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111.
Individual InAs/GaAs quantum dots are studied by micro-photoluminescence. By varying the strength of an applied external magnetic field and/or the temperature, it is demonstrated that the charge state of a single quantum dot can be tuned. This tuning effect is shown to be related to the in-plane electron and hole transport, prior to capture into the quantum dot, since the photo-excited carriers are primarily generated in the barrier. 相似文献
112.
Silvia Carlotto Ilaria Fortunati Camilla Ferrante Petra Schwille Antonino Polimeno 《Microfluidics and nanofluidics》2011,10(3):551-561
In this study, we explore and model the behavior of a prototype microfluidic device which employs two non-mixing fluids (sheath
and inlet fluids) displaying an asymmetric focused flow, in the presence of a fluorescent dye. Fluorescence correlation spectroscopy
is employed, allowing the precise measure of flow speeds across the channels and of the concentration profile of the central
focused flux along the flow direction. The system is modeled via a standard Navier–Stokes finite-element approach, coupled
to convection–diffusion equations for the solute. Simulations reproduce accurately the shape, the position, and the width
of the velocity and concentration profiles along the central channel and across the transversal and vertical sections of the
microfluidic device. The observed asymmetric flow with respect to the center of the channel is reproduced numerically with
an error in the position determination smaller than 1%. 相似文献
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114.
CAO DengQing WANG JinLin & HUANG WenHu School of Astronautics Harbin Institute of Technology PO Box Harbin China 《中国科学:信息科学(英文版)》2010,(3)
The concept of approximate inertial manifold (AIM) is extended to develop a kind of nonlinear order reduction technique for non-autonomous nonlinear systems in second-order form in this paper.Using the modal transformation,a large nonlinear dynamical system is split into a 'master' subsystem,a 'slave' subsystem,and a 'negligible' subsystem.Accordingly,a novel order reduction method (Method I) is developed to construct a low order subsystem by neglecting the 'negligible' subsystem and slaving the 'slave' sub... 相似文献
115.
P de Nully Brown PO Jensen M Diamant BT Mortensen D Hovgaard P Gimsing NI Nissen 《Canadian Metallurgical Quarterly》1998,22(11):983-989
The plasma cell labeling index (PCLI) in patients with multiple myeloma (MM) is relatively low and this has been associated with the low rate of remission following chemotherapy. Interleukin-6 (IL-6) has been demonstrated to be a major growth factor of myeloma cells. In order to increase the S-phase proportion of myeloma cells, which might increase the sensitivity to chemotherapy, we gave rhIL-6 followed by chemotherapy to 15 myeloma patients with refractory disease. A total of 25 treatment cycles were administered since ten patients had two cycles. The rhIL-6 dose was 2.5 (n = 3), 5.0 (n = 6) and 10.0 microg/kg (n = 6) by subcutaneous injection once daily for 5 days and chemotherapy was administered on the last day of rhIL-6 injection. The effect of rhIL-6 treatment on labeling index (LI) was heterogeneous, but no statistically significant change was noted for this particular group as a whole. In two patients an increase (mean 7.7%) in LI of mononuclear bone marrow cells during the rhIL-6 treatment was demonstrated and in one patient a decrease of 2.8% was seen. Assessment of PCLI demonstrated an increase of 2.9% in one out of six patients and a decrease of 1.9% in one out of six patients. None of the 15 patients achieved remission according to standard criteria. During the rhIL-6 treatment, 14 of the 15 patients developed mild constitutional adverse events (AE) well known in patients treated with IL-6, and none of the AE in the subsequent chemotherapy phase were related to IL-6. In conclusion, our study demonstrated that rhIL-6 can be administered safely to patients with refractory MM, but the cell cycle recruitment approach was not sufficiently effective to be of clinical value. 相似文献
116.
H. C. Mortensen General Manager B. Overgaard Head of Information Transmission Company Krumptappen PO Box 《Energy Policy》1992,20(12):1198-1206
Energy conservation and restructuring towards more energy-efficient technology have been keywords in Danish energy policy in the 1970s and 1980s. This has been reflected especially in domestic heating, where gross energy consumption per square metre has dropped approximately 45% from the early 1970s onwards. This drop is directly related to the massive expansion of combined generation of heat and power (CHP) effected in the same period. Consequently, some 30% of Danish heat requirements are now met by CHP. The intention is to increase this share by a further 7% over the next decade, resulting in a 37% share of Denmark's total heat requirements by CHP in the year 2000. 相似文献
117.
We report the construction of two Escherichia coli strains (294-Cre and 294-FLP) which express either Cre- or FLP-recombinase. Plasmids containing authentic recognition targets for either recombinase (loxPs or FRTs) are recombined when propagated in the appropriate strain. 294-Cre and 294-FLP thus provide a simple test for the recombination competence of constructs that are designed for use in Cre- or FLP-mediated genomic manipulations. 相似文献
118.
L Piculell J Borgstr?m IS Chronakis PO Quist C Viebke 《Canadian Metallurgical Quarterly》1997,21(1-2):141-153
Mixtures of the added salts NaI and CsI can be used to gradually 'tune' the propensity of kappa-carrageenan (KC) helices to aggregate in solution. We show that this method can be used to resolve the molecular events by which helix formation, under certain conditions, leads to gelation. We also present an overview of the various states of aggregation and organisation that appear for helical KC (non-degraded or ultrasonically degraded) when the NaI/CsI ratio and the concentration of KC are varied. A transition to rigid, superhelical rods is found above a well-defined fraction of cesium. This transition is reflected in a range of experimental measurements, such as cryo-transmission electron microscopy, optical rotation, viscometry and small deformation oscillatory measurements. The superhelical-rod state also seems essential for the association of KC with locust bean gum, and locust bean gum is found to stabilise this state. Novel states of KC alone have been found at cesium contents below the transition threshold. Non-degraded KC forms weak gels at sufficiently high concentrations (> ca. 1%). In contrast, ultrasonically degraded KC forms a chiral nematic liquid crystalline phase at sufficiently high concentrations (> ca. 5%) under these salt conditions. 相似文献
119.
120.