Wavelength calibration and spectral analysis of vacuum ultraviolet spectroscopy in EAST

A vacuum ultraviolet(VUV)spectroscopy with a focal length of 1 m has been engineered specifically for observing edge impurity emissions in Experimental Advanced Superconducting Tokamak(EAST).In this study,wavelength calibration for the VUV spectroscopy is achieved utilizing a zinc lamp.The grating angle and charge-coupled device(CCD)position are carefully calibrated for different wavelength positions.The wavelength calibration of the VUV spectroscopy is crucial for improving the accuracy of impurity spectral data,and is required to identify more impurity spectral lines for impurity transport research.Impurity spectra of EAST plasmas have also been obtained in the wavelength range of 50–300 nm with relatively high spectral resolution.It is found that the impurity emissions in the edge region are still dominated by low-Z impurities,such as carbon,oxygen,and nitrogen,albeit with the application of fulltungsten divertors on the EAST tokamak.

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.

盐酸米诺环素软膏联合双波长激光治疗牙周牙髓联合病变疗效观察

目的:探讨盐酸米诺环素软膏联合掺钕铒钇铝石榴石双波长(Nd∶YAG,Er∶YAG)激光治疗牙周牙髓联合病变的疗效。方法:选择2021年3月-2022年12月笔者医院就诊的106例牙周牙髓联合病变患者,采取随机数字法按1:1比例分为软膏组(53例,患牙89颗)和联合组(53例,患牙92颗)。两组均先行基础治疗,采用双氧水或生理盐水冲洗龈沟、牙周袋,软膏组向牙袋内注射盐酸米诺环素软膏,同时进行根管治疗至完善根管填充;联合组采用盐酸米诺环素软膏处理牙周袋,联合铒钕双波长激光消毒根管。比较两组临床疗效,于术后次日、12周比较两组视觉模拟疼痛评分(VAS),记录术前,术后6周、12周牙周指标[菌斑指数(Plaque index,PLI)、出血指数(Bleeding index,BI)、牙周探诊深度(Probing depth,PD)、临床附着水平(Clinical attachment level,CAL)]、龈沟液生化指标[单核细胞趋化蛋白-1(Active monocyte chemotactic protein 1,MCP-1)、基质金属蛋白酶-8(Matrix metalloproteinase-8,MMP-8)及白细胞介素-6(Interleukin-6,IL-6)]变化并行锥形束CT测量,对比两组术后6个月并发症发生情况及美观满意度。结果:联合组治疗总有效率为90.22%,显著高于软膏组的70.79%(P<0.05);治疗结束时、治疗后第6周,两组VAS评分逐渐降低,组内不同时间点差异有统计学意义(P<0.05),且联合组评分均显著低于软膏组(P<0.05);治疗后第6周、第12周,除软膏组PLI,两组间PLI、BI、PD、CAL逐渐降低,组内不同时间点比较差异有统计学意义(P<0.05),且联合组上述指标低于软膏组(P<0.05);治疗后第6周,两组牙槽骨高度和骨密度面积均显著升高,且联合组高于软膏组(均P<0.05),两组MCP-1、MMP-8、IL-6水平均显著降低,且联合组指标显著低于软膏组(均P<0.05);联合组牙周炎、牙齿叩痛、牙齿松动等并发症发生率显著低于软膏组(P<0.05),患者美观满意度显著高于软膏组(P<0.05)。结论:盐酸米诺环素联合双波长激光治疗牙周牙髓联合病疗效显著,能显著降低患者疼痛度,改善口腔环境和牙周健康,减少炎症发生,且并发症少,满意度高,值得临床推荐。

USING WAVELENGTH ROUTING IN THE OPTICAL INTERCONNECTION COMPUTER NETWORK

The wavelength routing technology applied to computer interconnection networks is introduced in this paper.By analyzing the relation between wavelength and network routing,we describe a concept of wavelength used as network IP address,and propose a wavelength routing topology to extend the scale of a network and realize the scalability of the network.Moreover,a twin wavelength ring network that is being developed in our laboratory to implement and test the function of wavelength routing is presented,and the main units of the twin wavelength ring network are presented also.According to the testing results based on a single wavelength ring network,it proves that the optical interconnection technology is a perfect technology to provide enough communication bandwidth for computer network.

Authentication of Cassia seeds on the basis of two-wavelength HPLC fingerprinting with the use of chemometrics

High performance liquid chromatographic(HPLC) fingerprints of Cassia seed,a traditional Chinese medicine(TCM),were developed by means of the chromatograms at two wavelengths of 238 and 282 nm.Then,the two data sets were combined into one matrix.The application of principal component analysis(PCA) for this data matrix showed that the samples were clustered into four groups in accordance with the plant sources and preparation procedures.Furthermore,partial least squares(PLS),back propagation artificial neural...

高效液相色谱法同时测定归芍舒肝散中6种成分含量

目的 建立同时测定归芍疏肝散中6种成分含量的高效液相色谱法。方法 色谱柱为Sepax Amethyst C18-H柱(250 mm×4.6 mm,5μm),流动相为乙腈-0.1%磷酸水溶液(梯度洗脱),流速为1.0 mL/min,检测波长为270 nm(没食子酸)、237 nm(芍药苷、甘草苷、阿魏酸、甘草酸铵)、323 nm(藁本内酯),柱温为30℃,进样量为10μL。结果 没食子酸、芍药苷、甘草苷、阿魏酸、甘草酸铵、藁本内酯质量浓度分别在0.99~14.86μg/mL、12.92~193.83μg/mL、2.74~41.16μg/mL、0.93~13.89μg/mL、11.36~170.43μg/mL、9.03~135.46μg/mL范围内与峰面积线性关系良好(r>0.999);精密度、稳定性、重复性试验结果的RSD均小于3.0%,平均加样回收率分别为98.12%,96.24%,96.98%,97.71%,95.61%,97.91%,RSD分别为1.51%,1.55%,1.87%,1.86%,1.58%,1.60%(n=6)。结论 该方法操作简便、准确,重复性好,可用于同时测定归芍疏肝散中6种成分含量。

Quantitative Determination of Benoxinate Hydrochloride by Three Wavelength Spectrophotometry

hree wavelength spectrophotometry was used to determine the content ofbenoxinate hydrochloride.Using this method could effectively eliminate the devia-tion of background absorption caused by the change of concentration and the errorof quantitative anaiysis caused by asymmetric peaks, and at the same time the lean-ing degree of base line was corrected.This method was simple, the recovery was98. 62% 101. 86% and the coefficient of variation was 0. 551%.

Two-wavelength Lidar Measurement of Cloud-aerosol Optical Properties

Based on ullstability of inversion algorithms of the lidar equation caused by molecular scattering,a new algorithm to derive both the aerosol extinction to backscatter ratio and the extinchon coefficient profile is proposed in this paper.As shown in numerical experiments,in case of a ground-based lidar,the error in the aerosol optical depth solution can be less than 10%,and the error of < 6.7 in the aerosol exhnction to backscatter ratio can be obtained if the error in the lidar constant is<6%;and in the case of a spaceborne lidar,the present method can be ugh to determine the lidar constant at a short wavelength with an accuracy of being better than 1%.

Joint Distribution of Wave Heights and Wavelengths and Distribution of Wave Steepness

A joint probability density is derived for wavelengths and wave heights. It is asymmetric and depends only on the spectral bandwidth epsilon defined by Cartwright and Longuet-Higgins (1956). After that a theoretical probability density for wave steepness is obtained. It tends to Rayleigh distribution as epsilon --> 0. A comparison between theoretical steepness distribution and laboratory experiment result shows good agreement.

Effect of radiation-induced mean wavelength shift in optical fibers on the scale factor of an interferometric fiber optic gyroscope at a wavelength of 1300 nm

In order to analyze the effect of wavelength-dependent radiation-induced attenuation （RIA） on the mean trans- mission wavelength in optical fiber and the scale factor of interferometric fiber optic gyroscopes （IFOGs）, three types of polarization-maintaining （PM） fibers are tested by using a 60Co γ-radiation source. The observed different mean wave- length shift （MWS） behaviors for different fibers are interpreted by color-center theory involving dose rate-dependent absorption bands in ultraviolet and visible ranges and total dose-dependent near-infrared absorption bands. To evaluate the mean wavelength variation in a fiber coil and the induced scale factor change for space-borne IFOGs under low radiation doses in a space environment, the influence of dose rate on the mean wavelength is investigated by testing four germanium （Ge） doped fibers and two germanium-phosphorus （Ge-P） codoped fibers irradiated at different dose rates. Experimental results indicate that the Ge-doped fibers show the least mean wavelength shift during irradiation and their mean wavelength of optical signal transmission in fibers will shift to a shorter wavelength in a low-dose-rate radiation environment. Finally, the change in the scale factor of IFOG resulting from the mean wavelength shift is estimated and tested, and it is found that the significant radiation-induced scale factor variation must be considered during the design of space-borne IFOGs.

Calibration-free wavelength modulation spectroscopy for gas concentration measurements under low-absorbance conditions

We derive the expressions of the first and second harmonic signals on the basis of absorption spectral and lock-in theories, and determine the gas concentration according to the ratio of second and first harmonic signals. It is found that the X and Y components of the harmonic signals are influenced by the phase shift between the detection and reference signal, and the phase shift can be any value in a range from 0 to 2π, which is different from the results obtained previously. Meanwhile, an additional item caused by the residual amplitude modulation will make a great contribution to the second harmonic signal, and may not be neglected under low absorbance conditions. Theoretical analysis indicates that subtracting back-ground signal from the second harmonic signal can remove the influence of this item, and can improve the measurement accuracy of gas concentration. On this basis, we select the transition of CO2 at 6527.64 cm-1 to analyse the approximation errors during the derivation by numerical simulation and then measure the CO2 concentration under low absorbance conditions, with absorbance varying from 1‰ to 6‰.

Wavelength Dependence in the Analysis of Carbon Content in Coal by Nanosecond 266 nm and 1064 nm Laser Induced Breakdown Spectroscopy

The wavelength dependence of laser induced breakdown spectroscopy （LIBS） in the analysis of the carbon contents of coal was studied using 266 nm and 1064 nm laser radiations. Compared with the 1064 nm wavelength laser ablation, the 266 nm wavelength laser ablation has less thermal effects, resulting in a better crater morphology on the coal pellets. Besides, the 266 nm wavelength laser ablation also provides better laser-sample coupling and less plasma shielding, resulting in a higher carbon line intensity and better signal reproducibility. The carbon contents in the bituminous coal samples have better linearity with the line intensities of atomic carbon measured by the 266 nm wavelength than those measured by the 1064 nm wavelength. The partial least square （PLS） model was established for the quantitative analysis of the carbon content in coal samples by LIBS. The results show that both of the 266 nm and 1064 nm wavelengths are capable of achieving good performance for the quantitative analysis of carbon content in coal using the PLS method.

A New Method to Determine Central Wavelength and Optimal Bandwidth for Predicting Plant Nitrogen Uptake in Winter Wheat

Plant nitrogen （N） uptake is a good indicator of crop N status. In this study, a new method was designed to determine the central wavelength, optimal bandwidth and vegetation indices for predicting plant N uptake （g N m-2） in winter wheat （Triticum aestivum L.）. The data were collected from the ground-based hyperspectral reflectance measurements in eight field experiments on winter wheat of different years, eco-sites, varieties, N rates, sowing dates, and densities. The plant N uptake index （PNUI） based on NDVI of 807 nm combined with 736 nm was selected as the optimal vegetation index, and a linear model was developed with R2 of 0.870 and RMSE of 1.546 g N m-2 for calibration, and R2 of 0.834, RMSE of 1.316 g N m-2, slope of 0.934, and intercept of 0.001 for validation. Then, the effect of the bandwidth of central wavelengths on model performance was determined based on the interaction between central wavelength and bandwidth expansion. The results indicated that the optimal bandwidth varies with the changes of the central wavelength and with the interaction between the two bands in one vegetation index. These findings are important for prediction and diagnosis of plant N uptake more precise and accurate in crop management.

Effects of the long wavelength-filtered continuousspectrum on natural refractive development in juvenile guinea pigs

AIM: To investigate the effects of spectral composition and light intensity on natural refractive development in guinea pigs.METHODS: A total of 124 pigmented guinea pigs(2-week-old) were randomly assigned to three groups at high(Hi;4000 lx), medium(Me;400 lx) and low(Lo;50 lx) light intensities under a 12:12 light/dark cycle for 6 wk. Each group was subdivided into subgroups with the following spectra: broad spectrum Solux halogen light(BS), 600 nm above-filtered continuous spectrum(600F), 530 nm above-filtered continuous spectrum(530F), and 480 nm above-filtered continuous spectrum(480F;HiBS: n=10, Hi600F: n=10, Hi530F: n=10, Hi480F: n=10, MeBS: n=10, Me600F: n=10, Me530F: n=10, Me480F: n=10, LoBS: n=11, Lo600F: n=12, Lo530F: n=10, Lo480F: n=11). Refractive error, corneal curvature radius, and axial dimensions were determined by cycloplegic retinoscopy, photokeratometry, and A-scan ultrasonography before and after 2, 4, and 6 wk of treatment. Average changes from both eyes in the ocular parameters and refractive error were compared among different subgroups.RESULTS: After 6 wk of exposure, high-intensity lighting enhanced hyperopic shift;medium-and low-intensity lighting enhanced myopic shift(P<0.05). Under the same spectrum, axial increase was larger in the low light intensity group than in the medium and high light intensity groups(HiBS: 0.65±0.02 mm, MeBS: 0.67±0.01 mm, LoBS:0.82±0.02 mm;Hi600 F: 0.64±0.02 mm, Me600F: 0.67±0.01 mm, Lo600F: 0.81±0.01 mm;Hi530F: 0.64±0.02 mm, Me530F: 0.67±0.01 mm, Lo530F: 0.73±0.02 mm;Hi480F: 0.64±0.01 mm, Me480F: 0.66±0.01 mm, Lo480F: 0.72±0.02 mm;P<0.05). Under 400 lx, there was a faster axial increase in the MeBS group than in the Me480F group(P<0.05). Under 50 lx, axial length changes were significantly larger in LoBS and Lo600F than in Lo530F and Lo480F(P<0.01).CONCLUSION: Under high-intensity lighting, high light intensity rather than spectrum distributions that inhibits axial increase. Under medium-and low-intensity lighting, filtering out the long wavelength inhibits axial growth in juvenile guinea pigs.

Sensitive absorption measurements of hydrogen sulfide at 1.578 μm using wavelength modulation spectroscopy

Sensitive detection of hydrogen sulfide（H2S） has been performed by means of wavelength modulation spectroscopy（WMS） near 1.578 μm. With the scan amplitude and the stability of the background baseline taken into account, the response time is 4 s for a 0.8 L multi-pass cell with a 56.7 m effective optical path length. Moreover, the linearity has been tested in the 0–50 ppmv range. The detection limit achievable by the Allan variance is 224 ppb within 24 s under room temperature and ambient pressure conditions. This tunable diode laser absorption spectroscopy（TDLAS） system for H2 S detection has the feasibility of real-time online monitoring in many applications.

A Dual Wavelength Differential First Derivative Spectrophotometric Method for Identification and Determination of Carbon Monoxide Generated During the Microsomal Metabolism of Xenobiotics in vitro

A dual wavelength differential first derivative spectrophotometric method has been developed to standardize the concentration of a saturated aqueous solution of carbon monoxide (CO) as the standard and to identify and to determine CO formed during the microsomal metabolism of xenobiotics in vitro. The method can significantly eliminate the background interference in the assay media and increase the quantitative accuracy and the sensitivity. There is a good linear relationship between CO concentration in the range of 2～10 μmol·L 1 CO and the distance D between the first derivative peak at 415 nm amd valley at 426 nm with r=0.9999(n=5),the regression equation being C (mmol·L 1 )=17.6D 0.4, the detection limit lower than 0.1 μmol·L 1 CO. The average recoveries of CO from the assay system and the sample were 102.1%, RSD=2.9% (n=7) and 79.7%, RSD=6.8% (n=12),respectively. The RSD of within day was 4.4%(n=18),and the RSD of day to day was 6.1%(n=16). By this method, four trihaloanilines and one trihalobenzene were tested, the results showed that only 2,4,5 trifluoroaniline could be converted to CO by the incubation with rat hepatic microsomes, NADPH and oxygen, the ability of phenobarbital or dexamethasone to induce rat hepatic microsomes to catalyze CO formation was 3 or 8 times higher than that of the control.

Telecom wavelength single photon sources

Single photon sources are key components for quantum technologies such as quantum communication, computing and metrology. A key challenge towards the realization of global quantum networks are transmission losses in optical fibers. Therefore, single photon sources are required to emit at the low-loss telecom wavelength bands. However, an ideal telecom wavelength single photon source has yet to be discovered. Here, we review the recent progress in realizing such sources. We start with single photon emission based on atomic ensembles and spontaneous parametric down conversion, and then focus on solid-state emitters including semiconductor quantum dots, defects in silicon carbide and carbon nanotubes. In conclusion, some state-of-the-art applications are highlighted.

Growth and characteristics of InAsSb epilayers with a cutoff wavelength of 4.8 μm prepared by one-step liquid phase epitaxy

InAsSb epilayers with a cutoff wavelength of 4.8 μm have been successfully grown on InAs substrates by one-step liquid phase epitaxy （LPE） technology. The epilayers were characterized by X-ray diffraction （XRD）, Fourier transform infrared （PTIR） transmittance measurements and scanning electron microscopy （SEM）. The influence of different growth conditions on the optical and structural properties of the materials was studied. The results revealed that the good crystalline quality, mirror smooth surface and flat interface of InAsSb epilayers were achieved. They benefited from optimized growth conditions, i.e., sufficient homogeneity of the growth melt and a very slow cooling rate.

共振光散射增强-双波长叠加法测定对乙酰氨基苯酚的含量

建立了共振光散射增强-双波长叠加法(ERLS-DWSM)测定对乙酰氨基苯酚含量的新方法,采用荧光分光光度计在pH值为2.40的B-R缓冲介质中,考察对乙酰氨基苯酚-结晶紫体系优化实验条件下对共振光散射强度的影响。实验结果表明:对乙酰氨基苯酚的质量浓度在0.05~0.40 mg/L范围内与散射强度(ΔI_(RLS))成线性关系,检出限为0.0325 mg/L。所拟方法用于对乙酰氨基苯酚含量的测定与紫外分光光度法一致。

Synthesis and Luminescence of SrZnO_2∶Eu^(3+), Li^+ Phosphor by Long Wavelength UV Excitation

SrZnO2 ： Eu^3 ＋ , Li^＋ phosphor powder by long wavelength UV excitation was synthesized by conventional solid-state reaction method. XRD and PL were employed to characterize their properties. The resuits show that Eu^3＋ ions preferentially occupy Sr^2＋ asymmetry cationic sites, thus emitting 612 nm red light originated from ^5D0 to ^7F2 transition. The luminescent intensity can be greatly enhanced with incorporation of Li^＋ ions. The excitation efficiency in range of 350 - 400 nm also increases greatly due to incorporating Li ^＋ ions. SrZnO2 ： Eu^3 ＋ , Li^＋ is a promising redemitting phosphor by long wavelength UV excitation.