Design of Electrical Downtilt Broadband Patch Antenna

针对室内壁挂基站应用要求,采用对称角形缝隙加载正方形贴片,实现具有电下倾辐射特性的低剖面宽带贴片天线结构。实验结果表明,设计天线S11参数小于-10db的相对阻抗带宽为5.15%。在工作频带内,天线辐射场可产生约30°的下倾角。并且可通过馈电位置的改变,实现辐射场下倾角的调整。水平平面辐射方向图表明,在120°范围内,其垂直极化辐射场要比水平极化高10db以上,表明天线具有良好的垂直线极化特性。工作频带内天线的增益约为6dbI。该天线可内置于壁挂基站以减小设备尺寸。To meet the requirements of electrical downtilt beam patterns and broad bandwidth for the indoor wallmounted base-station antennas,a symmetrically right-angled slot is loaded into the low-profile square patch antenna.The experimental results show that the relative impedance bandwidth with the parameter S11less than-10dB is 5.15% for the designed antenna.Over the operating frequency band,the electrical downtilt of radiation beams is about 30°.Meanwhile the downtilt can be adjusted by changing the feed position.In the angle range 120° of the horizontal plane pattern,the radiation level of the vertically polarized electric field is 10dB higher than the horizontal polarization,which indicates that the antenna has the radiation characteristics of vertically linear polarization.Over the working band the antenna gain is about 6dBi.The presented antenna can be built into the wall-mounted base station to reduce the device size.福建省重大科技专项(2010HZ0004-1

Relationship between Depression,Anxiety and Cardiac Events after Coronary Artery Bypass Grafting

目的:前瞻、序列、对比研究我科行冠状动脉旁路移植术(coronary artery bypass grafting,CABG)的患者术后1年抑郁、焦虑的状况以及心血管事件的发生率。方法:2005年10月至2006年8月,以我科连续行择期CABG术的69例患者为对象,分别在术前1周内、术后出院前1天、术后1年使用ZUNG氏抑郁自评量表和焦虑自评量表进行抑郁、焦虑状态评分,同时随访术后1年的心血管事件的发生率。结果:术前24例(34.8%)存在抑郁焦虑状态,出院前33例(47.8%)存在抑郁焦虑状态,术后1年随访时10例(14.5%)存在抑郁焦虑状态。术后1年随访时共有6例(8.7%)患者发生心血管病事件,其中5例再次入院。术前存在抑郁焦虑的患者与不存在抑郁焦虑的患者相比:术后住院时间延长[(19±8)dvs.(16±6)d,P=0.003],容易出现伤口并发症(3/24vs.0/45,P=0.039),出院前和术后12月随访时不良情绪的发生率较高(分别为75%vs.33%,P=0.001;29%vs.7%,P=0.017);随访时存在抑郁焦虑的患者与不存在抑郁焦虑的患者相比:术前和术后发生心律失常更多见(3/1..

Fatty acid composition of three species of marine microalgae during growth phases

球等鞭金藻、盐藻和小球藻脂肪酸组成气相色谱分析的结果表明 ,三种海洋微藻在指数生长期总多不饱和脂肪酸含量 (TPUFA)明显比稳定生长期高 ,而总饱和脂肪酸含量 (TSFA)在指数生长期间相对较低。球等鞭金藻的DHA ,小球藻的EPA和盐藻的C18∶3均在培养后的第 6d均达最大值。GC determination of fatty acid composition of Isochrysis galbana, Chlorella sp. and Dunaliella salina showed that TPUFA of the three species of microalgae in exponential phase were higher than those in stationary phase, otherwise, TSFA were relatively lower in exponential phase. DHA of Isochrysis galbana, EPA of Chlorella sp. and C18∶3 of Dunaliella salina were all the maximum at sixth day during cultural period.国家自然科学基金资助项目 (39870 5 6 5 ) ;; 福建省自然科学基金资助项目 (C970 0 6

Impact of sleep duration on cognitive functions among preschoolers

目的:探讨学龄前儿童白天睡眠以及晚上睡眠对其注意力、记忆力以及语言能力等认知能力的影响。方法:采用皮博迪图片词汇测验、图片划销测试以及空间工作记忆任务对杭州和北京的94名学龄前儿童的认知能力进行测试,并采用自编问卷调查儿童的人口学相关情况以及白天和晚上的睡眠情况。结果:学龄前儿童白天睡眠时长以及总睡眠时长的年级差异有统计学意义(F0.05(3,90)=6.346,P=0.001;F0.05(3,90)=2.925,P=0.038),晚上睡眠时长差异无统计学意义。晚上睡眠时长以及总睡眠时长与儿童的注意力和工作记忆广度呈显著正相关(r=0.202~0.282),与语言能力的相关差异无统计学意义。白天睡眠时长与各认知测试的得分相关均无统计学意义。回归分析结果显示,总睡眠时长对儿童的注意力以及工作记忆广度有较好的预测作用,进一步分析显示,晚上睡眠时长对儿童的注意力以及工作记忆广度有较好的预测作用。结论:总睡眠时长尤其是晚上睡眠时长可能影响学龄前儿童的注意力以及工作记忆等认知能力

自适应光学对大气扰动波前的补偿效果研究：II.水平大气传输时…

讨论了光波在水平大气湍流中传输时的情况。计算结果表明自适应光学系统的补偿效果与光波传播路径上的横向风有很大的关系。大气湍流的强度越大, 自适应光学系统的截止频率越高, 横向风的影响也越大。计算结果还表明在相同的r0 或者相同的大气湍流强度下, 球面波所受大气扰动的自适应光学补偿效果受横向风的影响要比平面波的厉害。本文还将理论分析的结果和数值模拟的结果进行了比较, 表明数值模拟结果受横向风的影响比理论分析结果受横向风的影响大。最后, 文中分析了以上现象并对此作出了合理的解释

农村留守经历大学生成人依恋及影响因素分析

目的探讨农村留守经历大学生(URLB)成人依恋现状及其影响因素。方法采用亲密关系体验问卷及自编问卷对河北省2所高校1062名有农村留守经历的大学生进行自填式问卷调查。结果成人依恋回避和依恋焦虑维度平均得分分别为(4.16±0.53),(3.82±0.82)分;多元线性回归分析表明,性别(β=0.236)及与父母联系频次(β=0.073)为URLB依恋回避的影响因素;性别(β=0.079)、留守家庭生活满意度(β=-0.074)、开始留守时间(β=-0.12)及与抚养人沟通情况(β=0.066)为URLB依恋焦虑的影响因素。结论性别以及童年期的留守经历对URLB成人依恋的发展有影响

农村留守经历大学生心理行为与人际关系分析

目的探讨农村留守经历大学生(URLB)心理行为特征以及与非URLB心理行为上的差异,为采取干预措施提供依据。方法采用流调中心用抑郁量表、状态特质焦虑问卷、简易应对方式问卷、自尊量表和大学生人际关系综合诊断量表对河北省2所高校的4080名大学生进行问卷调查。结果 URLB大学生负性情绪、积极应对方式、自尊和人际关系与非URLB大学生差异有统计学意义。相关分析表明,URLB大学生负性情绪、消极应对方式与人际关系呈显著正相关,积极应对方式、自尊与人际关系呈显著负相关。回归分析表明,URLB大学生负性情绪、应对方式和自尊对人际关系有显著的预测作用。结论 URLB与非URLB大学生在心理行为上差异有统计学意义,需要对URLB进行适当的心理干预

基于IPAT模型的福建环境效率定量测评

随着人们对资源和环境问题的关注逐渐加强,如何对这些问题进行定量分析成为一个重要的课题。其中一个很重要的方面,就是在现行的发展模式下,按照经济规划的发展要求,

Design of Ultra-wideband Printed Rectangular Monopole Antenna

针对超宽带通信应用,研究影响印制单极天线阻抗带宽的主要因素,设计基于微带馈电的小型化印制矩形单极天线。按照等效性原理,采用黄金分割比设计矩形振子体;通过接地面上端引入渐变梯形或凹形结构,同时调整馈入端接地面间隙,可实现印制矩形单极天线的超宽带特性。对具有渐变梯形或凹形接地面结构的微带馈电矩形印制单极天线结构进行优化,仿真结果表明,前者的阻抗带宽为2.96~17.94gHz,后者的阻抗带宽为2.9~13.3gHz,而两者的辐射方向基本保持不变。实测结果与仿真结果基本一致,达到了超宽带通信应用的要求。To achieve ultra-wideband(UWB)radio applications,the microstrip-fed printed rectangular monopole antenna is analyzed and devised.Using golden section ratio the rectangular monopole is of layout based on equivalent principle.To maximize the impedance bandwidth,it is necessary introducing the taper or concave ground plane and feed gap of microstrip line.The simulated results of the optimized-size antennas show that the impedance bandwidth defined by return loss less than-10dB is from 2.96GHz to 17.94GHz with a ratio of about 6.06∶1 for taper ground antenna and from 2.9GHz to 13.3GHz with a ratio of about 4.59∶1 for concave ground antenna.At the same time a nearly omnidirectional radiation pattern is exhibited.These results are confirmed by the experimental test and these compact size antennas are suitable for various wideband applications.福建省科技计划重点资助项目(2007H0036

THE RELATIONSHIP OF INFERIORITY BETWEEN SOCIAL SUPPORT AND MENTAL HEALTH AMONG ADOLESCENTS WITH INTERNET ADDICTION DISORDER

目的:探讨网络成瘾青少年的自卑与其社会支持﹑心理健康的关系。方法:82例符合网络成瘾诊断标准的住院青少年参与了自卑感量表﹑社会支持评定量表﹑症状自评量表测试。结果:(1)自卑与社会支持呈显著性负相关(r=0.233-0.445,PObjective： To explore the relationship of inferiority between social support and mental health among adolescents with Internet addiction disorder（IAD）.Methods：Eighty two in-patient adolescents who met IAD diagnostic criteria were assessed using the Feelings of Inadequacy Scale（FIS）,Social Support Rating Scale（SSRS） and Symptom Checklist-90（SCL-90）.Results：（1） The inferiority was significantly negatively correlated with social support（r=-0.233-0.445,P0.05）.（2） The inferiority was significantly positively correlated with mental health（r=0.226-0.411,P0.05）.（3） The interpersonal relationship factor,availability of social support,objective support and depression factor had important predictive effects on each factor of inferiority,respectively（R2=0.127-0.314）.（4） The physical inferiority,overall inferiority and self-esteem inferiority had positively predictive effects on the factors of compulsive,depression,anxiety,psychosis and others including eating and sleeping（R2=0.094-0.169）.Conclusion：Social support and mental health have significant interaction influences with inferiority in adolescents with IAD