We have developed a hybrid model that integrates chaos theory and an extreme learning machine with optimal parameters selected using an improved particle swarm optimization (ELM-IPSO) for monthly runoff analysis and prediction. Monthly streamflow data covering a period of 55 years from Daiying hydrological station in the Chaohe River basin in northern China were used for the study. The Lyapunov exponent, the correlation dimension method, and the nonlinear prediction method were used to characterize the streamflow data. With the time series of the reconstructed phase space matrix as input variables, an improved particle swarm optimization was used to improve the performance of the extreme learning machine. Finally, the optimal chaotic ensemble learning model for monthly streamflow prediction was obtained. The accuracy of the predictions of the streamflow series (linear correlation coefficient of about 0.89 and efficiency coefficient of about 0.78) indicate the validity of our approach for predicting streamflow dynamics. The developed method had a higher prediction accuracy compared with an auto-regression method, an artificial neural network, an extreme learning machine with genetic algorithm and with PSO algorithm, suggesting that ELM-IPSO is an efficient method for monthly streamflow prediction.

特使外交在中国抗战的危机关头发挥了常规外交所不可替代的重要作用,体现出很大的主动性和灵活性.而全面抗战爆发后初期蒋百里奉命出使意德等国正是这种特使外交的体现.虽然其目的并未完全达到,但蒋的出使却在一定程度上揭示出当时特使外交在出使背景、人员选定以及外交实践和效果上的相关机制和特点,展现出特使外交在其时的重要贡献.

The rapid growth of urbanization and industrialization, along with dramatic climate change, has strongly influenced hydrochemical characteristics in recent decades in China and thus could cause the variation of pH and general total hardness of a river. To explore such variations and their potential influencing factors in a river of the monsoon climate region, we analyzed a long-term monitoring dataset of pH, SO4 2−, NOx, general total hardness (GH), Mg2+, Ca2+, and Cl− in surface water and groundwater in the Luan River basin from 1985 to 2009. The nonparametric Seasonal Kendall trend test was used to test the long-term trends of pH and GH. Relationship between the affecting factors, pH and GH were discussed. Results showed that pH showed a decreasing trend and that GH had an increasing trend in the long-term. Seasonal variation of pH and GH was mainly due to the typical monsoon climate. Results of correlation analysis showed that the unit area usage amounts of chemical fertilizer, NO3 −, and SO4 2− were negatively correlated with pH in groundwater. In addition, mining activity affected GH spatial variation. Acid deposition, drought, and increasing the use of chemical fertilizers would contribute to the acidification trend, and mining activities would affect the spatial variation of GH. Variations of precipitation and runoff in semi-arid monsoon climate areas had significant influences on the pH and GH. Our findings implied that human activities played a critical role in river acidification in the semi-arid monsoon climate region of northern China.

The 1 9th Century is always considered as the era of reform in British history,and educational changes have also occurred during this period,in which the religion,especially denominational contro-versy plays an important role.With the development of religious diversity,the confrontation between Nonconformist and Anglicans is intense in education,which not only results in the breakdown of Church 's monopoly and weakening of the religious teaching in education,but also the rapid development of ele-mentary and higher education,and more educational reforms initiated by government.All these laid the foundation for the modernization of British educational system.

Organic alloy solid electrolytes based on the SCN:NPG (40:60mol%) exhibited very high conductivities of 2.14mScm−1 at room temperature and resulted in a quite high photoconversion efficiency of 4.4% in the solid-state DSSCs.

新闻文化的兴起是英国16、17世纪一个较为突出的历史现象.在都铎晚期,逐步形成了以口耳、手书和印刷新闻为基础的传播格局,尤其是小册子的显著增长,为新闻的广泛传播提供了便利,在人们了解时事和进行道德教化等方面具有作用.斯图亚特王朝早期,随着新闻书的出现以及口耳、手书等传播形式的进一步成熟,新闻文化得到了更为快速的发展.与此同时,新闻与政治的关系愈为紧密,并对英国民众的政治态度产生了重要影响,加速了斯图亚特王朝早期政治意识形态上的分歧.而这种新闻文化的兴起与近代早期英国的社会特性有着密切的联系,有其产生的深刻背景.

Coupler as an important component of the wireless power transfer system, its parameters properties are closely related to transmission efficiency of the wireless energy transmission system. This article discusses the optimum design of the coil, studies the impact of parameters of coil, including resistivity and number of turns, on the transmission efficiency in wireless energy transmission. Results from theoretical analyses and experiments indicate there is no relationship between the circle number of coil and the wireless energy transmission system transmission efficiency.

Particle Swarm Optimization (PSO) is a new optimization technique originating from artificial life and evolutionary computation. It completes optimization through following the personal best solution of each particle and the global best value of the whole swarm. PSO can be used to solve nonlinear programming problems for global optimal solutions efficiently, so a novel approach based on particle swarm optimization is proposed to solve nonlinear bilevel programming problem (NBLP). In the proposed approach, applying Karush–Kuhn–Tucker (KKT) condition to the lower level problem, we transform the NBLP into a regular nonlinear programming with complementary constraints, which is sequentially smoothed by Chen-Harker-Kanzow-Smale (CHKS) smoothing function. The PSO approach is then applied to solve the smoothed nonlinear programming for getting the approximate optimal solution of the NBLP problem. Simulations on 5 benchmark problems and practical example about watershed water trading decision-making problem are made and the results demonstrate the effectiveness of the proposed method for solving NBLP.

<正>2010年10月16日至17日,由中国古代中世纪史研究会中世纪史专业委员会、武汉大学历史学院、世界历史研究所、15—18世纪世界史研究所共同主办的"中国世界中世纪史研究会第七次代表大会暨学术研讨会"在武汉大学隆重召开。本次会议盛况空前,来自中国社会科学院、北京大学、清华大学、中国人民大学、南开大学、

2009年9月9日至10日,由武汉大学15至18世纪世界史研究所与英国伯明翰大学宗教改革和近代早期研究中心联合主办的"中世纪晚期近代早期英国政治和文化变革"国际学术研讨会在武汉大学隆重召开.

In this paper, a new method named MSSE-PSO (master–slave swarms shuffling evolution algorithm based on particle swarm optimization) is proposed. Firstly, a population of points is sampled randomly from the feasible space, and then partitioned into several sub-swarms (one master swarm and other slave swarms). Each slave swarm independently executes PSO or its variants, including the update of particles’ position and velocity. For the master swarm, the particles enhance themselves based on the social knowledge of master swarm and that of slave swarms. At periodic stage in the evolution, the master swarm and the whole slave swarms are forced to mix, and points are then reassigned to several sub-swarms to ensure the share of information. The process is repeated until a user-defined stopping criterion is reached. The tests of numerical simulation and the case study on hydrological model show that MSSE-PSO remarkably improves the accuracy of calibration, reduces the time of computation and enhances the performance of stability. Therefore, it is an effective and efficient global optimization method.

Witchcraft prosecution on a large scale was a prominent and ridiculous historical phenomenon in early modern Europe. Some historians hold that there is a close relationship between the craze for witchcraft prosecution and the rise of the modern sovereign state.However, according to the facts of England that the author has explored, it is not necessarily the truth. In fact, the central government of England did not intend to stimulate or provoke the craze for witchcraft prosecution,but rather,to a large extent, supervised and controlled witchcraft in consideration of social order.This on the contrary prevented unlimited expansion of witchcraft prosecution to some extent.

Taking the nonlinear nature of runoff system into account, and combining auto-regression method and multi-regression method, a Nonlinear Mixed Regression Model (NMR) was established to analyze the impact of temperature and precipitation changes on annual river runoff process. The model was calibrated and verified by using BP neural network with observed meteorological and runoff data from Daiying Hydrological Station in the Chaohe River of Hebei Province in 1956–2000. Compared with auto-regression model, linear multi-regression model and linear mixed regression model, NMR can improve forecasting precision remarkably. Therefore, the simulation of climate change scenarios was carried out by NMR. The results show that the nonlinear mixed regression model can simulate annual river runoff well.

A novel camera calibration approach based on particle swarm optimization (PSO) is put forward in this paper. Firstly, we designed 35 sample points on the calibration box; Secondly, the 3D point and their corresponding 2D image coordinate of these sample points were obtained; In this approach, PSO algorithm was adopted to obtain the camera intrinsic parameters. Among the 35 sample points, 30 points were used for training, and other 5 points were mainly used to evaluate the effectiveness of camera calibration. The techniques presented in this paper have been implemented and tested with both synthetic and real data. Our experimental results show that the method can obtain satisfying calibration accuracy.

A new fire-retardant, diethyl ethyl phosphate (DEEP), was tested as a nonflammable electrolyte solvent for dye-sensitized solar cells (DSSCs). Electrochemical measurements demonstrated that the DEEP electrolyte has a wide potential window (>5 V), sufficient ionic conductivity (3.5 × 10−3 S cm−1 at 25 °C), and electrochemical activity for the \( I^{ - } /I_{3}^{ - } \) redox couple. The DEEP-based DSSCs exhibited an open circuit voltage of 0.72 V, short circuit photocurrent of 10.45 mA cm−2, and a light-to-electricity conversion efficiency of 4.53%, which are almost the same as those observed from the DSSCs using currently optimized organic carbonate electrolytes. Meanwhile, the long-term stability of the DSSCs was greatly improved with the use of the DEEP electrolyte, showing a potential application of this new electrolyte for the construction of efficient, stable, and nonflammable DSSCs.

TiO2-coated multilayered SnO2 hollow microspheres exhibit a high overall photo-conversion efficiency of similar to 5.65% when used for dye-sensitized solar-cell photoelectrodes due to multiple reflecting and scattering of incident light in the hierarchical hollow spherical structure.

<正>20世纪是世界历史发生变动最为频繁的时期之一,期间发生的许多事件至今对整个世界的发展都具有重大影响。大国的兴衰也是其中的重要组成部分,而导致大国兴衰的重要因素之一就是教育问题。"教育"一直为世界各国

This paper has studied the change of streamflow and the impact of climatic variability conditions on regional hydrological cycle in the headwater of the Tarim River Basin. This study investigates possible causes of observed trends in streamflow in an environment which is highly variable in terms of atmospheric conditions, and where snow and ice melt play an important role in the natural hydrological regime. The discharge trends of three head streams have a significant increase trend from 1957 to 2002 with the Mann-Kendall test. Complex time-frequency distributions in the streamflow regime are demonstrated especially by Morlet wavelet analysis over 40 years. The purpose is to ascertain the nature of climatic factors spatial and temporal distribution, involved the use of EOF (Empirical Orthogonal Function) to compare the dominant temperature, precipitation and evaporation patterns from normally climatic records over the Tarim’s headwater basin. It shows that the first principal component was dominated since the 1990s for temperature and precipitation, which identifies the significant ascending trend of spatial and temporal pattern characteristics under the condition of the global warming. An exponential correlation is highlighted between surface air temperature and mean river discharge monthly, so the regional runoff increases by 10%–16% when surface air temperature rises by 1°C. Results suggest that headwater basins are the most vulnerable environments from the point of view of climate change, because their watershed properties promote runoff feeding by glacier and snow melt water and their fundamental vulnerability to temperature changes affects rainfall, snowfall, and glacier and ice melt.

Witch belief is a commonly existed historical phenomenon in early modern Europe,which has different expressions in different countries. In English witch beliefs,the notion of witch's familiar is one of the notable peculiarities that differ from others'.And through some discussions about its characteristics,the reason why it forms and its historical significance,this article reveals its importance in English witch beliefs,which is also signifying some certain feature of English witch beliefs in early modern Europe.

A shuffled complex evolution of particle swarm optimization algorithm called SCE-PSO is introduced in this paper. In the SCE-PSO, a population of points is sampled randomly in the feasible space. Then the population is partitioned into several complexes, which is made to evolve based on PSO. At periodic stages in the evolution, the entire population is shuffled and points are reassigned to complexes to ensure information sharing. Both theoretical and numerical studies of the SCE-PCO are presented. Five optimization problems with commonly used functions are utilized for evaluating the performance of the proposed algorithm, and the performance of the proposed algorithm is compared to PSO to demonstrate its efficiency.