633 nm热稳频He-Ne激光真空波长校准研究

633 nm热稳频He-Ne激光是激光干涉测量技术中应用最广泛的波长标准光源。633 nm激光波长是几何量计量中最重要的溯源路径。该文分析了633 nm热稳频He-Ne激光的频率特性,并以此为依据详细探讨了633 nm热稳频He-Ne激光器真空波长的校准内容和校准方法。在激光平均波长测量和波长不确定度评定中均考虑了波长复现性产生的影响,给出了校准数据处理方法和不确定度评定示例。结果显示,在633 nm热稳频He-Ne激光真空波长校准中,考虑复现性的影响是必要的。

Effects of the He-Ne laser with various power densities on the growth of cultured fibroblasts in hypertrophic scar

Objective To explore the relationship between power density of He -Ne laser with the growth of fibroblasts in hypertroph ic scar (HS).Methods The cultured fibroblasts in HS were i rradiated with He -Ne laser(Wavelenth 632.8nm),various power densities such as50mW/cm 2 ,100mW/cm 2 and 150mW/cm 2 were respectively adopted once a day for 10minutes.After 1,3and 5times o f He -Ne laser for dose rate irradiation separatedly ,the cell count and cell circle analysis were counted and examined by trypa n blue staining and flow cytometry .Results The amount of cell after 1times of 50mW /cm 2 laser irradiation was markedly more than teh control(P<0.01).The amount of cells after 5times of 100mW/cm 2 ,3and 5times of 150mW/cm 2 laser irradiation was less than the controls(P <0.05).The result of cell circle analysis was corresponded with that of the cell count.Conclusion Both stimualtion and inhibition of He -Ne laser on the growth of scar fibroblasts can be obtained with vario us power densities.Power density of He -Ne laser associates with the effects on the growth of scar fibroblasts.

The influence of He-Ne laser on scar formation after trabeculectomy in rabbits

AIMTo investigate the influence of He-Ne lasers on scar formation in the filtration canal after trabeculectomy in a rabbit model, as well as to explore the mechanisms for preventing scar formation when using He-Ne lasers in vivo.

The Effects of He-Ne Laser and Enhanced Ultraviolet-B Radiation on Proliferating-Cell Nuclear Antigen in Wheat Seedlings

The level of ultraviolet-B (UV-B) radiation on the Earth’s surface has increased due to depletion of the ozone layer. Here, we explored the effects of continuous wave He-Ne laser irradiation (632 nm, 5 mW·mm-2, 2 min·d-1) on proliferating-cell nuclear antigen (PCNA) damage repair function of wheat seedlings exposed to enhanced UV-B radiation (10.08 kJ&middotm-2·d-1) at the early growth stages. Wheat seedlings were irradiated with enhanced UV-B, He-Ne laser treatment or a combination of the two. We explored the transcripts of PCNA in each treatment group using RT-PCR. In addition, total proteins were extracted from the 7-day-old wheat leaves, analyzed by SDS-PAGE and identified by western blot. The results showed that the transcription of PCNA was weakened following UV-B radiation compared to the control. However, when seedlings were subjected to elevated UV-B-damaging radiation followed by He-Ne laser irradiation, the expression of PCNA was signifi-cantly higher than UV-B radiation alone. These results suggest that He-Ne laser has an active role in repairing the UV-B damaging effects. In order to further investigate the function of PCNA, dynamic arrangements of PCNA in wheat root-tip cells were observed with confocal laser scanning microscopy (CLSM). The PCNA was marked fluorescent dimming and strength weakened in en-hanced UV-B radiation (UV-B) compared with the control group (CK) during processing. It shows that PCNA may be involved in the separation of chromosomes.

Inhibitory effects of He-Ne laser repeated irradiation on collagen synthesis in hypertrophic scar-derived fibroblasts in culture

Objective To explore the inhibitory effects of He-Ne laser repeated irradiation on the collagen synthesis of cultured scar fibroblasts. Method Cultured fibroblasts derived from hypertrophic scars(HS) were irradiated with He-Ne laser for 30 minutes at various power densities(10,50,100 and 150 mW/cm2),once a day for 3 consecutive days.In 24 hours after repeated irradiation collagen production and type I procollagen mRNA level of fibroblasts were measured with the incorporation of 3H proline and blot hybridization techniques respectively.Results Collagen synthesis and type I procollagen mRNA level remained unchanged when the laser was irradiated at the power density of 10 mW/cm2 or 50 mW/cm2.Compared with control,collagen synthesis and type I procollagne mRNA level were significantly decreases at the power density of 100 mW/cm2 or 150mW/cm2(P< 0.05).Type I procollagen mRNA level at the power density of 150 mW/cm2 was lower than that at the 100 mW/cm2 (P< 0.05).Conclusion Repeated He-Ne laser irradiation at the power density of 100 mW/cm2 or 150 mW/cm2 can suppress collagen synthesis of cultured fibroblasts in HS.The cause of suppression may be associated with down regulation of type I procollagen mRNA expression.

Protecting effect of He-Ne laser on winter wheat from UV-B radiation damage by analyzing proteomic changes in leaves

The ultraviolet-B (UV-B) radiation can affect gene expression of plant in growth and development. Winter wheat (Triticum aestivum), as a kind of economic crop cultured in the Northern China, is also damaged by present-day ultraviolet-B (UV-B) radiation. It was reported that He-Ne lasers could alleviate cell damage caused by UV-B radiation in plants. To get the proteomic changes of wheat alleviated by He-Ne lasers, we studied protein expression profiles of winter wheat (Jin Mai NO.79) leaves by running 2-DE (two-dimensional gel electrophoresis), which allowed the identification of some significantly different gel spots. The spots were further verified by matrix-assisted laser desorption/ionization-time of flight mass spectrometry, in which they were confirmed to be winter wheat proteins. The results showed: 1) the proteomic changes between the ultraviolet-B radiation group and normal light group were significantly different on sixth day;2) The expression of some proteins such as catalase, DNA polymerase and reduced glutathione declines at the ultraviolet-B radiation group and increases at the UV-B + He-Ne laser group. This indicates UV-B could regulate genes encoding proteins in Winter wheat leaves and affect the growth of the Winter wheat. He-Ne lasers treatment could significantly alleviate UV-B-induced damage in wheat.

Enhancement of Human Blood Storage Period by Irradiation of Low Level He-Ne Laser

The aim of the present work is to investigate the effect of the He-Ne laser irradiation on the whole human blood (HB) in order to enhance the conditions of conservation. The HB was irradiated by He-Ne laser;(λ = 632 nm, continuous wave, power 30 mW, 2 mm diameter beam spot), electrical properties and complete blood count CBC were measured at three doses (0.0287, 0.0563 and 0.198 J/cm3) to the relevant best exposure dose during storage periods 9, 24, 30, 35 & 50 days. The irradiation process with the selected dose was performed by the exposure of the laser beam on the blood sample flow through narrow tube of cross section area, 0.0831 cm2. Blood dielectric parameters, (electric conductivity, dielectric constant, dielectric loss and dipole moment) and CBC, (red blood cell, white blood cell, hematocrit, hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin, and mean cell or corpuscular hemoglobin in concentration) were measured. The obtained results were compared with that of the control and showed that the best irradiation exposure dose suitable for increasing the time of blood storage with minimum changes in properties is 0.198 J/cm3 and storage period of about 50 days. The present study revealed that irradiation by He-Ne laser could be considered a good means to improve the conservation conditions of human blood.

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.

The Photopolymerization Kinetics of Acryl amide Sensitized with Toluidine Blue-Alcoholamine Induced by He-Ne Laser

Toluidine blue(TB) is a good sensitizer for the polymerization of acrylnmide(AM) induced by He-Ne laser. With TB as a sensitizer and various alcoholamine as donors, the photoredox of TB and the polymerization kinetics of AM induced by He-Ne laser were investigated. It was found that either for the photoredox of TB or for the polymerization of AM, the activity of alcoholamine increases in the order of EOA<DEOA <TEOA in TB-alcoholamine sensitized system. The overall apparent kinetic equations of AM polymerization at 30℃ have been determined. In addition, the molecular weights under various conditions was measured.

THE PHOTOPOLYMERIZATION KINETICS OF PHOTOSENSITIZED ACRYLAMIDE SYSTEM INDUCED BY He-Ne LASER

The kinetics of the photopolymerization of sensitized acrylamide (AM) system induced by He-Ne laser has been investigated. Using methylene blue (MB)-triethanolamine (TEOA) as the photosensitive system, the photopolymerization followed a nonsteady-state kinetic scheme in the initial period of polymerization (the monomer conversion C%<2%) and then followed a steady-state kinetic scheme (5% >C%>2%). Accirding to the steady-state hypothesis, the mechanism of photopolymerization was proposed. The deduced kinetic equation of the photopolymerization of AM is in good coincidence with the experimental results.

Efficacy of He-Ne Laser in Combination with Topical Clindamycin in the Treatment of Acne Vulgaris (AV)

Objective: To evaluate the efficacy of He-Ne laser in combination with topical clindamycin in the treatment of AV at 108 Military Central Hospital from Oct 2015 to Aug 2016. Subjects and Methods: 61 patients with AV were divided into 2 groups: Group 1: 31 patients were treated with He-Ne laser in combination with topical Clindamycin, Group 2: 30 patients were only treated with topical clindamycin. Laser HE-NE was applied 2 times/week for 6 weeks. Result: After 3 months of treatment Group 1: very good—51.6%, good—48.4%. Group 2: very good—30%, good—50% and moderate—20%. Conclusion: The combination of He-Ne laser with topical clindamycin shows more rapid clinical improvement compared to topical clindamycin alone in the treatment of mild and moderate AV.

Kinetic analysis of the factors limiting the output power of the Ne-CuBr UV laser

The parametric optimization of the Ne-CuBr UV laser excited by longitudinal pulsed discharge is analysed by using a self-consistent kinetic model. Consistent characteristics of the optimization process are obtained by comparing with the experimental results. Simulation results show that neon ions come into being along with considerable depletion of the ground-state copper atoms. And the optimization of the discharge tube diameter is the tradeoff between the specific output photon density and the total active volume. Both the optimal neon gas pressure and the optimal reservoir temperature result from the balance between the neon ion density and the ground-state copper atom density to arrive at a maximum of their product.

Theoretical research on enhancement of gain for Ni-like Ag 13.9 nm x-ray laser using a new two-layer target

For experiments such as on Ni-like Ag x-ray laser, driven by 1ω laser, the gain region is only several nm depth near the target surface, this paper proposes a new two-layer target, in which a thin layer （several nm depth） of silver is plated on the surface of some other materials. Furthermore, the Ni-like Ag 13.9 nm x-ray laser produced by three new kinds of two-layer target with CH, Al and Ge as foundation, was theoretically studied.

Applicability of an ultra-long-range terrestrial laser scanner to monitor the mass balance of Muz Taw Glacier,Sawir Mountains,China

Glacier mass balance is a key component of glacier monitoring programs. Information on the mass balance of Sawir Mountains is poor due to a dearth of in-situ measurements. This paper introduces the applicability of an ultra-long-range terrestrial laser scanner(TLS) to monitor the mass balance of Muz Taw Glacier, Sawir Mountains, China. The Riegl VZ?-6000 TLS is exceptionally well-suited for measuring snowy and icy terrain. Here, we use TLS to create repeated high spatiotemporal resolution DEMs, focusing on the annual mass balance(June 2, 2015 to July 25, 2016). According to TLS-derived high spatial resolution point clouds, the front variation(glacier retreat) of Muz Taw Glacier was 9.3 m. The mean geodetic elevation change was 4.55 m at the ablation area. By comparing with glaciological measurements, the glaciological elevation change of individual stakes and the TLS-derived geodetic elevation change of corresponding points matched closely, and the calculated balance was-3.864±0.378 m w.e.. This data indicates that TLS provides accurate results and is therefore suitable to monitor mass balance evolution of Muz Taw Glacier.

He-Ne激光对小麦幼苗增强UV-B辐射损伤修复的影响

采用 He-Ne激光 ( 5m W/ mm2 )来辐照处理经增强 UV-B( 1 0 .8k J· m- 2 · d- 1)辐射损伤的小麦幼苗 ,通过荧光光谱测定其中双链 DNA( ds DNA)的含量 ,分析研究了 He-Ne激光对小麦 DNA UV-B损伤的切除修复的影响和机制 ,以探明激光对 UV-B损伤的修复途径及机制 .结果表明 :He-Ne激光能明显增强 UV-B辐射处理后小麦种子的萌发力 ;小麦对 UV-B辐射损伤具有一定的切除修复能力 ,切除修复的高峰期发生在 UV-B辐射后 4～ 6 h内 ;He-Ne激光主要通过促进小麦的切除修复途径影响小麦对 UV-B损伤的修复 ,而且能增强小麦的切除修复能力 ,其促进作用在修复高峰期 ( 5h)表现尤为明显 .

He-Ne激光和KT对小麦种子萌发与幼苗生长的影响

以冬小麦为实验材料,研究了单纯He-Ne激光处理、单纯激动素处理和He-Ne激光与激动素复合处理对小麦种子发芽率、生长势及叶绿素、可溶性蛋品质和可溶性糖合成的影响。结果表明:(1)三种处理均能提高种子的活力,促进种子萌发,相比之下He-Ne激光处理效果最好。(2)三种处理对幼苗生长、可溶性蛋白质、可溶性糖以及叶绿素的合成具有显著的促进作用,从而加快了光合作用的进程。提高了幼苗干物质的含量,其中He-Ne激光与激动素复合处理效果最好,单纯He-Ne激光处理效果次之。

He-Ne激光对小麦幼苗增强UV-B辐射损伤的修复效应

采用 He- Ne激光辐照对增强 UV- B辐射后小麦幼苗的损伤修复作用进行了研究。小麦种子在盛有湿滤纸的培养皿内 2 5℃下进行萌发。萌发后小麦幼苗在光合有效辐射 (PAR)为 2 2 0 μmol· m- 2 · S- 1的光背景下 ,经 1 0 .0 8k J·m- 2 · d- 1的增强 UV- B辐射 ,然后再用 5m W· mm- 2的 He- Ne激光进行辐照。通过小麦幼苗丙二醛 (MDA)、抗坏血酸 (As A)、超氧化物歧化酶 (SOD)和紫外吸收物含量及活性的变化 ,测定了 He- Ne激光对小麦 UV- B损伤修复的作用。结果显示 ,MDA、SOD、As A和紫外吸收物的变化同小麦幼苗损伤修复的能力相关联。He- Ne激光辐照可使 UV- B辐射后小麦幼苗 MDA的含量明显减少、As A含量明显增加、SOD活性增强及紫外吸收物含量显著增加。说明增强 UV- B对小麦幼苗生理水平的辐射损伤 ,能够被一定剂量的 He- Ne激光辐照而得到部分修复。但是 ,采用同等波长和功率的红光照射 ,其 MDA、SOD、As A和紫外吸收物均无明显变化 。

He-Ne激光选育高木质素降解率的白腐真菌L_x

用 He-Ne激光对一株木质素降解活性较高的白腐真菌 L1进行选育 .将该菌的菌丝体和原生质体多次照射诱变 ,结果得出 :在波长 63 2 .5 nm,用功率为 6m W和 7m W照射该菌的菌丝体 ,选育出的菌株 L6 和 L7木质素降解率可达 3 8.1 %和 3 9.88% ,比出发菌株 L1提高了 3 3 %和 3 9% .用功率 9m W的 He-Ne激光辐照原生质体 ,照射 2 0 min时 ,原生质体致死率已达 1 0 0 % .在照射时间为 1 0 min时 ,选育出一株木质素降解率达 43 .0 3 %的菌株 Lx,比出发菌株 L1提高了 5 0 % .同工酶分析显示该菌株发生了稳定的遗传突变 .

采用He-Ne激光诱变选育速生高产茯苓菌

采用He- Ne激光对茯苓菌F9进行了 2次照射诱变处理 ,选育到 2株生长速率和产量均有较大提高的二次激光诱变株F2 . 10及F2 . 9。它们在PDA平板上培养 4d ,生长速率分别比原始菌株F9提高了 91 .1%和86 .8%。摇瓶发酵周期缩短了 2d左右 ,摇瓶发酵 5d后 ,它们的生物量最高 ,分别达到 39. 1g/ 10 .0mL和 37 .7g/ 10. 0mL ,比原始菌株F9培养 7d的最高生物量 2 .4 g/ 10. 0mL分别提高了 6 2 . 9%和 5 7 .1%。经传代培养分析 ,诱变株的产量性状稳定。表明激光诱变是获得高产茯苓菌的有效途径。

高功率碘稳频He-Ne激光波长参考源

为满足精密测量对高稳定激光单色光源功率的要求,研制了全封闭、一体化结构的高功率碘稳频He-Ne激光系统。对该系统所采用的饱和光谱探测原理、吸收峰识别与锁定方法以及激光波长的稳频效果进行了研究。首先,介绍了三次谐波方法探测饱和吸收光谱的基本原理,分析了其消除功率背景的方法。接着,分析了碘稳频激光中一体化谐振腔的稳定性,详细讨论了谐振腔轴向膨胀和横向非对称形变对输出功率的影响。然后,分析了激光输出功率与碘分子饱和吸收峰之间的对应关系,介绍了利用二次谐波信号实现吸收峰识别的可行性,并展示了高稳定谐振腔的长时间锁定能力。最后,分析了高功率碘稳频He-Ne激光波长的稳定度与复现性。实验结果表明:高功率碘稳频He-Ne激光波长抖动标准差为33 kHz,1 000 s稳定度达到4.1×10^(-13);三个月内激光波长的复现性达到3.3 kHz (7.0×10^(-12)),与国际计量委员会推荐的频率差为3.0 kHz。