排序方式: 共有22条查询结果,搜索用时 15 毫秒
1.
Fincke JR Lanier NE Batha SH Hueckstaedt RM Magelssen GR Rothman SD Parker KW Horsfield CJ 《Physical review letters》2004,93(11):115003
Strongly shocked cylindrically convergent implosions were conducted on the OMEGA laser. The directly driven targets consist of a low-density foam core and an embedded aluminum shell covered by an epoxy ablator. The outer surface of the aluminum shell has imposed single-mode perturbations with wave numbers k=0.08, 0.25, and 0.7 (rad/microm) and initial amplitudes eta(0)/lambda=0.013, 0.04 and 0.11. The perturbation growth rate is found to scale with k and, in our convergent geometry, no evidence of saturation for eta/lambda as large as 5 is observed. 相似文献
2.
Burke W Acheson L Botkin J Bridges K Davis A Evans J Frias J Hanson J Kahn N Kahn R Lanier D Pinsky LE Press N Lloyd-Puryear MA Rich E Stevens N Thomson E Wartman S Wilson M 《Community genetics》2002,5(2):138-146
The Genetics in Primary Care (GPC) project is a USA national faculty development initiative with the goal of enhancing the training of medical students and primary care residents by developing primary care faculty expertise in genetics. Educational strategies were developed for the project by an executive committee with input from an advisory committee, comprising individuals with primary care, medical education and genetics expertise. These committees identified the key issues in genetics education for primary care as (1) considering inherited disease in the differential diagnosis of common disorders; (2) using appropriate counseling strategies for genetic testing and diagnosis, and (3) understanding the implications of a genetic diagnosis for family members. The group emphasized the importance of a primary care perspective, which suggests that the clinical utility of genetic information is greatest when it has the potential to improve health outcomes. The group also noted that clinical practice already incorporates the use of family history information, providing a basis for discussing the application of genetic concepts in primary care. Genetics and primary care experts agreed that educational efforts will be most successful if they are integrated into existing primary care teaching programs, and use a case-based teaching format that incorporates both clinical and social dimensions of genetic disorders. Three core clinical skills were identified: (1) interpreting family history; (2) recognizing the variable clinical utility of genetic information, and (3) acquiring cultural competency. Three areas of potential controversy were identified as well: (1) the role of nondirective counseling versus shared decision-making in discussions of genetic testing; (2) the intrinsic value of genetic information when it does not influence health outcomes, and (3) indications for a genetics referral. The project provides an opportunity for ongoing discussion about these important issues. 相似文献
3.
K. H. Maier A. Aprahamian J. A. Becker D. J. Decman E. A. Henry R. G. Lanier L. G. Mann R. A. Meyer K. Sale N. Roy W. Stöffl G. L. Struble J. Blomqvist 《Zeitschrift für Physik A Hadrons and Nuclei》1989,332(3):263-268
Gamma rays and conversion electrons have been measured in211Bi populated by the209Bi(t,p) reaction, and the near yrast levels were observed up to 21/2?. The 21/2? state is isomeric withT 1/2=70(5) ns. No alpha decaying isomer was found in211Bi. ObservedM1 transitions reveal mixing of the210Pb parent states in the levels of211Bi. The levels and transitions are well reproduced by the shell model with experimental matrix elements and pure configurations. 相似文献
4.
E.R. Flynn Gorden L. Struble Robert G. Lanier Lloyd G. Mann 《Physics letters. [Part B]》1977,67(2):158-160
Previous reports of two-neutron stripping reactions in the actinide nuclei have not indicated any excited 0+ strength below an excitation energy of 1.5 MeV. In contrast, the 246 Cm(t,p) 248Cm reaction shows a relatively strong 0+ state at 1.084 MeV. We believe that this result, coupled with a marked change in ground-state transition strenghts between 246 Cm and 248 Cm targets, indicates a gap in the single-particle orbitals that is larger than the pairing gap. 相似文献
5.
6.
R.G. Lanier G.L. Struble L.G. Mann W. Stöffl I.C. Oelrich J. Scheerer I.D. Proctor D.W. Heikkinen R.H. Howell 《Physics letters. [Part B]》1981,99(1):23-27
The (p, t) reaction on radioactive targets of 152,154Eu has been used to study rotational states associated with the configuration in the transitional odd-odd 152Eu and 150Eu nuclei. Our studies yieldcompelling evidence that this configuration in 150Eu has a prolate structure which is strongly deformed and occurs at excitation energy of 1224 keV. 相似文献
7.
In inertial confinement fusion double-shell designs, the inner shell experiences heating that can amplify non-uniformities and consequently enhance mixing, which degrades capsule performance. Recent OMEGA experiments study the time-dependent evolution of mix under heated and shocked conditions. In each experiment, a cylindrical Be tube was filled with a layered system of a BeCu disk and low-density CH foam. The BeCu disks were machined with a multi-mode perturbation representative of the target surface roughness present in ICF capsules. The targets were heated from one end using a hohlraum and subsequently shocked using direct-drive from the opposite end. X-ray radiography was used to quantitatively diagnose the transmission profiles of the disk/foam interface. We focus primarily on an assessment of the applicability of the radiation transport models available in the RAGE (Radiation Adaptive Grid Eulerian) hydrodynamics code. These include grey diffusion, several types of multi-group diffusion, and a new frequency-dependent source capability that addresses the NLTE nature of the laser energy deposition. 相似文献
8.
Courtney H. Lanier Ann N. Chiaramonti Laurence D. Marks Kenneth R. Poeppelmeier 《Surface science》2009,603(16):2574-2579
The so-called Biphase termination on α-Fe2O3 has been widely accepted to be a structure with a 40 Å unit supercell composed of coexisting islands of Fe1−xO and α-Fe2O3. Based on thermodynamic arguments and experimental evidence, including transmission electron diffraction, imaging, magnetic and spectroscopic information, it is found that the previously proposed structure model is inaccurate. The actual Biphase structure is instead a layered structure related to the reduction of α-Fe2O3 to Fe3O4. A model for the Biphase termination is proposed which does not contain islands of Fe1−xO but instead consists of bulk α-Fe2O3 and a Fe3O4-derived overlayer. The proposed model is consistent with all current and previously reported experimental findings. 相似文献
9.
Debra D. Dolliver Thomas Sommerfeld Megan L. Lanier Jordan A. Dinser Richard P. Rucker Rebecca J. Weber Artie S. McKim 《Journal of Physical Organic Chemistry》2010,23(3):227-237
A new general route to N‐alkoxybenzimidoyl azides [ArC(N3)=NOR] from a reaction of N‐alkoxybenzimidoyl bromide [ArC(Br)=NOR] with sodium azide in DMSO is described. These reactions result in the Z‐geometric configuration. These compounds show a moderate degree of thermal stability as assessed by differential scanning calorimetry, and lack reactivity in traditional 1,3‐dipolar cycloaddition ‘click’ reactions. Upon exposure to electrophilic compounds (trifluoroacetic acid or acetyl chloride), these azide compounds can react by two pathways: a Schmidt‐type rearrangement to form an N‐alkoxyurea or an isomerization–cyclization reaction pathway to form an N‐alkoxytetrazole. The route of the reaction has no dependence on solvent polarity and appears to depend upon the electrophile (H+ vs. CH3CO+): reaction of the azide with trifluoroacetic acid results predominantly in the urea; reaction with acetyl chloride results solely in the tetrazole. Calculations indicate that the urea product is thermodynamically favored over the tetrazole product. They also indicate that both reaction conditions result in an equilibration between the starting azide and the tetrazole with the tetrazole being the major component in this equilibrium mixture. The fact that the azide also undergoes a Schmidt‐type rearrangement to form an N‐alkoxyurea when treated with trifluoroacetic acid appears to indicate that the barrier for aromatic ring migration is lower in the protonated azide produced on reaction with trifluoroacetic acid than in the acetylated azide produced on reaction with acetyl chloride. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
10.
R.G. Lanier R.K. Sheline G.L. Struble L.G. Mann J.A. Cizewski 《Nuclear Physics A》1984,413(2):236-246
A radioactive target of 154Eu(8.3y) has been used to study the 154Eu(t, p)156Eu reaction at an incident energy of 17 MeV. The bandhead and one rotational state of the configuration have been identified in 156Eu. The excitation energy of the 3? bandhead is determined to be 448 ± 15 keV. The angular distribution of the first excited rotational state is anamolous and may indicate evidence for a strong two-step component in the reaction mechanism. The energy systematics of the Eu-Sm transition region are also investigated. We find that the systematics of suggest that at N = 87 the 150Eu excited configurations has a significantly more stable deformed structure than the corresponding one-quasiparticle structure in 149Sm. 相似文献