Author Keywords: Radiation detection; Long-lasting phosphor; Luminescence; Temperature dependence; Fade-out effect 相似文献
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1.
Wesley P. Chan Hiroto Mizohana Xiangyu Chen Yasuto Shiigi Yoshiyuki Yamanoue Masaki Nagatsuka Masayuki Inaba 《野外机器人技术杂志》2019,36(1):17-33
The use of field robots can greatly decrease the amount of time, effort, and associated risk compared to if human workers were to carryout certain tasks such as disaster response. However, transportability and reliability remain two main issues for most current robot systems. To address the issue of transportability, we have developed a lightweight modularizable platform named AeroArm. To address the issue of reliability, we utilize a multimodal sensing approach, combining the use of multiple sensors and sensor types, and the use of different detection algorithms, as well as active continuous closed‐loop feedback to accurately estimate the state of the robot with respect to the environment. We used Challenge 2 of the 2017 Mohammed Bin Zayed International Robotics Competition as an example outdoor manipulation task, demonstrating the capabilities of our robot system and approach in achieving reliable performance in the fields, and ranked fifth place internationally in the competition. 相似文献
2.
A survey of the state of SQA in Japan finds that the situation is much like, but slightly different than, that in the US. 相似文献
3.
In this article, we consider a flexible beam with a rigid body, of which the bending vibration and the torsional vibration are decoupled. Therefore we need two control motors to suppress the vibrations. Each set of dynamic equations is treated in the form of an appropriate Hilbert space. A stabilizing feedback control law of each rotation motor will be established on the basis of modal analysis. A set of experiments has been carried out, and the results demonstrate the effectiveness of the dynamic model and the proposed control law. © 1994 John Wiley & Sons, Inc. 相似文献
4.
Yoshiyuki Uno Akira Okada Kensuke Uemura Purwadi Raharjo Toshihiko Furukawa Kosaku Karato 《Precision Engineering》2005,29(4):171-455
A new finishing process for metal molds by large-area electron beam (EB) irradiation is proposed in this study. In the large-area EB irradiation equipment used here, an EB with high-energy density is irradiated without focusing the beam, and so the EB with a maximum diameter of 60 mm can be used for melting or evaporating metal surface instantly. Experimental results show that the surface roughness decreases from 6 μmRz to less than 1 μmRz in just a few minutes under proper machining conditions. The corrosion resistance of metal mold surface also could be greatly improved by large-area EB irradiation. Furthermore, the surface roughness of tilting surface close to 90° could be well improved. Therefore, large-area EB irradiation method has a possibility to become a high-efficiency finishing process for metal molds. 相似文献
5.
Munehiko Kowatari Daisuke Koyama Yoshiyuki Satoh Kouichi Iinuma Shunsuke Uchida 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2002,480(2-3):431-439
The temperature dependence of luminescence from a long-lasting phosphor (LLP), SrAl2O4 : Eu2+,Dy3+, exposed to ionizing radiation has been measured to understand the LLP luminescence mechanism. Evaluation of the decay constants of the LLP exposed to -, β- or γ-rays at temperatures from 200 to 390 K showed that the decay constant is divided into four components ranging from 10−4 to 10−1 s−1 with activation energies of 0.02–0.35 eV.
Total luminous intensity from the LLP with changing irradiation temperature has its maximum value around the room temperature. Irradiation at elevated temperature (390 K) has the total luminescence pattern with monotonous decrease as temperature rises. As a result of evaluating the temperature dependence of luminescence, the luminescence mechanism is considered as follows:
6.
Yutaka Asako Hisayoshi KamikogaHisashi Nishimura Yoshiyuki Yamaguchi 《International Journal of Heat and Mass Transfer》2002,45(11):2243-2253
Compression is one solution to improve the strength of softwoods. The effective thermal conductivities of compressed Japanese cedars (cryptomeria japonica), which were compressed in the radial direction of the wood, were measured. Both the effective thermal conductivities in the tangential and fiber directions increase proportionally to the density increment due to the compression. However, the thermal conductivity in the radial direction (compression direction) increases slightly with the density increment. Numerical computations were conducted to explain the characteristics of thermal conductivity in the radial direction by using a microscopic heat conduction model for the compressed wood. The numerical results were compared with the measured values. And the physical mechanism of the heat conduction in the compressed woods is discussed. 相似文献
7.
Quantitative analysis of isothermal crystallization kinetics of PLA/clay nanocomposite and PLA/clay/regenerated cellulose fiber (RCF) hybrid composite has been conducted. The crystallization rate constant (k) according to Avrami equation was higher in PLA/clay nanocomposite than in PLA/clay/RCF hybrid composite at the same crystallization temperature. The equilibrium melting temperature obtained by Hoffman–Weeks equation was almost same in both composites, whereas stability parameter was greater in hybrid composite than in nanocomposite. Activation energy of hybrid composite for crystallization was larger than that of nanocomposite. The value of nucleation parameter (Kg) and surface free energy (se) of hybrid composite were larger than nanocomposite, indicating that hybrid composite has a less folding regularity than nanocomposite. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
8.
BACKGROUND: Major depressive disorder is often marked by repeated episodes of depression. We describe recovery from major depression across multiple mood episodes in patients with unipolar major depression at intake and examine the association of sociodemographic and clinical variables with duration of illness. METHODS: A cohort of 258 subjects treated for unipolar major depressive disorder was followed up prospectively for 10 years as part of the Collaborative Depression Study, a multicenter naturalistic study of the mood disorders. Diagnoses were made according to the Research Diagnostic Criteria, and the course of illness was assessed with the Longitudinal Interval Follow-up Evaluation. Survival analyses were used to calculate the duration of illness for the first 5 recurrent mood episodes after recovery from the index episode. RESULTS: Diagnosis remained unipolar major depressive disorder for 235 subjects (91%). The median duration of illness was 22 weeks for the first recurrent mood episode, 20 weeks for the second, 21 weeks for the third, and 19 weeks for the fourth and fifth recurrent mood episodes; the 95% confidence intervals were highly consistent. From one episode to the next, the proportion of subjects who recovered by any one time point was similar. For subjects with 2 or more recoveries, the consistency of duration of illness from one recovery to the next was low to moderate. None of the sociodemographic or clinical variables consistently predicted duration of illness. CONCLUSION: In this sample of patients treated at tertiary care centers for major depressive disorder, the duration of recurrent mood episodes was relatively uniform and averaged approximately 20 weeks. 相似文献
9.
Copoly(amide-ethers) containing two types of tertiary amine units were made as antistatic modifiers for poly(ethylene terephthalate) (PET) fibers. The filaments of the copolymers were melt-spun and reacted with three alkylating agents in order to quaternize the tertiary amine into a sulfo-betaine, a carbobetaine, and an ammonium ion. The apparent electric resistivity of the filaments was greatly reduced by this reaction, being in the range of 106 to 108 Ω/cm. However, because these quaternized copolymers incurred decomposition during blend spinning with PET, a blend PET fiber containing one type of copoly(amide-ether) was melt-spun and subjected to quaternization of the amino groups as well as to surface crosslinking with various alkylating and epoxy agents. The quaternized blend fibers obtained showed improved antistatic properties compared with the original blend fiber. Particularly, the fibers crosslinked with epoxy compounds were found to have the best antistatic properties that had ever been attained with this type of modification. The antistatic properties were retained even after dyeing, because both hydrophilic and ionic groups had been effectively immobilized on the surface. Since this quaternization and crosslinking could be conducted on-line with spinning and drawing within a short reaction time, this modification technique is called “spin-finishing method”, which should be superior to the conventional methods in terms of cost performance and productivity. 相似文献
10.
Hideto Matsuyama Kentarou Hayashi Taisuke Maki Masaaki Teramoto Noboru Kubota 《应用聚合物科学杂志》2004,93(1):471-474
Microporous high‐density polyethylene (HDPE) and low‐density polyethylene (LDPE) hollow fiber membranes were prepared from polyethylene–diisodecyl phthalate solution via thermally induced phase separation. Effect of the polyethylene density on the membrane structure and performance was investigated. The HDPE membrane showed about five times higher water permeability than the LDPE membrane because it had the larger pore and the higher porosity at the outer membrane surface. The formation of the larger pore was owing to both the initial larger structure formed by spinodal decomposition and the suppression of the diluent evaporation from the outer membrane surface due to the higher solution viscosity. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 471–474, 2004 相似文献