超窄带传输与缩频通信体制

文章介绍以VMSK、VWDK等为代表的超窄带高效调制,引出压缩传输带宽的缩频通信新体制,并探讨可能的应用。

数字有源室分pRRU缩频覆盖技术研究

经过多年的大力建设,各运营商4G网络已已基本实现全覆盖,但室内深度覆盖仍有不足,高校、高密度住宅区和高流量商业区,用户感知有差距。在4G投资逐步缩紧的情况,网络建设重点已从面覆盖转向点提质的精耕细作阶段。在5G网络建设中,因为无源器件频段支持和流量密度的原因,有源室分将逐渐取代无源室分而成为室内覆盖的主要组网方式,室分建设投资巨大。基于现状,创新提出了一种有源室分缩频覆盖覆盖,基本缩频技术原理理论和实际分析,对不同场景的缩频覆盖方案进行对比分析,提出具体应用场景和相关的覆盖组网建议。

硫酸特布他林在产程中抑制宫缩过频的应用效果

目的探讨硫酸特布他林在产程中抑制宫缩过频的应用效果。方法选取江西省新余市妇幼保健院2020年1月至2022年3月产科收治的80例产程过程中发生宫缩过频的产妇作为研究对象,采用随机数字表法将其分为研究组和对照组,每组各40例。对照组开展宫缩过频常规干预,研究组给予硫酸特布他林干预,比较两组产妇产时母体情况、分娩方式、妊娠结局等指标。结果胎儿娩出前研究组产妇心率、收缩压水平均高于对照组,差异有统计学意义(P<0.05)。研究组产妇阴道分娩率高于对照组,差异有统计学意义(P<0.05)。研究组产妇不良妊娠结局总发生率低于对照组,差异有统计学意义(P<0.05)。结论硫酸特布他林在产程中抑制宫缩过频的应用效果突出,有助于改善母婴结局,提升自然分娩率。

地诺前列酮栓引产出现宫缩过频后不同取药时机对分娩结局的影响

目的:了解地诺前列酮栓(欣普贝生)促宫颈成熟引产过程中出现宫缩过频后不同取药时机对分娩结局的影响。方法:回顾性分析本院使用欣普贝生促宫颈成熟引产患者88例的临床资料。根据发生宫缩过频后的处理结果将其分为立即取药组(立即取出欣普贝生)54例和继续放置组(继续放置至宫颈成熟再取药)34例,比较两组分娩结局。结果:继续放置组的药物放置时长长于立即取药组,放药至分娩时长短于立即取药组,24 h内阴道分娩比例高于立即取药组,剖宫产率低于立即取药组,羊水污染程度轻于立即取药组,比较差异均有统计学意义(P<0.05);两组经阴道分娩的产道及会阴裂伤情况、新生儿体重、入住NICU比例、产后2 h出血量、血红蛋白差值比较,差异均无统计学意义(P>0.05)。结论:欣普贝生促宫颈成熟引产过程中出现宫缩过频时,在严密监测下继续放置直至宫颈成熟再取出欣普贝生,能提高24 h内阴道分娩比例,减少剖宫产,且不增加分娩的母婴并发症。

OSAS患者经射频组织缩积术治疗的疗效评价

目的 观察射频组织缩积术 (RFTVR)行悬雍垂、软腭成形术治疗阻塞性睡眠呼吸暂停综合征的疗效。方法 应用RFTVR在局麻下对 1 8例平均年龄 (4 2 .2± 5 .6 )岁的男性轻、中度阻塞性睡眠呼吸暂停患者 (1 2例为软腭肥大者 ,6例为悬雍垂粗长患者 )行悬雍垂、软腭成形术治疗。手术前后均行多导睡眠图监测检查。结果 1 8例患者术后 4～ 8周随访 ,病情显著改善 ,各种临床症状缓解 ,打鼾明显降低 ,软腭游离缘、悬雍垂缩短。多导睡眠图检查提示 :患者平均呼吸暂停低通气指数 (AHI)由术前1 9 .1± 7.3减少至 5 .9± 4 .4 (P <0 .0 1 ) ,平均最低血氧饱和度 (SaO2 )由术前 (80 .5± 5 .7) %升高到 (91 .7± 7.3) % (P <0 .0 5 )。结论 射频组织缩积术是一项新的微创、安全的治疗方法 ,能够有效治疗轻、中度阻塞性睡眠呼吸暂停综合征。严格选择手术适应证大多数患者近期可收到显著疗效 。

温控的粘膜下射频组织缩积术治疗打鼾和阻塞性睡眠呼吸暂停综合征的新进展

射频组织缩积术(RFTVR)是利用可控的温度(60℃～90℃)在粘膜下造成下鼻甲、软腭悬雍垂、扁桃腺和舌根组织的局部凝固性坏死,由纤维组织修复、收缩,以缩小上述组织体积,解除上气道的阻塞,以治疗打鼾和阻塞性睡眠呼吸暂停综合征。该技术显示出一定的优越性,有效性,较小的不适和副作用,值得临床应用。但仍需长期严密临床随访观察。

应用地诺前列酮出现宫缩过频取药时机探讨

目的探讨地诺前列酮栓在足月单胎头位初产妇促宫颈成熟引产中出现宫缩过频时的取药时机。方法选取2020年4月至8月在我院应用地诺前列酮栓促熟引产的足月单胎头位初产妇为研究对象,依据促熟引产中是否发生宫缩过频将其分为过频组和正常组,分析比较两组孕妇的用药过程、分娩结局及取药时的VAS疼痛评分,分析取药时机。结果在226例孕妇中,宫缩过频组39例(17.3%),正常组187例(82.7%)。两组孕妇24h阴道分娩率的差异无统计学意义(χ^(2)=0.003,P>0.05);但过频组孕妇的剖宫产率和因引产失败致剖宫产者均显著高于正常组,差异有统计学意义(χ^(2)值分别是4.067、4.141,P<0.05)。促熟引产期间,过频组孕妇较正常组更容易出现胎心监护异常,更容易发生新生儿黄疸,差异有统计学意义(χ^(2)值分别是33.684、4.960,P<0.05)。与正常组孕妇相比,过频组孕妇置药时间短、取药时宫颈Bishop评分低(Z值分别是-5.353、-4.276,P<0.05),而宫缩抑制剂使用率高(χ^(2)=128.749,P<0.05)。过频组有92.3%的孕妇取药时VAS评分在5~8分之间;正常组则有86.1%者评分在4~8分之间。取药时,VAS在0~3分、4~8分孕妇的剖宫产率分别为61.5%、18.69%,差异具有统计学意义(χ^(2)=23.364,P<0.05)。结论地诺前列酮栓促宫颈成熟引产中,宫缩过频者的引产失败率高。孕妇取药时的VAS评分集中在4~8分之间,此疼痛强度下取药者的引产成功率高。早上8点前用药,结合VAS疼痛评分评价宫缩过频很可能会有助于提高引产的安全性和有效性。

缩宫素引产导致宫缩过频的相关因素分析

目的研究缩宫素引产导致产妇宫缩过频的相关因素。方法回顾性分析2020年1月-2021年5月于该院宫颈条件成熟、使用缩宫素引产的160例产妇,均为孕晚期、单胎妊娠、胎位正常、无子宫手术史,有明确引产指征,宫颈条件成熟。观察初始用药30 min内发生宫缩过频的情况,其中以55例发生宫缩过频的产妇为宫缩过频组,以未发生宫缩过频的105例产妇为宫缩正常组,比较两组产妇临床资料,使用Logistic回归分析缩宫素引产导致产妇宫缩过频的相关因素。结果 105例宫缩正常、55例发生宫缩过频,宫缩过频发生率为34.4%。宫缩过频组产妇中出现胎心减速的发生率为75.0%,明显高于宫缩正常组,差异有统计学意义(χ^(2)=105.241,P<0.001)。将孕前BMI、年龄、孕次、产次、Bishop宫颈评分、孕周、引产指征进行线性分析,显示年龄、孕次、产次、Bishop宫颈评分、孕周、引产指征与宫缩过频发生均无相关性(P>0.05),BMI与宫缩过频发生呈负性相关(P<0.05)。经二元Logistic回归分析,孕前BMI为缩宫素导致产妇宫缩过频的保护因素(P<0.05)。结论宫颈条件成熟的产妇静滴缩宫素引产容易出现宫缩过频,且孕前BMI越小发生宫缩过频的机率越大。对于孕前BMI越小的患者,使用缩宫素引产越需更加谨慎、用药过程中需特别监测宫缩及胎心情况,便于及时诊断产妇宫缩过频并给予对应治疗措施。

基于循环谱理论的时相调制信号分析

针对传统数字调制信号频谱扩展问题,提出具有相位突变特性的时相调制(TPM)方式。基于循环谱理论对TPM已调信号的谱相关特性进行了详细的理论分析,计算机仿真实验验证了分析得到的结果,为TPM调制信号的干扰与噪声抑制提供了一种较好的非平稳信号处理方案。

Low-frequency data analysis and expansion

The use of low-frequency seismic data improves the seismic resolution, and the imaging and inversion quality. Furthermore, low-frequency data are applied in hydrocarbon exploration; thus, we need to better use low-frequency data. In seismic wavelets, the loss of low-frequency data decreases the main lobe amplitude and increases the first side lobe amplitude and results in the periodic shocking attenuation of the secondary side lobe. The loss of low frequencies likely produces pseudo-events and the false appearance of higher resolution. We use models to examine the removal of low-frequency data in seismic data processing. The results suggest that the removal of low frequencies create distortions, especially for steep structures and thin layers. We also perform low-frequency expansion using compressed sensing and sparse constraints and develop the corresponding module. Finally, we apply the proposed method to real common image point gathers with good results.

临界压在睡眠呼吸暂停低通气综合征患者咽部塌陷中的意义

目的 在于阐明临界压 (Pcrit)与睡眠呼吸暂停低通气综合征 (SAHS)患者病情严重程度的关系 ,以及Pcrit对SAHS患者选择治疗方式上的指导意义。方法 分别对 165名男性行多导睡眠图检查 ,其中 3 3名为正常对照 ;用压力振荡技术 (Forcedoscillationtechnique ,FOT)对其余 13 2名男性SAHS患者 (分为S1、S2 、S3NOCPAP及S3CPAP4组 )进行压力和流量测定 ,根据最大通气量与压力的关系 ,用外推法在气流为零时作图解出Pcrit。 14名男性SAHS患者行射频组织缩积术 (Radiofre quencytissuevolumereduction ,RFTVR)治疗。结果 PcritS1组为 ( 1 2± 0 6)cmH2 O ,S2 组为 ( 1 7± 0 8)cmH2 O ,S3NOCPAP组为( 2 2± 0 8)cmH2 O ,S3CPAP组为 ( 2 6± 0 7)cmH2 O ;在S3CPAP组的AHI指数中OAI及MAI均非常显著地高于OHI(t =7 464 ,P <0 0 1;及t=3 718,P <0 0 1) ,其OAI亦非常显著地高于S3NOCPAP组的OAI(t=3 80 4,P <0 0 1) ;舌根RFTVR治疗使上气道阻力从 ( 6 3 8± 1 46)cmH2 O·L-1·s-1降低为 ( 4 5 8± 1 5 7)cmH2 O·L-1·s-1(P <0 0 5 ) ,Pcrit从 ( 3 2± 0 6)cmH2 O降低为 ( 2 0± 0 8)cmH2 O(P <0 0 5 )。结论 Pcrit能从功能上反映SAHS患者上气道的塌陷程度及病情严重程度 ;

Research on the imaging of concrete defect based on the pulse compression technique

When the synthetic aperture focusing technology （SAFT） is used for the detection of the concrete, the signal-to-noise ratio （SNR） and detection depth are not satisfactory. Therefore, the application of SAFT is usually limited. In this paper, we propose an improved SAFT technique for the detection of concrete based on the pulse compression technique used in the Radar domain. The proposed method first transmits a linear frequency modulation （LFM） signal, and then compresses the echo signal using the matched filtering method, after which a compressed signal with a narrower main lobe and higher SNR is obtained. With our improved SAFT, the compressed signals are manipulated in the imaging process and the image contrast is improved. Results show that the SNR is improved and the imaging resolution is guaranteed compared with the conventional short-pulse method. From theoretical and experimental results, we show that the proposed method can suppress noise and improve imaging contrast, and can also be used to detect multiple defects in concrete.

Digital broadcast channel estimation with compressive sensing

In order to reduce the pilot number and improve spectral efficiency, recently emerged compressive sensing （CS） is applied to the digital broadcast channel estimation. According to the six channel profiles of the European Telecommunication Standards Institute（ETSI） digital radio mondiale （DRM） standard, the subspace pursuit （SP） algorithm is employed for delay spread and attenuation estimation of each path in the case where the channel profile is identified and the multipath number is known. The stop condition for SP is that the sparsity of the estimation equals the multipath number. For the case where the multipath number is unknown, the orthogonal matching pursuit （OMP） algorithm is employed for channel estimation, while the stop condition is that the estimation achieves the noise variance. Simulation results show that with the same number of pilots, CS algorithms outperform the traditional cubic-spline-interpolation-based least squares （LS） channel estimation. SP is also demonstrated to be better than OMP when the multipath number is known as a priori.

DISCHARGE CHANNEL GROWTH IN MICRO EDM OF HIGH FREQUENCY PULSE

The influences of intense magnetic pinch effect caused by electromagnetic field with high frequency on discharge channel expansion and plasma configuration change are discussed. The change of Lorentz force exerting on charged particles in discharge channel is calculated under the electromagnetic field with high frequency. Through the theoretical analysis and experimental study, the forming process of discharge channel is conjectured. And it is considered that the changes of discharge channel, such as the decrease of diameter and increase of energy density, coming from the intense magnetic pinch effect in high frequency electromagnetic field, are the main reasons for a series of special phenomena on the machined surface in micro EDM.

Separation of inhomogeneous blended seismic data

The frequencies of sources involved m conventional blended acquisition are the same. Each source transmits the full frequency band, and in general, significant effort is required to successfully produce and operate wideband sources. To solve this problem, inhomogeneous blended or decentralized blended acquisition is used, in which the dominant frequency and bandwidth of the source units in a blended array are not equal. When the inhomogeneous and conventional blending acquisitions adopt the same geometry and separation methods, the former has low signal-to-blending noise ratio. Therefore, we present a new separation method for such blended acquisition based on the synchrosqueezed wavelet transform. The proposed method offers better separation quality and decreases the computation time to approximately 1/3.

米索前列醇用于足月妊娠引产安全性分析

观察米索前列醇用于足月妊娠引产的安全性 .方法 ;回顾性分析了 72例使用米索前列醇引产和 10 0例使用缩宫素引产的足月妊娠产妇的临床资料 .结果 :米索组出现过频宫缩 14例 ,而缩宫素组未出现异常宫缩 .两组羊水混浊发生率分别为 2 2 %、10 % ,差异有显著性 .剖宫产原因中 ,胎儿宫内窘迫均为两组主要手术指征 ,米索组 8例占 6 6 .7% ,缩宫素组 7例占 4 4 % ,差异有显著性 ,提示 :米索前列醇用于足月妊娠引产 ,对母亲和胎儿有潜在的不安全因素存在 .

A Q-Enhanced CMOS RF Filter for Multi-Band Wireless Communications

An RF bandpass filter with a Q-enhancement active inductor is presented. The design technique for a tunable Q-enhancement CMOS active inductor operating in the wide RF-band is described. Moreover,issues related to noise and stability of the active inductor are explained. The filter was fabricated in 0.18μm CMOS technolo- gy,and the circuit occupied an active area of only 150μm ×200μm. Measurement results show that the filter centered at 2. 44GHz with about 60MHz bandwidth （3dB） is tunable in center frequency from about 2.07 to 2. 44GHz. The ldB compression point is - 15dBm while consuming 10. 8mW of DC power,and a maximum quality factor of 103 is attained at the center frequency of 2.07GHz.

Methanol Adsorption on TiO2 Film Studied by Sum Frequency Generation Vibrational Spectroscopy

A broadband infrared surface sum frequency generation vibrational spectroscopy （SFG-VS） and an in situ UV excitation setup devoted to studying surface photocatalysis have been constructed. With a home-made compact high vacuum cell, organic contaminants on TiO2 thin film surface prepared by RF magnetron sputtering were in situ removed under 266 nm irradiation in 10 kPa 02 atmosphere. We obtained the methanol spectrum in the CH3 stretching vibration region on TiO2 surface with changing the methanol pressure at room temperature. Features of both molecular and dissociative methanol, methoxy, adsorbed on this surface were resolved. The CH3 symmetric stretching vibration frequency and Fermi resonance of molecular methanol is red-shifted by about 6-8 cm-1 from low to high coverage. Moreover, the recombination of dissociative methanol and H on Surfaces in vacuum was also observed. Our results suggest two equilibria exist： between molecular methanol in the gas phase and that on surfaces, and between molecular methanol and dissociative methanol on surfaces.