夯实基础 做好初高中英语衔接教学

阐述了如何夯实基础,做好初高中英语教学的衔接工作。     

论二阶电路的谐振频率

本文在二阶电路传输函数的基础上讨论了它的固有频率与输出响应峰值频率的关系和固有频率与输入电流电压同相频率关系,发现二阶电路的谐振频率不是零输入电抗的频率,而是它的固有频率．但在调谐实践中以输出响应的峰值频率作为谐振指示是合适的．     

MINIMAL INVERSION AND ITS ALGORITHMS OF DISCRETE-TIME NONLINEAR SYSTEMS

The left-inverse system with minimal order and its algorithms of discrete-time nonlinear systems are studied in a linear algebraic framework. The general structure of left-inverse system is described and computed in symbolic algorithm. Two algorithms are given for constructing left-inverse systems with minimal order.     

Effect of Mg substitution for La on microstructure, hydrogen storage and electrochemical properties of La1−xMgxNi3.5 (x=0.20, 0.23, 0.25 at%) alloys

The effect of Mg substitution for La on microstructure, hydrogen storage and electrochemical properties of the annealed La_(1-x) Mg_x Ni_3.5(x=0.20, 0.23, 0.25 at%) alloys have been studied. All the samples were mainly composed of(LaMg)_2Ni_7,(LaMg)Ni_3, and LaNi_5 phases. Mg substitution for La changed the phase abundance, but did not change the constitution of all phases, which is con fi rmed by the results of backscattered SEM images and EDS analysis. The P–C isotherms indicated that the La_(1-x) Mg_x Ni_3.5alloys reversibly absorbed and desorbed hydrogen smoothly at 298 K. The hydrogen absorption cyclic stabilities of La_(1-x) Mg_x Ni_3.5alloy after 5 hydrogen absorption/desorption cycles reached the maximum values of91.9% and 96.0% at 298 K and 323 K, respectively. The hydrogen desorption capacity and plateau pressure for the La_(1-x) Mg_x Ni_3.5alloy reached the maximum values of 1.055 H/M and 0.074 MPa, respectively. The desorption capacities of La_(1-x) Mg_x Ni_3.5reached 0.193 H/M and 0.565 H/M in the fi rst minute at 298 K and 323 K, respectively. Electrochemical property measurement indicated that La_(1-x) Mg_x Ni_3.5(x=0.20,0.23, 0.25 at%) alloys possessed excellent activation capability and were completely activated within3 cycles. Discharge capacities of La_(1-x) Mg_x Ni_3.5alloys reached 378.2 m A h/g(x = 0.20 at%), 342.7 m A h/g(x = 0.23 at%), and 369.6 m A h/g(x = 0.25 at%), respectively. Moreover, energy density of La_(1-x) Mg_x Ni_3.5alloy was much larger than that of La_0.80Mg_0.20Ni_3.5 alloy and nearly approaches the maximum value of La0.75Mg0.25Ni3.5. Thus, the La_(1-x) Mg_x Ni_3.5alloy exhibits optimum comprehensive properties of hydrogen storage and electrochemistry.     

通信辐射源运动轨迹相似性分析

针对传统运动轨迹相似性分析利用时空信息效率不高问题,结合通信辐射源主体特点,提出基于时空和语义信息的辐射源轨迹相似性分析算法。在该算法中,对相似运动轨迹距离测度进行改进,提出基于马氏距离的轨迹时空相似度算法,将轨迹分割后计算相似度,克服了时间不匹配轨迹和不同采样间隔对轨迹相似性判断的影响;同时,结合基于高效K近邻(K-nearest neighbor, KNN)相似搜索的语义相似数据搜索算法,实现对辐射源相似轨迹的准确判断。该算法能够准确判断相似轨迹,优于现有的相似轨迹判断方法,且适应噪声环境。仿真实验结果验证了该算法的性能。     

模拟电路双重故障的单端检测

模拟电路的Ｋ故障检测,初时要求测量点ｍ＝ｋ＋１,随后减至ｍ＝ｋ。本文中提出的双重故障（ｋ＝２）检测方法,只需要一个测量点（ｍ＝１）、在两个频率下进行测量,通过广义逆矩阵求解偏差方程,就可确定两个故障元件。若两个并联的阻抗元件同时发生参数偏差,方法仍然有效。     

灵巧式机械手研究现状综述

灵巧式机械手作为肢体的延伸可有效协助人类完成各类场合抓取动作。首先对机器人灵巧式机械手发展历程进行概括。总结出近10年灵巧式机械手发展成果,将灵巧式机械手按照特点和传动形式分类,并进行了性能分析。接着,对灵巧式机械手应用的关键技术进行总结概述。最后,对灵巧式机械手在新材料应用、智能协同化作业以及微动控制技术等方面的未来发展趋势进行了讨论。     

ON LOCAL STABILIZATION OF NONLINEAR CONTROL SYSTEMS

Based on the notion of maximal absolute observability and its normalforms,a new method for studying the local stabilization for a kind of nonlinearcontrol systems is established.Different from the previous results given by Byrnes-Isitori and others,this new method can deal with more general systems,and hasmuch simpler way to prove the stabilization conditions and to design the feedbacklaws.     

甘薯新品种“渝薯34~丰产的密肥模式研究

介绍了对甘薯新品种“渝薯３４”种植密度和施肥的试验结果，在一般条件下，“渝薯３４”的适宜种植密度为：春薯７５０００株／ｈｍ￣２，夏薯８２５００株／ｈｍ￣２，秋薯９００００株／ｈｍ￣２．其施肥模式是：栽插后１０ｄ施清粪水１５０００ｋｇ／ｈｍ￣２和尿素７５ｋｇ／ｈｍ￣２，栽插后５０ｄ施清粪水２２５００ｋｇ／ｈｍ￣２．栽插后９０ｄ施清粪水２２５００ｋｇ／ｈｍ￣２和草木灰１５００ｋｇ／ｈｍ￣２．     

DESIGN OF NONLINEAR OBSERVERS

ＤＥＳＩＧＮＯＦＮＯＮＬＩＮＥＡＲＯＢＳＥＲＶＥＲＳ￥ＺＨＥＮＧＹｕｆａｎ；ＣＨＥＮＳｈｕｚｈｏｎｇ（ＡｐｐｌｉｅｄＭａｔｈｅｍａｔｉｃｓＲｅｓｅａｒｃｈＬａｂｏｒｕｔｏｒｙ，ＥａｓｔＣｈｉｎａＮｏｒｍａｌＵｎｉｖｅｒｓｉｔｙ，Ｓｈａｎｇｈａｉ２００...