275 research outputs found

    Design of Electrical Downtilt Broadband Patch Antenna

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    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

    Mechanism Study of the Promoting Action of Elongated Needle Acupuncture on Functional Repair in Rats with Acute Spinal Cord Injury

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    目的 观察芒针对急性脊髓损伤炎症反应和神经细胞凋亡的影响,研究PI3K/Akt和MAPK/ERK信号转导途径是否参与芒针的神经保护作用,探讨芒针促脊髓损伤修复的具体作用机制.方法 将150只成年雄性SD大鼠随机分为A组、B组、C组、D组和E组,每组30只.采用改良Allen's法制作大鼠脊髓中度损伤模型,A组为假手术组,不予以损伤脊髓及芒针治疗;B组造模后不予以芒针治疗;C组造模后采用芒针治疗;D组造模前0.5 h鞘内注射LY294002,造模后采用芒针治疗;E组造模前0.5 h鞘内注射PD98059,造模后采用芒针治疗.分别采用BBB评分检测大鼠的自发活动;ELISA检测炎性因子TNF-α 、IL-6、IL-1β、NF-κB的含量;TUNEL检测细胞凋亡的程度;免疫组化检测Bcl-2和Bax阳性细胞水平;Western印迹分析p-Akt和p-ERK在脊髓组织的表达,RT-PCR分析Cyt-C和Caspase-3在体内的表达.相对的下行Akt和ERK信号通路通过LY294002和PD98059特异性抑制剂处理分析在体内的抑制作用.结果 炎症反应和PI3K/Akt和MAPK/ERK信号通路抑制的神经元凋亡参与了脊髓损伤大鼠模型的损害,芒针介导的神经保护作用与Bax蛋白阳性神经元数目的减少及Bcl-2蛋白阳性神经元数量的增加有关.芒针治疗能改善大鼠的运动功能,PI3K/Akt和MAPK/ERK信号通路中p-Akt和p-ERK的激活,通过下调Bax蛋白和Bcl-2表达上调,抑制了线粒体凋亡途径关键因子Cyt-C的表达.TUNEL法检测并抑制激活神经元凋亡的Caspase-3的级联.PI3K/Akt和MAPK/ERK信号通路特异性抑制剂LY294002和PD98059的应用抑制了p-Akt和p-ERK的表达.结论 芒针促脊髓损伤修复的神经保护作用可能与炎症反应和PI3K/Akt和MAPK/ERK信号通路的激活、通过下调Bax蛋白和Bcl-2表达上调以及抑制线粒体途径诱导的凋亡有关.Objective To observe the effect of elongated needle acupuncture on inflammatory reactions and apoptosis in acute spinal cord injury, investigate if PI3K/Akt and MAPK/ERK signal transduction pathways are involved in the neuroprotective effect of elongated needle acupuncture and explore the promoting action of elongated needle acupuncture on spinal cord injury repair.Method One hundred and fifty adult male SD rats were randomized into groups A, B, C, D and E, 30 each. A model of moderate spinal cord injury was made by modified Allen's method. Group A received a sham operation without spinal cord injury and no elongated needle acupuncture. Group B did not receive elongated needle acupuncture after model making. Group C received elongated needle acupuncture after model making. Group D received an intrathecal injection of LY294002 at 0.5 hour before model making and elongated needle acupuncture after model making. Group E received an intrathecal injection of PD98059 at 0.5 hour before model making and elongated needle acupuncture after model making. Rat spontaneous activity was examined using the BBB rating. Inflammatory cytokines TNF-α, IL-6, IL-1β and NF-κB contents were measured by ELISA. The degree of apoptosis was determined by TUNEL. Bcl-2- and Bax-positive cell levels were measured by an immunohistochemical method. Spinal p-Akt and p-ERK expressions were determined by Western blot. In vivo expressions of Cyt-C and Caspase-3 were determined by RT-PCR. The in vivo inhibitory effect on downstream Akt and ERK signaling pathways was investigated using specific inhibitors LY294002 and PD98059.Result Inflammatory reactions and neuronal apoptosis due to the inhibition of PI3K/Akt and MAPK/ERK signal pathways were involved in the damage in a rat model of spinal cord injury. The neuroprotective effect of elongated needle acupuncture was related to a decrease in the number of Bax protein-positive neurons and an increase in the number of Bcl-2 protein-positive neurons. Elongated needle acupuncture treatment improved r浙江省中医药科研计划项目(2008CB067

    Design of Ultra-wideband Printed Rectangular Monopole Antenna

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    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

    Maroteaux-Lamy综合征的ARSB基因分析及新突变的致病性鉴定

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    【目的】对7家拟诊为Maroteaux_Lamy综合征(MPSⅥ)的患儿及其父母进行ARSB基因的突变检测和新突变的致病性鉴定,以揭示其分子发病机制,为将来的产前/植入前基因诊断等创造前提条件。【方法】在临床初诊及GAG尿检和MPS酶检的基础上,抽取患儿及其父母EDTA抗凝血,进行ARSB基因的PCR扩增和Sanger测序。对所发现的新突变,在经HGMD、1000G和ExAC等数据库核实排查后,首先用SWISS-MODEL软件分析、比对突变蛋白和正常蛋白的空间构象,然后用Clustal X软件分析跨物种氨基酸的保守性,用PROVEAN、SIFT、PolyPhen-2软件预测新突变的致病性,最后用ACMG标准对新突变的致病性进行综合分析鉴定。【结果】1)7个家系先证者的基因检测结果分别为:No1:c.574T> C,p.C192R纯合错义突变;No2:c.160G> A/p.D54N(来自其母)和c.1197C> G/p.F399L(来自其父)的复合杂合子;No3:仅检出c.1072G> A/p.V358M和IVS5 as(-27)A>C变异,但酶检和临床表型符合Ⅵ型;No4:为c.281C> T,p.S94L(新突变,来自其母)和IVS5 as(-27)A> C(来自其父)的复合杂合子;No5:为c.1197 C> G,p.F399L纯合错义突变;No6:为c.1197 C> G,p.F399L(来自其母)和c.1379 C> T,p.S460F(新突变,来自其父)的复合杂合子;No7:为c.499 G> A,p.G167R(来自其父)和c.1325C>T,p.T442M(来自其母)的复合杂合子。2)新突变鉴定结果:对正常ARSB酶蛋白和p.S94L突变酶蛋白的空间构象的预测比对结果显示,两者有明显区别;跨物种保守性分析结果显示,p.94突变点所在氨基酸(S)在物种进化过程中具有高度保守性;PROVEAN、SIFT和PolyPhen-2软件对p.S94L预测结果分别为:Deleterious、Damaging和Probably damaging。用上述方法对p.S460F的预测结果及ACMG的综合分析结果也显示该突变可能是致病性的。【结论】1)家系4的p.S94L和家系6的p.S460F新突变可能都是新的致病性突变,有可能都是引起患儿发病的内在原因之一。2)家系1,2,5,6,7可以确诊为MPS Ⅵ型,其基因型和表现型具有显著的相关性,家系3虽经酶检确诊,临床症状和尿检结果也都与MPS Ⅵ型符合,但却未能在DNA水平查到明确的突变类型,其表现型与基因型的相关性还有待进一步证实。国家自然科学基金(30772069);;闽粤合作科研基金(71010025和71020010

    化学气相沉积SiC–B_xC涂层在高温模拟环境中的微观结构

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    将化学气相沉积在石墨基片上的SiC-BxC复合涂层在O2(8kPa)/H2O(14kPa)/Ar(78kPa)的模拟气氛中,分别加热到700,1000℃和1200℃处理10h。利用扫描电镜、X射线衍射、能谱分析、显微Raman和Fourier变换红外光谱仪研究其微观结构。结果表明:复合涂层中的BxC层在700~1000℃的模拟环境中会被完全氧化成B2O3和H3BO3;在1000~1200℃的模拟环境中,BxC层的氧化产物迅速挥发。经高温模拟环境处理后,复合涂层中生成了硼硅酸盐玻璃,且各氧化产物和SiC层的结晶度随处理温度的升高而下降。基于微观分析结果,对SiC-BxC复合涂层的自愈合抗氧化性能进行了分析

    Study of the GaN Film by Spectroscopic Ellipsometry

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    【中文摘要】 采用椭圆偏振光谱法,在1.50~6.50 eV光谱内,研究了在蓝宝石衬底(0001)面上使用金属有机化学气相沉积(MOCVD)的方法制备的非掺杂纤锌矿结构GaN薄膜的光学性质。建立GaN表面层/外延层/缓冲层/衬底四层物理结构模型。与Cauchy和Sellmeier色散公式比较后选择了Tanguy Extended色散公式来分析GaN薄膜的光学性质。椭圆偏振光谱拟合结果表明,Tanguy Extended色散公式能更准确、方便地描述GaN薄膜在全波段(特别是带隙及带隙之上波段)的色散关系。提供了GaN薄膜在1.50~6.50 eV光谱范围内的寻常光(o光)和非寻常光(e光)折射率和消光系数色散关系,为定量分析GaN薄膜带边附近各向异性的光学性质提供了依据。 【英文摘要】 Optical property of wurtzite GaN film was investigated by spectroscopic ellipsometry(SE) in the spectrum range of 1.50~6.50 eV.Unintentionally doped wurtzite GaN film was fabricated by metal-organic chemical vapor deposition(MOCVD) on(0001) sapphire.Four-layer physical structure model including surface layer,epilayer,buffer layer and substrate was built by analysis.Compared with common dispersion formulas such as Cauchy and Sellmeier,Tanguy Extended dispersion formulas was used to characterize optical prope...国家自然科学基金重点专项(60827004);国家自然科学基金(60776066);国家863计划项目资助项目(2011AA03A110

    量子点毒性效应的研究进展

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    量子点(quantum dots,QDs)作为一种新型的纳米材料已备受关注.由于其独特的荧光特性,量子点已经成功地应用于生命科学等领域.近年来,量子点的生物学毒性效应及其环境影响成为新的研究热点.本文综述了量子点毒性效应的相关研究,并对该领域的前景及研究方向进行了评述和展望.国家自然科学基金重点项目(批准号:20537020);; 国家重点基础研究发展计划(批准号:2003CB415001)资

    Effects of electro-acupuncture on neuronal apoptosis and associative function in rats with spinal cord injury

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    目的 :探讨电针对大鼠急性脊髓损伤后膀胱功能改善的影响及作用机制。方法 :取健康成年雄性SPf级Sd大鼠60只,体重220~250 g,适应性饲养1周后,将大鼠按照随机数字表法随机分为假手术组、模型组、电针组和电针对照组,各15只。假手术组不予任何刺激,模型组、电针组和电针对照组大鼠采用改良AllEnS法制作脊髓损伤中度损伤Sd大鼠模型,模型组不予治疗,电针组给予秩边与水道穴电针治疗,电针对照组给予秩边与水道穴旁开0.5寸电针治疗,频率2/100 Hz,电流1 M A,刺激15 MIn,电针左右隔次交替,每日1次,共7次;分别于术后1、7 d观察大鼠残余尿量、排尿量的变化;术后7 d处死大鼠取伤段脊髓观察各组大鼠凋亡情况,检测bCl-2、bAX、bAd含量的变化。结果:造模后3组大鼠均出现不同程度的膀胱功能障碍。术后7 d,电针组、电针对照组残余尿量较术后1 d明显降低(P<0.001),且电针组与电针对照组比较差异有统计学意义(P<0.01);电针组、电针对照组较模型组在术后7 d排尿量增加,且电针组与电针对照组比较差异有统计学意义(P<0.001);TunEl发现电针可以抑制脊髓神经细胞的凋亡,电针组、电针对照组与模型组相比在术后7 d脊髓神经细胞凋亡率显著增加(P<0.01,P<0.05),且电针组与电针对照组比较差异有统计学意义(P<0.05);与模型组相比,电针组、电针对照组bAX、bAd的阳性表达率降低(P<0.01,P<0.05),而bCl-2的阳性表达率升高(P<0.01);且电针组与电针对照组比较差异有统计学意义(P<0.05)。结论 :电针能明显促进急性脊髓损伤的修复,其机制可能为通过增加bCl-2、抑制bAX、bAd的表达,从而抑制脊髓神经元细胞的凋亡发生作用的。Objective:To explore the effect of electro acupuncture to improve the bladder function after acute spinal cord injury in rats and its possible mechanism.Methods:Sixty healthy adult male SD rats of SPF grade,with body weight of 220 to250 g,one week after feeding adaptation,were randomly divided into sham operation group,model group,electro acupuncture group,electro acupuncture control group with 15 rats in each group.Sham operation group underwent no stimulation,and the moderate damage model of spinal cord injury were made in other three groups according to modified Allens method.The model group were not treated,electro acupuncture group were treated with electro acupuncture on Zhibianxue and Shuidaoxue,and electro acupuncture control group were treated with electro acupuncture on 0.5 inch next to Zhibianxue and Shuidaoxue.The frequency of 2 / 100 Hz,current of 1 m A,stimulation time of 15 min,once a day,left and right alternately stimulate every time,for a total of 7 times.The changes of residual urine volume and urine output in rats at the 1st and the 7th days after operation were observed.And 7 d later,the rats were sacrificed and the injured spinal cord were taken out to observe the apoptosis,and to detect the changes of Bcl-2,Bax,Bad content.Results:After modeling,the rats of three groups showed different bladder dysfunction.In electro acupuncture group and electro acupuncture control group,the residual urine volume of the 7th day after operation was significant lower than the 1st day after operation(P<0.001),and there was statistically significant difference on the 7th day after operation between two groups(P<0.001).Compared with model group,the urine output of electro acupuncture group and electro acupuncture control group was significantly increased on the 7th day after operation,and there was significant difference between electro acupuncture group and electro acupuncture control group(P<0.001).Electro acupuncture can inhibit apoptosis of spinal cord neurons by TUNEL detection.Postoperative at 7 d,the rate of nerve cell apoptosis in electro acupuncture group and electro acupuncture control group was significant increased than model group(P<0.01,P<0.05),and there was significant difference between electro acupuncture group and electro acupuncture control group(P<0.005).Compared with model group,the positive expression rate of Bax,Bad decreased(P<0.01,P<0.05),and Bcl-2 increased(P<0.01)in electro acupuncture group and electro acupuncture control group,there was significant difference between electro acupuncture group and electro acupuncture control group(P<0.01).Conclusion:Electro acupuncture can obviously promote the repair of acute spinal cord injury,its mechanism may be through increasing Bcl-2,inhibiting the expression of Bax,Bad,which inhibits the apoptosis of spinal cord neurons.浙江省中医药科研计划项目(编号:2008CB067)~

    材料燃烧失效与防火阻燃特色课程体系建设的探索

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    阐述材料燃烧失效与防火阻燃课程建设的基本构想、定位和教学思路;从教材及教学内容优化、加强实验教学与革新教学方法、强化实践教学、规范课程管理模式入手,将其建设成材料学科的特色课程。国家自然科学基金(51173153;51103123); 福建省重大科技平台建设基金(2009J1009)、产学重大专项(2010H6021)、科技重点项目(2007T0013;2008H0033)、自然科学基金项目(2012J01234); 厦门市科技项目(3502Z20031078;3502Z20041054;3502Z20070010;3502Z20073006;3502Z20081045;3502Z20103004;3502Z20120015); 福建省产学研联合开发(省属)专项(闽经贸计

    Application of Fluorescent Probe Technique in Study of Polymer Self-Assembly

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    采用自组装技术制备新型功能性材料已成为聚合物材料的一个热门研究领域。大部分两亲性聚合物,如嵌段聚合物、接枝聚合物、星型聚合物、树枝状聚合物和部分无规聚合物及聚电解质,在特定条件下可发生自组装。在聚合物自组装的研究中,荧光技术已经得到了广泛的应用,尤其是荧光探针技术。根据荧光探针分子荧光光谱特征峰荧光波长、强度、偏振以及寿命等参数的变化,可以简便而又准确地研究聚合物的临界胶束浓度、温度和PH敏感性、结构与自组装形态的关系、微环境变化等信息。本文综述了荧光探针技术在两亲性聚合物自组装行为研究中的应用,重点介绍了荧光探针技术研究聚合物亲水亲油平衡值(Hlb值)、浓度、温度、PH、溶剂组成及离子强度等因素对聚合物自组装形貌和微观特性参数的影响。此外,结合我们的研究工作对本征荧光光谱方法在聚合物研究中的应用做了阐述和展望,以期为两亲性聚合物的设计合成、自组装行为控制及应用提供参考。Preparation of new functional materials by self-assembly technique has become a hot research field of polymeric materials science.Most of the amphiphilic polymers,such as block copolymers,graft copolymers,star copolymers,dendrimers,part of the random copolymer and polyelectrolyte,etc.can self-assemble under certain conditions.In the study of polymer self-assembly,fluorescent technique has been widely used,especially fluorescent probe technique.According to the changes of the characteristic fluorescence parameters of the probe molecules,such as wavelength,intensity,polarization,lifetime,etc.the critical micelle concentration,temperature and pH dependence,the relationship of structure and self-assemble morphology of the polymer could be easily and accurately studied.This paper is focused on the application of the fluorescent probe technique in investigation of self-assembly behavior of amphiphilic polymers.The effects of hydrophilic lipophilic balance(HLB),concentration,temperature,pH,solvent composition,ionic strength,etc.on self-assemble morphology and microscopic characteristics parameters of amphiphilic polymers are particularly reviewed.Furthermore,based on our own research work,the applications of intrinsic fluorescence spectroscopy method in polymer investigation are elaborated.It will characterize the conformation transitions of macromolecules during the self-assembly process more truly.This paper aims at providing reference for design,polymerization,self-assembly controlling and applications of amphiphilic polymers.国家自然科学基金项目(No.51103123); 福建省自然科学基金项目(No.2012J01234)资
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