海参胶囊中海参多糖的提取方法

对海参胶囊中海参多糖进行提取纯化。分别探讨了酶解法、超声波提取方法;双氧水、活性炭脱色法及乙酸钾、三氯乙酸法除蛋白方法对海参多糖的得率的影响。确定最适提取条件:1g胶囊在胰蛋白酶加酶量为8000U/g,温度为37℃,pH 8.1,酶解3h后酶解完全;醇沉得到粗多糖后,经双氧水脱色、乙酸钾除蛋白。     

太行山黄芪中黄芪多糖的提取工艺

采用碱性水提醇沉法进行黄芪多糖的提取,用蒽酮-浓硫酸比色法测定多糖的含量.通过改变黄芪的粒度,水浴比,水浴温度,提取次数,乙醇浓度及pH值等条件的研究,筛选出最佳提取工艺条件:于1:12的水浴比在70C水浴提取3次,乙醇浓度为90%,pH=10的条件下黄芪多糖的提取率最高,为19.2%.     

酶法提取番茄红素

在提取番茄中番茄红素时,添加果胶酶和纤维素酶,筛选出最佳工艺为:果胶酶和纤维素酶的比例为4:1、添加酶量为0.5%、酶的作用温度为40℃、pH4、浸提时间为4h.按此条件可大大提高番茄红素的提取率.     

酶法提取香椿叶中总黄酮的工艺研究

采用酶法工艺提取香椿叶中总黄酮,与传统水提工艺相比提取率明显提高,提取条件温和,且不使用有机溶剂。本实验确定的较佳工艺条件为:酶浓度0.20mg/mL,酶解温度45℃,酶解pH5.0,酶解时间120min,浸提温度90℃,浸提时间120min,料液比1∶40。     

回归正交试验设计优化猪苓多糖的提取工艺

以猪苓为原料,通过二次回归正交试验优化了猪苓多糖的提取工艺条件.结果表明:影响猪苓多糖提取率的因素顺序为:提取温度＞料液比＞pH＞微波提取时间＞微波功率;最佳提取工艺条件为提取时间3min,温度70.0℃,料液比1∶24.7 (g/mL),pH 6.91,微波功率400W,猪苓多糖的提取率为2.86％.     

海参胶原蛋白的提取及其基本成分的分析

提取海参中胶原蛋白并分析其基本成分.分别用碱解、酶解法提取胶原蛋白,Folin-酚试剂法测定多糖含量、蛋白含量,运用GC分析单糖成分.海参中多糖含量为14.35％,蛋白含量为0.989％.多糖的成分包括岩藻糖、甘露糖、半乳糖、葡萄糖,其中岩藻糖为主要单糖成分.本法简单,操作方便,实验灵敏,多糖得率高.     

白僵蚕多糖成分的释放方法探讨

白僵蚕是重要的中药材,采用微波辅助法释放白僵蚕的多糖成分。以白僵蚕多糖提取率为评价指标,采用微波辅助法提取分离白僵蚕多糖,用单因素实验法对影响多糖得率的料液比、微波功率、照射时间、提取次数4个因素进行了分析,用正交试验法优化白僵蚕多糖的提取工艺条件,提取白僵蚕多糖成分的最佳条件为：料液比1∶30、微波功率480W、提取次数3次、照射时间60s。在此提取条件下白僵蚕多糖干料的提取率为11.51%。     

响应面分析法优化玉竹多糖提取工艺

在提取时间、料液比、提取温度3个单因素实验的基础上,通过响应面法优选玉竹中多糖的提取条件.利用Box-Benhnken设计模型,研究3个变量对玉竹多糖提取率的影响.结果表明：最佳提取工艺为：提取时间72min,料液比1∶7.5g·mL^-1,提取温度81.6℃,在此条件下,玉竹中多糖的提取率可达10.82％,理论预测值为10.89％,相对误差为-0.64％.说明采用响应面分析法优化玉竹多糖的工艺条件准确、可靠.     

黄芩素的酶解提取工艺及其抑制弹性蛋白酶活性研究

利用正交试验对中药黄芩中提取黄芩素酶解工艺进行了初步探讨,确定最佳酶解工艺条件：温度为40℃、pH6.0、时间12h时,黄芩素含量最高;利用酶活力法对黄芩素体外抑制弹性蛋白酶活性进行了研究,发现黄芩素对弹性蛋白酶具有明显的抑制作用,抑制率达92.98%。     

香菇多糖L-2A的结构表征

从香菇子实体中提取纯化得到香菇多糖级分L-2A,利用紫外光谱、红外光谱、凝胶渗透色谱和气相色谱分析其结构特征.香菇多糖L-2A糖含量为90.14%;重均分子量是2.03×10 5道尔顿;具有D-葡萄吡喃糖构型,单糖组成主要是由吡喃型葡萄糖组成;香菇多糖L-2A多糖含有o-糖苷键,且主要是o-Ser连接方式;具有与刚果红结合的螺旋结构.香菇多糖L-2A为首次从香菇子实体中分离得到.     

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.