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.     

A fuzzy logic multicasting algorithm for ad hoc networks

To increase the multicasting efficiency of Ad hoc networks, a fuzzy logic multicasting algorithm (FLMA) is proposed. FLMA adopts the fuzzy logic to tolerate the imprecise information caused by dynamic network topology. The two input variables of the fuzzy logic system are the relative degree of the additional coverage node number and the relative degree of the residual energy. The deferring time of rebroadcast is the output variable of the fuzzy logic system, which is used to optimize the priority of the nodes to rebroadcast. FLMA reduces the redundant retransmission and the chance of the contention and collision, while balances the energy consumption of the nodes. Simulation results reveal that the FLMA achieves better performance than BCAST in terms of the network lifetime, average end-to-end delay, the average number of drops per node and the throughput.     

胆碱在奶牛生产中的研究与应用

胆碱作为一种B族维生素对反刍动物高产的潜在效益已引起人们的关注。文章综述了近年来胆碱的应用理论与研究进展,包括胆碱的生物学功能以及在反刍动物体内的消化、吸收、代谢和保护性胆碱在奶牛日粮中的应用功效等。     

猪凝血酶的亲和层析纯化及其酶原的激活研究

采用柠檬酸钡作吸附剂、ＥＤＴＡ溶解的方法从猪血浆提取凝血酶原，建立了凝血酶原激活的简单方法。并以环氧氯丙烷活化的Ｓｅｐｈａｒｏｓｅ４Ｂ为载体，采用１－乙基－３－（３－二甲氨丙基）碳二亚胺进行肝素的固定化，将固定化肝素用于猪凝血酶的亲和层析纯化。结果表明，通过一步亲和层析将猪凝血酶粗品提纯了８．２倍，获得了比活超过１１００Ｕ／ｍｇ的凝血酶，收率为６０％。     

江都市发展高效农业促进农村发展

近年来,江苏省江都市突出花木、蔬菜、特水特禽养殖、优质稻米生产等高效农业发展,加快结构调整步伐,取得了明显成效。但在农业结构调整和高效农业发展过程中,也存在着一些不足,面临着一些亟待解决的困难和问题。对此,应该正视存在的困难和问题,迎难而上,把结构调整和高效农业的发展提升到一个新的水平。     

木质石膏刨花板的研制

本文主要是对采用福建树种——马尾松与南方阔叶材为原料制造石膏刨花板的工艺进行探讨,并且通过试验确定了较佳的工艺参数。采用优化后的工艺参数所制得的石膏刨花板,其物理力学性能达到了国外同类产品的指标。     

景泰灌区土壤次生盐渍化浅析

本文研究了景泰灌不同含盐量土壤次生盐渍化的形成和灌水前后土壤盐分的变化,总结出灌区土壤返盐和脱盐过程与灌水周期、作物种类、耕作管理等条件的关系,初步提出封闭型氯化物—硫酸盐盐土的水利防治措施。     

水稻新品种“南京14”对病虫的多抗性研究

 经3年鉴定，中籼稻新品种南京14抗白叶枯病，抗稻瘟病中D#-3、中E#-3、中F#-1和中G#-1小种，抗褐稻虱，中抗白背稻虱，而且抗性稳定。在江淮稻区种植获得高产，且农药使用减少，有利无公害稻谷生产。     

珍珠鸡对马立克氏病抗性的研究

1日龄珍珠鸡和黄鸡经腹腔用马立克氏病毒攻击.攻毒后的黄鸡作为阳性对照,未攻毒珍珠鸡作为阴性对照。隔离饲养10周,珍珠鸡对马立克氏病产生抵抗力:(a)攻毒珍珠鸡和未攻毒珍珠鸡在增重和饲料转化率上均无明显差异(p>0.05);(b)攻毒珍珠鸡未发病和死亡,黄鸡组死亡率为50%;(c)攻毒珍珠鸡未见到任何肉眼病变;(d)羽囊琼脂扩散沉淀试验表明,所有珍珠鸡均阴性,黄鸡组阳性率达100%。     

黄地老虎发生程度中长期预测预报技术的研究

本文论述了利用冬前主要越冬场所平均越冬虫口基数,当年1月份平均气温,当年3月中旬至4月中旬的温湿度系数3个因子,用权重列联比预报法,对当年第一代黄地老虎的发生程度进行中长期预测预报。本方法具有取得资料容易,预报准确率高等特点。