A NEW SYNCHRONOUS DIGITAL HIERARCHICAL BI-DIRECTIONAL RING CAPACITY DESIGN ALGORITHM BASED ON THE SHORTEST-ROUTE TRAFFIC MATRIX

In this paper, the concept of the Shortest-Route Traffic Matrix(SRTM) was first presented, and the generalized formula for computing ring capacity requirement in use of SRTM is given. Then, a new capacity design algorithm which is based on SRTM was presented for Synchronous Digital Hierarchical(SDH) Bi-directional Self-Healing Ring (BSHR). The algorithm simulation results demonstrate that this algorithm is very efficient for SDH BSHR capacity design and can make less project investment and make high utilization of lines and equipment. By means of the algorithm in this paper, capacity optimization assignment for SDH Hierarchical Self-Healing Ring (HSHR) and for ATM Virtual Path (VP)-based Self-Healing Ring (SHR) is also discussed.

Numerical study of a bi-directional in-band pumped dysprosium-doped fluoride fiber laser at 3.2μm

Dy^(3+)-doped fluoride fiber lasers have important applications in environment monitoring,real-time sensing,and polymer processing.At present,achieving a high-efficiency and high-power Dy^(3+)-doped fluoride fiber laser in the mid-infrared(mid-IR)region over 3μm is a scientific and technological frontier.Typically,Dy^(3+)-doped fluoride fiber lasers use a unidirectional pumping method,which suffers from the drawback of high thermal loading density on the fiber tips,thus limiting power scalability.In this study,a bi-directional in-band pumping scheme,to address the limitations of output power scaling and to enhance the efficiency of the Dy^(3+)-doped fluoride fiber laser at 3.2μm,is investigated numerically based on rate equations and propagation equations.Detailed simulation results reveal that the optical‒optical efficiency of the bi-directional in-band pumped Dy^(3+)-doped fluoride fiber laser can reach 75.1%,approaching the Stokes limit of 87.3%.The potential for further improvement of the efficiency of the Dy^(3+)-doped fluoride fiber laser is also discussed.The bi-directional pumping scheme offers the intrinsic advantage of mitigating the thermal load on the fiber tips,unlike unidirectional pumping,in addition to its high efficiency.As a result,it is expected to significantly scale the power output of Dy^(3+)-doped fluoride fiber lasers in the mid-IR regime.

Using Brillouin fiber-optic ring laser to provide base station with uplink optical carrier in a 10 GHz radio over fiber system

In this paper, a 10 GHz radio over fiber system is analyzed. The Brillouin fiber-optic ring laser is used in the center station （CS） to suppress the optical carrier for the modulation depth enhancement. Simultaneously, the Stockes wave induced by the Brillouin amplification injects and locks the Fabry-Perot （FP） laser to output a signal-mode optical source, which works as the uplink optical carrier.

Semiconductor Optical Amplifier (SOA)-Fiber Ring Laser and Its Application to Stress Sensing

We have developed a novel optical fiber ring laser using a semiconductor optical amplifier (SOA) as the gain medium, and taking advantage of polarization anisotropy of its gain. The frequency difference of the bi-directional laser is controlled by birefringence which is introduced in the ring laser cavity. The beat frequency generated by combining two counter-propagating oscillations is proportional to the birefringence, the fiber ring laser of the present study is, therefore, applicable to the fiber sensor. The sensing signal is obtained in a frequency domain with the material which causes the retardation change by a physical phenomenon to be measured. For the application to stress sensing, the present laser was investigated with a photoelastic material.

Experimental investigation on chaos generation in erbium-doped fiber single-ring lasers

In this paper,the chaotic behaviors in an erbium-doped fiber（EDF） single-ring laser（EDFSRL） are investigated experimentally by using the loss modulation method.An electro-optic modulator（EOM） made of LiNbO 3 crystal is added to the system.Thus,by changing the modulation voltage and the modulation frequency of the EOM,the freedom of the EDFSRL system is increased.The chaotic characteristics of the system are studied by observing the time series and the power spectra.The experimental results indicate that the erbium-doped fiber single-ring laser system can enter into chaos states through period-doubling bifurcation and intermittency routes.

Er^(3+)-Yb^(3+) Co-Doped Fiber Ring and Line Laser

Er3+-Yb3+ co-doped fiber of 2 m long is used as the laser gain medium. Two fiber lasers with different structures have been set up, one is the line cavity fiber laser with the dielectric mirror being replaced by an all-fiber reflecting mirror,the other is the ring cavity all-fiber laser. Both set-ups have achieved lasing operation at the wavelength of 1.53 μm. Pumped by the 1 064 nm light from all-solid-state Nd ∶YAG laser, the two fiber lasers at 1 530 nm are operational. Their output powers are 7.8 mW and 2 mW with 130 mW and 160 mW pump powers.

Fiber Grating Ring Laser in All Optical Communication System

Erbium fiber grating ring laser (EFRL) witn an integrated travelling wave and low polarization mode noise is reported. Through modulated experiment of a successful 2.488 Gb/s RZ data, it is shown that the EFRL is a promising alternative to DFB lasers for high-speed transmission applications.

Characterization of a Novel RING-Type Ubiquitin E3 Ligase GhRING2 Differentially Expressed in Cotton Fiber

The ubiquitin-proteasome proteolysis pathway is responsible for the degradation of abnormal and short-lived proteins to regulate many important biochemical activities in eukaryotes. By employing affymetrix microarray analysis, we have identified a novel ubiquitin ligase E3 gene GhRING2 that is differentially expressed between two Gossypium hirsutum lines-Texas Marker-1 (TM-1) and Chromosome Substitution Line CS-B25. The CS-B25 line has chromosome 25 from G. barbadense substituted into TM-1. The complete nucleotide sequences of GhRING2 along with its 5’-flanking region were obtained by genomic walking. GhRING2 was highly expressed in elongating fiber, and GUS expression directed by the GhRING2 promoter was found in hypocotyls and young stems of transgenic Arabidopsis plants. Using a yeast two-hybrid assay GhRING2 was found to interact with a PROTODERMAL FACTOR1 (GhPDF1) protein. GhPDF1 was expressed preferentially in immature ovules and fiber initials, and the GhPDF1 gene had been suggested to play a role in cell fate determination and fiber development. Pull down and plasmid swap assays further confirmed the interaction between GhRING2 and GhPDF1. The expression and protein interaction data indicate that GhRING2 may be involved in the turnover of GhPDF1 and participation in the transition from initiation to elongation stages during fiber development. Our data strongly suggest that the ubiquitin-proteasome pathway may regulate cotton fiber growth and development. The nucleotide sequence data of GhRING2 in this article have been submitted to the Gen Bank Nucleotide Sequence Data Bases under the accession number BankIt 1,742,008 SeqKM 108,000.

庆城页岩油泵入式光纤监测技术实践

庆城油田页岩油水平井主体采用分段多簇细分切割体积压裂技术,但目前仍存在多簇起裂效率不清晰的问题。为了评价多簇起裂有效性及裂缝延伸规律,开展了水平井泵入式光纤测试技术先导性试验,该技术具有工艺灵活、便捷高效及成本低的独特优势。测试结果表明,水平井分段多簇细分切割体积压裂通过射孔限流+颗粒暂堵方式,能够实现100%多簇完全起裂,但各簇进砂(液)量差异明显,各簇裂缝延伸不均衡。该项研究初步回答了多簇起裂有效性问题,并验证了水平井套管内泵入式光纤监测技术的可行性,丰富了水平井体积压裂效果评估测试手段,同时为鄂尔多斯盆地页岩油水平井压裂工艺及参数优化提供了重要依据。

不同钢纤维类型对高性能混凝土抗折性能影响模拟分析

本文以钢纤维混凝土抗折强度计算理论为基础,分析混凝土在分别添加平直形和圆环形钢纤维的情况下抗折强度的变化。运用有限元模拟分析软件ABAQUS进行数值模拟,不同掺量的平直形和圆环形钢纤维掺入混凝土梁,得到梁受压损伤云图和荷载位移曲线的变化,分析平直形和圆环形钢纤维对高性能混凝土抗折性能的影响,验证了有限元模拟的合理性。通过对有限元数值模拟结果的分析,相比较钢纤维体积掺量为0.5%,当钢纤维体积掺量为1.0%和1.5%时,平直形钢纤维混凝土的抗折强度分别增加了20.02%和26.62%,圆环形钢纤维混凝土的抗折强度分别增加了9.64%和46.98%。而对比两种形状的钢纤维掺入,体积含量为1.5%的圆环形钢纤维对混凝土的抗折强度,延性性能的增强效果更优。

宽谱光源谐振式光纤陀螺谐振特性分析

为优化宽谱光源谐振式光纤陀螺(RFOG)谐振腔设计,进行了RFOG谐振特性分析。首先,根据光场传输理论完成了宽谱RFOG光场传输特性分析,建立了宽谱RFOG谐振频差曲线模型,给出了谐振特性参数表达式。理论证明了宽谱RFOG的陀螺精细度和半高全宽约为谐振腔光谱曲线的1/2和2倍。其次,基于宽谱RFOG光场理论模型,分析了耦合器交叉耦合系数、附加损耗和谐振腔腔长等谐振腔关键光学参数对陀螺精细度和极限灵敏度的影响。最后,实验验证了谐振特性理论分析的正确性,并通过优化谐振腔参数实现陀螺零偏不稳定性0.059°/h,对谐振式光纤陀螺工程设计具有理论指导意义。

多波长与横模可切换掺镱光纤激光器的研究

设计并制备了一种具有环形掺镱纤芯的光纤波导结构,并提出了一种基于该环芯掺镱光纤和少模光纤布拉格光栅的多波长与横模可切换光纤激光器。在这种光纤激光器中,只需简单调整腔内的偏振控制器,就可以实现单波长和双波长的激光稳定振荡。当激光器在单波长下工作时,可以切换两种横模输出,包括LP01模和LP11模,两种模式都获得了小于0.08 nm的3 dB窄线宽和大于45 dB的高边模抑制比,中心波长和光强的波动分别为±0.01 nm和±1 dB。试验表明:该环芯掺镱光纤有助于LP11模获得的增益高于LP01模,LP01模式激光的斜率效率为34.34%,而LP11模式激光的斜率效率高达49.09%。该光纤激光器可以在模分复用系统和激光加工等领域发挥重要的作用。

基于光纤环衰荡技术的锥形光纤磁场测量方法

针对目前光纤磁场传感器解调方法中存在的实用性差且造价昂贵的问题,提出了一种基于光纤环衰荡技术的锥形光纤磁场测量方法,实现了磁场的时间域解调。施加不同强度的磁场时,光在锥形光纤处引起的损耗不同,导致系统衰减时间不同。将系统衰减时间和磁场强度建立联系,实现了磁场测量。为降低传感单元温度和磁场之间的交叉敏感,设计了温度控制电路,将传感单元的温度设定在25.0℃。实验结果表明,该传感器在磁场强度2 mT~9 mT范围内时,磁场强度H和衰减时间τ具有R^(2)=0.98273的线性拟合度,计算得到该传感器的磁场灵敏度为-11.65μs/mT。与光纤磁场传感器的其他解调方式相比,采用光纤环衰荡技术的磁场测量方法,具有响应速度快、成本低、稳定性好的优点。

基于SOA光纤环形激光器的分布式声传感系统

为了降低传统分布式声学传感器(DAS)系统复杂度并提高信噪比(SNR),提出了一种基于半导体光放大器的光纤环形激光器(SOA-FRL)的DAS系统。该系统用SOA-FRL取代了传统的DAS系统中的窄线宽激光器和脉冲调制器,实现了高稳定的光脉冲输出;采用双脉冲外差探测方法,实现了精确的声信号探测和声源定位。实验结果表明:在频率为1 kHz、幅值为1.14 rad的声信号作用下,所提系统的解调SNR高达38.25 dB,空间分辨率为12 m。

耦合环辅助多模光纤受激布里渊散射阈值分析

为了降低模间串扰,提出了一种耦合环辅助多模光纤结构,通过仿真软件对其结构进行建模,并建立了其受激布里渊散射增益谱的数学模型;理论分析了耦合环辅助多模光纤的受激布里渊散射阈值以及光纤参量和模式对受激布里渊散射光谱阈值的影响,并通过了仿真实验验证。结果表明,耦合环辅助多模光纤增大关键模式有效折射率差值为原来的1.75倍,可有效抑制模间串扰;受激布里渊散射光谱阈值跟随光纤长度的增加,从急剧下降变至缓慢,最终在18 km处趋于定值30 dBm;在其它条件不变的情况下,阈值随着衰减系数、纤芯的有效截面积和光纤模式阶数的增加呈线性关系增加,随着纤芯半径的增加呈指数形式增长。该研究为提升光纤通信系统的传输距离和信道容量提供了理论参考。

不同尺寸囊袋张力环对高度近视合并白内障患者术后囊袋稳定性的影响

目的探讨植入不同尺寸囊袋张力环(CTR)对高度近视合并白内障患者术后囊袋稳定性的影响。方法前瞻性研究。选取2022年1月至6月于河北省眼科医院就诊的高度近视合并白内障患者75例(150眼)为研究对象,采用随机数字表法分为大尺寸组、小尺寸组和对照组,每组25例(50眼)。所有患眼均行超声乳化吸出联合人工晶状体(IOL)植入术,其中,大尺寸组患者术中联合植入CTR1311(开放直径13 mm),小尺寸组患者术中联合植入CTR1210(开放直径12 mm),对照组不植入CTR。比较各组患者术前和术后1周、1个月、3个月、6个月、1年的裸眼视力(UCVA)、最佳矫正视力(BCVA)、眼压、角膜内皮细胞密度、有效IOL位置(ELP)、平均屈光误差绝对值、前囊口面积及并发症发生情况。结果术后1年,三组患者UCVA、BCVA均优于术前(均为P<0.05),眼压、角膜内皮细胞密度与术前相比差异均无统计学意义(均为P>0.05)。术后不同时间点,大尺寸组、小尺寸组IOL倾斜度均较对照组明显降低(均为P<0.05),小尺寸组IOL倾斜度均高于大尺寸组(均为P<0.05)。术后不同时间点,三组患者间IOL偏心量相比差异均无统计学意义(均为P>0.05)。术后6个月,眼轴长度>30 mm大尺寸组患者术后IOL偏心量及倾斜度均较小尺寸组小(均为P<0.05)。术后不同时间点对照组前囊口面积均较大尺寸组和小尺寸组明显缩小(均为P<0.05),大尺寸组患者前囊口面积与小尺寸组相比差异均无统计学意义(均为P>0.05)。术后6个月,对照组患者术后平均屈光误差绝对值均较大尺寸组和小尺寸组大,差异均有统计学意义(均为P<0.05),大尺寸组与小尺寸组组间比较差异无统计学意义(P>0.05)。随访1年示,三组均未见严重并发症发生。结论白内障超声乳化吸除联合CTR植入对高度近视合并白内障患者疗效明确。大尺寸CTR较小尺寸CTR术后IOL更稳定,对于眼轴长度>30 mm的高度近视白内障患者,建议植入较大尺寸CTR。

GH3128薄板搭接环芯组合光纤激光焊接焊缝形貌调控

航空发动机因内流道结构的入口端和出口端不同,其焊接问题是一大难题,如何在实际焊接中做到焊缝熔宽连续可控已成为研究热点。针对GH3128高温合金开展环芯组合光纤进行激光搭接焊研究,通过纯中心激光焊接得到了焊缝深度为1.5 mm的工艺参数,在此基础上通过环芯组合焊接得到了实际熔深为1.51~1.81 mm、熔宽为0.25~0.75 mm的焊缝,对环芯组合光纤激光器的中心光束和环形光束传播规律及焊缝形貌调控原因进行分析。分析发现,环形光束的加入有利于降低激光束照射到材料表面的温度梯度,从而影响焊缝成形,通过环芯组合的激光焊接可得熔深合理、熔宽连续调控的GH3128薄板搭接焊缝。

椎间孔镜下腰椎间盘髓核摘除联合纤维环缝合修复对腰椎间盘突出症的效果

目的:本文主要探究经赣南医学院第二附属医院相关检查明确为腰椎间盘突出症的患者,临床给予椎间孔镜下腰椎间盘髓核摘除联合纤维环缝合修复治疗的可行性。方法:选取2020年11月—2022年11月赣南医学院第二附属医院医治的腰椎间盘突出症患者68例作为研究对象,根据电脑随机法将其分成对照组和观察组,各34例。对照组采取腰椎小开窗手术治疗,观察组采取椎间孔镜下腰椎间盘髓核摘除联合纤维环缝合修复治疗。比较两组术前术后疼痛因子水平、腰部活动度、脊柱稳定性的差异。结果:两组术前疼痛因子水平比较,差异均无统计学意义(P>0.05)。两组术后3个月β-内啡肽、前列腺素E2、5-羟色胺水平等疼痛因子水平均低于本组术前,差异均有统计学意义(P<0.05);观察组术后3个月β-内啡肽、前列腺素E2、5-羟色胺水平等疼痛因子水平均低于对照组,差异均有统计学意义(P<0.05)。两组术前腰部活动度比较,差异均无统计学意义(P>0.05)。两组术后3个月腰椎后伸、腰椎前屈、腰椎左侧屈、腰椎右侧屈等腰部活动度均高于本组术前,差异均有统计学意义(P<0.05);观察组术后3个月腰椎后伸、腰椎前屈、腰椎左侧屈、腰椎右侧屈等腰部活动度均高于对照组,差异均有统计学意义(P<0.05)。两组术前脊柱稳定性比较,差异均无统计学意义(P>0.50)。两组术后3个月胸椎后凸角均高于本组术前,腰椎前凸角、矢状面平衡、颌眉角均低于本组术前,差异均有统计学意义(P<0.05);观察组术后3个月胸椎后凸角高于对照组,腰椎前凸角、矢状面平衡、颌眉角均低于对照组,差异均有统计学意义(P<0.05)。结论:对于存在腰椎间盘突出症的患者,临床给予椎间孔镜下腰椎间盘髓核摘除联合纤维环缝合修复效果显著,该方案不仅能够改善腰椎间盘突出症患者疼痛情况及腰部活动度,还有助于恢复脊柱的稳定性,为广大腰椎间盘突出症患者提供了更加精准、高效的治疗新选择。

PLC自控系统在北河口水厂二期工程中的应用

结合北河口水厂二期工程实例,介绍了PLC自动控制系统在自来水厂中的应用情况,对自来水厂的建设有着重要参考价值。

基于激光拍频的高温传感技术研究

为实现强电磁及其他特殊高温环境的直接温度测量,提出并演示了一种新颖、简单、低成本的光纤高温温度检测系统,该系统利用法布里—珀罗激光二极管(FP-LD)的强反馈来实时检测反射光纤的温度。传感系统由通信用激光光源——FP-LD、光纤环镜Sagnac和光电探测器(PD)组成。利用该系统实现了温度变化范围为105~1025℃的高温温度传感。实验结果表明,在光纤软化温度内其强反馈拍频信号(BFS)的频率偏移与温度变化呈线性关系,可广泛应用于冶金、航空航天等领域的高温检测。