Simultaneous Determination of Six Constituents in Cangbaiqutong Capsule by HPLC Wavelength Switching Technique

[Objectives] To establish a high performance liquid chromatography (HPLC) wavelength switching method for the simultaneous determination of content of six constituents (phellodendrine chloride, gentiopicrin, paeoniflorin, tetrandrine, berberine hydrochloride and paeonol) in Cangbaiqutong capsules, and provide a scientific basis for the comprehensive evaluation of the quality of Cangbaiqutong capsule.[Methods] The chromatographic column of Waters XSELECT CSH-C 18 (4.6 mm × 150 mm, 5 μm), the mobile phase of acetonitrile-0.1% phosphate solution, gradient elution (0-15 min,10%-18% A;15-30 min,18%-50% A;30-35 min, 50%-10% A);the flow rate of 1.0 mL/min, wavelength switching of 284 (0-7 min, phellodendrine), 274 (7-10 min, gentiopicrin), 230 (10-14 min, paeoniflorin) and 274 nm (14-35 min, tetrandrine, berberine hydrochloride, paeonol), the injection volume of 10 μL.[Results] There was a good linear relationship between the area of chromatographic peak and the injection volume of phellodendrine chloride, gentiopicrin, paeoniflorin, tetrandrine, berberine hydrochloride and paeonol in the range of 0.150-1.504, 0.768-7.680, 1.096-10.960, 0.220-2.200, 0.296-2.956, 0.0345-0.345 μg, respectively;the average recovery rates ( n =6) were 98.3%, 99.2%, 98.8%, 98.8%, 99.1% and 98.2%, respectively;the RSD value was 1.32%, 1.46%, 1.08%, 1.31%, 1.26% and 1.21%, respectively.[Conclusions] The method can be used to determine many kinds of constituents at the same time, and the operation is simple, accurate and reproducible, and can be used for the quality control of compound Cangbaiqutong capsules.

Investigation on wavelength switching of widely tunable SGDBR lasers

The sampled-grating distributed Bragg reflector(SGDBR) laser is a typical and important photonic integrated device,and has potential wide application to agile optical networks.A new dynamic model for this device has been developed,which combines the traveling-wave method for the active region and the transfer-matrix method for the passive sections into a single procedure.The behaviors of wave-length switching of the SGDBR laser,which include the transient spectrum and mode competition,have been studied in detail using this model.A new efficient way has been proposed to improve the wavelength switching performance only by increasing the coupling coefficients without changing the carrier density.

Passively Q-switched dual-wavelength Yb：LSO laser based on tungsten disulphide saturable absorber

We demonstrate a passively Q-switched Yb：LSO laser based on tungsten disulphide （WS2） saturable absorber op- erating at 1034 nm and 1056 nm simultaneously. The saturable absorbers were fabricated by spin coating method. With low speed, the WS2 nanoplatelets embedded in polyvinyl alcohol could be coated on a BK7 glass substrate coated with high-refractive-index thin polymer. The shortest pulse width of 1.6 gs with a repetition rate of 76.9 kHz is obtained. As the pump power increases to 9 W, the maximum output power is measured to be 250 mW, corresponding to a single pulse energy of 3.25 μJ. To the best of our knowledge, this is the first time to obtain dual-wavelength Q-switched solid-state laser using few-layer WS2 nanoplatelets.

QoS aware routing and wavelength allocation in optical burst switching networks using differential evolution optimization

The issue of burst losses imposes a constraint on the development of Optical Burst Switching （OBS） networks. Heavy burst losses strongly affect the Quality of Service （QoS） intended by end users. This article presents a QoS aware Routing and Wavelength Allocation （RWA） technique for burst switching in OBS networks. The RWA problem is modeled as a bi-objective Integer Linear Programming （ILP） problem, where objective functions are based on minimizing the number of wavelengths used and the number of hops traversed to fulfill the burst transmission requests for a given set of node pairs. The ILP model is solved using a novel approach based on a Differential Evolution （DE） algorithm. Analytical results show that the DE algorithm provides a better performance compared to shortest path routing, which is a widely accepted routing strategy for OBS networks.

Mathematical Model for Dynamic Pump-Wavelength Selection Switch

This paper presents a mathematical model based on dynamic pump-wavelength selection for an optical packet switch (OPS). In the OPS, multiple packets that carry the same wavelength from different input ports could be addressed to the same output port at the same time slot. This condition is called wavelength contention. Of those contended packets, only one is forwarded to the output fiber while the others are dropped. Parametric wavelength conversion is used to convert the contended wavelengths into available non-contending wavelengths. The OPS based on the dynamic pump-wavelength selection scheme, where the pump-wavelengths are adjusted based on the requests in every time slot, uses a heuristic matching algorithm to minimize the number of packet losses. However, there is no guarantee that the heuristic algorithm outputs the optimum result. The mathematical model presented in this paper is used to confirm the performance of the heuristic matching algorithm for the DPS-based OPS. A simulation shows that the heuristic matching algorithm achieves the same performance as the optimum solution provided by the mathematical model.

A compact graphene Q-switched erbium-doped fiber laser using optical circulator and tunable fiber Bragg grating

We demonstrate a passively Q-switched tunable erbium-doped fiber laser （EDFL） based on graphene as a saturable absorber （SA）. A three-port optical circulator （OC） and a strain-induced tunable fiber Bragg grating （TFBG） are used as the two end mirrors in an all-fiber linear cavity. The Q-switched EDFL has a low pump threshold of 23.8 mW. The pulse repetition rate of the fiber laser can be widely changed from 9.3 kHz to 69.7 kHz by increasing the pump power from 23.8 mW to 219.9 mW. The minimum pulse duration is 1.7 p.s and the highest pulse energy is 25.4 nJ. The emission wavelength of the laser can be tuned from 1560.43 nm to 1566.27 nm by changing the central wavelength of the straininduced TFBG.

Design of LCoS-Based Twin 1×40 Wavelength Selective Switch

Wavelength selective switch(WSS)is the crucial component in the reconfigurable optical add/drop multiplexer(ROADM),which plays a pivotal role in the next-generation all-optical networks.We present a compact architecture of twin 1×40 liquid crystal on silicon(LCoS)-based WSS,which can be regarded as a 4f system in the wavelength direction and a 2f system in the switching direction.It is designed with theoretical analysis and simulation investigation.Polarization multiplexing is employed for two sources of twin WSS by polarization con-version before the common optical path.The WSS system attains a coupling efficacy exceeding 96%for 90%of the ports through simulation optimization.The 3 dB bandwidth can be achieved by more than 44 GHz at a 50 GHz grid for all 120 channels at all deflection ports.This work establishes a solid foundation for developing high-performance WSS with larger port counts.

Simultaneous all-solid-state multi-wavelength lasers——a promising pump source for generating highly coherent terahertz waves

A diode-end-pumped Nd：YAG dual-wavelength laser operating at 1319 and 1338 nm is demonstrated. The maximum average output power of the quasi-continuous wave linearly polarized dual-wavelength laser is obtained to be 2.1 W at a repetition rate of 50 kHz with an output power instability of less than 0.38% and beam quality factor M^2 of 1.45. Using the two lines, the highly coherent and narrow linewidth terahertz radiation of 3.23 THz can be generated in an organic 4-N, N-dimethylamino-methyl-stilbazolium tosylate （DAST） crystal. Meanwhile, the multi-wavelength red laser at 659.5, 664 and 669 nm is generated by frequency doubling and sum frequency processes in a lithium triborate （LBO） crystal. The average red laser output power is enhanced up to 1.625 W at a repetition rate of 15 kHz with an output power instability of better than 0.53% and beam quality factor M^2 of 6.05. Using the three lines, it is possible to generate the multi-wavelength THz radiation of 3.3, 3.43 and 6.73 THz in an appropriate difference frequency crystal.

HPLC多波长切换指纹图谱结合化学计量学研究白术土炒前后成分变化规律

目的 建立测定白术、土白术水溶性和脂溶性成分的高效液相色谱-二极管阵列检测器(HPLC-DAD)多波长切换指纹图谱,结合化学计量学研究白术土炒前后成分变化规律。方法 建立白术、土白术水溶性及脂溶性成分的HPLC-DAD多波长切换指纹图谱测定方法,测定17批白术和17批土白术的HPLC指纹图谱,采用相似度评价、聚类分析、OPLS-DA分析进行统计分析。结果 白术指纹图谱中共标定9个共有峰,土白术指纹图谱中共标定10个共有峰。指认了新绿原酸、绿原酸、白术内酯Ⅰ、白术内酯Ⅱ、白术内酯Ⅲ及苍术酮6个成分,土炒后1号峰、4号峰(白术内酯Ⅲ)、8号峰(白术内酯Ⅱ)峰面积增加,2号峰(新绿原酸)、3号峰(绿原酸)、5号峰、6号峰、7号峰、9号峰(白术内酯Ⅰ)、10号峰(苍术酮)土炒后峰面积均降低。结论 所建立指纹图谱方法能够系统地分析白术土炒前后化学成分的变化规律,可为进一步规范白术土炒工艺,制定土白术专属性质量标准,研究土白术炮制原理提供实验基础。

Deployment of the Content-Based Switching Network

In this paper, we propose a hybrid network architecture, called Content-based Switching Network (CSN), and its signaling scheme, which addresses the issues inherent to conventional hybrid networks which implement a horizontal separation over the entire network (from edge to edge). We will show how CSN nodes can flexibly choose their switching paradigm (store-and-forward, optical bypass, electrical bypass) during a path establishment. Contents being transferred in one piece from end-to-end, the concept of packet can be eluded in our network, and, in particular, the user is able to avoid complicated transport layer functions, like TCP, if they are not essential. In CSN, very large contents have a special status, since they cannot be store-and-forwarded. We will show how the resource management has been designed in order to deal with such contents. A section is dedicated to deployment and feasibility issues. Simulation results will show that CSN can successfully transfer contents at 1 Gbps and 10 Gbps, the maximum speed being limited by the state-of-the-art device technologies when buffering is required (memory speed), while no major limit is observed in the case of all-optical transfers other than the optical fiber speed. Other results concern the deployment of CSN from an unclean slate approach. They will show how beneficial can be the deployment of CSN from an Optical Circuit Switching network.

Simulation of Optical Packet-Switched Metropolitan Area Network

This paper introduces architectures of two types optical packet switched metropolitan area networks and their media access control protocols. We have designed related network simulation systems. With these simulation systems, the characteristics and performance of the two MANs can be achieved.

双波长LD泵浦Nd^(3+)∶YAG免温控被动调Q激光器的研究

传统的固体激光器体积、重量大,功耗高,限制了其在空间受限设备中的应用。被动调Q的LD泵浦免温控固体激光器省去了复杂的温度控制装置,调Q机构简单,能够满足复杂温度环境的特殊应用场景的小型化、低功耗要求。提出了基于双波长LD泵浦实现宽温度范围免温控阈值自适应的1.06μm激光脉冲输出方法。基于Nd∶YAG晶体设计了角锥棱镜谐振腔,仿真分析了LD泵浦源到激光棒的面心距对热负载的影响,并确定4 mm的最佳面心距。数值分析了相同泵浦功率下-40~60℃温度范围内激光静态能量输出变化,以及不同初始透过率的可饱和吸收体对激光阈值脉宽的影响。计算结果表明在-37℃~60℃范围内,阈值脉宽都在200μs以下,阈值脉宽最低点达到了29.4μs。构建主波实时探测的阈值自适应调节装置并搭建实验系统,实验结果表明,在温度范围为-35~60℃时,阈值脉宽变化范围为40~180μs。采用激光腔体一体加工成型,应用轻量化的铝合金材料,实现工程化应用,体积83.5 mm×44 mm×29.5 mm,重量约为230 g。在23.8%初始透过率的饱和吸收体条件下实现单脉冲输出能量42 mJ,脉冲宽度5.2 ns。

环回互连数据中心光网络(特邀)

【目的】针对数据中心交换网络,文章提出了一种基于商用光交换器件的环回互连数据中心光网络(LIDON)。【方法】文章所提架构主要由机架扩展模块(REM)和环回互连模块(LIM)两个光交换模块组成。数据中心中的组内和组间交换通过这两个模块共同工作来实现。通过开发波长选择开关诊断端口的新功能,LIDON具有较高的路径多样性和容错性等特点。此外,文章所提方案可以保证LIDON的可扩展性,以支持交换容量的灵活扩展。【结果】交换器件的滤波性能实验验证了LIDON交换网络分离传输组内和组间信号的可行性。对不同业务的任务完成时间的仿真验证了该架构的容错性能。【结论】测试和仿真结果展示了文章所提架构具有较高路径多样性和容错性能。

A Comparison and Performance of Different Optical Switching Architectures

Optical Packet Switching (OPS) and transmission networks based on Wavelength Division Multiplexing (WDM) have been increasingly deployed in the Internet infrastructure over the last decade in order to meet the huge increasing demand for bandwidth. Several different technologies have been developed for optical packet switching such as space switches, broadcast-and-select, input buffered switches and output buffered switches. These architectures vary based on several parameters such as the way of optical buffering, the placement of optical buffers, the way of solving the external blocking inherited from switching technologies in general and the components used to implement the WDM. This study surveys most of the exiting optical packet switching architectures. A simulation-based comparison of input buffered and output buffered architectures is presented. The performance analysis of the selected two architectures is derived using simulation program and compared at different scenarios. We found that the output buffered architectures give better performance than input buffered architectures. The simulation results show that the-broadcast-and-select architecture is attractive in terms that it has lees number of components compared to other switches.

UPLC-波长切换法测定柴银颗粒中6种成分的含量

目的建立超高效液相色谱(UPLC)-波长切换法同时测定柴银颗粒中6种成分(绿原酸、木犀草苷、黄芩苷、黄芩素、汉黄芩苷与汉黄芩素)含量的方法。选用Shim-pack C_(18)(100 mm×2.1 mm×1.9μm)色谱柱,方法选择乙腈-0.1%磷酸溶液为流动相,流速为0.3 ml/min,进行梯度洗脱,绿原酸和木犀草苷的检测波长为327 nm,黄芩苷、汉黄芩苷、黄芩素和汉黄芩素的检测波长为275 nm,柱温为35℃,进样量为5μl。结果绿原酸、木犀草苷、黄芩苷、汉黄芩苷、黄芩素与汉黄芩素质量浓度的线性范围分别为12.12~121.22μg/ml(r=0.9999)、2.07~20.74μg/ml(r=0.9998)、10.56~105.57μg/ml(r=0.9998)、1.55~15.48μg/ml(r=0.9999)、2.16~21.63μg/ml(r=0.9997)、1.21~12.13μg/ml(r=0.9996),平均回收率分别为95.62%(RSD=2.55%,n=6)、94.59%(RSD=2.16%,n=6)、93.66%(RSD=1.78%,n=6)、96.04%(RSD=3.66%,n=6)、94.66%(RSD=2.85%,n=6)、93.92%(RSD=2.46%,n=6)。结论UPLC-波长切换法的结果准确可靠,具有较好的重复性,为柴银颗粒质量控制提供了有效的测定方法。

2μm可调谐全光纤脉冲激光器

本文采用光纤尾纤型马赫曾德型(MZ)结构的周期性铌酸锂(LiNbO 3)电光强度调制器进行主动调Q,设计了在环形腔结构中加入可调谐滤波器,实现了波长在1882 nm~1992 nm可调谐脉冲激光的稳定输出。调节施加在调制器上的信号频率,产生了激光器重复频率在15~70 kHz可调的脉冲激光。在重复频率为15 kHz时,泵浦功率为1 W时,获得最大单脉冲能量6.4μJ,峰值功率5.1 W。本研究具有全光纤化,波长大范围可调等优势,有助于进一步探索调Q脉冲激光的可调谐范围及其潜在应用。

基于光开关阵列的灵活TWDM-PON系统研究

为了满足接入网日益增长的业务流量需求,解决当前因架构固定、资源维度有限而导致的不同无源光网络之间波长无法灵活分配的的问题,提出了一种将发射固定波长的激光器与光开关阵列组合的时分波分混合复用无源光网络结构。在这种新的系统结构中,下行波长资源被集中化处理,采用在局端配置光开关阵列的方法实现波长在不同网络之间的灵活调度,降低系统总体成本的同时能够用来解决负载平衡、流量“潮汐效应”、网络资源利用率低下等问题。通过理论分析和仿真实验验证了系统的可行性,得出该结构与传统无源光网络的兼容性、波长资源的共享性、系统低成本以及节能的特点。结果表明,在没有色散补偿的情况下,信号可以覆盖30 km的传输距离,同时服务512个用户。该研究可以为典型应用场景下的无源光网络部署提供参考。

光互连数据中心网络架构与业务路由技术研究

【目的】目前已提出的数据中心光互连网络结构中,大多将光网络用于交换机间的机架间通信,而机架内服务器之间的通信则通过电以太网交换机实现。由于电以太网交换机功率较大且数量众多,目前所提出的数据中心光互连网络存在能耗高、带宽低和分组时延大等问题。为了进一步改善数据中心光互连网络的性能,文章提出了一种基于可重排无阻塞三级Clos网络的机架内光互连网络结构。【方法】在此结构中,机架内服务器通过1个三级Clos网络实现相互连接,同时结合文章所提的多波长路由算法可实现机架内服务器间的无阻塞通信。【结果】文章使用OMNET++软件进行了仿真验证,结果显示,文章所提结构的吞吐量在同等条件下比传统机架内电交换提高20%,端到端平均时延减少90%,能耗减少67%。【结论】通过仿真对比可知,文章所提结构可以改善数据中心光互连网络的带宽利用、分组时延及能耗等性能。

HPLC-DAD法测定铁筷子中香草酸和阿魏酸的含量

本研究旨在建立高效液相色谱法(HPLC)-二极管阵列检测器(DAD)测定铁筷子药材中香草酸和阿魏酸的含量。采用ZORBAX Eclipse Plus C18色谱柱(4.6mm×25.0 mm,5μm);流动相为乙腈(A)-0.2%磷酸水(B),梯度洗脱,流速1.0 mL/min;柱温25℃;检测波长(0~15 min,280 nm,香草酸;15~70 min,327 nm,阿魏酸);进样量10μL。香草酸、阿魏酸的分离度均>1.5,分离效果好,分别在22.72~727.00μg/mL、9.69~310.00μg/mL范围内呈良好线性关系,r> 0.999;平均回收率(RSD)分别为101.08%(3.09%)、98.98%(3.11%),铁筷子样品S1中阿魏酸和香草酸的含量最高,S1中香草酸含量为(0.77±1.42) mg/g,阿魏酸含量为(0.36±1.32)mg/g。本研究建立的HPLC-DAD波长切换法灵敏、准确,重复性好,可用于铁筷子药材中香草酸和阿魏酸含量的测定。

HPLC波长切换法同时测定小儿氨酚那敏片中对乙酰氨基酚和马来酸氯苯那敏的含量

目的建立同时测定小儿氨酚那敏片中对乙酰氨基酚和氯苯那敏含量的高效液相色谱法,为提高该药品的质量标准提供依据。方法用HPLC多波长切换法。色谱柱为Shim-pack VP-ODS(150 mm×4.6 mm,5μm),流动相为0.025 mol·L^(−1)磷酸盐缓冲液(pH 3.0)-甲醇乙腈(1∶1)溶液(梯度洗脱)。流速为1.0 mL·min^(−1)。检测波长:310 nm(对乙酰氨基酚)、225 nm(氯苯那敏)。柱温为30℃。进样量为10μL。结果对乙酰氨基酚与氯苯那敏的分离度良好,溶剂和辅料均不产生干扰。对乙酰氨基酚在0.58~1.73 mg·mL^(−1)、氯苯那敏在2.50~7.49μg·mL^(−1)范围内与峰面积呈良好线性关系(r≥0.9997);精密度、重复性、稳定性(24 h)实验的RSD值均小于2.0%(n=6);加样回收率分别为98.14%~101.74%、98.00%~101.54%,RSD值均小于2.0%(n=9);耐用性考察符合要求。结论建立的HPLC多波长切换法操作简便、专属性强、稳定性好,可同时测定小儿氨酚那敏片中对乙酰氨基酚和氯苯那敏的含量。