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排序方式: 共有805条查询结果,搜索用时 265 毫秒
791.
Scheduling jobs and maintenances in flexible job shop with a hybrid genetic algorithm 总被引:3,自引:1,他引:3
Most flexible job shop scheduling models assume that the machines are available all of the time. However, in most realistic
situations, machines may be unavailable due to maintenances, pre-schedules and so on. In this paper, we study the flexible
job shop scheduling problem with availability constraints. The availability constraints are non-fixed in that the completion
time of the maintenance tasks is not fixed and has to be determined during the scheduling procedure. We then propose a hybrid
genetic algorithm to solve the flexible job shop scheduling problem with non-fixed availability constraints (fJSP-nfa). The
genetic algorithm uses an innovative representation method and applies genetic operations in phenotype space in order to enhance
the inheritability. We also define two kinds of neighbourhood for the problem based on the concept of critical path. A local
search procedure is then integrated under the framework of the genetic algorithm. Representative flexible job shop scheduling
benchmark problems and fJSP-nfa problems are solved in order to test the effectiveness and efficiency of the suggested methodology.
Received: June 2005 /Accepted: December 2005 相似文献
792.
793.
高盐试样中金属离子的固相萃取分离和测定 总被引:1,自引:0,他引:1
采用NOBIAS chelate-PA1吸附剂固相萃取法分离高盐试样中的V、Fe、Cd、Co、Cu、Zn、U和Th等8种金属离子,并用等离子体原子发射光谱仪(ICP-AES)和等离子体质谱仪(ICP-MS)对被分析物进行了测定.条件实验表明,当样品溶液的pH在5~6时,各元素可以在树脂上达到定量回收;3mL浓度为3mol/L的硝酸可将吸附的离子洗脱完毕;元素浓度在0~1.0μg/mL的范围内可得到定量回收,曲线呈线性关系.树脂的吸附容量为2.5mmol(Cu)/g干树脂.该方法应用于聚变堆用氧化锂球和生物样品海带中V、Fe、Cd、Co、Cu、Zn、U和Th等8种微量元素的测定,结果可靠. 相似文献
794.
Li Qiang Liu Tengfei Li Junjie Cheng Chao Niinomi Mitsuo Yamanaka Kenta Chiba Akihiko Nakano Takayoshi 《Journal of Materials Science》2022,57(9):5634-5644
Journal of Materials Science - Ti–26Nb–2Fe–(0, 2, 4, 6, 8)Sn alloys were prepared by arc melting and subjected to homogenization, cold rolling, and solution treatment. The β... 相似文献
795.
The optical path difference (OPD) and amplitude of a sinusoidal wavelength scanning (SWS) are controlled with a double feedback control system in an interferometer, so that a ruler marking every wavelength and a ruler with scales smaller than a wavelength are generated. These two rulers enable us to measure an OPD longer than a wavelength. A liquid-crystal Fabry-Perot interferometer (LC-FPI) is adopted as a wavelength-scanning device, and double sinusoidal phase modulation is incorporated in the SWS interferometer. Because of a high resolution of the LC-FPI, the upper limit of the measurement range can be extended to 280 microm by the use of the phase lock where the amplitude of the SWS is doubled in the feedback control. The ruler marking every wavelength is generated between 80 microm and 280 microm, and distances are measured with a high accuracy of the order of a nanometer in real time. 相似文献
796.
In spinal fixation devices, the Young's modulus of the metallic implant rod should be not only sufficiently low to prevent stress shielding for the patient but also sufficiently high to suppress springback for the surgeon. This paper proposes a novel function of biomedical titanium alloys—self-adjustment of Young's modulus. Deformation-induced ω phase transformation was introduced into β-type titanium alloys so that the Young's modulus of only the deformed part would increase during operation, while that of the non-deformed part would remain low. The Young's modulus increase by deformation was investigated for a binary Ti-12Cr alloy. This alloy successfully underwent deformation-induced ω phase transformation and exhibited the increase in the Young's modulus by deformation. 相似文献
797.
Enhancement of the specific growth rate of Thiobacillus ferrooxidans by diatomaceous earth 总被引:1,自引:0,他引:1
Diatomaceous earth is an effective carrier with a large surface area on which Thiobacillus ferrooxidans adsorbs, and enhances the oxidation rate of ferrous ions by the bacterium. The adsorption of T. ferrooxidans on diatomaceous earth was expressed by the Henry isotherm, and reached equilibrium within five minutes. The enhancement was due to an increase in the growth rate of the adsorbed cells, which were so active that their specific growth rate calculated using a Monod-type equation was higher than that of the free cells in the liquid phase. 相似文献
798.
Numata Y Kono H Kawano S Erata T Takai M 《Journal of Bioscience and Bioengineering》2003,96(5):461-466
Complete assignments of the cross-polarization/magic-angle spinning (CP/MAS) 13C nuclear magnetic resonance (NMR) spectrum of the cellulose I-ethylenediamine (EDA) complex, which is the intermediate of the reaction from cellulose I to cellulose III(I), were performed. In this paper, we used the 13C-enriched cellulose that was biosynthesized by Acetobacter xylinum ATCC10245 strain from culture medium containing D-(2-13C), D-(3-13C), or D-(5-13C)glucose as a carbon source. After conversion into cellulose I-EDA complex by sufficient EDA treatment, the CP/MAS 13C NMR spectra of the 13C-enriched cellulose I-EDA complexes were measured. As a result, 13C resonance lines of each carbon of the cellulose moiety in the complex appeared as a singlet, suggesting that all glucose residues of the complex are magnetically equivalent. The difference in chemical shifts for each carbon between cellulose I-EDA and cellulose I(alpha), I(beta), and III(I), respectively, suggests that the conformation of the cellulose chains for cellulose I-EDA differs from that for cellulose I(alpha), I(beta), and III(I). In addition, fitting analysis of the 13C spectrum of Valonia cellulose I-EDA complex revealed that the complex contains one EDA molecule per two glucose residues in the cellulose chain. 相似文献
799.
Positively charged nanogold label allows the observation of fine cell filopodia and flagella in solution by atmospheric scanning electron microscopy
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Hidetoshi Nishiyama Kanae Teramoto Mitsuo Suga Chikara Sato 《Microscopy research and technique》2014,77(2):153-160
Optical microscopy is generally the first choice to observe microbes and cells. However, its resolution is not always sufficient to reveal specific target structures, such as flagella and pili, which are only nanometers wide. ASEM is an attractive higher resolution alternative, as the sample is observed in aqueous solution at atmospheric pressure. Sample pretreatment for ASEM only comprises simple tasks including fixation, gold labeling, and reagent exchange, taking less than 1 h in total. The lengthy sample pretreatments often required for more classical electron microscopies, such as embedding and dehydration, are unnecessary, and native morphology is preserved. In this study, positively charged nanogold particles were used to label the surfaces of bacteria and cultured animal cells, exploiting their net negative surface charge. After gold enhancement to increase the size of the nanogold particles, ASEM imaging of the bacteria in aqueous solution revealed pili and delicate spiral flagella. This natural shape contrasts starkly with images of dried flagella recorded by standard SEM. Positively charged nanogold labeled the plasma membrane of cultured COS7 cells, and after enhancement allowed filopodia as thin as 100 nm in diameter to be clearly visualized. Based on these studies, ASEM combined with positively charged nanogold labeling promises to become an important tool for the study of cell morphology and dynamics in the near future. Microsc. Res. Tech. 77:153–160, 2014. © 2013 Wiley Periodicals, Inc. 相似文献
800.
Junichiro Otomo Mitsuo Koshi Teruo Mitsumori Hiroshi Iwasaki Koichi Yamada 《International Journal of Hydrogen Energy》2018,43(5):3004-3014
To achieve comprehensive prediction of ammonia combustion in terms of flame speed and ignition delay time, an improved mechanism of ammonia oxidation was proposed in this work. The present model (UT-LCS) was based on a previous work [Song et al., 2016] and improved by relevant elementary reactions including NH2, HNO, and N2H2. The model clearly explained reported values of laminar flame speed and ignition delay time in wide ranges of equivalence ratio and pressure. This suggests that NH2, HNO, and N2H2 reactivities play a key role to improve the reaction mechanism of ammonia oxidation in the present model. The model was also applied to demonstrate NH3/H2/air combustion. The present model also appropriately predicted the laminar flame speed of NH3/H2/air combustion as a function of equivalence ratio. Using the model, we discussed the reduction of NO concentration downstream and H2 formation via NH3 decomposition in NH3/H2 fuel-rich combustion. The results provide suggestions for effective combustion of NH3 for future applications. 相似文献