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| 1 | Relationships between the North Pacific Oscillation and the typhoon/hurricane frequencies显示文摘Relationships between the North Pacific Oscillation (NPO) and the typhoon as well as hurricane fre-quencies are documented. The correlation between NPO index in June-July-August-September and the annual typhoon number in the western North Pacific is 0.37 for the period of 1949―1998. The NPO is correlated with the annual hurricane number in the tropical Atlantic at -0.28 for the same period. The variability of NPO is found to be concurrent with the changes of the magnitude of vertical zonal wind shear, sea-level pressure patterns, as well as the sea surface temperature, which are physically asso- ciated with the typhoons and hurricanes genesis. The NPO associated atmospheric circulation vari- ability is analyzed to explain how NPO is linked with variability of the tropical atmospheric circulation in the western Pacific and the tropical Atlantic, via the atmospheric teleconnection. | WANG HuiJun SUN JianQi FAN Ke | 2007 | Science China Earth Sciences2007，50，9： | 37 |
| 2 | 北京地区五种常见鸣虫的鸣声结构显示文摘本文对寒蝉、蚱蝉、鸣鸣蝉、锐声鸣螽和大扁头蟋五种鸣虫雄虫的鸣声结构进行了较系统的研究。这些昆虫鸣声节律以及声谱和声压的瞬时变化均有显著的不同。一种昆虫的鸣声频谱范围虽然很大,但不同频率的图象却都和主频率的图象一样。 | 何忠 陈念丽 | 1985 | 动物学报1985，34，4： | 32 |
| 3 | Incidence and Risk Factors of Cognitive Impairment 3 Months after First-ever Stroke: A Cross-sectional Study of 5 Geographic Areas of China显示文摘This study examined the incidence, neuropsychological characteristics and risk factors of cognitive impairment 3 months after stroke in China. Five regions that differed in geography and economy in China were selected. Patients from the hospitals located in the five regions were prescreened at admission, and the demographic data, vascular risk factors and clinical characteristics of stroke were obtained. A battery of cognitive-specific domain tests was performed in the patients who failed to pass cognitive screening 3 months post stroke. Patients were diagnosed as having post-stroke cognitive impairment (PSCI) or no cognitive impairment (NCI) based on the results of the neuropsy-chological tests. Univariate analysis was performed for suspect risk factors, and significant variables were entered in multivariable logistic regression analysis. Our results showed that a total of 633 patients were recruited 3 months after stroke; complete cognitive tests were performed in 577 of the stroke pa-tients. The incidence of PSCI in these Chinese patients was 30.7%. There were 129 (22.4%) patients with visuospatial impairment, 67 (11.6%) with executive impairment, 60 (10.4%) with memory impairment and 18 (3.1%) with attention impairment. The risk factors associated with PSCI were older age (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.20-2.58), low education level (OR 2.45, 95% CI 1.65-3.64), depressive symptom (OR 1.69, 95% CI 1.09-2.61), obesity (OR 2.57, 95% CI 1.41-4.71), stroke severity 3 months post stroke (OR 1.62, 95%CI 1.10-2.37) and cortex lesion (OR 1.55, 95% CI 1.04-2.31). It was concluded that PSCI occurs commonly 3 months after first-ever stroke in Chinese patients. Visuospatial ability may be the most frequently impaired cognitive domain for the patients with stroke. The critical risk factors of PSCI are older age, low education level, depressive symptom, obesity, stroke severity 3 months post stroke and cortex lesion. | 张勇 张振馨 杨百渔 李延峰 张蕲 屈秋民 王延平 张世红 岳卫东 谭毓绘 张宝荣 徐涛 | 2012 | Journal of Huazhong University of Science and Technology(Medical Sciences)2012，32，6： | 29 |
| 4 | Self-tuning virtual synchronous generator control for improving frequency stability in autonomous photovoltaic-diesel microgrids显示文摘This paper investigates the use of a virtual synchronous generator(VSG) to improve frequency stability in an autonomous photovoltaic-diesel microgrid with energy storage. VSG control is designed to emulate inertial response and damping power via power injection from/to the energy storage system. The effect of a VSG with constant parameters(CP-VSG) on the system frequency is analyzed. Based on the case study, self-tuning algorithms are used to search for optimal parameters during the operation of the VSG in order to minimize the amplitude and rate of change of the frequency variations. The performances of the proposed self-tuning(ST)-VSG, the frequency droop method, and the CP-VSG are evaluated by comparing their effects on attenuating frequency variationsunder load variations. For both simulated and experimental cases, the ST-VSG was found to be more efficient than the other two methods in improving frequency stability. | Rongliang SHI Xing ZHANG Chao HU Haizhen XU Jun GU Wei CAO | 2018 | Journal of Modern Power Systems and Clean Energy2018，6，3： | 27 |
| 5 | Kinematics Modeling and Experiments of Pectoral Oscillation Propulsion Robotic Fish显示文摘A robotic fish driven by oscillating fins, 'Cownose Ray-I', is developed, which is in dorsoventrally flattened shape withouta tail. The robotic fish is composed of a body and two lateral fins. A three-factor kinematic model is established and used in thedesign of a mechanism. By controlling the three kinematic parameters, the robotic fish can accelerate and maneuver. Forwardvelocity is dependent on the largest amplitude and the number of waves in the fins, while the relative contribution of fin beatfrequency to the forward velocity of the robotic fish is different from the usual result. On the other hand, experimental results onmaneuvering show that phase difference has a stronger effect on swerving than the largest amplitude to some extent. In addition,as propulsion waves pass from the trailing edge to the leading edge, the robotic fish attains a backward velocity of 0. 15 m·s-1. | Shao-bo Yang,Jing Qiu,Xiao-yun HanInstitute of Mechatronical Engineering and Automatization,National University of Defense Technology,Changsha 410073,P.R.China | 2009 | Journal of Bionic Engineering2009，6，2： | 25 |
| 6 | State-of-the-art review on frequency response of wind power plants in power systems显示文摘With an increasing penetration of wind power in the modern electrical grid, the increasing replacement of large conventional synchronous generators by wind power plants will potentially result in deteriorated frequency regulation performance due to the reduced system inertia and primary frequency response. A series of challenging issues arise from the aspects of power system planning,operation, control and protection. Therefore, it is valuable to develop variable speed wind turbines(VSWTs) equipped with frequency regulation capabilities that allow them to effectively participate in addressing severe frequency contingencies. This paper provides a comprehensive surveyon frequency regulation methods for VSWTs. It fully describes the concepts, principles and control strategies of prevailing frequency controls of VSWTs, including future development trends. It concludes with a performance comparison of frequency regulation by the four main types of wind power plants. | Ziping WU Wenzhong GAO Tianqi GAO Weihang YAN Huaguang ZHANG Shijie YAN Xiao WANG | 2018 | Journal of Modern Power Systems and Clean Energy2018，6，1： | 26 |
| 7 | 一种基于聚类的PU主动文本分类方法显示文摘文本分类是信息检索的关键问题之一.提取更多的可信反例和构造准确高效的分类器是PU(positive and unlabeled)文本分类的两个重要问题.然而,在现有的可信反例提取方法中,很多方法提取的可信反例数量较少,构建的分类器质量有待提高.分别针对这两个重要步骤提供了一种基于聚类的半监督主动分类方法.与传统的反例提取方法不同,利用聚类技术和正例文档应与反例文档共享尽可能少的特征项这一特点,从未标识数据集中尽可能多地移除正例,从而可以获得更多的可信反例.结合SVM主动学习和改进的Rocchio构建分类器,并采用改进的TFIDF(term frequency inverse document frequency)进行特征提取,可以显著提高分类的准确度.分别在3个不同的数据集中测试了分类结果(RCV1,Reuters-21578,20 Newsgoups).实验结果表明,基于聚类寻找可信反例可以在保持较低错误率的情况下获取更多的可信反例,而且主动学习方法的引入也显著提升了分类精度. | 刘露 彭涛 左万利 戴耀康 | 2013 | 软件学报2013，24，11： | 23 |
| 8 | Why frequency can no longer be ignored in ELT?显示文摘I begin this paper with a brief survey of how frequency — in particular, frequency of words — had a role in language learning in the days before electronic corpora existed. Then I consider how the 'corpus revolution' made frequency information available in a totally unprecedented way from the 1960s onward. Finally I discuss the usefulness of frequency to the language learner and teacher, and some new directions in applied linguistics favourable to frequency. | Geoffrey Leech | 2011 | 外语教学与研究2011，43，1： | 21 |
| 9 | Intraperitoneal perfusion of cytokine-induced killer cells with local hyperthermia for advanced hepatocellular carcinoma显示文摘AIM:To study the effect and tolerance of intraperitoneal perfusion of cytokine-induced killer(CIK) cells in combination with local radio frequency(RF) hyperthermia in patients with advanced primary hepatocellular carcinoma(HCC).METHODS:Patients with advanced primary HCC were included in this study.CIK cells were perfused intraperitoneal twice a week,using 3.2 × 10 9 to 3.6 × 10 9 cells each session.Local RF hyperthermia was performed 2 h after intraperitoneal perfusion.Following an interval of one month,the next course of treatment was administered.Patients received treatment until disease progression.Tumor size,immune indices(CD3 +,CD4 +,CD3 + CD8 +,CD3 + CD56 +),alpha-fetoprotein(AFP) level,abdominal circumference and adverse events were recorded.Time to progression and overall survival(OS) were calculated.RESULTS:From June 2010 to July 2011,31 patients diagnosed with advanced primary HCC received intraperitoneal perfusion of CIK cells in combination with local RF hyperthermia in our study.Patients received an average of 4.2 ± 0.6 treatment courses(range,1-8 courses).Patients were followed up for 8.3 ± 0.7 mo(range,2-12 mo).Following combination treatment,CD4 +,CD3 + CD8 + and CD3 + CD56 + cells increased from 35.78% ± 3.51%,24.61% ± 4.19% and 5.94% ± 0.87% to 45.83% ± 2.48%(P = 0.016),39.67% ± 3.38%(P = 0.008) and 10.72% ± 0.67%(P = 0.001),respectively.AFP decreased from 167.67 ± 22.44 to 99.89 ± 22.05 ng/mL(P = 0.001) and abdominal circumference decreased from 97.50 ± 3.45 cm to 87.17 ± 4.40 cm(P = 0.002).The disease control rate was 67.7%.The most common adverse events were low fever and slight abdominal erubescence,which resolved without treatment.The median time to progression was 6.1 mo.The 3-,6-and 9-mo and 1-year survival rates were 93.5%,77.4%,41.9% and 17.4%,respectively.The median OS was 8.5 mo.CONCLUSION:Intraperitoneal perfusion of CIK cells in combination with local RF hyperthermia is safe,can efficiently improve immunological status,and may prolong survival in HCC patients. | Xiao-Pu Wang Meng Xu Hong-Fei Gao Jian-Fu Zhao Ke-Cheng Xu | 2013 | World Journal of Gastroenterology2013，19，19： | 20 |
| 10 | 基于有限状态机的RFID流数据过滤与清理技术显示文摘为了实现从大量不可靠、冗余的RFID(radio frequency identification)流数据中提取有效信息,提高RFID系统中数据的质量,提出了一种基于有限状态机的RFID流数据过滤与清理方法.实验结果表明:该方法能够有效过滤系统外标签数据,清理系统内部冗余标签数据,筛选有效标签数据,并能够降低漏读、误读带来的风险.最后,利用地理信息系统的可视化技术,将过滤与清理结果展示在地图上. | 罗元剑 姜建国 王思叶 景翔 丁昶 张珠君 张艳芳 | 2014 | 软件学报2014，25，8： | 20 |
| 11 | General Analytical Solution of Transverse Vibration For Orthotropic Rectangular Thin Plates显示文摘A general solution of differential equation for transverse displacement function of orthotropic rectangular thin plates in free vibration is established in this paper. It can be used to solve the vibration problem of plate with arbitrary boundaries. As an example, the frequencies of a composite laminated plate with four free edges have been solved. The result as compared with the experiment is satisfactory. | HUANG Yan,ZHANG Xiao-jinCollege of Astronautical Engineering, National University of Defense Technology, Changsha, 410073 , China | 2002 | 哈尔滨工程大学学报(英文版)2002，，2： | 17 |
| 12 | Hierarchical microstructures with high spatial frequency laser induced periodic surface structures possessing different orientations created by femtosecond laser ablation of silicon in liquids显示文摘High spatial frequency laser induced periodic surface structures(HSFLs)on silicon substrates are often developed on flat surfaces at low fluences near ablation threshold of 0.1 J/cm2,seldom on microstructures or microgrooves at relatively higher fluences above 1 J/cm^2.This work aims to enrich the variety of HSFLs-containing hierarchical microstructures,by femtosecond laser(pulse duration:457 fs,wavelength:1045 nm,and repetition rate:100 kHz)in liquids(water and acetone)at laser fluence of 1.7 J/cm^2.The period of Si-HSFLs in the range of 110–200 nm is independent of the scanning speeds(0.1,0.5,1 and 2 mm/s),line intervals(5,15 and 20μm)of scanning lines and scanning directions(perpendicular or parallel to light polarization direction).It is interestingly found that besides normal HSFLs whose orientations are perpendicular to the direction of light polarization,both clockwise or anticlockwise randomly tilted HSFLs with a maximal deviation angle of 50°as compared to those of normal HSFLSs are found on the microstructures with height gradients.Raman spectra and SEM characterization jointly clarify that surface melting and nanocapillary waves play important roles in the formation of Si-HSFLs.The fact that no HSFLs are produced by laser ablation in air indicates that moderate melting facilitated with ultrafast liquid cooling is beneficial for the formation of HSFLs by LALs.On the basis of our findings and previous reports,a synergistic formation mechanism for HSFLs at high fluence was proposed and discussed,including thermal melting with the concomitance of ultrafast cooling in liquids,transformation of the molten layers into ripples and nanotips by surface plasmon polaritons(SPP)and second-harmonic generation(SHG),and modulation of Si-HSFLs direction by both nanocapillary waves and the localized electric field coming from the excited large Si particles. | Dongshi Zhang Koji Sugioka | 2019 | Opto-Electronic Advances2019，2，3： | 17 |
| 13 | 频率切片小波变换在爆破振动信号时频特征精确提取中应用显示文摘基于频率切片小波变换(Frequency Slice Wavelet Transform,FSWT)技术研究爆破振动信号时频特征提取新方法。采用FSWT进行爆破振动信号分解,得到在全频带下的时频分布。在此基础上据其时频能量分布,选择时间、频率切片区间进行细化特征分析,通过信号特征频率切片区间信号重构,实现爆破振动时频特征分离及提取。通过与传统的STFT、WPT、WVD等算法进行对比分析表明,FSWT算法具有良好的时频聚集性、任意频带分量特征提取的灵活性及准确性。将FSWT算法引入爆破振动效应分析领域,可为爆破振动信号时频特征精确提取奠定基础,具应用前景较好。 | 郭涛 方向 谢全民 严中红 范磊 | 2013 | 振动与冲击2013，32，22： | 16 |
| 14 | Frequency modulated weak signal detection based on stochastic resonance and genetic algorithm显示文摘Stochastic resonance system is subject to the restriction of small frequency parameter in weak signal detection,in order to solve this problem,a frequency modulated weak signal detection method based on stochastic resonance and genetic algorithm is presented in this paper. The frequency limit of stochastic resonance is eliminated by introducing carrier signal,which is multiplied with the measured signal to be injected in the stochastic resonance system,meanwhile,using genetic algorithm to optimize the carrier signal frequency,which determine the generated difference-frequency signal in the lowfrequency range,so as to achieve the stochastic resonance weak signal detection. Results showthat the proposed method is feasible and effective,which can significantly improve the output SNR of stochastic resonance,in addition,the system has the better self-adaptability,according to the operation result and output phenomenon,the unknown frequency of the signal to be measured can be obtained,so as to realize the weak signal detection of arbitrary frequency. | XING Hongyan LU Chunxia ZHANG Qiang | 2016 | Instrumentation2016，3，1： | 16 |
| 15 | Coherent beam combining of high powerfiber lasers: Progress and prospect显示文摘The recent research progress of coherent beam combining of high power fiber lasers is reviewed. Key technologies like coherently combinable fiber laser, phase control of multiple beams and beam tilling are specially analyzed. Prospects for single coherently combinable high power fiber amplifier, beam tilling and target-in-the-loop control for propagation in real atmosphere are presented. | LIU ZeJin ZHOU Pu XU XiaoJun WANG XiaoLin MA YanXing | 2013 | Science China(Technological Sciences)2013，56，7： | 16 |
| 16 | Design of integrated radar and communication system based on MIMO-OFDM waveform显示文摘Orthogonal frequency division multiplexing(OFDM)waveform enables radar and communication functions simultaneously, which encounters low angle resolution and poor data rate for traditional single input single output(SISO) systems. To solve these problems, an integrated radar and communication system(IRCS) with multiple input multiple output(MIMO) OFDM waveform is proposed. The different limitations of radar and communication in designing such a system are investigated. Then, an optimization problem is devised to obtain suitable system parameters, including the number of subcarriers, subcarrier spacing, number of symbols,pulse repetition frequency(PRF) and length of cyclic prefix(CP).Finally, to satisfy the requirements of both radar and communication, the IRCS parameters are derived in three typical cases.Several numerical results are presented to illustrate the demands of radar and communication, inconsistent or consistent, for the IRCS parameters and the superiority of the proposed system. | Yongjun Liu Guisheng Liao Zhiwei Yang Jingwei Xu | 2017 | Journal of Systems Engineering and Electronics2017，28，4： | 16 |
| 17 | Hanning self-convolution window and its application to harmonic analysis显示文摘The Hanning self-convolution window (HSCW) is proposed in this paper. And the phase difference correction algorithm based on the discrete spectrum and the HSCW is given. The HSCW has a low peak side lobe level, a high side lobe roll-off rate, and a simple spectrum representation. Hence, leakage errors and harmonic interferences can be considerably reduced by weighting samples with the HSCW, the parameter estimation by the HSCW-based phase difference correction algorithm is free of solving high order equations, and the overall method can be easily implemented in embedded systems. Simulation and application results show that the HSCW-based phase difference correction algorithm can suppress the impacts of fundamental frequency fluctuation and white noise on harmonic parameter estimation, and the HSCW is advantageous over existing combined cosine windows in terms of harmonic analysis performance. | WEN He TENG ZhaoSheng GUO SiYu WANG JingXun YANG BuMing WANG Yi CHEN Tao | 2009 | Science China(Technological Sciences)2009，52，2： | 15 |
| 18 | Power system low frequency oscillation monitoring and analysis based on multi-signal online identification显示文摘The advance in the wide-area measurement system (WAMS) is driving the power system to the trend of wide-area monitoring and control.The Prony method is usually used for low frequency oscillation online identification.However,the identified amplitude and phase information is not sufficiently used.In this paper,the amplitude is adopted to detect the occurrence of the oscillation and to obtain the mode observability of the sites.The phase is adopted to identify the oscillation generator grouping and to obtain the mode shapes.The time varying characteristics of low frequency oscillations are studied.The behaviors and the characters of low frequency oscillations are displayed by dynamic visual techniques.Demonstrations on the '11.9' low frequency oscillation of the Guizhou Power Grid substantiate the feasibility and the validation of the proposed methods. | YUAN Ye1,2,SUN YuanZhang2,CHENG Lin2,CHEN Gang2 & WANG Peng3 1 State Nuclear Electric Power Planning Design and Research Institute,Beijing 100032,China 2 State Key Laboratory of Power Systems,Deptment of Electrical Engineering,Tsinghua University,Beijing 100084,China 3 EEE School,Nanyang Technological University,Singapore | 2010 | Science China(Technological Sciences)2010，53，9： | 13 |
| 19 | A New RFID Anti-collision Algorithm Based on the Q-Ary Search Scheme显示文摘Deterministic tree-based algorithms are mostly used to guarantee that all the tags in the reader field are successfully identified, and to achieve the best performance. Through an analysis of the deficiencies of existing tree-based algorithms, a Q-ary search algorithm was proposed. The Q-ary search(QAS) algorithm introduced a bit encoding mechanism of tag ID by which the multibit collision arbitration was implemented. According to the encoding mechanism, the collision cycle was reduced. The theoretical analysis and simulation results showed that the proposed MS algorithm overcame the shortcoming of existing tree-based algorithms and exhibited good performance during identification. | SU Jian WEN Guangjun HONG Danfeng | 2015 | Chinese Journal of Electronics2015，24，4： | 13 |
| 20 | Systematic error analysis and compensation for high accuracy star centroid estimation of star tracker显示文摘Subpixel centroid estimation is the most important star image location method of star tracker. This paper presents a theoretical analysis of the systematic error of subpixel centroid estimation algorithm utilizing frequency domain analysis under the con-sideration of sampling frequency limitation and sampling window limitation. Explicit expression of systematic error of cen-troid estimation is obtained, and the dependence of systematic error on Gaussian width of star image, actual star centroid loca-tion and the number of sampling pixels is derived. A systematic error compensation algorithm for star centroid estimation is proposed based on the result of theoretical analysis. Simulation results show that after compensation, the residual systematic errors of 3-pixel-and 5-pixel-windows’ centroid estimation are less than 2×10-3 pixels and 2×10-4 pixels respectively. | JIA Hui1, YANG JianKun1,2*, LI XiuJian1, YANG JunCai1,2, YANG MengFei2,3, LIU YiWu2 & HAO YunCai2 1 Institute of Technique Physics, Science College, National University of Defense Technology, Changsha 410037, China 2 Beijing Institute of Control Engineering, National Laboratory of Space Intelligent Control, Beijing 100190, China 3 China Academy of Space Technology, Beijing 100094, China | 2010 | Science China(Technological Sciences)2010，53，11： | 12 |
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