Phases of supersymmetric gauge theories with flavors

We explore the phases of supersymmetric U(N) gauge theories with fundamental matter that arise as deformations of SQCD by the addition of a superpotential for the adjoint chiral multiplet. As the parameters in the superpotential are varied, the vacua of this theory sweep out various branches, which in some cases have multiple semiclassical limits. In such limits, we recover the vacua of various product gauge group theories, with flavors charged under some group factors. We describe in detail the structure of the vacua in both classical and quantum regimes, and develop general techniques such as an addition and a multiplication map which relate vacua of different gauge theories. We also consider possible indices characterizing different branches and potential relationships with matrix models.     

Structure evolution and stoichiometry control of Pb(Zr, Ti)O3 thick films fabricated by electrospray assisted vapour deposition

Well-crystallized and stoichiometric Pb(Zr, Ti)O₃ (PZT) films, typically ∼5 μm thick, with pure perovskite-type rhombohedral structures have been successfully prepared via an electrospray assisted vapour deposition (ESAVD) method. Control of the deposition temperature within a narrow range of 300-400 °C resulted in films with the most desirable phases. PZT films with close stoichiometric match with the expected composition ratio and uniform element distribution were obtained by adding the appropriate levels of excess Pb in the precursor solutions. The annealed films were uniform, dense, compact and adherent to the substrates. The dielectric constant, ?_r, and loss tangent, tan δ, of the fabricated PZT films measured at 10 kHz were 442 and 0.09, respectively. The ESAVD deposited PZT films showed a remanent polarization, P_r, of 15.3 μC/cm² and coercive field, E_c, of 86.7 kV/cm. These results demonstrate the clear potential of the ESAVD method as a promising technique for the fabrication of thick PZT films.     

Spectral and kinetic characteristics of CdI<Subscript>2</Subscript> and CdI<Subscript>2</Subscript>:Pb scintillators

We have studied the effect of lead dopant on the optical absorption, photoluminescence, and x-ray luminescence spectra, and the scintillation characteristics of CdI₂ at room temperature. The crystals for the study were grown by the Stockbarger-Bridgman method. Activation of CdI₂ from the melt by the compound PbI₂ leads to the appearance in the absorption spectra in the near-edge region of an activator band at 395–405 nm, which is interpreted as an A band connected with electronic transitions from the ¹S₀ state to the ³P₁ levels in the Pb²⁺ ion. For x-ray excitation, CdI₂:Pb²⁺ crystals with optimal dopant concentration (∼1.0 mol%) are characterized by a light yield with maximum in the 570–580 nm region that is an order of magnitude higher than for CdI₂ crystals in the 490–500 nm band. For α excitation, the radioluminescence kinetics for cadmium iodide is characterized by a very short (∼0.3 nsec) rise time and fast decay of luminescence, with τ₁ ≈ 4 nsec and τ₂ = 10–76 nsec. Depending on the conditions under which the crystals were obtained, the fast component fraction is 95%–99%. The crystal is characterized by a similar scintillation pulse in the case of excitation by x-ray pulses. The radioluminescence pulse shape for CdI₂:Pb in the decay stage is predominantly exponential, with luminescence decay time constants τ₁ ≈ 10 nsec and τ₂ = 200–250 nsec. This system is characterized by low afterglow, at the level for the Bi₄G₃O₁₂ scintillator. We have demonstrated the feasibility of using CdI₂:Pb as a scintillator for detecting α particles. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 6, pp. 825–830, November–December, 2008.     

XRF测定铅锌矿选矿流程中铅,锌,铜

本文叙述一个ＸＲＦ粉末法测定铅锌矿选矿流程中铅，锌，铜的方法，选用精，中矿和原，尾矿两个标准系列。ＲｈＫａ康普顿散射线作内标克服质量吸收系数变化带来的影响，用经验系数法校正基体效应，与化学分析方法相比，本法县有测定组分含量范围广，简便，快速，准确和成本低等特点，配合选矿试验大大加快造矿周期，提高工效数倍。     

ICP-AES法测定丹参中的镉和铅

建立了利用电感耦合等离子体原子发射光谱(ICP-AES)法测定丹参中重金属元素Cd和Pb的方法,比较了干灰化法和湿化法两种样品处理方法对分析结果的影响,并测定了山东一些地区丹参中的Cd和Pb含量。结果表明：采用电感耦合等离子体原子发射光谱法检测丹参中的Cd和Pb,最低检出限(DL)分别为1.92和1.07 ng·mL-1;相对标准偏差(RSD)分别为3.14%和1.83%;回收率分别为103.05%和96.24%。利用湿法消解样品,精密度好,回收率高,优于干灰化法。干灰化法适合测定丹参中Pb,但不适合测定Cd,其回收率仅为0.1%。用湿法消解样品,测定不同产地丹参的Cd和Pb含量,结果表明：所测地区丹参的Cd, Pb含量大大低于《中华人民共和国药典》(2005)规定的中药材重金属含量标准,符合GAP生产的要求。     

ICP-MS测定动物肝脏中铅、镉和砷

利用电感耦合等离子体-质谱法(ICP-MS)同时测定动物肝脏中铅、镉、砷3种元素.样品经聚四氟乙烯高压消化罐消解后,以锗、铟、铋作为内标物质,补偿基体效应,直接用ICP-MS同时测定这3种元素,结果令人满意.该法线性范围宽,分析速度快,准确度和精密度均符合分析测试要求.     

ICP-AES测定葡萄糖酸钙中Pb、As、Cd等9个杂质元素

本文应用ICP-AES直接测定了葡萄糖酸钙中的Pb、As、Cd等9个杂质元素,对样品的消解方法、基体和酸介质的影响等进行了讨论.用基体匹配法消除钙基体的干扰,9个杂质元素测定的测定范围为:Pb 0.0008%-0.08%,Cu、Mg 0.0001%-0.01%,其余元素0.0003%-0.03%.加标回收率为95.8%-100.0%,相对标准偏差为0.16%-3.61%.     

Growth of tertiary dendritic arms during the transient directional solidification of hypoeutectic Pb–Sb alloys

Despite the importance of a complete characterization of dendritic patterns in castings, the availability of studies on the development of tertiary dendrite arms is scarce in the literature. In the present study, the tip cooling rate, local solidification time, primary and tertiary dendrite arm spacings have been determined in Pb–Sb alloys castings directionally solidified under unsteady-state heat flow conditions. The alloys compositions experimentally examined are widely used in the as-cast condition for the manufacture of positive and negative grids of lead-acid batteries. The initial growth of tertiary dendritic arms from the secondary branches was found to occur only for a Pb–3.5 wt% Sb alloy at cooling rates in the range 0.4–0.2?K/s, with no evidence of this spacing pattern for Pb–Sb alloys having lower solute content. Tertiary dendritic branches have been observed along the entire casting lengths for alloys of the Pb–Sb hypoeutectic range having compositions higher than 4.0 wt% Sb. It is shown that a power function experimental law with a characteristic ?0.55 exponent is able to characterize the tertiary spacing evolution with the solidification cooling rate for alloys compositions ≥4.0 wt% Sb. The only exception was the Pb–3.5 wt% Sb alloy for which λ ₃ exhibited significant lower values when compared with the experimental values obtained for the other Pb–Sb alloys for a same solidification cooling rate.     

微波消解ICP-AES法同时测定花岗石中铜、镉、铬和砷

本文采用微波消解和ICP－AES法，同时测定花岗石样品的铅、镉、铬、砷4有害元素，检出限分别为0．0008、0．0007、0．0018、0．0012μg.mL^-1,回收率为93．4％－102．5％，RSD为1．3％－3．6％，该法准确、快速、简便，结果令人满意。     

原子吸收法直接测定食用L-赖氨酸盐酸盐中的铜和铅

本文报道了用石墨炉-原子吸收分析法，将食用L-赖氨酸盐样品经稀酸溶解后，直接进样测定。该方法省去了通常必需的干灰化或湿消解过程，充分利用石墨炉本身所具的对样品进行部分预处理的功能，在无基体改进剂的条件下，快速测定样品中的Cu和Pb的含量。方法简便，快速，准确，实用，Cu和Pb的精密度试验的相对标准偏差分别为4.8%和5.3%；回收率分别为100%-110%和102%-105%。