基于双输出电流传输器的模拟浮地电感

由于电感不易集成，利用有源器件模拟电感一直是研究的热点．本文提出了一种新的模拟浮地电感，分析了该电感在理想情况和考虑有源器件非理想特性情况下的电感值，并把它应用到椭圆滤波器中．PSPICE仿真证实了此模拟浮地电感符合设计要求．该电感仅由2个第二代正电流传输器(简称CCⅡ )，1个双输出电流传输器(简称DOCCⅡ)和2个电阻，1个电容组成，结构简单；电感值可由无源元件参数控制．     

一种多尺度纹理主频的检测与分割

介绍了一种对含有多种纹理结构的图像的纹理主频检测——香农小波包分解的纹理主频检测 ,然后利用 Gabor滤波器确定主频 ,最后应用边缘提取实现纹理分割     

重视语言教与学中的“情感过滤”

本文在简要论述什么是第二语言习得及二语习得理论对语言教师实践的重要意义的基 础上，着重探讨了二语习得中情感因素的研究成果，特别是“情感过滤”现象的存在对外语教与学的启示。     

Shunt Active Power Filiter for Harmonic Compensation in DC Side of HVDC Transmission System

A shunt active power filiter(APF) used for harmonic treatment isintroduced in this paper. Basic circuit-theory and main configuration are analyzed. Control scheme and its realization are discussed. Computer simulation is used to verity theoretical analysis. It shows that APF is an interesting alternative for hasmonic treatment compared with conventional passive filter.     

Effect of Filter on Exit-age Distribution Function

Exit-age experiments have been carried out on the same reactor with and without filter. The effects of filter on exit-age distribution function have been studied. The specific formula of exit-age distribution function for the reactor with filter is: E(t)=f_1E_1(t)+(1-f_1)E_2(t)+E_3(t). In this formula,E_3(t) is a factor considering the filter effect on reactor.     

畜禽粪便堆肥养分释放及其合理施用

本文采用室内培养法和田间埋设玻璃滤纸包法研究了粉状畜禽粪便堆肥和颗粒堆肥的养分释放。结果表明,粉状堆肥经颗粒化处理后,养分释放速度变缓,适合在生长期较长的农作物上施用。在一个生长季中牛粪、猪粪和鸡粪颗粒堆肥N素释放率分别为30～35%,35%～45%和45～55%,但其中60～80%的N素释放主要集中在施用后的前二个月内。     

基于拖拉机作业轨迹的农田面积测量

为了精确测量拖拉机在农田作业时的作业面积,以评价拖拉机的作业效率。该文选用双星定位(GPS卫星和伽利略卫星)接收机采集定位数据,采用自适应卡尔曼滤波算法提高接收机单点定位精度,利用高斯投影算法将GPS接收机采集经纬度转化成平面坐标来计算面积。选用回耕法、梭形耕法、套耕法3种方法旋耕地块,利用安装拖拉机上的GPS识别出作业轨迹,利用图像处理计算3种方法的有效作业面积、实际作业面积和重漏耕面积。试验表明:卡尔曼滤波提高了GPS单点定位精度;面积测量相对误差为2.09%;地块1(回耕法)漏耕率为14.29%,重耕率为6.19%,地块2(梭形耕法)漏耕率为10.72%,重耕率为5.54%,地块3(套耕法)漏耕率为1.80%,重耕率为6.82%。随测量面积增加,测量精度越高;套耕法效率最高,梭形耕法其次;回耕法的漏耕率最大,作业效率最低。     

Image denoising using HMT in PDTDFB domain

Based on the dependency of the PDTDFB coefficients across the interscale and interdirection and the statistical properties of HMT for the correlation properties, a new HMT in PDTDFB domain was put forward. Compared with the other typical denoising methods, the experimental results demonstrate that the proposed method shows better performance in image denoising, especially in edge maintenance.     

Substrate integrated waveguide bandpass filter based on butterfly radial slot

A novel broadband substrate integrated waveguide bandpass filter was presented based on the highpass characteristics of substrate integrated waveguide(SIW) and the bandstop performance of butterfly radial slot photonic band gap(PBG) structure. In order to verify this idea,a wideband bandpass filter with 4.65 GHz center frequency and 40% fractional bandwidth was designed. The electromagnetic simulation results show good passband characteristics from 3.71 to 5.6 GHz, while the maximun insertion loss is about 0.40dB. An experimental filter prototype was fabricated with standard PCB process and measured by the vector network analyzer. The measured results show that, for the filter prototype, the passband is from 3.78 GHz to 5.76GHz, the fractional bandwidth is about 41%, the minimal insertion loss is about 0.72 dB and the maximun insertion loss is 1.65.dB The measured results are in good agreement with the simulated results.     

蚯蚓生物滤池处理城市污水初步试验

蚯蚓生物滤池(VBF)污水处理工艺是一种新型的污水处理技术,它具有处理工艺简单、处理效果好、规模灵活、二次污染少等优点。本文介绍了利用蚯蚓生物滤池处理城市生活污水初步试验的结果,当表面水力负荷为1m3/(m2·d)时,以细木屑、泥炭、石英砂为滤料,污水的CODCr去除率为72.4%;BOD5去除率为72.8%;SS去除率为90.5%。以粗木屑、泥炭、石英砂、谷壳为滤料,污水的CODCr去除率为80.5%、BOD5去除率为87.5%、SS去除率为93.2%。