排序方式: 共有28条查询结果,搜索用时 15 毫秒
1.
2.
By applying differential form theory, we consider the singular control problem for non-linear systems with control variables appearing linearly in both the system dynamics and the performance index. First, we derive necessary conditions of singular optimality for a single-input system, including the relation to the Euler-Poisson equation and to the generalized Legendre-Clebsch condition. Defining the degree of singularity, we develop necessary conditions satisfied by the singular trajectory embedded in a reduced space. For a time-invariant system, we clarify the relation between the dynamic and the related static optimality. Second, we derive necessary conditions for singular optimality for a multi-input system where the dimension of the control vector is equal to that of the state space. We show that the Shima-Sawaragi condition for the optimality of boundary controls and the generalized Legendre-Clebsch condition are obtained from these conditions. The results are also applied to the analysis of a time-invariant system. 相似文献
3.
MASATAKE TOYODA KAYOKO TAKAGI AKIO TSURUMIZU YUKIO SAITO HIROSHI KIKAWA TARO KAWAMURA YOSHIO SAKABE 《Journal of Food Safety》1989,10(3):191-200
Duplicate portions of the daily meals consumed by 30 housewives were collected for 3 consecutive days in the cities of Nagoya and Yokohama in Japan.
Meals were analyzed for chloroform, bromodichloromethane (BDCM), chlorodibromomethane (CDBM) and bromoform by using a purge-trap procedure. The average concentration (and the range) of these four kinds of trihalomethane in each of the 24 h duplicate meals were, chloroform 19.6±18.1 ppb(n.d.-106.8 ppb), BDCM 0.3±0.3 ppb(n.d.-1.7 ppb), CDBM 0.1±0.2 ppb(n.d.-0.6 ppb) and bromoform 0.5±1.3 ppb(n.d.-8.1 ppb).
The mean daily dietary intake of the four kinds of trihalomethane by housewives were, chloroform 40.0±25.4 μg, BDCM 0.6±0.5 μg, CDBM 0.3±0.3 μg and bromoform 0.9±1.3 μg. 相似文献
Meals were analyzed for chloroform, bromodichloromethane (BDCM), chlorodibromomethane (CDBM) and bromoform by using a purge-trap procedure. The average concentration (and the range) of these four kinds of trihalomethane in each of the 24 h duplicate meals were, chloroform 19.6±18.1 ppb(n.d.-106.8 ppb), BDCM 0.3±0.3 ppb(n.d.-1.7 ppb), CDBM 0.1±0.2 ppb(n.d.-0.6 ppb) and bromoform 0.5±1.3 ppb(n.d.-8.1 ppb).
The mean daily dietary intake of the four kinds of trihalomethane by housewives were, chloroform 40.0±25.4 μg, BDCM 0.6±0.5 μg, CDBM 0.3±0.3 μg and bromoform 0.9±1.3 μg. 相似文献
4.
Economic Evaluation of Power System Flexibility by Commercial Air Conditioner Control with Large Penetration of Photovoltaic Generation
下载免费PDF全文
![点击此处可从《Electrical Engineering in Japan》网站下载免费的PDF全文](/ch/ext_images/free.gif)
High penetration of intermittent renewable energy such as photovoltaic (PV) and wind power could cause shortage of power system flexibility. Demand response is expected to help supply ancillary service instead of the conventional power plant. Commercial air conditioners are a promising responsive load for demand response because they account for a large proportion of power consumption in the power system. We calculate a system operation cost and hourly operation pattern of each power plant by using the optimal power generation model considering flexibility supply from controlling commercial air conditioner. We obtained the following results as an effect of commercial air conditioner control. (1) The power generation of oil fired power plants decreases at peak time and annual fuel cost of oil fired plant is reduced by approximately 30% at most in Kanto area. (2) The percentage of rated operation mode of LNG combined cycle plants increases. (3) Curtailed energy rate of PV decreases because a power storage amount by pumped hydropower generation increases. (4) Required battery capacity to reduce PV curtailed amount decreased by combining battery energy storage system in case of high penetration of PV. 相似文献
5.
对碳纤维增强树脂基复合材料(CFRP)的细观结构成像方法进行了研究,利用涡流成像技术实现了CFRP层合板中纤维方向及纤维缺失、褶皱和空隙过大等缺陷的可视化。首先通过有限元仿真和电路理论分析了CFRP板中涡流的生成机制和分布特性,阐述了基于涡流法的CFRP细观结构成像机制。然后介绍了用于扫描成像的高频涡流检测(HF-ECT)实验系统并确定了涡流探头的形式及其参数。最后利用涡流成像技术分别对单层板、正交层合板和四方向斜交层合板进行了检测,绘制了涡流检测(ECT)信号的三维伪彩图并得到了清晰的纤维纹路分布。通过引入滤波去噪技术和二维快速傅里叶变换(2D-FFT)对图像进行进一步处理,提高了图像分辨率并完成了不同方向上纤维纹路的分离,从而实现对层合板每单向层中缺陷的精确定位。 相似文献
6.
ANDREA P. RODRIGUEZ HIDETSUGU TSUJIGIWA MEHMET GUNDUZ BEYHAN CENGIZ NORIYUKI NAGAI RYO TAMAMURA SILVIA S. BORKOSKY TOHRU TAKAGI MIHO INOUE HITOSHI NAGATSUKA 《Biocell》2009,33(1):39-47
Progenitor cells play an important biological role in tooth and bone formation, and previous analyses during bone and dentine induction have indicated that they may be a good alternative for tissue engineering. Thus, to clarify the influence of the microenvironment on protein and gene expression, MDPC23 cells (mouse dental papilla cell line) and KUSA/A1 cells (bone marrow stromal cell line) were used, both in vitro cell culture and in intra-abdominal diffusion chambers implanted in 4-week-old male immunodefficient mice (SCID mice). Our results indicate that KUSA/A1 cells differentiated into osteoblast-like cells and induced bone tissue inside the chamber, whereas, MDPC-23 showed odontoblast-like characteristics but with a low ability to induce dentin formation. This study shows that MDPC-23 cells are especial cells, which possess morphological and functional characteristics of odontoblast-like cells expressing dentin sialophosphoprotein in vivo. In contrast, dentin sialophosphoprotein gene and protein expression was not detected in both cell lines in vitro. The intra-abdominal diffusion chamber appears as an interesting experimental model for studying phenotypic expression of dental pulp cells in vivo. 相似文献
7.
Integrins are a large family of cell surface glycoproteins that mediate cell-cell and cell-extracellular matrix interactions.During the last 5 years,significant advances have been made in our understanding of the activation mechanism of integrins. 相似文献
8.
3-[(Dioctylamino)methyl]alizarin (C8AL), which is endowed with high solubility in nonpolar organic solvents through introduction of dioctylaminomethyl group into the alizarin nucleus was studied for extracting heavy metal ions such as Cu(II), Zn(II), Cd(II), Co(II), Mn(II), and Ni(II), from aqueous solution.Cu(II) was most readily extracted into chlorobenzene at low pH and thus was separated from other metal ions. The metal ions stabilized in alkaline solution in the presence of water-soluble chelating agents were found to be extracted by this, alizarin-type extraction agent into chlorobenzene with the assistance by lipophilic quaternary ammonium salt, Capriquat? (methyltrioctylammonium chloride, Q?C1?).The proton dissociation process of CRAL was studied, and the mechanism of these metal extractions was discussed.The separation of Cu(II) and Ni(II) from the mixture with other divalent metal ions was also studied. 相似文献
9.
AOGAKI Ryoichi TAKAGI Satoshi MORIMOTO Ryoichi SUGIYAMA Atsushi MOGI Iwao ASANUMA Miki MIURA Makoto OSHIKIRI Yoshinobu YAMAUCHI Yusuke 《钢铁研究学报(英文版)》2012,(Z2):1158-1161
The roles of the rotations in the process of chirality appearance in magnetoelectrodeposition were theoretically clarified.Electrodeposition in a vertical magnetic field induces a macroscopic fluid rotation called vertical MHD flow(VMHDF)over the electrode surface.Inside the rotation,minute numerous micro-vortexes called micro-MHD flow(MMHDF)arise from 2D and 3D nucleation,which interact with the mass flux of metallic ion,yielding chiral deposits with the characteristic features called micro-and nano-mystery circles.Generally,numerous vortexes always keep chiral symmetry,forming four types of vortexes,i.e.,with the combination of upward or downward and clockwise or counterclockwise.However,ionic vacancy acting as an atomic scale lubricant is created in electrodeposition,which gives a restriction to the vortexes;the bottom of an upward vortex covered with ionic vacancies becomes a free surface without friction,whereas the bottom of a downward vortex exposed without ionic vacancies remains rigid with friction.The rotation of VMHDF donates a precession to the upward vortexes to rotate in the same direction,which finally yield a chiral deposit.The similar effect to that of VMHDF can be expected for the system rotation(SR),where an electrolytic cell rotates in a vertical magnetic field.In this case,the SR gives the reverse rotation to the upward vortexes,so that a deposit with reverse chirality is obtained. 相似文献
10.
Carotene from crude palm oil (CPO) and degummed palm oil (DPO) was separated using synthetic polymer adsorption chromatography. Diaion HP-20 adsorbent was used for reverse-phase chromatography and column temperature was kept at 50C. Both 2-propanol and n-hexane were used as the first and the second eluting solvents, respectively. Phosphoric acid was used to remove the minor components in CPO in the degumming process. The turbidity of DPO was lower than that of CPO and the retention time in the column for DPO was shorter (21.3 min) compared to CPO (29 min) due to the removal of the minor components by phosphoric acid. Degumming process caused a reduction of 1.67 mg of total carotene content and 55.67 ppm of carotene concentration in CPO. This is probably due to the removal of carotenoids during the degumming process. After column chromatography, carotene recovery for CPO was 30.23% and 54.82% for the first and second fractions, respectively. On the other hand, carotene recovery for DPO was 33.91% for the first fraction and 46.25% for the second fraction. This indicated that the separation of carotene in CPO was more efficient than DPO in the column chromatography due to the longer retention time in the column. 相似文献