1.2μm新型放射型核壳色谱填料在加压毛细管电色谱中的性能评价

研究制备了1.2μm放射型核壳色谱填料,并对其表面进行了键合C18的改性,通过匀浆填充法制备了总长度为350 mm(固定相有效填充长度为70 mm)、内径为100μm的毛细管色谱柱,应用加压毛细管电色谱(pCEC)法考察了硫脲和萘在该色谱柱上的分离性能,同时讨论了流动相中有机相的比例、缓冲液的浓度、pH值、线性流速及施加电压对分离度的影响。实验结果表明,该新型核壳色谱填料在乙腈水体系中分离硫脲和萘时,表现出典型的反相色谱性能,当含有10 mmol/L磷酸的70%(v/v)乙腈水溶液为流动相、缓冲液pH为7.2、施加电压为-10kV时,柱效最高;在最佳线性流速为1 mm/s时,能够在8 min内实现8种中性物质的基线分离,且峰形较好,其中二苯甲酮的柱效高达19 072块/m。该研究表明1.2μm新型放射型核壳色谱填料适用于pCEC法的分离分析。

1.2 m风洞增量引射器控制系统

针对增量引射器无法实现自动控制,研制一套采用"PLC+变频器"技术的控制系统。系统通过Modbus和SSI总线通信协议构建了经济可靠的硬件平台,利用模糊控制规则进行位置和速度双反馈控制,实现了增量引射器本地/远程自动控制。运行结果表明:该系统已投入风洞试验运行1 a,能够实现增量引射器开度的自动控制,且能够提升定位控制精度。

1.2m望远镜跟踪架结构设计与分析

为提高望远镜系统的响应速度,增加伺服系统的控制带宽,望远镜的结构刚度需要得到有效保证。首先,根据望远镜力的传递路径,选择双排角接触球轴承作为承载元件,设计了适用于1.2m望远镜的地平式结构。然后,在ANSYS中使用Matrix27单元模拟轴承结构,并建立了望远镜的详细有限元模型,以预测该系统的性能。最后,通过有限元分析、模态测试以及扫频实验获得系统的性能,并借助于流场分析,研究了风载对望远镜性能的影响。仿真结果表明,系统的一阶谐振频率可达21.3Hz,能够满足前期设计要求;模态试验结果显示,系统的一阶谐振频率约为18.5Hz;扫频实验结果显示,方位轴一阶谐振频率为20.8Hz,进而验证了前期分析的正确性。流场分析显示,风载对望远镜驱动电机的力矩输出能够产生影响,控制系统校正后扰动力矩大小约为3.4Nm RMS。仿真和实验结果证明1.2m望远镜轴系的设计方案合理,测试方法可行,能够达到预期效果。

同带泵浦Ho^(3+)激光晶体1.2μm波段红外激光阈值功率（英文）

为探索同带泵浦掺杂Ho^(3+)激光晶体1.2μm波段红外激光输出,采用掺杂浓度为1 at%的Ho^(3+):LLF激光晶体作为激光增益介质,应用两种典型准三能级理论模型,计算了Ho^(3+)在5I6和5I8能级间跃迁辐射1.19μm激光的阈值功率,分析了泵浦光和激光束腰半径、激光晶体长度、吸收损耗、腔镜反射率等参量与阈值功率的变化关系,得出了吸收损耗是影响阈值功率最敏感因素的重要结论,确定了泵浦阈值功率的范围,为后续1.2μm波段红外激光实验研究提供了可靠的理论参考数据.

1.2m跨超声速风洞超扩段栅指控制系统

对 1 .2m跨、超声速风洞栅指M数控制系统作了较为详细的介绍 ,包括硬件系统的设计、硬件配置、功能选择和软件设计 ,以及本系统与风洞总压控制系统的连接和通讯 ,最后给出了 1 .2m跨。

1.2m跨超声速风洞柔壁喷管控制系统设计

1.2m风洞柔壁喷管控制系统采用恒定转速开环方式控制定位螺母位置,存在定位精度较差、试验效率低等问题,为此在保留现有电机及传动结构不变的基础上,提出一种以"PLC+变频器"技术为核心的控制方案,实现定位螺母精确位置控制,并在系统中增加监测手段,实时监测系统运行情况。经过近一年系统运行表明:定位螺母控制定位精度与喷管更换效率,达到了技术指标要求,在上位机以及触摸屏上均可以实时显示传感器监测信息,并实现软限位等功能,提升了风洞试验运行效率和运行安全。

济宁二号煤矿1.2～2.2m煤层开采工作面参数的设计与优化

为实现1.2～2.2m煤层安全高效开采,资源平衡开采,延长矿井寿命,通过对该类型工作面参数的设计与优化,使得工作面劳动组织、管理水平大幅提高。充分发挥出了工作面配套装备的最佳能力和作用,大幅提高了生产效率,提高了工效,减少了人员。为提高该条件下工作面综合管理水平和生产水平具有重要的现实意义。

离心铸造工艺参数对M2-1.2Si数控刀具材料性能的影响

采用不同的浇注温度和旋转速度进行了M2-1.2Si新型数控刀具材料的铸造试验,并进行了耐磨损性能和组织的测试与分析。结果表明:随浇注温度从1450℃提高至1650℃,旋转速度从200 r/min提高至600 r/min,材料的磨损体积和平均晶粒尺寸先减小后增大,耐磨损性能先提升后下降。M2-1.2Si刀具材料的浇注温度优选为1550℃,旋转速度优选为400 r/min。当浇注温度为1550℃时,M2-1.2Si刀具材料的磨损体积和平均晶粒尺寸分别较1450℃铸造时减小了31.3%和26.4%;当旋转速度为400 r/min时,M2-1.2Si刀具材料的磨损体积和平均晶粒尺寸较200 r/min铸造时分别减小了29%和24.3%。

皖北矿区1.2~1.8 m较薄煤层智能化综采总体配套研究

针对国内1.2~1.8 m较薄煤层综采工作面设备配套使用特点及实际使用情况,分析了现有较薄煤层综采工作面设备配套能力及使用效果。针对皖北矿区特点,提出了合理的较薄煤层综采工作面配套方案。

Thulium laser treatment for bladder cancer

Recent innovations in thulium laser techniques have allowed application in the treatment of bladder cancer.Laser en bloc resection of bladder cancer is a transurethral procedure that may offer an alternative to the conventional transurethral resection procedure.We conducted a review of basic thulium laser physics and laser en bloc resection procedures and summarized the current clinical literature with a focus on complications and outcomes.Literature evidence suggests that thulium laser techniques including smooth incision,tissue vaporization,and en bloc resection represent feasible,safe,and effective procedures in the treatment of bladder cancer.Moreover,these techniques allow improved specimen orientation and accurate determination of invasion depth,facilitating correct diagnosis,restaging,and reevaluation of the need for a second resection.Nonetheless,large-scale multicentre studies with longer follow-up are warranted for a robust assessment.The present review is meant as a quick reference for urologists.

In vitro comparison of the vaporesection of human benign prostatic hyperplasia using 70-and 120-W 2μm lasers

The purpose of the current ex vivo study was to compare the speed of vaporesection of human prostatic tissue with benign prostatic hyperplasia （BPH） and the depth of tissue damage using 70- and 120-W 2-tim laser devices. Fresh prostatic tissue specimens were obtained from five patients by open prostatectomy, and were divided into separate groups （70 and 120 W） based on the energy of the laser output （70 and 120 W, respectively）. The vaporesection speed, coagulation zone depth and the necrotic tissue layer in the prostatic tissue were evaluated. The current result showed that the speeds （mean±s.d.） of vaporesection were 5.21±0.66 and 10.39±1.15 g/5 min for the 70 and 120 W groups, respectively （P=0.000）. There was no difference in the depth of necrosis/ coagulation （0.98±0.1310.30±0.09 and 0.99±0.12/0.31±0.08 mm） for the 70 and 120 W groups, respectively. In conclusion, both 70- and 120-W 2μm laser devices had superficial tissue damage during the vaporesection of human prostate tissue; moreover, the 120-W laser offers a higher vaporesection speed than the 70-W laser.

Observation and optimization of 2 μm mode‐locked pulses in all‐fiber net anomalous dispersion laser cavity

We integrally demonstrate 2μm mode-locked pulses performances in all-fiber net anomalous dispersion cavity.Stable mode-locking operations with the center wavelength around 1950–1980 nm can be achieved by using the nonlinear polarization rotation structure and properly designing the dispersion management component.Conventional soliton is firstly obtained with a total anomalous dispersion cavity.Due to the contribution of commercial ultra-high numerical aperture fibers,net dispersion is reduced to-0.077 ps2.So that stretched pulse with 19.4 nm optical bandwidth is obtained and the de-chirped pulse-width can reach 312 fs using extra-cavity compression.Under pump power greater than 890 mW,stretched pulse can evolve into noise-like pulse with 41.3 nm bandwidth.The envelope and peak of such broadband pulse can be compressed with up to 2.2 ps and 145 fs,respectively.The single pulse energy of largely chirped stretched and noise-like pulse can reach 1.785 nJ and 1.53 nJ,respectively.Furthermore,extra-cavity compression can also contribute to a significant increase of peak power.

An Innovative Gas Sensor with On-Chip Reference Using Monolithic Twin Laser

An innovative gas sensor with on-chip reference using a monolithic twin laser is proposed. In this sensor a monolithic twin laser generates two closer laser beams with slight different wavelengths alternatively, one photodiode is used to catch both absorption and reference signals by time division multiplexing. The detection of nitrous oxide adopting this scheme using a 2.1 I^m antimonide laser and an InGaAs photodiode has been demonstrated experimentally with detection limit below i ppm. Using this on chip reference scheme the fluctuations from the optical path and devices can be compensated effectively; the sensor system is simplified distinctly.

Low noise,continuous-wave single-frequency 1.5-μm laser generated by a singly resonant optical parametric oscillator

We report a low noise continuous-wave （CW） single-frequency 1.5-μm laser source obtained by a singly resonant optical parametric oscillator （SRO） based on periodically poled lithium niobate （PPLN）. The SRO was pumped by a CW single-frequency Nd：YVO4 laser at 1.06μm. The 1.02 W of CW single-frequency signal laser at 1.5 μm was obtained at pump power of 6 W. At the output power of around 0.75 W, the power stability was better than ±l.5% and no mode-hopping was observed in 30 min and frequency stability was better than 8.5 MHz in 1 min. The signal wavelength could be tuned from 1.57 to 1.59 μm by varying the PPLN temperature. The 1.5-μm laser exhibits low noise characteristics, the intensity noise of the laser reaches the shot noise limit （SNL） at an analysis frequency of 4 MHz and the phase noise is less than 1 dB above the SNL at analysis frequencies above 10 MHz.

MXene Ti_3C_2T_x saturable absorber for pulsed laser at 1.3 μm

The excellent optical properties of MXene provide new opportunities for short-pulse lasers. A diode-pumped passively Q-switched laser at 1.3 μm wavelength with MXene Ti3C2Tx as saturable absorber was achieved for the first time. The stable passively Q-switched laser has 454 ns pulse width and 162 kHz repetition rate at 4.5 W incident pumped power. The experimental results show that the MXene Ti3C2Tx saturable absorber can be used as an optical modulator to generate short pulse lasers in a solid-state laser field.

High-Power Single-Spatial-Mode GaSb Tapered Laser around 2.0 μm with Very Small Lateral Beam Divergence

We report high-power single-spatial-mode type-I GaSb-based tapered lasers fabricated on the InGaSb/AlGaAsSb material system. A straight ridge and three different tapered waveguide structures with varying flare angles are fabricated to optimize the output power and spatial-mode performance. The best devices exhibit single-spatial-mode operation with room-temperature output power up to 350？mW in continuous-wave mode at an emission wavelength around 2.0？μm with a very small far-field lateral divergence angle, which is beyond state of the art in terms of single-spatial-mode output power.

Spectral and laser properties of Yb and Ho co-doped(YLa)_2O_3 transparent ceramic

Highly transparent Yb,Ho doped（YLa）2O3 ceramic was fabricated by conventional ceramic processing with nanopowders.The absorption and emission spectra of the ceramic was investigated.The energy transfer mechanism between Yb3＋ and Ho3＋ was also discussed.The strong emission band around 2 μm indicated that the Yb-Ho：（Y 0.90 La 0.10）2O3 transparent ceramic is a promising gain medium for the generation of 2 μm laser emissions.The laser operation of Yb-Ho co-doped（YLa）2O3 ceramic at 2.1 μm is first reported.

MICROSTRUCTURE IN LASER FUSED HIGH SPEED STEEL W6Mo5Cr4V2(M2)

Microstructure of the deepest zone of high speed steel W6Mo5Cr4V2(M2)melt after laser fu-sion was found to be so fine as the ehill zone of a solidified ingot.When narrower chill zoneformed,the long columnar dendrites grow into the melt and then the fine equiaxed cellularstructure appears in upper melt region nearly surface.The substructure of cellular grains anddendrites was observed to consist of martensite and retained austenile,while the carbides asM_6C_■ Cr_7C_3 and MC distributed at their boundaries.It is believed that the highermicrohardness up to HV_(0.1)=865-960 of the laser fused structure of the alloy is due to the oc-currence of martensite.

Optimization of High Power 1.55-μm Single Lateral Mode Fabry-Perot Ridge Waveguide Lasers

Optimization of the high power single-lateral-mode double-trench ridge waveguide semiconductor laser based on InGaAsP/InP quantum-well heterostructures with a separate confinement layer is reported. Two different waveguide structures of Fabry-Perot lasers emitting at a wavelength of 1.55 μm are fabricated. The influence of an effective lateral refractive index step on the maximum output power is investigated. A cw single mode output power of 165mW is obtained for a 1-mm-long uncoated laser.

1.2m望远镜激光光学净化室自控恒温系统

介绍了云南天文台 1 .2m望远镜激光光学净化室自动控制恒温系统的建立 ,实现了自动风流循环、净化空气 ,自动控制加热器使净化室内温度保持在恒定范围 ,从而保证光学系统工作在最佳状态。整个自动控制系统的新设计是建立在只具有风机。