基于SSPP技术的家庭网络多波束天线技术研究及应用

大带宽、广覆盖、低时延和抗干扰的高品质家庭无线网络是保障光纤入房(FTTR,fiber to the room)千兆光网用户体验的关键指标,传统家庭网络设备主要采用单波束单极化天线设计,在大衰减、强干扰背景下已经越来越无法满足高品质的网络产品需求。天线作为实现传导能量与空口电磁波变换必不可少的部件,利用其设计自由度可以实现多重功能。高增益能降低射频端的功耗需求,达到节能的目的,多波束能保持无死角的高性能网络覆盖,因此研究设计小尺寸、高增益且用法灵活的多波束天线价值巨大。紧跟实际工程痛点和当前学术研究方向,瞄准家庭网络产品设计开发了一种基于人工表面等离激元(SSPP,spoof surface plasmon polariton)技术的家庭网络多波束天线,覆盖Wi-Fi的5.1~5.9 GHz频段。实际测试验证表明,基于SSPP技术的天线设计能够获得更好的覆盖性能,相比传统小天线,在穿墙、跨层等弱信号场景下具有明显优势,在小型化的家庭网络产品中具有极大的应用前景。

人脐带间充质干细胞单次静脉注射NOG小鼠组织分布及其分析方法学研究

目的建立并验证小鼠组织中人源SRY基因DNA RT-qPCR分析方法学,研究人脐带间充质干细胞(human umbilical cord mesenchymal stem cells,HUCMSCs)单次静脉注射后在重度免疫缺陷NOG小鼠体内的组织分布情况。方法建立小鼠组织中人源SRY基因DNA的RT-qPCR分析方法,进行标准曲线与线性范围、准确度与精密度、稳定性等方法学验证。取NOG小鼠36只,雌雄各半,单次静脉注射给予HUCMSCs 3.5×10^(7)cells/kg,于6、12、24、72 h、1周、2周各取6只小鼠麻醉,采集血液(EDTA抗凝)后解剖,取肺、肾、心脏、肝、大脑、脊髓、胃、小肠、脂肪、皮肤、脾、睾丸(子宫、卵巢)提取DNA,用已验证的小鼠组织中人源SRY基因DNA RT-qPCR分析方法测定各组织中HUCMSCs的分布情况。另选取NOG小鼠18只,雌雄各半,分为对照组6只、给药组12只,分别静脉注射0.9%氯化钠注射液、HUCMSCs 3.5×10^(7)cells/kg,给药期间观察小鼠急性毒性反应情况,给药组于给药后72 h、2、4周各取4只动物剖检观察脏器组织大体观情况,取肺组织石蜡切片采用免疫组化法检测线粒体蛋白表达,分析HUCMSCs在肺组织中的定植情况。结果建立的小鼠组织中人源SRY基因DNA的RT-qPCR分析方法各考察指标均符合验证标准;NOG小鼠单次静脉注射HUCMSCs后,主要分布于肺和血液中(给药后1周内),肺组织浓度高于血液,肺组织、血液中HUCMSCs浓度分别在6~24 h、6~72 h之内维持相对平稳水平,之后随时间推移下降,其他组织各采样点均未测得HUCMSCs分布;定植结果显示静脉注射HUCMSCs后72 h可在肺部检测到其存在,2周和4周时则未检测到;单次静脉注射HUCMSCs后NOG小鼠未见明显急性毒性反应。结论建立的HUCMSCs小鼠组织中分布分析方法可靠、可行;NOG小鼠单次静脉注射HUCMSCs后主要于给药后1周内分布于肺和血液,72 h主要定植于肺组织;单次静脉注射HUCMSCs具有良好的安全性。

A COMPACT AND HANDHELD SURFACE PENETRATING RADAR FOR THE DETECTION OF REINFORCED CONCRETE STRUCTURES

Surface Penetrating Radar (SPR) is a recently developed technology for non-destructive testing. It can be used to image and interpret the inner structure of the reinforced concrete. This paper gives the details about a compact and handheld SPR developed recently for reinforced concrete structure detection. The center operation frequency of the radar is 1.6 GHz. Not only it has fast acquisition ability, but also it can display the testing result on the LCD screen in real-time. The testing results show that the radar has a penetrating range of more than 30 cm, and a lateral resolution better than 5 cm. The performance validates that the radar can meet the application requirements for reinforced concrete structure detection.

AN ULTRA-WIDEBAND ANTENNA FOR THE REINFORCED CONCRETE DETECTION

In this paper,an Ultra-Wideband(UWB) planar antenna is proposed for the reinforced concrete detection,which consists of a pair of planar waterdrop arms,a microstrip to coplanar parallel-strips transition and a shallow rectangular cavity.In order to overcome the disadvantages of the shallow cavity,some absorbing material is loaded to weaken the narrow-band effect of the cavity and the crosstalk interference.The simulated and measured results show that the proposed antenna has a large bandwidth from 0.48 GHz to 3.6 GHz with Voltage Standing Wave Ratio(VSWR) below 2 and a fractional bandwidth about 200% under the center frequency of 1.6 GHz,directional radiation characteristics and small late-time ringing in the time domain,which can be suitable for nondestructive detection of the reinforced concrete.

4-ELEMENT PLANAR ARRAY ANTENNA FOR UWB APPLICATION

A novel low-cost 4-element planar array antenna directly fed by a coaxial cable for Ultra-WideBand(UWB) application is presented. The proposed antenna consists of 2×2 bowtie elements and a simple 1:4 power divider feeding network. Compared to the basic bowtie element, the impedance bandwidth of the array antenna has a significant improvement that the low cut-off frequency is extended from 6 GHz of the bowtie element to 2 GHz. The measured results show that the proposed antenna has a large bandwidth of 2 GHz to 11 GHz for Voltage Standing Wave Ratio(VSWR)<2, and exhibits a bidirectional radiation pattern and a modest gain across the operating band and a peak gain of about 9 dBi at 11 GHz.

UWB TEM HORN ANTENNA FOR THE ASPHALT PAVEMENT INVESTIGATION

A simple Ultra-WideBand(UWB)exponentially-tapered Transverse ElectroMagnetic(TEM)horn antenna is presented for the asphalt detection based on Ground Penetrating Radar(GPR).In order to reduce the reflections from the antenna aperture,some absorbing material is loaded on the outer surface of the conductor.Comparing with the traditional TEM horn antenna,the proposed antenna has a small size and a large impedance bandwidth.Simulated and measured results show that the proposed TEM horn antenna has a low Voltage Standing Wave Ratio(VSWR)below 2 over the whole band from 0.35 GHz to 12 GHz,good radiation characteristics,and small late-time ringing,which can perfectly meet the requirements of the GPR application.

急性草酸二甲酯中毒致急性肾损伤四例

目的探讨草酸二甲酯(DMO)中毒致急性肾损伤的临床表现及非透析治疗的方法、疗效及预后。方法于2020年7月,对4例急性DMO中毒患者的职业资料、临床资料、实验室检查结果、治疗方法及病情转归等进行回顾性分析。结果急性事故后现场调查可见工作场所内有大量白色DMO晶体。4例患者同时、短期内接触DMO后急性起病,出现不同程度的乏力、腹胀、腰腹部绞痛及夜尿增多等症状。实验室检查均显示急性肾损伤,起病时患者血肌酐119~835μmol/L。早期予以休息、保护肾功能、水化碱化尿液等治疗,同时均给予百令胶囊治疗。4例患者症状缓解,肾功能完全恢复正常,临床预后良好。结论急性DMO中毒导致急性肾损伤主要以低比重尿、无菌性白细胞尿等肾小管间质病变为主,早期积极治疗,临床短期预后较好。