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| 1 | 超高效液相色谱-线性离子阱/静电场轨道阱高分辨质谱快速筛查化妆品中的24种激素显示文摘建立了超高效液相色谱-线性离子阱/静电场轨道阱组合式高分辨质谱联用(UPLC-LTQ/Orbitrap MS)快速筛查、定性识别化妆品中24种激素的分析方法。不同剂型的化妆品样品经甲醇超声提取,用Waters ACQUITY UPLC BEH C18色谱柱(50 mm×2.1 mm,1.7μm)分离,以乙腈和0.1%(v/v)甲酸水溶液为流动相进行梯度洗脱。通过静电场轨道阱全扫描得到激素化合物的准分子离子的精确质量数,实现对化妆品中激素的快速筛查;再以保留时间和数据依赖扫描(data dependent scan)模式获得的子离子质谱图进行定性确证。24种激素化合物的质量准确度误差小于3×10-6(3 ppm);线性良好,相关系数大于0.99;检出限≤10μg/kg(S/N=3),能满足实际化妆品样品的分析要求。应用该方法对不同剂型的50余种化妆品样品进行筛查分析,结果良好。该方法是化妆品中激素快速筛查、定性识别的有效方法。 | 李兆永 王凤美 牛增元 罗忻 张罡 陈军辉 | 2014 | 色谱2014，32，5： | 33 |
| 2 | Optimal Control of Nonlinear Inverted Pendulum System Using PID Controller and LQR: Performance Analysis Without and With Disturbance Input显示文摘Linear quadratic regulator(LQR) and proportional-integral-derivative(PID) control methods, which are generally used for control of linear dynamical systems, are used in this paper to control the nonlinear dynamical system. LQR is one of the optimal control techniques, which takes into account the states of the dynamical system and control input to make the optimal control decisions.The nonlinear system states are fed to LQR which is designed using a linear state-space model. This is simple as well as robust. The inverted pendulum, a highly nonlinear unstable system, is used as a benchmark for implementing the control methods. Here the control objective is to control the system such that the cart reaches a desired position and the inverted pendulum stabilizes in the upright position. In this paper, the modeling and simulation for optimal control design of nonlinear inverted pendulum-cart dynamic system using PID controller and LQR have been presented for both cases of without and with disturbance input. The Matlab-Simulink models have been developed for simulation and performance analysis of the control schemes. The simulation results justify the comparative advantage of LQR control method. | Lal Bahadur Prasad Barjeev Tyagi Hari Om Gupta | 2014 | International Journal of Automation and computing2014，11，6： | 32 |
| 3 | Selection of the Linear Regression Model According to the Parameter Estimation显示文摘In this paper,based on the theory of parameter estimation,we give a selection method and,in a sense or a good character of the parameter estimation,we think that it is very reasonable. Moreover,we offer a calculation method of selection statistic and an applied example. | Sun Dao-de Department of Computer, Fuyang Teachers College, Anhui 236032,China | 2000 | Wuhan University Journal of Natural Sciences2000，5，4： | 28 |
| 4 | Central Limit Theorems for Asymptotically Negatively Associated Random Fields | Lixin Zhang Department of Mathematics, Zhejiang University. Xixi Campus. Hangzhou 310028. P. R. China | 2000 | Acta Mathematica Sinica,English Series2000，16，4： | 25 |
| 5 | Nonlinear balance constraints in 3DVAR data assimilation显示文摘In many applications of 3DVAR, the balance constraints can be considered via two main approaches: weak constraint method which adds penalty terms to the cost function; and proper defi- nition of the background error covariance matrix with non-zero cross-correlation sub-matrices. The weak constraint approach requires determining the weighting matrices of the penalty terms. The background error covariance approach does not require determining those additional weighting ma- trices. However, it is only applicable to those linear or linearized balance constraints. A novel ap- proach is proposed based on the background error covariance approach by generalizing the so-called Derber-Bouttier formulation. An assimilation experiment of estimating temperature and salinity from the sea surface dynamic height observation is given to illustrate the proposed treatments of nonlinear balance constraints. | ZHU Jiang YAN Changxiang | 2006 | Science China Earth Sciences2006，49，3： | 24 |
| 6 | Estimating forest aboveground biomass using HJ-1 Satellite CCD and ICESat GLAS waveform data显示文摘The ecosystem in northeastern China and the Russian Far East is a hotspot of scientific research into the global carbon balance.Forest aboveground biomass(AGB) is an important component in the land surface carbon cycle.In this study,using forest inventory data and forest distribution data,the AGB was estimated for forest in Daxinganlin in northeastern China by combining charge-coupled device(CCD) data from the Small Satellite for Disaster and Environment Monitoring and Forecast(HJ-1) and Geoscience Laser Altimeter System(GLAS) waveform data from the Ice,Cloud and land Elevation Satellite(ICESat).The forest AGB prediction models were separately developed for different forest types in the research area at GLAS footprint level from GLAS waveform parameters and field survey plot biomass in the Changqing(CQ) Forest Center,which was calculated from forest inventory data.The resulted statistical regression models have a R2=0.68 for conifer and R2=0.71 for broadleaf forests.These models were used to estimate biomass for all GLAS footprints of forest located in the study area.All GLAS footprint biomass coupled with various spectral reflectivity parameters and vegetation indices derived from HJ-1 satellite CCD data were used in multiple regression analyses to establish biomass prediction models(R2=0.55 and R2=0.52 for needle and broadleaf respectively).Then the models were used to produce a forest AGB map for the whole study area using the HJ-1 data.Biomass data obtained from forest inventory data of the Zhuanglin(ZL) Forest Center were used as independent field measurements to validate the AGB estimated from HJ-1 CCD data(R2=0.71).About 80% of biomass samples had an error less than 20 t ha-1,and the mean error of all validation samples is 5.74 t ha-1.The pixel-level biomass map was then stratified into different biomass levels to illustrate the AGB spatial distribution pattern in this area.It was found that HJ-1 wide-swath data and GLAS waveform data can be combined to estimate forest biomass with good precision,and the biomass data can be used as input data for future carbon budget analysis. | GUO ZhiFeng1,CHI Hong1,2 & SUN GuoQing1,3 1State Key Laboratory of Remote Sensing Science,Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University,Institute of Remote Sensing Applications,Chinese Academy of Sciences,Beijing 100101,China 2Graduate University of Chinese Academy of Sciences,Beijing 100049,China 3Department of Geography University of Maryland,College Park,MD 20742,USA | 2010 | Science China Earth Sciences2010，53，S1： | 21 |
| 7 | 多时滞广域测量电力系统稳定分析与协调控制器设计显示文摘根据电力系统存在时滞的差异性,将控制器信号分为本地无时滞控制输入信号和广域异地多时滞控制输入信号两部分,建立了多时滞电力系统的模型。运用Lyapunov-Krasovskii泛函理论推导出了含有时滞分量的线性多时滞电力系统稳定判据,将控制问题转换为线性矩阵不等式的可行性问题,并采用模型降阶方法对原系统进行降阶,实现了含有多个时滞的广域输出反馈控制,并计算出了能够使闭环电力系统稳定的最大时滞时间。讨论了系统稳定判据中时滞分量与广域控制器参数之间的关系,以及对区域间振荡的控制效果。最后以两区域四机系统为例,用时域仿真的结果说明了本文所提出的多时滞控制方法的有效性。 | 古丽扎提.海拉提 王杰 | 2014 | 电工技术学报2014，29，2： | 19 |
| 8 | An Application of a Mountain Pass Theorem | ZHOU Huan Song Laboratory of Mathematical Physics. Wuhan Institute of Physics and Mathematics. Chinese Academy of Sciences, P. O. Box 71010, Wuhan 430071. P. R. China | 2002 | Acta Mathematica Sinica,English Series2002，18，1： | 18 |
| 9 | The optimal path of piston motion for Otto cycle with linear phenomenological heat transfer law显示文摘An Otto cycle engine with internal and external irreversibilities of friction and heat leakage, in which the heat transfer between the working fluid and the environment obeys linear phenomenological heat transfer law [q ∝△(T -1)], is studied in this paper. The optimal piston motion trajectory for maximizing the work output per cycle is derived for the fixed total cycle time and fuel consumed per cycle. Optimal control theory is applied to determine the optimal piston trajectories for the cases of with and without piston acceleration constraint on each stroke and the optimal distribution of the total cycle time among the strokes. The optimal piston motion with acceleration constraint for each stroke consists of three segments, including initial maximum acceleration and final maximum deceleration boundary segments, respectively. Numerical examples for optimal configuration are provided, and the obtained results are compared with those obtained with Newton’s heat transfer law [q ∝△(T )]. The results also show that optimizing the piston motion can improve power and efficiency of the engine by more than 9%. This is primarily due to the decrease in heat leakage loss on the initial portion of the power stroke. | XIA ShaoJun CHEN LinGen SUN FengRui | 2009 | Science China(Physics,Mechanics & Astronomy)2009，52，5： | 18 |
| 10 | 关于二阶变系数线性微分方程求解法的研究显示文摘求二阶变系数线性微分方程的解,至今为止没有一种成规的方法.推导二阶变系数线性微分方程的一般解法.从特殊型和一般型的二阶变系数线性微分方程进行研究,从方程的自身特点出发,巧妙构造结构,利用降阶法把二阶变系数线性微分方程的求解问题转嫁为求一阶线性微分方程的解.只须构造结构系数函数即可解决二阶变系数线性微分方程通解或特解.利用构造结构的系数函数,再用降阶法可以求得二阶变系数线性微分方程通解或特解的一般方法. | 李高 常秀芳 | 2010 | 河北北方学院学报(自然科学版)2010，26，6： | 18 |
| 11 | The minimum heat consumption for heat-driven binary separation processes with linear phenomenological heat transfer law显示文摘The optimal performance of heat-driven binary separation processes with linear phenomenological heat transfer law(q∝△(T-1)) is analyzed by taking the processes as heat engines which work between high-and low-temperature reservoirs and produce enthalpy and energy flows out of the system,and the temperatures of the heat reservoirs are assumed to be time-and space-variables.A numerical method is employed to solve convex optimization problem and Lagrangian function is employed to solve the average optimal control problem.The dimensionless entropy production rate coefficient and dimensionless enthalpy flow rate coefficient are adopted to indicate the major influence factors on the performance of the separation process,such as the properties of different materials and various separation requirements for the separation process.The dimensionless minimum average entropy production rate and dimensionless minimum average heat consumption of the heat-driven binary separation processes are obtained.The obtained results are compared with those obtained with the Newtonian heat transfer law(q∝△(T)). | SHU LiWei CHEN LinGen SUN FengRui | 2009 | Science China Chemistry2009，52，8： | 17 |
| 12 | Long-term system load forecasting based on data-driven linear clustering method显示文摘In this paper, a data-driven linear clustering(DLC) method is proposed to solve the long-term system load forecasting problem caused by load fluctuation in some developed cities. A large substation load dataset with annual interval is utilized and firstly preprocessed by the proposed linear clustering method to prepare for modelling.Then optimal autoregressive integrated moving average(ARIMA) models are constructed for the sum series of each obtained cluster to forecast their respective future load. Finally, the system load forecasting result is obtained by summing up all the ARIMA forecasts. From error analysis and application results, it is both theoretically and practically proved that the proposed DLC method can reduce random forecasting errors while guaranteeing modelling accuracy, so that a more stable and precise system load forecasting result can be obtained. | Yiyan LI Dong HAN Zheng YAN | 2018 | Journal of Modern Power Systems and Clean Energy2018，6，2： | 16 |
| 13 | MASLOV-TYPE INDEX, DEGENERATE CRITICAL POINTS, AND ASYMPTOTICALLY LINEAR HAMILTONIAN SYSTEMS显示文摘This paper introduces a Maslov-type index theory for paths in the symplectic groups, especially for the degenerate paths via rotational perturbation method, therefore gives a full classification of the linear Hamiltonian systems with continuous, periodic, and symmetric coefficients. Associating this index with each periodic solution, we establish the existence of muhiple periodic solutions of asymptotically linear Hamihonian systems. | 龙以明 | 1990 | Science China Mathematics1990，33，12： | 16 |
| 14 | Determining the Optimal Solution Set for Linear Fractional Programming显示文摘The structure of the optimal solution set is derived for linear fractional programming with the representation theorem of polyhedral sets. Based on an adaptation of the convex simplex method credited to Gilmore and Gomory, we give the uniqueness condition of optimal solution and the computational procedures to find all optimal solutions if the uniqueness condition is not satisfied. Finally, an illustrative example is also given. | Xue Shengjia Management College, Jinan University,Guangzhou 510632, P.R. China | 2002 | Journal of Systems Engineering and Electronics2002，13，3： | 15 |
| 15 | Optimal paths for a light-driven engine with a linear phenomenological heat transfer law显示文摘An irreversible light-driven engine is described in this paper, in which the heat transfer between the working fluid and the environment obeys a linear phenomenological heat transfer law [ q ∝Δ(T -1)], with a working fluid composed of the bimolecular reacting system 2SO 3 F■S 2 O 6 F2. Piston trajectories maximizing work output and minimizing entropy generation are determined for such an engine with rate-dependent loss mechanisms of friction and heat leakage. The optimal control theory is applied to determine the optimal configurations of the piston motion trajectory and the fluid temperature. Numerical examples for the optimal configuration are provided, and the obtained results are compared with those derived with Newtonian heat transfer law [ q ∝Δ(T )]. | MA Kang, CHEN LinGen & SUN FengRui Postgraduate School, Naval University of Engineering, Wuhan 430033, China | 2010 | Science China Chemistry2010，53，4： | 14 |
| 16 | 电力光纤通信网络的多环组网优化显示文摘依据电力系统通信业务的特点,提出了多环组网优化的整数线性规划算法,用于SDH组网优化设计。研究了在一个电力光纤网络中如何组成多个SDH环,以疏导所有低速业务流,并最小化组网成本。依据提出的算法开发了相应的软件,并以某中国东部一城市的电力光纤网络为例给出了具体的优化设计方案。 | 连纪文 刘逢清 | 2011 | 南京邮电大学学报(自然科学版)2011，31，6： | 14 |
| 17 | A SCALED CENTRAL PATH FOR LINEAR PROGRAMMING显示文摘Interior point methods are very efficient methods for solving large scale linear programming problems. The central path plays a very important role in interior point methods. In this paper we propose a new central path, which scales the variables. Thus it has the advantage of forcing the path to have roughly the same distance from each active constraint boundary near the solution. | Ya-xiang Yuan (State Key Laboratory of Scientific and Engineering Computing, Institute of Computational Mathematics and Scientific/Engineering Computing Chinese Academy of Sciences, Beijing 100080, China) | 2001 | Journal of Computational Mathematics2001，19，1： | 14 |
| 18 | Asymptotic normality and strong consistency of maximum quasi-likelihood estimates in generalized linear models显示文摘In a generalized linear model with q × 1 responses, the bounded and fixed (or adaptive) p × q regressors Zi and the general link function, under the most general assumption on the minimum eigenvalue of ∑ni=1 ZiZ'i, the moment condition on responses as weak as possible and the other mild regular conditions, we prove that the maximum quasi-likelihood estimates for the regression parameter vector are asymptotically normal and strongly consistent. | YIN Changming, ZHAO Lincheng & WEI Chengdong School of Mathematics and Information Science, Guangxi University, Manning 530004, China Department of Statistics and Finance, University of Science and Technology of China, Hefei 230026, China Department of Mathematics, Guangxi Teacher College, Manning 530001, China | 2006 | Science China Mathematics2006，49，2： | 13 |
| 19 | Empirical likelihood confidence regions of the parameters in a partially linear single-index model显示文摘In this paper, a partially linear single-index model is investigated, and three empirical log-likelihood ratio statistics for the unknown parameters in the model are suggested. It is proved that the proposed statistics are asymptotically standard chi-square under some suitable conditions, and hence can be used to construct the confidence regions of the parameters. Our methods can also deal with the confidence region construction for the index in the pure single-index model. A simulation study indicates that, in terms of coverage probabilities and average areas of the confidence regions, the proposed methods perform better than the least-squares method. | XUE Liugen~1 & ZHU Lixing~2 1. College of Applied Sciences,Beijing University of Technology,Beijing 100022,China 2. Department of Mathematics,Hong Kong Baptist University,Hong Kong,China | 2005 | Science China Mathematics2005，48，10： | 13 |
| 20 | A REGULARIZED CONJUGATE GRADIENT METHOD FOR SYMMETRIC POSITIVE DEFINITE SYSTEM OF LINEAR EQUATIONS显示文摘AbstractA class of regularized conjugate gradient methods is presented for solving the large sparse system of linear equations of which the coefficient matrix is an ill-conditioned symmetric positive definite matrix. The convergence properties of these methods are discussed in depth, and the best possible choices of the parameters involved in the new methods are investigated in detail. Numerical computations show that the new methods are more efficient and robust than both classical relaxation methods and classical conjugate direction methods. | Zhong-zhi Bai Shao-liang Zhang | 2002 | Journal of Computational Mathematics2002，20，4： | 13 |
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