120 research outputs found
New Quantum Theory of Laser Cooling Mechanisms
In this paper, we study the laser cooling mechanisms with a new quantum
theory approach by applying a new Schrodinger equation, which can describe a
particle in conservative and non-conservative force field. With the new theory,
we prove the atom in laser field can be cooled, and give the atom cooling
temperature, which is accordance with experiment result. Otherwise, we give new
prediction that the atom cooling temperature is directly proportional to the
atom vibration frequency. By calculation, we find they are: .Comment: arXiv admin note: text overlap with arXiv:physics/0601097,
arXiv:0710.5078, arXiv:0707.2280 by other authors without attributio
Plastic Flow in Two-Dimensional Solids
A time-dependent Ginzburg-Landau model of plastic deformation in
two-dimensional solids is presented. The fundamental dynamic variables are the
displacement field \bi u and the lattice velocity {\bi v}=\p {\bi u}/\p t.
Damping is assumed to arise from the shear viscosity in the momentum equation.
The elastic energy density is a periodic function of the shear and tetragonal
strains, which enables formation of slips at large strains. In this work we
neglect defects such as vacancies, interstitials, or grain boundaries. The
simplest slip consists of two edge dislocations with opposite Burgers vectors.
The formation energy of a slip is minimized if its orientation is parallel or
perpendicular to the flow in simple shear deformation and if it makes angles of
with respect to the stretched direction in uniaxial stretching.
High-density dislocations produced in plastic flow do not disappear even if
the flow is stopped. Thus large applied strains give rise to metastable,
structurally disordered states. We divide the elastic energy into an elastic
part due to affine deformation and a defect part. The latter represents degree
of disorder and is nearly constant in plastic flow under cyclic straining.Comment: 16pages, Figures can be obtained at
http://stat.scphys.kyoto-u.ac.jp/index-e.htm
The effect of liquid nitriding on the corrosion resistance of AISI 304 austenitic stainless steel in H2S environments
Pharmacokinetic study of isoquercitrin in rat plasma after intravenous administration at three different doses
Risk Factors and a Predictive Nomogram for Non-Sentinel Lymph Node Metastases in Chinese Breast Cancer Patients with One or Two Sentinel Lymph Node Macrometastases and Mastectomy
Background: Two ongoing prospective randomized trials are evaluating whether omitting axillary lymph node dissection (alnd) in patients with breast cancer (bca) and sentinel lymph node (sln) macrometastases undergoing mastectomy is safe. Determining predictive risk factors for non-sln metastases and developing a model to predict the probability of those patients having non-sln metastases is also important. Methods: This retrospective study enrolled 396 patients with bca and 1–2 slns with macrometastases who underwent alnd and mastectomy between January 2012 and December 2016. Factors influencing the non-sln metastases were determined, and a predictive nomogram was formulated. Performance of the nomogram was evaluated by its area under the curve (auc). Results: We developed a predictive nomogram with an auc of 0.81 (cross-validation 95% confidence interval: 0.75 to 0.86) that included 4 factors (tumour size, histologic grade, and number of negative slns and axillary lymph nodes on imaging). Conclusions: Our predictive nomogram assesses the risk of non-sln metastases in patients with bca and 1–2 sln macrometastases undergoing mastectomy
Syntheses, urease inhibition activities, and fluorescent properties of transition metal complexes
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