火焰原子吸引光谱法测定鱼腥草、西洋参和茯苓中的铜含量

用硝酸-高氯酸混合酸(4:1)消化鱼腥草、西洋参和茯苓,在波长324.8nm处,利用火焰原子吸收光谱法测定鱼腥草、西洋参和茯苓中铜的含量.线性回归方程为A=0.1708C 0.0004,相关系数r=0.9997,线性范围为0-5μg/ML,检出限为0.0035μg/ML,测定结果的相对标准偏差为0.09%,加标回收率为98.0%-104.2%.     

裸玻碳电极直接电化学发光测定诺氟沙星含量

基于诺氟沙星能够显著增强过硫酸根的电化学发光信号,建立了一种灵敏、简便而且价廉的测定诺氟沙星含量的新方法。在最佳实验条件下,诺氟沙星浓度在0.141—6.33μg/mL范围内,与电化学发光信号强度呈良好的线性关系,线性回归方程为IECL=116.4+73.5CNFLX(μg/mL),r=0.9968,检出限为0.039μg/mL(S/N=3)。对4.22μg/mL的诺氟沙星平行测定11次,RSD为1.3%,表明该方法具有良好的重现性,并成功地应用于人尿样中诺氟沙星含量的测定。     

RP-HPLC同时测定辛芷提取物中的木兰脂素和欧前胡素

建立了RP-HPLC同时测定辛芷提取物中木兰脂素和欧前胡素的含量。取辛芷鼻提取物,用甲醇溶解,0.45μm微孔滤膜过滤,取续滤液进样检测。采用Hedera C8分析柱(4.6mm×250mm,5μm),流动相为乙腈-水(50∶50,V/V),流速1mL/min,柱温25℃,检测波长为278nm。木兰脂素、欧前胡素的线性范围分别为21.88—350.00μg/mL(r=0.9996,n=5)、1.25—20.00μg/mL(r=0.9997,n=5),平均回收率分别为103.56%、102.79%。该法简便、快速,结果准确可靠。     

高效液相梯度洗脱法测定银黄含片中黄芩苷、绿原酸和芦丁

建立了反相高效液相色谱法同时测定银黄含片中的黄芩苷、绿原酸和芦丁。采用HypersilODSC18柱(200mm×4.6mm,粒径5μm),流动相A:甲醇-水-乙酸(10∶88∶2)和流动相B:甲醇-水-乙酸(88∶10∶2),梯度洗脱程序0min(A∶B/97∶3)-10min(A∶B/73∶27)-25min(A∶B/20∶80)-36min(A∶B/20∶80);流速1.0mL/min;检测波长为327nm和280nm;柱温25℃。黄芩苷线性范围为0.051—0.512μg/mL,r=0.9990,样品的平均加标回收率为98.23%,(RSD为2.13%);绿原酸线性范围为0.059—0.592μg/mL,r=0.9996,样品的平均加标回收率为97.61%,(RSD为2.13%);芦丁线性范围为0.087—0.868μg/mL,r=0.999,样品的平均加标回收率为98.56%,(RSD为1.13%),该方法专属性强,结果稳定,重现性好,能有效地控制药品的主成分含量,具有较强的实用价值。     

HPLC同时测定清胃黄连丸中的4种有效成分

建立同时测定清胃黄连丸中栀子苷、黄芩苷、小檗碱和巴马汀含量的HPLC方法。结果表明,栀子苷、黄芩苷、小檗碱和巴马汀分别在2.07—66.2μg/mL（r=0.9997）、2.72—86.9μg/mL（r=0.9998）、2.23—71.3μg/mL（r=0.9998）、2.13—68.1μg/mL（r=0.9998）范围内与峰面积呈良好的线性关系;平均回收率分别为103.2%（RSD=3.27%）、106.7%（RSD=2.46%）、103.5%（RSD=2.13%）、95.7%（RSD=2.68%）。该方法简便可行、重现性好、能更好的控制清胃黄连丸的质量。     

苯酚红褪色分光光度法测定小麦粉中的痕量溴酸钾

对苯酚红褪色分光光度法测定小麦粉中痕量溴酸钾进行了研究。实验考察了各种因素如酸度、苯酚红的浓度和用量、反应时间和温度等对测定的影响。结果表明,在最优化的实验条件下(最大吸收波长为504nm,0.5mol/L盐酸,1.00mL 1.00×10-4mol/L苯酚红,85℃水浴条件下加热10min),溴酸钾在0—0.45μg/mL范围内符合比耳定律,线性回归方程为ΔA=0.6094C-0.0013(C:μg/mL,相关系数r=0.9991),摩尔吸光系数ε=3.6×106L.mol-1.cm-1,检出限为0.01μg/g(取样量5g)。将该法用于小麦粉中痕量溴酸钾的测定,样品加标回收率在93%—103%,相对标准偏差RSD<5%,结果满意。     

胶束电泳法测定五味子中的3种有效成分

建立了基于一种快速、高效分离与测定五味子中五味子甲素、五味子乙素和五味子酯甲含量的胶束毛细管电泳-紫外检测分析新方法。以毛细管(70cm×50μm i.d×375μm o.d)为分离通道,在最佳电泳介质(30mmol/L SDS,pH=7.2,20mmol/L磷酸盐缓冲溶液)中,当分离电压为21kV时,3种待测物质在11min内达到基线分离。在254nm波长处,五味子甲素、五味子乙素和五味子酯甲的线性响应范围分别为5.0—150.0μg/mL、1.0—100.0μg/mL和1.5—150.0μg/mL;检出限分别为1.0、0.22μg/mL和0.4μg/mL。该方法具有良好的重现性,以100.0μg/mL的五味子甲素、五味子乙素和五味子酯甲测定其保留时间和峰高相对标准偏差(RSD)(n=7)均小于2.98%。本方法用于中药五味子中五味子甲素、五味子乙素和五味子酯甲的含量测定,结果令人满意。     

荧光法直接测定环境水中邻羟基苯甲酸和苯酚混合物的含量

本文研究了用荧光分光光度法测定环境水中苯酚和邻羟基苯甲酸的含量,在pH＞11时直接测定邻羟基苯甲酸的含量,波长为λex/λem=289/338nm,检出限为3.4ng/mL,线性范围0-6.0μg/mL.在pH=6,波长为λex/λem=270/297nm测得苯酚含量,检出限为4.0ng/mL,线性范围在0-0.85μg/mL,回收率为98%-101%,结果满意.     

硫氰酸钠中氰根测定方法的探讨

建立了分光光度法测定硫氰酸盐中氰根含量的方法。通过向硫氰酸盐溶液中加入硫酸亚铁饱和溶液,使氰根转化为普鲁士蓝而显色,测定其在700nm波长处的吸光度,避免了硫氰酸根的干扰。该法在氰根含量为6—30μg/mL范围内呈很好的线性,得线性回归方程为y=0.0266x-0.0537,相关系数r为0.9999。本方法测定氰根浓度相对标准偏差小于0.6%,加标回收率为97.0%—105.0%,检出限为2.04μg/mL,具有准确、快速、简便等特点。     

食品中汞含量的直接进样测定

建立直接进样测定食品中汞含量的无损分析方法.在最佳测定条件下的线性回归方程为y=0.0261x 0.0006,线性范围为0.5-10.0μg/mL,相关系数为r=0.9999,检出限为0.0044μg/mL,加标回收率为98.7%-104.3%,RSD为0.38%.本方法具有简便、快速、灵敏度高等优点,用于食品中汞含量测定,结果满意.     

Theoretical analysis and simulation of conjugate heights for dual-conjugate AO system in lidar

A multi-conjugate adaptive optics （MCAO） can offer a possibility of widening field of view （FOV） characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle＇s expressions of two deformable mirrors （DMs） MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.     

Quick single-photon detector with many avalanche photo diodes working on the time division

Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.     

Characterization of PolyA and PolyC mismatches by Raman spectroscopy

A.C mismatches are studied by Raman spectral characterization of PolyA, PolyC, and their equimolar complex in solution of 0.14 mol/L Na ,pH7.0.Experimental results show that A·C mismatches occur to be A/B (mainly A) conformers, and unlike Watson-Crick base pairing, this kind of mismatches is stabilized by only one hydrogen bond involving cytosine N4H2 and adenine N7.The formation of A·C complex makes the base stacking interactions much stronger, and conformation of the backbone more ordered, which leads to obvious Raman hypochromic effect with some shifts in corresponding bands.     

Improvement of four-wave mixing-based wavelength conversion efficiency in dispersion shifted fiber by 40-GHz clock pumping

40-GHz clock modulated signal as a pump to improve the efficiency of four-wave mixing (FWM)-based wavelength conversion in a 26.5-km dispersion shifted fiber (DSF) is investigated. The experimental results demonstrate that the conjugated FWM component has higher intensity with the clock pumping than that with the continuous-wave (CW) light pumping. The improvement of FWM-based wavelength conversion efficiency is negligible when the pump power is less than Brillouin threshold. But when the pump power is greater than Brillouin threshold, the improvement becomes significant and increases with the increment of pump power. The improvement can increase up to 9 dB if pump power reaches 17 dBm.     

Multi-pulse operation of a Kerr-lens mode-locked femtosecond laser

Our experimental results show that the presence of a proper amount of negative group velocity dispersion is essential to multi-pulse operation of a Kerr-lens mode-locked femtosecond laser. We demonstrate that the pulse separations and the number of pulses contained within a cavity round trip are strongly dependent on the initial perturbations. The results allow us to get a better understanding on the influences of the convoluted self-phase modulation and intra-cavity dispersions on the stable multi-pulse oscillation in a Kerr-lens mode-locked femtosecond laser.     

Propagation of Helmholtz-Gauss beams in weak turbulent atmosphere

Based on the Rytov approximation of light propagation in weak turbulent atmosphere,the closed-form expressions of field and average irradiance of each one of the four fundamental families of Helmholtz-Gauss (HzG)beams:cosine-Gauss beams,stationary Mathieu-Gauss beams,stationary parabolic-Gauss beams,and Bessel-Gauss beams,which are propagating in weak turbulent atmosphere,are obtained.The results show that the field and average irradiance can be written as the product of four factors:complex amplitude depending on the z-coordinate only,a Ganssian beam.a factor of complex phase perturbation induced by atmospheric turbulence,and a complex scaled version of the transverse shape of the non-diffracting beam.The effect of weak atmospheric turbulence on irradiance distribution of the HzG beam can be ignored.     

An effective method for reducing speckle noise in digital holography

An effective method for reducing the speckle noise in digital holography is proposed in this paper.Different from the methods based on classical filtering technique,it utilizes the multiple holograms which are generated by rotating the illuminating light continuously.The intensity images reconstructed by a series of holograms generated by rotating the illuminating light possess different speckle patterns.Hence by properly averaging the reconstructed intensity fields,the speckle noises can be reduced greatly.Experimental results show that the proposed method is simple and effective to reduce speckle noise in digital holography.     

Influence of purity of HfO2 on reflectance of ultraviolet multilayer

The impurities in two kinds of HfO2 materials and in their corresponding single layer thin films were determined through glow discharge mass spectrum technology and secondary ion mass spectrometry(SIMS) equipment respectively.It was found that ZrO2 was the main impurity in the two kinds of HfO2 either in the original HfO2 materials or in the electron beam deposited films.In addition,the difference of Zr content in the two kinds of HfO2 single laver films was much laxger than that of the other impurities such as Ti and Fe.which showed that it was just ZrO2 that made the difference between the optical performance of the film products including the two kinds of HfO2.With these two kinds of HfO2 and the same kind of SiO2.we deposited HfO2/SiO2 multilayer reflective coatings at the wavelength of 266 nm.Experimental results showed that the reflectances of these two mirrors were about 99.85% and 99.15% respectively,which agreed well with the designed results what were based on the optical constants obtained from the corresponding single layer thin films.     

Speech enhancement by array crosstalk resistant ANC and spectrum subtraction

Microphone array-based speech enhancement has great importance for speech communications and speech recognition. To reduce the aperture of the microphone array and to increase the effect of the speech enhancement will greatly broaden the application areas of the microphone array. An array crosstalk resistant adaptive noise cancellation method is therefore presented. And then an improved spectral subtraction algorithm is further cascaded to obtain better enhancement results. Theoretic analysis and experiments indicate that the proposed scheme needs only a very small microphone array while it simultaneously achieves a higher SNR improvement. Besides, the proposed scheme can be used in many noisy environments and is easy for real-time implementation.