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51.
Hong Y.D. Yew Tong Yeow Chim W.K. Jian Yan Kin Mun Wong 《Electron Devices, IEEE Transactions on》2006,53(3):499-506
Scanning capacitance microscopy (SCM) is a dopant profile extraction tool with nanometer spatial resolution. While it is based on the high-frequency MOS capacitor theory, there are crucial second-order effects which make the extraction of dopant profile from SCM data a challenging task. Due to the small size of the SCM probe, the trapped charges in the interface traps at the oxide-silicon dioxide interface surrounding the probe significantly affect the measured SCM data through the fringing electric field created by the trapped charges. In this paper, we present numerical simulation results to investigate the nature of SCM dC/dV data in the presence of interface traps. The simulation takes into consideration the traps' response to the ac signal used to measure dC/dV as well as the fringing field of the trapped charge surrounding the probe tip. In this paper, we present an error estimation of experimental SCM dopant concentration extraction when the interface traps and fringing field are ignored. The trap distribution in a typical SCM sample is also investigated. 相似文献
52.
53.
Beng Tan Swan Seng Yang Kin Choo Loy Wei 《Bulletin of Engineering Geology and the Environment》1982,26(1):321-326
Bulletin of Engineering Geology and the Environment - Geophysical methods of site investigation have been used in civil engineering for many years. Of these methods, seismic refraction survey is... 相似文献
54.
Dunmin Lin Kin Wing Kwok Helen Wong Lai-wa Chan 《Journal of the American Ceramic Society》2009,92(6):1362-1365
In this work, the double-loop-like characteristics of K0.5 Na0.5 NbO3 + x mol% K5.4 Cu1.3 Ta10 O9 ceramic and its relationships with the transition temperature, aging, and switching have been investigated. Our results reveal that the phase transition temperature is an important parameter determining the aging requirement for the ceramics to exhibit the double-loop-like characteristics. For a ceramic with a high transition temperature, e.g. the ceramic with x =0.75 (tetragonal–orthorhombic phase temperature ∼206°C), the vacancies can migrate during the crystal transformation and settle in a distribution with the same symmetry as the crystal after the transformation. As a result, defect dipoles along the polarization direction are formed and provide restoring forces to reverse the switched polarizations, and thus producing a double polarization hysteresis ( P – E ) loop. On the other hand, aging is required for a ceramic with a low transition temperature, e.g. aging at 80°C for 30 days is required for the ceramic with x =1.5 (transition temperature ∼175°C). Our results also reveal that the defect dipoles can be switched under a slow-switching electric field (<1 Hz) or at high temperatures (>100°C), thus leading to an opening of the double P – E loop. 相似文献
55.
56.
In open railway access markets, a train service provider (TSP) negotiates with an infrastructure provider (IP) for track access rights. This negotiation has been modeled by a multiagent system in which the IP and the TSP are represented by separate software agents. One of the tasks of the IP agent is to generate feasible (and preferably optimal) track access rights, subject to the constraints submitted by the TSP agent. This paper formulates an IP-TSP transaction and proposes a branch-and-bound algorithm for the IP agent to identify the optimal track access rights. Empirical simulation results show that the model is able to emulate rational agent behaviors. The simulation results also show good consistency between the timetables that were attained from the proposed methods and those that were derived by the scheduling principles adopted in practice. 相似文献
57.
为了克服MoS2薄膜在大气环境下极易氧化失效且耐磨性能差的缺点,采用非平衡直流磁控溅射技术制备了MoS2/Ti复合膜,研究了Ti靶电流对复合膜结构和性能的影响。电子探针(EPMA)测定表明,膜中Ti的含量随着Ti靶电流的增加而增加。场发射扫描电子显微镜(FE.SEM)对膜的表面和截面形貌观察发现,膜的表面由尺寸为几十~几百纳米的颗粒组成,而膜的截面呈柱状晶结构。膜的致密性和Ti靶电流有关,电流越高,膜的致密性越好,从而膜的硬度也越高。 相似文献
58.
Hui Li Tyler Garner Francisco Diaz Pak Kin Wong 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(28)
Birth control and family planning play pivotal roles in the economic growth and reduction of maternal, infant, and child mortality. Current contraceptives, such as hormonal agents and intrauterine devices, target only a small subset of reproductive processes and can have serious side effects on the health of women. To develop novel contraceptive agents, a scalable microfluidic device is established for analyzing and screening the effects of potential contraceptive agents on the maturation of the cumulus–oocyte complex. The microfluidic device performs on‐chip incubation for studying oocyte maturation and cumulus expansion and isolates the microwells by oil–water interfaces to avoid crosstalk between the wells. A filter membrane is incorporated in the device to simplify incubation, medium exchange, washing, and fluorescence staining of oocytes. Cumulus expansion can be monitored directly in the device and oocyte maturation can be examined after enzymatic removal of cumulus cells and on‐chip fluorescence staining. The performance of the device is evaluated by studying the influence of three drugs known to block oocyte maturation and/or cumulus expansion. 相似文献
59.
Kin Yuen Leong Z. A. Najwa K. Z. Ku Ahmad Hwai Chyuan Ong 《International Journal of Thermophysics》2017,38(5):77
Water is regarded as a poor absorber of solar energy. This affects the efficiency of solar thermal systems. The addition of nanoparticles to heat transfer fluids used in solar thermal systems can enhance their optical properties. These new-generation heat transfer fluids are known as nanofluids. The present study investigates the stability and optical properties of three nanofluids, including aluminum oxide (13 nm and <50 nm) and titanium dioxide (21 nm) nanofluids. The stability of the nanofluids was observed through a photo-capturing method and zeta potential measurements. Ultraviolet–visible (UV–Vis) spectrophotometer was used to measure the absorbance and transmittance of the prepared nanofluids. The effect of factors such as type of particle, type of surfactant, and pH of the solution on the optical properties of the nanofluids was also investigated. We found that the titanium dioxide nanofluid had better optical properties but lower stability compared to aluminum oxide nanofluids. 相似文献
60.
Scientometrics - In this paper, we analyze the structure of the article citation network of a particular subject obtained from the Web of Science (WoS) database. In specific, we modify a model... 相似文献