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31.
An amalgam exchange technique has been used for the rapid radiochemical separation of lead. A number of variables which affect the exchange were studied and a lead yield of 88.5 %was obtained. At room temperature the procedure requires about 13 min, whereas at 40 degrees it can be completed in about 9 min. Radioactive tracers of 16 different elements were used to check the selectivity of this procedure, which has also been applied for the separation of (212)Pb from thorium nitrate solution. 相似文献
32.
Christian G Frank N Ash S Baumann T Bazin D Brown J DeYoung PA Finck JE Gade A Grinyer GF Grovom A Hinnefeld JD Lunderberg EM Luther B Mosby M Mosby S Nagi T Peaslee GF Rogers WF Smith JK Snyder J Spyrou A Strongman MJ Thoennessen M Warren M Weisshaar D Wersal A 《Physical review letters》2012,108(3):032501
The technique of invariant mass spectroscopy has been used to measure, for the first time, the ground state energy of neutron-unbound (28)F, determined to be a resonance in the (27)F+n continuum at 220(50) keV. States in (28)F were populated by the reactions of a 62 MeV/u (29)Ne beam impinging on a 288 mg/cm(2) beryllium target. The measured (28)F ground state energy is in good agreement with USDA/USDB shell model predictions, indicating that pf shell intruder configurations play only a small role in the ground state structure of (28)F and establishing a low-Z boundary of the island of inversion for N=19 isotones. 相似文献
33.
The effect of a homogeneous magnetic field, H0. on the ground state of an antiferromagnetic superconductor has been investigated. Assuming a one-dimensional like half-filled band, we have found a new state having gapless superconductivity and H0-dependent order parameter. This state exists for HQ/Δ0>0.22 and when ∣Δ ? HQ∣?H0 < Δ + HQ (HQ is the staggered magnetic field, Δ is the superconducting order parameter and Δ0 is Δ in the absence of HQ and H0). 相似文献
34.
N Nagi N Ohno S Tanaka J Aketagawa Y Shibata T Yadomae 《Chemical & pharmaceutical bulletin》1992,40(6):1532-1536
Solubilization of limulus test reactive materials from Candida was examined in the presence or absence of phagocytic cells. Solubilized limulus test reactive materials (LTRM) were detected in culture supernatant, and hot water and sodium hydroxide extracts of the acetone dried cells of Candida parapsilosis. Suspensions of Candida cells also reacted with limulus test, and LTRM were released from the acetone dried cells by serum treatment. After treatment of the acetone dried cells with polymorphonuclear leucocytes (PMN) or macrophages (M phi), a significant amount of LTRM was solubilized. Significant amounts of LTRM were also released by PMN during treatment of live and growing C. parapsilosis. The reactivity of LTRM was completely inhibited by the addition of excess amount of purified (1----3)-beta-D-glucan, suggesting LTRM from Candida cells as described above would contain (1----3)-beta-D-glucan. These results suggested that LTRM during fungal infection would come from the extracellular water soluble polysaccharide fraction as well as the insoluble cell wall fraction solubilized by the action of phagocytes. 相似文献
35.
A green and operationally simple approach for the synthesis of novel isoxazolyl amino furo[3,2-c]quinolinone derivatives by a one-pot three-component reaction of 4-amino-3-methyl-5 styrylisoxazoles, aryl glyoxal monohydrates and 4-hydroxy-1-methyl-2-quinolinone using p-TSA as the catalyst in aqueous medium was developed. The protocol proves to be an efficient and an environmentally benign in terms of high yields, operational simplicity, clean reaction profile, compatibility with wide range of substrates, water as a solvent and easy purification. 相似文献
36.
A formalism for studying the interference between the direct reaction and the compound resonance processes is presented by the S-matrix theory; The mechanism of 12C(d, d) 12C, 12C(d, p1) 13C* and 12C(d, p2) 13C* reactions in the energy range Ed=1.63 MeV to 2.05 MeV is analysed.Te results show that: the interference between these two processes exists; and the quantitative relation between them is given. While the parameters of direct reactions and compound resonance processes, particularly for four resonance states with Ed=1.726, 1.767, 1.792 and 1.86 MeV are determined. 相似文献
37.
The benefits of simultaneous consideration of siting and sizing of distribution centers have been well acknowledged in supply
chain design. Most formulations assume that the potential DC sites are known and the decision on location is to select sites
from the finite potential DC sites. However, the quality of this discrete version problem depends on the selection of potential
DC sites. In this paper we present a planar version of the problem, which assumes that there is no a priori knowledge of DC
sites and DCs can be located anywhere in the plane. The goal of the problem is to simultaneously find locations and sizing
of DC sites. The solution of the planar problem provides a lower bound for the discrete problem. The objective of the problem
is to minimize the total of inbound and outbound transportation costs and distribution center construction costs—which include
its fixed charge cost and concave sizing cost. The problem is initially formulated as a nonlinear programming model. We then
reformulate it as a set covering problem after establishing certain key properties. A greedy drop heuristic and a column generation
heuristic are developed to solve the problem. Computational experiments are provided. 相似文献
38.
Barriers commonly occur in practical location and layout problems and are regions where neither travel through nor location of the new facility is permitted. Along the lines of (Larson and Sadiq, 1983) we divide the feasible location region into cells. To overcome the additional complications introduced by the center objective, we develop new analysis and classify cells based on number of cell corners. A procedure to determine the optimal location is established for each class of cells. The overall complexity of the approach is shown to be polynomially bounded. Also, an analogy is drawn to the center problem on a network and generalizations of the model are discussed. 相似文献
39.
40.