3,494 research outputs found
Exploration of the memory effect on the photon-assisted tunneling via a single quantum dot: A generalized Floquet theoretical approach
The generalized Floquet approach is developed to study memory effect on
electron transport phenomena through a periodically driven single quantum dot
in an electrode-multi-level dot-electrode nanoscale quantum device. The memory
effect is treated using a multi-function Lorentzian spectral density (LSD)
model that mimics the spectral density of each electrode in terms of multiple
Lorentzian functions. For the symmetric single-function LSD model involving a
single-level dot, the underlying single-particle propagator is shown to be
related to a 2 x 2 effective time-dependent Hamiltonian that includes both the
periodic external field and the electrode memory effect. By invoking the
generalized Van Vleck (GVV) nearly degenerate perturbation theory, an
analytical Tien-Gordon-like expression is derived for arbitrary order multi-
photon resonance d.c. tunneling current. Numerically converged simulations and
the GVV analytical results are in good agreement, revealing the origin of
multi- photon coherent destruction of tunneling and accounting for the
suppression of the staircase jumps of d.c. current due to the memory effect.
Specially, a novel blockade phenomenon is observed, showing distinctive
oscillations in the field-induced current in the large bias voltage limit
How to Use Telephone Marketing to Improve Performance of Customers’ Development
Diversified information has indicated the technology of Telephone marketing has gradually become matured and popular. The purpose of this study is to research to find out a whole set of Telephone Marketing by which the staffs are able to accomplish their missions to closely talk to the policy holders and further succeed to get their sustained policies through telephone as well as accomplish the results mission of the company
Fatigue Deformation Mechanisms of Zirconia Ceramics
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65237/1/j.1151-2916.1992.tb05558.x.pd
Fatigue of Yttria-Stabilized Zirconia: I, Fatigue Damage, Fracture Origins, and Lifetime Prediction
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65792/1/j.1151-2916.1991.tb04088.x.pd
Memory effect on the multiphoton coherent destruction of tunneling in the electron transport of nanoscale systems driven by a periodic field: A generalized Floquet approach
This is the published version, also available here: http://dx.doi.org/10.1103/PhysRevB.79.235323.Time-dependent electron-transport processes are often studied in the wide-band limit. In this paper, a generalized Floquet approach beyond the wide-band limit is developed for the general treatment of memory effect on the virtually unexplored multiphoton (MP) coherent destruction of tunneling (CDT) phenomenon of periodically driven electrode-wire-electrode nanoscale systems. As a case study, we apply the approach for a detailed analysis of the electron-transport dc current in the electrode-quantum double dot-electrode system, showing the significance of memory effect as well as illustrating the origin of the MP-CDT phenomenon
A Local-Pattern Related Look-Up Table
This paper describes a Relevance-Zone pattern table (RZT) that can be used to
replace a traditional transposition table. An RZT stores exact game values for
patterns that are discovered during a Relevance-Zone-Based Search (RZS), which
is the current state-of-the-art in solving L&D problems in Go. Positions that
share the same pattern can reuse the same exact game value in the RZT. The
pattern matching scheme for RZTs is implemented using a radix tree, taking into
consideration patterns with different shapes. To improve the efficiency of
table lookups, we designed a heuristic that prevents redundant lookups. The
heuristic can safely skip previously queried patterns for a given position,
reducing the overhead to 10% of the original cost. We also analyze the time
complexity of the RZT both theoretically and empirically. Experiments show the
overhead of traversing the radix tree in practice during lookup remain flat
logarithmically in relation to the number of entries stored in the table.
Experiments also show that the use of an RZT instead of a traditional
transposition table significantly reduces the number of searched nodes on two
data sets of 7x7 and 19x19 L&D Go problems.Comment: Submitted to IEEE Transactions on Games (under review
Composite type A thymoma and diffuse large B-cell lymphoma
AbstractThe concurrent occurrence of thymoma and diffuse large B-cell lymphoma in the thymus has not been previously reported. We describe a 74-year-old man who presented with general weakness, neck lymphadenopathy, night sweats, and body weight loss. A right anterior mediastinal mass was found on computed tomography of the chest. The immunohistochemical stains AE1/AE3, CD20, CD3, and MUM-1 confirmed the different components of the mediastinal tumor. A heavy-chain gene clonality assay and light-chain gene clonality assay confirmed the B-cell clonality of the mediastinal tumor and neck lymph node. The patient had received a complete course of chemotherapy, and the result of positron emission tomography–computed tomography showed complete remission. The pathologic report of this mass revealed composite type A thymoma and diffuse large B-cell lymphoma. If concurrent or composite thymoma and lymphoma are suspected, a thorough examination of the thymoma with a combination of ancillary studies is recommended to rule out the possibility of concurrent lymphoma
The role of trauma team activation by emergency physicians on outcomes in severe trauma patients
AbstractBackgroundIn our region, trauma team activation (TTA) is initiated by emergency physicians once an injured patient meets any of the criteria of TTA after the injured patient arrives at the emergency department (ED).PurposeTo evaluate the role of TTA on outcomes in patients with severe trauma.MethodsAll trauma patients who had injury severity score (ISS) >15 and were admitted from ED between January 2010 to December 2010 were included in the study. Mann–Whitney U test (non-normal distribution) or Student's t test (normal distribution) for continuous variables and Fisher exact test or Chi-square test for categorical variables were used to compare the statistically significant differences between TTA and non-TTA groups. Logistic regression was applied to determine any significant differences found in the statistical analysis for 30-day mortality.ResultsA total of 231 patients were signed up in the study. The TTA group had shorter time from ED to operation room (170 minutes vs. 534 minutes, p = 0.02) and tended to have more emergent operations (42.7% vs. 23.2%, p = 0.002). Emergent operation [odds ratio (OR), 0.34; 95% confidence interval (CI), 0.12–0.92, p = 0.035) was associated with lower mortality while ISS > 25 (OR, 7.48; 95% CI, 2.48–22.57, p < 0.0001), Glasgow coma scale score <13 (OR, 32.1; 95% CI, 4.30–94.6, p < 0.0001), hypotension (OR, 3.0; 95% CI, 1.1–7.9, p = 0.03), and coagulopathy (OR, 9.3; 95% CI, 1.2–71.4, p = 0.033) were associated with higher mortality.ConclusionThis study shows that TTA may shorten the time from ED to operation room in trauma patients with an ISS > 15
Percutaneous Endoscopic Gastrostomy in the Enteral Feeding of the Elderly
SummaryToday we are faced with an aging society that may develop malnutrition because of dysphagia related to dementia, stroke, and malignancy seen often in the elderly. The preferred form of nutritional supplementation for this group is enteral nutrition, and the most appropriate long-term method is by use of a gastrostomy. Percutaneous endoscopic gastrostomy (PEG) was first introduced in 1980 as an alternative to the traditional operative procedure and rapidly became the preferred procedure. In geriatric patients, the principal indications are neurological dysphagia and malnutrition, related to an underlying disease or anorexia-cachexia in very elderly. PEG is contraindicated in the presence of respiratory distress, previous gastric resection, total esophageal obstruction, coagulation disorders and sepsis in the elderly. Common complications include wound infection, leakage, hemorrhage, and fistula in the general population, but aspiration pneumonia is the major case of death in this group. Risks and complications of PEG must be discussed with patients and their families; and the decision for percutaneous endoscopic gastrostomy insertion should only be made after careful consideration and discussion between managing physicians, allied health professionals, and the patient and/or family. Four ethical principles may help make feeding decisions: beneficence, non-maleficence, autonomy and justice. Attentive long-term care after tube replacement is mandatory. Acceptance of percutaneous endoscopic gastrostomy placement by patients and their families tends to increase once favorable outcomes are offered
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