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881.
This paper presents a methodology which determines the allocation of power demand among the committed generating units while minimizes number of objectives as well as meets physical and technological system constraints. The procedure considers two decoupled problems based upon the dependency of their goals on either active power or reactive power generation. Both the problems have been solved sequentially to achieve optimal allocation of active and reactive power generation while minimizes operating cost, gaseous pollutants emission objectives and active power transmission loss with consideration of system operating constraints along with generators prohibited operating zones and transmission line flow limits. The active and reactive power line flows are obtained with the help of generalized generation shift distribution factors (GGDF) and generalized Z-bus distribution factors (GZBDF), respectively. First problem is solved in multi-objective framework in which the best weights assigned to objectives are determined while employing weighting method and in second problem, active power loss of the system is minimized subject to system constraints. The validity of the proposed method is demonstrated on 30-bus IEEE power system. 相似文献
882.
本文以LabVIEW程序语言为核心,介绍了远程温度采集系统的原理、软硬件组成和实现过程,并以化学反应中的温度测量为例,通过串口完成了温度数据的快速采集。此类测控系统价格低廉且构建快速,可以方便的移植到其他众多领域。 相似文献
883.
Alexander V. Zhdanov Ruslan I. Dmitriev Dmitri B. Papkovsky 《Cellular and molecular life sciences : CMLS》2011,68(5):903-917
Bafilomycin A1 (Baf) induces an elevation of cytosolic Ca2+ and acidification in neuronal cells via inhibition of the V-ATPase. Also, Baf uncouples mitochondria in differentiated PC12
(dPC12), dSH-SY5Y cells and cerebellar granule neurons, and markedly elevates their respiration. This respiratory response in dPC12 is accompanied by morphological changes in the mitochondria and decreases the mitochondrial pH, Ca2+ and ΔΨm. The response to Baf is regulated by cytosolic Ca2+ fluxes from the endoplasmic reticulum. Inhibition of permeability transition pore opening increases the depolarizing effect
of Baf on the ΔΨm. Baf induces stochastic flickering of the ΔΨm with a period of 20 ± 10 s. Under conditions of suppressed
ATP production by glycolysis, oxidative phosphorylation impaired by Baf does not provide cells with sufficient ATP levels.
Cells treated with Baf become more susceptible to excitation with KCl. Such mitochondrial uncoupling may play a role in a
number of (patho)physiological conditions induced by Baf. 相似文献
884.
During the first leg of a Chinese research cruise to the Southeast Indian Ridge (SEIR) in 2007, we revisited the K-segment of the SEIR and observed a water column turbidity anomaly at a CTD cast station. This station was located ~400 m from a dredge site on a plume anomaly detected in 1996 by US scientists. The characteristics of the turbidity anomaly detected in our survey are different from those observed 11 years previously, implying that either the detected anomalies have distinct and different plume sources or the robustness of the plume has changed in the intervening time. In addition, turbidity anomalies were observed at two localities on the K-segment in a deep tow-yo profile. If these two anomalies are not connected, the plume incidence calculated would be about 0.28, larger than the predicted value of 0.25 for a 65 mm/a spreading rate. This increase in plume incidence on the K-segment seems to be related to the influence of the St. Paul-Amsterdam hotspot, located about 300 km to the northwest. 相似文献
885.
分析了双筒缠绕式提升机卷筒的受力情况,并对自由筒壳区的强度、支轮强度以及筒壳稳定性计算作了详细介绍,对今后有针对性地设计合理的卷筒结构,减轻卷筒质量,节省材料有着重要的意义,完善了卷筒强度的设计方法. 相似文献
886.
Coordination polymers (or metal-organic frameworks, MOFs), as one of the essences of crystal engineering and coordination chemistry, have attracted considerable atten-tion from chemists, 相似文献
887.
A number of recently evolved animals possess poison glands for feeding and/or defense.However,examples of such animals are rare in the fossil record.We report a fossil arthropod Isoxys curvirostratus from the Early Cambrian Chengjiang biota of China.This species is regarded as the oldest known venomous arthropod based on the presence of venomous glands in its head region.The adult animal is 2-5 cm long and the body is covered entirely with a carapace.The presence of large stalk eyes and a pair of stout grasping appendages with a terminal spine suggest it was raptorial.Interestingly,the two pear-shaped,three-dimensionally preserved objects that are present in the head region and at the base of the grasping appendages closely resemble the venom glands of some living arthropods in size,shape,and position.These features indicate that the presence of venomous predators could date back 520 million years.Furthermore,our observations suggest that the feeding strategies and organs adapted for this purpose had already reached a high level of diversity and anatomical sophistication in the Early Cambrian ecosystems. 相似文献
888.
ShangJian Zhang ChangYu Lin Xuan Li Zhitai Zou Yong Liu YongZhi Liu 《科学通报(英文版)》2011,56(15):1633-1636
A novel method for characterizing the nonlinearity of all-optical sampling is proposed based on the normalized transfer function.Simulation results demonstrate the effectiveness of our method.Furthermore,an all-optical sampling experiment is performed to verify our method.Both simulation and experiment show consistency between our method and the measurements.The method only requires normalization and polynomial fitting of the transfer curve,and enables direct expression of the nonlinearity with the coefficients of the normalized transfer function. 相似文献
889.
本文在对常用单片机中断功能扩展方法优缺点分析的基础上 ,用编码器扩展单片机中断功能 ,提出了采用中断向量表实现中断功能的软件设计方法 ,并给出了参考程序。这种扩展方法具有接口电路简单 ,软件实现容易 ,不耗费单片机内部资源 ,中断响应快的特点。 相似文献
890.
Dennis Duke 《Archive for History of Exact Sciences》2009,63(6):635-654
In the Planetary Hypotheses, Ptolemy summarizes the planetary models that he discusses in great detail in the Almagest, but he changes the mean motions to account for more prolonged comparison of observations. He gives the mean motions in two
different forms: first, in terms of ‘simple, unmixed’ periods and next, in terms of ‘particular, complex’ periods, which are
approximations to linear combinations of the simple periods. As a consequence, all of the epoch values for the Moon and the
planets are different at era Philip. This is in part a consequence of the changes in the mean motions and in part due to changes
in Ptolemy’s time in the anomaly, but not the longitude or latitude, of the Moon, the mean longitude of Saturn and Jupiter,
but not Mars, and the anomaly of Venus and Mercury, the former a large change, the latter a small one. The pattern of parameter
changes we see suggests that the analyses that yielded the Planetary Hypotheses parameters were not the elegant trio analyses of the Almagest but some sort of serial determinations of the parameters based on sequences of independent observations. 相似文献