit)4.9.1 Statistische AuswertungTabelle 2 Kurzzeichen Federn (4.9.2) Stabilisatoren (4.9.3)Min. Prüfteile pro Los n 4 4*)350.000 Nass 100 000 Mindest-Lastspielzahl NPü 85%max. Prüflastspielzahl 1 000 000 200 000Streuung s lg s ≤ 0,2 **) lg s ≤ 0,2 **)*) gilt für logarithmische Normalverteilung**) lg s = 0,2 entspricht einer Streuung von 1:3,25 bei N90 / N104.9.2 Einstufenprüfung an FedernFedern sind mit Systemeinfederung unter Korrosion zu prüfen.AnforderungAuswertung für Bruchlastspielzahl siehe Pkt. 4.9.1PrüfungPrüfparameter:Schwingung sinusförmig um Normallage L NFalls aus Kinematikgründen nicht möglich, ist die Mittelpunktslage so zu verschieben, dass der geforderte Hub möglich wirdAmplitude a [mm] 75 % •(L N - L oA) oder lt. Zchg.bzw. über Definition der Radeinfederung Abbildung 14Frequenz f [Hz] ≤1,5Bei höheren Prüffrequenzen bis maximal 5 Hz ist die erreichte Lastspielzahlmit dem folgenden Ansatz von Hück zu korrigieren:312121⎟⎟⎠⎞⎜⎜⎝⎛=f f N Nf1 [Hz] geforderte Prüffrequenzf2 [Hz] tatsächliche PrüffrequenzN1[-] korrigierte erreichte Lastspielzahl bis Bruch beigeforderter Prüffrequenz f1N2 [-] erreichte Lastspielzahl bei Prüfung mit Frequenz f2Korrosionsmedium 5%ige NaCl-LösungKorrosionszyklus 5 min Beregnung, 25 ±5 min TrockenPrüfvorgang (dynamische Prüfung):Nach dem Federneinbau werden die Federn auf die Einbaulänge L N zusammengefahren. Die Federn werden dann mit dem Prüfhub (Amplitude a) dynamisch belastet.Prüfanordnung:Prüfaufbau lt. Zchg.Die Prüfanordnung für Systemeinfederung ist abhängig von der jeweiligen Achskonstruktion, für welche die Federn bestimmt sind. Als Beispiel hierfür ist in Abbildung 10 die vereinfachte Systemeinfederung einer Hinterachse dargestellt. Die Ableitung der Systemvereinfachung ist als Beispiel in Abbildung 7, Abbildung 8 und Abbildung 9 dargestellt. Die für die Generierung eines Ersatzsystems notwendigen Einstellparameter können idealerweise mit Hilfe eines Mehrkörpersimulationsmodell, in dem die Kinematik der Achse abgebildet ist ermittelt werden.Für Achskonstruktionen mit Systemeinfederung ist eine Zeichnung bzw. Skizze mit dem ent-sprechenden Prüfaufbau zu erstellen.Abbildung 7: Beispiel eines GesamtsystemsAbbildung 8: Definition der FederebeneB_1F _1H _1F _2R_1H_1 = Höhe Federsystem B_1 = Breite Federsystem R_1 = SystemradiusF_1 = Länge der Feder in NormallageF_2 = Länge der Feder in Normallage (Alternativmaß)Abbildung 9: Schnittdarstellung in der FederebeneAbbildung 10: Systematische Darstellung der Einfedergeometrie4.9.3 Einstufenprüfung an StabilisatorenAnforderungAuswertung der Schwingfestigkeit nach Pkt. 4.9.1Beim Erreichen der Mindestlastspielzahl dürfen keine optisch erkennbaren Schäden am Stabi-lisator vorhanden sein.Diese Prüfung gilt nicht für radführende Stabilisatoren. Bei diesen ist die Prüfung lt. Zchg.durchzuführen.DurchführungPrüfaufbau: Der Stabilisator ist im ZSB unter Berücksichtigung der Achskinematikzu prüfen. Nach Absprache mit jeweiligem OEM ist ggf. eineVereinfachungen des Prüfaufbaus möglich. Hierzu muss ein Nachweismittels geeigneter Methoden (z. B. FE-Rechnung) vorliegen, der dieVereinfachung des Prüfaufbaus zulässt.Prüffrequenz: f [Hz] 1 bis 40Prüfverschränkung: Vorder- / Hinterachse a/α[mm/°] 55 % der max. konstuktivmöglichen oder 80% der max.Verschränkunggemessenen(Die Prüfverschränkung wird als Verschränkungsweg a oder alsVerschängungswinkel α angegeben)Die Stabilisatorenden sind bei der Prüfung ausgehend von der Normallage jeweils um denselben Betrag a/2 bzw. α/2 auszulenken (siehe Abbildung 11).Abbildung 11: Definition Prüfverschränkung4.9.4 Umweltsimulationsprüfung an Tragfedern (Verschmutzung und Korrosion imFederauflagebereichDie Anforderung gilt für Neukonstruktionen und Modifikationen bestehender Systeme imFederauflagenbereich.Ziel ist die Bewertung von Umwelteinflüssen/Korrosion und den daraus resultierenden Belastungen für Fahrzeugtragfedern und angrenzende Bauteile während ihrer Lebensdauer. Es sind mindestens 4 Federn zu prüfen (jede Feder durchläuft nacheinander die nachfolgend beschriebenen Teilprüfungen 1.-3.).1. Vorkonditionierung, dynamischTrocken-Schwingversuch in Systemeinfederung (in Einbaulage):Es sind Original-Anbauteile/-Federteller einzusetzen.Verwendet wird folgendes entsprechend dem maximalen Einfederweg zu skalierendes Weg-Blockprogramm:Stufe Einfeder-Amplitude,normiert [%] Häufigkeit [-] Summenhäufigkeit [-]1 100 500 5002 90 20.000 20.5003 65 10.0000 120.5004 40 200.000 320.5005 25 700.000 1.020.500Die Anregung erfolgt sinusförmig mit der Einfederamplitude um die Normallage (Konstruktionslage, Lage entsprechend Normallänge L N der Feder), die Gesamt-Lastwechselzahl beträgt 1.020.500. Zur besseren Durchmischung ist das Blockprogramm in 100 Teilabschnitte aufzuteilen, jeweils beginnend mit der größten Wegamplitude. Die Prüffrequenz ist im Bereich von 0,5 Hz bis 10 Hz frei wählbar.Die Feder ist im eingebauten Zustand im unteren Auflagebereich zu Beginn der Prüfung und während der Prüfung jeweils täglich mit einer Mischung aus Basalt-Splitt (Korngrößen 2 bis ca.6 mm) und Quarzsand/Streusand (Korngrößen 0,2 mm bis 2 mm) zu beaufschlagen. Die aufzubringende Menge soll einer im Kundenbetrieb maximal möglichen Verschmutzung entsprechen. Zur besseren Haftung kann der aufgebrachte Schmutz (Basaltsplitt, Quarzsand/Streusand) mit Wasser befeuchtet werden.2. VDA-Wechseltest (VDA 621-415)Es sind 4 Zyklen zu durchfahren. Die Feder ist während allen 4 Zyklen auf Normallänge L N (entsprechend der Belastung in Konstruktionslage) vorgespannt. Hierbei sind Original-Anbauteile/-Federteller zu verwenden.Ein Prüfzyklus dauert 7 Tage und besteht aus1 Tag = 24 h Salzsprühnebelprüfung DIN EN ISO 9227 - NSS4 Tage= 4 Zyklen Kondenswasser-Wechselklima DIN EN ISO 6270-2 - AHT2 Tage= 48h Raumtemperatur 18 °C bis 28 °C nach DIN 500143. Ermittlung der RestlebensdauerEinstufen-Nass-Schwingversuch in Systemeinfederung analog Abschnitt 4.9.2.Geforderte Lastwechselzahl bis Bruch lt. Zeichnung bzw. Komponenten-Lastenheft des OEM.5 Anforderung Berechnung Schraubenfeder5.1 Anwendungsbereich5.1.1 ZweckDieser Teil des Lastenhefts beschreibt die Mindestanforderungen an die elastische Berechnung des Spannungsfelds in Schraubendruckfedern, die als Tragfedern in Fahrzeugen eingesetzt werden. Das Ziel ist die zuverlässige Ermittlung der Spannungen in der idealen Feder als Grundlage für die Beurteilung der Lebensdauer.Ein weiteres Ziel der Berechnung ist die Aufdeckung von Schwachstellen im Krafteinleitungsbereich, insbesondere• die Auswirkungen der Reibung in der Aufstandsfläche,• der Einfluss der Geometrie (Ungünstige Kontaktbereiche, Bruchgefahr am Windungsende).Die hier zusammengestellten Vorschriften sollen eine hinreichende Genauigkeit und Reproduzierbarkeit der Spannungsberechnung sicherstellen und einen Rahmen definieren für die Erstellung des Modells und die Auswertung der Ergebnisse.5.1.2 HaupteffekteFolgende Haupteffekte sind Grundlage der Berechnung:• Ideale Geometrie (Nennmaße).• Statische Lastaufbringung.• Linearelastisches Werkstoffverhalten.• Nichtlineare Kinematik.• Reibung und Kontakt im Krafteinleitungsbereich.5.1.3 RechenverfahrenAls Rechenverfahren wird die Methode der Finiten Elemente (FEM) eingesetzt für große Verschiebungen bei kleinen Dehnungen (linearelastischer Werkstoff und nichtlineare Kinematik).Wenn in begründeten Einzelfällen und in Absprache mit dem Auftraggeber andere Rechenverfahren eingesetzt werden, sind die Vorschriften für die Modellbildung und die Auswertung der Ergebnisse sinngemäß anzuwenden.5.2 Anforderungen an das Rechenmodell5.2.1 Begriffsdefinitionen zur Federgeometrie und zur Kinematik der EinfederungDie in diesem Abschnitt durch Fettdruck hervorgehobenen Begriffe werden bei der Formulierung der Anforderungen benötigt (siehe auch Abbildung 12 und Abbildung 14).。