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1.
用透射电子显微镜观察GF-AAS中作为基体改进剂的锡或铟与钯的金属间化合物的汽体YASVDAKazuo1,HIRANOYoshihirto1andHIROKAWAKichinosuke2日本日立有限公司测试设备部,312.茨城县日本日本东北大学材料研...  相似文献   

2.
D2EHPA萃取稀土的有机相红外光谱及添加DMHPA的影响   总被引:6,自引:1,他引:5  
本文研究了部分皂化的二(2-乙基己基)磷酸(D2EHPA)-正庚烷体系萃取稀土离子Y^3+,Pr^3+,Nd^3+,Eu^3+后有机的傅里叶变换红外光谱(FT-IR)。发现不同稀土离子与萃取剂的配位能力有差异,并且皂化度对萃取有机相中的P=O谱带的频率和吸收强度皆有影响,在D2EHPA中加入二(1-甲基庚基)磷酸(DMHPA)导致P=O谱带形状和吸收强度发生变化。  相似文献   

3.
EFFECTOFRADIALELECTRICALFIELDONNEOCLASSICALTRANSPORTINTOKAMAKSEFFECTOFRADIALELECTRICALFIELDONNEOCLASSICALTRANSPORTINTOKAMAKS¥...  相似文献   

4.
自适应卡尔曼滤波分光光度法同时测定铜,锌,钴,镍   总被引:3,自引:0,他引:3  
本文采用自适应卡尔曼滤波(AKF)分光光度法,分析了以5-Br-PADAP为显色剂。OP为增溶剂的Cu、Zn、Co、Ni混合体系,探讨了显色条件、滤波参数选择问题。合成试样解析结果表明:AKF法能很好地消除由于这四个元素的络合物光谱严重重叠而致的相互干扰,获得准确的分析结果,同时因AKF法可在一定程度上校正混合体系吸光度对加和性的偏离,故而计算结果优于普通卡尔曼滤波法(KF)。  相似文献   

5.
致冷型FLIR系统组件由于HgCdTe探测器需要致冷到77K,所以要使用杜瓦瓶组件。陆军有一项为二代FLIR系统研制几种SADA(标准高级杜瓦瓶组件)的方案。已有将SADA方案与DARA提供资金的红外焦平面列阵方案组合的方案。例如,休斯公司的坦克跟踪...  相似文献   

6.
LaserInducedDamageinCVDDiamondFilmsQIUHongFANZhengxiu(ShanghaiInstituteofOpticsandFineMechanics,ChineseAcademyofSciences,P.O....  相似文献   

7.
GIANTMAGNETO-IMPEDANCEINFe-BASEDSOFTFERROMAGNETICRIBBONSChenChenMeiLiangmoDepartmentofPhysics,ShandongUniversity,Jinan250100...  相似文献   

8.
用ICP-AES法测定KDP晶体及其培养液中微量的Fe、Cr、Mn、Ca、Mg、Al、Sr、Ba,并对KDP基体对被测元素谱线强度的影响进行考察。以Sc作内标,方法简便,可获得满意的分析结果。  相似文献   

9.
使用abinitio计算HF/LANL2DZ方法优化出了基态KrHF为C∞v结构,而基态KrFH为Cs结构,同时,计算了平衡几何和离解能,并用abinitio计算MP2/LANL2DZ方法计算了谐性力常数。应用多体项展式法导出了KrFH(X1A′)体系的分析势能函数,研究了势能面上的主要特征  相似文献   

10.
用溶胶-凝胶法合成了非晶态Fe0.5Al0.5PO4。用XRD和TPR表征了其结构和晶格氧的活性;用IR和TPD表征了CH4在其表面上的吸附行为;用LSSR方法考察了CH4直接氧化合成CH3OH的反应规律。结果表明,Fe0.5Al0.5PO4具有非晶态的结构,FePO4和AlPO4的微区被均匀地相互隔离,导致固体本身不具有长程有序性。非晶态的Fe0.5Al0.5PO4与晶态的Fe0.5Al0.5P  相似文献   

11.
Hard disk drives (HDD) are increasingly being used in mobile applications and consumer electronic devices in potentially harsh dynamic environments. In mission-critical applications such as in computers on board trains and military vehicles, the vibration experienced by the operating HDD can be very severe. An effective suspension system is necessary to isolate the HDD from the strong vibration transmitted from the ground, vehicle engine, etc. This paper gives details on how to design, test and evaluate vibration isolation systems for operating HDD subjected to very severe random vibrations based on military specifications MIL-STD-810E. One design is presented and evaluated based on well-defined criteria. Design principles on how to achieve the required degree of vibration isolation is described. A computer simulation model of an example design is formulated and correlated with experiments. It is shown that a low-cost, vibration isolation system can indeed be made that will allow an HDD to operate well when subjected to strong input vibration.  相似文献   

12.
《Journal of Electrostatics》2006,64(11):768-772
A technique for monitoring electrostatic charge accumulation inside a hard disk drive (HDD) is described: a miniature charged plate is built into the top cover of the HDD, connected to a charged plate monitor. Experiments show that the miniature plate technique can be used for detection and measurement of the voltage induced by the charge generated inside the grounded enclosure of a hard drive.  相似文献   

13.
The coordinated multi-point (CoMP) transmission is a well-recognized promising technique for achieving high spectral efficiency. In this paper, we study the performance of the spectrum allocation and the system utility of the CoMP systems. First, we combine the hybrid division duplex (HDD) with a CoMP system to form a CoMP–HDD system, for the purpose of guaranteeing the quality demand of the channel state information (CSI) feedback. Second, in order to improve the system utility and the spectrum allocation efficiency of the CoMP–HDD system, we utilize the auction theory for the spectrum allocation. A system utility maximization problem is formulated as an NP-hard problem. Finally, we propose a multi-band multi-winner (MBMW) greedy algorithm to optimize the system utility and the spectrum allocation efficiency. Our simulation results demonstrate the effectiveness of the proposed algorithm.  相似文献   

14.
The pivot bearing is an important mechanical component in HDD. Several quasi-rigid (QR) body motion modes of the HDD are related to the stiffness of the pivot bearing such as the axial translation mode, the lateral translation mode and the rocking mode. In the shock simulation of the HDD, the pivot bearing is often simplified to identical theoretical models wherein the bearing is simulated with springs or beams. The overall axial stiffness and the radial stiffness of these models are often carefully checked and match well with the experimental values. However, how well these theoretical models represent the rotational stiffness of the bearing is still not fully understood. This is partly due to the difficulties in obtaining the experimental rotational stiffness of the pivot bearing. In this paper, three different theoretical models are examined for the simulation of the bearing. The rotational stiffness of these three theoretical models is derived analytically. The theoretical formulations are verified with the finite element analysis results.  相似文献   

15.
There is much demand for improvement in the performance of a hard disk drive (HDD) along with recent rapid developments of information technology. While high-speed disk rotation of a HDD is necessary to accommodate such needs, it causes disk flutter induced by pressure fluctuation on disks and degrades reliability of a HDD. In order to understand the mechanism of the fluttering phenomenon, it is important to know pressure field on the rotating disk. However, it is impossible to measure the pressure by ordinary methods such as pressure taps. Pressure-sensitive paint (PSP) is a pressure measurement technique based on the oxygen quenching of luminescence and enables us to measure the pressure non-invasively. In general, however, the temperature sensitivity of PSP makes it difficult to measure the precise pressure on the surface with temperature distribution. We measured the time-averaged pressure on the disk rotating at 10 000-20 000 rpm for the first time by adopting a temperature-insensitive PSP composed of pyrene sulfonic acid (PySO3H) as a luminophore. It was found that the pressure forms a concentric circular distribution and decreases toward the center of the disk. Additionally, we elucidate how disk rotational speed and spacing between co-rotating disks influence on the pressure field.  相似文献   

16.
In this study, the terrain correction for lunar free-air gravity anomaly (FAGA) is calculated in spherical coordinates based on the global topography data detected by the laser altimeter on Chang’E-1 (CE-1). The obtained lunar Bouguer gravity anomaly (BGA) reveals density irregularities of the interior mass. BGA is important in characterizing the mascon basins. According to the BGA of the Moon, the South Pole-Aitken (SPA) basin is considered the largest mascon basin on the Moon, and the feature of BGA in the basin implies the impacting direction. Further, the mascon basins seem to be classified into two types, Type Highland and Type Plain. For the mascon basins of Type Highland the dense materials mainly come from the shallow crust, which are associated with the basalt deposits. The other type, Type Plain, includes mascon basins whose major dense materials may be located deep at the lithosphere, corresponding to the uplifted mantle.  相似文献   

17.
The causes of the variability in mechanical behaviour of various silks obtained from silkworms (Bombyx mori, Antheraea/Tussah) and spiders (Nephila madagascarensis) have been studied by tensile uniaxial tests, differential scanning calorimetry and Raman microspectrometry. Analyses of tensile stress–strain curves recorded for different silkworm and spider baves and single fibres, undergoing different histories (age, degumming, thermal/chemical treatments), allow the behaviour to be classified into five groups and correlated with the fibroin/spidroin structural status: (1) Type I exhibits linear elastic behaviour and then a quasi plateau, (2) Type II has a two‐step linear elastic behaviour with kinks then a quasi plateau, (3) Type III exhibits a smooth transition from a linear behaviour to a plateau, (4) Type IV has a behaviour rather similar to that of Type I but above ~8–12% hardening occurs, and (5) Type V results in the breakage of fibres during the first elastic stage. Unambiguously, Type IV is more frequent for degummed, very dried fibres and Type III for water‐saturated fibres. The most striking Raman signature differences are observed in the Raman intensity of the amorphous/‘ordered’ νN–H and H2O band components and correlated to the water content and disorder degree according to the calorimetry study. Types I and II are frequently observed for fresh (largely amorphous) spun fibres/baves. Type V is characteristic of degraded fibres. Type IV represents the most ordered state. The similar stress–strain types for dried silkworm and spider fibres show that the general difference in amino acid contents is not the most pertinent parameter for the mechanical behaviour. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

18.
Bin Li 《哲学杂志》2013,93(13):1582-1603
Reports of Type II twins are quite rare for most crystal structures. When they do occur, they are usually one of a number of possible twinning modes observed in a particular material. However, for the triclinic phase devitrite, Na2Ca3Si6O16, which nucleates from commercial soda?lime?silica float glass subjected to suitable heat treatments, the only reported twinning mode to date is a Type II twinning mode. In this study, this Type II twinning mode is first examined by molecular dynamics simulation to determine the lowest energy configuration of perfect twin boundaries for the twin mode. This is then compared with the lowest energy configurations of perfect twin boundaries found for six possible Type I twinning modes for devitrite for which the formal deformation twinning shear is less than 0.6. The most favourable twin plane configuration for the Type II twinning crystallography is shown to produce reasonably low twin boundary energies and sensible predictions for the optimum locations of the twin plane, K 1, and the [1?0?0] rotation axis, η 1, about which the 180° Type II twinning operation takes place. By comparison, all the Type I twinning modes were found to have very energetically unstable atomic configurations, and for each of these twinning modes, the lowest energy configurations found all led to high effective K 1 twin boundary energies relative to perfect crystal. These results therefore provide a rationale for the experimental observation of the particular Type II twinning mode seen in devitrite.  相似文献   

19.
A study is made of the implications of heterotic string T-duality and extended gauge symmetry for the conjectured equivalence of heterotic and Type I superstrings. While at first sight heterotic string world-sheet dynamics appears to conflict with Type I perturbation theory, a closer look shows that Type I perturbation theory “miraculously” breaks down, in some cases via novel mechanisms, whenever the heterotic string has massless particles not present in Type I perturbation theory. This strongly suggests that the two theories actually are equivalent. As further evidence in the same direction, we show that the Dirichlet one-brane of Type I string theory has the same world-sheet structure as the heterotic string.  相似文献   

20.
 对大口径、高功率情况下的三次谐波转换,选择KDP晶体TypeⅠ/TypeⅡ匹配角度失谐的三倍频方案,并从非线性三波耦合方程组出发,采用离散傅立叶变换和四阶龙格库塔(R-K)积分方法,编制了二维模拟三次谐波转换的计算程序。计算了各种晶体厚度和不同失谐角条件下,二、三次谐波的转换特性和效率。并对入射基频光为六阶超高斯分布时的三倍频器进行了优化,三倍频转换效率达80%,此时具有较大的动态范围和较高的三倍频转换效率。  相似文献   

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