具有4个传输零点的源-负载耦合滤波器

为了得到高选择性、小尺寸、低损耗和低成本的射频带通滤波器,提出了一种具有4个传输零点的源–负载耦合滤波器的设计方法.该滤波器采用二分之一波长T形多模谐振器,以减小滤波器尺寸和方便带宽设计.同时,根据信号的多路径传输产生零点原理,在滤波器的输入和输出端口之间加入可控耦合元件,为信号的传输提供多条路径,使得该滤波器可产生4个独立于带宽和中心频率的可控零点.文中最后设计和制作了一个带内最小测量插损为1.4dB、相对带宽为10%、具有4个传输零点的小型微带滤波器,并对其进行了测试,测试结果与仿真结果吻合良好,说明这种设计方法是有效的.     

Undoped semi-insulating indium phosphide (InP) and its applications

During the past several years, the research and development of InP material has made great progress due to serving as the substrate for most optoelectronic devices operating at the communications wavelength of 1.31 and 1.55 μm. At present, InP has become an important semiconductor material together with Si and GaAs. When compared to GaAs, InP has higher electron velocity, higher radiation hardness and better heat-conducting property. The advantage of InP crystal material allows higher frequency operation and lower power requirements. Therefore, InP is widely being used for the manufacture of microwave devices, high-frequency devices and optoelectronic integrated circuits (OEICs) which are indispensable for wireless technology, satellite communications^[1—3]. Although n-type and p-type InP can meet actual needs, semi-insulating InP substrates remain to be improved due to their poor uniformity and consistency. For this reason, several possible approaches have been reported to the preparation of SI InP by wafer annealing under different conditions^[4—9].     

A study on nano-sized NiO electrodes doping with C and Co prepared by electrochemical deposition-sintering processes and their capacitance performance

In the present work, it was studied that nanoosized NiO electrodes doping with C and Co were prepared by electrochemical deposition in an ethanol solution containing nickel nitrate and cobalt nitrate and sintering processes. The capacitance performance of such electrodes was also studied. The results reveal that samples obtained by electrochemical deposition first on a porous nickel cathode in an ethanol solution contain 0.5 mol/L nitrates, in which Ni(NO3)2 and Co(NO3)2 were mixed in a molar proportion of 8 : 2. After sintering at 300℃ for 2 h, they exhibited the best performance. XRD analysis illustrates that the essential phase of the product is NiO doping with certain content of C and Co. The particles of product imaged a spherical morphology with sizes of 20---30 nm in diameter, and with an average crystal size of 4--5 nm. The capacitance measurement of the simulating C/NiO capacitors indicates that a single electrode can reach as high as 410.0 F/g, and still maintain the value of 323 F/g after 30 recycles showed as a stabilized value with increasing recycles, when it was discharged at a current of 5 mA.     

一种新的量化Markov跳变网络化系统的分析与设计

为了研究一类具有信号量化的随机网络化控制系统,采用时变量化器建立该系统的随机动态数学模型.利用Lyapunov稳定性理论,结合线性矩阵不等式(LMI)技术对随机系统进行稳定性分析和控制器设计,最终给出了指数稳定性判据,并进一步设计相应的时变量化状态反馈控制器.分析和处理过程中,通过引入新的Lyapunov函数,利用矩阵...     

人力资本与剩余劳动力转移

我国的劳动力剩余问题具有特殊的表现形式：一方面我国劳动力数量充足，低素质的劳动力大量剩余；另一方面。高素质的劳动力极其短缺。人力资本短缺是我国劳动力结构性剩余的最根本原因，分析人力资本与经济发展、产业结构调整、科学技术水平提高的关系及其各自对劳动力就业的影响，以人力资本投资为核心，充分合理地利用人力资本，成为促进我国剩余劳动力转移的必由之路。     

SHRIMP zircon U-Pb ages of Kalatongke No. 1 and Huangshandong Cu-Ni-bearing mafic-ultramafic complexes,North Xinjiang,and geological implications

In Xinjiang, northwestern China, there are some veryimportant magmatic Cu-Ni sulfide deposits hosted by ma-fic-ultramafic complexes. In addition to the Jingbulake inwestern Tianshan and the Xingdi in northeastern Tarimblock, the others are concentrated in the Kalatongke andHuangshan-Jingerquan mafic-ultramafic complex beltsand two largest Cu-Ni sulfide deposits occur in the Kala-tongke No.1 and Huangshandong complexes. In the pastdecade, a great number of researches have been conductedfo…     

具有复O－正则拟单调系数的Fourier级数L~1－收敛

本文把文［１］的一个具有复拟单调系数的Ｆｏｕｒｉｅｒ级数Ｌ１－收敛的充要条件推广到具有复Ｏ－正则拟单调系数的Ｆｏｕｒｉｅｒ级数上，所得的结果推广了文［１］和［５］的主要结论．     

地理和地形影响下我国区域的气温空间分布

不同于以往基于最小二乘的多元线性回归方法,本文将新型的第二代回归分析方法一偏最小二乘回归分析方法应用到中国区域气温空间分布的建模中．利用区域内394个气象观测站建站到2000年45年（及以上）的逐日气温资料,建立了一个简洁的年、季平均气温和地理、地形因子（包括纬度、经度、地形高程、坡度、坡向和遮蔽度）的关系模型,估算了区域地理、地形影响下气温的空间分布,并分析了这种影响的特征．结果表明,此模型具有88％的平均拟合能力,平均相关系数达到0．94,经交叉有效性检验,模型的回归效果较显著．分析表明,在多元线性回归不适用的情况下,本文基于偏最小二乘法的简单模型能够准确地再现我国实际气温的空间分布,具有一定的使用价值．     

基于SWAT的涟水河上游流域非点源污染模拟

以涟水河娄底水文站上游流域为研究区域,应用SWAT模型对该区域的径流、泥沙及非点源氨氮、总磷污染负荷进行模拟计算.将1998年设置为模型启动期,即＂模型预热＂,利用娄底水文站1999～2002年的实测月径流、氨氮及总磷的实测数据进行模型参数确定,运用2003～2005年实测的月径流、氨氮及总磷数据对调参后的模型进行模型验证,验证结果表明模型基本合理可行,可用于涟水河上游流域的非点源污染模拟计算.运用率定后的模型,去除点源污染,重新进行模拟得到最终的非点源污染氨氮、总磷.根据模拟结果对该区域的径流、泥沙、氨氮及总磷污染负荷的时空分布特点进行了分析,为涟水河娄底水文站上游流域非点源污染的综合防治规划提供了参考和依据.     

Distribution of lanthanum among the chloroplast subcomponents of spinach and its biological effects on photosynthesis： location of the lanthanum binding sites in photosystem Ⅱ

The effects of lanthanum at different concentrations on the related photosynthetic activities of Hill reaction, Mg^2＋-ATPase and Ca^2＋-ATPase in spinach chloroplast were studied. Experimental results showed that lanthanum can increase all the activities at suitable concentration （15-30 mg· L^-1）, however, it behaves toxically on them when over used （60 mg. L^-1）. To get an improved understanding of the mechanism of lanthanum effects on the photosynthesis of spinach, the different subcomponents in the chloroplast of the cultured spinach were isolated, and the content of lanthanum in each subcomponent was determined by ICP-MS. The results obtained indicated that among these different subcomponents, about 90% out of the total chloroplast lanthanum was located in photosystem Ⅱ （PS Ⅱ） while there was little lanthanum in photosystem Ⅰ （PS Ⅰ）. Moreover, size exclusion high performance liquid chromatography （SE-HPLC） coupled with online UV and ICP-MS detections was novelly used for locating lanthanum binding sites in PS Ⅱ proteins for the first time. It was found that lanthanum has two binding sites in PS Ⅱ： La associates with chlorophyll together with magnesium in PS Ⅱ by partly replacing magnesium and also shares the common binding sites of PS Ⅱ proteins together with the inorganic cofactors of calcium and manganese, influencing the process of photosynthesis.