[en] Only a decade ago the study and fabrication of electron devices whose smallest features were just under 1 micro represented the forefront of the field. Today that position has advanced an order of magnitude to 100 nanometers. Quantum effects are unavoidable in devices with dimensions smaller than 100 nanometers. A variety of quantum effects have been discovered over the years, such as tunneling, resonant tunneling, weak and strong localization, and the quantum Hall effect. Since 1985, experiments on nanostructures (dimension < 100 nm) have revealed a number of new effects such as the Aharanov-Bohm effect, conductance fluctuations, non-local effects and the quantized resistance of point contacts. For nanostructures at low temperature, these phenomena clearly show that electron transport is influenced by wave interference effects similar to those well-known in microwave and optical networks. New device concepts now being proposed and demonstrated are based on these wave properties. This thesis discusses our study of electron transport in nanostructures. All of the quantum phenomena that we address here are essentially one-electron phenomena, although many-body effects will sometimes play a more significant role in the electronic properties of small structures. Most of the experimental observations to date are particularly well explained, at least qualitatively, in terms of the simple one-particle picture. (au)

No abstract available

No abstract available

No abstract available

[en] Highlights: • An ultra-thin flat heat pipe was developed. • The wick was treated to be superhydrophilic. • The flat heat pipe can manage heat flux up to 490 W/cm². • An extremely low thermal resistance was obtained. - Abstract: Miniaturization of high-performance electronics demands heat dissipation components with small size while high performance. This paper presents an ultra-thin flat heat pipe (UTFHP) with a total thickness of 0.95 mm and an inner height of 0.55 mm. Novel wick structure made of superhydrophilic sintered copper mesh screen was employed to provide strong capillary force as well as low flow resistance for the working fluid. Two high-heat-flux heaters were soldered discretely on the UTFHP to evaluate its heat transfer characteristics both under natural air convection and forced water cooling conditions. It is found that the UTFHP had much lower evaporator temperature and much smaller thermal resistance compared with copper sheet, no matter for one heater or two heaters situation, demonstrating excellent heat transfer capability. Moreover, the UTFHP could tolerate 490 W/cm² without dryout. The transition heat flux was 302.5 W/cm² in term of thermal resistance, at which the minimum thermal resistance was 0.039 °C cm²/W, indicating the proposed ultra-thin flat heat pipe can be a promising solution for cooling high power density electronics.

[en] This paper describes the investigation and application of scandate cathodes in Beijing Vacuum Electronics Research Institute (BVERI). The data of emission performance and lifetime were acquired both in closed-spaced diodes and in microwave tubes. Evaporation rates and gas poisoning properties have been determined. From the results of a series of diode experiments and the feedback information of practical usage in tubes, there are three key factors that in our opinion limit the practical application of scandate cathodes in general. These are no obvious saturation onset of I/U characteristics, weak ion bombardment resistivity and non-uniform emission. The authors conclude that to a certain extent, impregnated scandate cathodes (I-Sc) can be used as alternative electron sources instead of M-type cathode in microwave tubes

[en] We theoretically propose a method to measure the one-dimensional harmonic trap frequency with the Bose–Einstein condensate (BEC) in this trap. In contrast to measuring the frequency using ultracold atoms oscillating in a harmonic trap, two Kapitza–Dirac pulses were applied to the BEC. These Kapitza–Dirac pulses act as beam splitters, which divide the BEC into modes with different momenta and evolutionary paths. The weak interatomic interaction causes each mode to have a different distribution of ultracold atoms. According to the density distribution function without any interatomic interactions, the sensitivity of measuring the harmonic trap frequency can reach 10−7, which can be improved by increasing the number of modes. For a system with weak interatomic interactions, the attractive interactions of Bose–Einstein condensation can slightly improve the sensitivity. Increasing the number of modes can reduce the negative influence of weak interatomic interactions on the sensitivity. (author)

[en] Objective: To investigate the effects of a new radiosensitizer, nitroimidazole-derivative--Doranidazole on pancreatic cancer cells under hypoxic condition. Methods: The human pancreatic cancer cell lines were exposed in vitro to a single fraction of high dose γ-ray radiation either with doranidazole or under hypoxic condition. The percentage of dead cells was analyzed with a multi well plated reader and the fluorescence intensities of propidium iodide before and after a digitonin treatment were measured. The sensitizing effect of doranidazole on cell killing by high-dose irradiation was evaluated by time-course, dose-dependency, and microscopic observations. The selective radiosensitive effect of doranidazole on hypoxic cells was evaluated by flow cytometry. Results: Of seven pancreatic cancer cell lines , the mortalities of 5 cell lines were significantly increased in presence of doranidazole under hypoxic condition 5 days after 30 Gy irradiation, but not under aerobic condition. Meanwhile, the radiosensitizing effect of Doranidazole on pancreatic cancer cells was demonstrated as time- and dose-dependent manner. Conclusion: Doranidazole can enhance the radiosensitivity on pancreatic cancer cells under hypoxic condition with high-dose irradiation. (authors)

[en] It introduces a method of a software development which is based on high speed PC oscilloscope for pulsed magnetic field measurement system. The previous design has been improved by this design, high-speed virtual oscilloscope has been used in the field for the first time. In the design, the automatic data acquisition, data process, data analysis and storage have been realized. Automated point checking reduces the workload. The use of precise motion bench increases the positioning accuracy. The software gets the data from PC oscilloscope by calling DLLs and includes the function of oscilloscope, such as trigger, ranges, and sample rate setting etc. Spline Interpolation and Bandstop Filter are used to denoise the signals. The core of the software is the state machine which controls the motion of stepper motors and data acquisition and stores the data automatically. NI Vision Acquisition Software and Database Connectivity Toolkit make the video surveillance of laboratory and MySQL database connectivity available. The raw signal and processed signal have been compared in this paper. The waveform has been greatly improved by the signal processing. (authors)

[en] Objective: To investigate correlation between glycemic excursion by CGMS and diabetic retinopathy among type 2 diabetes mellitus. Methods: Used continuous glucose monitoring system (CGMS) to monitoring glycemic excursion within a day of twenty four patients with type 2 diabetes mellitus, and inspect fundus photography, correlation was analyzed. Results: Glycemic excursion might reveal the risk for diabetic retinopathy better than HbA1c does. Conclusion: Diabetic retinopathy may correlate with glycemic excursion. (authors)