Results 1 - 10 of 22
Results 1 - 10 of 22. Search took: 0.024 seconds
|Sort by: date | relevance|
[en] A new method of enhancing operation economy without loss any reliability method is called Proactive Ageing Management (PAM in short). PAM can be used for generic and specific plant in almost all situations that concern reliability and economy problem. PAM 2.0 software, which is a professional software during PAM process application, plays an important role to help analysts evaluate all strategies showed above and also provides decision advises to nuclear power plant manager using Net Present Values (NPV) criteria. Additionally, one case was taken as an example to illustrate PAM process, the role of software and explain the results for use. (authors)
[en] We report a giant Seebeck coefficient (S) thermoelectric (TE) material—MnO2 powder—and the design of a practical MnO2 TE generator to light up a regular light emitting diode (LED). The S of MnO2 powder was measured to be higher than 20 000 μV K−1, which is about 100 times higher than the state-of-the-art of Bi2Te3, one of the best TE materials. The giant S is very possibly closely related to the surface density of the electronic state (DOS), the Fermi energy level. The very high S and therefore high power factor is technologically important for transient TE cooling. (paper)
[en] Objective: To estimate some typical radiodiagnosis projection conditions for adult patients' organic dose and effective dose by the WINODS included in DOSEGUARD100. Change some parameters to test the applicability of WINODS and the infcuence on projection dose. Methods: Compare the result from the WINODS with experiment results achived by the research group. Results: Lumbar AP(male, female) 0.301 mGy, 0.743 mGy; pelvis AP (made, female) 0.23 mGy, 0.639 mGy; sternum AP(male, female) 0.021 mGy, 0.029 mGy; abdomen (male, female) 0.303 ,Gy, 0.414 mGy. Change the high voltage from 68 kV to 120 kV without any change of exit dose, ESD and effective dose level would come down. Change the total filter from 1.5 mmaAl to 3.0 mmAl without any change of exit dose, ESD and effective dose level would also come down. In this test the results are in accordance with the experiment results on the whole. Conclusion: The test results show WINODS is suited to the estimation of the organic dose and effective dose. WINODS can be used to improve the optimization work. (authors)
[en] Objective: To determine guidance levels for patient doses in diagnostic radiology in china. Methods: Investigations on annual frequencies and patient doses for radiological diagnostic examinations. Results: Recommendations of quantities of reference dose, measurement methods and guidance levels for 18 types of radiological diagnostic examination. Conclusion: Establishment of guidance levels for patient dose in diagnostic radiology will greatly promote the development of optimization of radiation protection in medical exposure
[en] An intelligent hydrogel with both pH and temperature sensitivity was obtained by grafting acrylic acid and dimethylaminoethylmethacrylate onto preirradiated polypropylene (PP) film by two-step reactions. The effect of first and second reactions on the degree of grafting was studied. The grafted sample films were checked by Fourier transform infrared spectrophotometry in the attenuated total reflectance mode. The morphology of the PP samples was observed by scanning electron microscope in different conditions before and after grafting, respectively. (author)
[en] We report a practical vacuum pressure sensor based on a ZnO nanowire array (NWA). An oriented single-crystal ZnO NWA was synthesized by electrodeposition. The device consists of two ITO glass plates coated with a ZnO NWA. Scanning electron microscopy (SEM) and the x-ray diffraction (XRD) pattern show that the as-grown ZnO NWAs are single-crystal and roughly oriented with the ZnO(002) plane parallel to the substrate. Through measuring the pressure dependent resistance of the sensor at different gas species and temperatures, we discovered that the resistance increases monotonically with vacuum pressure. This demonstrates that a practical vacuum sensor could be fabricated since measurements were carried out with a normal multimeter, with no need for the high sensitivity and costly equipment as routinely required in nanotechnology for extremely weak signals. Measurement at elevated temperature (300 deg. C) showed that the vacuum sensor is much stabler and more sensitive to O2 pressure. The principle of the device relates to the adsorbed oxygen species on the large surface area of a ZnO NWA to form a resistive depletion layer at the nanowire (NW) surface.
[en] Health impact assessment (HIA) is a useful tool to predict and estimate the potential health impact associated with programs, projects, and policies by comprehensively identifying relevant health determinants and their consequences. China is undergoing massive and rapid socio-economic changes leading to environment and population health challenges such as a large increase in non-communicable diseases, the emergence and re-emergence of infectious diseases, new health risks associated with environmental pollutants and escalating health inequality. These health issues are affected by multiple determinants which can be influenced by planned policies, programs, and projects. This paper discusses the needs for health impact assessment in China in order to minimize the negative health consequences from projects, programs and policies associated with rapid social and economic development. It first describes the scope of China's current impact assessment system and points out its inadequacy in meeting the requirements of population health protection and promotion. It then analyses the potential use of HIA and why China needs to develop and apply HIA as a tool to identify potential health impacts of proposed programs, projects and policies so as to influence decision-making early in the planning process. Thus, the paper recommends the development of HIA as a useful tool in China to enhance decision-making for the protection and promotion of population health. For this to happen, the paper outlines steps necessary for the establishment and successful implementation of HIA in China: beginning with the establishment of a HIA framework, followed by workforce capacity building, methodology design, and intersectoral collaboration and stakeholder engagement.
[en] The hierarchical branched nanostructures have been widely studied for optoelectronics application due to their unique optical and electrical properties. Three-dimensional (3D) hierarchical branched Au-cadmium sulfide (CdS) nano-composite structures were successfully synthesized on Si substrate utilizing facile chemical vapor deposition (CVD) method combined with thermal evaporation method. Here, a simple in situ method combined with photolithography technology was carried out to investigate the photoluminescence (PL) 3D hierarchical branched CdS decorated with Au NPs. Compared with pure 3D hierarchical branched CdS, the PL emission of 3D hierarchical branched CdS decorated with Au NPs can be quenched and enhanced. The enhancement of the PL emission is attributed to the localized surface plasmons response (LSPR) of Au NPs, and the electrons transfer from Au NPs to CdS. While, the quenching is due to the light scattering of Au NPs, and the electrons transfer from CdS to Au NPs. The results can be used for in situ study of material properties, which is very important for the nano devices based on a single nanowire. And the results can also help to make clear the coupling mechanism of metal NPs and semiconductor. So, the PL emission quenching or enhancement of the metal NPs coupled with a semiconductor can be effectively controlled. (paper)
[en] The influence of air, dry oxygen and humidity on the performance of a top-contact polymer field-effect transistor using poly(3-hexylthiophene) (P3HT) as an active layer is investigated. It is demonstrated that high relative humidity (92%) causes the device to degrade rapidly, while the influence of dry oxygen on the device is relatively small, indicating that the harmful influences are mainly the result of atmospheric water due to the enhancement of carrier conduction in the vicinity of the active-layer surface caused by the absorption of water molecules on the surface, rather than the p-type doping effect of O2. A photoresist or paraffin layer is utilized as a passivation layer on top of the P3HT film, and the effects of the passivation layer on the performance and stability of the device are investigated. Results indicate that the passivation layer can effectively improve the stability of the device exposed to air, and enhance its field-effect mobility
[en] Wavy fluorinated ethylene propylene (FEP) electret films with negative charges were prepared by a patterning method followed by a corona charging process. The thermal stability of these films was characterized by the surface potential decay with annealing time at elevated temperatures. The results show that thermally stable electret films can be made by corona charging followed by pre-aging treatment. Vibration energy harvesters having a very simple sandwich structure, consisting of a central wavy FEP electret film and two outside metal plates, were designed and their performance, including the resonance frequency, output power, half power bandwidth, and device stability, was investigated. These harvesters show a broad bandwidth as well as high output power. Their performance can be further improved by using a wavy-shaped counter electrode. For an energy harvester with an area of 4 cm2 and a seismic mass of 80 g, the output power referred to 1 g (g is the gravity of the earth), the resonance frequency, and the 3 dB bandwidth are 1.85 mW, 90 Hz, and 24 Hz, respectively. The output power is sufficient to power some electronic devices. Such devices may be embedded in shoe soles, carpets or seat cushions where the flexibility is required and large force is available. (paper)